Search

Enterococcus spp. are opportunistic pathogens that cause lameness in broiler chickens, resulting in serious economic losses worldwide. Virulence of Enterococcus spp. is associated with several putative virulence genes including fsr , efm , esp , cylA , cad1 , ace , gelE , and asa1 . In this study, multiplex polymerase chain reaction (PCR) for the simultaneous detection of these virulence genes in Enterococcus spp. was developed, and detection limits for E. faecium , E. faecalis , and E. hirae were 64.0 pg/μL, 320.0 pg/μL, and 1.6 ng/μL DNA, respectively. Among 80 Enterococcus isolates tested, efm and cad1 were detected in all 26 E. faecium samples, and only cad1 was observed in E. hirae . Additionally, the presence of virulence genes in 25 E. faecalis isolates were 100% for cad1 , 88.0% for gelE , 64.0% for fsr , 44.0% for asa1 , 16.0% for cylA , and 4.0% for esp . No virulence genes were found in E. gallinarum isolates. A total of 49 isolates were resistant to tigecycline and to at least 2 different classes of antibiotics. The most prevalent resistance was to ciprofloxacin (73.5%), quinupristin/dalfopristin (55.1%), and tetracycline (49.0%). No strains were resistant to vancomycin or linezolid. This is the first multiplex PCR assay to simultaneously detect eight virulence genes in Enterococcus spp., and the method provides diagnostic value for accurate, rapid, and convenient detection of virulence genes. Additionally, we report the prevalence of virulence genes and antimicrobial resistance in Enterococcus isolates from commercial broiler chickens suffering lameness., Competing Interests: The authors declare no conflicts of interest., (© 2019 The Korean Society of Veterinary Science.)

Bacterial chondronecrosis with osteomyelitis (BCO) is a major cause of lameness in broiler chicken, and results in serious economic losses worldwide. Although the pathogenesis mechanism leading to lameness is not entirely understood, some strains of Enterococcus sp. avian pathogenic Escherichia coli or Staphylococcus aureus have been long recognized as important causative pathogens. To prevent the progression of Enterococcus sp. avian pathogenic E. coli or S. aureus infections, we developed rapid, sensitive and convenient diagnostic assays using loop-mediated isothermal amplification (LAMP). Entero-Common-LAMP assays were developed for simultaneous detection of eight Enterococcus species. To target specific microorganisms, seven Entero-Specific-LAMP assays for E. faecalis, E. faecium, E. hirae, E. gallinarum, E. avium, E. durans and E. cecorum were developed, as well as E. coli -LAMP and S. aureus -LAMP assays. Considering the prevalence and economic impact of Enterococcus sp. E. coli and S. aureus, the 10 different LAMP assays which were developed have considerable potential as routine diagnostic methods in the field or in resource-limited environments. [ABSTRACT FROM AUTHOR]