Chapter 38 Human Diseases Caused  by Bacteria 2 1

Transcription

Chapter 38 Human Diseases Caused  by Bacteria 2 1
Chapter 38
Human Diseases Caused by Bacteria 2
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직접 접촉 질병
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가스괴저
B그룹 연쇄상 구균 질병
마이코박테리아의 피부감염
위궤양과 위염
성병
포도상구균 질병
연쇄상구균 질병
파상풍
트라코마
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가스괴저
(클로스트리디아성 근괴사)
• Gas gangrene or clostridial myonecrosis
• Clostridium perfringens (웰치균)
– Gram‐positive, spore (포자)‐forming rod (간균)
– 절대 혐기성
– Secretes toxin and tissue‐damaging enzymes
• Transmitted through wounds by contamination of injured tissue by spores from soil (토양) or bowel microbiota
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가스괴저
(클로스트리디아성 근괴사)
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가스괴저
(클로스트리디아성 근괴사)
• Clinical manifestations
– Severe pain, edema (부종), drainage (고름배출), muscle necrosis (근육괴사)
• Treatment, prevention, and control
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Surgical debridement (괴사조직제거)
Administration of antitoxin (항독소)
Antibiotic therapy (penicillin or tetracycline) Hyperbaric oxygen therapy (고압산소요법)
Amputation of limbs (수족절단)
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B 그룹 연쇄상 구균 질병
• Group B streptococcal disease
• Gram positive • Streptococcus agalactiae or Group B streptococcus (GBS)
• Common cause of neonatal and newborn (신생아) diseases such as sepsis (패혈증), meningitis (수막
염), and pneumonia (폐렴)
• Vagina (질) may be source for newborns
• Treatment, prevention, and control
– Detect pregnant carriers
– Antibiotics (penicillin or ampicillin)
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마이코박테리아의 피부감염
• Mycobacterial skin infections
• 나병 (leprosy)
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나병
• Leprosy or Hansen’s disease
• Most common in tropics (열대지역)
• Mycobacterium leprae
– Invades peripheral nerve (말초신경) and skin cells – Obligate intracellular parasite (절대 세포내 기생생물)
• Humans are only significant reservoir
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나병
• Transmission
– Prolonged exposure to infected individuals
– Probably spread in nasal secretions (비강분비물)
• Clinical manifestations
– Incubation usually 3 to 5 years
– Slightly pigmented skin eruption (착색된 피부발진)
– Varies with cell‐mediated immune response (세포매개
면역반응) to bacterium
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나병의 종류
결핵성 (tuberculoid)
나종성 (lepromatous)
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나병의 종류
• 결핵성 나병 (tuberculoid leprosy)
– Mild, non‐progressive form (비진행형)
– Neural (신경) leprosy
– Associated with delayed‐type hypersensitivity (지연형 과민반응)
– Immune cells attack peripheral nerve cells
– Damaged nerves and regions of skin have lost sensation (신경손상) – Surrounded by a border of nodules (소결절)
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나병의 종류
• 나종성 나병 (lepromatous leprosy)
– Progressive (진행형) leprosy
– Individuals do not develop hypersensitivity
– Skin tissue killed, leading to progressive loss of facial features, fingers, toes, and other structures
– Disfiguring nodules (기형의 소결절) form all over body
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나병
• Diagnosis
– Direct fluorescent antibody staining of biopsy specimens, sero‐diagnostic tests, DNA amplification, and ELISA
• Treatment, prevention, and control
– Long‐term antibiotic and drug therapy
– Dapsone, rifampin, clofazimine, ethionamide, and prothionamide
– Immunotherapy with vaccine
– Identification and treatment of patients
– Prophylactic therapy (예방치료) for uninfected household members
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위궤양과 위염
• Peptic ulcer disease and gastritis
• Gram‐negative Helicobacter pylori
– Colonizes gastric mucus‐secreting cells (점액분비세포)
– Produces urease (요소분해효소), which acts to increase pH
– Releases toxins that damage epithelial mucosal cells
• Class I carcinogen (발암물질)
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위궤양과 위염
• Colonizes gastric mucus‐secreting cells, beneath gastric mucosa (위점막) by aid of surface fimbriae (adhesins)
• Binds sialic acid in gastric epithelial cells
• Produces ureases (요소분해효소) which hydrolyses ammonia and provides a local alkaline environment
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위궤양과 위염
• Transmission probably person to person
• Diagnosis
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Culture of gastric biopsy specimens
Examination of stained biopsies
Serological testing (혈청 IgG 검출)
Urea breath test (요소호흡검사)
Tests for ammonia in urine
Detection of urease activity (요소분해효소 활성검사) in biopsies
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위궤양과 위염
• Treatment, prevention, and control
– A combination of drugs to decrease stomach acid (antacid, 위산제) and antibiotics to kill the bacteria (항
생제)
– Bismuth subsalicylate (위산제) + metronidazole (항생
제) + tetracycline or amoxicillin (항생제) – Ranitidine (위산제, histamine H2‐receptor antagonist) + clarithromycin + bismuth citrate (점액보호제)
– Lansoprazole (위산제, proton pump inhibitor) + clarithromycin (항생제) + amoxicillin (항생제) 17
성병
• Sexually transmitted diseases (STD)
• Major worldwide public health problem (~300 M new cases/year, 3억건)
• Some also transmitted by nonsexual means
• Some cured easily, others difficult or impossible to cure
• Most frequent in 15–30‐year age group but also others sexually active
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성병
• 임질
• 비임균성 요도염
• 매독
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임질
• Gonorrhea
• Neisseria gonorrhoeae
– Gram‐negative, oxidase‐positive diplococcus
– Gonococcus, (pl. gonococci) • Disease of mucous membranes (점막) of the genitourinary tract (생식요도관), eye, rectum (직장), and throat
• Can also be transmitted from mother to child during birth
– Neonatal conjunctivitis (신생아 결막염)
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임질균 독성인자
• Attach to microvilli (미세융모) or mucosal cells by pili (선모) and protein II adhesins (부착분자)
• Survive phagocytosis by neutrophils (호중구)
• Fibrosis (섬유화) results and may lead to stricture or urethral closing (요도관 협착)
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임질
• Clinical manifestations
– Symptoms in males
• Urethral discharge (요도 분비물) of yellow, creamy pus (고름), and painful, burning urination
– Symptoms in females
• Vaginal discharge (질 분비물) beginning 7 to 21 days after infection
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임질
• Pelvic inflammatory disease (PID, 골반염증질환)
– Infection of fallopian tubes (나팔관) and surrounding tissue
– Major cause of sterility (불임) and ectopic pregnancy (자궁 외 임신) • Disseminated gonococcal infections
– Bacteremia (세균혈증)
– Involvement of joints, heart, and throat
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신생아 결막염
• Neonatal conjunctivitis
– Newborns’ eyes infected as they pass the birth canal of an infected mother
– Also caused by Chlamydia
– Prevention is by antibiotic eye drops (tetracycline or erythromycin) or silver nitrate (질산은) in newborns at birth 24
임질
• Diagnosis
– Culture of bacterium followed by gram stain, oxidase test, and determination of cell and colony morphology DNA probe test
• Treatment, prevention, and control
– Antibiotic therapy
• Cefixime, ceftriaxone
• Penicillin, tetracycline, spectinomycin, fluoroquinolone에 대
한 저항성 임질균 발견됨
– Public education, diagnosis and treatment of asymptomatic individuals, condom use
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비임균성 요도염
• Nongonococcal urethritis (NGU)
• Any inflammation of the urethra (요도) not due to the bacterium Neisseria gonorrhoeae
• Caused by variety of agents
– Chlamydia trachomatis (most common)
– Ureaplasma urealyticum
– Mycoplasma hominis
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비임균성 요도염
• Clinical manifestations
– In males
• Asymptomatic or urethral discharge (요도의 분비물), and itching (가려움) and inflammation of genital tract (생식기 염증)
– In females
• Sometimes asymptomatic
• Pelvic inflammatory disease (PID, 골반염증질환)
• Miscarriage (유산), stillbirth (사산), inclusion conjunctivitis (봉입체 결막염), and infant pneumonia
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비임균성 요도염
• Diagnosis
– Demonstration of leukocyte exudate (삼출), exclusion of urethral gonorrhea by gram stain and culture, rapid diagnostic tests
• Treatment, prevention, and control
– Antibiotic therapy
– Macrolide or tetracycline
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매독
• Syphilis
• Treponema pallidum
• Venereal syphilis (성병성 매독) – sexually transmitted
• Congenital syphilis (선천성 매독)– acquired in utero (자궁내에서 감염)
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매독의 3단계
• Primary stage (3주) – Chancre (small, painless, reddened ulcer (궤양), 경성
하감) at infection site
• Secondary stage (6‐8주) – Highly variable skin rash (피부발진) • Latent stage (잠재기) • Tertiary stage (수년) – Formation of gummas (degenerative lesions (퇴행성
병변), 고무종) in skin, bone, and nervous systems
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매독의 3단계
chancre
경성하감
skin rash
피부발진
gummas
고무종
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매독
• Diagnosis
– Clinical history, microscopic examination, and serology
• Treatment, prevention, and control
– Antibiotic therapy most effective in early stages (penicillin)
– Public education, prompt treatment of new cases, follow‐up on sources and contacts, sexual hygiene, and use of condoms
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포도상구균 질병
• Staphylococcal diseases
• Caused by members of the genus Staphylococcus
– Gram‐positive cocci, occurring singly, in pairs, tetrads, or grape‐like clusters
– Facultative anaerobes (통성혐기성) and usually catalase positive
– Pyogenic, pus‐producing (화농성)
– Normal inhabitants of upper respiratory tract, skin, intestines, and vagina
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포도상구균 분류 1
• Coagulase (혈장응고효소)‐positive
– Pathogenic (병원성)
– Staphylococcus aureus (황색포도상구균) • Coagulase (혈장응고효소)‐negative
– Less pathogenic
– Staphylococcus epidermidis
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포도상구균 분류 2
• Slime producers (점액질 생성자) – Pathogenic (병원성)
– Viscous extracellular glycoconjugate (당접합체) – Allows bacteria to adhere to smooth surfaces form biofilms (생물막) – Inhibits neutrophil chemotaxis, phagocytosis, and antimicrobial agents
• Non‐slime producers (점액질 비생성자)
– Less pathogenic
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포도상구균 질병
• Harbored by asymptomatic carriers or active carriers (have the disease)
• Spread by hands, inanimate objects or expelled by respiratory tract, or through blood
• May produce disease in almost every organ and tissue
• Immunocompromised most at risk
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포도상구균 질병
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포도상구균 독성인자
• Exotoxins (외독소) and enzymes involved in invasiveness (세균침입)
• Toxin genes may reside on plasmids and on chromosome
• Examples
– Enterotoxin (장독소) – food intoxication
– Bacteremia (세균혈증) and abscess (농양) formation
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포도상구균 병변
• Localized abscess (국소적 농양)
– Established in a hair follicle (모낭), tissue necrosis results
– Liquefaction (액화) of necrotic tissue in center of lesion occurs
– May be a furuncle (부스럼,boil(종기)) or carbuncle (큰
종기) 39
포도상구균 열상피부증
• Staphylococcal scalded skin syndrome (SSSS)
• Exfoliative toxin (박탈성독소)
• Epidermis (표피) peels off revealing red area underneath
• Diagnosis
– Isolation/identification of staphylococcus involved or use of commercial kits
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독성쇼크증후군
• Toxic shock syndrome (TSS)
• By toxic shock syndrome toxin and other toxins
• Disease results from body’s response to staphylococcal super antigens
• Clinical manifestations
– Low blood pressure (저혈압), fever (발열), diarrhea (설사), extensive skin rash (발진), and shedding of skin
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포도상구균 질병
• Treatment, prevention, and control
– Isolation and identification based on catalase test, coagulase test, serology, DNA fingerprinting
– Antibiotic therapy
• Penicillin, cloxacillin, methicillin, vancomycin, oxacillin, cefotaxime, ceftriaxone, cephalosporin
• Many drug‐resistant strains found
– Personal hygiene, food handling, and aseptic (무균) management of lesions
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메티실린 내성 황색포도상구균
• Methicillin‐resistant Staphylococcus aureus (MRSA)
• S. aureus (황색포도상구균) isolates that are resistant to β‐lactam antibiotics (penicillins and cephalosporins)
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메티실린 내성 황색포도상구균
• Treatment – Incision and drainage of purulent wound (고름이 흐르
는 상처)
– Antimicrobial therapy
– Vancomycin resistant strains exist
– Hand‐washing and aseptic technique is critical in preventing spread in hospitals
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연쇄상구균 질병
• Streptococcal diseases
• Superficial cutaneous (피부표면) diseases – Cellulitis (봉와직염)
– Impetigo (농가진)
– Erysipelas (단독)
• Invasive diseases (침입성) – May reach underlying muscle
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피부표면 연쇄상구균 질병
농가진
단독
봉와직염
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침입성 연쇄상구균 감염
• Invasive streptococcal infections
• Streptococcus pyogenes
• Rapidly progressive
– Carry genes for exotoxins
– Superantigens
– Tissue‐destroying protease
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침입성 연쇄상구균 감염
• Clinical manifestations
– Necrotizing fasciitis (괴사성 근막염 “flesh eating”)
• Destruction of sheath covering skeletal muscle
– Myositis (근염)
• Inflammation and destruction of skeletal muscle and fat tissue
– Toxic shock‐like syndrome (TSLS)
• Precipitous drop of blood pressure, failure of multiple organs, and high fever
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파상풍
• Tetanus
• Clostridium tetani
– Anaerobic, gram‐positive spore‐former
– Endospores (내포자) found in soil, dust, hospital environments, and mammalian feces
– Causes prolonged muscle spasms (근육 경련)
• Portal of entry – skin wounds
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후궁반장
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파상풍
• Clinical manifestations
– Early in disease – tension (긴장) or cramping and twisting of skeletal muscles (골격근) and tightness of jaw muscle (턱근육)
– Advanced disease – 입벌림 장애, 비웃는듯한 경련미
소, 뻣뻣한 몸통, 긴장성 경련, and backward bowing of back (후궁반장)
– Death usually results from spasms of diaphragm (횡경
막) and intercostal respiratory muscles (늑간의 호흡근)
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파상풍
• Diagnosis
– Clinical history of wound infection and muscle stiffness
• Treatment, prevention, and control
– Antibiotic therapy and treatment with antitoxin
– Active immunization with toxoid (DPT vaccine), and proper care of wounds contaminated with soil, prophylactic use of antitoxin
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트라코마 (trachoma)
• Chlamydia trachomatis
• Transmitted by hand‐to‐hand contact, contact with infected soaps and towels, and flies, • Mother–child contact in adults
• The greatest single cause of blindness throughout the world
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트라코마
(trachoma)
• Clinical manifestations
– First infection
• Abrupt onset of inflamed conjunctiva (결막염), leading to inflammatory cell exudate (삼출액) and necrotic eyelash follicles (속눈썹 소포괴사)
• Usually heals spontaneously
– Reinfection
• Pannus formation (혈관신생, vascularization of cornea), leading to scarring of conjunctiva
• If scarring of cornea (각막) also occurs, blindness results
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트라코마 (trachoma)
• Treatment, prevention, and control
– Diagnosis and treatment same as for inclusion conjunctivitis
– Tetracycline, macrolide, doxycycline
– Health education, personal hygiene, and access to clean water for washing
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