Molecular characterization of African swine fever virus in apparently healthy domestic pigs in Uganda

African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Uganda where outbreaks regularly occur. There is neither a vaccine nor treatment available for ASF control. Twenty two African swine fever virus (ASFV) genotypes (I - XXII) have been identified based on partial sequencing of the C-terminus of the major capsid protein p72 encoded by the B646L gene. The majority of previously characterized Ugandan ASFV strains belong to genotype IX. The major aim of the current study was to determine the ASFV genotypes among asymptomatic slaughter pigs at Wambizi slaughterhouse and in some parts of the country where surveillance was done. Three discrete regions of the ASFV were analysed in the genomes of viruses detected in asymptomatic domestic pigs. The analysis was conducted by genotyping based on sequence data from three single copy ASFV genes. The E183L gene encoding the structural protein P54 and part of the gene encoding the p72 protein were used to delineate genotypes, before intra-genotypic resolution of viral relationships by analysis of tetramer amino acid repeats within the hypervariable central variable region (CVR) of the B602L gene. All the ASF viruses obtained from this study clustered with previous viruses in genotype IX based on analysis of the p72 and P54 genes. Analysis of the CVR gene grouped the viruses in three different subgroups; 13, 23 and 25. Only one genotype is circulating in Uganda among asymptomatic domestic pigs and it is the same virus causing outbreaks in the country and parts of neighbouring Kenya.Keywords: African swine fever virus, asymptomatic, slaughterhouse, P54, p72, CVR gene, genotypesAfrican Journal of Biotechnology, Vol 13(25)2491-249

Characterisation and evaluation of the efficiency of petroleum degrading bacteria isolated from soils around the oil exploration areas in western Uganda

Contamination with petroleum and its products is an environmental threat in oil producing countries. Microbes have been used to clean up petroleum contaminated environments, which has been demonstrated to be an appropriate and more practical alternative compared to the mechanical and chemical techniques. In this study, crude oil degrading indigenous bacteria were isolated from soils around the oil exploration sites in Western Uganda and their efficiency of oil biodegradation and presence of the catabolic gene xylE in the isolates to relate with their biodegradation efficiency were determined. The organisms with oil degrading activity were screened by isolating them from crude oil supplemented mineral salts medium (MSM). The isolates were tentatively identified phenotypically and confirmed genotypically by 16S ribosomal ribonucleic acid (rRNA) gene sequencing. Hydrocarbon degradation in the culture fluids was analyzed by a gas chromatography mass spectrometer (GC/MS); and amplification of catabolic gene xylE by polymerase chain reaction (PCR) was done in order to relate with the degradation activity. Forty four indigenous oil degrading bacteria were isolated and categorized into eight groups based on their morphological and biochemical properties; and were identified as belonging to the genera; Corynebacterium, Pseudomonas, Moraxella, Bacillus, Enterobacteriaceae, Nocardia, Serratia and Rhodococcus. Eight isolates that exhibited a relatively higher biodegradation activity in the first five days of incubation were selected for a detailed analysis. Based on 16S rRNA gene sequence analyses, the eight selected isolates were identical to Stenotrophomonas maltophilia, Burkholderia sp., Delftia tsuruhatensis, Pseudomonas aeruginosa, Acinetobacter sp., Curtobacterium sp. and Paenibacillus agaridevorans. The selected isolates; Ngara-T1, Kig5-1, Kig5-T2, Kig3-T3, Kig3-T4, Kas2-T7, Kas2-T5  and Gat-3 degraded the total petroleum hydrocarbons (TPHs) up to:  91.9, 79.9, 89.2, 73.1, 94.2, 83.2, 77.0 and 67.2%, respectively, by the end of 21 days of incubation as compared to 29.7% degradation in the control experiment (without bacteria). The catabolic gene xylE was detected in two of the selected isolates, Ngara T-1 and Kig5-T2. It could be concluded that the oil degrading bacteria identified in this study showed diverse and varying capacities to degrade the crude oil; with some degrading up to 90% and can be exploited for cleaning up hydrocarbon contaminated sites in western Uganda.Keywords: Bacteria, bioremediation, degradation, oil, hydrocarbons, UgandaAfrican Journal of Biotechnology, Vol 13(48) 4458-447

Haematological, biochemical and clinical changes in domestic pigs experimentally infected with african swine fever virus Isolates from Uganda

African swine fever (ASF) is a highly contagious often fatal viral disease of pigs caused by asfivirus. The disease causes marked leucopaenia, depletion of lymphocytes in the lymphoid tissues, changes in biochemical parameters, haemorrhages and necrosis in multiple organs of the infected pigs. We studied the pathogenic effect of three different Ugandan ASF virus (ASFV) isolates on twelve infected and six uninfected pigs. Each pig in the infected group was inoculated per os with 2 mls of ASFV culture solution containing 1X 108 H.A.D.U/ml of the viral culture solution while the control group were given 2 mls of uninfected porcine alveolar macrophages culture per-os. Clinical parameters were monitored daily and blood samples collected for leucocytes count and biochemical tests. In the present study, the incubation period of the disease ranged from 7 - 15 days and in average the clinical disease lasted for 5 days. On the eighth day post infection, all test pigs had significant leucopaenia (p = 0.000) and number of lymphocytes reduced significantly (p =0.001,). Band neutrophils progressively increased in number as the disease progressed, however when the changes in mean band neutrophils in the three groups were compared it was not statistically significant (p= 0.52). There were no significant variations in the mean basophils and eosinophil counts in all experimental groups during study period (p = 0.30 and p = 0.32 respectively). Nevertheless, mean monocytes counts significantly increased in infected pigs (p = 0.01), while in uninfected group there was no significant variation in the mean monocytes counts. The majority of the pigs, 83.3% (n = 10) in the test groups had elevated levels of gamma-glutamyl transferase (GGT). The Level of Alanine Amino Transferase (ALT) at 8 days post infection was elevated in all infected pigs in the three groups. In 66.7% (n = 8) infected pigs, Albumin (ALB) levels were elevated in the serum samples above the normal range of 18 – 33 g/l. The levels of other biochemicals in the serum samples such as Creatine kinase (CK), Creatinine (CREA), and Alkaline Phosphatase (ALKP) remained within the normal range (50- 3531 μ/L, 44 -186μmol/L, 92 - 294 μ/L, respectively). We concluded that ASF causes significant deviation in leucocytes counts, increased levels of GGT, ALT and ALB and clinical parameters in pigs infected with Ugandan isolates of ASF virus.Key words: African swine fever (ASF), Domestic pigs Haematological, biochemical and clinical parameter

Haematological, biochemical and clinical changes in domestic pigs experimentally infected with african swine fever virus Isolates from Uganda

African swine fever (ASF) is a highly contagious often fatal viral disease of pigs caused by asfivirus. The disease causes marked leucopaenia, depletion of lymphocytes in the lymphoid tissues, changes in biochemical parameters, haemorrhages and necrosis in multiple organs of the infected pigs. We studied the pathogenic effect of three different Ugandan ASF virus (ASFV) isolates on twelve infected and six uninfected pigs. Each pig in the infected group was inoculated per os with 2 mls of ASFV culture solution containing 1X 108 H.A.D.U/ml of the viral culture solution while the control group were given 2 mls of uninfected porcine alveolar macrophages culture per-os. Clinical parameters were monitored daily and blood samples collected for leucocytes count and biochemical tests. In the present study, the incubation period of the disease ranged from 7 - 15 days and in average the clinical disease lasted for 5 days. On the eighth day post infection, all test pigs had significant leucopaenia (p = 0.000) and number of lymphocytes reduced significantly (p =0.001,). Band neutrophils progressively increased in number as the disease progressed, however when the changes in mean band neutrophils in the three groups were compared it was not statistically significant (p= 0.52). There were no significant variations in the mean basophils and eosinophil counts in all experimental groups during study period (p = 0.30 and p = 0.32 respectively). Nevertheless, mean monocytes counts significantly increased in infected pigs (p = 0.01), while in uninfected group there was no significant variation in the mean monocytes counts. The majority of the pigs, 83.3% (n = 10) in the test groups had elevated levels of gamma-glutamyl transferase (GGT). The Level of Alanine Amino Transferase (ALT) at 8 days post infection was elevated in all infected pigs in the three groups. In 66.7% (n = 8) infected pigs, Albumin (ALB) levels were elevated in the serum samples above the normal range of 18 – 33 g/l. The levels of other biochemicals in the serum samples such as Creatine kinase (CK), Creatinine (CREA), and Alkaline Phosphatase (ALKP) remained within the normal range (50- 3531 μ/L, 44 -186μmol/L, 92 - 294 μ/L, respectively). We concluded that ASF causes significant deviation in leucocytes counts, increased levels of GGT, ALT and ALB and clinical parameters in pigs infected with Ugandan isolates of ASF virus.Key words: African swine fever (ASF), Domestic pigs Haematological, biochemical and clinical parameter