Carbapenem-resistant Isolates Research Articles

Virulence and resistance patterns of Vibrio cholerae non-O1/non-O139 acquired in Germany and other European countries

Global warming has caused an increase in the emergence of Vibrio species in marine and estuarine environments as well as fresh water bodies. Over the past decades, antimicrobial resistance (AMR) has evolved among Vibrio species toward various antibiotics commonly used for the treatment of Vibrio infections. In this study, we assessed virulence and resistance patterns of Vibrio cholerae non-O1/non-O139 strains derived from Germany and other European countries. A total of 63 clinical and 24 environmental Vibrio cholerae non-O1/non-O139 strains, collected between 2011 and 2021, were analyzed. In silico antibiotic resistances were compared with resistance phenotypes according to EUCAST breakpoints. Additionally, genetic relatedness between isolates was assessed by two cgMLST schemes (SeqSphere +, pubMLST). Both cgMLST schemes yielded similar results, indicating high genetic diversity among V. cholerae non-O1/non-O139 isolates. Some isolates were found to be genetically closely related (allelic distance < 20), which suggests an epidemiological link. Thirty-seven virulence genes (VGs) were identified among 87 V. cholerae non-O1/non-O139 isolates, which resulted in 38 virulence profiles (VPs). VPs were similar between clinical and environmental isolates, with the exception of one clinical isolate that displayed a higher abundance of VGs. Also, a cluster of 11 environmental isolates was identified to have the lowest number of VGs. Among all strains, the predominant virulence factors were quorum sensing protein (luxS), repeats-in-toxins (rtxC/rtxD), hemolysin (hlyA) and different type VI secretion systems (T6SS) genes. The genotypic profiles revealed antibiotic resistance genes (ARGs) associated with resistance to beta-lactams, quinolones, macrolides, tetracycline, antifolate, aminoglycosides, fosfomycin, phenicols and sulfonamide. Carbapenemase gene VCC-1 was detected in 10 meropenem-resistant V. cholerae non-O1/non-O139 isolates derived from surface water in Germany. The proportion of resistance among V. cholerae non-O1/non-O139 species isolates against first line treatment (3rd generation cephalosporin, tetracycline and fluoroquinolone) was low. Empirical treatment would likely have been effective for all of the clinical V. cholerae non-O1/non-O139 isolates examined. Nevertheless, carbapenem-resistant isolates have been present in fresh water in Germany and might represent a reservoir for ARGs. Monitoring antimicrobial resistance is crucial for public health authorities to minimize the risks for the human population.

Multilocus sequence typing analysis and molecular characterization of carbapenemase related genes in Acinetobacter baumannii isolated from hospitalized patients in Erbil city, Iraq.

Acinetobacter baumannii, has been recognized by (WHO) as a global priority pathogen. It has been demonstrated to quickly pick up antimicrobial resistance genes. Multilocus sequence typing (MLST) is an unambiguous typing method for identifying accurate and portable nucleotide sequences of internal fragments of multiple housekeeping genes. The present study aimed to determine the sequence type using MLST, genetically define the carbapenem resistance phenotype and clarify the epidemiology of multidrug resistant (MDR) A. baumannii in the Kurdistan region of Iraq. Clinical samples were collected from ICU patients. VITEK 2 compact system was used for bacterial identification and antimicrobial susceptibility profile. PCR was used for detecting carbapenemase-related genes. Additionally, MLST was used to evaluate the genetic diversity of carbapenem-resistant isolates using Oxford scheme primers. In this investigation, 63 non-duplicate A. baumannii isolates from hospitalized patients were identified. According to CLSI standards, 75% and 73.4% of isolates were resistant to meropenem and imipenem respectively. Tigecycline and colistin were the most effective antibacterial agents. Of the various combinations of carbapenemase genes identified, the most common co-existence of genes present among clinical isolates were BlaOXA-23, and BlaOXA-51 (95.31%). While the less common combination of genes was detected in 4 isolates (6.25 %) consisting of the co-existence of all tested carbapenemase genes in the present study (BlaOXA-23, BlaOXA-51, BlaOXA-58, BlaIMP, BlaVIM, BlaNDM). Regarding MLST analysis, the results confirmed that ST 556 (n=4) had the greatest frequency rate among clinical isolates, followed by ST 218 (n=3). Notably, the most common worldwide clonal lineage was CC92, which corresponded to (ICII). Only two isolates from ST 441, on the other hand, matched CC109/ ICI. The present investigation revealed a significant level of diversity among A. baumannii isolates.

Prevalence of Carbapenem-Resistant Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa in a Tertiary Care Hospital in Eastern India: A Pilot Study

In recent years, a wide range of clinical infections are being caused by carbapenem-resistant Enterobacterales, Acinetobacter baumannii and Pseudomonas aeruginosa. This is a matter of great concern, as carbapenem-resistant infections have fewer treatment options. The Enterobacterales comprises a large group of bacterial species commonly causing infections in healthcare settings. The most common bacteria are Escherichia coli and Klebsiella pneumoniae, which can cause both nosocomial and community-acquired infections. This study aimed to determine the prevalence of carbapenem-resistant Enterobacterales, P. aeruginosa, and A. baumannii, in a tertiary care center in India. The study was conducted over a period of seven months, from May 2022 to November 2022. The specimens were processed at the Microbiology Laboratory of Kalinga Institute of Medical Sciences- Pradyumna Bal Memorial Hospital, Bhubaneswar. Standard procedures were used to process the clinical specimens brought to the laboratory. Carbapenem-resistant isolates were screened according to the CLSI 2022 guidelines. This study included 3,006 isolates of Enterobacterales, A. baumannii, and P. aeruginosa. Of these, 29.40% (n = 844) were found to be carbapenem resistant. The breakup is as follows: 689 (77.94%) were Enterobacterales, 108 (12.21%) were A. baumannii, and 87 (9.84%) were P. aeruginosa. Thus, our investigation revealed an overall prevalence of carbapenem-resistant Enterobacterales, A. baumannii, and P. aeruginosa of 29.40%, which corresponds to previous studies in India. Early patient screening, isolation, and contact prevention measures will help reduce infection transmission. Further, larger multi-centric studies are required to obtain a wider perspective regarding this issue.

Antimicrobial Activities of Aztreonam-Avibactam and Comparator Agents against Enterobacterales Analyzed by ICU and Non-ICU Wards, Infection Sources, and Geographic Regions: ATLAS Program 2016-2020.

Increasing antimicrobial resistance among multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales (CPE), in particular metallo-β-lactamase (MBL)-positive strains, has led to limited treatment options in these isolates. This study evaluated the activity of aztreonam-avibactam (ATM-AVI) and comparator antimicrobials against Enterobacterales isolates and key resistance phenotypes stratified by wards, infection sources and geographic regions as part of the ATLAS program between 2016 and 2020. Minimum inhibitory concentrations (MICs) were determined per Clinical and Laboratory Standards Institute (CLSI) guidelines. The susceptibility of antimicrobials were interpreted using CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. A tentative pharmacokinetic/pharmacodynamic breakpoint of 8 µg/mL was considered for ATM-AVI activity. ATM-AVI inhibited ≥99.2% of Enterobacterales isolates across wards and ≥99.7% isolates across infection sources globally and in all regions at ≤8 µg/mL. For resistance phenotypes, ATM-AVI demonstrated sustained activity across wards and infection sources by inhibiting ≥98.5% and ≥99.1% of multidrug-resistant (MDR) isolates, ≥98.6% and ≥99.1% of ESBL-positive isolates, ≥96.8% and ≥90.9% of carbapenem-resistant (CR) isolates, and ≥96.8% and ≥97.4% of MBL-positive isolates, respectively, at ≤8 µg/mL globally and across regions. Overall, our study demonstrated that ATM-AVI represents an important therapeutic option for infections caused by Enterobacterales, including key resistance phenotypes across different wards and infection sources.

Prevalence of carbapenem-resistant and extended-spectrum beta-lactamase-producing Enterobacteriaceae in a teaching hospital in Ghana.

Carbapenem-resistant Enterobacteriaceae (CRE) and Extended-spectrum beta-lactamase (ESBL) production among Gram-negative Enterobacteriaceae is an increasing global challenge due to the high morbidity and mortality associated with their infections, especially in developing countries where there are little antibiotic treatment options. Despite these challenges, few studies in Ghana have described the burden of CRE. Therefore, this study aimed to determine the prevalence of carbapenem-resistant Enterobacteriaceae isolated from patients at the Cape Coast Teaching Hospital (CCTH) in the Central region of Ghana. Enterobacteriaceae isolates were collected from April to July 2019 at the bacteriology unit of CCTH using a consecutive sampling method. Isolates were identified by standard microbiological techniques and confirmed using API 20E. Kirby Bauer disc diffusion method was used to determine the antibiogram of isolates. Isolates were also subjected to ESBL testing using the single-disc combination method. Carbapenem-resistant isolates were identified by the Kirby Bauer disc diffusion method and then examined genotypically for the presence of blaKPC-1, blaIMP-1, blaVIM-1, blaNDM-1, and blaOXA-48 genes via polymerase chain reaction (PCR). Of the 230 isolates comprising E. coli (40.9%), Citrobacter spp. (32.6%), K. pneumoniae (9.1%), P. mirabilis (6.1%), P. vulgaris (5.2%), Enterobacter spp (3.5%)., K. oxytoca (2.2%), and Serratia marcenses (0.4%). Most isolates were from urine 162(70.4%) and wound samples. The isolates showed high resistance to ampicillin 171 (74.3%) and cefuroxime 134(58.3%). The prevalence of MDR was 35.2% (81), with E. coli 40(42.6%) being the majority that exhibited MDR. Of the 230 isolates, 113(49.1%) were ESBL producers, with E. coli 54(57.5%) accounting for the majority, while Serratia marcenses was the least. Of the 13 (5.7%) CRE isolates that showed resistance towards carbapenem in the disc diffusion method, 11 showed the presence of the blaNDM-1 gene, while all isolates showed the presence of the blaOXA-48 gene. The prevalence of carbapenem resistance and ESBL-producing Enterobacteriaceae pathogens among patients at the Cape Coast Teaching Hospital is high and alarming. Therefore, it is imperative to consider effective infection prevention and control measures should be implemented at the hospital to prevent the rapid spread of these dangerous organisms.

Multidrug-Resistant and Extensively Drug-Resistant Escherichia coli in Sewage in Kuwait: Their Implications.

In Kuwait, some sewage is discharged into the sea untreated, causing a health risk. Previously, we investigated the presence of pathogenic E. coli among the 140 isolates of E. coli cultured from the raw sewage from three sites in Kuwait. The aim of the current study was to characterize the antimicrobial resistance of these isolates and the implications of resistance. Susceptibility to 15 antibiotic classes was tested. Selected genes mediating resistance to cephalosporins and carbapenems were sought. ESBL and carbapenemase production were also determined. Two virulent global clones, ST131 and ST648, were sought. A total of 136 (97.1%), 14 (10.0%), 128 (91.4%), and 2 (1.4%) isolates were cephalosporin-resistant, carbapenem-resistant, multidrug-resistant (MDR), and extensively drug-resistant (XDR), respectively. Among the cephalosporin-resistant isolates, ampC, blaTEM, blaCTX-M, blaOXA-1, and blaCMY-2 were found. Eighteen (12.9%) samples were ESBL producers. All carbapenem-resistant isolates were negative for carbapenemase genes (blaOXA-48, blaIMP, blaGES, blaVIM, blaNDM, and blaKPC), and for carbapenemase production. Resistance rates in carbapenem-resistant isolates to many other antibiotics were significantly higher than in susceptible isolates. A total of four ST131 and ST648 isolates were detected. The presence of MDR and XDR E. coli and global clones in sewage poses a threat in treating E. coli infections.

Risk factor and resistance profile of colistin resistant Acinetobacter baumannii and Klebsiellapneumoniae

PurposeAntimicrobial resistance is one of the major global health concerns, which is relentless despite multipronged measures. Carbapenems and colistin, drug of choice for multi drug resistant Klebsiella pneumoniae and Acinetobacter species, have also been rendered of less use. This underlines the need to decipher prevalence of colistin resistance comprehensively for formulation of hospital and country-wise antibiogram. We conducted this study to decipher the prevalence of colistin resistance in our tertiary care centre of North India. Materials and methodsThis was a prospective, case control study conducted over a period of one and half years. All carbapenem resistant Klebsiella pneumoniae and Acinetobacter isolates were included. Kirby-Bauer method of disc diffusion was used for all antibiotics, except colistin for which broth microdilution was performed and interpreted using CLSI guidelines. Demographic details, risk factors and outcome details were recorded. Genotypic characterization was performed using representative strains, for blaNDM, blaKPC and blaOXA-48. ResultsOf 103 carbapenem resistant isolates, 7 were found to be colistin resistant. Median age was 43 years, with male:female ratio of 1.1:1. 35% isolates were from pus samples, followed by endotracheal aspirate. Colistin resistance was more in ICUs than wards. Presence of indwelling devices was noted as the most common risk factor, followed by previous antibiotic exposure and use of steroids/immunosuppressants. Indwelling devices, steroids/immunosuppressants usage, length of hospital stay, COPD, prior usage of carbapenems, piperacillin-tazobactam and colistin, usage of ampicillin-sulbactam during hospital stay, were statistically significant. Mortality was noted in 4 cases, with statistical difference between control and case arm. The blaNDM and blaOXA-48 were noted in 3 and 2 isolates respectively, with absence of blaKPC. ConclusionThe present study unravels incidence, risk factors and resistance encoding genes at our centre. This is of immense help in formulation of antibiotic policies and guidance for infection control measures.

Comparison of loop-mediated isothermal amplification, multiplex PCR, and REP- PCR techniques for identification of carbapenem-resistant Acinetobacter baumannii clinical isolates

Background and Objectives: Acinetobacter baumannii, an opportunistic pathogen, is related to hospital-acquired infections and increased mortality. This study aimed to develop the loop-mediated isothermal amplification (LAMP) test for the fast-de- tecting of A. baumannii isolates as well as determining genetic relatedness for these isolates via the REP-PCR technique.
 Materials and Methods: LAMP primers and multiplex PCR primers were designed for recognizing A. baumannii isolates harboring the bla SHV-1 , bla PER-1 , bla , AMPC, qnr, and aac (6)-1 genes, were collected (October 2020 to February 2021) from Shahid Motahari Hospital, Tehran, Iran. Combination disc test (CDT) results were used to assess the phenotypic iden- tification of isolates from ESBL producers. The sensitivity of the LAMP method was evaluated using a range of serial dilu- tions of genomic DNA. Results were compared between the LAMP technique, and multiplex PCR. The genetic diversity of clinical isolates was determined by REP-PCR.
 Results: Among one hundred A. baumannii samples and based on the combined disc test, 56% of isolates were ESBL pro- ducers. The sensitivity of the LAMP technique for the identification of A. baumannii was 4.06 ng/μl whilst the multiplex PCR was (16.2 ng/μl). Regarding multiplex PCR, (68%) of the isolates were bla SHV-1 positive, (40%) bla , (85%) aac (6́)-1, AMPC (67%), bla TEM-1 (63%), and (15%) qnr respectively. While in LAMP, (69%) of isolates were bla positive, (86%) aac (6')-1, and (20%) qnr. The results of AMPC, bla TEM-1 , and bla PER-1 genes showed 100% compatibility between multiplex PCR and LAMP assays. The results of REP-PCR indicated there were 17 clones, clone A at 14% was the most prevalent of the isolates.
 Conclusion: Wherever equipment and financial constraints are crucial, the LAMP test offers a better and more potent detec- tion rate for the identification of A. baumannii isolates than multiplex PCR. Furthermore, the genetic diversity of A. bauman- nii in these clinical isolates showed frequent commonality of genotypes.

Whole-genome sequencing of carbapenem-resistant Enterobacterales isolates in southeast Louisiana reveals persistent genetic clusters spanning multiple locations

BackgroundWe investigated 51 g-negative carbapenem-resistant Enterobacterales (CRE) isolates collected from 22 patients over a five-year period from six health care institutions in the Ochsner Health network in southeast Louisiana. MethodsShort genomic reads were generated using Illumina sequencing and assembled for each isolate. Isolates were classified as Enterobacter spp. (n = 20), Klebsiella spp. (n = 30), and Escherichia coli (n = 1) and grouped into 19 different multi-locus sequence types (MLST). Species and patient-specific core genomes were constructed representing ∼50% of the chromosomal genome. ResultsWe identified two sets of patients with genetically related infections; in both cases, the related isolates were collected > 6 months apart, and in one case, the isolates were collected in different locations. On the other hand, we identified four sets of patients with isolates of the same species collected within 21 days from the same location; however, none had genetically related infections. Genes associated with resistance to carbapenem drugs (blaKPC and/or blaCTX-M-15) were found in 76% of the isolates. We found three blaKPC variants (blaKPC-2, blaKPC-3, and blaKPC-4) associated with four different Enterobacter MLST variants, and two blaKPC variants (blaKPC-2, blaKPC-3) associated with seven different Klebsiella MLST variants. ConclusionsMolecular surveillance is increasingly becoming a powerful tool to understand bacterial spread in both community and clinical settings. This study provides evidence that genetically related infections in clinical settings do not necessarily reflect temporal associations, and vice versa. Our results also highlight the regional genomic and resistance diversity within related bacterial lineages.

Evaluation of different methods for in vitro susceptibility testing of colistin in carbapenem resistant Gram-negative bacilli.

The increasing antibiotic resistance like the advent of carbapenem resistant Enterobactarales (CRE), Carbapenem Resistant Acinetobacter baumanii (CRAB), and Carbapenem Resistant Pseudomonas aeruginosa (CRPA) has led to to the use of toxic and older drugs like colistin for these organisms. But worldwide there is an increase in resistance even to colistin mediated both by chromosomes and plasmids. This necessitates accurate detection of resistance. This is impeded by the unavailability of a user-friendly phenotypic methods for use in routine clinical microbiology practice. The present study attempts to evaluate two different methods - colistin broth disc elution and MIC detection by Vitek two in comparison to CLSI approved broth microdilution (BMD) for colistin for Enterobactarales, Pseudomonas aeruginosa , and Acinetobacter baumanii clinical isolates. Colistin susceptibility of 6013 carbapenem resistant isolates was determined by BMD, Colistin Broth Disc Elution (CBDE), and Vitek two methods and was interpreted as per CLSI guidelines. The MIC results of CBDE, Vitek two were compared with that of BMD and essential agreement (EA), categorical agreement (CA), sensitivity, specificity, very major error (VME), major error (ME) and Cohen's kappa (CK) was calculated. The presence of any plasmid-mediated colistin resistance (mcr-1, 2, 3, 4 and 5) was evaluated in all colistin-resistant isolates by conventional polymerase chain reaction. Colistin resistance was found in 778 (12.9 %) strains among the carbapenem resistant isolates. Klebsiella pneumoniae had the highest (18.9 %) colistin resistance by the BMD method. MIC of Vitek two had sensitivity ranging from 78.2-84.8% and specificity of >92 %. There were 171 VMEs and 323 MEs by Vitek two method, much more than CLSI acceptable range. The highest percentage of errors was committed for Acinetobacter baumanii (27.8 % of VME and 7.9 % ME). On the other hand, the CBDE method performed well with EA, CA, VME and ME within acceptable range for all the organisms. The sensitivity of the CBDE method compared to gold standard BMD varied from 97.5-98.8 % for different strains with a specificity of more than 97.6 %. None of the isolated colistin resistant organisms harboured mcr plasmids. As BMD has many technical complexities, CBDE is the best viable alternative available for countries like India. A sensitive MIC reported by Vitek two needs to be carefully considered due high propensity for VMEs particularly for Klebsiella spp.

Characterization of carbapenemase-producing Gram-negative bacilli: first report of blaNDM-1 in Enterobacter cloacae.

The spread of multidrug-resistant bacteria, particularly carbapenem-resistant Gram-negative bacilli (CR-GNB), has become a serious challenge for clinicians due to limited therapeutic options. The aim of the study was to investigate the prevalence of carbapenemase production among clinical isolates recovered from 352 samples collected in Tebessa hospital, Algeria. Bacterial isolates were identified by 16S RNA gene sequencing and susceptibility to antibiotics was determined by disk diffusion method. Carbapenem-resistant isolates were screened for carbapenemase production using modified carba Nordmann-Poirel test, modified Hodge test and imipenem-EDTA combined disc test. Extended-spectrum β-lactamases (ESBL) were detected using double-disk synergy test. Molecular characterization of carbapenemases and ESBL genes was performed by polymerase chain reaction (PCR) and sequencing. A total of 85 Gram-negative bacilli isolates were recovered mainly from urine samples and were identified as: Klebsiella pneumoniae (17.65%), Serratia odorifera (15.29%), Escherichia coli (12.94%), Raoultella ornithinolytica, Enterobacter cloacae (11.76%), Serratia marcescens (10.59%), Morganella morganii (7.06%), Proteus mirabilis (5.88%), Acinetobacter baumannii (4.70%) and Pseudomonas aeruginosa (2.35%). All strains were resistant or intermediate to imipenem and/or ertapenem. ESBL, carbapenemase and metallo-beta-lactamases (MBL) phenotypes were detected in 19 (22.35%), 9 (10.59%) and 2 (2.35%) GNB isolates, respectively. PCR results in nine carbapenemase-producing GNB strains chosen showed the presence of one to four carbapenemase genes (blaGES, blaSME, blaNDM-1, blaVIM, blaGIM, blaSPM, blaOXA-48) in four strains; however, seven strains had at least one ESBL gene (blaTEM-1, blaCTXM-15, blaSHV). In this study, we report the first incidence of blaNDM-1 gene in Enterobacter cloacae isolated from urine sample in Algeria.

Kolistin direncinin moleküler tespitinde yanlış tanı: kolistine duyarlı Acinetobacter baumannii izolatlarında yanlış mcr-1-PCR pozitifliği

Purpose: The aim of this study was to investigate the presence of the mcr-1 gene, which is responsible for colistin resistance, in carbapenem-resistant Gram-negative bacteria that cause difficult-to-treat infections in a research hospital in Turkey. 
 Materials and Methods: The mcr-1 gene was examined using PCR in 103 carbapenem-resistant isolates, including 75 Acinetobacter baumannii, 19 Pseudomonas aeruginosa, and 9 Klebsiella pneumoniae. DNA sequencing was performed to confirm the mcr-1 positivity. Other antimicrobial resistance genes were investigated in isolates that were found to be mcr-1-positive by PCR and colistin-resistant isolates. 
 Results: Four (3.9% of the 103 carbapenem-resistant isolates and 5.3% of the 75 A. baumannii isolates) A. baumannii isolates, all susceptible to colistin, were found to be mcr-1-positive by PCR, whereas mcr-1 was not detected in four colistin-resistant isolates, one in A. baumannii and three in K. pneumoniae. DNA sequencing analysis determined that none of the amplification products was the targeted fragment, but they matched more than 70% with the chromosomal DNA fragments of A. baumannii strains. Therefore, these results were considered false-positive. Although these false-positive isolates were susceptible to colistin, they were extensively drug-resistant (XDR). Two of them were found to carry blaOXA23-like and blaTEM genes, another blaOXA23-like, blaTEM and blaOXA48-like genes, and the fourth one to have blaOXA23-like and blaCTXM genes. 
 Conclusion: Although the specificity of the primers used to detect the mcr-1 gene by PCR was reported as 100% in most studies, we concluded that PCR tests are insufficient yet to use alone or with antibiotic susceptibility tests in rapid routine diagnosis. Confirming at least PCR-positive samples using DNA sequence analysis would be appropriate for a certain period.

The prevalence of Carbapenem Resistance Gram negative pathogens in a Tertiary Teaching Hospital in Jordan

BackgroundWith the absence of new antimicrobial drugs being developed to replace those facing resistance, bacterial resistance continues to grow. Despite previous studies conducted in various countries, there is a lack of comprehensive local reporting on the occurrence of carbapenem resistance among gram-negative bacteria.ObjectiveThis study aims to identify the prevalence of carbapenem-resistant gram-negative bacterial isolates.MethodA retrospective cross-sectional study was conducted at an academic hospital in Jordan over an eight-month period, spanning from November 2021 to June 2022. The study involved screening electronic medical records to identify patients with clinical cultures showing the growth of Gram-negative bacteria. Antimicrobial susceptibility results of the Gram-negative isolates were recorded.ResultsA total of 1,043 isolated Gram-negative bacteria were analyzed for carbapenem susceptibility. Among the species tested, the most common carbapenem-resistant bacteria were Acinetobacter baumannii (153/164, 93.3%), followed by Klebsiella pneumonia (184/311, 59.2%), and Pseudomonas aeruginosa (67/160, 41.9%). The least commonly isolated species resistant to carbapenem were Escherichia coli (25/361, 6.9%) and Proteus mirabilis (1/30, 3.3%). None of Serratia marcescens or Proteus vulgaris isolates were resistant to carbapenem (0%). Overall, the prevalence of carbapenem-resistance gram-negative isolates was 41.2% (430 out of 1,043).ConclusionThis study provides population-specific data that are crucial for guiding empirical antimicrobial treatment decisions not only within the participating hospital but also in other nearby healthcare facilities. The results underscore the urgent need for coordinated efforts to address antibiotic resistance in Jordan. Comprehensive measures such as strict infection control methods, annual nationwide surveillance programs, and effective antimicrobial stewardship programs at the national level are imperative to reduce the overuse of broad-spectrum antibiotics.

In Vitro Activity of New β-Lactamase Inhibitor Combinations against blaNDM, blaKPC, and ESBL-Producing Enterobacteriales Uropathogens.

Antibiotic resistance in uropathogens has increased substantially and severely affected treatment of urinary tract infections (UTIs). Lately, some new formulations, including meropenem/vaborbactam (MEV), ceftazidime/avibactam (CZA), and ceftolozane/tazobactam (C/T) have been introduced to treat infections caused by drug-resistant pathogens. This study was designed to screen Enterobacteriales isolates from UTI patients and to assess their antimicrobial resistance pattern, particularly against the mentioned (new) antibiotics. Phenotypic screening of extended-spectrum β-lactamase (ESBL) and carbapenem resistance was followed by inhibitor-based assays to detect K. pneumoniae carbapenemase (KPC), metallo-β-lactamase (MBL), and class D oxacillinases (OXA). Among 289 Enterobacteriales, E. coli (66.4%) was the most predominant pathogen, followed by K. pneumoniae (13.8%) and P. mirabilis (8.3%). The isolates showed higher resistance to penicillins and cephalosporins (70-87%) than to non-β-lactam antimicrobials (33.2-41.5%). NDM production was a common feature among carbapenem-resistant (CR) isolates, followed by KPC and OXA. ESBL producers were susceptible to the tested new antibiotics, but NDM-positive isolates appeared resistant to these combinations. KPC-producers showed resistance to only C/T. ESBLs and carbapenemase encoding genes were located on plasmids and most of the genes were successfully transferred to recipient cells. This study revealed that MEV and CZA had significant activity against ESBL and KPC producers.

Colistin Susceptibility Testing by Colistin Broth Disk Elution MIC Method among Carbapenem-resistant Gram-negative Blood Culture Clinical Isolates in a Tertiary Care Setting, East Delhi, India.

Antibiotic resistance is a growing concern for bloodstream infections (BSIs), especially with the emergence of multidrug-resistant (MDR) gram-negative bacteria. In this study, we aimed to assess the pattern of colistin susceptibility using the colistin broth disc elution (CBDE) method among carbapenem-resistant gram-negative clinical isolates from blood cultures in a high burden tertiary healthcare setting in East Delhi. A total of 106 carbapenem-resistant gram-negative clinical isolates were tested. The most common isolates were Klebsiella pneumoniae, Escherichia coli, Enterobacter species, and Klebsiella oxytoca by CBDE method. All the carbapenem resistant gram-negative bacterial blood culture isolates showed intermediate colistin susceptibility. This was statistically significant by chi-square test (p<0.5). This study highlights the need to monitor colistin resistance trends in the face of increasing antimicrobial resistance. Accurate surveillance of emerging colistin resistance is crucial for effective management of BSIs caused by carbapenem-resistant gram-negative bacteria.

Detection of carbapenem resistant Pseudomonas aeruginosa co-harboring blaVIM-2 and blaGES-5 in burn patients.

Pseudomonas aeruginosa is one of the major infectious agents in burn patients. Globally, high rates of antimicrobial resistance in P. aeruginosa have been reported, which is a cause of concern. The objective of this study was to determine the rate of resistance to carbapenems in P. aeruginosa isolates recovered from burn patients in Tunisia, to search genes encoding for carbapenemases and to determine their epidemiological markers (serotypes). A retrospective study was conducted in the Burn Intensive Care Unit (BICU) of the Trauma and Burn Centre of Ben Arous, Tunisia, and P.aeruginosa isolates collected from burn patients, from January to December 2018 were investigated. Carbapenemase screening was performed by Carbapenem Inactivation Method (CIM) and by EDTA-disk test for all carbapenem resistant isolates. Genes encoding carbapenemases (blaVIM, blaIMP, blaGES, blaNDM, and blaKPC) were investigated by PCR and selected carbapenemase genes were sequenced. During the study period, 104 non duplicated P. aeruginosa isolates were recovered. Most of them were isolated from skin samples (45.1%) and blood culture (22.1%) and belonged to O:11 (19.2%), O:12, and O:5 (12.5%, each) serotypes. High rates of resistance were observed for carbapenems (64.4%). Among the 67 carbapenem resistant isolates, 58 (86.5%) harbored blaVIM gene and 55 (82%) blaGES gene; in addition, 48 (71.6%) co-harbored blaVIM and blaGES genes. After sequencing, the blaVIM-2 and blaGES-5 gene variants were identified in seven randomly selected isolates. To the best of our knowledge, this is the first description of P. aeruginosa simultaneously harboring blaVIM-2 and blaGES-5 genes.

Prevalence of Type III Secretion System (T3SS) and Biofilm Development in Genetically Heterogeneous Clinical Isolates of Pseudomonas aeruginosa from Nigeria.

Pseudomonas aeruginosa infection in seriously ill patients is a major concern due to its ability to form biofilm and secrete effector toxins. There is little information on the prevalence of T3SS effector toxins and biofilm production in clinical isolates of P. aeruginosa from Nigeria. The goal of this study is to evaluate the prevalence of T3SS toxins and biofilm production among isolates from selected tertiary hospitals in Nigeria. This study examined 430 clinical isolates from our previous work, comprising 181 MDR (multidrug-resistant) and 249 non-MDR isolates. Biofilm production and type III secretion toxins were determined using colorimetric microtiter plate assay and polymerase chain reaction, respectively. Carbapenem-resistant isolates were typed using REP-PCR and BOX-PCR. Biofilm production was detected in 386/430 (89.8%) of the isolates. Out of 386 biofilm producers, 167 (43.3%) were multidrug-resistant isolates. PCR identified four T3SS virulence types among 430 isolates, including 78 (18.1%) exoU+/exoS- isolates, 343 (79.8%) exoU-/exoS + isolates, 5 (1.2%) exoU+/exoS + isolates, and 4 (0.9%) exoU-/exoS- isolates. Both REP- and BOX-PCR consist of eight clusters. On the REP-PCR dendrogram, ExoU+/ExoS- isolates majorly occupied cluster IV. Clusters IV, VII, and VIII consist of isolates from wounds on BOX-PCR dendrogram. There was a positive association between strong biofilm production and multidrug resistance in our P. aeruginosa isolates. This study identified multidrug-resistant, biofilm-producing P. aeruginosa strains that secrete cytotoxic effectors which are significant virulence factors in P. aeruginosa. This poses a severe risk to our healthcare system and highlights the importance of continuous surveillance to prevent infectious disease outbreaks.

Prevalence and molecular characterization of carbapenem resistant gram-negative bacilli in a tertiary care hospital in Mumbai

Carbapenem (CR) among gram-negative bacteria is a worldwide problem. It is ranked in the highest priority category in the World Health Organization (WHO) global priority list of pathogens.It is responsible for therapeutic failure in both hospital and community-acquired infections.Identifying and monitoring the local epidemiology of the carbapenem resistant organisms, understanding specific mechanisms underlying the resistance and implementing measures to prevent their spread is the need of the hour.The aim of the study was to determine the prevalence and molecular epidemiology of Carbapenem resistant Gram negative bacilli in this hospital.: A retrospective study was carried out in the Department of Microbiology of a tertiary care Hospital in Mumbai from January to December 2022. All Gram negative bacilli from various specimens were identified and antimicrobial susceptibility was reported using the VITEK2 automated system (BioMerieux, Durham, North Carolina) and interpreted as per CLSI 2022 guidelines. The resistant genes in the isolates were detected by Xpert Carba-R assay (Cepheid, Sunnyvale, CA) on request by a consulting physician.: Out of 2,351 gram negative bacilli isolates, 624 were Carbapenem resistant (26.5%). (59.9%) was the most common CR isolate. Molecular testing was done for 190 of these 624 CR isolates. In which New Delhi Metallo beta lactamase (NDM (33.68%) was the most common resistant gene identified followed by NDM &amp; OXA-48(32.63%). With the prevalence of Carbapenem resistant isolates in the settings, adherence to infection control practices and stringent implementation of antimicrobial stewardship is crucial to curb the rate of infection.

A gold nanoparticle colorimetric probe-based biosensor for rapid detection of VIM-2 and IMP-1 metallo-beta lactamase genes

Despite actions to reduce the prevalence of antibiotic resistance, antibiotic resistance remains a major threat in the treatment and control of infections. Therefore, the development of rapid diagnostic methods plays a significant role in the detection of antibiotic resistance genes and the management of hospital infections. This study aimed to design and develop a gold nanoparticle colorimetric probe-based biosensor was developed for faster and more accurate detection of VIM-2 and IMP-1 Metallo-Beta-Lactamases (MBLs) genes in different clinical samples. After identifying 248 clinical isolates of bacteria with standard biochemical methods and evaluation of antibiotic resistance and identifying MBL-producing strains, PCR method was carried out for detecting VIM-2 and IMP-1 genes as a gold standard. Synthesis of AuNPs were done by citrate reduction method and AuNP -IMP-1 biosensor was used for detecting IMP-1 gene, after functionalization of thiol modified oligonucleotides. AuNP biosensor and IMP-1 PCR were compared in terms of detection indices. Method PCR was defined as the gold standard. Bacteria examined, 87 isolates were resistant to carbapenems. Out of the 87 carbapenem-resistant isolates, 85 (34.2%) were phenotypically positive for MBLs. Also, 7 isolates had IMP-1 gene, but none of them carried VIM-2 gene. The AuNP biosensor had 100% sensitivity, specificity, PPV and NPV, respectively. The final detection limit of IMP-1 genomic DNA (LOD) by PCR and AuNP-IMP-1 biosensor technique was 0.1 fg/μl (2.5 fg/25 reactions) and 0.001 fg/μl (0.025 fg/25 reaction), respectively. According to the promising results of Diagnostic indices, AuNP biosensor is a more efficient and accurate method for direct and indirect detection of antibiotic resistance genes in clinical samples.

Fecal Carriage of Carbapenem Resistant Enterobacterales and Associated Factors Among Admitted Patients in Saint Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia.

The Enterobacterales family colonizes the human gut as normal flora in all age groups, with bacterial infections being the most common cause. Resistance is currently observed in all normal flora. The aim of this study was to determine the frequency of fecal carriage of carbapenem-resistant Enterobacterales (CRE), carbapenemase-producing Enterobacterales (CPE), and associated factors in the faeces of admitted patients. A cross-sectional study was conducted in Saint Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia. A total of 384 rectal swabs were collected from various wards in admitted patients who have consented to participate. The specimens were inoculated on a MacConkey agar plate, and then they were incubated at 37 °C for 18 to 24 hours. Using the BD PhoenixTM M50 compact system identification and antimicrobial susceptibility testing were performed. Using the modified carbapenem inactivation method, it was determined whether the carbapenem-resistant bacterial isolate produced carbapenemase or not. Overall prevalence of carbapenem-resistant Enterobacterales carriage and carbapenemase producing Enterobacterales in admitted patients was 17.2% (95%, Confidence Interval: 13.3-21.1%) and 7% (95%, Confidence Interval: 4.7-9.9%), respectively. The predominate carbapenem-resistant Enterobacterales in fecal carriage was K. pneumoniae, 15.4% (23/149), E. cloacae 15.4% (6/39), followed by E. coli 12.4% (37/307) of carbapenem-resistant Enterobacterales (CRE) isolate. Carbapenem-resistant Enterobacterales carriage isolates showed large level of resistance to ciprofloxacin, and sulfamethoxazole-trimethoprim. Prior intake of antibiotics (Odds Ratio 2.42, 95% CI: 11.186-4.95) was significantly associated with higher carbapenem-resistant Enterobacterales carriage. We observed a high prevalence of carbapenem-resistant Enterobacterales carriage and carbapenemase-producing Enterobacterales among admitted patients. There were only amikacin and colistin that could be effective for carbapenem-resistant Enterobacterales isolates. Hence, the control of carbapenem-resistant Enterobacterales carriage should be given priority by carbapenem-resistant Enterobacterales screening for fecal of admitted patients, and adhering to good infection prevention practice in hospital settings.