Tewodros W, Nordstrand A, Kronvall G, Holm S E, Norgren M
Department of Clinical Microbiology, Karolinska Institute and Hospital, S-171 76, Stockholm, Sweden.
Microb Pathog. 1993 Oct;15(4):303-11. doi: 10.1006/mpat.1993.1080.
Certain variants of streptokinase from group A streptococci have been associated with acute post-streptococcal glomerulonephritis (APSGN). The streptokinase gene (ska) has previously been grouped into nine different polymorphic genotypes of which ska1, ska2, ska6, and ska9 were identified in group A streptococci associated with clinical and experimental APSGN. A total of 53 group A streptococci isolated from Ethiopian children: five from acute rheumatic fever, 18 from APSGN, ten each from tonsillitis, impetigo and healthy carriers, were analyzed for ska gene polymorphism using polymerase chain reaction (PCR) and restriction enzyme analysis. The frequency of the nephritis-associated streptokinase genotypes was 83% among the APSGN isolates and 74% in the non-ASPGN isolates. ska2 was the most commonly found genotype with a frequency of 64% among all isolates, 66% among the APSGN isolates, and 63% among the non-APSGN isolates. ska1 was identified in 13% among all isolates and 17% among the APSGN isolates. Seventeen non-APSGN isolates from Scandinavian countries were studied for comparison and all carried either ska1 or ska2. The other nephritis-associated ska6 and ska9 were not detected among the 53 Ethiopian isolates. ska1 was exclusively associated with serum opacity reaction (SOR) producers. ska2 was evenly distributed among SOR-positive and SOR-negative isolates. The other genotypes were detected only among SOR-negative strains. The findings of the present study showed an even distribution of the nephritis-associated streptokinase gene among group A streptococcal isolates with no correlation to disease pattern. Thus additional factors must also be operative in the pathogenesis of APSGN.
A组链球菌的某些链激酶变体与急性链球菌感染后肾小球肾炎（APSGN）有关。链激酶基因（ska）先前已被分为九种不同的多态基因型，其中ska1、ska2、ska6和ska9在与临床和实验性APSGN相关的A组链球菌中被鉴定出来。对从埃塞俄比亚儿童中分离出的53株A组链球菌进行了分析：5株来自急性风湿热，18株来自APSGN，扁桃体炎、脓疱病和健康携带者各10株，采用聚合酶链反应（PCR）和限制性酶切分析检测ska基因多态性。APSGN分离株中与肾炎相关的链激酶基因型频率为83%，非APSGN分离株中为74%。ska2是最常见的基因型，在所有分离株中的频率为64%，在APSGN分离株中为66%，在非APSGN分离株中为63%。ska1在所有分离株中的检出率为13%，在APSGN分离株中的检出率为17%。研究了来自斯堪的纳维亚国家的17株非APSGN分离株以作比较，所有分离株均携带ska1或ska2。在53株埃塞俄比亚分离株中未检测到其他与肾炎相关的ska6和ska9。ska1仅与血清混浊反应（SOR）产生菌相关。ska2在SOR阳性和SOR阴性分离株中分布均匀。其他基因型仅在SOR阴性菌株中检出。本研究结果表明，与肾炎相关的链激酶基因在A组链球菌分离株中分布均匀，与疾病模式无关。因此，在APSGN的发病机制中必定还有其他因素起作用。
