Detection and characterization of extended-spectrum beta-lactamase-producing Enterobacteriaceae in high-risk patients in an Irish tertiary care hospital

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

Transfer of Extended Spectrum Cephalosporin Resistant Enterobacteriaceae Among Patients on an HSCT Unit and the Value of Surveillance and Contact Isolation

The mechanism(s) of acquisition of extended-spectrum cephalosporin-resistant Enterobacteriaceae (ESCRE) on inpatient hospital units dedicated to hematopoietic stem cell transplantation (HSCT) is unclear. The objectives of this study were to determine whether ESCRE organisms are transmitted among patients housed on a HSCT unit, clarify the mechanisms involved, and determine whether routine surveillance for ESCRE carriage and contact isolation for ESCRE carriers is beneficial. The study was conducted on a 30-bed inpatient unit dedicated to the care of patients with hematologic malignancies and HSCT recipients. To investigate whether ESCRE organisms may be transmitted vertically to subsequent room occupants, presumably through contamination of room surfaces, we (1) cultured 6 high touch areas in 10 rooms before and 9 rooms after terminal cleaning that had been occupied by patients with ESCRE carriage, (2) determined the in vitro survivals of our most common clinical ESCRE species, and (3) followed the subsequent room occupants of 54 consecutive ESCRE colonized patients for the development of inpatient acquired ESCRE carriage. To investigate whether ESCRE organisms are transmitted horizontally among inpatients we (1) sequenced 60 available ESCRE Escherichia coli isolates obtained from unit inpatients and searched for identities using complete-genome multisequence locus typing (cgMLST) and (2) retrospectively tabulated the cumulative rates of acquired ESCRE carriage in 356 patients admitted for a first HSCT before (200 patients) or after (156 patients) institution of universal ESCRE stool surveillance and contact isolation for carriers. No ESCRE organisms were cultured from patient rooms before or after terminal cleaning. In vitro, few, if any, ESCRE organisms survived longer than 2 hours. Nine of the subsequent occupants of a room in which a patient with ESCRE carriage had resided were detected with ESCRE carriage, only 2 of whom carried the same species as that of the prior occupant. DNA sequencing and cgMLST determination of the 60 E. coli isolates showed 53 cgMLST strains. Seven of the 53 strains were shared by 2 patients. After institution of universal ESCRE surveillance/isolation there was a significant decline in acquired ESCRE carriage among HSCT recipients. We conclude that vertical transmission of ESCRE organisms through room contamination appears to be uncommon on modern HSCT units. Conversely, our results are consistent with the horizontal spread of ESCRE organisms, probably mediated by intermediate vectors such as personnel or shared equipment. Further studies are needed to better define the magnitude of and risk factors for ESCRE horizontal transfers and the benefits of ESCRE surveillance/isolation.

Distribution of bla CTX - M , bla TEM , bla SHV and bla OXA genes in Extended-spectrum-β-lactamase-producing Clinical isolates: A three-year multi-center study from Lahore, Pakistan

Background

Frequency of extended-spectrum-β-lactamase-producing clinical isolates is increasing worldwide. This is a multi-center study which was aimed to check the frequency of third-generation cephalosporin resistance and distribution of the key genetic determinants of Extended-spectrum-β-lactamase-producing Clinical isolates in Pakistan.

Methods

A total of 2372 samples were processed in three tertiary care hospitals and one diagnostic research center of Lahore, Pakistan during Aug-2014 to Sep-2017. Analytical profile index (API 20-E) was used for biochemical characterization of isolates. Antibiotic susceptibility testing (AST) and third generation cephalosporin resistant (3GC-R) isolates were subjected to: double disc synergism test (DDST), combination disc test (CDST) and epsilometric test (E-test) for confirmation of ESBL-production. PCR amplification of isolates with plasmid and genomic DNA was performed. Amplicon sequences were checked for gene-variants and statistical analyses were performed to check the significance of data.

Results

A total of 497/995 (50%) isolates including Escherichia coli 65% (n = 321), Klebsiella spp. 25% (n = 124) and Pseudomonas. 5% (n = 24), Enterobacter spp. 4% (n = 20) and Acinetobacter spp. 2% (n = 8) were screened as third generation cephalosporin resistant (3GC-R). Urine 56% (n = 278) followed by pus 20% (n = 99) and wound swab 6% (n = 29) were frequent sources. Incidence of ESBL-producers detected by combination disc test was 79% (n = 392). PCR revealed bla_{CTX − M} (76%) gene followed by bla_OXA (52%), bla_TEM (28%) and bla_SHV (21%) were most prevalent among ESBL-producers detected by CDST. bla_{CTX − M − 1}(65%), bla_OXA (78%) and bla_TEM (57%) genes were carried on plasmids. Amplicon sequencing revealed bla_{CTX − M − 15} (75%), bla_OXA − 1 (49%) and bla_{TEM − 1B} (34%) and 21 (n = 28) isolates carried three genes in them.

Conclusion

Prevalence of ESBL-producing isolates has increased 1.13 folds during study years. Isolates had high prevalence of ESBL-encoding bla_{CTXM − 15} gene and narrow spectrum bla_OXA − 1 and bla_{TEM − 1B} were also prevalent.

Is systematic fecal carriage screening of extended-spectrum beta-lactamase-producing Enterobacteriaceae still useful in intensive care unit: a systematic review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are disseminating worldwide leading to increased hospital length of stay and mortality in intensive care units (ICU). ESBL-E dissemination was first due to outbreaks in hospital settings which led to the implementation of systematic fecal carriage screening to improve hygiene procedures by contact precautions. ESBLs have since spread in the community, and the relevance of contact precautions is questioned. ESBL-E dissemination led to an overuse of carbapenems triggering the emergence of carbapenem-resistant Enterobacteriaceae. Empirical antimicrobial therapy based on ESBL-E fecal carriage has been proposed but is debated as it could increase the consumption of carbapenems among ESBL-E carriers without any clinical benefit. Finally, selective decontamination among ESBL-E fecal carriers is evoked to decrease the risk for subsequent ESBL-E infection, but its efficacy remains debated. We propose to systematically review the evidence to recommend or not such systematic ESBL-E fecal carriage screening in adult ICU.

METHODS

Every article focusing on ESBL-E and ICU available on the MEDLINE database was assessed. Articles were included if focusing on cross-transmission, efficacy of hygiene procedures, link between ESBL-E colonization and infection or guidance of empirical therapy or selective decontamination efficacy.

RESULTS

Among 330 articles referenced on PubMed, 39 abstracts were selected for full-text assessment and 25 studies were included. Systematic screening of ESBL-E fecal carriage to guide contact precautions do not seem to decrease the rate of ESBL-E cross-transmission. It has a very good negative predictive value for subsequent ESBL-E infections but a positive predictive value between 40 and 50% and so does not help to spare carbapenems. Cessation of ESBL-E carriage systematic screening could decrease the use of carbapenems in ICU without any clinical harm. Nevertheless, further studies are needed to validate these results from monocentric before-after study. Selective decontamination strategy applied to ESBL-E fecal carriers could be helpful, but available data are conflicting.

CONCLUSION

Current knowledge lacks of high-quality evidence to strongly recommend in favor of or against a systematic ESBL-E fecal carriage screening policy for ICU patients in a non-outbreak situation. Further evaluation of selective decontamination or fecal microbiota transplantation among ESBL-E fecal carriers is needed.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

Colonization and infection with extended-spectrum beta-lactamase producing Enterobacteriaceae in patients with malignancy

INTRODUCTION

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) constitute a global threat and are prevalent in both nosocomial and community settings. These pathogens have been associated with delays in initiation of appropriate antimicrobial therapy and worse clinical outcomes. Patients with solid or hematologic malignancy represent a high-risk population for both colonization and infection with ESBL-PE. Areas covered: A description of the microbiology and epidemiology of the ESBL-PE is presented. Also, we explore studies on ESBL-PE colonization and infection, and examine areas where future research is needed. Expert commentary: ESBL-PE constitute an increasing threat to patients with malignancy. Unfortunately, substantial geographic variations as well as knowledge gaps in certain regions of the world limit our ability to reach conclusions that are valid globally. Furthermore, there is limited evidence regarding the optimal ways to prevent and manage infections caused by ESBL-PE. Research is urgently needed to elucidate these areas and allow the institution of appropriate infection control and antimicrobial stewardship policies and recommendations.

Colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae in solid organ transplantation: A meta-analysis and review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) may cause severe infections, often preceded by ESBL-E gastrointestinal (GI) colonization.

METHODS

We conducted a review of the literature, investigating the prevalence of ESBL-E GI colonization in solid organ transplant (SOT) patients and the risk for subsequent ESBL-E infection. We searched the PubMed and EMBASE databases (to April 1, 2016) looking for studies that contained data on ESBL-E colonization among transplant patients.

RESULTS

Of 341 non-duplicate citations, four studies reporting data on 1089 patients fulfilled our inclusion criteria. Among them, the pooled prevalence for ESBL-E colonization was 18% (95% confidence interval [CI] 5%-36%). Stratifying by transplant type, we identified an ESBL-E colonization rate of 17% (95% CI 3%-39%) among liver transplant recipients and 24% (single report) among kidney transplant recipients.

CONCLUSIONS

Among SOT patients, approximately one in five patients is colonized with ESBL-E, although this finding may be skewed by reporting bias from centers with high ESBL-E prevalence. ESBL-E screening in SOT patients should be considered and evaluated in future studies.

Fecal carriage of extended spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae after urinary tract infection - A three year prospective cohort study

We have performed a prospective cohort study to investigate the duration of and risk factors for prolonged fecal carriage of ESBL-producing Escherichia coli or Klebsiella pneumoniae in patients with community acquired urinary tract infection caused by these bacteria. From 2009 to 2011, 101 Norwegian patients were recruited. Stool swabs and questionnaires were collected every three months for one year and at the end of the study in 2012. Information on antibiotic prescriptions was collected from the Norwegian Prescription Database. Stool samples were cultured directly on ChromID ESBL agar as well as in an enrichment broth, and culture positive isolates were examined by blaCTX-M multiplex PCR. Isolates without blaCTX-M were investigated for alternative ESBL-determinants with a commercial microarray system. Time to fecal clearance of ESBL producing Enterobacteriaceae was also analysed using Kaplan-Meier estimates. Uni- and multivariate logistic regression was used to compare groups according to previously described risk factors. The ESBL point prevalence of fecal carriage were 61% at 4 months, 56% at 7 months, 48% at 10 months, 39% at 13 months, 19% after two years, and 15% after three years or more. We found no correlation between duration of carriage, comorbidity, antibiotic use or travel to ESBL high-prevalence countries. Prolonged carriage was associated with E. coli isolates of phylogroup B2 or D. Importantly, comparative MLST and MLVA analyses of individual paired urine and fecal E. coli isolates revealed that ESBL production commonly occurred in diverse strains within the same host. When investigating cross-transmission of ESBL producing bacteria in health care institutions, this notion should be taken into account.

Colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae and risk for infection among patients with solid or haematological malignancy: a systematic review and meta-analysis

Cancer patients are vulnerable to infections, including those with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), and most of these infections are associated with colonisation of the gastrointestinal tract. The aim of this study was to estimate the prevalence of gastrointestinal colonisation with ESBL-PE cancer populations and to determine the risk for subsequent bloodstream infection (BSI) with these pathogens. PubMed and EMBASE databases were searched from 1 January 1991 to 1 March 2016 to identify studies regarding ESBL-PE colonisation among patients with malignancies. Ten studies (out of 561 non-duplicate articles) were included, providing data on 2211 patients. The pooled prevalence of ESBL-PE colonisation was 19% [95% confidence interval (CI) 8-32%]. Stratifying per region, the pooled prevalence in Europe was 15% (95% CI 10-21%), whereas in Asia the pooled prevalence was 31% (95% CI 4-69%). In addition, the pooled prevalence was 15% (95% CI 7-24%) among patients with haematological malignancy, whereas no studies were identified that included solely patients with solid tumours. Notably, cancer patients with ESBL-PE colonisation were 12.98 times (95% CI 3.91-43.06) more likely to develop a BSI with ESBL-PE during their hospitalisation compared with non-colonised patients. We found that, overall, one in five patients with cancer is colonised with ESBL-PE and the incidence can be as high as one in three in Asia. This is important because colonisation was associated with an almost 13 times higher risk for developing BSI with ESBL-PE. Screening measures should be evaluated to identify their clinical benefit in patients with malignancy.

Colonisation with extended-spectrum beta-lactamase (ESBL) not detected in a prevalence study

BACKGROUND

The Mid-West of Ireland has higher than average national rates of invasive extended-spectrum beta-lactamase (ESBL) bloodstream infections and carbapenemase-producing Enterobacteriaceae (CPE), with increasing numbers of ESBL isolates detected in community-dwelling patients.

AIMS

To conduct a point prevalence study in a convenience sample of the Mid-West population with the aim of determining the extent of ESBL colonisation.

METHODS

Utilising anonymised community stool samples that had completed routine analysis, we conducted a point prevalence study over a 4-week period on all samples that met defined inclusion and exclusion criteria. Limited epidemiological data was recorded: (1) age of patient, (2) gender, and (3) sender location. From these stool specimens, rectal swabs were inoculated (eSwab™ 480CE, Copan, Italy), which were subsequently cultured on selective chromogenic agar (Colorex™ ESBL). Culture plates were incubated aerobically at 37 °C for 24 h.

RESULTS

Of 195 samples processed, 58 % (n = 112) were from females. The median patient age was 62.4 years (range 20-94 years). 186 samples (95 %) originated from general practitioner clinics. During the study period, only nine eligible stool samples were received from LTCF (6 public). From 195 Colorex™ ESBL chromogenic agar plates cultured, no ESBL-producing organisms were detected.

CONCLUSIONS

This community point prevalence study did not identify ESBL colonisation despite high numbers of patients with invasive ESBL bloodstream infections presenting for admission in our institution. We believe this may be because of our small sample size. Data regarding antimicrobial exposure and other risk factors for ESBL colonisation were also not available. We remain vigilant for ESBL-producing organisms.