Kateete David P, Nakanjako Ritah, Namugenyi Juliet, Erume Joseph, Joloba Moses L, Najjuka Christine F
Department of Immunology and Molecular Biology, College of Health Sciences, Makerere University, Kampala, Uganda ; Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda.
Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda ; College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.
Springerplus. 2016 Aug 9;5(1):1308. doi: 10.1186/s40064-016-2986-7. eCollection 2016.
Multidrug resistant Pseudomonas aeruginosa and Acinetobacter baumannii are common causes of health care associated infections worldwide. Carbapenems are effective against infections caused by multidrug resistant Gram-negative bacteria including Pseudomonas and Acinetobacter species. However, their use is threatened by the emergence of carbapenemase-producing strains. The aim of this study was to determine the prevalence of carbapenem-resistant P. aeruginosa and A. baumannii at Mulago Hospital in Kampala Uganda, and to establish whether the hospital environment harbors carbapenem-resistant Gram-negative rods.
Between February 2007 and September 2009, a total of 869 clinical specimens were processed for culture and sensitivity testing yielding 42 (5 %) P. aeruginosa and 29 (3 %) A. baumannii isolates, of which 24 % (10/42) P. aeruginosa and 31 % (9/29) A. baumannii were carbapenem-resistant. Additionally, 80 samples from the hospital environment were randomly collected and similarly processed yielding 58 % (46/80) P. aeruginosa and 14 % (11/80) A. baumannii, of which 33 % (15/46) P. aeruginosa and 55 % (6/11) A. baumannii were carbapenem-resistant. The total number of isolates studied was 128. Carbapenemase genes detected were bla IMP-like (36 %, 9/25), bla VIM-like (32 %, 8/25), bla SPM-like (16 %, 4/25); bla NDM-1-like (4 %, 1/25) in carbapenem-resistant P. aeruginosa, and bla OXA-23-like (60 %, 9/15), bla OXA-24-like (7 %, 1/15), bla OXA-58-like (13 %, 2/15), and bla VIM-like (13 %, 2/15) in carbapenem-resistant A. baumannii. Furthermore, class 1 integrons were detected in 38 % (48/128) of P. aeruginosa and Acinetobacter, 37 % (26/71) of which were in clinical isolates and 39 % (22/57) in environment isolates. Gene cassettes were found in 25 % (12/48) of integron-positive isolates. These were aminoglycoside adenylyltransferase ant(4')-IIb (3 isolates); trimethoprim-resistant dihydrofolate reductase dfrA (2 isolates); adenyltransferase aadAB (3 isolates); QacE delta1 multidrug exporter (2 isolates); quinolone resistance pentapeptide repeat protein qnr (1 isolate); and metallo-β-lactamase genes bla VIM-4-like, bla IMP-19-like, and bla IMP-26-like (1 isolate each). Gene cassettes were missing in 75 % (36/48) of the integron-positive isolates.
The prevalence of carbapenem-resistant P. aeruginosa and Acinetobacter among hospitalized patients at Mulago Hospital is low compared to rates from South-East Asia. However, it is high among isolates and in the environment, which is of concern given that the hospital environment is a potential source of infection for hospitalized patients and health care workers.
耐多药铜绿假单胞菌和鲍曼不动杆菌是全球医疗保健相关感染的常见病因。碳青霉烯类药物对包括假单胞菌属和不动杆菌属在内的耐多药革兰氏阴性菌引起的感染有效。然而，产碳青霉烯酶菌株的出现威胁到了它们的使用。本研究的目的是确定乌干达坎帕拉穆拉戈医院耐碳青霉烯铜绿假单胞菌和鲍曼不动杆菌的流行情况，并确定医院环境中是否存在耐碳青霉烯革兰氏阴性杆菌。
在2007年2月至2009年9月期间，共处理了869份临床标本进行培养和药敏试验，分离出42株（5%）铜绿假单胞菌和29株（3%）鲍曼不动杆菌，其中24%（10/42）的铜绿假单胞菌和31%（9/29）的鲍曼不动杆菌对碳青霉烯类耐药。此外，随机收集了80份医院环境样本并进行类似处理，分离出58%（46/80）的铜绿假单胞菌和14%（11/80）的鲍曼不动杆菌，其中33%（15/46）的铜绿假单胞菌和55%（6/11）的鲍曼不动杆菌对碳青霉烯类耐药。研究的分离株总数为128株。在耐碳青霉烯铜绿假单胞菌中检测到的碳青霉烯酶基因有bla IMP样（36%，9/25）、bla VIM样（32%，8/25）、bla SPM样（16%，4/25）、bla NDM-1样（4%，1/25）；在耐碳青霉烯鲍曼不动杆菌中检测到的有bla OXA-23样（60%，9/15）、bla OXA-24样（7%，1/15）、bla OXA-58样（13%，2/15）和bla VIM样（13%，2/15）。此外，在38%（48/128）的铜绿假单胞菌和不动杆菌中检测到1类整合子，其中37%（26/71）在临床分离株中，39%（22/57）在环境分离株中。在25%（12/48）的整合子阳性分离株中发现了基因盒。这些基因盒包括氨基糖苷腺苷酰转移酶ant(4')-IIb（3株）；甲氧苄啶耐药二氢叶酸还原酶dfrA（2株）；腺苷转移酶aadAB（3株）；QacE delta1多药外排蛋白（2株）；喹诺酮耐药五肽重复蛋白qnr（1株）；以及金属β-内酰胺酶基因bla VIM-4样、bla IMP-19样和bla IMP-26样（各1株）。75%（36/48）的整合子阳性分离株中未发现基因盒。
与东南亚的发生率相比，穆拉戈医院住院患者中耐碳青霉烯铜绿假单胞菌和不动杆菌的流行率较低。然而，在分离株和环境中的流行率较高，鉴于医院环境是住院患者和医护人员潜在的感染源，这令人担忧。
