Phenotypic and genotypic study on antibiotic resistance and pathogenic factors of <em>Staphylococcus aureus</em> isolates from small ruminant mastitis milk in South of Italy (Sicily)

Abstract

Staphyloccoccus aureus is the major cause of mastitis in small ruminants in the Mediterranean farms causing severe losses to dairy industry. Antibiotic treatment has been the most common approach to control these infections. Aim of this study was to investigate antimicrobial resistance (AMR), virulence factors and biofilm-related genes of 84 Sicilian strains of S. aureus isolated from sheep and goats milk during two different periods δT1 (2006-2009) and δT2 (2013-2015). Kirby Bauer method and Polymerase Chain Reaction (PCR) were utilized to monitor AMR and related genes (mecA, tetK, tetM, ermA, ermC). Moreover, toxin genes (tsst-1, sea-see, seg-sej, and sep) and biofilm genes (bap, ica, sasC) were studied. Twenty-six isolates (30.9%) showed multidrug resistance. The two groups showed similar results with exception for higher values of resistance for tilmicosin and lower for sulfamethoxazole and vancomycin of the second group. MecA gene was detected in one isolate. Tetracycline resistance was higher than 20%, with an increase in δT2 group. Toxin genes were found in 5 isolates (5.9%), belonging of δT2 group, while 57 of isolates (67.8%) showed biofilm related genes. The high presence of multi-resistant isolates suggests the need of more responsible use of antibiotic therapy for the control of these infections.

Multiple antibiotic resistance and virulence factors of Staphylococcus aureus strains isolated from dairy farms in South Sulawesi, Indonesia

“…Staphylococcus aureus isolates from animals (raw milk) did not harbor mecA and mecC, similar to the findings of a previous study (Andrade et al 2021). In contrast, Parco et al (2021) reported the isolation of S. aureus strains from milk samples that harbor mecA. In this study, the mecA gene was detected in S. aureus from a human sample.…”

Whole Genome Sequencing Identifies Enterotoxigenic and Antimicrobial Resistance Potential of Staphylococcus aureus from Maine Dairy Farms

“…As with SEs, WGS is bene cial for identi cation of AMR genes. WGS enables comprehensive analysis of complete virulence and antimicrobial resistance gene pro les without the labor and expenses that limit such analysis through traditional methods (12) and avoids false-negative results possible in PCR-based identi cation methods (13).…”