Emergence and dissemination of bla(KPC-31) and bla(PAC-2) among different species of Enterobacterales in Colombia: a new challenge for the microbiological laboratories. - Related Documents




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182101.0000Emergence and dissemination of bla(KPC-31) and bla(PAC-2) among different species of Enterobacterales in Colombia: a new challenge for the microbiological laboratories. Ceftazidime/avibactam (CZA) is a promising treatment option for infections caused by carbapenem-resistant Enterobacterales (CRE). However, CZA resistance is increasingly reported worldwide, largely due to the emergence of KPC variants and increase of metallo-β-lactamases (MBL). This study describes the mechanisms associated with CZA resistance in circulating Enterobacterales isolates from Colombia, highlighting the challenge this represents for microbiological identification. Between 2021 and 2024, 68 CZA-resistant Enterobacterales isolates were identified by automated methods in seven Colombian cities. Resistance to CZA was subsequently confirmed by broth microdilution and E-test. Carbapenemase production was evaluated using phenotypic tests, such as the mCIM test, Carba NP, lateral flow assay, and qPCR (bla(KPC), bla(NDM), bla(VIM), bla(IMP), and bla(OXA-48)). Whole-genome sequencing was performed on 15 isolates that tested negative for MBL genes. Whole-genome sequencing of these 15 isolates revealed a variety of resistance determinants: six isolates harbored bla(KPC-31), one bla(KPC-33), one bla(KPC-8), five harbored bla(PAC-2), and two co-harbored bla(PAC-2) and bla(KPC-2). Notably, bla(PAC-2) was located on an IncQ plasmid. However, some of these variants were not detected by phenotypic assays, likely due to their low or undetectable carbapenemase activity. CZA resistance in non-MBL producing Enterobacterales in Colombia is primarily mediated by the presence of bla(KPC-31) and emergence of bla(PAC-2). These resistance mechanisms pose significant diagnostic, therapeutic, and epidemiological challenges, as they frequently go undetected by conventional microbiological methods. In this context, enhanced molecular surveillance and improved diagnostic strategies are urgently needed to enable early detection, guide antimicrobial therapy, and support infection control and stewardship efforts.IMPORTANCEAntibiotic resistance is a serious global health threat. Ceftazidime/avibactam (CZA) is a key treatment option for multidrug-resistant (MDR) Enterobacterales often used when other antibiotics fail. However, bacteria are now developing resistance to this drug as well, making infections increasingly difficult to treat. In this study, we examined CZA-resistant bacteria from multiple cities in Colombia and found uncommon resistance genes across several bacterial species. These genes are frequently missed, as they often do not test positive due to the limitations of most routinely used laboratory tests. Importantly, some of these genes can be transferred between bacteria, increasing the likelihood of indiscriminate dissemination in the hospital setting. Therefore, our findings highlight the urgent need for improved diagnostic tools and molecular surveillance. Early detection will help physicians select effective treatments quickly and prevent the wider dissemination of these MDR-resistant bacteria.202541070989
168010.9998Emergence 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
167820.9998Molecular characterization and descriptive analysis of carbapenemase-producing Gram-negative rod infections in Bogota, Colombia. In this study, the genetic differences and clinical impact of the carbapenemase-encoding genes among the community and healthcare-acquired infections were assessed. This retrospective, multicenter cohort study was conducted in Colombia and included patients infected with carbapenem-resistant Gram-negative rods between 2017 and 2021. Carbapenem resistance was identified by Vitek, and carbapenemase-encoding genes were identified by whole-genome sequencing (WGS) to classify the alleles and sequence types (STs). Descriptive statistics were used to determine the association of any pathogen or gene with clinical outcomes. A total of 248 patients were included, of which only 0.8% (2/248) had community-acquired infections. Regarding the identified bacteria, the most prevalent pathogens were Pseudomonas aeruginosa and Klebsiella pneumoniae. In the WGS analysis, 228 isolates passed all the quality criteria and were analyzed. The principal carbapenemase-encoding gene was blaKPC, specifically blaKPC-2 [38.6% (88/228)] and blaKPC-3 [36.4% (83/228)]. These were frequently detected in co-concurrence with blaVIM-2 and blaNDM-1 in healthcare-acquired infections. Notably, the only identified allele among community-acquired infections was blaKPC-3 [50.0% (1/2)]. In reference to the STs, 78 were identified, of which Pseudomonas aeruginosa ST111 was mainly related to blaKPC-3. Klebsiella pneumoniae ST512, ST258, ST14, and ST1082 were exclusively associated with blaKPC-3. Finally, no particular carbapenemase-encoding gene was associated with worse clinical outcomes. The most identified genes in carbapenemase-producing Gram-negative rods were blaKPC-2 and blaKPC-3, both related to gene co-occurrence and diverse STs in the healthcare environment. Patients had several systemic complications and poor clinical outcomes that were not associated with a particular gene.IMPORTANCEAntimicrobial resistance is a pandemic and a worldwide public health problem, especially carbapenem resistance in low- and middle-income countries. Limited data regarding the molecular characteristics and clinical outcomes of patients infected with these bacteria are available. Thus, our study described the carbapenemase-encoding genes among community- and healthcare-acquired infections. Notably, the co-occurrence of carbapenemase-encoding genes was frequently identified. We also found 78 distinct sequence types, of which two were novel Pseudomonas aeruginosa, which could represent challenges in treating these infections. Our study shows that in low and middle-income countries, such as Colombia, the burden of carbapenem resistance in Gram-negative rods is a concern for public health, and regardless of the allele, these infections are associated with poor clinical outcomes. Thus, studies assessing local epidemiology, prevention strategies (including trials), and underpinning genetic mechanisms are urgently needed, especially in low and middle-income countries.202438629835
157130.9998Klebsiella pneumoniae ST147 harboring bla(NDM-1), multidrug resistance and hypervirulence plasmids. The spread of hypervirulent (hv) and carbapenem-/multidrug-resistant Klebsiella pneumoniae is an emerging problem in healthcare settings. The New Delhi metallo-β-lactamase-1 (bla(NDM-1)) is found in Enterobacteriaceae including K. pneumoniae. The bla(NDM-1) is capable of hydrolyzing β-lactam antibiotics which are used for treatment of severe infections caused by multidrug-resistant Gram-negative bacteria. This is associated with the unacceptably high mortality rate in immunocompromised burn injury patients. This study reports on the characterization of bla(NDM-1) gene and virulence factors in hv carbapenem-/multidrug-resistant K. pneumoniae ST147 in the burns unit of a tertiary teaching hospital during routine surveillance. Two K. pneumoniae strains were obtained from wounds of burn-infected patients from May 2020 to July 2021. The hypervirulence genes and genetic context of the bla(NDM-1) gene and mobile genetic elements potentially involved in the transposition of the gene were analyzed. We identified a conserved genetic background and an IS26 and open reading frame flanking the bla(NDM-1) gene that could suggest its involvement in the mobilization of the gene. The plasmid harbored additional antibiotic resistance predicted regions that were responsible for resistance to almost all the routinely used antibiotics. To ensure the identification of potential outbreak strains during routine surveillance, investigations on resistance genes and their environment in relation to evolution are necessary for molecular epidemiology.IMPORTANCEData obtained from this study will aid in the prompt identification of disease outbreaks including evolving resistance and virulence of the outbreak bacteria. This will help establish and implement antimicrobial stewardship programs and infection prevention protocols in fragile health systems in countries with limited resources. Integration of molecular surveillance and translation of whole-genome sequencing in routine diagnosis will provide valuable data for control of infection. This study reports for the first time a high-risk clone K. pneumoniae ST147 with hypervirulence and multidrug-resistance features in Ghana.202438315028
190740.9997Nationwide surveillance of carbapenem-resistant Gram-negative pathogens in the Lebanese environment. Gram-negative ESKAPE pathogens with carbapenem resistance pose a significant health threat. Despite extensive research on the spread of these pathogens within Lebanese hospital settings, their emergence in environmental settings remains understudied. This study aimed to explore the environmental spread of carbapenem resistance among Gram-negative bacteria isolated from environmental samples in nine districts across Lebanon. A total of 250 samples were collected from wild animals, sewage, water, and soil between June 2022 and September 2023. Samples were streaked on MacConkey agar plates supplemented with 2 mg/L meropenem. Bacterial species were identified primarily using API20E. Antimicrobial susceptibility profiles were determined by the disk diffusion method and the Vitek 2 compact system. Meropenem-resistant Gram-negative bacteria were further characterized by whole-genome sequencing, and each of the bacterial species, sequence types, resistance genes, and plasmids was detected by sequence data analysis. We successfully isolated 130 carbapenem-resistant isolates from various samples, 67 of which belonged to the ESKAPE pathogens list and showed a multidrug-resistant (MDR) profile. The distribution of the latter was as follows: Escherichia coli (65.67%), Acinetobacter baumannii (16.42%), Pseudomonas aeruginosa (11.94%), and Klebsiella pneumoniae (5.97%). Several carbapenem resistance genes were detected, with a prevalence of blaNDM-5 in Escherichia coli and Klebsiella pneumoniae, blaIMP-1 and mexAB-OprM efflux pumps in Pseudomonas aeruginosa, and blaOXA-23 in Acinetobacter baumannii. Our findings revealed a widespread distribution of carbapenem-resistant ESKAPE bacteria in Lebanon, underscoring the significant public health risk posed by these pathogens. This highlights the urgent need to address the dissemination of antibiotic resistance in Lebanese environmental settings. IMPORTANCE: The emergence of antimicrobial resistance (AMR) extremely burdens public health and increases morbid and mortal threats in Lebanon. While the majority of the studies in our country target antimicrobial resistance in clinical settings, fewer studies focus on antimicrobial resistance dissemination in the environment. The significance of our research is that it sheds light on the environment as a less explored yet equally crucial sector in the spread of AMR. Here, we isolated carbapenemase-producing bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) that were categorized as multidrug resistant (MDR) from diverse environmental sources in multiple provinces across Lebanon. The finding of carbapenem-resistant bacteria carrying plasmids represents a potential risk due to the possible spread of resistance genes via horizontal gene transfer across the environment and hospital settings. This highly recommends the implementation of regular surveillance to monitor the spread of antimicrobial resistance among environmental bacteria, which consequently leads to its spread within communities and thus poses a great threat to human health.202540492734
167450.9997Bloodstream infections caused by multidrug-resistant gram-negative bacteria: epidemiological, clinical and microbiological features. BACKGROUND: Bloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB). METHODS: We conducted a laboratory-based surveillance for gram-negative bacteremia over a 1-year period. The bacterial isolates were identified by MALDI-TOF/MS and the antimicrobial susceptibility testing was performed by VITEK®2. Resistance genes were identified through PCR assays. RESULTS: Of the 143 patients, 28.7% had infections caused by MDR-GNB. The risk factors for MDR bacteremia were male sex, age ≥ 60, previous antimicrobial use, liver disease and bacteremia caused by K. pneumoniae. K. pneumoniae was the most frequently observed causative agent and had the highest resistance level. Regarding the resistance determinants, SHV, TEM, OXA-1-like and CTX-M-gp1 were predominant enzymatic variants, whereas CTX-M-gp9, CTX-M-gp2, KPC, VIM, GES, OXA-48-like, NDM and OXA-23-like were considered emerging enzymes. CONCLUSIONS: Here we demonstrate that clinically relevant antibiotic resistance genes are prevalent in this setting. We hope our findings support the development of intervention measures by policy makers and healthcare professionals to face antibiotic resistance.201931296179
182860.9997Monitoring of hospital sewage shows both promise and limitations as an early-warning system for carbapenemase-producing Enterobacterales in a low-prevalence setting. Carbapenemase-producing Enterobacterales (CPE) constitute a significant threat to healthcare systems. Continuous surveillance is important for the management and early warning of these bacteria. Sewage monitoring has been suggested as a possible resource-efficient complement to traditional clinical surveillance. It should not least be suitable for rare forms of resistance since a single sewage sample contains bacteria from a large number of individuals. Here, the value of sewage monitoring in early warning of CPE was assessed at the Sahlgrenska University Hospital in Gothenburg, Sweden, a setting with low prevalence of CPE. Twenty composite hospital sewage samples were collected during a two-year period. Carbapenemase genes in the complex samples were analyzed by quantitative PCR and the CPE loads were assessed through cultures on CPE-selective agar followed by species determination as well as phenotypic and genotypic tests targeting carbapenemases of presumed CPE. The findings were related to CPE detected in hospitalized patients. A subset of CPE isolates from sewage and patients were subjected to whole genome sequencing. For three of the investigated carbapenemase genes, bla(NDM), bla(OXA-48-like) and bla(KPC), there was concordance between gene levels and abundance of corresponding CPE in sewage. For the other two analyzed genes, bla(VIM) and bla(IMP), there was no such concordance, most likely due to the presence of those genes in non-Enterobacterales populating the sewage samples. In line with the detection of OXA-48-like- and NDM-producing CPE in sewage, these were also the most commonly detected CPE in patients. NDM-producing CPE were detected on a single occasion in sewage and isolated strains were shown to match strains detected in a patient. A marked peak in CPE producing OXA-48-like enzymes was observed in sewage during a few months. When levels started to increase there were no known cases of such CPE at the hospital but soon after a few cases were detected in samples from patients. The OXA-48-like-producing CPE from sewage and patients represented different strains, but they carried similar bla(OXA-48-like)-harbouring mobile genetic elements. In conclusion, sewage analyses show both promise and limitations as a complement to traditional clinical resistance surveillance for early warning of rare forms of resistance. Further evaluation and careful interpretation are needed to fully assess the value of such a sewage monitoring system.202134082263
182370.9997Finding the Missing IMP Gene: Overcoming the Imipenemase IMP Gene Drop-Out in Automated Molecular Testing for Carbapenem-Resistant Bacteria Circulating in Latin America. Carbapenem resistance is considered one of the greatest current threats to public health, particularly in the management of infections in clinical settings. Carbapenem resistance in bacteria is mainly due to mechanisms such as the production of carbapenemases (such as the imipenemase IMP, or other enzymes like VIM, NDM, and KPC), that can be detected by several laboratory tests, including immunochromatography and automated real-time PCR (qPCR). Methods: As part of local studies to monitor carbapenem-resistant bacteria in Costa Rica, two cases were initially identified with inconsistent IMP detection results. A possible gene drop-out in the automated qPCR test was suggested based on the negative result, contrasting with the positive result by immunochromatography and whole-genome sequencing. We hypothesized that molecular testing could be optimized through the development of tailored assays to improve the detection of IMP genes. Thus, using IMP gene sequences from the local isolates and regional sequences in databases, primers were redesigned to extend the detection of IMP alleles of regional relevance. Results: The tailored qPCR was applied to a local collection of 119 carbapenem-resistant isolates. The genomes of all 14 positive cases were sequenced, verifying the results of the custom qPCR, despite the negative results of the automated testing. Conclusions: Guided by whole-genome sequencing, it was possible to extend the molecular detection of IMP alleles circulating in Latin America using a tailored qPCR to overcome IMP gene drop-out and false-negative results in an automated qPCR.202540867967
182280.9997Carriage of two carbapenem-resistance genes in Pseudomonas aeruginosa isolated from hospital-acquired infections in children from Costa Rica: the importance of local epidemiology. BACKGROUND: The assessment of Hospital-acquired infections due to multidrug-resistant bacteria involves the use of a variety of commercial and laboratory-developed tests to detect antimicrobial resistance genes in bacterial pathogens; however, few are evaluated for use in low- and middle-income countries. METHODS: We used whole-genome sequencing, rapid commercial molecular tests, laboratory-developed tests and routine culture testing. RESULTS: We identified the carriage of the metallo-β-lactamase bla(VIM-2) and bla(IMP-18) alleles in Carbapenem-Resistant Pseudomonas aeruginosa infections among children in Costa Rica. CONCLUSIONS: The bla(IMP-18) allele is not present in the most frequently used commercial tests; thus, it is possible that the circulation of this resistance gene may be underdiagnosed in Costa Rica.202133910633
225490.9997Hospitalized Pets as a Source of Carbapenem-Resistance. The massive and irrational use of antibiotics in livestock productions has fostered the occurrence and spread of resistance to "old class antimicrobials." To cope with that phenomenon, some regulations have been already enforced in the member states of the European Union. However, a role of livestock animals in the relatively recent alerts on the rapid worldwide increase of resistance to last-choice antimicrobials as carbapenems is very unlikely. Conversely, these antimicrobials are increasingly administered in veterinary hospitals whose role in spreading bacteria or mobile genetic elements has not adequately been addressed so far. A cross-sectional study was carried out on 105 hospitalized and 100 non-hospitalized pets with the aim of measuring the prevalence of carbapenem-resistant Gram-negative bacteria (GNB) colonizing dogs and cats, either hospitalized or not hospitalized and estimating the relative odds. Stool samples were inoculated on MacConkey agar plates containing 1 mg/L imipenem which were then incubated aerobically at 37°C ± 1 for 48 h. Isolated bacteria were identified first by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were confirmed by 16S rRNA sequencing. The genetic basis of resistance was investigated using PCR methods, gene or whole genome sequencing (WGS). The prevalence of pets harboring carbapenem-resistant bacteria was 11.4 and 1.0% in hospitalized and not-hospitalized animals, respectively, with an odds ratio of 12.8 (p < 0.01). One pet carried two diverse isolates. Overall, 14 gram-negative non-fermenting bacteria, specifically, one Acinetobacter radioresistens, five Acinetobacter baumannii, six Pseudomonas aeruginosa and two Stenotrophomonas maltophilia were isolated. The Acinetobacter species carried acquired carbapenemases genes encoded by bla (NDM-1) and bla (OXA-23). In contrast, Pseudomonas phenotypic resistance was associated with the presence of mutations in the oprD gene. Notably, inherent carbapenem-resistant isolates of S. maltophilia were also resistant to the first-line recommended chemotherapeutic trimethoprim/sulfamethoxazole. This study estimates the risk of colonization by carbapenem-resistant non-fermenting GNB in pets hospitalized in veterinary tertiary care centers and highlights their potential role in spreading resistance genes among the animal and human community. Public health authorities should consider extending surveillance systems and putting the release of critical antibiotics under more strict control in order to manage the infection/colonization of pets in veterinary settings.201830574124
2249100.9997Tracking Multidrug Resistance in Gram-Negative Bacteria in Alexandria, Egypt (2020-2023): An Integrated Analysis of Patient Data and Diagnostic Tools. BACKGROUND: The rise in carbapenem-resistant Enterobacteriaceae (CRE) in Egypt, particularly in hospital settings, poses a significant public health challenge. This study aims to develop a combined epidemiological surveillance tool utilizing the Microreact online platform (version 269) and molecular microarray technology to track and analyze carbapenem-resistant Escherichia coli strains in Egypt. The objective is to integrate molecular diagnostics and real-time data visualization to better understand the spread and evolution of multidrug-resistant (MDR) bacteria. METHODS: The study analyzed 43 E. coli isolates collected from Egyptian hospitals between 2020 and 2023. Nanopore sequencing and microarray analysis were used to identify carbapenemase genes and other resistance markers, whereas the VITEK2 system was employed for phenotypic antibiotic susceptibility testing. Microreact was used to visualize epidemiological data, mapping the geographic and temporal distribution of resistant strains. RESULTS: We found that 72.09% of the isolates, predominantly from pediatric patients, carried the blaNDM-5 gene, while other carbapenemase genes, including blaOXA-48 and blaVIM, were also detected. The microarray method demonstrated 92.9% diagnostic sensitivity and 87.7% diagnostic specificity compared to whole-genome sequencing. Phenotypic resistance correlated strongly with next-generation sequencing (NGS) genotypic data, achieving 95.6% sensitivity and 95.2% specificity. CONCLUSIONS: This method establishes the utility of combining microarray technology, NGS and real-time data visualization for the surveillance of carbapenem-resistant Enterobacteriaceae, especially E. coli. The high concordance between genotypic and phenotypic data underscores the potential of DNA microarrays as a cost-effective alternative to whole-genome sequencing, especially in resource-limited settings. This integrated approach can enhance public health responses to MDR bacteria in Egypt.202439766575
1829110.9997Environmental surveillance of ESBL and carbapenemase-producing gram-negative bacteria in a Ghanaian Tertiary Hospital. BACKGROUND: The burden of antibiotic resistant infection is mainly felt in low-to-middle income countries, where the rate of antimicrobial resistance is largely under-surveyed and under huge pressure from unregulated, disparate and often self-guided access to antimicrobials. Nosocomial infections from hospital environments have been shown to be a particularly prevalent source of multi-drug resistant strains, yet surveillance of hospital environmental contamination is often not investigated. METHODS: The study was prospective, observational and cross-sectional, sampling 231 high and low touch surfaces from 15th March to 13th April 2021, from five wards in the Cape Coast Teaching Hospital, Ghana. Microbial growth in the presence of vancomycin and either meropenem or cefotaxime was examined and bacterial species were identified by MALDI-TOF. The presence of common extended-spectrum β-lactamases (ESBL) and carbapenemase antimicrobial resistance genes (ARG) were identified through PCR screening, which were confirmed by phenotypic antimicrobial susceptibility determination. Isolates positive for carbapenem resistance genes were sequenced using a multi-platform approach. RESULTS: We recovered microbial growth from 99% of swabs (n = 229/231) plated on agar in the absence of antimicrobials. Multiple sites were found to be colonised with resistant bacteria throughout the hospital setting. Bacteria with multi-drug resistance and ARG of concern were isolated from high and low touch points with evidence of strain dissemination throughout the environment. A total of 21 differing species of bacteria carrying ARG were isolated. The high prevalence of Acinetobacter baumannii carrying bla(NDM-1) observed was further characterised by whole genome sequencing and phylogenetic analysis to determine the relationship between resistant strains found in different wards. CONCLUSION: Evidence of multiple clonal incursions of MDR bacteria of high sepsis risk were found in two separate wards for a regional hospital in Ghana. The prevalence of multiple bla(NDM) carrying species in combination with combinations of ESBLs was particularly concerning and unexpected in Africa. We also identify strains carrying tet(X3), bla(VIM-5) or bla(DIM-1) showing a high diversity of carbapenamases present as a reservoir in a hospital setting. Findings of multi-drug resistant bacteria from multiple environmental sites throughout the hospital will inform future IPC practices and aid research prioritisation for AMR in Ghana.202235296353
1552120.9997Evolution of β-Lactam Antibiotic Resistance in Proteus Species: From Extended-Spectrum and Plasmid-Mediated AmpC β-Lactamases to Carbapenemases. The management of infectious diseases has proven to be a daunting task for clinicians worldwide, and the rapid development of antibiotic resistance among Gram-negative bacteria is making it even more challenging. The first-line therapy is empirical, and it most often comprises β-lactam antibiotics. Among Gram-negative bacteria, Proteus mirabilis, an important community and hospital pathogen associated primarily with urinary tract and wound infection, holds a special place. This review's aim was to collate and examine recent studies investigating β-lactam resistance phenotypes and mechanisms of Proteus species and the global significance of its β-lactam resistance evolution. Moreover, the genetic background of resistance traits and the role of mobile genetic elements in the dissemination of resistance genes were evaluated. P. mirabilis as the dominant pathogen develops resistance to expanded-spectrum cephalosporins (ESC) by producing extended-spectrum β-lactamases (ESBL) and plasmid-mediated AmpC β-lactamases (p-AmpC). β-lactamase-mediated resistance to carbapenems in Enterobacterales, including Proteus spp., is mostly due to expression of carbapenemases of class A (KPC); class B (metallo-β-lactamases or MBLs of IMP, VIM, or NDM series); or class D or carbapenem-hydrolyzing oxacillinases (CHDL). Previously, a dominant ESBL type in P. mirabilis was TEM-52; yet, lately, it has been replaced by CTX-M variants, particularly CTX-M-14. ESC resistance can also be mediated by p-AmpC, with CMY-16 as the dominant variant. Carbapenem resistance in Proteus spp. is a challenge due to its intrinsic resistance to colistin and tigecyclin. The first carbapenemases reported belonged to class B, most frequently VIM-1 and NDM-5. In Europe, predominantly France and Belgium, a clonal lineage positive for OXA-23 CHDL spreads rapidly undetected, due to its low-level resistance to carbapenems. The amazing capacity of Proteus spp. to accumulate a plethora of various resistance traits is leading to multidrug or extensively drug-resistant phenotypes.202540142401
904130.9997High prevalence of contamination of sink drains with carbapenemase-producing Enterobacteriaceae in 4 intensive care units apart from any epidemic context. We report a high prevalence (28%) of sink drains contaminated with carbapenemase-producing Enterobacteriaceae (CPE) in 4 intensive care units with a history of CPE carriage in hospitalized patients within the previous 5 years, but apart from any current epidemic context. Carbapenemase genes, particularly bla(VIM) and bla(NDM), were identified by polymerase chain reaction in sink drains in which no CPE was detected, but very few data are available in the literature concerning their presence in sink drains.202031495643
1677140.9997A systematic review of the current status of carbapenem resistance in Nigeria: Its public health implication for national intervention. Carbapenem antibiotics are considered one of the most effective and the last-resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, with the advent of carbapenem resistance, it becomes obvious that quality health-care delivery will be hampered if adequate measure is not put in place. This review assessed the prevalence of carbapenem-resistant Gram-negative bacteria (CR-GNB) and also provided an up-to-date position on carbapenem resistance (CR) in Nigeria. Three electronic databases (Google Scholar, PubMed and African Journal online) were searched for relevant literatures, and 38 articles published between January 2013 and June 2022 that met the criteria for inclusion were recruited into the study. The mean prevalence of CR in Nigeria stands at 21.3%, with the southern and northern regions documenting a mean prevalence of 22.0% and 20.9%, respectively. Most of the reviewed articles were from clinical settings (81.6%), with urine samples (38.7%) constituting the most prevalent clinical sample in which CR-GNB were detected. The preponderance of phenotypic methods (55.3%) over molecular method (44.7%), particularly the use of disk diffusion test breakpoint and Modified Hodge test was documented. The most prevalent carbapenem-resistant bacteria were Escherichia coli (50.0%) and Klebsiella pneumoniae (26.3%). The blaNDM and blaVIM were the major reported carbapenemase-encoded genes, particularly among E. coli, K. pneumoniae and Pseudomonas species. This systematic review revealed a mean prevalence of CR-GNB in Nigeria that required urgent attention. Furthermore, the detection of clinically and epidemiologically important carbapenemase coding genes is of public health importance.202336814157
1668150.9997Detection 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
1686160.9997Resistome 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
1676170.9997Evaluation of carbapenem resistance using phenotypic and genotypic techniques in Enterobacteriaceae isolates. BACKGROUND: Bacterial resistance to antibiotics is increasing worldwide. Antibiotic-resistant strains can lead to serious problems regarding treatment of infection. Carbapenem antibiotics are the final treatment option for infections caused by serious and life-threatening multidrug-resistant gram-negative bacteria. Therefore, an understanding of carbapenem resistance is important for infection control. In the study described herein, the phenotypic and genotypic features of carbapenem-resistant Enterobacteriaceae strains isolated in our hospital were evaluated. METHODS: In total, 43 carbapenem-resistant strains were included in this study. Sensitivity to antibiotics was determined using the VITEK(®)2 system. The modified Hodge test (MHT) and metallo-β-lactamase (MBL) antimicrobial gradient test were performed for phenotypic identification. Resistance genes IMP, VIM, KPC, NDM-1, and OXA-48 were amplified by multiplex PCR. RESULTS: The OXA-48 gene was detected in seven strains, and the NDM-1 gene in one strain. No resistance genes were detected in the remainder of strains. A significant correlation was observed between the MHT test and OXA-48 positivity, and between the MBL antimicrobial gradient test and positivity for resistance genes (p < 0.05). CONCLUSION: The finding of one NDM-1-positive isolate in this study indicates that carbapenem resistance is spreading in Turkey. Carbapenem resistance spreads rapidly and causes challenges in treatment, and results in high mortality/morbidity rates. Therefore, is necessary to determine carbapenem resistance in Enterobacteriaceae isolates and to take essential infection control precautions to avoid spread of this resistance.201526444537
2229180.9997A pentaplex real-time PCR assay for rapid identification of major beta-lactamase genes KPC, NDM, CTX, CMY, and OXA-48 directly from bacteria in blood. Introduction. Antibiotic resistance, particularly in cases of sepsis, has emerged as a growing global public health concern and economic burden. Current methods of blood culture and antimicrobial susceptibility testing of agents involved in sepsis can take as long as 3-5 days. It is vital to rapidly identify which antimicrobials can be used to effectively treat sepsis cases on an individual basis. Here, we present a pentaplex, real-time PCR-based assay that can quickly identify the most common beta-lactamase genes (Klebsiella pneumoniae carbapenemase (KPC); New Delhi metallo-beta-lactamase (NDM); cefotaximase-Munich (CTX-M); cephamycin AmpC beta-lactamases (CMY); and Oxacillinase-48 (OXA-48)) from pathogens derived directly from the blood of patients presenting with bacterial septicemia.Aim. To develop an assay which can rapidly identify the most common beta-lactamase genes in Carbapenem-resistant Enterobacteriaceae bacteria (CREs) from the United States.Hypothesis/Gap Statement. Septicemia caused by carbapenem-resistant bacteria has a death rate of 40-60 %. Rapid diagnosis of antibiotic susceptibility directly from bacteria in blood by identification of beta-lactamase genes will greatly improve survival rates. In this work, we develop an assay capable of concurrently identifying the five most common beta-lactamase and carbapenemase genes.Methodology. Primers and probes were created which can identify all subtypes of Klebsiella pneumoniae carbapenemase (KPC); New Delhi metallo-beta-lactamase (NDM); cefotaximase-Munich (CTX); cephamycin AmpC beta-lactamase (CMY); and oxacillinase-48 (OXA-48). The assay was validated using 13 isolates containing various PCR targets from the Centre for Disease Control Antimicrobial Resistance Isolate Bank Enterobacterales Carbapenemase Diversity Panel. Blood obtained from volunteers was spiked with CREs and bacteria were separated, lysed, and subjected to analysis via the pentaplex assay.Results. This pentaplex assay successfully identified beta-lactamase genes derived from bacteria separated from blood at concentrations of 4-8 c.f.u. ml(-1).Conclusion. This assay will improve patient outcomes by supplying physicians with critical drug resistance information within 2 h of septicemia onset, allowing them to prescribe effective antimicrobials corresponding to the resistance gene(s) present in the pathogen. In addition, information supplied by this assay will lessen the inappropriate use of broad-spectrum antimicrobials and prevent the evolution of further antibiotic resistance.202134878374
1842190.9997Emergence of mcr-9.1 in Extended-Spectrum-β-Lactamase-Producing Clinical Enterobacteriaceae in Pretoria, South Africa: Global Evolutionary Phylogenomics, Resistome, and Mobilome. Extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae are critical-priority pathogens that cause substantial fatalities. With the emergence of mobile mcr genes mediating resistance to colistin in Enterobacteriaceae, clinicians are now left with few therapeutic options. Eleven clinical Enterobacteriaceae strains with resistance to cephems and/or colistin were genomically analyzed to determine their resistomes, mobilomes, and evolutionary relationships to global strains. The global phylogenomics of mcr genes and mcr-9.1-bearing genomes were further analyzed. Ten isolates were ESBL positive. The isolates were multidrug resistant and phylogenetically related to global clones but distant from local strains. Multiple resistance genes, including bla (CTX-M-15) bla (TEM-1), and mcr-9.1, were found in single isolates; ISEc9, IS19, and Tn3 transposons bracketed bla (CTX-M-15) and bla (TEM-1) Common plasmid types included IncF, IncH, and ColRNAI. mcr-9 was of close sequence identity to mcr-3, mcr-5, mcr-7, mcr-8, and mcr-10. Genomes bearing mcr-9.1 clustered into six main phyletic groups (A to F), with those of this study belonging to clade B. Enterobacter species and Salmonella species are the main hosts of mcr-9.1 globally, although diverse promiscuous plasmids disseminate mcr-9.1 across different bacterial species. Emergence of mcr-9.1 in ESBL-producing Enterobacteriaceae in South Africa is worrying, due to the restricted therapeutic options. Intensive One Health molecular surveillance might discover other mcr alleles and inform infection management and antibiotic choices.IMPORTANCE Colistin is currently the last-resort antibiotic for difficult-to-treat bacterial infections. However, colistin resistance genes that can move from bacteria to bacteria have emerged, threatening the safe treatment of many bacterial infections. One of these genes, mcr-9.1, has emerged in South Africa in bacteria that are multidrug resistant, further limiting treatment options for clinicians. In this work, we show that this new gene is disseminating worldwide through Enterobacter and Salmonella species through multiple plasmids. This worrying observation requires urgent action to prevent further escalation of this gene in South Africa and Africa.202032430406