Chapter 38 Human Diseases Caused  by Bacteria 1 1

Chapter 38
Human Diseases Caused by Bacteria 1
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공기매개 질병
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클라미디아 폐렴
디프테리아
재향군인병
수막염
마이코박테리아 감염
마이코플라즈마성 폐렴
백일해
연쇄상구균 질병
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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)
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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
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디프테리아
• Diphtheria
• Corynebacterium diphtheriae
– Gram‐positive
– Exotoxin (외독소) inhibits protein synthesis and is responsible for pathogenesis
• Airborne transmission by nasopharyngeal (비인두) secretions
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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)
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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
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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)
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재향군인병
• Treatment, prevention, and control
– Isolation of bacteria and immunodiagnostics
– Antibiotic therapy
• Rifampin or erythromycin
– Eliminate nosocomial spread (병원내감염)
– Identify and eliminate environmental source
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수막염
• Meningitis
• Inflammation in the brain or spinal cord meninges (뇌척수막)
• Diagnosed by gram stain of cerebrospinal fluid (CSF, 뇌척수액)
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수막염
• Major bacterial causes include
– Neisseria meningitidis (수막염균) – Hemophilus influenza serotype b (인플루엔자균 b
혈청형)
– Streptococcus pneumoniae (폐렴 연쇄상구균)
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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
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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
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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)
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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.
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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)
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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
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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
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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
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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
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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
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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
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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)
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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
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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
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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
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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
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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
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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)
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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
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연쇄상구균 질병
• Transmission
– Respiratory droplets, direct or indirect contact
• Diagnosis
– Based on clinical and laboratory findings
– Rapid diagnostic tests available
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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
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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
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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.
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절지동물매개 질병
• Arthropod‐borne diseases
• 라임병 (Lyme disease)
• 페스트 (Plague)
• 록키산 홍반열 (Rocky mountain spotted fever)
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라임병
유주성 홍반
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Lyme disease 참진드기
Borrelia burgdorferi (스피로헤타)
장기손상, 염증, 자가면역질환
Amoxicillin, tetracycline, ceftriaxone (BBB)
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페스트 (흑사병)
가래톳(buboes)
Enlarged lymph nodes
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Plague
Yersinia pestis
피하출혈로 피부가 검게 변함(흑사병)
Streptomycin, chloramphenicol, or tetracycline
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록키산 홍반열
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Rocky mountain spotted fever
참진드기
Rickettsia rickettsii
Chloramphenicol or chlortetracycline
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