Micro Block 3-Pt 2

ptheodore's version from 2015-08-02 19:42


Question Answer
Pink Growth on MacConkey plateEnterobacteriaceae
Lipopolysaccharide (Endotoxin); Lipid-A of LPS binds to TLR4/CD14Enterobacteriaceae
Too much ____ from enterobacteriaceae causes septic ShockTNF α
E.coli O157:H7EHEC
E.coli K1NMEC
Type 3 Secretion System T3SSEnterobacteriaceae

GNB Enterobacteriaceae Opportunistic

Question Answer
Gram Negative Bacilli. Lactose Fermenter. Reduce Nitrate to NitriteUroPathogenic E.coli (UPEC)
Fimbriae & Pili attaches to uro-epithelial (transitional epithelium) cells and biofilm is formed. Pyogenic symptoms are mediated by hemolysin and immune response to LPSUroPathogenic E.coli UPEC
Treatment for UroPathogenic E.coli (UPEC)Cotrimoxazole (TMP-SMX trimethoprim-Sulfamethoxazole) & Cipro (Fluoroquinolones-Based on urinalysis Antibiotic-R/S)
Virulence Factor Uropathogenic E.Coli (UPEC)LPS, Pili and hemolysin
Neonatal Meningitis (High fever, vomiting, irritability lethargy, bulging fontanelle)E.Coli K1 (NMEC)
Gram Negative Bacilli. Lactose Fermenter. Encapsulated K-1E.Coli K1 (NMEC)
Treatment for E.Coli K1 (NMEC)Cephalosporin/Cefotaxime
Virulence Factor for E.Coli K1 (NMEC)LPS, K1 capsule
UTI/Kidney StonesProteus
Lactose Non-Fermenter. Urease (+). Swarming MotilityProteus
Fimbriae attaches to uro-epithelial cells. Motility promotes migration to kidneys. Urease reduces urea->ammonia-> kidney stones.Proteus
Treatment for ProteusCotrimoxazole (TMP-SMX trimethoprim-Sulfamethoxazole) & Cipro (Fluoroquinolones-Based on urinalysis Antibiotic-R/S)
Virulence Factor Proteus LPS, Urease and flagella
Systemic, alcoholics prone to pneumonia. UTI/Cystitis. Pneumonia esp. D-VAP. MeningitisKlebsiella pneumoniae
Lactose Fermenter, Purple Mucoid. Encapsulated.Klebsiella pneumoniae
Treatment for KlebsiellaCefotaxime, Ceftriaxone, Ceftazidime (3rd Generation Cephalosporin)
Carbepenem-Resistance (CRKP) is major health threatKlebsiella pneumoniae
KlebsiellaLPS, Capsule
UTI. Wound and soft tissue infections. Pulmonary infections. Pneumonia/Systemic. Common nosocomial infections (esp. ICU). Can be very resistant to many antibioticsEnterobacter
Virulence Factor Enterobacter/CitrobacterLPS
Gram Negative Bacilli. Lactose Fermenter. Red prodigiosin-pigment. UTI. Pneumonia. Sepsis->Meningitis. Capsulated. OsteomyelitisSerratia marcescens
Treatment for Serratia marcescensCipro (Fluoroquinolones)
Virulence Factor SerratiaLPS

GNB Enterobacteriaceae Strict Pathogens


Question Answer
GNB. “Rice-water” / profuse diarrhea NO fever.ETEC
Fimbriae, ST/LT EnterotoxinETEC
LT (heat-labile toxin) increasescAMP
ST (heat-stable toxin) increasescGMP
GNB. Watery diarrhea in children NO feverEPEC
Attaching and Effacing A/E Lesions ONLYEPEC
Dysentery; infection of colon, tenesmus, significant pus/RBC/WBC and low volume diarrhea +FeverEIEC
GNB. Motile, Cell-to-cell rocketing, hemolysinEIEC
GNB. Watery Diarrhea followed by Profuse Bloody Diarrhea without fever or WBCs.Can lead to Hemolytic Uremic Syndrome (HUS)EHEC O157:H7
GNB. Grossly bloody diarrhea, cattle reservoirEHEC O157:H7
Attaching and Effacing A/E Lesions & Shiga-toxinEHEC O157:H7
Toxin that cleaves host 28s RNA ribosome of 60sEHEC/Shiga like toxin
Does not ferment sorbitol, yields white colonies on Sorbitol-MacConkey agar (S-Mac). EHEC O157:H7
Systemic TyphoidSalmonella typhi
Motile, peritrichous flagella. Oxidase (-). Non-lactose fermenting. H2S production.Salmonella
Gram Negative Bacilli. Capsule – Vi antigen. Motile, Non-fermenter, H2S productionSalmonella Typhi
Survive within macrophages and colonize liver, spleen, and can permanently live in gall bladder. High fever lasting >7days with Rash “Rose SpotsSalmonella Typhi
Treatment for Salmonella TyphiCipro (Fluoroquinolones)
Attenuated Live Vaccine (Vi capsule)Salmonella Typhi
Osteomyelitis **esp. sickle-cell patients. Gastroenteritis (healthy host). Bacteremia (young/old hosts). Typhoid-like disease (AIDS). Reiter’s Syndrome (Reactive Arthritis-HLA-B27 Patients)NT. Salmonella
Fecal-oral ZOONOTIC transmission (poultry, pigs, reptiles) OR produce washed with contaminated waterNT. Salmonella
Black Colonies on Hektoen (HE) AgarSalmonella
Gram Negative Bacilli. Motile, Non-fermenter, H2S productionCMI activates macrophages. Gastroenteritis. Systemic Reactive or Septic Arthritis. OsteomyelitisNT. Salmonella
Gram Negative Bacilli. Non-Motile, Non-fermenter, No H2S production. Dysentery->grossly bloody diarrheaShigella
“Rocket” from Intestinal Endothelial Cells (cell-to-cell), causing severe tissue damage. Produces toxin that targets 28s rRNA, ceasing translation in endothelial cells. Reactive Arthritis (HLA-B27). Seizures. Hemolytic Uremic Syndrome (HUS)Shigella
White Colonies on Hektoen (HE) AgarShigella
Treatment for shigella patients that are immune-compromisedCipro (Fluoroquinolones)
Motile at 25°, not at 37°. Coagulase (+) . Cold Growth. Localizes to mesenteric lymph nodes.Yersinia enterocolitica
Variable motility. Oxidase (-). Non-lactose fermenting. No H2S production, ferments sucroseYersinia enterocolitica
Zoonotic (puppy poop), fecal-oral. Milk and undercooked pork products esp. cold climates. Gastroenteritis/pseudoappendicitis. Reactive arthritis. Erythema nodosumYersinia enterocolitica
Yellow Colonies on Hektoen (HE) AgarYersinia enterocolitica
Treatment for Yersinia enterocolitica if systemic. Also for children more severe disease (STX) immunocompromisedCipro (Fluoroquinolones)

GNB Curved

Question Answer
“Rice-water” diarrhea. GNB CurvedVibrio cholerae
Gastroenteritis/skin lesionsV.vulnificus/V.parahamaemolyticus
Gram negative “comma” bacilli. Motile. Oxidase +. Ingestion of contaminated seafood or water. Associated with natural disastersVibrio cholerae
Toxin co-regulated pilus (TCP); adhesion to small intestine epitheliumVibrio cholerae
Cholera Toxin that targets Gαs subunit of GCPR, increases Adenylate Cyclase activity -> increased cAMP -> efflux of Cl- and secretion of H2OCholera A toxin
MC cause of seafood gastroenteritis in USA esp. shellfish. Eating OystersVibrio parahaemolyticus
Gastroenteritis along with Cellulitis in wounds after exposure to salt water. Septicemia and necrotizing fasciitis in immune-compromised esp. chronic liver disease.Vibrio vulnificus
Culture on TCBS agar (Thiosulphate Citrate Bile Salt); high alkalinityVibrio Cholera
Treatment for VibrioFluid and electrolyte replacement
Gram-negative curved rod. Microaerobic 42°C growth (high heat). Poultry reservoirsCampylobacter jejuni
Skirrow agar at 42°C. Gastroenteritis. Invades mucosa of colon; destroys colon mucosal surfaces; inflammatory bloody diarrhea!Campylobacter jejuni
Guillain-Barre Syndrome (Ascending paralysis; legs & up) and Reactive Arthritis (As a result of molecular mimicry)Campylobacter jejuni
Chicken, Fever, blood and WBC in feces. Abdominal pain.Campylobacter jejuni
Gastritis/ulcersHelicobacter pylori
Gram Negative Curved, Oxidase +, Urease +, Gastritis/ulcersHelicobacter pylori
Mucinase (penetration of mucous layer). Urease positive (ammonium cloud neutralizes stomach acid). Invasive (cagA): into stomach lining Helicobacter pylori
Diagnosis; Biopsy with culture, histology with Giemsa or silver stain.Breath Test (ammonia). Serology Helicobacter pylori
Treatment for Helicobacter pyloriProton pump inhibitor (omeprazole) AND Macrolides (clarithromycin) AND B-lactam (amoxicillin)

Recent badges