Leptospira

• Leptospira
• Leptonema

Taxonometry

The Leptospiraceae family (usually refered to by genus name Leptospira) groups a small number of both pathogenic and saprophytic microorganisms. The first Leptospira to become described - Leptospira interrogans (1907) as Spirochaeta Interrogans) was isolated from kidney tissue slices of a Leptospirosis victim. For quite a time, the genus only had two members - the pathogenic (L. interrogans) and saprophytic (L. biflexia).

The current (2004)classification of leptospira bacteria (family Leptospiraceae) is as follows:

• Genus Leptospira

Leptospira interrogans (aka Spirochaeta interrogans aka Spirochaeta icterohaemorrhagiae aka Spirochaeta icterogenes aka Leptospira icteroides)

Leptospira biflexa

Leptospira alexanderi

Leptospira borgpetersenii

Leptospira fainei

Leptospira inadai

Leptospira kirschneri

Leptospira meyeri

Leptospira noguchii

Leptospira parva

Leptospira santarosai

Leptospira weilii

Leptospira wolbachii

• Genus Leptonema

Leptonema illini

The IUMS (2002) confirmed nomenclature for leptospira is as follows: Genus species serovar Serovar_name : i.e. genus and species italicised, serovar name in plain text, genus and serovar capitalised and species lowercase. Examples include: Leptospira interrogans serovar Ballum Leptospira biflexa serovar Codice

Description

Leptospira interrogans (image courtesy of Johnson & Faine and Bergeys Manual Trust)

Leptospira interrogans (image courtesy of Johnson & Faine and Bergeys Manual Trust)

The leptospira are an extremaly varied (over 200 serovars known) group of helix-shaped motile gram-negative bacteria; if straightened, they'd measure 6-20 μm long and 0.1-0.15μm in diameter. The number of curls depends on the straightened length and varius up to as much as 20. The bacteria have a number of freedom degrees; when ready to proliferate via binary fision, the bacterium noticably bends in the place of the future split. Leptospira, both pathogenic and saprophytic, can occupy diverse environments, habitats and life cycles; it generally recognized these bacteria are virtually ubiquitous in terms of geographic distribution (present everywhere except Antarctica). Most of Leptospira, however, are hydrophilic - high humidity and neutral (6.9-7.4) pH are essential for their survival in the environment, with stagnant water reservoirs - shallow lakes, ponds, etc - being natural source of bacteria. Proliferation rate is typically slow; growth in an artificial nutrient environment (for L. interrogans, one typicaly contains human blood serum) becomes noticable in around 5-7 days. Parasitic species' optimal growth temperature is 28-32 degrees Celsius, while saprophytic one can grow at as low as 13 degrees Celsius. Due to high variance of the pathogens, leptospira-caused diseases leave immunity only to a particular serovar that actually caused the infection. This circumstance prevents creation of effective vaccines agains Leptospirosis