1. health and fitness
2. disease

PREVALENCE OF Staphylococcus spp. IN FRESH
MEAT IN KHARTOUM STATE
By
Arafat Mohammed Goja
B.Sc. (Honors) 2000
Faculty of Natural Resources and Environmental Studies,
University of Kordofan, Elobeid, Sudan.
A thesis submitted in partial fulfillment of the requirements of
the degree of M.Sc. in Food Science and Technology
Supervisor:
Prof. Hamid Ahmed Dirar
Department of Food Science and Technology
Faculty of Agriculture, University of Khartoum
2004
1
DEDICATION
TO MY FAMILY
TO MY FRIENDS AND
COLLEAGUES
TO MY SUPERVISOR
I DEDICATE THIS WORK
WITH MY DEEP LOVE
ARAFAT
2
ACKNOWLEDGEMENTS
FIRST I THANK ALLAH, WHO GAVE ME THE ABILITY TO
COMPLETE THIS WORK.
MY DEEP THANKS GO TO MY SUPERVISIOR PROFESSOR
HAMID AHMED DIRAR, FOR HIS GUIDAANCE, ADVICE,
ENCOURAGEMENT AND HELP.
I WOULD LIKE TO THANK ALL THE TECHNICAL STAFF
MEMBERS OF THE
DEPT. OF MICROBIOLOGY, FACULTY OF
VETERINARY MEDCINE, ESPECIALY A/ALLAH, MONA,
FAWZIA, A/AZIZ AND HASHIM FOR HELP.
I DEEPLY THANK MY FRIENDS, ALI KARAR AND TAGELDIEN FOR THEIR GREAT HELP.
MY THANKS ALSO EXTEND TO MY COLLEAGUES IN THE
FACULTY OF
AGRICULTURE AND NATURAL RESOUCES-
UNIVERSITY OF BAKHT-ERUDA.
3
ABSTARACT
THE
PRESENT WORK WAS DONE TO KNOW THE TOTAL VIABLE
COUNT OF
STAPHYLOCOCCUS
AND TO IDENTIFY
SPP.PRESENT IN FRESH MEAT.
STAPHYLOCOCCUS
STAPH. COUNT RANGED FROM
3.23×103 TO 8.7 ×103 AND TOTAL VIABLE COUNT RANGED FROM 4.78 ×
104 TO 3.39 × 105 CFU/G.
IN
THIS STUDY,
58 STAPH.
ISOLATES WERE MADE FROM
40
SAMPLES OF FRESH BEEF COLLECTED FROM DIFFERENT MARKETS IN
KHARTOUM STATE.THEY
BELONGED TO
STAPHYLOCOCCUS. THE
ISOLATES
19
SPECIES OF THE GENUS
SPECIES
WERE
GROUPED
AS
FOLLOWS:
* COAGULASE- POSITIVE SPECIES, WAS STAPHYLOCOCCUS AUREUS
*
COAGULASE-NEGATIVE SPECIES
ISOLATES,
STAPH.
LUGDUNENSIS,
STAPH.
EPIDERMIDIS,
STAPH.
WARNERI,
STAPH.
CHROMOGENES,
STAPH.
(NOVOBIOCIN-SENSITIVE):
CASEOLYTICUS,
STAPH.
HAEMOLYTICUS,
TEN
STAPH.
CAPITIS,
STAPH.
FELIS,
STAPH.
CAPITIS
SSP.
UREALYTICUS AND STAPH. HYCIUS.
*
COAGULASE-NEGATIVE
EIGHT ISOLATES,
STAPH.
KLOOSII, STAPH.
LENTUS,
(NOVOBIOCIN-RESISTANT):
SPECIES
SAPROPHYTICUS,
STAPH.
COHNI,
STAPH.
STAPH.
XYLOSUS,
STAPH.
SCIURI,
STAPH.
GALLINARUM AND STAPH. COHNI SSP. UREALYTICUS.
THE
FREQUENCY
KHARTOUM STATE
FOLLOWED BY
AMONG
OF
ISOLATION
WAS HIGHER IN
BAHRI CITY (31%)
OF
IN
OMDURMAN CITY (39.7 %)
AND
KHARTOUM CITY (29.3%).
THESE ISOLATES OF STAPHYLOCOCCI,
4
STAPHYLOCOCCI
STAPH.
EPIDERMIDIS,
STAPH.
AUREUS
, STAPH.
CASEOLYTICUS AND
WERE THE MOST ABUNDANT ISOLATES.
5
STAPH.
SAPROPHYTICUS
‫ﻣﻠﺨﺺ اﻷﻃﺮوﺣﺔ‬
‫أﺟﺮﻳ ﺖ ه ﺬﻩ اﻟﺪراﺳ ﺔ ﻟﻤﻌﺮﻓ ﺔ اﻟﺤﻤ ﻞ اﻟﻤﻴﻜﺮوﺑ ﻲ ﻟﻠﺤ ﻮم اﻷﺑﻘ ﺎر اﻟﻄﺎزﺟ ﺔ ﺑﻮﻻﻳ ﺔ‬
‫اﻟﺨﺮﻃﻮم وآﺬﻟﻚ ﻣﻌﺮﻓﺔ أﻧﻮاع وأﻋﺪاد ﻣﻴﻜﺮوﺑﺎت اﻟﺒﻜﺘﺮﻳﺎ اﻟﻌﻨﻘﻮدﻳﺔ‪.‬‬
‫‪5‬‬
‫وﺟﺪ أن ﻋﺪد اﻟﺘﻘﺪﻳﺮ اﻟﻜﻠﻰ ﻟﻠﻤﻜﺮوﺑﺎت ﻳﺘ ﺮاوح ﺑ ﻴﻦ ‪ 410 × 4.78‬إﻟ ﻰ ‪10× 3.39‬‬
‫ﺑﻴﻨﻤ ﺎ ﺑﻜﺘﺮﻳ ﺎ اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ ﺗﺘ ﺮاوح ﺑ ﻴﻦ ‪ 310× 3.23‬إﻟ ﻰ ‪ 310 × 8.7‬وﺣ ﺪة ﻣﻜﻮﻧ ﺔ‬
‫ﻟﻠﻤﺴﺘﻌﻤﺮات ﺑﺎﻟﺠﺮام ‪.‬‬
‫ﺑﻠﻐ ﺖ ﺟﻤﻠ ﺔ اﻟﻌﻴﻨ ﺎت اﻟﺘ ﻲ ﺗ ﻢ اﺧﺘﻴﺎره ﺎ ‪ 40‬ﻋﻴﻨ ﺔ‪ ،‬وﺗ ﻢ ﻋ ﺰل‪ 58‬ﻋﺰﻟ ﺔ ﻣ ﻦ ﺑﻜﺘﺮﻳ ﺎ‬
‫اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﻳﺔ ﻣﻦ ﻣﺠﻤﻮﻋﺎت اﻟﻌﻴﻨ ﺎت اﻟﺘ ﻲ ﺷ ﻤﻠﺘﻬﺎ اﻟﺪراﺳ ﺔ ‪ .‬وﺻ ﻨﻔﺖ ﺗﻠ ﻚ اﻟﻌ ﺰﻻت‬
‫ﻋﺎ وﺗﻢ ﺗﻘﺴﻴﻤﻬﺎ إﻟﻰ ﻣﺠﻤﻮﻋﺎت آﻤﺎ ﻳﻠﻲ‪:‬‬
‫إﻟﻰ ‪ 19‬ﻧﻮ ً‬
‫ﻋ ﺎ واﺣ ًﺪا ﻓﻘ ﻂ ه ﻲ اﻟﻤﻜ ﻮرات‬
‫اﻟﻤﺠﻤﻮﻋﺔ اﻟﻤﻮﺟﺒﺔ ﻻﺧﺘﺒﺎر ﺗﺨﺜ ﺮ اﻟﺒﻼزﻣ ﺎ وﺗ ﻀﻢ ﻧﻮ ً‬
‫اﻟﻌﻨﻘﻮدﻳﺔ اﻟﺬهﺒﻴﺔ اﻟﻤﻤﺮﺿﺔ )‪(STAPHYLOCOCCUS AUREUS‬‬
‫اﻟﻤﺠﻤﻮﻋ ﺔ اﻟ ﺴﺎﻟﺒﺔ ﻻﺧﺘﺒ ﺎر ﺗﺨﺜ ﺮ اﻟﺒﻼزﻣ ﺎ اﻟﺤ ﺴﺎﺳﺔ ﻻﺧﺘﺒ ﺎر اﻟﻨﻮﻓ ﻮ ﺑﺎﻳﻮﺳ ﻴﻦ وﺗ ﻀﻢ ‪10‬‬
‫أﻧﻮاع هﻲ‪:‬‬
‫اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺒ ﺸﺮﻳﺔ ) ‪ ،(SAPH.EPIDRMIDIS‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ‬
‫اﻟﻤﺘﺠﺒﻨ‬
‫ﺔ )‪ ، (STAPH.CASEOLYTICUS‬اﻟﻤﻜ‬
‫)‪، (STAPH.LUGDUNENSIS‬اﻟﻤﻜ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫ﺔ اﻟﻠﻘﺪوﻧ‬
‫ﺴﻴﺔ‬
‫ﺔ اﻟﻜﺮوﻣﻮﺟﻴﻨﻴ‬
‫ﺔ‬
‫)‪ ،(STAPH.CHROMOGENES‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺮأﺳ ﻴﺔ ) ‪(STAPH.CAPITIS‬‬
‫‪،‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻘﻄﻴ ﺔ ) ‪ ،(STAPH.FELIS‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻮرﻧﻴ ﺔ‬
‫)‪ ،( STAPH.WARNERI‬اﻟﻤﻜ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫ﺔ اﻟﻤﺤﻠﻠ‬
‫ﺔ ﻟﻠ‬
‫ﺪم‬
‫)‪ ، ( STAPH.HAEMOLYTICUS‬اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺮأﺳ ﻴﺔ ﻣ ﺎ ﺗﺤ ﺖ اﻟ ﺴﻼﻟﺔ اﻟﺒﻮﻟﻴ ﺔ‬
‫)‪SSP. UREALYTICUS‬‬
‫‪ ( STAPH.CAPITIS‬و اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺤﻴ ﺴﻴﺔ )‬
‫‪(STAPH. HYCIUS‬‬
‫‪6‬‬
‫اﻟﻤﺠﻤﻮﻋﺔ اﻟﺴﺎﻟﺒﺔ ﻻﺧﺘﺒﺎر ﺗﺨﺜﺮ اﻟﺒﻼزﻣﺎ اﻟﻤﻘﺎوﻣﺔ ﻻﺧﺘﺒﺎر اﻟﻨﻮﻓ ﻮ ﺑﺎﻳﻮﺳ ﻴﻦ وﺗ ﻀﻢ‬
‫‪ 8‬اﻧﻮاع هﻰ ‪:‬‬
‫اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟ ﺴﺎﺑﺮو ﻓﻴﺘﻴ ﺔ )‪ ،( STAPH.SAPROPHYTICUS‬اﻟﻤﻜ ﻮرات‬
‫اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺰاﻳﻠﻮﺳ ﻴﺔ ) هﺎﺿ ﻤﺔ زﻳ ﺖ اﻟﺨ ﺸﺐ()‪ ،( STAPH.XYLOSUS‬اﻟﻤﻜ ﻮرات‬
‫اﻟﻌﻨﻘﻮدﻳ‬
‫ﺔ اﻟﻜﻠ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫ﺴﻴﺔ )‪ ،( STAPH.KLOOSII‬اﻟﻤﻜ‬
‫ﺔ اﻟﻌﺪﺳ‬
‫ﻴﺔ‬
‫)‪ ،( STAPH.LENTUS‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻜﻮﻧﻴ ﺔ)‪ ،(STAPH.COHNI‬اﻟﻤﻜ ﻮرات‬
‫اﻟﻌﻨﻘﻮدﻳ‬
‫ﺔ اﻟ‬
‫ﺴﻨﺠﺎﺑﻴﺔ )‪ ،( STAPH.SCIURI‬اﻟﻤﻜ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫ﺔ اﻟﻘﺎﻟﻨﻴﺮﻳ‬
‫ﺔ‬
‫)‪ ( STAPH.GALINARUM‬واﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻜﻮﻧﻴ ﺔ ﻣ ﺎ ﺗﺤ ﺖ اﻟ ﺴﻼﻟﺔ‬
‫اﻟﺒﻮﻟﻴﺔ)‪.( STAPH.COHNI SSP. UREALYTICUS‬‬
‫آ ﺎن ﻣﻌ ﺪل ﻋ ﺰل ه ﺬﻩ اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ ﻋﺎﻟﻴ ًﺎ ﻓ ﻲ ﻣﺪﻳﻨ ﺔ ام درﻣ ﺎن ) ‪( 39.2%‬‬
‫ﺗﻠﺘﻬﺎ ﻣﺪﻳﻨﺔ ﺑﺤﺮي )‪ (31%‬ﺛﻢ ﻣﺪﻳﻨﺔ اﻟﺨﺮﻃﻮم)‪ . (29.3 %‬ﻣﻦ ﺑ ﻴﻦ أﻧ ﻮاع ه ﺬﻩ اﻟﻤﻜ ﻮرات‬
‫اﻟﻌﻨﻘﻮدﻳﺔ اﻟﻤﻌﺰوﻟﺔ‪ ،‬ﻇﻬ ﺮت اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﺒ ﺸﺮﻳﺔ )‪،( STAPH.EPIDERMIDIS‬‬
‫اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻤﻤﺮﺿ ﺔ )‪ ،( STAPH.AUREUS‬اﻟﻤﻜ ﻮرات اﻟﻌﻨﻘﻮدﻳ ﺔ اﻟﻤﺘﺠﺒﻨ ﺔ‬
‫)‪، ( STAPH.CASEOLYTICUS‬اﻟﻤﻜ‬
‫ﻮرات اﻟﻌﻨﻘﻮدﻳ‬
‫)‪ ( STAPH.SAPROPHYTICUS‬ﺑﻨﺴﺐ أآﺜﺮ ﻣﻦ ﻏﻴﺮهﺎ ‪.‬‬
‫‪7‬‬
‫ﺔ اﻟ‬
‫ﺴﺎﺑﺮو ﻓﻴﺘﻴ‬
‫ﺔ‬
LIST OF CONTENTS
PAGE
DEDICATION..........................................................................................................................
I
......
ACKNOWLEDGEMENT
.............................................................................................................
II
ABSTRACT
...................................................................................................................................
III
ARABIC ABSTRACT
....................................................................................................................
IV
LIST OF CONTENTS
...................................................................................................................
VI
LIST OF
TABLES.........................................................................................................................
IX
LIST OF FIGURES
.....................................................................................................................
X
CHAPTER ONE: INTRODUCTION .................................................................
1
CHAPTER TWO: LITERATURE REVIEW.................................................
3
2.1. THE GENUS STAPHYLOCOCCUS...................................................................
3
2.2. COAGULASE-POSITIVE
STAPHYLOCOCCI......................................................................
4
2.2.1. STAPHYLOCOCCUS
AUREUS.........................................................................................
4
2.3. COAGULASE-NEGATIVE
STAPHYLOCOCCI....................................................................
5
2.3.1. STAPHYLOCOCCUS
EPIDERMIDIS..............................................................................
6
2.3.2 STAPHYLOCOCCUS
6
8
SAPROPHYTICUS..........................................................................
2.3.3 STAPHYLOCOCCUS
7
CASEOLYTICUS..............................................................................
2.4
STAPHYLOCOCCUS
CHARACTERISTICS....................................................................
2.4.1 MORPHOLOGICAL
7
CHARACTERISTICS............................................................................
7
2-4-2 COLONIES
PIGMENTATION..........................................................................................
7
2-4-3
HAEMOLYSIS................................................................................................................
8
2.5 MEAT
CONTAMINATION.....................................................................................................
9
2.6 STAPHYLOCOCCAL FOOD
POISONING............................................................................
10
2.7 STAPHYLOCOCCAL TOXIN, ENZYMES AND
11
DISEASES.................................................
2.7.1
EXOTOXIN........................................................................................................................
11
2.7.1.1 LEUKOCIDIN
TOXIN..................................................................................................
12
2.7.1.2 TOXIC SHOCK SYNDROME TOXIN
12
.........................................................................
2.7.1.3 EXFOLIATIVE
TOXIN...................................................................................................
12
2.7.2
ENTEROTOXIN..................................................................................................................
9
13
2.7.3 COAGULASE
13
ENZYME...................................................................................................
2.8 SELECTIVE
14
MEDIA............................................................................................................
2.8.1 BAIRD-PARKER
14
MEDIUM..........................................................................................
2.8.2 MANNITOL SALT AGAR MEDIUM (M.S.A)
14
...........................................................
CHPTER THREE: MATERIALS AND
METHODS……………………..….
16
3.1.
STERILIZATION....................................................................................................................
16
3.1.1. HOT-AIR OVEN (160 – 170OC FOR ONE HOUR)
16
...................................................
3.1.2. AUTOCLAVING (121ºC – 15IB./ SQUARE INCH)
16
..............................................
3.1.3. IRRADIATION AND
16
DISINFECTION.................................................................................
3.2. COLLECTION OF BLOOD, PLASMA AND FIBRIN CLOTS FROM
LABORATORY
ANIMALS
16
.....................................................................................................................................
3.3
PREPARATION
OF
MEDIA...................................................................................................
3.3.1.
SOLID
MEDIA
...............................................................................................................
17
3.3.1.1 NUTRIENT
17
AGAR...........................................................................................................
17
3.3.1.2 BLOOD AGAR MEDIUM (OXOID)
17
10
...........................................................................
3.3.1.3 BAIRD-PARKER MEDIUM (OXOID)
18
.......................................................................
3.3.1.4 MANNITAL SALT AGAR MEDIUM (OXOID)
18
...........................................................
3.3.2
SEMISOLID
MEDIA
.......................................................................................................
18
3.3.2.1 HUGH AND LEIFSON'S (O/F MEDIUM )
18
.............................................................
3.3.2.2 CHRISTENSEN'S UREA MEDIUM (OXOID)
19
............................................................
3.3.3
LIQUID
MEDIA
............................................................................................................
19
3.3.3.1 NUTRIENT BROTH (OXOID)
......................................................................................
19
3.3.3.2 PEPTONE WATER (OXOID)
......................................................................................
19
3.3.3.3 GLUCOSE PHOSPHATE
MEDIUM...........................................................................
19
3.3.3.4 COOKED MEAT
MEDIUM.......................................................................................
20
3.4 COLLECTION OF
SAMPLES………………………………………………………….........
3.5 MICROBIOLOGICAL
20
METHODS..........................................................................................
20
3. 5.1 PRIMARY
ISOLATION.....................................................................................................
20
3.5.2 PREPARING THE
DILUTION.............................................................................................
11
21
3.5.3 PURIFICATION, IDENFIFICATION AND
21
PRESERVATION...............................................
3.6 BIOCHEMICAL METHODS ......................................................................................
3.61 COAGULASE-TEST ................................................................................................
21
3.6.1.1 SLIDE COAGULASE
21
TEST..............................................................................................
21
3.6.1.2 TUBE COAGELASE
TEST..............................................................................................
22
3.6.2 CATALASE
TEST...............................................................................................................
22
3.6.3 OXIDASE
TEST.................................................................................................................
22
3.6.4 UREA
TEST.......................................................................................................................
22
3.6.5 V P TEST (VOGES–PROSKAUER TEST)
22
.......................................................................
3.6.6 SUGAR
FERMENTATION...................................................................................................
23
3.6.7 NOVOBIOCIN SENSITIVITY
TEST..................................................................................
23
CHAPTER FOUR: RESULTS AND DISCUSSION...................................
24
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION …...
42
REFERENCES...................................................................................................................
45
APPENDIX..........................................................................................................................
53
12
LIST OF TABLES
TITLE
PAGE NO.
TABLE (1) TOTAL VIABLE COUNT AND STAPHYLOCOCCUS COUNT
OF FRESH BEEF COLLECTED FROM KHARTOUM
STATE............................................................
25
TABLE (2) SOURCE AND PREVALENCE OF ISOLATED OF
STAPHYLOCOCCI FROM FRESH BEEF SAMPLES COLLECTED
FROM KHARTOUM STATE...................................
26
TABLE (3) THE PERCENTAGE OF INDIVIDUAL STAPHYLOCOCCUS
SPP. TO THE TOTAL NO. OF
ISOLATES..................................................................................................
26
TABLE (4): COAGULASE-POSITIVE AND COAGULASE-NEGATIVE
STAPHYLOCCUS SPECIES ISOLATED FROM FRESH BEEF SAMPLES
COLLECTED
KHARTOUM
FROM
STATE...............................................................................................
28
TABLE (5) STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF
IN KHARTOUM
CITY..........................................................................................................
31
TABLE (6) STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF
IN BAHRI
CITY................................................................................................................................
33
..
TABLE (7) STAPHYLOCOCCUS SPP. ISOLATION FROM FRESH BEEF
IN OMDURMAN
CITY........................................................................................................
34
TABLE (8) PREVALENCE OF STAPHYLOCOCCI IN KHARTOUM,
BAHRI AND
OMDURMAN................................................................................................................
13
38
..
TABLE (9) PERCENTAGE OF STAPHYLOCOCCUS SPP. ISOLATED
FROM FRESH BEEF COLLECTED FROM KHARTOUM
STATE...............................................................
39
TABLE (10) % ISOLATES OF STAPH. EPIDERMIDIS, STAPH.
AUREUS, STAPH. CASEOLYTICUS AND STAPH. SAPROPHYTICUS
FROM FRESH BEEF COLLECTED FROM
KHARTOUM, BAHRI AND
OMDURMAN....................................................
40
14
LIST OF FIGURES
FIG.
TITLE
NO
.
1.
COLONIES OF STAPH. EPIDERMIDIS ON MANNITOL SALT AGAR
MEDIUM.
2.
29
COLONIES OF STAPH. EPIDERMIDIS ON BAIRD-PARKER
29
MEDIUM. ................
3.
COLONIES OF STAPH. AURES ON MANNITOL SALT AGAR
29
MEDIUM....................
4.
COLONIES OF STAPH. AURES ON BAIRD-PARKER MEDIUM.
29
.............................
5.
NOVOBIOCIN RESISTANCE OF STAPH. SAPROPHYTICUS.
36
...................................
6.
NOVOBIOCIN SENSITIVITY OF STAPH. EPIDERMIDIS.
36
.......................................
7.
ß-HEMOLYSIS OF STAPH. AUREUS.
.......................................................................
8.
Α-HEMOLYSIS OF STAPH. LUGDUNENSIS.
36
..........................................................
9.
36
COLONIES OF STAPH. SAPROPHYTICUS ON MANNITOL SALT
AGAR. .................
41
15
10.
COLONIES OF STAPH. CASEOLYTICUS ON MANNITOL SALT
41
AGAR MEDIUM
11.
SUGAR TEST. RIGHT, A POSITIVE TEST. MIDDLE, A NEGATIVE
TEST. LEFT, IS A CONTROL.
................................................................................................................
12.
UREASE TEST. RIGHT, A NEGATIVE TEST. LEFT, A POSITIVE
TEST......................
13.
41
PREVALENCE OF STAPHYLOCOCCI SPP. IN KHARTOUM
STATE...........................
14.
55
STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF IN
KHARTOUM CITY
15.
55
STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF IN BAHRI
CITY..............
16.
56
STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF IN
56
OMDURMAN CITY
17.
41
PREVALENCE OF THE MOST ABUNDANT OF STAPHYLOCOCCI
SPP. IN KHARTOUM
STATE.......................................................................................................
16
57
CHAPTER ONE
INTRODUCTION
FOODS
ARE SUBJECT TO ATTACK BY MICROORGANISM IN A
VARIETY OF WAYS, AND SUCH ATTACK IS USUALLY HARMFUL TO THE
FOOD.
THE
PHYSICAL AND CHEMICAL CHARACTERISTICS OF THE FOOD
DETERMINE ITS DEGREE OF SUSCEPTIBILITY TO MICROBIAL ATTACK,
THE KIND OF MICROORGANISM THAT WILL INFECT IT, AND KIND OF
SPOILAGE THAT WILL RESULT (1).
MEAT IS A MAJOR CONSTITUENT OF THE HUMAN DIET IN SUDAN.
IT
IS AN ESSENTIAL FOOD ITEM AND ONE OF THE MAIN SOURCES OF
PROTEIN, FATS, MINERALS AND VITAMINS.
BEING A GOOD MATERIAL FOR BACTERIAL GROWTH, ITS QUALITY
DEPENDS
ON
THE
INITIAL
CONTAMINATION CAUSES
BACTERIAL
CONTAMINATION.
THIS
MEAT DETERIORATION, LOWERS QUALITY,
AND SOMETIMES ILLNESS MAY BE CAUSED BY BACTERIAL PATHOGENS
OR THEIR TOXINS THROUGH MEAT AND MEAT PRODUCTS.
IN SUDAN,
THERE ARE STUDIES ON THE GENERA OF AEROBIC BACTERIA IN FRESH
MEAT
(2,3). BACILLUS SPP., MICROCOCCUS SPP., STAPHYLOCOCCUS SPP.,
PSEUDOMONUS
SPP.,
ACINETOBACTER
17
SPP. AND
PROTEUS
SPP. WERE
ISOLATED FROM BEEF
. BUT
ADDITIONAL RESEARCH IS NEEDED TO
KNOW THE SPECIES OF EACH SPECIFIC GENUS. THE PRESENT WORK WAS
DONE TO KNOW THE STAPHYLOCOCCUS SPP. PRESENT IN FRESH MEAT.
STAPHYLOCOCCUS
EXISTS IN AIR, DUST, SEWAGE, WATER, MILK,
FOOD OR FOOD EQUIPMENT, ENVIRONMENTAL SURFACE, HUMANS AND
ANIMALS; SOME OF
USEFUL
IN
STAPHYLOCOCCUS
AGRICULTURAL
ARE SAPROPHYTIC AND MAY BE
PROCESSES
BECAUSE
OF
THEIR
FERMENTATIVE ACTIVITY, AND OTHERS ARE PATHOGENIC TO HUMAN
BEINGS AND ANIMALS (4; 5).
THE OBJECTIVE OF THIS STUDY WAS TO:
- KNOW MICROBIAL LOAD OF FRESH MEAT.
- IDENTIFY STAPHYLOCOCCI PRESENT IN FRESH MEAT.
- INVESTIGATE
THE PRESENCE OF STAPHYLOCOCCAL PATHOGENS
THAT MAY CONSTITUTE A PUBLIC HEALTH HAZARD FROM
CONSUMPTION OF MEAT.
18
CHAPTER TWO
LITERATURE REVIEW
2.1. THE GENUS STAPHYLOCOCCUS
STAPHYLOCOCCUS
WAS SEEN IN PUS BY
KOCK
IN
1878
AND WAS
CULTIVATED BY PASTEUR IN 1880 AND SHOWN BY OGSTON IN 1881 (6).
THE NAME STAPHYLOCOCCUS IS DERIVED FROM THE GREEK TERM
STAPHYLE, MEANING "A BUNCH OF GRAPES". THIS NAME REFERS TO THE
FACT THAT THE CELLS OF THESE GRAM-POSITIVE COCCI GROW IN A
PATTERN RESEMBLING A CLUSTER OF GRAPES (7).
STAPHYLOCOCCI
ARE GRAM-POSITIVE COCCI
(0.5
TO
1.5
µM
DIAMETER) THAT OCCUR SINGLY AND IN PAIRS, TETRADS, LIKE
CLUSTERS. THEY ARE NON-MOTILE, NON-SPORE-FORMING AND USUALLY
CATALASE-POSITIVE, FACULTATIVE ANAEROBES AND FERMENT SUGAR
WITH FORMATION OF LACTIC ACID AS ONE OF THE MAJOR PRODUCTS (8;
9).
STAPHYLOCOCCI
ARE SOME OF THE MOST RESISTANT OF ALL
NON-SPORE-FORMING ORGANISMS TO SUCH DESTRUCTIVE INFLUENCES
AS HEAT, DRYING AND THE ACTION OF CHEMICALS.
ALTHOUGH
VEGETATIVE BACTERIA ARE DESTROYED BY A TEMPERATURE OF
FOR
30
MINUTES,
STAPHYLOCOCCI
19
FREQUENTLY
MOST
60ºC
RESIST
A
TEMPERATURE OF
60ºC FOR AN HOUR AND SOME STRAINS MAY RESIST A
TEMPERATURE OF 80ºC FOR 30 MINUTES (10).
HISTORICALLY,
STAPHYLOCOCCI HAVE BEEN CLASSIFIED INTO
COAGULASE- POSITIVE AND COAGULASE-NEGATIVE ON THE BASIS OF
COAGULASE PRODUCTION (5).
THE
GENUS
STAPHYLOCOCCUS
HAS AT LEAST
30
THREE MAIN SPECIES OF CLINICAL IMPORTANCE ARE
SPECIES.
STAPH.
THE
AUREUS,
STAPH. EPIDERMIDIS AND STAPH. SAPROPHYTICUS (11).
Natural populations of staphylococci are associated with skin, skin glands and
mucous membranes of warm-blooded animals; they are also found in varying number
in air and dust, as well as in water, milk, food, feaces and sewage (6; 12).
2.2. COAGULASE-POSITIVE STAPHYLOCOCCI
COAGULASE-POSITIVE
THREE SPECIES,
SAPH.
STAPHYLOCOCCI WERE DIVIDED INTO
AUREUS,
STAPH.
INTERMIDIUS AND
STAPH.
HYCIUS; ALL THESE MEMBERS HAVE THE ABILITY TO PRODUCE
COAGULASE-ENZYME WHICH CLOTS PLASMA (13; 16).
2.2.1. STAPHYLOCOCCUS AUREUS
IT FORMS A FAIRLY LARGE YELLOW COLONY ON RICH MEDIA AND
IS HEMOLYTIC ON BLOOD AGAR, GROWS AT TEMPERATURES
AND AT
ENZYME
NACL
CONCENTRATIONS AS HIGH AS
COAGULASE
AND
SHOULD
20
ALWAYS
15%,
BE
15 – 45ºC
PRODUCES THE
CONSIDERED
A
POTENTIAL PATHOGEN. IT IS FOUND ON THE ANTERIOR NASAL MUCOSA
OF 40 – 50% OF HEALTHY ADULTS, IN THE THROATS OF MANY OF THEM,
IN FACES OF ABOUT 20% AND ON THE SKIN OF 5 – 10% (14. 15).
THE PRESENCE OF STAPH. AUREUS IN FOOD IS USUALLY TAKEN TO
INDICATE CONTAMINATION FROM THE SKIN, MOUTH OR NOSE OF
WORKERS
HANDLING
THE
FOOD,
BUT
INADEQUATELY
EQUIPMENT MAY ALSO BE A SOURCE OF CONTAMINATION
NAIROBI
(17). IN
CLEANED
(16). IN
IT WAS ISOLATED FROM BEEF CARCASSES AND MINCED BEEF
THE
SUDAN
IT WAS ISOLATED FROM SAUSAGE, MINCED MEAT
AND BEEF-BURGER MEAT (18).
2.3. COAGULASE-NEGATIVE STAPHYLOCOCCI
THESE
ANIMALS
SPECIES ARE ENDOGENOUS TO HUMAN AND CERTAIN
AND
HAVE
PREVIOUSLY
BEEN
CONSIDERED
TO
BE
SAPROPHYTIC OR OF LOW PATHOGENICITY. SEVERAL OF THESE SPECIES
WERE
DESIGNATIONS
OF
A
SINGLE
SPECIES,
STAPHYLOCOCCUS
EPIDERMIDIS OR STAPH. ALBUS (8).
COAGULASE-NEGATIVE
STAPHYLOCOCCI ARE FOUND IN BOTH
HUMAN AND ANIMAL AS PART OF THE NORMAL FLORA AND AS
INFECTION AGENTS (19, 20).
21
MOST OF STAPHYLOCOCCI FOUND ON THE SKIN AND IN THE UPPER
RESPIRATORY TRACT ARE COAGULASE-NEGATIVE STAPHYLOCOCCI;
AND OTHERS ARE ENVIRONMENTAL (15; 21).
ALTHOUGH COAGULASE-NEGATIVE SPECIES OTHER THAN STAPH.
EPIDERMIDIS
AND
SAPROPHYTICUS ARE NOT FREQUENTLY
STAPH.
RECOVERED FROM SIGNIFICANT INFECTION, SEVERAL OTHER SPECIES
HAVE BEEN REPORTED PRINCIPALLY IN WOUNDS AND URINARY TRACT
INFECTION.
STAPH.
THEY
INCLUDE
LUGDUNENSIS,
STAPH.
STAPH.
HAEMOLYTICUS,
HOMINIS AND
STAPH.
STAPH.
WARNERI,
SACCHAROLYTICUS
(22).
2.3.1. STAPHYLOCOCCUS EPIDERMIDIS
RESEMBLES STAPH.
AUREUS IN MOST RESPECTS EXCEPT THAT IT
IS COAGULASE-NEGATIVE, USUALLY FORMS WHITE COLONIES, FOUND IN
LARGE NUMBERS ALL OVER THE HUMAN SKIN AND ON MANY MUCOUS
SURFACES, CAUSES INFECTION AROUND CEREBROSPINAL FLUID, SHUTS,
ARTIFICIAL HEART VALVES AND OTHER PROSTHESES. IT IS COMMONLY
RESPONSIBLE FOR URINARY TRACT INFECTIONS IN ELDERLY MALES,
PARTICULARLY
AFTER
BLADDER
PROSTATECTOMY (15).
22
INSTRUMENTATION
OR
CLINICAL
STUDIES DONE FOUND THAT
STAPH.
EPIDERMIDIS WAS
THE MOST FREQUENTLY RECOVERED ORGANISM ISOLATED FROM
CLINICAL INFECTIONS(23, 24).
IN SUDAN,
THIS ORGANISM WAS ISOLATED FROM THE MEDICAL
LABORATORY ENVIRONMENTS (25) AND FROM EYE, EAR, SKIN, NOSE AND
THROAT(26).
2.3.2 STAPHYLOCOCCUS SAPROPHYTICUS
THIS
SPECIES IS A WELL DOCUMENTED PATHOGEN CAUSING
PRIMARILY ACUTE URINARY TRACT INFECTION IN YOUNG WOMEN
(22,27&28). IT
IS THE SECOND MOST COMMON CAUSE OF CYSTITIS
AFTER ESCHERICHIA COLI (22).
IN SUDAN, IT WAS ISOLATED FROM SKIN (26) AND FROM MEDICAL
LABORATORY EQUIPMENT, SAUSAGE AND MINCED MEAT (25).
IT
2.3.3 STAPHYLOCOCCUS CASEOLYTICUS
WAS RECOGNIZED AS ENVIRONMENTAL COAGULASE-NEGATIVE SPECIES,
FOUND IN MILK AND OTHER DAIRY PRODUCTS
(22). IN SUDAN,
IT WAS
ISOLATED FROM SAUSAGE, BEEF BURGER AND MINCED MEAT (18), FROM
HUMAN MOUTH, NOSE, AXILLA AND THROAT
MOUTH AND ABSCESS (26).
2.4STAPHYLOCOCCUS CHARACTERISTICS
2.4.1 MORPHOLOGICAL CHARACTERISTICS
23
(29)
AND FROM EYE,
STAPHYLOCOCCAL
CELLS
ARE
PERFECTLY
SPHERICAL,
NON-
MOTILE CELLS WHICH GROW IN CLUSTERS, AND ARE CATALASEPOSITIVE WHICH HELPS TO DISTINGUISH STAPHYLOCOCCI FROM
STREPTOCOCCI.
YOUNG
COCCI STAIN STRONGLY GRAM- POSITIVE, BUT
ON AGING THEY MAY BECOME GRAM-NEGATIVE; THEIR COLONIES ARE
SMOOTH, CIRCULAR, LOW CONVEX, GLISTENING AND BUTYROUS.
THEY
ARE DISTINGUISHED FROM THOSE OF MOST OTHER BACTERIA BY THEIR
GOLDEN OR WHITE PIGMENTATION
(14; 30). STAPHYLOCOCCI
READILY ON MOST BACTERIOLOGICAL MEDIA AT
OR MICROAEROBIC CONDITIONS.
THEY
GROW
37OC UNDER AEROBIC
ARE ABLE TO GROW ON MEDIA
CONTAINING HIGH CONCENTRATIONS OF (10% OR MORE) NACL, WHICH
IS INHIBITORY TO MANY OTHER BACTERIA, PARTICULARLY THE GRAMNEGATIVE ORGANISMS (11; 30).
2-4-2 COLONIES PIGMENTATION
COLONIAL PIGMENT IS VARIABLE AND IS INFLUENCED BY
GROWTH CONDITIONS (31).
PIGMENT PRODUCTION TENDS TO BE ENHANCED WITH AGE OR STORAGE
AT REFRIGERATOR TEMPERATURE.
ON
NUTRIENT AGAR, MAXIMUM
PIGMENTATION OCCURS AFTER OVERNIGHT INCUBATION IN THE DARK
AT
37OC
FOLLOWED BY INCUBATION IN THE LIGHT AT ROOM
24
TEMPERATURE
(6). THE
COLONIES CAN BE WHITE, GRAY-WHITE, OR
YELLOW DEPENDING ON THE SPECIES (32).
2-4-3 HAEMOLYSIS
STAPHYLOCOCCUS PRODUCES AT LEAST FOUR HAEMOLYSINS: Α, Β,
Γ AND ∆, WHICH ARE ANTIGENICALLY DISTINCT AND DIFFER FROM ONE
ANOTHER IN THEIR ACTIVITY AGAINST THE RED BLOOD CELLS OF
DIFFERENT ANIMAL SPECIES.
ALPHA- TOXIN IS MOST STRONGLY ACTIVE
ON RABBIT CELLS, Β- TOXIN ON SHEEP CELLS, WHILST Γ -AND ∆ –TOXINS
ARE ABOUT AS STRONG ON BOTH HORSE AND HUMAN CELLS
HOWEVER,
(29).
ALPH-LYSIN PRODUCES A WIDE CLEAR ZONE ON BLOOD
AGAR MEDIUM WITH ILL- DEFINED OUTER MARGIN
(33,34). BETA
HAEMOLYSIN CAUSES PARTIAL HAEMOLYSIS OF RABBIT AND HUMAN
ERYTHROCYTES (34).
THE
TERMS Α.HAEMOLYSIN AND Β- HAEMOLYSIN HAVE A
SIGNIFICANCE WHICH DEPENDS ON WHETHER THEY ARE USED WITH
REFERENCE TO STREPTOCOCCI OR STAPHYLOCOCCI. IN THE CASE OF
STAPHYLOCOCCI, Α. HAEMOLYSIN PRODUCES CLEAR ZONES, WHILE ΒHAEMOLYSIN PRODUCES DARK HAZY ZONES (35).
25
2.5 MEAT CONTAMINATION
THE
HEALTHY INNER FLESH OF MEATS HAS BEEN FOUND TO
CONTAIN FEW OR NO MICROORGANISMS, ALTHOUGH MICROBES HAVE
BEEN FOUND IN LYMPH NODES, BONE MARROW, AND EVEN FLESH.
STAPHYLOCOCCI,
STREPTOCOCCI, CLOSTRIDIA AND SALMONELLAE
HAVE BEEN ISOLATED FROM THE LYMPH OF RED MEAT ANIMALS.
IMPORTANT CONTAMINATION CAME FROM EXTERNAL SOURCES DURING
BLEEDING, HANDLING, AND PROCESSING. IT HAS BEAN MENTIONED THAT
DURING BLEEDING, SKINNING, AND CUTTING, THE MAIN SOURCES OF
MICROORGANISM ARE THE EXTERIOR OF THE ANIMAL (HIDE, HOOFS,
AND HAIR) AND THE INTESTINAL TRACT.
CONTAMINATION ALSO COMES
FROM KNIVES, AIR, CLOTHS, HANDS AND CLOTHING OF THE WORKERS.
DURING
THE HANDLING, THE CONTAMINATION CAME FROM
CARTS, BOXES, OR OTHER CONTAINERS FROM OTHER CONTAMINATED
MEAT,
FROM
AIR
AND
FROM
PERSONNEL,
AND
ADDITIONAL
CONTAMINATION TAKES PLACE IN THE RETAIL MARKETS, AND FROM
KNIVE, SAWS, CLEAVERS, SLICERS, GRINDERS, CHOPPERS, SCALES,
SAWDUST, AND CONTAINERS, AS WELL AS FROM THE MARKET (36).
THE
EVALUATION OF FRESH FOOD CONDITION, HANDLING,
PROCESSING AND SANITARY QUALITY OF FOOD PRODUCTS FOCUSES ON
26
THE TOTAL NUMBER OF MICROORGANISMS PER GRAM OR ML AND THE
TYPE OF THE ORGANISM REPRESENTED IN THIS NUMBER (37).
THE CANADIAN GOVERNMENT
THAT THE AEROBIC PLATE COUNT
IN
1977
(APC)
GROUND BEEF SHOULD BE LESS THAN
AT
ADOPTED GUIDELINES
35ºC
1.0 × 107
FOR NON-FROZEN
COLONIES FORIMNG
UNITS (CFU)/G (37).
IN FRESH MEAT THE INITIAL LOAD OF AEROBIC BACTERIA WAS 106
CFU/G AT MARKETING LEVEL (38). IT
THE
HAS ALSO BEEN REPORTED THAT
APC OF THE FRESH MEAT BEFORE PROCESSING WAS 1 ×102 -1 ×103
CFU/G AND AFTER PROCESSING WAS 1.0 ×10 7-1 ×10 8 CUF/G (39).
BACTERIA
CAN BE TRANSFERRED TO THE SURFACE OF MEAT BY
DIRECT CONTACT OF THE OUTER HIDES WITH MEAT, BY SKINNING KNIFE
USED TO CUT THROUGH HIDE AND THROUGH CONTACT OF WORKERS
CLOTHING AND HANDS (40).
2.6 STAPHYLOCOCCAL FOOD POISONING
ALL FOODBORNE DISEASES ARE CLASSIFIED AS FOOD INFECTIONS
OR FOOD INTOXICATIONS.
FOOD INFECTIONS ARE THOSE IN WHICH THE
BACTERIA PRESENT IN THE FOOD AT THE TIME OF EATING GROW IN THE
HOST AND CAUSE DISEASE.
FOOD
INTOXICATIONS ARE THOSE DISEASES
IN WHICH BACTERIA GROW IN FOOD, PRODUCING SUBSTANCE THERE
WHICH IS TOXIC TO HUMAN (40).
27
STAPHYLOCOCCAL
FOOD POISONING IS ONE OF THE MOST
COMMON FOOD BORNE ILLNESSES
(7). TODAY, STAPHYLOCOCCAL FOOD
POISONING RANKS AS THE SECOND MOST COMMON IMPORTED DISEASE
OF ALL TYPE OF FOODBORNE DISEASES, WITH
SALMONELLA – RELATED
ILLNESS RANKING FIRST (41).
STAPHYLOCOCCAL
FOOD POISONING IS AN INTOXICATION THAT
DEPENDS ON THE ABILITY OF FOOD CONCERNED TO SUPPORT THE
GROWTH OF STAPHYLOCOCCI WHICH PRODUCE THE TOXIN (42).
MEATS
ARE FREQUENTLY INCRIMINATED IN STAPHYLOCOCCAL
FOOD POISONING. THIS POISONING OCCURS DUE TO THE ABSORPTION OF
STAPHYLOCOCCAL ENTEROTOXIN PREFORMED IN FOOD
(14; 43). THE
ENTEROTOXIN PRODUCED BY STRAINS OF STAPH. AUREUS IS NOT KNOWN
WHETHER IT ACTS DIRECTLY ON THE STOMACH WALL OR ACTS ON
CENTRAL NERVOUS SYSTEM FOLLOWING ABSORPTION IN THE UPPER
GASTROINTESTINAL TRACT(43).
USUALLY
WITHIN
1-7
HOURS, ABDOMINAL PAIN, NAUSEA, AND
VOMITING CAN BE VIOLENT, DIARRHEA IS SOMETIMES PRESENT, BUT
FEVER IS RARE(9).
2.7 STAPHYLOCOCCAL TOXIN, ENZYMES AND DISEASES
2.7.1 EXOTOXIN
28
THIS
IS TOXIN PRODUCED BY MICROORGANISMS AND EXCRETED
INTO THE SURROUND MEDIUM
(44). IT INCLUDES SEVERAL TOXINS THAT
ARE LETHAL FOR ANIMALS. ALPHA- TOXIN, IS TOXIC TO MANY TYPES OF
CELLS,
AND
ACTS
ON
CELL
MEMBRANES,
CAUSING
INCREASING
PERMEABILITY, INTERACTING WITH LIPIDS, AND PENETRATES THE
HYDROPHOBIC REGION OF RED BLOOD CELL MEMBRANE
(45). BETA-
TOXIN, IS A SPHINGOMYELINASE WHICH DAMAGES MEMBRANES RICH IN
THIS LIPID (14).
29
2.7.1.1 LEUKOCIDIN TOXIN
A SOLUBLE MATERIAL THAT KILLS EXPOSED WHITE BLOOD CELLS
OF A VARIETY OF ANIMAL SPECIES.
THE
TOXIN REACTS IN A COMPLEX
WAY WITHIN THE SURFACE OF SENSITIVE LEUKOCYTES, CAUSING
INCREASED PERMEABILITY TO CATIONS (45).
2.7.1.2 TOXIC SHOCK SYNDROME TOXIN
PRODUCED
BY
STAPHYLOCOCCUS
AUREUS
STRAINS;
IT
CAUSATIVE AGENT IN TOXIN SHOCK SYNDROME IN HUMANS
IS
(46).
SYMPTOMS ARE CHARACTERIZED BY LOW BLOOD PRESSURE, FEVER AND
AN EXTENSIVE SKIN RASH; DIARRHEA AND VOMITING ARE ALSO
COMMON.
MORE
YEARS OLD.
THAN
30%
OF CASES OCCUR IN WOMEN UNDER
30
THE ONSET USUALLY OCCURS DURING MENSTRUATION AND
IT IS ASSOCIATED WITH USE OF TAMPONS THAT ARE NOT CHANGED
FREQUENTLY.
THE
DISEASE OCCURS WHEN THE
STAPH.AUREUS
GROWS
IN THE VAGINA AND SECRETES TOXIN (9).
MAXIMUM TOXIN PRODUCTION OCCURS AT PH BETWEEN 7 AND 8,
AND
DECREASES
UNDER
ANAEROBIC
CONCENTRATIONS OF GLUCOSE (6).
2.7.1.3 EXFOLIATIVE TOXIN
30
CONDITIONS
AND
IN
HIGH
THIS
NEONATES.
TOXIN CAUSES THE SCALDED SKIN SYNDROME
IT
(S.S.S.)
IN
IS SEEN MOSTLY IN YOUNG CHILDREN AND RARELY IN
OLDER CHILDREN AND ADULTS (7).
IT HAS BEE REPORTED THAT THIS TOXIN CAN BE ALSO PRODUCED
BY STAPH.HYCIUS STRAINS (47).
2.7.2 ENTEROTOXIN
THIS
IS
TOXIN
PRODUCED
RETAINED WITH THE CELL
BY
STAPH.AUREUS
HOWEVER
NOT
(44). MOST
CULTURES
ALL
BY
THE
MICROORGANISM
AND
ENTEROTOXINS ARE PROVIDED
THAT
ARE
COAGLASE-POSITIVE
COAGULASE-POSITIVE,
STAPHYLOCOCCI
ARE
NECESSARILY ENTEROTOXIGENIC (48).
THERE
ARE AT LEAST SIX
(A-F)
SOLUBLE TOXINS PRODUCED BY
NEARLY 50% OF STAPH. AUREUS STRAINS(11).
THE ENTEROTOXINS ARE RESISTANT TO HYDROLYSIS BY
GASTRIC AND JEJUNAL ENZYMES AND ARE STABLE TO
HEATING AT 100ºC FOR 30 MINUTES; REHEATING THE FOOD
WILL NOT BE PROTECTIVE (7).
THE
PRODUCTION OF ENTEROTOXIN IS INFLUENCED BY THE
PRESENCE OF THE ORGANISM IN THE FOOD, TEMPERATURE AND TIME,
31
COMPOSITION
OF
FOOD,
PH,
MOISTURE
CONTENT
AND
THE
ATMOSPHERIC CONDITIONS (49).
2.7.3 COAGULASE ENZYME
Most staphylococci pathogenic for humans produce coagulase enzyme. This is
an enzyme-like protein that clots oxalated or citrated plasma in the presence of a
factor contained in many sera. The serum factor reacts with coagulase and gives
clotting activities in a manner similar to the activation of prothrombin to thrombin.
Coagulase may deposit fibrin on the surface of staphylococci, perhaps altering their
ingestion by phagocyte cells or their destruction by these cells (11).
Coagulase-negative staphylococci do not possess this enzyme and, therefor,
do not form a clot (32).
2.8 SELECTIVE MEDIA
MOST
OF STAPHYLOCOCCI GROW ON ANY NUTRIENT MEDIUM
CONTAINING PEPTONE; HOWEVER, A SELECTIVE MEDIUM IS A SUITABLE
MEDIUM USED TO ISOLATE STAPHYLOCOCCI FROM SPECIMENS THAT
ARE LIKELY TO BE CONTAMINATED HEAVILY WITH OTHER BACTERIAL
FLORA (50).
2.8.1 BAIRD-PARKER MEDIUM
BAIRD-PARKER
MEDIUM.
MAINLY
MEDIUM IS A SELECTIVE AND DIAGNOSTIC
USED
FOR
COAGULASE-POSITIVE
PATHOGENIC
SPECIES, IT WAS ORIGINALLY USED FOR ISOLATING THE ORGANISM
FROM FOODS
(51). THIS
SELECTIVE MEDIUM IS HIGHLY SPECIFIC FOR
32
STAPH.AUREUS WHICH GIVES BLACK COLONIES SURROUNDED BY CLEAR
ZONES; WITH THE CLEAR ZONES, SMALLER OPAQUE ZONE MAY
DEVELOP.
GROW
OTHER
SLOWLY
STAPHYLOCOCCI AND MICROCOCCI SOMETIMES
BUT
DO
NOT
GIVE
CLEAR
ZONES,
OR
GIVE
IRREGULARLY-SHAPED COLONIES. PROTEUS MAY BE A NUISANCE (52).
2.8.2 MANNITOL SALT AGAR MEDIUM (M.S.A)
THE M.S.A
IS
A
SELECTIVE
MEDIUM,
MAINLY
USED
TO
DISTINGUISH ACID PRODUCING STAPHYLOCOCCAL SPECIES FROM NONACID-PRODUCING STAPHYLOCOCCAL SPECIES.
STRAINS
CAPABLE OF
PRODUCING ACID FROM MANNITOL USUALLY DO THIS WITHIN
24 TO 48
HOURS. THEIR COLONIES AND SURROUNDING MEDIUM ARE YELLOW AS A
RESULT
OF
ACIDIFICATION
IN
THE
INDICATOR (8).
33
PRESENCE
OF
PHENOL
RED
THIS SELECTIVE MEDIUM IS BASED ON ITS
HIGH
CONCENTRATION
OF
SALT.
STAPHYLOCOCCI ARE ABLE TO TOLERATE
THESE HIGH CONCENTRATIONS OF SALT (UP
TO 10%) WHEREAS MOST OTHER ORGANISMS
GROW POORLY OR NOT AT ALL (50).
34
CHAPTER THREE
MATERIALS AND METHODS
3.1. STERILIZATION:
3.1.1. HOT-AIR OVEN (160 – 170OC FOR ONE HOUR)
GLASSWARE
LIKE
PETRI
DISHES, PIPETTES, TUBES, FLASKS AND
GLASS RODS AS WELL AS MORTAR AND PESTLE
(WRAPPED
WITH
ALUMINUM FOIL) WERE STERILIZED IN THE HOT AIR OVEN AT 160ºC FOR
ONE HOUR (27).
3.1.2. AUTOCLAVING
USED
FOR STERILIZATION OF MEDIA, SOLUTIONS AND MATERIAL
WHICH COULD NOT WITHSTAND THE DRY HEAT.
WERE
15 – 20
MINUTES AT
115º
TO
121ºC
THE
UNDER
EXPOSURE TIMES
10 – 15
POUNDS
PRESSURE (27).
3.1.3. IRRADIATION AND DISINFECTION
FOR
ASEPTIC WORK AND TRANSFERS, ADDITION AND POURING
PLATES, PHENOLIC OR ABSOLUTE ALCOHOL WAS USED FIRST FOR
DISINFECTING FLOORS AND UV ROOM, FOLLOWED BY UV IRRADIATION
FOR 20 MINUTES.
3.2. COLLECTION
OF
BLOOD,
PLASMA
LABORATORY ANIMALS
35
AND
FIBRIN
CLOTS
FROM
BLOOD
FOR ENRICHMENT OF MEDIA WAS COLLECTED BY
VENIPUNCTURE OF THE JUGULAR VEIN OF A HEALTHY DONOR SHEEP
KEPT AT THE DEPARTMENT FOR THE SAME PURPOSE.
THE
BLOOD WAS
DEFIBRINATED BY SHAKING THE STERILE FLASK CONTAINING GLASS
BEADS.
PLASMA FOR COAGULASE TEST WAS ASPIRATED DIRECTLY FROM
A RABBIT HEART OR FROM EAR VEIN.
HUMAN
BLOOD WAS OBTAINED
FROM VOLUNTEERS, AND PLASMA WAS ASEPTICALLY SEPARATED BY
SUBJECTING BLOOD TO CENTRIFUGATION.
3.3 PREPARATION OF MEDIA
3.3.1. SOLID MEDIA
3.3.1.1 NUTRIENT AGAR
TWENTY-EIGHT
GRAMS OF DEHYDRATED NUTRIENT AGAR WERE
SUSPENDED IN A LITER OF DISTILLED WATER, STEAMED TO DISSOLVE
COMPLETELY, THE PH ADJUSTED TO
7.4
AND THEN THE MEDIUM
STERILIZED BY AUTOCLAVING AT 121ºC FOR 15 MINUTES.
3.3.1.2 BLOOD AGAR MEDIUM (OXOID)
FORTY
GRAMS OF BLOOD AGAR BASE WERE SUSPENDED IN A
LITER OF DISTILLED WATER, STEAMED TO DISSOLVE, COOLED AND THEN
PH ADJUSTED TO
AUTOCLAVING AT
7.4
121ºC
THEN THE MEDIUM WAS STERILIZED BY
FOR
15
MINUTES.
36
AFTER
COOLING TO ABOUT
50OC,
DEFIBRINATED SHEEP BLOOD WAS ADDED ASEPTICALLY IN
(7-
10%) CONCENTRATED BEFORE POURING ONTO PLATES.
3.3.1.3 BAIRD -PARKER MEDIUM (OXOID)
IN
A LITER OF DISTILLED WATER,
BAIRD –PARKER
63
GRAMS OF DEHYDRATED
MEDIUM WERE SUSPENDED, MIXED AND STEAMED TO
DISSOLVE, THEN PH WAS
ADJUSTED TO
AFTER
6.8
121OC
BEFORE AUTOCLAVING AT
COOLING TO
50ºC,
FOR
15
MINUTES.
EGGYOLK FROM FOUR CHICKEN EGGS WAS
ADDED TO A HALF A LITER OF THIS MEDIUM AND TWO ML OF POTASSIUM
TELLURITE SOLUTION
(1%)
WERE ADDED ASEPTICALLY AND MIXED
WELL BEFORE POURING THESE PLATES.
3.3.1.4 MANNITOL SALT AGAR MEDIUM (OXOID)
IN
A LITER OF DISTILLED WATER,
111
GRAMS OF DEHYDRATED
MANNITOL SALT AGAR WERE SUSPENDED, MIXED WELL, STEAMED TO
DISSOLVE AND THE PH ADJUSTED TO
121ºC
FOR
15
MINUTES.
THEN
7.2
BEFORE AUTOCLAVING AT
COOLING TO
50ºC
AND POURING ONTO
THE PLATES.
3.3.2 SEMISOLID MEDIA
3.3.2.1 HUGH AND LEIFSON’S (O/F MEDIUM )
PEPTONE, 2
GRAM;
NACL, 5
GRAMS; AGAR,
3
GRAMS AND
K2HPO4 , 0.3 GRAMS WERE DISSOLVED IN ONE LITER DISTILLED WATER
37
BY HEATING, THEN THE PH WAS ADJUSTED TO
BROMTHYMOL BLUE,AQUEOUS SOLUTION
(0.2%)
7.1, 15ML
WERE ADDED THEN
THEN THE MEDIUM WAS STERILIZED BY AUTOCLAVING AT 115
MINUTES,
TEN
ASEPTICALLY
OF
O
C FOR 20
ML OF STERILE GLUCOSE SOLUTION WERE ADDED
TO
CONCENTRATION OF
90
ML OF THE MEDIUM TO GIVE THE FINAL
1%
AND THE MEDIUM DISTRIBUTED
INTO TEST
TUBES, EACH TUBES CONTAINING 10 ML (27).
3.3.2.2 CHRISTENSEN'S UREA MEDIUM (OXOID)
TWO
TO FOUR GRAMS OF DEHYDRATED UREA AGAR BASE WERE
SUSPENDED IN
95 ML OF DISTILLED WATER AND STEAMED TO DISSOLVE.
THEN THE MEDIUM WAS STERILIZED BY AUTOCLAVING AT 115ºC FOR 20
MINUTES AND COOLED TO
50ºC. ASEPTICALLY 5
ML OF STERILE
40%
UREA SOLUTION WERE ADDED, MIXED WELL AND DISTRIBUTED IN
SCREW-CAPPED BOTTLES AND ALLOWED TO SET IN SLANT POSITION.
3.3.3 LIQUID MEDIA
3.3.3.1 NUTRIENT BROTH (OXOID)
THIRTEEN
GRAMS OF DEHYDRATED NUTRIENT BROTH WERE
SUSPENDED IN LITER OF DISTILLED WATER, THEN MIXED WELL AND THE
PH ADJUSTED TO
7.4 AND THEN STERILIZED BY AUTOCLAVING AT 121ºC
FOR 15 MINUTES.
3.3.3.2 PEPTONE WATER (OXOID)
38
Fifteen grams of dehydrated peptone water were suspended in a liter of
distilled water, mixed well, then pH adjusted to 7.2 and autoclaved at 121ºC for 15
minutes.
3.3.3.3 GLUCOSE PHOSPHATE MEDIUM
PEPTONE, 10 GRAMS AND K2HPO4, 5 GRAMS WERE DISSOLVED IN
1
LITER OF DISTILLED WATER,
ADJUSTED TO
7.5
AFTER
5
STEAMED TO DISSOLVE AND PH WAS
GRAMS OF GLUCOSE WERE ADDED, MIXED
WELL AND DISTRIBUTED INTO TEST TUBES AND THEN STERILIZED AT
110ºC FOR 10 MINUTES.
3.3.3.4 COOKED MEAT MEDIUM
FAT-FREE MINCED MEAT (450 GRAMS) WAS ADDED TO 1 LITER OF
DISTILLED
WATER,
THEN
FILTERED
AND
PARTICLES WERE ADDED TO A DEPTH OF
2.5
PRESSED
DRY.
DRIED
–
CAPPED
CM IN SCREW
BOTTLES AND THEN NUTRIENT BROTH WAS ADDED TO THE DEPTH OF
CM.
THEN
THIS WAS STERILIZED BY AUTOCLAVING AT
115ºC
FOR
5
20
MINUTES.
3.4 COLLECTION OF SAMPLES
A
TOTAL OF
40
FRESH BEEF SAMPLES WERE COLLECTED FROM
DIFFERENT MARKETS IN
KHARTOUM STATE:
THE SAMPLES WERE
WRAPPED WITH STERILE ALUMINUM FOIL, LABELED AND STORED IN
39
STERILE CONTAINERS IN ICE WATER AND TRANSFERRED IMMEDIATELY
TO THE LABORATORY.
3.5 MICROBIOLOGICAL METHODS
3. 5.1 PRIMARY ISOLATION
SELECTIVE MEDIA WERE USED FOR PRIMARY ISOLATION, (BAIRD–
PARKER AND MANNITOL SALT AGAR). UNDER ASEPTIC CONDITIONS THE
SAMPLES WERE OPENED, L GRAM OF SAMPLE WAS TAKEN, POUNDED
WITH STERILE MORTAR AND PESTLE AND SUSPENDED IN
NORMAL SALINE.
A
ONTO SOLID MEDIA
10
ML OF
LOOPFUL OF THE MIXURE WAS USED TO STREAK
(SELECTIVE
MEDIA), THEN THE PLATES WERE
INCUBATED AT 37ºC FOR 24 HARS.
3.5.2 PREPARING THE DILUTION
ONE
ML FROM THE SAMPLE WAS TAKEN BY STERILE PIPETTE AND
TRANSFERRED TO THE FIRST TUBE OF DILUTION
PIPETTE
(10-1); WITH A STERILE
1 ML FROM THE FIRST DILUTION TUBE WAS TRANSFERRED TO A
SECOND TUBE OF STERILE DILUENT
(10-2),
THEN FURTHER DILUTIONS
WERE MADE.
3.5.3 PURIFICATION, IDENFIFICATION AND PRESERVATION
STAPHYLOCOCCAL COLONIES OBTAINED ON PRIMARY ISOLATION
MEDIA
WERE
USED
FOR
GRAM
40
STAINING
AND
CATALASE
TEST
.PURIFICATION
WAS
CORRESPONDING
BIOCHEMICAL
(APPENDIX)
DONE
MEDIA.
TEST
BY
SEVERAL
PURE
ACCORDING
SUB-CULTURINGS
COLONIES
TO
FOR IDENTIFICATION OF
37ºC
FOR
STAPHYLOCOCCUS
24-48
USED
PROF ELSANOUSI
PURE CULTURES WERE INOCULATED ON COOKED
THEN INCUBATED AT
WERE
- MEAT
ON
FOR
SCHEME
SPECIES.
THE
MEDIUM AND
HRS, THEN STORED AT
4ºC
IN
REFRIGERATOR.
3.6 BIOCHEMICAL METHODS
3.6.1 COAGULASE TEST
3.6.1.1 SLIDE COAGULASE TEST
THIS
WAS PERFORMED ON A CLEAN SLIDE, BY PLACING A
LOOPFUL OF NORMAL SALINE AND A SMALL AMOUNT OF AN
18-24HRS
AGE CULTURE MIXED IN UNTIL A HOMOGENEOUS SUSPENSION WAS
OBTAINED; THEN A DROP OF HUMAN PLASMA OR RABBIT PLASMA WAS
ADDED TO THE SUSPENSION; CLUMPING OCCURRED WITHIN
IN A POSITIVE TEST.
THE
5
SECONDS
SLIDE TEST WAS CONFIRMED BY THE TUBE
TEST (42).
3.6.1.2 TUBE COAGULASE TEST
HALF ML OF DILUTED FRESH HUMAN PLASMA WAS ADDED TO
SMALL TEST TUBES, THEN
0.5ML OF AN 18-24 HRS BROTH CULTURE WAS
41
ADDED AND INCUBATED AT 37ºC. COAGULASE WAS EXAMINED AFTER AN
HOUR THEN AT FOR INTERVALS UP TO 24 HRS (42).
3.6.2 CATALASE TEST
A
DROP OF
30%
AQUEOUS SOLUTION OF HYDROGEN PEROXIDE
WAS PLACED ON A CLEAN A SLIDE, A LOOPFUL OF GROWTH CULTURE
WAS PLACED IN THE HYDROGEN PEROXIDE
AND OBSERVED FOR
PRODUCTION OF GAS BUBBLES (42).
3.6.3 OXIDASE TEST
ONE
PERCENT
AQUEOUS
SOLUTION
OF
TETRA
METHYL-P-
PHENYLENE DIAMINE HYDROCHLORIDE WAS USED TO SOAK A FILTER
PAPER. WITH A GLASS ROD A COLONY WAS PICKED AND RUBBED ON THE
SURFACE OF THE PAPER, PRODUCTION OF PURPLE COLOUR WITHIN
5-10
SECONDS WAS RECORDED AS OXIDASE POSITIVE (42).
3.6.4 UREA TEST
A UREA AGAR SLANT WAS STOPPED WITH THE TEST CULTURE AND
THEN INCUBATED AT
37OC
FOR
24-48HRS. DEVELOPMENT
OF PINK
COLOUR WAS INDICATIVE OF NH3 PRODUCTION. NEGATIVE TESTS WERE
LEFT FOR A WEEK BEFORE TAKING THE FINAL RESULT.
3.6.5 VP TEST (VOGES–PROSKAUER TEST)
42
CULTURES WERE INOCULATED IN TEST TUBES CONTAINING 1-5ML
GLUCOSE PHOSPHATE BROTH AND INCUBATED AT
37OC FOR TWO DAYS.
HALF
OF
ML OF CULTURE WAS ADDED TO
SOLUTION AND
0.5ML
5%
Α-NAPHTHOL
0.5ML 16% KOH. DEVELOPMENT OF A RED COLOUR AT
THE SURFACE WAS RECODED AS POSITIVE REACTION.
3.6.6 SUGAR FERMENTATION
THIS
CELLOBIOSE,
MANNITOL,
9
SUGARS, XYLOSE,
MALTOSE,
D-MANNOSE, D,
TEST WAS CARRIED OUT USING
RAFFINOSE,
D-TREHALOSE
SUCROSE,
AND LACTOSE.
THE
CONCENTRATION OF
SUGAR AND ANDRADE’S INDICATOR WERE 1% IN PEPTONE WATER.
EACH
TUBES,
FOR
14
WHEN
TEST CULTURE WAS INOCULATED INTO A SET OF SUGAR
INCUBATED AT
DAYS.
PINK
37OC
AND EXAMINED FOR ACID PRODUCTION
COLOUR OCCURRED WHEN ACID WAS PRODUCED.
THERE WAS NO ACID THE MEDIUM COLOUR REMAINED
UNCHANGED (42).
3.6.7 NOVOBIOCIN SENSITIVITY TEST
THIS
WAS DETERMINED BY THE STANDARD DISC DIFFUSION
METHOD (34).
AFTER
NUTRIENT AGAR PLATES WERE DRIED, TWO ML OF DILUTED
CULTURE WERE DISTRIBUTED EVENLY OVER THE SURFACE OF MEDIUM
43
.EXCESS
FLUID WAS REMOVED AND PLATES WERE ALLOWED TO DRY
.OXOID DISC OF NOVOBIOCIN (5MG) WERE APPLIED TO THE SURFACE OF
THE MEDIA AND PRESSED GENTLY BY USING STERILE FORCEPS, THEN
INCUBATED AT
37OC FOR 24-48 HOURS AND ZONES OF INHIBITION WERE
MEASURED IN
(MM)
TO DETERMINE WHETHER THE ORGANISM WAS
SENSITIVE TO NOVOBIOCIN.
44
CHAPTER FOUR
RESULTS AND DISCUSSION
THIS STUDY WAS DESIGNED TO KNOW THE TOTAL VIABLE COUNT,
STAPHYLOCOCCUS
COUNT AND THE PREVALENCE OF STAPHYLOCOCCI
SPECIES IN FRESH MEAT IN KHARTOUM STATE.
IN THIS CHAPTER ALL MICROBIAL COUNTS ARE GIVEN AS COLONY
FORMING UNITS (CFU) PER GRAM.
THE STAPHYLOCOCCUS
FOUND TO RANGE FROM
3.23
COUNT OF FRESH MEAT SAMPLES WAS
X
103
3
THE RANGE WAS 4.46 × 10 TO.8.71 × 10
AND
8.7 × 103. IN KHARTOUM CITY
TO
3
, BAHRI 3.81 × 103
TO 4.46 × 10
3
OMDURMAN 3.23 × 103 TO 5.01 × 103. TOTAL VIABLE COUNT WAS
RANGED
4.78 × 104 TO 3.39 × 105, WHEREAS IN KHARTOUM IT WAS 4.78
×104
9.55 × 104, BAHRI 6.31 × 104 TO 3.39 × 105
TO
7.07× 104
THAT
TO
1.41 × 105
STAPHYLOCOCCUS
LOWEST IN
AS SHOWN IN
TABLE 1. THE
COUNT WAS HIGHEST IN
KHARTOUM. HOWEVER,
AND
OMDURMAN
RESULTS SHOW
OMDURMAN
AND
THE TOTAL VIABLE COUNT WAS
HIGHEST IN BAHRI.
THE RESULT OBTAINED IN THIS STUDY WAS IN
CANADIAN GOVERNMENT
AGREEMENT WITH
GUIDELINES, WHICH SPECIFIED THAT THE
45
AEROBIC PLATE COUNT (APC) AT 35
SHOULD BE LESS THAN
THIS
C FOR NON-FROZEN GROUND BEEF
1.0 ×107 CFU/G. OUR FINDING DIFFERED
THE FINDING THAT, IN MEAT,
CFU/G(39).
O
APC
RANGED BETWEEN
102
FROM
AND
103
DIFFERENCE WILL BE DUE TO DIFFERENT FACTORS
SUCH AS DIFFERENT LOCATIONS. IN THIS LAST WORK
(39) THE SAMPLES
WERE TAKEN FROM ABATTOIRS, WHILE THE FRESH MEAT IN THIS STUDY
WAS TAKEN FROM BUTCHERIES FROM DIFFERENT MARKETS WHERE
ADDITIONAL CONTAMINATION MAY HAVE TAKEN PLACE DURING
TRANSPORTATION.
TABLE 1 TOTAL VIABLE COUNT AND STAPHYLOCOCCUS COUNT OF FRESH
BEEF COLLECTED FROM KHARTOUM STATE
TOTAL VIABLE COUNT
STD.
STAPH. COUNT
STD.
LOCATION
MINIMUM
MEAN
MAXIMUM
DEVIATION
MINIMUM
MEAN
MAXIMUM
DEVIATION
KHARTOUM
4.78×104
6.31×104
9.55×104
0.15
4.46×103
6.02×103
8.71×103
0.1473
BAHRI
6.31×104
1.39×105
3.39×105
0.36
3.81×103
4.16×103
4.46×103
3.61
OMDURMAN
7.07×104
5.0×105
1.41×105
0.15
3.23×103
3.98×103
5.01×103
9.50
TOTAL
4.78×104
9.55×104
3.39×105
0.25
3.23×103
4.57×103
8.7×103
0.12
IN THIS STUDY, 40 BEEF SAMPLES WERE USED, 14 SAMPLES WERE
COLLECTED FROM
KHARTOUM
AND
13
SAMPLES COLLECTED FROM
EACH OF BAHRI AND OMDURMAN MARKETS AS SHOWN IN TABLE 2. THE
46
RESULTS OBTAINED IN THIS STUDY WERE AS FOLLOWS:
BELONG TO
19
TABLE 3. IT
ISOLATES
SPECIES OF THE GENUS STAPHYLOCOCCI AS SHOWN IN
WAS OBSERVED THAT, THE HIGHEST PREVALENCE OF
STAPHYLOCOCCI SPECIES WAS THAT OF
THIS
58
STAPH.
EPIDERMIDIS
(13.8%).
FINDING IS IN AGREEMENT WITH OTHER WORKERS WHO FOUND
THAT
TABLE 2 SOURCE
AND PREVALENCE OF ISOLATES OF STAPHYLOCOCCI
FROM FRESH BEEF SAMPLES COLLECTED FROM KHARTOUM STATE.
NO. OF
LOCATION
NO. OF SAMPLES
KHARTOUM
14
17
29.3%
BAHRI
13
18
31%
OMDURMAN
13
23
39.7%
ISOLATES
ISOLATION%*
* PERCENT OF SAMPLES FROM WHICH STAPHYLOCOCCUS WAS ISOLATED
TABLE 3 THE
PERCENTAGE OF INDIVIDUAL
STAPHYLOCOCCUS
SPP. TO
THE TOTAL NO. OF ISOLATES*
STAPHYLOCOCCUS
NO. OF PERCENTAGE
SPECIES
ISOLATES
8
7
7
6
5
STAPH. EPIDERMIDIS
STAPH. AUROUS
STAPH. CASEOLYTIUS
STAPH.SAPROPHYTIUS
STAPH. SCUIRI
47
13.8
12.0
12.0
10.3
8.6
STAPH. CPITIS
STAPH. LUGDUNENSIS
STAPH. COHNI
STAPH. XYLOSUS
STAPH. KLOOSII
STAPH. CAPITIS SSP.
UREALYTICUS
STAPH.
COHNI
SSP.
UREALYTICUS
STAPH.FELIS
STAPH. WARNERI
STAPH. GALLINARUM
STAPH. HYCIUS
STAPH. CHROMOGENS
STAPH.LENTUS
STAPH. HAEMOLYTICUS
4
4
3
2
2
6.9
6.9
5.2
3.4
3.4
2
3.4
1
1.7
1
1
1
1
1
1
1
1.7
1.7
1.7
1.7
1.7
1.7
1.7
*: TOTAL NO. OF ISOLATES=58
STAPH.
EPIDERMIDIS
WAS
THE
MOST
FREQUENTLY
RECOVERED
ORGANISM ISOLATED FROM CLINICAL INFECTION, AND ALSO IN
AGREEMENT WITH OTHERS WHO REPORTED
that Staph. epidermidis was found in large numbers all over human skin and mucous
membrane (23, 24, 15). The study showed that this organism cannot acidify mannitol
on mannitol salt agar medium and appears as black colonies on Baird-Parker medium,
as shown in Figs. 1 and 2, respectively.
48
Staphylococcus aureus ranks as a second. The presence of this organism could
be indicative of contamination of meat from skin, mouth and nose of butchers and
this is in agreement with others who reported that Staph. aureus was found on the
anterior of nasal mucosa of 40-50% of healthy adults and in the throats of many of
them (15). This may contaminate food during handling and cutting, but
contamination may also come from other sources. Staph. aureus appeared as thin
black colonies on Baird-Parker medium and fermented mannitol in mannitol salt agar
medium as shown in Figs.3 and 4.
In the present study, the isolates of staphylococci were divided into two
groups according to the coagulase test, as shown in Table 4:
1\ Coagulase-positive, Staph. aureus.
TABLE
4
COAGULASE-POSITIVE
STAPHYLOCOCCUS
AND
COAGULASE-NEGATIVE
SPECIES ISOLATED FROM FRESH BEEF SAMPLES
COLLECTED FROM KHARTOUM STATE.
LOCATION
COAGULASEPOSITIVE
STAPH.SPP.
COAGULASE- NEGATIVE STAPHYLOCCUS
SPECIES
NOVOBIOCISENSITIVE
KHARTOUM STAPHYLOCOCCUS STAPH.
AUREUS
NOVOBIOCINRESISTANT
STAPH. XYLOSUS
EPIDERMIDIS
STAPH.
STAPH.
SAPROPHYTICUS
CASEOLYTICUS
STAPH. LENTUS
STAPH.
STAPH. SCIURI
LUGDUNENSIS
49
STAPH.
CHROMOGENES
STAPH. CAPITIS
SSP.
UREALYTICUS
BAHRI
STAPHYLOCOCCUS STAPH.
STAPH. SCIURI
AUREUS
EPIDERMIDIS
STAPH. COHNI
STAPH.
STAPH.
CASEOLYTICUS
SAPROPHYTICUS
STAPH.
LUGDUNENSIS
STAPH.HYCIUS
STAPH. CPITIS
OMDURMAN STAPHYLOCOCCUS STAPH.
AUREUS
STAPH.SAPROPHYTICUS
EPIDERMIDIS
STAPH. KLOOSII
STAPH.
STAPH. COHNI
CASEOLYTICUS
STAPH.
STAPH.
UREALYTICUS
CPITIS
STAPH.FELIS
STAPH.
LUGDUNENSIS
STAPH. WARNERI
STAPH.
HAEMOLYTICUS
STAPH. CAPITIS
SSP.
UREALYTICUS
50
COHNI
SSP.
STAPH. GALLINARUM
51
FIG.1: COLONIES OF STAPH. EPIDERMIDS ON
FIG.2:
COLONIES OF STAPH. EPIDERMIDIS
BAIRD-PARKER MEDIUM.
ON M.S. A. MEDIUM.
52
FIG.4: COLONIES OF
FIG.3: COLONIES OF STAPH. AUREUS ON
STAPH. AUREUS ON
M.S. A. MEDIUM.
BAIRD-PARKER
MEDIUM.
53
2\ Coagulase-negative (novobiocin-sensitive), Staph. epidermidis, Staph.
caseolyticus, Staph. lugdunensis, Staph. capitis, Staph. capitis ssp. urealyticus, Staph.
felis, Staph. warneri, Staph. hycius, Staph. chromogenes and Staph. haemolyticus.
Coagulase-negative (novobiocin-resistance), Staph. saprophyticus Staph.
sciuri, Staph. cohni, Staph. cohni ssp. urealyticus, Staph. xylosus, Staph. kloosii, and
Staph. gallinarum.
The sensitivity of staphylococci to novobiocin is shown in Figs. 5 and 6.
These results show that most of staphylococci isolates were coagulasenegative, and this was in agreement with other researchers who reported that most of
staphylococci found in the skin and respiratory tract are coagulase-negative (15). This
could be due to the presence of isolates which come from human skin by contact.
Table 5 illustrates that Staphylococcus spp. isolated from Khartoum beef
samples (17 isolates, 29.3% of staphylococci) were identified during this study to
belong to 10 species, Staph. caseolyticus, Staph .epidermidis, Staph. aureus, Staph.
saprophyticus, Staph. sciuri, Staph. xylosus, Staph. lugdunensis, Staph. chromogenes,
Staph. lentus and Staph. capitis ssp. urealyticus. The number of staphylococci species
isolated in Khartoum City was lower than that in Bahri and Omdurman.
Among the 10 species isolated from Khartoum City, Staph. caseolyticus was
representing the most common species 17.6% compared to 11.8% for each of Staph.
epidermidis, Staph. aureus, Staph. saprophyticus, Staph. Sciuri and Staph. xylosus
and 5.9% for each of Staph. lugdunensis, Staph. chromogenes, Staph. lentus and
54
Staph. capitis ssp. urealyticus. These results are in agreement with those who found
that the Staph. caseolyticus is the most frequently isolated species from meat (20).
TABLE 5 STAPHYLOCOCCUS
SPP. ISOLATED FROM FRESH BEEF IN
KHARTOUM CITY.
NO. OF
STAPHYLOCOCCUS SPECIES
PERCENTAGE
ISOLATES
STAPH. CASEOLYTICUS
3
17.6
STAPH. EPIDERMIDIS
2
11.8
STAPH. AUREUS
2
11.8
STAPH.SAPROPHYTICUS
2
11.8
STAPH. SCIURI
2
11.8
STAPH. XYLOSUS
2
11.8
STAPH. LUGDUNENSIS
1
5.9
STAPH. CHROMOGENES
1
5.9
STAPH. LENTUS
1
5.9
1
5.9
STAPH.
CAPITIS
SSP.
UREALYTICUS
55
IN BAHRI CITY 18 ISOLATES (31% OF STAPHYLOCOCCI) BELONGED TO 9
SPECIES OF THE GENUS
STAPHYLOCOCCUS, STAPH.
EPIDERMIDIS,
STAPH. AUREUS, STAPH. SAPROPHYTICUS, STAPH. SCIURI, STAPH. COHNI
, STAPH.
CASEOLYTICUS,
STAPH.
LUGDUNENSIS,
STAPH.
HYCIUS AND
STAPH. CAPITIS AS SHOWN IN TABLE 6.
Staph. epidermidis and Staph. Sciuri rank first
with 16.7% for each, followed by Staph. aureus,
Staph.
cohni,
Staph
caseolyticus
and
Staph.
capitis(11.1% each ) and Staph. saprophyticus and
Staph. hycius (5.6% each). Most of the isolates were
coagulase-negative. This is due to the normal flora
found in human and animals and
this was in
agreement with others who stated that the coagulasenegative staphlococci are endogenous to human and
certain animals (8).
The isolated species are
in agreement with
studies done in Sudan where these species were
isolated from various organs of man and animals (26;
29).
56
In
Omdurman
23
isolates
(39.7%
of
staphylococci) belonged to 14 species of the genus
Staphylococcus
as
shown
in
Table
7.
Staph.
epidermidis, Staph. saprophyticus and Staph. aureus,
were the top isolates (13% each). Staph. caseolyticus,
Staph. capitis and Staph. kloosii came second (8.7%
each). Staph. cohni, Staph. felis, Staph. lugdunensis,
Staph. cohni ssp. urealyticus,
Staph. gallinarum,
Staph. warneri , Staph. haemolyticus and Staph. capitis
ssp. urealyticus came as the last isolates (4.3% each).
The first isolates were considered to be well- known
TABLE 6 STAPHYLOCOCCUS SPP. ISOLATED FROM FRESH BEEF IN BAHRI
CITY.
STAPHYLOCOCCUS
NO. OF
57
PERCENTAGE
SPECIES
ISOLATES
STAPH. EPIDERMIDIS
3
16.7
STAPH. SCIURI
3
16.7
STAPH. AUREUS
2
11.1
STAPH.COHNI
2
11.1
STAPH. CASEOLYTIUS
2
11.1
STAPH. CPITIS
2
11.1
STAPH. LUGDUNENSIS
2
11.1
STAPH.SAPROPHYTICUS
1
5.6
STAPH.HYCIUS
1
5.6
58
TABLE 7 STAPHYLOCOCCUS
SPP. ISOLATED FROM FRESH BEEF IN
OMDURMAN CITY.
STAPHYLOCOCCUS
NO. OF
SPECIES
ISOLATE
PERCENTAGE
S
STAPH. EPIDERMIDIS
3
13.0
STAPH.SAPORPHYTICUS
3
13.0
STAPH. AUREUS
3
13.0
STAPH. CASEOLYTICUS
2
8.7
STAPH. CPITIS
2
8.7
STAPH. KLOOSII
2
8.7
STAPH. COHNI
1
4.3
STAPH.FELIS
1
4.3
STAPH. LUGDUNENSIS
1
4.3
1
4.3
STAPH. GALLINARUM
1
4.3
STAPH. WARNERI
1
4.3
STAPH.
COHNI
SSP
UREALYTICUS
59
STAPH. HAEMOLYTICUS
STAPH.
CAPITIS
SSP.
UREALYTICUS
60
1
4.3
1
4.3
pathogens to humans and animals, specially
Staph. aureus. Their presence could be due to the
insanitary condition of the butcher and absene of the
health services in butcheries. This was in agreement
with others who reported that Staph. aureus should
be considered a potential pathogen (14; 8). However,
Staph. epidermidis, and Staph. saprophyticus have low
pathogenicity. Staph. aureus, and Staph. lugdunensis,
produced
partial
and
complete
hemolysin,
respectively, as shown in Figs. 7 and 8 and this was in
agreement with other researchers (34).
Our finding in this study was in agreement with
isolation done
from various organs and materials
(18; 29; 26).
Generally, in this study, the prevalence rate did vary
with different places under studies, for example in
61
Omdurman, where the number of isolates were
higher and also in their species , that is to say 23
isolates from 13 fresh beef samples contained 14
species. This means that more contamination takes
place during the handling and preparation of the
meat and also from air dust and personal contact
during selling and this is in agreement with others
who reported that the contamination of meat came
from external sources during bleeding, handling,
skinning and cutting, and additional contamination
took place in the retails markets, chopping blocks,
sawdust and containers (35).
62
RESISTANCE OF STAPH. SAPROPHTICUS :FIG.5
SENSITIVITY OF STAPH. EPIDERMIDIS :FIG.6
TO NOVOBIOCIN.
TO NOVOBIOCIN
63
FIG.7:Β-HAEMOLYSIS OF STAPH. AUREUS
FIG.8: Α -HAEMOLYSIS OF STAPH.
LUGDUNENSIS
ON BLOOD AGAR MEDIUM.
ON BLOOD AGAR MEDIUM
According to the results some Staphylococcus
species appeared in some places and were absent in
others. As shown in Table 8, Staph. kloosii, Staph.
cohni ssp urealyticus, Staph. felis, Staph. warneri ,
Staph. gallinarum, and Staph. haemolyticus were
isolated from Omdurman samples and were absent in
both Khartoum and Bahri. Staph. lentus, Staph.
chromogenes, and Staph. xylosus were found in
Khartoum samples but were absent in both Bahri
and Omdurman. Staph. sciuri was found in Bahri
64
samples and Staph. capitis and Staph. cohni were
found in Bahri and Omdurman and were not found
in Khartoum.
These differences may be attributed to the
differences in cities, location, handling, selling way
and methods of meat exposure in markets and
whether the meat was sold on the same table as the
viscera.
In this present work, the Staphylococcus species
isolated from different cities appeared at different
frequencies, some of them appeared more than once
and others appeared once, as shown in Table 9
Data in Table 10 show that the first four
predominant species whith their percent appearance
in khartoum, Bahri,and Omdurman respectively, in
brackets): Staph. epidermidis (25, 37.5& 37.5), Staph.
65
aureus, (28.6, 28.6 & 42.), Staph. caseolyticus (42.9,
28.6 &28.6), and Staph. saprophyticus (33.3, 16.7 &
50). All these species are associated with human,
especially in the skin and mucosa membrane and are
considered as normal human flora. In the Sudan,
these species were isolated by others (18,26,25,29) at
various rates.
TABLE 8 PREVALENCE
OF STAPHYLOCCI IN
KHARTOUM, BAHRI
AND
OMDURMAN
STAPHYLOCOCCUS
KHARTOUM BAHRI OMDURMAN
SPECIES
STAPH. EPIDERMIDIS
+
+
+
STAPH. AUREUS
+
+
+
STAPH. CASEOLYTICUS
+
+
+
STAPH.SAPORPHYTICUS
+
+
+
STAPH. SCIURI
+
+
-
66
STAPH. CPITIS
-
+
+
STAPH. LUGDUNENSIS
+
+
+
STAPH. COHNI
-
+
+
STAPH. XYLOSUS
+
-
-
STAPH. KLOOSII
-
-
+
+
-
+
-
-
+
STAPH.FELIS
-
-
+
STAPH. WARNERI
-
-
+
STAPH. GALLINARUM
-
-
+
STAPH. HYCIUS
-
+
-
STAPH. CHROMOGENES
+
-
-
STAPH.LENTUS
+
-
-
STAPH. HAEMOLYTICUS
-
-
+
STAPH. CAPITIS SSP.
UREALYTICUS
STAPH.
COHNI
SSP.
UREALYTICUS
67
TABLE (9) PERCENTAGE
OF
STAPHYLOCOCCUS
SPP. ISOLATED FROM
FRESH BEEF COLLECTED FROM KHARTOUM STATE.
TOTAL
STAPHYLOCOCCUS
NO .
SPECIES
OF
PERCENTAGE
KHARTOUM OMDURMAN BAHRI
ISOLATES
STAPH. EPIDERMIDIS
8
25
37.5
37.5
STAPH. AUREUS
7
28.6
42.9
28.6
STAPH. CASEOLYTICUS
7
42.9
28.6
28.6
STAPH.SAPORPHYTICUS
6
33.3
50
16.7
STAPH. SCIURI
5
40
0
60
STAPH. CPITIS
4
0
50
50
STAPH. LUGDUNENSIS
4
25
25
50
STAPH. COHNI
3
0
33.3
66.7
STAPH. XYLOSUS
2
100
0
0
STAPH. KLOOSII
2
0
100
0
2
50
50
0
1
0
100
0
STAPH. FELIS
1
0
100
0
STAPH. WARNERI
1
0
100
0
STAPH. CAPITIS SSP.
UREALYTICUS
STAPH.
COHNI
SSP.
UREALYTICUS
68
STAPH. GALLINARUM
1
0
100
0
STAPH. HYCIUS
1
0
0
100
STAPH. CHROMOGNES
1
100
0
0
STAPH. LENTUS
1
100
0
0
STAPH. HAEMOLYTICUS
1
0
100
0
69
FIGS. 9
AND
10
SHOW THAT
STAPH.
SAPROPHYTICUS ACIDIFIED
MANNITOL ON MANNITOL SALT AGAR MEDIUM AND CHANGED THE
COLOUR MEDIUM TO YELLOW.
HOWEVER, STAPH.
CASEOLYTICUS DID
NOT ACIDIFY MANNITOL AND KEPT THE COLOUR UNCHANGED
ALSO
THE UTILIZATION OF SUGARS WHICH WERE USED IN THE
IDENTIFICATION OF STAPHYLOCOCCI, SHOWED ACID PRODUCTION BY
CHANGING THE COLOUR TO PINK AND WHEN NO ACID WAS PRODUCED
THE MEDIUM COLOUR DID NOT CHANGE AS SHOWN IN
SHOWS PRODUCTION OF
FIG.13 (APPENDIX II)
SPP. IN
NH3
BY
STAPH.
STAPHYLOCOCCUS
OMDURMAN
CAPITIS SSP.
SHOWS THE PREVALENCE OF
KHARTOUM STATE. FIGS. 14, 15
AND
SPP. ISOLATED FROM
SAMPLES, RESPECTIVELY.
FIG. 11. FIG. 12
UREALYTICUS.
STAPHYLOCOCCUS
16 (APPENDIX II)
SHOW
KHARTOUM, BAHRI
FIG. 17 (APPENDIX II)
AND
SHOWS
THE MOST ABUNDANT STAPHYLOCOCCUS SPP. IN KHARTOUM STATE.
TABLE 10. % ISOLATES OF STAPH. EPIDERMIDIS, STAPH. AUREUS, STAPH.
CASEOLYTICUS
AND
STAPH.
SAPROPHYTICUS
FROM
FRESH
BEEF
COLLECTED FROM KHARTOUM, BAHRI AND OMDURMAN
ISOLATION
KHARTOU
M
STAPH.
STAPHYLOCOCCUS SPECIES
STAPH.
STAPH.
STAPH.
EPIDERMIDIS
AUREUS
CASEOLYTICUS
SAPROPHYTICUS
%
%
%
%
25
28.6
42.9
33.3
70
BAHRI
OMDURMA
N
37.5
28.6
28.6
16.7
37.5
42.9
28.6
50
FIG.10: STAPH. SAPROPHYTICUS
MEDIUM.
FIG.9: STAPH. CASEOLYTICUS ON M.S. A.
MEDIUM. ON M.S. A.
71
FIG.12: UREASE TEST. RIGHT, A
FIG.11: SUGAR TEST. RIGHT, A POSITIVE.
NEGATIVE TEST.
LEFT, A POSITIVE
MIDDLE, A NEGATIVE. LEFT, IS A CONTROL
TEST.
72
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
CONCLUSION:
The study was done to know the microbial load of fresh meat and their source
of contamination and how to prevent our fresh meat, and also to assess
Staphylococcus count and identify the species and investigate the pathogen species
that may cause public hazard to human:
THE STUDY SHOWED THAT TOTAL VIABLE COUNT RANGED FROM
4.78X104 TO 3.39 X 105 AND STAPH. COUNT RANGED FROM 3.23 X 103 TO
8.7X103
CUF/G.
THIS
RANGE
WAS
COMPARABLE
TO
OTHER
RESEARCHERS, WHICH REPORTED THAT THE AEROBIC PLATE COUNT OF
NON-FROZEN BEEF SHOULD BE LESS THAN 1.0X10
THE
ISOLATION
PERCENT
OMDURMAN (39.7%)
OF
7
(37).
STAPHYLOCOCCI
FOLLOWED BY
WAS
BAHRI (31 %)
AND
HIGHER
IN
KHARTOUM
(29.3 %). AMONG THESE ISOLATION OF STAPHYLOCOCCI COAGULASE NEGATIVE STAPHYLOCOCCI WERE THE MAJOR ISOLATES.
THIS
MEAN
THAT ALL THESE SPECIES WERE ASSOCIATED WITH HUMAN SPECIALLY
ON THE SKIN AND MUCOUS MEMBRANE AND CONSIDERED AS NORMAL
HUMAN FLORA, SOME OF THESE ISOLATES (STAPH. EPIDERMIDIS, STAPH.
73
SAPROPHYTICUS,
STAPH.
WARNERI,
STAPH.
HEAMOLYTICUS)
HAVE
BECOME
A
INFECTION.
THEY
LUGDUNENSIS AND
MAJOR
PROBLEM
IN
STAPH.
HUMAN
CAUSE NOSOCOMIAL INFECTION IN NEONATAL AND
URINARY TRACT INFECTIONS, PARTICULARLY IN YOUNG WOMEN.
MOREOVER,
SYNDROME
AND
STAPHYLOCOCCAL FOOD POISONING, TOXIC SHOCK
SCALED
SKIN
STAPH.AUREUS.
74
SYNDROME
ARE
CAUSED
BY
RECOMMENDA TION
THE STUDY RECOMMEND THAT:
•
THEY SHOULD BE ROUTINE INVESTIGATE OF
THE ABATTOIRS
FOR HYGIENE.
•
WORKERS IN CONNECTION WITH MEAT PRODUCTION AND
•
DISTRIBUTION MUST BE ROUTINELY MEDICAL EXAMINED.
•
INFECTED
PARTS OF THE CARCASSES MUST BE SAFELY
DISPOSED OFF.
•
MEAT
MUST BE TRANSPORTED BY SPECIAL REFRIGERATOR
CARS AND STORED AT LOW TEMPERATURE TO PREVENT
STAPHYLOCOCCAL GROWTH, BECAUSE FOOD POISONING IS
CAUSED BY INGESTION OF IMPROPERLY STORED FOOD IN
WHICH STAPHYLOCOCCUS AUREUS HAS GROW.
•
MEAT MUST BE STORED IN REFRIGERATED CASES AT SELLING
POINT, SO AS TO
AVOID CONTAMINATION RESULTING FROM
AN, DUST…ETC.
•
MEAT
SHOULD BE SALED IN BIG CUTS AS FURTHER CUTTING
INCREASES CONTAMINATION.
•
CUTTING
BOARDS AND UTENSILS MUST BE KEPT CLEAN AND
BUTCHERS SHOULD USE GLOVES DURING WORK.
75
•
MEAT
MUST BE KEPT AWAY FROM VISCERA DURING THE
TRANSPORTATION AND SELLING, ESPECIALLY IN REMOTE
AREA.
76
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83
APPENDIX (I)
IDENTIFICATION FORM OF STAPHYLOCOCCUS SPP ACCORDING TO
PROF.ELSANOUSI SCHEME
NO. OF SAMPLE …………………
TYPE: ……………………..…..
PRELIMINARY TEST
NO.
I
II
III
IV
V
SOURCE: …………………….
CODE: ……………………….
TEST
RESULT
TEST
RESULT
GRAM STAIN
SHAPE
CATALASE
OXIDASE
O/F
NO.
COAGULASE TEST
NAVOBIOCINE
V.P TEST
UREASE TEST
NITRATE TEST
HAEMOLYSIS
COL.SIZEZ >6MM
PIGMENT.COL.
SUGAR FERMENTATION
MANNOSE
RAFFINOSE
SUCROSE
MANNITOL
TREHALOSE
XYLOSE
LACTOSE
MALTOSE
FRUCTOSE
CELLOBIOSE
TURANOSE
THE IDENTIFIED RESULT……………..…………………………………………
OTHER TEST:
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
84
85
APPENDIX (II)
45%
40%
35%
Isolation %
30%
25%
20%
15%
10%
5%
0%
Khartoum
Bahri
Omdurman
Fig. (13) Prevelance of staphylococci spp in Khartoum State
20
18
16
Isolation %
14
12
10
8
6
4
2
0
S.
S.
S.
S.
S.
S.
pi
t is
s
ss
p
s
ea
s
ur
ne
s is
ge
en
s
s
cu
di
cu
yt i
mo
tu
ro
un
s
su
gd
ca
l en
ch
lu
lo
ri
ph
mi
yti
us
ro
iu
xy
sc
ap
re
ol
er
se
id
au
ep
ca
S .s
S.
S.
S.
l yt
icu
s
Fig. (14) Staphylococcus spp isolated from fresh beef in Khartoum City
86
S.
S.
sa
op
s
hy
us
is
s
is
ti c
ns
id
ic u
ne
yt
us
i
ol
du
s
iti
c iu
pr
hy
cp
g
lu
se
hn
ca
co
re
rm
ri
e
id
iu
au
sc
ep
i
ep
s
icu
lyt
ea
ur
p
ss
tis
pi
s
ca
cu
S.
yti
ol
em
ha
S.
i
er
rn
s
wa
m
S.
ru
icu
lyt
na
lli
ea
ga
ur
S.
sp
is
hn
co
sis
S.
en
un
gd
lu
S.
lis
fe
S.
i
hn
co
S.
sii
oo
kl
S.
s
iti
s
cp
cu
S.
yti
ol
se
ca
S.
us
re
s
au
cu
yti
S.
h
rp
po
is
sa
id
S.
rm
de
S.
87
S.
S.
S.
S.
S.
S.
S.
8
6
Isolation %
10
8
6
Isolation %
18
16
14
12
4
2
0
Fig. (15) Staphylococcus spp isolated from fresh beef in Bahri City
14
12
10
4
2
0
Fig. (16) Staphylococcus spp isolated from fresh beef in Omdurman City
16
14
Isolation %
12
10
8
6
4
2
0
S.
S.
S.
S.
s
is
s
tiu
hy
op
pr
sa
iu
lyt
s
ou
o
se
ca
r
au
id
m
er
id
ep
Fig. (17) Prevelance of the most abundant of staphylococci spp in
Khartoum State
88
89
90
91
92