Characterization of the most frequently encountered Staphylococcus sp. in the rumen of deer

The total enumeration and biotyping of staphylococci isolated from the rumen content of deer is presented in this study. The total counts of staphylococcal isolates from deer reached 1.5 x 10(3) cfu/ml. Of 960 colonies, 904 were taxonomically identified. Coagulase-negative staphylococci mainly Staphylococcus simulans and Staph. xylosus were the most frequently isolated species, followed by Staph. warneri, Staph. lentus, Staph. saprophyticus, Staph. epidermidis and Staph. hominis. Moreover, the atypical species were isolated, such as Staph. chromogenes, Staph. capitis, Staph. caseolyticus and Staph. auricularis. Except Staph. aureus, no coagulase-positive staphylococci were found. The strain identified showed high resistance to vancomycin (61.2%) and to chloramphenicol (41.9%). The resistance to erythromycin and bacitracin was demonstrated in 16.1% and 35.5% of isolates. On the other hand, 99% of isolates were sensitive to gentamycin, 96% to linkomycin, 93% to methicilin and 87% of isolates were sensitive to bacitracin and virginiamycin. The mean value of lactic acid production was 0.446 +/- 0.026 mol/l. The majority of strains belonged to ureolytic bacteria with low urease production. However, eight different species showed urease activity higher than 30 nkat/ml. No bacteriocin active strain was detected by indicator organisms used. Although the percentage of nonidentifiable strains was high (64.7%), the detection of different species improved and confirmed species variability in the rumen microbial ecosystem of deer as well as in total. Moreover, additional tests are under way, especially those regarding bacteriocin production.