Abstract
We studied 12 coryneform isolates having similar biochemical profiles which did not permit their assignment to any recognized taxa. Human semen was the source for seven of these strains, whereas the other strains were isolated from urethra, urine, and blood specimens of adult male patients. These bacteria were found in significant quantities (10(4) to 10(5) CFU/ml) in semen specimens from infertile male patients with the diagnosis of prostatitis. These strains had characteristics of the genus Corynebacterium, such as 60 mol% G + C in the DNA and corynemycolic acids, meso-diaminopimelic acid, arabinose, and galactose in the cell wall. Quantitative DNA-DNA hybridizations (S1 nuclease procedure) and phylogenies based on comparisons of almost-complete small-subunit ribosomal DNA sequences confirmed that these strains constitute a single new species within the genus Corynebacterium. All 12 strains showed similar phenotypic features, i.e., good growth on sheep blood agar in contrast with poor growth on the same medium supplemented with 1% Tween 80, a positive CAMP test in the presence of Staphylococcus aureus, glucose and sucrose fermentation, and the presence of beta-glucuronidase. Some strains reduced nitrate and hydrolyzed urea or esculin. These features allowed us to distinguish these strains from members of any other coryneform taxon, and the proposed name is Corynebacterium seminale with strain IBS B12915 (CIP 104297) as the type strain. The description and delineation of these strains as a new species should be useful for further studies, including evaluations of their prevalence among the normal flora and their clinical implications.