Dokaz protutijela za virus newcastleske bolesti u poluudomaćenih slobodno živućih ptica (Numida meleagris i Columba livia domestica) te rizik za prijenos bolesti na piliće u seoskim gospodarstvima - kratko priopćenje

A seroprevalence study for Newcastle disease (ND) in semi-domesticated birds was carried out in Morogoro Municipality. The results showed that haemagglutination-inhibition (HI) antibodies to Newcastle disease virus (NDV) were detected in 75% (n = 36) and 10% (n = 20) of serum samples collected from guinea fowl and pigeons, respectively. Studies have shown that guinea fowl and pigeons are susceptible to NDV. In village husbandry practices, by which different species of birds are raised together in the same compound, the risk of the transmission of NDV from guinea fowl and pigeons to village chickens may arise. Therefore there is a need to conduct regular and strategic vaccination programs against ND for chickens, guinea fowl and pigeons in village settings.Istraživanje seroprevalencije newcastleske bolesti u poluudomaćenih ptica provedeno je u okrugu Morogoro. Protutijela inhibicije hemaglutinacije za virus newcastleske bolesti bila su dokazana u 75% (n=36) pretraženih uzoraka seruma biserki i 10% (n = 20) uzoraka seruma golubova. Istraživanje je pokazalo da su biserke i golubovi prijemljivi na virus newcastleske bolesti. U seoskim gospodarstvima, gdje se različite vrste ptica uzgajaju zajedno u istom prostoru, postoji rizik za prijenos virusa newcastleske bolesti s biserki i golubova na domaću perad. Stoga je potrebno osmisliti i poduzeti program cijepljenja pilića, biserki i golubova u seoskim gospodarstvima protiv newcastleske bolesti

Survival of avirulent thermostable Newcastle disease virus (strain I-2) in raw, baked, oiled, and cooked white rice at ambient temperatures

Raw white rice has not been considered a good carrier for oral vaccination, probably because of its antiviral activity. Methods are required to overcome antiviral activity in raw white rice. This study was carried out to determine the effects of various treatments of raw white rice on the survival of strain I-2 of Newcastle disease virus. These included cooking and baking the rice or mixing the rice with vegetable oil prior to coating with vaccine virus. The vaccine-coated rice was then stored for 30 min and 24 h, followed by quantitative recovery of the virus. Thirty min after mixing, uncooked, cooked, and baked rice, and rice mixed with vegetable oil showed titers of 106.2, 107.2, 106.6, and 107.0 EID50/0.1 ml, respectively. After storage for 24 h at 22-25℃, the titers dropped to 105.0, 106.5, 105.0, and 106.0 EID50/0.1 ml for uncooked, cooked, baked, and oiled rice, respectively

Current State of Modern Biotechnological-Based Vaccines for Aquaculture: A Systematic Review.

This research article published by Hindawi, 2019This systematic review describes what "the cutting edge vaccines for are". The focus is on types of high tech biotechnological based vaccines, target gene or antigen in developing these vaccines, and challenge model fish species used in vaccines efficacy testing. Vaccines delivery methods, immune response, and their efficacy, adjuvant or carrier systems used, and the overall experimental setup or design of the vaccines under investigation are also described. The search for the original papers published between 2009 and 2018 was conducted in June of 2018, using the PubMed and Google scholar electronic database. Twenty-three (23/4386) studies were included in the final assembly using PRISMA guidelines (Protocol not registered). Recombinant protein vaccines were the highly experimented type of the modern biotechnological based vaccines identified in the selected studies (16/23; 70%). Outer membrane proteins (OMPs) of different -barrels were shown to be a potential antigenic entity for vaccines (57%). Intraperitoneal route with conventional carries or adjuvants was the highly applied delivery system while very few studies used herbal based vaccine adjuvants and nanomaterial as a vaccine carrier. Variation was observed in terms of protection levels in the selected studies. The experimental designs partly contributed to the observed variation. Therefore, recombinant vaccines that use new carrier system technologies and delivered through oral route in feeds would have been of great value for use in the prevention and control of infections in fish. Despite the usefulness as academic tools to identify what is important in pathogenicity of the etiological agent to the host fish, these vaccines are only economically viable in very high-value animals. Therefore, if vaccination is a good option for group, then simple autogenous vaccines based on accurate typing and evidence-based definition of the epidemiological unit for their use would be the most viable approach in terms of both efficacy and economic feasibility especially in low and middle-income countries (LMIC)

Phenotypic and molecular detection of Aeromonads infection in farmed Nile tilapia in Southern highland and Northern Tanzania

This research article published by Elsevier Ltd., 201

Present status of aquaculture and the challenge of bacterial diseases in freshwater farmed fish in Tanzania; A call for sustainable strategies

This research article published by Elsevier, 2020Aquaculture provides significant contributions to household food security, as the capture of wild fish from lakes, dams, and oceans do not meet the current demand for animal protein in Tanzania. Sustainable aquaculture requires well-established regulatory systems and extension services for good pond management practices and maintaining fish health by fish farmers. Fish farming is practiced widely in Tanzania, from small-to large-scale ponds and these farming systems are moving from extensive normal operations (low input demand) to intensive farming (high input demand). However, the industry is largely still operating at a subsistence level with low production. Bacterial infections have been occurring in these fish farms and will continue to be an issue of concern into the future. This review highlights the current challenges, successes, and prospects towards a sustainable aquaculture industry in Tanzania, including: limited extension services mirroring the limited knowledge by farmers regarding pond management practices; the inadequacy of funds to carry out fish disease research or implement a surveillance system; little expertise in fish disease diagnosis and treatment; and poor management options. To minimize disease outbreaks and optimize production in the future, we suggest a strengthening of extension services, augmented with on-farm knowledge transfer. Emphasis should be on pond management practices and fish disease management; the creation of a well-functioning fish disease surveillance system; and strengthening collaborative research on aquaculture between the government research institutions and academia. Establishing small cooperative fish farmer groups within the Aquaculture Association of Tanzania (AAT) for easy access to information is also recommended

Virulence pattern of circulating aeromonads isolated from farmed Nile tilapia in Tanzania and novel antibiotic free attenuation of Aeromonas hydrophila strain TZR7-2018

This research article published by Elsevier B.V., 2020Aeromonads are gram-negative, rod-shaped, facultative anaerobes bacteria known to cause motile aeromonads septicemia diseases (MAS) in warm freshwater farmed fish. Outbreaks are associated with pathogenicity of aeromonads in fish which is partly contributed by virulence characteristics of the etiological agent. The objective of this study was to assess the virulence characteristics of the previously isolated and identified aeromonads, and attenuate potential Aeromonas hydrophila strain TZR7-2018 to serve as local vaccine candidate. Six virulence genes and other virulence characteristics were molecularly and phenotypically assessed both using in-vitro and in-vivo approaches. Attenuation of A. hydrophila parent strain TZR7-2018+ was performed by passaging through thermal continuous sub-culturing 40 times in Tryptic soy agar (TSA). Bacterin was prepared by formalin inactivation from the same parent strain. Humoral responses were assayed using quantitative serological agglutination test (qSAT) while protective efficacy was measured through relative percent survival (RPS). A total 240 Nile tilapia fingerlings with an average weight of 8.1 ± 0.4 g were used in all in-vivo studies. The presence of aerolysin (aer), cytotoxic enterotoxin (act), elastase (ahy), haemolysin (hly), serine (ser) and polar flagella (fla) genes were determined using PCR. Out of 201 isolates, 75.1 % (151/201) of the aeromonads possessed virulence genes (120=A. hydrophila and 31=Aeromonas veronii). The virulence gene pattern of aer/hly/fla was the most prominent with the prevalence of 12.6 %. The attenuated strain TZR7-2018− showed reduced: colon size, multiplication rate, cell size and loss in; haemolysis, motility and capsule. Humoral responses increased gradually and reached maximum at day 28 in both attenuated and bacterin formulation given through intraperitoneal (IP) injection and immersion (IM). A RPS of 82.3 %, 71.4 % and 85.1 %, were recorded to the attenuated vaccine given through IP and IM and bacterin provided through IP respectively. Therefore the attenuated strain TZR7-2018− obtained through thermal continuous subculture technique and the bacterin proved to be efficacious and can serve as vaccine candidate

Safety and immunogenicity of Rift Valley fever MP-12 and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) from Tanzania

Vaccination of domestic ruminants is considered to be an effective strategy for protecting these animals against Rift Valley fever (RVF), but available vaccines have limitations. Therefore, the aim of this study was to determine the safety and immunogenicity of RVF virus (RVFV) mutagenesis passage 12 (MP-12) and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) in Tanzania. Goats were vaccinated intramuscularly with RVFV MP-12 or arMP-12ΔNSm21/384, and then on Day 87 post-vaccination (PV) all animals were revaccinated using the RVFV MP-12 vaccine candidate. Serum samples were collected from the animals before and after vaccination at various intervals to test for RVFV using a Vero cell culture assay and reverse transcription polymerase chain reaction and for RVFV-neutralising antibody using a plaque reduction neutralisation assay. Serum samples collected before vaccination on Days -14 and 0, and on Days 3, 4 and 5 PV were negative for RVFV and neutralising antibody. All animals remained healthy, and viremia was not detected in any of the animals. Rift Valley fever virus antibody was first detected on Day 5 PV at a 1:10 dilution in five of five animals vaccinated with the MP-12 vaccine and in five of eight animals vaccinated with arMP-12ΔNSm21/384. Titres then increased and were sustained at 1:40 to 1:640 through to Day 87 PV. All animals that were revaccinated on Day 87 PV with MP-12 developed antibody titres ranging from 1:160 to as high as 1:10 240 on Days 14 and 21 PV. Although the antibody titres for goats vaccinated with RVF MP-12 were slightly higher than titres elicited by the arMP-12ΔNSm21/384 vaccine, these findings demonstrated that both vaccines are promising candidates for the prevention of RVF among Tansanian goats

Foot-and-mouth disease virus serotypes detected in Tanzania from 2003 to 2010: Conjectured status and future prospects

This study was conducted to investigate the presence of foot-and-mouth disease virus (FMDV) in different geographic locations of Tanzania. Epithelial tissues and fluids (n = 364) were collected from cattle exhibiting oral and foot vesicular lesions suggestive of FMD and submitted for routine FMD diagnosis. The analysis of these samples collected during the period of 2002 and 2010 was performed by serotype-specific antigen capture ELISA to determine the presence of FMDV. The results of this study indicated that 167 out of 364 (46.1%) of the samples contained FMDV antigen. Of the 167 positive samples, 37 (28.4%) were type O, 7 (4.1%) type A, 45 (21.9%) SAT 1 and 79 (45.6%) SAT 2. Two FMDV serotypes (O and SAT 2) were widely distributed throughout Tanzania whilst SAT 1 and A types were only found in the Eastern zone. Our findings suggest that serotypes A, O, SAT 1 and SAT 2 prevail in Tanzania and are associated with the recent FMD outbreaks. The lack of comprehensive animal movement records and inconsistent vaccination programmes make it difficult to determine the exact source of FMD outbreaks or to trace the transmission of the disease over time. Therefore, further collection and analysis of samples from domestic and wild animals are being undertaken to investigate the genetic and antigenic characteristics of the circulating strains, so that a rational method to control FMD in Tanzania and the neighbouring countries can be recommended