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The present study depicts the disease incidences in the aqua farms of Moyna, West Bengal, India, during 2018-2020 and aqua-drugs used by farmers to combat diseases. A total of 132 fish disease incidences were reported, among which parasitic diseases were the most common (53.03%) followed by bacterial diseases (27.27%), diseases due to poor nutrition and environmental fluctuations (10.61%), and fungal diseases (9.09%), respectively. Out of the 53.03% parasitic disease incidences reported, Argulus (22.86%), Dactylogyrus (17.14%), Gyrodactylus (10.00%), Myxospores (10.00%), Lernaea (8.57%), Ichthyophthirius (5.71%) and Trichodina (4.29%) were the major disease-causing parasites. Among bacteria, Pseudomonas spp. and Aeromonas spp. were the most dominant genera encountered in diseased fish. Labeo catla was the most susceptible fish species followed by Labeo rohita, and Cirrhinus mrigala. Seasonal influence in disease occurrence was noticed. Monsoon and winter were favorable seasons for disease outbreaks. The influence of water quality parameters like hardness, pH, ammonia, total dissolved solids of water, and total organic carbon of sediment had a significant correlation with parasite abundance. Farmers of Moyna were observed to use a wide range of chemicals and aqua-drugs to control diseases and related problems. The majority of the fish farms of Moyna were found using feed additives and supplements (32.00%) followed by sanitizers and disinfectants (24.00%), probiotics (17.00%), anti-parasitic drugs (11.00%), antibiotics (8.00%), and other chemicals (20.00%). Lime (calcium carbonate) and zeolite along with sodium chloride, potassium permanganate, formalin, and calcium hypochlorite were extensively used as disinfectants in Moyna. Farmers being unaware of the adverse consequences of using chemicals and aqua-medicines are fully dependent on private aquaculture consultants for time-to-time advice, which may have augmented their indiscriminate use. Initiative for implementation of better management practices by creating awareness among farmers and adopting strict aquaculture policy guidelines might improve the scenario. [ABSTRACT FROM AUTHOR]

Emerging pathogen, carp edema virus (CEV) causes koi sleepy disease (KSD) in Koi and common carp causing severe mortalities worldwide. In the present study, a total of 150 fish species belonging to eight different families were sampled from the ornamental fish retailers and farms, located in Karnataka, India. The OIE protocol viz., level-I, II and III diagnoses confirmed the infection of CEV in 10 koi fish. Interestingly, other fish species belonging to different fish family including cyprinidae family were negative to CEV. Further, CEV infection was confirmed by sequencing (partial 4a gene); it showed the similarity with that of CEV reported from India and Germany strains with similarity of 97.4–99.94% and belonged to genogroup IIa. TEM analysis of purified CEV, in vivo cohabitation and tissue infection experiments confirmed the CEV infection. In addition, viral load was significantly higher (106−7 copies) in koi collected from Dakshina Kannada than of Bengaluru (103−4 copies). To understand the host–pathogen interaction, different organs such as gill, kidney, liver and spleen from naturally (CEV) infected koi were used to study the immune gene responses by using eight innate and one adaptive immune response. Results indicated that TNF-α, RohTNF-α, iNOS, IFN-γ and IL-10, and catalyze β-2M of MHC class I pathway genes were upregulated in koi. Higher expression of immune genes during the CEV infection may have inhibited viral replication and mount an antigenic adaptive response. Similar to other viral infections, interferon-γ play an important role during poxvirus infections. Quantification of immune genes in infected fish will provide insights into the host responses and provide valuable information to devise intervention strategies to prevent and control disease due to CEV. • Ornamental fish species were screened for CEV, only ten koi were found to be positive. • TEM analysis and in vivo experiments confirmed the CEV infection. • Viral load was high in koi from Dakshina Kannada followed by Bengaluru. • Upregulation of immune genes such as TNF-α, RohTNF-α, iNOS, IFN-γ and IL-10 in koi. [ABSTRACT FROM AUTHOR]

Epizootic Ulcerative Syndrome (EUS) has been causing large-scale mortality among the freshwater fishes of the globe since the 1070s. The symptoms include large haemorrhagic cutaneous ulcers, epidermal degeneration and necrosis followed by sloughing of scales. There have been many studies on EUS throughout the world. In India, since the initiation of EUS, in 1988, our study tried to reveal the aetiology of the disease through extensive and intensive studies on different aspects, like limnological, physical, chemical, bacteriological, fungal, viral including electron microscopic studies. Details of EUS investigation has been discussed in the present paper. [ABSTRACT FROM AUTHOR]

Fish farming contributes to aquaculture production for the domestic and international markets in India. Intensification of the aquaculture production systems has led to increased stress to fish. Thus, diseases occur more frequently across the entire region of India. One of the most common types is hemorrhagic septicemia caused by Aeromonas hydrophila. A. hydrophila is an opportunistic pathogenic bacterium causing diseases in human and fish. The emergence of multidrug-resistant A. hydrophila isolates has been increasing in recent years. In this study, we performed antibiotic susceptibility to A. hydrophila Ah34 strain. The MAR index of A. hydrophilaAh34 is 0.372 which infers the predominate use of antibiotics in aquatic environments. To develop an alternative bio-control measure for multi-drug resistant pathogenic Aeromonas hydrophila, which causes motile Aeromonas septicemia in fish, a novel virulent bacteriophage (AhFM22) was isolated from sewage water sample. The titer value of the purified phage AhFM22 was 1.29 x 107 PFU/mL. AhFM22 displayed latent period of 40 min with burst size of 670 PFU per infected cell. Since AhFM22 has a narrow host range, for effective phage therapy, different phages are needed for preparation of cocktails that are capable of killing the heterogeneous A. hydrophila strains. Further detailed in vivo studies are needed to confirm the protective efficacy of newly isolated AhFM22 against A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Cell lines are important in vitro models to answer biological mechanisms with less genetic variations. The present study was attempted to develop a cell line from rainbow trout, where we obtained a cell line from the heart, named "RBT-H." The cell line was authenticated using karyotyping and cytochrome c oxidase subunit I (COI) gene sequencing. The karyotype demonstrated diploid chromosome number (2n) as 62 and the sequence of partial COI gene was 99.84% similar to rainbow trout COI data set, both suggesting the origin of RBT-H from the rainbow trout. The heart cell line was mycoplasma-free and found to be refractory to infection with the Tilapia lake virus. The RBT-H cell line is deposited in the National Repository of Fish Cell Line (NRFC) at ICAR-NBFGR, Lucknow, India, with Accession no. NRFC0075 for maintenance and distribution to researchers on request for R&D., (© 2024 International Federation of Cell Biology.)

Of the total 47 species in the subgenus Acanthosentis, 43 have been reported from the freshwater fishes of Asia. Amin et al . (2017) provided a key to the 23 species of the genus Acanthogyrus reported from the Indian subcontinent. The present study reports two new species: Acanthogyrus bispinosa n. sp. and A. garciai n. sp. from Cirrhinus mrigala Hamilton and Labeo calbasu Hamilton, respectively, and two previously described species: A. golvani Gupta and Jain, 1980 and A. hereterospinus Khan and Bilqees, 1990 from L. rohita Hamilton and L. catla Hamilton, respectively. A. bispinosa n. sp. comprises 3 circles of 6 proboscis hooks each. Trunk spines in A. bispinosa n. sp are divided into two groups: anterior and posterior separated by unarmed region, which has not been previously reported in the subgenus. Anterior spines are present in 7-8 and 7-10 circles in females and males, respectively, whereas posterior spines are in 23-28 and 31-38 circles in males and females, respectively. A. garciai n. sp. comprises 3 circles of 6-8 hooks each and a single set of trunk spines is present in A. garciai n. sp., comprising 35-42 and 25-45 circles in males and females, respectively. All four species were also characterised based on the 18S, 28S, and ITS1-5.8S-ITS2 rRNA molecular markers. The Bayesian inference tree generated based on these markers showed distinct identities of all the species, with a significant molecular divergence, ranging from 3.2 to 53.6%.

White sardine, Escualosa thoracata (Valenciennes, 1847) forms a minor fishery along the west coast of India. An abnormal specimen of white sardine, lacking anal fin, was collected from Mangalore coast along with the normal specimens. The characters of the abnormal specimen are described along with normal specimens. The report is the first of its kind for E. thoracta from Indian waters. The possible causes of the abnormality in this species have been discussed in this communication. [ABSTRACT FROM AUTHOR]

In India, culture of tilapines has been gaining importance over last few decades and it is the second widely farmed fish species in the World. There have been increased large-scale mortalities observed in last few years due to DNA and RNA virus associated with coinfection of bacteria, fungi, parasites etc., were considered as a major global threat to the tilapia and aquaculture industry. In this study, large scale mortality of tilapia (Oreochromis mossambicus) was observed in wild populations located in Krishna Raja Sagara reservoir in Mysuru, Thonnur Lake and Erode Lake in Pandavapura, Mandya. A detailed investigation was performed from these regions which reported mass mortality in these water bodies. Tissues from the fishes (brain, gill, kidney, spleen and liver) were collected for examination of parasites, histology and molecular detection (virus and bacteria). The results of polymerase chain reaction showed that all the samples were found negative for DNA viruses and for one RNA virus namely VNN but all the samples from 3 regions (reservoir and lakes) were positive for TiLV. Syncytial hepatitis lesion along with glial cells were observed in the TiLV-infected tilapia. TiLV isolated from this study (OM1 and OM2) shared 94.30% and 95.52% nucleotide identity with the TiLV isolated from West Bengal, India (MF502419.1) and Israel (KJ605629.1) respectively. NCBI-BLAST search results using gyrB gene revealed that the isolates G 1 & H 2 were identified and confirmed as Aeromonas veronii with 99.52% and 99.42% nucleotide similarity to the A. veronii isolate XX-57 (JX025939.1) from diseased Chub and A. veronii isolate JH-12 (JX025895.1) from diseased gold fish from China respectively. To the best of our knowledge, this is the first report of concurrent infection TiLV and A. veronii associated with mass mortality in Oreochromis mossambicus in Karnataka, India. In vitro study showed the cytopathic effects on OniL cell lines with initially elongated cells followed by rounding and finally detachment leading to death of the cells. • Syncytial hepatitis lesion was observed in the TiLV-infected Oreochromis mossambicus. • TiLV isolated from this study (OM1 and OM2) shared 94.30% and 95.52% nucleotide identity with West Bengal, India and Israel respectively. • A. veronii was resistant to several antibiotics with MAR index of 0.675. • Aeromonas veronii with 99.52% and 99.42% nucleotide similarity to the isolate XX-57 from diseased Chub and JH-12 goldfish respectively. • This is the first report of concurrent infection TiLV and multidrug-resistant A. veronii associated with mass mortality in O. mossambicus in Karnataka, India [ABSTRACT FROM AUTHOR]

Coral reefs are constantly subjected to multiple stresses like diseases and fish predation, which can profoundly influence the coral microbiome. This study investigated the differences in bacterial community structure of healthy, white syndrome affected and blenny nipped coral colonies of Porites lutea, collected from the coral reefs of Gulf of Kachchh, north-west coast of India. Present study observed that the stressed coral colonies harbored more OTUs and contained higher diversity values compared to healthy corals colonies. Similarly, beta diversity analysis indicated the dissimilarities among the three coral samples analyzed. Though the taxonomy analysis indicated bacterial phyla like Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria among the entire coral samples studied, there was a variation in their relative abundances. Huge variations were observed in the relative dominance at the bacterial genera level. About 13phyla and 11 genera was identified in healthy coral. The PBN sample was found to contain Proteobacteria, Cyanobacteria, Verrucomicrobia, and Lentisphaerae as dominant phyla and Endozoicomonas, Dyella, Woeseia, and Winogradskyella as dominant genera. The PWS sample contained Proteobacteria, Lentisphaerae, Spirochaetes, and Tenericutes as dominant phyla and Endozoicomonas, Arcobacter, Sunxiuqinia, and Carboxylicivirgia as dominant genera. Among the healthy samples, sequences belonging to Uncultured Rhodospirillaceae were dominant, while Woeseia and sequences belonging to Uncultured Rhodovibrionaceae were dominant among the blenny nipped white syndrome infected corals. Although any previously established pathogen was not identified, present study revealed the presence of a potentially pathogenic bacterium, Arcobacter, among the diseased corals. It also demonstrated a dynamic microbiome among the Porites lutea colonies on subjecting to various stresses. [ABSTRACT FROM AUTHOR]

The article talks about leiomyosarcoma in pickhandle barracuda, Sphyraena jello found in India. The article mentions how the besides other related neoplasms, it has also been reported that the S. jello suffers from conditions such as the compound odontoma. It adds that the tumors was measured with a Vernier caliper and their location, appearance and consistency noted only after that the biopsies were performed.

Aim: To investigate the incidence and virulence properties of E. coli in fresh fish and ready-to-eat fish products from retail markets of the Ludhiana the present study was conducted. Materials and Methods: Total of 184 samples comprising 96 raw fish and 88 ready- to-eat (RTE) fish products were collected from Ludhiana and other parts of Punjab and were subjected to suitable microbiological methods for E. coli isolation. E. coli isolates were subjected for haemolytic activity and indicators of plausible cytotoxicity (lecithinase, protease and gelatinase production), congo red dye biding assay. To assess virulence potential isolates were molecularly screened for stx 1 and 2 genes. Results: From raw fish samples 47(48.95%), E. coli, were isolated. From RTE fish products 7(12.96%), E. coli were isolated. Overall incidence for E. coli was 54 (29.34%). In vitro virulence characterization of isolates exhibited that all E. coli isolates were haemolytic while indicators of plausible cytotoxicity ( lecithinase, protease and gelatinase production) were in the range of 16.67% to 35.19% indicated that though the isolates were haemolytic they were perhaps less likely to be cytotoxic. Congo Red binding assay for E. coli isolates revealed that majority (88.89%) of the isolates failed to uptake the dye and only few (11.11%) could bind the dye. Results of serotyping revealed a total of 15 different serotypes among the E. coli isolates. More variation was observed among isolates from raw fish samples (12 serotypes) while RTE fish products harboured only 5 different serotypes. Molecular characterization of E. coli isolates revealed that PCR screening of isolates revealed that total 39 (72.22%) samples out of 54 E. coli isolates were positive for stx1 gene and 28 (51.85%) of isolates were positive for stx2 gene. Sources wise, 36 (66.66%) of isolates from raw fish and 3(5.55%) of isolates from RTE fish products were positive for stx1 while and stx2 gene could be detected in 24(44.44%) isolates from raw fish and 4(7.4%) isolates from RTE fish products.Interestingly, about 20% (37.03%) isolates were positive for both stx1 and stx2 genes. Among these multivirulent isolates majority (n=18) belonged to raw fish samples compared to a few (n=2) from RTE fish products. Conclusion: The results of the present study highlighted the possible risks to consumers of fish and fish products in the region that demand action to address this public health concern. [ABSTRACT FROM AUTHOR]

This study reports the occurrence of cyprinid herpesvirus 3 (CyHV-3) in koi carp (Cyprinus carpio koi) for the first time in India. The koi carp, with clinical signs of ulcer with haemorrhage on body surface, necrosis of fin and discolouration of gill associated with huge mortality, were observed in aquarium shops, rearing tanks and grow-out ponds located in Chennai, India. The PCR assay carried out on infected fish samples using different primer sets specific to CyHV-3 confirmed its presence in the infected fish. Sequence analysis of partial thymidine kinase gene revealed 100% similarity with the sequence of CyHV-3 available in GenBank. Cell lines of koi carp and catla were found to be susceptible to CyHV-3 and its replication was confirmed by viral-specific cytopathic effect, PCR and bioassay. The CyHV-3 infection was reproduced by intramuscular injection of inoculum prepared from CyHV-3-infected fish to satisfy Koch's postulates. Tissue tropism of CyHV-3 in infected fish by PCR assay revealed the presence of CyHV-3 in all vital organs with prominent band in gill and gut tissue., (© 2022 John Wiley & Sons Ltd.)

An epidemiological investigation was done in brackish water culture systems in three coastal districts of West Bengal. A total of 198 farms were randomly surveyed with a structured questionnaire. The data showed that there was a significant difference in outbreak of white spot disease (WSD) (p < 0.01), shell-associated problems (p < 0.01), and gill-associated problems (p < 0.05) among the culture systems. Among all systems, stunted and uneven growth and white fecal disease (only in shrimp monoculture) were the dominant emerging disorders. WSD remained the most prevalent disease. Some farms tested (polymerase chain reaction [PCR]) positive for WSD, but the animals were apparently healthy. Chlorination, use of PCR screening, application of immunostimulants, and strict bio-security measures play major roles in containing disease outbreaks. [ABSTRACT FROM PUBLISHER]

The use of immunostimulants as an alternative to the drugs, chemicals and antibiotics currently being used to control fish diseases in fish culture is attracting the attention of many researchers. In this context, many have focused on the use of medicinal plant products as potential therapeutic measures for modulating the immune response and, specifically, on the use of herbs to prevent and control fish diseases. Medicinal plants (plant remedies) are a deeply rooted component of the cultural heritage of many people from diverse cultures and countries and are, as such, closely linked to the maintenance of good health. The aim of this paper is to review research currently being carried out on the herbs and herbal extracts that have been shown to modulate the immune system of fish. Special attention is given to the use of Chinese and Indian herbs. [ABSTRACT FROM AUTHOR]

The present research is an outcome of the comprehensive studies on the hydrobiology. and fisheries of Leond Tal of district Siddharthanagar, in Uttar Pradesh with special reference to aquaculture development in lake during the 1995-97. The aspects of study pertain to physiography, physico-chemical conditions of water, sediment nutrient status, biotic productivity including plankton, macrophytes, primary production, benthic productivity, fish fauna, fish catch, fishing gears used in Leond Tal, fish yield, production efficiencies, multi-commodity production, fish diseases, socio-economic condition of fishermen community and aquaculture based management system for accelerating fish yield of Leond Tal. The salient observations made and conclusions drawn are discussed in this paper. [ABSTRACT FROM AUTHOR]

White spot syndrome virus (WSSV) was first reported in farmed Litopenaeus vannamei stocks in Sinaloa and Sonora, Mexico during 1999 and continues to cause severe shrimp losses. WSSV genes encoding nucleocapsid (VP26 and VP15) and envelope proteins (VP19 and VP28) of a Mexican isolate were cloned in the pMosBlue vector. The nucleotide sequences of these genes were compared with WSSV isolates in GenBank. VP15 is highly conserved, and VP26 showed 99% homology to a Chinese isolate. The VP28 fragment demonstrated 100% homology to the majority of the isolates analysed (UniProt accession no. Q91CB7), differing from two Indian WSSV and one Chinese WSSV isolates by two non-conserved and one conserved replacements, respectively. Because of their highly conserved nature, these three structural proteins are good candidates for the development of antibody-based WSSV diagnostic tools or for the production of recombinant protein vaccines to stimulate the quasi-immune response of shrimp. In contrast, VP19 of the Mexican isolate was distinguishable from almost all isolates tested, including an American strain of WSSV (US98/South Carolina, GenBank accession no. ). Although homology was found with isolates from Taiwan (GenBank accession no. ) and India (GenBank accession no. ), VP19 may have application as a genetic marker. [ABSTRACT FROM AUTHOR]

Abstract: White tail disease is a recently reported disease of giant freshwater prawn, Macrobrachium rosenbergii associated with M. rosenbergii nodavirus (MrNV). The present study is the first report on RT-PCR and sequence analysis of MrNV of an Indian isolate confirming the nodavirus infection in M. rosenbergii from India. Total RNA was extracted and the cDNA was synthesized from the infected post larvae collected from a hatchery located in Chennai, India. An 850-bp amplified product could be obtained by RT-PCR. The nucleotide sequence analysis of this 850-bp segment showed 98% nucleotide and 99% amino acid sequence identity with the reported sequence of an MrNV isolate from the West Indies. [Copyright &y& Elsevier]

White tail disease of the farmed freshwater prawn,Macrobrachium rosenbergii, is the cause of mortalities in the French West Indies, China and India. Two different sized particles, both developing in the cytoplasm of target cells, are found associated with diseased animals. These two viruses were separated, purified and subsequently characterized. The larger one, calledMrNV, is icosahedral in shape and 27 nm in diameter. Its genome is composed of two fragments of linear single-stranded RNA (ss-RNA), of 2.9 and 1.3 kb, respectively and its capsids exhibited a single polypeptide of 43 kDa. These characteristics and the partial sequence of a cloned fragment of RNA-1 suggest this agent is a member of the family Nodaviridae, but with differences from both the generaAlphanodavirusandBetanodavirus. The smaller virus, named XSV, is icosahedral in shape, 15 nm in diameter, possesses a linear ss-RNA genome of about 0.9 kb, and its capsid exhibits two polypeptides of 16 and 17 kDa, respectively. The relationships between these two viruses remain unknown. [ABSTRACT FROM AUTHOR]

Samples of white leg shrimp, Penaeus vannamei, were collected on a monthly basis from freshwater ponds with the salinity of 0 ppt located at Tiruvannamalai and Villupuram districts in Tamil Nadu, India for screening of viral and fungal pathogens. Totally, 130 shrimp samples were collected from 67 freshwater ponds and screened for white spot syndrome virus (WSSV), infectious myonecrosis virus (IMNV), infectious hypodermal and haematopoietic necrosis virus (IHHNV) and Enterocytozoon hepatopenaei (EHP) by PCR and RT-PCR using pathogen-specific primers. Among the samples screened, one sample was found to be positive to WSSV, two samples showed positive to IMNV and two samples positive for EHP. No sample showed positive to IHHNV. The WSSV detected in the sample was found to be a new strain of WSSV and highly virulent. The inoculum prepared from freshwater reared WSSV or IMNV-infected shrimp caused 100% mortality in experimental infection studies. The PCR and RT-PCR results revealed the presence of WSSV and IMNV in different organs of experimentally infected shrimp, respectively. No clinical signs were observed in experimentally EHP-injected shrimp, although the PCR results revealed the presence of EHP in experimentally infected shrimp., (© 2022 John Wiley & Sons Ltd.)

A new genus, Mystocestus, is proposed to accommodate a new species, Mystocestus anindoi n. g., n. sp. from Mystus vittatus (Bloch) (type host) in West Bengal and Mystus cavasius (Hamilton) (Siluriformes: Bagridae) in Maharashtra, India. The new genus is most similar to Lucknowia Gupta, 1961 in the shape of the body, which is elongate, slightly tapering towards the anterior end, and scolex, which is digitiform, but differs in the shape of the ovary, which is H-shaped (vs. inverted A-shaped in Lucknowia), the absence of a seminal receptacle (present in Lucknowia) and exclusively cortical vitelline follicles (vs. some follicles in the medulla in the latter genus). Molecular data support the erection of the new genus and place it close to Bovienia Fuhrmann, 1931, species of which can be easily distinguished by exclusively lateral vitelline follicles (lateral and median in the new genus), the presence of a seminal receptacle (absent in Mystocestus) and scolex shape (digitiform, with blunt or slightly concave anterior edge in the new genus vs. small, unspecialized or spatulate in Bovienia). The convoluted taxonomy of tapeworms placed in Mystoides Mathur, 1992 is critically reviewed to clean up taxonomic chaos in Indo-Malayan caryophyllideans. Mystoides was erected in an unpublished PhD thesis and thus its generic name becomes unavailable and also, its type species is conspecific with Lucknowia fossilisi Gupta, 1961 from the stinging catfish, Heteropneustes fossilis (Bloch). Other species of this genus are also conspecific with L. fossilisi. In addition, specific names of most of these taxa are unavailable because they were described in unpublished theses or conference abstracts. Based on recent revisions of Indo-Malayan caryophyllideans, the following nine genera with 15 species are considered valid (numbers of species of individual genera are provided in parentheses): Bovienia (3), Djombangia (1), Lucknowia (2), Lytocestus (2), Mystocestus (1), Pseudocaryophyllaeus (2) (all family Lytocestidae); Adenoscolex (1), Lobulovarium (2), Paracaryophyllaeus (1) (all family Caryophyllaeidae).

Bacillus licheniformis , a pathogenic new strain of bacteria is considered as the main cause of high mortalities and economic losses among the ornamental fish farms of India. The present study aimed to investigate the anti-bacterial and Immunostimulant activity of three selected Indian medicinal plants, Allium sativum, Adhatoda vasica and Centella asiatica for treating Bacillus licheniformis PKBMS 16 by subsequent experimental and clinical trials using different organic polar and non-polar solvents. The antimicrobial and Immunostimulant activity of methanolic crude extracts of Adhatoda vasica was fractions and active constituents was further characterized by chromatography and mass spectroscopy studies using FTIR, 1HNMR and 13c NMR to identify as well as to determine the nature of the pure compound which is phytol (C 20 H 40 O), a diterpene alcohol with a molecular weight of m / z 297. In order to study the in vivo anti-pathogenic influence of the biologically active compounds, phytol were incorporated to the artificial diets at the concentration of 2, 5 and 8 mg/kg and fed to the1.0 × 105 CFU/ml of Bacillus licheniformis PKBMS 16 injected experimentally challenged ornamental goldfish Carassius auratus for twenty days. Phytol treated group significantly (P < 0.01 and P < 0.05) reduced the rate of fish mortality. After the termination of survivability assay the estimation of hemato-biochemical parameters have been performed and revealed the significant recovery of health condition on 20th days post treatment. Therefore, the present study concluded that the low toxicity along with high bioactivity and tolerance by lower vertebrate supports the potential of phytol as a new compound for inducing fish immunity. Image 1 • Anti-bacterial and Immunostimulant activity of Adhatoda vasica , for treating Bacillus licheniformis PKBMS 16. • The active fraction of Adhatoda vasica was characterized by chromatography and mass spectroscopy studies using FTIR, 1HNMR and 13 CNMR to identify the pure compound. • This active biological molecule is phytol (C 20 H 40 O), a diterpene alcohol with a molecular wt. of m / z 297. • Phytol (2, 5 and 8 mg/kg doses) applied to experimentally challenged Carassius auratus infected by Bacillus licheniformis PKBMS 16 (1.0 × 105 CFU/ml). • Haemato-biochemical parameters revealed the significant recovery of health condition by 20th days. [ABSTRACT FROM AUTHOR]

The present study describes a new species of myxosporean, Ellipsomyxa ariusi sp. nov., infecting the gallbladder of the threadfin sea catfish Arius arius (Hamilton, 1822). E. ariusi sp. nov. is characterized by bivalvular, ellipsoid or elongate-oval myxospores with smooth spore valves and a straight suture, arranged at an angle to the longitudinal spore axis. Mature myxospores measured 10.1 ± 0.8 µm in length, 6.8 ± 0.5 µm in width and 7.7 ± 0.7 µm in thickness. Polar capsules are equal in size and oval to pyriform in shape. They are positioned at an angle to the longitudinal myxospore axis and open in opposite directions. Polar capsules measured 2.8 ± 0.3 µm in length and 2.5 ± 0.4 µm in width; polar filaments formed 4-5 coils, and extended to 32.2 ± 2.1 µm in length. Monosporic and disporic plasmodial stages attached to the wall of gallbladder. Molecular analysis of the type specimen generated a 1703 bp partial SSU rDNA sequence (MN892546), which was identical to the isolates from 3 other locations. In phylogenetic analyses, genus Ellipsomyxa appeared monophyletic and E. ariusi sp. nov. occupied an independent position in maximum likelihood and Bayesian inference trees with high bootstrap values. The overall prevalence of infection was 54.8% and multiway ANOVA revealed that it varied significantly with location, year, season, sex and size of the fish host. Histopathological changes associated with E. ariusi sp. nov. infection included swelling, vacuolation and detachment of epithelial layer, reduced mucus production and altered consistency and colour of bile. Based on the morphologic, morphometric and molecular differences with known species of Ellipsomyxa, and considering differences in host and geographic locations, the present species is treated as new and the name Ellipsomyxa ariusi sp. nov. is proposed.

Aquaculture of popular freshwater species, Nile tilapia (Oreochromis niloticus), accounts for around 71% of the total global tilapia production. Frequent use of antibiotics for treating bacterial infections in tilapia leads to the emergence of antimicrobial resistance. To mitigate the issue, proper evaluation methods and control strategies have to be implemented. This study was aimed to analyze the antimicrobial resistance of bacterial isolates from the infected Nile tilapia cultured in freshwater. The recovered isolates were identified as Pseudomonas entomophila, Edwardsiella tarda, Comamonas sp, Delftia tsuruhatensis, Aeromonas dhakensis, A. sobria, A. hydrophila, A. lacus, Plesiomonas shigelloides and Vogesella perlucida through phenotypic and genotypic analyses. Using Primer-E software, Shannon Wiener diversity index of the isolates was determined as H' (loge) = 2.58. Antibiotic susceptibility test of the recovered strains through disk diffusion using 47 antibiotics, showed an elevated resistance pattern for Aeromonas hydrophila, Pseudomonas entomophila and Comamonas with higher multiple antibiotic resistance indexes (MAR index > 0.3). The minimum inhibitory concentration of antibiotics was > 256 mcg/ml for most of the resistant isolates. Meanwhile, all the recovered isolates were susceptible to amikacin, aztreonam, kanamycin, cefalexin, cefotaxime, levofloxacin, norfloxacin, piperacillin, and polymyxin-B.

Most environmental parameters have no consistent effect on the expression of bacterial genes responsible for their virulence. However, as fish are poikilothermic, the possibility of temperature variation having a pronounced effect on the expression of virulence-associated gene(s) of bacteria infecting the host needs to be investigated. In this study, the diversity of virulence genes in seven Aeromonas hydrophila isolates collected from diseased fish from different parts of India was characterized, and the effect of temperature variation on the extent of expression of their virulence was investigated. All bacterial isolates were screened for a total of nine bacterial virulent genes {aerolysin, hemolysin, cytoen, outer membrane protein TS (Omp TS), elastase, flagellin, lipase, β hemolysin and type 3 secretion system}, and the diversity in their presence or absence were marked at a particular in vitro condition. Three bacterial isolates (nos. 1, 7 and 2) were selected for further study, based on their ability to cause varied mortalities (20-100%) in Labeo rohita juveniles in intraperitoneal challenge study. Further, three isolates were injected intraperitoneally into L. rohita fingerlings at three different temperatures (i.e., 20, 28 and 37 °C) and at 6 h post-challenge, the kidney samples were collected to measure the levels of all nine bacterial virulence genes using semi-quantitative PCR. The maximum level of amplicons of virulence genes in all three A. hydrophila isolates was noticed at 28 °C as compared to 37 °C and 20 °C. It was also observed that haemolysin played a more prominent role in the expression of virulence, when compared to cytoen gene. Hence, it was concluded that water temperature does play a crucial role in governing virulence gene expression, and a temperature of 28 °C would be considered as suitable for looking into the pathogenicity of A. hydrophila for conducting any challenge study with this organism in tropical environment., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Lactococcus garvieae is one of the emerging zoonotic bacterial pathogen, causes fatal hemorrhagic septicemia in cultured fish species, animals and humans, worldwide. Here, we report the genomic features of whole-genome sequence (WGS) of L. garvieae strain RTCLI04, recovered from lower intestine of farmed rainbow trout, Oncorhynchus mykiss in the northwest Himalayan region India. The genome of L. garvieae RTCLI04 is a single circular chromosome of 2,054,885 base pairs (bp), which encodes 1993 proteins and has G + C content of 39%. The bioinformatics analysis of WGS of RTCLI04, confirmed the presence of 51 tRNAs genes (including two pseudogenes), six rRNAs genes (four genes for 5S rRNA; one gene for 16S rRNA and one gene for 23S rRNA), five virulent domains, and twenty eight different genetic pathways. A Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) finder tool indicates that three different CRISPR and one cas system with common spacer was present in the genome of L. garvieae RTCLI04. Pan-genome analysis of RTCLI04 and all the other reference L. garvieae strains shows that pan-genome of this bacterium consisted of 2239 putative protein-coding genes in which 1850 genes are core gene, 389 genes are dispensable gene, and 221 genes are unique to RTCLI04. L. garvieae RTCLI04 lacks genomic island of 16.5 Kb capsule gene cluster. In addition, 39 virulence-associated genes (VAGs) including hly1,-2,-3; PavA, PsaA; eno; LPxTG containing surface proteins 1, 2, 3 and 4; pgm, sod and 29 antimicrobial resistant genes (ARGs) including mefE (clindamycin), srmB (lincomycin), dfrA26 (trimethoprim), gyrB (nalidixic acid), arr-3 (rifampin), otrB (tetracycline), aac(6)-Ic (tobramycin), IrgB (penicillin), mecA (oxacillin), vanRB (vancomycin) and mfpA (fluoroquinolone) were also predicted in the genome of L. garvieae RTCLI04. Our study provides new insight into understanding the virulence mechanism, antimicrobial resistance, and development of effective therapeutic measures against L. garvieae during a disease outbreak in aquaculture., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Epizootic ulcerative syndrome (EUS), primarily caused by the water mold Aphanomyces invadans, is an OIE-notifiable disease, having potential impacts on fisheries. We report EUS epizootics among estuarine fishes of Kerala, India, during 2018, under post-flood conditions 3 decades after its primary outbreak. Six fish species (Mugil cephalus, Platycephalus sp., Scatophagus argus, Arius sp., Planiliza macrolepis and Epinephelus malabaricus) were infected, including the first confirmed natural case in E. malabaricus and P. macrolepis. Salinity, surface temperature, dissolved oxygen and pH of resident water during the epizootic were <2 ppt, 25°C, 4.1 ppm and 7.0. The presence of zoonotic bacterial pathogens (Aeromonas veronii, Shewanella putrefaciens, Vibrio vulnificus and V. parahaemolyticus) in tissues of affected fish indicates that EUS-infected fish may pose a public health hazard if not handled properly. Lack of clinical evidence in the region during the last 3 decades, a high number of affected fishes, including 2 new fish species, the severity of skin lesions and very low water salinity (<2 ppt) during the outbreak in contrast to historical water salinity records suggest relatively recent invasion by A. invadans. Phylogenetic analysis based on the internal transcribed spacer region of the rRNA gene showed that the same clone of pathogen has spread across different continents regardless of fish species and ecotypes (fresh/estuarine environments). Altogether, the present study provides baseline data which can be applied in EUS management strategies within brackish-water ecosystems. We recommend strict surveillance and development of sound biosecurity measures against the disease.

The fish, Aplocheilus panchax (Hamilton-Buchanan, 1839), is recorded as a new host of Aphanomyces laevis de Bary, 1860. It is the first and only report of any oomycete causing disease on A. panchax. Aphanomyces laevis was found to be a virulent parasite of A. panchax that caused cotton-wool disease involving the skin and fins. The hyphae also penetrated deep into the tissues of the infected fish and all of them ultimately died.