Mirshekar Maryam, Shahcheraghi Fereshteh, Azizi Omid, Solgi Hamid, Badmasti Farzad
1 Department of Bacteriology, Microbiology Research Center, Pasteur Institute of Iran , Tehran, Iran .
2 Department of Basic Sciences, Torbat Heydariyeh University of Medical Sciences , Torbat Heydariyeh, Iran .
Microb Drug Resist. 2018 May;24(4):359-366. doi: 10.1089/mdr.2017.0152. Epub 2017 Oct 3.
Acinetobacter baumannii is an important nosocomial pathogen which causes a wide range of infections. In this study, we addressed the role of class 1 integron, ISAba1 and ISAba125 associated with antimicrobial resistance in 72 clinical isolates of A. baumannii collected from clinical settings in Tehran, Iran. Moreover, to study the clonal relatedness of strains, repetitive extragenic palindromic-PCR (rep-PCR) assay was carried out. PCR revealed that bla-like, bla-like, bla-like, bla-like, bla, integrase gene (intI1), ISAba1, and ISAba125 were present in 86.11% (62/72), 84.72% (61/72), 30.55% (22/72), 0% (0/72), 0% (0/72), 58.33% (42/72), 97.22% (70/72), and 65.27% (47/72) of the strains, respectively. Sequencing of 39 internal variable regions of class 1 integrons showed seven gene cassette arrays, including aadA4-catB8-aadA1 (2.77%), aadA1-aadA4 (1.38%), aacC4-aadA1 (2.77%), aacC4 (22.22%), aadA1 (13.88%), aadA4 (5.55%), and catB8 (5.55%). We detected ISAba1 in the upstream of bla-like, bla-like, and bla in 54.16% (39/72), 9.72% (7/72), and 56.94% (41/72) of the strains, respectively. Whereas, there was a low frequency of disruptions in carO and dacD genes: 5.55% (4/72) and 4.16% (3/72). Rep-PCR analysis revealed that the isolates were genetically diverse. However, Cl-12 and Cl-15 were the largest clusters and they were recovered from various hospitals. Our analysis showed the high rates of class 1 integrons as a repertoire of aminoglycoside-modifying enzymes. It seems that linkages of ISAba1-bla-like and ISAba1-bla, and disruptions in carO or dacD can develop resistance to carbapenems among clinical isolates of A. baumannii.
鲍曼不动杆菌是一种重要的医院病原体，可引起多种感染。在本研究中，我们探讨了1类整合子、ISAba1和ISAba125在从伊朗德黑兰临床环境收集的72株鲍曼不动杆菌临床分离株中与抗菌药物耐药性的关系。此外，为了研究菌株的克隆相关性，进行了重复外显子回文PCR（rep-PCR）分析。PCR结果显示，bla样、bla样、bla样、bla样、bla、整合酶基因（intI1）、ISAba1和ISAba125分别存在于86.11%（62/72）、84.72%（61/72）、30.55%（22/72）、0%（0/72）、0%（0/72）、58.33%（42/72）、97.22%（70/72）和65.27%（47/72）的菌株中。对1类整合子的39个内部可变区进行测序，发现7种基因盒阵列，包括aadA4-catB8-aadA1（2.77%）、aadA1-aadA4（1.38%）、aacC4-aadA1（2.77%）、aacC4（22.22%）、aadA1（13.88%）、aadA4（5.55%）和catB8（5.55%）。我们分别在54.16%（39/72）、9.72%（7/72）和56.94%（41/72）的菌株中检测到ISAba1位于bla样、bla样和bla的上游。而carO和dacD基因的破坏频率较低：分别为5.55%（4/72）和4.16%（3/72）。Rep-PCR分析表明，分离株在基因上具有多样性。然而，Cl-12和Cl-15是最大的簇，它们来自不同的医院。我们的分析显示，1类整合子作为氨基糖苷类修饰酶的一个库，其发生率很高。似乎ISAba1-bla样和ISAba1-bla的连接以及carO或dacD的破坏可使鲍曼不动杆菌临床分离株对碳青霉烯类药物产生耐药性。
