Khamnoi Phadungkiat, Jumroon Noppadon, Khamphakul Jakkrit, Chaihongsa Narong, Santanirand Pitak
Microbiology Unit, Diagnostic Laboratory, Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Department of Medical Technology, Faculty of Allied Health Science, Naresuan University, Phitsanulok, Thailand.
Microb Drug Resist. 2023 Sep;29(9):416-422. doi: 10.1089/mdr.2023.0070. Epub 2023 Jul 3.
This study aimed to establish the efficacy and susceptibility profiles of new β-lactam antibiotics against clinically isolated carbapenemase-producing (CPKP) strains. A total of 117 nonduplicated CPKP isolates were tested against cefiderocol, cefepime-zidebactam, ceftazidime-avibactam, tigecycline, and other 20 antibiotics by broth microdilution. The carbapenemase genes were identified using PCR and sequencing, while multilocus sequence typing established the bacterial strains. Three significant sequence types (STs), including ST147, ST16, and ST11, were shown to be the dominant STs, which occupied ∼90% of the tested population. Three carbapenemase genes, , and , were detected. The was found in ST147 and ST16 but not in ST11, while the was not detected in ST147. The majority of ST16 isolates contained both and , which was not seen in other strains. Cefiderocol, cefepime-zidebactam, and tigecycline were the most active agents against CPKP. Both MIC and MIC of these three antibiotics remained within the susceptible categories, while nearly all other antibiotics were in the resistant levels. However, in ST11, which carried only genes without , ceftazidime-avibactam was effective with the MIC at 2 μg/mL. In addition, amikacin was shown to have good activity in ST11. In contrast, gentamicin was active in only ST16 and ST147. This study is the first report that demonstrates the prevalence of CPKP, distribution of strains, resistant genes, and antimicrobial susceptibility profiles in northern Thailand. These data would contribute to appropriate individual treatment and the selection of infection control strategies.
本研究旨在确定新型β-内酰胺类抗生素对临床分离的产碳青霉烯酶（CPKP）菌株的疗效和药敏谱。通过肉汤微量稀释法，对117株非重复的CPKP分离株进行了头孢地尔、头孢吡肟-西他唑巴坦、头孢他啶-阿维巴坦、替加环素及其他20种抗生素的测试。采用聚合酶链反应（PCR）和测序鉴定碳青霉烯酶基因，同时通过多位点序列分型确定菌株。结果显示，三种主要序列类型（STs），即ST147、ST16和ST11，占测试群体的约90%。检测到三种碳青霉烯酶基因，分别为、和。在ST147和ST16中发现了，但在ST11中未发现，而在ST147中未检测到。大多数ST16分离株同时含有和，其他菌株未见此情况。头孢地尔、头孢吡肟-西他唑巴坦和替加环素是对CPKP最有效的药物。这三种抗生素的最低抑菌浓度（MIC）和均保持在敏感范围内，而几乎所有其他抗生素均处于耐药水平。然而，在仅携带基因而无基因的ST11中，头孢他啶-阿维巴坦有效，MIC为2μg/mL。此外，阿米卡星在ST11中显示出良好的活性。相比之下，庆大霉素仅在ST16和ST147中有活性。本研究是首次报道泰国北部CPKP的流行情况、菌株分布、耐药基因及抗菌药敏谱。这些数据将有助于进行适当的个体化治疗及选择感染控制策略。
