Carbapenemase-producing Organisms Research Articles

Brazilian Study on the Prevalence of Carbapenemase Producing Organisms and Their Relation with Patients’ Death Rate

Aims: Determine the clinical characteristics of patients and the microbiological characteristics of the isolated Gram-negative microorganisms; Analyze the relationship between hospitalization sectors and the occurrence of bacteria resistant to carbapenems; Determine the prevalence of Gram-negative in clinical sectors of a University Hospital from Fortaleza, Brazil; Relate the prevalence to resistent Gram-negative bacteria with patients’ death rate.
 Study Design: This is a descriptive, retrospective and cross-sectional study, carried out between January and December 2022 at a university hospital in Fortaleza, Brazil.
 Place and Duration of Study: Microbiology Sector of the Central Laboratory of the Walter Cantídio University Hospital between January 2022 and December 2022.
 Methodology: All reports that showed a positive culture for Gram-negative bacilli and that carried out antibiotic sensitivity testing were included in the study. Their identification (ID) and the Antibiotic Sensitivity Test (TSA) were carried out using the automated system VITEK® 2 (BioMérieux®, Marcyl’Etoile, France), which uses the OBSERVA system for data archiving. The data was collected on a specific form and collected through patient reports issued by the hospital system. The forms were reviewed by a microbiologist pharmacist from the microbiology service. The data were analyzed and audited in the Excel® program for statistical validation using the SPSS Statistics® program, version 17.0.
 Results: 398 samples positive for Gram-negative microorganisms were collected. These samples referred to 236 patients admitted to different sectors of the hospital. It was seen that the Surgical Center concentrated a greater number of patients, representing 66 individuals (28%). The most frequently isolated species (n=217) were Klebsiella pneumoniae (n= 70; 23%) and Pseudomonas aeruginosa (n= 70; 23%), followed by Escherichia coli (n= 43; 14%) and Acinetobacter baumannii (n = 34; 11%), respectively. It was observed that 29.9% of GNB were isolated from blood samples, this being the most prevalent biological site. Bloodstream infection (BSI) was identified as the biological site with the highest number of cases, recording 65 (29.9%) positive isolates in the blood. It was found that 131 isolates of Gram-negative bacteria presented resistance mechanisms, with resistance to carbapenems being the most prevalent, corresponding to 42.75% of cases originating from enterobacteria. It was found that admission to the adult ICU increases the chances of death by 6.017 (OR) times in patients who isolated carbapenem-resistant GNBs (p <0.001).
 Conclusion: The study analyzed the microbial profile of patients at a university hospital, identifying a significant association between death and microbial resistance, especially with Klebsiella pneumoniae. Bloodstream infections were frequent, being the site with the highest number of cases. The predominant resistance mechanism was Carbapenem-Resistant Enterobacteriaceae (CRE). The results highlight the need for continuous monitoring and control of antimicrobial resistance to guide epidemiological strategies.

Extensively Drug-Resistant Pseudomonas aeruginosa Outbreak associated with Artificial Tears.

Carbapenemase-producing, carbapenem-resistant Pseudomonas aeruginosa (CP-CRPA) are extensively drug resistant bacteria. We investigated the source of a multistate CP-CRPA outbreak. Cases were defined as a U.S. patient's first isolation of P. aeruginosa sequence type 1203 with the carbapenemase gene blaVIM-80 and cephalosporinase gene blaGES-9 from any specimen source collected and reported to CDC between January 1, 2022-May 15, 2023. We conducted a 1:1 matched case-control study at the post-acute care facility with the most cases, assessed exposures associated with case status for all case-patients, and tested products for bacterial contamination. We identified 81 case-patients from 18 states, 27 of whom were identified through surveillance cultures. Four (7%) of 54 case-patients with clinical cultures died within 30 days of culture collection, and four (22%) of 18 with eye infections underwent enucleation. In the case-control study, case-patients had increased odds of receiving artificial tears compared to controls (crude matched OR: 5.0, 95% CI: 1.1, 22.8). Overall, artificial tears use was reported by 61 (87%) of 70 case-patients with information; 43 (77%) of 56 case-patients with brand information reported use of Brand A, an imported, preservative-free, over-the-counter (OTC) product. Bacteria isolated from opened and unopened bottles of Brand A were genetically related to patient isolates. FDA inspection of the manufacturing plant identified likely sources of contamination. A manufactured medical product serving as the vehicle for carbapenemase-producing organisms is unprecedented in the U.S. The clinical impacts from this outbreak underscore the need for improved requirements for U.S. OTC product importers.

Concurrent transmission of multiple carbapenemases in a long-term acute-care hospital.

We investigated concurrent outbreaks of Pseudomonas aeruginosa carrying blaVIM (VIM-CRPA) and Enterobacterales carrying blaKPC (KPC-CRE) at a long-term acute-care hospital (LTACH A). We defined an incident case as the first detection of blaKPC or blaVIM from a patient's clinical cultures or colonization screening test. We reviewed medical records and performed infection control assessments, colonization screening, environmental sampling, and molecular characterization of carbapenemase-producing organisms from clinical and environmental sources by pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. From July 2017 to December 2018, 76 incident cases were identified from 69 case patients: 51 had blaKPC, 11 had blaVIM, and 7 had blaVIM and blaKPC. Also, blaKPC were identified from 7 Enterobacterales, and all blaVIM were P. aeruginosa. We observed gaps in hand hygiene, and we recovered KPC-CRE and VIM-CRPA from drains and toilets. We identified 4 KPC alleles and 2 VIM alleles; 2 KPC alleles were located on plasmids that were identified across multiple Enterobacterales and in both clinical and environmental isolates. Our response to a single patient colonized with VIM-CRPA and KPC-CRE identified concurrent CPO outbreaks at LTACH A. Epidemiologic and genomic investigations indicated that the observed diversity was due to a combination of multiple introductions of VIM-CRPA and KPC-CRE and to the transfer of carbapenemase genes across different bacteria species and strains. Improved infection control, including interventions that minimized potential spread from wastewater premise plumbing, stopped transmission.

Rapid Direct Identification of Microbial Pathogens and Antimicrobial Resistance Genes in Positive Blood Cultures Using a Fully Automated Multiplex PCR Assay.

This study assessed the performance of the BioFire Blood Culture Identification 2 (BCID2) panel in identifying microorganisms and antimicrobial resistance (AMR) profiles in positive blood cultures (BCs) and its influence on turnaround time (TAT) compared with conventional culture methods. We obtained 117 positive BCs, of these, 102 (87.2%) were correctly identified using BCID2. The discordance was due to off-panel pathogens detected by culture (n = 13), and additional pathogens identified by BCID2 (n = 2). On-panel pathogen concordance between the conventional culture and BCID2 methods was 98.1% (102/104). The conventional method detected 19 carbapenemase-producing organisms, 14 extended-spectrum beta-lactamase-producing Enterobacterales, 18 methicillin-resistant Staphylococcus spp., and four vancomycin-resistant Enterococcus faecium. BCID2 correctly predicted 53 (96.4%) of 55 phenotypic resistance patterns by detecting AMR genes. The TAT for BCID2 was significantly lower than that for the conventional method. BCID2 rapidly identifies pathogens and AMR genes in positive BCs.

Detection of Carbapenemase Producing Gram-negative Bacteria at a Tertiary Care Hospital: A Cross-sectional Study

Introduction: Gram-negative bacteria have developed a broad spectrum of resistance due to antibiotic degradation enzymes, including Extended-spectrum Beta-lactamases (ESBL), AmpC β-lactamases, and carbapenemases. Carbapenemase- producing organisms, such as Escherichia coli, Klebsiella species, Acinetobacter species, and Pseudomonas species, have become one of the most important causes of nosocomial and community-acquired infections. Aim: To identify carbapenemase-producing organisms among Multidrug-resistant (MDR) clinical isolates and detect Metallo β-Lactam Carbapenemases (MBL). Materials and Methods: The present study is a cross-sectional study that included 1266 clinical samples from patients visiting the Department of Microbiology, Ranagaraya Medical College, Kakinada, Andhra Pradesh, India. from July 2022 to December 2022. The samples were processed using the standard culture and antimicrobial susceptibility test, employing the Kirby-Bauer Disk Diffusion method. The present study included organisms that were resistant to either imipenem or meropenem. Carbapenemases were detected using the Modified Hodge test (MHT), and MBL carbapenemases were detected using the Imipenem Ethylene Diamine Tetraacetic acid (EDTA) Double Disk Test (DDT) following the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Descriptive statistics were performed on the collected data. Results: The study samples comprised 842 (66.5%) Gram- negative isolates and 424 (33.5%) Gram-positive isolates. Among the Gram-negative isolates, 80 (9.5%) were carbapenem- resistant, of which MHT showed 56 (70%) positive isolates (carbapenemase-producing) and 24 (30%) negative isolates. Imipenem-EDTA DDT showed 50 (62.5%) positive isolates (MBL-producing) and 30 (37.5%) negative isolates. Conclusion: Carbapenemase production in Gram-negative organisms has reduced the clinical utility of the carbapenem group of drugs, posing a major challenge in the treatment of severe infections. In summary, the majority of carbapenem-resistant isolates in the present study were from the Enterobacteriaceae family. These isolates were subjected carbapenem-resistant isolates to MHT and DDT tests to identify carbapenemase and metallo-beta-lactamase-producing strains that were resistant to a wide spectrum of antibiotics. The present study enables the early detection of these MDR strains, ensuring appropriate management.

Clinical, microbiological and genomic characterization of Gram-negative bacteria with dual carbapenemases as identified by rapid molecular testing.

Dual carbapenemase-producing organisms (DCPOs) are an emerging threat that expands the spectrum of antimicrobial resistance. There is limited literature on the clinical and genetic epidemiology of DCPOs. DCPO isolates were identified by Xpert® Carba-R PCR testing of routine diagnostic cultures performed from 2018 to 2021 at a New York City health system. WGS was performed by Illumina and/or PacBio. Medical records of patients were reviewed for clinical and epidemiological data. Twenty-six DCPO isolates were obtained from 13 patients. Klebsiella pneumoniae (n = 22) was most frequent, followed by Pseudomonas aeruginosa (n = 2), Escherichia coli (n = 1) and Enterobacter cloacae (n = 1). The most common DCPO combination was blaNDM/blaOXA-48-like (n = 16). Notably, 1.05% (24/2290) of carbapenem-resistant Enterobacterales isolates were identified as DCPOs. The susceptibility profiles matched the identified resistance genes, except for a K. pneumoniae (blaKPC/blaOXA-48-like) isolate that was phenotypically susceptible to meropenem. Eleven patients were hospitalized within the year prior to admission, and received antibiotic(s) 1 month prior. Seven patients were originally from outside the USA. Hypertension, kidney disease and diabetes were frequent comorbidities. Death in two cases was attributed to DCPO infection. WGS of eight isolates showed that carbapenemases were located on distinct plasmids, except for one K. pneumoniae isolate where NDM and KPC carbapenemases were located on a single IncC-type plasmid backbone. Here we characterized a series of DCPOs from New York City. Foreign travel, prior hospitalization, antibiotic usage and comorbidities were common among DCPO cases. All carbapenemases were encoded on plasmids, which may facilitate horizontal transfer.

Municipal wastewater monitoring revealed the predominance of blaGES genes with diverse variants among carbapenemase-producing organisms: high occurrence and persistence of Aeromonas caviae harboring the new blaGES variant blaGES-48.

We characterized carbapenemase-producing organism (CPO) detected in municipal wastewater to better understand the epidemiology of CPOs in the community. In total, 36 samples were collected at six sampling sites every other month from December 2020 to October 2021. CPOs were not recovered from influent taken from inlet A receiving separated sewer line, treated effluents, and river water samples upstream and downstream of the effluent outlet. By contrast, 75 CPOs were detected in all influent samples taken from inlets B and C receiving combined sewer lines collecting both domestic/industrial wastewater and rainwater runoff. Aeromonas caviae was the dominant species (25/75, 33.3%), and the other 11 Aeromonas spp. together accounted for 48% of CPOs. The remaining 39 Enterobacterales strains mainly comprised 17 Klebsiella spp. and 10 Raoultella spp. CPOs carrying blaGES carbapenemase genes were overwhelmingly dominant, accounting for 72 of 75 isolates, including two isolates harboring both blaGES-24 and blaIMP-1 (96%), followed by three blaIMPs-positive isolates, where those carbapenemase genes were mainly carried in diverse class 1 integrons. Among blaGES variants, including six new variants (blaGES-47, blaGES-48, blaGES-49, blaGES-50, blaGES-51, and blaGES-54), blaGES-5 was detected in 28 CPOs, with Aeromonas spp. accounting for 53.6% of these organisms. Quantitative analysis revealed that the repeated detection of blaGES-48-positive A. caviae ST1056 from both inlets B and C ranked the total number of this bacterial clone highest in the wastewater influent. In summary, our study revealed the high prevalence and persistence of diverse blaGES carbapenemase genes among CPOs isolated from influent inlets connected to combined sewer systems.IMPORTANCEThe emergence and spread of carbapenemase-producing organisms (CPOs) represent a global health threat because they are associated with limited treatment options and poor clinical outcomes. Wastewater is considered a hotspot for the evolution and dissemination of antimicrobial resistance. Thus, analyses of municipal wastewater are critical for understanding the circulation of these CPOs and carbapenemase genes in local communities, which remains scarcely known in Japan. This study resulted in several key observations: (i) the vast majority of blaGES genes, including six new blaGES variants, and less frequent blaIMP genes were carbapenemase genes encountered exclusively in wastewater influent; (ii) the most dominant CPO species were Aeromonas spp., in which a remarkable diversity of new sequence types was observed; and (iii) CPOs were detected from combined sewer wastewater, but not from separate sewer wastewater, suggesting that the load of CPOs from unrecognized environmental sources could greatly contribute to their detection in influent wastewater.

Long-term intensive care unit outbreak of carbapenemase-producing organisms associated with contaminated sink drains

Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P.aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU). To investigate this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir. Active case finding, environmental sampling, whole-genome sequencing (WGS) analysis of patient and environmental strains, and implemented control strategies were described in this study. From 2018 to 2022, 37 patients became colonized or infected with PA-VIM and/or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strain dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pump genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented recolonization of the proximal sink drain by CPO. The persistence in the hospital environment of antibiotic- and disinfectant-resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat to ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.

Carbapenemase-producing organisms under the covid 19 pandemic

Abstract Background Antibiotic resistance is a widely recognised public health problem. Probably the factor most clearly associated with the emergence of carbapenemase-producing organisms (CPOs) is the use of antimicrobials. During the covid-19 pandemic, most patients with covid-19 received antibiotics. In addition, it is possible that the extra burden of work affected antimicrobial stewardship and infection prevention and control (IPC). The aim of the present study was to investigate the association between the frequency of carbapenemase-producing organisms (CPO) isolates and the excess of workload experienced during the covid-19 pandemic in a regional hospital in south-eastern Spain. Methods Descriptive study. Isolates producing one or more carbapenemases were collected from January 2015 to March 2022. Isolates of the same microorganism were grouped by individual, assuming that they correspond to the same episode of infection or colonisation. To estimate the workload, the rate of admissions of covid-19 cases in intensive care (ICU) and the total number of beds in covid-19 ICU each month were collected. Results The frequency of episodes shows an upward trend since 2018. From the 4th quarter of 2020 there is a clear acceleration until the 2nd quarter of 2021 (20 episodes per month), when a decrease to less than pre-pandemic frequencies is observed (10 episodes per month). The increase in episodes is parallel to the beginning of c ovid-19 admissions observed from the 4th quarter onwards. The decrease of episodes coincides with the increase of bed capacity, even with a maintained rate of admissions. CPO with two carbapenamases occur regularly from the 2nd quarter of 2020. Conclusions The occurrence of CPO may be related to the burden of work in healthcare systems. Disruption of antimicrobial stewardship and IPC could mediate this relationship. The decrease of episodes with a maintained rate of admissions may indicate that antibiotic use is not directly associated with CPO emergence. Key messages • Maintaining healthcare capacities related to antimicrobial stewardship and IPC may be critical in limiting the emergence of CPO. • Antibiotic use may not be directly related to the increase of CPO.

Carriage of multidrug-resistant carbapenemase-producing gram-negative bacteria in patients admitted to NHS Greater Glasgow and Clyde hospitals: Implications for treatment.

Infections caused by gram-negative carbapenemase-producing organisms (CPO) have become a global phenomenon. Screening of patients for CPO that was carried out at 48-h intervals enables early detection of carriers for infection control purposes and planning therapy. We investigated the bacterial flora detected on screening, the enzymes that conferred resistance and the proportion of patients who developed bacteraemia with CPO and their therapy. In all, 27 patients had a positive screen for CPO. A small but significant (7.5%) proportion of patients were not detected on initial screening. Escherichia coli and Klebsiella were predominant. New-Delhi metallo β-lactamase and oxacillin carbapenemases were the main enzymatic mechanisms of resistance. Four (14.8%) patients developed bacteraemia with CPO (30- and 90-day survival 100% and 75%, respectively). A single negative screen does not rule out colonisation. A significant proportion of patients colonised with CPO develop bacteraemia. Vigilance is needed to prevent the nosocomial spread of CPO.

Phenotypic Detection of Carbapenemase Production in Gram Negative Bacilli from Clinical Isolates in a Tertiary Care Hospital in Telangana

Antimicrobial resistance (AMR) in Gram negative bacteria (GNB) has become a critical health concern across the globe. Unveiling of β-lactamase, extended spectrum β-lactamase (ESBL) and AmpC β-lactamase producing bacteria has led to the development of multidrug-resistant organisms (MDRO’s). Carbapenems are considered to be very effective in morbid infections caused by MDRO’s. Now, the upsurge of carbapenem resistance among GNB is an issue of concern as these infections are very difficult to treat. Rapid and reliable methods to detect these CPO’s in all Microbiology laboratories is essential to streamline the antimicrobial therapy. Accordingly, this study is conducted to determine the enormity of CPO’s among clinical isolates by various phenotypic tests along with differentiation of serine β-lactamases from metallo-β-lactamases. This is a Prospective Cross-sectional study meticulously planned & conducted for a period of one year. Among the 76 suspected Carbapenemase Producing Organisms (CPO’s), 42% were Klebsiella spp. followed by Escherichia coli (25%), Pseudomonas aeruginosa (24%), Citrobacter spp. (5%) and Proteus spp. (4%). Out of the total isolates 82% of the isolates were confirmed as CPO’s by Carba NP test, whereas 93% by mCIM test. 53% of the total isolates tested were Serine-β-lactamase producers and 41% were Metallo-β-lactamase producers. In conclusion, Carba NP test and mCIM in conjunction with eCIM test could be considered as reliable phenotypic diagnostic methods for carbapenemase detection to guide the clinicians for initiating antibiotic therapy.

Genomic dissection of endemic carbapenem resistance reveals metallo-beta-lactamase dissemination through clonal, plasmid and integron transfer

Infections caused by metallo-beta-lactamase-producing organisms (MBLs) are a global health threat. Our understanding of transmission dynamics and how MBLs establish endemicity remains limited. We analysed two decades of blaIMP-4 evolution in a hospital using sequence data from 270 clinical and environmental isolates (including 169 completed genomes) and identified the blaIMP-4 gene across 7 Gram-negative genera, 68 bacterial strains and 7 distinct plasmid types. We showed how an initial multi-species outbreak of conserved IncC plasmids (95 genomes across 37 strains) allowed endemicity to be established through the ability of blaIMP-4 to disseminate in successful strain-genetic setting pairs we termed propagators, in particular Serratia marcescens and Enterobacter hormaechei. From this reservoir, blaIMP-4 persisted through diversification of genetic settings that resulted from transfer of blaIMP-4 plasmids between bacterial hosts and of the integron carrying blaIMP-4 between plasmids. Our findings provide a framework for understanding endemicity and spread of MBLs and may have broader applicability to other carbapenemase-producing organisms.

Evaluation of the BD Phoenix CPO Detect Panel for Detection and Classification of Carbapenemase Producing Enterobacterales.

Carbapenem-resistant Enterobacterales (CRE) pose a serious public health threat due to their resistance to most antibiotics. Rapid and correct detection of carbapenemase producing organisms (CPOs) can help inform clinician decision making on antibiotic therapy. The BD Phoenix™ CPO detect panel, as part of antimicrobial susceptibility testing (AST), detects carbapenemase activity (P/N) and categorizes CPOs according to Ambler classes. We evaluated a CPO detect panel against 109 carbapenemase producing Enterobacterales (CPE) clinical isolates from Korea. The panel correctly detected carbapenemases production in 98.2% (n = 107/109) isolates and identified 78.8% (n = 26/33) class A, 65.9% (n = 29/44) class B, and 56.3% (n = 18/32) class D carbapenemase producers as harboring their corresponding Ambler classes. Specifically, the panel correctly classified 81.3% (n = 13/16) of K. pneumoniae KPC isolates to class A. However, the panel failed to classify 40.0% (n = 4/10) IMP and 63.6% (n = 7/11) VIM isolates to class B. Despite 27.5% (n = 30/109) CPE not being assigned Ambler classes, all of them tested carbapenemase positive. Our results demonstrate that the CPO detect panel is a sensitive test for detecting CPE and classifying KPC as class A, helping with antibiotics selection, but one-third of CPE remained unclassified for Ambler classes.

Long-read sequencing reveals genomic diversity and associated plasmid movement of carbapenemase-producing bacteria in a UK hospital over 6 years.

Healthcare-associated infections (HCAIs) affect the most vulnerable people in society and are increasingly difficult to treat in the face of mounting antimicrobial resistance (AMR). Routine surveillance represents an effective way of understanding the circulation and burden of bacterial resistance and transmission in hospital settings. Here, we used whole-genome sequencing (WGS) to retrospectively analyse carbapenemase-producing Gram-negative bacteria from a single hospital in the UK over 6 years (n=165). We found that the vast majority of isolates were either hospital-onset (HAI) or HCAI. Most carbapenemase-producing organisms were carriage isolates, with 71 % isolated from screening (rectal) swabs. Using WGS, we identified 15 species, the most common being Escherichia coli and Klebsiella pneumoniae. Only one significant clonal outbreak occurred during the study period and involved a sequence type (ST)78 K. pneumoniae carrying bla NDM-1 on an IncFIB/IncHI1B plasmid. Contextualization with public data revealed little evidence of this ST outside of the study hospital, warranting ongoing surveillance. Carbapenemase genes were found on plasmids in 86 % of isolates, the most common types being bla NDM- and bla OXA-type alleles. Using long-read sequencing, we determined that approximately 30 % of isolates with carbapenemase genes on plasmids had acquired them via horizontal transmission. Overall, a national framework to collate more contextual genomic data, particularly for plasmids and resistant bacteria in the community, is needed to better understand how carbapenemase genes are transmitted in the UK.

Sink Drain Survey of Carbapenemase-Producing Organisms at a Kentucky Academic Medical Center

Sink Drain Survey of Carbapenemase-Producing Organisms at a Kentucky Academic Medical Center

Comparing the broth enrichment-multiplex lateral flow immunochromatographic assay with real time quantitative PCR for the rapid detection of carbapenemase-producing organisms in rectal swabs

BackgroundRapid and accurate identification of carbapenemase-producing organism (CPO) intestinal carriers is essential for infection prevention and control. Molecular diagnostic methods can produce results in as little as 1 h, but require special instrumentation and are expensive. Therefore, it is urgent to find an alternative method. The broth enrichment-multiplex lateral flow immunochromatographic assay was recently reported, but using it to directly detect CPO intestinal carriers in rectal swabs still requires the evaluation of many samples. The aim of this study was to compare the performance of these two methods, and to explore the control measures of CPO infection.MethodsThrough CPO selective culture, PCR and DNA sequencing, 100 rectal swabs confirmed to be CPO-positive and 100 rectal swabs with negative results were collected continuously. After eluting the rectal swabs with saline, three aliquots were used: one for counting, one for detection by Xpert Carba-R, and one for culture in broth for 0 h, 1 h, 2 h, 3 h and 4 h, followed by NG-Test CARBA 5 assessment. The sensitivity and specificity of the NG-Test CARBA 5 method after different incubation times were calculated. The limit of detection (LoD) of this assay after 4 h broth incubation was estimated by examining the bacterial suspensions and simulated faecal suspensions prepared with CPOs producing different types of carbapenemases.ResultsXpert Carba-R demonstrated a combined sensitivity of 99.0% and specificity of 98.0%. The sensitivity and specificity were higher than 90.0% for the different enzyme types. The specificities of five common carbapenemases detected by the broth enrichment NG-Test CARBA 5 combined method after different incubation times were 100%. The sensitivities increased with increasing incubation time. At 4 h, the Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-beta-lactamase (NDM), imipenemase (IMP), Verona integron-encoded metallo-beta-lactamase (VIM), and oxacillinase (OXA) -48 detection sensitivities were 93.0%, 96.3%, 100%, 100% and 85.7%, respectively. The LoDs were between 102 and 104 CFU/mL for all five enzymes after 4 h of incubation.ConclusionsThis investigation highlighted that the broth enrichment-multiplex lateral flow immunochromatographic assay can be used as a new method for screening CPOs in rectal swabs.

PREVELANCE OF CARBAPENEMASE PRODUCING ORGANISMS AND MOLECULAR RAPID DETECTION OF DIFFERENT GENES FROM VARIOUS CLINICAL ISOLATES IN PATIENTS ADMITTED AT TERTIARY CARE HOSPITALS OF VADODARA

Introduction- Carbapenemase-producing organisms (CPO) have been identied as an urgent healthcare threat. The spread of carbapenemase-producing Enterobacterales (CPE) is a global health problem of great concern. Rapid detection of carbapenemase-producing organisms is clinically desirable for hospital infection control and antibiotic stewardship. Recently, an on-demand polymerase chain reaction (PCR) assay, namely, the Xpert CarbaR assay, that requires less than an hour of turnaround time, had been developed for CPO detection in clinical samples to identify and guide infection control programs to contain the spread of CPO within a hospital. Objective- Carba-R assay is a qualitative multiplex real-time PCR method that qualitatively detects and differentiates ve common carbapenemase genes blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP) directly from clinical samples or puried colonies within approximately 1 hour. This benets hospitals and patients by facilitating timely Infection Prevention & Control measures, thereby reducing risk of exposure, transmission and bed-days lost. Materials & Methods- In this study, the Xpert Carba-R assay was evaluated for detection of the ve carbapenemase genes (blaKPC, blaNDM, blaIMP, blaOXA-48, and blaVIM) in total of 40 non duplicate various clinical samples of admitted patients in tertiary care hospitals of Vadodara. Result- We performed Carba-R on 40 isolates: 18 blood samples, 06 urine, 05 rectal swabs, 03 Endotracheal secretion, 03 Pus, 02 wound discharge, 01 Bronchoalveolar lavage uid, 01 sputum, and 01 ERCP stent isolates. 36/40 (90%) isolates had one or more carbapenemase genes. They were as follows: 19/40 (47.5%) both OXA48 and NDM , 12/40 (30%) NDM and 05/40(12.5%) OXA-48. There were 04/40 (10 %) isolates which were Carbapenem resistant on disc diffusion & VITEK but none of the resistant genes were detected possibly due to other resistant mechanism like efux pump and porin channels. Klebsiella pneumoniae was the most common isolate with CR, 34/40 (85%). The most frequent genes encountered in Klebsiella pneumoniae were both OXA48 and NDM, 19/34 (55.88%), NDM 08/34 (23.53%) followed by OXA 48, 05/34 (14.71%) and Out of 34 Klebsiella isolates, 02 isolates failed to detect any of these ve carbapenemase genes. Conclusion- Xpert Carba-R assay provides good reliable results for detection and differentiation of ve carbapenemase genes in clinical isolates. Compared to bacterial culture followed by PCR identication of resistance genes from colonies, the Carba-R assay reduced turnaround time from 48 to 72 hours to less than 1 hour. Carbapenemase genes were detected by the Carba-R assay in Klebsiella pneumoniae (34/40), Escherichia coli (5/40), Acinetobacter spp (1/40). The Carba-R assay detected 19 both OXA48 and NDM (47.5%), 12 blaNDM (30% and 05 blaOXA-48 (12.5%) genes. Laboratory detection of these genes may help improve patient outcomes by tailoring therapy. This study was conducted for understanding the molecular epidemiology of Carbapenemase producing Enterobacteriaceae in a tertiary care hospital. The combined use of the Xpert Carba-R assay and culture produces rapid and reliable results for the active surveillance of CPO in patients

Carbapenemase-producing uropathogens in real life: epidemiology and treatment at a County Emergency Hospital from Eastern Romania.

Urinary tract infections are a public health problem exacerbated by the rising concern of antibiotic resistance. Carbapenem-resistant Enterobacterales (CRE), mostly isolated from urine samples, represent an immediate public health threat, often associated with healthcare settings. This study investigated 27 cases of carbapenemase-producing organisms (CPO) detected in urinalysis over one year. There was a significant association between the presence of chronic indwelling urinary catheters and the temporary use of urinary catheters, with both groups accounting for 66.7% of all cases. We identified two modes of transmission for extended drug-resistant microorganisms: inter-hospital spread, covering wide geographical distances (involving four healthcare units across two other counties), and intra-hospital transmission (12 departments within our institution). Medium-size hospitals should thoroughly investigate their specific carbapenemase-producing strains. Their laboratories must be well-supplied to handle this situation and perform the necessary testing accurately. Treatment options should be available based on presumed susceptibility and antimicrobial susceptibility testing, with a range of antibiotics available, including novel agents such as Ceftazidime-avibactam, as well as established options like Aminoglycosides and Colistin. Adherence to rigorous catheter handling protocols, as emphasized by national and international guidelines, is essential and should be implemented consistently across all hospital departments.

Customized molecular diagnostics of bacterial bloodstream infections for carbapenem resistance: A convenient and affordable approach

ABSTRACT The acute crisis of carbapenem resistance impedes the empirical use of carbapenems in medical emergencies, especially, bloodstream infections. Carbapenemase-producing carbapenem-resistant organisms (CP-CROs) attribute high case-fatality, necessitating rapid diagnostics to initiate early targeted antibiotics. Expensive diagnostics are the major driver of antibiotic misuse, neglecting evidence-based treatment in India. One in-house molecular diagnostics assay was customized for rapid detection of CP-CROs using positive blood-culture (BC) broths at a low-cost. The assay was validated using a known-set of isolates and evaluated on positive BC broths. DNA was extracted from positive BC broths using a modified alkali-wash/heat-lysis method. One end-point multiplex-PCR was customized targeting five carbapenemases (KPC, NDM, VIM, OXA-48-, and OXA-23-type) with 16S-rDNA as internal extraction control. Carbapenem resistance due to other carbapenemases, efflux-pump activity, and loss of porins was not under the scope of the assay. Promising analytical performances (sensitivity and specificity, >90%; kappa = 0.87), encouraged to assess diagnostic value, qualified the assay for the WHO minimal requirements (both≥95%) for a multiplex-PCR. Higher LR+ (>10) and lower LR− (<0.1) indicate a good diagnostic tool for ruling in or ruling out CRO bloodstream infections. Inclusion of OXA-23-type improved assay positivity. Multiple carbapenemases were detected in>30% of samples. Good concordance was found (kappa = 0.91) with twenty-six discrepant results. The results were available in 3 hours. The running cost of the assay was US$10 per sample. Fast and reliable detection of carbapenemase(s) allows clinicians and infection-control practitioners to execute early-directed therapy and containment measures. This convenient approach facilitates implementing the assay in resource-limited healthcare settings.

Containment of a Verona Integron-Encoded Metallo-Beta-Lactamase-Producing Pseudomonas aeruginosa Outbreak Associated With an Acute Care Hospital Sink-Tennessee, 2018-2020.

Contaminated healthcare facility wastewater plumbing is recognized as a source of carbapenemase-producing organism transmission. In August 2019, the Tennessee Department of Health (TDH) identified a patient colonized with Verona integron-encoded metallo-beta-lactamase-producing carbapenem-resistant Pseudomonas aeruginosa (VIM-CRPA). A record review revealed that 33% (4 of 12) of all reported patients in Tennessee with VIM had history of prior admission to acute care hospital (ACH) A intensive care unit (ICU) Room X, prompting further investigation. A case was defined as polymerase chain reaction detection of blaVIM in a patient with prior admission to ACH A from November 2017 to November 2020. The TDH performed point prevalence surveys, discharge screening, onsite observations, and environmental testing at ACH A. The VIM-CRPA isolates underwent whole-genome sequencing (WGS). In a screening of 44% (n = 11) of 25 patients admitted to Room X between January and June 2020, we identified 36% (n = 4) colonized with VIM-CRPA, resulting in 8 cases associated with Room X from March 2018 to June 2020. No additional cases were identified in 2 point-prevalence surveys of the ACH A ICU. Samples from the bathroom and handwashing sink drains in Room X grew VIM-CRPA; all available case and environmental isolates were found to be ST253 harboring blaVIM-1 and to be closely related by WGS. Transmission ended after implementation of intensive water management and infection control interventions. A single ICU room's contaminated drains were associated with 8 VIM-CRPA cases over a 2-year period. This outbreak highlights the need to include wastewater plumbing in hospital water management plans to mitigate the risk of transmission of antibiotic-resistant organisms to patients.