Plasmid-Mediated Colistin Resistance Gene mcr-1 in an Escherichia coli ST10 Bloodstream Isolate in the Sultanate of Oman.

AIMS: To identify plasmid-mediated colistin resistance in clinical Enterobacteriaceae isolates in Oman, where this resistance mechanism has not been encountered yet. MATERIALS/METHODS: Twenty-two colistin-resistant Enterobacteriaceae clinical isolates collected between July 2014 and June 2016 in a tertiary care hospital in Muscat were screened by PCR for the mcr-1 and mcr-2 genes. The strain identified as mcr-1 positive was genotyped and its antibiotic susceptibility was established. The mcr-1 containing plasmid was mobilized into Escherichia coli K-12 and its sequence was determined. RESULTS: A single E. coli isolate (OM97) carrying mcr-1 gene was identified, while no strains carrying the mcr-2 gene was found. E. coli OM97 was isolated in June 2016 from blood culture of a male patient with multiple comorbidities. It belonged to ST10. Beyond colistin, it was resistant to amoxicillin-clavulanic acid, piperacillin-tazobactam, amikacin, ciprofloxacin, tetracycline, and cotrimoxazole. The mcr-1 gene was located on a conjugative IncI2-type plasmid of 63722 bp size, which did not harbor any further resistance genes. The genetic surrounding of the mcr-1 gene lacked the ISApl1 element. CONCLUSIONS: Although colistin resistance caused by the mcr-1 gene is not common in our collection of clinical isolates, the occurrence of the plasmid-mediated colistin resistance in an E. coli ST10 strain is of concern as this clonal group was already shown to spread ESBL genes and quinolone resistance worldwide. It is especially worrisome that as the mcr-1 gene occurred in a non-ESBL, carbapenem-susceptible E. coli strain, current susceptibility testing algorithms may not detect its presence.

Management of infections in critically ill returning travellers in the intensive care unit-II: clinical syndromes and special considerations in immunocompromised patients.

This position paper is the second ESCMID Consensus Document on this subject and aims to provide intensivists, infectious disease specialists, and emergency physicians with a standardized approach to the management of serious travel-related infections in the intensive care unit (ICU) or the emergency department. This document is a cooperative effort between members of two European Society of Clinical Microbiology and Infectious Diseases (ESCMID) study groups and was coordinated by Hakan Leblebicioglu and Jordi Rello for ESGITM (ESCMID Study Group for Infections in Travellers and Migrants) and ESGCIP (ESCMID Study Group for Infections in Critically Ill Patients), respectively. A relevant expert on the subject of each section prepared the first draft which was then edited and approved by additional members from both ESCMID study groups. This article summarizes considerations regarding clinical syndromes requiring ICU admission in travellers, covering immunocompromised patients.

[Traveller's medicine on the Internet]. / Rejsemedicin på internettet.

The Internet has become an invaluable source of information for both travellers and physicians. Travellers are better informed than previously and expect their physicians to organise the wide variety of information found on the Net. There is no peer review of information on the Net, and the best course for a physician is to use a few, authoritative Web sites such as those of the World Health Organization and the Centers for Disease Control and Prevention. Supplementary information can be found on the Web sites of professional societies such as the International Society for Travel Medicine, the Danish Society for Travel Medicine and ProMED mail.

[Malaria chemoprophylaxis]. / Malariakemoprofylakse.

Malaria is a serious infection, and prevention traditionally relies on chemoprophylaxis during and after exposure. The risk of side effects from chemoprophylaxis needs to be balanced against the risk of infection, and there has been conducted only one prospective, double-blind study comparing the suspected side effects of mefloquine (Lariam), atovaquone/proguanil (Malarone), doxycycline and chloroquine/proguanil. Therefore the current recommendations are based on descriptive studies and case reports. There is a lack of data on the risk of infection in travellers, and the national statistics on the number of imported cases are not very useful as long as the total number of travellers at risk is not known. The risk to travellers is therefore estimated from data on malaria in the indigenous population, while the risk for travellers is expected to be lower. Atovaquone/proguanil has been registered in Europe for travels of up to four weeks, but in the United States there is no upper limit for the duration of use. It is not possible to prescribe efficient prophylaxis to pregnant women in the first trimester or infants below 11 kilograms of body weight travelling to tropical Africa.