Kedi ve köpek kökenli Klebsiella pneumoniae suşlarının virülens genlerinin ve antibiyotik direnç profilinin belirlenmesi

Klebsiella pneumoniae, a multidrug-resistant pathogen, poses a significant threat in both human and animal infections. Its pathogenicity arises from various virulence factors and antibiotic resistance, leading to treatment challenges and failure. The emergence of hypervirulent K. pneumoniae strains (hvKP) in recent years, particularly affecting immunocompromised patients, heightens health risks. Virulence of hvKP is attributed to increased capsular or extracapsular polysaccharide production compared to classical K. pneumoniae (cKp), along with iron acquisition system. Key genes linked to hypermucoviscosity, including siderophore-encoding genes (e.g., enterobactin) and capsular polysaccharide regulatory genes (rmpA and rmpA2), contribute to the enhanced virulence of hvKP. Strains of hvKP possess virulence factors such as rmpA, entB, fimH, and mrkD, promoting biofilm formation and binding to the extracellular matrix. This study aimed to explore the antibiotic resistance profile and key virulence genes (magA, fimH, rpmA, mrkD, and entB) in K. pneumoniae isolates from dogs and cats in Samsun. Among 32 isolates tested for hvKP using the "string" test, only one isolate showed positive results. Antibiotic susceptibility testing revealed resistance rates, to amoxicillin+clavulanic acid 53.1%, imipenem 3.1%, ampicillin 62.5%, penicillin 43.7%, cefoperazone 12.5%, gentamicin 40.6%, amikacin 9.3%, ciprofloxacin 40.6%, enrofloxacin 37.5%, nitrofurantoin 65.6%, trimethoprim+sulfamethoxazole 37.5%, oxytetracycline 46.8%, cefquinome 34.3% and chloramphenicol 28.1%, cefquinoma, 25% cefepime and 43.75% to cefoxitin. Notably, all isolates remained susceptible to meropenem, while 62.5% exhibited a multidrug resistance profile. PCR analysis of virulence genes showed the absence of rpmA in all isolates, while magA, fimH, entB and mrkD genes were detected in 4, 9, 5, 5 and 15 isolates, respectively. The string test-positive isolate was identified to possess only the mrkD gene. In conclusion, this study indicates a low probability of hypervirulent phenotype among K. pneumoniae strains from cats and dogs. However, further investigation into genes associated with this phenotype and their correlation with antibiotic resistance profiles is warranted.