Urea Utilization by Leptospira

Abstract

One representative of each of five different pathogenic serotypes of Leptospira as well as one saprophytic strain were capable of growing on medium containing urea in place of an ammonium salt as a nitrogen source. Growth of all of the organisms tested on 1% urea was substantial, but only those that exhibited strong urease activity could grow to any appreciable extent on urea at a concentration as high as 2%. Intact urea-grown cells of the pathogenic serotypes tested (grippotyphosa and icterohaemorrhagiae) exhibited urease activity, with the level of activity of the former being considerably greater. No urease could be detected in cells of the saprophytic strain. When the pathogenic leptospires were sonicated or treated with toluene, the urease activity was greatly enhanced. When cultivated

Physiology and evolution of spirochetes.

“…Representatives of different pathogenic leptospiral serotypes were found to utilize urea as a nitrogen source and to possess urease activity (102). These findings may be useful in interpreting the localization of certain leptospires in the kidney during leptospirosis.…”

Critical Knowledge Gaps in Our Understanding of Environmental Cycling and Transmission of Leptospira spp

“…These pathogenic spirochetes can live in soil with a moisture content of >20% ( 43 , 59 ), water and soil with pHs around 5.5 and 7.6 ( 43 , 59 – 62 ), and temperatures ranging from 4 to 40°C ( 36 , 60 , 63 , 64 ). Likewise, it has been reported that pathogenic Leptospira bacteria can metabolize urea ( 65 ) and that they are able to survive for 6 to 18 h in pure (pH 7 to 8) cattle urine, although longer survival times have been observed when urine is diluted ( 62 , 66 ). Also, the ability of infectious Leptospira bacteria to survive in the environment might be assisted by their ability to resist changes in osmolality ( 67 ).…”

Urease assay and urease-producing species of anaerobes in the bovine rumen and human feces

“…Whether urease formation is typical of rumen or other species of the genus Treponema is not known, but this appears to be the first report of urease formation by any spirochete other than Leptospira. Some strains of Leptospira have a urease that is strongly repressed by ammonia (20). The three strains identified asRuminococcus bromii were representative of five strains isolated from three samples from two cows on diets 65 and 66.…”