Occurrence of virulent multidrug-resistant Enterococcus faecalis and Enterococcus faecium in the pigs, farmers and farm environments in Malaysia

• Published in: PeerJ (San Francisco, CA) Vol. 6; p. e5353
• Main Authors: Tan, Shiang Chiet, Chong, Chun Wie, Teh, Cindy Shuan Ju, Ooi, Peck Toung, Thong, Kwai Lin
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 06.08.2018; PeerJ, Inc; PeerJ Inc
• Subjects: Agriculture; Animal husbandry; Antibiotic resistance; Antibiotics; Antimicrobial agents; Antimicrobial resistance; Bacteria; Biofilms; Body temperature; Chemotherapy; Chloramphenicol; Ciprofloxacin; Distribution; Drug resistance; Drug resistance in microorganisms; Enterococcal infections; Enterococcus faecalis; Enterococcus faecium; Environmental factors; Erythromycin; Farmers; Farms; Feces; Food contamination & poisoning; Gel electrophoresis; Gene expression; Genetic aspects; Genotypes; Health aspects; Hogs; Human subjects; Hygiene; Livestock; Livestock farms; MDR; Microbiology; Molecular Biology; Multidrug resistance; Opportunist infection; Pathogenicity; Pigs; Polymerase chain reaction; Proteins; Public Health; Pulsed-field gel electrophoresis; Rectum; Statistical analysis; Strains (organisms); Suidae; Swine; Urine; Veterinarians; Veterinary medicine; Virulence (Microbiology); Virulence factors; Virulence genes; Malaysia; Kuala Lumpur Malaysia; United Kingdom > UK; France; Enterococcus faecalis; Pigs; Enterococcus faecium; MDR; Farmers; Virulence genes
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.5353

and are ubiquitous opportunistic pathogens found in the guts of humans and farmed animals. This study aimed to determine the occurrence, antimicrobial resistance, virulence, biofilm-forming ability and genotypes of and from swine farms. Correlations between the genotypes, virulotypes, antibiotic resistance, and the environmental factors such as locality of farms and farm hygiene practice were explored. and strains were isolated from the oral, rectal and fecal samples of 140 pigs; nasal, urine and fecal samples of 34 farmers working in the farms and 42 environmental samples collected from seven swine farms located in Peninsular Malaysia. Antibiotic susceptibility test was performed using the disk diffusion method, and the antibiotic resistance and virulence genes were detected by Polymerase Chain Reaction. Repetitive Extragenic Palindromic-Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis were performed to determine the clonality of the strains. Crosstab/Chi-square test and DistLM statistical analyses methods were used to determine the correlations between the genotypes, virulence factors, antibiotic resistance, and the environmental factors. A total of 211 and 42 were recovered from 140 pigs, 34 farmers and 42 environmental samples collected from seven swine farms in Peninsular Malaysia. Ninety-eight percent of the strains were multidrug-resistant (resistant to chloramphenicol, tetracycline, ciprofloxacin and erythromycin). Fifty-two percent of the strains formed biofilms. Virulence genes I E, , and genes were detected. Virulence genes and I were most prevalent in (90%) and (43%), respectively. Cluster analyses based on REP-PCR and PFGE showed the strains were genetically diverse. Overall, the strains isolated from pigs and farmers were distinct, except for three highly similar strains found in pigs and farmers. The strains were regional- and host-specific. This study revealed alarming high frequencies of multidrug-resistant enterococci in pigs and swine farmers. The presence of resistance and virulence genes and the ability to form biofilm further enhance the persistence and pathogenicity of the strains. Although the overall clonality of the strains were regionals and host-specific, strains with high similarity were found in different hosts. This study reiterates a need of a more stringent regulation to ensure the proper use of antibiotics in swine husbandry to reduce the wide spread of multidrug-resistant strains.