Department of Pharmaceutical Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria.
Department of Pharmaceutical Microbiology, University of Ibadan, Ibadan, Nigeria.
Curr Microbiol. 2021 Dec 14;79(1):27. doi: 10.1007/s00284-021-02706-3.
Pseudomonas aeruginosa, resistant to multiple antibacterial agents including carbapenems, is of great global public health concern. There is limited data available regarding incidence of Metallo-Beta Lactamase producing P. aeruginosa, their molecular basis of resistance in particular carbapenem resistance and any genetic relatedness among circulating clinical isolates in Southwest Nigeria. Four hundred and thirty P. aeruginosa isolates were collected from seven tertiary care hospitals (predominantly from wound, ear, and urinary tract infections) and verified by PCR targeting oprI and oprL. Antibiotic susceptibility using 16 selected antibiotics and MBL screening was performed. The integrons (class 1, 2 and 3) and carbapenemase genes- bla, bla, bla, bla, bla, bla, bla bla bla, bla, bla, bla, bla, bla were detected by PCR and were sequenced. Quantitative real-time polymerase chain reaction was used to quantify expression levels of eight efflux pump genes, ampC cephalosporinase and outer membrane porin, oprD. The isolates were genotyped using Enterobacterial Repetitive Intergenic Consensus sequence Polymerase Chain Reaction (ERIC-PCR). Four hundred and thirty P. aeruginosa isolates were subjected to antibiotic susceptibility testing, revealing that 109 (25.4%) isolates were multidrug-resistant, 47 (10.9%) were extensively drug-resistant and 25 (5.8%) were pandrug-resistant. MBL was seen in 17.0% (73/430) isolates. MBL-encoding genes; bla and bla were detected in 86.3% (63/73) isolates, with bla and bla in 35.6% (26/73) and 38.4% (28/73), respectively, whereas co-occurrence of bla and bla was found in 12.3% (9/73). Forty-one (56.2%) carbapenem-resistant P. aeruginosa strains carried class 1 integrons, while co-occurrence of class 1 and 2 integrons was seen in 12.3%. qPCR results indicated that MexXY-OprM was highly expressed pump in 58.9%, ampC upregulated in 26.0%, while oprD porin was downregulated in 65.8% isolates. ERIC-PCR results suggest that carbapenem-resistant strains exhibit genetic heterogeneity. The high incidence of MBL-encoding genes and integrons in diversified clinical P. aeruginosa from southwestern Nigeria is of great concern. The co-occurrence of bla and bla as well as resistance in general manifesting a gradient based on genotypic variation suggests that there is a strong need for efficient surveillance programs and antibiotic stewardship.
铜绿假单胞菌对包括碳青霉烯类在内的多种抗菌药物具有耐药性，这是一个全球性的公共卫生问题。关于产金属β-内酰胺酶的铜绿假单胞菌的发病率、其对碳青霉烯类耐药的分子基础以及在尼日利亚西南部循环临床分离株中的遗传相关性，目前数据有限。从 7 家三级护理医院（主要来自伤口、耳朵和尿路感染）采集了 430 株铜绿假单胞菌分离株，并通过针对 oprI 和 oprL 的 PCR 进行了验证。使用 16 种选定的抗生素进行抗生素敏感性检测和 MBL 筛选。通过 PCR 检测整合子（1 类、2 类和 3 类）和碳青霉烯酶基因- bla、 bla、 bla、 bla、 bla、 bla、 bla bla bla、 bla、 bla、 bla、 bla、 bla，并对其进行测序。采用定量实时聚合酶链反应检测 8 种外排泵基因、ampC 头孢菌素酶和外膜孔蛋白的表达水平， oprD。采用肠杆菌重复基因间一致性聚合酶链反应（ERIC-PCR）对分离株进行基因分型。对 430 株铜绿假单胞菌进行了抗生素敏感性测试，结果显示 109 株（25.4%）分离株为多药耐药株，47 株（10.9%）为广泛耐药株，25 株（5.8%）为泛耐药株。17.0%（73/430）的分离株出现 MBL。在 86.3%（63/73）的分离株中检测到 MBL 编码基因； bla 和 bla，其中 bla 和 bla 分别占 35.6%（26/73）和 38.4%（28/73），而 bla 和 bla 的共存率为 12.3%（9/73）。41 株（56.2%）耐碳青霉烯铜绿假单胞菌菌株携带 1 类整合子，而 12.3%的菌株同时携带 1 类和 2 类整合子。qPCR 结果表明，MexXY-OprM 在 58.9%的菌株中高表达泵，ampC 在 26.0%的菌株中上调，而 oprD 孔蛋白在 65.8%的菌株中下调。ERIC-PCR 结果表明，耐碳青霉烯类铜绿假单胞菌菌株具有遗传异质性。尼日利亚西南部多样化临床分离株中产金属β-内酰胺酶编码基因和整合子的高发生率令人担忧。 bla 和 bla 的共存以及普遍存在的耐药性表明，基于基因型变异，迫切需要有效的监测计划和抗生素管理。
