[Carbapenemase-producing enterobacteriae: epidemiology, strategies to control their spread and issues]

A Method for Detecting Five Carbapenemases in Bacteria Based on CRISPR-Cas12a Multiple RPA Rapid Detection Technology

Introduction

As the last line of defense for clinical treatment, Carbapenem antibiotics are increasingly challenged by multi-drug resistant bacteria containing carbapenemases. The rapid spread of these multidrug-resistant bacteria is the greatest threat to severe global health problems.

Methods

To solve the problem of rapid transmission of this multidrug-resistant bacteria, we have developed a rapid detection technology using CRPSPR-Cas12a gene editing based on multiple Recombinase polymerase amplification. This technical method can directly isolate the genes of carbapenemase-containing bacteria from samples, with a relatively short detection time of 30 minutes. The instrument used for the detection is relatively inexpensive. Only a water bath can complete the entire experiment of Recombinase polymerase amplification and trans cleavage. This reaction requires no lid during the entire process while reducing a large amount of aerosol pollution.

Results

The detection sensitivity of this method is 1.5 CFU/mL, and the specificity is 100%.

Discussion

This multi-scene detection method is suitable for screening populations in wild low-resource environments and large-scale indoor crowds. It can be widely used in hospital infection control and prevention and to provide theoretical insights for clinical diagnosis and treatment.

Germs of thrones - spontaneous decolonization of Carbapenem-Resistant Enterobacteriaceae (CRE) and Vancomycin-Resistant Enterococci (VRE) in Western Europe: is this myth or reality?

Background

In France, Carbapenem-Resistant Enterobacteriaceae (CRE) and Vancomycin-Resistant Enterococci (VRE) are considered as Extensively Drug-Resistant (XDR) bacteria. Their management requires reinforcement of hospital’s hygiene policies, and currently there is few consistent data concerning the spontaneous decolonization in XDR colonized patients. Our aim is to study the natural history of decolonization of XDR carriers over time in a hospital setting in a low prevalence country.

Material and methods

Retrospective multicenter study over 2 years (2015–2016) in 2 different tertiary care hospital sites and units having an agreement for permanent cohorting of such XDR carriers. We gathered the type of microorganisms, risk factors for colonization and rectal swabs from patient’s follow-up. We also evaluated patient care considering isolation precautions.

Results

We included 125 patients, aged 63+/−19y, including 72.8% of CRE (n = 91), 24.8% of VRE (n = 31) and 2.4% (n = 3) co-colonized with CRE and VRE. CRE were mainly E. coli (n = 54), K. pneumoniae (n = 51) and E. cloacae (n = 6). Mechanisms of resistance were mainly OXA-48 (n = 69), NDM-1 (n = 11), OXA-232 (n = 8) and KPC (n = 3).

Prior antibiotic therapy was reported in 38.4% (n = 48) of cases. Conversely, 17.6% (n = 22) received antibiotics during follow-up.

Spontaneous decolonization occurred within the first 30 days in 16.4% (n = 19/116) of cases and up to 48.2% after day-90 with a median follow-up of 96 days (0–974).

We estimated that XDR carriage was associated with a larger care burden in 13.6% (n = 17) of cases, especially due to a prolongation of hospitalization of 32.5 days (15–300).

Conclusions

Our study shows that spontaneous decolonization is increasing over time (up to 48.2%). We can regret that only few patients underwent screening after 1 year, emphasizing the need for more monitoring and prospective studies.

[Resistant phenotypes of Escherichia coli strains responsible for urinary tract infection in the laboratory of the University Hospital Joseph Raseta Befelatanana, Antananarivo]

Introduction

I’infection urinaire à Escherichia coli est fréquente en milieu hospitalier. Cette étude se propose de décrire les différents phénotypes de résistance des souches d’Escherichia coli afin de surveiller leur émergence.

Méthodes

Il s’agit d’une étude rétrospective de type descriptif de 102 souches d’Escherchia coli responsables d’infection urinaire sur une période allant du mois de Janvier 2014 au mois d’Octobre 2016 au Laboratoire du Centre Hospitalo-Universitaire Befelatanana Antananarivo.

Résultats

La résistance aux béta-lactamines a identifié des pénicillinases de haut niveau 50% (n=51), des Escherichia coli sécrétrices de Béta-Lactamase à Spectre Etendu E-BLSE 22,5% (n=23), des céphalosporinases de haut niveau 14,7% (n=15), des pénicillinases de bas niveau 5,9% (n=6), des souches sauvages 5,9% (n=6) et une souche d’Escherichia coli hautement résistante émergente. La résistance aux aminosides a concerné 58 (56,9%) phénotypes sauvages, 29 (28,4%) souches sensibles à l’amikacine et 15 (14,7%) résistants à tous les aminosides. La résistance aux fluoroquinolones a identifiée 52 (51%) souches sauvages, 9 (8,8%) souches sensibles à la ciprofloxacine et 41 (40,2%) résistantes à tous les fluoroquinolones. Les femmes (25, 7%) (p= 0,25, NS), les sujets de plus de 60 ans (38,7%) (p=0,02), les sujets hospitalisés dans le service de néphrologie (53,8%) (p=0,04), ayant présenté des troubles urinaires et rénaux (29, 7%) (p= 0,2, NS), ont été les plus affectés par les E-BLSE.

Conclusion

La multi-résistance élevée des souches d’Escherichia coli interpelle sur une révision du traitement empirique des infections urinaires.

Control of emerging extensively drug-resistant organisms (eXDRO) in France: a survey among infection preventionists from 286 healthcare facilities

We performed a multicenter survey in May-June 2012 to assess strategies in preventing the spread of emerging extensively drug-resistant organisms (eXDRO), including glycopeptide-resistant enterococci and carbapenemase-producing Enterobacteriaceae, in a convenient sample of French healthcare facilities (HCFs). The collected data included organization and measures to: (1) identify patients at risk for carrying eXDRO, (2) investigate and control sporadic cases or outbreaks, and (3) describe prior 2010-2012 episodes with one or more colonized patients. Of the 286 participating HCFs, 163 (57 %) and 134 (47 %) reported having a specific procedure to detect repatriates or patients hospitalized in foreign countries within the last year, respectively. Among the 97 HCFs with prior at-risk patient management experience, contact precautions, hospitalization in a single room, and screening for eXDRO carriage were quasi-systematically performed (n = 92/97, 95 %). The alleged time between admission and alert ranged from 24 to 48 h after the patient's admission; 203 (71 %) HCFs recommended obtaining three successive negative screening samples to declare a patient free of eXDRO colonization. During the last two years, 64 HCFs (23 %) had to manage at least one eXDRO case, with a total of 20 outbreaks with more than one secondary case. This first national survey shows that French HCFs were not totally ready to control eXDRO spread in 2012. Their previous experiences and capacities in controlling eXDRO outbreaks are quite heterogeneous from one hospital to another. Further researches are needed in order to understand the constraints in applying national guidance.