Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Foodborne Pathog Dis. 2011 Apr;8(4):547-53. doi: 10.1089/fpd.2010.0736. Epub 2011 Jan 4.
The present study was conducted to investigate serotype distribution, antimicrobial resistance patterns, carriage of class 1 integron, and clonality of Salmonella strains isolated from patients aged 0-12 years in Tehran, Iran, during 2007-2008. A total of 139 Salmonella isolates were studied. Salmonella serotypes Enteritidis, Infantis, and Typhimurium included 84.9% of isolates, Enteritidis accounting for 41.7%. The most prevalent resistances were to doxycycline (64.7%), nalidixic acid (61.2%), tetracycline (51.8%), and streptomycin (42.8%). Fifty-three (38.1%) isolates contained class 1 integron. Eight different gene cassettes were identified, aadA1 being the most frequently encountered. Pulsed-field gel electrophoresis showed that integron-positive Salmonella strains belonging to serotypes Infantis, Enteritidis, and Typhimurium were attributed to two, three, and five different pulsotypes, respectively. The findings indicated that the distribution and drug resistance pattern of most prevalent Salmonella serotypes were broadly similar to that reported globally from human isolates. Presence of class 1 integrons was common among Salmonella serotypes in Tehran, Iran. Concurrent clonal expansion and horizontal transmission events seem to contribute to increase in drug resistance prevalence among Salmonella serotypes.
本研究旨在调查 2007-2008 年期间，伊朗德黑兰年龄在 0-12 岁的患者中分离出的沙门氏菌的血清型分布、抗生素耐药模式、1 类整合子的携带情况和克隆性。共研究了 139 株沙门氏菌。肠炎沙门氏菌、婴儿沙门氏菌和鼠伤寒沙门氏菌占分离株的 84.9%，其中肠炎沙门氏菌占 41.7%。最常见的耐药性是对强力霉素（64.7%）、萘啶酸（61.2%）、四环素（51.8%）和链霉素（42.8%）。53 株（38.1%）分离株含有 1 类整合子。鉴定出 8 种不同的基因盒，aadA1 是最常见的。脉冲场凝胶电泳显示，整合子阳性的肠炎沙门氏菌、婴儿沙门氏菌和鼠伤寒沙门氏菌分别属于 2、3 和 5 种不同的脉冲场凝胶电泳型。研究结果表明，最常见的沙门氏菌血清型的分布和耐药模式与全球从人类分离株中报道的广泛相似。1 类整合子在伊朗德黑兰的沙门氏菌血清型中很常见。同时，克隆扩展和水平传播事件似乎导致沙门氏菌血清型中耐药性的流行增加。
