Fecal matter is considered as one of the worst pollutants in waterbodies due to the potential spread of waterborne diseases. This study aimed to determine the host-specific fecal contamination in two Brazilian watersheds and to predict the possible impacts on human health. Fecal sources were enumerated using host-specific genetic markers to swine (16S rRNA), human and bovine (archaeal nifH), and equine (archaeal mcrA). A single cycling condition was established for four markers aiming to decrease the analysis time. Fifteen samples from São João watershed (75%) and 25 from Guandu (62.5%) presenting Escherichia coli enumeration in compliance with Brazilian guidelines (<1,000 MPN/100 mL) showed the human marker. Furthermore, the bovine, swine, and equine markers were present in 92% (59/64), 89% (57/64), and 81% (52/64) of the water samples, respectively. The molecular markers proposed for qPCR in our study were sensitivity and specific enough to detect host-specific fecal pollution in all samples regardless of E. coli levels reaffirming the low correlation among them and supporting their use in water quality monitoring programs. To our knowledge, this is the first study using this approach for quantification of nifH, mcrA, and rrs gene-associated human and animal fecal pollution in waters intended for drinking water supply in Brazil.
Aims
To investigate the occurrence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and their clonal relationships from hospital and municipal wastewater treatment plants (WWTPs).
Methods and Results
Eighteen K. pneumoniae strains recovered from three WWTPs were identified by MALDI-TOF. The antimicrobial susceptibility were evaluated by disk-diffusion and the carbapenemases production by Carbapenembac®. The carbapenemases genes were investigated by real-time PCR and the clonal relationship through multi-locus sequence typing (MLST). Thirty nine percent (7/18) of isolates were classified as multidrug-resistant (MDR), 61.1% (11/18) extensively drug-resistant (XDR) and 83.3% (15/18) showed carbapenemase activity. Three carbapenemase-encoding genes were found, blaKPC (55%), blaNDM (27.8%) and blaOXA-370 (11.1%) as well five sequencing types ST11, ST37, ST147, ST244 and ST281. ST11 and ST244, sharing four alleles were grouped into clonal complex 11 (CC11).
Conclusions
Our results show the importance of monitoring antimicrobial resistance in WWTPs effluents to minimize the risk of spreading bacterial load and ARGs in aquatic ecosystems, using advanced treatment technologies to reduce these emerging pollutants at WWTPs.
The emergence of vancomycin-resistant Enterococcus faecium (Efm) harboring vanA gene and multidrugresistant determinants is a relevant public health concern. It is an opportunistic pathogen responsible for nosocomial infections widely distributed in the environment, including wastewater treatment plants (WWTPs). Our study addresses a genomic investigation of vanA-carrying Efm from WWTPs in Brazil. Samples from five WWTPs supplied with sewage from different sources were evaluated. Here we present whole-genome sequencing of eight vanA-Efm isolates performed on Illumina MiSeq platform. All these isolates presented multidrugresistant profile, and five strains were from treated wastewater. Multiple antimicrobial resistance genes (ARGs) were found, such as aph(3¢)-IIIa, ant(6¢)-Ia, erm(B), and msrC, some of them being allocated in plasmids. The virulence profile was predominantly constituted by efaAfm and acm genes and all isolates, except for one, were predicted as human pathogens. Multilocus sequence typing analysis revealed a new allele and five different STs, three previously described (ST32, ST168, and ST253) and two novel ones (ST1893 and ST1894). Six strains belonged to CC17, often associated with hospital outbreaks. As far as our knowledge, no genomic studies of vanA-Efm recovered from WWTPs revealed isolates belonging to CC17 in Brazil. Therefore, our findings point to the environmental spread of Efm carrying multiple ARGs.
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