金黄色葡萄球菌肠毒素的检测和耐药性分析

Detection of Enterotoxin and Analysis of the Drug-resistant Staphylococcus aureus

目的了解临床分离的金黄色葡萄球菌(SA)产肠毒素(SE)的情况及耐药现状。方法对从临床标本中分离出的260株SA,用反向间接血凝试验检测其肠毒素,按2005年美国临床实验室标准化委员会(NCCLS)的标准,用K-B法对260株SA进行药物敏感性试验,耐甲氧西林金黄色葡萄球菌(MRSA)检测分别用检测头孢西丁及乳胶凝集检测PBP2a方法进行。结果260株SA中有172株携带肠毒素,占66.2%,主要为SEA型10.8%(28/260)、SEB型14.6%(38/260)、SEC型10.0%(26/260),同时携带二种或二种以上肠毒素的占23.8%(62/260);其中MRSA134株,全部携带肠毒素,且以SEA、SEB和SEC为主,分别为19.4%、16.4%和13.4%;甲氧西林敏感金黄色葡萄球菌(MSSA)126株,携带肠毒素率为30.0%(38/126),以SEB为主,占9.5%。用头孢西丁及检测PBP2a的方法检测MRSA,检出率无显著意义(P>0.05);SA对临床常用的抗菌素除万古霉素及替考拉宁较敏感(100.0%敏感),其它的抗菌素存在多重耐药性,且MRSA的耐药性比MSSA的强。结论临床分离的SA株大部分都携带肠毒素,MRSA的带毒率及耐药性均高于MSSA;临床应重视SA肠毒素和MRSA的检测,合理使用抗菌素。

Objective To analyze the occurrence of enteroteoxin-producing strains and drug-resistant Staphylococcus aure us （ SA ） isolated from clinical samples. Methods Rreverse passive hemagglutination （ RPHA ） method was used in the determination of enterotoxin. Analysis was performed according to the methods recommended by NCCLS. K-B method was used to test for the antibiotics sensitivity of the bacterial isolates.Methicillin-resistant Staphylococcus aureus（MRSA）was identified using latex fixation test and FOX test. Results 66.2%（ 172/260）of Staphylococcus aureus isolates were enterotoxin-producing strains SEA 10.8% （28/260）; SEB 14.6% （38/260）;and SEC 10.0%（26/260）. 23.8% （62/260）of the isolates produced two or more than two types of enterotoxins.All 134 MRSA isolates produced enterotoxin （SEA 19.4%,SEB 16.4%, and SEC 13.4%）. Among the 126 MSSA isolates, 38 strains were enterotoxinproducing strains. There was no significant difference in the identification rate between the FOX and PBP2a method （P〉 0.05）. Most of the Staphylococcus aureus isolates were sensitive to vancomycin and Teicoplanin. The antibiotic-resistance of MRSA was higher than MSSA.Conelusion Most of the clinical isolates of Staphylococcus aureus are enterotoxinproducing strains. The frequency of enterotoxin-producing and antibiotic-resistance of MRSA strains was higher than MSSA.Effort should be made on the detection of enterotoxin-producing Staphylococcus aureus and MRSA. Antibiotics should also be used with caution.