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137 result(s) for "Babesia microti - genetics"
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Screening for Babesia microti in the U.S. Blood Supply
Babesia microti is a leading cause of blood transfusion–associated infection in the United States. Investigators from the American Red Cross present data establishing a potential donor-screening test approach to decrease this risk. Babesia microti is an intraerythrocytic parasite that causes babesiosis. 1 The severity of babesia infection ranges from asymptomatic, most commonly in healthy persons, to fatal, most frequently in persons older than 50 years of age, those who have no spleen (or no functional spleen), and those who are immunocompromised. 2 In the United States, B. microti is transmitted to humans primarily by means of the bite of Ixodes scapularis (also called the deer tick). 3 Babesiosis became a nationally notifiable disease (as defined by the Centers for Disease Control and Prevention [CDC]) in 2011 and was reportable (i.e., reportable to the state, which . . .
Prevalence and molecular detection of Babesia microti in rodents in Southeastern Shanxi, China
Babesia is a tick-transmitted parasite that infects wild and domestic animals, causes babesiosis in humans, and is an increasing public health concern. Here, we investigated the prevalence and molecular characteristics of Babesia infections in the rodents in Southeastern Shanxi, China. Small rodents were captured, and the liver and spleen tissues were used for Babesia detection using traditional PCR and sequencing of the partial 18S rRNA gene. The analysis revealed that 27 of 252 small rodents were positive for Babesia , with an infection rate of 10.71%. The infection rates in different sexes and rodent tissues were not statistically different, but those in different rodent species, habitats, and sampling sites were statistically different. The highest risk of Babesia infection was observed in Niviventer confucianus captured from the forests in Huguan County. Forty-three sequences from 27 small rodents positive for Babesia infection were identified as Babesia microti , including 42 sequences from 26 N . confucianus , and one sequence from Apodemus agrarius . Phylogenetic analysis showed that all sequences were clustered together and had the closest genetic relationship with Babesia microti strains isolated from Rattus losea and N . confucianus in China, and belonged to the Kobe-type, which is pathogenic to humans. Compared to other Kobe-type strains based on the nearly complete 18S rRNA gene, the sequences obtained in this study showed the difference by 1–3 bp. Overall, a high prevalence of Babesia microti infection was observed in small rodents in Southeastern Shanxi, China, which could benefit us to take the implementation of relevant prevention and control measures in this area.
Prevalence and genetic diversity of Babesia microti in rodents from central and southern Shanxi, China
Background Babesiosis, a globally emerging tick-borne zoonosis caused by intraerythrocytic protozoan Babesia species, poses a significant threat to both animal and human health. This study investigated the prevalence and genetic diversity of Babesia sp. in small rodents in central and southern Shanxi Province, China. Methods Rodents were captured from central and southern Shanxi Province, China. Liver, spleen, and kidney specimens were collected and screened for Babesia sp. based on 18S rRNA gene amplification and sequencing. For genetic and evolutionary analysis of Babesia sp. sequences based on the 18S rRNA gene, a phylogenetic tree was created using MEGA 11. Genetic diversity was analyzed using DNASP 6.12.03, and haplotype networks in Babesia microti from different regions and hosts were constructed using PopART software. Results Three hundred and one rodents were captured; PCR screening revealed a 6.64% (20/301) prevalence of Babesia sp. infection, detected in Niviventer confucianus (16.87%, 14/83) and Apodemus agrarius (3.85%, 6/156). Detection rates did not differ significantly according to sex, tissue, or habitat type. Geographically, central Shanxi exhibited significantly higher detection rates than southern Shanxi (9.74% vs. 0.94%, χ 2  = 8.573, P  = 0.003). Phylogenetic analysis of the partial 18S rRNA gene (1083 bp) confirmed that all sequences obtained in this study were the B. microti Kobe type, closely related to sequences from southeastern Shanxi obtained in our previous study (with 99.7–100% identity), with the ability to infect humans. Genetic diversity analysis of 65 B. microti sequences from China (20 sequences from the present study and 45 from GenBank) identified 21 haplotypes with host- and geography-specific patterns. Host-specific analysis of  18S rRNA  gene polymorphisms revealed higher genetic diversity in tick-derived sequences than in rodent- or human-derived sequences. Haplotype network analysis suggested that Shanxi sequences (Hap-1, Hap-10, and Hap-11) exhibited close genetic proximity of 1–3 nucleotide substitutions with rodent-derived sequences from Yunnan and Fujian provinces and human-derived sequences from Yunnan and Zhejiang provinces. Conclusions This study found a high prevalence and low genetic diversity of B. microti infection in wild rodents in central Shanxi, which could provide a basis for local corresponding prevention and control strategies. Graphical Abstract
Disruption of bacterial interactions and community assembly in Babesia-infected Haemaphysalis longicornis following antibiotic treatment
Background A previous study highlighted the role of antibiotic-induced dysbiosis in the tick microbiota, facilitating the transstadial transmission of Babesia microti from nymph to adult in Haemaphysalis longicornis . This study builds on previous findings by analyzing sequence data from an earlier study to investigate bacterial interactions that could be linked to enhanced transstadial transmission of Babesia in ticks. The study employed antibiotic-treated (AT) and control-treated (CT) Haemaphysalis longicornis ticks to investigate shifts in microbial community assembly. Network analysis techniques were utilized to assess bacterial interactions, comparing network centrality measures between AT and CT groups, alongside studying network robustness and connectivity loss. Additionally, functional profiling was conducted to evaluate metabolic diversity in response to antibiotic treatment. Results The analysis revealed notable changes in microbial community assembly in response to antibiotic treatment. Antibiotic-treated (AT) ticks displayed a greater number of connected nodes but fewer correlations compared to control-treated (CT) ticks, indicating a less interactive yet more connected microbial community. Network centrality measures such as degree, betweenness, closeness, and eigenvector centrality, differed significantly between AT and CT groups, suggesting alterations in local network dynamics due to antibiotic intervention. Coxiella and Acinetobacter exhibited disrupted connectivity and roles, with the former showing reduced interactions in AT group and the latter displaying a loss of connected nodes, emphasizing their crucial roles in microbial network stability. Robustness tests against node removal showed decreased stability in AT networks, particularly under directed attacks, confirming a susceptibility of the microbial community to disturbances. Functional profile analysis further indicated a higher diversity and richness in metabolic capabilities in the AT group, reflecting potential shifts in microbial metabolism as a consequence of antimicrobial treatment. Conclusions Our findings support that bacterial interaction traits boosting the transstadial transmission of Babesia could be associated with reduced colonization resistance. The disrupted microbial interactions and decreased network robustness in AT ticks suggest critical vulnerabilities that could be targeted for managing tick-borne diseases.
Metagenomic Nanopore Sequencing of Tickborne Pathogens, Mongolia
We performed nanopore-based metagenomic screening on 885 ticks collected from 6 locations in Mongolia and divided the results into 68 samples: 23 individual samples and 45 pools of 2-12 tick samples each. We detected bacterial and parasitic pathogens Anaplasma ovis, Babesia microti, Coxiella burnetii, Borrelia miyamotoi, Francisella tularensis subsp. holarctica and novicida, Spiroplasma ixodetis, Theileria equi, and Rickettsia spp., including R. raoultii, R. slovaca, and R. canadensis. We identified the viral pathogens Crimean-Congo hemorrhagic fever virus (2.9%), recently described Alongshan virus (ALSV) (2.9%), and Beiji nairovirus (5.8%). We assembled ALSV genomes, and maximum-likelihood analyses revealed clustering with viruses reported in humans and ticks from China. For ALSV, we identified surface glycoprotein markers associated with isolates from Asia viruses hosted by Ixodes persulcatus ticks. We also detected 20 virus species of unknown public health impact, including a near-complete Yanggou tick virus genome. Our findings demonstrate that nanopore sequencing can aid in detecting endemic and emerging tickborne pathogens.
Prevalence, genetic identity and vertical transmission of Babesia microti in three naturally infected species of vole, Microtus spp. (Cricetidae)
Background Vertical transmission is one of the transmission routes for Babesia microti , the causative agent of the zoonotic disease, babesiosis. Congenital Babesia invasions have been recorded in laboratory mice, dogs and humans. The aim of our study was to determine if vertical transmission of B. microti occurs in naturally-infected reservoir hosts of the genus Microtus . Methods We sampled 124 common voles, Microtus arvalis ; 76 root voles, M. oeconomus and 17 field voles, M. agrestis. In total, 113 embryos were isolated from 20 pregnant females. Another 11 pregnant females were kept in the animal house at the field station in Urwitałt until they had given birth and weaned their pups ( n  = 62). Blood smears and/or PCR targeting the 550 bp 18S rRNA gene fragment were used for the detection of B. microti . Selected PCR products, including isolates from females/dams and their embryos/pups, were sequenced. Results Positive PCR reactions were obtained for 41% (89/217) of the wild-caught voles. The highest prevalence of B. microti was recorded in M. arvalis (56/124; 45.2%), then in M. oeconomus (30/76; 39.5%) and the lowest in M. agrestis (3/17; 17.7%). Babesia microti DNA was detected in 61.4% (27/44) of pregnant females. Vertical transmission was confirmed in 81% (61/75) of the embryos recovered from Babesia -positive wild-caught pregnant females. The DNA of B. microti was detected in the hearts, lungs and livers of embryos from 98% of M. arvalis , 46% of M. oeconomus and 0% of M. agrestis embryos from Babesia -positive females. Of the pups born in captivity, 90% were born to Babesia -positive dams. Babesia microti DNA was detected in 70% (35/50) of M. arvalis and 83% (5/6) of M. oeconomus pups. Congenitally acquired infections had no impact on the survival of pups over a 3-week period post partum . Among 97 B. microti sequences, two genotypes were found. The IRU1 genotype (Jena-like) was dominant in wild-caught voles (49/53; 92%), pregnant females (9/11; 82%) and dams (3/5; 60%). The IRU2 genotype (Munich-like) was dominant among B. microti positive embryos (20/27; 74%) and pups (12/17; 71%). Conclusion A high rate of vertical transmission of the two main rodent genotypes of B. microti was confirmed in two species of naturally infected voles, M. arvalis and M. oeconomus .
Genome-wide diversity and gene expression profiling of Babesia microti isolates identify polymorphic genes that mediate host-pathogen interactions
Babesia microti , a tick-transmitted, intraerythrocytic protozoan parasite circulating mainly among small mammals, is the primary cause of human babesiosis. While most cases are transmitted by Ixodes ticks, the disease may also be transmitted through blood transfusion and perinatally. A comprehensive analysis of genome composition, genetic diversity, and gene expression profiling of seven B. microti isolates revealed that genetic variation in isolates from the Northeast United States is almost exclusively associated with genes encoding the surface proteome and secretome of the parasite. Furthermore, we found that polymorphism is restricted to a small number of genes, which are highly expressed during infection. In order to identify pathogen-encoded factors involved in host-parasite interactions, we screened a proteome array comprised of 174 B. microti proteins, including several predicted members of the parasite secretome. Using this immuno-proteomic approach we identified several novel antigens that trigger strong host immune responses during the onset of infection. The genomic and immunological data presented herein provide the first insights into the determinants of B. microti interaction with its mammalian hosts and their relevance for understanding the selective pressures acting on parasite evolution.
Imported Human Babesiosis, Singapore, 2018
In 2018, Babesia microti infection was diagnosed for a 37-year-old man in Singapore who acquired the infection in the United States. This case highlights the recent rise of tickborne infections in the United States and the risk for their spread, because of increasing global interconnectivity, to regions where they are not endemic.
Molecular detection of Babesia microti in dromedary camels in Egypt
Babesiamicroti (Apicomplexa: Piroplasmida) causes a medically important tick-borne zoonotic protozoan disease. Egyptian camels are susceptible to Babesia infection; however, just a few cases have been documented. This study aimed to identify Babesia species, specifically Babesia microti, and their genetic diversity in dromedary camels in Egypt and associated hard ticks. Blood and hard tick samples were taken from 133 infested dromedary camels slaughtered in Cairo and Giza abattoirs. The study was conducted from February to November 2021. The 18S rRNA gene was amplified by polymerase chain reaction (PCR) to identify Babesia species. Nested PCR targeting the β-tubulin gene was used to identify B. microti. The PCR results were confirmed by DNA sequencing. Phylogenetic analysis based on the ß-tubulin gene was used to detect and genotype B. microti. Three tick genera were identified in infested camels (Hyalomma, Rhipicephalus, and Amblyomma). Babesia species were detected in 3 out of 133 blood samples (2.3%), while Babesia spp. were not detected in hard ticks by using the 18S rRNA gene. B. microti was identified in 9 out of 133 blood samples (6.8%) and isolated from Rhipicephalus annulatus and Amblyomma cohaerens by the β-tubulin gene. The phylogenetic analysis of the β-tubulin gene revealed that USA-type B. microti was prevalent in Egyptian camels. The results of this study suggested that the Egyptian camels may be infected with Babesia spp. and the zoonotic B. microti strains, which pose a potential risk to public health.
Antigen Discovery, Bioinformatics and Biological Characterization of Novel Immunodominant Babesia microti Antigens
Babesia microti is an intraerythrocytic parasite and the primary causative agent of human babesiosis. It is transmitted by Ixodes ticks, transfusion of blood and blood products, organ donation, and perinatally. Despite its global public health impact, limited progress has been made to identify and characterize immunodominant B. microti antigens for diagnostic and vaccine use. Using genome-wide immunoscreening, we identified 56 B. microti antigens, including some previously uncharacterized antigens. Thirty of the most immunodominant B. microti antigens were expressed as recombinant proteins in E. coli . Among these, the combined use of two novel antigens and one previously described antigen provided 96% sensitivity and 100% specificity in identifying B. microti antibody containing sera in an ELISA. Using extensive computational sequence and bioinformatics analyses and cellular localization studies, we have clarified the domain architectures, potential biological functions, and evolutionary relationships of the most immunodominant B. microti antigens. Notably, we found that the BMN-family antigens are not monophyletic as currently annotated, but rather can be categorized into two evolutionary unrelated groups of BMN proteins respectively defined by two structurally distinct classes of extracellular domains. Our studies have enhanced the repertoire of immunodominant B. microti antigens, and assigned potential biological function to these antigens, which can be evaluated to develop novel assays and candidate vaccines.