Delayed diagnosis of high drug-resistant microorganisms carriage in repatriated patients: three cases in a French intensive care unit

Investigation of a vanA linezolid- and vancomycin-resistant Enterococcus faecium outbreak in the Southwest Indian Ocean (Reunion Island)

INTRODUCTION

Dual resistance to linezolid and glycopeptides is a milestone reached by certain extensively drug-resistant (XDR) enterococci. This paper describes the molecular and epidemiological investigations of a linezolid-resistant and vancomycin-resistant Enterococcus faecium (E. faecium) (LVREf) outbreak in the French overseas territory of Reunion Island (Indian Ocean).

METHODS

All vancomycin-resistant Enterococcus (VRE) isolates detected on Reunion Island between 2015 and 2019 were included in the study. The VRE isolates were phenotypically characterised and genetically explored by whole-genome sequencing (WGS).

RESULTS

Sixteen vancomycin-resistant E. faecium (VREf) isolates were retrieved between 2015 and 2019. Seven isolates obtained in 2019 were involved in the outbreak. These seven LVREf isolates from the 2019 outbreak at the University Hospital of Reunion Island (UHRI) were suspected to be related to a linezolid-susceptible VREf strain imported from India. An epidemiological link was highlighted for six of the seven outbreak cases. All the LVREf outbreak isolates were obtained from rectal swabs (colonisation) and resistant to vancomycin (MIC > 128 mg/L) and linezolid (MIC 8-32 mg/L); one isolate was also resistant to daptomycin (MIC 8 mg/L). The seven outbreak isolates were positive for the vanA and optrA genes and belonged to ST761.

CONCLUSIONS

These results argue for the strict application of control and prevention measures for VRE clones at high risk of spread, particularly in areas such as Reunion Island where the risk of importation from the Indian subcontinent is high. The regional spread of optrA linezolid-resistance genes in VRE isolates is a matter of concern, due to possibility of treatment failure.

Molecular and epidemiological investigation of a colistin-resistant OXA-23-/NDM-1-producing Acinetobacter baumannii outbreak in the Southwest Indian Ocean Area

Dual resistance to colistin and carbapenems is a milestone reached by certain extensively-drug resistant (XDR) Gram-negative bacteria. This study describes the first outbreak of XDR colistin- and carbapenem-resistant OXA-23-/NDM-1-producing Acinetobacter baumannii (CCRAB) in the European overseas territory of Reunion Island (France, Indian Ocean). Between April 2019 and June 2020, 13 patients admitted to the University Hospital of Reunion Island were involved in the outbreak, of whom eight were infected and six died. The first case was traced to a medical evacuation from Mayotte Island (Comoros archipelago). An epidemiological link could be established for 11 patients. All of the collected CCRAB isolates showed the same resistance profile and co-produced intrinsic β-lactamases OXA-69 and ADC-191, together with acquired carbapenem-hydrolysing β-lactamases OXA-23 and NDM-1. A mutation likely involved in colistin resistance was detected in the two-component system PmrAB (D82N in PmrA). All of the isolates were found to belong to ST^Pas1/ST^Ox231 clonal complex and were phylogenetically indistinguishable. Their further characterization by whole-genome sequence analyses (whole-genome multi-locus sequence typing, single nucleotide polymorphisms) provided hints about the transmission pathways. This study pleads for strict application of control and prevention measures in institutions where the risk of imported XDR bacteria is high.

Travel-Related Antimicrobial Resistance: A Systematic Review

There is increasing evidence that human movement facilitates the global spread of resistant bacteria and antimicrobial resistance (AMR) genes. We systematically reviewed the literature on the impact of travel on the dissemination of AMR. We searched the databases Medline, EMBASE and SCOPUS from database inception until the end of June 2019. Of the 3052 titles identified, 2253 articles passed the initial screening, of which 238 met the inclusion criteria. The studies covered 30,060 drug-resistant isolates from 26 identified bacterial species. Most were enteric, accounting for 65% of the identified species and 92% of all documented isolates. High-income countries were more likely to be recipient nations for AMR originating from middle- and low-income countries. The most common origin of travellers with resistant bacteria was Asia, covering 36% of the total isolates. Beta-lactams and quinolones were the most documented drug-resistant organisms, accounting for 35% and 31% of the overall drug resistance, respectively. Medical tourism was twice as likely to be associated with multidrug-resistant organisms than general travel. International travel is a vehicle for the transmission of antimicrobial resistance globally. Health systems should identify recent travellers to ensure that adequate precautions are taken.

Surveillance of carbapenemase-producing Enterobacteriaceae in the Indian Ocean Region between January 2010 and December 2015

BACKGROUND

The aim of this study was to trace the emergence of carbapenemase-producing Enterobacteriaceae (CPE) on Reunion Island, a French overseas territory well suited for the surveillance of CPE emergence in patients from the entire Indian Ocean Region.

METHODS

This retrospective multicenter study was conducted on Reunion Island between 2010 and 2015.

RESULTS

A total of 43 CPEs were isolated during the course of the study, in 36 patients (50% in the last year alone). Among these patients, 21 had a link with a foreign country (58%), mainly Mauritius (47.6%). Over the same period, CPEs were isolated from 13 of 1735 (0.7%) repatriated patients to Reunion Island from another country of the Indian Ocean Region. The incidence of isolation of CPEs in the repatriated patients treated in Mauritius was higher (9.2%) than in patients treated in Madagascar or the Comoros Islands (<1%, P<0.001). The most commonly isolated microorganism was Klebsiella pneumoniae (39.5%). The most frequently identified carbapenemase was NDM-1 (81.4%); 100% and 56% of the NDM-1 strains were susceptible to tigecycline and colistin, respectively. In-hospital mortality rate was higher in patients presenting with CPE infection than in patients without CPE infection (75% vs. 25%, P=0.04).

CONCLUSION

As elsewhere in the world, the number of CPE cases on Reunion Island is on the rise. Most cases involve patients from Mauritius, which justifies screening and isolating CPE in patients from that country.

KlebSeq, a Diagnostic Tool for Surveillance, Detection, and Monitoring of Klebsiella pneumoniae

Health care-acquired infections (HAIs) kill tens of thousands of people each year and add significantly to health care costs. Multidrug-resistant and epidemic strains are a large proportion of HAI agents, and multidrug-resistant strains of Klebsiella pneumoniae, a leading HAI agent, have caused an urgent public health crisis. In the health care environment, patient colonization by K. pneumoniae precedes infection, and transmission via colonization leads to outbreaks. Periodic patient screening for K. pneumoniae colonization has the potential to curb the number of HAIs. In this report, we describe the design and validation of KlebSeq, a highly informative screening tool that detects Klebsiella species and identifies clinically important strains and characteristics by using highly multiplexed amplicon sequencing without a live-culturing step. We demonstrate the utility of this tool on several complex specimen types, including urine, wound swabs and tissue, and several types of respiratory and fecal specimens, showing K. pneumoniae species and clonal group identification and antimicrobial resistance and virulence profiling, including capsule typing. Use of this amplicon sequencing tool to screen patients for Klebsiella carriage could inform health care staff of the risk of infection and outbreak potential. KlebSeq also serves as a model for next-generation molecular tools for public health and health care, as expansion of this tool can be used for several other HAI agents or applications.

Risk Factors for Colonization With Multidrug-Resistant Bacteria Among Patients Admitted to the Intensive Care Unit After Returning From Abroad

BACKGROUND

Few national recommendations exist on management of patients returning from abroad and all focus on hospitalized patients. Our purpose was to compare, in an intensive care unit (ICU), the admission prevalence and acquisition of multidrug-resistant (MDR) bacteria carriage in patients with ("Abroad") or without ("Local") a recent stay abroad, and then identify the risk factors in "Abroad" patients.

METHODS

In this retrospective study, we reviewed charts of all the patients hospitalized in the ICU unit from January 2011 through July 2013 with hygiene samplings performed. We identified all patients who had stayed abroad ("Abroad") within 6 months prior to ICU admission.

RESULTS

Of 1,842 ICU patients, 129 (7%) "Abroad" patients were reported. In the "Abroad" group, the rate of MDR strain carriage was higher at admission (33% vs 6.7%, p < 0.001) and also more often diagnosed during the ICU stay (acquisition rate: 17% vs 5.2%, p < 0.001) than in "Local" patients. Risk factors associated with MDR bacteria carriage at admission in "Abroad" patients were diabetes mellitus [odds ratio (OR) 5.1 (1.7-14.8), p = 0.003] and "hospitalization abroad with antibiotic treatment" [OR 10.7 (4.2-27.3), p < 0.001]. Hospitalization abroad without antibiotic treatment was not identified as a risk factor.

CONCLUSIONS

The main factor associated with MDR bacteria carriage after a stay abroad seems to be a hospitalization abroad only in case of antibiotic treatment abroad. Screening and isolation of "Abroad" patients should be recommended, even in case of a first negative screening.