Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/1996
Publication Date: N/A
Interpretive Summary: The intestines of mammals and birds contain many different kinds of bacteria. Most of these bacteria are necessary in the digestive process or keep harmful organisms from growing and making the animals sick. Occasionally, some bacteria and other organisms are unhealthy for the animal. Recently, new bacteria have been discovered in the intestines of chickens and other birds. These bacteria are corkscrew-shaped (spirochetes). However, what they are (classification) or what they do (ecology) is not known. This study used a sophisticated molecular technique to determine the genetics of these spirochetes, or in other words determined what they are. The spirochetes were classified into several existing or new species of spirochetes within the genus Serpulina. Some of the spirochetes caused disease in chickens while others were harmless. This data will help veterinarians distinguish between different t spirochetes from the intestines of birds and determine the role of intestinal spirochetes in producing diarrhea or other intestinal diseases.
Technical Abstract: Multilocus enzyme electrophoresis (MEE) analyzed the extent of genetic diversity among 56 intestinal spirochetes isolated from chickens in Australia, the USA and the Netherlands. Strength of beta-hemolysis on blood agar, indole production, API-ZYM enzyme profiles, and cellular morphology also were determined. The isolates from chickens were shown to be genetically heterogeneous. They were divided into 40 electrophoretic types distributed among six diverse genetic groups (b to g), and had a mean genetic diversity of 0.587. Two of these groups, d and e, may represent new species of Serpulina, and contained only strains isolated from chickens. Three separate genetic groups contained isolates previously shown to be pathogenic for chickens. These corresponded to the proposed species "Serpulina intermedius", to an unnamed group (e), and to Serpulina pilosicoli. Two of the chicken isolates were strongly beta-hemolytic (one "S. intermedius" and one S. pilosicoli isolate), two had an intermediate level of beta-hemolysis (both "S. intermedius"), and the rest were weakly beta-hemolytic. Fourteen isolates of "S. intermedius" produced indole, as did one isolate from group d. Isolates identified as S. pilosicoli resembled procine isolates of this species, having four to six periplasmic flagella and having tapered cell ends. All other spirochetes had seven or more periplasmic flagella and had blunt cell ends.