Gram + Bacilli Flashcards
Non branching
Non spore forming
Gram + rods/bacilli
Only species of Listeria pathogenic for humans
Once phagocytosed by WBCs, it produces Listeriolysin O + phospholipase enabling it to escape from WBC and spreads to blood stream -> reaches CNS and placenta
Listeria monocytogenes
Listeria motility pattern
Tumbling motility of saline suspensions of colonies
occur at RT but rarely 5 deg
Tumbling motility
Inverted Christmas tree pattern
Across placenta or by contact during delivery
Ingestion of unpasteurized milk products (eg. cheese)
High risk group: pregnant women, neonates and immunocompromised
Pregnant women
Listeria monocytogenes
Listeria infection in pregnant most commonly occurs in
third trimester
Listeria risk factors
Bacteremia
Amnionitis
Premature labor or septic abortion in 3-7 days
Unpasteurized milk organisms
Brucella
Listeria
Neonatal sepsis
Neonata meningitis
Neonatal pneumonia
Group B Agalactiae
E coli
Listeria
Stillbirth Granulomatosis infantisepticum (1st 4 days of life) Meningitis Meningoencephalitis Brain abscess Pneumonia
Listeria monocytogenes
Unpasteurized milk
Cabbage/coleslaw
Listeria
Listeria Tx
Ampicillin +/- Gentamycin
Ampicillin + Gentamycin SE
Nephrotoxicity
Aminoglycoside SE
Ototoxicity
Nephrotoxicity
Ampicillin SE
Interstitial nephritis
Catalase - Non spore forming Non motile Anaerobic Gram + bacillus
Short rod with rounded ends occurs singly in short chains or in non branching filaments
Erysipelothrix
Animals to humans (skin wound produced by contaminated objects or in contact with blood, flesh, viscera or feces of infected animals)
At risk of infection, butchers, abattoir workers, fishermen, fish handlers, poultry processors and veterinarians
Erysipelothrix
Rhusiopathiae
Erysipelothrix virulence factors
Capsule
Neuraminidase
Hyaluronidase
Surface proteins
Most common form of erysipeloid
Pain, swelling, cutaneous eruption (slowly progressive, slightly elevated, violaceous zones around the site of inoculation)
Local cutaneous infection Erysipelothrix Rhusiopathiae
Best specimen for culture of Erysipelothrix
Biopsy
Tissue aspirates from erysipeloid lesions
Pipe cleaner pattern of growth in Gelatin Stab cultures incubated at 22 deg C
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae tx
Penicillin
Most are Catalase -
Round terminal spores
Drumstick
True exotoxin
C tetani
Catalase +
Oval, subterminal spores
Tennis rackets
True exotoxin
C botulinum
Motile, drumstick appearance
Tetanospasmin inhibits GABA and Glycine
Muscle spasm, lock jaw, risus sardonicus, respiratory paralysis, opistothonusc
Dysautonomia
C tetani
C tetani tx
Metronidazole Antitoxin Tetanus toxoid Spasmolytic drug Penicillin
Long acting inhibitor of spasm
Benzodiazepine - Diazepam
Very potent neurotoxin and probably is solely responsible for the disease
Tetanospasmin
Tetanolysin
Spores germinate under anaerobic condition in the wound
C tetani
Protease that cleaves the proteins involved in the release of glycine from Renshaw cells of sc
Continuous stimulation by excitatory transmitter
Tetanus toxin (tetanospasmin)
Most common form of tetanus
Generalized tetanus
Earliest manifestation of generalized tetanus
Trismus
Lock jaw
Earliest manifestation of neonatal tetanus
Poor suck
Penicillin should not be used for c tetani because
it inhibits glycine
Nonmotile Double zone of hemolysis Alpha toxin (lecithinase) Clostridial myonecrosis Nagler reaction +
Clostridium perfringens
C perfringens Tx
If with gas gangrene
Penicillin
Clindamycin
Add hyperbaric oxygen
C perfringens toxins
Lecithinase
Exotoxins
C perfringes in culture
Stormy fermentation
Litmus milk cultures
turbidity gas
Spectrum of C perfringens
Gas gangrene - pain, edema, cellulitis with crepitation, hemolysis and jaundice
Food poisoning - 8-16 h incubation period; characterized by watery diarrhea with cramps and little vomiting; resolves within 24 h
Nagler’s reaction in C perfringens tests
Lecithinase activity of alpha toxin
Gram +
Alpha toxin producing lecithinase
C perfringens
Myonecrosis
Skin crepitation
Gangrenous wound
Death march of bataan
C perfringens