Temporo-spatial variations in resistance determinants and clonality of Acinetobacter baumannii and Pseudomonas aeruginosa strains from Romanian hospitals and wastewaters

Abstract

Background Romania is one of the European countries reporting very high antimicrobial resistance (AMR) rates and consumption of antimicrobials. We aimed to characterize the AMR profiles and clonality of 304 multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) strains isolated during two consecutive years (2018 and 2019) from hospital settings, hospital collecting sewage tanks and the receiving wastewater treatment plants (WWTPs) located in the main geographical regions of Romania. Methods The strains were isolated on chromogenic media and identified by MALDI-TOF-MS. Antibiotic susceptibility testing and confirmation of ESBL- and CP- producing phenotypes and genotypes were performed. The genetic characterization also included horizontal gene transfer experiments, whole-genome sequencing (WGS), assembling, annotation and characterization. Results Both clinical and aquatic isolates exhibited high MDR rates, especially the Ab strains isolated from nosocomial infections and hospital effluents. The phenotypic resistance profiles and MDR rates have largely varied by sampling point and geographic location. The highest MDR rates in the aquatic isolates were recorded in Galați WWTP, followed by Bucharest. The Ab strains harbored mostly blaOXA-23, blaOXA-24, blaSHV, blaTEM and blaGES, while Pa strains blaIMP, blaVIM, blaNDM, blaVEB, blaGES and blaTEM, with high variations depending on the geographical zone and the sampling point. The WGS analysis revealed the presence of antibiotic resistance genes (ARGs) to other antibiotic classes, such as aminoglycosides, tetracyclines, sulphonamides, fosfomycin, phenicols, trimethoprim-sulfamethoxazole as well as class 1 integrons. The molecular analyses highlighted: (i) The presence of epidemic clones such as ST2 for Ab and ST233 and ST357 for Pa; (ii) The relatedness between clinical and hospital wastewater strains and (iii) The possible dissemination of clinical Ab belonging to ST2 (also proved in the conjugation assays for blaOXA-23 or blaOXA-72 genes), ST79 and ST492 and of Pa strains belonging to ST357, ST640 and ST621 in the wastewaters. Conclusion Our study reveals the presence of CP-producing Ab and Pa in all sampling points and the clonal dissemination of clinical Ab ST2 strains in the wastewaters. The prevalent clones were correlated with the presence of class 1 integrons, suggesting that these isolates could be a significant reservoir of ARGs, being able to persist in the environment.

Whole-Genome Sequencing-Based Resistome Analysis of Nosocomial Multidrug-Resistant Non-Fermenting Gram-Negative Pathogens from the Balkans

“…In order to estimate the effects of the high consumption of antimicrobials in Romania on the AMR profile of NFGNBs, Gheorghe-Barbu et al sequenced the genomes of 34 MDR A. baumannii and 20 MDR P. aeruginosa strains [ 130 ]. These isolates were recovered in the 2018–2019 period from hospital settings, hospital collecting sewage tanks, and the receiving wastewater treatment plants located in seven different geographic locations, and the sequencing was performed by Illumina MiSeq (2 × 300 bp).…”

“…A major limitation of this study is the way of presenting the results from the resistome analyses. It is focused entirely on summarization of all data into a single table and suffers by the insufficient description of the individual isolates and their AMR determinants [ 130 ]. Despite that, it successfully demonstrates how WGS could provide important information about AMR determinants’ transmission from the hospital environment to wastewater.…”

Wastewater treatment plants, an “escape gate” for ESCAPE pathogens

“…A study performed on A. baumannii isolated in 2018 and 2019 from hospital settings, hospital collecting sewage tanks, and the receiving WWTPs located in the central geographical regions of Romania has shown that the strains isolated from hospital effluents belonged to epidemic clones, such as ST2 and exhibited high MDR rates. The WGS analysis revealed the relatedness between clinical and hospital wastewater strains and the possible dissemination of clinical A. baumannii belonging to ST2 in the wastewater ( Gheorghe-Barbu et al, 2022 ).…”

“…The analysis of MDR P. aeruginosa strains isolated during two consecutive years (2018 and 2019) from hospital settings and hospital collecting sewage tanks. WWTPs located in the central geographical regions of Romania have revealed the presence of epidemic clones ST233, and ST357 in the wastewater and the release of P. aeruginosa strains belonging to ST357, ST640c, and ST621 from hospitals into the wastewaters ( Gheorghe-Barbu et al, 2022 ).…”

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

“…It frequently causes pulmonary infections and septicemia in immunocompromised patients [ 231 ]. Its antibiotic resistance and increased survival in harsh environments [ 232 , 233 , 234 ] further enhance its pathogenicity. At the moment, the results of the kaempferol-containing compounds against this pathogen are quite promising, and this can be important in the face of ever-increasing antibiotic resistance [ 96 , 215 ].…”