Emerging and existing diseases are the major havoc to the shrimp aquaculture industry. Outbreaks of viral epidemics severely hinder the sustainable farming system with significant economic losses ...worldwide. The Pacific white shrimp, Penaeus vannamei farming was seriously affected by infectious myonecrosis caused by a double-stranded RNA virus, infectious myonecrosis virus (IMNV). Early and rapid diagnostics is the priority on considering the efficient management and prevention measures. So, the present study utilized the accurate, rapid and specific detection capabilities of real-time PCR on SYBR Green platform to diagnose and quantify the viral load from the infected tissues by designing an efficient PCR primer set. The developed PCR could detect the virus at 98% efficiency with 10 viral copy number as the limit of detection. The standard curve analysis and amplification arithmetics have shown that it can even detect even less than 10 copy numbers of virus in a sample. The standard curve of the assay has shown R2 value of 0.98 and slope of −3.3834 without any significant variations in inter- and intra- assays. The validated PCR primer pairs and developed SYBR green-based real-time PCR is highly specific, equally sensitive and comparatively economic than the existing TaqMan probe-based PCR for detection of IMNV.
•Validated a new set of PCR primers for SYBR green-based qPCR for the detection and quantification of IMNV infection in India•The developed PCR could detect the virus at 98% efficiency with 10 viral copy number as the limit of detection.•The standard curve of assay was showing an R2 value of 0.98 and a slope of −3.3834 without any statistical variations.•The assay can be implemented for the accurate diagnosis and viral load quantification of the IMNV from infected shrimps.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
A 90‐day experiment was conducted by rearing 1020 prawn juveniles (0.54 ± 0.03 g) in water supplemented with three different concentrations of probiotic bacteria viz. T1 (10⁷ cfu L⁻¹), T2 ...(10⁸ cfu L⁻¹), T3 (10⁹ cfu L⁻¹) and the control (C) (unsupplemented water), to evaluate probiotic effect of Lactobacillus plantarum. In the present study, the growth parameters (WG%, SGR) and feed utilization parameters (FCR, PER) significantly improved (P < 0.05) in T3. The growth and feed utilization parameters though improved marginally in T1 and T2, the difference was not significant (P > 0.05) compared to the control. The gastro‐intestinal Lactobacillus sp. count increased significantly (P < 0.05) in all the treatment groups, whereas the decrease in harmful bacteria was significant (P < 0.05) in T3 compared to the control. Similarly, the Lactobacillus sp. count in culture water increased significantly (P < 0.05) in all the experimental groups, whereas the decrease in harmful bacteria was significant (P < 0.05) in T2 and T3. The immune parameters (THC, PO and RB activity) and clearance efficiency significantly improved (P < 0.05) in T3 with concurrent decrease (P < 0.05) in cumulative mortality against Aeromonas hydrophila challenge. However, water quality did not improved (P > 0.05) in any of the treatment groups. The results indicate that Lactobacillus plantarum at a minimum concentration of 10⁹ cfu L⁻¹ could be used as water additive to confer its probiotic effect in prawn, Macrobrachium rosenbergii. Moreover, future studies with higher probiotic concentrations should be conducted for its efficient commercial scale field application.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Bacillus subtilis, a Gram-positive, aerobic, endospore-forming bacterium, was evaluated for its probiotic potential in Indian major carp, Labeo rohita. Labeo rohita (15±2 g) were fed a feed ...containing B. subtilis in three concentrations for 2 weeks, e.g., 0.5 (T₂), 1.0 (T₃) and 1.5 (T₄) x 10⁷ CFU g⁻¹ feed. The control group (T₁) was fed feed without B. subtilis for the same period. Haematological and serum parameters were monitored at weekly intervals. The response variables were total erythrocyte count, total leucocyte count (TLC), haemoglobin, total protein, albumin, globulin, albumin-globulin ratio, alkaline phosphatase activity, alanine aminotransferase activity and aspartate aminotransferase activity. Fish were challenged intraperitoneally with a virulent strain of Aeromonas hydrophila after 2 weeks of feeding to the treatment groups and positive control group, while the negative control group was challenged with phosphate-buffered saline only. Clinical signs and symptoms, and mortality/survival percentage were noted in each group. The haematological and serum parameters were monitored each week and during post challenge on the third and tenth day. The B. subtilis-treated fish (T₄, 1.5 x 10⁷ CFU g⁻¹ feed) showed maximum per cent survival (87.50%), weight gain (35.5%), TLCs (3.23 x 10⁴ cells mm⁻³), haemoglobin content (7.4 g%), total protein (2.37 gdL⁻¹) and globulin content (1.28 g dL⁻¹) during the pre-challenge. Enzymes showed higher activities during post challenge (P<0.05). The result suggests that B. subtilis can be used effectively as a commercial product for use in aquaculture.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future ...global health are still being investigated, including the pandemic’s potential effect on the emergence and spread of global antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19 infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the authors present a brief overview of the COVID-19 pandemic and associated issues that could influence the pandemic’s effect on global AMR.
Pangasius (Pangasianodon hypophthalmus) is a commercially important candidate species in freshwater aquaculture and it is important to understand the immune system of pangasius against infectious ...disease. The present study was aimed at the purification, characterization and quantification of serum IgM in pangasius (P. hypophthalmus). Serum IgM was purified by diethylaminoethyl (DEAE) cellulose based ion exchange chromatography. The molecular weight of native immunoglobulin was found to be 798 kDa. Heavy (H) and light chains were found to possess molecular weight of 70.1 and 26 kDa respectively. A 248 bp segment of IgM H chain gene of pangasius was amplified and sequenced (partial). The antisera raised against pangasius immunoglobulin cross‐reacted with the immunoglobulin H chain of catfish such as Clarias gariepinus and Clarias batrachus, but not with their light chain indicating epitope sharing among IgM H chains in these catfish. The produced polyclonal antisera were used to develop an enzyme linked immuosorbent assay to quantify IgM levels in pangasius. In conclusion, the present study provides its future implications for epidemiology and immunology studies in pangasius.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
White spot syndrome virus
(WSSV) is one of the major pathogens in shrimp aquaculture. Four proteins of WSSV are predicted to encode a RING H2 domain, which in presence of ubiquitin conjugating enzyme ...(E2) in shrimps can function as viral E3 ligase and modulate the host ubiquitin proteasome pathway. Modulation of host ubiquitin proteasome pathway by viral proteins is implicated in viral pathogenesis. In the present study, expression profile of
Penaeus monodon
Ubiquitin conjugating enzyme (PmUbc) was studied at protein level in WSSV challenged shrimp. A time point analysis of the expression of PmUbc was carried out at 0, 3, 6, 12, 24, 48 and 72 h post WSSV challenge in
P. monodon
. Recombinant PmUbc (rPmUbc) was produced in prokaryotic expression vector, BL21 (DE3) pLys S. The PmUbc expression pattern was studied by ELISA with rPmUbc antibodies raised in rabbit. A significant increase in PmUbc expression at 24 h post infection (hpi) was observed followed by a decline till 72 hpi. Since the up-regulation and a tremendous decline of PmUbc protein expression was observed at 24 and in 72 hpi respectively in ELISA, it can be speculated that these proteins might interact with host ubiquitination pathway for viral pathogenesis. Many findings have shown that viral infection can up-regulate expression of ubiquitin and that the ubiquitin system plays a key role in the course of viral infection. The present study reveals the expression patterns of PmUbc at protein level in WSSV infected
P. monodon
. However, further studies are to be carried out to unfold the molecular mechanism of interaction between host and virus to devise efficient control strategies for this major culprit in shrimp culture industry.
PDF
