The data ofthis study represents the first time to detect a multi-resistant E. coliwhich is resistant to both carbapenem and colistin in Egypt. Additionally, ourgenetic analysis reveals that mcr-1 was the causative agent. Consequently,it is considered as alarming sign in our area. Later in 2016 it was a publishedcase for mcr-1 which was detected using PCR and DNA sequencing to screenfor its presence in 241 Gram-negative clinical bacterial isolates collected inEgypt (Elnahriry S. S. et al., 2016).
Their analysis showed that mcr-1was present in only one E. coli isolate (SP-1). This E.coli hadphenotypic resistance to colistin, ciprofloxacin, nalidixic acid, kanamycin,tetracycline, chloramphenicol, ceftriaxone, ampicillin, and cefotaxime but wassusceptible to carbapenemes.
(Elnahriry S. S. et al., 2016). Another groupof researchers detected the mcr-1 gene in four Escherichia coliisolates (Linda Falgenhauer et al., 2016). Three were originated from swine (R253,V163, 112065) and one from a human wound infection (NRZ14408).
R253, V163, and112065 were extended-spectrum ?-lactamase-producing isolates that harbour blaCTX-M-1,whereas the NRZ14408 human isolate carries a blaKPC-2 carbapenemesgene in addition to mcr-1 (LindaFalgenhauer et al.,2016). In Denmark mcr-1gene was detected (Hasman, et al., 2015). It was also detected previouslyin China by Yi-Yun Liu and colleagues (Liu, Y-Y et al.
, 2015). In FranceESBL-positive E. coli isolates were collected for examining colistinresistance.
Their genetic experiments confirmed the genetic origin of mcr-1which was carried on plasmid (MarisaHaenni et al., 2016). Other researchersreported E. coli strain harboring both mcr-1 andcarbapenemase gene blaNDM-5, originally isolated from a US patient inAugust 2014. The patient had emigrated from India and resided continuously inthe United States for 1 year before their study (José R et al.
,2016).In Venezuela researchersstudied the presence of mcr-1 in human, animal, and environmental Enterobacteriaceaesamples from Cumana, Venezuela, that were collected in 2015. The mcr-1gene was detected in 2 isolates of E. coli from swine (novel ST452) andhuman (ST19) samples that were resistant to colistin. Whole-genome sequencingand transformation experiments identified mcr-1 on an IncI2 plasmid.
Oneof the isolates also bore the widely spread carbapenemase NDM-1 (Delgado etal., 2016).In this study,we found that the carbapenem-colistin double resistant E. coli wassensitive to levofloxacin and gentamycin alleviating the situation.
Therefore,we suggest that colistin and polymyxin could be combined with levofloxacin orgentamycin in line with the common attempt of combining colistin with powerful?-lactams.