New Mutations in GyrA Gene of Escherichia Coli Isolated form Iraqi Patients

Abstract

The present study included a collecting of 165 specimens form different sources,
93 isolates were identified as Escherichia coli depending on morphological and
biochemical tests in addition to automated systems such as VITEK 2 and api 20E.
All isolates under study developed high resistance toward cefotaxime, ceftazidime,
ceftriaxone, and ciprofloxacin estimated by minimum inhibitory concentration. Stool
and wound specimens characterized by harbouring the highest resistant isolates in a
percentage reached 100% against antibiotics under study. Insignificant differences
were found between isolates collected from males and females. Upon using disk
displacement method to detect extended spectrum beta lactamases (ESBL), it was
found that 37.73% of isolates were ESBL producers. However, stool and urine
specimens harboured the highest percentage of producers. The present study
findings revealed a presence of efflux pump in 77.5% of tested isolates using
cartwheel method. Nevertheless, PCR technique exposed about 85% of isolates
harboured acrAB efflux pump gene. Moreover, the results of this study illustrated
that all isolates contained gyrA and parC using PCR technique. Accordingly, three
isolates were chosen for nucleotide alignment study; one of them is sensitive and the
other two are resistant to ciprofloxacin (acrAB free). The results showed a presence
of stable and frequent three mutations in the resistant isolates (14 and 3). A
transition mutation found in the site 4808116 in which guanine is replaced by
adenine. Furthermore, two transversion mutations were located in 4804221 and
4808222 sites. Additionally, a hot spot was detected in the site 4808109.