Chapter 38 Human Diseases Caused by Bacteria 1 1 공기매개 질병 • • • • • • • • 클라미디아 폐렴 디프테리아 재향군인병 수막염 마이코박테리아 감염 마이코플라즈마성 폐렴 백일해 연쇄상구균 질병 2 클라미디아 폐렴 • Chlamydial pneumonia • Chlamydia pneumoniae – Obligate intracellular parasite (세포내 절대기 생 세균) – Coronary artery disease (관상동맥질환) and vascular disease (혈관성질환) • Transmission by respiratory secretions – Elementary bodies (기본소체) infect (감염) – Reticular bodies (망상체) replicate (복제) 3 클라미디아 폐렴 • Clinical manifestations – Fever, productive cough (습성기침, 객담 (sputum)), and mild pharyngitis (인두염), bronchitis (기관지염), and sinusitis (부비동염, 축농증) • Diagnosis, treatment, prevention – Immunofluorescence test (면역형광법) – Antibiotic therapy • Tetracycline and erythromycin 4 디프테리아 • Diphtheria • Corynebacterium diphtheriae – Gram‐positive – Exotoxin (외독소) inhibits protein synthesis and is responsible for pathogenesis • Airborne transmission by nasopharyngeal (비인두) secretions 5 디프테리아 • Diagnosis – Pseudomembrane (위막) in throat – 인두와 편도선에 심한 염증 – Bacterial culture • Treatment, prevention, and control – Antitoxin (항독소) given to neutralize unabsorbed exotoxin in patient’s tissues – Antibiotic therapy – Penicillin and erythromycin – Active immunization with DPT vaccine – Diphtheria (디프테리아)‐Pertussis (백일해)‐Tetanus (파상풍) 6 재향군인병 • Legionnaires’ disease • Legionella pneumophila – Gram‐negative rod – Harbored by free‐living amoebae and ciliated protozoa (원생동물) • Spread by airborne transmission from environmental reservoir to human host – Soil, aquatic ecosystems, air‐conditioning systems, and shower stalls 7 재향군인병 • Reproduction of bacterium in alveolar macrophages (폐포의 대식세포) causes localized tissue destruction • Produce cytotoxic (세포독성) exo‐protease • Clinical manifestations – Fever, cough, headache, neuralgia (신경통), and bronchopneumonia (기관지 폐렴) – Severe in immunocompromised (면역저하자) 8 재향군인병 • Treatment, prevention, and control – Isolation of bacteria and immunodiagnostics – Antibiotic therapy • Rifampin or erythromycin – Eliminate nosocomial spread (병원내감염) – Identify and eliminate environmental source 9 수막염 • Meningitis • Inflammation in the brain or spinal cord meninges (뇌척수막) • Diagnosed by gram stain of cerebrospinal fluid (CSF, 뇌척수액) 10 수막염 • Major bacterial causes include – Neisseria meningitidis (수막염균) – Hemophilus influenza serotype b (인플루엔자균 b 혈청형) – Streptococcus pneumoniae (폐렴 연쇄상구균) 11 수막염 • Transmitted by respiratory droplets (호흡 기 비말) • Clinical manifestations – Initial respiratory illness or sore throat (인후염) – Vomiting, headache, lethargy (졸음증), confusion, and stiffness in neck and back 12 수막염 • Treatment, prevention, and control – Neisseria meningitidis (수막염균) • Antibiotics ‐ penicillin, chloramphenicol, cefotaxime, ceftriaxone, and ofloxacin • Vaccine – Hemophilus influenza serotype b (인플루엔자균) • Antibiotic ‐ rifampin • Vaccine (Hib) – Streptococcus pneumoniae (폐렴 연쇄상구균) • Antibiotics • Vaccine 13 마이코박테리아 감염 • Mycobacterium infections • In soil, water, and house dust • Mycolic acid in cell wall (세포벽) is protective waxy material that is acid‐fast (항산성) • Resistant to penetration of some antibiotics • M. avium 복합체 (MAC) • 결핵 (tuberculosis) 14 M. avium 복합체 (MAC) • Mycobacterium avium complex (MAC) – Normal inhabitants of soil and water – Infect variety of insects, birds, and other animals • Respiratory and gastrointestinal tracts have been proposed as portals of entry – Most common cause of mycobacterial infections in the U.S. 15 M. avium 복합체(MAC) • Pulmonary infection (폐 감염) – Similar to tuberculosis (결핵) – Usually observed in elderly patients with pre‐ existing pulmonary disease • Gastrointestinal infection (위장관 감염) – Common in AIDS patients – Fever, malaise (권태감), weight loss, and diarrhea (설사) 16 M. avium 복합체(MAC) • Treatment, prevention, and control – Isolation from sources such as sputum (객담), blood, and bone marrow – Acid‐fast stain (항산성 염색), and immunodiagnostic tests – Multiple drug therapy • Azithromycin, clarithromycin, ethambutol • Clofazimine, rifabutin, rifampin, ciprofloxacin, and amikacin 17 결핵균 • Tuberculosis (TB) • Mycobacterium tuberculosis (Mtb) • ~1/3 of world’s population infected • World‐wide distribution • Over 7% are HIV positive, over 50% deaths in AIDS patients • U.S. elderly, homeless, alcoholic, prisons, and immigrants are some groups 18 결핵균 • Transmission – Spread of droplet nuclei (비말핵) in respiratory tract – Transmitted from infected animals and their products – Reactivation of old, dormant infections • Disease develops slowly 19 결핵균 독성인자 (Virulence factor) • Unique toxic cell wall components – Mycolic acid and lipoarabinomannan – Kill eukaryotic cells and protect Mtb from lysozyme and osmotic lysis – Resistant to entry of antibiotics into bacteria • Survive phagocytosis – Kill macrophages – Resistant to oxidative killing – Inhibit fusion of phagosome and lysosome 20 결핵 발병과정 • Lung macrophages that have phagocytosed Mycobacterium tuberculosis often die in the attempt to kill the bacteria • Tubercles (결절) form – Composed of bacteria, macrophages, T cells, and human proteins 21 결핵균 감염 • Develop cell‐mediated immunity (sensitized T cells) – Basis for tuberculin skin test (투베르쿨린 피부검사) • Incubation period – 4–12 weeks • Symptoms – Fever, fatigue, weight loss, cough, and bloody sputum (혈객담) 22 결핵균 • Diagnosis – Observation of acid‐fast (항산성) bacteria – Chest X‐ray – Mantoux, or tuberculin skin test • Delayed hypersensitivity reaction (48hr) • Injection of PPD (purified bacterial protein derivatives) – DNA‐based tests 23 결핵균 • Antimicrobial therapy – Isoniazid, rifampin, ethambutol, and pyrazinamide – Multi‐drug‐resistant strains (MDR‐TB) – Extensively drug resistant strains (XDR‐TB) – Resistance develops due to • Naturally occurring chromosomal mutations • Natural selection of resistant Mtb due to lack of adherence to treatment protocol 24 결핵균 • Prevention and control – Rapid, specific therapy to interrupt spread – Retreatment of patients with MDR‐TB – Immunization with BCG vaccine – Improved sanitation and housing – Reduction in homelessness and drug abuse – Directly observed treatment short course (DOTS) 25 마이코플라즈마성 폐렴 • Mycoplasmal pneumonia • Mycoplasma pneumoniae – Atypical pneumonia (비정형 폐렴) – Typical pneumonia (정형 폐렴) caused by Streptococcus pneumoniae • World‐wide distribution • Transmission by close contact and airborne droplets 26 마이코플라즈마성 폐렴 • Mycoplasma pneumoniae lacks cell wall (세포벽) – Resistant to beta lactam antibiotics – Attach to lower respiratory tract cells – Produces peroxide, which may be toxic factor • Clinical manifestations – Usually mild in infants and more serious in older children and young adults – Headache, weakness, low fever, characteristic cough, and pneumonia that persists for weeks 27 마이코플라즈마성 폐렴 • Diagnosis – Rapid immunological tests – Isolation from respiratory secretions  “fried egg” appearance of organisms on agar • Treatment, prevention, and control – Immunodiagnostic tests – Antibiotic therapy (tetracycline and erythromycin) – No preventive measures 28 백일해 • Purtussis or whooping cough, – Gram‐negative Bordetella pertussis – Highly contagious disease that primarily affects children • Transmission by droplet inhalation • Pertussis toxin (PTx) – A‐B exotoxin – ADP ribosylation of Gi protein ‐> activation of adenylate cyclase ‐> increased cAMP level 29 백일해 • Clinical manifestations – 7‐ to 14‐day incubation – Initially cold‐like symptoms (감기증상) and inflamed mucous membranes (점막염증) – Followed by prolonged coughing sieges with inspiratory whoop – Permanent or long‐lasting immunity develops 30 백일해 • Treatment, prevention, and control – Bacterial culture, fluorescent antibody staining, and serological tests – Antibiotic therapy (erythromycin, tetracycline, and cloramphenicol) – Immunization with DPT 31 연쇄상구균 질병 • Streptococcal diseases • Gram‐positive bacteria • Streptococcus pyogenes (화농성 연쇄상구 균) – Group A β‐hemolytic (용혈성) streptococci (GAS) 32 연쇄상구균 질병 • Virulence factors – Extracellular enzymes that break down host molecules – Streptokinases – dissolve clots – Streptolysin O and S – kill host leukocytes – Capsules and M protein for attachment 33 연쇄상구균 질병 • Transmission – Respiratory droplets, direct or indirect contact • Diagnosis – Based on clinical and laboratory findings – Rapid diagnostic tests available 34 연쇄상구균성 인두염 • Streptococcal pharyngitis • Strep throat • Spread by droplets of saliva or nasal secretions • Infection in throat (pharyngitis, 인두염) or on tonsils (tonsillitis, 편도염) • Physical manifestations – Redness and edema around throat, exudate (염 증성 삼출액) in 50% – Lymph node enlargement in throat 35 연쇄상구균성 인두염 • Diagnosis – Rapid diagnostic kits • Treatment and control – Antibiotics (penicillin G or macrolide antibiotics) – Control by preventing contact with contaminated materials or discharges from infected individuals 36 후발성 연쇄상구균 질병 • Post‐streptococcal diseases • Glomerulonephritis (사구체신염) • Rheumatic fever (류마티스열) – Autoimmune disease involving heart valves, joints, subcutaneous tissues, and central nervous system • 1–4 weeks after an acute streptococcal infection • No pus‐producing (고름이 없음) • Most serious problems associated with streptococcal infections in U.S. 37 절지동물매개 질병 • Arthropod‐borne diseases • 라임병 (Lyme disease) • 페스트 (Plague) • 록키산 홍반열 (Rocky mountain spotted fever) 38 라임병 유주성 홍반 • • • • • Lyme disease 참진드기 Borrelia burgdorferi (스피로헤타) 장기손상, 염증, 자가면역질환 Amoxicillin, tetracycline, ceftriaxone (BBB) 39 페스트 (흑사병) 가래톳(buboes) Enlarged lymph nodes • • • • Plague Yersinia pestis 피하출혈로 피부가 검게 변함(흑사병) Streptomycin, chloramphenicol, or tetracycline 40 록키산 홍반열 • • • • Rocky mountain spotted fever 참진드기 Rickettsia rickettsii Chloramphenicol or chlortetracycline 41