To investigate the occurrence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and their clonal relationships from hospital and municipal wastewater treatment plants (WWTPs). 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, bla_KPC (55%), bla_NDM (27.8%) and bla_OXA-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). 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.

Pseudomonas aeruginosa is an opportunistic pathogen commonly associated with nosocomial infections and environmental dissemination. Among its high-risk clones, ST244 is notable for its global distribution and distinctive genomic traits. This study reports whole-genome sequencing of ten ST244 isolates from hospitalized patients and wastewater in a healthcare complex in Southeastern Brazil. Genomic comparisons revealed a highly conserved clonal group, with nine isolates forming a tight monophyletic cluster based on rMLST, SNP phylogeny, and average nucleotide identity (>99.5%). One isolate showed close phylogenetic proximity to strains from Asia and North America, suggesting international dissemination. Serotype analysis revealed both O5 and O12 variants, indicating intra-lineage antigenic diversity. Resistance profiling identified multidrug-resistant phenotypes carrying carbapenemase genes (bla_OXA-494, bla_OXA-396) and diverse insertion sequences (ISPa1, ISPa6, ISPa22, ISPa32, and ISPa37), facilitating horizontal gene transfer. Virulence gene analysis showed conserved elements related to adhesion, iron uptake, secretion systems, and quorum sensing, while the cytotoxin gene exoU was absent. These results highlight clonal persistence, possible intra-hospital transmission, and links to globally circulating ST244 sublineages. Our findings underscore the importance of genomic surveillance to track high-risk P. aeruginosa clones at the clinical–environmental interface.

This study investigated the phylogenetic relatedness of multi-drug resistant Elizabethkingia anophelis recovered from an industrial effluent treatment plant (WWTPi). The wastewater samples were plated in Brain Heart Infusion agar (4 mg/L ceftazidime, 8 mg/L meropenem and 2 mg/L polimixin). Four isolates recovered from four stages of WWTPi (influent, aeration, decantation and treated effluent) were identified and evaluated of susceptibility profiles in the VITEK 2 system. These strains identified as E. meningoseptica were confirmed to be E. anophelis by whole genomic sequencing (Miseq-Illumina) and showed antimicrobial resistance genes of β-lactams, aminoglycosides, and tetracycline's classes. The rMLST showed that they belong to the rST 65620 together with clinical strains. The phylogenomic tree revealed the similarity of our strains to those belonging to sublineage 11 and the SNP analysis confirmed that they belong to a single clade. To the best of our knowledge, this is the first study reporting the persistence of multidrug-resistant E.anophelis sublineage 11 along the wastewater treatment.

Wastewater treatment plants (WWTPs) are important interfaces for the persistence and dissemination of antimicrobial resistance genes (ARGs) in the environment. This study investigated colistin resistance and the presence of mobile colistin resistance (mcr) genes in Enterobacterales isolated from a poultry slaughterhouse WWTP in Brazil. Samples were collected from raw sewage, an equalization tank, and treated effluent. A total of 27 Enterobacter spp. isolates were identified, of which 70.4% showed resistance to colistin (MIC range: 2 to ≥512 mg/L). PCR screening detected mcr-1 in two isolates and mcr-10 in three isolates distributed across all treatment stages, including the final effluent. Whole-genome sequencing of a representative isolate from treated effluent identified Enterobacter vonholyi ST3343, carrying a plasmid-borne mcr-10 gene on an ~107 kb IncFII(Yp) plasmid, along with additional resistance determinants. Phylogenetic analysis supported the classification of this gene as a novel allele, mcr-10.6. The persistence of a clonal lineage harboring mcr-10.6 throughout the treatment system indicates that conventional wastewater treatment may not effectively eliminate clinically relevant ARGs. These findings highlight treated effluent as a potential route for environmental dissemination of colistin resistance and reinforce the need for improved monitoring and mitigation strategies within a One Health framework.

. Uropathogenic Escherichia coli (UPEC) poses a significant public health challenge due to increasing antimicrobial resistance (AMR) and severe infections. This study aimed to investigate the genetic heterogeneity and AMR mechanisms of a clinical UPEC strain associated with a fatal healthcare-associated infection. . Whole-genome sequencing (WGS) was performed on a multidrug-resistant (MDR) UPEC strain isolated from a pediatric patient by using an Illumina Miseq platform. The genome was assembled using Unicycler v0.4.8 and was annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). Genomic analysis included characterization of the resistome, virulome, and phylogenetic profile using various bioinformatics tools such as ResFinder v4.7.2, VFDB, and PubMLST. . The isolate has a genome with a size of 4,681,240 bp, a GC content of 50.60% and harbor seven plasmids. Genomic analysis revealed multiple genetic determinants contributing to a multidrug-resistant profile, including efflux systems, enzymatic target alterations, and antibiotic transporter modifications. Adhesin genes (fimH, afaA-D, lpfA, fdeC, csgA), hemolysins (hlyE, hlyF), iron acquisition systems (iucC, iutA, sitA), and genes related to antimicrobial peptide degradation (ompT, traJ) and colicin production (cma, cvaC) were identified. Resistance to heavy metals (tellurium, copper/silver, arsenic) was also detected. These findings characterize the isolate as a highly virulent, multidrug-resistant, and environmentally resilient emerging UPEC clone. . This study highlights the convergence of virulence, AMR, and environmental adaptability in an ST131-H30 UPEC strain. The findings underscore the critical need for comprehensive genomic surveillance, infection control strategies to mitigate the public health impact of MDR E. coli.