Curved Gram Negative Rods - Borrelia, Leptospira, and Vibrio

Borrelia

fast moving spirochete; transmitted by ticks/louse

Borrelia burgdorferi

causes Lyme Disease; can lead to relapsing fever

Lyme Disease

an endemic inflammatory disorder; starts with bulls eye rash at the site of tick bite (erythema migrans); can cause chronic arthritis

What is the history of Lyme disease?

in 1975 a mother in Lyme, CT reported several cases of juvenile arthritis amongst children, leading to an investigation

Leptospira

tightly coiled spirochete w/ hooked ends; causes leptospirosis; pathogenic species are always fresh water

Leptospirosis

occurs when broken skin is exposed to animal urine (rats), or ingestion of contaminated water/soil

What is the best specimen for lab identification of Leptospira?

urine

Weil’s disease

caused by Leptospira; causes liver and kidney failure

How can Leptospira be grown in the lab, diagnosed, and treated?

Leptospira must grow at 30 degrees on special media; can be observed in urine using a dark field microscope; serology; treated with penicillin

Vibrio

curved rods; all species tolerant to salt; found in fresh or salt water; oxidase positive; easy to culture

Vibrio cholerae

causes cholera; symptoms include loose “rice water” stools progressing to water and vomiting, NO FEVER

How should cholera be treated?

Electrolyte replacement therapy

Cholera Toxin

enterotoxin that causes the hypersecretion of water and electrolytes; activates adenylate cyclase which converts ATP to cAMP

Vibrio parahaemolyticus

the most common cause of gastroenteritis in Japan; only found in salt water

Vibrio vulnificus

can be acquired by eating raw oysters or swimming with open wounds; causes most seafood related deaths in US