Antimicrobial resistance profiles of 5 common bovine mastitis pathogens in large Chinese dairy herds

Abstract

The prevalence of antimicrobial resistance (AMR) is increasing in human and animal pathogens, becoming a concern worldwide. However, prevalence and characteristics of AMR of bovine mastitis pathogens in large Chinese dairy herds are still unclear. Therefore, our objective was to determine the AMR profile of bacteria isolated from clinical mastitis in large (>500 cows) Chinese dairy herds. A total of 541 isolates of the 5 most common species, Staphylococcus aureus (n = 103), non-aureus staphylococci (NAS; n = 107), Streptococcus species (n = 101), Klebsiella species (n = 130), and Escherichia coli (n = 100), isolated from bovine clinical mastitis on 45 dairy farms located in 10 provinces of China were included. Presence of AMR was determined by minimum inhibitory concentrations using the microdilution method. Prevalence of multidrug resistance (resistance to >2 antimicrobials) was 27% (148/541). A very wide distribution of minimum inhibitory concentrations was screened in all isolates, including Staph. aureus isolates, which were resistant to penicillin (66%). In addition, NAS (30%) were more resistant than Staph. aureus to oxacillin (84%), penicillin (62%), tetracycline (34%), and clindamycin (33%). Prevalence of resistance to tetracycline was high (59%) in Streptococcus spp. Additionally, prevalence of resistance of both E. coli and Klebsiella spp. was high to amoxicillin/clavulanate potassium (81 and 38%, respectively), followed by tetracycline (only Klebsiella spp. 32%). A high proportion (27%) of isolates were multidrug resistant; the most frequent combinations were clindamycin-cefalexin-tetracycline or enrofloxacin-cefalexin-penicillin patterns for Staph. aureus; enrofloxacin-oxacillin-penicillin-tetracycline patterns for NAS; clindamycin-enrofloxacin-tetracycline patterns for Streptococcus spp.; amoxicillin/clavulanate potassiumceftiofur-polymyxin B patterns for Klebsiella spp.; and amoxicillin/clavulanate potassium-ceftiofur-polymyxin B patterns for E. coli. Resistance for 4 kinds of antimicrobials highly critical for human medicine, including daptomycin, vancomycin, imipenem, and polymyxin B, ranged from 0 to 24%. In conclusion, prevalence of AMR in mastitis pathogens was high on large Chinese dairy farms, potentially jeopardizing both antimicrobial efficacy and public health. Results of this study highlighted the need for improvements in antimicrobial stewardship and infection control programs in large Chinese dairy farms to reduce emergence of AMR.

Monitoring and Characteristics of Major Mastitis Pathogens from Bulk Tank Milk in Korea

“…In addition, Streptococcus spp. was highly resistant to clindamycin (35.5%) and this percentage was slightly higher than in reports from China (28.7%) and Argentina (25.5%) [13,43]. Resistance to chloramphenicol was also found in all mastitis pathogens in this study (2.1-26.1%), as other studies in Korea have reported [38,44].…”

“…Antimicrobial therapy is common in Korea, which is one of the key components for the control of infectious mastitis, so the emergence of the antimicrobial resistance in major mastitis pathogens such as methicillin-resistant S. aureus (MRSA) has been reported [12], and is a public health concern [13]. The dairy farm environment has also been reported as a reservoir for the distribution of antimicrobial resistance [14].…”

Insights Into the Resistome of Bovine Clinical Mastitis Microbiome, a Key Factor in Disease Complication

“…The most frequently isolated pathogens are Staphylococcus aureus, Escherichia coli, Klebsiella spp., Streptococcus spp., Mycoplasma spp., Enterobacter spp., Bacillus spp., and Corynebacterium species (Abebe et al, 2016;Gao et al, 2017;Hoque et al, 2018). Therefore, the accurate identification of pathogens that cause CM enables appropriate choices for antimicrobial treatment and preventive mastitis management (Preethirani et al, 2015;Van Boeckel et al, 2015;Cheng et al, 2019). Over the past two decades, a wide range of phenotyping and genotyping methods have been implemented to study mastitis-causing bacteria (Preethirani et al, 2015;Gao et al, 2017;Hoque et al, 2018;Cheng et al, 2019).…”

“…Therefore, the accurate identification of pathogens that cause CM enables appropriate choices for antimicrobial treatment and preventive mastitis management (Preethirani et al, 2015;Van Boeckel et al, 2015;Cheng et al, 2019). Over the past two decades, a wide range of phenotyping and genotyping methods have been implemented to study mastitis-causing bacteria (Preethirani et al, 2015;Gao et al, 2017;Hoque et al, 2018;Cheng et al, 2019). Although culture-based techniques are traditionally used to detect CM bacteria, these methods are time-consuming and have the inherent drawback of not being applicable to non-cultivable bacteria (Baron et al, 2018).…”

Rac1 signaling regulates LPS-induced mouse mastitis via inhibition of NLRP3, NF-κB and MAPK signaling pathways

“…However, the excessive use of antibiotics contributes to the development of antibiotic-resistant pathogens. In large Chinese dairy herds, the prevalence of antimicrobial resistance in mastitis pathogens is comparatively high [2]. Thus, exploring alternatives to antibiotics in mastitis therapy is urgently needed.…”