Staphylococcus spp. associated with subclinical bovine mastitis in central and northeast provinces of Thailand.

Background

Staphylococcus spp. is the main cause of bovine mastitis (BM) worldwide cause economic damage to cattle and the public health threat. More recently, a new argenteus Staphylococcus appearing to have been found as pathogens of humans and animals. molecular characteristics, virulence and Porcine Clia Kits antibiotic resistant phenotype of the bacterium that causes BM in Thailand are rare. This study aims to investigate Staphylococcus spp. cattle associated with subclinical mastitis (SCM) in Thailand.

method

Milk samples were collected from 224 cows from 52 herds of milk in four central and northeastern provinces. Total somatic cell count (SCC) and California mastitis test (CMT) is used to identify cattle SCM. Milk samples were cultured for Staphylococcus spp. coagulase-positive isolates undergo pulsed-field gel electrophoresis (PFGE) and multilokus sequence typing (MLST). The organisms are suspected as S. argenteus verified by detecting peptide synthetase gene nonribosomal. All isolates were examined for antibiograms and their various virulence genes.

result

Of the 224 samples from 224 dairy cows, 132 (59%) were positive for SCM by SCC and CMT and 229 isolates of staphylococci were recovered. They are 32 coagulase-positive (24 S. aureus and S. argenteus eight) and 197 coagulase-negative. PFGE of S. aureus and S. argenteus revealed 11 clusters and patterns of non-typeable. MLST of representatives  https://gentaur.cz/ of 11 groups PFGE, three PFGE non-typeable S. aureus isolate from different locations and S. argenteus showed 12 types of sequences. Eight S. argenteus isolates belonging to ST1223 (three isolates), ST2250 (two isolates), and ST2793 (two isolates).

 Antimicrobial test identified 11 (46%) of methicillin-resistant S. aureus and 25 (13%) coagulase-negative isolates were methicillin-resistant, while seven S. argenteus were methicillin-susceptible and one isolates were methicillin-resistant. All 229 isolates of multiply resistant to other antibiotics. The most common virulence genes of 24 S. aureus isolates were clfA, coa and spa (X and IgG-binding regions) (100%), HLA (96%), PVL (96%) and sec (79%). Six isolates of S. argenteus do an enterotoxin gene respectively and other virulence genes including coa, clfA, HLA / HLB, spa, TSST and PVL, indicating their pathogenic potential.

Conclusions and perspectives

This is the first report on S. argenteus from cow milk samples with SCM. The data on the molecular characteristics, and antibiograms virulence genes of Staphylococcus spp. obtained from this study indicate widespread and increasing the likelihood of methicillin-resistance and multiple resistance to other antibiotics. 

This shows that the "One Health" practice should be maintained, not only at the level of the dairy farm, but also at the national or even international level through cooperation of various sectors (dairy farmers, veterinarians, medical personnel and medical community and scientists) in order to effectively combat and control the spread of this pathogen.