Determination of Antimicrobial Susceptibility and Some Virulence Genes of Staphylocococcus spp. Strains Isolated from Keratoconjunctivitis Cases in Sheep and Goats

Abstract

This study aimed to isolate Staphylococcus spp. from sheep and goats clinically diagnosed with keratoconjunctivitis, and to determine their antimicrobial susceptibility. Phenotypic and genotypic characterisation of biofilm forming ability of the isolates obtained was carried out. Staphylococcus spp. strains isolated from 288 ocular swab samples were identified by MALDI-TOF MS. Antimicrobial susceptibilities of the isolates were determined by the using disk diffusion method. The Congo-red agar method was used to determine the ability to form biofilms. The presence of genes associated to formation of biofilm and toxin synthesis was investigated by PCR. While Staphylococcus aureus was identified in 2 of the 35 strains identified in the research, the remaining isolates were found to be coagulase-negative Staphylococcus spp. The most frequently isolated coagulase-negative strain was identified to be Staphylococcus equorum. The strains were susceptible to enrofloxacin, gentamicin, and tobramycin. While 68.57% of the isolates phenotypically formed biofilms, the AtlE gene had a high positivity rate. Furthermore, the presence of genes responsible for toxin synthesis was not identified in the strains analysed. Based on the findings of the study, it was determined that Staphylococcus spp. isolates should be considered for small ruminant keratoconjunctivitis cases. It was concluded that antimicrobial agents such as enrofloxacin, gentamicin, and tobramycin would achieve success in the treatment of the disease caused by the causative agents.