Background:Characterization of Plasmodium falciparum diversity is commonly achieved by amplification of the polymorphic regions of the merozoite surface proteins 1 (MSP1) and 2 (MSP2) genes.Aims:The present study aimed to determine the allelic variants distribution of MSP1 and MSP2 and multiplicity of infection in P. falciparum field isolates from Kosti, central Sudan, an area characterized by seasonal malaria transmission.Materials and Methods:Total 121 samples (N = 121) were collected during a cross-sectional survey between March and April 2003. DNA was extracted and MSP1 and MSP2 polymorphic loci were genotyped.Results:The total number of alleles identified in MSP1 block 2 was 11, while 16 alleles were observed in MSP2 block 3. In MSP1, RO33 was found to be the predominant allelic type, carried alone or in combination with MAD20 and K1 types, whereas FC27 family was the most prevalent in MSP2. Sixty two percent of isolates had multiple genotypes and the overall mean multiplicity of infection was 1.93 (CI 95% 1.66-2.20). Age correlated with parasite density (P = 0.017). In addition, a positive correlation was observed between parasite densities and the number of alleles (P = 0.022).Conclusion:Genetic diversity in P. falciparum field isolates in central Sudan was high and consisted of multiple clones.

SummaryHeat-shock proteins (HSPs) refer to a group of proteins whose synthesis is enhanced upon sudden increase in temperature or exposure to a variety of other stressors. In this study, Theileria annulata (T. annulata) HSP90 was identified and characterized as a first step to understand the function of this molecule in T. annulata-infected cells. Our results indicated the existence in the genome of T. annulata of two HSP90 genes: one located in chromosome one (TaHSP90-Chr1) and the other in chromosome four (TaHSP90-Chr4). The amino acid alignment between the two isoforms has shown identity and similarity values of 23.52% and 30.26%, respectively. Theileria annulata recombinant HSP90 proteins were expressed using a bacterial expression system and could be recognized in Western blots by rabbit anti-serum raised against an antigenic peptide derived from a unique sequence of TaHSP90-Chr1. On the other hand, bovine HSP90 was detected in T. annulata-infected cells using Western blot and immunocytostaining. To demonstrate the effect of the inhibition of HSP90 on the survival of T. annulata-infected cells, Geldanamycin (GA), a specific inhibitor for HSP90, was used. Upon GA treatment, p53 was observed to translocate into the host cell nucleus, a phenomenon that occurs in cells undergoing apoptosis. Using flowcytometry, a significant increase (P = 0.028) in cell death (%) was observed in T. annulata-infected cells treated with two different GA concentrations, 0.5 and 1 lM, and incubated for 24, 48 and 72 h.

A cross-sectional study was performed 200 blood samples and 314 tick samples in El Huda and El Nuhud animals production research stations, Sudan, in May (summer) and December (winter) in 2016, to determine the prevalence of Theileria lestoquardi in sheep and the potential risk factors associated with the infection. A total of 200 blood samples and 314 tick samples were collected from El Huda (n = 103 blood, 97 tick) and El Nuhud (n = 97 blood, 217 tick) stations. Data on the risk factors, such as age, sex, ecotype of sheep, body condition score and seasons were recorded. The overall prevalence of Theileria lestoquardi was 13% (26/200) using PCR. A significant variation in the prevalence of Theileria lestoquardi was observed between the stations and the ecotype of sheep ( p ≤ 0.05), whereas the highest prevalence was recorded in El-Huda station (19.4%) as well as in Shugor (22.8%). Other risk factors, like age, sex, body condition, and seasons were not found to be significantly associated with infection. However, the highest prevalence rate was recorded in old animals (21.6%) than the other, in males (17.9%) than females (12.2%), in animals with poor body condition (26.1%) than the other, and in winter (16%) than summer (10%). Four tick species i.e. Rhipicephalus evertsi evertsi (63.1%), Hyalomma anatolicum (13.8%), Hyalomma dromedarii (8.8%), and Hyalomma impeltatum (14.3%) were recorded in El Nuhud station. While in El Huda station, only Rhipicephalus evertsi evertsi (79.4%), Hyalomma anatolicum (20.6%) were recorded. This study revealed that 13% of sheep were suffering from Theileria lestoquardi which is a considerable number at the stations. Therefore, further epidemiological investigations on disease throughout the year are required in order to set a well-coordinated control program.

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