In Vitro Activities of Ertapenem and Imipenem against Clinical Extended Spectrum Beta-Lactamase-Producing Enterobacteriaceae Collected in Military Teaching Hospital Mohammed V of Rabat

Predominance of OXA-48 Carbapenemase-Producing Enterobacterales in a Moroccan Hospital

Objective

The emergence of carbapenemase-producing Enterobacterales (CPE) is a major concern that is increasingly reported worldwide. Our study aimed at investigating the resistance of CPE isolates in a Moroccan teaching hospital using phenotypic and genotypic methods.

Methods

Enterobacterales strains from March to June 2018 were collected from different clinical samples. The Enterobacterales isolates resistant to third-generation cephalosporins (3GC) and/or carbapenems were subjected to the Carba NP test and an immunochromatographic test for phenotypic detection. Detection of extended-spectrum β-lactamases (ESBL) was also performed following standards. Molecular screening of carbapenemases genes (OXA-48, NDM, blaKPC, blaIMP, blaVIM, and blaOXA-24, blaOXA-23, OXA-51, OXA-58) using conventional multiplex PCR assays was also performed on 143 isolates.

Results

Enterobacterales represented 52.7% with a proportion of 21.8% of bacteria resistant to 3GC and/or carbapenems. Within 143 isolates MDR to 3GC, K. pneumoniae, E. coli, and E. cloacae represent 53.1%, 40.6%, and 6.3%, respectively. These strains were isolated mainly from urinary samples (74.8%) in patients admitted to emergency and surgical units. 81.1% of strains are producing ESBL and 29% are carbapenemase producers as confirmed by the Carba NP test, immunochromatographic test, and molecular testing. OXA-48 carriers represent 83.3% of these strains, followed by NDM with 16.7%. blaKPC, blaIMP, blaVIM, and blaOXA-24, blaOXA-23, OXA-51, OXA-58 were not detected in any of these bacteria.

Conclusions

A high rate of CPE carrying OXA-48 among Enterobacterales resistant to 3GC and/or carbapenems isolates was found. Strict observance of hospital hygiene measures and more rational use of antibiotics are mandatory. Implantation of carbapenemases detection should be encouraged in our hospital settings to estimate the true burden of the CPE.

Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) colonization as a risk factor for developing ESBL infections in pediatric cardiac surgery patients: "retrospective cohort study"

Background

Children with cardiac defects need many hospitalizations and repetitive antibiotic therapies, with an increasing risk of colonization with multidrug-resistant bacteria (MDRB) such as extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) Post-operative infections with these bacteria in paediatric cardiac surgery are life threatening. This article aims to study the prevalence of ESBL colonization among paediatric cardiac surgery patients, and to compare occurrence of post-operative infections with and without ESBL colonization. We also aim to study the correlation between the onset of postoperative infection and other parameters such as age, length of stay and preoperative antibiotic therapy.

Methods

A retrospective cohort study included paediatric cardiac surgery patients in Cheikh Zaid hospital in Rabat, Morocco, between the 1st of January 2011 and 31 December 2014. A screening for ESBL colonization was requested for children who had a risk factor (previous hospitalization and/or taking antibiotics) at admission. Swabs were collected from three sites (throat, nose and anus). Two groups were compared – patients colonized and not colonized with ESBLs. Statistical analysis was performed using R software.

Results

ESBL colonization screening was performed in 111 patients. Positive colonization was detected in 17 cases (15%). Klebsiella pneumoniae (KP): 9 (53%) was the most frequently isolated species. Among the 17 patients, 23.5% (4/17) developed a postoperative infection due to ESBLs versus only one patient without colonization (1%).

There was a statically significant difference in terms of occurrence of postoperative infection between the two groups (p = 0.001). Relative risk of developing a postoperative infection with positive colonization was 22 (95% CI, 8.37–58.5).

Conclusions

The analysis of colonization with multidrug-resistant bacteria and the prevention of nosocomial infections appear to be important challenges for paediatric cardiac surgery. Systematic screening of ESBL colonization for cardiac surgery could have a significant contribution, on one hand to guide prophylactic antibiotic therapy of patients, and on the other, to prevent spread of those infections.