Metallo-beta-lactamase Producing Pseudomonas aeruginosa in Neonatal Septicemia

Prevalence of Extended Spectrum Betalactamase (ESBL) and Metallobetalactamase (MBL) Producing Pseudomonas aeruginosa and Acinetobacter baumannii Isolated from Various Clinical Samples

This study was conducted with an objective to find the prevalence of extended spectrum betalactamase (ESBL) and metallobetalactamase (MBL) in P. aeruginosa and A. baumannii isolates obtained from various clinical samples. It was conducted in the Department of Microbiology, Adesh Institute of Medical Sciences and Research, Bathinda, over a period of two years from July 2014 to June 2016. Clinical specimens including urine, pus, blood, high vaginal swabs, respiratory samples, and various body fluids were processed and P. aeruginosa and A. baumannii isolates were identified by standard protocols. Antibiotic sensitivity testing for all isolates was done using Kirby-Bauer disc diffusion method. Disc potentiation test was performed to check ESBL and MBL production in these bacteria. Maximum ESBL positive isolates of P. aeruginosa were observed among pus samples and maximum MBL positive isolates were detected in tracheal aspirates. A. baumannii showed maximum positivity for ESBL and MBL production in endotracheal secretions. This study gives an alarming sign towards high prevalence of cephalosporin and carbapenem resistance due to production of extended spectrum betalactamases and metallobetalactamases, respectively. Early detection, stringent antibiotic policies, and compliance towards infection control practices are the best defenses against these organisms.

Mortality in patients with multidrug-resistant Pseudomonas aeruginosa infections: a meta-analysis

Pseudomonas aeruginosa is the leading cause of nosocomial infections with high mortality rates owing to the limited therapeutic options for multidrug-resistant Pseudomonas aeruginosa (MDRPA) and metallo-beta-lactamase (MBL)-producing strains. Herein, we present a meta-analysis exploring the association between MDRPA and São Paulo MBL-1 (SPM-1)-producing strains vs. mortality. Online databases were screened to identify studies published between 2006 and 2016. A total of 15 studies, comprising 3,201 cases of P. aeruginosa infection, were included. Our results demonstrated a higher mortality rate among patients infected with MDRPA (44.6%, 363/813) than those with non-MDRPA infection (24.8%, 593/2,388) [odds ratio (OR) 2.39, 95% confidence interval (CI) 1.70-3.36, p <0.00001]. The risk of mortality in patients with non-SPM-1 strains was four times higher than that observed in the patients of the SPM-1 group; however, no statistically significant difference was observed (p = 0.43). In conclusion, the results of our study demonstrated that patients infected with MDRPA had a significantly higher mortality rate than that of patients infected with non-MDRPA strains, especially patients with bloodstream infection (BSI), immunosuppression, and inadequate antimicrobial therapy. The absence of studies on the molecular aspects of blaSPM-1 and its association with mortality limited the analysis; therefore, our results should be interpreted with caution. Our findings also highlight the need for more studies on the molecular aspects of resistance and the peculiarities of different nosocomial settings.

Detection of metallo-beta-lactamase producing Pseudomonas aeruginosa in intensive care units

BACKGROUND

Metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa has emerged as a threat to hospital infection control, due to its multi-drug resistance, especially in intensive care units (ICUs).

AIMS

This study was carried out to detect MBL producing P. aeruginosa isolates from medical and surgical ICUs, to compare and evaluate different phenotypic methods currently in use and to determine antibiograms.

METHOD

A prospective study was undertaken to detect MBLs in P. aeruginosa isolates obtained from various clinical samples. A total of 49 strains were recovered from patients admitted in inpatient wards and ICUs, and screened for imipenem resistance by Kirby Bauer disk diffusion method. Detection of MBLs was further done by imipenem-EDTA disk synergy test and combined disk test.

RESULTS

Out of 49 isolates, 11 isolates (22.4 per cent) were imipenem resistant. All 11 imipenem resistant P. aeruginosa strains, when further tested, were positive for MBL production by combined disk test, but, only eight showed positive results by imipenem-EDTA disk synergy test.

CONCLUSION

MBL production was the main resistance mechanism in the 11 carbapenem resistant P. aeruginosa isolates collected, with multidrug resistance associating significantly with MBL production in P. aeruginosa from our institution.