Oral Administration Of Oxytetracycline Research Articles

Metagenomic and transcriptomic analysis revealing the impact of oxytetracycline and ciprofloxacin on gut microbiota and gene expression in the Chinese giant salamander (Andrias davidianus)

Excessive antibiotic use has led to the spread of antibiotic resistance genes (ARGs), impacting gut microbiota and host health. However, the effects of antibiotics on amphibian populations remain unclear. We investigated the impact of oxytetracycline (OTC) and ciprofloxacin (CIP) on Chinese giant salamanders (Andrias davidianus), focusing on gut microbiota, ARGs, and gene expression by performing metagenome and transcriptome sequencing. A. davidianus were given OTC (20 or 40 mg/kg) or CIP (50 or 100 mg/kg) orally for 7 days. The results revealed that oral administration of OTC and CIP led to distinct changes in microbial composition and functional potential, with CIP treatment having a greater impact than OTC. Antibiotic treatment also influenced the abundance of ARGs, with an increase in fluoroquinolone and multi-drug resistance genes observed post-treatment. The construction of metagenome-assembled genomes (MAGs) accurately validated that CIP intervention enriched fish-associated potential pathogens Aeromonas hydrophila carrying an increased number of ARGs. Additionally, mobile genetic elements (MGEs), such as phages and plasmids, were implicated in the dissemination of ARGs. Transcriptomic analysis of the gut revealed significant alterations in gene expression, particularly in immune-related pathways, with differential effects observed between OTC and CIP treatments. Integration of metagenomic and transcriptomic data highlighted potential correlations between gut gene expression and microbial composition, suggesting complex interactions between the host gut and its gut microbiota in response to antibiotic exposure. These findings underscore the importance of understanding the impact of antibiotic intervention on the gut microbiome and host health in amphibians, particularly in the context of antibiotic resistance and immune function.

Residue depletion and histopathological alterations in gilthead sea bream (Sparus aurata) after oral administration of oxytetracycline

ABSTRACT Aquaculture is a key component of the animal food industry, but intensive farming conditions increase the incidence of infectious diseases. Oxytetracycline (OTC) plays a major role for infectious diseases in fishes. Its MRLs include their 4-epimers, so in this trial, the depletion of residues of OTC and 4-epioxytetracycline in muscle and liver have been evaluated in gilthead sea bream (Sparus aurata) after oral administration. Hepatotoxicity has been investigated with histopathological effects on target tissues. A validated DAD-HPLC with SPE extraction has been applied. Residual levels in muscle and liver depleted with a similar k el, but mean retention time and t ½ß resulted longer in muscle than in liver because of different vascularization. The OTC concentrations were below the LMR at 48 h after dosing. No analytical peaks ascribable to 4-epi-OTC or other derivatives were detected, while histopathology of liver showed degenerated parenchymal hepatocytes, nuclear pyknosis, focal necrosis and inflammatory leucocytes infiltration. It can be concluded that the assessment of pharmacokinetic and residual depletion of antibiotics result fundamental to determine the most suitable therapeutic regime and to minimize the toxic effects in fish species.

Oxytetracycline does not cause growth promotion in finfish.

Until recently, use of antibiotics to enhance terrestrial animal growth performance was a common, U.S. Food and Drug Administration (FDA)-approved, but controversial practice. There are no FDA-approved production claims for antibiotic drug use in fish, but it is a common misconception that antibiotics are widely used for this purpose in U.S. aquaculture. Antibiotics are not thought to be effective growth promoters in fish, but there is little quantitative data available to address whether there are growth-promoting effects that might incentivize the use of antibiotics in this way, despite legal prohibitions. Therefore, this study was conducted to determine if oral administration of oxytetracycline, an antibiotic with known growth-promoting effects in terrestrial livestock, has a similar effect when applied to channel catfish Ictalurus punctatus, hybrid striped bass Morone chrysops × M. saxatilis, Nile tilapia Oreochromis niloticus, or rainbow trout Oncorhynchus mykiss. Oxytetracycline products with production claims are typically applied at doses substantially lower than the approved therapeutic doses for the same products. Medication (0, 0.24, or 1.2 g oxytetracycline dihydrate kg-1 feed) and feeding rates (3% BW d-1) were selected to achieve target daily doses of 0, 16, or 80 mg kg-1 fish representing control, subtherapeutic, and therapeutic treatments. Replicate groups of fish (N = 4) were fed accordingly for 8 wk. Overall, oral administration of oxytetracycline did not affect survival or promote growth of the selected taxa, with no significant differences observed for weight gain, feed conversion ratio, or specific growth rate (P > 0.05 in all cases). Few differences were observed in organosomatic indices and in the frequency of tissue abnormalities; where present, these differences tended to suggest a negative effect of long-term dietary exposure to oxytetracycline. These data demonstrate that there is no benefit to dietary supplementation with oxytetracycline for nontherapeutic purposes in a range of economically important finfish species. As such, our results indicate there is little incentive to misuse oxytetracycline products for purposes of growth promotion in U.S. aquaculture.

Effect of oral administration of oxytetra cycline on the oxygen uptake of the Indian major carp, Catla catla.

Effect of oral administration of oxytetra cycline on the oxygen uptake of the Indian major carp, Catla catla.

Oxytetracycline water bath treatment of juvenile blue abalone Haliotis fulgens (Philippi 1845) affected by the withering syndrom

The fatal abalone disease named withering syndrome (WS), caused by a Rickettsiales-like prokaryote classified as Xenohaliotis californiensis, has been treated by injections and oral administration of oxytetracycline (OTC) with relatively successful results. These therapeutic treatments have practical limitations for their application in aquacultural and experimental facilities due to the inability to eat of severely ill organisms, and the need to incorporate the antibiotic in pelletized food, increasing production costs. During an experiment to determine the effect of photoperiod and temperature on the growth of juvenile blue abalone Haliotis fulgens, some animals showed overt symptoms of WS. Oxytetracycline baths at 400 mg L–1 were used for one hour daily during seven days to treat diseased animals. The metabolic rate of one group of these organisms was also assessed. Recovery time (time for an organism to regain the upright position) and size were assessed on days 0, 14, and 29. By the third day of treatment, most treated animals regained a limited adhesion capacity, and began to ingest food and to produce feces. After one week, more than 50% of the treated abalone were capable of regaining the upright position within the first 10 min of being turned upside down. After 30 days all organisms showed strong adhesion to the substrate. Metabolic rate declined from 380 (initially) to 280 µL O2 ind–1 h–1 after two weeks of treatment. This study opens the door for further research on the use of OTC baths for practical use in abalone culture and management.

Oxytetracycline Attenuates Allergic Airway Inflammation in Mice via Inhibition of the NF-κB Pathway

Oxytetracycline has been used in the treatment of acute and chronic bronchial inflammation and infectious asthma. However, its potential use for non-infectious asthma has not yet been studied. The objective of this study was to investigate the anti-inflammatory properties of oxytetracycline using a mouse asthma model. Female BALB/c mice, sensitized and challenged with ovalbumin. Naive CD4+ T cells from spleen were stimulated for 72h with anti-CD3 (5μg/ml) plus anti-CD28 (2.5μg/ml) and differentiated into Th2 cells. IL-4, IL-5, IL-9, IL-13, and ovalbumin (OVA)-specific IgE production were measured by ELISA in BALF and cell supernatants. Histopathological evaluation was used to study the alterations in lung tissue. The mRNA levels of CCL5, CCL11, CCR1, and CCR3 were detected by real-time PCR. In addition, the protein levels of p-Akt, Akt, nuclear factor kappa B (NF-κB), IκBα and p-IκBα in lung tissue and cells were measured by western blot or immunofluorescence analysis. Oxytetracycline treatment caused a marked reduction in IL-4, IL-5, IL-13, immune cells, and the level of ovalbumin-specific IgE. Real-time PCR studies demonstrated that oxytetracycline can significantly reduce CCL5, CCL11 and their specific receptor CCR1 and CCR3. Histological studies demonstrated that oxytetracycline substantially inhibited ovalbumin-induced inflammatory cell infiltration in lung tissue and goblet cell hyperplasia in airway. Oxytetracycline inhibited the NF-κB activation via phosphorylation and degradation of IκBα both in vivo and in vitro. Furthermore, the increased phosphorylated Akt but not Akt protein levels in lung tissues after OVA inhalation were significantly reduced by the oral administration of oxytetracycline. These findings demonstrate an anti-inflammatory effect of oxytetracycline that might be mediated via reduction of inflammatory mediators and activation of transcription factors.

Antioxidant Effect of Caffeic Acid on Oxytetracycline Induced Lipid Peroxidation in Albino Rats

Caffeic acid is a well-known phenolic compound widely present in plant kingdom. The aim of this study was to investigate the possible protective effect of caffeic acid (CA) against oxytetracycline (OXT) induced hepatotoxicity in male Albino Wistar rats. A total of 30 rats weighing 150-170g were randomly divided into five groups of six rats in each group. Oral administration of OXT (200mg/kg body weight/day) for 15days produced hepatic damage as manifested by a significant increase in serum hepatic markers namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), bilirubin and increased plasma and hepatic lipid peroxidation indices (TBARS and hydroperoxide). The present finding shows that the levels of enzymatic antioxidants namely superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were significantly decreased in OXT intoxicated rats. Upon oral administration of caffeic acid (40mg/kg body weight/day) there were decreased hepatic marker activities, bilirubin and lipid peroxidation and increased enzymatic antioxidants in OXT+Caffeic acid group compared to Normal+OXT group(P<0.05). Our study suggests that caffeic acid has antioxidant property and hepatoprotective ability against OXT induced toxicity.

Changes in the Intestinal Flora of Japanese flounder,Paralichthys olivaceus, with the Oral Administration of Oxytetracycline and Immuno-enhancing Agents

Changes in the Intestinal Flora of Japanese flounder,<I>Paralichthys olivaceus</I>, with the Oral Administration of Oxytetracycline and Immuno-enhancing Agents

On the validity of setting breakpoint minimum inhibition concentrations at one quarter of the plasma concentration achieved following oral administration of oxytetracycline

Abstract Plasma concentrations of oxytetracycline (OTC) were established in two Atlantic salmon ( Salmo salar ) pre-smolts populations after they had received OTC medicated feed at a rate of 75 mg OTC/kg over 10 days. One population was experiencing an epizootic of furunculosis in a commercial freshwater farm and the other was held in a laboratory. Both populations were maintained at approximately 13 °C. The mean plasma concentration in 26 health farm fish was 0.25±0.06 and the 80th percentile was 0.21 mg/l. The mean concentration for 26 laboratory fish was 0.21±0.06 mg/l with an 80th percentile of 0.15 mg/l. The validity of setting a breakpoint minimum inhibitory concentration (MIC) at a quarter of these plasma concentrations was investigated. The MIC of the Aeromonas salmonicida isolated from the farmed fish ( n =7) was 0.5 mg/l and the breakpoints generated by application of the 4:1 ratio were in the range 0.03125–0.0625 mg/l. These breakpoint values would, therefore, predict that the therapy should have had no beneficial effect and that any strain of A. salmonicida with MIC>0.0625 mg/l must be considered as resistant. A consideration of the pattern of the mortalities before and during the period of therapy suggests that the therapy was probably beneficial. Thus, the data obtained in this work suggest that the application of the 4:1 ratio is not a valid method of generating meaningful breakpoint MIC values. Published values for the MIC of OTC against A. salmonicida and the plasma concentrations achieved after oral administration of OTC medicated feed were applied to investigate the validity of the application of the 4:1 ratio. Breakpoints generated by the application of this ratio to these data would suggest that OTC could never have had any value in combating A. salmonicida infections. As this conclusion is contrary to experience, it is argued that examination of the published data reinforces the conclusion that the 4:1 ratio has little value in the oral therapy of fish disease.

Poor bioavailability of oxytetracycline in sharpsnout sea bream Diplodus puntazzo

Abstract The pharmacokinetics of oxytetracycline (OTC) were investigated following single intravascular injection (40 mg/kg) in sharpsnout sea bream (90 g) at 19 °C. The distribution half-life (t1/2α) and the elimination half-life (t1/2β) of OTC were calculated to be 1.4 and 35 h, respectively. The apparent volume of distribution of the drug at steady-state (Vd(ss)) was found to be 4 l/kg. The total clearance rate (CLT) of the drug was low (0.08 l/kg h). Repeated attempts to investigate the bioavailability of OTC following oral administration (75 mg/kg; forced-fed or via the feed), revealed undetectable levels of the drug in plasma and muscle samples. Poor tissue absorption is likely due to significant hepatic metabolism of OTC in sharpsnout sea bream, but this requires further investigation. Thus, oral administration of OTC in farmed sharpsnout sea bream should be discouraged in favour of other routes of administration or other antibiotic drugs.

Combined parenteral and oral administration of oxytetracycline for control of infectious bovine keratoconjunctivitis

Objective To determine whether combined parenteral and oral administration of oxytetracycline would ameliorate a herd outbreak of infectious bovine keratoconjunctivitis (IBK) and to compare efficacy of this regimen with that of subconjunctival administration of procaine penicillin G. Design Randomized field trial. Animals 119 Hereford calves in a herd undergoing a naturally occurring outbreak of IBK. Procedure Calves were randomly assigned to 1 of the following 3 groups: oxytetracycline treatment, procaine penicillin G treatment, and control. After initial treatment, calves were examined 3 times/wk for 7 weeks. The surface area of all corneal ulcers was measured during each examination. Ocular secretions were collected from all calves at least weekly and were tested for Moraxella bovis. Results Calves treated with oxytetracycline had a lower prevalence of IBK than did calves treated with procaine penicillin G or control calves and required fewer additional treatments than did calves treated with procaine penicillin G. Mean time for healing of corneal ulcers was significantly less for calves that received oxytetracycline or procaine penicillin G than for control calves. Calves treated with oxytetracycline developed fewer corneal ulcers and fewer recurrent ulcers than did calves in the other groups. Moraxella bovis was isolated less often from ocular secretions collected from calves in the oxytetracycline group than from calves in the other groups. Clinical Implications Combined parenteral and oral administration of oxytetracycline appears to be an effective method of reducing severity of a herd outbreak of IBK and may be superior to treatment of affected animals with procaine penicillin G. (J Am Vet Med Assoc 1998; 212:560-563)

Outbreaks of a Disease Caused by Rickettsia-like Organism in Cultured Tilapias in Taiwan.

An organism, measuring 0.86±0.32×0.63 ±0.24 μm, likely to be member of family Rickettsiaceae, was detected for the first time from an outbreak of a disease with mass mortality among pond-reared tilapia in Taiwan. The pathogen was demonstrated to be Gram-negative and stained positively with Liu's solution and to grow on To2 and EPC cell cultures but not on nine artificial media selected and the pathogenicity was confirmed by Koch's postulates. Haematocrit in affected fish was decreased to 16.1±5.2% versus 28.3±5.1% for normal value. Typical lesions in moribund fish included marked white nodules and microscopical granulomatous formation all over the organs. The spleen enlarged to 5-50 times of the normal organ. Horizontal transmission without parasite vectors occurred. The experimental infection showed higher mortality at 15°C than at 30°C. In vitro experiments revealed that oxytetracycline which is legally permitted would probably be an effective antibiotic to control this disease. A field test showed that oral administration of oxytetracycline at a dose of 30-50 mg per kg body weight for 10-14 days was effective to control the disease. Clinical signs, susceptibility of various fishes to the pathogen and transmission electron-microscopy findings are described.