Establishment of a suspension array for Pseudomonas aeruginosa O-antigen serotyping

Pseudomonas aeruginosa (P. aeruginosa) is widespread in the environment. It readily infects hospital and immunocompromised patients. Traditional biochemical and immunological diagnoses of P. aeruginosa infection cannot meet clinical demands. The variability of O-antigens is the primary basis for the serotyping schemes of many gram-negative bacteria, which is the most widely used method for pathogenic epidemiological purposes. In this study, we developed a suspension array that can accurately diagnose and identify 19 different P. aeruginosa O-antigen serotypes except O15, whose O-antigen gene cluster has not been characterized. In this assay, wzx/wzy genes were selected as the sero-specific gene for 18 serotypes other than O6, for which the glycosyl-transferase gene wbpP was utilized. Meanwhile, the wzy(beta) gene was added to separate O2/16 from O5/18/20, and the insertion sequence (IS) in wzx was used to separate O17 from O11. Eighty-two clinical isolates were screened to test our assay. A total of 65 isolates (79.3%) could be serotyped, and the result were confirmed to be correct by sequencing. Sensitivity analysis indicated that at least 5 ng DNA or 10(3) CFU cells could be detected using our suspension array. To our knowledge, this is the first report on serotyping P. aeruginosa by suspension array and may be of great value in the clinical diagnostics of P. aeruginosa infection.

铜绿假单胞菌（铜绿假单胞菌）在环境中很普遍。它很容易感染医院和免疫功能低下的患者。铜绿假单胞菌感染的传统生化和免疫学诊断无法满足临床需求。 O-抗原的可变性是许多革兰氏阴性细菌的血清分型方案的主要基础，这是用于致病性流行病学目的最广泛使用的方法。在这项研究中，我们开发了一个悬浮阵列，可以准确诊断并鉴定19种不同的铜绿假单胞菌O-抗原血清型，除O15以外的O15（其O-抗原基因簇尚未表征）。在此测定中，选择了WZX/WZY基因作为除O6以外的18种血清型的血清特异性基因，为此使用了糖基转移酶基因WBPP。同时，将WZY（beta）基因添加到与O5/18/20的单独的O2/16中，并且使用WZX中的插入序列（IS）将O17与O11分开。筛选了82个临床分离株以测试我们的测定。总共可以使用65个分离株（79.3％）进行型型，并通过测序确认结果是正确的。灵敏度分析表明，使用我们的悬浮阵列可以检测到至少5 ng DNA或10（3）CFU细胞。据我们所知，这是悬浮阵列上有关血清分型铜绿假单胞菌的第一份报告，在铜绿假单胞菌感染的临床诊断中可能具有很高的价值。