Isolation and characterization of Saprolegnia parasitica from cage-reared Pangasianodon hypophthalmus and its sensitivity to different antifungal compounds.

Saprolegniasis is one of the most dangerous fungal diseases of fish, causing significant mortality in fish hatcheries and young ones. The present study aimed to isolate and characterize the causative fungus from fingerlings of Pangasianodon hypophthalmus cultured intensively in freshwater cages in Indian reservoirs and to determine minimum inhibitory concentrations of different antifungal compounds against the fungal hyphae and zoospores. The fungal isolates grown on potato dextrose agar showed an abundance of gemmae, elongated mycelia, non-septate hyphae, primary zoospores, mature zoosporangia with numerous zoospores, cysts with bundles of long hairs and were further identified as Saprolegnia parasitica following PCR amplification and sequencing of internal transcribed spacer region.

Gut microbes of a high-value marine fish, Snubnose Pompano (Trachinotus blochii) are resilient to therapeutic dosing of oxytetracycline.

Trachinotus blochii is a high-value tropical mariculture species. The present study evaluated the gut microbial impact of therapeutic exposure (80 mg/day/kg biomass for 10 days) to oxytetracycline, the most common aquaculture antibiotic in T. blochii.

Assessing the effect of therapeutic level of oxytetracycline dihydrate on pharmacokinetics and biosafety in Oncorhynchus mykiss (Walbaum, 1792).

The aim of the experiment was to investigate the pharmacokinetics of oxytetracycline dihydrate after a single oral administration of 80 mg kg day in rainbow trout and assess its biosafety at concentration of 80, 240, 400, and 800 mg kg day over 30 days, focusing on various aspects such as effective feed consumption, physiological responses, drug tolerance, and detection of low drug concentrations in rainbow trout. The pharmacokinetics study spanned a duration of 5 days, while the assessment of biosafety extended for a 30-day safety margin, followed by a subsequent 10-day residual analysis. Pharmacokinetic analysis revealed slow absorption with low-rate constant in tissues.

Impact of graded doses of enrofloxacin on the safety and biological responses of Nile tilapia .

The cultivation of tilapias, the third most farmed fish group globally, has been rapidly growing, especially in Southeast Asia. This surge in tilapia farming intensification has led to increased use of antibiotics to control bacterial diseases. This study investigated the safety implications of administering graded doses of enrofloxacin (ENF) at 0 (control), 10, 30, 50 and 100 mg/kg biomass/day orally to .

In vitro efficacy of aquaculture antimicrobials and genetic determinants of resistance in bacterial isolates from tropical aquaculture disease outbreaks.

Understanding the efficacy of antimicrobials against pathogens from clinical samples is critical for their responsible use. The manuscript presents in vitro efficacy and antimicrobial resistance (AMR) genes in seven species of fish pathogens from the disease outbreaks of Indian aquaculture against oxytetracycline, florfenicol, oxolinic acid, and enrofloxacin. In vitro efficacy was evaluated by minimum inhibitory concentration and minimum bactericidal concentration.

Assessment of Single-Dose Pharmacokinetics of Oxolinic Acid in Rainbow Trout and Determination of In Vitro Antibacterial Activity Against Pathogenic Bacteria From Diseased Fish.

In response to the heightened risk of bacterial diseases in fish farms caused by increased demand for fish consumption and subsequent overcrowding, researchers are currently investigating the efficacy and residue management of oxolinic acid (OA) as a treatment for bacterial infections in fish. This research is crucial for gaining a comprehensive understanding of the pharmacokinetics of OA. The present study investigates pharmacokinetics of OA in juvenile rainbow trout.

Pharmacokinetics and residues of florfenicol in Nile tilapia (Oreochromis niloticus) post-oral gavage.

In the study on Oreochromis niloticus, singular oral gavage of florfenicol (FFC) at 15 mg/kg biomass/day was conducted, mimicking approved aquaculture dosing. Samples of plasma, bile, muscle, intestine, skin, liver, kidney, gill, and brain tissues were collected at 0, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, and 128 hours (h) after oral gavage. LC-MS/MS analysis revealed FFC concentrations peaked at 12.

Intestinal Histopathological Aberrations in Oreochromis niloticus Juveniles upon Dietary Florfenicol Administration.

The aquaculture use of antibiotics can cause detrimental effects on fish organs and gut microbial dysbiosis. The impact of florfenicol (FFC) on fish intestinal histology, an approved antibiotic, remains unclear. This study aimed to investigate the effects of FFC on Oreochromis niloticus juveniles by administering FFC at 10 mg and 30 mg/kg biomass/day for 30 consecutive days to mimic long-term use.

Assessing safety, efficacy and residue depletion in golden mahseer, Tor putitora (Hamilton, 1822): biochemical and physiological responses to graded concentrations of oxytetracycline dietary supplementation.

The safety and effectiveness of oxytetracycline can potentially manage bacterial infections in fish. This, in turn, might reduce the concerns related to its use in aquaculture and human consumption, such as toxicity, antimicrobial resistance, and other associated risks. The primary objective of this study was to assess how adding oxytetracycline dihydrate to the diet affects its effectiveness, safety, and the presence of residues in T.

Safety, tolerability and biological responses of Oreochromis niloticus juveniles upon oral oxolinic acid administration.

In aquaculture, oxolinic acid (OA) is used as a second-line treatment at 12 mg/kg biomass/day for seven consecutive days. The present study evaluated the biosafety of 21 days of dietary administration of OA at 0, 12, 36, 60 and 120 mg by assessing the growth, biochemical, erythrocytic morphological and histopathological alterations and residue levels in Oreochromis niloticus. A significant dose-dependent reduction in feed intake and biomass and an increase in mortalities and erythrocytic cellular and nuclear changes were recorded.

Development of microbial enrichments for simultaneous removal of sulfur and nitrogenous metabolites in saline water aquaculture.

Aim: The aim of the study was to develop microbial enrichments from the nitrifying microbial consortia and the environment for simultaneous removal of ammonia, nitrate, and sulfide in aquaculture systems at varied salinities.

Methods And Results: Sulfur and nitrogen metabolites are the major factors affecting the farmed aquatic animal species and deteriorate the receiving environments causing ecological damage. The present study reports the development of microbial enrichments from the nitrifying microbial consortia and the environment.

In-feed emamectin benzoate abuse affects the biological responses and erythrocytes of Nile tilapia .

In aquaculture, drugs are often abused to accomplish disease control without considering the negative effects on fish health. This study aimed at elucidating the pernicious effects of in-feed antiparasitic drug emamectin benzoate (EB) abuse on the haemato-biochemistry and erythro-morphometry of healthy Nile tilapia The fish were fed EB at 50 μg (1×) and 150 μg/kg biomass/d (3×) for 14 d as against the recommended 7 d and periodically assessed the blood parameters. A significant dose- and time-dependent reduction in feed intake, survival, total erythrocytes (TEC), monocytes (MC), hemoglobin (Hb), hematocrit (Ht) and mean corpuscular Hb concentration were noted.

Natural infestation of an anchor worm, sp. in cage culture of Asian Seabass, juveniles and its control using an anti-parasitic drug, emamectin benzoate.

Parasitic infestations and their control programmes are one among the challenges to be considered the most significant in aquaculture. A parasitic infestation was studied elaborately in Asian Seabass, juveniles with clinical signs, post-mortem findings, morphological and molecular identifications. In addition, those fish were also treated with emamectin benzoate (EMB) @ 50 µg kg of fish body weight (BW) d for 10 consecutive days under the controlled wet lab facility by feeding through the medicated feed at 4% BW.

Biosafety, histological alterations and residue depletion of feed administered anti-parasitic drug emamectin benzoate in golden mahseer, (Hamilton, 1822) as a model candidate fish for sport fishery and conservation in temperate waters.

In the present experiment, the attempt has been made to study the biosafety, toxicity, residue depletion and drug tolerance of graded doses of emamectin benzoate (EB) in juveniles of golden mahseer, as a model candidate fish for sport fishery and conservation in temperate waters through an extended medicated feeding. The graded doses of EB , 1× (50 μg/kg fish/day), 2 × (100 μg/kg fish/day), 5 × (250 μg/kg fish/day) and 10 × (500 μg/kg fish/day) were administered to golden mahseer juveniles through medicated diet for 21 days at water temperature of 18.6°C.

Pharmacokinetics and biosafety evaluation of a veterinary drug florfenicol in rainbow trout, (Walbaum 1792) as a model cultivable fish species in temperate water.

In two experimental trials; florfenicol pharmacokinetics following a single dose oral administration at 15 mg kg fish body weight and biosafety through extended medicated feeding were studied in the rainbow trout, . The pharmacokinetic trial was conducted for 5 days, whereas the biosafety experiment lasted for a 30-day safety margin followed by a 20-day residual period analysis at 3, 5 and 10 times greater than the therapeutic dose 10 mg kg biomass day. µg kg calculated for florfenicol were found to be 5,360 in intestine, 2,890 in gill, 2,250 in kidney, 973 in liver and 273 in plasma, obtained at of 16 h.

Impacts of Oral Florfenicol Medication and Residues on the Kidney and Liver of Nile Tilapia Oreochromis niloticus (L.).

Florfenicol (FFC), an approved aquaculture antibiotic, is administered in feed at doses of 10-15 mg kg biomass day for 10 successive days. In this study, healthy were fed with 0-10 times the therapeutic dose of 15 mg kg biomass day for 10 days and tracked for 43 days post dosing. Assessments of residue accrual and depletion, oxidative stress, serum biochemistry, histopathology and extent of kidney and liver damages were made.

Biological Responses of Nile tilapia as Influenced by Dietary Florfenicol.

Antibiotics are used in the treatment of bacterial diseases in commercial aquaculture. In this study, we the biological responses of juveniles upon dietary florfenicol (FFC) administration at 15 mg (1×) and 45 mg kg biomass day (3×) for 10 days in terms of feed intake, survival, biomass, hematological, erythro-morphological, serum biochemical, and histopathological aberrations as compared with controls. FFC caused a dose-dependent reduction in feed intake, survival, and biomass, with marked variations in hematology, hematological indices, and erythrocytic cellular and nuclear abnormalities, suggesting its apparent cytotoxic and nucleotoxic effects.

Dysbiosis and Restoration Dynamics of the Gut Microbiome Following Therapeutic Exposure to Florfenicol in Snubnose Pompano () to Aid in Sustainable Aquaculture Production Strategies.

Information on unintended effects of therapeutic exposure of antibiotics on the fish gut microbiome is a vital prerequisite for ensuring fish and environmental health during sustainable aquaculture production strategies. The present study forms the first report on the impact of florfenicol (FFC), a recommended antibiotic for aquaculture, on the gut microbiome of snubnose pompano (), a high-value marine aquaculture candidate. Both culture-dependent and independent techniques were applied to identify the possible dysbiosis and restoration dynamics, pointing out the probable risks to the host and environment health.

The effects of extended feeding of florfenicol coated medicated diets on the safety, serum biomarkers and blood cells morphology of Nile tilapia Oreochromis niloticus (L.).

Tilapia is one of the most consumed farmed fish, which requires the use of antibiotics in certain phases of its production. This study assessed the safety of 30 days of oral florfenicol (FFC) dosing at 0-10 times the therapeutic dose (1 × : 10 mg/kg biomass/day) in Oreochromis niloticus juveniles. Behavioural changes, feed consumption, mortality and biomass were evaluated.

Pharmacokinetics, bioavailability and withdrawal period of antibiotic oxytetracycline in catfish Pangasianodon hypophthalmus.

The antibiotic oxytetracycline (OTC) has been widely used for therapeutic and preventive management of bacterial diseases in finfish and shellfish. In the present study the bioavailability, pharmacokinetics, and withdrawal period of the OTC have been determined following in-feed administration in intensively cultured catfish Pangasianodon hypophthalmus. Furthermore, the pharmacokinetic parameters of oral route were also compared with parenteral route.

Influence of dietary emamectin benzoate on the biological responses of monosex (all-male) Oreochromis niloticus (L.) fries.

The application of antiparasitic drugs plays a crucial role in the removal of infectious parasites in aquaculture. Emamectin benzoate (EB) is predominantly used as a feed premix against ectoparasites on temperate fish. This study evaluated the influence of 14 days of EB-dosing at 0-10 times the recommended dose (1X: 50 μg/kg biomass/day) on the biological responses and accrual/depletion of EB-residues in a tropical fish monosex Oreochromis niloticus fries.

Prediction of Novel Probiotic Species Limiting Pathogenic Growth Using Constraint-Based Genome Scale Metabolic Modeling.

The prevalence of bacterial diseases and the application of probiotics to prevent them is a common practice in shrimp aquaculture. A wide range of bacterial species/strains is utilized in probiotic formulations, with proven beneficial effects. However, knowledge of their role in inhibiting the growth of a specific pathogen is restricted.

16 S rRNA gene diversity and gut microbial composition of the Indian white shrimp (Penaeus indicus).

The endemic Indian white shrimp (Penaeus indicus) is an economically important crustacean species, distributed in the Indo-West Pacific region. Knowledge of its gut microbial composition helps in dietary interventions to ensure improved health and production. Here we analyzed V3-V4 hypervariable regions of the 16 S rRNA gene to examine intestinal microbiota in wild and domesticated farmed P.

Accumulation and clearance of tissue residues and health status of Nile tilapia Oreochromis niloticus (L.) juveniles as influenced by the extended oral oxytetracycline-dosing.

Antibiotics are considered an important primary therapy for bacterial diseases in aquaculture. This study evaluated the influence of oral administration of oxytetracycline (OTC) on feed intake, growth, mortality, residue accumulation and clearance, and histopathological changes in the vital organs of six groups of Nile tilapia Oreochromis niloticus when fed at 0-10 times the therapeutic dose (1×: 80 mg/kg biomass/day) for 10 and 20 consecutive days. The feed intake was reduced only slightly, viz.

Dietary therapeutic dose of oxytetracycline negatively influences the antioxidant capacity and immune-related genes expression in Nile tilapia Oreochromis niloticus (L.).

Effects of the dietary therapeutic dose of oxytetracycline (OTC) at 80 mg/kg biomass/day for consecutive 10 days on the behaviour, feed intake, mortality, residue accumulation and depletion, antioxidant capacity and immune-related genes expression in juvenile Nile tilapia Oreochromis niloticus were evaluated. OTC-dosing caused mortalities, reduced feed intake, and biomass reduction at 24.5-28.