Antimicrobial resistance and virulence-related genes ofStreptococcusobtained from dairy cows with mastitis in Inner Mongolia, China

Abstract

Context: Mastitis is the most expensive disease in the dairy cattle industry and results in decreased reproductive performance. Streptococcus, especially Streptococcus agalactiae, possesses a variety of virulence factors that contribute to pathogenicity. Objective: Streptococcus isolated from mastitis was tested to assess the prevalence of antimicrobial resistance and distribution of antibiotic resistance-and virulence-related genes. Materials and methods: Eighty-one Streptococcus isolates were phenotypically characterized for antimicrobial resistance against 15 antibiotics by determining minimum inhibitory concentrations (MIC) using a micro-dilution method. Resistance-and virulence-related genes were detected by PCR. Results: High percentage of resistance to b-lactams, along with tetracycline and erythromycin, was found. Resistance to three or more of seven antimicrobial agents was observed at 88.9%, with penicillin-tetracycline-erythromycin-clindamycin as the major profile in Streptococcus isolates. Resistant genes were detected by PCR, the result showed that 86.4, 86.4, 81.5, and 38.3% of isolates were mainly carrying the pbp2b, tetL, tetM, and ermB genes, respectively. Nine virulence genes were investigated. Genes cyl, glnA, cfb, hylB, and scaA were found to be in 50% of isolates, while 3.7, 21, and 4.9% of isolates were positive for bca, lmb, and scpB, genes, respectively. None of the isolates carried the bac gene. Discussion and conclusion: This study suggests the need for prudent use of antimicrobial agents in veterinary clinical medicine to avoid the increase and dissemination of antimicrobial resistance arising from the use of antimicrobial drugs in animals.

Mastitis treatment—Reduction in antibiotic usage in dairy cows

“…To date, the issue of resistant or multiresistant MCP such as methicillin‐resistant S. aureus (MRSA) seems to play a subordinate role in dairy industry (Erskine et al., ; Kreausukon et al., ; Oliver, Murinda, & Jayarao, ; Pol & Ruegg, ; Schröder, Hoedemaker, & Klein, ; Tenhagen et al., ). However, the number of studies reporting of enhanced emergence of AMR increases (da Costa Krewer et al., ; Ding et al., ; Fairbrother et al., ; Jagielski et al., ; Petrovski et al., ; Ruegg, Oliveira, Jin, & Okwumabua, ; Saini, McClure, Scholl, DeVries, & Barkema, ; Spohr et al., ).…”

Phenotypic and genotypic evaluation of antibiotic resistance and molecular characterization of Streptococcus species isolated from hospital cockroaches

“…This gene was also predominant in the Streptococcus spp. strains isolated from different hospital infections [43,44].…”

Determination of milk/plasma ratio and milk and plasma pharmacokinetics of amoxicillin after intramuscular administration in lactating cows

“…The minimum inhibitory concentration (MIC) value for amoxicillin and its combination with β‐lactamase inhibitors was above 0.25 and 0.125 μg/ml, respectively, for most susceptible bacteria (Bingen et al., ; De Oliveira, Watts, Salmon, & Aarestrup, ; Diarrassouba et al., ; Ding et al., ; Gianneechini, Concha, & Franklin, ; Li et al., ; Maisak, Tipmongkolsilp, & Wongtavatchai, ; McDougall, Hussein, & Petrovski, ; Payne et al., ). Amoxicillin level above 0.125 μg/ml was maintained for >12 hr in plasma and 8 hr in milk when the aforementioned amoxicillin MIC values were compared with the values in the present study.…”