title: Epidemiology of infections caused by polymyxin-resistant pathogens.
abstract: Confronting the storm of carbapenemase-producing Gram-negative pathogens and thus facing the threat of untreatable infections, the medical community revived colistin. Not long since its re-introduction and despite the fact that resistance to colistin at least in Escherichia coli is rare, chromosomally-mediated colistin resistance in metallo-β-lactamase-producing Klebsiella pneumoniae strains was reported in 2004 from Greece. Subsequent studies revealed the highest predominance in Italy (38%) and Greece (26%), with colistin-resistant (Col-R) strains frequently carrying a carbapenemase. On the other hand, the international prevalence of Col-R Acinetobacter baumannii varied, predominantly in Southern Europe and Southeast Asia, with rates exceeding 80% in Italy and Greece. Risk factors have mainly incriminated the selective pressure of excess consumption of colistin both in animals and humans. In November 2015, emergence of plasmid-mediated colistin resistance due to the mcr-1 gene was reported from China, mostly in community-derived E. coli strains. As of 1 September 2016, the mcr-1 gene was detected in 35 countries worldwide in livestock/retail meat and in human sources from 29 and 22 countries, respectively. Heavy usage of polymyxins in animals has been incriminated as the reservoir of the mcr-1 gene. Therefore, it is imperative that: (i) polymyxins are banned as growth promoters and for prophylaxis in animals; (ii) targeted surveillance plus molecular epidemiology is performed in hospitals; (iii) carriers or patients infected with isolates harbouring both mcr-1 and carbapenemase genes are strictly isolated; (iv) susceptibilities are based on exact colistin minimum inhibitory concentration (MIC) determination; and (v) rational use of colistin is audited in hospitals.
authors.affiliation: Internal Medicine, Athens University School of Medicine, Athens, Greece; 6th Department of Internal Medicine, Hygeia General Hospital, 4 Erythrou Stavrou Str. & Kifisias Avenue, Marousi, Athens 15123, Greece. Electronic address: e.giamarellou@hygeia.gr.
authors.forename: Helen
authors.initials: H
authors.lastname: Giamarellou
mesh_terms: D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis / Q000379:methods; D024881:Drug Resistance, Bacterial; D014943:Global Health; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000662:veterinary*; D006801:Humans; D008826:Microbial Sensitivity Tests; D011113:Polymyxins / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D011113:Polymyxins
keywords: Chromosomal; Colistin; Gram-negatives; Plasmid-mediated; Resistance; mcr-1 gene