Bacteria

Bacteria

1. G-

   • bacilli
     • Gram negative bacilli
       • pathogen
         • Shigella
           • gastroenteritis with blood and mucus in diarrhoea. very low infectious dose (10-100)
           • S dysenteriae
             • Shiga toxin
         • Salmonella
           • Diarrhoeal disease
           • Typhoid
             • S typhi and S paratyphi
       • Normal flora
         • E. coli
           • Commensal of intestinal tract. Common cause of UTI infections Commonest cause of gram negative bacteraemia
           • Pathogenic E coli
             • Enterotoxigenic E coli
               • Cholera-like symptoms
             • Enteropathogenic E coli
               • infantile gastroenteritis
             • Verocytotoxin producing E coli (VTEC) - E coli 0157
               • Haemolytic-uraemic syndrome and thrombotic thrombocytopaenic purpura
         • Klebsiella
         • Proteus
     • Small gram negative bacilli/cocco-bacilli
       • Haemophilus influenzae
         • Epiglottitis, meningitis, lower respiratory tract infections, otitis media
       • Legionella pneumophila
         • Lives in water systems, causes atypical pneumonia
     • Curved gram negative bacilli
       • Campylobacter - foodborne pathogen, cramping abdo pain, bloody diarrhoea
       • Helicobacter - peptic ulcer disease
       • Vibrio cholera - rice water stools
   • cocci
     • Gram negative cocci
       • Neisseria
         • Neisseria meningitidis
           • Acute Cerebrospinal Meningitis transmitted by droplet site is Nasopharynx as a carrier
         • Neisseria gonorrhoea
           • Gonorrhea causes urethritis
           • Ophthalmia neonatorum from mother birth canal sexual or non sexual genital tract

2. G+

   • Gram positive cocci
     • Aerobic
       • Staphylococcus: in clusters, catalase positive
         • Staphylococcus aureus:
           • Pneumonia, Cellulitis, Septic arthritis, Infective endocarditis, Line associated infection
           • MSSA – Methicillin sensitive SA MRSA – Methicillin resistant SA
           • Toxins: Scalded skin syndrome, Toxic shock syndrome, food poisoning
           • coagulase positive
         • Staphylococcus epidermidis
           • Coagulase negative
           • Part of normal skin flora, opportunistic pathogen
         • Staphylococcus saprophyticus
           • Causes UTI in women
           • Coagulase negative
       • Streptococcus - in chains, catalase negative
         • Beta haemolytic streptococci - Lancefield grouping
           • Group A - strep pyogenes Very sensitive to penicillin!
             • Non-invasive infection - scarlet fever, pharyngitis (strep throat), erysipelas (infection of the skin affecting the upper layers)
             • Invasive infections - streptococcal toxic shock syndrome, necrotising fasciitis, bacteraemia
             • Delayed antibody mediated immune response - response to past strep infection
               • Rheumatic fever
               • Acute post strep glomerulonephritis
           • Group B – strep agalactiae
             • Colonises the vagina, major cause of neonatal infections
               • Cellulitis, meningitis, endocarditis, bacteraemia
             • Adults - cellulitis, pneumonia, bone infection, UTI
         • Alpha haemolytic streptococci
           • Strep pneumoniae (diplococci, sensitive to penicillin))
             • Adults - pneumonia and bacterial meningitis
             • Children - otitis media
           • Strep viridans
             • Commensals of upper respiratory and GI tract, colonise the mouth, cause infective endocarditis
   • Gram positive bacilli
     • Aerobic
       • Bacillus (Spore forming)
         • Bacillus anthracis
           • polypeptide Capsule. potential bioterrorism agent.
             • Malignant pustule. cause:contact with infected
             • wool sorter's disease cause: Inhalation of spores.
           • polypeptide Capsule. potential bioterrorism agent.
             • Malignant pustule. cause:contact with infected
             • wool sorter's disease cause: Inhalation of spores.
         • Bacilllus cereus
           • SAPROPHYTE Food Poison,Chinese fried rice syndrome
       • Corynebacterium diphtheriae
         • Called Club-shaped or chinese letter men only transmitted by droplets forms toxins and diphtheria
     • Anaerobic
       • Clostridium (Spore Forming)
         • Clostridium botulinum
           • transmission:Food-borne. V.F:botulinum toxin. causes food poisoning.
           • transmission:Food-borne. V.F:botulinum toxin. causes food poisoning.
         • Clostridium tetani
           • Transmission:Trauma/puncture wound V.F:tetanus toxin causes tetanus disease.
           • Transmission:Trauma/puncture wound V.F:tetanus toxin causes tetanus disease.
         • Clostridium difficile
           • antibiotic associated diarrhoea and pseudomembranous colitis
           • transmitted by Exogenous and endogenous ways. V.F: enterotoxin +cytotoxin
           • transmitted by Exogenous and endogenous ways. V.F: enterotoxin +cytotoxin
         • clostridium perfringes
           • caused by trauma and food brone Causes Food poisoning or gas gangrene
         • clostridium perfringes
           • caused by trauma and food brone Causes Food poisoning or gas gangrene
   • Spirochaetes
     • Treponema pallidum
       • Syphilis
     • Borrelia burgdorferi
       • Lyme disease