Microbiological and molecular genetic characteristics of Staphylococcus aureus isolated from raw horse meat

Abstract

Background and Aim. Staphylococcal food poisoning is caused by the consumption of food contaminated with Staphylococcus aureus and represents a global public health concern. Food products of animal origin can serve as reservoirs for multi-drug resistant strains of S. aureus. This study aimed to characterize the microbiological and molecular genetic properties of S. aureus isolated from raw horse meat.

Materials and Methods. Species identification of S. aureus was performed using 16S rRNA gene analysis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The sensitivity of the isolate to antibiotics was investigated using the disc diffusion method. Genetic determinants of resistance were identified using whole genome sequencing. High-throughput sequencing was performed on an Illumina MiSeq platform. DNA quantity was assessed spectrophotometrically, and quality was evaluated by electrophoresis on a 1% agarose gel. Genome assemblies based on short reads were obtained using SPAdes v. 4.0.0. Assembly quality assessment, organism verification, and initial annotation were performed using FastQC v.0.11.9. Antibiotic resistance genes were identified using the CARD and PATRIC databases.

Results. The S. aureus 76_KZ strain was isolated from a raw horse meat sample. Morphologically, it is a Gram-positive coccus arranged in irregular clusters resembling grape bunches. The identified antibiotic resistance profile of S. aureus 76_KZ characterizes this strain as a multidrug resistant isolate with sensitivity to a limited spectrum of antibacterial drugs. This study presents the results of wholegenome sequencing of S. aureus isolated from raw horse meat in the Republic of Kazakhstan. The sequencing yielded a genome coverage of 173×. The sequenced genome of the S. aureus 76_KZ isolate, consisting of 2.616.354 bp, has been deposited in the GenBank genetic database under accession number JBNBZR000000000.1.

Conclusion. The whole-genome data obtained for S. aureus 76_KZ enable the assessment of the isolate's resistance to antimicrobial drugs and facilitate the identification of genetic features relevant to epidemiological typing.