Nabi Ibrahim, Achek Rachid, Karim Abdelkadir, Melzer Falk, Brangsch Hanka, Elschner Mandy C, Neubauer Heinrich, El-Adawy Hosny
Department of Nature and Life Sciences, Laboratory of Biotechnology and Valorisation of Biological Resources (BVRB), Faculty of Sciences, University Dr. Yahia Farès, Médéa, Algeria.
Department of Biology, Faculty of Nature and Life and Earth Sciences, DjilaliBounaama University, Khemis-Miliana, Algeria.
Front Microbiol. 2025 Jan 13;15:1505294. doi: 10.3389/fmicb.2024.1505294. eCollection 2024.
Brucellosis is considered a common bacterial zoonotic disease of high prevalence in countries of the Middle East and the Mediterranean region with economic and public health impact. The present study aimed to investigate the current situation of brucellosis in small ruminants reared in Médéa and Sidi Bel-Abbès provinces, north Algeria. To achieve this objective, 96 sera (77 sheep and 19 goat) and 57 milk (42 sheep and 15 goat) samples were collected from suspected infected animals and serologically analyzed by using ELISA. For isolation of spp., four placentas, two fetuses and forty-four milk samples were subjected to microbiological investigation. Whole genome sequencing (WGS) was used for genomic analysis of isolated species. The results of this study showed that anti- antibodies were detected in 46 (83.6%) and 52 (54.2%) milk and serum samples, respectively. However, among 27 cases where blood samples were negative, anti- antibodies were still detected in 19 of the corresponding milk samples, resulting in an overall discordance rate of 36.5%. Ten were isolated and identified from six sheep and four goats. Of these, eight originated from milk samples. The isolated strains were assigned to sequence type ST-11 using Multilocus sequence typing (MLST). Five isolates revealing high similarity (0-2 nucleotide differences) originated from different farms, indicating a close transmission link. However, two identical caprine isolates and three other isolates showed notable genotypic variation, in comparison. The highest base difference (449-462 nucleotides) was observed for an ovine isolate originating from Sidi Bel-Abbès. The phylogenetic analysis and clustering with the West Mediterranean lineage of revealed high genetic similarity of the investigated isolates with of human origin from North Africa and travel-associated 'European' cases, especially from Morroco, Tunisia, Sweden and Italy. The results of this study highlight brucellosis in small ruminants as a significant public health risk and will help to develop effective control strategies in Algeria. These findings provide specific evidence of this risk, with isolation from milk and by linking theses isolates to human cases in Algeria and abroad. The use of WGS-based analysis has revealed effective in tracing patterns of transmission, and can be recommended for tracking outbreaks at a high resolution.
布鲁氏菌病被认为是中东和地中海地区国家一种常见的细菌性人畜共患病，具有较高的发病率，对经济和公共卫生有影响。本研究旨在调查阿尔及利亚北部麦迪亚省和西迪贝勒阿巴斯省饲养的小反刍动物的布鲁氏菌病现状。为实现这一目标，从疑似感染动物中采集了96份血清样本（77份绵羊血清和19份山羊血清）和57份乳样（42份绵羊乳样和15份山羊乳样），并采用酶联免疫吸附测定法（ELISA）进行血清学分析。为分离布鲁氏菌属，对4个胎盘、2个胎儿和44份乳样进行了微生物学调查。全基因组测序（WGS）用于对分离出的布鲁氏菌属物种进行基因组分析。本研究结果表明，分别在46份（83.6%）乳样和52份（54.2%）血清样本中检测到抗布鲁氏菌抗体。然而，在27份血样为阴性的病例中，仍在19份相应的乳样中检测到抗布鲁氏菌抗体，总体不一致率为36.5%。从6只绵羊和4只山羊中分离并鉴定出10株布鲁氏菌。其中，8株来自乳样。使用多位点序列分型（MLST）将分离出的菌株归为序列型ST-11。5株显示高度相似性（0-2个核苷酸差异）的分离株来自不同农场，表明存在密切的传播联系。然而，相比之下，2株相同的山羊分离株和其他3株分离株表现出明显的基因型变异。在一株来自西迪贝勒阿巴斯的绵羊分离株中观察到最高的碱基差异（449-462个核苷酸）。系统发育分析以及与布鲁氏菌西地中海谱系的聚类显示，所调查的分离株与来自北非的人类源布鲁氏菌以及与旅行相关的“欧洲”病例（特别是来自摩洛哥、突尼斯、瑞典和意大利的病例）具有高度的遗传相似性。本研究结果突出了小反刍动物中的布鲁氏菌病是一个重大的公共卫生风险，并将有助于在阿尔及利亚制定有效的控制策略。这些发现提供了这种风险的具体证据，包括从乳样中分离出布鲁氏菌以及将这些分离株与阿尔及利亚国内外的人类病例联系起来。基于WGS的分析已证明在追踪传播模式方面是有效的，可推荐用于高分辨率追踪疫情爆发。
