• Parasites, Hosts and Diseases
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• v.60 no.3
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• pp.201-205
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• 2022

Babesia microti is one of the most common causative agents of babesiosis. A sensitive and rapid detection is necessary for screening potentially infected individuals. In this study, B. microti cytochrome c oxidase subunit I (cox1) was selected as the target gene, multiple primers were designed, and optimized by a recombinase-aided amplification (RAA) assay. The optimal primers and probe were labeled with fluorescein. The sensitivity of fluorescent RAA (fRAA) was evaluated using gradient diluents of the cox1 recombinant plasmid and genomic DNA extracted from whole blood of B. microti infected mice. The specificity of fRAA was assessed by other transfusion transmitted parasites. The analytical sensitivity of the fRAA assay was 10 copies of recombinant plasmid per reaction and 10 fg/µl B. microti genomic DNA. No cross-reaction with any other blood-transmitted parasites was observed. Our results demonstrated that the fRAA assay would be rapid, sensitive, and specific for the detection of B. microti.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.72-77
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• 2023

Human babesiosis is a tick-borne disease induced by the genus Babesia and has been significantly reported in the Republic of Korea. This report shows the cases of 2 patients with human babesiosis who traveled to the USA in 2019. The 2 patients experienced fever and had travel histories to babesiosis-endemic regions. The diagnoses of both cases were verified by the identification of Babesia-infected red blood cells on blood smears. One patient was found to be infected with Babesia microti using polymerase chain reaction (PCR) for 18S rRNA, which discovered the phylogenetic link to the B. microti strain endemic in the USA. The 2 patients recovered from fever with subsequent hemoparasite clearance. Babesiosis could be diagnosed in anyone with histories of travel to babesiosis-endemic countries and tick bites. Furthermore, Babesia-specific PCR is required for determining geno-and phenotypic characteristics.

• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.443-447
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• 2014

Babesiosis is an emerging tick-borne disease in humans worldwide; however, little is known about the frequency of infection or prevalence of this disease in other parts of the world, excluding North America. In this study, we aimed to investigate Babesia microti infection frequency in a human population in Mongolia. One hundred blood samples were collected from stock farmers living in Khutul city of Selenge province, Mongolia. The sera and DNA from blood samples were evaluated for the presence of B. microti infection by using indirect fluorescent antibody (IFA) tests and PCR. The positive detection rates obtained using the IFA tests and PCR assays were 7% and 3%, respectively. This study is the first to detect of B. microti infections based on antibody seroprevalence or PCR assays for the presence of B. microti DNA in a Mongolian population.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.53-63
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• 2024

The intracellular parasite Babesia microti is among the most significant species causing human babesiosis and is an emerging threat to human health worldwide. Unravelling the pathogenic molecular mechanisms of babesiosis is crucial in developing new diagnostic and preventive methods. This study assessed how priming with B. microti surface antigen 1 (BHSA 1) and seroreactive antigen 5-1-1 (BHSA 5-1-1) mediate protection against B. microti infection. The results showed that 500 ㎍/ml rBMSA1 and rBMSA5-1-1 partially inhibited the invasion of B. microti in vitro by 42.0±3.0%, and 48.0±2.1%, respectively. Blood smears revealed that peak infection at 7 days post-infection (dpi) was 19.6%, 24.7%, and 46.7% in the rBMSA1, rBmSA5-1-1, compared to the control groups (healthy mice infected with B. microti only), respectively. Routine blood tests showed higher white blood cell, red blood cell counts, and haemoglobin levels in the 2 groups (BMSA1 and BMSA5 5-1-1) than in the infection control group at 0-28 dpi. Moreover, the 2 groups had higher serum interferon-γ, tumor necrosis factor-α and Interleukin-17A levels, and lower IL-10 levels than the infection control group throughout the study. These 2 potential vaccine candidate proteins partially inhibit in vitro and in vivo B. microti infection and enhance host immunological response against B. microti infection.

• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.207-212
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• 2017

Infections of Toxoplasma gondii and Babesia microti are reported in many wild animals worldwide, but information on their incidence and molecular detection in Korean wild fields is limited. In this study, the prevalence of T. gondii and B. microti infection in blood samples of 5 animal species (37 Chinese water deer, 23 raccoon dogs, 6 roe deer, 1 wild boar, and 3 Eurasian badgers) was examined during 2008-2009 in Gangwon-do (Province), the Republic of Korea (=Korea) by using serological and molecular tests. The overall seropositivity of T. gondii was 8.6% (6/70); 10.8% in Chinese water deer, 4.3% in raccoon dogs, and 16.7% in roe deer. PCR revealed only 1 case of T. gondii infection in Chinese water deer, and phylogenic analysis showed that the positive isolate was practically identical to the highly pathogenetic strain type I. In B. microti PCR, the positive rate was 5.7% (4/70), including 2 Chinese water deer and 2 Eurasian badgers. Phylogenetic analysis results of 18S rRNA and the ${\beta}$-tubulin gene showed that all positive isolates were US-type B. microti. To our knowledge, this is the first report of B. microti detected in Chinese water deer and Eurasian badger from Korea. These results indicate a potentially high prevalence of T. gondii and B. microti in wild animals of Gangwon-do, Korea. Furthermore, Chinese water deer might act as a reservoir for parasite infections of domestic animals.

• Parasites, Hosts and Diseases
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• v.56 no.6
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• pp.609-613
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• 2018

Babesiosis, caused by Babesia microti and B. divergens, is transmitted by Ixodid ticks. Symptoms of babesiosis vary from a mild flu-like illness to acute, severe, and sometimes fatal and fulminant disease. In Korea, 7 imported babesiosis cases and 1 endemic case have been reported. We report 2 cases of severe babesiosis initially mistaken as malaria. The first patient was complicated by shock and splenic infarction, the other co-infected with Lyme disease. As the population traveling abroad increases every year, physicians should be aware of babesiosis which mimics malaria, co-infection with other diseases, and its complications.