Coagulase gene polymorphism, enterotoxigenecity, biofilm production, and antibiotic resistance in Staphylococcus aureus isolated from bovine raw milk in North West India

Abstract

Background Staphylococcus aureus is the predominant bacterium responsible for various diseases in animals and humans. Preventive strategies could be better implemented by understanding the prevalence, genetic patterns, and the presence of enterotoxin and biofilm-producing genes along with the antibiotic susceptibility of this organism. This study was conducted in Rajasthan, the northwestern state of India, holding the largest population of cattle that makes it the second largest milk producer in India and no such prior information is available on these aspects.MethodsA total of 368 individual quarter bovine raw milk samples were collected from 13 districts of Rajasthan, and screened for the presence of S. aureus. Microbiological and molecular approaches were followed for bacterial identification. Genetic diversity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) of coagulase gene (coa), whereas enterotoxin and biofilm-producing genes were studied by PCR analysis. Antibiotic strips were employed to study the antibiotic resistance among strains.ResultsIn all, 73 S. aureus strains were obtained from 368 bovine raw milk samples out of that only 30 showed the presence of coa. Nine types of coa patterns ranging from 730 to 1130 bp were observed among these isolates. PCR–RFLP of coa distinguished the isolates into 15 genotypic patterns, of which patterns I, IV, V, and VI were predominant. Of the isolates, 30% were positive for sec, 10% for sea, and 3.3% for seb; these genes are responsible for enterotoxin production, whereas all isolates were found positive for icaAD and eno. The prevalence rates of other biofilm-producing genes fnbA, clfB, ebpS, sasG, fnbB, sasC, cna, bap, fib and, bbp were 97, 93, 90, 80, 80, 77, 53, 27, 10, and 6.6%, respectively. Twenty-seven (90%) strains were multidrug resistant, of which 15 were methicillin resistant. Maximum sensitivity was reported for kanamycin and it could be considered as a drug of choice for controlling S. aureus mediated cattle infections in the studied regions.ConclusionsOverall, these strains could cause several diseases to humans, insisting the need for developing a stricter hygiene program for improving milking practices and animal health.

Diverse Profiles of Biofilm and Adhesion Genes in Staphylococcus Aureus Food Strains Isolated from Sushi and Sashimi

“…In this study, our findings are in agreement with Tang, Chen, Li, Zeng, and Li (2013), who observed that contributions of adhesion genes vary greatly within strains. Among 15 MSCRAMMS tested genes, eno (96%), clfB (94%), and icaBC (94%) genes were found at a high prevalence and our results are in accordance with the findings of Tang et al (2013) and Sharma et al (2017). The eno gene encodes a laminin binding protein which is expressed on the surface of S. aureus.…”

“…() and Sharma et al. (). The eno gene encodes a laminin binding protein which is expressed on the surface of S. aureus .…”

Staphylococcus aureus Isolates from Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes

“…Among the 120 isolates analyzed, only 17 (14%) were not enterotoxigenic (1 from Argentina, 1 from Colombia, 2 isolates from Germany, 3 from Italy, 1 from New York State, 1 from South Africa, and 8 from Tunisia). The remaining 103 isolates (86%) harboured a combination of at least 2 up to 5 enterotoxins with the linkages between sea , sed , seg and seh confirming their predominance in cows, as previously described [ 21 , 22 , 23 , 24 ]. The absence of the enterotoxin genes seb and see in our isolates was in accordance with previous results [ 15 , 22 , 25 , 26 ].…”

Diversity of antibiotic‐resistant Shiga toxin‐producing Escherichia coli serogroups in foodstuffs of animal origin in northern India

“…The current study highlights the prevalence of antibiotic‐resistant STEC serogroups in the northern regions of India, other studies have also reported the prevalence of other antibiotic resistance foodborne pathogens, Staphylococcus aureus , Listeria monocytogenes , and Campylobacter jejuni (Khan et al, ; Sharma et al, , ), within the food chain in the north India, which further highlight the significance and importance of controlling the use of antibiotics in agriculture, as well as improving the hygiene practices in public and the food industry.…”

“…Staphylococcus aureus, Listeria monocytogenes, and Campylobacter jejuniSharma et al, 2017aSharma et al, , 2017b, within the food chain in the north India, which further highlight the significance and importance of controlling the use of antibiotics in agriculture, as well as improving the hygiene practices in public and the food industry.…”