2nd Internals important Flashcards
Bacteria, virus, protozoa, fungi of GIT, RT, SKIN
Biochemical tests of staph aureus
Gram +
B hemolytic
Catalase, coagulase +
Biochemical tests of staph. Epidermidis
Catalase + Coagulase - Urease + Novobiocin sensitive Does not ferment mannitol
Biochemical tests of Staph. Saprophyticus
Catalase +
Coagulase -
Urease +
Novobiocin resistant
Biochemical tests of strep. Pneumoniae
A hemolytic
Lancelet shaped
Optochin sensitive
Bile soluble
Biochemical tests of strep. Viridans
A hemolytic
Optochin resistant
Bile insoluble
Cell wall VIRULENCE factors of Staph. Aureus
Peptidoglycan
Teichoic acid
Clumping factor - slide coagulase
Protein A - coaggultination - binds to Fc-IgG and protects from complement and phagocytosis
Toxins of staph. Aureus
Alpha, beta, gamma, delta hemolysins PV toxin Exfoliative toxin Enterotoxin TSST-1, TSST-2
Toxic manifestations of staph. Aureus
Toxic shock syndrome
Food poisoning (6-8 hrs)
Scalded Skin Syndrome
Inflammatory manifestations of staph. Aureus
Endocarditis Abscesses Impetigo Pneumonia Septic arthritis Osteomyelitis Skin infections
MRSA due to
Alteration in penicillin binding protein coded by mecA gene
Staph. Epidermidis causes
Prosthetic device related infections
Stitch abscess
Staph epidermidis protected by
Biofilm formation.
Protects it from host defence and antibiotics
Staph. Saprophyticus manifestations
UTI in female genital tract
Cell wall VIRULENCE factors of strep. Pyogenes
Lipoteichoic Acid
C carbohydrate antigens
M proteins
Capsule
Toxins of strep. Pyogenes
Streptolysin O
Streptolysin S
Streptococcal pyrogenic exotoxin - superantigens
Enzymes of strep. Pyogenes
Streptokinase
DNAse
Hyaluronidase
Immunological manifestations of strep. Pyogenes
Rheumatic fever
Glomerulonephritis
Toxin mediated manifestations of strep. Pyogenes
Toxic Shock like syndrome
Scarlet fever
Necrotising fasciitis
Pyogenic manifestations of strep. Pyogenes
Pharyngitis
Cellulitis
Impetigo - honey crusted lesions
Erysipelas
Biochemical tests of strep. Pyogenes
Bactiracin sensitive
Pyrrolidonyl arylamidase +
VIRULENCE factors of clostridium perfringes
Alpha, beta, epsilon, iota toxins
Heat labile enterotoxin
Bursting factor
Neuraminidase
Wound infections of c. Perfringens
Contamination
Cellulitis
Gas gangrene
Enteric infections of c. Perfringens
Food poisoning
Enteritis necroticans (Gas gangrene of bowel)
Necrotising enterocolitis
Gangrenous appendicitis
Mechanism of viridans streptococci
Makes dextrans that bind to fibrin-platelet aggregates on damaged heart valves -> subacute bacterial endocarditis
Scarlet fever
Blanching
Sandpaper like body rash
Strawberry tongue
Circumoral pallor
Biochemical tests of strep. Agalactiae
Bactiracin resistant Beta hemolytic Hippurate + PYR - CAMP + with staph. Aureus
Strep. Agalactiae affects
Babies (pneumonia)
Enterococci tests
Gram + Penicillin G resistant Catalase - PYR + Can grow in 6.5 percent NaCl and bile No hemolysis VRE
Bacillus cereus Manifestations
Emetic type - cereulide - 1-5 hrs
Diarrhreal type - water, non bloody diarrhea - 8-18hrs
Keratitis, meningitis, osteomyelitis, pneumonia
Properties of spores of bacillus cereus
Spores survive cooking rice (reheated rice syndrome)
Cooking - germination of spores and enterotoxin formation
Agar of bacillus cereus
MYPA - Mannitol, Egg Yolk, Polymyxin B, Phenol red agar
Clostridium botulinum toxin and it’s mechanism
Heat labile
Inhibits ACh release at NMJ
Clostridium botulinum mode of transmission
Baby - ingestion of spores (floppy baby syndrome)
Adult - ingestion of performed toxin
Clostridium botulinum treatment
Human botulinum Ig
Clostridium botulinum symptoms
Diplopia Dysarthria Dysphagia Dyspnea Descending flaccid paralysis
Clostridium botulinum toxin A therapeutic uses
Focal dystonia
Muscle spasms
Hyperhidrosis
Reduction of facial wrinkles
Morphology of Clostridium botulinum
Non capsulated
Gram +
Bacilli
Peritrichate flagella
Lab DX of Clostridium botulinum
RCM broth
Toxin demonstration: mouse bioassay
Clostridium perfringens causes
Gas gangrene
Food poisoning
Necrotising enterocolitis
Clostridium perfringens toxin and mechanism
Alpha toxin - lecithinase (phospholipase)
Activates platelet GP 2b/3a receptors on platelet -> platelet aggregation -> b.v occlusion
Also directly decreases myocardial contractility
Gas gangrene symptoms
Crepitus Foul smelling discharge Edema Pain Gangrenous tissue gets liquefied and is sloughed off
Lab DX of clostridium perfringens
Gram + Subterminal spores
Thick stubby bacilli
RCMB
Naeglers rxn - opalscene around streak line in egg yolk agar
Reverse CAMP - with S. Agalactiae
Clostridioides difficle toxins and mechanism
A and B - damage actin - cell shape and size -> water diarrhea, pseudomembranous colitis
Clostridioides difficle infection is due to
Prolonged antibiotic use (cephalosporin)