A seasonal study of the mecA gene and Staphylococcus aureus including methicillin-resistant S. aureus in a municipal wastewater treatment plant

Abstract

The spread of methicillin-resistant Staphylococcus aureus (MRSA), in which the mecA gene mediates resistance, threatens the treatment of staphylococcal diseases. The aims were to determine the effect of wastewater treatment processes on mecA gene concentrations, and the prevalence of S. aureus and MRSA over time. To achieve this a municipal wastewater treatment plant was investigated for the mecA gene, S. aureus and MRSA, using real-time PCR assays. Water samples were collected monthly for one year, at eight sites in the plant, reflecting different aspects of the treatment process. The mecA gene and S. aureus could be detected throughout the year at all sampling sites. MRSA could also be detected, but mainly in the early treatment steps. The presence of MRSA was verified through cultivation from inlet water. The concentration of the mecA gene varied between months and sampling sites, but no obvious seasonal variation could be determined. The wastewater treatment process reduced the mecA gene concentration in most months. Taken together our results show that the mecA gene, S. aureus and MRSA occur over the year at all sites investigated.

Prevalence of norovirus and factors influencing virus concentrations during one year in a full-scale wastewater treatment plant

“…(Börjesson et al, 2008) Concentration of virus using ultracentrifugation 14 ml of the wastewater sample was put into a 15 ml falcon tube and centrifuged at 3000 x g at 4ºC for 10 minutes. The supernatants were poured into a 13.5 ml Ultra-Clear™ ultracentrifuge tube (Beckman-Coulter, Stockholm, Sweden) and centrifuged at 180 000 x g for 2 h. The supernatants were discarded and the pellet redissolved in 500 µl RNAse free water.…”

Impact of type of wastewater treatment process on the antibiotic resistance of bacterial populations

“…These ARB are characterized by higher resistance to antibiotics due to the transfer of genes between bacteria present in the wastewater [19]. Their higher number is still observed in the treated sewage [20,21], which can be transferred to subsequent environments, posing a potential threat to their safety and public health. Therefore, in this article we compare the use of various modifications of the wastewater treatment technologies based on activated sludge in the removal of both the total number of antibiotic-resistant bacteria and E. coli resistant to the most commonly used class of antibiotics which are beta-lactams and tetracyclines.…”

The Effect of Primary, Secondary, and Tertiary Wastewater Treatment Processes on Antibiotic Resistance Gene (ARG) Concentrations in Solid and Dissolved Wastewater Fractions

“…Presently there is no consensus as to whether ARGs are selected for or against during wastewater treatment with published reports illustrating both scenarios [17,20,24,54,[64][65][66][67][68][69]. However, the activated sludge treatment stage in particular, has been proposed as a potential source for ARG transfer [56].…”