Yuexia Ding1,2, Junli Zhao3, Xiuling He1,2, Man Li1,2, Hong Guan1,2, Ziying Zhang4, Peifeng Li1,2. 1. a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China . 2. b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China . 3. c Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences , Hohhot , Inner Mongolia Autonomous Region , PR China , and. 4. d College of Basic, Inner Mongolia Medical University , Hohhot , Inner Mongolia Autonomous Region , PR 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 β-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.
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 β-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.
Authors: Norhan K Abd El-Aziz; Ahmed M Ammar; El-Sayed Y M El-Naenaeey; Hend M El Damaty; Asmaa A Elazazy; Ahmed A Hefny; Asmaa Shaker; Ibrahim E Eldesoukey Journal: BMC Vet Res Date: 2021-03-31 Impact factor: 2.741
Authors: Ahmed H Abed; Ahmed M S Menshawy; Mohamed M A Zeinhom; Delower Hossain; Eman Khalifa; Gamal Wareth; Mohamed F Awad Journal: Microorganisms Date: 2021-05-29