The application of nanotechnology in aquaculture for developing efficient vaccines has shown grea... more The application of nanotechnology in aquaculture for developing efficient vaccines has shown great potential in recent years. Nanovaccination, which involves encapsulating antigens of fish pathogens in various polymeric materials and nanoparticles, can afford protection to the antigens and a sustained release of the molecule. Oral administration of nanoparticles would be a convenient and cost-effective method for delivering vaccines in aquaculture while eliminating the need for stressful, labour-intensive injectables. The small size of nanoparticles allows them to overcome the degradative digestive enzymes and help deliver antigens to the target site of the fish more effectively. This targeted-delivery approach would help trigger cellular and humoral immune responses more efficiently, thereby enhancing the protective efficacy of vaccines. This is particularly relevant for combating diseases caused by pathogens like Aeromonas hydrophila, a major fish pathogen responsible for signific...
TargetFish is a large collaborative project funded by the European Commission under the 7th Frame... more TargetFish is a large collaborative project funded by the European Commission under the 7th Framework Programme for Research and Technological Development (FP7) of the European Union (Grant Agreement 311993). The project will run for 5 years, started in November 2012 and thus is approximately halfway. TargetFish brings together a large number of leading European research groups (RTD) that are experts on fish pathology and immunology and small-to-medium enterprises (SME) as well as some larger industries from the Biotech and Veterinary sectors, which all share a common interest and experience: vaccination of fish. To achieve this challenging task, we brought together approximately 30 partners from 10 EU member states, two associated countries and one International Cooperation Partner Country (Chile). In this large multidisciplinary consortium an approximate equal number of RTD and SME partners cooperate closely while keeping an intensive communication with the vaccine and nutrition industries. The main objectives of the project are to: 1) generate knowledge by studying antigens and adjuvants for different routes of administration while analyzing the underpinning protective immune mechanisms; 2) validate this knowledge with response assays for monitoring vaccine efficacy and safety, including issues associated with DNA vaccines; 3) approach implementation of prototype vaccines shortening the route to exploitation and 4) optimize vaccination strategies in order to obtain maximum protection in different sizes of fish. At present, progress has been made in particular with regard to main objectives 1-3. The vaccine delivery systems under investigation include oral routes of administration using, for example, alginate microencapsulation and MicroMatrixTM technologies. TargetFish also focuses on investigating mucosal vaccination routes and associated immunity and in developing antigens and adjuvants specifically suited for mucosal delivery. Most fish vaccines on the market are delivered by injection, being this a labour-intensive, expensive method that provokes stress in the fish. Mucosal vaccination routes (immersion or oral) would certainly be more desirable.
Aquatic food is becoming an important food source that provides micronutrients to human beings. T... more Aquatic food is becoming an important food source that provides micronutrients to human beings. The decline of wild aquatic animals makes aquaculture become increasingly important to play this role. However, infectious diseases, especially bacterial infection, represent severe threat to aquaculture, which causes huge economic loss. Meanwhile, strategies in managing bacterial infection in an antibiotic-independent way are still lacking. In this study, we monitor the metabolomic shift of crucian carp upon Aeromonas hydrophila infection. We find that the metabolism of the fish that died of infection is distinct from the ones that survived. By multivariate analysis, we identify fructose as a crucial biomarker whose abundance is significantly different from the dying and surviving groups where the surviving group has a higher content of fructose than the dying group. Exogenous supplementation of fructose increases fish survival rate by 27.2%. Quantitative gene expression analysis demonst...
Proceedings of the 35 scientific conference of the Tanzania Veterinary Association held at AICC, ... more Proceedings of the 35 scientific conference of the Tanzania Veterinary Association held at AICC, Arusha, December 2017.ilapia lake virus (TiLV) is an emerging pathogen of Tilapiines associated with high mortalities of wild and farmed tilapia posing great threat to the fishery industry worldwide. The virus has been reported in Israel, Ecuador, Colombia, Thailand, Egypt, Taiwan, India and Malaysia. In this study, a reverse transcription polymerase chain reaction (RT-PCR) assay was developed and used to detect TiLV genome in Nile tilapia from Lake Victoria. Nile tilapia samples were collected from the Tanzanian (108 fish) and Ugandan (83 fish) parts of Lake Victoria in 2015 and 2016, respectively. Samples were screened for TiLV by using RT-PCR and the PCR products were sequenced. The findings show that out of the 191 fish examined, 28 had PCR products showing the presence of TiLV genome. The TiLV nucleic acids were detected in the spleen (10.99%, N=191), head kidney (7.69%, N=65), hear...
Mycobacterium bovis (M. bovis) causes tuberculosis in mammals and is a major public health threat... more Mycobacterium bovis (M. bovis) causes tuberculosis in mammals and is a major public health threat worldwide. While M. bovis has been reported in humans, domestic and wild ruminants at the human-wildlife-livestock interface area in Zambia, there is paucity of information on the role of primates as reservoir hosts. We screened seven wild chacma baboons (Papio ursinus) for tuberculosis at the human-wildlife interface area in Lochinvar National Park in the Kafue Flats, Zambia. Following necropsy, lung tissue and associated lymph nodes with tuberculous-like lesions collected from four adult male baboons were prepared for Mycobacterium culture. The isolates were initially typed using the Mycobacterium tuberculosis complex-discrimination multiplex PCR assay and further characterized by spoligotyping and 26-loci MIRU-VNTR. Mycobacteria was isolated from all four animals and identified as M. bovis by PCR. On Spoligotyping, all isolates belonged to SB 0120 spoligotype, which is similar to what was previously reported in humans, cattle and Kafue lechwe antelopes in Kafue Flats ecosystem. Furthermore, on MIRU-VNTR typing, the baboon isolates clustered with cattle and Kafue lechwe isolates from the same catchment area. This finding intimates probable cross species transmission of M. bovis in the Kafue Flats ecosystem. Due to the close interaction of baboons and humans at interface areas in Zambia, our results have potential implications for public health. Equally, this finding raises concerns for conservation.
Objectives Aeromonads cause severe diseases in farmed aquatic organisms. Herein, we examined 28 i... more Objectives Aeromonads cause severe diseases in farmed aquatic organisms. Herein, we examined 28 isolates causing disease in farmed aquatic organisms from India (n = 24) and Taiwan (n = 4) to gain insight of their genotypic and phenotypic properties. Results API 20NE biochemical phenotyping showed ≥ 90% similarity classifying all isolates as Aeromonas hydrophila . 16S rRNA genotyping showed ≥ 98% homology among all isolates with A. sobria (NR119044.1ATCC), A . veronii (MK990549.1), A. caviae (NR029252.1) and A. hydrophila (MG984625.1ATCC) and other reference strains. In contrast, gyrB showed a higher intraspecies diversity (≥ 96%) than 16S rRNA delineating the 28 isolates into three groups. Group-I consisted of seven Indian isolates clustered with A. sobria (MK484163.1ATCC), group-II comprised of five Indian and two Taiwanese isolates clustered with A. veronii AF417626.1ATCC while group-III had 11 Indian and three Taiwanese isolates grouped with A. hydrophila (AY987520.1 and DQ519366...
Tilapia lake virus (TiLV) causes high mortality and high economic losses in tilapines. We describ... more Tilapia lake virus (TiLV) causes high mortality and high economic losses in tilapines. We describe an experimental challenge study focusing on early post challenge innate immune responses. Nile tilapia (Oreochromis niloticus) were infected with 105 TCID50/mL TiLV intraperitoneally, followed by virus quantification, histopathology and gene expression analysis in target (brain/liver) and lymphoid (spleen/headkidney) organs at 3, 7, 12, 17, and 34 days post challenge (dpc). Onset of mortality was from 21 dpc, and cumulative mortality was 38.5% by 34 dpc. Liver and kidney histopathology developed over the period 3–17 dpc, characterized by anisocytosis, anisokaryocytosis, and formation of multinucleated hepatocytes. Viral loads were highest at early time (3 dpc) in liver, spleen and kidney, declining towards 34 dpc. In brain, viral titer peaked 17 dpc. Innate sensors, TLRs 3/7 were inversely correlated with virus titer in brain and headkidney, and IFN-ß and Mx showed a similar pattern. A...
Tilapia culture is a very promising industry within the aquaculture sector. However, disease outb... more Tilapia culture is a very promising industry within the aquaculture sector. However, disease outbreaks have continued to threaten the industry, causing serious economic losses among the producers. Streptococcosis has become the major bacterial disease affecting tilapia production in most regions of the world. To combat the disease and minimize its economic impact on fish producers, numerous preventive and control measures have been developed and reported over the years. This paper aims to systematically review the measures that could be used to manage the disease outbreaks and maintain fish health based on previously published scientific studies. Although numerous measures currently available have been highlighted, it is far better for the producers to maximize the preventive measures for management to be economically feasible. Among the currently available preventive measures, the use of vaccines has been shown to have the most promise, while the use of herbs has been demonstrated ...
The Chinese soft-shelled turtle ( Pelodiscus sinensis) has become one of the leading cultured org... more The Chinese soft-shelled turtle ( Pelodiscus sinensis) has become one of the leading cultured organisms in China and South East Asia. The objectives of the present study were to use next generation sequencing to identify viral genomes present in liver tissues from Chinese soft-shelled turtle in China. BLAST analysis of viral sequences from liver samples showed high homology with the human adenovirus (HAdV) penton base and encapsidation proteins. This homology points to possible existence of HAdV in freshwater environments used for the culture of soft-shelled turtles. Therefore, our findings merit further investigations to determine possible contamination of HAdV in aquaculture environments and the possible role of the Chinese soft-shelled turtle in transmitting HAdV to humans.
The application of nanotechnology in aquaculture for developing efficient vaccines has shown grea... more The application of nanotechnology in aquaculture for developing efficient vaccines has shown great potential in recent years. Nanovaccination, which involves encapsulating antigens of fish pathogens in various polymeric materials and nanoparticles, can afford protection to the antigens and a sustained release of the molecule. Oral administration of nanoparticles would be a convenient and cost-effective method for delivering vaccines in aquaculture while eliminating the need for stressful, labour-intensive injectables. The small size of nanoparticles allows them to overcome the degradative digestive enzymes and help deliver antigens to the target site of the fish more effectively. This targeted-delivery approach would help trigger cellular and humoral immune responses more efficiently, thereby enhancing the protective efficacy of vaccines. This is particularly relevant for combating diseases caused by pathogens like Aeromonas hydrophila, a major fish pathogen responsible for signific...
TargetFish is a large collaborative project funded by the European Commission under the 7th Frame... more TargetFish is a large collaborative project funded by the European Commission under the 7th Framework Programme for Research and Technological Development (FP7) of the European Union (Grant Agreement 311993). The project will run for 5 years, started in November 2012 and thus is approximately halfway. TargetFish brings together a large number of leading European research groups (RTD) that are experts on fish pathology and immunology and small-to-medium enterprises (SME) as well as some larger industries from the Biotech and Veterinary sectors, which all share a common interest and experience: vaccination of fish. To achieve this challenging task, we brought together approximately 30 partners from 10 EU member states, two associated countries and one International Cooperation Partner Country (Chile). In this large multidisciplinary consortium an approximate equal number of RTD and SME partners cooperate closely while keeping an intensive communication with the vaccine and nutrition industries. The main objectives of the project are to: 1) generate knowledge by studying antigens and adjuvants for different routes of administration while analyzing the underpinning protective immune mechanisms; 2) validate this knowledge with response assays for monitoring vaccine efficacy and safety, including issues associated with DNA vaccines; 3) approach implementation of prototype vaccines shortening the route to exploitation and 4) optimize vaccination strategies in order to obtain maximum protection in different sizes of fish. At present, progress has been made in particular with regard to main objectives 1-3. The vaccine delivery systems under investigation include oral routes of administration using, for example, alginate microencapsulation and MicroMatrixTM technologies. TargetFish also focuses on investigating mucosal vaccination routes and associated immunity and in developing antigens and adjuvants specifically suited for mucosal delivery. Most fish vaccines on the market are delivered by injection, being this a labour-intensive, expensive method that provokes stress in the fish. Mucosal vaccination routes (immersion or oral) would certainly be more desirable.
Aquatic food is becoming an important food source that provides micronutrients to human beings. T... more Aquatic food is becoming an important food source that provides micronutrients to human beings. The decline of wild aquatic animals makes aquaculture become increasingly important to play this role. However, infectious diseases, especially bacterial infection, represent severe threat to aquaculture, which causes huge economic loss. Meanwhile, strategies in managing bacterial infection in an antibiotic-independent way are still lacking. In this study, we monitor the metabolomic shift of crucian carp upon Aeromonas hydrophila infection. We find that the metabolism of the fish that died of infection is distinct from the ones that survived. By multivariate analysis, we identify fructose as a crucial biomarker whose abundance is significantly different from the dying and surviving groups where the surviving group has a higher content of fructose than the dying group. Exogenous supplementation of fructose increases fish survival rate by 27.2%. Quantitative gene expression analysis demonst...
Proceedings of the 35 scientific conference of the Tanzania Veterinary Association held at AICC, ... more Proceedings of the 35 scientific conference of the Tanzania Veterinary Association held at AICC, Arusha, December 2017.ilapia lake virus (TiLV) is an emerging pathogen of Tilapiines associated with high mortalities of wild and farmed tilapia posing great threat to the fishery industry worldwide. The virus has been reported in Israel, Ecuador, Colombia, Thailand, Egypt, Taiwan, India and Malaysia. In this study, a reverse transcription polymerase chain reaction (RT-PCR) assay was developed and used to detect TiLV genome in Nile tilapia from Lake Victoria. Nile tilapia samples were collected from the Tanzanian (108 fish) and Ugandan (83 fish) parts of Lake Victoria in 2015 and 2016, respectively. Samples were screened for TiLV by using RT-PCR and the PCR products were sequenced. The findings show that out of the 191 fish examined, 28 had PCR products showing the presence of TiLV genome. The TiLV nucleic acids were detected in the spleen (10.99%, N=191), head kidney (7.69%, N=65), hear...
Mycobacterium bovis (M. bovis) causes tuberculosis in mammals and is a major public health threat... more Mycobacterium bovis (M. bovis) causes tuberculosis in mammals and is a major public health threat worldwide. While M. bovis has been reported in humans, domestic and wild ruminants at the human-wildlife-livestock interface area in Zambia, there is paucity of information on the role of primates as reservoir hosts. We screened seven wild chacma baboons (Papio ursinus) for tuberculosis at the human-wildlife interface area in Lochinvar National Park in the Kafue Flats, Zambia. Following necropsy, lung tissue and associated lymph nodes with tuberculous-like lesions collected from four adult male baboons were prepared for Mycobacterium culture. The isolates were initially typed using the Mycobacterium tuberculosis complex-discrimination multiplex PCR assay and further characterized by spoligotyping and 26-loci MIRU-VNTR. Mycobacteria was isolated from all four animals and identified as M. bovis by PCR. On Spoligotyping, all isolates belonged to SB 0120 spoligotype, which is similar to what was previously reported in humans, cattle and Kafue lechwe antelopes in Kafue Flats ecosystem. Furthermore, on MIRU-VNTR typing, the baboon isolates clustered with cattle and Kafue lechwe isolates from the same catchment area. This finding intimates probable cross species transmission of M. bovis in the Kafue Flats ecosystem. Due to the close interaction of baboons and humans at interface areas in Zambia, our results have potential implications for public health. Equally, this finding raises concerns for conservation.
Objectives Aeromonads cause severe diseases in farmed aquatic organisms. Herein, we examined 28 i... more Objectives Aeromonads cause severe diseases in farmed aquatic organisms. Herein, we examined 28 isolates causing disease in farmed aquatic organisms from India (n = 24) and Taiwan (n = 4) to gain insight of their genotypic and phenotypic properties. Results API 20NE biochemical phenotyping showed ≥ 90% similarity classifying all isolates as Aeromonas hydrophila . 16S rRNA genotyping showed ≥ 98% homology among all isolates with A. sobria (NR119044.1ATCC), A . veronii (MK990549.1), A. caviae (NR029252.1) and A. hydrophila (MG984625.1ATCC) and other reference strains. In contrast, gyrB showed a higher intraspecies diversity (≥ 96%) than 16S rRNA delineating the 28 isolates into three groups. Group-I consisted of seven Indian isolates clustered with A. sobria (MK484163.1ATCC), group-II comprised of five Indian and two Taiwanese isolates clustered with A. veronii AF417626.1ATCC while group-III had 11 Indian and three Taiwanese isolates grouped with A. hydrophila (AY987520.1 and DQ519366...
Tilapia lake virus (TiLV) causes high mortality and high economic losses in tilapines. We describ... more Tilapia lake virus (TiLV) causes high mortality and high economic losses in tilapines. We describe an experimental challenge study focusing on early post challenge innate immune responses. Nile tilapia (Oreochromis niloticus) were infected with 105 TCID50/mL TiLV intraperitoneally, followed by virus quantification, histopathology and gene expression analysis in target (brain/liver) and lymphoid (spleen/headkidney) organs at 3, 7, 12, 17, and 34 days post challenge (dpc). Onset of mortality was from 21 dpc, and cumulative mortality was 38.5% by 34 dpc. Liver and kidney histopathology developed over the period 3–17 dpc, characterized by anisocytosis, anisokaryocytosis, and formation of multinucleated hepatocytes. Viral loads were highest at early time (3 dpc) in liver, spleen and kidney, declining towards 34 dpc. In brain, viral titer peaked 17 dpc. Innate sensors, TLRs 3/7 were inversely correlated with virus titer in brain and headkidney, and IFN-ß and Mx showed a similar pattern. A...
Tilapia culture is a very promising industry within the aquaculture sector. However, disease outb... more Tilapia culture is a very promising industry within the aquaculture sector. However, disease outbreaks have continued to threaten the industry, causing serious economic losses among the producers. Streptococcosis has become the major bacterial disease affecting tilapia production in most regions of the world. To combat the disease and minimize its economic impact on fish producers, numerous preventive and control measures have been developed and reported over the years. This paper aims to systematically review the measures that could be used to manage the disease outbreaks and maintain fish health based on previously published scientific studies. Although numerous measures currently available have been highlighted, it is far better for the producers to maximize the preventive measures for management to be economically feasible. Among the currently available preventive measures, the use of vaccines has been shown to have the most promise, while the use of herbs has been demonstrated ...
The Chinese soft-shelled turtle ( Pelodiscus sinensis) has become one of the leading cultured org... more The Chinese soft-shelled turtle ( Pelodiscus sinensis) has become one of the leading cultured organisms in China and South East Asia. The objectives of the present study were to use next generation sequencing to identify viral genomes present in liver tissues from Chinese soft-shelled turtle in China. BLAST analysis of viral sequences from liver samples showed high homology with the human adenovirus (HAdV) penton base and encapsidation proteins. This homology points to possible existence of HAdV in freshwater environments used for the culture of soft-shelled turtles. Therefore, our findings merit further investigations to determine possible contamination of HAdV in aquaculture environments and the possible role of the Chinese soft-shelled turtle in transmitting HAdV to humans.
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Papers by Hetron Munang'andu