Frequently used therapeutic antimicrobials and their resistance patterns on Staphylococcus aureus and Escherichia coli in mastitis affected lactating cows

Abstract

Mastitis is one of the most frequent and costly production diseases of dairy cattle. It is frequently treated with broad-spectrum antimicrobials. The objectives of this work were to investigate the prevalence of Staphylococcus aureus and Escherichia coli , find out the antimicrobials used in mastitis treatment, and explore the antimicrobial resistance profile including detection of resistance genes. Bacterial species and antimicrobial resistance genes were confirmed by the polymerase-chain reaction. A total of 450 cows were screened, where 23 (5.11%) and 173 (38.44%) were affected with clinical and sub-clinical mastitis, respectively. The prevalence of S. aureus was 39.13% (n = 9) and 47.97%(n = 83) while, E. coli was 30.43% (n = 7) and 15.60% (n = 27) in clinical and sub-clinical mastitis affected cows, respectively. The highest antimicrobials used for mastitis treatment were ciprofloxacin (83.34%), amoxycillin (80%) and ceftriaxone (76.67%). More than, 70% of S. aureus showed resistance against ampicillin, oxacillin, and tetracycline and more than 60% of E. coli exhibited resistance against oxacillin and sulfamethoxazole-trimethoprim. Selected antimicrobial resistance genes ( mec A, tet K, tet L, tet M, tet A, tet B, tet C, sul 1, sul 2 and sul 3) were identified from S. aureus and E. coli . Surprisingly, 7 (7.61%) S. aureus carried the mec A gene and were confirmed as methicillin-resistant S. aureus (MRSA). The most prevalent resistance genes were tet K 18 (19.57%) and tet L 13 (14.13%) for S. aureus , whereas sul 1 16 (47.06%), tet A 12 (35.29%), sul 2 11 (32.35%) and tet B 7 (20.59%) were the most common resistance genes in E. coli . Indiscriminate use of antimicrobials and the presence of multidrug-resistant bacteria suggest a potential threat to public health.

Antimicrobial resistance and molecular characterization of Escherichia coli isolated from bovine mastitis samples in Nghe An province, Vietnam

“…The target of SUL, and the basis for their selectivity, is the enzyme dihydropteroate synthase in the folic acid pathway [ 52 ]. Our study found that 26% and 30% of isolates carried sul 1 and sul 2 genes ( Table-5 ), which was supported by a study in Bangladesh with 47.1% and 32.4% abundance, respectively [ 51 ]. The resistance to β-lactam antibiotics in pathogens from livestock has been continuously reported in recent years [ 53 , 54 ], and predominantly ESBLs produced from E. coli are considered a key resistance mechanism [ 55 ].…”

“…The antimicrobial resistance profile is helpful for understanding the pathogenesis of E. coli infection in bovine mastitis [ 49 ]. Some studies have shown that the tet A gene is more prevalent than the tet B gene in E. coli strains [ 11 , 44 , 50 , 51 ], and our results ( Table-5 ) were different with similar proportions in both tet A and tet B ( Figure-3 ). Our study revealed that six isolates that carried tet A were tetracycline-resistant, similar to the isolates that carried tet B, but none of the tetracycline-resistant isolates harbored both these genes.…”

Prevalence, Virulence, and Antimicrobial Resistance of Major Mastitis Pathogens Isolated from Taiwanese Dairy Farms

“…(45.20%) and Staphylococcus spp. (43.75%) and one-third of coliforms (31.57%) developed resistance to ampicillin, as observed in previous findings on Staphylococcus and coliforms [22,24], while contrasting with the findings of [13] regarding Streptococcus. Ampicillin intramammary ointment is highly accessible for mastitis treatments in Taiwan; therefore, bacteria are likely to develop resistance against ampicillin on dairy farms.…”

“…showed a negative correlation between phenotypic and genotypic antimicrobial resistance to tetracycline; however, a previous study found a positive correlation in Staph. aureus [24].…”

Zinc Oxide Nanoparticles Promise Anticancer and Antibacterial Activity in Ovarian Cancer

“…Regarding E. coli, the highest resistance was observed against oxacillin (64.71%) and ampicillin (58.82%) antibiotics. Oproxamitelly 30% of E. coli isolates were resistant to ceftriaxone, ciprofloxacin and cefaclor [ 60 ]. That supported the urgent need for exploring alternative antibacterial agents to avoid AMR phenomena.…”