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.

Keywords

• Biofilm
• Goat
• Keratoconjunctivitis
• Sheep
• Staphylococcus spp.

Koyun ve Keçilerde Keratokonjunktivitis Olgularından İzole Edilen Staphylocococcus Spp. Suşlarının Antimikrobiyal Duyarlılığının ve Bazı Virülens Genlerinin Belirlenmesi

Abstract

Bu çalışmada koyun ve keçilerde klinik olarak tespit edilen keratokonjunktivitis olgularından Staphylococcus spp. izolasyonu ve antimikrobiyal duyarlılığının belirlenmesi amaçlandı. Elde edilen izolatlarda biyofilm oluşturma yeteneğinin fenotipik ve genotipik karakterizasyonu gerçekleştirildi. Koyun ve keçilerden alınan 288 adet göz svabı örneğinden izole edilen Staphylococcus spp. suşları MALDI-TOF MS yöntemiyle identifiye edildi. İzolatların antimikrobiyal duyarlılıkları disk difüzyon testi ile belirlendi. Biyofilm oluşturma yeteneğinin belirlenmesinde Kongo-red agar yöntemi kullanıldı. Biyofilm oluşumundan ve toksin sentezinden sorumlu gen varlığı ise PCR ile araştırıldı. Araştırmada izole edilen 35 suşun 2’si Staphylococcus aureus olarak identifiye edilirken, geri kalan izolatların koagulaz negatif Staphylococcus spp. olduğu belirlendi. Koagulaz negatif türler arasında çoğunlukla izole edilen türün Staphylococcus equorum olduğu tespit edildi. Suşlar, enrofloksasin, gentamisin ve tobramisine duyarlı bulundu. İzolatların %68.57’sinin fenotipik olarak biyofilm oluşturduğu belirlenirken, AtlE gen pozitiflik oranının da yüksek olduğu görüldü. Ancak, çalışmada biyofilm oluşturma yeteneği ile antimikrobiyal direnç profili arasında herhangi bir ilişki saptanmadı. Bununla birlikte incelenen suşlarda toksin sentezinden sorumlu gen varlığı da tespit edilmedi. Çalışmadan elde edilen bulgular doğrultusunda küçük ruminant keratokonjunktivitis olgularında Staphylococcus spp. izolatlarının göz önünde bulundurulması gerektiği belirlendi. Etkenlerin neden olduğu enfeksiyonların tedavisinde enrofloksasin, gentamisin ve tobramisin gibi antimikrobiyal maddelerin başarı sağlayacağı kanısına varıldı.

Keywords

• Biyofilm
• Keçi
• Keratokonjunktivitis
• Koyun
• Staphylococcus spp.

Ethical Statement

Bu çalışma, Siirt Üniversitesi Hayvan Deneyleri Yerel Etik Kurulu’nun 30/04/2024 tarih ve 2024/04/22 sayılı kararıyla onaylandı.

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