Growth enhancement and protective potential of feed-based outer membrane proteins against vibriosis in Macrobrachium rosenbergii

The use of antibiotics to curtail vibriosis, which is a major infectious disease, plaguing shrimp and prawn is rather becoming less effective and the need for a better alternative is expedient. The outer membrane proteins (OMPs) of V. alginolyticus were extracted, mixed with powdered commercial feed and fed to the prawns to evaluate its effect on growth performance and protective potential. Sixty prawns were divided into groups A, B and C of 10 prawns each, with two replicates in six (150 L) glass aquaria. Groups A, B and C were fed with OMPs mixed diet, with OMPs-Freund’s incomplete adjuvant mixed diet and OMPs or adjuvant free diet (control diet) respectively. All the prawns were weighed weekly, and haemolymph was collected to determine the total haemocyte count (THC) and phenoloxidase (PO) activity. At the end of the feeding trial, prawns were intramuscularly challenged with 50 μL of 107 CFU V. alginolyticus. The treated groups were significantly higher in growth performance and THC than the control group, but no significant difference between the groups in terms of PO activity and mortality rate. The study, however, submitted that oral administration of OMPs with or without adjuvant is a good growth promoter and has the potential for protection against vibriosis in giant freshwater prawn (Macrobrachium rosenbergii)

Dexamethasone-induced stress exacerbates shedding, tissue antigen distribution, and pathology of caprine Brucellosis

This study investigated dexamethasone-treatment, shedding routes, tissue antigen distribution, and pathology of caprine Brucellosis. Eighteen non-pregnant goats were randomly grouped into A, B, and C. Group A was administered dexamethasone for 7 days at 2 mg/kg before inoculating 0.5 mL B. melitensis at 107 CFU ocularly while group B was inoculated 0.5 mL B. melitensis only, and C as control negative. Blood samples, ocular, nasal, and vaginal swabs were obtained for evaluation. Three goats were sacrificed from each group at days 21 and 42 post-inoculation (pi) and selected tissues collected for PCR, histopathology, and immunohistochemistry. Brucella melitensis was detected in the ocular swabs of group A significantly higher than group B. Shedding was prolonged in group A compared to B. The overall shedding was 22.2% in group A and 9.4% in group B. The uterus of both groups A and B revealed mild inflammation and microgranuloma, extensive necrotic lesions in lymph nodes. Liver showed multifocal necrosis predominantly in group A. Lesion scoring showed significantly higher scores in A compared to B. Strong immunostaining was observed in the liver, lungs, and spleen, predominantly at day 21 pi. This study demonstrated dexamethasone prolonged shedding, tissue antigen distribution, and pathology in dexamethasone-treated goats

Immunoprophylaxis: a better alternative protective measure against shrimp vibriosis – a review

Aquaculture, especially shrimp production is the world`s fastest growing food production industry, due to increased demands for seafood. Conceivably, disease outbreak is the major setback which brings about high mortality and reduction or loss of production. The conventional use of antibiotics both prophylactically and therapeutically had recently not only been ineffective but incriminated, in drug residue which poise danger to consumption by humans. Hence, a better alternative was importantly required. The use of Immunoprophylaxis has potential of being a safety measure in the prevention of outbreak of diseases or spread of already established disease in aquatic invertebrates, where the shrimps and prawns belong. Immunoprophylaxis includes the prevention of disease by production of passive immunity. The major infectious agents that are responsible for high morbidity and high mortality in shrimp industry are viruses and bacteria. Others include fungi, parasites and protozoans but less threatening than the two former. Among the referenced groups of bacteria in shrimp disease, gram negative bacteria are more virulent. Vibrio, a member of this gram negative groups has been implicated to be the most causative agent of bacterial infections in shrimps. This review examined the components of the cell membrane of these bacteria that have been reported to confer immunity on the host. They include outer membrane proteins, lipopolysaccharide and peptidoglycan. These components could elicit immune response and confer protection

Oral administration assessment of outer membrane proteins of Vibrio alginolyticus on the growth of giant freshwater prawns (Macrobrachium rosenbergii De Man)

The production of prawns is unarguably a fast-growing global aquaculture. This is evident in the culture of freshwater prawns which is rapidly gaining momentum in terms of productions and values in Malaysia and the world at large. Vibrio alginolyticus is one of the most pathogenic species of Vibrio that cause high mortality in freshwater prawns. The conventional use of antibiotics in the treatment of this disease has remained ineffective and resulted in an exponential increase in virulence and pathogenicity of the microbes. Hence, the need for better and practicable measures of disease prevention and treatment. This was the first study to investigate the effects of oral administration of outer membrane protein of vibrio in Macrobrachium rosenbergii experimentally infected with V. alginolyticus. Prawns were divided into three groups A, B, and C of 10 prawns each with replicates in 6 (150 L) glass aquaria. Group A was fed with OMPs-mixed diet, group B with OMPs-FIA (Freund's incomplete adjuvants) mixed diet while group C was fed with OMPs or adjuvant-free diet (control diet). Groups A and B were fed for seven days, alternated with control diet for seven days and a booster dose for another seven days. All prawns were weighed weekly, and haemolymph was collected to examine the total haemocytes counts (THC), phenoloxidase activity (PO) and the presence of OMPs in the haemolymph. All prawns were challenged intramuscularly with 50 μL of 107 CFU of V. alginolyticus. The results of the analysis revealed significance difference in mean weight gain and THC (P 0.05) in the level of mortality in all the groups after 24 h, this was not unconnected to pains from the injection coupled with stress, as this was also observed in blank control (not challenged with V. alginolyticus). In the second experiment, 45 prawns were divided into three different groups of 15 prawns each. Group A was treated with formalin killed Vibrio cell by immersion only, B with OMPs by intramuscular injection and boosted by immersion and C with PBS by immersion only at days 0, 3, 5 and 7. A bacterial challenge was carried out by immersion on day 9 and observed for mortality for seven days. The total haemocyte count (THC) increased in the treatment groups more than the control but no significant difference in the level of THC increment between the treatment groups. There was no mortality in the treatment groups, but the mortality rate in the control group was 55% over the period of seven days. Haemolymph (both coagulated and non-coagulated) that was also collected to detect the presence of OMPs in the system using SDS-PAGE revealed no bands of OMPs but only those of the plasma proteins, this could be as a result of natural clearance activity of the prawns to get rid of foreign agents. Gross examination of the experimentally challenged prawns was carried out following the mortality and tissues were processed for histopathological lesions and immuno-histochemical reaction. The untreated group showed more pronounced lesions than the treatment groups. This study, however, concluded that oral administration of OMPs with or without Freund's incomplete adjuvant is a good growth promoter and has the potential for protection against vibriosis in Macrobrachium rosenbergii when administered with unique antigen protection vehicle and at appropriate dosages, but the protection may be for a short period of time

Pathology and immunohistochemical evaluation of Vibrio alginolyticus infection in Macrobrachium rosenberbergii

Vibriosis is one of the common bacterial diseases plaguing the prawn and shrimp industry. However, the sequential histopathological changes associated with Vibrio alginolyticus-induced vibriosis is scanty in literature. This study investigated the histological alterations in groups of Macrobrachium rosenbergii experimentally injected intramuscularly between the second and third abdominal segment with 50 μL of 107 CFU of V. alginolyticus. Twenty-four hours post inoculation, the organism was isolated and molecularly characterized while infected giant freshwater prawns were observed for histological alterations and immunoreactivity in different tissues due to the experimental challenge. The lesions observed in the organs include incipient haemocytic infiltration into the interstitial space of the tubules of the hepatopancreas and loss of epithelial layer, muscular necrosis and disruption of muscular layer with haemocytic infiltration, hyperplasia of epithelial cells and degeneration of the epithelium, deformed and necrotizing lamellae, and enlargement of the lamellar sinus of the gill, and the heart is characterized by localized nodular haemocytic reaction and melanization. Organs such as the heart, gill, hepatopancreas and muscle following injection of the putative bacteria showed immunohistochemical activity. Hence, histology and immunohistochemistry still remain important tools for vibriosis disease diagnoses in giant freshwater prawns

Waste production in aquaculture: Sources, components and managements in different culture systems

The intensification of aquaculture has emerged as a viable alternative for increasing aquaculture production due to competition that arose from the use of natural resources, such as land and water, by other production and developmental sectors. However, intensification demands increased inputs, such as fish and feed per unit culture area and, therefore, increased waste generation from the aquaculture production systems. The impact of waste products from aquaculture has increased public concern and threatens the sustainability of aquaculture practices. The need for increasing the production of aquaculture products cannot be overemphasized and, therefore, there is a need to develop culture systems that will increase fish production with efficient waste management in order to limit environmental degradation resulting from aquaculture wastes and ensure its sustainability. This paper reviewed various aspects of waste production from aquaculture, their sources, components, and methods of management, in different culture systems, primarily discussing waste production from feed, chemicals, and pathogens. We aimed to establish the sources of wastes, their contents, and potential harms to both the fish culture and the environment. Suggestions for managing wastes in different culture systems were made to ensure an improved and sustainable aquaculture production. Keywords: Fish farming, Aquaculture effluents, Environmental degradation, Waste management, Sustainable aquacultur

Global, regional, and national incidence of six major immune-mediated inflammatory diseases: findings from the global burden of disease study 2019Research in context

Summary: Background: The causes for immune-mediated inflammatory diseases (IMIDs) are diverse and the incidence trends of IMIDs from specific causes are rarely studied. The study aims to investigate the pattern and trend of IMIDs from 1990 to 2019. Methods: We collected detailed information on six major causes of IMIDs, including asthma, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, and atopic dermatitis, between 1990 and 2019, derived from the Global Burden of Disease study in 2019. The average annual percent change (AAPC) in number of incidents and age standardized incidence rate (ASR) on IMIDs, by sex, age, region, and causes, were calculated to quantify the temporal trends. Findings: In 2019, rheumatoid arthritis, atopic dermatitis, asthma, multiple sclerosis, psoriasis, inflammatory bowel disease accounted 1.59%, 36.17%, 54.71%, 0.09%, 6.84%, 0.60% of overall new IMIDs cases, respectively. The ASR of IMIDs showed substantial regional and global variation with the highest in High SDI region, High-income North America, and United States of America. Throughout human lifespan, the age distribution of incident cases from six IMIDs was quite different. Globally, incident cases of IMIDs increased with an AAPC of 0.68 and the ASR decreased with an AAPC of −0.34 from 1990 to 2019. The incident cases increased across six IMIDs, the ASR of rheumatoid arthritis increased (0.21, 95% CI 0.18, 0.25), while the ASR of asthma (AAPC = −0.41), inflammatory bowel disease (AAPC = −0.72), multiple sclerosis (AAPC = −0.26), psoriasis (AAPC = −0.77), and atopic dermatitis (AAPC = −0.15) decreased. The ASR of overall and six individual IMID increased with SDI at regional and global level. Countries with higher ASR in 1990 experienced a more rapid decrease in ASR. Interpretation: The incidence patterns of IMIDs varied considerably across the world. Innovative prevention and integrative management strategy are urgently needed to mitigate the increasing ASR of rheumatoid arthritis and upsurging new cases of other five IMIDs, respectively. Funding: The Global Burden of Disease Study is funded by the Bill and Melinda Gates Foundation. The project funded by Scientific Research Fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital (2022QN38)