Penatti M P A, Hollanda L M, Nakazato G, Campos T A, Lancellotti M, Angellini M, Brocchi M, Rocha M M M, Dias da Silveira W
Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, 13081-970 Campinas, SP, Brazil.
Braz J Med Biol Res. 2007 Feb;40(2):249-58. doi: 10.1590/s0100-879x2007000200012.
Shigella spp are Gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the Enterobacteriaceae family responsible for "Shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. However, despite this, there are very few epidemiological studies about this bacterium in Brazil. We studied the antibiotic resistance profiles and the clonal structure of 60 Shigella strains (30 S. flexneri and 30 S. sonnei) isolated from shigellosis cases in different cities within the metropolitan area of Campinas, State of São Paulo, Brazil. We used the following well-characterized molecular techniques: enterobacterial repetitive intergenic consensus, repetitive extragenic palindromic, and double-repetitive element-polymerase chain reaction to characterize the bacteria. Also, the antibiotic resistance of the strains was determined by the diffusion disk method. Many strains of S. flexneri and S. sonnei were found to be multi-resistant. S. flexneri strains were resistant to ampicillin in 83.3% of cases, chloramphenicol in 70.0%, streptomycin in 86.7%, sulfamethoxazole in 80.0%, and tetracycline in 80.0%, while a smaller number of strains were resistant to cephalothin (3.3%) and sulfazotrim (10.0%). S. sonnei strains were mainly resistant to sulfamethoxazole (100.0%) and tetracycline (96.7%) and, to a lesser extent, to ampicillin (6.7%) and streptomycin (26.7%). Polymerase chain reaction-based typing supported the existence of specific clones responsible for the shigellosis cases in the different cities and there was evidence of transmission between cities. This clonal structure would probably be the result of selection for virulence and resistance phenotypes. These data indicate that the human sanitary conditions of the cities investigated should be improved.
志贺氏菌属是肠杆菌科革兰氏阴性、兼性厌氧、无动力且不产芽孢的杆菌，可引发“志贺氏菌病”或细菌性痢疾，这是全球发病率和死亡率的重要成因。然而，尽管如此，巴西针对这种细菌的流行病学研究却非常少。我们研究了从巴西圣保罗州坎皮纳斯大都市区不同城市的志贺氏菌病病例中分离出的60株志贺氏菌（30株福氏志贺氏菌和30株宋内志贺氏菌）的抗生素耐药谱和克隆结构。我们采用了以下特征明确的分子技术：肠杆菌重复基因间共有序列、重复外显子回文序列以及双重复元件聚合酶链反应来鉴定细菌。此外，通过扩散纸片法测定菌株的抗生素耐药性。发现许多福氏志贺氏菌和宋内志贺氏菌菌株具有多重耐药性。福氏志贺氏菌菌株对氨苄青霉素的耐药率为83.3%，对氯霉素为70.0%，对链霉素为86.7%，对磺胺甲恶唑为80.0%，对四环素为80.0%，而对头孢噻吩（3.3%）和复方新诺明（10.0%）耐药的菌株数量较少。宋内志贺氏菌菌株主要对磺胺甲恶唑（100.0%）和四环素（96.7%）耐药，对氨苄青霉素（6.7%）和链霉素（26.7%）耐药程度较低。基于聚合酶链反应的分型支持了不同城市中导致志贺氏菌病病例的特定克隆的存在，并且有城市间传播的证据。这种克隆结构可能是毒力和耐药表型选择的结果。这些数据表明，所调查城市的人类卫生条件应加以改善。
