Chapter 38. Human Diseases Caused by Bacteria 1

Transcription

1 Chapter 38 Human Diseases Caused by Bacteria 1 1

2 공기매개질병 클라미디아폐렴 디프테리아 재향군인병 수막염 마이코박테리아감염 마이코플라즈마성폐렴 백일해 연쇄상구균질병 2

3 클라미디아폐렴 Chlamydial pneumonia Chlamydia pneumoniae Obligate intracellular parasite ( 세포내절대기생세균 ) Coronary artery disease ( 관상동맥질환 ) and vascular disease ( 혈관성질환 ) Transmission by respiratory secretions Elementary bodies ( 기본소체 ) infect ( 감염 ) Reticular bodies ( 망상체 ) replicate ( 복제 ) 3

4 클라미디아폐렴 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

5 디프테리아 Diphtheria Corynebacterium diphtheriae Gram positive Exotoxin ( 외독소 ) inhibits protein synthesis and is responsible for pathogenesis Airborne transmission by nasopharyngeal ( 비인두 ) secretions 5

6 디프테리아 Diagnosis Pseudomembrane ( 위막 ) in throat 인두와편도선에심한염증 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

7 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

8 재향군인병 Reproduction of bacterium in alveolar macrophages ( 폐포의대식세포 ) causes localized tissue destruction Produce cytotoxic ( 세포독성 ) exo protease Clinical manifestations Fever, cough, headache, neuralgia ( 신경통 ), and bronchopneumonia ( 기관지폐렴 ) Severe in immunocompromised ( 면역저하자 ) 8

9 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

10 수막염 Meningitis Inflammation in the brain or spinal cord meninges ( 뇌척수막 ) Diagnosed by gram stain of cerebrospinal fluid (CSF, 뇌척수액 ) 10

11 수막염 Major bacterial causes include Neisseria meningitidis ( 수막염균 ) Hemophilus influenza serotype b ( 인플루엔자균 b 혈청형 ) Streptococcus pneumoniae ( 폐렴연쇄상구균 ) 11

12 수막염 Transmitted by respiratory droplets ( 호흡기비말 ) Clinical manifestations Initial respiratory illness or sore throat ( 인후염 ) Vomiting, headache, lethargy ( 졸음증 ), confusion, and stiffness in neck and back 12

13 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 ( 폐렴연쇄상구균 ) Antibiotics Vaccine 13

14 마이코박테리아감염 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

15 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

16 M. avium 복합체 (MAC) Pulmonary infection ( 폐감염 ) Similar to tuberculosis ( 결핵 ) Usually observed in elderly patients with preexisting pulmonary disease Gastrointestinal infection ( 위장관감염 ) Common in AIDS patients Fever, malaise ( 권태감 ), weight loss, and diarrhea ( 설사 ) 16

17 M. avium 복합체 (MAC) Treatment, prevention, and control Isolation from sources such as sputum ( 객담 ), blood, and bone marrow Acid fast stain ( 항산성염색 ), and immunodiagnostic tests Multiple drug therapy Azithromycin, clarithromycin, ethambutol Clofazimine, rifabutin, rifampin, ciprofloxacin, and amikacin 17

18 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

19 Transmission 결핵균 Spread of droplet nuclei ( 비말핵 ) in respiratory tract Transmitted from infected animals and their products Reactivation of old, dormant infections Disease develops slowly 19

20 결핵균독성인자 (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

21 결핵발병과정 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

22 결핵균감염 Develop cell mediated immunity (sensitized T cells) Basis for tuberculin skin test ( 투베르쿨린피부검사 ) Incubation period 4 12 weeks Symptoms Fever, fatigue, weight loss, cough, and bloody sputum ( 혈객담 ) 22

23 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

24 Antimicrobial therapy 결핵균 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

25 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

26 마이코플라즈마성폐렴 Mycoplasmal pneumonia Mycoplasma pneumoniae Atypical pneumonia ( 비정형폐렴 ) Typical pneumonia ( 정형폐렴 ) caused by Streptococcus pneumoniae World wide distribution Transmission by close contact and airborne droplets 26

27 마이코플라즈마성폐렴 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

28 마이코플라즈마성폐렴 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

29 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

30 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

31 백일해 Treatment, prevention, and control Bacterial culture, fluorescent antibody staining, and serological tests Antibiotic therapy (erythromycin, tetracycline, and cloramphenicol) Immunization with DPT 31

32 연쇄상구균질병 Streptococcal diseases Gram positive bacteria Streptococcus pyogenes ( 화농성연쇄상구균 ) Group A β hemolytic ( 용혈성 ) streptococci (GAS) 32

33 연쇄상구균질병 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

34 연쇄상구균질병 Transmission Respiratory droplets, direct or indirect contact Diagnosis Based on clinical and laboratory findings Rapid diagnostic tests available 34

35 연쇄상구균성인두염 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 ( 염증성삼출액 ) in 50% Lymph node enlargement in throat 35

36 Diagnosis 연쇄상구균성인두염 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

37 후발성연쇄상구균질병 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 ( 고름이없음 ) Most serious problems associated with streptococcal infections in U.S. 37

38 절지동물매개질병 Arthropod borne diseases 라임병 (Lyme disease) 페스트 (Plague) 록키산홍반열 (Rocky mountain spotted fever) 38

39 라임병 유주성홍반 Lyme disease 참진드기 Borrelia burgdorferi ( 스피로헤타 ) 장기손상, 염증, 자가면역질환 Amoxicillin, tetracycline, ceftriaxone (BBB) 39

40 페스트 ( 흑사병 ) 가래톳 (buboes) Enlarged lymph nodes Plague Yersinia pestis 피하출혈로피부가검게변함 ( 흑사병 ) Streptomycin, chloramphenicol, or tetracycline 40

41 록키산홍반열 Rocky mountain spotted fever 참진드기 Rickettsia rickettsii Chloramphenicol or chlortetracycline 41