環境所及疾病管制局公佈的方法調查水中退伍軍人菌的偵測率及菌種類別並探討兩種方法之異同

Based on the Detection Rate and Serotypes of Legionella Species to Analyze the Differences between Methods Proclaimed by both Centers for Disease Control (CDC) and Environmental Analysis Laboratory (NIEA), Taiwan

劉梅玉(Mei-Yu Liu) ； 蔡岳廷(Yueh-Ting Tsai)

《檢驗及品保雜誌》 1卷3期 (2012/08) Pp. 144-151

https://doi.org/10.6573/JTQA.201208_1(3).06

摘要

2010年疾病管制局（CDC，簡稱疾管局）及環境檢驗所（簡稱環檢所）分別針對退伍軍人菌公告檢測方法，本實驗室於2011年01月~2011年12月共12個月，同時以環檢所及疾管局方法進行退伍軍人菌之檢測，共操作1,121件檢體，發現陽性件數佔168件，陽性率為15.0%；另再分析退伍軍人菌菌種之血清型，指出L. pneumophilia serogroup 1（嗜肺退伍軍人菌第1血清群）佔45.8%（77/168），L.pneumophilia serogroup 2-14（嗜肺退伍軍人菌第2-14血清群）佔了38.1%（64/168），另外不屬於L. pneumophilia的Legionellaspp.（退伍軍人菌菌種）佔16.1%（27/168）。從檢體操作的經驗，本文將就兩種方法如下項目進行比較：（i）以適用範圍而言，環檢所主要是地面水體、地下水體及空調冷卻之水塔水；而疾管局方法是以醫療院所內環境的水檢體為主；（ii）在水樣前處理的部份，環檢所方法中其水樣量較疾管局方法為多；（iii）培養條件比較，兩者均需在CO2培養箱中進行培養，且均需控制濃度，但疾管局方法中除控制CO_2濃度外，還需控制相對濕度及（iv）培養天數：也以疾管局的方法7~14天較久，環檢所方法為5±2天。另外，疾管局方法除了半胱氨酸需求（L-cysteine requirement test）、革蘭氏染色（Gram stain）、乳膠凝集試驗（latex agglutination test）及直接螢光抗體試驗（direct immunofluorescent antibody test，DFA）進行分型外，尚建議操作觸酶試驗（catalase test）、氧化酶試驗（oxidase test）、馬尿酸水解試驗（hippurate hydrolysis test）及分子生物學試驗，並可利用PCR或即時PCR（real-time PCR）做進一步的確認。兩種方法最終出俱報告的單位會因濃縮倍數不同而異，若是濃縮10倍其單位為CFU/mL，濃縮100倍則單位為CFU/L。從上述兩種試驗方法差異之比較顯示並無優缺點之分，只有適用範圍及培養條件的不同，因此選擇檢測方法的依據可包括針對欲監測水樣之性質、所歸屬的規範及預定出俱的報告型式而定。

關鍵字

嗜肺退伍軍人菌 ； 環檢所方法 ； 疾管局方法

並列摘要

In 2010, the testing method of Legionella species were proclaimed by the Center for Disease Control (CDC) and the Environmental Analysis Laboratory (National Institute of Environmental Analysis, NIEA), Environmental Protection Administration, Executive Yuan, Taiwan, Republic of China respectively. For 12 months, from January to December 2011, we has used both methods simultaneously to evaluate 1,121 water specimens from different environmental sources and found 168 samples produced positive results, for a detection rate of 15.0%. Serotyping for Legionella strains was performed, 45.8% (77/168) were found to be L. pneumophila serogroup 1, 38.1% (64/168) were L. pneumophila serogroups 2-14, and 16.1% (27/168) were Legionella spp. other than L. pneumophila. Based on our laboratory experiences, we compared the two methods: (1) The scope of application of both methods differs; sample collected by the NIEA method are mainly from surface, underground, and cooling tower water system, while samples collected by the CDC method are mainly from hospital environments; (2) the quantity of sample collected by the NIEA method for pre-treatment is larger than that collected by the CDC method; (3) Incubation condition and inoculated media by both methods requires to be incubate in a CO_2 incubator with the concentration of CO_2 controlled. However, the CDC method also requires control of relative humidity in the incubator; and (4) the CDC method requires 7-14 days of incubation, while the NIEA method require 5±2 days). The CDC method includes a catalase test, oxidase test, hippiurate hydrolysis, and molecular diagnostic kethods, PCR or realtime PCR, in addition to a L-cysteine requirement test, Gram stain, latex agglutination, and direct immunofluorescent antibody test for serotyping. The units of final report by these methods were different because of the dilution factors. If the concentrates of specimens was 10-fold, then the unit used in the final report was CFU/mL, whereas 100-fold, CFU/L. The above comparison did not indicate significant strengths or weaknesses for either of the two methods but did show the scope of application and the culture conditions for both methods are different. Therefore, which method is more suitable may be determined based on the nature of the water target, the scope of application, and the pre-determined report format.

並列關鍵字

Legionella pneumophila ； NIEA analysis method ； CDC test method