Detection of high frequency of MAD20 allelic variants of Plasmodium falciparum merozoite surface protein 1 gene from Adama and its surroundings, Oromia, Ethiopia

Background One of the major challenges in developing an effective vaccine against asexual stages of Plasmodium falciparum is genetic polymorphism within parasite population. Understanding the genetic polymorphism like block 2 region of merozoite surface protein-1 (msp-1) gene of P. falciparum enlighten mechanisms underlining disease pathology, identification of the parasite clone profile from the isolates, transmission intensity and potential deficiencies of the ongoing malaria control and elimination efforts in the locality. Detailed understanding of local genetic polymorphism is an input to pave the way for better management, control and elimination of malaria. The aim of this study was to detect the most frequent allelic variant of the msp-1 gene of P. falciparum clinical isolates from selected health facilities in Adama town and its surroundings, Oromia, Ethiopia. Methods One hundred thirty-nine clinical isolates were successfully amplified for msp-1 gene using specific primers. Nested PCR amplification was conducted targeting K1, MAD20, and R033 alleles followed by gel electrophoresis for fragment analysis. Based on the detection of a PCR fragment, infections were classified as monoclonal or multiple infections. Results 19 different size polymorphism of msp-1 gene were identified in the study, with 67(48%) MAD20, 18 (13%) K-1 and 18 (13%) RO33 allelic family. Whereas, the multiple infections were 21(15%), 8 (5.8%), 4(2.9%), 3(2.2%) for MAD20 + K-1, MAD20 + RO33, K-1 + RO33, and MAD20 + K-1, RO33, respectively. The overall Multiplicity of infection (MOI) was 1.3 and the expected heterozygosity (He) was 0.39 indicating slightly low falciparum malaria transmission. Conclusion The status of msp-1 allele size polymorphism, MOI and He observed in the study revealed the presence of slightly low genetic diversity of P. falciparum clinical isolates. However, highly frequent MAD20 allelic variant was detected from clinical isolates in the study area. Moreover, the driving force that led to high predominance of MAD20 allelic variant revealed in such malaria declining region demands further research.

Differentiation of Candida albicans complex species isolated from invasive and non-invasive infections using HWP1 gene size polymorphism

Background and Purpose: The taxonomy of Candida is controversial and has undergone changes due to the investigation of the novel species. Candida africana and Candida dubliniensis are new members of C. albicans complex that are currently gaining both clinical and epidemiologic significance. This study reports the prevalence of C. africana among the strains isolated from patients, by using HWP1 gene size polymorphism. Materials and Methods: A total of 235 yeasts confirmed as C. albicans complex based on chromogenic media and ITS-sequencing isolated from various clinical forms of invasive and non-invasive candidiasis mainly candidemia, were re-identified based on HWP1 gene polymorphisms. The Hwp1-PCR amplicons were re-confirmed by sequencing and BLAST analysis. Results: Based on the HWP1 gene size polymorphism, 223 strains were identified as C. albicans (94.89%) from which 7 isolates produced two DNA fragments (850 and 941 bp). C. dubliniensis (n=4, 1.7%), C. africana (n=1, 0.42%) and mix of C. albicans and C. africana (n=7, 2.97%) were also identified. Conclusion: Although C. albicans remains the most common Candida species, C. dubliniensis and C. africana are rarely found among the patient isolates. Due to limited information on the molecular epidemiology of this novel yeast, more studies using molecular methods are recommended.

Detection of High Frequency of MAD20 Allelic Variants of Plasmodium Falciparum Merozoite Surface Protein 1 Gene from Adama and its Surroundings, Oromia, Ethiopia

Background: One of the major challenges in developing an effective vaccine against asexual stages of Plasmodium falciparum is genetic polymorphism within parasite population. Understanding the genetic polymorphism like block 2 region of merozoite surface protein (msp-1) genes of P. falciparum enlighten mechanisms underlining disease pathology, identification of the parasite clone profile from the isolates, transmission intensity and potential deficiencies of the ongoing malaria control and elimination effort in the locality. Detailed understanding of local genetic polymorphism is an input to pave the way for better management, control and elimination of malaria. The aim of this study was to detect the most frequent allelic variant of the merozoite surface protein (msp-1) gene of P. falciparum clinical isolates from selected health facilities in Adama town and its surroundings, Oromia, Ethiopia.Methods: A total of 139 clinical isolates were successfully amplified for msp-1 gene using specific sets of primer. Nested PCR amplification conducted, using specific primers targeting K1, MAD20, and R033 alleles followed by gel electrophoresis for fragment analysis. Based on the detection of a PCR fragment, infections were classified as monoclonal or multiple infections.Result: 19 different size polymorphism of msp-1 gene were identified in the study, with 67(48 %) MAD20, 18 (13 %) K-1 and 18 (13 %) RO33 allelic family. Whereas, the multiple infections were 21(15 %), 8(5.8 %), 4(2.9 %), 3(2.2 %) for MAD20+K-1, MAD20+RO33, K-1+ RO33, and MAD20+K-1, RO33, respectively. The overall Multiplicity of Infection (MOI) was 1.3 and the expected heterozygosity (He) was 0.58 indicating intermediate falciparum malaria transmission.Conclusion: The status of msp-1 allele size polymorphism, MOI and He observed in the study revealed an intermediate genetic diversity of P. falciparum clinical isolates, indicating that the ongoing malaria control and elimination effort should be intensified to effectively monitor the potential malaria resurgence in the study area. Moreover, deriving force that led to high predominance of MAD20 allelic variant revealed in such malaria declining region demands further research.