Animal Medicine Department (Infectious Diseases), Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh, Egypt.
Brucellosis Research Department, Animal Health Research Institute, Agricultural Research Center, Giza, Egypt.
J Appl Microbiol. 2022 Jan;132(1):90-100. doi: 10.1111/jam.15173. Epub 2021 Jul 6.
This study aimed to identify the genotypic fingerprinting of Brucella melitensis biovar 3 isolates from ruminants in Kafr El-Sheikh, Egypt, to compare with other peers globally and to highlight the epidemiology and potential causes of brucellosis control failure.
A multilocus variable-number tandem-repeat analysis (MLVA 16) was carried out on 41 B. melitensis bv3 isolates, 31 from the preferential hosts (28 sheep and three goats) and 10 from atypical hosts (nine cattle and one buffalo), identified by bacteriological and molecular techniques. MLVA-16 analysis revealed 19 genotypes with nine as singletons. The most prevalent genotypes were M3_K.E (3,5,3,13,1,1,3,3,7,43,8,7,6,7,5,3), M13_K.E (3,5,3,13,1,1,3,3,7,43,8,5,8,7,7,3) and M5_K.E (3,5,3,13,1,1,3,3,7,43,8,4,8,7,11,3) circulating between different animal species. The B. melitensis isolation from aborted cows in farms that had never reared small ruminants indicates the likelihood of cow to cow B. melitensis transmission. Different genotypes of B. melitensis could be isolated from the same animal. The local geographic distribution of genotypes showed a very close genetic relatedness with genotypes reported outside the study area. Worldwide, our genotypes were mostly related to the Western Mediterranean lineage and less likely to the America's clonal lineage.
There is a high genetic similarity of B. melitensis bv3 genotypes among different ruminant species, and the same animal could be infected with different genotypes. There is a high probability of spreading of B. melitensis among atypical hosts in the absence of the original hosts. The genetic relatedness of B. melitensis bv3 genotypes in the study area with other different geographic areas highlighted the national and international ruminants movement role as a potential factor for maintaining B. melitensis infection.
Further investigations are required to understand the impact of the presence of more than one genotype of B. melitensis in the same animal on the efficacy of brucellosis control strategies.
本研究旨在鉴定来自埃及卡夫尔谢赫省反刍动物的布鲁氏菌 melitensis 生物型 3 分离株的基因型指纹图谱，与全球其他同行进行比较，并强调布鲁氏菌病控制失败的流行病学和潜在原因。
对通过细菌学和分子技术鉴定的 31 个优先宿主（28 只绵羊和 3 只山羊）和 10 个非典型宿主（9 头牛和 1 头水牛）的 41 株 B. melitensis bv3 分离株进行了多位点可变数串联重复分析（MLVA 16）。MLVA-16 分析显示有 19 种基因型，其中 9 种为单倍型。最常见的基因型是 M3_K.E（3,5,3,13,1,1,3,3,7,43,8,7,6,7,5,3）、M13_K.E（3,5,3,13,1,1,3,3,7,43,8,5,8,7,7,3）和 M5_K.E（3,5,3,13,1,1,3,3,7,43,8,4,8,7,11,3），它们在不同的动物物种之间传播。从从未饲养过小反刍动物的农场流产奶牛中分离出的布鲁氏菌 melitensis 表明，牛与牛之间可能存在布鲁氏菌 melitensis 传播。同一动物可能会感染不同的基因型。基因型的局部地理分布与研究区域外报告的基因型非常接近，表明存在很高的遗传相关性。在全球范围内，我们的基因型主要与西地中海谱系有关，而与美洲克隆谱系的关系较小。
不同反刍动物物种之间的布鲁氏菌 melitensis bv3 基因型具有很高的遗传相似性，同一动物可能会感染不同的基因型。在没有原始宿主的情况下，布鲁氏菌 melitensis 很可能在非典型宿主之间传播。研究区域与其他不同地理区域的布鲁氏菌 melitensis bv3 基因型的遗传关系突出了国家和国际反刍动物运动作为维持布鲁氏菌感染的潜在因素的作用。
需要进一步研究以了解同一动物中存在不止一种布鲁氏菌 melitensis 基因型对布鲁氏菌病控制策略的效果的影响。
