Rapid Detection of Extended Spectrum β-Lactamases (ESBLs) Producing E.coli by Normann-Dortet-Poirel (NDP) Test

Abstract

SUMMARY M ultidrug resistance poses a major threat by causing a wide range of infections at an increasing rate. The main cause for such dilemma is the improper & unjustified use of antibiotics (Schwaber et al., 2006). The Enterobacteriaceae family is held responsible for many cases of antibiotic resistance, mainly by the means of ESBLs production (Pitout and Laupland, 2008 and Coque et al., 2011). ESBL producers, which are mostly E.coli and Klebsiella pneumoniae species, are not only found as source of nosocomial but also of community-acquired infections (Coque et al., 2008; Pitout and Laupland, 2008 and Poirel et al., 2012). The problem with ESBL-producing bacteria is the significant resistance to β-lactam antibiotics and commonly to other drugs as aminoglycosides & fluoroquinolones. This widely limits the treatment choices to the carbapenems as a last resort, which in turn contributes to the emergence of carbapenem-resistant bacterial strains overtime (Parveen et al., 2010). The objective of this study was to evaluate the performance of the NDP test for rapid detection of ESBLs producing bacteria in order to choose an appropriate anti-microbial therapy for patients infected by such bacteria. This work was carried out on 50 clinical E.coli and 25 fecal E.coli isolates. These isolates were tested for ESBL prodution by DDT, MDDST and NDPT. The results are summarized as follows:  The frequency of ESBL production among clinical E.coli isolates was 32% by MDDST and 40% by NDPT.  The frequency of ESBL production among fecal E.coli isolates was 36% by MDDST & 40% by NDPT.  The NDPT gave higher positive results for ESBL production than the MDDST among the clinical and fecal Ecoli isolates.  There was no significant relation between the frequency of ESBL production and age/gender of the patients.

SUMMARY M ultidrug resistance poses a major threat by causing a wide range of infections at an increasing rate. The main cause for such dilemma is the improper & unjustified use of antibiotics (Schwaber et al., 2006). The Enterobacteriaceae family is held responsible for many cases of antibiotic resistance, mainly by the means of ESBLs production (Pitout and Laupland, 2008 and Coque et al., 2011). ESBL producers, which are mostly E.coli and Klebsiella pneumoniae species, are not only found as source of nosocomial but also of community-acquired infections (Coque et al., 2008; Pitout and Laupland, 2008 and Poirel et al., 2012). The problem with ESBL-producing bacteria is the significant resistance to β-lactam antibiotics and commonly to other drugs as aminoglycosides & fluoroquinolones. This widely limits the treatment choices to the carbapenems as a last resort, which in turn contributes to the emergence of carbapenem-resistant bacterial strains overtime (Parveen et al., 2010). The objective of this study was to evaluate the performance of the NDP test for rapid detection of ESBLs producing bacteria in order to choose an appropriate anti-microbial therapy for patients infected by such bacteria. This work was carried out on 50 clinical E.coli and 25 fecal E.coli isolates. These isolates were tested for ESBL prodution by DDT, MDDST and NDPT. The results are summarized as follows:  The frequency of ESBL production among clinical E.coli isolates was 32% by MDDST and 40% by NDPT.  The frequency of ESBL production among fecal E.coli isolates was 36% by MDDST & 40% by NDPT.  The NDPT gave higher positive results for ESBL production than the MDDST among the clinical and fecal Ecoli isolates.  There was no significant relation between the frequency of ESBL production and age/gender of the patients.