Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis

Abstract

More than 100 Babesia spp. tick-borne parasites are known to infect mammalian and avian hosts. Babesia belong to Order Piroplasmid ranked in the Phylum Apicomplexa. Recent phylogenetic studies have revealed that of the three genera that constitute Piroplasmida, Babesia and Theileria are polyphyletic while Cytauxzoon is nested within a clade of Theileria. Several Babesia spp. and sub-types have been found to cause human disease. Babesia microti, the most common species that infects humans, is endemic in the Northeastern and upper Midwestern United States and is sporadically reported elsewhere in the world. Most infections are transmitted by Ixodid (hard-bodied) ticks, although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation. Babesiosis most often presents as a mild to moderate disease, however infection severity ranges from asymptomatic to lethal. Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR). Treatment consists of atovaquone and azithromycin or clindamycin and quinine and usually is effective but may be problematic in immunocompromised hosts. There is no human Babesia vaccine. B. microti genomics studies have only recently been initiated, however they already have yielded important new insights regarding the pathogen, population structure, and pathogenesis. Continued genomic research holds great promise for improving the diagnosis, management, and prevention of human babesiosis, and in particular, the identification of lineage-specific families of cell-surface proteins with potential roles in cytoadherence, immune evasion and pathogenesis.

Identification of antiviral phytochemicals as a potential SARS-CoV-2 main protease (Mpro) inhibitor using docking and molecular dynamics simulations

“…Muhseen et al used the above two methods to identify M pro inhibitors from MPD3 phytochemical database 21 – 24 . Certain database-specific inhibitors search were also made including Super Natural II 25 , Marine Natural Product (MNP) 26 and Traditional Chinese Medicine 27 . Fragment-based computational screening with constraints to target His45, Cys145 and His163 key residues identified a potent molecule with a triazole scaffold 28 .…”

The Global Emergence of Human Babesiosis

“…1996 [36] United States Unknown Babesia microti-like (TW1) 1997 [30] Taiwan, Japan Unknown adapted from Puri et al Frontiers in Microbiology, 2021 [37].…”

“…It focuses on the characterization and quantification of all the genes and their interactions that affect the function of the organism. The study of genomics has provided important new insights into the genetic basis of pathogen populations, their structure, diversity, evolution, and emergence; as well as pathogenesis, biomarkers of detection, drug resistance markers, targets for novel therapeutics, and vaccines [37,44,[79][80][81][82].…”

Major Surface Antigens in Zoonotic Babesia

“…These data allow better characterization of the parasite proteome and metabolic pathways, including the protein post-translational modification machinery. The immune response against B. microti and the most relevant antigens have been reviewed previously [43]; therefore, in this paper, we focus on one of the most characterized antigens without ignoring the role of other proteins.…”