Poster session 4: Microbiology
P4.01
MRSA and presence of inflammation are associated with increased overall mortality in
patients with diabetic foot ostemyelitis
Carlo Tascini, Pisa University Hospital, Pisa, Italy
Elisabetta Iacopi, Pisa University Hospital, Pisa, Italy
Alberto Coppelli, Pisa University Hospital, Pisa, Italy
Chiara Goretti, Pisa University Hospital, Pisa, Italy
Alberto Piaggesi, University of Pisa, Pisa, Italy
Aim: Diabetic foot osteomyelitis (DFO) may be caused by multi-drug resistant microorganisms (MDRO) and is associated with an high incidence of mortality. To check if MDRO
are predictors of mortality in DFO we analyzed retrospectively our microbiological database,
from 2001 to 2013.
Methods: These characteristics were studied: 1) Methicillin-Resistant Staphylococcus
Aureus (MRSA) vs Methicillin-Susceptible Staphylococcus Aureus (MSSA); 2) Ciprofloxacin
resistant Pseudomonas aeruginosa (CiproRPA) vs Cipro- susceptible Pseudomonas
aeruginosa (CiproSPA); 3) Carbapenem resistant Pseudomonas aeruginosa (CRPA) vs
Carbapenem suspceptible Pseudomonas aeruginosa (CSPA); 4) Ciprofloxacin resistant
enterobacteria (CiproRE) vs Ciprofloxacin susceptible enterobacteria (CiproSE); 5) Extended
spectrum Beta Lactamase (ESBL) producers enterobacteria (ESBL+) vs non ESBL
producers enterobacteria (ESBL-); 6) Candida parapsilosis (CP) vs Candida non
parapsilosis (CNP). Presence of polymorphonuclear leukocytes (PMN) at Gram stain of DFO
was recorded. Clinical characteristics studied were: overall mortality, and time to healing
(TH) of DFO.
Results: 401 patients with DFO were found. From bone specimens analyzed in microbiology
laboratory were recovered 625 isolates. Redundant isolates were eliminated.
Staphylococcus aureus was found in 140 DFO (78 MRSA – 55.7%); Enterobacteria in 117
DFO (Cipro RE 46 - 39.5%, ESBL+ 34 – 34.3%); Pseudomonas aeruginosa in 95 DFO (53
CiproRPA – 55.2%, 31 CRPA – 32.1%); Yeasts in 32.
DFO caused by MRSA was associated with increased overall mortality (p= 0.005) and
increased TH (p= 0.024). Presence of PMN was associated with increased overall mortality
(p= 0.008) and TH (p= 0.026).
Conclusion: MRSA and presence of PMN at gram stain of bone obtained from DFO was
associated with increased overall mortality and increased TH in diabetic patients with DFO.
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Page 1 of 10
P4.02
Differences between etiopathogeny of diabetic foot infections in two different clinics,
diabetes and surgery
Eduard Lucian Catrina, UMF Carol Davila, Bucharest, Romania
Andra Andreescu, I.Cantacuzino Hospital, Bucharest, Romania
Raluca Maria Popescu, UMF Gr.T.Popa, Iasi, Romania
Development of an infection in diabetic foot lesions is the leading cause of admissions of
patients with diabetic foot.
Aim: The paper compare the etiopathogenic aspects of diabetic foot infections (DFI) in
patients admitted in two different clinics: Diabetes and General Surgery ones.
Methods: The study compares in a observational manner and analizes retrospectively two
groups of patients, both consisting of 25 patients, consecutively admitted in each of two
clinics. Every patient has DFI confirmed in terms of bacteriology. The microbiological sample
was collected by swab in Diabetes Clinic (DC), while all patients in the Surgery Clinic (SC)
were operated and bacteriological sample was harvested, during the operation, by excision
of infected tissue (soft tissue or bone).
Results: In SC prevailed extended soft tissue infections (phlegmons, necrotizing infections,
extensive gangrene) classified as infection gr. 3 and 4, in PEDIS clasification. Regarding
etiopathogeny it prevailed infections with a single germ comparing with polymicrobial
infections (17 cases vs 8 cases). The most common germ was Staph aureus, which was
found to be involved in 15 from all cases (4 cases MRSA) and only in 9 monomicrobial
infections (2 MRSA). From all 25 cases, it was necessary minor amputation in 7 and major
amputation in 4 cases.
In DC were hospitalized patients with limited lesions, as infected neuropathic ulcers and
limited toe gangrene, classified as mild infections (PEDIS 2) and just fewer mild/severe
infections (PEDIS 3). There were more frequently polymicrobial than monobacterial
infections (14 vs 11 cases) and Staph aureus in 19 from all cases, of which was 7
monobacterial infections. In only 2 cases it was identified MRSA. In 16 cases the evolution
was favorable under antibiotics. 9 patients were transferred for surgery.
No anaerobic germ was identified.
Discusion: Not to draw a conclusion, there is a difference between severity of cases
admitted in each of two clinics. Differences between etiopathogeny, such as higher number
of polymicrobial infections and Staph aureus infections in patients from DC may be the result
of different methods of bacteriological sample collection or suggests that is a direct
relationship between Staph infection and mild/moderate infections.
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Page 2 of 10
P4.03
Comparison of diabetic foot ulcer culture techniques
Yuehong Shen, Zhejiang University School of Medicine, Hangzhou, China
Wu Ding, Zhejiang University School of Medicine, Hangzhou, China
Aim: Wound cultures is part of the diabetic foot clinical assessment as the basis of medicine
application. Swabbing is the ordinary specimen-taking technique in most hospital in China
and there is no worldwide standard. This study compares two wound culture techniques in
diabetic foot ulcers swab and curetted tissue for microbial recovery,
Methods:For each wound, two sampling approaches were applied during the same visit:
swab culture and curetted tissue culture.
Results:A total of 10 diabetic foot, ulcers were assessed among 10 patients.8 ulcers' culture
result is same between two methods.
Results: Swab and curetted tissue cultures yielded similar recovery rates for common wound
bacteria.
Conclusions: The swabbased and curetted tissue culture method for diabetic foot ulcer is
similar.
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Page 3 of 10
P4.04
The bacterial profile of infected and hidden neuropathic diabetic foot ulcer in type II
diabetes mellitus in Saudi Arabia
Osman Habeeb Basheir, Alrajhi medical college, Albukaryiah, Saudi Arabia
Abdallah Algoblan, King Fahad diabetic center, Buraidah, Saudi Arabia
Ahmed Gamal Frag, Alrajhi medical collge, Albukariyah, Saudi Arabia
Mohamad Saddik, Alrajhi medical college, Albukariyah, Saudi Arabia
Mohammad Suliman Alasiri, Alrajhi medical college, Albukariyah, Saudi Arabia
Diabetes mellitus and it is foot complications is one of the major health problems in Saudi
Arabia with an overall prevalence of 23.7%. Most of the diabetic foot ulcer in Saudi Arabia
had a neuropathic character and many of them carries a hidden bacterial load.
Aim: To study the bacterial pattern and antimicrobial susceptibility in neuropathic diabetic
foot ulcers
Methods: A cross-sectional study was conducted over a period of 10 month from January to
October 2014. Samplings from neuropathic diabetic foot ulcer (infected and non infected)
were assessed for bacteriology and antimicrobial sensitivity using stander microbiological
technique.
Result: Out of 360 diabetic feet patients; sample were taken from 145 patients with
neuropathic ulcers. 63.4% (n=92) of them were male and 36.6% (n=53) were female. The
mean age is 56 Stander Deviation (STD 9.9), mean body mass index is 31.2 (STD 3), and
the mean HbAc1 is 9.5 (STD 2.1). The duration of diabetes is varies between 6 -15 years in
most patients (60.3%). Of the 145 patents with neuropathic diabetic foot ulcer a total of 220
organism was isolated, 63% of these patients showed polymicrobial in the culture and 29.7%
with monomicrobilal growth. Gram negative organism (63%) reports prevalence more than
the gram negative pathogen (37%)., Staph aureus is the commonest organism isolated
(19.5%). Wears klebsiella pneumonia, Escherichia coli and Proteus mirabillis reports as
common gram negative isolates 17.7%, 14.5 %, & 11.8% respectively (Table 1). All isolated
organism showed a variable degree of resistance to the commonly used antimicrobials
except for amikacin. However imipenem and vancomicin showed high sensitivity to most of
the isolated pathogens. Most of the patients 67% take more than one antibiotics at one time,
however 46% of the patients not completed the course duration of at least one of their drugs.
Conclusion: The study shows predominance of gram negative organism in neuropathic
diabetic ulcers and the pattern of the bacteriological susceptibility is mainly towards higher
cephalosporin expensive groups ( Imipenem) or to the harmful drugs to the kidney
(gentamycin, vancomicin.) this make a high economic burden for diabetic ulcer management
in the future.
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P4.06
Microbiology of moderate-severe diabetic foot infection - a prospective study
Andre Couto de Carvalho, Centro Hospitalar Porto, Porto, Portugal
Teresa Pereira, Centro Hospitalar Porto, Porto, Portugal
Susana Garrido, Centro Hospitalar Porto, Porto, Portugal
Rui Carvalho, Centro Hospitalar Porto, Porto, Portugal
Aim: Our objective is to present the microbiology and antimicrobial susceptibility of
moderate-severe diabetic foot infections (DFI) evaluated in a tertiary referral center.
Methods: A prospective study of diabetic patients with moderate-severe DFI episodes was
performed between October 2012 and June 2014 (21 months). At each infection episode
microbiological cultures were taken at deepest level after cleansing the ulcer and
antimicrobial susceptibility was performed by the disk diffusion method. Those cases with
positive deep tissue or aspirate culture samples were included in this study.
Results: Data from a total of 134 patients with moderate-severe DFI was obtained. Fortyseven different subjects (51.1% with neuro-ischaemic ulcer) have provided 65 positive deep
tissue, aspirate and/or exudate culture samples. These positive samples were polymicrobial
in 57% of cases, providing 112 distinct isolates, with a mean 1.7 microorganism per culture
specimen. The predominant isolate was the Staphylococcus aureus, present in 35.4% of DFI
samples (61% of which MRSA). Enterococcus spp. was identified in 32.3% (100%
vancomycin-sensitive). Importantly, Enterobacteriaceae were recognized in 43.1% of all DFI
episode samples (32% of which ESBL producers). Pseudomonas aeruginosa were found in
18.5% (25% ciprofloxacin-sensitive) and anaerobes species in 4.6% of cases.
Conclusions: Bacteriology in our moderate-severe DFI prospective cohort was highly
heterogeneous with increasing prevalence of multiresistant Gram-negative bacteria. This
data may help develop and update local DFI clinical guidelines regarding empirical antibiotic
therapy.
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P4.07
Microbiology of deep diabetic foot infection in surgery patients
Tatiana Zelenina, Northwestern Medical University n.a. I.I. Mechnikov, St. Petersburg,
Russia
Alexandr Zemlyanoy, Northwestern Medical University n.a. I.I. Mechnikov, St. Petersburg,
Russia
Natalia Vorokhobina, Northwestern Medical University n.a. I.I. Mechnikov, St. Petersburg,
Russia
Aim: We investigated specificity of pathogens in patients with diabetic foot deep infection
who was required hospitalization and surgery intervention.
Methods: We analyzed cultures of 201 inpatients who were hospitalized at the diabetic foot
surgery department of City Hospital № 14 from September 2012 to May 2013. 152 patients
were primary and 49 had already required previous surgery interventions on foot. All patients
had deep diabetic foot infections, underwent surgery debridement, and 63.2% and 62.5% of
them were amputated. Major amputations were performed in 26.6% and 33.3% patients
respectively. Mean duration of hospitalization was 25.3±17.2 days (1-90 days). Cultures
were obtained after surgery interventions immediately and on 10-14 days of hospitalization.
We also analyzed cultures of 102 diabetic foot outpatients with post surgery wounds after
discharge from the Hospital.
Results: St. aureus was the most frequently isolated in primary patients (59% of cultures),
including MRSA in 13.5%., Gram-negative bacilli were found: Acinetobacter baumanii in
20.5% cases, Enterococcus faecalis in 16%, Pseudomonas aeruginosae in 13.6%. St.
aureus was the most frequently isolated in patients with previous history of surgery
interventions too (75.7% cultures), including MRSA in 39.3%. Acinetobacter baumanii and
Enterococcus faecalis were obtained in 35% specimens, Pseudomonas aeruginosae in 27%.
After 14 days of hospitalization St. aureus was isolated in 47% and 62% specimens
respectively, including MRSA in 33.3% and 61%., Acinetobacter baumanii was obtained in
27 6% and 36%, Enterococcus faecalis in 55% and 59% specimens respectively.
Post surgery wounds were clinically infected in 55.9% outpatients. St. aureus was isolated in
78% specimens, including 53.1% MRSA. Acinetobacter baumani was obtained in 24.4%
cultures, Enterococcus feacalis in 29.3%, Pseudomonas aeruginosa in 24.4%.
Conclusions: The infections of surgery patients are polymicrobial. St. aureus is most
frequently isolated pathogen. The prevalence of MRSA and gram-negative bacilli
(Acinetobacter baumanii, Enterococcus faecalis) should be taking into account for patients
with previous history of surgery interventions and with infected post surgery wounds.
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P4.08
A hospital based study of multi drug resistance bacteria in diabetic foot infection from
North India
Shailesh K. Shahi, Banaras Hindu University, Varanasi- 221005, India, Varanasi, India
Ashok Kumar, Banaras Hindu University, Varanasi- 221005, India, Varanasi, India
Sanjeev K. Gupta, Institute of Medical Sciences, Banaras Hindu University, Varanasi221005, India, Varanasi, India
Background: Diabetic foot infection is a common cause of lower extremity amputations.
Increasing incidence of antimicrobial resistance is becoming a serious problem in India,
there is paucity of data dealing with the incidence of multiple-drug resistance (MDR),
bacteria from Diabetic foot ulcers (DFUs).
Aim: Isolation and characterization of multiple-drug resistance bacteria from Diabetic foot
ulcers.
Materials and Methods: The study was conducted at S.S. Hospital, Institute of Medical
Sciences and School of Biotechnology, Banaras Hindu University, Varanasi. Antibiotic
sensitivity test was performed by disk diffusion method. Identification of bacteria was done
by 16S rDNA sequencing. The presence of β-lactamase genes and class-1 integron gene
responsible for multiple antibiotic resistance was detected by PCR.
Result: Altogether 142 aerobic bacteria were isolated from swab and tissue samples of 42
severe DFUs patients. Antibiotic sensitivity test of was performed against sixteen antibiotics
belonging to eight classes. Of the 142 isolates, 38 (26.76%) showed resistance to eight or
more than eight antibiotics. 38 isolates with MDR characteristics were identified by 16S
rRNA gene sequencing. All the sequences have been deposited to the NCBI GenBank.
Majority of isolates were identified as Enterococcus spp., Staphylococcus aureus,
Pseudomonas spp., Stenotrophomonas spp., Klebsiella pneumonia, Escherichia coli, and
Alcaligenes spp. With a view to understand the mechanism (s) of multi drug resistance
(MDR), screening of integron and β-lactamases was made. Multiplex PCR reveled that
89.47 % of MDR isolates carried blaTEM, blaOXA, blaSHV and blaCTX-M like β-lactamase
genes. Furthermore, class 1 integrons of size ranging from 0.3 to 4.0 kb were noted in
68.42% of MDR isolates.
Conclusion: The high prevalence of MDR bacteria in DFUs from North India is found in the
present study. It is felt that proper management of antibiotics must be implemented to lower
the incidence of MDR bacterial infection considering the risks of amputation in DFU patients.
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P4.09
Clinical and microbiological characteristics of infected diabetic ulcers in siriraj
hospital, the largest university hospital Thailand
Oranich Navanukroh, Siriraj hospital, Bangkok, Thailand
Pornpan Koomanachai, Siriraj hospital, Bangkok, Thailand
Introduction: Diabetic foot infection (DFI) is one of the most common causes of
hospitalization in diabetes mellitus patients. DFI cause both physical and mental morbidity.
However, there were no clinical characteristics and causative pathogens of DFI available in
Thailand. This study aimed to explore the epidemiological data of DFI in Thai patients who
were treated at Siriraj hospital, Thailand.
Methods: The retrospective study was conducted at Siriraj hospital, Bangkok, Thailand. All
medical records of type 2 diabetic patients with DFI during January 2012 to December 2013
were reviewed. The patients’ demographic data, ulcer characteristics, culture results and
treatment outcome were collected and analyzed.
Results: One hundred and five patients were enrolled, 63 patients were male. Mean
duration of diabetes was 689.4 ± 464.4 weeks. Mean ulcer duration was 36.58 ± 6.02 days.
Mean glysated hemoglobin was 8.3%. One hundred and eighty two ulcers were obtained
clinical specimens for culture. Poly-microbial infection was 65%. Gram-negative bacteria was
common pathogens of DFI, 231 isolates vs. 159 gram-positive bacteria. The most common
gram-negative and gram-positive pathogen was Escherichia coli and Staphylococcus
aureus, respectively. For E. coli, 74.2% of 31 E. coli isolates were ESBL-producer.
Fluoroquinolone-resistance was found 80.6% for E. coli and 60% Klebsiella pneumonia.
Previous antibiotic used within 3 months had tendency to associate with drug-resistance
organisms. Overall mortality rate was 11 out of 105 patients; 3 were from DFI and 8 were
from other organs infection acquired during hospitalization for DFI. Univariate analysis
showed severe ulcer grading, poly-microbial infection and inappropriate empiric antibiotics
were associated with unfavorable outcome of amputation. Mortality associated with high
HDL-cholesterol and high serum creatinine.
Conclusion: Multidrug- resistance organisms were demonstrated in DFI. Appropriate
antimicrobial therapy, especially in severe ulcer, using pathogens and antibiogram-guided is
very important in conjunction with surgical treatment and revascularization to improve
outcome of DFI in Siriraj hospital.
Main drug-resistant organisms cultured from diabetic foot ulcers
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P4.10
Management of diabetic foot infections in a tertiary hospital in UK: Microbiological
testing strongly influences the antibiotic treatment
Danielle Lowry, University Hospital Birmingham NHS Foundation Trust, Birmingham, United
Kingdom
Robin Chisman, University of Birmingham, Birmingham, United Kingdom
Mujahid Saeed, University Hospital Birmingham NHS Foundation Trust, Birmingham, United
Kingdom
Alok Tiwari, University Hospital Birmingham NHS Foundation Trust, Birmingham, United
Kingdom
Miruna David, University Hospital Birmingham NHS Foundation Trust, Birmingham, United
Kingdom
Aim: To characterise the results of microbiological testing and examine its influence on the
antibiotic (AB) choice in diabetic foot disease.
Methods: Retrospective analysis of all diabetic patients who had deep tissue samples from
the foot between January 2012 and December 2013. Using the Infectious Diseases Society
of America (IDSA) and International Working Group on the Diabetic Foot (PEDIS)
classifications, each patient’s presenting condition was graded 1 (no infection) to 4 (severe
infection) with osteomyelitis (OM) as a discrete diagnostic entity. Information was collected
on gram stain, culture result and AB therapy.
Results: 118 samples from 74 patients (mean age 63 years (range 27-88 years)) were
examined. Gram stain showed poor correlation with the final culture, with an overall
sensitivity of 76% and specificity 73%. Sensitivity was especially low in detecting the
presence of gram negative rods (24%) and specificity was poorest when gram positive cocci
were seen (35%). Up to five organisms per sample were isolated in culture. Excluding
anaerobic growth, gram positive organisms were isolated in 54% of samples and gram
negatives in 41%. There was no significant difference between organisms grown and grade
of infection. At the time the sample was taken, only 34% of patients were on an appropriate
empirical AB regimen. After the final culture report was received, 70% of patients had a
change of AB regimen and 86% of patients were on an appropriate AB regimen.
Conclusions: Gram stain is poorly representative of the tissue culture result in this cohort.
Considerable adjustment of AB regimens was made in response to the final microbiology
culture and sensitivity report. Despite improved guidance both internationally and locally,
many diabetic patients are still started on inappropriate empirical ABs for their foot infection
by non-specialist clinicians. In many cases, this is represented by the use of a narrowspectrum agent (e.g. flucloxacillin) for grade 4 infections or OM. This may be due to
clinicians erroneously considering the treatment of a diabetic foot infection to be the same as
that for cellulitis in a non-diabetic patient, misclassification of severity, unfamiliarity with the
PEDIS classification and/or non-adherence to local AB guidelines.
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P4.11
Surgical wound cultures: A subanalysis of a randomized controlled trial
Caitlin Garwood, Medstar Georgetown University Hospital, Washington, DC, United States
Paul Kim, Medstar Georgetown University Hospital, Washington, DC, United States
John Steinberg, Medstar Georgetown University Hospital, Washington, DC, United States
Karen Evans, Medstar Georgetown University Hospital, Washington, DC, United States
Christopher Attinger, Medstar Georgetown University Hospital, Washington, DC, United
States
The aim of this study was to perform an in-depth analysis of the pre and post-debridement
wound culture data from patients undergoing serial surgical debridements., The data was
collected and analyzed as a sub-analysis of a randomized controlled trial. Of the 100
patients enrolled in the study, 35 were excluded for the following: 15 for incomplete culture
data sets, 9 with more than 3 operating room (OR) visits, 5 were not covered or closed at
final surgical procedure, and 6 had no 30-day follow-up. Specimen counts and semiquantitative culture data, both pre-debridement and post-debridement, were recorded and
analyzed for each OR visit. 30-day follow-up was analyzed to compare final OR cultures with
outcomes. 65 patients were included in this sub-analysis. Pre-debridement cultures from the
1st OR visit showed 8 patients (12.1%) had no growth, 29 (44.6%) grew 1 species, 19 grew
2 species, and 9 had 3-5 species. Comparing the pre and post-debridement cultures from
the 1st OR visit, 56.9% decreased in the number of species., Similar decreases were seen
after each debridement. The semiquantitative culture data shows that after 2 debridements
all patients either had no growth (35 patients) or scant/rare/ growth in broth (30 patients). 14
patients (21.5%) dehisced by their 30 day follow-up and 51 remained closed. There was no
difference in the number of OR visits or the rate of dehiscence. The final post-debridement
culture on the date of closure had no growth in 64.6% of patients (6 dehisced, 36 remained
closed) and there was no statistically significant difference., 23 patients still had positive
cultures with all of them only having scant/rare/broth growth and 8 dehisced (35%) while 15
(65%) remained closed. Surgical wound cultures have long been a staple in the
management of wounds., They often serve as a guide for antibiotic selection and
determining when a wound is considered clean, which aids surgical decision making. This
data demonstrates that surgical debridement significantly decreases number of species and
semiquantitative cultures. There was no statistical significance in the rate of dehiscence
between those with no growth and those with positive final cultures, but there is a trend
suggesting a positive culture may yield a higher rate of dehiscence.
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