Emergence of Plasmid-Mediated Colistin Resistance Gene mcr-1 in a Clinical Escherichia coli Isolate from Egypt

Abstract

C olistin is considered a last resort for the treatment of infections caused by carbapenemase-producing members of the family Enterobacteriaceae. Recently, a transferable plasmid conferring resistance to colistin was discovered in Escherichia coli and Klebsiella pneumoniae from China (1) and was then reported in various bacteria from many other countries (2-4). This spread of antibiotic resistance heralds a return to the preantibiotic era, especially with no new antibiotics in the pipeline. The plasmid-mediated colistin resistance gene mcr-1 has been identified mainly in bacterial species from animals and animal products (pork and chicken meat) (1, 2). However, it was also detected in humans, i.e., patients (1-4), asymptomatic people (5), and some people by whom it was community acquired (6). Therefore, we used PCR and DNA sequencing to screen for the presence of mcr-1 in 241 nonduplicate Gram-negative clinical bacterial isolates collected from hospitals in different cities in Egypt during 2015. A universal primer pair, CLR5-F (5=-CGGTCAGTCCGTT TGTTC-3=) and CLR5-R (5=-CTTGGTCGGTCTGTAGGG-3=), was used for screening as previously described (1). In addition, the entire mcr-1 region was amplified and sequenced with MCR-1-F2 (5=-CTCATGATGCAGCATACTTC-3=) and MCR-1-R2 (5=-CGAATGGAGTGTGCGGTG-3=), which were based on the consensus sequences that flank mcr-1 (GenBank accession no. KP347127). Analysis showed that mcr-1 was present in only one E. coli isolate (SP-1), which was from the sputum of a patient with bacteremia who was hospitalized in the intensive care unit of a Cairo City hospital with no history of traveling abroad. The MIC of both colistin and polymyxin B for this isolate was 16 mg/liter. E. coli SP-1 had phenotypic resistance to colistin, ciprofloxacin, nalidixic acid, kanamycin, tetracycline, chloramphenicol, ceftriaxone, ampicillin, and cefotaxime but was susceptible to carbapenems. Multilocus sequence typing (MLST) indicated that E. coli SP-1 belonged to sequence type 1011 (ST1011), which differed from sequence types identified for clinical E. coli isolates harboring mcr-1 in Denmark (ST744) (2) and Cambodia (ST354) (3). According to the MLST database (http://mlst.ucc.ie/mlst/mlst /dbs/Ecoli), E. coli ST1011 was reported in humans in Egypt and in cats and swine in Germany. Of note, E. coli ST1011 was detected previously as an avian fecal E. coli strain in Egypt (7) and it was found to be shared by avian pathogenic E. coli and human extraintestinal pathogenic E. coli by phylogenetic grouping in Brazil (8). Also, it was found as CTX-M-64-harboring E. coli isolates from chickens in China (9). Therefore, E. coli ST1011 may have potential zoonotic importance. Southern hybridization showed that mcr-1 was located on a plasmid of Ͼ90 kb. This plasmid was successfully transferred to E. coli J53 recipient cells through conjugation.

First Indian report on genome-wide comparison of multidrug-resistant Escherichia coli from blood stream infections

“…Similarly, ST167 and ST410 carried bla CMY in addition for cephalosporin resistance which was not seen in ST131 and ST405. Recently, plasmid-mediated colistin resistance is being increasingly reported in E. coli [32][33][34]. This study also observed two isolates (B7532, B9021) with mcr-1.1 expressing high MIC of >32 μg/ml to colistin and both the isolates, from the same time period and ward, were closely related with same sequence type (ST624).…”

Frequency of MCR-1-mediated colistin resistance among Escherichia coli clinical isolates obtained from patients in Canadian hospitals (CANWARD 2008-2015)

“…23,25 In addition, clinical isolates that contain the mcr-1 gene have been reported in Vietnam, China, Taiwan, Thailand, Laos, Cambodia, the Netherlands, Sweden, the UK, Germany, Denmark, Switzerland, Italy, South Africa, Egypt, Argentina and the United States. 23,[25][26][27][28][29][30] Of interest, Shen and colleagues 31 showed the presence of mcr-1 in 3 E. coli isolates of chicken origin from China dating back to the 1980s, which supports the view that this is not a new resistance mechanism despite its recent recognition. The mcr-1 gene has been found most commonly in E. coli but has also been detected in Salmonella spp.…”

Dendritic Fe3O4@Poly(dopamine)@PAMAM Nanocomposite as Controllable NO‐Releasing Material: A Synergistic Photothermal and NO Antibacterial Study

“…The conventional way to cure bacteria infections is the use of antibiotics, but the efficiency of antibiotics is threatened by the increased antibiotic resistance of bacteria . For instance, the superbug E. coli bacteria with mcr‐1 gene is resistant to colistin, an antibiotic which is the last choice for treating multidrug‐resistant (MDR) bacterial infections . The increasing emergence of MDR bacteria not only caused the failure of antibiotic treatment but also aggravated the economic burden of the patients due to the prolonged hospitalizations .…”