High intermittent colonization by diverse clones of β-lactam-resistant Gram-negative bacilli suggests an excessive antibiotic use and different sources of transmission in haemodialysis patients

The impact of enhanced screening for carbapenemase-producing Enterobacterales in an acute care hospital in South Korea

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) poses a significant challenge to infection control in healthcare settings. Active screening is recommended to prevent intra-hospital CPE transmission.

METHODS

CPE screening was initiated at a 660-bed hospital in South Korea in September 2018, targeting patients previously colonized/infected or admitted to outside healthcare facilities (HCFs) within 1 month. Universal intensive care unit (ICU) screening was performed at the time of admission. After a hospital-wide CPE outbreak in July-September 2019, the screening program was enhanced by extending the indications (admission to any HCF within 6 months, receipt of hemodialysis) with weekly screening of ICU patients. The initial screening method was changed from screening cultures to the Xpert Carba-R assay. The impact was assessed by comparing the CPE incidence per 1000 admissions before (phase 1, September 2018-August 2019) and after instituting the enhanced screening program (phase 2, September 2019-December 2020).

RESULTS

A total of 13,962 (2,149 and 11,813 in each phase) were screened as indicated, among 49,490 inpatients, and monthly screening compliance increased from 18.3 to 93.5%. Compared to phase 1, the incidence of screening positive patients increased from 1.2 to 2.3 per 1,000 admissions (P = 0.005) during phase 2. The incidence of newly detected CPE patients was similar (3.1 vs. 3.4, P = 0.613) between two phases, but the incidence of hospital-onset CPE patients decreased (1.9 vs. 1.1, P = 0.018). A significant decrease was observed (0.5 to 0.1, P = 0.014) in the incidence of patients who first confirmed CPE positive through clinical cultures without a preceding positive screening. Compared to phase 1, the median exposure duration and number of CPE contacts were also markedly reduced in phase 2: 10.8 days vs. 1 day (P < 0.001) and 11 contacts vs. 1 contact (P < 0.001), respectively. During phase 2, 42 additional patients were identified by extending the admission screening indications (n = 30) and weekly in-ICU screening (n = 12).

CONCLUSIONS

The enhanced screening program enabled us to identify previously unrecognized CPE patients in a rapid manner and curtailed a hospital-wide CPE outbreak. As CPE prevalence increases, risk factors for CPE colonization can broaden, and hospital prevention strategies should be tailored to the changing local CPE epidemiology.

Prevalence and incidence of carbapenem-resistant K. pneumoniae colonization: systematic review and meta-analysis

BACKGROUND

Klebsiella pneumoniae is a gram-negative rod belonging to the order Enterobacterales and having a wide distribution in the environment, including the human colon. Recently, the bacterium is one of the known problems in the healthcare setting as it has become resistant to last-resort drugs like carbapenems. The colonized person can serve as a reservoir for his/herself and others, especially in the healthcare setting leading to nosocomial and opportunistic infections. Therefore, we aimed to quantitatively estimate the rate of prevalence and incidence of colonization with carbapenem-resistant K. pneumoniae.

METHODS

A literature search was conducted on PubMed/MEDLINE, Google Scholar, Science Direct, Cochrane Library, WHO Index Medicus, and university databases. The study includes all published and unpublished papers that addressed the prevalence or incidence of K. pneumoniae colonization. Data were extracted onto format in Microsoft Excel and pooled estimates with a 95% confidence interval calculated using Der-Simonian-Laird random-effects model. With the use of I² statistics and prediction intervals, the level of heterogeneity was displayed. Egger's tests and funnel plots of standard error were used to demonstrate the publication bias.

RESULTS

A total of 35 studies were included in the review and 32 records with 37,661 patients for assessment of prevalence, while ten studies with 3643 patients for incidence of colonization. The prevalence of carbapenem-resistant K. pneumoniae colonization varies by location and ranges from 0.13 to 22%, with a pooled prevalence of 5.43%. (3.73-7.42). Whereas the incidence of colonization ranges from 2 to 73% with a pooled incidence of 22.3% (CI 12.74-31.87), both prevalence and incidence reports are majorly from developed countries. There was a variation in the distribution of carbapenem resistance genes among colonizing isolates with KPC as a prominent gene reported from many studies and NDM being reported mainly by studies from Asian countries. A univariate meta-regression analysis indicated continent, patient type, study design, and admission ward do not affect the heterogeneity (p value>0.05).

CONCLUSION

The review revealed that colonization with K. pneumoniae is higher in a healthcare setting with variable distribution in different localities, and resistance genes for carbapenem drugs also have unstable distribution in different geographic areas.

High frequency of colonization by extended-spectrum beta-lactamase-producing Gram-negative bacilli in hemodialysis patients and their household contacts in Colombia: dissemination between the community and the hospital

OBJECTIVES

Increasing colonization by beta-lactam-resistant Gram-negative bacilli (BR-GNB) represents a risk for infections and bacterial resistance spread, both in hospitals and the community. Hemodialysis patients and their household contacts regularly transit between these environments. This study investigated the clinical and epidemiological characteristics of BR-GNB colonization in hemodialysis patients and their household contacts, as well as the genetic relationship between their isolates.

METHODS

A cross-sectional study was conducted on hemodialysis patients at a hospital-associated dialysis center in Medellín, Colombia and their household contacts. Clinical and epidemiological information was collected. Colonization was assessed from stool or rectal swab samples. Bacterial identification and susceptibility were determined using chromogenic media and Vitek-2. Molecular characterization included beta-lactamase detection by polymerase chain reaction, multiple-locus sequence typing (MLST), pulsed-field gel electrophoresis, and identification of Escherichia coli phylogroups by the Clermont protocol.

RESULTS

This study included 36 hemodialysis patients and 90 household contacts. Colonization by BR-GNB occurred in 58.3% of patients and 22.2% of household contacts. The main beta-lactamase detected was CTX-M group-1 (40.5%). In 3 of the 9 homes that had more than 1 colonized individual, a genetic relationship was found. MLST showed a high diversity in E. coli isolates, and the most frequent phylogroups were B1 and B2.

CONCLUSIONS

These results show a high frequency of colonization and the presence of potentially pathogenic BR-GBN both in hospitals and the community. This highlights the importance of populations who move between those 2 environments, and the need to prevent the spread of bacterial resistance outside hospitals.

Carriage Duration and Household Transmission of Enterobacterales Producing Extended-Spectrum Beta-Lactamase in the Community: A Systematic Review and Meta-Analysis

An attributing factor to Enterobacterales producing extended-spectrum beta-lactamase (ESBL-E) community spread is human-to-human transmission. This systematic review and meta-analysis aimed to estimate the duration of ESBL-E carriage in the community and the rate of household transmission. Literature search was performed on PubMed, EMBASE, and Scopus. Dose-response meta-analysis was planned to model the proportion of ESBL-E carriers and household transmission over time. Twenty-six studies (n = 2,505 participants) were included. The median carriage duration was 2 months. Approximately 22% (95% confidence interval: 16-28) had persistent carriage after 12 months. Travelers had significantly shorter carriage (median 1-2 months) than discharged hospital patients (median 6 months) at all measured time points. There were insufficient data to robustly meta-analyze household transmission. Nonetheless, five longitudinal studies reported 18.4% to 35.2% of contacts acquired ESBL-E within 4 to 36 months from hospital discharge of index case. Transmission events from travelers to their contacts appeared lower. Travelers with travel-acquired ESBL-E had significantly faster decolonization rate than discharged patients, suggesting that travel-associated import of multidrug-resistant pathogen may have limited contribution to community transmission of ESBL-E. The substantial prevalence of persistent carriers warrant consideration for additional measures to mitigate exposure risk of ESBL-E from discharged patients in the community and from readmitting patients in the hospital.

The lived experience of haemodialysis patients managed with transmission-based precautions for MDRO colonisation: A qualitative study

BACKGROUND

Patients undergoing haemodialysis colonised with multi-drug resistant organisms (MDROs) are commonly managed with transmission-based precautions (TBP) to prevent nosocomial transmission. TBP have been linked to mixed effects on patient psychological well-being and clinical care. This study was designed to report the lived experience of dialysis patients managed with TBP.

METHODS

A qualitative study of 15 patients undergoing haemodialysis managed with TBP was performed. Participants took part in individual semi-structured interviews. Data was analysed utilising an interpretive phenomenological approach.

RESULTS

Four themes were identified. 1. Communication of what MDRO screening meant, the results, and implications of MDRO positivity was perceived by many patients as insufficient and inconsistent. 2. Experiences of care in isolation were described, with both positive (privacy) and negative (reduced interaction) experiences identified. 3. Psychosocial and emotional responses including concern about health implications and stigma were reported, but also screening was described by some as increasing their perception of being cared for by health care workers, as they felt all health risks were being managed. 4. Confusion around perceived inconsistencies of management, particularly across different environments (eg hospital vs home) and staff.

CONCLUSION

TBP have complex positive and negative impacts on patients which should be considered when developing MDRO management policy and communication around such policy. Strategies to improve communication, patient and staff education, and remove (or explain) perceived inconsistencies of practice may reduce the negative consequences of TBP leading to improved delivery of quality, person-centred care.

Intestinal Carriage of Extended-spectrum β-lactamase and Carbapenemase-producing Enterobacteriaceae in Hemodialysis Patients

Background: Gastrointestinal colonization with resistant pathogens is significant because they could be easily transmitted to other hosts or spread to different microbiota through mobile genetic elements. Objectives: This study assessed the prevalence of fecal carriage of extended-spectrum β-lactamase-producing and carbapenemase-producing Enterobacteriaceae (ESBL-E and CPE, respectively) among hemodialysis patients and the factors affecting its occurrence in a hospital in Tehran. Methods: From January 2018 to May 2019, 150 hemodialysis patients referred to a hospital in Tehran were sampled in this study. Stool samples of the patients were diluted in saline and cultured on MacConkey agar plates containing cefotaxime, ceftazidime, imipenem, and meropenem discs. The clinical data were analyzed to identify the risk factors using a logistic regression model. Results: The colonization rate of ESBL-E was 48.6%, while only 2% of patients were identified as the carriers of CPE (3 of 150). A higher prevalence rate was obtained for intestinal carriage of ESBL-E among hemodialysis patients aged 18 to 42 years using multivariate analysis. The prevalence rate of multidrug-resistant isolates was 73.8%. The blaCTX-M1 gene was identified as the most prevalent ESBL gene. Among carbapenemase-encoding genes, blaKPC and blaoxa-48 were found in 12 and two isolates, respectively. Conclusions: These results demonstrated a high prevalence rate of ESBLs among hemodialysis patients, although this rate was low for carbapenemases. Therefore, more control measures should be taken in hospitals to prevent the spread of antibiotic resistance genes in healthcare settings.