New Delhi metallo-β-lactamase - type carbapenemases producing Escherichia coli isolates from hospitalized patients: A pilot study

Molecular Epidemiology of Carbapenemase-Producing Pseudomonas aeruginosa: An Iranian Referral Hospital-Based Study

In recent years, there has been a significant increase in infections caused by carbapenemase-producing strains, with carbapenem-resistant Pseudomonas aeruginosa (CRPA) emerging as a priority pathogen according to the World Health Organization. This study aimed to evaluate the molecular epidemiology of CRPA isolated from patients referred to Children's Medical Center in Tehran, Iran. P. aeruginosa isolates collected from different children's wards were screened for common carbapenem-resistant genes by polymerase chain reaction (PCR). Genetic relatedness between isolates was assessed by pulsed-field gel electrophoresis (PFGE). The study included 133 participants, with 50% being male, and revealed a median age of 2 years (interquartile range: 6 months to 6 years). Carbapenem resistance was detected in 15% of cases (n = 20), with CRPA isolates predominantly found in the emergency ward (60%). The median age of patients with CRPA was significantly higher than those with carbapenem-susceptible P. aeruginosa (6 years vs. 1 year). PCR analysis revealed metallo-β-lactamase production in 45% of CRPA isolates (n = 9), with blaNDM being the most prevalent gene. PFGE analysis of the CRPA isolates identified three clusters (Cluster I, II, and III). Cluster I, comprising 65% of all isolates (n = 13), was predominantly found in the emergency ward. Notably, blaNDM-producing strains were prevalent in the emergency ward. Our study highlights the significant prevalence of CRPA in the emergency ward of our hospital and underscores the importance of targeted surveillance and infection control measures to curb its spread within health care settings.

An engineered prodrug selectively suppresses β-lactam resistant bacteria in a mixed microbial setting

The rise of β-lactam resistance necessitates new strategies to combat bacterial infections. We purposefully engineered the β-lactam prodrug AcephPT to exploit β-lactamase activity to selectively suppress resistant bacteria producing extended-spectrum-β-lactamases (ESBLs). Selective targeting of resistant bacteria requires avoiding interaction with penicillin-binding proteins, the conventional targets of β-lactam antibiotics, while maintaining recognition by ESBLs to activate AcephPT only in resistant cells. Computational approaches provide a rationale for structural modifications to the prodrug to achieve this biased activity. We show AcephPT selectively suppresses gram-negative ESBL-producing bacteria in clonal populations and in mixed microbial cultures, with effective selectivity for both lab strains and clinical isolates expressing ESBLs. Time-course NMR experiments confirm hydrolytic activation of AcephPT exclusively by ESBL-producing bacteria. In mixed microbial cultures, AcephPT suppresses proliferation of ESBL-producing strains while sustaining growth of β-lactamase-non-producing bacteria, highlighting its potential to combat β-lactam resistance while promoting antimicrobial stewardship.

Integration of phenotypic, qPCR and genome sequencing methodologies for the detection of antimicrobial resistance and virulence in clinical isolates of a tertiary hospital, India

The emergence of antimicrobial resistance (AMR) and virulence in clinical isolates is a significant public health concern. The rapid and accurate detection of these traits in clinical isolates is essential for effective infection control and treatment. We demonstrated the integration of multiple detection methodologies, including phenotypic testing, quantitative polymerase chain reaction (qPCR), and genome sequencing, to detect AMR and virulence in clinical isolates. One hundred sixty-two gram-negative bacterial clinical isolates were selected for this study from the Shri Vinoba Bhave Civil Hospital, Silvassa, a tertiary government hospital. Antimicrobial susceptibility was detected by determining the Minimum Inhibitory Concentration (MIC) using Vitek-2, whereas the combined disk (CD) method was used for phenotypic detection of carbapenemase activity. The highest sensitivity rates were obtained for antibiotics colistin 87.93%, amikacin 67.52%, tigecycline 63.39%, nitrofurantoin 60.87%, and gentamycin 56.08%. The most resistant antibiotics were ceftazidime (71.93%), ciprofloxacin (67.95%) and trimethoprim/sulfamethoxazole (65.56%). Approximately 46.91% (76) of all the isolates were MBL isolates. The qPCR results confirmed the presence of blaNDM-1 in 29.01% of the isolates. The blaNDM-1 harbouring isolates in descending order, were Acinetobacter, Enterobacter cloacae, and Klebsiella pneumoniae. Klebsiella and Acinetobacter isolates were extensively drug-resistant. Whole genome sequencing performed on one of the Klebsiella pneumoniae isolates revealed the presence of many virulence factors, which increased the pathogenicity of the clinical isolates. The results showed that antimicrobial resistance, including carbapenem resistance, blaNDM-1, and virulence factors, was highly prevalent among isolates from tertiary clinical hospitals. The integration of multiple detection methodologies can potentially improve the detection of AMR and virulence in clinical isolates, leading to better patient outcomes and a reduced spread of these essential traits.

Can a UV-C box help the cinema industry by disinfecting video cameras?

Introduction

UV-C has proven to be an effective virucide and microbicide, and its cost-effectiveness allowed it to spread as a disinfecting procedure in different environments.

Methods

The study aims to determine the microbicide activity on Staphylococcus aureus, Escherichia coli and SARS-CoV-2 of the UV-C Boxer by Cartoni S.p.A. Three separate experiments were performed to assess the effectiveness of the UV-C disinfection device on different materials, directly on surfaces of a video camera and on a specific carrier for SARS-CoV-2.

Results

In all three experiments, a significant abatement of bacterial and viral contamination was reached after 60 seconds on carriers and after 3 minutes on all examined surfaces of the video camera, with a higher reduction on glass carriers.

Conclusions

UV-C devices may be a valuable tool to implement in the working routine to achieve a higher level of safety in work environments.

Epidemiology of extended-spectrum β-lactamase and metallo-β-lactamase-producing Escherichia coli in South Asia

Aim: To determine the prevalence of extended-spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL)-producing Escherichia coli in South Asia. Methodology: A systematic review and meta-analysis of data published in PubMed, EMBASE, Web of Science and Scopus. Results: The pooled prevalence of ESBL and MBL-producing E. coli in South Asia were 33% (95% CI: 27-40%) and 17% (95% CI: 12-24%), respectively. The prevalence of bla_CTX-M type was 58% (95% CI: 49-66%) with bla_CTX-M-15 being the most prevalent (51%, 95% CI: 40-62%) variant. The most prevalent MBL variant was bla_NDM-1 (33%, 95% CI: 20-50%). Conclusion: This study suggests a high prevalence of ESBLs and MBLs among E. coli clinical isolates. Comprehensive resistance surveillance is required to guide clinicians prescribing antibiotics in South Asia.

Impact of an antimicrobial stewardship and monitoring of infection control bundle in a surgical intensive care unit of a tertiary-care hospital in India

OBJECTIVES

Antimicrobial stewardship (AMS) in resource-limited settings lacks models that can be readily adapted to their settings. Here we discuss the impact of a combined strategy of AMS and monitoring of infection control practices in a tertiary-care centre of a developing country.

METHODS

This study was undertaken in the surgical unit of a tertiary-care hospital over an 8-month period. In the first 2 months (baseline phase), prospective audit and feedback alone was undertaken, while in the next 6 months (intervention phase) this was supplemented with strategies such as antimicrobial timeout, correction of doses and bundle approach for prevention of hospital-acquired infections.

RESULTS

A total of 337 patients were included (94 in the baseline phase and 243 in the intervention phase). There was a decrease in days of therapy per 1000 patient-days (1000PD) (1112.3 days vs. 1048.6 days), length of therapy per 1000PD (956 days vs. 936.3 days) and defined daily doses (DDD) per 1000PD for most antimicrobials. A decrease in double cover for Gram-negative infections (9.6% vs. 2.9%) but an increase in double anaerobic cover (4.2% vs. 7.4%) was observed. There was a decrease in the incidence of ventilator-associated pneumonia per 1000 ventilator-days in the intervention phase (46.4 vs. 35.4), whereas central line-associated bloodstream infections per 1000 central line-days remained the same (14.7 vs. 14.8).

CONCLUSION

This study shows that implementation of routine AMS activities with monitoring of infection control practices can help decrease overall antimicrobial use. With furtherance of measures to control infection, antimicrobial use may be further curtailed.

The present danger of New Delhi metallo-β-lactamase: a threat to public health

The evolution of antimicrobial-resistant Gram-negative pathogens is a substantial menace to public health sectors, notably in developing countries because of the scarcity of healthcare facilities. New Delhi metallo-β-lactamase (NDM) is a potent β-lactam enzyme able to hydrolyze several available antibiotics. NDM was identified from the clinical isolates of Klebsiella pneumoniae and Escherichia coli from a Swedish patient in New Delhi, India. This enzyme horizontally passed on to various Gram-negative bacteria developing resistance against a variety of antibiotics which cause treatment crucial. These bacteria increase fatality rates and play an integral role in the economic burden. The efficient management of NDM-producing isolates requires the coordination between each healthcare setting in a region. In this review, we present the prevalence of NDM in children, fatality and the economic burden of resistant bacteria, the clonal spread of NDM harboring bacteria and modern techniques for the detection of NDM producing pathogens.

Increasing Prevalence of Escherichia coli and Klebsiella pneumoniae Producing CTX-M-Type Extended-Spectrum Beta-Lactamase, Carbapenemase, and NDM-1 in Patients from a Rural Community with Community Acquired Infections: A 3-Year Study

Background

Increasing prevalence of community-acquired infections (CAIs) due to Escherichia coli and Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL), especially the Cefotaxime-Munich (CTX-M) type, carbapenemase, and New Delhi metallo-β-lactamase (NDM), has been reported globally posing a serious public health threat that has complicated treatment strategies for Gram-negative bacterial infections. While most of the reports in this regard are based on hospitalized patients from the urban community, there is a paucity of data in a rural community presenting with CAIs.

Materials and Methods

A total of 1275 strains of E. coli and K. pneumoniae isolated over a period of 3 years from patients with CAIs were subjected to the detection of ESBL by double-disc synergy test; carbapenemase by modified Hodge test; metallo-β-lactamase by MIC test strip metallo-β-lactamase (MBL); and bla _TEM, bla _SHV, bla _CTX-M, and bla _NDM genes by polymerase chain reaction.

Results

Among 1275 E. coli and K. pneumoniae isolated during the study period, 773 (60.6%), 102 (8%), and 28 (2.2%) isolates were detected as ESBL, carbapenemase and MBL producers, respectively. Of the 773 ESBL producers, 635 (82.1%) were found to harbor bla _CTX-M genes, and of the 102 carbapenemase producers, 12 (11.8%) were found to harbor bla _NDM genes. Gene sequencing of all the 12 NDM-positive isolates revealed bla _NDM-1 genes. Antibiotic resistance pattern of the ESBL-positive isolates revealed a high degree of co-resistance to noncephalosporin antibiotics such as amoxyclav, co-trimoxazole, chloramphenicol, and fluoroquinolones.

Conclusion

The present study showed the increasing the prevalence of ESBL including CTX-M variety, carbapenemase production by E. coli and K. pneumoniae isolates, and spread of NDM-1 in the patients from the rural community of North India.

Ciprofloxacin, amoxicillin, and aminoglycosides stimulate genetic and phenotypic changes in uropathogenic Escherichia coli strains

Antibiotic therapy and its consequences in bacterial and human aspects are widely investigated. Despite this, the emergence of new multidrug resistant bacteria is still a current problem. The scope of our work included the observation of changes among uropathogenic Escherichia coli strains after the treatment with a subinhibitory concentration of different antibiotics. The sensitive strains with or without virulence factors were incubated with amoxicillin, ciprofloxacin, gentamycin, or tobramycin. After each passage, the E. coli derivatives were compared to their wild types based on their susceptibility profiles, virulence genes, biofilm formations and the fingerprint profiles of PCR products amplified with using the (N)(6)(CGG)(4) primer. It turned out that antibiotics caused significant changes in the repertoire of bacterial virulence and biofilm formation, corresponding to acquired cross-resistance. The genomic changes among the studied bacteria were reflected in the changed profiles of the CGG-PCR products. In conclusion, the inappropriate application of antibiotics may cause a rapid rise of Multidrug Resistant (MDR) strains and give bacteria a chance to modulate their own pathogenicity. This phenomenon has been easily observed among uropathogenic E. coli strains and it is one of the main reasons for recurrent infections of the urinary tract.

Carbapenem resistance in Escherichia coli and Klebsiella pneumoniae among Indian and international patients in North India

The aim of the study was to find out the carbapenem resistance rate and prevalence of different carbapenemase genes in Klebsiella pneumoniae and Escherichia coli from a North Indian corporate hospital that receives both Indian and international patients. A total of 528 clinical isolates of E. coli and K. pneumoniae were included in the study. All isolates that were found resistant to carbapenems by MIC testing (Vitek II Compact^®) were screened for NDM, OXA-48, VIM, and KPC genes by PCR. Sequencing of NDM gene and transmissibility by conjugation assay were checked on 22 randomly selected NDM-positive isolates. One hundred and fifty-six isolates (29.54%) were carbapenem-resistant. The rate of carbapenem resistance was significantly higher in K. pneumoniae as compared to E. coli (53.9% vs. 15.6%; p < 0.05). The NDM gene was found in 34.6% (54/156), OXA-48 in 31.4% (49/156), co-expression of NDM + OXA-48 in 15.3% (24/156) of the carbapenem-resistant isolates. VIM and KPC were absent in all isolates. NDM gene was significantly more prevalent in E. coli than K. pneumoniae (p < 0.05). All the tested isolates formed transconjugants and NDM-5 was the most common variant in both species (15/22). The presence of plasmid-based NDM calls for stricter surveillance measures in our hospital settings.

Complete Genome Sequence of a Carbapenem-Resistant Escherichia coli Isolate with bla NDM-5 from a Dog in the United States

The carbapenem resistance gene bla_NDM-5 was identified in an Escherichia coli strain isolated from a dog. We report here the complete genome sequence of this E. coli strain; the bla_NDM-5 gene was present on a large IncFII multidrug-resistant plasmid. This is the first bla_NDM-5-carrying E. coli strain from an animal in the United States.

The carbapenem resistance gene bla_NDM-5 was identified in an Escherichia coli strain isolated from a dog. We report here the complete genome sequence of this E. coli strain; the bla_NDM-5 gene was present on a large IncFII multidrug-resistant plasmid. This is the first bla_NDM-5-carrying E. coli strain from an animal in the United States.