Legionella pneumophila is a fastidious, aerobic bacterium that stains poorly and requires special staining techniques. It can cause pneumonia by growing in warm, moist environments like air conditioning systems and shower heads. It is susceptible to erythromycin and other drugs. Several other Bartonella species can cause diseases in humans transmitted via insect bites like trench fever. Bacterial vaginosis is associated with Gardnerella vaginalis, which is detected in wet smears as it covers vaginal cells. It has a fishy odor and high pH. Metronidazole is used to treat it.

1. Not normally isolateable
Usually gram variable

2.  L. pneumophila is the prototype bacterium of
this group
 Fastidious, aerobic and stains poorly with
gram stain
 Basic fuchsin must be used as a counterstain
 Can be grown in buffered charcoal-yeast
extract (BCYE), pH 6.9, 35 degrees & 90%
humidity
 Catalase positive & oxidase positive

3.  Ubiquitous in warm and moist environment
 Can multiply in free living amoebas and
coexist with them in biofilms
 Contamination from inhalation from
airconditioning systems, shower heads
 Causes pneumonia and lesions within
phagocytic cells
 Susceptible to erythromycin and other drugs
such as Rifampin

4.  B. bacilliformis – causes Oroya fever
 B. quintana – causes trench fever
 B. henselae – Cat scratch fever
 Pleaomorphic and slow growing, difficult to
isolate in the laboratory
 Can be seen in infected tissues stained with
Warthin-Starry silver impregnation stain

5.  Caused by Bartonella, is a disease
predominantly of immunosuppressed
individuals, particularly AIDS patients
 Present as an enlarging red ( cranberry like )
papule, often with surrounding scale and
erythma
 Clinical appearance similar with Kaposi’s
sarcoma, form of the disease is called
peliosis hepatis

6.  Serologically distinct organism isolated in the
female genitourinary tract and associated
with vaginosis ( no inflammatory cells )
 In wet smears, the bacterial vaginosis yields
clue cells ( vaginal epithelial cells covered
with many gram variable bacilli
 Vaginal discharge often have a strange fishy
odor with pH over 4.5
 Drug of choice is oral metronidazole

7.  Motile, curved, gram variable, anaerobic
rods isolated from “bacterial vaginosis”
 Possibly part of the vaginal normal anaerobic
flora
 The organisms are most commonly detected
but grow with difficulty in aerobic cultures

8.  Aerobic, highly pleomorphic organism that
forms irregular chains of bacilli interspersed
with fusiform enlargements and large round
bodies
 Mesophilic, in media with serum, protein,
egg yolk, starch & ceases to grow at 22 C
 Normal inhabitants of rat throats, and
humans can be infected with rat bites
characterized by septic fever, petechial
rashes, and a very painful polyarthritis

9.  C. granulomatis, related to Klebsiella and
causes granuloma inguinale, an uncommon
STD characterized by genital ulcers.
 Hard to culture even with media enriched
with egg yolk
 Effective treatment with ampicillin and
tetracycline
 CausesWhipples disease, stain with Periodic
Acid Schiff Stain ( PAS )