Prevalence of metallo-β-lactamases as a correlate of multidrug resistance among clinical Pseudomonas aeruginosa isolates in Nepal

Extended-spectrum β-lactamases producing Enterobacteriaceae (ESBL-PE) prevalence in Nepal: A systematic review and meta-analysis

An alarming increase in the occurrence of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has threatened the treatment and management of bacterial infections. This systematic review and meta-analysis aimed to provide a quantitative estimate of the prevalence of ESBL among the members of the Enterobacteriaceae family by analyzing the community-based and clinical studies published between 2011 and 2021 from Nepal and determine if ESBL-PE correlates with multidrug resistance (MDR). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed for systematic review and meta-analysis and the articles' quality was assessed using the Newcastle-Ottawa scale. Of the 2529 articles screened, 65 articles were systematically reviewed, data extracted, and included in in-depth meta-analysis. The overall pooled prevalence of ESBL-producers in Enterobacteriaceae was 29 % (95 % CI: 26-32 %) with high heterogeneity (I2 = 96 %, p < 0.001). Escherichia coli was the predominant ESBL-producing member of the Enterobacteriaceae family, followed by Citrobacter spp. and Klebsiella spp. The prevalence of ESBL-PE increased from 18.7 % in 2011 to 29.5 % in 2021. A strong positive correlation (r = 0.98) was observed between ESBL production and MDR in Enterobacteriaceae. ESBL-PE isolates showed high resistance to ampicillin, cephalosporins, and amoxicillin-clavulanic acid, and blaCTX-M type was the most reported gene variant among ESBL-PE. In conclusion, this study demonstrated an increased prevalence of ESBL-PE in Nepal over the last decade, and such isolates showed a high level of MDR against the β-lactams and non-β-lactam antibiotics. Tackling the rising antibiotic resistance (AR) and MDR in ESBL-PE would require concerted efforts from all stakeholders to institute effective infection control programs in the community and clinical settings.

The Prevalence of Metallo-Beta-Lactamese-(MβL)-Producing Pseudomonas aeruginosa Isolates in Brazil: A Systematic Review and Meta-Analysis

The purpose of the current study is to describe the prevalence of Pseudomonas aeruginosa (PA)-producing MβL among Brazilian isolates and the frequency of blaSPM-1 in MβL-PA-producing isolates. From January 2009 to August 2023, we carried out an investigation on this subject in the internet databases SciELO, PubMed, Science Direct, and LILACS. A total of 20 papers that met the eligibility requirements were chosen by comprehensive meta-analysis software v2.2 for data retrieval and analysis by one meta-analysis using a fixed-effects model for the two investigations. The prevalence of MβL-producing P. aeruginosa was 35.8% or 0.358 (95% CI = 0.324-0.393). The studies' differences were significantly different from one another (x2 = 243.15; p < 0.001; I2 = 92.18%), so they were divided into subgroups based on Brazilian regions. There was indication of asymmetry in the meta-analyses' publishing bias funnel plot; so, a meta-regression was conducted by the study's publication year. According to the findings of Begg's test, no discernible publishing bias was found. blaSPM-1 prevalence was estimated at 66.9% or 0.669 in MβL-PA isolates (95% CI = 0.593-0.738). The analysis of this one showed an average heterogeneity (x2 = 90.93; p < 0.001; I2 = 80.20%). According to the results of Begg's test and a funnel plot, no discernible publishing bias was found. The research showed that MβL-P. aeruginosa and SPM-1 isolates were relatively common among individuals in Brazil. P. aeruginosa and other opportunistic bacteria are spreading quickly and causing severe infections, so efforts are needed to pinpoint risk factors, reservoirs, transmission pathways, and the origin of infection.

Genomic characterisation of multi-drug resistant Escherichia coli and Klebsiella pneumoniae co-harbouring mcr-1 and mcr-3 genes on a single plasmid from paediatric clinical cases

OBJECTIVES

Emergence of the plasmid-born mobile colistin resistance (mcr) gene is a growing concern in healthcare. Therefore, this study aimed to genomically characterise multidrug-resistant Escherichia coli and Klebsiella pneumoniae co-harbouring the mcr-1 and mcr-3 genes in young children.

METHODS

E. coli (n = 3) and K. pneumoniae (n = 2) were collected from abdominal secretions and blood, respectively. The isolates were screened using tryptone soy broth with 4 µL/mL polymyxin-B. Growing bacteria were identified using the VITEK-2 system, matrix-assisted laser desorption/ionisation time-of-flight, and 16s RNA sequencing, followed by antibiotic susceptibility testing. Metallo-β-lactamase (MBL) and extended-spectrum β-lactamase (ESBL) production was also detected. Afterwards, strains were subjected to molecular screening targeting mcr variants and ESBL/MBL-encoding genes. Conjugation, pulsed-field gel electrophoresis, Southern hybridisation, multilocus sequence typing, and phylogenic group detection were performed, along with plasmid-genome sequencing and bioinformatics analysis.

RESULTS

E. coli isolates (EC-19-322, 323, and 331) and K. pneumoniae isolates (KP-19-225 and 226) harboured both mcr-1 and mcr-3 genes. These strains were also found to be resistant to more than three classes of antibiotics. The conjugation experiment revealed the presence of mcr-1 and mcr-3 on a single plasmid, and the transmission frequency was 10-2 to 10-3. Both strains were found to be able to produce ESBLs and MBL. E. coli EC-19-322 and 323 were identified as ST131(O25a:H41); SP-19-331, as ST1577 (O16:H30); and K. pneumoniae, as ST231 (K2). All E. coli strains belonged to phylogenetic group B2, and the results of pulsed-field gel electrophoresis supported the multilocus sequence typing findings.

CONCLUSION

This study reported the co-occurrence of mcr-1 and mcr-3 genes on a single plasmid in pathogenic ESBL/MBL-producing E. coli and K. pneumoniae isolated from young children.

Antimicrobial Resistance, Genetic Lineages, and Biofilm Formation in Pseudomonas aeruginosa Isolated from Human Infections: An Emerging One Health Concern

Pseudomonas aeruginosa (PA) is a leading nosocomial pathogen and has great versatility due to a complex interplay between antimicrobial resistance and virulence factors. PA has also turned into one the most relevant model organisms for the study of biofilm-associated infections. The objective of the study focused on analyzing the antimicrobial susceptibility, resistance genes, virulence factors, and biofilm formation ability of thirty-two isolates of PA. PA isolates were characterized by the following analyses: susceptibility to 12 antimicrobial agents, the presence of resistance genes and virulence factors in PCR assays, and the quantification of biofilm production as evaluated by two distinct assays. Selected PA isolates were analyzed through multilocus sequence typing (MLST). Thirty PA isolates have a multi-resistant phenotype, and most of the isolates showed high levels of resistance to the tested antibiotics. Carbapenems showed the highest prevalence of resistance. Various virulence factors were detected and, for the quantification of biofilm production, the effectiveness of different methods was assessed. The microtiter plate method showed the highest accuracy and reproducibility for detecting biofilm-producing bacteria. MLST revealed four distinct sequence types (STs) in clinical PA, with three of them considered high-risk clones of PA, namely ST175, ST235, and ST244. These clones are associated with multidrug resistance and are prevalent in hospitals worldwide. Overall, the study highlights the high prevalence of antibiotic resistance, the presence of carbapenemase genes, the diversity of virulence factors, and the importance of biofilm formation in PA clinical isolates. Understanding these factors is crucial for effective infection control measures and the development of targeted treatment strategies.

Multi-drug Resistance, β-Lactamases Production, and Coexistence of bla NDM-1 and mcr-1 in Escherichia coli Clinical Isolates From a Referral Hospital in Kathmandu, Nepal

The ability of pathogenic Escherichia coli to produce carbapenemase enzymes is a characteristic that allows them to resist various antibiotics, including last-resort antibiotics like colistin and carbapenem. Our objectives were to identify rapidly developing antibiotic resistance (AR), assess β-lactamases production, and detect mcr-1 and bla _NDM-1 genes in the isolates. A prospective cross-sectional study was carried out in a referral hospital located in Kathmandu from November 2019 to December 2020 using standard laboratory and molecular protocols. Among 77 total E. coli isolates, 64 (83.1%) of them were categorized as MDR. Phenotypically 13 (20.3%) colistin-resistant, 30 (46.9%) ESBL and 8 (12.5%) AmpC producers, and 5 (7.8%) ESBL/AmpC co-producers were distributed among MDR-E. coli. Minimum inhibitory concentrations (MIC) against the majority of MDR isolates were exhibited at 1 g/L. Of these 77 E. coli isolates, 24 (31.2%) were carbapenem-resistant. Among these carbapenem-resistant bacteria, 11 (45.9%) isolates were reported to be colistin-resistant, while 15 (62.5%) and 2 (8.3%) were MBL and KPC producers, respectively. Out of 15 MBL producers, 6 (40%) harbored bla _NDM-1, and 8 (61.5%) out of 13 colistin-resistant pathogens possessed mcr-1. The resistance by colistin- and carbapenem were statistically associated (P < .001). However, only 2 (18.2%) of the co-resistant bacteria were found to have both genes. Our study revealed the highly prevalent MDR and the carbapenem-resistant E. coli and emphasized that the pathogens possess a wide range of capabilities to synthesize β-lactamases. These findings could assist to expand the understanding of AR in terms of enzyme production.

Systematic Review and Meta-analysis on Extended-Spectrum β-lactamases Producing Klebsiella pneumoniae in Nepal

Objective

This systematic review and meta-analysis aimed to assess the pool estimates of extended-spectrum β-lactamases producing K. pneumoniae (ESBL-KP) and study their drug resistance profile by evaluating the studies from Nepal.

Methods

A literature search was carried out in PubMed, Google Scholar, and NepJOL to screen all articles on ESBL-KP published between 2011 and 2021 from Nepal. This review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Relevant data were extracted, and R language 4.2.0 software was used for statistical analysis.

Results

The pooled prevalence of K. pneumoniae was 5%, while the pooled prevalence of ESBL and multidrug resistance (MDR) in K. pneumoniae were 23% and 55%, respectively. Imipenem was the drug of choice (in vitro) against ESBL-KP infection.

Conclusion

Our analyses showed a high prevalence of ESBL-KP and their high resistance toward commonly used drugs. This study highlights the need for the development of new antibiotics for the management of ESBL-KP infections.

Epidemiology and Multidrug Resistance of Pseudomonas aeruginosa and Acinetobacter baumanni Isolated from Clinical Samples in Ethiopia

Background

A. baumannii and P. aeruginosa are important nosocomial pathogens in health-care settings. Both are intrinsically resistant to many drugs and are able to become resistant to the virtually most antimicrobial agents. An increasing prevalence of infections caused by multidrug-resistant isolates has been reported in many countries.

Methods

An institutional-based cross-sectional five-year retrospective study was conducted to assess the antimicrobial resistance trend of P. aeruginosa and A. baumani. 893 A. baumani and 729 P. aeruginosa isolates were included in the study. Conventional method was used for identification and antimicrobial susceptibility was determined by Kirby-Bauer disc-diffusion method. The isolates were from suspected bloodstream infections, wound infections, urinary tract, or surgical site nosocomial infections. Socio-demographic and other variables of interest were collected using a structured check list from a patient record data. Data were analyzed using SPSS version 26 software. P value <0.05 was considered statistically significant.

Results

A total of 1622 A. baumanii and P. aeruginosa were isolated from various clinical specimens recorded from the year 2017-2021. Out of which A. baumanni was 893 (60.6%) and P. aeruginosa was 729 (39.4%). Blood was the major source of the isolates (18.3%), followed by urine (16%), and tracheal aspirate (10.6%). Antimicrobial resistance among A. baumanni over the five years were; ampicillin (86% to 92%), ceftriaxone (66.7% to 82.2%), and ciprofloxacin (58.5% to 66.7%). In P. aeruginosa a significant increase in resistance was seen from 2017 to 2021 to Amoxicillin-clavulanate (74.1% to 84.2%), chloramphenicol (62% to 81.9%), and gentamicin (40% to 44.8%).

Conclusion

A five-year antimicrobial resistance trend analysis of A. baumanni and P. aeruginosa showed increasing multi drug resistance and resistance to highly potent antimicrobial agents in Ethiopia. It should be addressed with infection control measures, surveillance, and alternative new therapeutic strategies to circumvent the spread of multi-drug resistance.