Not normally isolateable

Usually gram variable

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

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

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

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

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

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

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

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

Causes Whipples disease, stain with Periodic

Acid Schiff Stain ( PAS )