Nafplioti Konstantina, Souli Maria, Adamou Panagiota, Moraitou Eleni, Giannopoulou Panagiota, Chra Paraskevi, Damala Maria, Vogiatzakis Evangelos, Trikka-Graphakos Eleftheria, Baka Vasiliki, Prifti Eleni, Antoniadou Anastasia, Galani Irene
4th Department of Internal Medicine, Infectious Diseases Laboratory, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece.
Department of Clinical Microbiology, Sotiria General Hospital of Chest Diseases, Athens, Greece.
Eur J Clin Microbiol Infect Dis. 2021 Jan;40(1):111-121. doi: 10.1007/s10096-020-04006-3. Epub 2020 Aug 14.
The aim of this study was to characterize the 16S rRNA methylase (RMT) genes in aminoglycoside-resistant Enterobacterales and Pseudomonas aeruginosa isolates in 2015-2016 in hospitals in Athens, Greece. Single-patient, Gram-negative clinical isolates resistant to both amikacin and gentamicin (n = 292) were consecutively collected during a two-year period (2015-2016) in five tertiary care hospitals in Athens. RMT genes were detected by PCR. In all RMT-producing isolates, ESBL and carbapenemase production was confirmed by PCR, and the clonal relatedness and the plasmid contents were also characterized. None of the 138 P. aeruginosa isolates harbored any of the RMT genes surveyed although some were highly resistant to aminoglycosides (MICs > = 512 mg/L). Among 154 Enterobacterales, 31 Providencia stuartii (93.9%), 42 Klebsiella pneumoniae (37.8%), six Proteus mirabilis (75%), and two Escherichia coli (100%) isolates were confirmed as highly resistant to amikacin, gentamicin, and tobramycin with MICs ≥ 512 mg/L, harboring mainly the rmtB (98.8%). All were carbapenemase producers. P. stuartii, P. mirabilis, and E. coli produced VIM-type carbapenemases. K. pneumoniae produced KPC- (n = 34, 81.0%), OXA-48 (n = 4, 9.5%), KPC- and VIM- (n = 3, 7.1%), or only VIM-type (n = 1, 2.4%) enzymes. Two groups of similar IncC plasmids were detected one harboring rmtB1, bla, bla, and bla, and the other additionally bla and bla. Among RMT-producing Enterobacterales, rmtB1 predominated and was associated with carbapenemase-encoding gene(s). Similar IncC plasmids carrying a multiresistant region, including ESBL genes, and in the case of VIM-producing isolates, the bla, were responsible for this dissemination. The co-dissemination of these genes poses a public health threat.
本研究的目的是对2015 - 2016年希腊雅典医院中耐氨基糖苷类肠杆菌科细菌和铜绿假单胞菌分离株中的16S rRNA甲基化酶（RMT）基因进行特征分析。在雅典的五家三级护理医院，于两年期间（2015 - 2016年）连续收集了对阿米卡星和庆大霉素均耐药的单患者革兰氏阴性临床分离株（n = 292）。通过PCR检测RMT基因。在所有产生RMT的分离株中，通过PCR确认了超广谱β-内酰胺酶（ESBL）和碳青霉烯酶的产生，并且还对克隆相关性和质粒内容物进行了特征分析。138株铜绿假单胞菌分离株中无一携带所检测的任何RMT基因，尽管有些对氨基糖苷类具有高度耐药性（最低抑菌浓度[MIC]≥512mg/L）。在154株肠杆菌科细菌中，31株斯氏普罗威登斯菌（93.9%）、42株肺炎克雷伯菌（37.8%）、6株奇异变形杆菌（75%）和2株大肠埃希菌（100%）分离株被确认为对阿米卡星、庆大霉素和妥布霉素高度耐药，MIC≥512mg/L，主要携带rmtB（98.8%）。所有这些菌株均产生碳青霉烯酶。斯氏普罗威登斯菌、奇异变形杆菌和大肠埃希菌产生VIM型碳青霉烯酶。肺炎克雷伯菌产生KPC型（n = 34，81.0%）、OXA - 48型（n = 4，9.5%）、KPC型和VIM型（n = 3，7.1%）或仅VIM型（n = 1，2.4%）酶。检测到两组相似的IncC质粒，一组携带rmtB1、bla、bla和bla，另一组还额外携带bla和bla。在产生RMT的肠杆菌科细菌中，rmtB1占主导地位，并且与碳青霉烯酶编码基因相关。携带包括ESBL基因在内的多耐药区域的相似IncC质粒，以及在产生VIM的分离株中携带bla的质粒，是造成这种传播的原因。这些基因的共同传播对公共卫生构成威胁。
