Resistome of carbapenem- and colistin-resistant Klebsiella pneumoniae clinical isolates. - Related Documents




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168601.0000Resistome 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.201829883490
168510.9999Molecular 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.202438479059
168020.9999Emergence 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.202438494251
168930.9999Occurrence 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.202235138190
162940.9999Molecular 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.201829463301
168450.9999Plasmid-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.202438469349
86960.9999The Prevalence of Antibiotic Resistance Phenotypes and Genotypes in Multidrug-Resistant Bacterial Isolates from the Academic Hospital of Jaén, Spain. The heterogenicity of antimicrobial resistance genes described in clinically significant bacterial isolates and their potential role in reducing the efficacy of classically effective antibiotics pose a major challenge for global healthcare, especially in infections caused by Gram-negative bacteria. We analyzed 112 multidrug-resistant (MDR) isolates from clinical samples in order to detect high resistance profiles, both phenotypically and genotypically, among four Gram-negative genera (Acinetobacter, Escherichia, Klebsiella, and Pseudomonas). We found that 9.8% of the total selected isolates were classified as extensively drug-resistant (XDR) (six isolates identified as A. baumannii and five among P. pneumoniae isolates). All other isolates were classified as MDR. Almost 100% of the isolates showed positive results for bla(OXA-23) and bla(NDM-1) genes among the A. baumannii samples, one resistance gene (bla(CTX-M)) among E. coli, and two genetic determinants (bla(CTX-M) and aac(6')-Ib) among Klebsiella. In contrast, P. aeruginosa showed just one high-frequency antibiotic resistance gene (dfrA), which was present in 68.42% of the isolates studied. We also describe positive associations between ampicillin and cefotaxime resistance in A. baumannii and the presence of bla(VEB) and bla(GES) genes, as well as between the aztreonam resistance phenotype and the presence of bla(GES) gene in E. coli. These data may be useful in achieving a better control of infection strategies and antibiotic management in clinical scenarios where these multidrug-resistant Gram-negative pathogens cause higher morbidity and mortality.202438786157
166770.9999Colistin Resistance Gene mcr-8 in a High-Risk Sequence Type 15 Klebsiella pneumoniae Isolate from Kenya. The emergence and rise of mobile colistin resistance genes are of great global concern due to the ease of transfer of resistance to other bacteria. This report describes the genome of a colistin- and multidrug-resistant Klebsiella pneumoniae isolate bearing mcr-8, obtained from a hospitalized patient in Kenya.202032972937
168280.9999Multidrug-Resistant and Clinically Relevant Gram-Negative Bacteria Are Present in German Surface Waters. Water is considered to play a role in the dissemination of antibiotic-resistant Gram-negative bacteria including those encoding Extended-spectrum beta-lactamases (ESBL) and carbapenemases. To investigate the role of water for their spread in more detail, we characterized ESBL/Carbapenemase-producing bacteria from surface water and sediment samples using phenotypic and genotypic approaches. ESBL/Carbapenemase-producing isolates were obtained from water/sediment samples. Species and antibiotic resistance were determined. A subset of these isolates (n = 33) was whole-genome-sequenced and analyzed for the presence of antibiotic resistance genes and virulence determinants. Their relatedness to isolates associated with human infections was investigated using multilocus sequence type and cgMLST-based analysis. Eighty-nine percent of the isolates comprised of clinically relevant species. Fifty-eight percent exhibited a multidrug-resistance phenotype. Two isolates harbored the mobile colistin resistance gene mcr-1. One carbapenemase-producing isolate identified as Enterobacter kobei harbored bla (VIM-) (1). Two Escherichia coli isolates had sequence types (ST) associated with human infections (ST131 and ST1485) and a Klebsiella pneumoniae isolate was classified as hypervirulent. A multidrug-resistant (MDR) Pseudomonas aeruginosa isolate encoding known virulence genes associated with severe lung infections in cystic fibrosis patients was also detected. The presence of MDR and clinically relevant isolates in recreational and surface water underlines the role of aquatic environments as both reservoirs and hot spots for MDR bacteria. Future assessment of water quality should include the examination of the multidrug resistance of clinically relevant bacterial species and thus provide an important link regarding the spread of MDR bacteria in a One Health context.201931849911
189990.9999Characteristics 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.201222808141
1630100.9999One Health study of mobile colistin resistance (mcr) in Salmonella enterica in Canada, 2017-2022. Colistin is a last-resort treatment for highly drug-resistant bacterial infections. Of 47,184 Salmonella isolates collected from 2017 to 2022 in Canada from human and animal/food sources, mobile colistin resistance (mcr) variants conferring colistin resistance were detected exclusively in humans (n = 15). These variants were mcr-1.1 (n = 7), mcr-3.1 (n = 5), mcr-3.2 (n = 2), and mcr-1.2 (n = 1). The most common mcr-containing serotypes were I 4,[5],12:i:- (n = 8) and Typhimurium (n = 3). The proportion of Salmonella carrying mcr genes remains low in Canada (0.03%). IMPORTANCE: Colistin can be used in combination with other drugs as salvage therapy for extensively drug-resistant infections. If mobile colistin resistance (mcr) becomes widely disseminated in Enterobacterales, colistin will no longer be an option for salvage therapy in otherwise untreatable infections. While colistin is not commonly used to treat human Salmonella infections, Salmonella represents an important reservoir of mcr genes that may be transmitted to other gram-negative bacteria. Our aim was to determine the occurrence of mcr genes in Salmonella isolates collected from humans, food animals, and retail meats in Canada.202540387317
859110.9999Analysis of mcr family of colistin resistance genes in Gram-negative isolates from a tertiary care hospital in India. AIM: Colistin serves as the drug of last resort for combating numerous multidrug-resistant (MDR) Gram-negative infections. Its efficacy is hampered by the prevalent issue of colistin resistance, which severely limits treatment options for critically ill patients. Identifying resistance genes is crucial for controlling resistance spread, with horizontal gene transfer being the primary mechanism among bacteria. This study aimed to assess the prevalence of plasmid-mediated mcr genes associated with colistin resistance in Gram-negative bacteria, utilizing both genotypic and phenotypic tests. METHODS AND RESULTS: The clinical isolates (n = 913) were obtained from a tertiary care center in Chennai, India. Colistin resistance was seen among Gram-negative isolates. These strains underwent screening for mcr-1, mcr-3, mcr-4, and mcr-5 genes via conventional PCR. Additionally, mcr-positive isolates were confirmed through Sanger sequencing and phenotypic testing. The bacterial isolates predominantly comprised Klebsiella pneumoniae (62.43%), Escherichia coli (19.71%), Pseudomonas aeruginosa (10.73%), and Acinetobacter baumannii (4.81%), along with other species. All isolates exhibited multidrug resistance to three or more antibiotic classes. Colistin resistance, determined via broth microdilution (BMD) using CLSI guidelines, was observed in 13.08% of the isolates studied. Notably, mcr-5 was detected in K. pneumoniae in PCR, despite its absence in Sanger sequencing and phenotypic tests (including the combined-disk test, colistin MIC in the presence of EDTA, and Zeta potential assays). This finding underscores the importance of employing multiple diagnostic approaches to accurately identify colistin resistance mechanisms.202438986507
1574120.9999Plethora of Resistance Genes in Carbapenem-Resistant Gram-Negative Bacteria in Greece: No End to a Continuous Genetic Evolution. Carbapenem-resistant Gram-negative bacteria are a public health threat that requires urgent action. The fact that these pathogens commonly also harbor resistance mechanisms for several other antimicrobial classes further reduces patient treatment options. The present study aimed to provide information regarding the multidrug resistance genetic background of carbapenem-resistant Gram-negative bacteria in Central Greece. Strains from a tertiary care hospital, collected during routine practice, were characterized using a DNA microarray-based assay. Various different resistance determinants for carbapenems, other beta-lactams, aminoglycosides, quinolones, trimethoprim, sulfonamides and macrolides were detected among isolates of the same sequence type. Eighteen different multidrug resistance genomic profiles were identified among the twenty-four K. pneumoniae ST258, seven different profiles among the eight K. pneumoniae ST11, four profiles among the six A. baumannii ST409 and two among the three K. oxytoca. This report describes the multidrug resistance genomic background of carbapenem-resistant Gram-negative bacteria from a tertiary care hospital in Central Greece, providing evidence of their continuous genetic evolution.202235056608
1687130.9999Multiple NDM-5-Expressing Escherichia Coli Isolates From an Immunocompromised Pediatric Host. BACKGROUND: Genes conferring carbapenem resistance have disseminated worldwide among Gram-negative bacteria. Here we present longitudinal changes in clinically obtained Escherichia coli isolates from 1 immunocompromised pediatric patient. This report demonstrates potential for antibiotic resistance genes and plasmids to emerge over time in clinical isolates from patients receiving intensive anticancer chemotherapy and broad-spectrum antibiotics. METHODS: Thirty-three isolates obtained over 7 months from 1 patient were included. Clinical data were abstracted from the medical record. For each isolate, studies included phenotypic antibacterial resistance patterns, sequence typing, bacterial isolate sequencing, plasmid identification, and antibiotic resistance gene identification. RESULTS: Sites of isolation included blood, wound culture, and culture for surveillance purposes from the perianal area. Isolates were of 5 sequence types (STs). All were resistant to multiple classes of antibiotics; 23 (69.6%) were phenotypically resistant to all carbapenems. The blaNDM-5 gene was identified in 22 (67%) isolates, all of ST-167 and ST-940, and appeared to coincide with the presence of the IncFII and IncX3 plasmid. CONCLUSIONS: We present unique microbiologic data from 33 multidrug-resistant E. coli isolates obtained over the course of 7 months from an individual patient in the United States. Two E. coli sequence types causing invasive infection in the same patient and harboring the blaNDM-5 gene, encoded on the IncX3 plasmid and the IncFII plasmid, were identified. This study highlights the emergence of multidrug-resistant bacteria on antibiotic therapy and the necessity of adequate neutrophil number and function in the clearance of bacteremia.202032047833
1668140.9999Detection of OXA-181 Carbapenemase in Shigella flexneri. We report the detection of OXA-181 carbapenemase in an azithromycin-resistant Shigella spp. bacteria in an immunocompromised patient. The emergence of OXA-181 in Shigella spp. bacteria raises concerns about the global dissemination of carbapenem resistance in Enterobacterales and its implications for the treatment of infections caused by Shigella bacteria.202438666725
877150.9999Drug resistance analysis of three types of avian-origin carbapenem-resistant Enterobacteriaceae in Shandong Province, China. Animal-derived Enterobacteriaceae bacteria such as Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), and Klebsiella pneumoniae (K. pneumoniae) are important food-borne zoonotic bacilli that exist widely in the broiler-breeding industry. Although carbapenem antibiotics are considered to be the last line of defense against multidrug-resistant bacteria, carbapenem-resistant Enterobacteriaceae (CRE) break through them. In our study, we therefore, examined the prevalence of CRE and characteristics of antimicrobial resistance in 6 conventional broiler-fattening farms in Shandong Province, China. Our study revealed isolation rates of 3.57% (6/168) for carbapenem-resistant E. coli, 10% (5/50) for carbapenem-resistant P. mirabilis, and 3.03% (1/33) for carbapenem-resistant K. pneumoniae. All 12 CRE bacterial strains showed varying degrees of resistance to 27 antibiotics in 8 classes and were multidrug-resistant. The rate of the strains containing bla(NDM) genes, at 91.67% (11/12), was especially high. Among other results, the carrying rate of integrons in CRE bacteria was 91.67% (11/12), and 2 strains carried both class I and class II integrons, which accelerated the lateral transmission of resistant bacteria. Our first-ever finding of the 3 CRE bacteria E. coli, P. mirabilis, and K. pneumoniae on the same broiler farm suggests that poultry-derived CRE strains may pose a risk to humans. Moreover, our findings from surveillance can inform current understandings of the prevalence and characteristics of multidrug-resistant CRE in Shandong Province and, in turn, help to curb threats to food safety and public health and better prevent and control infectious zoonotic diseases.202336682131
1732160.9999High 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.202135052892
1526170.9999Carbapenem 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.202337871361
1714180.9999Carbapenemase-producing enterobacteriaceae recovered from a Spanish river ecosystem. The increasing resistance to carbapenems is an alarming threat in the fight against multiresistant bacteria. The dissemination properties of antimicrobial resistance genes are supported by their detection in a diverse population of bacteria, including strains isolated from the environment. The objective of this study was to investigate the presence of carbapenemase-producing Enterobacteriaceae (CPE) collected from a river ecosystem in the Barcelona metropolitan area (Spain). Identification of β-lactamases and other resistance determinants was determined as was the antimicrobial susceptibility profile. Moreover, screening of virulence factors, plasmid addiction systems, plasmid partition systems and replicon typing was performed. The results identified 8 isolates belonging to different species (Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Raoultella ornithinolytica). The most prevalent enzyme was KPC-2 (n = 6), followed by VIM-1 (n = 2) and IMI-2 (n = 1), whereas no OXA-48-type was detected. In addition, one strain was positive for both KPC-2 and VIM-1 enzymes. All the carbapenemase-encoding plasmids carried at least one plasmid addiction or partition system, being vagCD and parAB the most frequently detected, respectively. E. coli and K. pneumoniae isolates carried a low number of virulence-associated factors and none of the detected clones has previously been identified in the clinical setting. These findings support the high dissemination potential of the carbapanemase-encoding genes and reinforce the idea that the environment is another reservoir that may play an important role in the capture, selection and dissemination of carbapenem resistance genes.201728380016
1688190.9999Carriage of colistin-resistant Gram-negative bacteria in children from communities in Cape Town (Tuberculosis child multidrug-resistant preventive therapy trial sub-study). Colistin is a last-resort antibiotic against multidrug-resistant, Gram-negative bacteria. Colistin resistance has been described in the clinical settings in South Africa. However, information on carriage of these bacteria in communities is limited. This study investigated gastrointestinal carriage of colistin-resistant Escherichia coli and Klebsiella spp. and mcr genes in children from communities in Cape Town. Colistin-resistant E. coli was isolated from two participants (4%, 2/50), and mcr-1-mcr-9 genes were not detected. Gastrointestinal carriage of colistin-resistant Enterobacterales was rare; however, continuous extensive surveillance is necessary to determine the extent of carriage and its contribution to resistance observed in clinical settings.202134485500