Environmental enterococci: I. Prevalence of virulence, antibiotic resistance and species distribution in poultry and its related environment in Karachi, Pakistan

Abstract

Significance and Impact of the Study: This study demonstrates that poultry environment of Karachi city harbours a diverse reservoir of Enterococcus spp. with multiple antibiotic resistance and virulence determinants. It is expected that the results will help in assessing the impact of multiple antibiotic resistance and virulent enterococci on public health, improvement of farm management practices and preventing their dissemination. Our findings strongly suggest the need for reducing antibiotic usage during poultry production, particularly those that are being used to treat human infections. AbstractEnterococci are well-established causative agents of a number of diseases in humans and animals alike. A total of 1047 isolates (838 presumptive enterococci and 209 non-enterococci), related to poultry environment (faeces/ manure, feed, water and air), were evaluated for species diversity, virulence potential, antibiotic resistance and associated threats. Multiplex PCR of 204 presumptive enterococci using genus (16s rDNA)-and species-specific (superoxide dismutase) primer set leads to identification of six Enterococcus spp., i.e. Ent. faecium, Ent. faecalis, Ent. mundtti, Ent. hirae, Ent. gallinarum and Ent. casseliflavus. BOX-PCR analysis of the representative strains confirmed inter-strain variation among species. Although enterococci generally appear to be catalase negative, Ent. faecalis from some faecal, water and air samples showed catalase production. In vitro assays identified poultry environment as a reservoir of MVD and MAR enterococci and non-enterococci. In addition to vancomycin, high-level-ampicillin-, clarithromycin-, erythromycin-, kanamycinand gentamicin-resistant enterococci and non-enterococci are also indicated. Our results show that virulence potential and resistance vary with the source of isolation. Our studies on MAR and MVD enterococci in environment, especially in air and water, clearly indicate the need for a serious commitment to deal with pathogenic enterococci associated with poultry for preventing transmission of infectious agent to humans.

Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry

“…Enterococcus faecium and E. faecalis are usually the most prevalent enterococcal species among isolates recovered from environmental samples such as poultry faeces/manure, feed, water and air (Yoshimura et al, 2000;Ruzauskas et al, 2009;Ali et al, 2013;Furtula et al, 2013), but very few data are available on enterococci from internal organs of healthy or diseased poultry (Tankson et al, 2002;Maasjost et al, 2015). In contrast to these data, the results obtained in this study indicate that E. faecalis accounted for the highest percentage of enterococci isolated from the internal organs of poultry, followed by E. faecium.…”

“…This is why we observed low resistance to florfenicol in E. faecium (8.6%), E. hire (9.5%), E. cecorum (10.8%), E. gallinarum (12%) and E. faecalis (17.5%). Higher resistance to chloramphenicol in E. faecium (80.8%) and E. faecalis (21.2%) isolated from chicken faeces was observed by Ali et al (2013).…”

The unravelled Enterococcus faecalis zoonotic superbugs: Emerging multiple resistant and virulent lineages isolated from poultry environment

“…A dark red pure colony per sample was obtained after streaking on Slanetz and Bartley agar (SBA) plate (Oxoid, UK). Air samples were collected using Petri dishes (100 mm diameter) containing freshly prepared SBA as described by Ali, Hasan, Bin‐Asif, and Abbasi (). E. faecalis strains were sub‐cultured in brain heart infusion broth (BHI, Oxoid, UK) and subjected for molecular characterization, virulence assays, anti‐biogram profiling and molecular characterization of genotypes associated with them.…”

“…The cell‐free lysates were used as genomic DNA for all polymerase chain reactions optimized in reduced volumes (8–19 μl), simplex (sPCR) and multiplex PCR (mPCR) using Master cycler ProS Eppendorf, Germany (Iyavoo et al, ; Olsen et al, ). All primer sets used in this study were synthesized from Europhins (Operon, USA), and stock/working solutions were prepared in Tris‐EDTA buffer (Ali et al, ).…”

“…Bacteriocinogenic activity of E. faecalis strains against E. faecium NA283 and S. aureus Sau‐2 was evaluated by agar overly method as described previously (Gebreyohannes, Moges, Sahile, & Raja, ). For the production of secretory proteases, the isolates were grown onto trypticase soya agar containing 3% (w/v) gelatine (Oxoid, UK) and/or 9% (v/v) human plasma (Ali et al, ).…”