Prevalence, antibiotic resistance, virulence and genetic diversity of Staphylococcus aureus isolated from bulk tank milk samples of U.S. dairy herds
| Autor: | Sandra Godden, Timothy J. Johnson, K. Patel, Erin Royster, Emily A. Smith, Brian A Crooker, Srinand Sreevatsan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Methicillin-Resistant Staphylococcus aureus
Veterinary medicine Staphylococcus aureus medicine.drug_class Antibiotic resistance Antibiotics Virulence Enterotoxin Microbial Sensitivity Tests Biology QH426-470 medicine.disease_cause Genetic diversity 03 medical and health sciences medicine Prevalence Genetics Bulk tank Animals 030304 developmental biology 0303 health sciences Bovine mastitis 030306 microbiology SCCmec Genetic Variation Drug Resistance Microbial Staphylococcal Infections medicine.disease Mastitis Anti-Bacterial Agents Milk Cattle Female TP248.13-248.65 Research Article Biotechnology |
| Zdroj: | BMC Genomics, Vol 22, Iss 1, Pp 1-13 (2021) BMC Genomics |
| ISSN: | 1471-2164 |
| Popis: | Background Colonization of dairy cows by Staphylococcus aureus (S. aureus), especially those which are multi-drug resistant and toxin producing, is a concern for animal health and well-being as well as public health. The objective of this study was to investigate the prevalence, antibiotic resistance, gene content and virulence determinants of S. aureus in bulk tank milk samples (BTM) from U.S. dairy herds. Results BTM samples were collected, once in winter and once in summer, from 189 U.S. dairy herds. Of 365 BTM samples cultured, the sample and herd prevalence of S. aureus in BTM was 46.6% (170 of 365 samples) and 62.4% (118 of 189 herds), respectively. Among a subset of 138 S. aureus isolates that were stored for further analysis, 124 were genome sequenced after being confirmed as S. aureus using phenotypic tests. The most commonly identified antimicrobial resistance-associated gene was norA (99.2%) and mecA gene responsible for methicillin resistance (MRSA) was identified in one isolate (0.8%). The most frequently detected putative virulence genes were aur (100%), hlgB (100%), hlgA, hlgC, hlb (99.2%), lukE (95.9%) and lukD (94.3%). In the 53 staphylococcal enterotoxin positive isolates, sen (37.9%), sem (35.5%), sei (35.5%) and seg (33.1%) were the most frequently detected enterotoxin genes. Among the 14 sequence types (ST) and 18 spa types identified, the most common was ST2187 (20.9%) and t529 (28.2%), respectively. The most predominant clone was CC97 (47.6%) followed by CC unknown (36.3%). The single MRSA isolate belonged to ST72-CC8, spa type t126 and was negative for the tst gene but harbored all the other virulence genes investigated. Conclusion Our findings indicated a high prevalence of S. aureus in BTM of U.S. dairy herds, with isolates showing little evidence of resistance to antibiotics commonly used to treat mastitis. However, isolates often carried genes for the various enterotoxins. This study identified predominant genetic clones. Despite lower prevalence, the presence of MRSA and multi-drug resistant strains in BTM poses a significant risk to animal and public health if their number were to increase in dairy environment. Therefore, it is necessary to continuously monitor the use of antibiotics in dairy cows. |
| Databáze: | OpenAIRE |
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