CAMPYLOBACTER
LEGIONELLA
BARTONELLA
Campylobacter sp.
Organism
Source(s)
Human disease(s)
C. coli
Pigs, poultry, sheep,
bulls, birds
Gastroenteritis,
septicemia
C. jejuni ssp. jejuni
Poultry, pigs, bulls,
dogs, cats, birds, others
Gastroenteritis,
septicemia, meningitis,
proctitis
C. jejuni ssp. doylei
Humans
Gastroenteritis,
gastritis, septicemia
C. fetus ssp. fetus
Cattle, sheep
Septicemia,
gastroenteritis,
abortion, meningitis
Clinical characteristics
• C. coli and C. fetus cause most human disease
• Transmitted through contaminated food, milk, or water
• Campylobacter does not multiply in food
• Person-to-person transmission is rare
Clinical characteristics, cont.
• Seasonality in the U.S.; late summer-early fall peak
• Most common etiology of gastroenteritis in U.S.
• GI disease is typically self-limiting
• Post-infectious complications can include Guillain-Barré
Laboratory Diagnosis
Specimen collection
• No special requirements; stool and blood 1° specimens
• For stool delayed more than 2 hrs:
Cary-Blair transport
Campy thio (thio broth with 0.16% agar and
vancomycin, trimethoprim, cephalothin,
polymyxin B and amphotericin B)
Laboratory Diagnosis, cont.
Stool Culture
• Selective media and optimal conditions required
• Campy-CVA at UMHS
Brucella agar base with antibiotics
(cefoparazone, vancomycin, and amphotericin B)
5% sheep blood
• 42°C, microaerobic (10% CO2, 5% O2, 85% N2), 72 hrs
Laboratory Diagnosis, cont.
Blood Culture
• Can routinely be detected in commercial systems
• Some isolates may require 2 weeks to be detected
• Subcultures require incubation microaerobically
Laboratory Diagnosis, cont.
Microbiologic characteristics
• Growth at 42°C, microaerobically, grayish colonies
• Gram-negative bacillus; faintly staining
• Small rods, curved or seagull-winged
• Motile (darting on wet prep)
• Oxidase and catalase positive
• Reported as Campylobacter sp.
CDC Public Health Image Library (PHIL)
http://www.lf3.cuni.cz/ustavy/mikrobiologie/rep/caje.htm
Treatment
Antimicrobial Susceptibility Testing
• Standardized methods recently made available, but
not routinely performed
Therapy
• Susceptible to macrolides, tetracyclines,
aminoglycosides, and quinolones
• Erythromycin is drug of choice for severe GI illness,
with Ciprofloxacin as an alternative
• Parenteral therapy required for systemic infections
Legionella sp.
Species isolated
from humans
Species isolated from
environment only
L. pneumophila, serotypes 1-15
L. micdadei
L. bozemanii
L. dumoffii
L. feelei
L. gormanii
L. hackeliae
L. longbeachae
L. oakridgensis
L. wadsworthii
L. cherrii
L. erythra
L. gratiana
L. jamestowniensis
L. brunensis
L. brunensis
L. fairfieldensis
L. santicrusis
• Over 40 species in the genus
• L. pneumophila is the predominant pathogen
Epidemiology and pathogenesis
• Ubiquitous in environment; primarily aquatic habitat
• Widely distributed in natural and man-made environments
• Acquired environmentally, not person-to-person
• Exposure through inhalation of aerosolized organisms
• Can infect and multiply within free-living parasites
- survival in environment
• Resist destruction following phagocytosis
- survival in host
Clinical characteristics
• Causative agent of Legionnaires’ Disease
- identified in 1976 following outbreak of
severe respiratory illness at an American
Legion convention in Philadelphia
- organism did not grow on routine media
- identification required months by CDC
• Fever, pneumonia; case-fatality rate of 10-20%
Clinical characteristics, cont.
• Pontiac fever
- identified in Pontiac, MI
- self-limiting, not-fatal respiratory infection
• Other infections
- wound abscesses, encephalitis, endocarditis
Clinical characteristics, cont.
• Highest at-risk populations
Immunocompromised
Heavy smoker
Over age 60
• Same organisms may manifest itself differently in
different individuals
• Also impacted by baseline immunity and dose
Laboratory Diagnosis
Specimen collection
• Respiratory tract specimens
- sputum, BAL, pleural fluid
• Blood, tissue, biopsy material
Specimen processing
• Standard precautions (BSC)
• Concentration of dilute specimens
Laboratory Diagnosis, cont.
Direct detection
• DFA for organism in respiratory specimens
• Urine antigen test
Immunochromatographic commercial test
Only detects L. pneumophila, serogroup 1
Legionella DFA
Legionella Urine Ag
Laboratory Diagnosis, cont.
Culture
• Include Buffered Charcoal Yeast Extract (BCYE) Agar
Charcoal to detoxify specimen
Cysteine
Inhibitors (polymixin B, anisomycin, cefamandole)
• Incubate 35 – 37°C, room air, for 7-10 days
Laboratory Diagnosis, cont.
Identification
• Small, gray-white to blue-green colonies
wet, ground-glass speckling
• Gram stain yields thin, gram-negative rods
• ID of colony using FA reagents
• Report as Legionella sp.
Colonies on
BCYE
http://www.rivm.nl/infectieziektenbulletin/bul1212/diagnose_en_preventie.html
Gram stain
http://reaannecy.free.fr/Documents/infectio/legionellose.htm
Laboratory Diagnosis, cont.
Serodiagnosis
• Turkey RBCs sensitized with Legionella antigens
• Set up in pools for screening purposes
• Incubate with patient serum and look for agglutination
• Test against individual antigens for type-specificity
• Only available at MDCH
Treatment
Antimicrobial Susceptibility Testing
• In vitro results do not correlate with clinical outcome,
so not routinely performed
Therapy
• Azithromycin is effective against this and other causes
of “atypical pneumonia”
• Fluoroquinolone for severely ill
• Penicillins, cephalosporins, and aminoglycosides are
not effective
Bartonella sp.
Organism
Resevoir
Transmission
Disease(s)
B. bacilliformis
?humans
Sand flies
Carrión’s disease
B. quintana
?humans
?rodents
Human body
louse
Trench fever, relapsing
fever, bacteremia,
endocarditis, bacillary
angiomatosis,
lymphadenopathy
B. henselae
Domestic
cats
Cat bites or
scratches
Cat-scratch disease,
bacteremia, endocarditis,
bacillary angiomatosis,
peliosis hepatitis
• Bartonella currently includes 16 species, only 5 cause human disease
Epidemiology and pathogenesis
• Agent primarily of zoonotic infections
• Increasing in importance as a pathogen in
immunocompromised hosts
• Pathogenesis is not well understood, but diseases
caused by all species seem to be pathologically similar
Clinical characteristics
• Trench fever (B. quintana)
- transmitted from infected body louse
- affected many soldiers in battle
- influenza-like headache, bone pain,
splenomegaly, maculopapular rash
Clinical characteristics
• Cat-scratch disease (B. henselae)
- papule or pustule develops at site
of cat bite/scratch
- regional tender lymphadenopathy develops
in 1-7 weeks
- disease ranges from chronic, self-limited
adenopathy, to severe systemic illness
Cat-scratch disease
Los Angeles Co. West Vector Control District
http://www.lawestvector.org/bartonella.htm
http://www.uvp5.univ-paris5.fr/
MICROBES/Diagnostic/Bartonella/Bartonella.asp
Clinical characteristics
• Bacillary angiomatosis (B. quintana and B. henselae)
- vascular proliferative disease (organisms
stimulate angiogenesis)
- small papules enlarge to form red – purple nodules
- can occur on the skin surface, in subcutaneous
tissue, or in visceral organs
- primarily seen in HIV+; some reports in transplant
patients
Bacillary angiomatosis
http://www.emedicine.com/derm/topic44.htm
Laboratory Diagnosis
Specimen collection
• Blood, tissue, biopsy material
Direct detection
• Histopathologic detection in tissue using WarthinStarry silver stain
• PCR for detection in tissue and body fluids
Demonstration of Bartonella henselae in cardiac valve of a
patient with blood culture-negative endocarditis. The bacilli
appear as black granulations (Warthin Starry, original
magnification X250).
http://www.cdc.gov/ncidod/eid/vol8no2/01-0141-G2.htm
Laboratory Diagnosis, cont.
Culture
• Fastidious organism; culture infrequently performed
Laboratory Diagnosis, cont.
Serodiagnosis
• Main method for diagnosis
• IFA using antigen prepared from co-cultures
• HIV-infected patients may not mount an antibody
response to infection
Treatment
Antimicrobial Susceptibility Testing
• In vitro testing is difficult because of limited availability
of strains and fastidious nature of organism
Therapy
• Aminoglycosides, beta-lactam agents, erythromycin,
and doxycycline
• At-risk individuals should avoid exposures to cats