Post on 21-Aug-2015
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BACILLUS• ENDEMIC • SOIL-WATER,AIR,VEGETATION DWELLING• AEROBES• CELLS: 1-3 um• SQUARE ENDS• LONG CHAINS• SPORE: CENTRAL• NON MOTILE/MOTILE• Mesophile: 20-40 0 C
BACILLUS CEREUS
• GROWS IN FOOD from soil: plants, eggs, meat, dairy; spore-dose 105-108/ gm of food
• Food poisoning: toxin produced in food/GIT 1 Emetic type: e.g fried rice, pasta; large quantity
cooked but cools slowly. Spores germinate in log phase to vegetative form & release toxin.
N & V ,crampsOnset; 1-5 hrs; self limiting, 24 hrs. 2. Diarrheal type: meat dishes & sauces
Diarrheal form
• Incubation: 1-24 hrs• Profuse diarrhea, pain, cramps• No fever / vomit2.EYE INFECTION: trauma-associated; FBSevere keratitisEndophthalmitisPanophthalmitisRetinal damage; blindness
Local & Systemic infectionsopportunistic
periodontal diseaseDEVICE ASSOCIATED/ IV DRUGS• Endocarditis• Meningitis• Osteomyelitis• PneumoniaT/M:• R: Pencillin, cephalosporins• Use: Vancomycin, clindamycin alone or Amino-Glyco
OTHER BACILLI
• B THURINGIENSIS• INSECT PATHOGEN/ pesticide role• Produces a crystal toxin• USED AS INSECTICIDE : genetic material
inserted in genetic material of plants• Concern???/
BACILLUS ANTHRAX
• PATHOGENESIS:ZOONOSIS:• Herbivores; goats, sheep, cattle, horses, rats-R
via mouth with spiny vegetation irritating gut-GIT• HUMANS: 3 portals• Cutaneous Anthrax: injured skin• GIT Anthrax: mm; animals; n & v
bloody diarrhea• Inhalation Anthrax: lung
EPIDEMIOLOGY
SOIL: • contaminated from caracasses of dead
animalsSpores viable for decades• Germinate at pH 6.5 & suitable temperatureAnimals: Grazing animals with injured mm
perpetuate chainHUMANS: contact; animals, hides, hair, brushes
ENTRANCE
• Germination of spores• Vegetative form: gelatinous oedema/congestion• Spread: lymphatics…blood…tissues…deathVirulence:• CAPSULE:• Plasmid born Poly-D-Glutamic acid antiphagocytosis
TOXIN
• CONSTITUTED BY 3 PROTEINS• 1.Protective antigen: PA binds receptor to
facilitate entry of 2,3• 2. Edema Factor: EF is adenylyl cyclase 1&2 make oedema toxin• 3. Lethal Factor: LA 1 & 3 make “lethal toxin’…death of host:
plasmid borne: different plasmid
Wool sorter disease• Inhalation anthrax• Incubation: upto 6 weeks• Spores inhaled: wool, hair, hides• LUNGS: phagocytosed…lymph…Mediastinal LNGermination…TOXIN…hagic mediastinitis & necrosis…
oedema..sepsis..git..hagic ulcers; hagic meningitis...fatal.
Hagic pleural effusionCough: tracheal comressionPAIN; substernalX RAY: mediastinal wideningLethal spore dose : >107/ml in blood
PATHOLOGY• Site of entry: proliferate• Capsule: intact• Proteinaceous fluid: surrounds• Few leukocytes• Disseminate rapidlyResistant animals• proliferation takes hours,• WBC accumulate massively• Capsule disintegrates• Organism remains locally
CLINICAL FINDINGS • Cutaneous anthrax: 95%• Inhalation: 5%• Git: rare infected meat associated; Asia, Africa,US• BIOTERRORISM: 2001;22 cases;11 each; 5 diedCUTANEOUS ANTHRAX• Exposed surfaces: Arms, hands, face, neck• Entry of spore: scratch• Pruritic papule in 1-7 days• Papule…vesicle/ small ring vesicles…coalasce…necrotic
ulcer; 1-3 cms• Central black eschar;
• OEDEMA: marked: may take weeks to subside• Lymphangitis… Lymphadenopathy• Sytemic signs: fever, malaise, headache ESCHAR: fully developed in 7-10 days• Dries, loosens, separates• Healing; granulation; after weeks• Scar• Complication: Cut anth…sepsis…meningitis…death• ABiotics no role in progress of disease
SPECIMEN
• Local lesion: fluid; blood• Sputum• Blood• Smears; fresh: large Gram + rods• dried; IF technique• BA: grey…white colonies medusa heads (coma
shape outgrowth) may project; ground glass; rough
• Non-hemolytic;
• Non motile (d/d B cereus; swarms in semi fluid)• Guniea pig: killed by intra peritoneal injection• Capsular growth: bicarbonate medium, CO2 5-
7%• Anthrax specific Phage lysis• ELISA: for AB on sera 4 weeks apart for toxin• 4* increase titre or > 1:32 diagnostic value• PCR• Suspicious organism…dispatch to Referral labs
immunity
• ANIMALS: annual vaccination especially in fields with spores
• Broth cultures at 42-52 0 C for several months lost virulence; so can inject in sheep
• Attenuated live strains• Spore suspensions; attenuate; inject by scar• PA filterates• Russia, China; spore vaccine• US , Britain; bacteria-free filterate of cultures
• FDA: approve toxigenic but nonvirulent, noncapsule strain, bacteria-free filterate
• All 3 proteins present• Adsorbed to Aluminium OH• Dose: 2, 4 weeks then 6,12,18 months• Annual boosters• New recombinant PA vaccine + AlOH: under trial• Well tolerated, immunogenic• Department of defense; exposure prone
TREATMENT
• Ciprofloxacin• Pencillin G with Gentamycin/streptomycin• Bioterrorism: potential exposure• Prophylaxis; cipro or doxycycline• 4 weeks with vaccine;3 doses• 8 weeks without