Bacteria gram negative Flashcards
Gram neg. “coccoid” rods include what?
H. Influenzae, Pasteurella, Brucella and Bordetella
differentiating b/w N. meningitidis and N. gonorrhoeae?
Meningitiditis= Maltose fermenter Gonorrhoeae=nonfermenter (but does ferment Glucose)
two subclasses of gram neg. Rods?
lactose fermenter and lactose nonfermenter
two subclasses of gram neg. lactose fermenting rods?
slow vs fast
List the gram neg. lactose fermenting rods with associated subclass
Fast: Klebsiella, E. Coli, Enterobacter (MacConKEE’s agar)Slow: Citrobacter, Serratia (also use MacConkey’s agar, just Crappy and Slowly)
Subclasses of gram neg. Lactose nonfermenting rods?
oxidase + vs oxidase -
List gram neg. Lactose nonfermenting rods and their associated subclass
Oxidase neg.: Shigella, Salmonella, Proteus, Yersinia (PYSS)Oxidase pos.: Pseudomonas
List different kinds of oxidase + comma shaped gram neg. bacteria and how to differentiate them from the rest
Campylobacter Jejuni: (grows in 42 degree C) Vibrio cholerae: (grows in alkaline media) Helicobacter (Produces urease)
EMB agar?
Another option used to grow lactose fermenting gram neg. (along with MacConkey’s). They grow as purple/black colonies. E. oil grows as purple colonies with green sheen.
Differences b/w N. Meningitidis and Gonorrhoeae
Meningicocci: Maltose fermenters, has polysachharide capsule, Vaccine, Respiratory and oral secretions, Causes meningococcemia, meningitis, waterhouse-friderichsen syndrome, Prophylaxis with rifampin, cipro ceftriaxone for those in close contact, treatment with CeftriaxoneGonococci: Glucose fermenters, no polysaccharide capsule, no vaccine, STI, causes gonorrhea, septic arthritis, conjunctivitis in babies, PID, Fitz-Hugh curtis syndrome, prevention with condoms and treatment ceftriaxone (+azithromycin against chlamydia)
H Influenzae:classification in lab algorithm?mode of transmission?Media it grows on?different disease it can cause?Other?
-coccoid gram neg. rod -aerosols-Chocolate agar with factor V (NAD+) and X (hematin)-HaEMOPhilus causes: Epiglottis, Meningitis, Otitis media, Pneumonia -HiB is most invasive type
Legionellamode of transmission?Media it grows on?different disease it can cause?Other?
-aerosol transmission from environmental water source habitat-charcoal yeast extract cultured with iron and cysteine -legionnaire’s disease: severe pneumonia, fever, GI and CNS symptoms-Pontiac fever: mild flu-like syndrome -Treat with macrolides or quinolone. -Lab can show hyponatremia
P. aeruginosaclassification in lab algorithm?mode of transmission?different disease it can cause?Other?
- lactose non-fermenting oxidase +-Water source-PSEUDOH- Pneumonia, Sepsis, External otitis (malignant in diabetics)/Ecthyma gangrenosum (rapidly progressive necrotic cuteaneous lesions caused by bacteremia…seen in immunocompromised ppl), UTI, Diabetic osteomyelitis, hot tub folliculitis-produces blue-green pigment
- treat with (depending on source) aminoglycosides ( gentamicin/tobramycin) plus extended spectrum penicillin (piperacillin, ticarcillin, cefepime) carbapenema (imepenem, meropenem) monobactams ( aztreonem), fluroquinolones (cipro), or multiparty res (colistin, polymyxin)
Different types of E Coli
EIEC: Invasive dysentery; invades intestinal mucosa and causes necrosis and inflammation; clinical pic similar to shigellaETEC: Traveller’s diarrhea; heat labile and stable toxinsEPEC: Pediatric diarrhea; Adheres to apical surface and flattens villi preventing absorptionEHEC: Dysentery and possible HUS with O157:H7; Shiga-like toxin causes necrosis and inflammation and can sometimes incite cytokine response to lead to HUS (micro thrombi form on endothelium damaged by Toxin)…does not ferment sorbitol unlike the other E. Coli
Klebsiellaclassification in lab algorithm?mode of transmission?different disease it can cause?Other?
-Fast Lactose fermenting gram neg.-intestinal flora that can cause lobar pneumonia in alcoholics and diabetics when aspirated. - You don’t drink or have diabetes, do you have Klebsiella?: NAA; nosocomial UTIs, Aspiration pneumonia, Abscesses on liver and lungs
Salmonella vs Shigella
Salmonella: have flagella (SALMON swim), can disseminate hematogenously, antibiotics may prolong fecal exertion of organism, invades intestinal mucosa and causes a monocytic response, can cause bloody diarrheaShigella: no flagella, spreads cell to cell, antibiotics shorten duration of fecal excretion of organism, invades intestinal mucosa and causes PMN response, often causes bloody diarrhea
Salmonella typhi
causes typhoid fever and only found in humans. characterized by rose spots on abdomen, fever, headache and diarrhea. Can remain in gallbladder and cause a carrier state.
Campylobacter jejuniclassification in lab algorithm?mode of transmission?different disease it can cause?Other?
-oxidase + comma shaped gram neg. that grows in 42degrees celcius (hot like CAMPfire)- fecal-oral spread through foods such as poultry, meat, unpasteurized milk. -major cause bloody diarrhea, especially in children-common antecedent to GBS and reactive arthritis
vibrio cholerae classification in lab algorithm?mode of transmission?different disease it can cause?Other?
- oxidase + comma shaped gram neg. that grows in alkaline media-unsanitary water; endemic in developing countries -Produces profuse rice-water diarrhea via cholera toxin that permanently activates protein G, inc. cAMP
Yersinia
usually transmitted from pet feces, contaminated milk or pork. Causes mesenteric adenines that can mimic crohn’s dz or appendicitis
H. Pylori
-oxidase + comma shaped gram neg. that is urease +. -causes gastritis and peptic ulcers in duodenum. risk factor for gastric adenocarcinoma and lymphoma.-treatment is triple therapy: PPI, clarithromycin and amoxicillin/flagyl
leptospiraclassification?mode of transmission?different disease it can cause?Other?
-spirochete-found in water contaminated with animal urine - can cause photophobia with conjunctival suffusion (erythema without exudate)…Weil disease: severe form with jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage and anemia
Borrelia Burgdorferi
-spread through tick bites (Ixodes tick; same as babesia)-LymeEarly localized: erythema migrans, flu-like symptoms, +/-facial nerve palsyEarly disseminated: arthralgias, polyneuritis, 3rd degree heart block Late disseminated: migratory polyarthritis, polyneuropathy, encephalopathy, B/L FACIAL NERVE PALSYTreatment: doxycycline, ceftriaxone
Treponema pallidum
Syphillis:-primary: painless chancre sore on genitals. If available, use dark-field microscopy to visualize treponemes influid from chancre B . Serologic testing: VDRL/RPR (non-specifc), confirm diagnosis with specific test (e.g., FTA-ABS)-secondary: Disseminated disease with constitutional symptoms, maculopapular rash (palms and soles), condylomata lata (also confirmable with dark-field microscopy). Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (e.g., FTA-ABS).-Tertiary: Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, “general paresis”), Argyll Robertsonpupil. Signs include broad-based ataxia,+ Romberg, Charcot joint, stroke without hypertension. For neurosyphilis: test spinal fluid with VDRLor RPR.Congenital syphillis:- Later presentation: Saber shins, saddle nose, CN VIII deafness, Hutchinson teeth, mulberry molars.-To prevent, treat mother early in pregnancy, as placental transmission typically occurs after first trimester.
