Characterization of an unclassified microaerophilic bacterium associated with gastroenteritis

Abstract

Four isolates of an unclassified microaerophilic bacterium resembling Campylobacter species were characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, and protein profile analysis. The unclassified isolates were differentiated from Campylobacter jejuni, Campylobacter coli, Campylobacter fetus subsp. fetus, Campylobacter laridis, Campylobacter pylori, and an ovine isolate. The bacterium was fusiform shaped with a corrugated surface due to the presence of periplasmic fibers and had multiple bipolar flagella. Biochemically, the bacterium was separated from the Campylobacter controls by its negative catalase reaction, negative nitrate reduction, and no growth in 1% glycine. It was also resistant to ampicillin. Protein profile analysis demonstrated nine major protein bands present in the unclassified isolates that were absent in the Campylobacter controls. The bacterium also differed from the ovine isolate by its negative catalase reaction, rapid urea hydrolysis, and susceptibility to clindamycin, erythromycin, and tetracycline. Our results showed that the unclassified bacterium was distinct from the recognized Campylobacter species.

Isolation and characterization of "Flexispira rappini" from laboratory mice

“…The organism grew as a thin, spreading film on the surface of the plate. Optimal growth occurred under microaerophilic conditions on plates that had not been predried as described previously (1,16). The organism did not grow under anaerobic conditions, nor did it grow in the presence of ambient concentrations of 02.…”

“…Organisms typically had between five and nine 38-nm-wide sheathed flagella originating from each pole, but some organisms with tufts of flagella at only a single pole were found. The periplasmic fibers coiling around the bacterial protoplasmic cylinder gave the surface of the organism a criss-cross appearance, which is characteristic of both "F. rappini" (1,9) and H. muridarum (16,18).…”

“…The murine isolate grew under microaerophilic conditions, but not under strict anaerobic conditions or in air, as has been described for both H. muridarum (12,16) and "F. rappini" (1). The original ovine isolate of "F. rappini" has been described as an anaerobic bacterium (9), but Archer et al (1) could not grow this organism anaerobically. The murine isolate was negative for catalase, as were the human isolates of "F. rappini," while the sheep isolate of "F. rappini" is catalase positive (1).…”

Helicobacter pylori Induces Inflammation in Mouse Urinary Bladder and Pelvis

“…Similar pH change was observed in experimental infection of human stomach ( 10). This organism has been characterized to be strikingly urease positive (1,4,9). The enzyme hydrolyzes urea, generating ammonia, which may cause direct cellular injury or be toxic to intercellular junctions.…”

Helicobacter muricola sp. nov., a novel Helicobacter species isolated from the ceca and feces of Korean wild mouse (Mus musculus molossinus)

“…Both species were isolated from the livers of animal with hepatitis [8,9]. H. rappini is associated with abortion in sheep and intestinal disease in animals and humans [10], and was also isolated from the colons and ceca of mice [11]. Recently, urease-negative H. typhlonicus was isolated from interleukin-10-de¢cient mice with colitis and typhlitis, and also from immunode¢cient CB-17 scid/scid mice [12,13].…”