Genotyping of Brucella melitensis strains from dromedary camels (Camelus dromedarius) from the United Arab Emirates with multiple-locus variable-number tandem repeat analysis.

Camel brucellosis is a widespread zoonotic disease in camel-rearing countries caused by Brucella melitensis and Brucella abortus. The aim of this study was the first genetic analysis of B. melitensis strains isolated from dromedary camels (Camelus dromedarius) using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA 16 and its MLVA 8 and MLVA11 subsets were used to determine the genotypes of 15 B. melitensis isolates from dromedary camels (11 strains) and other host species (4 strains) from the United Arab Emirates and the results were then compared to B. melitensis MLVA genotypes from other parts of the world. Five, including two novel genotypes were identified with MLVA 8. MLVA 16 further discriminated these five genotypes to ten variants. The eleven camel isolates clustered into four main genetic groups within the East-Mediterranean and African clades and this clustering correlated with the geographic origin of the hosts (United Arab Emirates, Kingdom of Saudi Arabia and Sudan) and the date of their isolation. The camel strains were also genetically related to strains isolated from wild and domestic ruminants from their close habitat or from other parts of the world. Although limited number of strains were analysed, based on our data imported animals from foreign countries, local small ruminants and wildlife species are hypothesized to be the main sources of camel brucellosis in the United Arab Emirates. MLVA was successfully applied to determine the epidemiological links between the different camel B. melitensis infections in the United Arab Emirates and it can be a beneficial tool in future disease control programs.

Gyuranecz M ，Wernery U ，Kreizinger Z ，Juhász J ，Felde O ，Nagy P ... -  《-》

Genetic diversity of Brucella abortus and Brucella melitensis in Kazakhstan using MLVA-16.

Brucellosis is an endemic disease in Central Asia characterized by high infection rates in humans and animals. Currently, little is known about the genetic diversity of Brucella spp. circulating in the region, despite the high prevalence of brucellosis. This study aimed to analyze the genetic diversity of Brucella melitensis and Brucella abortus strains circulating in the Republic of Kazakhstan. We genotyped 128 B. melitensis and 124 B. abortus strains collected in regions with the highest prevalence of brucellosis. Genotyping was performed using multi-locus variable-number tandem-repeat analysis (MLVA). Analysis of a subset of 8 loci (MLVA-8) of 128 B. melitensis strains identified genotypes 42 (n=108), 43 (n=2), and 63 (n=19) related to the 'East Mediterranean' group. An MLVA-16 assay sorted 128 B. melitensis strains into 25 different genotypes. Excluding one variable locus, MLVA-15 of B. melitensis was distinct from strains originating in the Mediterranean region; however, 77% of them were identical to strains isolated in China. A minimum spanning tree for B. melitensis using MLVA-15 analysis clustered the local strains together with strains previously collected in China. MLVA-8 analysis of 124 B. abortus strains identified them as genotype 36, suggesting Eurasian distribution of this lineage. Complete MLVA-16 assay analysis clustered the strains into five genotypes, revealing little diversity of B. abortus when compared on the global scale. A minimum spanning tree for B. abortus obtained using MLVA-15 analysis clustered the 2 most prevalent genotypes (n=117) together with strains previously collected in China. Thus, MLVA analysis was used to characterize 252 strains of Brucella collected in Kazakhstan. The analysis revealed genetic homogeneity among the strains. Interestingly, identical MLVA-15 profiles were found in seemingly unrelated outbreaks in China, Turkey, and Kazakhstan. Further analysis is needed for better understanding of the epidemiology of brucellosis in Asia.

Shevtsov A ，Ramanculov E ，Shevtsova E ，Kairzhanova A ，Tarlykov P ，Filipenko M ，Dymova M ，Abisheva G ，Jailbekova A ，Kamalova D ，Chsherbakov A ，Tulegenov S ，Akhmetova A ，Sytnik I ，Karibaev T ，Mukanov K ... -  《-》

MLVA fingerprinting of Brucella melitensis circulating among livestock and cases of sporadic human illness in Egypt.

Brucella melitensis is a serious public health threat, with human infection exhibiting acute febrile illness and chronic health problems. The present study investigated the genetic diversity and epidemiological links of the important zoonotic bacterium B. melitensis in Egypt using multilocus variable-number tandem repeat analysis (MLVA-16) including eight minisatellite (panel 1) and eight microsatellite (panel 2, subdivided into 2A and 2B) markers. A total of 118 isolates were identified as B. melitensis biovar 3 by classical biotyping and Bruce-ladder assay. Although B. melitensis is primarily associated with infection in sheep and goats, most of B. melitensis isolates in this study were obtained from secondary hosts (cattle, buffaloes, humans and a camel) suggesting cross-species adaptation of B. melitensis to large ruminants in Egypt. The MLVA-16 scheme competently discriminated 70 genotypes, with 51 genotypes represented by single isolates, and the remaining 19 genotypes were shared among 67 isolates, suggesting both sporadic and epidemiologically related characteristics of B. melitensis infection. Matching of local genotypes with representatives of global genotypes revealed that the majority of Egyptian isolates analysed had a West Mediterranean descendance. As this study represents the first comprehensive genotyping and genetic analysis of B. melitensis from different sources in Egypt, the information generated from this study will augment knowledge about the main epidemiological links associated with this bacterium and will allow a better understanding of the current epidemiological situation of brucellosis in Egypt. Ultimately, this will help to adopt effective brucellosis intervention strategies in Egypt and other developing nations.

Sayour AE ，Elbauomy E ，Abdel-Hamid NH ，Mahrous A ，Carychao D ，Cooley MB ，Elhadidy M ... -  《-》

Genotyping of Brucella melitensis and Brucella abortus strains currently circulating in Xinjiang, China.

Brucellosis is a well-known zoonotic disease that can cause severe economic and healthcare losses. Xinjiang, one of the biggest livestock husbandry sectors in China, has gone through increasing incidence of brucellosis in cattle and small ruminants recently. In this paper, 50 B. melitensis strains and 9 B. abortus strains collected from across Xinjiang area (from 2010 to 2015) were genotyped using multiple locus variable-number tandem-repeat (VNTR) analysis (MLVA) and multi-locus sequence typing (MLST). Based on 8 loci (MLVA-8), 50 B. melitensis strains were classified into three genotypes. Genotypes 42 (n=38, 76%) and 63 (n=11, 22%) were part of the East Mediterranean group, and one genotype with pattern of 1-5-3-13-2-4-3-2 represents a single-locus variant from genotype 63. MLVA-16 resolved 50 B. melitensis strains into 28 genotypes, of which 15 are unique to Xinjiang and 10 are in common with those in adjacent country Kazakhstan and neighboring provinces of China. Minimum Spanning Tree (MST) analysis implies that B. melitensis strains collected from across Kazakhstan, Xinjiang and China areas may share a common origin. Nine B. abortus strains were sorted into three genotypes by MLVA-8, genotypes 36 (n=7, 77.8%), 86 (n=1, 11.1%) and a new genotype with pattern of 4-5-3-13-2-2-3-1. Each B. abortus strain showed distinct MLVA-16 genotypes, suggesting that B. abortus species may possess more genetic diversity than B. melitensis. Using MLST, most B. melitensis strains (n=49) were identified as sequence type ST8, and most B. abortus strains (n=8) were recognized as ST2. Two new sequence types, ST37 and ST38, represented by single strain from B. melitensis and B. abortus species respectively, were also detected in this study. These results could facilitate the pathogen surveillance in the forthcoming eradication programs and serve as a guide in source tracking in case of new outbreaks occur.

Sun MJ ，Di DD ，Li Y ，Zhang ZC ，Yan H ，Tian LL ，Jing ZG ，Li JP ，Jiang H ，Fan WX ... -  《-》

Evaluation of a multilocus variable-number tandem-repeat analysis scheme for typing human Brucella isolates in a region of brucellosis endemicity.

Kattar MM ，Jaafar RF ，Araj GF ，Le Flèche P ，Matar GM ，Abi Rached R ，Khalife S ，Vergnaud G ... -  《-》