Pseudomonads & Acinetobacters
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Transcript of Pseudomonads & Acinetobacters
PSEUDOMONADS, ACINETOBACTERS AND OTHER UNCOMMON GRAM
NEGATIVE BACTERIA
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
The Pseudomonad Group
Morphology
Oxygen Requirement
Sugar fermentation
Important members:
Pseudomonas spp.
Burkholderia spp.
Stenotrophomonas spp.
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Classification of Some of the
Medically Important Pseudomonads rRNA Homology Group
and Subgroup Genus & Species
I Fluorescent Group
Nonfluorescent Grp. P. aeruginosa, P. fluorescens, P. putida
P. stutzeri, P. mendocina
II B. pseudomallei, B. mallei, B. cepacia,
R. pickettii
III Comamonas species, Acidovorax species
IV Brevundimonas species
V Stenotrophomonas maltophilia
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Pseudomonas aeruginosa
Morphology
Flagellation
Strict aerobes
Oxidase
Good growth on MAC
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Gram stain of P. aeruginosa
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
P. aeruginosa
Habitat
Environmental water sources (e.g. hospital
respirators & humidifiers)
May inhabit skin, URT and colon
Transmission
Water aerosols, aspiration and fecal
contamination
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
P. aeruginosa Pathogenicity/Virulence
Pili
Exotoxin A – diphtheria-like toxin
Endotoxin
Diseases
Wound infections
Ecthyma gangrenosum
UTI
Pneumonia in cystic fibrosis
Nosocomial infections in burn patients
Bacteremia and sepsis
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Ecthyma gangrenosum
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Lab. Diagnosis of P. aeruginosa
Microscopic
Cultural: “grape or tortilla corn”
Biochemical
Oxidase
Growth at 42oC
Hydrolysis of acetamide
Growth on cetrimide agar
Nitrate reduction
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
P. aeruginosa
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Pigments Produced by P.
aeruginosa
Pyocyanin
Pyoverdin
Pyorubrin
Pyomelanin
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Epidemiology of P. aeruginosa
Treatment
Ticarcillin/Piperacillin with tobramycin
Aztreonam, imipinem, ciprofloxacin
Ceftazidime and cefoperazone
Prevention
Moist environments: sinks, showers, tubs,
etc.
Control
Vaccine from appropriate types
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Other Pseudomonas species
P. fluorescens and P. putida
Pyocyanin production
Hydrolysis of acetamide
Nitrate reduction
Growth at 42oC
P. fluorescens is positive for gelatinase and
lecithinase, P. putida is negative to both.
Diseases
Respiratory infection, wound infection and UTI
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Burkholderia species
Burkholderia pseudomallei
Morphology
Oxidase test
Disease: MELIOIDOSIS
A.k.a. _____________________________
Commonly a pulmonary infection, primarily
a pneumonitis
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Burkholderia species
Burkholderia mallei
Morphology
Oxidase test
Causes GLANDERS in horses
May be transmitted to man
Cutaneous involvement with thickening of the
superficial lymphatics
Burkholderia cepacia
May cause pneumonia, UTI and other
infections
Oxidase test
Potent nosocomial infection in cystic fibrosis
patients ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Other Pseudomonads
Stenotrophomonas maltophilia
Nosocomial LRTI
Oxidase negative, motile, LDC (+), DNAse
(+), oxidizes OF maltose (maltophilia)
Shewanella putrifaciens
Only nonfermentor that produces H2S in TSI
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
The Acinetobacter
Important members
A. baumannii, A. lwoffi, A. johnsonii, A.
haemolyticus
Habitat
Skin, oropharynx, vagina
Diseases
UTI, LRTI
Lab. Diagnosis
G(-) coccobacilli to diplococci, Oxidase (-), non-
motile
A. baumannii produces acid from 10% lactose
A. lwoffi is asaccharolytic
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Uncommon G(-) Bacteria
Moraxella
M. lacunata
M. nonliquifaciens
M. osloensis
M. phenylpyruvica
Chryseobacterium (Flavobacterium)
C. indologenes – wound infection
C. meningosepticum – neonatal meningitis
Produces yellow-pigmented colonies on BAM
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Uncommon G(-) Bacteria
Alcaligenes
A. faecalis
A. xylosoxidans spp. xylosoxidans
A. xylosoxidans spp. denitrificans
Eikenella
E. corrodens
Normal inhabitant of oral cavity and URT of
humans
Causes gingivitis, tooth infection, neck & facial
abscess, pneumonia, clinched fist injury,
bacteremia
BAP: bleach-like odor
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Uncommon G(-) Bacteria
Streptobacillus moniliformis GNR in chains with irregular bulbous swelling
Grown on HI agar or broth
Causes Rat bite fever (Haverhill disease)
Spirillum minor Small G(-) spiral shaped rods
Darkfield microscopy
Causes Rat bite fever (Soduku)
Calymmatobacterium granulomatis Causes granuloma inguinale
Diagnosis: Donovan bodies in Wright’s stain
ALLAN JAY C. ESPIRITU, RMT, M.Sc.
Uncommon G(-) Bacteria
Bartonella bacilliformis
Transmission: Phlebotomus sandfly (vector)
Causes Carrion’s disease
Oroya fever: severe febrile anemia
Verruga peruana: nodular disease of
cutaneous tissues
Cardiobacterium hominis
Dumb-bell shaped GNR
Causes endocarditis
ALLAN JAY C. ESPIRITU, RMT, M.Sc.