Antibiotic resistance in coagulase negative staphylococci isolated from wastewater and drinking water

Abstract

This study reports the antibiotic resistance patterns of coagulase negative staphylococci (CNS) isolated from a drinking water treatment plant (WTP), a drinking water distribution network, responsible for supplying water to the consumers (WDN), and a wastewater treatment plant (WWTP), responsible for receiving and treating domestic residual effluents. Genotyping and the 16S rRNA gene sequence analysis demonstrated a higher diversity of species both in the WTP (6 species/19 isolates) and WWTP (12 species/47 isolates) than in the WDN (6 species/172 isolates). Staphylococcus pasteuri and Staphylococcus epidermidis prevailed in the WTP and WDN and Staphylococcus saprophyticus in the WWTP. Staphylococci with reduced susceptibility (resistance or intermediary phenotype) to beta-lactams, tetracycline, clindamycin and erythromycin were observed in all types of water and belonged to the three major species groups. The highest resistance rate was found against erythromycin, presumably due to the presence of the efflux pump encoded by the determinant msrA, detected in the majority of the resistant isolates. This study demonstrates that antibiotic resistant CNS may colonize different types of water, namely drinking water fulfilling all the quality standards.

Antibiotic resistance of enterococci, coagulase negative staphylococci and Staphylococcus aureus isolated from chicken meat

“…Under other circumstances, some species of coagulase-negative staphylococci can present a medical risk. Some coagulase-negative staphylococci (CNS) may behave as opportunistic pathogens, often introduced by medical devices or colonising exposed wounds (Veras et al 2008;Faria et al 2009).…”

“…Preliminary characterisation included Gram staining and tests for cytochrome c oxidase, catalase, and coagulase (Faria et al 2009). …”

“…Even though CNS opportunistic infections are most of the times regarded as being of environmental origin, the distribution and antibiotic resistance patterns of these organisms in the environment are poorly characterised (Veras et al 2008;Faria et al 2009). …”

Virulence factors and antimicrobial resistance of coagulase-negative staphylococci isolated from drinking water

“…The occurrence of staphylococci has mainly been reported in polluted surface water [40] or in the biofilm from hospital wastewater [41]. In this study, eight out of ten species of coagulase-negative staphylococci identified (except for S. caprae and S. chromogenes) were also isolated from samples of drinking water and wastewater in Portugal [42]. The authors of the Portuguese study report dominance of S. pasteuri and S. epidermidis in samples taken from a drinking water treatment plant as well as from a drinking water distribution network.…”

“…In contrast, none of the 57 CoNS isolates tested in the present study were resistant to gentamicin. Another study which isolated CoNS from Portuguese water supplies [42] found that antibiotic-resistant CoNS may colonize different types of water, including drinking water that fulfills all the quality standards. In agreement with our results, the Portuguese study also found CoNS species were resistant to β-lactams, tetracycline, clindamycin and erythromycin, the last of which was highly prevalent (34.7%).…”