blaVIM- and blaOXA-mediated carbapenem resistance among Acinetobacter baumannii and Pseudomonas aeruginosa isolates from the Mulago hospital intensive care unit in Kampala, Uganda
blaVIM- and blaOXA-mediated carbapenem resistance among Acinetobacter baumannii and Pseudomonas aeruginosa isolates from the Mulago hospital intensive care unit in Kampala, Uganda
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DOI：
10.1186/s12879-019-4510-5
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发表时间：
2019-10-16
影响因子：
3.7
通讯作者：
Kateete, David P.
中科院分区：
文献类型：
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作者：
Aruhomukama, Dickson;Najjuka, Christine F.;Kateete, David P.
2015年1月至2017年7月，我们调查了乌干达坎帕拉穆拉戈医院重症监护病房（ICU）耐碳青霉烯类鲍曼不动杆菌（CRAB）和耐碳青霉烯类铜绿假单胞菌（CRPA）的频率。测定螃蟹和CRPA的碳青霉烯酶产量和碳青霉烯酶基因携带情况；研究了碳青霉烯酶基因在水平基因转移过程中的迁移潜力。方法对9269例患者临床标本进行CRAB和CRPA分离处理。药敏试验采用纸片扩散法。通过PCR检测碳青霉烯酶基因和1类整合子的携带情况。用bla（VIM）阳性的CRAB/CRPA（供体）和耐叠氮化钠的大肠杆菌J53（受体）进行偶联实验。结果9269份标本检出鲍曼不动杆菌1077株，铜绿假单胞菌488株。其中，2.7%（29/1077）和7.4%（36/488）为CRAB和CRPA，但有46例（21例为CRAB， 25例为CRPA）可供分析。大多数螃蟹和CRPA标本来自ICU(78%)，耳鼻喉科和烧伤科分别占20%和2%。MHT法测定碳青霉烯酶结果表明，CRPA和CRAB分别有40%和33%的菌株产生碳青霉烯酶。CRPA和CRAB分别有72%和48%的菌株产生金属β -内酰胺酶。产碳青霉烯酶的分离株均对多药耐药，但对粘菌素敏感。bla（VIM）是最常见的碳青霉烯酶基因，在所有螃蟹和CRPA分离株中均检测到该基因，而在29%和24%的螃蟹分离株中分别检测到bla（OXA-23）和bla（OXA-24）。14%的螃蟹分离株同时携带bla（OXA-23）和bla（OXA-24）。此外，63%的研究分离物携带1类整合子；其中31%成功将bla（VIM）转移到大肠杆菌J53上。结论在穆拉戈医院ICU中，CRAB和CRPA的患病率相对较低，但碳青霉烯酶基因以bla（VIM）和bla（OXA-23）为主。这需要加强感染控制措施，以遏制这些菌株在医院的选择和传播。
Background Between January 2015 and July 2017, we investigated the frequency of carbapenem resistant Acinetobacter baumannii (CRAB) and carbapenem resistant Pseudomonas aeruginosa (CRPA) at the Mulago Hospital intensive care unit (ICU) in Kampala, Uganda. Carbapenemase production and carbapenemase gene carriage among CRAB and CRPA were determined; mobility potential of carbapenemase genes via horizontal gene transfer processes was also studied. Methods Clinical specimens from 9269 patients were processed for isolation of CRAB and CRPA. Drug susceptibility testing was performed with the disk diffusion method. Carriage of carbapenemase genes and class 1 integrons was determined by PCR. Conjugation experiments that involved bla(VIM) positive CRAB/CRPA (donors) and sodium azide resistant Escherichia coli J53 (recipient) were performed. Results The 9269 specimens processed yielded 1077 and 488 isolates of Acinetobacter baumannii and Pseudomonas aeruginosa, respectively. Of these, 2.7% (29/1077) and 7.4% (36/488) were confirmed to be CRAB and CRPA respectively, but 46 were available for analysis (21 CRAB and 25 CRPA). Majority of specimens yielding CRAB and CRPA were from the ICU (78%) while 20 and 2% were from the ENT (Ear Nose & Throat) Department and the Burns Unit, respectively. Carbapenemase assays performed with the MHT assay showed that 40 and 33% of CRPA and CRAB isolates respectively, were carbapenemase producers. Also, 72 and 48% of CRPA and CRAB isolates respectively, were metallo-beta-lactamase producers. All the carbapenemase producing isolates were multidrug resistant but susceptible to colistin. bla(VIM) was the most prevalent carbapenemase gene, and it was detected in all CRAB and CRPA isolates while bla(OXA-23) and bla(OXA-24) were detected in 29 and 24% of CRAB isolates, respectively. Co-carriage of bla(OXA-23) and bla(OXA-24) occurred in 14% of CRAB isolates. Moreover, 63% of the study isolates carried class 1 integrons; of these 31% successfully transferred bla(VIM) to E. coli J53. Conclusions CRAB and CRPA prevalence at the Mulago Hospital ICU is relatively low but carbapenemase genes especially bla(VIM) and bla(OXA-23) are prevalent among them. This requires strengthening of infection control practices to curb selection and transmission of these strains in the hospital.