# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1526 | 0 | 1.0000 | Carbapenem resistance determinants and their transmissibility among clinically isolated Enterobacterales in Lebanon. BACKGROUND: The occurrence of carbapenem-resistant bacterial infections has increased significantly over the years with Gram-negative bacteria exhibiting the broadest resistance range. In this study we aimed to investigate the genomic characteristics of clinical carbapenem-resistant Enterobacterales (CRE). METHODS: Seventeen representative multi-drug resistant (MDR) isolates from a hospital setting showing high level of resistance to carbapenems (ertapenem, meropenem and imipenem) were chosen for further characterization through whole-genome sequencing. Resistance mechanisms and transferability of plasmids carrying carbapenemase-encoding genes were also determined in silico and through conjugative mating assays. RESULTS: We detected 18 different β-lactamases, including four carbapenemases (bla(NDM-1), bla(NDM-5), bla(NDM-7), bla(OXA-48)) on plasmids with different Inc groups. The combined results from PBRT and in silico replicon typing revealed 20 different replicons linked to plasmids ranging in size between 80 and 200 kb. The most prevalent Inc groups were IncFIB(K) and IncM. OXA-48, detected on 76-kb IncM1 conjugable plasmid, was the most common carbapenemase. We also detected other conjugative plasmids with different carbapenemases confirming the role of horizontal gene transfer in the dissemination of antimicrobial resistance genes. CONCLUSION: Our findings verified the continuing spread of carbapenemases in Enterobacterales and revealed the types of mobile elements circulating in a hospital setting and contributing to the spread of resistance determinants. The occurrence and transmission of plasmids carrying carbapenemase-encoding genes call for strengthening active surveillance and prevention efforts to control antimicrobial resistance dissemination in healthcare settings. | 2023 | 37871361 |
| 1686 | 1 | 0.9999 | Resistome of carbapenem- and colistin-resistant Klebsiella pneumoniae clinical isolates. The emergence and dissemination of carbapenemases, bacterial enzymes able to inactivate most β-lactam antibiotics, in Enterobacteriaceae is of increasing concern. The concurrent spread of resistance against colistin, an antibiotic of last resort, further compounds this challenge further. Whole-genome sequencing (WGS) can play a significant role in the rapid and accurate detection/characterization of existing and emergent resistance determinants, an essential aspect of public health surveillance and response activities to combat the spread of antimicrobial resistant bacteria. In the current study, WGS data was used to characterize the genomic content of antimicrobial resistance genes, including those encoding carbapenemases, in 10 multidrug-resistant Klebsiella pneumoniae isolates from Pakistan. These clinical isolates represented five sequence types: ST11 (n = 3 isolates), ST14 (n = 3), ST15 (n = 1), ST101 (n = 2), and ST307 (n = 1). Resistance profiles against 25 clinically-relevant antimicrobials were determined by broth microdilution; resistant phenotypes were observed for at least 15 of the 25 antibiotics tested in all isolates except one. Specifically, 8/10 isolates were carbapenem-resistant and 7/10 isolates were colistin-resistant. The blaNDM-1 and blaOXA-48 carbapenemase genes were present in 7/10 and 5/10 isolates, respectively; including 2 isolates carrying both genes. No plasmid-mediated determinants for colistin resistance (e.g. mcr) were detected, but disruptions and mutations in chromosomal loci (i.e. mgrB and pmrB) previously reported to confer colistin resistance were observed. A blaOXA-48-carrying IncL/M-type plasmid was found in all blaOXA-48-positive isolates. The application of WGS to molecular epidemiology and surveillance studies, as exemplified here, will provide both a more complete understanding of the global distribution of MDR isolates and a robust surveillance tool useful for detecting emerging threats to public health. | 2018 | 29883490 |
| 1527 | 2 | 0.9999 | Emergence of an Escherichia coli strain co-harbouring mcr-1 and bla(NDM-9) from a urinary tract infection in Taiwan. OBJECTIVES: Multidrug-resistant bacteria have become a serious threat worldwide. In particular, the coexistence of carbapenemase genes and mcr-1 leaves few available treatment options. Here we report a multidrug-resistant Escherichia coli isolate harbouring both mcr-1 and bla(NDM-9) from a patient with a urinary tract infection. METHODS: Antimicrobial susceptibility and resistance genes of the E. coli isolate were characterised. Furthermore, the assembled genome sequences of mcr-1- and bla(NDM-9)-carrying plasmids were determined and comparative genetic analysis with closely related plasmids was carried out. RESULTS: Three contigs were assembled comprising the E. coli chromosome and two plasmids harbouring mcr-1 (p5CRE51-MCR-1) and bla(NDM-9) (p5CRE51-NDM-9), respectively. Whole-genome sequencing revealed that the two antimicrobial resistance genes are located on individual plasmids. CONCLUSIONS: The emergence of coexistence of carbapenemase genes and mcr-1 in Enterobacteriaceae highlights a serious threat to antimicrobial therapy. | 2019 | 30312830 |
| 1689 | 3 | 0.9999 | Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China. The aim of this study was to determine the occurrence of mobilized colistin resistance (mcr) genes in Gram-negative bacteria causing bloodstream infections of child inpatients in China. Bacteria were collected between 2006 and 2019 in a maternal and child health hospital, and mcr genes were screened by PCR. Five of 252 isolates were mcr-positive, including one mcr-1-positive colistin-resistant Escherichia coli isolate, two mcr-9-positive colistin-susceptible Salmonella enterica isolates, and two mcr-9-positive colistin-susceptible Enterobacter hormaechei isolates. These were obtained from two neonate and three infant patients admitted between 2009 and 2018. The E. coli isolate was obtained from a neonate aged 20 min, suggestive of a possible mother-to-neonate transmission. The five mcr-positive isolates were multidrug resistant, and two S. enterica and one E. hormaechei isolate showed a hypervirulent phenotype compared to a hypervirulent Klebsiella pneumoniae type strain in a Galleria mellonella infection model. The mcr-1 gene was carried by an IncX4-type pA1-like epidemic plasmid, and the mcr-9 gene was detected on IncHI2/2A-type novel plasmids co-carrying multiple resistance genes. The four IncHI2/2A-type plasmids shared a backbone and a high similarity (≥77% coverage and ≥ 90% nucleotide identity), suggesting that they were derived from a common ancestor with cross-species transmission and have circulated locally over a long period. The conjugation assay showed that the mcr-1-encoding plasmid and one mcr-9-encoding plasmid were self-transmissible to E. coli with high conjugation frequencies. Our findings demonstrate that mcr genes have disseminated in the community and/or hospitals, mediated by epidemic/endemic plasmids over a long period. The study shows that continuous monitoring of mcr genes is imperative for understanding and tackling their dissemination. IMPORTANCE Antimicrobial resistance, especially the spread of carbapenemase-producing Enterobacteriaceae (CPE), represents one of the largest challenges to One Health coverage of environmental, animal, and human sectors. Colistin is one of the last-line antibiotics for clinical treatment of CPE. However, the emergence of the mobilized colistin resistance (mcr) gene largely threatens the usage of colistin in the clinical setting. In this study, we investigated the existence of mcr genes in 252 Gram-negative bacteria collected between 2006 and 2019 which caused bloodstream infections of child inpatients in China. We found a high prevalence of mcr carriage among children inpatients in the absence of professional exposure, and mcr might have widely disseminated in the community via different routes. This study emphasizes the importance of rational use of colistin in the One Health frame, and highlights both the urgent need for understanding the prevalence and dissemination of mcr genes in different populations and the importance of effective measures to control their spread. | 2022 | 35138190 |
| 1897 | 4 | 0.9998 | Plasmid-based replicon typing: Useful tool in demonstrating the silent pandemic of plasmid-mediated multi-drug resistance in Enterobacterales. BACKGROUND: Multi-drug resistant Enterobacterales increasingly isolated in hospital settings have a significant impact on therapy and overall treatment costs. Conjugative plasmids carrying relevant resistance genes have been described as the most frequent mechanism of acquisition and spread of resistance. PCR-based replicon typing (PBRT) is a method for plasmid identification and incompatibility typing which helps detect the presence of plasmid families in these bacteria. This study was undertaken to provide an insight into the prevalence of resistance plasmids in MDR Enterobacterales in our tertiary care setting. METHODS: A selection of one hundred multi-drug resistant Enterobacterale isolates sourced from clinical samples were subjected to PCR-based replicon typing. RESULTS: A total of 21 plasmid replicon types were detected from 85% of the isolates out of the 28 families described in literature. Majority of the isolates (54%) showed three or more replicons. IncF was the most frequent plasmid family detected with FIA being the most common replicon type (43%) followed by FII (29%) and FIB (28%) replicons. Among the IncX plasmid family, X3 replicon was the commonest (14%). IncF and IncX plasmid families are known to carry a large spectrum of resistance genes. CONCLUSION: The presence of these plasmids engenders emergent steps to be taken for prevention of their transmission in the form of strict infection control measures in the hospital and adoption of novel methods of plasmid curing to eliminate the plasmids from these organisms rendering them susceptible to the currently used antimicrobials. | 2025 | 40463599 |
| 1685 | 5 | 0.9998 | Molecular epidemiology and mechanisms of carbapenem and colistin resistance in Klebsiella and other Enterobacterales from treated wastewater in Croatia. Among the most problematic bacteria with clinical relevance are the carbapenem-resistant Enterobacterales (CRE), as there are very limited options for their treatment. Treated wastewater can be a route for the release of these bacteria into the environment and the population. The aim of this study was to isolate CRE from treated wastewater from the Zagreb wastewater treatment plant and to determine their phenotypic and genomic characteristics. A total of 200 suspected CRE were isolated, 148 of which were confirmed as Enterobacterales by MALDI-TOF MS. The predominant species was Klebsiella spp. (n = 47), followed by Citrobacter spp. (n = 40) and Enterobacter cloacae complex (cplx.) (n = 35). All 148 isolates were carbapenemase producers with a multidrug-resistant phenotype. Using multi-locus sequence typing and whole-genome sequencing (WGS), 18 different sequence types were identified among these isolates, 14 of which were associated with human-associated clones. The virulence gene analysis of the sequenced Klebsiella isolates (n = 7) revealed their potential pathogenicity. PCR and WGS showed that the most frequent carbapenemase genes in K. pneumoniae were bla(OXA-48) and bla(NDM-1), which frequently occurred together, while bla(KPC-2) together with bla(NDM-1) was mainly detected in K. oxytoca, E. cloacae cplx. and Citrobacter spp. Colistin resistance was observed in 40% of Klebsiella and 57% of Enterobacter isolates. Underlying mechanisms identified by WGS include known and potentially novel intrinsic mechanisms (point mutations in the pmrA/B, phoP/Q, mgrB and crrB genes) and acquired mechanisms (mcr-4.3 gene). The mcr-4.3 gene was identified for the first time in K. pneumoniae and is probably located on the conjugative IncHI1B plasmid. In addition, WGS analysis of 13 isolates revealed various virulence genes and resistance genes to other clinically relevant antibiotics as well as different plasmids possibly associated with carbapenemase genes. Our study demonstrates the important role that treated municipal wastewater plays in harboring and spreading enterobacterial pathogens that are resistant to last-resort antibiotics. | 2024 | 38479059 |
| 1637 | 6 | 0.9998 | Genomic surveillance of antimicrobial resistance in bovine fecal samples from Lebanon. Antimicrobial resistance (AMR) threatens human and animal health worldwide, driven by the spread of extended-spectrum β-lactamase (ESBL)-producing, and carbapenem-resistant Gram-negative bacteria. In Lebanon, inadequate surveillance and antibiotic misuse worsen the issue. Animal fecal material is an important reservoir of resistance genes and mobile elements. This study aims to address AMR in bovine feces. To achieve this, bovine fecal samples were collected from 24 farms in Lebanon. Sixty-two ESBL-producing bacteria were recovered on CHROMagar ESBL and whole-genome sequencing followed by in silico typing was used to determine the resistance genes, virulence factors, and mobile genetic elements. Disk diffusion assay revealed the prevalence of multidrug-resistant (MDR) Gram-negative bacteria (33/62) with Escherichia coli being the most common (37/62). Resistance to amoxicillin, ceftriaxone, and cefotaxime was detected in all 37 E. coli isolates, with one also exhibiting resistance to colistin. β-lactam resistance was primarily associated with bla(CTX-M-15) and bla(TEM-1B), while colistin resistance was linked to mcr-1.1 on an IncHI2A/IncFIC multi-replicon plasmid. Plasmid typing identified 22 replicons, the most common being IncFIB and IncFII. Virulence factor analysis identified enterotoxin-encoding genes in one E. coli isolate, suggesting a potentially pathogenic strain with diarrheagenic properties among the recovered isolates. The findings of this study revealed highly resistant Gram-negative bacteria with plasmid-mediated resistance to critical antibiotics such as colistin, emphasizing the risks posed to human and livestock health. Comprehensive surveillance and responsible antibiotic use, guided by an integrated One Health approach, are essential steps to effectively tackle the interconnected challenges of AMR. | 2025 | 40482361 |
| 1853 | 7 | 0.9998 | Dissemination dynamics of colistin resistance genes mcr-9 and mcr-10 across diverse Inc plasmid backbones. BACKGROUND: The polymyxin antibiotic colistin is used as a final line of treatment for life threatening infections caused by multidrug resistant and carbapenem-resistant Gram-negative bacteria. Mobile colistin resistance genes mcr-9 and mcr-10 are increasingly detected in Enterobacteriaceae but their epidemiology is poorly understood. METHODS: The genetic characteristics of mcr-9 and mcr-10, being the only mobile colistin resistance genes detected in a local population of Enterobacter species isolated from bloodstream infections in Dartmouth Hitchcock Medical Center, USA, were elucidated and contextualized against a global dataset of mcr-9/10-bearing plasmids using genomic and phylogenetic tools. RESULTS: Seven out of 59 Enterobacter isolates carry either an mcr-9 or mcr-10 on a plasmid with distinct single and multiple replicon configurations, including IncFIB(pECLA), IncFIB(K), IncFIA(HI1)-IncFIB(K), IncFIB(pECLA)--IncFII(pECLA) and IncFIB(K)--IncFII(pECLA), whereas two genomes harbor mcr-9 on their chromosome. Global contextualization reveals that allelic variants of mcr-9 and mcr-10 are widely disseminated across diverse Inc-type plasmids, transcending geographic and taxonomic boundaries. Plasmid-borne genes conferring resistance to other antimicrobial agents, such as aminoglycoside, tetracycline and trimethoprim, tend to co-occur with mcr-9.1 and mcr-9.2 alleles. CONCLUSIONS: Findings from this study enhance our understanding of the plasmid backgrounds of mcr-9 and mcr-10, their associated antimicrobial resistance gene carriage and co-occurrence. This knowledge may be critical to inform scalable and effective public health interventions aimed at preserving the efficacy of colistin. | 2025 | 40999001 |
| 1732 | 8 | 0.9998 | High Carriage Rate of the Multiple Resistant Plasmids Harboring Quinolone Resistance Genes in Enterobacter spp. Isolated from Healthy Individuals. Antimicrobial-resistant bacteria causing intractable and even fatal infections are a major health concern. Resistant bacteria residing in the intestinal tract of healthy individuals present a silent threat because of frequent transmission via conjugation and transposition. Plasmids harboring quinolone resistance genes are increasingly detected in clinical isolates worldwide. Here, we investigated the molecular epidemiology of plasmid-mediated quinolone resistance (PMQR) in Gram-negative bacteria from healthy service trade workers. From 157 rectal swab samples, 125 ciprofloxacin-resistant strains, including 112 Escherichia coli, 10 Klebsiella pneumoniae, two Proteus mirabilis, and one Citrobacter braakii, were isolated. Multiplex PCR screening identified 39 strains harboring the PMQR genes (including 17 qnr,19 aac(6')-Ib-cr, and 22 oqxA/oqxB). The genome and plasmid sequences of 39 and 31 strains, respectively, were obtained by short- and long-read sequencing. PMQR genes mainly resided in the IncFIB, IncFII, and IncR plasmids, and coexisted with 3-11 other resistance genes. The high PMQR gene carriage rate among Gram-negative bacteria isolated from healthy individuals suggests the high-frequency transmission of these genes via plasmids, along with other resistance genes. Thus, healthy individuals may spread antibiotic-resistant bacterial, highlighting the need for improved monitoring and control of the spread of antibiotic-resistant bacteria and genes in healthy individuals. | 2021 | 35052892 |
| 1525 | 9 | 0.9998 | Genetic Characterization of Enterobacter hormaechei Co-Harboring bla (NDM-1) and mcr-9 Causing Upper Respiratory Tract Infection. PURPOSE: With the spread of multiple drug-resistant bacteria, bla (NDM-1) and mcr-9 have been detected in various bacteria worldwide. However, the simultaneous detection of bla (NDM-1) and mcr-9 in Enterobacter hormaechei has been rarely reported. This study identified an E. hormaechei strain carrying both bla (NDM-1) and mcr-9. We investigated the genetic characteristics of these two resistance genes in detail, elucidating various potential mechanisms by which they may be transmitted. METHODS: Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) with Illumina and PacBio platforms and phylogenetic analysis. Subsequent investigations were performed, including antimicrobial susceptibility testing and multilocus sequence typing (MLST). RESULTS: We isolated an E. hormaechei strain DY1901 carrying both bla (NDM-1) and mcr-9 from the sputum sample. Susceptibility testing showed that the isolate was multidrug-resistant. Multiple antibiotic resistance genes and virulence genes are widely distributed in DY1901. S1-PFGE, Southern blotting, and plasmid replicon typing showed that DY1901 carried four plasmids. The plasmid carrying mcr-9 was 259Kb in size and belonged to IncHI2, while the plasmid carrying bla (NDM-1) was 45Kb in length and belonged to IncX3. CONCLUSION: The E. hormaechei strain isolated in this study has a broad antibiotic resistance spectrum, posing a challenge to clinical treatment. Plasmids carrying mcr-9 are fusion plasmids, and those taking NDM are widely disseminated in China, suggesting that we should conduct routine genomic surveillance on such plasmids to curb the spread of drug-resistant bacteria in the region. | 2022 | 36068833 |
| 1858 | 10 | 0.9998 | Molecular Characteristics of Antimicrobial Resistance and Virulence in Klebsiella pneumoniae Strains Isolated from Goose Farms in Hainan, China. We retrospectively investigated 326 samples that were collected from goose farms in Hainan Province, China, in 2017. A total of 33 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates were identified from 326 samples, and the 33 CRKP isolates were characterized based on whole-genome sequencing (WGS) data from the Illumina and Oxford Nanopore Technologies (ONT) platforms. All of these 33 CRKP isolates possessed bla(NDM-5), and a single isolate coharbored mcr-1 and bla(NDM-5), while 4 isolates carried multiple virulence and metal tolerance gene clusters. One CRKP strain (CMG-35-2) was selected for long sequence reading. A hybrid plasmid carrying the virulence, resistance, and metal resistance gene in the strain was found. It possessed 2 backbones [IncFIB(K)-IncFII(K)] within a single plasmid that were closely related to K. pneumoniae plasmids from a human-associated habitat in the United States and from a human isolate in Hong Kong. A mouse abdominal infection model indicated that that strain was of the moderate virulence phenotype. This study revealed that K. pneumoniae on goose farms is an important reservoir for bla(NDM-5) and these bacteria are represented by a diversity of sequence types. The heterozygous multiple drug resistance genes carried on plasmids highlighted the genetic complexity of CRKP and the urgent need for continued active surveillance. IMPORTANCE CRKP is one of the most important pathogens, which can cause infection not only in humans but also in waterfowl. The discovery of bla(NDM-5)-producing K. pneumoniae in waterfowl farms in recent years suggests that waterfowl are an important reservoir for bla(NDM-5)-producing Enterobacteriaceae. However, there are few studies on the spread of bla(NDM-5)-producing bacteria in waterfowl farms. Our study showed that the IncX3 plasmid carrying bla(NDM-5) in goose farms is widely present in K. pneumoniae isolates and a large number of resistance genes are accumulated in it. We found a transferable IncFIB-FII hybrid plasmid that combines virulence, resistance, and metal resistance genes, which allow transfer of these traits between bacteria in different regions. The results of this study contribute to a better understanding of the prevalence and transmission of carbapenem-resistant K. pneumoniae in goose farms. | 2022 | 35389252 |
| 1902 | 11 | 0.9998 | Large-scale analysis of putative plasmids in clinical multidrug-resistant Escherichia coli isolates from Vietnamese patients. INTRODUCTION: In the past decades, extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Escherichia coli isolates have been detected in Vietnamese hospitals. The transfer of antimicrobial resistance (AMR) genes carried on plasmids is mainly responsible for the emergence of multidrug-resistant E. coli strains and the spread of AMR genes through horizontal gene transfer. Therefore, it is important to thoroughly study the characteristics of AMR gene-harboring plasmids in clinical multidrug-resistant bacterial isolates. METHODS: The profiles of plasmid assemblies were determined by analyzing previously published whole-genome sequencing data of 751 multidrug-resistant E. coli isolates from Vietnamese hospitals in order to identify the risk of AMR gene horizontal transfer and dissemination. RESULTS: The number of putative plasmids in isolates was independent of the sequencing coverage. These putative plasmids originated from various bacterial species, but mostly from the Escherichia genus, particularly E. coli species. Many different AMR genes were detected in plasmid contigs of the studied isolates, and their number was higher in CR isolates than in ESBL-producing isolates. Similarly, the bla(KPC-2), bla(NDM-5), bla(OXA-1), bla(OXA-48), and bla(OXA-181) β-lactamase genes, associated with resistance to carbapenems, were more frequent in CR strains. Sequence similarity network and genome annotation analyses revealed high conservation of the β-lactamase gene clusters in plasmid contigs that carried the same AMR genes. DISCUSSION: Our study provides evidence of horizontal gene transfer in multidrug-resistant E. coli isolates via conjugative plasmids, thus rapidly accelerating the emergence of resistant bacteria. Besides reducing antibiotic misuse, prevention of plasmid transmission also is essential to limit antibiotic resistance. | 2023 | 37323902 |
| 918 | 12 | 0.9998 | Carbapenem Resistance in Gram-Negative Bacteria: A Hospital-Based Study in Egypt. Background and Objectives: The global spread of carbapenem resistance and the resulting increase in mortality forced the World Health Organization (WHO) to claim carbapenem-resistant enterobacteriaceae (CRE) as global priority pathogens. Our study aimed to determine the prevalence of carbapenemase-encoding genes and major plasmid incompatibility groups among Gram-negative hospital-based isolates in Egypt. Material and Methods: This cross-sectional study was carried out at Mansoura University Hospitals over 12 months, from January to December 2019. All the isolates were tested for carbapenem resistance. The selected isolates were screened by conventional polymerase chain reaction (PCR) for the presence of carbapenemase genes, namely bla(KPC), bla(IMP), bla(VIM), and bla(NDM-1). PCR-based plasmid replicon typing was performed using the commercial PBRT kit. Results: Out of 150 isolates, only 30 (20.0%) demonstrated carbapenem resistance. Klebsiella pneumoniae was the most resistant of all isolated bacteria, and bla(NDM) was the predominant carbapenemases gene, while the most prevalent plasmid replicons were the F replicon combination (FIA, FIB, and FII) and A/C. Plasmids were detected only in Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. Remarkably, we found a statistically significant association between carbapenemase genes and plasmid replicons, including bla(NDM), IncA/C, and IncX. Conclusions: Our study demonstrated an alarming rise of plasmid-mediated carbapenem-resistant bacteria in our locality. The coexistence of resistance genes and plasmids highlights the importance of a targeted antibiotic surveillance program and the development of alternative therapeutic options at the local and international levels. Based on our results, we suggest a large-scale study with more Enterobacteriaceae isolates, testing other carbapenemase-encoding genes, and comparing the replicon typing method with other plasmid detection methods. We also recommend a national action plan to control the irrational use of antibiotics in Egypt. | 2023 | 36837486 |
| 1680 | 13 | 0.9998 | Emergence of carbapenem resistant gram-negative pathogens with high rate of colistin resistance in Egypt: A cross sectional study to assess resistance trends during the COVID-19 pandemic. The current study investigated the temporal phenotypic and genotypic antimicrobial resistance (AMR) trends among multi-drug resistant and carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa recovered from Egyptian clinical settings between 2020 and 2021. Bacterial identification and antimicrobial sensitivity of 111 clinical isolates against a panel of antibiotics were performed. Molecular screening for antibiotic resistance determinants along with integrons and associated gene cassettes was implemented. An alarming rate (98.2%) of these isolates were found to be phenotypically resistant to carbapenem. Although 23.9 % K. pneumoniae isolates were phenotypically resistant to colistin, no mobile colistin resistance (mcr) genes were detected. Among carbapenem-resistant isolates, bla(NDM) and bla(OXA-48)-like were the most prevalent genetic determinants and were significantly overrepresented among K. pneumoniae. Furthermore, 84.78% of K. pneumoniae isolates co-produced these two carbapenemase genes. The plasmid-mediated quinolone resistance genes (qnrS and qnrB) were detected among the bacterial species and were significantly more prevalent among K. pneumoniae. Moreover, Class 1 integron was detected in 82% of the bacterial isolates. This study alarmingly reveals elevated resistance to last-resort antibiotics such as carbapenems as well as colistin which impose a considerable burden in the health care settings in Egypt. Our future work will implement high throughput sequencing-based antimicrobial resistance surveillance analysis for characterization of novel AMR determinants. This information could be applied as a step forward to establish a robust antibiotic stewardship program in Egyptian clinical settings, thereby addressing the rising challenges of AMR. | 2024 | 38494251 |
| 1899 | 14 | 0.9998 | Characteristics of plasmids in multi-drug-resistant Enterobacteriaceae isolated during prospective surveillance of a newly opened hospital in Iraq. BACKGROUND: Gram-negative multidrug-resistant (MDR) bacteria are major causes of nosocomial infections, and antibiotic resistance in these organisms is often plasmid mediated. Data are scarce pertaining to molecular mechanisms of antibiotic resistance in resource constrained areas such as Iraq. METHODOLOGY/PRINCIPAL FINDINGS: In this study, all MDR Enterobacteriaceae (n = 38) and randomly selected non-MDR counterparts (n = 41) isolated from patients, healthcare workers and environmental surfaces in a newly opened hospital in Iraq were investigated to characterize plasmids found in these isolates and determine their contribution to antibiotic resistance. Our results demonstrated that MDR E. coli and K. pneumoniae isolates harbored significantly more (≥ 3) plasmids compared to their non-MDR counterparts, which carried ≤ 2 plasmids (p<0.01). Various large plasmids (~52 to 100 kb) from representative isolates were confirmed to contain multiple resistance genes by DNA microarray analysis. Aminoglycoside (acc, aadA, aph, strA/B, and ksgA), β-lactam (bla(TEM1), bla(AMPC), bla(CTX-M-15), bla(OXA-1), bla(VIM-2) and bla(SHV)), sulfamethoxazole/trimethoprim (sul/dfr), tetracycline (tet) and chloramphenicol (cat) resistance genes were detected on these plasmids. Additionally, multiple plasmids carrying multiple antibiotic resistance genes were found in the same host strain. Genetic transfer-associated genes were identified on the plasmids from both MDR and non-MDR isolates. Seven plasmid replicon types (FII, FIA, FIB, B/O, K, I1 and N) were detected in the isolates, while globally disseminated IncA/C and IncHI1 plasmids were not detected in these isolates. CONCLUSIONS/SIGNIFICANCE: This is the first report of the characteristics of the plasmids found in Enterobacteriaceae isolated following the opening of a new hospital in Iraq. The information provided here furthers our understanding of the mechanisms of drug resistance in this specific region and their evolutionary relationship with other parts of world. The large plasmids, carrying resistance genes and transfer-associated genes, may be potential factors for regional dissemination of antibiotic resistance. | 2012 | 22808141 |
| 839 | 15 | 0.9998 | Molecular characterization of carbapenemase-producing Enterobacterales in a tertiary hospital in Lima, Peru. Carbapenemase-producing Enterobacterales (CPE) are a growing threat to global health and the economy. Understanding the interactions between resistance and virulence mechanisms of CPE is crucial for managing difficult-to-treat infections and informing outbreak prevention and control programs. Here, we report the characterization of 21 consecutive, unique clinical isolates of CPE collected in 2018 at a tertiary hospital in Lima, Peru. Isolates were characterized by phenotypic antimicrobial susceptibility testing and whole-genome sequencing to identify resistance determinants and virulence factors. Seven Klebsiella pneumoniae isolates were classified as extensively drug-resistant. The remaining Klebsiella, Enterobacter hormaechei, and Escherichia coli isolates were multidrug-resistant. Eighteen strains carried the metallo-β-lactamase NDM-1, two the serine-carbapenemase KPC-2, and one isolate had both carbapenemases. The bla(NDM-1) gene was located in the truncated ΔISAba125 element, and the bla(KPC-2) gene was in the Tn4401a transposon. ST147 was the most frequent sequence type among K. pneumoniae isolates. Our findings highlight the urgent need to address the emergence of CPE and strengthen control measures and antibiotic stewardship programs in low- and middle-income settings.IMPORTANCEGenomic surveillance of antimicrobial resistance contributes to monitoring the spread of resistance and informs treatment and prevention strategies. We characterized 21 carbapenemase-producing Enterobacterales collected at a Peruvian tertiary hospital in 2018, which exhibited very high levels of resistance and carried numerous resistance genes. We detected the coexistence of carbapenemase-encoding genes (bla(NDM-1) and bla(KPC-2)) in a Klebsiella pneumoniae isolate that also had the PmrB(R256G) mutation associated with colistin resistance. The bla(KPC-2) genes were located in Tn4401a transposons, while the bla(NDM-1) genes were in the genetic structure Tn125 (ΔISAba125). The presence of high-risk clones among Klebsiella pneumoniae (ST11 and ST147) and Escherichia coli (ST410) isolates is also reported. The study reveals the emergence of highly resistant bacteria in a Peruvian hospital, which could compromise the effectiveness of current treatments and control. | 2024 | 38193666 |
| 910 | 16 | 0.9998 | Analysis of Antimicrobial Resistance Genes (ARGs) in Enterobacterales and A. baumannii Clinical Strains Colonizing a Single Italian Patient. The dramatic increase in infections caused by critically multidrug-resistant bacteria is a global health concern. In this study, we characterized the antimicrobial resistance genes (ARGs) of K. pneumoniae, P. mirabilis, E. cloacae and A. baumannii isolated from both surgical wound and rectal swab of a single Italian patient. Bacterial identification was performed by MALDI-TOF MS and the antimicrobial susceptibility was carried out by Vitek 2 system. The characterization of ARGs was performed using next-generation sequencing (NGS) methodology (MiSeq Illumina apparatus). K. pneumoniae, P. mirabilis and E. cloacae were resistant to most β-lactams and β-lactam/β-lactamases inhibitor combinations. A. baumannii strain was susceptible only to colistin. The presence of plasmids (IncN, IncR, IncFIB, ColRNAI and Col (MGD2)) was detected in all Enterobacterales but not in A. baumannii strain. The IncN plasmid and bla(NDM-1) gene were found in K. pneumoniae, P. mirabilis and E. cloacae, suggesting a possible transfer of this gene among the three clinical species. Conjugation experiments were performed using K. pneumoniae (1 isolate), P. mirabilis (2 isolates) and E. cloacae (2 isolates) as donors and E. coli J53 as a recipient. The bla(NDM-1) gene was identified by PCR analysis in all transconjugants obtained. The presence of four different bacterial species harboring resistance genes to different classes of antibiotics in a single patient substantially reduced the therapeutic options. | 2023 | 36978306 |
| 888 | 17 | 0.9998 | Identification of New Delhi metallo-β-lactamase 1 in Acinetobacter lwoffii of food animal origin. BACKGROUND: To investigate the presence of metallo-β-lactamase (MBL) genes and the genetic environment of the New Delhi metallo-β-lactamase gene bla(NDM-1) in bacteria of food animal origin. METHODOLOGY/PRINCIPAL FINDINGS: Gram-negative bacteria with low susceptibility to imipenem (MIC>8 µg/mL) were isolated from swab samples collected from 15 animal farms and one slaughterhouse in eastern China. These bacteria were selected for phenotypic and molecular detection of known MBL genes and antimicrobial susceptibility testing. For the bla(NDM-1) positive isolate, conjugation and transformation experiments were carried out to assess plasmid transfer. Southern blotting was conducted to localize the bla(NDM-1) genes, and DNA sequencing was performed to determine the sequences of bla(NDM-1) and the flanking genes. In total, nine gram-negative bacteria of four different species presented a MBL phenotype. bla(NDM-1) was identified on a mobile plasmid named pAL-01 in an Acinetobacter lwoffii isolate of chicken origin. Transfer of pAL-01 from this isolate to E. coli J53 and JM109 resulted in resistance to multiple β-lactams. Sequence analysis revealed that the bla(NDM-1) gene is attached to an intact insertion element ISAba125, whose right inverted repeat (IR-R) overlaps with the promoter sequence of bla(NDM-1). Thus, insertion of ISAba125 likely enhances the expression of bla(NDM-1). CONCLUSION: The identification of a bla(NDM-1)- carrying strain of A. lwoffii in chickens suggests the potential for zoonotic transmission of bla(NDM-1) and has important implications for food safety. | 2012 | 22629360 |
| 1629 | 18 | 0.9998 | Molecular detection of colistin resistance genes (mcr-1 to mcr-5) in human vaginal swabs. OBJECTIVE: Colistin resistance has emerged worldwide and has been threatening the efficacy of one of the last-resort antimicrobials used for treatment of multidrug resistant Gram-negative bacteria. While five colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5) have been described, few data are available on the prevalence of mcr-genes other than mcr-1 in human samples. RESULTS: In this study, the presence of five currently described colistin resistance genes (mcr 1-5) in vaginal swabs of women undergoing infertility evaluation was reported. Most samples were found to be positive for the mcr-4 (12.7%), followed by two for the mcr-2 (1.5%), two for the mcr-3 (1.5%), one for the mcr-1 (0.7%), and one for the mcr-5 (0.7%). Phylogenetic comparison demonstrated identical (mcr-1, mcr-2, mcr-3, mcr-5) or similar (mcr-4) nucleotide sequences of human samples and those of animal origins from the same city, suggesting the potential transmission of mcr genes from animals to humans. This is the first detection of mcr-2, mcr-4 and mcr-5 genes in human samples, and warrants further research to determine the spread of the mcr genes and elucidate the full epidemiology of colistin resistance genes in humans. | 2018 | 29463301 |
| 1684 | 19 | 0.9998 | Plasmid-encoded gene duplications of extended-spectrum β-lactamases in clinical bacterial isolates. INTRODUCTION: The emergence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is an urgent and alarming One Health problem. This study aimed to investigate duplications of plasmid-encoded ESBL genes and their impact on antimicrobial resistance (AMR) phenotypes in clinical and screening isolates. METHODS: Multi-drug-resistant bacteria from hospitalized patients were collected during routine clinical surveillance from January 2022 to June 2023, and their antimicrobial susceptibility patterns were determined. Genotypes were extracted from long-read whole-genome sequencing data. Furthermore, plasmids and other mobile genetic elements associated with ESBL genes were characterized, and the ESBL genes were correlated to ceftazidime minimal inhibitory concentration (MIC). RESULTS: In total, we identified four cases of plasmid-encoded ESBL gene duplications that match four genetically similar plasmids during the 18-month surveillance period: five Escherichia coli and three Klebsiella pneumoniae isolates. As the ESBL genes were part of transposable elements, the surrounding sequence regions were duplicated as well. In-depth analysis revealed insertion sequence (IS)-mediated transposition mechanisms. Isolates with duplicated ESBL genes exhibited a higher MIC for ceftazidime in comparison to isolates with a single gene copy (3-256 vs. 1.5-32 mg/L, respectively). CONCLUSION: ESBL gene duplications led to an increased phenotypic resistance against ceftazidime. Our data suggest that ESBL gene duplications by an IS-mediated transposition are a relevant mechanism for how AMR develops in the clinical setting and is part of the microevolution of plasmids. | 2024 | 38469349 |