• Enterobacteriaceae
• Pseudomonaceae
• Moraxellaceae

• G/C ratio
• PCR
• DNA hybridization
• pulse field gel electrophoresis
• ribotyping (rRNA)

• O antigen (somatic antigen)- polysac side chain of LPS
  • smooth strains with polysac. side chains
  • rough strains have no polysac.
• H antigen (flagellar Ag)
• K antigen (capsular Ag)

• adhesion/colonization- pili/fimbrae
• exotoxins (invasins)
• endotoxins
• capsules- evade complement mediated lysis
• siderophoroes- enterochelin scavenges bound Fe
• Ag variation
• antimicrobial resistance

• attachment/internalization- AB toxins (cholera toxin)
• export/injection via secretion systems (Type I-VI)

• permeability changes
• efflux pumps
• resistance enzymes (beta lactamase)

• energy dep. process
• coded on for PI's of chromosome next to gens of secretion aparatus
• secondary secretion system
  • ATP binding cassete
• proteins contain an N terminal signal peptide

• non spore forming facultative anerobes
• metabolic properties
  • ferment glucose to acid and gas
  • reduce nitrate to nitrate
  • catalse positive
  • oxidase negative
  • variable ability to ferment lactose
    • lactose fermenting or non lactose fermenting or resitant to bile salts
• most motile
  • mono or peritrichous flagellae

enterobacter

escherichia

klebsiella

proteus

serratia

• normal microflora
  • occasionally oropharyngeal
  • normally GI tract
  • frequently in faginal flora

soil

water

• UTI
• gastroenteritis
• pneumonia
• bone, soft tissue
• meningitis
• intraabdominal
  • peritonitis
  • abscess
• biliary tract
• female pelvis

• 1/3 septicemia
• 2/3 bacterial gastroenteritis
• 3/4 UT isolates
• Conc. in:
  • E coli
  • Klebsiella pneumonia
  • Proteus miabilis

• mucoid appearance
• thick polysac capsule
• 70 Ag variations
• survives by inh. phagocytosis

• chrom. gene encode beta lactamase
• plasmid mediated extended spectrum beta lactamse

• biochemical property
  • produce urease (urea to CO2 and amonia)
  • this increases urine pH leading to precipitation of struvite and formation of stones
• Char- swarming motility
  • differentiate into highly elongated rods with thousands of flagellae

• many strains produce red pigment (prodigiosin)
• mainly environmental rather than part of flora
• resistance
  • can survive some disinfectants and nonbacterial soap, and has been a source of related outbraks

• Char.
  • lactose fermentation
  • motile
  • mucoid
• mostly nosocomial pathogen
• inducible chrom. beta lactamase

cloacae

aerogens

sakazakii

• bipolar staining
• nonlactose fermenting
• optimal growth at 28 degrees, but at low as 4
• invasive (resistant to serum complement)

enterocolitis

mesenteric adentitis (mimic appendicitis)

septicemia

• cold temp. (banked blood, chocolate milk, ice cream)
• iron chelators
  • enhance growth

• dont produce a siderophore
• increases risk with Fe overload syndromes such as hemolytic amenias

• cause
  • bacteremia
  • GI infection
  • soft tissue infection
• nosocomial and community acquired (mostly lower resp. such as pneumonia)
• associated with mutli drug resistance
• gram negative bacilli
• single polar flagellum
• erratic movement on microspcopy
• grow on 3% NaCl (TCBS agar)

• location- exposure to brakish or salt water
• clinical manifestation
  • rapidly progressive cellulitis with bacteremia (esp. w/cirrhosis)
  • abrupt onset:
    • fever
    • chills hypotension
    • metastatic skin lessions
  • 50% mortality

• cellulitis
• acute otitis media and externa after seawater contact
• rarely bacteremia

• diarrheal pathogen
• associated with use of medical leeches
• usually cause:
  • soft tissue infection which ulcerate
  • bacteremia

• soft tissue infections
• bacteremia
• septic shock

More severe than A hydrophilia

• infection from bites, scratches, licking (esp. cat bites)
• nonmotile coccobacillus
• found in animals and humans in:
  • nasopharynx
  • GI tract
• usually cause focal soft tissue infections w/:
  • acute onset (hrs)
  • erythema
  • pain
  • swelling

• aerobic, nonspore forming, coccobacilli
• at risk when:
  • ingest unpasteurized diary products (worldwide problem)
  • abattoir workers
  • veterinarians (its a disease of animals: zoonosis)

• abortus- cattle, buffalo, yaks, camels
• mellitensis- sheep, goats, camels (usually bring more severe infections)
• suis- swine, reindeer, caribou
• canis- kennel raised dogs

• entry through abrasions in skin or by ingestion of unpasteurized dairy products
• multiply in lymph nodes (specifically the macrophages), disseminate, localize in liver, spleen, kidney (RES)
• form granuloma in tissues
• facultative intracellular parasites

So, you need cell mediated immunity to control this infection

• incubation period variabe (2-8 wks)
• acute (resolve in few weeks)
  • high fever
  • sweats
  • malaise
  • headache
  • anorexia
  • abdominal pain
  • back pain
• lymphadenopathy (10%) and hepatosplenomegaly (40%)
• subacute- followed by "undulant" fever (fevers that come and go)
• complications
  • arthritis
  • ostemyelitis
  • meningitis

• intracellular pathogen
• acute febrile bacteremia
• persistent asymptomatic bacteremia
• indolent vascular skin infection
• lab properties
  • seen on silver stain
  • difficult to grow, may take several weeks

• causes oroya fever, verruga peruana after 1-2 (cutaneous nodules)
• clinical manifestation
  • fever
  • myalgias
  • arthralgias
  • headache
• transmitted by sandfly
• found in: Andes, Peru, Columbia, Ecuador
• patholgy
  • penetrate into erythrocyts

• clinical manifestations
  • fever
  • malaise
  • local papule
  • enlarged, tender lymp nodes
• pathology- granulomas with central necrosis and giant cells
• "cat scratch disease"- tranmitted by cat flea

• cause of trench fever
  • incubated 3-38 days
  • symp: fever, headach, rash, splenomegally
• tranmitted by body louse faeces
• bactermia and endocarditis
• vulnerable: homeless, alcoholics
• cause of culture negative endocarditis