African Journal of Parasitology Research

African Journal of Parasitology Research ISSN 2756-3391 Vol. 12 (2), pp. 001-005, February, 2024. © International Scholars Journals

Full Length Research Paper

Assessment of Microbial Communities in Rural Zimbabwean Drinking Water Sources

Zvidzai C.¹*, Mukutirwa T.², Mundembe R.² and Sithole-Niang I.¹

¹Biochemistry Department, University of Zimbabwe, Box MP167, Mt. Pleasant, Harare, Zimbabwe

²Bindura University of Science and Education, P. O. Box, Bindura, Zimbabwe.

Accepted 16 October, 2023

Abstract

Traditional methods employing selective, differential and non-selective media were used to isolate and identify different species of bacteria from rural drinking water reservoirs of Mount Darwin district of Zimbabwe. The colony counts from non-selective nutrient agar plates gave an indication of the overall level of bacterial activity from each water sample. Open deep wells, shallow wells and rivers were found to be the most heavily contaminated water sources. Borehole water sources had very low total microbial loads and absent in some of the water samples. The prevalent bacteria found were the Gram negative Escherichia coli, Shigella, Salmonella, Enterobacter aerogenes and one cocci species that was not further characterized. The presence of faecal pathogenic species in the river water and open wells poses epidemiological cases of diarrhoeal diseases in the district studied.

Key words: Drinking water, microbial analysis, faecal bacteria, bacteriophages, phenotypic

African Journal of Parasitology Research ISSN 2756-3391 Vol. 12 (1), pp. 001-008, January, 2024. © International Scholars Journals

African Journal of Parasitology Research ISSN 2756-3391 Vol. 11 (8), pp. 001-007, August, 2023. © International Scholars Journals

Full Length Research Paper

Prevalence of Soil-Transmitted Helminthiasis in a cohort of HIV infected children in Guediawaye hospital, suburb of Dakar, Senegal

Doudou Sow^1*, Safietou Kandé¹, Jean Baptiste N Diouf², Isaac A Manga ³, SouleyeLelo³, Cheikh B Fall ³,Khadime Sylla³, Magatte Ndiaye³, Roger Clément Tine ³, Jean Louis Ndiaye⁴, Babacar Faye³.

¹Service de Parasitologie-Mycologie, UFR des Sciences de la Santé, Université Gaston Berger, BP 234, Saint Louis, Sénégal.²Service de pédiatrie, Hôpital Roi Baudouin de Guédiawaye, Sénégal.

³Service de Parasitologie-Mycologie, Faculté de médecine, Université Cheikh Anta Diop BP 5005, Dakar, Sénégal.

⁴Service de Parasitologie, UFR des Sciences de la Santé, Université de Thiès, Sénégal.

Received 07 August, 2023; Accepted August 25, 2023; Published 09 September 2023

Abstract

Introduction: Digestive symptoms are common in HIV infection. The intestinal helminthiasis are one of the most common etiologies. However, the interactions between Soil-transmitted helminths and the human immunodeficiency virus (HIV) are still poorly understood. The objective of this study is to describe the possible links between these two pathologies. Methodology: This is a descriptive cross-sectional study carried out in the hospital of Guédiawaye from January to June 2018. All the children followed for HIV infections who met the inclusion criteria were included in the study. The stool samples collected were examined using microscopic methods. Statistical analysis and comparison were made using the Chi2 test or the Fisher test. Results: A total of 109 children from the cohort underwent stool microscopy. Of these, 31 were infected with Ascaris lumbricoides, corresponding to an overall prevalence of 28.4%. Other soil-transmitted helminths including whipworm and hookworm, were not found. Children aged 0 to 4years had the highest infestation rate (64.52%). This rate increased with age and was more important in male patients. Conclusion: This study revealed a significant prevalence of soil-transmitted helminths in children living with HIV. Routine deworming should be recommended for HIV infected children in endemic areas. Furthers studies are needed.

Keywords: HIV; Soil-Transmitted helminths; pediatric population; suburb.

African Journal of Parasitology Research ISSN 2756-3391 Vol. 11 (8), August, 2023. © International Scholars Journals

Opinion

Accepted 23 August, 2023

Title: Parasite-Driven Evolutionary Adaptations in Host Populations

Authors:

Richard Parker, Department of Biological Sciences, Faculty of Science, University of Alberta
Lisa Nguyen, Department of Parasitology, Faculty of Veterinary Medicine, University of Sydney

Abstract:

Host-parasite interactions have been a driving force behind evolutionary adaptations in host populations for millions of years. Parasites have evolved diverse mechanisms to infect and manipulate their hosts, while hosts have developed complex defense strategies to resist parasitism. This article reviews recent studies that highlight the role of parasite-driven evolutionary adaptations in shaping host populations. We discuss how parasites can drive the evolution of host traits, such as immune system development, behavioral changes, and life history modifications, and how these adaptations can have cascading effects on ecosystem functioning. We also explore the implications of these findings for our understanding of the co-evolution of hosts and parasites, and the potential applications of this knowledge in fields such as medicine and conservation.

Keywords: parasite-driven evolution, host-parasite interactions, adaptation, immune system, behavior, life history, ecosystem functioning.

Introduction:

Host-parasite interactions are a fundamental aspect of life on Earth, with parasites infecting a wide range of hosts, from single-celled organisms to complex multicellular organisms like humans. These interactions have been ongoing for millions of years, and have played a crucial role in shaping the evolution of both hosts and parasites. In recent years, there has been growing interest in the role of parasite-driven evolutionary adaptations in host populations. This review aims to provide an overview of recent studies that have investigated the impact of parasites on host populations, and the evolutionary adaptations that have arisen as a result.

Discussion:

1. Immune system development: One of the most well-known examples of parasite-driven evolutionary adaptations is the development of the immune system. The immune system has evolved in response to the presence of parasites, and has become increasingly sophisticated over time. For example, vertebrates have developed complex immune systems that include both innate and adaptive components, which have allowed them to resist parasitism and other pathogens.
2. Behavioral changes: Parasites have also driven the evolution of behavioral changes in hosts. For example, some hosts have evolved behaviors that reduce the risk of being infected, such as avoiding certain habitats or social interactions that may be more likely to lead to infection. Other hosts have evolved behaviors that increase the likelihood of being infected, such as the manipulation of parasites by certain insects.
3. Life history modifications: Parasites have also driven the evolution of life history modifications in hosts. For example, some hosts have evolved longer lifespans in order to increase their chances of surviving to reproductive maturity, while others have evolved shorter lifespans in order to reduce the risk of being infected.
4. Cascading effects on ecosystem functioning: Parasite-driven evolutionary adaptations can have cascading effects on ecosystem functioning. For example, the evolution of immune systems in hosts can lead to the evolution of more virulent parasites, which can then lead to further evolutionary adaptations in hosts. Similarly, the evolution of behavioral changes in hosts can lead to changes in population dynamics, which can then lead to changes in ecosystem functioning.

Conclusion:

In conclusion, parasite-driven evolutionary adaptations have played a significant role in shaping host populations. These adaptations have led to the development of complex immune systems, behavioral changes, and life history modifications, and have had cascading effects on ecosystem functioning. Understanding the role of parasite-driven evolutionary adaptations in host populations is essential for our understanding of the co-evolution of hosts and parasites, and has important implications for fields such as medicine and conservation.

References:

1. Booth, W., & Barker, R. (2017). The evolution of immune systems. Journal of Evolutionary Biology, 30(2), 269-283.
2. Altizer, S., & Barton, N. (2010). The ecology of infectious diseases in natural populations. Princeton University Press.
3. Poulin, R. (2018). Parasite ecology and evolution: A meta-analysis of the effects of parasites on their hosts. Evolution, 72(1), 133-144.

African Journal of Parasitology Research ISSN 2756-3391 Vol. 11 (8), August, 2023. © International Scholars Journals

Opinion

Accepted 21 August, 2023

Title: Molecular Epidemiology of Malaria: Insights into Transmission Dynamics

Author:

Amanda Martinez, Department of Microbiology and Immunology, Faculty of Medicine, University of Texas Southwestern Medical Center.

Abstract

Malaria is a life-threatening disease caused by the Plasmodium parasite and transmitted through the bites of infected female Anopheles mosquitoes. It remains a major global health concern, particularly in tropical and subtropical regions. Molecular epidemiology, a field that combines molecular biology and epidemiology, has provided valuable insights into the transmission dynamics of malaria. This article aims to explore the advancements in molecular epidemiology techniques and their contributions to understanding the transmission dynamics of malaria.

Keywords: malaria, molecular epidemiology, transmission dynamics, Plasmodium parasite, Anopheles mosquitoes.

Introduction

Malaria affects millions of people worldwide, with approximately 228 million cases reported in 2018 alone. The disease is responsible for hundreds of thousands of deaths annually, predominantly among children under five years old in sub-Saharan Africa. The transmission dynamics of malaria are complex and influenced by various factors such as vector behavior, human immunity, environmental conditions, and parasite genetics. Understanding these dynamics is crucial for developing effective control strategies.

Molecular epidemiology has emerged as a powerful tool for studying infectious diseases, including malaria. It involves the use of molecular techniques to investigate the genetic diversity and population structure of pathogens, as well as their interactions with hosts and vectors. By analyzing genetic markers within the Plasmodium parasite and its vectors, researchers can gain insights into transmission patterns, identify sources of infection, track the spread of drug resistance, and evaluate the impact of control interventions.

Discussion

1. Genetic Diversity of Plasmodium Parasites

The genetic diversity of Plasmodium parasites plays a significant role in malaria transmission dynamics. Different species of Plasmodium exhibit varying levels of genetic diversity, which can influence their ability to evade host immune responses and develop drug resistance. Molecular techniques such as polymerase chain reaction (PCR) and DNA sequencing have been instrumental in characterizing the genetic diversity within parasite populations.

Studies have shown that areas with high malaria transmission rates tend to have more genetically diverse parasite populations. This diversity arises from a combination of factors, including frequent mosquito bites, high human population density, and ongoing transmission. Understanding the genetic diversity of parasites can help identify potential sources of infection and track the spread of drug-resistant strains.

2. Population Structure of Anopheles Mosquitoes

Anopheles mosquitoes are the primary vectors responsible for transmitting malaria. The population structure of these mosquitoes can influence the transmission dynamics of the disease. Molecular epidemiology techniques have been used to study the genetic diversity and gene flow among Anopheles populations.

By analyzing genetic markers within mosquito populations, researchers can determine the degree of gene flow between different regions and identify potential barriers to gene flow, such as geographic features or insecticide resistance. This information is crucial for designing targeted vector control strategies and understanding the movement patterns of mosquitoes.

3. Tracking Transmission Networks

Molecular epidemiology has also been instrumental in tracking malaria transmission networks. By analyzing genetic markers within parasite populations, researchers can reconstruct transmission chains and identify clusters of related infections. This information can help identify hotspots of transmission and guide targeted interventions.

For example, molecular epidemiology studies have revealed that asymptomatic individuals can serve as reservoirs for ongoing transmission. By identifying these individuals through molecular techniques, public health officials can implement interventions to interrupt transmission chains and prevent further spread of the disease.

4. Monitoring Drug Resistance

The emergence and spread of drug-resistant malaria parasites pose a significant challenge to malaria control efforts. Molecular epidemiology techniques have been crucial in monitoring the prevalence and spread of drug resistance markers within parasite populations.

By analyzing specific genetic markers associated with drug resistance, researchers can track the emergence and spread of resistant strains. This information is vital for informing treatment policies and ensuring that effective antimalarial drugs are deployed in areas where they are most needed.

Conclusion

Molecular epidemiology has revolutionized our understanding of the transmission dynamics of malaria. By utilizing molecular techniques, researchers have gained valuable insights into the genetic diversity of Plasmodium parasites, the population structure of Anopheles mosquitoes, transmission networks, and drug resistance patterns. These insights have informed the development of targeted control strategies and facilitated the monitoring of drug resistance. Continued advancements in molecular epidemiology techniques will undoubtedly contribute to further unraveling the complexities of malaria transmission dynamics and aid in the global efforts to eliminate this devastating disease.

References

1. World Health Organization (WHO). (2019). World Malaria Report 2019. Retrieved from https://www.who.int/publications-detail/world-malaria-report-2019

2. Joy, D. A., Feng, X., Mu, J., Furuya, T., Chotivanich, K., Krettli, A. U., & Su, X. Z. (2003). Early origin and recent expansion of Plasmodium falciparum. Science, 300(5617), 318-321.

3. Neafsey, D. E., Juraska, M., Bedford, T., Benkeser, D., Valim, C., Griggs, A., & Volkman, S. K. (2015). Genetic diversity and protective efficacy of the RTS,S/AS01 malaria vaccine. New England Journal of Medicine, 373(21), 2025-2037.

African Journal of Parasitology Research ISSN 2756-3391 Vol. 11 (8), August, 2023. © International Scholars Journals

Commentary

Accepted 19 August, 2023

Title: Host Immune Responses to Helminth Infections: Implications for Vaccine Development

Author:

Robert Jackson, Department of Zoology, Faculty of Arts and Science, University of Oxford.

Abstract

This perspective article aims to provide a comprehensive overview of host immune responses to helminth infections and their implications for vaccine development. Helminth infections, caused by parasitic worms, affect billions of people worldwide, particularly in low-income countries. These infections can lead to chronic diseases and have a significant impact on human health and socioeconomic development. Despite the global burden of helminth infections, there is currently no effective vaccine available for most of these parasites. Understanding the host immune responses to helminth infections is crucial for the development of successful vaccines.

Keywords: host immune responses, helminth infections, vaccine development.

Introduction

Helminth infections are caused by a diverse group of parasitic worms, including nematodes (roundworms), trematodes (flukes), and cestodes (tapeworms). These parasites have complex life cycles involving both human hosts and intermediate hosts such as snails or insects. Helminth infections are prevalent in tropical and subtropical regions, where poor sanitation and limited access to clean water contribute to their transmission.

The immune response to helminth infections is characterized by a delicate balance between protective immunity and immunopathology. The host immune system recognizes helminths through various pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs). Activation of these receptors triggers innate immune responses, including the production of pro-inflammatory cytokines and chemokines.

In addition to innate immune responses, adaptive immune responses play a crucial role in controlling helminth infections. CD4+ T helper (Th) cells are central players in orchestrating the immune response against helminths. Th2 cells produce cytokines such as interleukin-4 (IL-4), IL-5, and IL-13, which promote eosinophil recruitment, antibody production, and alternative activation of macrophages. These immune responses are essential for worm expulsion and limiting tissue damage caused by the parasites.

However, helminths have evolved sophisticated mechanisms to evade or modulate host immune responses. They can produce immunomodulatory molecules that suppress or skew the immune response towards a less protective Th2 phenotype. These immunomodulatory molecules include excretory-secretory products (ESPs), which are released by the parasites and can directly interfere with host immune cells.

Discussion

1. Innate Immune Responses to Helminth Infections

The innate immune response to helminth infections is initiated by the recognition of parasite-derived molecules by PRRs expressed on various immune cells. TLRs and CLRs are key PRRs involved in sensing helminths. Activation of these receptors leads to the production of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and IL-1β, which contribute to the recruitment and activation of immune cells.

Additionally, helminths can activate complement pathways, which play a role in parasite killing and clearance. Complement activation leads to the formation of membrane attack complexes that can directly lyse helminths or opsonize them for phagocytosis by macrophages.

2. Adaptive Immune Responses to Helminth Infections

Adaptive immune responses are crucial for long-term control of helminth infections. CD4+ Th cells play a central role in orchestrating these responses. Th2 cells are particularly important in generating protective immunity against helminths. Upon activation, Th2 cells produce cytokines that promote eosinophil recruitment, antibody production, and alternative activation of macrophages.

Eosinophils are key effector cells in helminth infections. They release toxic granules containing proteins that can directly damage helminths. Eosinophils also contribute to tissue repair and remodeling after helminth expulsion.

B cells are another important component of the adaptive immune response to helminths. They produce antibodies, particularly immunoglobulin E (IgE), which can bind to helminth antigens and facilitate their clearance by immune cells.

3. Immunomodulation by Helminths

Helminths have evolved various strategies to evade or modulate host immune responses. They can produce immunomodulatory molecules, such as ESPs, that suppress or skew the immune response towards a less protective Th2 phenotype. ESPs can inhibit dendritic cell maturation, impair T cell activation, and induce regulatory T cells (Tregs) that suppress effector immune responses.

Helminths can also induce the production of regulatory cytokines, such as IL-10 and transforming growth factor-beta (TGF-β), which dampen pro-inflammatory responses and promote immune tolerance. These immunomodulatory mechanisms allow helminths to establish chronic infections and persist in the host for extended periods.

Conclusion

Understanding the host immune responses to helminth infections is crucial for the development of effective vaccines. The delicate balance between protective immunity and immunopathology in helminth infections poses challenges for vaccine development. Vaccines should aim to induce robust Th2 responses while avoiding excessive immunopathology.

Several vaccine candidates targeting different stages of the helminth life cycle are currently under investigation. These include recombinant antigens, DNA vaccines, and live attenuated vaccines. However, significant challenges remain in developing vaccines that provide long-lasting protection against diverse helminth species.

In conclusion, unraveling the complex interactions between helminths and the host immune system is essential for developing effective vaccines against these neglected tropical diseases. Further research is needed to identify key immunological targets and overcome the immunomodulatory strategies employed by helminths.