快速、特异的MRSA检测方法

xiangboshu

Combined use of Pastorex Staph-Plus and either of two new chromogenic agars, MRSA ID and CHROMagar MRSA, for detection of methicillin-resistant Staphylococcus aureus.
联合Pastorex Staph-Plus与任一种新的显色琼脂――MRSA ID或CHROMagar MRSA 用于MRSA的检测

J Clin Microbiol. 2007 Jan;45(1):154-8. Epub 2006 Nov 8.
Compernolle V, Verschraegen G, Claeys G.
Department of Microbiology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium.

We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillin-resistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h). Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination). When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl, subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates combined with Gram staining and the direct_Pastorex agglutination test; and (iv) direct inoculation of C_MRSA plates combined with Gram staining and the direct_Pastorex agglutination test. We concluded that the use of MRSA_ID in combination with Gram staining and the direct_Pastorex agglutination test is faster and more specific than the other strategies tested.

PMID: 17093032 [PubMed - indexed for MEDLINE]

联合Pastorex Staph-Plus与任一种新的显色琼脂――MRSA ID或CHROMagar MRSA 用于MRSA的检测
我们介绍一项关于在筛查标本中快速、可靠的检测和确认MRSA的研究。首先，我们对几种用于检测MRSA的培养基的敏感性和特异性进行了评估，培养基分别是：添加了增菌培养基（胰大豆肉汤）联合甲氧西林耐药筛选琼脂（TSB-ORSA）、无需增菌的甲氧西林耐药筛选琼脂（ORSA）、MRSA鉴定平板（MRSA-ID）和CHROMagar MRSA平板(C_MRSA) 。将筛查的拭子标本浸入生理盐水中，充分混合，取相等量的悬浮液接种在这四种培养基上。培养48小时后，所有培养基的敏感性都较为相似（MRSA-ID和ORSA　77%，C_MRSA和 TSB-ORSA均为73%），然而MRSA-ID和 C_MRSA的特异性明显优于ORSA和TSB-ORSA，分别为MRSA_ID (24h的特异性为98%；48h为94%)、C_MRSA (24h 98% ；48h 90%)、 ORSAs (24h 92% ； 48h 83%) and TSB-ORSA (24h 86%；  48h 81%)。紧接着，使用Pastorex Staph-Plus葡萄球凝集试剂检测直接从显色平板上挑取的疑似MRSA菌落（称之为直接Pastorex 凝集），并与次培养到血平板上的菌落的Pastorex Staph-Plus凝集试验（称之为传统Pastorex 凝集）的结果进行比较。Staph-Plus葡萄球凝集试剂用于检测细菌是否为金葡菌。当使用MRSA-ID平板上的菌落做直接Pastorex 凝集检测时，若与革兰染色相结合，MRSA-ID平板的直接Pastorex 凝集与传统Pastorex 凝集一样准确。但相反地，C_MRSA平板上的菌落的直接Pastorex 凝集试验会出现假阴性结果。最后，我们比较了四种方法所需用的时间：①先用添加NaCl 的TSB增菌，再转种到ORSA，再做传统的Pastorex 凝集试验；②直接接种到ORSA，再做传统的Pastorex 凝集试验；③直接接种MRSA_ID平板，结合革兰染色和直接Pastorex 凝集试验；④直接接种到C_MRSA平板，结合革兰染色和直接Pastorex 凝集试验。我们的结论是MRSA_ID平板结合革兰染色和直接Pastorex 凝集试验与其他方法相比是一种更快速、更特异的MRSA检测方法。

[ 本帖最后由 xiangboshu 于 2007-9-17 22:09 编辑 ]

潮水

临床检验的版主就是专业啊！

xiangboshu

谢谢夸奖，小xiang不才，请wzcdcyxh 版多提意见。

楚楚

谢谢分享！第三种方法是最快速、最特异的检测方法！请问这种方法一般实验室均可以做到吗？

巴斯德之徒

xiang版你看这样翻译是不是更忠实于原著?

Combined Use of Pastorex Staph-Plus and Either of Two New
Chromogenic Agars, MRSA ID and CHROMagar MRSA, for
Detection of Methicillin-Resistant Staphylococcus aureus_
联合应用Pastorex Staph-Plus乳胶凝集试验和MRSA ID 和 CHROMagar MRSA中的任意一种显色培养基，检测耐甲氧西林金黄色葡萄球菌
Veerle Compernolle, Gerda Verschraegen, and Geert Claeys*
Department of Microbiology, Ghent University Hospital, Ghent, Belgium
Received 31 May 2006/Returned for modification 25 August 2006/Accepted 24 October 2006

We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillinresistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA  [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA  (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h).  Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination).  When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl,  subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates combined with Gram staining and the direct_Pastorex agglutination test; and (iv) direct inoculation of C_MRSA plates combined with Gram staining and the direct_Pastorex agglutination test. We concluded that the use of MRSA_ID in combination with Gram staining and the direct_Pastorex agglutination test is faster and more specific than the other strategies tested.
我们的研究描述了一种能更快速和可靠地从初筛标本中检测和证实耐甲氧西林金黄色葡萄球菌（MRSA）的策略。首先，我们评价了苯唑西林耐药性筛选琼脂（ORSA）采用胰酶消化大豆肉汤先增菌后接种（TSB-ORSA）和不经增菌接种（ORSA）、与(直接)接种MRSA ID (MRSA_ID)培养基、和CHROMagar MRSA  (C_MRSA) 显色培养基这几种方案的灵敏度和特异性，采用将筛选（采样后的）用的拭子洗入盐水中混匀后等量接种到各培养基中的方法来实现。结果所有的培养基在经过48h后得出的敏感性均接近（MRSA_ID 和 ORSA的敏感性为77%; C_MRSA和[TSB-ORSA]的敏感性为73%），而特异性则是以MRSA_ID (24 h为98% ，48 h 为94%) 和 C_MRSA (24 h为98% ，48 h为90%)为优，优于ORSAs (24 h 为92% ，48 h为83%) 和 TSB-ORSA (24 h为86%，48 h为81%)。随后，我们采用Pastorex Staph-Plus乳胶试剂对显色培养基上被推断为MRSA的菌落进行直接乳胶凝集试验，同时采用接种在血琼脂上进行传代的纯培养菌落进行经典的乳胶凝集试验与之进行比较。同时比较了采用MRSA ID培养基上的细菌作直接乳胶凝集试验联合革蓝染色，并对接种MRSA ID培养基的标本进行直接乳胶凝集试验，结果和采用经从MRSA ID培养基上传代到血琼脂上的纯培养物作的经典凝集试验得到的结果是同样可靠的。但相反的是，采用接种C_MRSA培养基的标本做的直接凝集试验却得到了假阴性结果。最后，我们统计了来自四组不同检测方案的测试时间，分别是(i)先经补充NaCl的胰大豆肉汤增菌后传代到ORSA培养基上，再采用经典Pastorex乳胶凝集试验；(ii)直接接种ORSA培养基联合经典Pastorex乳胶凝集试验；(iii) 直接接种MRSA_ID培养基联合革蓝染色与标本直接Pastorex乳胶凝集试验；与(iv) 直接接种C_MRSA培养基联合革蓝染色与标本直接Pastorex乳胶凝集试验。我们得出了采用接种MRSA_ID培养基联合革蓝染色与标本直接Pastorex乳胶凝集试验的方案是相对于其他几种方案最快而且也是特异性最好的方案的结论。

xiangboshu

是的，更加忠实原著，语言运用的很好，谢谢你，看来以后要更加认真呀。:P

txzhou

梅里埃有商品化的MRSA-ID平板供应，但本实验室未使用过，不知效果到底如何？

xiangboshu

这些培养基都有商品化的，你只有购买了就可以用的。

巴斯德之徒

做院感监测和大规模初筛时是非常实用的,但对临床微生物室常规检验意义不大的,除非是针对高度怀疑为MRSA感染的标本.但这样的标本占不了微生物室总体标本的多少,为此专门去购买这样的培养基实在没必要的.灵敏度与苯唑西林盐琼脂相仿,要讲特异性在微生物室采用检测PBPs的乳胶试剂更方便更准确,与采用分子生物学手段检测mecA基因差不多的.

冰上芭蕾

是啊！我院检验科说国内没有有证件的多重耐药菌检验试剂盒或其它，不知是否，梅里埃的有证吗？