Gram Negative Bacilli Flashcards
Major gram negative group oxidase negative
Enterobacteriaceae
Risk factors for typical pneumonia caused by pseudomonas aeruginosa
Chronic granulomatous disease
Cystic fibrosis
Virulence factors of pseudomonas aeruginosa
Endotoxin ▶️ shock in septicemia
Pseudomonas exotoxin A ADP ribosylates eEF-2 ▶️ (-) elongation in protein synthesis
Capsule/slime layer ▶️ pulmonary microcolonies ▶️ hard to phagocyte
Principal mechanisms of pseudomonas aeruginosa antibiotic resistant
Intrinsic resistance ▶️ loss affinity by porin (drug entry)
Plasmid-mediated B-lactamases
Acetylating enzymes
Triad clinically seen in legionnaires disease. Important virulence factor of the microorganism and other disease caused by it.
Atypical pneumonia
Hyponatremia
Diarrhea
Facultative intracellular
Endotoxin
Pontiac fever
Different presentations of tularemia and how is transmitted each one?
Ulceroglandular disease ▶️ tick bite (dermacentor), traumatic implantation skinning rabbits
Pneumonia ▶️ skinning rabbit (aerosols)
GI disease ▶️ “typhoidal tularemia”: undercooked or infected meat, contaminated water
Toxins of bordetella pertussis
Adenylate cyclase toxin
Pertussis toxin
Endotoxin
Tracheal toxin
Complication of whooping cough
Seizures
Encephalopathy
Pneumonia
What do you use to diagnose brucellosis?
Serum agglutination test ▶️ fourfold increase in titer
Antibodies against brucella ▶️ >1:160 to be (+)
Primary source of transmission of campylobacter jejuni, and serotype associated with is major complication and what is it?
Fecal-oral poultry
Guillain-Barré syndrome ▶️ serotype O:19
Toxins of vibrio cholerae. What do you use to diagnose?
Cholerae toxin ▶️ ADP ribosylation Gs alpha ▶️ (+) adenylate cyclase ▶️ ⬆️ cAMP ▶️ efflux Cl, H2O
Motility, mucinase, toxin coregulated pili (TCP)
Dx: culture stool on TBCS, Oxidase (+)
Diagnose of Gastroenteritis by ETEC. Pathogenesis.
Identify LT (Heat labile toxin) ▶️ immunoassay, bioassay, DNA probe
- LT ▶️ ADP ribosylation of Gs ▶️ (+) adenylate cyclase
- ST ▶️ (+) guanylate cyclase
Type of E. Coli that causes inflammatory diarrhea. Closely related with which microorganism?
E. Coli Enteroinvasive (EIEC) ▶️ unique of all types to cause inflammatory diarrhea
Closely related with shigella
Pathogenic mechanism and diagnose of EHEC gastroenteritis. What is particular in its clinical presentation?
Verotoxin ▶️ shigella-like toxins 1 and 2 ▶️ block 60S subunit ▶️ ⬇️ protein synthesis.
Dx: no fermentation of sorbitol
bloody diarrhea but NO INVASIVE
How do you focus the treatment of EHEC gastroenteritis?
Avoid antibiotics ▶️ ⬆️ risk of HUS
What medium do you culture klebsiella pneumoniae, how do you identify? Why does it have that presentation?
McConkey agar
Pink colonies ▶️ lactose fermentation
How do expect the culture report of a shigellosis?
Gram (-) bacilli, lactose fermenter (-) [colorless in McConkey of EMB], produce H2S (-), nonmotile
Important toxins of shigella. Most severe strain.
M cells invasion ▶️ shallow ulcers
Endotoxin
Shiga toxin ▶️ clipping 60S subunit ▶️ (-) protein synthesis [produced by S. dysenteriae type 1 strain ▶️ most severe]
Diagnosis of yersinia pestis infection
Serodiagnosis or Direct immunofluorescence
Triad in clinical presentation of bubonic plague. How can you get bubonic and pneumonic plague?
- Bubonic plague: fever, regional buboes, conjunctivitis. Transmitted by flea bite.
- Pneumonic plague: highly contagious, human-human by respiratory droplets and biowarfare (aerosol)
Why does proteus mirabilis induce formation of struvite stones? Diseases that can cause.
Urease (+)
UTI, septicemia
Predisposing factors to salmonella infections
Decreased stomach acid
Impairment mononuclear cells (sickle cell disease)
What is the use of the widal test?
Antibodies to O, Vi, and H Ag by agglutination ▶️ Dx salmonella subspecies other than typhi
Complications of typhoid fever if untreated
Necrosis of Peter patches ▶️ perforation Thrombophlebitis Cholecystitis Pneumonia Abscess
