Zeng Weiliang, Liao Wenli, Zhao Yajie, Wang Lingbo, Shu Hongyun, Jia Huaiyu, Chen Tao, Zhang Ying, Zhou Tieli, Wu Qing
Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Department of Laboratory, Yongzhou Central Hospital, Yongzhou, China.
Front Microbiol. 2022 Jul 12;13:956044. doi: 10.3389/fmicb.2022.956044. eCollection 2022.
Ceftazidime/avibactam (CZA) is an alternative antibiotic used for the treatment of infections caused by carbapenem-resistant (CRE). However, the CZA-resistant CRE strains have been detected worldwide. Therefore, it is critical to screen CZA-resistant CRE strains in colonized patients or a specific population so as to rapidly implement infection control measures to limit their transmission. In this study, we developed a - (SS) CZA-selective medium and assessed its performance to screen for clinical CZA-resistant CRE isolates in both pure-strain specimens and stool samples. A total of 150 non-duplicated isolates, including 75 CZA-susceptible and 75 CZA-resistant CRE pathogens, were tested by using the broth microdilution method and the SS CZA medium, respectively. The bacterial suspensions were serially diluted in the SS CZA medium, which showed excellent screening performance in both pure CZA-resistant CRE strain and the stool samples with the lowest detection limit of 10-10 and 10-10 CFU/ml, respectively. Notably, none of the susceptible isolates showed growth even at the highest dilution concentration of 10 CFU/ml. Most importantly, the SS CZA medium demonstrated excellent performance in screening simulated clinical polymicrobial specimens. Moreover, its screening performance was unaffected by the different resistance determinants for tested isolates. Cumulatively, our data suggest that the SS CZA medium can be used as a promising selective medium to screen CZA-resistant CRE, irrespective of their resistance mechanisms.
头孢他啶/阿维巴坦（CZA）是一种用于治疗耐碳青霉烯类肠杆菌科细菌（CRE）所致感染的替代抗生素。然而，全球已检测到耐CZA的CRE菌株。因此，对定植患者或特定人群中的耐CZA的CRE菌株进行筛查，以便迅速实施感染控制措施以限制其传播至关重要。在本研究中，我们开发了一种选择性CZA培养基（SS CZA），并评估了其在纯菌株标本和粪便样本中筛查临床耐CZA的CRE分离株的性能。分别使用肉汤微量稀释法和SS CZA培养基对总共150株非重复分离株进行了测试，其中包括75株对CZA敏感和75株耐CZA的CRE病原体。细菌悬液在SS CZA培养基中进行系列稀释，该培养基在纯耐CZA的CRE菌株和粪便样本中均表现出出色的筛查性能，最低检测限分别为10-10和10-10 CFU/ml。值得注意的是，即使在最高稀释浓度10 CFU/ml时，所有敏感分离株均未生长。最重要的是，SS CZA培养基在筛查模拟临床多微生物标本方面表现出色。此外，其筛查性能不受测试分离株不同耐药决定因素的影响。总体而言，我们的数据表明，无论耐药机制如何，SS CZA培养基都可作为一种有前景的选择性培养基来筛查耐CZA的CRE。
