Abstract:
Bacteria from clinical and non-clinical settings are
becoming increasingly resistant to conventional antibiotics
and broader infection-control problem. Patients admitted
to hospitals for the treatment of resistant bacterial
infections are adding to the already too high costs of
healthcare and are a source of resistant bacteria and/or
resistance-encoding genes.
The aim of the study was to identify the genes (CTX-M,
SHV and TEM) responsible for extended-spectrum beta-
lactamase (ESBL) phenomenon among Gram negative
bacteria isolated from Sudanese patients infected with
urinary tract infection (UTI).
Three hundred and thirty two (n=332) urine specimens
were collected from patients attending different hospitals
in Khartoum State during the period from May to
November 2011. The isolates were identified by using
conventional biochemical methods and microbact 2000
24E (OXOID) system. All Isolates were tested for their
antimicrobial resistance. ESBL screening was confirmed by
double disk synergy test and VITEK 2 system.
Results showed that frequency rate of urinary Gram
negative isolates was 218 (65.7%). The major isolate was
E. coli 157 (72.0%), followed by K. pneumoniae 32
(14.7%). The maximum sensitivity was seen for imipenem
(100%). The maximum resistance was seen against
ceftazidime 163 (74.8%). ESBL producing bacteria was
130 (59.6%) and was mostly
K. pneumoniae 22/32
(68.8%). ESBL producing bacteria showed maximum
resistance to ceftazidime 124/130 (95.4%). ESBLs positive
strains were tested for the presence of ESBL encoding
genes using PCR with specific primers for the detection of
CTX-M, SHV and TEM genes. The presence of CTX-M, SHV
and TEM genes was confirmed in 68/130 (52.3%) of the
isolates. The ESBL genes were detected in 19 Klebsiella
strains and in 49 of Escherichia coli isolates.
The genes detected were found to be carried by K.
pneumoniae and Escherichia coli strains. ESBL was found
to be higher in Sudan compared with other countries.
Among urinary isolates the commonest prevalence ESBL
gene was CTX-M gene followed by TEM; while the least
one detected was SHV gene.
