Antimicrobial resistance and virulence genes of Streptococcus isolated from dairy cows with mastitis in China. (June 2019)

• Record Type: Journal Article
• Authors: Tian, X.Y.; Zheng, N.; Han, R.W.; Ho, H.; Wang, J.; Wang, Y.T.; Wang, S.Q.; Li, H.G.; Liu, H.W.; Yu, Z.N.
• Is Part Of: Microbial pathogenesis. Volume 131(2019)
• Page Start: 33
• Page End: 39
• Publication Date: 2019-06
• Subjects: Streptococcus -- Mastitis -- Antimicrobial resistance -- Resistance genes -- Virulence gene; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2019.03.035
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Streptococcus is a major mastitis-causing pathogen in dairy cows. To investigate the prevalence, antimicrobial resistance and virulence gene of Streptococcus in mastitic milk, a total of 735 mastitic raw milk samples from dairy cows in 11 provinces of China were collected and tested. Antimicrobial resistance of Streptococcus isolates was determined by disc diffusion against 8 classes 29 antimicrobial agents, and Streptococcus resistant genes and virulence genes were determined by PCR and agarose gel electrophoresis. A total of 64 (8.71%) isolates of Streptococcus were isolated and identified using biochemical profiling, including 22 isolates of Streptococcus agalactiae, 13 isolates of Streptococcus dysgalactiae, and 29 isolates of Streptococcus uberis . Out of 64 resistant Streptococcus isolates, all isolates (100%) were resistant to 3 or more antimicrobials. The most frequency (n = 18, 28.12%) of the isolates were multi-resistant to 5–7 antimicrobials and the highest multi-resistant number was 29 (n = 1, 1.56%). Streptococcus isolates had the highest resistance rate to tetracycline (98.44%) and oxacillin (98.44%), followed by penicillin G (96.88%) and doxycycline (96.88%), and the lowest resistance was observed with respect to ciprofloxacin (1.56%). A total of 16 antimicrobials resistance genes with 25 combination patterns were detected in the isolates. The gene combination of Sul1/Sul2/Sul3 + gyrA/parC + cat1/cat2 was the most common pattern (12.5%). The correlation between resistant phenotypes and resistance genes in Streptococcs was 35.87%. A total of 7 virulence genes were detected and 59 (92.19%) isolates harbored at least one gene. Twenty-four classes of gene patterns were found in the isolates and the patterns of bca (9.38%) and cfb (9.38%) were the most prevalent form. In conclusion, the issue of drug resistance of Streptococcus is still a great concern in cattle health in China. Highlights: A total of 64 isolates of Streptococcus were isolated from 735 mastitic milk samples from 11 provinces in China. The consistency between phenotype resistance and resistance genes of Streptococcus were analyzed. The prevalent virulence genes in Streptococcus were analyzed.