Departamento de Análises Clínicas, Toxicológicas E Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Av. Do Café, S/N°, Ribeirão Preto, SP, 14040-903, Brasil.
Departamento de Biologia Celular E Molecular E Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto - USP, Av. Do Café, S/N°, Ribeirão Preto, SP, 14040-903, Brasil.
Braz J Microbiol. 2023 Dec;54(4):2827-2843. doi: 10.1007/s42770-023-01145-5. Epub 2023 Oct 10.
Salmonella 1,4, [5],12:i:- is one of the most prevalent serovars associated with gastroenteritis in several countries, including Brazil. However, few studies have analyzed the virulence potential of this variant in this country. Therefore, this study aimed to characterize S. 1,4, [5],12:i:- strains isolated in Southeast Brazil. To this end, 113 S. 1,4, [5],12:i:- strains isolated from different sources between 1983 and 2020 were analyzed. For all strains, the frequencies of 11 virulence genes were investigated using PCR and the molecular typing was performed using pulsed-field gel electrophoresis (PFGE). Furthermore, 40 strains isolated from human and non-human sources were characterized by survival under acid and oxidative stress, and virulence analysis in Galleria mellonella was performed for 20 selected strains. All virulence genes were detected in more than 91% of the strains. The studied strains were grouped into four clusters using PFGE. Most strains were present in one cluster, named PFGE-A, with a genetic similarity of ≥ 79.5%. All 40 strains survived acid stress after 10 min and 1 h of exposure. Under oxidative stress, all 40 strains survived after 10 min, and 36 survived after 1 h of exposure. In the G. mellonella assay, nine isolates from non-human sources and six isolates from human showed high-to-intermediate virulence profiles. In conclusion, the pathogenic potential of the strains studied was corroborated by the high frequency of all the virulence genes identified. The PFGE results suggested that most strains belonged to one main cluster that has been prevailing in the São Paulo State, Brazil. The S. 1,4, [5],12:i:- strains isolated from human and non-human sources successfully survived the unfavorable conditions in the human gastrointestinal tract. Finally, strains isolated from non-human sources showed a higher proportion of isolates with high to intermediate virulence profiles in G. mellonella than in human isolates, suggesting a possible difference between isolates from different origins.
肠炎沙门氏菌 1,4, [5],12:i:- 是与包括巴西在内的几个国家的胃肠炎相关的最普遍血清型之一。然而，很少有研究分析过该变体在该国的毒力潜力。因此，本研究旨在表征在巴西东南部分离的肠炎沙门氏菌 1,4, [5],12:i:- 菌株。为此，分析了 1983 年至 2020 年间从不同来源分离的 113 株肠炎沙门氏菌 1,4, [5],12:i:- 菌株。对于所有菌株，使用 PCR 检测了 11 种毒力基因的频率，并使用脉冲场凝胶电泳 (PFGE) 进行了分子分型。此外，对 40 株来自人类和非人类来源的菌株进行了耐酸和氧化应激生存能力的表征，并对 20 株选定菌株进行了在 Galleria mellonella 中的毒力分析。所有毒力基因均在超过 91%的菌株中检出。PFGE 将研究菌株分为四个聚类。大多数菌株存在于一个聚类中，命名为 PFGE-A，遗传相似度为≥79.5%。所有 40 株菌株在暴露 10 分钟和 1 小时后均能耐受酸应激。在氧化应激下，所有 40 株菌株在暴露 10 分钟后存活，36 株菌株在暴露 1 小时后存活。在 G. mellonella 试验中，来自非人类来源的 9 株分离株和来自人类的 6 株分离株显示出高至中度毒力特征。总之，研究菌株所有鉴定的毒力基因的高频率证实了其致病潜力。PFGE 结果表明，大多数菌株属于在巴西圣保罗州流行的一个主要聚类。从人类和非人类来源分离的肠炎沙门氏菌 1,4, [5],12:i:- 菌株成功耐受了人类胃肠道中的不利条件。最后，与人类分离株相比，来自非人类来源的分离株在 G. mellonella 中显示出更高比例的高至中度毒力特征分离株，这表明来自不同来源的分离株之间可能存在差异。
