Inhibitory effects of 19 antiprotozoal drugs and antibiotics on Babesia microti infection in BALB/c mice

Yao, Jincao; Zhang, Haobing; Liu, Congshan; Yi, Tao; Yin, Meng

doi:10.3855/jidc.5500

Cited by 13 publications

(20 citation statements)

References 25 publications

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“…Therefore, the dosage was gradually lowered to 25 mg/kg. The result showed that, despite its guanidino structure, chloroguanide hydrochloride could not inhibit B. microti, which is concordant with the results of our previous study [15].…”

Section: Drug-suppressive Testsupporting

confidence: 91%

“…Six healthy female BALB/c mice, aged 6-8 weeks, were inoculated with anticoagulated blood (200 μL for each) from six infected mice in each group 28 days post-infection (dpi), as described in a previous study [14,15]. Thin blood smears were prepared on microscope slides from 7 dpi to 30 dpi, stained with Giemsa stain, and observed under the microscope, as described in Method 2, for parasites.…”

Section: Subpassage Testingmentioning

confidence: 99%

“…The combination of atovaquone and azithromycin is most commonly used for the treatment of patients with B. microti infection and was used as a reference to study the e cacy of ROBH. Mice were treated with the drug daily for 10 days from 10 dpi and blood was inspected 10,13,15,18,21,24,28,31, and 56 dpi. All inoculated mice were successfully infected with B. microti.…”

Section: Drug-therapeutic Testmentioning

confidence: 99%

“…This method has high accuracy but a long experimental period, large number of test animals, and high requirements for experimenters. Yao conducted preliminary screening experiments on 19 drugs (antibiotics and antiprotozoal drugs) based on this method in BALB/c mice and demonstrated that robenidine hydrochloride (ROBH), a drug used for the prevention of coccidiosis in chickens, has the best e cacy on B. microti [15].…”

Section: Introductionmentioning

confidence: 99%

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Establishment and Optimisation of Anti-Babesia microti Drug Efficacy Evaluation Method

Yin¹,

Zhang²,

Yi³

et al. 2020

Preprint

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BackgroundBabesiosis, an infectious zoonotic parasitic disease that occurs globally, is most commonly caused by Babesia microti. For a severe infection, a combination of exchange transfusion and support-therapy is used and, for a mild infection, single antibiotics, or a combination of antibiotics and antiprotozoal drugs, are used for 7–10 days for the treatment of babesiosis; however, as these treatments have problems, a new therapy is needed. Although aetiological and molecular biology methods are often used in drug screening, these methods have disadvantages and there is no standard anti-B. microti drug screening method.MethodThis study was consisted of basal test, drug-suppressive test and drug-therapeutic test. BALB/c mice were used as the animal model and robenidine hydrochloride (ROBH) was used as a positive drug. By modifying Peter’s 4-day suppression method, immunosuppressive and subpassage tests were conducted, in combination with microscopy and real-time fluorescent quantitative PCR (qPCR), the current anti-B. microti drug screening method was optimised. SPSS was used for data analysis.Result1) In the basal test, there were significant differences in the erythrocyte infection rate (EIR) and relative value of the target gene (P = 0.011 and 0.012, respectively) among days. The blood of infected mice 28, 35, and 37 days post-infection (dpi) could infect healthy second-generation mice, even if no parasites could be observed under a light microscope. Resurgence occurred when the immunity of an infected mouse decreased to a certain extent after using an immunosuppressant.2) In the drug-suppressive test, no B. microti was observed under the light microscope in any ROBH group after drug administration. Significant differences were observed in the EIR and relative value of the target gene (both P < 0.001) between the control group and ROBH groups. No B. microti was observed after the administration of an immunosuppressant or in second-generation mice in ROBH-treated groups; however, B. microti was observed in control and proguanil hydrochloride-treated groups.3) In the drug-therapeutic test, there were significant differences in the EIR and relative value of the target gene between the 100 mg/kg ROBH groups and the control group (P = 0.049 and < 0.001, respectively) but not between ROBH groups and atovaquone-azithromycin group (P = 0.587 and 0.418, respectively). None of the second-generation mice in any drug-treated group were infected, whereas all the second-generation mice in the control group were infected; parasites could be observed in the control group from the 2nd day after the administration of an immunosuppressant, several parasites were observed in the atovaquone-azithromycin group from the 10th day after the administration of an immunosuppressant, and no parasites were observed in ROBH groups. ConclusionROBH can be used as a positive drug in anti-B. microti drug screening trials. qPCR results can be used as a judgment standard in preliminary screening tests and the combination of immunosuppressive and subpassage experiments can be used to validate drug efficacy.

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Section: Drug-suppressive Testsupporting

confidence: 91%

Section: Subpassage Testingmentioning

confidence: 99%

Section: Drug-therapeutic Testmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Establishment and Optimisation of Anti-Babesia microti Drug Efficacy Evaluation Method

Yin¹,

Zhang²,

Yi³

et al. 2020

Preprint

Self Cite

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“…Especially for genetic manipulation study, the common drug selection systems used for Babesia parasites, such as human dihydrofolate reductase (hDHFR)/WR99210 and blasticidin-S deaminase (BSD)/bsd selection systems, cannot be used for B. microti [28]. Additionally, B. microti is not sensitive to pyrimethamine, which is the only drug for rodent malaria parasites selection in vivo [29,30]. Overall, stable transfection cannot be fully assessed based on the present study due to challenges such as a lack of a continuous in vitro culture system and unclear selection markers.…”

Section: Discussionmentioning

confidence: 99%

Transient Transfection of the Zoonotic Parasite Babesia microti

Liu

Rizk

et al. 2020

Pathogens

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The development of genetic manipulation techniques has been reported in many protozoan parasites over the past few years. However, these techniques have not been established for Babesia microti. Here, we report the first successful transient transfection of B. microti. The plasmids containing the firefly luciferase reporter gene were transfected into B. microti by an AMAXA 4D Nucleofection system. Twenty-four-hour synchronization, the 5 -actin promoter, program FA100, and 50 µg of plasmid DNA constituted the best conditions for the transient transfection of B. microti. This finding is the first step towards a stable transfection method for B. microti, which may contribute to a better understanding of the biology of the parasite.

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