Bacteria ppt.ppt
- 1. Systemic Bacteriology Section 4 Basic microbiology teaching group
- 2. ļSpherical, clusters. ļGolden color ā carotenoid pigment ļCatalase and coagulase ā positive ļĪ² ā hemolytic Gram positive bacteria Staphylococcus aureus
- 4. Virulence factors ļCell wall structural components: Polysaccharides,teichoic acid,protein A(bind IgG) ,capsule ļToxin production: hemolysin, enterotoxin, fibrinolysin ,toxic shock syndrome toxin ,etcā¦. ļEnzyme productiion: Catalse,coagulase, lipase,etcā¦. ļProtein receptors: facilitate staphylococcal adhesion to host cell tissues ļResistance to antibitics: B-lactamase, methicillin resistance(MRSA),etcā¦..
- 5. Pathogenicity 1.Cutaneous lesions: ļFuruncles( infection of hair follicle), abscess, impetigo(contagious superficial skin infection), etcā¦.. 2.Staphylococcal food poisoning: ļEnterotoxin -Diarrhea and vomiting set in within 6 hours of taking contaminated food. 3.Other infections : septicemia, scalded skinā syndrome, Toxic shock syndrome, etcā¦..
- 6. ļCocci , chains, Catalase ā negative ļStreptococcus pyogenes: B-hemolytic ļ Streptococcus pneumoniae: alpha hemolytic Gram positive bacteria Streptococccus
- 7. Virulence factors Streptococcus pyogenes ļToxin production: ļ¼Hemolysins ļ¼Erythrogenic toxin-- scarlet fever(fever, skin rash, sore throat). ļEnzymes: Streptokinase (fibrinolysin, Deoxyribonucleases, Hyaluronidase(a spreading factor),etcā¦
- 8. Streptococcus pyogenes Pathogenicity: 1. Respiratory infection: ļThroat is the primary site of invasion causing sore throat ļScarlet fever, Otitis media, and Bronchopneumonia 2. Skin infection: cause suppurative infection isolated from wound burns 3.Genital tract: ļPuerperal sepsis ļThe source of infection is nasopharynx of doctors, nurses and attendants, etc. 4.Non-suppurative complications: a. Acute rheumatic fever b. Acute glomerulonephritis.
- 9. Streptoccocus pneumoniae ļ Capsulated ļ Most common cause of pneumoniae in human Virulence Factors 1. Toxins like hemolysin 2. Capsule : association with virulence. 3. Enzymes ā(neuraminidase): resembling receptor destroying enzyme of influenza virus
- 10. Gram positive bacteria Clostridium: Obligate anaerobes, rod - shaped , contain endospores C. tetani C. botulinum C. perfringens C.difficile
- 11. Virulence and pathogenicity ļ± Clostridium tetani: (drum stick appearance) ļ Toxin : hemolysin , neurotixins ļ Tetanus: due to contamination of wound ļ± Clostridium pyrfringes ļ Toxin : 4 major toxins alpha, beta, epsilon, Iota ļ Capsule ļ Alpha toxin cause toxemia of gas gangrene(tissue death) ļ Food poisoning (cause diarrhea recovered after 24-48 hr)
- 12. virulence and pathogenicity ļ±Clostridium botulinum: ļExotoxin :botulinum toxin ļCause botulism of preserved and canned foodā severe form of food poisoning cause death ļ±Clostridium difficileāpart of intestinal normal flora ļEnterotoxin----diarrhea ļCytotoxin----cytopathogenic effects in several tissues ļPseudo membraneous colitis due to prolonged use of broad spectrum antibiotics disrupt intestinal normal flora
- 13. Gram positive bacteria Bacillus Rods,endospore forming, aerobic ļ±Bacillus anthracis ā Non motile ļ¼Have three main antigens: capsular, somatic polysaccharide, somatic protein ļ¼Somatic protein ---is the only antigen that produce protective antibodies ļ¼Exotoxin like substance ļcauses anthrax transmitted by accidental contact with infected animals ļ± Bacillus cereus āmotile ļ food poisoning due to enterotoxin that causes diarrhea
- 14. Gram Negative bacteria Pseudomonas Aerobic, motile rods, produce pigments ļ± Pseudomonas aeruginosa Virulence factors: ļ Srtuctural antigens:somatic and flagellar ļ¼ Somatic antigens ,flagellar antigens ,plasma prtoteins ļ Enzymes and hemolysin ļ Exotoxin and endotoxin Pathogensis: ļ Nosocomial infections ļ Secondary infections of wound , burns, chronic skin ulcers ļ Cause infantile diarrhea due to enterotoxin production ļ (Catheter associated) urinary tract infection , Chronic otitis media , pulmonary infection,etcā¦
- 15. Gram Negative bacteria Enterobactriaceae Escherichia coli(opportunistic pathogen) : ļ¼Motile bacilli, extra-intestinal species are encapsulated , facultative anaerobe ļ¼One of the most common inhabitants of the human and animal intestinal tract ļ¼The most common cause of nosocomial infections, ļ¼It is a leading cause of community-acquired urinary tract infections. ļ¼Indicates fecal contamination (water and food resources) ļ¼Most common cause UTI in females ļ¼Travelers Diarrhea by ETEC(poor personal hygiene) ļ¼Food poisoning ā E. coli 0157:H7
- 16. Gram Negative bacteria Enterobactriaceae ļ Mode of transmission: ļ¬ Endogenous spread (UTI) ļ¬ Person-Person in hospitals ļ¬ Fecal -oral for strains that are toxin producers Proteus:(Opportunistic pathogen) ļ Highly motile, inhabit human bowel , it produce Urease enzyme ļ Proteus cause: UTI , Wounds and ears infection
- 17. Gram Negative bacteria Enterobactriaceae ļ Common species(P.vulgaris and P.Mirbilis ļ Mode of transmission: ļ¬ Endogenous spread (UTI) ļ¬ Person-Person in hospitals settings ļKlebsiella: opportunistic pathogen ļ It is commonly found in ļ¬ Environment like water and in soil ļ¬ Mammals mucosal surfaces including animal human
- 18. Gram Negative bacteria Enterobactriaceae Klebsiella Klebsiella pneumoniae and K.oxytoca causes community acquired and nosocomial pneumonia and UTI in humans. ļMode of transmission: ļ¬ Endogenous spread (UTI) ļ¬ P-P in hospitals settings ļEmergence of drug resistant Klebsiella in hospital setting which can be detected by rectal swabs as ļ¬ ESBL: Extended Spectrum B lactamase producer ļ¬ CRE :carbapenem-resistant
- 19. Gram Negative bacteria Enterobactriaceae Shigella : (overt pathogen; not part of human normal flora, only human pathogen) ļ± Shigella dysenteriae ļ± S. sonnei Causes ļ¼bacillary dysentery which is defined as acute inflammatory colitis and bloody diarrhea characterized by cramps, and bloody, mucoid stools. ļ¼S. sonni may produce only watery diarrhea. ļ¼ Mode of transmission: ļ¼Person-to-person spread by fecal-oral route, especially in overcrowded areas, group settings
- 20. Gram Negative bacteria Enterobactriaceae ļ Salmonella (overt pathogen) ā¢ Salmonellae inhabit intestinal tracts of human and many animals especially poultry and cattle Pathogenesis ļ Enteric fever ā typhoid fever-S. enterica servar Typhi --infects only human -Paratyphoid fever--S.Paratyphi A,S.Paratyphi B ļ Salmonellosis(Gastroentiritis)---food poisining ļ S. Typhimurium , S. Enteritides (mucous and blood in stool) ā¢ SepticemiaāS. Choleraesuis , S.Typhi & S. Paratyphi ā¢ Mode of transmission ļ¬ Person-to-person spread by fecal-oral route/ ingestion of contaminated food
- 21. Gram Negative bacteria Vibrio Curved , curved comma shaped actively motile Vibrio cholerae Virulence ļEnterotxin- Pathogenesis ļ Cause cholera āWatery diarrhea V. Parahaemolyticus - causes food poisining Transmitted to humans mostly by raw or undercooked shellfish.
- 22. Gram Negative bacteria Neisseria Aerobic, non motile , oxidase positive cocci arranged in pairs. Strict human parasite ļ±N.meningitidisāintracellular diplococci Virulence ļ Endotoxin , Blocking IgA ļ Pathogenicity ļ Inter body through nasopharynx ļ Cause meningococcal septicemia ļ±N.gonorrhoeae Virulence ļ IgA protease , Antibiotic resistance Pathogenecity: ļ Gonorheaāvenereal disease ļ Opthalmia neonatorumānew born infection during delivery
- 23. Gram Negative bacteria Gram negative coccobacilli Brucella----Non motile,capsulated Brucella abortus(from cattles) Brucella melitensis(from goat) Brucella suis(from pigs) Antigenic structure: ļ(A & M) are present in different proportions among the different species. ļSuperficial L antigen resembles the Vi antigen (virulence) of Salmonella. Pathogenicity ļCause brucellosis (malta fever, undulent fever)āzoonotic
- 24. Gram Negative bacteria Gram negative coccobacilli Hemophilus Aerobic,Non motile,some strains are capsulated,pleomorphic,have one or both accessory factros (X ) hemin and( V)NAD present in blood ļ±H.infleunzae ļType type b accounts for most infections ļCause meningitis,otitis media,pneumonia,etcā ļ±H.aegypticus ļCause contagious form of conjunctivitis ļ±Hemophilus ducreyi ļCause chancroid---venereal disease
- 25. Acid Fast Bacteria Mycobacteria Gram positive bacilli , aerobic, non motile
- 26. Acid Fast Bacteria M. tuberculosis----human pathogen Infection : inhalation,ingestion,inoculation Virulence ļCording factors ---derivatives of mycolic acid ļCell wall glycolipids---inhibits phagolysome formation allows intracellular survival ļAntibiotic resistance Pathogenesis ļTuberculosis---infection of the lungs
- 27. Spirochaetes Motile without flagella ,,elongated spiral rods Treponema ļ±Treponema pallidum---venereal syphilis Pathogenicity: ļCongenital syphilis---from mother to fetus ļAcquired syphilis---acquired by sexual contact