Fire blight caused by Erwinia amylovora reached Kazakhstan in 2008. Here, the disease poses a threat not only to agricultural production of apples and pears, but also to the forests of wild Malus sieversii, the progenitor of most domesticated apple varieties worldwide. In the period 2019–2021, the spread of fire blight in the growth area of wild apples was limited by the weather conditions. In 2022, late spring and early summer were characterized by increased rainfall and moderate temperatures favorable for the disease. The goal of this study was to monitor the distribution of fire blight in private households and small orchards in the zones adjacent to wild apple distribution areas. A total of 91 samples with fire blight-compatible symptoms were collected from cultural apples (68), wild apple (10), pear (5), hawthorn (7), and quince (1) in south-eastern and eastern Kazakhstan, resulting in 21 isolates (one from pear, one from quince, and 19 from apple) of E. amylovora. All isolates belonged to the archetypal CRISPR genotype A. Considering the relative proximity of the infections to the forests of wild M. sieversii, additional measures for fire blight control and prevention will have to be implemented, including state monitoring of the wild apple forests for disease symptoms and awareness campaigns for specially protected natural territories that safeguard M. sieversii, as well as for local pomaceous-fruit growing communities.
Wild birds are natural reservoirs of many emerging viruses, including some zoonoses. Considering that the territory of Kazakhstan is crossed by several bird migration routes, it is important to know pathogenic viruses circulating in migratory birds in this region. Therefore, the aim of this study was to identify the host range, diversity and spatial distribution of avian paramyxoviruses, coronaviruses, and astroviruses in free-ranging wild birds in the southeastern region of Kazakhstan. For this purpose, we collected tracheal and cloacal swabs from 242 wild birds belonging to 51 species and screened them using conventional PCR assays. Overall, 4.1% (10/242) and 2.9% (7/242) of all examined birds tested positive for coronaviruses and astroviruses, respectively. Coronaviruses were found in the orders Pelecaniformes (30%; 3/10), Charadriiformes (30%; 3/10), Columbiformes (20%; 2/10), Anseriformes (10%; 1/10), and Passeriformes (10%; 1/10). All detected strains belonged to the genus Gammacoronavirus. Astroviruses were detected in birds representing the orders Passeriformes (57%; 4/7), Coraciiformes (14%; 1/7), Charadriiformes (14%; 1/7), and Columbiformes (14%; 1/7). Paramyxoviruses were observed in only two birds (0.8%; 2/242). Both strains were closely related to the species APMV-22, which had not been previously detected in Kazakhstan. Phylogenetic analysis of the partial RdRp gene sequences of the virus strains revealed three different clades of astroviruses, two clades of coronaviruses, and one clade of paramyxoviruses. The results of this study provide valuable information on the diversity and spatial distribution of paramyxoviruses, coronaviruses, and astroviruses in wild birds in southeastern Kazakhstan and highlight the importance of further thorough monitoring of wild birds in this region.
Ticks are involved in the circulation of a number of human pathogens, including spotted fever group (SFG) Rickettsia spp. and Coxiella burnetii. Little is known about the occurrence of these microorganisms in the southern region of Kazakhstan. In 2018-2022, a total of 726 ticks were collected from bitten humans, livestock, and vegetation in four oblasts of the southern region of Kazakhstan and subjected to DNA extraction. The overall infection rate of Coxiella spp. and Rickettsia spp. in the ticks was 3.3% (24/726) and 69.9% (300/429), respectively. Phylogenetic analysis of ompA and gltA genes revealed the presence of three pathogenic SFG rickettsiae: Candidatus R. tarasevichiae, R. aeschlimannii and R. raoultii in ticks collected from bitten humans. In addition, Candidatus R. barbariae was detected in six Rhipicephalus turanicus ticks for the first time in Kazakhstan. To determine the seroprevalence of C. burnetii infection, we performed a serological analysis of samples collected from 656 domestic ruminants (cattle, sheep, and goats) in the region. Overall, 23.5% (154/656) of the animals tested were positive for IgG against C. burnetii. Seroprevalence at the herd level was 54% (28/52). Goats (43%; 12/28; odds ratio (OD) = 28.9, p < 0.05) and sheep (31.9%; 137/430; OD = 18.1, p < 0.05) had higher seroprevalence than cattle (2.5%; 5/198). Among the risk factors considered in this study, age (p = 0.003) and the oblast in which the animals were sampled (p = 0.049) were statistically associated with seropostivity for Q fever in sheep, according to the results of multivariate logistic regression analysis. Seroprevalence ranged from 0% to 55.5% in animals in different districts of the southern region of Kazakhstan. Active C. burnetii bacteremia was detected in four of 154 (2.6%) seropositive animals. The data obtained provide strong evidence of the presence of pathogenic rickettsiae and C. burnetii in the southern region of Kazakhstan and emphasize the need to improve epidemiological surveillance in the region.
Fire blight disease of apples continues its worldwide spread, having reached Kazakhstan in 2010. It is a great threat to the wild apple forests of Malus sieversii. The introduction of fire blight is already showing a considerable impact on cultural apple growing and demands radical efforts for conservation of the wild apple forests. A number of studies have been conducted to examine the presence of fire blight distribution within apples in agricultural areas; however, there has been no large-scale monitoring of wild apple tree populations. Here we present the results of three years of monitoring wild apples in three protected areas of Kazakhstan, looking for the presence of fire blight (Erwinia amylovora). A visual inspection showed no signs of fire blight on the trees of M. sieversii in three consecutive years. These findings were confirmed by lateral flow immunochromatography, and conventional and real-time polymerase chain reaction tests of the asymptomatic samples. The findings of this study will be used to produce recommendations for state authorities to prevent fire blight in wild apple forests of Kazakhstan.
Fire blight, caused by Erwinia amylovora , poses a serious threat to both cultivated and wild apple populations in Kazakhstan, including Malus sieversii , a key progenitor of the domesticated apple. In 2024, systematic monitoring was carried out in the Almaty and Turkestan regions under meteorological conditions favorable for fire blight development. A total of 131 samples was collected from symptomatic and asymptomatic trees of apple, pear, quince, hawthorn, walnut, and wild M. sieversii . Most samples (77.9%) originated from cultivated apple trees, while 9.2% were collected from wild populations, including from the Sayram-Ugam State National Natural Park, where wild and cultivated apple trees coexist. Molecular screening of plant wash samples confirmed E. amylovora in 31 cases, none of which were collected from M. sieversii trees. Pure bacterial cultures were successfully isolated from 24 samples, while for seven additional qPCR-positive samples pure cultures could not be obtained. Diagnostic confirmation relied on real-time PCR targeting the chromosomal amsC gene and immunochromatographic assays. Genotyping was successfully conducted for 26 positive samples, including 24 isolates and two samples of nucleic acids extracted directly from plant washes. Our results revealed the coexistence of two archetypal E. amylovora CRISPR genotypes in Kazakhstan. Genotype A, previously reported lineage in the Almaty region, was predominantly identified in the southeast, while genotype D, in contrast, was detected as major genotype in southern Kazakhstan. The simultaneous detection of these genotypes suggests a diversification of the E. amylovora population after its first introduction in the country, that could be originating from adaptation to local conditions or from a novel introduction event. These findings underscore the importance of continued molecular surveillance to inform quarantine measures and guide strategies for the conservation of wild apple genetic resources.