The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread

Clinician views on selective decontamination of the digestive tract in mechanically ventilated patients in intensive care units: A survey

OBJECTIVE

Selective decontamination of the digestive tract (SDD) has been investigated as a strategy to reduce the incidence of ventilator-associated pneumonia (VAP) and other healthcare-associated infections in intensive care unit (ICU) patients receiving mechanical ventilation. There is some evidence to suggest that the use of SDD is associated with a reduction in healthcare-associated infection and mortality; however, the uptake of SDD in ICUs in Australia and New Zealand (ANZ) remains low. To better understand the potential reasons, we designed a questionnaire to gather views from specialists in intensive care medicine, infectious diseases, and medical microbiology.

DESIGN

The study incorporated an online survey.

SETTING AND PARTICIPANTS

An online survey was distributed to specialists in intensive care medicine, infectious diseases, and medical microbiology working in ANZ.

MAIN OUTCOME MEASURES

The main outcome measures are views about SDD and perceived barriers to implementation in ICUs in ANZ.

RESULTS

A total of 103 responses were obtained, of which 55 were from intensive care medicine specialists and the remainder from infectious disease/medical microbiology specialists. No respondents currently used SDD in their hospital ICU. Intensive care medicine specialists self-reported better understanding of the evidence base regarding SDD (P = 0.032) and were more likely to believe that SDD was a safe therapy (P < 0.001) and that it was associated with a reduction in the incidence of VAP (P < 0.001) and ICU mortality (P < 0.001). Infectious disease/medical microbiology specialists were more likely to believe there is currently a lack of evidence of benefit (P < 0.001) and a risk of harm (P < 0.001) associated with SDD.

CONCLUSIONS

Specialists in intensive care medicine had more positive views about use of SDD in ventilated patients than did specialists in infectious diseases/medical microbiology, but no respondents reported using SDD in their clinical practice.

Global epidemiology of high priority and pandemic Pseudomonas aeruginosa in pets, livestock, wild, and aquatic animals: a systematic review and meta-analysis

High-priority and international high-risk Pseudomonas aeruginosa (PA) are emergent strains. Here, we performed the first systematic review and meta-analysis of studies that reported the frequency of PA, carbapenem (CARBR), and colistin (COLR) resistant PA in healthy and sick livestock (A), pets (B), wild (C), and aquatic animals (D) from January 2013 to January 2023, globally. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 57 cross-sectional and eight prospective studies were found eligible. Random-effect models were used to determine the pooled prevalences. Phylogenetic analyses based on core-genome single nucleotide polymorphisms (SNPs) were performed using CSI Phylogeny 1.4. The overall pooled prevalence of PA, COLR-PA, and CARBR-PA were 18.6%, 4%, and 11.7%, respectively. Wild animals had the highest pooled prevalence of PA, 33.5%. The pooled prevalence of COLR was significantly higher in PA strains from sick than healthy animals (P < 0.0001). Furthermore, COLR was significantly highest in PA strains from wild animals, 9.8% [95% confidence interval (CI): 0.8-58.9], while CARBR was highest in PA strains from pets, 14.8% (95% CI: 6.7-29.8). Seven (ST235, ST111, ST233, ST244, ST357, ST308, and ST277) of the 10 high-risk CARBR-PA clones carrying ExoS/U were reported in animals. The SNP-based phylogenetic analysis of 23 genomes of CARBR-PA from animals obtained from publicly available databases revealed two closely related blaGES-carrying strains (<100 SNPs) in sick pets, suggesting a transmission event. A higher frequency of high-risk carbapenem than colistin-resistant PA strains exists in animals. These findings highlight the roles of different animal species, especially pets and wild animals in the persistence and dissemination of high-priority PA.

Genomic investigation unveils high-risk ESBL producing Enterobacteriaceae within a rural environmental water body

Antimicrobial resistance is regarded as a global threat to public health, animals, and the environment, emerging in response to extensive utilization of antimicrobials. The determinants of antimicrobial resistance are transported to susceptible bacterial populations through genetic recombination or through gene transfer, mediated by bacteriophages, plasmids, transposons, and insertion sequences. To determine the penetration of antimicrobial resistance into the bacterial population of the Thiruvandarkoil Lake, a water body located in the rural settings of Puducherry, India, culture-based microbiological and genomic approaches were used. Resistant bacterial isolates obtained from microbiological screening were subjected to whole genome sequencing and the genetic determinants of antimicrobial resistance were identified using in silico genomic tools. Cephalosporin-resistant isolates were found to produce extended spectrum beta lactamases, encoded by blaVEB-6 (in Proteus mirabilis PS01), blaSHV-12 and ompK36 mutation (in Klebsiella quasipneumoniae PS02) and blaSHV-12, blaACT-16, blaCTX-M and blaNDM-1 in (Enterobacter hormaechei PS03). Genes encoding heavy metal resistance, virulence and resistance to detergents were also detected in these resistant isolates. Among ESBL-producing organisms, one mcr-9-positive Enterobacter hormaechei was also identified in this study. To our knowledge, this is the first report of mcr-9 carrying bacterium in the environment in India. This study seeks the immediate attention of policy makers, researchers, government officials and environmental activists in India, to develop surveillance programs to monitor the dissemination of antimicrobial resistance in the environment.

Risk Factors and Outcomes for Isolation with Polymyxin B-Resistant Enterobacterales from 2018-2022: A Case-Control Study

Purpose

To analyze the risk factors and clinical outcomes of patients isolated with polymyxin B-resistant (PR) Enterobacterales from various clinical specimens to prevent and control the spread of these strains.

Methods

This retrospective case-control study included 72 PR Enterobacterales-positive cases and 144 polymyxin B-susceptible (PS) Enterobacterales controls from 2018 to 2022. Patients with PR Enterobacterales isolated in various clinical cultures were defined as cases. Patients with PS Enterobacterales cultures at similar anatomic sites during the same period were randomly selected as controls. Data were collected from clinical and laboratory test records. Bivariable logistic regression and Pearson's chi-square tests were used to assess risk factors.

Results

PR strains were predominantly Klebsiella pneumoniae (72.2%) and Salmonella enteritidis (8.3%). Of the patients, 66.04% were admitted to an intensive care unit (ICU). Risk factors for isolation with PR strains included chronic heart disease (P = 0.012; odds ratio [OR] 1.15; 95% confidence interval [CI] 1.03-1.28), immunosuppressant use (P = 0.016; OR 1.04 [1.0-1.07), drainage tube [head] (P = 0.006; OR 1.1 [1.0-1.1]), and polymyxin B exposure (P = 0.007; OR 1.03 [1.0-1.06]. With respect to outcomes, admission to an ICU (P = 0.003; OR 7.1 [1.9-25.4]), hypertension (P = 0.035; OR 1.4 [1.02-1.83]), and drainage tube [head] (P = 0.044; OR 1.1 [1.0-1.15]) were associated with treatment failure. Additionally, treatment failure was more frequent in patients (45.83%) than in controls (14.58%).

Conclusion

The major risk factors for isolation with PR strains were chronic heart disease, exposure to immunosuppressants, use of drainage tubes, and polymyxin B exposure. The isolation of PR strains in patients was a predictor of unfavorable outcomes. These findings provide a basis for monitoring the spread of PR Enterobacterales.