Antimicrobial Resistance and Virulence Genes inEnterococcus faeciumandEnterococcus faecalisfrom Humans and Retail Red Meat

Abstract

The emergence of antimicrobial-resistant and virulent enterococci is a major public health concern. While enterococci are commonly found in food of animal origin, the knowledge on their zoonotic potential is limited. The aim of this study was to determine and compare the antimicrobial susceptibility and virulence traits of Enterococcus faecalis and Enterococcus faecium isolates from human clinical specimens and retail red meat in Slovenia. A total of 242 isolates were investigated: 101 from humans (71 E. faecalis, 30 E. faecium) and 141 from fresh beef and pork (120 E. faecalis, 21 E. faecium). The susceptibility to 12 antimicrobials was tested using a broth microdilution method, and the presence of seven common virulence genes was investigated using PCR. In both species, the distribution of several resistance phenotypes and virulence genes was disparate for isolates of different origin. All isolates were susceptible to daptomycin, linezolid, teicoplanin, and vancomycin. In both species, the susceptibility to antimicrobials was strongly associated with a food origin and the multidrug resistance, observed in 29.6% of E. faecalis and 73.3% E. faecium clinical isolates, with a clinical origin (Fisher’s exact test). Among meat isolates, in total 66.0% of E. faecalis and E. faecium isolates were susceptible to all antimicrobials tested and 32.6% were resistant to either one or two antimicrobials. In E. faecalis, several virulence genes were significantly associated with a clinical origin; the most common (31.0%) gene pattern included all the tested genes except hyl. In meat isolates, the virulence genes were detected in E. faecalis only and the most common pattern included ace, efaA, and gelE (32.5%), of which gelE showed a statistically significant association with a clinical origin. These results emphasize the importance of E. faecalis in red meat as a reservoir of virulence genes involved in its persistence and human infections with reported severe outcomes.

Occurrence, Antimicrobial Resistance and Molecular Diversity of Enterococcus faecium in Processed Pork Meat Products in Korea

“…In this study, E. faecium and E. faecalis were observed in 15.3% and 20.2% of the processed pork meat products, while a previous study suggested that E. faecium and E. faecalis was detected in 11.3% and 69.5% of red meat [11]. In Argentinean artisanal dry fermented sausages, the most frequently isolated enterococci was E. faecium (56%), followed by E. faecalis (17%) and other species (E. durans, E. casseliflavus, and E. mundtii) [21].…”

“…Interestingly, the prevalence of E. faecium in the total sample was 15.3% (Table 1), but E. faecium was isolated from 68.8% of the FP samples, which suggested that some of the common ingredients might be contaminated with E. faecium, or E. faecium might be cross-contaminated from processing environments, including water. Other enterococci, including E. avium, E. raffinose, E. casseliflavus, E. gallinarum, E. durans, were also isolated from processed pork meat products, which is supported by the previous study on the isolation of enterococci, i.e., Enterococcus spp., including E. hirae, E. casselifavus, E. durans, E. devriesei, E. gilvus, E. mundtii, and E. thailandicus, which were also isolated from beef and pork samples [11]. SRP and SSP contained a variety of ingredients including seasoning and fresh vegetables such as garlic, green onion and onions, and thus, different enterococci might originate from seasoning and raw vegetables.…”

“…Enterococci play a beneficial role in the production of traditional fermented foods, giving unique organoleptic properties [5,10]. However, their ability to harbor and easily acquire virulence and antibiotic resistance genes through horizontal gene transfer hampers their use as probiotics or as starter/adjunct cultures in foods [11].…”

Improved detection of esp, hyl, asa1, gelE, cylA virulence genes among clinical isolates of Enterococci

“…As reported earlier, hyl was detected only in E. faecium [33]. Nevertheless, a few studies have reported the incidence of hyl in both species [29,[34][35][36][37][38][39]. Significant difference was observed in the VF score between species.…”

“…Nevertheless, the presence of virulence determinants in the clinical isolates might contribute to increased severity as they could be expressed under optimum conditions in vivo. Metadata of the previous studies on the detection of virulence genes of enterococci by multiplex/duplex/simplex PCR is depicted in Additional file 1: Table S1 [18,27,29,[33][34][35][36][37][38][39][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59].…”