# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1218 | 0 | 0.9748 | Whole genome sequencing snapshot of multi-drug resistant Klebsiella pneumoniae strains from hospitals and receiving wastewater treatment plants in Southern Romania. We report on the genomic characterization of 47 multi-drug resistant, carbapenem resistant and ESBL-producing K. pneumoniae isolates from the influent (I) and effluent (E) of three wastewater treatment plants (WWTPs) and from Romanian hospital units which are discharging the wastewater in the sampled WWTPs. The K. pneumoniae whole genome sequences were analyzed for antibiotic resistance genes (ARGs), virulence genes and sequence types (STs) in order to compare their distribution in C, I and E samples. Both clinical and environmental samples harbored prevalent and widely distributed ESBL genes, i.e. blaSHV, blaOXA, blaTEM and blaCTX M. The most prevalent carbapenemase genes were blaNDM-1, blaOXA-48 and blaKPC-2. They were found in all types of isolates, while blaOXA-162, a rare blaOXA-48 variant, was found exclusively in water samples. A higher diversity of carbapenemases genes was seen in wastewater isolates. The aminoglycoside modifying enzymes (AME) genes found in all types of samples were aac(6'), ant(2'')Ia, aph(3'), aaD, aac(3) and aph(6). Quinolone resistance gene qnrS1 and the multi-drug resistance oqxA/B pump gene were found in all samples, while qnrD and qnrB were associated to aquatic isolates. The antiseptics resistance gene qacEdelta1 was found in all samples, while qacE was detected exclusively in the clinical ones. Trimethroprim-sulfamethoxazole (dfrA, sul1 and sul2), tetracyclines (tetA and tetD) and fosfomycin (fosA6, known to be located on a transpozon) resistance genes were found in all samples, while for choramphenicol and macrolides some ARGs were detected in all samples (catA1 and catB3 / mphA), while other (catA2, cmIA5 and aac(6')Ib / mphE and msrE) only in wastewater samples. The rifampin resistance genes arr2 and 3 (both carried by class I integrons) were detected only in water samples. The highly prevalent ARGs preferentially associating with aquatic versus clinical samples could ascribe potential markers for the aquatic (blaSHV-145, qacEdelta1, sul1, aadA1, aadA2) and clinical (blaOXA-1, blaSHV-106,blaTEM-150, aac(3)Iia, dfrA14, oqxA10; oqxB17,catB3, tetD) reservoirs of AR. Moreover, some ARGs (oqxA10; blaSHV-145; blaSHV-100, aac(6')Il, aph(3')VI, armA, arr2, cmlA5, blaCMY-4, mphE, msrE, oqxB13, blaOXA-10) showing decreased prevalence in influent versus effluent wastewater samples could be used as markers for the efficiency of the WWTPs in eliminating AR bacteria and ARGs. The highest number of virulence genes (75) was recorded for the I samples, while for E and C samples it was reduced to half. The most prevalent belong to three functional groups: adherence (fim genes), iron acquisition (ent, fep, fyu, irp and ybt genes) and the secretion system (omp genes). However, none of the genes associated with hypervirulent K. pneumoniae have been found. A total of 14 STs were identified. The most prevalent clones were ST101, ST219 in clinical samples and ST258, ST395 in aquatic isolates. These STs were also the most frequently associated with integrons. ST45 and ST485 were exclusively associated with I samples, ST11, ST35, ST364 with E and ST1564 with C samples. The less frequent ST17 and ST307 aquatic isolates harbored blaOXA-162, which was co-expressed in our strains with blaCTX-M-15 and blaOXA-1. | 2020 | 31999747 |
| 5261 | 1 | 0.9746 | Prevalence of antibiotic resistance genes from effluent of coastal aquaculture, South Korea. The wide use of antibiotics in aquaculture for prophylactic and therapeutic purposes can potentially lead to the prevalence of antibiotic resistance genes (ARGs). This study reports for the first time the profile of ARGs from effluents of coastal aquaculture located in South Jeolla province and Jeju Island, South Korea. Using quantitative PCR (qPCR), twenty-two ARGs encoding tetracycline resistance (tetA, tetB, tetD, tetE, tetG, tetH, tetM, tetQ, tetX, tetZ, tetBP), sulfonamide resistance (sul1, sul2), quinolone resistance (qnrD, qnrS, aac(6')-Ib-cr), β-lactams resistance (bla(TEM), bla(CTX), bla(SHV)), macrolide resistance (ermC), florfenicol resistance (floR) and multidrug resistance (oqxA) and a class 1 integrons-integrase gene (intI1) were quantified. In addition, Illumina Miseq sequencing was applied to investigate microbial community differences across fish farm effluents. Results from qPCR showed that the total number of detected ARGs ranged from 4.24 × 10(-3) to 1.46 × 10(-2) copies/16S rRNA gene. Among them, tetB and tetD were predominant, accounting for 74.8%-98.0% of the total ARGs. Furthermore, intI1 gene showed positive correlation with tetB, tetD, tetE, tetH, tetX, tetZ tetQ and sul1. Microbial community analysis revealed potential host bacteria for ARGs and intI1. Two genera, Vibrio and Marinomonas belonging to Gammaproteobacteria, showed significant correlation with tetB and tetD, the most dominant ARGs in all samples. Also, operational taxonomic units (OTUs)-based network analysis revealed that ten OTUs, classified into the phyla Proteobacteria, Cyanobacteria/Chloroplast, Bacteroidetes, Verrucomicrobia and an unclassified phylum, were potential hosts of tetracycline resistance genes (i.e., tetA, tetG, tetH, tetM, tetQ and tetZ). Further systematic monitoring of ARGs is warranted for risk assessment and management of antibacterial resistance from fish farm effluents. | 2018 | 29031406 |
| 5262 | 2 | 0.9742 | High abundances of class 1 integrase and sulfonamide resistance genes, and characterisation of class 1 integron gene cassettes in four urban wetlands in Nigeria. There is little information about environmental contamination with antibiotic resistance genes (ARG) in Sub-Saharan Africa, home to about 1 billion people. In this study we measured the abundance of three genes (sul1, sul2, and intI1) used as indicators of environmental contamination with ARGs in the sediments of four urban wetlands in southwestern Nigeria by qPCR. In addition, we characterised the variable regions of class 1 integrons in sulfamethoxazole/trimethoprim (SMX/TRI)-resistant bacteria isolated from the wetlands by PCR and DNA sequencing. The indicator ARGs were present in all wetlands with mean absolute copy numbers/gram of sediment ranging between 4.7x106 and 1.2x108 for sul1, 1.1x107 and 1x108 for sul2, and 5.3x105 and 1.9x107 for intI1. The relative abundances (ARG/16S rRNA copy number) ranged from about 10-3 to 10-1. These levels of ARG contamination were similar to those previously reported for polluted environments in other parts of the world. The integrase genes intI1 and intI2 were detected in 72% and 11.4% SMX/TRI-resistant isolates, respectively. Five different cassette array types (dfrA7; aadA2; aadA1|dfrA1; acc(6')lb-cr|arr3|dfrA27; arr3|acc(6')lb-cr|dfrA27) were detected among 34 (59.6%) intI1-positive isolates. No gene cassettes were found in the nine intI2-positive isolates. These results show that African urban ecosystems impacted by anthropogenic activities are reservoirs of bacteria harbouring transferable ARG. | 2018 | 30496274 |
| 833 | 3 | 0.9742 | Diverse gene cassettes in class 1 integrons of facultative oligotrophic bacteria of River Mahananda,West Bengal, India. BACKGROUND: In this study a large random collection (n=2188) of facultative oligotrophic bacteria, from 90 water samples gathered in three consecutive years (2007-2009) from three different sampling sites of River Mahananda in Siliguri, West Bengal, India, were investigated for the presence of class 1 integrons and sequences of the amplification products. METHODOLOGY/PRINCIPAL FINDINGS: Replica plating method was employed for determining the antibiotic resistance profile of the randomly assorted facultative oligotrophic isolates. Genomic DNA from each isolate was analyzed by PCR for the presence of class 1 integron. Amplicons were cloned and sequenced. Numerical taxonomy and 16S rRNA gene sequence analyses were done to ascertain putative genera of the class 1 integron bearing isolates. Out of 2188 isolates, 1667 (76.19%) were antibiotic-resistant comprising of both single-antibiotic resistance (SAR) and multiple-antibiotic resistant (MAR), and 521 (23.81%) were sensitive to all twelve different antibiotics used in this study. Ninety out of 2188 isolates produced amplicon(s) of varying sizes from 0.15 to 3.45 KB. Chi-square (χ(2)) test revealed that the possession of class 1 integron in sensitive, SAR and MAR is not equally probable at the 1% level of significance. Diverse antibiotic-resistance gene cassettes, aadA1, aadA2, aadA4, aadA5, dfrA1, dfrA5, dfrA7, dfrA12, dfrA16, dfrA17, dfrA28, dfrA30, dfr-IIe, blaIMP-9, aacA4, Ac-6'-Ib, oxa1, oxa10 and arr2 were detected in 64 isolates. The novel cassettes encoding proteins unrelated to any known antibiotic resistance gene function were identified in 26 isolates. Antibiotic-sensitive isolates have a greater propensity to carry gene cassettes unrelated to known antibiotic-resistance genes. The integron-positive isolates under the class Betaproteobacteria comprised of only two genera, Comamonas and Acidovorax of family Comamonadaceae, while isolates under class Gammaproteobacteria fell under the families, Moraxellaceae, Pseudomonadaceae, Aeromonadaceae and Enterobacteriaceae. CONCLUSIONS: Oligotrophic bacteria are good sources of novel genes as well as potential reservoirs of antibiotic resistance gene casettes. | 2013 | 23951238 |
| 834 | 4 | 0.9740 | Molecular diversity of class 2 integrons in antibiotic-resistant gram-negative bacteria found in wastewater environments in China. The molecular architecture of class 2 integrons among gram-negative bacteria from wastewater environments was investigated in Jinan, China. Out of the 391 antibiotic-resistant bacteria found, 38 isolates harboring class 2 integrons encoding potentially transferrable genes that could confer antibiotic resistance were found. These isolates were classified into 19 REP-PCR types. These strains were identified using 16S rRNA gene sequencing and found to be as follows: Proteus mirabilis (16), Escherichia coli (7), Providencia spp. (7), Proteus spp. (2), P. vulgaris (3), Shigella sp. (1), Citrobacter freundii (1), and Acinetobacter sp. (1). Their class 2 integron cassette arrays were amplified and then either analyzed using PCR-RFLP or sequenced. The typical array dfrA1-sat2-aadA1 was detected in 27 isolates. Six atypical arrays were observed, including three kinds of novel arrangements (linF2(∆attC1)-dfrA1(∆attC2)-aadA1-orf441 or linF2(∆attC1)-dfrA1(∆attC2)-aadA1, dfrA1-catB2-sat2-aadA1, and estX(Vr)-sat2-aadA1) and a hybrid with the 3'CS of class 1 integrons (dfrA1-sat2-aadA1-qacH), and dfrA1-sat1. Twenty-four isolates were also found to carry class 1 integrons with 10 types of gene cassette arrays. Several non-integron-associated antibiotic resistance genes were found, and their transferability was investigated. Results showed that water sources in the Jinan region harbored a diverse community of both typical and atypical class 2 integrons, raising concerns about the overuse of antibiotics and their careless disposal into the environment. | 2013 | 23264021 |
| 7779 | 5 | 0.9739 | Metagenomic and Resistome Analysis of a Full-Scale Municipal Wastewater Treatment Plant in Singapore Containing Membrane Bioreactors. Reclaimed water provides a water supply alternative to address problems of scarcity in urbanized cities with high living densities and limited natural water resources. In this study, wastewater metagenomes from 6 stages of a wastewater treatment plant (WWTP) integrating conventional and membrane bioreactor (MBR) treatment were evaluated for diversity of antibiotic resistance genes (ARGs) and bacteria, and relative abundance of class 1 integron integrases (intl1). ARGs confering resistance to 12 classes of antibiotics (ARG types) persisted through the treatment stages, which included genes that confer resistance to aminoglycoside [aadA, aph(6)-I, aph(3')-I, aac(6')-I, aac(6')-II, ant(2″)-I], beta-lactams [class A, class C, class D beta-lactamases (bla (OXA))], chloramphenicol (acetyltransferase, exporters, floR, cmIA), fosmidomycin (rosAB), macrolide-lincosamide-streptogramin (macAB, ereA, ermFB), multidrug resistance (subunits of transporters), polymyxin (arnA), quinolone (qnrS), rifamycin (arr), sulfonamide (sul1, sul2), and tetracycline (tetM, tetG, tetE, tet36, tet39, tetR, tet43, tetQ, tetX). Although the ARG subtypes in sludge and MBR effluents reduced in diversity relative to the influent, clinically relevant beta lactamases (i.e., bla (KPC), bla (OXA)) were detected, casting light on other potential point sources of ARG dissemination within the wastewater treatment process. To gain a deeper insight into the types of bacteria that may survive the MBR removal process, genome bins were recovered from metagenomic data of MBR effluents. A total of 101 close to complete draft genomes were assembled and annotated to reveal a variety of bacteria bearing metal resistance genes and ARGs in the MBR effluent. Three bins in particular were affiliated to Mycobacterium smegmatis, Acinetobacter Iwoffii, and Flavobacterium psychrophila, and carried aquired ARGs aac(2')-Ib, bla (OXA-278), and tet36 respectively. In terms of indicator organisms, cumulative log removal values (LRV) of Escherichia coli, Enterococci, and P. aeruginosa from influent to conventional treated effluent was lower (0-2.4), compared to MBR effluent (5.3-7.4). We conclude that MBR is an effective treatment method for reducing fecal indicators and ARGs; however, incomplete removal of P. aeruginosa in MBR treated effluents (<8 MPN/100 mL) and the presence of ARGs and intl1 underscores the need to establish if further treatment should be applied prior to reuse. | 2019 | 30833934 |
| 2768 | 6 | 0.9738 | Prevalence and abundance of antibiotic-resistant genes in culturable bacteria inhabiting a non-polar passu glacier, karakorum mountains range, Pakistan. Natural pristine environments including cold habitats are thought to be the potent reservoirs of antibiotic-resistant genes and have been recurrently reported in polar glaciers' native bacteria, nevertheless, their abundance among the non-polar glaciers' inhabitant bacteria is mostly uncharted. Herein we evaluated antibiotic resistance profile, abundance of antibiotic-resistant genes plus class 1, 2, and 3 integron integrases in 65 culturable bacterial isolates retrieved from a non-polar glacier. The 16S rRNA gene sequencing analysis identified predominantly Gram-negative 43 (66.15%) and Gram-positive 22 (33.84%) isolates. Among the Gram-negative bacteria, Gammaproteobacteria were dominant (62.79%), followed by Betaproteobacteria (18.60%) and Alphaproteobacteria (9.30%), whereas Phyla Actinobacteria (50%) and Firmicutes (40.90%) were predominant among Gram-positive. The Kirby Bauer disc diffusion method evaluated significant antibiotic resistance among the isolates. PCR amplification revealed phylum Proteobacteria predominantly carrying 21 disparate antibiotic-resistant genes like; (bla)AmpC 6 (100%), (bla)VIM-1, (bla)SHV and (bla)DHA 5 (100%) each, (bla)OXA-1 1 (100%), (bla)CMY-4 4 (100%), followed by Actinobacteria 14, Firmicutes 13 and Bacteroidetes 11. Tested isolates were negative for (bla)KPC, qnrA, vanA, ermA, ermB, intl2, and intl3. Predominant Gram-negative isolates had higher MAR index values, compared to Gram-positive. Alignment of protein homology sequences of antibiotic-resistant genes with references revealed amino acid variations in (bla)NDM-1, (bla)OXA-1, (bla)SHV, mecA, aac(6)-Ib3, tetA, tetB, sul2, qnrB, gyrA, and intI1. Promising antibiotic-resistant bacteria, harbored with numerous antibiotic-resistant genes and class 1 integron integrase with some amino acid variations detected, accentuating the mandatory focus to evaluate the intricate transcriptome analysis of glaciated bacteria conferring antibiotic resistance. | 2023 | 36754876 |
| 2767 | 7 | 0.9738 | Characterisation of class 3 integrons with oxacillinase gene cassettes in hospital sewage and sludge samples from France and Luxembourg. In this study, antibiotic resistance class 3 integrons in Gram-negative bacteria isolated from hospital sewage and sludge and their genetic contents were characterised. Two samples of hospital effluent from France and Luxembourg and one sample of sludge from a wastewater treatment plant in France were collected in 2010 and 2011. Bacteria were cultured on selective agar plates and integrons were detected in colonies by quantitative PCR. Integron gene cassette arrays and their genetic environments were analysed by next-generation sequencing. Three class 3 integron-positive isolates were detected, including Acinetobacter johnsonii LIM75 (French hospital effluent), Aeromonas allosaccharophila LIM82 (sludge) and Citrobacter freundii LIM86 (Luxembourg hospital effluent). The gene cassettes were all implicated in antibiotic (aminoglycoside and β-lactam) or antiseptic resistance. An oxacillinase gene cassette (blaOXA-10, blaOXA-368 or blaOXA-2) was found in each integron. All of the class 3 integrons were located on small mobilisable plasmids. This study highlights the role of class 3 integrons in the dissemination of clinically relevant antibiotic resistance genes, notably oxacillinase genes, in hospital effluent. | 2016 | 27499434 |
| 5238 | 8 | 0.9738 | Snapshot of resistome, virulome and mobilome in aquaculture. Aquaculture environments can be hotspots for resistance genes through the surrounding environment. Our objective was to study the resistome, virulome and mobilome of Gram-negative bacteria isolated in seabream and bivalve molluscs, using a WGS approach. Sixty-six Gram-negative strains (Aeromonadaceae, Enterobacteriaceae, Hafniaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Vibrionaceae, and Yersiniaceae families) were selected for genomic characterization. The species and MLST were determined, and antibiotic/disinfectants/heavy metals resistance genes, virulence determinants, MGE, and pathogenicity to humans were investigated. Our study revealed new sequence-types (e.g. Aeromonas spp. ST879, ST880, ST881, ST882, ST883, ST887, ST888; Shewanella spp. ST40, ST57, ST58, ST60, ST61, ST62; Vibrio spp. ST206, ST205). >140 different genes were identified in the resistome of seabream and bivalve molluscs, encompassing genes associated with β-lactams, tetracyclines, aminoglycosides, quinolones, sulfonamides, trimethoprim, phenicols, macrolides and fosfomycin resistance. Disinfectant resistance genes qacE-type, sitABCD-type and formA-type were found. Heavy metals resistance genes mdt, acr and sil stood out as the most frequent. Most resistance genes were associated with antibiotics/disinfectants/heavy metals commonly used in aquaculture settings. We also identified 25 different genes related with increased virulence, namely associated with adherence, colonization, toxins production, red blood cell lysis, iron metabolism, escape from the immune system of the host. Furthermore, 74.2 % of the strains analysed were considered pathogenic to humans. We investigated the genetic environment of several antibiotic resistance genes, including bla(TEM-1B), bla(FOX-18), aph(3″)-Ib, dfrA-type, aadA1, catA1-type, tet(A)/(E), qnrB19 and sul1/2. Our analysis also focused on identifying MGE in proximity to these genes (e.g. IntI1, plasmids and TnAs), which could potentially facilitate the spread of resistance among bacteria across different environments. This study provides a comprehensive examination of the diversity of resistance genes that can be transferred to both humans and the environment, with the recognition that aquaculture and the broader environment play crucial roles as intermediaries within this complex transmission network. | 2023 | 37604365 |
| 1214 | 9 | 0.9738 | Plasmid-mediated quinolone resistance genes in fecal bacteria from rooks commonly wintering throughout Europe. This study concerned the occurrence of fecal bacteria with plasmid-mediated quinolone resistance (PMQR) genes in rooks (Corvus frugilegus, medium-sized corvid birds) wintering in continental Europe during winter 2010/2011. Samples of fresh rook feces were taken by cotton swabs at nine roosting places in eight European countries. Samples were transported to one laboratory and placed in buffered peptone water (BPW). The samples from BPW were enriched and subcultivated onto MacConkey agar (MCA) supplemented with ciprofloxacin (0.06 mg/L) to isolate fluoroquinolone-resistant bacteria. DNA was isolated from smears of bacterial colonies growing on MCA and tested by PCR for PMQR genes aac(6')-Ib, qepA, qnrA, qnrB, qnrC, qnrD, qnrS, and oqxAB. All the PCR products were further analyzed by sequencing. Ciprofloxacin-resistant bacteria were isolated from 37% (392 positive/1,073 examined) of samples. Frequencies of samples with ciprofloxacin-resistant isolates ranged significantly from 3% to 92% in different countries. The qnrS1 gene was found in 154 samples and qnrS2 in 2 samples. The gene aac(6')-Ib-cr was found in 16 samples. Thirteen samples were positive for qnrB genes in variants qnrB6 (one sample), qnrB18 (one), qnrB19 (one), qnrB29 (one), and qnrB49 (new variant) (one). Both the qnrD and oqxAB genes were detected in six samples. The genes qnrA, qnrC, and qepA were not found. Wintering omnivorous rooks in Europe were commonly colonized by bacteria supposedly Enterobacteriaceae with PMQR genes. Rooks may disseminate these epidemiologically important bacteria over long distances and pose a risk for environmental contamination. | 2012 | 22731858 |
| 2769 | 10 | 0.9736 | Occurrences and Characterization of Antibiotic-Resistant Bacteria and Genetic Determinants of Hospital Wastewater in a Tropical Country. Wastewater discharged from clinical isolation and general wards at two hospitals in Singapore was examined to determine the emerging trends of antibiotic resistance (AR). We quantified the concentrations of 12 antibiotic compounds by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS), antibiotic-resistant bacteria (ARB), the class 1 integrase gene (intI1), and 16 antibiotic resistance genes (ARGs) that confer resistance to 10 different clinically relevant antibiotics. A subset of 119 antibiotic-resistant isolates were phylogenetically classified and tested for the presence of ARGs encoding resistance to β-lactam antibiotics (bla(NDM), bla(KPC), bla(SHV), bla(CTX-M)), amikacin [aac(6')-Ib], co-trimoxazole (sul1, sul2, dfrA), ciprofloxacin (qnrA, qnrB), and the intI1 gene. Among these resistant isolates, 80.7% were detected with intI1 and 66.4% were found to carry at least 1 of the tested ARGs. Among 3 sampled locations, the clinical isolation ward had the highest concentrations of ARB and the highest levels of ARGs linked to resistance to β-lactam (bla(KPC)), co-trimoxazole (sul1, sul2, dfrA), amikacin [aac(6')-Ib], ciprofloxacin (qnrA), and intI1 We found strong positive correlations (P < 0.05) between concentrations of bacteria resistant to meropenem, ceftazidime, amikacin, co-trimoxazole, and ciprofloxacin and abundances of bla(KPC), aac(6')-Ib, sul1, sul2, dfrA, qnrA, and intI1 genes. | 2016 | 27736769 |
| 1189 | 11 | 0.9736 | Detection of the carbapenemase gene bla(VIM-5) in members of the Pseudomonas putida group isolated from polluted Nigerian wetlands. There are increasing concerns about possible dissemination of clinically relevant antibiotic resistance genes, including genes encoding for carbapenemases in the environment. However, little is known about environmental distribution of antibiotic resistance in Africa. In this study, four polluted urban wetlands in Nigeria were investigated as potential reservoirs of carbapenem-resistant bacteria (CRB). CRB were isolated from the wetlands, characterized by Blue-Carba test, MIC determinations and whole genome sequencing (WGS). Nine of 65 bacterial isolates identified as members of the Pseudomonas putida group (P. plecoglossicida and P. guariconensis, respectively) harboured the metallo-beta-lactamase gene bla(VIM-5). WGS revealed the bla(VIM-5) in three novel Tn402-like class 1 integron structures containing the cassette arrays aadB|bla(VIM-5)|bla(PSE-1), aadB|bla(VIM-5)|aadB|bla(PSE-1), and bla(VIM-5)|aadB|tnpA|bla(PSE-1)|smr2|tnpA, respectively. Strains carrying the aadB|bla(VIM-5)|bla(PSE-1) cassette also carried an identical integron without bla(VIM-5). In addition(,) the strains harboured another Tn402-like class 1 integron carrying bcr2, several multidrug resistance efflux pumps, and at least one of ampC, aph(3")-lb, aph(6)-ld, tetB, tetC, tetG, floR, and macAB. This is the first report of a carbapenemase gene in bacteria from environmental sources in Nigeria and the first report of bla(VIM-5) in environmental bacteria isolates. This result underscores the role of the Nigerian environment as reservoir of bacteria carrying clinically relevant antibiotic resistance genes. | 2018 | 30310126 |
| 1183 | 12 | 0.9735 | Prevalence, transmission, and molecular epidemiology of tet(X)-positive bacteria among humans, animals, and environmental niches in China: An epidemiological, and genomic-based study. Plasmid-mediated, transmissible, tigecycline-inactivating enzyme Tet(X) has attracted considerable public attention. However, so far studies have not addressed its impact on public health and the ecosystem. Herein, we report the prevalence and molecular epidemiology of tet(X)-positive bacteria (TPB) from diverse sources, investigate the host-specificity of TPB and the transferability of tet(X). Sample collection was conducted between 2018 and 2020 in 30 provinces in China. PCR screening suggested tet(X) was prevalent among freshwater fishes (24.7%, 95% CI 19.4-30.7%), followed by chickens (23.6%, 21.2-26.2%), cattle (19.3%, 16.4-22.5%), healthy individuals (6.2%, 5.4-7.1%), and patients (0.3%, 0.0-1.1%). Soil and freshwater samples all tested negative for tet(X). A total of 289 TPB were isolated from 7516 samples (120/1181 chicken, 82/669 cattle, 68/3229 healthy individual, 17/239 freshwater fish and 2/2121 clinical samples). TPB distributed in six major families of bacteria including Moraxellaceae (n = 99, 34.3%), Flavobacteriaceae (n = 95, 32.9%), Enterobacteriaceae (n = 83, 28.7%), Pseudomonadaceae (n = 9, 3.1%), Sphingobacteriaceae (n = 2, 0.7%) and unclassified Gammaproteobacteria (n = 1, 0.3%). Diverse tet(X) genes including tet(X2), tet(X3), tet(X4), tet(X5) and tet(X6) were identified from different TPB. The tet(X)-positive bacteria were highly diverse, with ST10 complex belonging to the dominant E. coli clone. Novel hosts of tet(X) including Enterobacter hormaechei, Ignatzschineria indica and Oblitimonas alkaliphila were identified. Isolates from different families exhibited different antimicrobial resistance profiles. Co-existence of tet(X) with other resistance genes such as floR (66.8%) and carbapenemase genes (33.2%) was commonly observed. tet(X) could be transferred among E. coli isolates at frequencies from 10(-4) to 10(-10). Species other than E. coli failed to transfer tet(X) gene to the E. coli recipient via conjugation. Discriminant analysis of principal components analysis suggested inter-host transmission of tet(X)-positive E. coli among diverse hosts was not observed. Future studies are needed to monitor the transmission trend as well as the impact of this resistance gene in clinical infection control. | 2022 | 34801490 |
| 832 | 13 | 0.9735 | Development of antibiotic resistance in the ocular Pseudomonas aeruginosa clone ST308 over twenty years. Corneal infection caused by a bacteria Pseudomonas aeruginosa is common cause of ocular morbidity. Increasing antibiotic resistance by ocular P. aeruginosa is an emerging concern. In this study the resistome of ocular isolates of Pseudomonas aeruginosa clone ST308 isolated in India in 1997 (PA31, PA32, PA33, PA35 and PA37) and 2018 (PA198 and PA219) were investigated. All the isolates of ST308 had >95% nucleotide similarity. The isolates from 2018 had larger genomes, coding sequences, accessory and pan genes compared to the older isolates from 1997. The 2018 isolate PA219 was resistant to all antibiotics except polymyxin B, while the 2018 isolate PA198 was resistant to ciprofloxacin, levofloxacin, gentamicin and tobramycin. Among the isolates from 1997, five were resistant to gentamicin, tobramycin and ciprofloxacin, four were resistant to levofloxacin while two were resistant to polymyxin B. Twenty-four acquired resistance genes were present in the 2018 isolates compared to 11 in the historical isolates. All isolates contained genes encoding for aminoglycoside (aph(6)-Id, aph(3')-lIb, aph(3″)-Ib), beta-lactam (blaPAO), tetracycline (tet(G)), fosfomycin (fosA), chloramphenicol (catB7), sulphonamide (sul1), quaternary ammonium (qacEdelta1) and fluoroquinolone (crpP) resistance. Isolate PA198 possessed aph(3')-VI, rmtD2, qnrVC1, blaOXA-488, blaPME-1, while PA219 possessed aadA1, rmtB, qnrVC1, aac(6')-Ib-cr, blaTEM-1B, blaVIM-2, blaPAO-1, mph(E), mph(A), msr(E). In both recent isolates qnrVC1 was present in Tn3 transposon. In 219 blaTEM-1 was carried on a transposon and blaOXA-10 on a class 1 integron. There were no notable differences in the number of single nucleotide polymorphisms, but recent isolates carried more insertions and deletions in their genes. These findings suggest that genomes of P. aeruginosa ocular clonal strains with >95% nucleotide identity isolated twenty years apart had changed over time with the acquisition of resistance genes. The pattern of gene mutations also varied with more insertions and deletions in their chromosomal genes which confer resistance to antibiotics. | 2021 | 33610601 |
| 3069 | 14 | 0.9732 | The hospital sink drain biofilm resistome is independent of the corresponding microbiota, the environment and disinfection measures. In hospitals, the transmission of antibiotic-resistant bacteria (ARB) may occur via biofilms present in sink drains, which can lead to infections. Despite the potential role of sink drains in the transmission of ARB in nosocomial infections, routine surveillance of these drains is lacking in most hospitals. As a result, there is currently no comprehensive understanding of the transmission of ARB and the dissemination of antimicrobial resistance genes (ARGs) and associated mobile genetic elements (MGEs) via sink drains. This study employed a multifaceted approach to monitor the total aerobic bacteria as well as the presence of carbapenemase-producing Enterobacterales (CPEs), the microbiota and the resistome of sink drain biofilms (SDBs) and hospital wastewater (WW) of two separate intensive care units (ICUs) in the same healthcare facility in France. Samples of SDB and WW were collected on a monthly basis, from January to April 2023, in the neonatal (NICU) and the adult (AICU) ICUs of Grenoble Alpes University Hospital. In the NICU, sink drain disinfection with surfactants was performed routinely. In the AICU, routine disinfection is not carried out. Culturable aerobic bacteria were quantified on non-selective media, and CPEs were screened using two selective agars. Isolates were identified by MALDI-TOF MS, and antibiotic susceptibility testing (AST) was performed on Enterobacterales and P. aeruginosa. The resistome was analyzed by high-throughput qPCR targeting >80 ARGs and MGEs. The overall bacterial microbiota was assessed via full-length 16S rRNA sequencing. No CPEs were isolated from SDBs in either ICU by bacterial culture. Culture-independent approaches revealed an overall distinct microbiota composition of the SDBs in the two ICUs. The AICU SDBs were dominated by pathogens containing Gram-negative bacterial genera including Pseudomonas, Stenotrophomona, Klebsiella, and Gram-positive Staphylococcus, while the NICU SDBs were dominated by the Gram-negative genera Achromobacter, Serratia, and Acidovorax, as well as the Gram-positive genera Weisella and Lactiplantibacillus. In contrast, the resistome of the SDBs exhibited no significant differences between the two ICUs, indicating that the abundance of ARGs and MGEs is independent of microbiota composition and disinfection practices. The AICU WW exhibited more distinct aerobic bacteria than the NICU WW. In addition, the AICU WW yielded 15 CPEs, whereas the NICU WW yielded a single CPE. All the CPEs were characterized at the species level. The microbiota of the NICU and AICU WW samples differed from their respective SDBs and exhibited distinct variations over the four-month period:the AICU WW contained a greater number of genes conferring resistance to quinolones and integron integrase genes, whereas the NICU WW exhibited a higher abundance of streptogramin resistance genes. Our study demonstrated that the resistome of the hospital SDBs in the two ICUs of the investigated healthcare institute is independent of the microbiota, the environment, and the local disinfection measures. However, the prevalence of CPEs in the WW pipes collecting the waste from the investigated drains differed. These findings offer valuable insights into the resilience of resistance genes in SDBs in ICUs, underscoring the necessity for innovative strategies to combat antimicrobial resistance in clinical environments. | 2025 | 40483807 |
| 3498 | 15 | 0.9732 | Comparative study on the bacterial diversity and antibiotic resistance genes of urban landscape waters replenished by reclaimed water and surface water in Xi'an, China. Pathogenic bacteria and antibiotic resistance genes (ARGs) in urban landscape waters may pose a potential threat to human health. However, the investigation of their occurrence in the urban landscape waters replenished by reclaimed water (RW) and surface water (SW) is still insufficient. The water samples collected from six urban landscape waters replenished by RW or SW were used to analyze bacterial diversity using high-throughput sequencing of 16S rRNA gene and to detect 18 ARGs and 2 integron-integrase genes by means of quantitative PCR array. Results indicated that Proteobacteria was the dominant phylum in all six urban landscape waters. The bacterial species richness was lower in urban landscape waters replenished by RW than that by SW. Sulfonamide resistance genes (sulI and sulIII) were the major ARGs in these urban landscape waters. No significant difference in the relative abundance of sulfonamide resistance genes, tetracycline resistance genes, and most of beta-lactam resistance genes was observed between RW-replenished and SW-replenished urban landscape waters. By contrast, the relative abundance of bla(ampC) gene and qnrA gene in RW-replenished urban landscape waters was significantly higher than that in SW-replenished urban landscape waters (p < 0.05), which suggested that use of RW may increase the amount of specific ARGs to urban landscape waters. Interestingly, among six urban landscape waters, RW-replenished urban landscape waters had a relatively rich variety of ARGs (12-15 of 18 ARGs) but a low relative abundance of ARGs (458.90-1944.67 copies/16S × 10(6)). The RW replenishment was found to have a certain impact on the bacterial diversity and prevalence of ARGs in urban landscape waters, which provide new insight into the effect of RW replenishment on urban landscape waters. | 2021 | 33786766 |
| 1810 | 16 | 0.9731 | Characterization of Metagenomes in Urban Aquatic Compartments Reveals High Prevalence of Clinically Relevant Antibiotic Resistance Genes in Wastewaters. The dissemination of antimicrobial resistance (AMR) is an escalating problem and a threat to public health. Comparative metagenomics was used to investigate the occurrence of antibiotic resistant genes (ARGs) in wastewater and urban surface water environments in Singapore. Hospital and municipal wastewater (n = 6) were found to have higher diversity and average abundance of ARGs (303 ARG subtypes, 197,816 x/Gb) compared to treated wastewater effluent (n = 2, 58 ARG subtypes, 2,692 x/Gb) and surface water (n = 5, 35 subtypes, 7,985 x/Gb). A cluster analysis showed that the taxonomic composition of wastewaters was highly similar and had a bacterial community composition enriched in gut bacteria (Bacteroides, Faecalibacterium, Bifidobacterium, Blautia, Roseburia, Ruminococcus), the Enterobacteriaceae group (Klebsiella, Aeromonas, Enterobacter) and opportunistic pathogens (Prevotella, Comamonas, Neisseria). Wastewater, treated effluents and surface waters had a shared resistome of 21 ARGs encoding multidrug resistant efflux pumps or resistance to aminoglycoside, macrolide-lincosamide-streptogramins (MLS), quinolones, sulfonamide, and tetracycline resistance which suggests that these genes are wide spread across different environments. Wastewater had a distinctively higher average abundance of clinically relevant, class A beta-lactamase resistant genes (i.e., bla(KPC), bla(CTX-M), bla(SHV), bla(TEM)). The wastewaters from clinical isolation wards, in particular, had a exceedingly high levels of bla(KPC-2) genes (142,200 x/Gb), encoding for carbapenem resistance. Assembled scaffolds (16 and 30 kbp) from isolation ward wastewater samples indicated this gene was located on a Tn3-based transposon (Tn4401), a mobilization element found in Klebsiella pneumonia plasmids. In the longer scaffold, transposable elements were flanked by a toxin-antitoxin (TA) system and other metal resistant genes that likely increase the persistence, fitness and propagation of the plasmid in the bacterial host under conditions of stress. A few bacterial species (Enterobacter cloacae, Klebsiella pneumoniae, Citrobacter freundii, Pseudomonas aeruginosa) that were cultured from the isolation ward wastewaters on CHROMagar media harbored the bla(KPC-2) gene. This suggests that hospital wastewaters derived from clinical specialty wards are hotspots for the spread of AMR. Assembled scaffolds of other mobile genetic elements such as IncQ and IncF plasmids bearing quinolone resistance genes (qnrS1, qnrS2) and the class A beta-lactamase gene (bla(TEM-1)) were recovered in wastewater samples which may aid the transfer of AMR. | 2017 | 29201017 |
| 3488 | 17 | 0.9730 | Characteristics of Antibiotic Resistance Genes and Antibiotic-Resistant Bacteria in Full-Scale Drinking Water Treatment System Using Metagenomics and Culturing. The contamination of antibiotic resistance genes (ARGs) may directly threaten human health. This study used a metagenomic approach to investigate the ARG profile in a drinking water treatment system (DWTS) in south China. In total, 317 ARG subtypes were detected; specifically, genes encoding bacitracin, multidrug, and sulfonamide were widely detected in the DWTS. Putative ARG hosts included Acidovorax (6.0%), Polynucleobacter (4.3%), Pseudomonas (3.4%), Escherichia (1.7%), and Klebsiella (1.5%) as the enriched biomarkers in the DWTS, which mainly carried bacitracin, beta-lactam, and aminoglycoside ARGs. From a further analysis of ARG-carrying contigs (ACCs), Stenotrophomonas maltophilia and Pseudomonas aeruginosa were the most common pathogens among the 49 ACC pathogens in the DWTS. The metagenomic binning results demonstrated that 33 high-quality metagenome-assembled genomes (MAGs) were discovered in the DWTS; particularly, the MAG identified as S. maltophilia-like (bin.195) harbored the greatest number of ARG subtypes (n = 8), namely, multidrug (n = 6; smeD, semE, multidrug_transporter, mexE, semB, and smeC), beta-lactam (n = 1; metallo-beta-lactamase), and aminoglycoside [n = 1; aph(3')-IIb]. The strong positive correlation between MGEs and ARG subtypes revealed a high ARG dissemination risk in the DWTS. Based on the pure-culture method, 93 isolates that belong to 30 genera were recovered from the DWTS. Specifically, multidrug-resistant pathogens and opportunistic pathogens such as P. aeruginosa, Bacillus cereus, and S. maltophilia were detected in the DWTS. These insights into the DWTS's antibiotic resistome indicated the need for more comprehensive ARG monitoring and management in the DWTS. Furthermore, more effective disinfection methods need to be developed to remove ARGs in DWTSs, and these findings could assist governing bodies in the surveillance of antibiotic resistance in DWTSs. | 2021 | 35273579 |
| 2614 | 18 | 0.9730 | Distribution of Beta-Lactamase Producing Gram-Negative Bacterial Isolates in Isabela River of Santo Domingo, Dominican Republic. Bacteria carrying antibiotic resistance genes (ARGs) are naturally prevalent in lotic ecosystems such as rivers. Their ability to spread in anthropogenic waters could lead to the emergence of multidrug-resistant bacteria of clinical importance. For this study, three regions of the Isabela river, an important urban river in the city of Santo Domingo, were evaluated for the presence of ARGs. The Isabela river is surrounded by communities that do not have access to proper sewage systems; furthermore, water from this river is consumed daily for many activities, including recreation and sanitation. To assess the state of antibiotic resistance dissemination in the Isabela river, nine samples were collected from these three bluedistinct sites in June 2019 and isolates obtained from these sites were selected based on resistance to beta-lactams. Physico-chemical and microbiological parameters were in accordance with the Dominican legislation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses of ribosomal protein composition revealed a total of 8 different genera. Most common genera were as follows: Acinetobacter (44.6%) and Escherichia (18%). Twenty clinically important bacterial isolates were identified from urban regions of the river; these belonged to genera Escherichia (n = 9), Acinetobacter (n = 8), Enterobacter (n = 2), and Klebsiella (n = 1). Clinically important multi-resistant isolates were not obtained from rural areas. Fifteen isolates were selected for genome sequencing and analysis. Most isolates were resistant to at least three different families of antibiotics. Among beta-lactamase genes encountered, we found the presence of bla(TEM), bla(OXA), bla(SHV), and bla(KPC) through both deep sequencing and PCR amplification. Bacteria found from genus Klebsiella and Enterobacter demonstrated ample repertoire of antibiotic resistance genes, including resistance from a family of last resort antibiotics reserved for dire infections: carbapenems. Some of the alleles found were KPC-3, OXA-1, OXA-72, OXA-132, CTX-M-55, CTX-M-15, and TEM-1. | 2020 | 33519720 |
| 7772 | 19 | 0.9730 | Metagenomic community composition and resistome analysis in a full-scale cold climate wastewater treatment plant. BACKGROUND: Wastewater treatment plants are an essential part of maintaining the health and safety of the general public. However, they are also an anthropogenic source of antibiotic resistance genes. In this study, we characterized the resistome, the distribution of classes 1-3 integron-integrase genes (intI1, intI2, and intI3) as mobile genetic element biomarkers, and the bacterial and phage community compositions in the North End Sewage Treatment Plant in Winnipeg, Manitoba. Samples were collected from raw sewage, returned activated sludge, final effluent, and dewatered sludge. A total of 28 bacterial and viral metagenomes were sequenced over two seasons, fall and winter. Integron-integrase genes, the 16S rRNA gene, and the coliform beta-glucuronidase gene were also quantified during this time period. RESULTS: Bacterial classes observed above 1% relative abundance in all treatments were Actinobacteria (39.24% ± 0.25%), Beta-proteobacteria (23.99% ± 0.16%), Gamma-proteobacteria (11.06% ± 0.09%), and Alpha-proteobacteria (9.18 ± 0.04%). Families within the Caudovirales order: Siphoviridae (48.69% ± 0.10%), Podoviridae (23.99% ± 0.07%), and Myoviridae (19.94% ± 0.09%) were the dominant phage observed throughout the NESTP. The most abundant bacterial genera (in terms of average percent relative abundance) in influent, returned activated sludge, final effluent, and sludge, respectively, includes Mycobacterium (37.4%, 18.3%, 46.1%, and 7.7%), Acidovorax (8.9%, 10.8%, 5.4%, and 1.3%), and Polaromonas (2.5%, 3.3%, 1.4%, and 0.4%). The most abundant class of antibiotic resistance in bacterial samples was tetracycline resistance (17.86% ± 0.03%) followed by peptide antibiotics (14.24% ± 0.03%), and macrolides (10.63% ± 0.02%). Similarly, the phage samples contained a higher prevalence of macrolide (30.12% ± 0.30%), peptide antibiotic (10.78% ± 0.13%), and tetracycline (8.69% ± 0.11%) resistance. In addition, intI1 was the most abundant integron-integrase gene throughout treatment (1.14 × 10(4) gene copies/mL) followed by intI3 (4.97 × 10(3) gene copies/mL) while intI2 abundance remained low (6.4 × 10(1) gene copies/mL). CONCLUSIONS: Wastewater treatment successfully reduced the abundance of bacteria, DNA phage and antibiotic resistance genes although many antibiotic resistance genes remained in effluent and biosolids. The presence of integron-integrase genes throughout treatment and in effluent suggests that antibiotic resistance genes could be actively disseminating resistance between both environmental and pathogenic bacteria. | 2022 | 35033203 |