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Clinical Microbiology
Different Organisms
42
Biology
Undergraduate 4
04/06/2009

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Term
Campylobacter jejeuni
Definition
  • Most common source: Poultry (Chicken)
  • Non-Sacrylitic
  • Gram - Bacilli (Gull-winged)
  • Medium: CAMPe Blood Agar
  • 42°C, 5% O2, 10% CO2, 85% N
  • Hippurate +
  • Oxidase +
  • Catalase +
  • Spread by Direct contact, exposure to animals, contaminated water, dairy products, improperly cooked poultry, & sexual transmission
  • Self-Limiting in MOST people
  • Can cause septic arthritis, meningitis, & pre-disposes people to Guilliane-Barre Syndrome (paralysis)
Term
Heliobacter pylori
Definition
  • Formally Campylobacter
  • microaerophilic
  • capnophilic
  • motile
  • strongly urease +
  • produces endotoxin, but less toxic than endotoxins from other Gm -'s
  • Medium: CAMPe blood plate
  • Beta-hemolytic
  • incubation = 3-5 days
  • resistant to quinnalones, macrolides
  • penicillins do NOT work well in stomach B/C of acidity in stomach
Term
HACEK
Definition

H = Haemophilus aprophilus

A = Actinobacillus actinomyecetemcomitans

C = Cardiobacterium hominis

E = Eikenella corrodens

K = Kingella

  • Gm - Fastidious Bacilli
  • Needs CO2 atmosphere OR special nutritional requirements
  • Grows SLOWLY
  • Can enhance growth by putting into candle jar
Term
Haemophilus
Definition
  • Haemophilus = Blood Loving
  • X-factor = Hemin (Blood)
  • V-factor = NAD (Staph/Neisseria)
  • Problem: dies Rapidly!!
  • Most will NOT grow on plain Blood Agar - need Choc. Agar
  • Temps: 27-37°C
  • Mousy, bleach-like odor
  • pleomorphic
  • H. aprophilus - X & V Independent!
    • Catalase -
    • Oxidase -
    • grows on blood, but better on choc. -- NO growth on MacConkey
    • Illnesses:
      • Sinusitis
      • Ear infections
      • Endocarditis (if gets into blood)
  • H. aegyptus - X & V Dependent!
    • Causes Pink Eye & Brazilian purpuric fever
  • H. ducreyi - X Dependent!
    • STD (Chanchroid)
  • H. influenza - X & V Dependent!
    • Causes meningitis mainly in kids <2 B/C have NOT been vaccinated yet
    • VF's:
      • capsule
      • endotoxin
      • adherence w/ fimbriae
      • produces protease
    • does NOT cause influenza!!!
Term
Actinobacillus Actinomycetemcomitans
Definition
  • animal pathogen
  • non-motile
  • usually assoc. w/ mouth flora
  • in humans, caused:
    • meningitis
    • UTI
    • endocarditis
    • dental infections
  • like CO2.....candle jar
  • fermentative
  • looks like star on media
  • occasionally shows in throat cultures
  • inubation temp = 24+ hrs
  • catalase +
  • oxidase -
  • do NOT grow on enteric media, rather grows nicely on choc. agar
  • usually NEVER isolated by itself
  • causes Wompey Jaw (in cows)
Term
Cardiobacterium hominis
Definition
  • non-motile
  • alpha-hemolytic
  • catalase -
  • oxidase +
  • causes pitting in media
  • normal flora in nose, mouth, throat & GI tract
Term
Eikenella corrodens
Definition
  • yellow pigment
  • ~50% of strains corrode agar in for of pitting
  • Aroma: bleach
  • non-motile
  • catalase -
  • oxidase +
  • non-sacrylitic
  • indole -
  • causes:
    • periodontal infections
    • clenched fist syndrome
    • skin popping syndrome
      • caused by licking needles before drug use
      • lesions around injection site ocurrs
Term
Kingella
Definition
  • part of Neisseria group
  • coccobacillus
  • grows better at 42C
  • glucose fermenter
  • nitrate +
  • oxidase +
  • catalase -
  • "twitching" motility
Term
Pasturella multocida
Definition
  • usually causes wound infections assoc. w/ animal bites
    • osteomilitis (bone infection) & resp. tract infections can develop
  • does NOT grow on MacConkey --> but on Blood or Choc. Agar
  • Oxidase test = VERY weak/delayed!!
  • Catalase +
  • Indole +
  • Gram Stain = Bipolar stain (safety pin)
Term
Francisella tularensis
Definition
  • Tularemia - Rabbit Fever
    • Reservoir = Rabbits
    • Highly Infectious Disease
  • grows poorly on MacConkey
  • Oxidase -
  • Biochemically INERT
  • growth enhanced w/ sulfur-containing amino acids (i.e. Cystine)
  • can be transferred mother to baby rabbits via oavries
  • people who hunt rabbits more prone to disease
    • usually from break in skin while skinning & cleaning
  • most common clinical symptom: small sores that appear where bacteria enters body
  • bacteria engulfed by WBC's, but NOT destroyed....enter bloodstream causing:
    • high fever
    • chills
    • shaking episodes
    • debilitating headaches
  • diagnosing = HARD!
    • common to other diseases
    • good to know history of pt
  • culturing = HARD!
    • usually done serologically
  • responds to antibiotics, esp. tetracyclins!
Term
Bordetella pertussis
Definition
  • Whooping Cough
  • Reservoir = Humans
  • VERY CONTAGIOUS!!
  • can be life threatening in infants ot pt's w/ cardiac or pulmonary conditions
  • aerobic
  • slow growing (2-3 days)
  • needs complex media containing blood & potatoes
    • Bordet-Gengou Agar (Cough Plate)
    • colonies look silvery, metallic
  • vaccine: DPT (to prevent) BUT complications occur - cause:
    • fever
    • convulsions
    • CNS problems
  • ID:
    • fluorescent antibody test
    • Biochem Tests = INERT
    • DIFFICULT!!!!
Term
Brucella
Definition
  • Brucellosis
  • Undulant fever, Malta Fever
  • Zoonotic
  • does NOT grow on enteric media, instead on Bloog & Choc. Agar
  • ~5-7 days to grow
  • H2S +, BUT use lead strips which are put into culture - will not do this for TSI or SIM
  • B. abortus
    • cattle
    • causes spontaneous abortion in cows
  • B. suis = pigs
  • B. melitensis = goats/sheeps
  • seen mainly in people who have gone abroad B/C many countries do NOT pasteurize their dairy products
    • U.S. pasteurizes ALL dairy product
Term
Legionella pneumophila
Definition
  • Legionnaire disease
  • microbe likes moist areas (pipes, showers, misters in supermarket, etc.)
  • causes resp., pulmonary infection
  • treated w/ antibiotics
  • only grows on media w/ iron, decreased amount of sodium, & amino acid L-cysteine
    • Buffered-Charcoal
      • contains yeast extract
      • microbe tiny & glistens
      • does NOT grow on blood or choc.
  • Hippurate +
  • most biochem tests = INERT
  • survives temps up to 60°C
  • can adhere to rubber, piping, plastics - able to stay in water systems, even if systems flushed out!
  • resistant to chlorine!! (Bleach NOT work)
  • rapidly ID'd by ELISA test
  • symptoms:
    • flu-like or pneumonia
    • nausea
    • diarrhea in ~50% cases
    • decrease in blood O2 level
      • problem: most elderly misdiagnosed as having dementia
Term
Neisseria
Definition
  • Gm - diplococci
  • capnophiles
  • oxidase +
  • MOST catalase +, EXCEPT N. elongate
  • inhabit mucus membrane in resp. & urogenital tract
  • primary human pathogens:
    • N. meningitidis
    • N. gonorrhea
  • VF's:
    • capsule
    • pili
    • LPS (endotoxin)
    • IgA proteases
  • specimen collection:
    • vaginal smears/swabs
      • NO COTTON SWABS B/C inhibitory!
    • penal discharge
    • blood
    • joint fluid
    • throat swabs
    • special transport media
    • susceptible to cold temps
  • Lab ID:
    • smear - look for diplococci
    • use choc. & NYC agar
    • samples streaked in Z-formation
    • incubate @ 35-37°C in CO2 (candle jar)
    • sugar fermentation:
      • CTA Agar
        • N. gonorrhea - CTA w/ GLU
        • N. meningitidis - CTA w/ GLU & MAL
        • N. catarrhalis - Asacrylitic
      • look for growth patterns
      • RED --> YELLOW = +
  • Immunological tests:
    • fluorescent antibodies
    • quellung - capsule swelling
    • some strains:
      • penicillinase +
      • beta-lactamase +
    • catalase test
      • use 30% instead of 3% H2O2
        • Neisseria bubbles, but is WEAK!
Term
N. meningitidis
Definition
  • epidemic spinal meningitis
  • humans ONLY host
  • 3-30% pop. asymptomatic
  • ~14% cases FATAL
  • if recover, many have:
    • permanent hearing loss
    • mental retardation
    • loss of limbs (B/C of DIC)
  • NOT resistant!
    • penicillins, antibiotics, sulfur drugs WORK
  • specimen collection:
    • CSF
    • blood
    • nasal pharyngeal swabs
  • once collected:
    • gm stain - CSF centrifuged 1st to increase 100 fold of finding microbe
    • grown in candle jar
    • grows on blood, but Choc. is better
      • look small & gray and kind of muccoid
Term
N. gonarrhea
Definition
  • Pili - Virulent - T1 & T2
  • NO Pili - Avirulent - T3 - T5
  • transmitted sexually
  • primary reservoir = asymptomatic carrier
  • incubation period = 2 days - 1 wk
  • Males:
    • acute urethritis resulting in white/yellow discharge
    • burn upon urination
    • painful/swollen testicles w/ 3-5% being asymptomatic
  • Females:
    • ~50% asymptomatic
    • vaginal bleeding
    • lower abdominal pain
    • can lead to PID (pelvic inflammatory disease)
      • internal absesses
      • long-lasting
      • damage to fallopian tubes
        • can lead to infertility
      • ectopic pregnancies
        • when egg grows outside of uterus
        • can be life threatening
      • can cause infections in rectal area (bloody stools), pharyngitis, blindness, etc.
Term
Moraxella
Definition
  • M. catarrhalis (formally Branhamella)
    • ONLY isolated in humans
    • Normal flora in resp. tract
  • opportunistic
  • causes:
    • pneumonia
    • sinusitis
    • ear infections
  • contains beta-lactamase
    • resistant to penicillin-derivatives
  • oxidase +
  • catalase +
  • grow on sheep blood choc. agar
  • sugar tests -
  • DNAse + (turns plate red)
Term
Gram NEG. Non-fermenting Bacilli
Definition
  • Most oxidase +
  • Most non-reactive on TSI
  • Most resistant to antibiotics
    • prob. B/C tend to be nosocomial
  • organized into smaller grps based on:
    • growth on MacConkey
    • Oxidase +/-
    • whether microbe can use glucose oxidatively?
  • most commonly isolated:
    • pseudomonas aeruginosa
    • xanthomonas maltophila
    • Acinetobacter sp.
  • Biochem tests:
    • TSI - non-reactive, stays red
    • OF Medium - Weak/Strong +
      • ferments glucose EXCEPT pseudomonas in closed tube w/o oil
Term
Pseudomonas aeruginosa
Definition
  • aerobic
  • oxidase +
  • motile
  • grows on MacConkey
  • oxidizes carbohydrates
  • produces blue/green pigment - pyocyanin
  • grape, fruity odor
  • diseases:
    • primarily wound infections
    • pulmonary infections
    • burn infections
    • Jacuzzi/Hot Tub Syndrome
      • necrotizing skin rash
  • VF's:
    • LPS (endo- & exotoxin)
    • homolysin
    • anti-phagocytic slime layers
    • elastase (breaks down collagen)
    • coagulase +
    • DNAse +
    • Lipase +
  • grows at 42°C
    • can tolerte HIGH temps
  • Citrate +
  • blue/green sheen on media
  • Treatment = HARD! B/C resistant to many antibiotics
    • double drug therapy used
Term
Burkholderi cepacia
Definition
  • oxidative
  • plant pathogen
  • used to be considered low-grade
  • assoc. w/ pneumonia in pt's w/ cystic fibrosis
  • causes pneumonia & dermatitis
  • isolated from contaminated water, anesthestics, nebulizers, disinfectants, detergents
  • tends to grow better @30°C
Term
Xanthomonas maltophilia
Definition
  • oxidative
  • 3rd most common Gm - nonfermenter isolated
  • WAS considered plant pathogen, BUT also assoc. w/ water, sewage
    • NOW, human pathogen
  • isolated in hospital as well
  • VERY resistant to antibiotics
    • treatment = HARD!
    • quinnalones used
Term
Salmonella
Definition
  • motile
  • primary intestinal pathogen
  • inhabits GI tract of animals
  • H2S +
  • urease -
  • non-lactose fermenter
  • VF's:
    • LPS
    • w/ fimbriae = more virulent B/C can adhere to intestinal mucosa
    • enterotoxin (like shigella - Shiga toxin)
      • cause GI problems
  • to isolate - enrichment media used
  • VERY susceptible to chem. agents (disinfectants)
  • diseases:
    • Salmonellosis
      • GI problem
      • vomiting/diarrhea
      • fecal-oral route from person to person
      • NO animal reservoir
      • symptoms:
        • high fever
        • pain from ulcerations in intestinal tract
        • mucus, blood, pus in stool
      • pt gets better within a few days
    • Typhoid fever
      • MOST severe of enteric fevers
      • prolonged fever
      • microbe moves to multiple organs in body
      • spread person to person
      • NO animal reservoir
      • can be transmitted thru fomites
      • Symptoms start 9-14 days after contact w/ Salmonella typhi:
        • fever
        • muscle pains
        • malaise
        • frontal headache
        • microbe invades gall bladder & intestines - remains viable
        • can terminate by antibiotics OR surgically removing gall bladder
    • Food poisoning = common
      • 8-36 hrs after ingestion
      • nausea, vomiting, diarrhea
      • worst in young kids/elderly
Term
Yersinia
Definition
  • motile
  • primary intestinal pathogen
  • pneumonic/bubonic plague
  • Gm - bacilli
  • grow @ 37°C, but prefer 25-30°C
  • stain bipolar (safety pin)
  • humans can pick up from pets (cats, dogs, pigs)
  • appears as Appendicitis
  • can produce arthritis & itchy, red nodules & burn - more prevalent in females
  • Y. enterocolitica
    • mimics GI problems
    • most commonly from contaminated water
  • Y. pestis
    • buboes/lesions along lymphatic system
    • can become resp. (pneumonic)
  • Y. pseudotuburculosis
    • primarily attacks rodents
    • extremely rare as human infection
Term
Shigella
Definition
  • 4 different species:
    • S. sonnei
    • S. flexneri
    • S. boydii
    • S. dysenteriae
  • cause basillary dysentry
    • produce mucus/blood/pus in stolld B/C of ulceration of colon
  • Non-Motile
  • primary intestinal pathogen
  • NO animal reservoir
  • S. sonnei = most common in U.S.
    • Grp D
    • H2S -
    • NO gas production from glucose fermentation
    • non-lactose fermenter
    • colonies very fragile in terms of environmental changes
Term
Klebsiella
Definition
  • Non-motile
  • Klebsiella pneumoniae - possesses polysaccharide capsule to prevent phagocytosis
  • assoc. w/ resp. tract infections of hospitalized pts
  • causes lower resp. tract infections
Term
Enterobacter
Definition
  • motile
  • isolated from wounds, urine, blood, CSF
Term
Serratia
Definition
  • motile
  • opportunistic
  • SLOW lactose fermenter
  • Resistant to many antimicrobials
  • Serratia marcescens
    • pink/red color
    • found in nosocomial infections of urinary/resp. tract & in bacteremic outbreaks in nurseries, cardiac surgeries, & burn units
Term
Hafnia
Definition
  • motile
  • delayed + citrate rxn
  • causes gastroenteritis
  • occassionally isolated from stools
Term
Proteus
Definition
  • motile
  • opportunistic
  • normal intestinal flora
  • deaminates PHE
  • lactose -
  • urease +
  • H2S +
  • Odor - burned choc./choc. cake
  • isolated from wounds, urine, ears, & bacteremic infections
Term
Morganella
Definition
  • motile
  • causes UTI & diarrheal illness
Term
Providencia
Definition
  • motile
  • causes UTI
  • occasional nosocomial outbreak in burn units
  • found in feces of children w/ diarrhea
  • isolated from urine cultures of immunocompromised pts
Term
Citrobacter
Definition
  • motile
  • causes UTI, pneumonias, intra-abdominal absesses, endocarditis
  • nosocomial infections
  • isolated from diarrheal stools
  • ~80% H2S +
  • mistaken for Salmonella
Term

Enteropathogenic E. coli

 

(EPEC)

Definition
  • infantile diarrhea
  • symptoms:
    • low grade fever
    • malaise
    • vomiting
    • diarrhea
    • stool contains LOTS of mucus, NO blood
Term

Enterotoxigenic E. coli

 

(ETEC)

Definition
  • Traveler's diarrhea
  • Symptoms:
    • nausea
    • abdominal cramps
    • low grade fever
  • assoc. w/ contaminated food/water
  • infective dose = HIGH (106 - 1010 bacteria)
  • stomach acidity - inhibits colonization & initiation of disease - Achlorhydria
  • LT - heat labile toxin
  • ST - heat stabile toxin
  • Non-bloody, watery diarrhea
  • lasts 1-5 days
Term

Enteroinvasive E. coli

 

(EIEC)

Definition
  • Dysentry
  • penetrates, invades, & destroys intestinal mucosa
  • via fecal-oral route
  • symptoms:
    • fever
    • severe abdominal cramps
    • malaise
    • watery diarrhea
    • stool - pus/mucus/blood
  • non-motile
  • lactose -
Term

Enterohemorrhagic E. coli

 

(EHEC)

Definition
  • hemorrhagic diarrhea & colitis & hemolytic uremic syndrome (HUS)
  • HUS:
    • low platelet count
    • hemolytic anemia
    • kidney failure
    • watery diarrhea --> bloody diarrhea
    • abdominal pain
    • low grade fever or NO fever
    • infection potentially fatal
  • E. coli O157:H7
    • produces 2 cytotoxins:
      • Verotoxin I - phage encoded
        • identical to Shiga toxin
      • Verotoxin II
Term

Enteroadherent E. coli

 

(EAEC)

Definition
  • causes diarrhea
  • adheres to mucosal surface of intestine
  • symptoms:
    • watery diarrhea
    • vomiting
    • dehydration
    • abdominal pain
Term
Other E. coli infections....
Definition
  • urinary tract infections - UTI & kidney infections in humans
  • Septicemia & meningitis
    • newborn acquires infection through birth canal
Term
Agrobacterium
Definition
  • plant cancer
  • Crown Gall
Term

LAB Diagnosis

of

Enterobacteriaceae

Definition
  • Media:
    • non-selective - Blood/Choc.
    • Selective - MacConkey
    • Highly Selective - HE/XLD (for stools)
  • lactose vs non-lactose fermentation**
    • MacConkey
      • lactose = pink/red
      • non-lactose = colorless
    • HE
      • lactose = salmon/orange
      • non-lactose = colorless
    • XLD
      • lactose = yellow
      • non-lactose = colorless
  • Environmental Requirements:
    • 1-5°C for Serratia
    • 45-50°C for E. coli
Term

ID

of

Emterobacteriaceae

Definition
  • ALL oxidase -
  • ALL ferment glucose
  • ALL reduce nitrates --> nitrites
Term
Enterobacteriaceae
Definition
  • referred to as enterics
  • Gm - bacilli
  • non-spore forming
  • facultative anaerobes
  • most present in intestinal tract of animals/humans as commensal flora
  • live in soil, water, sewage
  • plant pathogens
  • opportunistic
  • VF's:
    • ability to colonize, adhere, produce toxins & invade tissues
    • antigens:
      • O (somatic) - heat stabile; cell wall
      • H (flagellar) - heat labile; flagellum
      • K (capsular) - heat labile; in certain species
  • Escherichia - E. coli
    • lactose fermenter
    • motile
    • contain pili & fimbriae
    • O, H, K antigen
    • Indole +
    • MR +
    • ferments glucose, trehalose, xylose
    • normal intestinal tract flora
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