Effect of Saw Dust Biochar and NPK 15:15:15 Inorganic Fertilizer on Moringa oleifera Seedlings Grown in an Oxisol.

A factorialexperiment was conducted in the screen house of Bowen University, Iwo, Nigeria to examine the response of Moringa oleifera Lam. seedlings to saw dust biochar and NPK 15:15:15 inorganic fertilizer amendments. The plants were grown for twelve weeks in top soil (0-30cm) collected from an Oxisol in the University Research Farm. Biochar and NPK inorganic fertilizer were applied at four levels, viz 0, 5, 10 & 20 t C ha-1 and 0, 22.5, 45 & 90 kgNha-1 respectively. The results indicated that the tree species responded positively to sole application of either inorganic fertilizer or saw dust biochar. Tree height, stem diameter and dry matter yield increased, in all cases, over the non-treated control. The higher the application rate of either NPK inorganic fertilizer or saw dust biochar, the more beneficial their effects were on all the plant parameters considered except for the number of branches produced which did not appear to be affected. No significant positive correlation was established between application rates of inorganic fertilizer and tree parameters. However, rates of application of saw dust biochar were significantly and positivelycorrelated with tree height (r= 0.98*), stem diameter (r=0.99**) and dry matter yield (r=0.96*). Interaction between biochar and inorganic fertilizer was not statistically significant for tree height, stem diameter and number of branches but it was significant for dry matter yield and root: shoot ratio. The combined effects of biochar (20t Cha-1)and NPK inorganic fertilizer (90kgNha-1) resulted in the production of seedling that was superior in dry matter yield to any other seedlings produced at any biochar inorganic fertilizer combination level. Therefore, complementary use of inorganic fertilizer and saw dust biochar at the highest application level of each gave the best result in producing healthy Moringa seedlings in this study.Keyword: Biochar, Moringa oleifera, nursery, saw dus

Withdrawn Article: A comparative study on the toxicity of three commercial detergents on the survival of the Nile Tilapia, Oreochromis niloticus

This paper has been removed at the request of the JARD Editorial Committee as well as the authors

Review Article: Prospect and Progress of Malaria Vaccine Development

Malaria kills one child every 30 seconds in Africa. The development of a safe vaccine remains an urgent unmet need which could greatly control and even lead to the eradication of the disease. The success recorded in the recent vaccine trials have given some ray of hope that a safe and effective vaccine against malaria will soon be produced. In this article, we bring together important published information on the status of malaria vaccine development and reviewed some field trials and the obstacles as well as prospect for effective malaria vaccination. Key words: Malaria vaccine, prospect, review Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 145-15

Allelic Diversity of Merozoite Surface Protein 2 Gene of P Falciparum among Children in Osogbo, Nigeria

The genetic diversity of Plasmodium falciparum (P falciparum) infections in humans is implicated in the pathogenesis of malaria. This study provides the first estimate of the genetic diversity and genotype multiplicity of Plasmodium falciparum infection in children with uncomplicated P falciparum malaria in Osogbo, Nigeria. One hundred and one isolates were used for analysis of parasite population polymorphism and genotyped by nested-PCR of merozoite surface protein 2 (MSP2) block 3. Amplicons were obtained for all the 101 genotyped samples in MSP2 PCR with 9 alleles varying in size between 300 and 800 base pair. Thirty-three (31.7%) samples had FC27 allele while 27 (26.7%) had 3D7 allele and 35 (34.7%) had mixed alleles (3D7+FC27). The Multiplicity of Infection (MOI) in the population was 1.6. Children in the age group of > 4–8 years had the highest number of different genotypes in their samples (1.8). The number of MSP2 bands per isolate was lower in the older age group (1.3) but the difference was not statistically significant. Children with parasite density range 5001–10 000 had the highest MOI of 2 while those with parasite density range 1000–5000 had the lowest of 1.5. In conclusion, the present study shows that the field isolates are highly diverse in respect of MSP2 and multiplicity of infection was neither age nor parasite density dependent in the study population. Keyword: Genetic diversity, MSP2, Nigeria, plasmodium falciparum. Diversidad Alélica del Gen de la Proteína de Superficie del Merozoíto 2 del P Falciparum entre los Niños de Osogobo, en Nigeria RESUMEN La diversidad genética de las infecciones por Plasmodium falciparum en los humanos se halla implícita en la patogénesis de la malaria. Este estudio proporciona un primer estimado de la diversidad genética y multiplicidad del genotipo de la infección por Plasmodium falciparum en los niños con malaria por P falciparum malaria sin complicaciones en Osogbo, Nigeria. Ciento un aislados fueron usados para el análisis del polimorfismo de la población parasitaria, y genotipificados mediante reacción en cadena de la polimerasa (RCP) anidada de la proteína de superficie del merozoíto 2 (MSP2) bloque 3. Se obtuvieron amplicones para las 101 muestras genotipificadas con RCP de MSP2, con 9 alelos variando en tamaño entre 300 y 800 par de bases. Treinta y tres (31.7%) muestras tenían el alelo FC27 mientras 27 (26.7%) tenían el alelo 3D7 y 35 (34.7%) tenían alelos mezclado (3D7+FC27). La multiplicidad de infección (MOI) en la población fue 1.6. Los niños en el grupo etario de > 4–8 años tenían el número más alto de genotipos diferentes en sus muestras (1.8). El número de bandas de MSP2 por aislado era más bajo en el grupo etario de mayor edad (1.3) pero la diferencia no era estadísticamente significativa. Los niños con un rango de densidad parasitaria 5001–10 000 tenían el MOI más alto equivalente a 2, mientras aquéllos con rango de densidad parasitaria 1000–5000 tenían el MOI más bajo equivalente a 1.5. En conclusión, el presente estudio muestra que los aislados de campo son altamente diversos con respecto al MSP2, y que la multiplicidad de la infección no depende ni de la edad ni de la densidad parasitaria de la población en estudio. Palabras claves: Diversidad genética, MSP2, Nigeria, plasmodium falciparum

Human African trypanosomes: challenges posed to the human immune system.

Human infection by either Trypanosoma brucei gambiense (Tbg) or Trypanosoma brucei rhodesiense (Tbr) and the establishment of disease is made possible by the intermittent switching of their variant surfaceglycoprotein (VSG) and expression of serum resistance associated (SRA) protein (by Tbr) which nullifies the lytic action of the normal human serum. The ability to switch expression from one VSG to the other is recognized to be the major mechanism that permits the parasite to evade the otherwise efficient host antibody, hence preventing parasite elimination and allowing the establishment of a chronic infection. These changes were reported to: disable the host’s capacity to mount a protective anti-parasite antibody response and prevent the development of effective B-cell memory against encountered variant antigenic parasite types (VATs). Both B cell-mediated antibody response and the Th1 cell responses leading to the production of interferon-gamma (IFN-ϒ) are required for maximum host resistance to trypanosomes, with IFN-ϒ acting to induce macrophage trypanolytic and trypanostatic activities. High levels of both tumor necrosis factor alpha (TNFα) and interleukin 10 (IL-10) have been associated with trypanosomal infection. Trypanosomal genetics (including the parasite’s intrinsic characteristics), human immune response polymorphisms and geographical locations are important elements that describe the severity or mildness of HAT. As the parasite devices ways to evade thehuman immune system, and in the absence of a suitable vaccine, surveillance, prompt diagnosis and treatment with available drugs and vector control efforts will go along way in reducing the incidence of HAT.Keywords: African trypanosomes, Variant surface glycoprotein, Serum resistance associated (SRA) protein, Trypanosomal genetic polymorphisms, Immune response polymorphism

Environmental impact on the bacteriological quality of domestic water supplies in Lagos, Nigeria Impacto ambiental sobre a qualidade bacteriológica do abastecimento domiciliar de água em Lagos, Nigéria

OBJECTIVE: To assess the impact of town planning, infrastructure, sanitation and rainfall on the bacteriological quality of domestic water supplies. METHODS: Water samples obtained from deep and shallow wells, boreholes and public taps were cultured to determine the most probable number of Escherichia coli and total coliform using the multiple tube technique. Presence of enteric pathogens was detected using selective and differential media. Samples were collected during both periods of heavy and low rainfall and from municipalities that are unique with respect to infrastructure planning, town planning and sanitation. RESULTS: Contamination of treated and pipe distributed water was related with distance of the collection point from a utility station. Faults in pipelines increased the rate of contamination (p<0.5) and this occurred mostly in densely populated areas with dilapidated infrastructure. Wastewater from drains was the main source of contamination of pipe-borne water. Shallow wells were more contaminated than deep wells and boreholes and contamination was higher during period of heavy rainfall (p<0.05). E. coli and enteric pathogens were isolated from contaminated supplies. CONCLUSIONS: Poor town planning, dilapidated infrastructure and indiscriminate siting of wells and boreholes contributed to the low bacteriological quality of domestic water supplies. Rainfall accentuated the impact.<br>OBJETIVO: Avaliar o impacto do planejamento urbano, da infra-estrutura, do saneamento e dos índices pluviométricos sobre a qualidade bacteriológica do abastecimento domiciliar de água. MÉTODOS: Foi realizada cultura de amostras de água obtida de poços superficiais e profundos, fossos e água corrente de bicas públicas para determinar o número mais provável de Escherichia coli e coliformes totais por meio da técnica de múltiplos tubos. Patógenos entéricos foram detectados pelo uso de meios diferenciais e seletivos. Amostras foram coletadas durante os períodos de seca e de chuvas intensas em municípios com características singulares de infra-estrutura, planejamento urbano e saneamento. RESULTADOS: A contaminação de água tratada ou encanada esteve relacionada à distância do ponto de coleta com relação à estação de tratamento. Defeitos na canalização aumentaram o índice de contaminação (p<0,5), principalmente em áreas densamente povoadas com infra-estrutura arruinada. Os despejos de bueiros representaram a principal fonte de contaminação da água encanada. Houve maior contaminação em poços superficiais do que em fossos e durante os períodos de chuvas intensas (p<0,05). E. coli e outros patógenos entéricos foram isolados de fontes de abastecimento contaminadas. CONCLUSÕES: A falta de planejamento urbano, as más condições de infra-estrutura e a localização indiscriminada de poços e fossos contribuíram para a baixa qualidade bacteriológica do abastecimento domiciliar de água. As águas das chuvas agravaram o impacto

Effects of partial or total fish meal replacement by agricultural by-product diets on gonad maturation, sex steroids and vitellogenin dynamics of African catfish (Clarias gariepinus)

The establishment of the first sexual maturation was characterized in African catfish (Clarias gariepinus) in order to study the efficiency of replacement of fish meal (FM) by diets composed of local vegetable ingredients. Four diets were formulated containing decreasing levels of FM (50-0% for diet 1 to diet 4) and increasing proportions of vegetable ingredients (50-100%). Gonadosomatic index (GSI), diameter and percentages of developmental stages of oocytes, plasma sex steroids and vitellogenin dynamics were investigated from February to June using one-year-old fish. Fish were individually tagged, and 12 individuals from each diet were investigated monthly. Replacement of FM with plant ingredients did not affect the GSI neither in males, nor in females. All males were spermiating, and no abnormal gonads were found. In females, GSI and percentages of advanced stages of oocytes decreased during the dry season, indicating seasonal changes in gonad development. Moreover, oocytes were in late exogenous vitellogenesis, but no final maturation stages were observed, whatever the diet. Higher plasma levels of E2 in females and of androgens (T and 11-KT) in both sexes were observed in fish fed diet 4 than in those receiving diet 1 depending on the season. Levels of plasma E2 and ALP (indicator for vitellogenin) in males did not differ among treatments and seasons suggesting no phytoestrogenic activity. The results showed that total replacement of FM by vegetable diets composed of groundnut oilcakes, bean and sunflower meals has no deleterious effect on the onset of sexual maturation in African catfish but, may stimulate the sex steroid production and in turns may potentially exert some positive actions on reproductive success