Rafaï Clotaire, Frank Thierry, Manirakiza Alexandre, Gaudeuille Alfred, Mbecko Jean-Robert, Nghario Luc, Serdouma Eugene, Tekpa Bertrand, Garin Benoit, Breurec Sebastien
Institut Pasteur, Laboratory of Bacteriology, Avenue de l'Independance, BP 923, Bangui, Central African Republic.
Institut Pasteur, Unit of Epidemiology, Avenue de l'Independance, BP 923, Bangui, Central African Republic.
BMC Microbiol. 2015 Feb 4;15(1):15. doi: 10.1186/s12866-015-0348-1.
Surgical-site infection is the most frequent health care-associated infection in the developing world, with a strikingly higher prevalence than in developed countries We studied the prevalence of resistance to antibiotics in Enterobacteriaceae isolates from surgical-site infections collected in three major tertiary care centres in Bangui, Central African Republic. We also studied the genetic basis for antibiotic resistance and the genetic background of third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae.
Between April 2011 and April 2012, 195 patients with nosocomial surgical-site infections were consecutively recruited into the study at five surgical departments in three major tertiary care centres. Of the 165 bacterial isolates collected, most were Enterobacteriaceae (102/165, 61.8%). Of these, 65/102 (63.7%) were 3GC-R, which were characterized for resistance gene determinants and genetic background. The bla CTX-M-15 and aac(6')-Ib-cr genes were detected in all strains, usually associated with qnr genes (98.5%). Escherichia coli, the most commonly recovered species (33/65, 50.8%), occurred in six different sequence types, including the pandemic B2-O25b-ST131 group (12/33, 36.4%). Resistance transfer was studied in one representative strain of the resistance gene content in each repetitive extragenic palindromic and enterobacterial repetitive intergenic consensus sequence-PCR banding pattern. Plasmids were characterized by PCR-based replicon typing and sub-typing schemes. In most isolates (18/27, 66.7%), bla CTX-M-15 genes were found in incompatibility groups F/F31:A4:B1 and F/F36:A4:B1 conjugative plasmids. Horizontal transfer of both plasmids is probably an important mechanism for the spread of bla CTX-M-15 among Enterobacteriaceae species and hospitals. The presence of sets of antibiotic resistance genes in these two plasmids indicates their capacity for gene rearrangement and their evolution into new variants.
Diverse modes are involved in transmission of resistance, plasmid dissemination probably playing a major role.
手术部位感染是发展中国家最常见的医疗相关感染，其患病率显著高于发达国家。我们研究了中非共和国班吉市三个主要三级医疗中心收集的手术部位感染患者分离出的肠杆菌科细菌对抗生素的耐药率。我们还研究了抗生素耐药的遗传基础以及第三代头孢菌素耐药（3GC-R）肠杆菌科细菌的遗传背景。
2011年4月至2012年4月期间，在三个主要三级医疗中心的五个外科科室，195例医院手术部位感染患者被连续纳入研究。在收集的165株细菌分离物中，大多数为肠杆菌科细菌（102/165，61.8%）。其中，65/102（63.7%）为3GC-R，对其耐药基因决定因素和遗传背景进行了表征。在所有菌株中均检测到bla CTX-M-15和aac(6')-Ib-cr基因，通常与qnr基因相关（98.5%）。大肠埃希菌是最常分离出的菌种（33/65，50.8%），出现于六种不同的序列类型中，包括流行的B2-O25b-ST131组（12/33，36.4%）。在每个重复外显子回文序列和肠杆菌重复基因间共有序列-PCR条带模式中，对一种具有代表性的耐药基因含量菌株进行了耐药转移研究。通过基于PCR的复制子分型和亚型分类方案对质粒进行了表征。在大多数分离株（18/27，66.7%）中，bla CTX-M-15基因存在于不相容群F/F31:A4:B1和F/F36:A4:B1接合质粒中。这两种质粒的水平转移可能是bla CTX-M-15在肠杆菌科菌种和医院中传播的重要机制。这两种质粒中存在的一组抗生素耐药基因表明它们具有基因重排能力以及进化为新变体的能力。
耐药性传播涉及多种方式，质粒传播可能起主要作用。
