Abstract:
The presence of extended spectrum ß-lactamase (ESBL)- producing bacteria significantly affects
the infection management worldwide. The objective of this study was to detect and characterize
ESBL-producing enterobacteria in Khartoum hospitals.
A total of 350 clinical specimens were collected from different hospitals in Khartoum State. The
specimens cultivated on selective agar media. Identification was done by Gram's stain and API
20E. The presence of ESBLs was determined by double disk synergy test, combination test and
E-test. The genotypic characterization of ESBLs was done by polymerase chain reaction
technique.
The results revealed that 125 enterobacterial species were identified. The identified bacteria
include Escherichia coli 47 (37.6%), Klebsiella pneumoniae 27 (21.6%) Proteus mirabilis 10
(8%), Enterobacter cloacae 2 (1.6%), Pantoea spp. 15(12.0%), Klyvera spp. 5 (4.0%), Serratia
odorifera 3 (2.4%), Serratia marcescens 2 (11.6%), Proteus vulgaris 2 (1.6%), Citrobacter spp.
4 (3.2%), Klebsiella ozania 1 (0.8%), Klebsiella oxytoca 1 (0.8%), Enterobacter sakazakii 5
(4.0%), Proteus peneri 1 (0.8%). 50(40%) species were found ESBLs-producers by double disk
synergy test. 36(28.8%) of the isolates gave ESBLs positive by combination test and E-test. 40
genes (CTX-M 26(65%), TEM 8(20%) and SHV 6(15%) were detected. 3 (Proteus mirabilis,
Enterobacter sakazaki and E. coli) out of 36 isolates gave ESBLs positive when tested by
multiplex PCR technique.Among three species only 4 genes were detected. These genes were
CTX-M( 2) and TEM (2).
It is concluded that the most prevalent enterobacterial species is E. coli followed by Klebsiella
pneumoniae. The two genera wer ESBL- producers. The CTX-M gene was the most common,
followed by TEM and SHV. Further studies about ESBLs-producing bacteria in community
setting are highly recommended.
