The importance of genetics in the diagnosis of animal diseases - A review

Genetic diseases have always been present in the animal population but their significance has increased in recent decades. The wealth of knowledge on genomic information, systems biology and mechanisms of diseases provide great opportunities to elucidate the genetic bases of diseases. The use of recombinant DNA techniques in conjunction with conventional genetic methods have led to a rapid increase in knowledge of the genetic map. Many animal genes have been mapped to chromosomes. A detailed genetic map has become of great value in the diagnosis of genetic diseases and in the development of potential cures through gene transfer therapy. In view of the emerging animal diseases like avian influenza, swine influenza among others with serious health implications for humans, this review aims at highlighting the association between diseases and genes in animals. The information derived could assist in the prevention and management of emerging animal diseases and in future drug discovery processes

The Differential Susceptibility of Yoruba Ecotype Nigerian Indigenous Chicken Varieties To Newcastle Disease

This experiment was conducted to assess and compare the susceptibility of the varieties of Yoruba indigenous chicken ecotype: Yoruba Smooth Feathered (YSF), Yoruba Frizzled Feathered (YFF) and Yoruba Naked Neck (YNN) to Newcastle disease. A total of sixty (60) 16 weeks old chickens were used comprising of twenty (20) chickens per variety. The assessmentof their susceptibility to Newcastle disease was by evaluation of clinical signs, humoral response, mortality, pathology following contact with Newcastle disease infected chickens. The experimental chickens developed clinical signs of Newcastle disease from day 9 after infection. Haemagglutination inhibition (HI) titre was determined on days 0, 21and28 post-infection. On day 0, the HI titre of the 3 genotypes were below 3log2, on day 21, there were significant differences within the group (P<0.05) where in YNN had the highest mean HI titre of 7.5. Therewas decrease in the mean HI titre in all on day 28 with the YNN having the least reduction (P<0.05). The antibody titre against Newcastle disease was higher in the YNN than all the other varieties. The mortality commenced on day 10 after infection with 70% mortality in YSF, 40% in YFF and 30% in YNN. The proventricular, enteric and caecal tonsilar haemorrhages associated with the disease were more frequent and severe in YSF.This finding indicated that YFF and YSF may possibly be more susceptible to Newcastle disease than the YNN. It was concluded that indigenous chickens of Yoruba ecotype in Nigeria differ in their susceptibility to ND with YNN being possibly the most resistant to Newcastle disease followed by YFF and the least, YSF.Keywords: Hemagglutination inhibition, Newcastle Disease, indigenous Chicken, Ecotype, Varietie

Genetic differentiation and inheritance of random amplified polymorphic DNA (RAPD) markers in pectoral spine phenotypic sub-groups of Clarias gariepinus

Information on genetic relationship of phenotypically divergent sub-groups would be useful for better identification, utilization and management of species. Recent study revealed phenotypic divergence in a reservoir population of Clarias gariepinus. Genetic variability of polymerase chain reaction (PCR) products of the phenotypic divergent sub-groups was investigated in this study. Polymorphism and genetic variability were investigated in electrophoresed random amplified polymorphic DNA (RAPD)-PCR products of blood samples of twenty (20) C. gariepinus individuals. The population comprised of five (5) individuals of the non-peses phenotypic sub-group- individuals that did not possess anteriorly serrated pectoral spines denoted by S and fifteen (15) individuals of peses sub-groups that possessed anteriorly serrated pectoral spines denoted as C. Standard protocols were followed in analyzing six screened RAPD primers per individuals DNA fragment. Produced bands of pheno-grams were scored and analyzed to establish polymorphism as well as within and between sub-populations allelic variability using unweighted paired group method of algorithms (UPGMA) and dendrograms cluster analysis. Genotype data of individuals in the groups were tested for canonically significant discriminant grouping using discriminant function analysis (DFA). Results reveal that the primers were polymorphic: 746 bands were obtained from 63 detected loci which gave 80.95% polymorphism. Polymorphic information content (PIC) ranged between 0.18 and 0.49. Percentage polymorphic band were 78.00 and 69.84% for peses and non peses sub-groups, respectively. Dendrogram separated the population to two groups. All peses individuals were in one cluster while all the non-peses individuals were on the second cluster. Within group variations were also observed: DFA revealed that 100% of original phenotypically grouped cases were correctly classified. It was concluded that RAPD primers are suitable genetic markers for establishing variability in C. gariepinus sub-populations; the pectoral spine phenotypic groups are genetic variants and are potential varieties for the species. The results would have wide application in identification, utilization and management of genetic resources of C. gariepinus.Keywords: Random amplified polymorphic DNA (RAPD) marker, morphologic and genetic variability, Clarias gariepinus.African Journal of Biotechnology Vol. 12(37), pp. 5567-557

The comparative susceptibility of commercial and Nigerian indigenous chicken ecotypes to Salmonella gallinarum infection

This study was to evaluate the possible genetic resistance of exotic and indigenous chicks to Salmonella gallinarum. A total of 72 nine weeks-old chicks were used for the study. The Fulani ecotype (Fulani smooth feathers - FSF), Yoruba ecotype (Yoruba smooth feathers - YSF), and the Exotic  breed (Nera Black) chicks were infected with a dose of S. gallinarum (8.3 x 106 CFU) and were observed for 16 days. Evaluation of resistance was  based on clinical signs, mortality, pathology, leukocyte count, bacterial  count from liver and spleen of infected chicks. The highest peak for clinical signs in S. gallinarum infected chicks coincides with highest mortalities  recorded on day 11-12 dpi and bacterial count of both liver and spleen on day 8. The lymphocytes count declined on day 8 for all the experimental chicks except for the exotic breed. There was no significant difference between the bacterial counts of the different groups on day 8. In S. gallinarum infected chicks, 94.4% of all the chicks showed clinical signs after infection, the exotic breed showed a prolonged clinical signs while the Yoruba ecotype showed the least. 87.5%, 80.0% and 37.5% mortality were recorded in the exotic breed, Fulani and Yoruba ecotypes respectively. The study showed that the exotic chicken (Nera Black) was more susceptible to Salmonella gallinarum infection. It also indicated that within the ecotypes in Nigeria, Fulani ecotype was more susceptible to Salmonella gallinarum infection than the Yoruba ecotype. The lower clinical signs and mortality observed in Yoruba ecotype indicated a resistance of the ecotype to S. gallinarum infection.Keywords: Ecotypes, Nigerian Indigenous chicken, Salmonella gallinarum infection

Impact of repeated four-monthly anthelmintic treatment on Plasmodium infection in preschool children: a double-blind placebo-controlled randomized trial

<p>Abstract</p> <p>Background</p> <p>Helminth infections can alter susceptibility to malaria. Studies need to determine whether or not deworming programs can impact on <it>Plasmodium </it>infections in preschool children.</p> <p>Methods</p> <p>A double-blind placebo-controlled randomised trial was conducted to investigate the impact of anthelmintic treatment on <it>Plasmodium </it>infection in children aged 12-59 months. Children were randomly assigned to receive either albendazole or placebo every four months for 12 months with a follow-up at 14 months.</p> <p>Results</p> <p>320 children (out of 1228, 26.1%) complied with all the follow-up assessments. <it>Plasmodium </it>prevalence and mean <it>Plasmodium </it>parasite density was significantly higher in the treatment group (44.9% and 2319 ± SE 511) compared to the placebo group (33.3% and 1471 ± 341) at baseline. The odds of having <it>Plasmodium </it>infection increased over time for children in both the placebo and treatment groups, however this increase was significantly slower for children in the treatment group (P = 0.002). By month 14, mean <it>Plasmodium </it>density had increased by 156% in the placebo group and 98% in the treatment group but the rate of change in <it>Plasmodium </it>density was not significantly different between the groups. The change from baseline in haemoglobin had a steeper increase among children in the treatment group when compared to the placebo group but this was not statistically significant.</p> <p>Conclusions</p> <p>Repeated four-monthly anthelminthic treatments for 14 months resulted in a significantly lower increase in the prevalence of <it>Plasmodium </it>infection in preschool children which coincided with a reduction in both the prevalence and intensity of <it>A. lumbricoides </it>infections.</p> <p>Trial Registration</p> <p>Current controlled trials ISRCTN44215995</p

Quinine, an old anti-malarial drug in a modern world: role in the treatment of malaria

Quinine remains an important anti-malarial drug almost 400 years after its effectiveness was first documented. However, its continued use is challenged by its poor tolerability, poor compliance with complex dosing regimens, and the availability of more efficacious anti-malarial drugs. This article reviews the historical role of quinine, considers its current usage and provides insight into its appropriate future use in the treatment of malaria. In light of recent research findings intravenous artesunate should be the first-line drug for severe malaria, with quinine as an alternative. The role of rectal quinine as pre-referral treatment for severe malaria has not been fully explored, but it remains a promising intervention. In pregnancy, quinine continues to play a critical role in the management of malaria, especially in the first trimester, and it will remain a mainstay of treatment until safer alternatives become available. For uncomplicated malaria, artemisinin-based combination therapy (ACT) offers a better option than quinine though the difficulty of maintaining a steady supply of ACT in resource-limited settings renders the rapid withdrawal of quinine for uncomplicated malaria cases risky. The best approach would be to identify solutions to ACT stock-outs, maintain quinine in case of ACT stock-outs, and evaluate strategies for improving quinine treatment outcomes by combining it with antibiotics. In HIV and TB infected populations, concerns about potential interactions between quinine and antiretroviral and anti-tuberculosis drugs exist, and these will need further research and pharmacovigilance

A Large-Scale Multi-ancestry Genome-wide Study Accounting for Smoking Behavior Identifies Multiple Significant Loci for Blood Pressure

Genome-wide association analysis advanced understanding of blood pressure (BP), a major risk factor for vascular conditions such as coronary heart disease and stroke. Accounting for smoking behavior may help identify BP loci and extend our knowledge of its genetic architecture. We performed genome-wide association meta-analyses of systolic and diastolic BP incorporating gene-smoking interactions in 610,091 individuals. Stage 1 analysis examined similar to 18.8 million SNPs and small insertion/deletion variants in 129,913 individuals from four ancestries (European, African, Asian, and Hispanic) with follow-up analysis of promising variants in 480,178 additional individuals from five ancestries. We identified 15 loci that were genome-wide significant (p <5 x 10(-8)) in stage 1 and formally replicated in stage 2. A combined stage 1 and 2 meta-analysis identified 66 additional genome-wide significant loci (13, 35, and 18 loci in European, African, and trans-ancestry, respectively). A total of 56 known BP loci were also identified by our results (p <5 x 10(-8)). Of the newly identified loci, ten showed significant interaction with smoking status, but none of them were replicated in stage 2. Several loci were identified in African ancestry, highlighting the importance of genetic studies in diverse populations. The identified loci show strong evidence for regulatory features and support shared pathophysiology with cardiometabolic and addiction traits. They also highlight a role in BP regulation for biological candidates such as modulators of vascular structure and function (CDKN1B, BCAR1-CFDP1, PXDN, EEA1), ciliopathies (SDCCAG8, RPGRIP1L), telomere maintenance (TNKS, PINX1, AKTIP), and central dopaminergic signaling MSRA, EBF2).Peer reviewe