ABSTRACT
Background:
The multidrug resistant among
uropathogenic E. coli has become a potential threat to
global health. The aim of the current study to evaluate the antimicrobial activities of
nitrofurantoin and
fosfomycin along with other antimicrobials against Extended Spectrum β-Lactamases (ESBL) and AmpC producer isolates from the most common organism E. coli.
Methods:
A total of 6046 clean catch midstream
urine samples were collected and processed in
Microbiology department of
tertiary care hospital. The antimicrobial susceptibility of E. coli isolates was initially screened by Kirby-Bauer disk
diffusion method. The resistant isolates were confirmed to be ESBL and AmpC producers by their respective phenotypic confirmatory tests of combined disc
method.
Results:
Out of 6046
patients there were 1855 E. coli positive
patients. Maximum
patients in the
age group of 21-30 years were 51.5% followed by 31-40 years where
patients were 26%. 64.4% E. coli were isolated from
female patients and 35.6% from
male patients. E. coli showed higher
sensitivity towards,
fosfomycin (100%),
imipenem (100%),
nitrofurantoin (84.1%),
piperacillin and
tazobactam (77.3%),
amikacin (76.1%) and while they showed high degree resistance pattern against
Penicillin,
cotrimoxazole,
ciprofloxacin,
norfloxacin and 2nd and 3rd generation
cephalosporin. Out of 1855 E. coli, multi
drug resistance was seen in 520 E. coli isolates. ESBL
production was observed among 50% of E. coli isolates by combined disk
method. Out of 520 isolates, 150 isolates showed resistance to one or more extended-spectrum
cephalosporins and
cefoxitin by Kirby-Bauer disk
diffusion method. These were selected and screened for ESBL and AmpC
production. Among 150
cefoxitin-resistant isolates, AmpC
phenotype was detected in 100 isolates (66.6%) by AmpC disc
method. The overall occurrence of AmpC in the study was found to be 19.2%. Susceptibility of ESBL and AmpC producers to
fosfomycin,
imipenem,
nitrofurantoin and
amikacin were found to be 100%, 98.5%, 89% and 75% respectively.
Conclusions:
There is increased
prevalence of ESBL and AmpC producing E. coli. Thus, early
detection of ESBL and AmpC producer E. coli by simple phenotypic
methods is necessary to avoid
treatment failure, where molecular
techniques are not available.