Borowiak Maria, Baumann Beatrice, Fischer Jennie, Thomas Katharina, Deneke Carlus, Hammerl Jens Andre, Szabo Istvan, Malorny Burkhard
Department Biological Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
Front Microbiol. 2020 Feb 4;11:80. doi: 10.3389/fmicb.2020.00080. eCollection 2020.
The polymyxin antibiotic colistin has been used in decades for treatment and prevention of infectious diseases in livestock. Nowadays, it is even considered as last-line treatment option for severe human infections caused by multidrug- and carbapenem-resistant Gram-negative bacteria. Therefore, the discovery of plasmid-mediated mobile colistin resistance () genes raised major public health concern. The aim of our study was to analyze colistin-resistant strains from animals, food, feed and the environment collected at the National Reference Laboratory for in Germany on the presence of to genes. Altogether 407 colistin-resistant (MIC >2 mg/L) isolates received between 2011 and 2018 were selected and screened by PCR using a published to as well as a newly developed to multiplex PCR protocol. 254 of 407 (62.4%) isolates harbored either ( = 175), ( = 53), ( = 18) or and ( = 8). The number of -positive isolates ranged from 19 (2017) to 64 (2012) per year. WGS revealed that none of our isolates harbored the gene. Instead, two novel variants were observed, which both were affected by frameshift mutations and are probably non-functional. The -harboring isolates were mainly derived from animals (77.2%) or food (20.1%) and could be assigned to ten different serovars. Many of the isolates were multidrug-resistant. Co-occurrence of and AmpC or ESBL genes was observed in eight isolates. Our findings suggest that genes are widely spread among colistin-resistant isolates from livestock and food in Germany. Potential transfer of -harboring isolates along the food chain has to be considered critically.
多粘菌素类抗生素粘菌素已被用于家畜传染病的治疗和预防数十年。如今，它甚至被视为治疗由多重耐药和碳青霉烯耐药革兰氏阴性菌引起的严重人类感染的最后一线治疗选择。因此，质粒介导的可移动粘菌素耐药（）基因的发现引起了重大的公共卫生关注。我们研究的目的是分析从德国国家参考实验室收集的动物、食品、饲料和环境中的耐粘菌素菌株中是否存在至基因。总共选择了2011年至2018年间收到的407株耐粘菌素（MIC>2mg/L）分离株，并使用已发表的至以及新开发的至多重PCR方案通过PCR进行筛选。407株分离株中有254株（62.4%）携带（=175）、（=53）、（=18）或和（=8）。每年阳性分离株的数量从19株（2017年）到64株（2012年）不等。全基因组测序显示，我们的分离株均未携带基因。相反，观察到两个新的变体，它们都受到移码突变的影响，可能无功能。携带的分离株主要来自动物（77.2%）或食品（20.1%），可分为十个不同的血清型。许多分离株具有多重耐药性。在八株分离株中观察到和AmpC或ESBL基因的共现。我们的研究结果表明，基因在德国家畜和食品来源的耐粘菌素分离株中广泛传播。必须严格考虑携带的分离株沿食物链的潜在转移。
