Epidemiology of Brucellosis and Genetic Diversity of Brucella abortus in Kazakhstan

Brucellosis is a major zoonotic infection in Kazakhstan. However, there is limited data on its incidence in humans and animals, and the genetic diversity of prevalent strains is virtually unstudied. Additionally, there is no detailed overview of Kazakhstan brucellosis control and eradication programs. Here, we analyzed brucellosis epidemiological data, and assessed the effectiveness of eradication strategies employed over the past 70 years to counteract this infection. We also conducted multiple loci variable-number tandem repeat analysis (MLVA) of Brucella abortus strains found in Kazakhstan. We analyzed official data on the incidence of animal brucellosis in Kazakhstan. The records span more than 70 years of antibrucellosis campaigns, and contain a brief description of the applied control strategies, their effectiveness, and their impact on the incidence in humans. The MLVA-16 method was used to type 94 strains of B. abortus and serial passages of B. abortus 82, a strain used in vaccines. MLVA-8 and MLVA-11 analyses clustered strains into a total of four and sevengenotypes, respectively; it is the first time that four of these genotypes have been described. MLVA-16 analysis divided strains into 28 distinct genotypes having genetic similarity coefficient that varies from 60 to100% and a Hunter & Gaston diversity index of 0.871. MST analysis reconstruction revealed clustering into "Kazakhstani-Chinese (Central Asian)", "European" and "American" lines. Detection of multiple genotypes in a single outbreak confirms that poorly controlled trade of livestock plays a crucial role in the spread of infection. Notably, the MLVA-16 profile of the B. abortus 82 strain was unique and did not change during 33 serial passages. MLVA genotyping may thus be useful for epidemiological monitoring of brucellosis, and for tracking the source(s) of infection. We suggest that countrywide application of MLVA genotyping would improve the control of brucellosis in Kazakhstan

Draft Genome Sequences of Three Pasteurella multocida Strains Isolated from Domestic Animals in Kazakhstan

We report here the draft genome sequences of three strains of Pasteurella multocida isolated in Kazakhstan from domestic animals that died due to hemorrhagic septicemia

Molecular epidemiological study of animal rabies in Kazakhstan

Rabies is a serious public health issue in Kazakhstan, with high economic impact and social burden. As part of a routine surveillance, 31 rabies-positive brain specimens taken from livestock (cattle) and carnivores (dogs, foxes, and cats) during 2013–2021 were subject to viral sequencing. Phylogenetic and Bayesian analysis were performed using obtained rabies virus (RABV) sequences. All 31 strains of RABV candidate belonged to the Cosmopolitan clade, of which 30 strains belonged to steppe-type subclade, and 1 dog strain belonged to Other subclade. The 31 strains did not diverge from RABV strains in Kazakhstan and neighboring countries, including Russia, Mongolia, and China, suggesting that animal rabies has close relationship and transmission between borders. Fox-originated strains and cattle strains shared similar sequence signature, and some animal rabies cases had space–time intersection, showing that infected foxes were a major transmission source of cattle rabies in different Kazakhstan regions. Besides, free-roaming dogs played a pivotal role in rabies epizootics of cattle in Kazakhstan. The recent spread of animal rabies presents an increasing threat to public health, and provides updated information for improving current control and prevention strategies at the source for Kazakhstan and neighboring countries

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

Abstract 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

Epidemiology of Brucellosis and Genetic Diversity of <i>Brucella abortus</i> in Kazakhstan

<div><p>Brucellosis is a major zoonotic infection in Kazakhstan. However, there is limited data on its incidence in humans and animals, and the genetic diversity of prevalent strains is virtually unstudied. Additionally, there is no detailed overview of Kazakhstan brucellosis control and eradication programs. Here, we analyzed brucellosis epidemiological data, and assessed the effectiveness of eradication strategies employed over the past 70 years to counteract this infection. We also conducted multiple loci variable-number tandem repeat analysis (MLVA) of <i>Brucella abortus</i> strains found in Kazakhstan. We analyzed official data on the incidence of animal brucellosis in Kazakhstan. The records span more than 70 years of anti-brucellosis campaigns, and contain a brief description of the applied control strategies, their effectiveness, and their impact on the incidence in humans. The MLVA-16 method was used to type 94 strains of <i>B</i>. <i>abortus</i> and serial passages of <i>B</i>. <i>abortus</i> 82, a strain used in vaccines. MLVA-8 and MLVA-11 analyses clustered strains into a total of four and seven genotypes, respectively; it is the first time that four of these genotypes have been described. MLVA-16 analysis divided strains into 28 distinct genotypes having genetic similarity coefficient that varies from 60 to100% and a Hunter & Gaston diversity index of 0.871. MST analysis reconstruction revealed clustering into "Kazakhstani-Chinese (Central Asian)", "European" and "American" lines. Detection of multiple genotypes in a single outbreak confirms that poorly controlled trade of livestock plays a crucial role in the spread of infection. Notably, the MLVA-16 profile of the <i>B</i>. <i>abortus</i> 82 strain was unique and did not change during 33 serial passages. MLVA genotyping may thus be useful for epidemiological monitoring of brucellosis, and for tracking the source(s) of infection. We suggest that countrywide application of MLVA genotyping would improve the control of brucellosis in Kazakhstan.</p></div

Allelic types and HGDI of <i>B</i>. <i>abortus</i> strains for 16 loci in this study.

<p>Allelic types and HGDI of <i>B</i>. <i>abortus</i> strains for 16 loci in this study.</p

Cluster analysis for 94 strains of <i>Brucella abortus</i> based on the MLVA-16 dataset.

<p>In the columns, the following data for strains are indicated: Key, serial number for the strain in the MLVA bank; GT, genotype MLVA16 in this study; MLVA-8 and MLVA-11, genotype numbers associated with the genotypes corresponding to each strain in the database; region, geographic region (NKR, North Kazakhstan Region; EKR, East Kazakhstan Region; WKR, West Kazakhstan Region); host, animal host; year, year of isolation.</p

Incidence of human brucellosis.

<p>Time in years is on the x-axis, incidence per 100,000 population is on the y-axis.</p

Geographical representation of <i>Brucella abortus</i> sample collection sites.

<p>Geographical representation of <i>Brucella abortus</i> sample collection sites.</p

Incidence of animal brucellosis.

<p>Time in years is on the x-axis, seroprevalence (%) is on the y-axis.</p