Nosocomial infections with extended spectrum beta lactamase producing enterobacteriaceae in pediatric intensive care unit of Zagazig university hospitals

ABSTRACT

Enterobacteriaceae are of great concern because antimicrobial therapy of infections due to these resistant pathogens remains a clinical dilemma in hospitalized patients. It is also noted that there is an increase in the antibiotic resistance among Gram negative bacilli to third generation cephalosporins which is caused by expression of ESBL enzymes. Therefore, infections due to ESBL producing isolates continue to pose a challenge to infection management worldwide. The present study was conducted to highlight ESBL production among Eenterobacteriaceae isolated from nosocomial infections [NI] acquired in PICU of Zagazig University hospital by phenotypic and molecular method. The study was done on 604 PICU patients. Specimens for cultures were obtained according to site of NI blood, urine, CSF, endotracheal tube [ET] aspirates and tips. isolates were confirmed by API 20E and subjected to double disc diffusion test for Phenotypic detection of the extended spectrum beta lactamases. The SHV genes were amplified by PCR, each on a 930 bp fragment. Resulting amplicons were subjected to restriction enzyme digestion for genotypic detection of SHV ESBL. From positive 96 specimens, 68 Enterobacteriaceae were isolated. The most numerous isolated enterobacteria were klebsiella spp [40.6 %], followed by E.coli [9.4%], Enterobacter Spp and Proteus spp [6.3% each], Serratia spp[5.2%], and Citrobacter spp [3.1%].66.2% of Enterobacteriaceae were ESBL producing isolates. Klebsiella pneumonia showed the highest percentage of ESBL producing strains [84.6%], followed by Citrobacter spp [66.7%], Serratia [60%], Enterobacter [50%], Porteus [33.3 %], and the least ESBL producer was E.coli [22.2%]. There is high significant difference between ESBL and Non ESBL producing organisms as regarding the presence of SHV ESBL type gene. 41 Out of 45 isolates [91.1%] of phenotypically ESBL producing Enterobacteriaceae carried the SHV ESBL type gene as indicated by presence of 2 bands of 768 and 162 by RFLP. This study concludes that extended spectrum beta lactamase [ESBL] producing Enterobacteriaciaeae should be put in mind while dealing with specimens of PICU. Double disc diffusion test is a simple and sensitive confirmatory test for ESBL detection. Also, PCR-RFLP is a rapid test for genotypic ESBL detection but needs molecular equipments and facilities