Characteristic profiles of biofilm, enterotoxins and virulence of Staphylococcus aureus isolates from dairy cows in Xinjiang Province, China

Abstract

As an important zoonotic pathogen, Staphylococcus aureus has led to serious mastitis and endometritis in infected dairy cows. In this study, a total of 164 strains of S. aureus were isolated from dairy cows in Xinjiang Province, China, and subjected to assays to determine drug susceptibility and biofilm (BF) formation ability. Enterotoxin-related genes were detected, and the transcription levels of genes related to BF formation were determined by using reverse transcription-quantitative polymerase chain reaction. Moreover, the pathogenicity of isolates with different BF formation abilities was determined by measuring their hemolysis activity, half lethal dose (LD50) and organ bacterial load. The results showed that 86.0% of S. aureus isolates could form BF. Among them, 42.1% of the strains had weak BF formation ability, and most strains with a strong BF formation ability were ica gene carriers. The S. aureus isolates displayed multidrug resistance and their drug resistance was positively correlated with their BF formation ability. Moreover, 96.3% of the S. aureus isolates carried enterotoxin genes. Among them, the detection rates of the novel enterotoxin genes were higher than those of conventional enterotoxin genes. Furthermore, isolates with a strong BF formation ability had higher LD50 but lower hemolysis ability and organ bacterial load than those of the isolates with weak or no BF ability. However, isolates without BF ability produced more severe pathological changes than those of isolates with strong BF formation ability. These findings suggest that higher BF ability and presence of novel enterotoxin genes are important characteristics of S. aureus isolates from dairy cows in Xinjiang Province, China, and such isolates may pose potential threats to food safety.

Biofilm Production Ability, Virulence and Antimicrobial Resistance Genes in Staphylococcus aureus from Various Veterinary Hospitals

“…The presence of ST88 isolates carrying lukS/F-PV gene in veterinarians reminded us that humans could be reservoirs of PVL-positive S. aureus isolates and were at risk of infecting with PVL-positive S. aureus. Most of the previous studies focused primarily on SEs causing Staphylococcal food poisoning (SFP) [45][46][47][48][49][50]. Our results showed that SEs genes (sea, seb, sed-sej, seg-sei-sem-sen-seo, seh and sek) expressed specific host specificity.…”

Biofilm Formation of Staphylococcus aureus from Pets, Livestock, and Wild Animals: Relationship with Clonal Lineages and Antimicrobial Resistance

“…Concordant results were obtained by Rodríguez-López et al, who studied the presence of biofilm-forming MRSA in pigs and showed that, although most isolates were biofilm-producers, most of the producers displayed low levels of biofilm production [ 52 ]. Studies conducted with S. aureus isolated from dairy also showed that most isolates were weak-biofilm producers [ 56 , 57 , 58 ]. In our study, S. aureus isolates colonizing wild animals were strong biofilm producers.…”

Therapeutic potential of a designed CSαβ peptide ID13 in Staphylococcus aureus-induced endometritis of mice

“…Antibiotics are widely used in the clinical prevention and treatment of endometritis, which has increased the emergence of antibiotic-resistant bacteria, especially multidrug resistant (MDR) bacteria (Eslami et al 2015). It has been found that S. aureus is resistant to tetracycline (43.5%), penicillin (81%), erythromycin (44.5%), clindamycin (51.2%), and ciprofloxacin (30%) (Wu et al 2019). Meanwhile, the traditional screening of new antibacterial has suffered a considerable decline (da Cunha et al 2017).…”