1
|
Hernández-Zambrano LJ, Alfonso-González H, Buitrago SP, Castro-Cavadía CJ, Garzón-Ospina D. Exploring the genetic diversity pattern of PvEBP/DBP2: A promising candidate for an effective Plasmodium vivax vaccine. Acta Trop 2024; 255:107231. [PMID: 38685340 DOI: 10.1016/j.actatropica.2024.107231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
Malaria remains a public health challenge. Since many control strategies have proven ineffective in eradicating this disease, new strategies are required, among which the design of a multivalent vaccine stands out. However, the effectiveness of this strategy has been hindered, among other reasons, by the genetic diversity observed in parasite antigens. In Plasmodium vivax, the Erythrocyte Binding Protein (PvEBP, also known as DBP2) is an alternate ligand to Duffy Binding Protein (DBP); given its structural resemblance to DBP, EBP/DBP2 is proposed as a promising antigen for inclusion in vaccine design. However, the extent of genetic diversity within the locus encoding this protein has not been comprehensively assessed. Thus, this study aimed to characterize the genetic diversity of the locus encoding the P. vivax EBP/DBP2 protein and to determine the evolutionary mechanisms modulating this diversity. Several intrapopulation genetic variation parameters were estimated using 36 gene sequences of PvEBP/DBP2 from Colombian P. vivax clinical isolates and 186 sequences available in databases. The study then evaluated the worldwide genetic structure and the evolutionary forces that may influence the observed patterns of genetic variation. It was found that the PvEBP/DBP2 gene exhibits one of the lowest levels of genetic diversity compared to other vaccine-candidate antigens. Four major haplotypes were shared worldwide. Analysis of the protein's 3D structure and epitope prediction identified five regions with potential antigenic properties. The results suggest that the PvEBP/DBP2 protein possesses ideal characteristics to be considered when designing a multivalent effective antimalarial vaccine against P. vivax.
Collapse
Affiliation(s)
- Laura J Hernández-Zambrano
- Grupo de Estudios en Genética y Biología Molecular (GEBIMOL), School of Biological Sciences, Universidad Pedagógica y Tecnológica de Colombia - UPTC, Tunja, Boyacá, Colombia; Population Genetics And Molecular Evolution (PGAME), Fundación Scient, Tunja, Boyacá, Colombia
| | - Heliairis Alfonso-González
- Grupo de Estudios en Genética y Biología Molecular (GEBIMOL), School of Biological Sciences, Universidad Pedagógica y Tecnológica de Colombia - UPTC, Tunja, Boyacá, Colombia; Population Genetics And Molecular Evolution (PGAME), Fundación Scient, Tunja, Boyacá, Colombia
| | - Sindy P Buitrago
- Grupo de Estudios en Genética y Biología Molecular (GEBIMOL), School of Biological Sciences, Universidad Pedagógica y Tecnológica de Colombia - UPTC, Tunja, Boyacá, Colombia; Population Genetics And Molecular Evolution (PGAME), Fundación Scient, Tunja, Boyacá, Colombia
| | - Carlos J Castro-Cavadía
- Grupo de Investigaciones Microbiológicas y Biomédicas de Córdoba (GIMBIC), School of Health Sciences, Universidad de Córdoba, Montería, Córdoba, Colombia
| | - Diego Garzón-Ospina
- Grupo de Estudios en Genética y Biología Molecular (GEBIMOL), School of Biological Sciences, Universidad Pedagógica y Tecnológica de Colombia - UPTC, Tunja, Boyacá, Colombia; Population Genetics And Molecular Evolution (PGAME), Fundación Scient, Tunja, Boyacá, Colombia.
| |
Collapse
|
2
|
Ren Z, Shi Q, Xu S, Xu J, Yin Y, Lin Z, Xu S, Ma X, Liu Y, Zhu G, He X, Lu J, Li Y, Zhang W, Liu J, Yang Y, Han ET, Cao J, Lu F. Elicitation of T-cell-derived IFN-γ-dependent immunity by highly conserved Plasmodium ovale curtisi Duffy binding protein domain region II (PocDBP-RII). Parasit Vectors 2023; 16:269. [PMID: 37553591 PMCID: PMC10410920 DOI: 10.1186/s13071-023-05897-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/27/2023] [Indexed: 08/10/2023] Open
Abstract
BACKGROUND Infections with Plasmodium ovale are widely distributed but rarely investigated, and the resulting burden of disease has been underestimated. Plasmodium ovale curtisi Duffy binding protein domain region II (PocDBP-RII) is an essential ligand for reticulocyte recognition and host cell invasion by P. ovale curtisi. However, the genomic variation, antigenicity and immunogenicity of PocDBP-RII remain major knowledge gaps. METHODS A total of 93 P. ovale curtisi samples were collected from migrant workers who returned to China from 17 countries in Africa between 2012 and 2016. The genetic polymorphism, natural selection and copy number variation (CNV) were investigated by sequencing and real-time PCR. The antigenicity and immunogenicity of the recombinant PocDBP-RII (rPocDBP-RII) protein were further examined, and the humoral and cellular responses of immunized mice were assessed using protein microarrays and flow cytometry. RESULTS Efficiently expressed and purified rPocDBP-RII (39 kDa) was successfully used as an antigen for immunization in mice. The haplotype diversity (Hd) of PocDBP-RII gene was 0.105, and the nucleotide diversity index (π) was 0.00011. No increased copy number was found among the collected isolates of P. ovale curtisi. Furthermore, rPocDBP-RII induced persistent antigen-specific antibody production with a serum IgG antibody titer of 1: 16,000. IFN-γ-producing T cells, rather than IL-10-producing cells, were activated in response to the stimulation of rPocDBP-RII. Compared to PBS-immunized mice (negative control), there was a higher percentage of CD4+CD44highCD62L- T cells (effector memory T cells) and CD8+CD44highCD62L+ T cells (central memory T cells) in rPocDBP-RII‑immunized mice. CONCLUSIONS PocDBP-RII sequences were highly conserved in clinical isolates of P. ovale curtisi. rPocDBP-RII protein could mediate protective blood-stage immunity through IFN-γ-producing CD4+ and CD8+ T cells and memory T cells, in addition to inducing specific antibodies. Our results suggested that rPocDBP-RII protein has potential as a vaccine candidate to provide assessment and guidance for malaria control and elimination activities.
Collapse
Affiliation(s)
- Zhenyu Ren
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Qiyang Shi
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China
| | - Simin Xu
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Changshu Second People's Hospital, Suzhou, 215500, Jiangsu, People's Republic of China
| | - Jiahui Xu
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Yi Yin
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Zhijie Lin
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Jiangsu Key Laboratory of Experimental & Translational Non-Coding RNA Research, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Sui Xu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China
| | - Xiaoqin Ma
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China
| | - Yaobao Liu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China
| | - Guoding Zhu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China
| | - Xinlong He
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Jingyuan Lu
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Yinyue Li
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Wenwen Zhang
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Jiali Liu
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Yun Yang
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory On Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, People's Republic of China.
| | - Feng Lu
- Department of Pathogenic Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China.
- Affiliated Hospital of Yangzhou University, Yangzhou, 225000, People's Republic of China.
- Jiangsu Key Laboratory of Experimental & Translational Non-Coding RNA Research, School of Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China.
| |
Collapse
|
3
|
Park JH, Kim MH, Sutanto E, Na SW, Kim MJ, Yeom JS, Nyunt MH, Abbas Elfaki MM, Abdel Hamid MM, Cha SH, Alemu SG, Sriprawat K, Anstey NM, Grigg MJ, Barber BE, William T, Gao Q, Liu Y, Pearson RD, Price RN, Nosten F, Yoon SI, No JH, Han ET, Auburn S, Russell B, Han JH. Geographical distribution and genetic diversity of Plasmodium vivax reticulocyte binding protein 1a correlates with patient antigenicity. PLoS Negl Trop Dis 2022; 16:e0010492. [PMID: 35737709 PMCID: PMC9258880 DOI: 10.1371/journal.pntd.0010492] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 07/06/2022] [Accepted: 05/12/2022] [Indexed: 01/12/2023] Open
Abstract
Plasmodium vivax is the most widespread cause of human malaria. Recent reports of drug resistant vivax malaria and the challenge of eradicating the dormant liver forms increase the importance of vaccine development against this relapsing disease. P. vivax reticulocyte binding protein 1a (PvRBP1a) is a potential vaccine candidate, which is involved in red cell tropism, a crucial step in the merozoite invasion of host reticulocytes. As part of the initial evaluation of the PvRBP1a vaccine candidate, we investigated its genetic diversity and antigenicity using geographically diverse clinical isolates. We analysed pvrbp1a genetic polymorphisms using 202 vivax clinical isolates from six countries. Pvrbp1a was separated into six regions based on specific domain features, sequence conserved/polymorphic regions, and the reticulocyte binding like (RBL) domains. In the fragmented gene sequence analysis, PvRBP1a region II (RII) and RIII (head and tail structure homolog, 152-625 aa.) showed extensive polymorphism caused by random point mutations. The haplotype network of these polymorphic regions was classified into three clusters that converged to independent populations. Antigenicity screening was performed using recombinant proteins PvRBP1a-N (157-560 aa.) and PvRBP1a-C (606-962 aa.), which contained head and tail structure region and sequence conserved region, respectively. Sensitivity against PvRBP1a-N (46.7%) was higher than PvRBP1a-C (17.8%). PvRBP1a-N was reported as a reticulocyte binding domain and this study identified a linear epitope with moderate antigenicity, thus an attractive domain for merozoite invasion-blocking vaccine development. However, our study highlights that a global PvRBP1a-based vaccine design needs to overcome several difficulties due to three distinct genotypes and low antigenicity levels.
Collapse
Affiliation(s)
- Ji-Hoon Park
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Min-Hee Kim
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Edwin Sutanto
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Seok-Won Na
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Min-Jae Kim
- Department of Infectious Diseases, Asan Medical Center, Seoul, Republic of Korea
| | - Joon Sup Yeom
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Mohammed Mohieldien Abbas Elfaki
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
- Department of Microbiology and Parasitology, Faculty of Medicine, Jazan University, Jizan, Saudi Arabia
| | - Muzamil Mahdi Abdel Hamid
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Seok Ho Cha
- Department of Parasitology and Tropical Medicine, Inha University School of Medicine, Incheon, Republic of Korea
| | - Sisay Getachew Alemu
- College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- Armauer Hansen Research Institute, Jimma Road, Addis Ababa, Ethiopia
- Bioreliance, Rockville, Maryland, United States of America
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Matthew J. Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Sabah, Malaysia
| | - Bridget E. Barber
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Sabah, Malaysia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Sabah, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Sabah, Malaysia
- Gleneagles Hospital, Sabah, Malaysia
| | - Qi Gao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Yaobao Liu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
- School of Public Health, Nanjing Medical University, Nanjing, China
| | | | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine Research Building, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine Research Building, University of Oxford, Oxford, United Kingdom
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, Republic of Korea
| | - Joo Hwan No
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Seongnam, Republic of Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine Research Building, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
- * E-mail:
| |
Collapse
|
4
|
Lee S, Choi YK, Goo YK. Humoral and cellular immune response to Plasmodium vivax VIR recombinant and synthetic antigens in individuals naturally exposed to P. vivax in the Republic of Korea. Malar J 2021; 20:288. [PMID: 34183015 PMCID: PMC8237554 DOI: 10.1186/s12936-021-03810-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/08/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium vivax proteins with variant interspersed repeats (VIR) are the key proteins used by the parasite to escape from the host immune system through the creation of antigenic variations. However, few studies have been done to elucidate their role as targets of immunity. Thus, this study evaluated the naturally-acquired immune response against VIR proteins in vivax malaria-infected individuals in the Republic of Korea (ROK). METHODS Seven recombinant VIR proteins and two synthetic peptides previously studied in other countries that elicited a robust immune response were used to investigate the antibody and cellular immune response in 681 P. vivax-infected people in ROK. The expression of IgM, IgG, and IgG subclasses against each VIR antigen or against PvMSP1-19 was analysed by ELISA. PvMSP1-19, known as a promising vaccine candidate of P. vivax, was used as the positive control for immune response assessment. Furthermore, the cellular immune response to VIR antigens was evaluated by in vitro proliferative assay, cellular activation assay, and cytokine detection in mononuclear cells of the P. vivax-infected population. RESULTS IgM or IgG were detected in 52.4% of the population. Among all the VIR antigens, VIR25 elicited the highest humoral immune response in the whole population with IgG and IgM prevalence of 27.8% and 29.2%, respectively, while PvMSP1-19 elicited even higher prevalence (92%) of IgG in the population. As for the cellular immune response, VIR-C2, PvLP2, and PvMSP1-19 induced high cell activation and secretion of IL-2, IL-6, IL-10, and G-CSF in mononuclear cells from the P. vivax-infected population, comparable with results from PvMSP1-19. However, no significant proliferation response to these antigens was observed between the malaria-infected and healthy groups. CONCLUSION Moderate natural acquisition of antibody and cellular responses in P. vivax-infected Korean malaria patients presented here are similar to that in other countries. It is interesting that the immune response to VIR antigens is conserved among malaria parasites in different countries, considering that VIR genes are highly polymorphic. This thus warrants further studies to elucidate molecular mechanisms by which human elicit immune response to the malaria parasite VIR antigens.
Collapse
Affiliation(s)
- Sanghyun Lee
- Division of Bio Bigdata, Department of Precision Medicine, Korea National Institute of Health, Korea Disease Control and Prevention Agency, Cheongju, Chungbuk, 28159, Republic of Korea.,Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Young-Ki Choi
- Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, 28644, Republic of Korea.
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
| |
Collapse
|
5
|
Kepple D, Pestana K, Tomida J, Abebe A, Golassa L, Lo E. Alternative Invasion Mechanisms and Host Immune Response to Plasmodium vivax Malaria: Trends and Future Directions. Microorganisms 2020; 9:E15. [PMID: 33374596 PMCID: PMC7822457 DOI: 10.3390/microorganisms9010015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 11/21/2022] Open
Abstract
Plasmodium vivax malaria is a neglected tropical disease, despite being more geographically widespread than any other form of malaria. The documentation of P. vivax infections in different parts of Africa where Duffy-negative individuals are predominant suggested that there are alternative pathways for P. vivax to invade human erythrocytes. Duffy-negative individuals may be just as fit as Duffy-positive individuals and are no longer resistant to P.vivax malaria. In this review, we describe the complexity of P. vivax malaria, characterize pathogenesis and candidate invasion genes of P. vivax, and host immune responses to P. vivax infections. We provide a comprehensive review on parasite ligands in several Plasmodium species that further justify candidate genes in P. vivax. We also summarize previous genomic and transcriptomic studies related to the identification of ligand and receptor proteins in P. vivax erythrocyte invasion. Finally, we identify topics that remain unclear and propose future studies that will greatly contribute to our knowledge of P. vivax.
Collapse
Affiliation(s)
- Daniel Kepple
- Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA; (K.P.); (J.T.)
| | - Kareen Pestana
- Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA; (K.P.); (J.T.)
| | - Junya Tomida
- Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA; (K.P.); (J.T.)
| | - Abnet Abebe
- Ethiopian Public Health Institute, Addis Ababa 1000, Ethiopia;
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa 1000, Ethiopia;
| | - Eugenia Lo
- Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA; (K.P.); (J.T.)
| |
Collapse
|