scholarly journals THE ABUNDANCE OF BORRELIA INIXODID TICKS OF BAIKAL REGION

2021 ◽  
pp. 12-20
Author(s):  
O.V. Mel’nikova ◽  
◽  
Yu.N. Trushina ◽  
R.V. Adel’shin ◽  
N.V. Yakovchits ◽  
...  
Keyword(s):  
Infection Rate ◽  
Baikal Region ◽  
Ixodid Tick ◽  
Ixodid Ticks ◽  
Infection Rates ◽  
Survey Period ◽  
Taiga Tick ◽  
Irkutsk Region ◽  
Natural Foci ◽  
Activity Season

Ixodid ticks (n=3714) from natural foci of Baikal Region (Irkutsk Region and Republic of Buryatia) have been examined for pathogenic Borrelia DNA during 2013-2010. On average 40.9 % of the samples were positive for Borrelia markers during the survey period; the range of variantion was – 32–55 %. The increasing of infection rate in ticks is traced in multi-year trends. During the ticks’ activity season, maximal infection rates have been noted at the end of the season (60 %), minimal – at the very beginning of the season (28,6 %) and on the peak of vectors’ abundance (36-39 %). The significant geographical, species and age differences have been detected in Borrelia infection rate of Ixodid ticks. Borrelia DNA have been detected considerably more often in taiga tick (the main vector of Ixodid tick borrelioses in Siberia) and in its nymphs more often, than in adult ticks. There was no difference in the infection rate of male and female ticks, and also between ticks, collected from the vegetation and from human and animals. The ratio og genotyped Borrelia species had been as follows: 64.2 % – B. garinii, 21,7 % – B. afzelii, 14,2 % – B. miyamotoi. Key words: Ixodid ticks, pathogenic Borrelia, PCR, genotyping, Baikal Region.

О находках Rhipicephalus (Boophilus) annulatus (Say, 1821) (Acari, Ixodidae) на западе Атырауской области

2021 ◽  
Vol 3 ◽  
pp. 36-45
Author(s):  
Z.Z. Sayakova ◽  
A.A. Bashmakova ◽  
I.G. Kozulina ◽  
I.B. Mellatova
Keyword(s):  
Rapid Development ◽  
Hydrological Regime ◽  
Ixodid Tick ◽  
Climatic Conditions ◽  
Ixodid Ticks ◽  
Economic Activities ◽  
Blood Sucking ◽  
Natural Foci ◽  
Ixodes Ticks ◽  
Rickettsial Diseases

Blood-sucking ticks are vectors of protozoal, bacterial, viral and rickettsial diseases. The study of ixodes ticks: fauna, ecology, biology is of great importance not only for epidemiology but is also of scientific interest. Changes in natural and climatic conditions, hydrological regime, rapid development of human economic activities lead to the changes in the fauna of invertebrates including ixodid ticks. As they invade new territories ticks may expand their habitats for these dangerous for animals and humans infections. That is why the study of tick fauna, changes in species diversity of ticks and monitoring of their abundance is so important for monitoring of natural foci. The emergence of a new species of ixodid tick Rhipicephalus annulatus, in western Kazakhstan, which began to be registered from 2019 in Kurmangazy district of Atyrau region, bordering the Astrakhan region of the Russian Federation and its re-finding in 2020 is a very important fact to assess the epidemiological danger for humans and animals in this territory.

scholarly journals Gene-specific features of tick-borne borreliosis in Russia

2021 ◽  
Vol 6 (3) ◽  
pp. 94-99
Author(s):  
S. A. Rudakova ◽  
N. V. Rudakov ◽  
S. V. Shtrek ◽  
O. E. Teslova ◽  
N. E. Kaneshova
Keyword(s):  
Western Siberia ◽  
Intergenic Spacer ◽  
Ixodid Tick ◽  
Ixodid Ticks ◽  
Specific Composition ◽  
Novosibirsk Region ◽  
Natural Foci ◽  
The Russian Federation ◽  
Polymerase Chain

Aim. To study the gene-specific composition of Borrelia spp. in ixodid ticks inhabiting the foci of ixodid tick-borne borreliosis (ITBB) in the south of Western Siberia.Materials and Methods. The gene-specific composition of Borrelia spp. in ixodid ticks was determined by inoculation on a BSK-H nutrient medium, real-time polymerase chain reaction, and sequencing (1148 specimens of ixodid ticks collected from vegetation and 2183 specimens withdrawn from humans).Results. Infection of ticks with borrelia ranged from 22.4% in the Altai Republic to 56.9% in the Novosibirsk Region. There were no significant differences in the levels of Borrelia infection between two major ixodides, I. persulcatus and I. pavlovskiy (average infection levels 40.0% and 38.8%, respectively). At least five gene species of pathogenic Borrelia (B. garinii, B. afzelii, B. bavariensis, B. miyamotoi, and B. spielmanii) have been identified. The GenBank database contains 45 nucleotide sequences of the intergenic spacer rrf (5S)-rrl (23S). Prevalence of gene species B. garinii and B. afzelii in different ticks (I. persulcatus and I. pavlovskiy) did not differ significantly, yet B. garinii was found to be more frequent than B. afzelii. The frequency of infection of I. persulcatus ticks with B. miyamotoi was significantly (3.5-fold) as compared to those of B. garinii and B. afzelii. In D. reticulatus ticks, the DNA of B. spielmanii and B. miyamotoi was detected.Conclusion. It is necessary to continue studies to assess the role of the meadow ticks D. reticulatus in the circulation of different Borrelia spp. in various natural foci within the Russian Federation.

Analysis of laboratory methods for monitoring of tick-borne encephalitis natural foci

2021 ◽  
pp. 26-32
Author(s):  
Olga Vitalievna Melnikova ◽  
Yuliya Nikolaevna Trushina ◽  
Renat Viktorovich Adelshin ◽  
Nikolay Vasilievich Yakovchits ◽  
Evgeniy Ivanovich Andaev ◽  
...  
Keyword(s):  
Baikal Region ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Isolation And Identification ◽  
Tick Borne Encephalitis ◽  
Natural Foci ◽  
Group 2 ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection ◽  
Group 1

Introduction. Ixodid ticks simultaneously are hosts and vectors of tick-borne encephalitis virus (TBEV), presenting a high risk to humans. Monitoring of the vectors part of TBEV population is usually held by means of express analysis methods (ELISA and PCR), but only isolation and identification of infectious virus is reliable evidence of TBEV circulation in the natural foci. Objectives — to demonstrate the TBEV infection rates of Ixodid ticks from natural TBE foci of Baikal Region, based on comprehensive study, including ELISA, PCR and isolation of virus on laboratory mice (LM) model. Methods. Questing adult Ixodid ticks (n = 20 111, mainly — Ixodes persulcatus Schulze, 1930), were collected in TBE natural foci of Baikal Region during 2013–2020. The suspension on saline solution was prepared from the each tick and analyzed by ELISA first. The samples with positive ELISA results were verified in PCR-RT. Furthermore, randomly selected samples with negative ELISA results were analyzed by PCR. Suspensions with positive ELISA and PCR results have been inoculated to suckling LM intracerebrally. Results. The samples with positive PCR results have been divided into two groups: group 1 — all suspensions with positive ELISA results, group 2 — randomly selected samples with negative ELISA results. The positive PCR results in group 1 made up 70.5 % with average Ct rate 24.9. The positive PCR results in group 2 have been obtained in 2.2 % of cases with average Ct rate 30.7. The isolation on LM model was more successful in group 1 (25.8 vs 13.0 %; р < 0.01; df = 69). Conclusion. ELISA is more useful for study of large amounts of ticks during monitoring of natural TBE foci, offering insight into the epidemically important vectors rate. To get the more full assessment of the ticks’ infection rate one must use ELISA and PCR simultaneously, and sum the results into general rate. For high strains isolation results the LM should be inoculated with the suspensions, which had shown positive both ELISA and PCR results.

scholarly journals ABOUT POSSIBLITY OF TICK-BORNE INFECTIONS NATURAL FOCI FORMATION OUTSIDE NORTHEN BORDERS OF TAIGA TICK HABITATS

2017 ◽  
pp. 50-56
Author(s):  
T.F. Stepanova ◽  
E.A. Bragina ◽  
A.A. Katin ◽  
L.A. Nechеpurenko ◽  
V.V. Kharkov ◽  
...  
Keyword(s):  
Causative Agent ◽  
Preliminary Data ◽  
Ixodid Ticks ◽  
Environmental Objects ◽  
Taiga Tick ◽  
Tick Borne Encephalitis ◽  
Natural Foci ◽  
Northern Territories

It has been noticed since the very first steps in research on tick-borne encephalitis that not all the patients were exposed to ticks, even in the territory of their habitat. Moreover, the causative agent of tick-borne encephalitis is known to be isolated from environmental objects, there also has been found a specific immune layer among the population of northern territories that are free from ixodid ticks. According to preliminary data, similar peculiarities are true for newly discovered tick-borne infections (НМЕ, HGA). There is an opinion that the reason for that lies in the possibility of the foci of these infections to exist outside habitats of ixodid ticks owing to their mosquitoes and nidicolous stage in the presence of mole mites and flees.

scholarly journals Moleculare detection of Bartonella in ixodid ticks and plateau pika (Ochotona curzoniae) in Shiqu county, China

2019 ◽  
Author(s):  
Tiancai Tang ◽  
Chengcheng Liu ◽  
Aiguo Yang ◽  
Dongbo Yuan ◽  
Li Guo ◽  
...  
Keyword(s):  
Infection Rate ◽  
Ixodid Ticks ◽  
Infection Rates ◽  
Bartonella Species ◽  
Plateau Pika ◽  
Total Prevalence ◽  
Wide Range ◽  
Significant Difference ◽  
Study Sites ◽  
Dermacentor Everestianus

Abstract Background Bartonella bacteria have been associated with an increasingly wide range of human and animal diseases and were also recognized to be globally dispersed as emergent pathogens. Ticks and small rodents are known vectors of human and animal bartonellosis and play important roles in maintenance and circulation of bartonellae in nature. In China, Shiqu county is located on the eastern Qinghai-Tibetan plateau and about 26 thousands square kilometers with an average altitude of above 4,200 meters and vast area of pastureland. In present study, the occurrence of Bartonella spp. in ticks and plateau pika was firstly investigated in Shiqu county.Results A total of 818 ticks ( Dermacentor everestianus , 79.0%, 646/818; Haemphysalis qinghaiensis , 21.0%, 172/818), were collected in 4 villages in Shiqu county. Only Bartonella melophagi was detected in tick samples with a total prevalence of 30.1% (246/818). Significant difference was observed (P<0.05) between D.everestianus (17.0%) and H.qinghaiensis (79.1%).The infection rates of Bartonella spp. in ticks from Arizha, Maga, Derongma and Changxgma villages were 4.8%, 76.8%, 12.5% and 18.0%, respectively. Compared with other villages, the infection rate of Bartonella spp. in Maga was higher (P<0.01). As for plateau pika, total infection rate of Bartonella spp was 24.1%, with 20.8% (15/72), 30.9% (25/81), 13.8% (9/65) and 29.4% (20/68) in Arizha, Maga, Derongma and Changxgma, respectively. Totally, B. queenslandensis , B.grahamii and two unvalidated Bartonella species were detected. No significant difference in infection rates was observed (P>0.05) between theses study sites. Conclusion At present, only D.everestianus and H.qinghaiensis were found in Shiqu county with high infection of Bartonella spp. in theses ticks and plateau pika. The threats to public health by these Bartonella species should be monitored.

scholarly journals Molecular detection of Bartonella in ixodid ticks and plateau pika (Ochotona curzoniae) in Shiqu County, China

2020 ◽  
Author(s):  
Lili Hao ◽  
Dongbo Yuan ◽  
Li Guo ◽  
Wei Hou ◽  
Xi Mo ◽  
...  
Keyword(s):  
Infection Rate ◽  
Ixodid Ticks ◽  
Infection Rates ◽  
Emerging Pathogens ◽  
Plateau Pika ◽  
Total Prevalence ◽  
Wide Range ◽  
Significant Difference ◽  
Study Sites ◽  
Dermacentor Everestianus

Abstract Background: Bartonella bacteria have been associated with an increasingly wide range of human and animal diseases. They were identified as being globally dispersed as emerging pathogens. Ticks and small rodents are known as hosts of human and animal bartonellosis. They play a significant role in the preservation and circulation of bartonellae in nature. This study investigates the occurrence of Bartonella spp. in ticks and plateau pika in Shiqu county which is located on the Eastern Qinghai-Tibetan plateau in China. Shiqu county is spread over approximately 26,000 square kilometers, with an average altitude of above 4,200 meters and vast area of pastureland.Results: A total of 818 ticks (Dermacentor everestianus, 79.0%, 646/818; Haemphysalis qinghaiensis, 21.0%, 172/818) were collected in 4 villages of Shiqu county. Only Bartonella melophagi was detected in tick samples with a total prevalence of 30.1% (246/818). The infection rates of Bartonella spp. in ticks from Arizha, Maga, Derongma, and Changxgma were 4.8%, 76.8%, 12.5%, and 18.0% respectively. The infection rate of Bartonella spp. in Maga was higher (p< 0.01) than in other villages. Regarding plateau pika, the total infection rate of Bartonella spp was 24.1%, with 20.8% (15/72), 30.9% (25/81), 13.8% (9/65), and 29.4% (20/68) in Arizha, Maga, Derongma, and Changxgma respectively. Finally, B. queenslandensis, B. grahamii, and two unvalidated Bartonella species were detected. No significant difference was observed (p> 0.05) in the infection rates between these study sites.Conclusion: To date, only D. everestianus and H. qinghaiensis were found in Shiqu county with high infection of Bartonella spp. in the ticks and plateau pika. The threats of Bartonella species to the public health should be closely monitored.

scholarly journals Spiroplasma Infection among Ixodid Ticks Exhibits Species Dependence and Suggests a Vertical Pattern of Transmission

2021 ◽  
Vol 9 (2) ◽  
pp. 333
Author(s):  
Shohei Ogata ◽  
Wessam Mohamed Ahmed Mohamed ◽  
Kodai Kusakisako ◽  
May June Thu ◽  
Yongjin Qiu ◽  
...  
Keyword(s):  
16S Rdna ◽  
Tick Species ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Horizontal Transmission ◽  
Ixodid Ticks ◽  
Infection Rates ◽  
Transmission Cycle ◽  
Frequent Event ◽  
Pcr Targeting

Members of the genus Spiroplasma are Gram-positive bacteria without cell walls. Some Spiroplasma species can cause disease in arthropods such as bees, whereas others provide their host with resistance to pathogens. Ticks also harbour Spiroplasma, but their role has not been elucidated yet. Here, the infection status and genetic diversity of Spiroplasma in ticks were investigated using samples collected from different geographic regions in Japan. A total of 712 ticks were tested for Spiroplasma infection by PCR targeting 16S rDNA, and Spiroplasma species were genetically characterized based on 16S rDNA, ITS, dnaA, and rpoB gene sequences. A total of 109 samples originating from eight tick species were positive for Spiroplasma infection, with infection rates ranging from 0% to 84% depending on the species. A linear mixed model indicated that tick species was the primary factor associated with Spiroplasma infection. Moreover, certain Spiroplasma alleles that are highly adapted to specific tick species may explain the high infection rates in Ixodes ovatus and Haemaphysalis kitaokai. A comparison of the alleles obtained suggests that horizontal transmission between tick species may not be a frequent event. These findings provide clues to understand the transmission cycle of Spiroplasma species in wild tick populations and their roles in host ticks.

scholarly journals Toxoplasma gondii in Sheep and Goats from Central Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mojtaba Bahreh ◽  
Bahador Hajimohammadi ◽  
Gilda Eslami
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Extraction ◽  
Infection Rate ◽  
Nested Pcr ◽  
Prevention Programs ◽  
Central Iran ◽  
Infection Rates ◽  
Sheep And Goats ◽  
One Year ◽  
Undercooked Meat

Abstract Objective Toxoplasmosis, caused by Toxoplasma gondii, infects humans by consuming infected raw or undercooked meat and foods harboring mature oocysts. In this study, we assessed the prevalence of T. gondii in sheep and goats coming from central Iran. After completing the questionnaire, about one gram of liver or diaphragm tissue was taken as a sample from 90 sheep and 90 goats slaughtered in Yazd Province and stored at – 20 ºC. DNA extraction was done, and then T. gondii was detected using nested PCR. Results This study indicated that the prevalence of T. gondii in all slaughtered animals was 11.6% (21 of 180), including 14.4% (13/90) in sheep and 8.8% (8/90) in goats. The infection rates in liver and diaphragm samples were 12.2% (11/90) and 11.1% (10/90), respectively (p = 0.8163). The infection rate in animals older than one was 16.3% (15/92), and it was 6.8% (6/88) in animals under one year of age. Therefore, no significant differences were found (p = 0.475). Infection rates were 19.5% (18/92) in males and 3.4% (3/88) in females (p = 0.0007). In conclusion, the infection rates of toxoplasmosis in livestock in this area are almost high, and therefore, it is necessary to design appropriate prevention programs to control the disease.

scholarly journals The Effect of Vaccination Rates on the Infection of COVID-19 under the Vaccination Rate below the Herd Immunity Threshold

2021 ◽  
Vol 18 (14) ◽  
pp. 7491
Author(s):  
Yi-Tui Chen
Keyword(s):  
Infection Rate ◽  
Herd Immunity ◽  
The United States ◽  
Vaccination Rate ◽  
Infection Rates ◽  
Vaccination Rates ◽  
The United Kingdom ◽  
The World ◽  
Almost All ◽  
The Impact

Although vaccination is carried out worldwide, the vaccination rate varies greatly. As of 24 May 2021, in some countries, the proportion of the population fully vaccinated against COVID-19 has exceeded 50%, but in many countries, this proportion is still very low, less than 1%. This article aims to explore the impact of vaccination on the spread of the COVID-19 pandemic. As the herd immunity of almost all countries in the world has not been reached, several countries were selected as sample cases by employing the following criteria: more than 60 vaccine doses per 100 people and a population of more than one million people. In the end, a total of eight countries/regions were selected, including Israel, the UAE, Chile, the United Kingdom, the United States, Hungary, and Qatar. The results find that vaccination has a major impact on reducing infection rates in all countries. However, the infection rate after vaccination showed two trends. One is an inverted U-shaped trend, and the other is an L-shaped trend. For those countries with an inverted U-shaped trend, the infection rate begins to decline when the vaccination rate reaches 1.46–50.91 doses per 100 people.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

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