Prevalence and molecular characterization of extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae isolated from Al Shifa hospital, Gaza, Palestine

Abstract EN

Extended spectrum beta-lactamase (ESBL) producing members of the Enterobacteriaceae most notably Escherichia coli and Klebsiella pneumoniae, are a major problem in hospitals worldwide.

This study was undertaken to determine the frequency of ESBLs producing E.

coli and K.

pneumoniae in Al Shifa hospital in Gaza.

Two hundred bacterial isolates including 159(79.5%) E.

coli and 41(20.5%) K.

pneumoniae were collected from Al Shifa hospital – Gaza Strip.

They were isolated from different clinical samples including urine and pus.

The bacterial isolates were tested for ESBL production using Double Disc Synergy Test.

Using PCR, ESBL producing E.

coli and K.

pneumoniae were examined for the presence of ESBL genes including CTX-M, TEM and SHV.

Out of 200 clinical isolates of E.

coli and K.

pneumoniae, 56(28%) were ESBL producers while 144(72%) were of non-ESBL phenotype.

Out of 159 E.

coli, 41 K.

pneumoniae isolates ESBL production was detected in 45(27%), 11(26.8%) respectively.

ESBL producing E.

coli and K.

pneumoniae were isolated from various clinical samples including urine 41/139 (29.4%) and pus 15/61 (24%).

Both ESBL and non-ESBL isolates were resistant to amoxicillin (100%).

ESBL producing isolates were resistant to cephalexin, ceftazidim, ceftriaxone and cefotaxime (94.6%, 96.4%, 98.2% and 100%) respectively.

The resistance rate to four antibiotics or more among ESBL and non ESBL producing organisms (E.

coli and K.

pneumoniae) was 100% and 70% respectively.

The resistance rate of ESBL producing isolates to meropenem reached 10%, while all non- ESBL producers were sensitive.

Phenotypic positive ESBL producers were further tested by PCR, the prevalence of each of the following genes SHV, TEM and CTX-M were 26.7%, 51.7% and 81.7%, respectively.

The prevalence of detection of one, two and three genes were 44.6%, 46.4% and 8.9% respectively.

In conclusion, this study revealed high prevalence of ESBL producing organisms in Al Shifa hospital and high levels of resistance to third generation cephalosporins.

CTX-M was the predominant gene among ESBL producers.

Our results emphasize the urgent need for formulation of an antibiotic policy in Gaza strip to prevent spread of these organisms.