content BACTERIAL INFECTION Pyogenic gram positive cocci Bacterial infection of childhood Sexually transmitted bacterial disease Enteropathogenic bacteria Clostridial infection Bacterial infection with animal reservoirs or insect vectors Bacterial infection with immunocompromised host Filamentous bacteria Mycobacterial infection Ratirath Samol, MD. Clamydia infection Mycoplasma infection RATIRATH SAMOL, MD Rickettsia infection Pyogenic gram positive cocci Pyogenic gram positive Staphylococcal infection cocci - coagulase positive (S. aureus) - coagulase negative (S. epidermidis, S. saprophyticus ) Streptococcal infection - S. pyogenes (group A) - S. agalactiae (group B) - S. pneumoniae -S. mutans Staphylococcus spp. Streptococcus spp. 1 Staphylococcus aureus Furuncles - infection in and around hair follicles - common in scalp, face, axillary Carbuncles - infection around hair follicle and produce draining sinuses Hydradenitis suppurativa furuncles - infection in sweat gland carbuncles Staphylococcus aureus Staphylococcus aureus Osteomyelitis Food poisoning - infection in bone - diarrhea, nausea, vomiting Toxic shock syndrome (TSS) - symptom present < 6 hours after - infection in surgical wound, tampons produce high fever, nausea, vomiting and contaminated food shock Staphylococcus aureus SSSS Staphylocoocal scalded skin syndrome (SSSS) - severe skin infection - organism produce exfoliatin that destroys granulosa of epidermis Æ bullae, rupture, skin scald - other organs : lung, heart valve, bone 2 Staphylococcus epidermidis Staphylococcus saprophyticus causes opportunistic infections in common cause of urinary tract infections in catheterized patients, patients with young women. prosthetic cardiac valves, and drug addicts. Streptococcal infection α-hemolytic streptococci 3 types S. pneumoniae is a common cause of - α hemolytic streptococci community-acquired pneumonia and eg. S. pneumoniae, S. viridans, S. mutans meningitis in adults - β hemolytic streptococci S. viridans are part of the normal oral flora eg. S. pyogenes (group A), S. agalactiae (group B) but are also a common cause of endocarditis - γ hemolytic streptococci (non-hemolytic) S. mutans is the major cause of dental caries eg. S. faecalis (group D) β-hemolytic streptococci Pharyngitis S. pyogenes (group A) Infection in throat (tonsillitis) - pharyngitis Clinical: high grade fever, sorethroat - scarlet fever Complication : - erysipelas - glomerulonephritis, rheumatic fever - impetigo - cross reaction of immune system to M - cellulitis protein of bacteria 3 Scarlet fever Common in childhood Erythematous rash at trunk, extremities and face except around the mouth (circumoral pallor), strawberry tongue Cause by erythrogenic toxin Scarlet fever Erysipelas Erythematous rash, rapid distribution at face, particullary both cheeck Rash at trunk, extrimities (uncommon) strawberry tongue circumoral pallor Erysipelas Impetigo Infection in epidermis Erythrematous papule Æ pustule May be caused by S. pyogenes or S. aureus 4 Cellulitis Cellulitis Infection in deep dermis S. pyogenes invade through wound Pustule in deep dermis Clinical : fever, erythrematous skin lesion β-hemolytic streptococci Bacterial infection of S. agalactiae (group B) - meningitis childhood - chorioamnionitis - septicemia Diphtheria Bacterial infection of childhood Diphtheria Caused by Corynebacterium diphtheriae (gram positive bacilli) Pertussis (Whooping cough) Transmitted as respiration Haemophilus influenzae infection Immunization with diphtheria toxoid (formalin-fixed Neisseria meningitidis infection toxin) does not prevent colonization with C. diphtheriae but protects immunized people from the lethal effects of the toxin. 5 Diphtheria Pertussis Tracheal colonization may lead to - Mucosal erosion, exudate Bordetella pertussis infection(gram negative coccobacilli ) (pseudomembrane) → obstruct airway Toxin-mediated damage to the heart, nerves, Common in childhood (<5 yrs) liver, or kidneys Causes as laryngotracheobronchitis, ciliated respiratory epithelium necrosis Clinical: severe cough (whooping) Haemophilus influenzae infection Neisseria meningitidis infection gram negative coccobacilli Gram negative diplococci 6 serotype (a-f), type b causes as severe Caused by disease - meningitis (fever, stiff neck, headache, Caused by shock and dead) - pneumonia - vasculitis (petechiae and purpura at skin - meningitis and internal organs) - upper respiratory infection (otitis media, sinusitis, epiglottitis) Meningitis Bacterial meningitis เชื้อที่เปนสาเหตุ Streptococcus pneumoniae 50% Neisseria meningitidis 25% Group B streptococci 15% Listeria monocytogenes 10% Haemophilus influenzae (type b) <10% From Harrison ed. 16th N. meningitidis 6 Sexually transmitted bacterial disease Sexually transmitted Gonorrhea bacterial disease Chancroid (soft chancre) Granuloma inguinale Syphilis Gonorrhea Gonorrhea Nesseria gonorrhoeae (gram negative diplococci) Caused by - male: urethritis, epididymitis - female: endometritis, salpingitis, PID - neonatal infection: conjunctivitis, Nesseria gonorrhoeae blindness Chancroid (soft chancre) Chancroid (soft chancre) Haemophilus ducreyi (gram negative bacilli) Clinical feature: - Painful multiple genital ulcer and dirty based ulcer - 50% inguinal lymphadenitis 7 Granuloma inguinale Syphilis Treponema pallidum (spirochete) Calymmatobacterium granulomatis (gram negative 3 stages coccobacilli) - primary syphilis Clinical feature: - raised, soft red papule and ulcer at - secondary syphilis genital area Æ chronic inflammation Æ scar - tertiary syphilis Syphilis Primary syphilis Primary syphilis - chancre : painless, a clean based ulcer and regression 3-6 weeks - inguinal lymphadenopathy - microscopic: chronic inflammation and organisms Syphilis Syphilis Secondary syphilis Secondary syphilis - condyloma lata (exudative plaques in - systemic dissemination to many organs eg. perineum, vulva, scrotum) skin, LN, meninges, liver, mucous membrane - white mucous patch (rash at mucous - common presentation: rash at trunk, extremities, palm, sole appears from 2 wks to membrane at mouth, genital organs) 6 months after chancre heals - fever, anorexia, alopecia - microscopic: chronic inflammation, many organisms 8 Secondary syphilis Syphilis Tertiary syphilis - 1/3 of untreated patient develop tertiary syphilis (no organisms) - syphilitic aortitis (80%) Æ aortic regurgitation, aneurysm - neurosyphilis Æ paralysis, seizure - gumma : granulomatous inflammation in any organs eg. skin, bone, liver Tertiary syphilis Congenital syphilis Intrauterine infection of fetus Common in primary and secondary syphilis (many organisms) of pregnant women Organisms transferred to fetus by placenta Causes late abortion, stillbirth, or death soon after delivery 2 stages - early syphilis syphilitic aortitis with aneurysm - late syphilis Congenital syphilis Congenital syphilis early syphilis (< 2 yrs) late syphilis (> 2 yrs) - extensive cutaneous rash containing many - Hutchinson triad spirochetes eighth nerve deafness - Osteochondritis with collapse of the bridge interstitial keratitis (blindness) of the nose (saddle nose) notched central incisors (hutchinson teeth) - Periostitis with bowing of the tibia 9 notched central incisors Laboratory diagnosis Nontreponemal antibody test - detect Ab againt cardiolipin in blood - RPR, VDRL - screening test, follow up - false positive : SLE, acute infection, leprosy -cureÆ negative result Laboratory diagnosis Antitreponemal antibody test - detect Ab againt T. pallidum Enteropathogenic bacteria - FTA-Abs, MHATP - positive after infection 4-6 wks and continuous positive until cure Enteropathogenic bacteria Salmonella infection and typhoid fever Salmonella infection and typhoid fever Gram negative bacilli Shigella infection Salmonella typhi Campylobacter infection - caused by typhoid fever Cholera - contaminated food and water Helicobacter pylori - organisms contaminates in feces of Escherichia coli carrier 10 Salmonella infection and typhoid fever Typhoid fever Salmonella typhi (typhoid fever) - septicemia, fever,abdominal pain - bacterial replication in macrophages of Peyer patches of terminal ileum Æ nodule - ulcer along the intestine Æmucous bloody diarrheaÆ shock Shigella infection Campylobacter infection Gram negative bacilli Comma shaped, flagellated gram negative S. boydii, S. flexneri, S.dysenteriae Common pathogen: C. jejuni Infection small and large intestine Transmitted by contaminated food Transmitted by fecal-oral route Inflammation of jejunum continues to anus s/s: diarrhea, fever s/s: dysentery (cramping, tenemus, mucous bloody diarrhea) Microscopic: ulcer, neutrophils Microscopic: ulcer of intestine covered by neutrophils, enlarged mucosal lymphoid follicles Cholera Mechanism of cholera Vibrio cholerae (comma shaped, flagellated gram negative) Many serotypes (01 serotype=pathogen) s/s: massive rice-watery diarrhea Gross: non-specific Micro: scant neutrophils 11 Escherichia coli Escherichia coli Gram negative bacilli Bacteria produce toxins Æ damage enterocytes and Flora in lower intestines (colon) vascular endothelial cells assists with waste processing, vitamin K Clinical features: production, and food absorption - abdominal pain and diarrhea cause several intestinal and extra-intestinal infections eg. urinary tract infections (UTI), meningitis, pneumonia Helicobacter pylori Helicobacter pylori Curvilinear gram negative bacilli Caused by chronic