Babesia Microti Infection Research Articles

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.

Unrevealing the therapeutic potential of artesunate against emerging zoonotic Babesia microti infection in the murine model.

Babesiosis, a zoonotic blood protozoal disease, threatens humans and animals and is difficult to treat due to growing antimicrobial resistance. The study aimed to investigate the therapeutic efficacy of artesunate (AS), a well-known derivative of artemisinin, against Babesia microti (B. microti) using a murine infection model. Male BALB/c mice (6 weeks old; 15 per group) were chosen and randomly divided into 1) the control group, 2) the B. microti group, and 3) the B. microti + artesunate treatment groups. AS treatment at 2 mg/kg, 4 mg/kg, and 8 mg/kg of body weight significantly (p < 0.05) reduced the B. microti load in blood smears in a dose-dependent manner. Additionally, AS treatment mitigated the decrease in body weight and restored the normal state of the liver and spleen viscera index compared to the B. microti-infected group after 28 days. Hematological analysis revealed significant increases in RBC, WBC, and PLT counts post-AS treatment compared to the B. microti-infected group. Furthermore, AS administration resulted in significant reductions in total protein, bilirubin, ALT, AST, and ALP levels, along with reduced liver and spleen inflammation and lesions as observed through histopathological analysis. AS also elicited dose-dependent changes in mRNA and protein expression levels of apoptotic, proinflammatory, and anti-inflammatory cytokines in the liver compared to the control and B. microti-infected groups. Immunolabeling revealed decreased expression of apoptotic and inflammation-related proteins in AS-treated hepatic cytoplasm compared to the B. microti-infected group. AS also in dose-dependent manner decreased apoptotic protein and increased Bcl-2. Overall, these findings underscore the potential of AS as an anti-parasitic candidate in combating B. microti pathogenesis in an in vivo infection model, suggesting its promise for clinical trials as a treatment for babesiosis.

The protective effects of BMSA1 and BMSA5-1-1 proteins against Babesia microti infection.

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 µg/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.

Detection of US and Kobe‐type Babesia microti in ticks collected from small mammals of the Republic of Korea

AbstractHuman babesiosis is an emerging tick‐borne zoonotic disease prevalent in large parts of the world. This study aimed to examine the status of Babesia microti infection in ticks collected from small mammals captured during the nationwide survey of the Republic of Korea (ROK), 2017. Ixodid ticks from small mammals of three species, Apodemus agrarius, Crocidura lasiura, and Tscherskia triton, were used for the molecular detection of B. microti. PCR analyses amplifying 18S ribosomal RNA (rRNA) of the genus Babesia showed 8.4% of the ticks to be positive. Nucleotide sequencing of the PCR products revealed two different genotypes of B. microti, the US and Kobe‐type. The US‐types of B. microti were detected in ticks from small mammals of almost all study sites, whereas detections of Kobe‐types were restricted to ticks from southern part of ROK. Phylogenetic analysis also indicated that each of the two types of B. microti clustered into two distinct clades. This is the first report on the presence of the US and Kobe‐type B. microti in ticks collected from small mammals trapped on a national scale in ROK.

Histopathological Aspects of the Influence of Babesia microti on the Placentas of Infected Female Rats.

Babesiosis is perceived mainly an animal disease; however, awareness that Babesia spp. parasites that can cause diseases in humans is increasing significantly. Babesiosis is spread by the bite of an infected tick (Ixodes spp.), but it can also be transmitted by transfusion of infected blood and from an infected mother to her child during pregnancy or childbirth. The parasites multiply in the bloodstream and destroy red blood cells. This study aimed to assess the influence of Babesia microti on the histological structure of the placenta. Histopathological material collected from pregnant rats infected with Babesia microti was used in the experiment. Microscopic images of the placentas were assessed by Mallory staining and by using methylene blue-stained semi-thin sections. In addition, FISH was used to detect parasite DNA. The presence of piroplasms in both maternal and fetal vessels was demonstrated. Babesia microti infection caused vacuolization of syncytioblasts and cytotrophoblasts, accumulation of collagen fibers in placental villi, and increased adhesion of erythrocytes to the vascular walls. These results indicate that Babesia may influence the course of pregnancy and invite further research on the mechanism of piroplasm penetration into cells.

A Fatal Case of Hemophagocytic Lymphohistiocytosis Triggered By Babesiosis

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a rare condition characterized by hyperactivation of macrophages and T lymphocytes. While HLH is primarily inherited in a recessive manner among children, in adults, it is more commonly associated with underlying infections, autoimmune disorders, and malignancies. However, the association between HLH and Babesia infection remains exceptionally uncommon, with only a few reported cases in the medical literature. In this report, we present a unique case of HLH in the context of babesiosis, shedding light on the crucial clinical features and risk factors. By raising awareness of this rare differential diagnosis, we aim to contribute to early recognition and timely treatment, potentially reducing mortality from this treatable illness. Case Presentation: A 77-year-old male with history of deep vein thrombosis (DVT), Parkinson's disease, and lumbar radiculopathy on chronic prednisone, presented for progressive generalized weakness, leg pain, and confusion. Initial labs showed normocytic anemia, thrombocytopenia, low fibrinogen and elevated INR and liver enzymes (Table 1). Multiple ischemic signs were noted including acute on chronic DVT, as well as findings of marked splenomegaly with wedge infarcts and periportal lymphadenopathy on abdominal ultrasound and CT (Figure 1). The underlying etiology of these findings was unclear and broad differential work up was pursued. Given the anemia and thrombocytopenia on presentation, the patient received multiple blood products including platelets, red blood cells, fresh frozen plasma and cryoprecipitate, in addition to vitamin K. No schistocytes were seen peripherally, and DIC/TTP workup was negative. Multidisciplinary teams evaluated the risk versus benefit of anticoagulation with heparin drip considering evidence of multi-organ ischemic damage. It was briefly initiated, but later held due to persistent thrombocytopenia and abnormal liver function. Further work up only revealed hemolysis with a low haptoglobin and elevated LDH (Table 1). However, the follow up Coombs test was negative, ruling out immune mediated hemolysis. While symptomatic management continued, blood parasite screen obtained on admission indicated Babesia microti infection. Upon repeat testing, no evidence of babesia was identified on labs or blood smear. However, this finding was skewed by the multiple transfusions the patient received. Unfortunately, the clinical course rapidly declined, and the patient's family elected a transition to comfort care measures whereby the patient expired within two days of presentation. Remaining work up resulted posthumously, with CD25 levels elevated at 38,354.0 pg/mL. Coupled with the previously established splenomegaly, pancytopenia, hypertriglyceridemia, and elevated ferritin, these findings indicate a diagnosis of HLH, likely triggered by Babesia microti infection. Conclusion: HLH should be strongly suspected in patients from endemic regions, especially with additional risk factors such as age, genetics, and immunosuppression. Tools such as the HScore and the HLH-2004 criteria can aid in further patient risk stratification. Urgent treatment with steroids and addressing underlying babesiosis with atovaquone, azithromycin, and potentially red blood cell exchange transfusion, remains crucial for preventing decompensation and improving outcomes.

Immune Control in Repeated Babesia microti Infection in a Patient With B-Cell Deficiency.

The immunology of human babesiosis is poorly investigated. We present a comprehensive investigation of a 75-year-old man with B-cell deficiency who experienced 3 episodes of babesiosis over a 6-year period. Slowly evolving clinical immunity was observed, as evidenced by milder clinical symptoms and lower peak parasite burden after each subsequent babesiosis episode. The patient exhibited several striking immunologic findings. First, the patient had exceptionally high Babesia microti-specific antibodies despite very few circulating B cells, which predominantly coexpressed CD27 (memory marker) and CD95 (death receptor). Second, we demonstrated the presence of long-lasting NK cells and expansion of T memory stem cells. Third, levels of the IP-10 cytokine directly correlated with parasite burden. These results raise fundamental questions on the priming, maintenance, and location of a B-cell population that produces high antibody levels in the face of severe B-cell deficiency. Our results should invoke interest among researchers to study the immunology and pathogenesis of human babesiosis.

Plasma Blood Levels of Tafenoquine following a Single Oral Dosage in BALBc Mice with Acute Babesia microti Infection That Resulted in Rapid Clearance of Microscopically Detectable Parasitemia.

Previous studies of mice infected with Babesia microti have shown that a single dose of tafenoquine administered orally is extremely effective at decreasing microscopically detectable parasitemia. However, a critical limitation of studies to date is the lack of data concerning the plasma levels of tafenoquine that are needed to treat babesiosis. In the current study, we begin to address this gap by examining the plasma levels of tafenoquine associated with the rapid reduction of B. microti patent parasitemia in a mouse model of babesiosis. In the current study, we infected BALB/c mice with 1 × 107B. microti-infected red blood cells. Two days post-infection, mice were treated with 20 mg/kg of tafenoquine succinate or vehicle control administered orally by gavage. Parasitemia and plasma levels of tafenoquine were evaluated every 24 h post-treatment for 96 h. This allowed us to correlate blood plasma levels of tafenoquine with reductions in parasitemia in treated mice. Consistent with previous studies, a single oral dose of 20 mg/kg tafenoquine resulted in a rapid reduction in parasitemia. Plasma levels of tafenoquine 24 h post-administration ranged from 347 to 503 ng/mL and declined thereafter. This blood plasma tafenoquine level is similar to that achieved in humans using the current FDA-approved dose for the prevention of malaria.

Relapsing Babesiosis With Molecular Evidence of Resistance to Certain Antimicrobials Commonly Used to Treat Babesia microti Infections.

Human babesiosis cases are emerging with an increased incidence and a wider geographic range worldwide. Relapsing babesiosis cases are becoming more frequently encountered in clinical practice associated with the use of immunosuppressive medications. The 2020 Infectious Diseases Society of America babesiosis guideline recommends at least 6 weeks of antimicrobial treatment for highly immunocompromised patients with Babesia microti infection. Nevertheless, cases have relapsed even after 6 weeks of treatment. Genetic mutations regarded as the potential cause of antimicrobial resistance in B microti have been identified in certain relapsing cases. A few alternative antimicrobial regimens have been used successfully to achieve cure for some of these cases, but other cases have had fatal outcomes. In this review, we discuss the molecular evidence of genetic resistance to certain antimicrobials commonly used to treat B microti infections based on an evaluation of 9 patients with relapsing infection.

Methemoglobinemia Secondary to Babesia Microti Infection: A Novel Case Report

BackgroundTick-borne illnesses and methemoglobinemia have not been known to occur together in humans. Few cases have been documented in various animals of methemoglobinemia secondary to tick-borne infections. Case ReportA 49-year-old man with no significant medical history presented to the emergency department from an urgent care with hypoxia saturating in the mid 80s. He also reported a pruritic rash on his back and right shoulder as well as both of his lower extremities. The rash had been present for 4 days. The patient was tachycardic and hypoxic at 90% but denied shortness of breath. He had cyanosis of the lips and fingertips and multiple erythematous, raised, ovoid lesions on the right shoulder and left lower extremity. Methemoglobin levels were elevated at 26%. He was treated with methylene blue, supplemental oxygen, and empiric doxycycline with improvement in his oxygenation. A tick-borne illness panel later tested positive for Babesia microti infection. His skin lesions resolved with the above described treatment. Why Should an Emergency Physician Be Aware of This?Both tick-borne illnesses and methemoglobinemia are typically easily treatable with proper antimicrobial coverage and methylene blue, respectively. The current literature is bare regarding concurrent tick-borne illnesses, specifically babesiosis, and methemoglobinemia. Without knowledge and documentation of a potential link between the two conditions, hypoxia, if found to be due to methemoglobinemia, may be treated adequately, but a potentially life-threatening tick-borne illness may continue to cause damage and disease to the patient if not tested for, identified, and treated.

Serum metabolomic profiles in BALB/c mice induced by Babesia microti infection.

The protozoan parasite Babesia microti is the primary cause of human babesiosis. This parasite invades and multiplies inside red blood cells (RBCs), and infections differ significantly based on the age and immune competency of the host. The aim of this study was to investigate the use of serum metabolic profiling to identify systemic metabolic variations between B. microti-infected mice and noninfected controls. A serum metabolomics analysis of BALB/c mice that had been intraperitoneally injected with 107 B. microti-infected RBCs was performed. Serum samples from the early infected group (2 days postinfection), the acutely infected group (9 days postinfection), and the noninfected group were collected and evaluated using a liquid chromatography-mass spectrometry (LC-MS) platform. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA) identified metabolomic profiles that differentiated the B. microti-infected and noninfected groups. Our results confirm that the serum metabolome is significantly influenced by acute B. microti infection and show that infection results in dysregulation of metabolic pathways and perturbation of metabolites. Acutely infected mice displayed perturbations in metabolites associated with taurine and hypotaurine metabolism, histidine metabolism, and arachidonic acid metabolism. Taurocholic acid, anserine, and arachidonic acid may be potential candidates as serological biomarkers for diagnosing B. microti infection at the acute stage. These metabolites could be further examined for their role in disease complexity. Our findings demonstrate that the acute stage of B. microti infection induces abnormalities in the metabolites present in mouse serum and provide new insight into the mechanisms involved in systemic metabolic changes that occur during B. microti infection.

The impact of ABO and RhD blood types on Babesia microti infection.

Babesiosis is an emerging infectious disease caused by intraerythrocytic Babesia parasites that can cause severe disease and death. While blood type is known to affect the mortality of Plasmodium falciparum malaria patients, associations between red blood cell (RBC) antigens and Babesia microti infection and disease severity are lacking. We evaluated RhD and ABO blood types of Babesia-infected (18S rRNA reactive) blood donors in 10 endemic states in the Northeastern and northern Midwestern United States. We also assessed possible associations between RhD and ABO blood types and disease severity among hospitalized babesiosis patients in Connecticut. A total of 768 Babesia-infected blood donors were analyzed, of which 750 (97.7%) had detectable B. microti-specific antibodies. B. microti-infected blood donors were more likely to be RhD- (OR of 1.22, p-value 0.024) than RhD+ donors. Hospitalized RhD- babesiosis patients were more likely than RhD+ patients to have high peak parasitemia (p-value 0.017), which is a marker for disease severity. No differences in RhD+ blood type were noted between residents of the Northeast (OR of 0.82, p-value 0.033) and the Midwest (OR of 0.74, p-value 0.23). Overall, ABO blood type was not associated with blood donor B. microti infection, however, B. microti-infected donors in Maine and New Jersey were more likely to be blood type B compared to non-type B (OR 2.49 [p = 0.008] and 2.07 [p = 0.009], respectively), while infected donors from Pennsylvania were less likely to be type B compared to non-type B (OR 0.32 [p = 0.02]). People expressing RhD antigen may have a decreased risk of B. microti infection and babesiosis severity. The association of B antigen with B. microti infection is less clear because the antigen appeared to be less prevalent in infected Pennsylvania blood donors but more prevalent in Maine and New Jersey infected donors. Future studies should quantify associations between B. microti genotypes, RBC antigens, and the frequency and severity of B. microti infection to increase our understanding of human Babesia pathogenesis and improve antibody, vaccine, and RBC exchange transfusion strategies.

BABESIA MICROTI INFECTION WITH LOW-GRADE PARASITEMIA CAUSING ARDS IN AN IMMUNOCOMPETENT PATIENT

BABESIA MICROTI INFECTION WITH LOW-GRADE PARASITEMIA CAUSING ARDS IN AN IMMUNOCOMPETENT PATIENT

Prevalence and phylogenetic analysis of Babesia parasites in reservoir host species in Fujian province, Southeast China.

Babesiosis is a tick-borne disease that mainly affects small mammals and has been reported in at least five provinces in China. However, the host range and geographical distribution of the parasite in Fujian province are unclear. Therefore, we investigated the prevalence and genetic characteristics of Babesia in Fujian province, Southeast China, between 2015 and 2020. Rodent blood samples were collected from 26 different surveillance sites across Fujian province. Genomic DNA was extracted to screen for Babesia infection using polymerase chain reaction based on 18S rRNA. DNA samples from 316 domestic goats, 85 water buffalo, 56 domestic dogs and 18 domestic pigs were examined. The prevalence of Babesia was statistically analysed using the Chi-square test or Fisher's exact test. Babesia infections were detected in 3.96% (43/1,087; 95%CI: 2.80%, 5.12%) of rodents and 1.26% (6/475; 95%CI: 0.26%, 2.26%) of other mammals. Multivariate logistic regression analysis revealed that irrigated cropland, shrubs and forests were risk factors for Babesia microti infections. The infection rates among domestic pigs, dogs and goats were 5.56%, 1.79% and 1.27%, respectively, with no infection found in water buffalo. The 18S rRNA gene sequencing revealed that rodents were infected with Babesia (sensu lato), whereas other mammals were infected with Babesia (sensu stricto). The geographical distribution and phylogenetic relationship of Babesia was determined in Southeast China. Mammals, particularly wild rodents, maybe the main natural hosts of Babesia in Fujian. Our findings provide a foundation for public health officials to develop prevention and control measures for Babesia.

Babesia microti Infection Inhibits Melanoma Growth by Activating Macrophages in Mice.

Babesia microti is an obligate intraerythrocytic protozoan transmitted by an Ixodes tick. Infections caused by protozoa, including Plasmodium yoelii and Toxoplasma gondii, are shown to inhibit tumor development by activating immune responses. Th1 immune response and macrophages not only are essential key factors in Babesia infection control but also play an important role in regulating tumor development. In this study, we investigated the effects of B. microti infection on melanoma in tumor-bearing mice. The results showed that B. microti infection could inhibit the growth of melanoma, significantly enlarge the spleen size (p ≤ 0.0001), and increase the survival period (over 7 days) of tumor-bearing mice. Mouse spleen immune cell analysis revealed that B. microti-infected tumor-bearing mice could increase the number of macrophages and CD4+ T cells, as well as the proportion of CD4+ T cells and M1 macrophages in the tumor. Immunohistochemical assays showed that B. microti infection could inhibit tumor angiogenesis (p ≤ 0.0032). Meanwhile, both B. microti-infected erythrocytes and culture supernatant were observed to significantly (p ≤ 0.0021) induce the mRNA expression of iNOS, IL-6, and TNF-α in macrophages. Moreover, B. microti culture supernatant could also repolarize IL-4-induced M2 macrophages to the M1 type. Overall, B. microti exerted antitumor effects by stimulating the immune system of tumor-bearing mice and inducing the polarization of immunosuppressive M2 macrophages to pro-inflammatory M1 macrophages.

Zoonotic Babesia microti infection in wild rodents in Erzurum province, northeastern Turkey.

Wild rodents are natural reservoir hosts of various pathogens, including Babesia microti. This study investigated the presence of B.microti in rodents from Erzurum province in Turkey. A total of 498 rodents and 21 rodent-fed ticks were analysed using the polymerase chain reaction (PCR) technique to test for the presence of B.microti. Babesia spp. were detected in three (0.6%) of the 498 rodent spleen samples. The Babesia-positive rodent species were identified as Microtus socialis by means of molecular analysis. The rodent-fed ticks comprised 15 Ixodes laguri and 6 Rhipicephalus sanguineus, none of which tested positive for Babesia spp. A sequence analysis of the 18S PCR amplicons confirmed the three Babesia-positive samples to be B.microti. The Erzurum isolates were 100% identical to the zoonotic Jena strain. The results of this study indicate the existence of zoonotic B.microti strains that may constitute a potential public health risk in Erzurum province. Future studies should determine the tick vector and other reservoir rodent species of B.microti in Erzurum.

Canadian blood suppliers: An expanding role in public health surveillance?

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic galvanized blood donor seroprevalence studies, which continue to inform public health policy. We propose that the two Canadian blood suppliers, Héma-Québec and Canadian Blood Services, expand their role in public health surveillance in the post-pandemic period. Together blood suppliers have near-national reach, collecting blood donations nearly every day in all larger cities and many smaller municipalities. Blood donors are a healthy subset of the general population. Demographic data, routine infectious disease testing and screening questionnaire data are collected for all donations. Close to one million blood samples per year could be made available for surveillance. With 90% repeat donors, longitudinal sampling is possible. Current blood donor surveillance includes monitoring infectious marker rates in low risk (e.g. HIV, hepatitis C virus) or asymptomatic (e.g. West Nile virus) populations, and ad hoc studies to monitor transfusion-transmissible infections. These include tick-borne infections such as Babesia microti and foodborne infections such as hepatitis E. Canadian Blood Services and Héma-Québec are actively seeking to engage with public health professionals to further develop a role in public health surveillance.

Frequency and Geographic Distribution of Borrelia miyamotoi, Borrelia burgdorferi, and Babesia microti Infections in New England Residents.

Borrelia miyamotoi is a relapsing fever spirochete that relatively recently has been reported to infect humans. It causes an acute undifferentiated febrile illness that can include meningoencephalitis and relapsing fever. Like Borrelia burgdorferi, it is transmitted by Ixodes scapularis ticks in the northeastern United States and by Ixodes pacificus ticks in the western United States. Despite reports of clinical cases from North America, Europe, and Asia, the prevalence, geographic range, and pattern of expansion of human B. miyamotoi infection are uncertain. To better understand these characteristics of B. miyamotoi in relation to other tickborne infections, we carried out a cross-sectional seroprevalence study across New England that surveyed B. miyamotoi, B. burgdorferi, and Babesia microti infections. We measured specific antibodies against B. miyamotoi, B. burgdorferi, and B. microti among individuals living in 5 New England states in 2018. Analysis of 1153 serum samples collected at 11 catchment sites showed that the average seroprevalence for B. miyamotoi was 2.8% (range, 0.6%-5.2%), which was less than that of B. burgdorferi (11.0%; range, 6.8%-15.6%) and B. microti (10.0%; range, 6.5%-13.6%). Antibody screening within county residence in New England showed varying levels of seroprevalence for these pathogens but did not reveal a vectoral geographical pattern of distribution. Human infections caused by B. miyamotoi, B. burgdorferi, and B. microti are widespread with varying prevalence throughout New England.

The regulatory strategy of proteins in the mouse kidney during Babesia microti infection

Babesia is a protozoan that mainly parasitizes mammalian red blood cells. It causes damage to multiple organs of the host, even threatening the life of the host when the infection is severe. This study found that the mouse kidney was injured after Babesia infection, leading to changes such as ischaemia and an abnormal morphology of renal and epithelial cells. Serum tests showed that indices reflecting renal abnormalities (including serum creatinine, uric acid, and bilirubin) appeared to be abnormal. To further explore the molecular mechanism underlying kidney injury and self-healing in infected hosts, we employed a data-independent acquisition (DIA) proteomics method to investigate large-scale B. microti infection-induced changes in protein expression and phosphorylation in mouse kidneys. This study identified and analysed the reasons for the obvious changes in kidney injury-related proteins, repair-related proteins, immune-related proteins, and lipid metabolism-related proteins. The results provide a strong theoretical basis for effective treatments of the kidney disease caused by Babesia infection.

Optimization of an Evaluation Method for Anti-Babesia microti Drug Efficacy

Babesiosis is an emerging zoonotic disease that is typically caused by Babesia microti infection. Clinical treatment of B. microti infection is challenging; hence, it is crucial to find new effective drugs. The current laboratory screening methods for anti-B. microti drugs are not optimized. We conducted drug-suppressive and drug-therapeutic tests to investigate whether use of an immunosuppressant and the target gene-based qPCR are helpful to reduce the number of animals affected and to improve parasite detection in an immunocompetent mouse model. These results were verified by subpassage test. In the drug-suppressive test, no B. microti were observed after immunosuppressant administration or in subpassage mice in the 100 mg/kg robenidine hydrochloride (ROBH) group. The opposite results were observed in the control, 50 mg/kg ROBH, atovaquone (ATO) + azithromycin (AZM), and proguanil hydrochloride (PGH) groups. Significant differences were observed in the EIR and target gene relative values (both P < 0.001) between the control group and any ROBH groups. In the drug-therapeutic test, recrudescence occurred in the 50 mg/kg ROBH, ATO+AZM, and control groups. This was not observed in the 100 mg/kg ROBH group after immunosuppressant administration. Similar findings were observed in the subpassage test. This suggests that a 4-day anti-B. microti drug-suppressive test can be used in preliminary drug screening. Potentially effective drugs can be verified by immunosuppressant test in subsequent drug-therapeutic tests. Thus, a laboratory evaluation method of anti-B. microti drug efficacy was optimized, which is highly accurate and requires a short drug screening time.