The influence of enrofloxacin, florfenicol, ceftiofur and E. coli LPS interaction on T and B cells subset in chicks

Effects of adding antibiotics to an inactivated oil-adjuvant avian influenza vaccine on vaccine characteristics and chick health

During poultry immunization, antibiotics are typically added to inactivated oil-adjuvant avian influenza (AI) vaccines. Here, we evaluated the effects of adding ceftiofur, a third-generation cephalosporin, to an AI vaccine on vaccine stability and structure and on chick growth, immune efficacy, blood concentrations, biochemical and immunological indices, and gut microbiota. The results demonstrated that neither aqueous ceftiofur sodium nor ceftiofur hydrochloride oil emulsion formed a stable mixture with the vaccine. Adding ceftiofur formulations, particularly ceftiofur hydrochloride, at >4% significantly destabilized the vaccine's water-in-oil structures. Adding ceftiofur also increased vaccine malabsorption at the injection site; specifically, adding ceftiofur hydrochloride reduced H5N8 and H7N9 antibody titers after the first immunization (P < 0.05) and H7N9 antibody titers after the second immunization (P < 0.01). Serum drug concentrations did not differ significantly between the groups with ceftiofur sodium and hydrochloride addition. Ceftiofur addition increased postvaccination chick weight loss; compared with the vaccine alone, ceftiofur sodium-vaccine mixture increased chick weight significantly (P < 0.05). Ceftiofur addition also increased stress indices and reduced antioxidant capacity significantly (P < 0.05 or P < 0.01). Vaccination-related immune stress reduced gut microbiota diversity in chicks; ceftiofur addition reversed this change. AI vaccine immunization significantly reduced the relative abundance of Lactobacillus and Muribaculaceae but significantly increased that of Bacteroides and Eubacterium coprostanoligenes group. Ceftiofur addition restored the gut microbiota structure; in particular, ceftiofur hydrochloride addition significantly increased the abundance of the harmful gut microbes Escherichia-Shigella and Enterococcus, whereas ceftiofur sodium addition significantly reduced it. The changes in gut microbiota led to alterations in metabolic pathways related to membrane transport, amino acids, and carbohydrates. In conclusion, adding ceftiofur to the AI vaccine had positive effects on chick growth and gut microbiota modulation; however, different antibiotic concentrations and formulations may disrupt vaccine structure, possibly affecting vaccine safety and immunization efficacy. Thus, the addition of antibiotics to oil-adjuvant vaccines is associated with a risk of immunization failure and should be applied to poultry with caution.

Impact of dietary-nucleotides and Saccharomyces cerevisiae-derivatives on growth-performance, antioxidant-capacity, immune-response, small-intestine histomorphometry, caecal-Clostridia, and litter-hygiene of broiler-chickens treated with florfenicol

Stress in poultry production is energy-demanding. Nucleotides and yeast cell-wall products are essential nutrients for broiler performance, gut function, and immune response. Antibiotics, like florfenicol, negatively affect the immune system. A total of 600 one-d-old broiler chickens (Cobb-500) were weighed and randomly allotted into four groups with three replicates each. The control group (G1) received the basal diet, G2 received a diet supplemented with a combination of nucleotides and Saccharomyces cerevisiae derivatives (250 g/Ton), G3 received the basal diet and medicated with florfenicol (25 mg/Kg body weight) in drinking water for 5 days, while G4 received a combination of nucleotides and Saccharomyces cerevisiae-derivatives (250 g/Ton) and medicated with florfenicol in drinking water. Growth performance criteria were recorded weekly. Blood, intestinal contents, small-intestine sections, and litter samples were collected to measure birds' performance, carcass yields, leukocytic counts, antioxidant capacity, antibody titres, phagocytic index, caecal Clostridia, intestinal histomorphometry, and litter hygiene. Nucleotide-supplemented groups (G2 and G4) revealed significant (p ≤ 0.05) improvements in feed conversion, and body weight, but not for carcass yields in comparison to the control. Dietary nucleotides in G2 elevated blood total proteins, leucocytic count, antioxidant capacity, and phagocytic index, while they lowered blood lipids and litter moisture and nitrogen (p ≤ 0.05). Dietary nucleotides in G4 ameliorated the immunosuppressive effect of florfenicol (p ≤ 0.05) indicated in reducing caecal Clostridia, improving duodenal and ileal villi length, and increasing blood albumin and globulin levels, and phagocytosis%. Supplementing diets with nucleotides and yeast products has improved the immune system and provided a healthier gut for broilers.

Characterizing the influence of various antimicrobials used for metaphylaxis against bovine respiratory disease on host transcriptome responses

Currently, control against bovine respiratory disease (BRD) primarily consists of mass administration of an antimicrobial upon arrival to facility, termed "metaphylaxis." The objective of this study was to determine the influence of six different antimicrobials used as metaphylaxis on the whole blood host transcriptome in healthy steers upon and following arrival to the feedlot. One hundred and five steers were stratified by arrival body weight (BW = 247 ± 28 kg) and randomly and equally allocated to one of seven treatments: negative control (NC), ceftiofur (CEFT), enrofloxacin (ENRO), florfenicol (FLOR), oxytetracycline (OXYT), tildipirosin (TILD), or tulathromycin (TULA). On day 0, whole blood samples and BW were collected prior to a one-time administration of the assigned antimicrobial. Blood samples were collected again on days 3, 7, 14, 21, and 56. A subset of cattle (n = 6) per treatment group were selected randomly for RNA sequencing across all time points. Isolated RNA was sequenced (NovaSeq 6,000; ~35 M paired-end reads/sample), where sequenced reads were processed with ARS-UCD1.3 reference-guided assembly (HISAT2/StringTie2). Differential expression analysis comparing treatment groups to NC was performed with glmmSeq (FDR ≤ 0.05) and edgeR (FDR ≤ 0.1). Functional enrichment was performed with KOBAS-i (FDR ≤ 0.05). When compared only to NC, unique differentially expressed genes (DEGs) found within both edgeR and glmmSeq were identified for CEFT (n = 526), ENRO (n = 340), FLOR (n = 56), OXYT (n = 111), TILD (n = 3,001), and TULA (n = 87). At day 3, CEFT, TILD, and OXYT shared multiple functional enrichment pathways related to T-cell receptor signaling and FcεRI-mediated NF-kappa beta (kB) activation. On day 7, Class I major histocompatibility complex (MHC)-mediated antigen presentation pathways were enriched in ENRO and CEFT groups, and CEFT and FLOR had DEGs that affected IL-17 signaling pathways. There were no shared pathways or Gene Ontology (GO) terms among treatments at day 14, but TULA had 19 pathways and eight GO terms enriched related to NF- κβ activation, and interleukin/interferon signaling. Pathways related to cytokine signaling were enriched by TILD on day 21. Our research demonstrates immunomodulation and potential secondary therapeutic mechanisms induced by antimicrobials commonly used for metaphylaxis, providing insight into the beneficial anti-inflammatory properties antimicrobials possess.

The effect of early administration of antibiotics or feeding a diet containing a coccidiostat on inflammatory responses and the morphological structure of selected organs of the immune system in young meat-type turkeys

It was assumed that early administration of enrofloxacin or doxycycline may impair immune function and alter the morphology of organs of the immune system in turkeys, and that diets containing the coccidiostat monensin, an ionophore antibiotic, can exert similar effects. The aim of this study was to determine whether early antibiotic administration or feeding a diet containing a coccidiostat affect immune function in young turkeys. The experiment had a completely randomized design, with 8 groups (a total of 3,080 one-day-old turkeys), 7 replicate pens per group and 55 birds per pen. The experiment had a 2-factorial design, with 4 treatments (C-control, M-monensin, E-enrofloxacin, and D-doxycycline) and 2 groups of birds (vaccinated and unvaccinated) per treatment. Control group birds did not receive the coccidiostat or antibiotics. Group M was administered monensin at 90 mg/kg feed for the first 5 d of life, group E received enrofloxacin at 10 mg/kg BW, added to drinking water, for the first 5 d of life, and group D received doxycycline at 50 mg/kg BW, added to drinking water, for the first 5 d of life. One-day old turkeys from groups C+, M+, E+, and D+ were administered live-attenuated vaccines against turkey rhinotracheitis (TRT) (Poulvac TRT; Zoetis, Parsippany, NJ) and Newcastle disease (ND) (Nobilis ND clone 30; Merck, Rahway, NJ) by coarse spray; 28-day-old birds were administered a subcutaneously injected inactivated vaccine against Ornithobacterium rhinotracheale (ORT) (Ornitin, Phibro, Poland). Turkeys from groups C-, M-, E-, and D- were not vaccinated. It was found that early administration of enrofloxacin or doxycycline, or feeding a diet containing monensin, did not weaken the immune system of turkeys. The administration of monensin, in particular when combined with vaccination, was least effective in inhibiting inflammatory responses. Histological changes in immunocompetent organs (fatty degeneration) were also most severe in birds receiving monensin, followed by those administered doxycycline and enrofloxacin. The observed changes were exacerbated by vaccination.

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. Besides, the levels of serum glucose, calcium, chloride, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and blood cell morphology were determined at scheduled intervals. The 30 days of oral FFC dosing caused 3.33% (1 ×) to 18.33% (10 ×) mortalities, reduced feed intake and biomass in a dose-dependent manner. The fish fed the therapeutic dose recorded 1.25-fold increase in biomass, while the control group recorded 1.45-fold increase in 30 days. No significant erythrocyte morphological alterations were observed in the 1 × group compared to the control. However, marked morphological alterations like tear-shaped, spindle-shaped and degenerative erythrocytes in higher dosing groups indicated FFC cytotoxicity. All the serum biomarkers of O. niloticus increased significantly on day 10 and day 30 FFC dosing in a dose-dependent manner, except for calcium and chloride, which reduced significantly during the dosing period. Within 2 weeks of suspension of FFC dosing, the serum biomarker levels became normal except for alkaline phosphatase and creatinine. The recovery of biomass, feed intake, serum biomarker levels and erythrocyte morphological changes suggested that the FFC-induced changes are reversible. This study has, thus, proclaimed the safety of FFC at the therapeutic dose in O. niloticus.

Immune Parameters in Chickens Treated with Antibiotics and Probiotics during Early Life

The aim of the study was to compare the effect of the administration of antibiotics or probiotics on chickens in their first week of life, on selected parameters of humoral and cellular immunity, and on the bursa of Fabricius and spleen indices. The experiment was carried out on 90 one-day-old male broilers. The control group received no additive in the drinking water; the group GP received a probiotic providing Enterococcus faecium and Bacillus amyloliquefaciens; and the group GA received 10% enrofloxacin in the drinking water on the first five days of life. Administration of the antibiotic enrofloxacin or a probiotic containing E. faecium and B. amyloliquefaciens strains to chickens in their first week of life exerts pronounced immunomodulatory effects on humoral and cellular defense mechanisms in these birds. The changes in the subpopulations of B and T cells immediately following early administration of enrofloxacin or the probiotic were not observed at the age of 35 days. Early administration of enrofloxacin can pose a risk of suppression of humoral immunity, as indicated by the significant decrease in the total IgY concentration in the plasma of the chickens.

Comparative Study on Synergistic Toxicity of Enrofloxacin Combined with Three Antibiotics on Proliferation of THLE-2 Cell

Little attention has been paid to the problem of the combined toxicity of accumulated antibiotics on humans from food and clinical treatments. Therefore, we used human hepatocytes to study the joint toxicity of four common antibiotics. The cytotoxicity of enrofloxacin (ENR), combined with ciprofloxacin (CFX), florfenicol (FFC), or sulfadimidine (SMD) on THLE-2 cells was determined by CCK-8 assays; then their joint toxicity was evaluated using CalcuSyn 2.0. Dose–effect curves and median-effect plots established on large amounts of data and CI values were calculated to judge the nature of the combination’s interaction. ED50, ED75, and ED90 were predicted to elucidate the changing trend of the concentration on the toxicity of each drug pair. The ENR-CFX and ENR-FFC pairs exhibited synergistic toxicity only at special concentration rates, while ENR and SMD synergistically induced cytotoxicity at almost all the concentration rates studied. The mixed ratio was a significant factor for synergistic toxicity and should be evaluated in all combined effect studies. These results suggested that the combined toxicity of these four drugs should be taken into account in their risk assessment.

Toxicity induced by ciprofloxacin and enrofloxacin: oxidative stress and metabolism

Ciprofloxacin (CIP) (human use) and enrofloxacin (ENR) (veterinary use) are synthetic anti-infectious medications that belong to the second generation of fluoroquinolones. They have a wide antimicrobial spectrum and strong bactericidal effects at very low concentrations via enzymatic inhibition of DNA gyrase and topoisomerase IV, which are required for DNA replication. They also have high bioavailability, rapid absorption with favorable pharmacokinetics and excellent tissue penetration, including cerebral spinal fluid. These features have made them the most applied antibiotics in both human and veterinary medicine. ENR is marketed exclusively for animal medicine and has been widely used as a therapeutic veterinary antibiotic, resulting in its residue in edible tissues and aquatic environments, as well as the development of resistance and toxicity. Estimation of the risks to humans due to antimicrobial resistance produced by CIP and ENR is important and of great interest. Moreover, in rare cases due to their overdose and/or prolonged administration, the development of CIP and ENR toxicity may occur. The toxicity of these fluoroquinolones antimicrobials is mainly related to reactive oxygen species (ROS) and oxidative stress (OS) generation, besides metabolism-related toxicity. Therefore, CIP is restricted in pregnant and lactating women, pediatrics and elderly similarly ENR do in the veterinary field. This review manuscript aims to identify the toxicity induced by ROS and OS as a common sequel of CIP and ENR. Furthermore, their metabolism and the role of metabolizing enzymes were reported.

Changes in immune system and intestinal bacteria of cows during the transition period

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Transitional high-energy diets reduce peripheral blood lymphocytes in dairy cows.

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High-energy diets upregulate IL-1β and IL-2 and downregulate IL-10 expression.

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Functional lactobacillus plantarum LP1 restores normal levels of lymphocytes subset.

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Lactobacillus plantarum LP1-added diets reduce inflammatory cytokine expression.

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LP1 mitigates immune response imbalances caused by transitional high energy diets.

High-yield dairy cows need high energy feed during periods of increased milk production. The transitional feeding to high energy feed increases the risk of developing a variety of metabolic disorders. Here, five Holstein cows were fed a four-stage feeding protocol (3 weeks for each stage) ranging from 54.9 to 73.7% total digestive nutrients (TDN). The purpose of the study was to investigate the effect of lactic acid bacteria on high-energy-fed cows associated with transitional feeding, and to evaluate the effects of probiotics on intestinal bacterial changes and inflammatory responses. Three feed transition periods were established for five cows, and Lactobacillus plantarum RGU-LP1 (LP1) was fed as a probiotic during the high-energy feeding period. The number of lymphocyte subsets such as CD3-, CD4-, and CD8 positive cells decreased in response to the high energy feed. Lipopolysaccharide (LPS)-induced cytokine (IL-1β and IL-2) gene expression in peripheral blood mononuclear cells (PBMCs) was shown to increase in those animals receiving the high energy feed. However, supplementation with LP1 resulted in an increase in the number of lymphocyte subsets and the expression of IL-1β and IL-2 were returned to the level at low energy diet. These results suggest that high energy diets induce inflammatory cytokine responses following LPS stimulation, and that the addition of LP1 mitigates these results by regulating the LPS-induced inflammatory reaction. Therefore, the functional lactic acid bacteria LP1 is expected to regulate inflammation resulting from high energy feeding, and this probiotic could be applied to support inflammatory regulation in high-yield dairy cows.

The influence of immune stress induced by Escherichia coli lipopolysaccharide on the pharmacokinetics of danofloxacin in broilers

This study aimed to determine whether the challenge from Escherichia coli (E. coli) lipopolysaccharide (LPS) affects the pharmacokinetics of danofloxacin in broilers. Twenty 1-day-old Arbor Acres (AA) broilers were equally and randomly divided into 2 groups. When the chickens were 23, 25, 27, and 29 days old, E. coli LPS (1 mL; 0.5 mg/kg body weight [BW]) and sterile saline (1 mL) were intraperitoneally injected into the two groups. After the last injection, danofloxacin was given to all chickens by gavage at the dose of 5 mg/kg BW. Then serum and plasma samples at each time point were collected through the wing vein. Danofloxacin concentrations in plasma were detected through the high-performance liquid chromatography (HPLC) method and subjected to noncompartmental analysis using Phoenix software. The levels of chicken interleukin-1β (IL-1β) and corticosterone (CORT) in serum were measured by the Enzyme-linked immunosorbent assay (ELISA) kit. In addition, after the collection of plasma or serum samples, 7 chickens (31 days of age) in each group were killed to calculate the organ indices. Compared with the control group, the challenge of LPS significantly decreased the parameters of AUC_0-∞, C_max, and t_1/2λz and increased the parameters of T_max and λz. Additionally, in the LPS group, the absorption time of danofloxacin was prolonged; however, the elimination was accelerated, which resulted in reduced internal exposure.

Toxicologic effect and transcriptome analysis for short-term orally dosed enrofloxacin combined with two veterinary antimicrobials on rat liver

Presently, toxicological assessment of multiple veterinary antimicrobials has not been performed on mammals. In this study, we assessed the short-term toxicity of enrofloxacin (E) combined with colistin (C) and quinocetone (Q). Young male rats were orally dosed drug mixtures and single drugs in 14 consecutive days, each at the dose of 20, 80, and 400 mg/(kg·BW) for environmental toxicologic study. The results showed that at the high dose treatment, the combination of E + C+Q significantly decreased body intake, lymphocytes count on rats; significantly increased the values of Alanine aminotransferase (ALT), Glutamic oxaloacetic transaminase (AST) and, cholinesterase (CHE); it also got the severest histopathological changes, where sinusoidal congestion and a large number of black particles in sinusoids were observed. This means E + C+Q in the high dose groups was able to cause significant damage to the liver. Other combinations or doses did not induce significant liver damage. Transcriptome analysis was then performed on rats in high dose group for further research. For E + C and E + Q, an amount of 375 and 480 differently expressed genes were filtered out, revealing their possible underlying effect on genomes. For E + C+Q, a weighted gene co-expression network analysis was performed and 96 hub genes were identified to reveal the specific effect induced by this combination. This study indicates that joint toxicity should be taken into consideration when involving the risk assessment of these antimicrobials.

Effects of Artemisia argyi flavonoids on growth performance and immune function in broilers challenged with lipopolysaccharide

Objective

This research aimed to study the effects of Artemisia argyi flavonoids (AAF) supplemented in diets on the growth performance and immune function of broiler chickens challenged with lipopolysaccharide (LPS).

Methods

A total of one hundred and ninety-two 1-d-old broiler chicks were assigned into 4 treatment groups, which were, respectively, fed a basal diet (control), fed a diet with 750 mg/kg AAF, fed a basal diet, and challenged with LPS, fed a diet with 750 mg/kg AAF, and challenged with LPS. Each treatment had six pens with 8 chicks per pen. On days 14, 16, 18, 20 (stress phase I) and 28, 30, 32, 34 (stress phase II), broilers were injected with LPS (500 μg/kg body weight) or an equivalent amount of saline.

Results

The results demonstrated that dietary AAF significantly improved the body weight (d 21) and alleviated the decrease of average daily gain in broilers challenged with LPS on d 21 and d 35 (p<0.05). Dietary AAF increased bursa fabricius index, and dramatically attenuated the elevation of spleen index caused by LPS on d 35 (p<0.05). Furthermore, serum interleukin-6 (IL-6) concentration decreased with AAF supplementation on d 21 (p<0.05). Diet treatment and LPS challenge exhibited a significant interaction for the concentration of IL-1β (d 21) and IL-6 (d 35) in serum (p<0.05). Additionally, AAF supplementation mitigated the increase of IL-1β, IL-6 in liver and spleen induced by LPS on d 21 and 35 (p<0.05). This study also showed that AAF supplementation significantly reduced the expression of IL-1β (d 21) and nuclear transcription factor kappa-B p65 (d 21 and 35) in liver (p<0.05), and dietary AAF and LPS treatment exhibited significant interaction for the gene expression of IL-6 (d 21), toll like receptor 4 (d 35) and myeloid differentiation factor 88 (d 35) in spleen (p<0.05).

Conclusion

In conclusion, AAF could be used as a potential natural immunomodulator to improve growth performance and alleviate immune stress in broilers challenged with LPS.

Oxidative and Epigenetic Changes and Gut Permeability Response in Early-Treated Chickens with Antibiotic or Probiotic

The aim of this study was to compare the effect of the use of enrofloxacin and a probiotic containing Enterococcus faecium and Bacillus amyloliquefaciens strains in the first week of life of chickens on oxidative and epigenetic changes in molecules and intestinal integrity. The three treatments were as follows: the control group received no additive in the drinking water (GC); the second group (GP) received a probiotic preparation in the drinking water during the first five days of life, providing E. faecium strain 4a1713 at 1.0 × 107 CFU/L water and B. amyloliquefaciens 4b1822 at 1.0 × 107 CFU/L water, the third group (GA) received an antibiotic (enrofloxacin 0.5 mL/L water) in the drinking water during the first five days of life. The use of both enrofloxacin and a probiotic containing E. faecium and B. amyloliquefaciens strains in chickens' first week of life improved intestinal integrity and reduced inflammation and oxidative and epigenetic changes in the small intestine. This effect was evident both at 6 days of age and at the end of the rearing period.

A Novel Cecropin-LL37 Hybrid Peptide Protects Mice Against EHEC Infection-Mediated Changes in Gut Microbiota, Intestinal Inflammation, and Impairment of Mucosal Barrier Functions

Intestinal inflammation can cause impaired epithelial barrier function and disrupt immune homeostasis, which increases the risks of developing many highly fatal diseases. Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes intestinal infections worldwide and is a major pathogen that induces intestinal inflammation. Various antibacterial peptides have been described as having the potential to suppress and treat pathogen-induced intestinal inflammation. Cecropin A (1–8)-LL37 (17–30) (C-L), a novel hybrid peptide designed in our laboratory that combines the active center of C with the core functional region of L, shows superior antibacterial properties and minimized cytotoxicity compared to its parental peptides. Herein, to examine whether C-L could inhibit pathogen-induced intestinal inflammation, we investigated the anti-inflammatory effects of C-L in EHEC O157:H7-infected mice. C-L treatment improved the microbiota composition and microbial community balance in mouse intestines. The hybrid peptide exhibited improved anti-inflammatory effects than did the antibiotic, enrofloxacin. Hybrid peptide treated infected mice demonstrated reduced clinical signs of inflammation, reduced weight loss, reduced expression of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interferon-gamma (IFN-γ)], reduced apoptosis, and reduced markers of jejunal epithelial barrier function. The peptide also affected the MyD88–nuclear factor κB signaling pathway, thereby modulating inflammatory responses upon EHEC stimulation. Collectively, these findings suggest that the novel hybrid peptide C-L could be developed into a new anti-inflammatory agent for use in animals or humans.

Changes in circulating lymphocyte subpopulations in pigs receiving therapeutic doses of ceftiofur and tulathromycin

Introduction: The aim of the study was to evaluate the effect of administration of therapeutic doses of ceftiofur and tulathromycin on the circulating lymphocyte subpopulations in healthy pigs. Material and Methods: The study was conducted on thirty healthy 7- to 10-week-old pigs, assigned to three groups: the TUL group, injected with tulathromycin (n = 10); the CEF group, injected with ceftiofur (n = 10); and the C group, the control with no antibiotic administration (n = 10). Blood samples were collected before, during, and after treatment with antimicrobials. Lymphocyte subpopulations circulating in the blood were determined by immunostaining and flow cytometry analyses. Results: Following administration of a therapeutic dose of tulathromycin, there were no changes in the lymphocyte subpopulations circulating in blood. In contrast, administration of ceftiofur at the recommended dose decreased the absolute number of CD3+, CD21+, CD4+CD8-, CD4-CD8+, and double positive CD4CD8 cells. Conclusion: Results from the study indicate that ceftiofur possesses the ability to modulate the immune system in healthy pigs by decreasing lymphocyte subpopulations circulating in blood.

The regulation effects of danofloxacin on pig immune stress induced by LPS

Danofloxacin (DAN) is one of the Fluoroquinolone drugs (FQs) that has been widely used in the control and prevention of bacterial infectious disease in animal production. Most of the FQs have an obvious protective effect against lipopolysaccharide (LPS) induced Immune stress. However, the effect of DAN on the host immune system of animals remains unknown. In this study, a fever piglet model was built and a systematic survey of the response of inflammatory genes and mediators to DAN treatment and LPS induction was performed in the pig. The results indicated that the IL-1β, TNF-α, IL-6, NO (nitric oxide), and PGE2 (prostaglandin E2) levels were significantly suppressed in plasma and porcine alveolar macrophage 3D4/2 cells compared with the LPS treatment group. Interestingly, the IL-10 production was further stimulated by DAN treatment in the LPS challenged piglet. Our results suggested that DAN could relieve acute inflammation through inhibiting the activation of inflammatory genes introduced by LPS.

Ceftiofur hydrochloride affects the humoral and cellular immune response in pigs after vaccination against swine influenza and pseudorabies

Background

Cephalosporins are a class of antibiotics that are active against many Gram-positive and some Gram-negative bacteria. Beyond their antibacterial activity, they are reported to have various immunomodulatory properties. It has been shown that they reduce the secretion of cytokines as well as influence the humoral and cellular immune response.

In the field conditions antibiotics are frequently administered at the same time as vaccines in pigs and, in the view of their potential immunomodulatory properties, it is important to examine their effect on the development and persistence of the post-vaccinal immune response. Ceftiofur is a very popular veterinary medicine third-generation cephalosporin with a broad spectrum of activity. It has been shown that it can inhibit cytokines secretion and in this way can potentially affect host immune response. The influence of ceftiofur on the immune response has not yet been investigated in pigs. In the present study we evaluated the influence of therapeutic doses of ceftiofur hydrochloride on the post-vaccinal immune response after vaccination with two model vaccines (live and inactivated).

Methods

Seventy pigs were divided into five groups: control, unvaccinated (C), control vaccinated against swine influenza (SI-V), control vaccinated against pseudorabies (PR-V), vaccinated against SI during ceftiofur administration (SI-CEF) and vaccinated against PR during ceftiofur administration (PR-CEF). Pigs from SICEF and PR-CEF groups received therapeutic dose of ceftiofur for five days. Pigs from SI-CEF, PR-CEF, SIV and PR-V groups were vaccinated against SI and PR. Antibodies to PRV were determined with the use of blocking ELISA tests (IDEXX Laboratories, USA). Humoral responses to SIV were assessed based on haemagglutination inhibition assay. T-cell response was analyzed with the use of proliferation test. The concentrations of IFN- γ and IL-4 in culture supernatant were determined with the use of ELISA kits Invitrogen Corporation, USA).

Results

The significant delay in the development of humoral response against pseudorabies virus (PRV) as well as a significant suppression of production of antibodies against swine influenza virus (SIV) was found in pigs receiving ceftiofur hydrochloride at the time of vaccination. The cellular immune response against PRV was also significantly affected by ceftiofur. In contrast, there were no significant differences between vaccinated groups with regard to the T-cell response against SIV.

From day 28 of study to day 70, the concentration of INF-γ in culture supernatants were significantly lower in group treated with ceftiofur after restimulation with PRV. While, no significant differences were observed after restimulation of PBMC with H3N2 SIV.

Conclusions

The effect of an antibiotic therapy with ceftiofur hydrochloride on the humoral and cellular post-vaccinal immune responses in pigs was investigated. Ceftiofur hydrochloride was given in therapeutic doses. The results of the present study indicate that both, humoral and cell-mediated post-vaccinal immune responses can be modulated by treatment with ceftiofur hydrochloride. The results of our study point out that caution should be taken when administered this antibiotic during vaccination of pigs.