Isolation of bacteriophage for typing Staphylococcus intermedius isolated from dogs

Abstract

Staphylococcus intermedius, a coagulase-positive staphylococcal species, is a common canine pathogen and pus-forming bacterium in skin of dogs. Bacteriophage was isolated from 32 (71.1%) of 45 samples, including 32 dog skins and 13 feces, and some of these phage isolates showed same lytic pattern on S. intermedius isolates. Therefore, finally 20 different phages were used for typing 36 S. intermedius isolates, (12 nasal discharge, 11 bacterial dermatitis, 6 otitis externa, 2 cystitis, 1 pyometra and 4 isolates from nasal cavity of healthy dog) by the agar over layer method using nutrient medium. Primary phage tirers were ranging from 10³ to 10^(7) PFU/ml but the titers were expended ranging from 2 x 10^(6) to 7 x 10^(11) PFU/ml to use as routine test dilution (RTD). Thirty-one (86.1%) of the 36 strains were typed either RTD or 100 X RTD into 25 phage patterns. Phage type (PT)-16 was the most common, but included only 4 S. intermedius isolates (11.1%). PT-8 and PT-16 have mainly participated in the respiratory disease, and PT-1 was associated with almost all kinds of diseases. Although, the bacterial lytic capability of 20 S. intemedius phage (SiP) was various, but at least SiP-1, SiP-2, SiP-3, and SiP-4 lysed many S. intermedius isolates.