A Polymorphic Multigene Family Encoding an Immunodominant Protein from Babesia microti

2000 ◽  
Vol 38 (1) ◽  
pp. 362-368
Author(s):  
M. J. Homer ◽  
E. S. Bruinsma ◽  
M. J. Lodes ◽  
M. H. Moro ◽  
S. Telford ◽  
...  

ABSTRACT Human babesiosis in the United States is caused predominantly by Babesia microti , a tick-transmitted blood parasite. Improved testing methods for the detection of infection with this parasite are needed, since asymptomatic B. microti infection represents a potential threat to the blood supply in areas where B. microti is endemic. We performed immunoscreening of an expression library of genomic DNA from a human isolate of B. microti (strain MN1). Among 17 unique immunoreactive clones, we identified 9 which represent a related family of genes with little sequence homology to other known sequences but with an architecture resembling that of several surface proteins of Plasmodium . Within this family, a tandem array of a degenerate six-amino-acid repeat (SEAGGP, SEAGWP, SGTGWP, SGTVGP) was found in various lengths between relatively well conserved segments at the N and C termini. In order to examine within-clone variation, we developed a PCR protocol for direct recovery of a specific bmn1-6 homologue directly from 30 human blood isolates, 4 corresponding hamster isolates, and 5 geographically corresponding Peromyscus leucopus (white-footed mouse) isolates. Isolates from the hamsters had the same sequences as those found in the corresponding human blood, suggesting that genetic variation of bmn1-6 does not occur during passage. However, clones from different patients were often substantially different from each other with regard to the number and location of the degenerate repeats within the bmn1-6 homologue. Moreover, we found that strains that were closely related geographically were also closely related at the sequence level; nine patients, all from Nantucket Island, Mass., harbored clones that were indistinguishable from each other but that were distinct from those found in other northeastern or upper midwestern strains. We conclude that considerable genetic and antigenic diversity exists among isolates of B. microti from the United States and that geographic clustering of subtypes may exist. The nature of the bmn1-6 gene family suggests a mechanism of antigenic variation in B. microti that may occur by recombination, differential expression, or a combination of both mechanisms.

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kristen L. Knapp ◽  
Nancy A. Rice

Borrelia burgdorferi, the causative agent of Lyme disease, andBabesia microti, a causative agent of babesiosis, are increasingly implicated in the growing tick-borne disease burden in the northeastern United States. These pathogens are transmitted via the bite of an infected tick vector,Ixodes scapularis, which is capable of harboring and inoculating a host with multiple pathogens simultaneously. Clinical presentation of the diseases is heterogeneous and ranges from mild flu-like symptoms to near-fatal cardiac arrhythmias. While the reason for the variability is not known, the possibility exists that concomitant infection with bothB. burgdorferiandB. microtimay synergistically increase disease severity. In an effort to clarify the current state of understanding regarding coinfection withB. burgdorferiandB. microti, in this review, we discuss the geographical distribution and pathogenesis of Lyme disease and babesiosis in the United States, the immunological response of humans toB. burgdorferiorB. microtiinfection, the existing knowledge regarding coinfection disease pathology, and critical factors that have led to ambiguity in the literature regarding coinfection, in order to eliminate confusion in future experimental design and investigation.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1447
Author(s):  
Abhinav Kumar ◽  
Jane O'Bryan ◽  
Peter J. Krause

Babesiosis is an emerging tick-borne disease caused by intraerythrocytic protozoa that are primarily transmitted by hard-bodied (Ixodid) ticks and rarely through blood transfusion, perinatally, and organ transplantation. More than 100 Babesia species infect a wide spectrum of wild and domestic animals worldwide and six have been identified as human pathogens. Babesia microti is the predominant species that infects humans, is found throughout the world, and causes endemic disease in the United States and China. Babesia venatorum and Babesia crassa-like agent also cause endemic disease in China. Babesia divergens is the predominant species in Europe where fulminant cases have been reported sporadically. The number of B. microti infections has been increasing globally in recent decades. In the United States, more than 2000 cases are reported each year, although the actual number is thought to be much higher. In this review of the epidemiology of human babesiosis, we discuss epidemiologic tools used to monitor disease location and frequency; demographics and modes of transmission; the location of human babesiosis; the causative Babesia species in the Americas, Europe, Asia, Africa, and Australia; the primary clinical characteristics associated with each of these infections; and the increasing global health burden of this disease.


2020 ◽  
Vol 4 (2) ◽  
pp. 177-188

Сertain organophosphates are highly toxic and can be used as chemical warfare agents. However, some classes of organic phosphorus compounds can cause so-called delayed neurotoxicity. Since the discovery of this phenomenon in 1899, extensive research has been conducted on delayed neurotoxicity caused by organophosphates. Mass poisoning of residents of the United States and Morocco in the last century demonstrated the high danger of substances that cause neurotoxicity, and gave a powerful impetus to research into this phenomenon. In addition to delayed effects, some phosphorus compounds potentiate the action of already known chemical warfare agents, increasing their toxicity by more than 10 times. Research in this direction is conducted under the auspices of the defense departments of the United States, Canada and the Netherlands. The wide distribution of phosphorus compounds in various industries and agriculture, the long hidden period and the irreversibility of lesions caused by neurotoxic organic phosphorus compounds, cause their potential threat to the security of the Russian Federation


Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1563
Author(s):  
Scott Meredith ◽  
Miranda Oakley ◽  
Sanjai Kumar

The biology of intraerythrocytic Babesia parasites presents unique challenges for the diagnosis of human babesiosis. Antibody-based assays are highly sensitive but fail to detect early stage Babesia infections prior to seroconversion (window period) and cannot distinguish between an active infection and a previously resolved infection. On the other hand, nucleic acid-based tests (NAT) may lack the sensitivity to detect window cases when parasite burden is below detection limits and asymptomatic low-grade infections. Recent technological advances have improved the sensitivity, specificity and high throughput of NAT and the antibody-based detection of Babesia. Some of these advances include genomics approaches for the identification of novel high-copy-number targets for NAT and immunodominant antigens for superior antigen and antibody-based assays for Babesia. Future advances would also rely on next generation sequencing and CRISPR technology to improve Babesia detection. This review article will discuss the historical perspective and current status of technologies for the detection of Babesia microti, the most common Babesia species causing human babesiosis in the United States, and their implications for early diagnosis of acute babesiosis, blood safety and surveillance studies to monitor areas of expansion and emergence and spread of Babesia species and their genetic variants in the United States and globally.


2005 ◽  
Vol 73 (9) ◽  
pp. 5685-5696 ◽  
Author(s):  
Indira T. Kudva ◽  
Robert W. Griffin ◽  
Jeonifer M. Garren ◽  
Stephen B. Calderwood ◽  
Manohar John

ABSTRACTWe identified spore targets of Anthrax Vaccine Adsorbed (AVA)-induced immunity in humans by screening recombinant clones of a previously generated, limited genomicBacillus anthracisSterne (pXO1+, pXO2−) expression library of putative spore surface (spore-associated [SA]) proteins with pooled sera from human adults immunized with AVA (immune sera), the anthrax vaccine currently approved for use by humans in the United States. We identified 69 clones that reacted specifically with pooled immune sera but not with pooled sera obtained from the same individuals prior to immunization. Positive clones expressed proteins previously identified as localized on the anthrax spore surface, proteins highly expressed during spore germination, orthologs of proteins of diverse pathogens under investigation as drug targets, and orthologs of proteins contributing to the virulence of both gram-positive and gram-negative pathogens. Among the reactive clones identified by this immunological screen was one expressing a 15.2-kDa hypothetical protein encoded by a gene with no significant homology to sequences contained in databases. Further studies are required to define the subset of SA proteins identified in this study that contribute to the virulence of this pathogen. We hypothesize that optimal delivery of a subset of SA proteins identified by such studies to the immune system in combination with protective antigen (PA), the principal immunogen in AVA, might facilitate the development of defined, nonreactogenic, more-efficacious PA-based anthrax vaccines. Future studies might also facilitate the identification of SA proteins with potential to serve as targets for drug design, spore inactivation, or spore detection strategies.


Author(s):  
Min-hyung Kim

Abstract Given the limits of the prevailing hedging account for Seoul’s puzzling behavior that is in conformity with the interests of its adversary (i.e. North Korea) and potential threat (i.e. China) rather than those of its principal ally (i.e. the United States) and security cooperation partner (i.e. Japan), this article emphasizes the impact of the progressive ideology on Seoul’s security policy. In doing so, it calls for attention to a domestic source of ideology in explaining the security behaviors of a secondary state, which is under-researched and thus is poorly understood.


Author(s):  
Richard M. Titmuss

This chapter examines the demand for blood in England and Wales and the United States. Between 1948 and 1967, the annual number of donations of blood in England and Wales rose by 269 per cent. Some part of this increase in supply has met the increase in the amount of blood actually demanded and used per 100 patients treated in hospitals. Meanwhile, estimates have been made that 5,100,000 pints of blood were collected in the United States in 1956 and around 6,000,000 pints in 1966–7. Some of the factors responsible for this world trend relate to the major life-saving role of blood. Others are adding yearly to the relatively new role for human blood of acting as a vital preventive and therapeutic agent. Surgery in its many branches has, for example, been given a new lease of life by increases in the volume of blood available and the advent of effective blood transfusion services.


2020 ◽  
Vol 57 (5) ◽  
pp. 1640-1647
Author(s):  
Catherine A Pruszynski ◽  
Tanise Stenn ◽  
Carolina Acevedo ◽  
Andrea L Leal ◽  
Nathan D Burkett-Cadena

Abstract Aedes aegypti L. is considered to have a proclivity for feeding on human blood even when other hosts are available. However, few studies have demonstrated host use by this mosquito in the continental United States, where local transmission of dengue, Zika, and chikungunya viruses has been recently documented. This study investigated the bloodmeal sources of female Ae. aegypti in the subtropical city of Key West and the surrounding county in Florida with the goal of identifying preferred hosts. Blood-engorged Ae. aegypti mosquitoes were collected from BG Sentinel traps used as part of a routine surveillance program in the Florida Keys (Monroe County, Florida). Bloodmeal samples were analyzed using PCR assays, sequencing, and comparison with reference sequences in GenBank. Aedes aegypti females from Key West fed predominantly on humans (79.6%) and did not differ statistically from females collected from the rest of the Florida Keys (69.5%). Culex quinquefasciatus Say (Diptera: Culicidae), considered a host generalist, was collected and analyzed from the same sites for comparative purposes. Females of Cx. quinquefasciatus fed predominantly (70.7%) on birds and nonhuman mammals in the Florida Keys, corroborating the validity of molecular assay breadth and demonstrating that given the same group of available hosts Ae. aegypti selects humans. Our results indicated that Ae. aegypti has a high rate of human-biting in a subtropical area within the United States, supporting its role in recent local transmission of dengue and other viruses.


2020 ◽  
pp. 136078042092224
Author(s):  
Todd C Couch

In recent years, colleges and universities in the United States have considered allowing concealed firearms on their campuses. Yet, substantive research on why a minority of students’ desire to arm themselves is scarce. Addressing this gap in the literature, this study examines 30 interviews with chapter presidents of a national student gun rights organization. Using racialized narratives, participants express intense feelings of vulnerability on campus and in the larger society. Extending Feagin’s theory of systemic racism to gun politics, I argue respondents’ belief that they must be armed to co-exist with people of color reproduces racial inequality and poses a potential threat to students, faculty, and staff of color.


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