Antibiotics Chlortetracycline Research Articles

Co-existing antibiotics alter the enantioselective dissipation characteristics of zoxamide and drive combined impact on soil microenvironment

Co-existence of antibiotics (ABX) in soil may expand the environmental harm of pesticide pollution. Our study investigated the combined effects of five antibiotics chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TC), sulfamethoxazole (SMX), enrofloxacin (ENR) on enantioselective fate of zoxamide (ZXM) and soil health. The results showed that S-(+)-ZXM preferentially dissipated in soil. ABX prolonged dissipation half-life and reduced enantioselectivity of ZXM. Soil was detected to be more acidic after long-term treatment of ZXM and ABX. Lowest soil available N, P, K were found in ZXM + SMX, ZXM + OTC and ZXM + SMX groups at 80 days, respectively. ABX had demonstrated effective promotion of catalase (S-CAT), urease (S-UE) and negative impact on dehydrogenase (S-DHA), sucrase (S-SC) activities. Bacteria Lysobacter, Sphingomonas and fungus Mortierella were identified as the most dominant genera, which possessed as potential microbial resources for removal of composite pollution from ZXM and ABX. SMX and TC, SMX, ENR, respectively, contributed to the alteration of bacteria and fungi community abundance. Soil acidity, available N and enzyme activity showed stronger correlations with bacteria and fungi compared to other environmental factors. Our findings highlighted the interactions between ZXM and ABX from the perspective of soil microenvironment changes. Moreover, a theoretical basis for the mechanism was actively provided.

The use of smartphone and chemometric analysis for determination of tetracyclines in natural water by sensitized solid phase fluorescence of Eu on europium hydroxide

The possibility of identification and determination of tetracycline antibiotics (tetracycline, doxycycline, oxytetracycline, demeclocycline, metacycline and chlortetracycline) in natural water using digital colorimetry based on sensitized fluorescence of Eu (III) on europium hydroxide is studied. It is shown that complexes of Eu (III) with tetracyclines in an alkaline medium are adsorbed on europium hydroxide with preservation of their fluorescent properties. When the precipitate is irradiated with monochromatic ultraviolet light, pink fluorescence is observed. The colorimetric parameters of the precipitate in the RGB additive system after centrifugation were measured using a smartphone. The use of chemometric analysis provides shortening of the analysis procedure and visualizing of data obtained. The data set was processed using principal component analysis (PCA), hierarchical cluster analysis (HCA), and k-means method with XLSTAT software. The additional use of chemometric methods for processing of the analytical signal contributes to an increase in the reliability of the analyte identification. The methods used in the study make it possible to quantify the content of antibiotics in water bodies. The calibration dependences in the methods of principal components and k-means have a logarithmic form and are linear in the ranges of the determined contents — 0.005 – 0.1 μg/ml (R2 ≥ 0.99). The developed method for determining the total content of tetracycline antibiotics in natural waters is easy to use and is characterized by the availability of instrumentation. The environmental friendliness of this approach is attributed to a small set of inorganic salts required for concentration of the chelate complexes of tetracyclines with Eu (III) ions on europium hydroxide. The use of mobile digital technology (smartphones) and modern software products for data processing contributes to the development of rapid analysis. The approbation of the method was carried out using a sample of river water, the correctness of the analysis was proved by the spike test. The relative error of the analysis results does not exceed 15%.

Facile and green synthesis of carbon nanopinnacles for the removal of chlortetracycline: Performance, mechanism and biotoxicity

In an attempt to convert environmental pollutants into wealth, a new-type carbon nanopinnacles (CNPs) has been first designed and synthesized by high-temperature carbonization of chemical pollutant RB19 for the efficient removal of chlortetracycline via a non-radical pathway. • Chemical pollutant Reactive Blue 19 was first transformed into carbon nanopinnacles. • Carbon nanopinnacle was found to be an efficient metal-free catalyst for CTC removal via a non-radical pathway. • The surface-confined electron transfer between CTC and PMS is the major contribution for CTC degradation. • Zebrafish toxicology assays verifed that the biotoxicity of degradation products was dramatically reduced. In an attempt to convert environmental pollutants into wealth, herein, we have first designed and synthesized a new-type carbon nanopinnacles (CNPs) from Reactive Blue 19 (RB19), as a common dye pollutant, for chlortetracycline removal via a non-radical pathway. The kinetic model, quenching experiments and mechanism studies have verified that singlet oxygen ( 1 O 2 ) is selectively generated from CNPs/PMS system without any radicals (e. g. SO 4 − , HO and O 2 − ), but it is only contributed to 18.0 % of total chlortetracycline (CTC) degradation. The major contribution (82.20%) for CTC degradation probably is attributed to the surface-confined electron transfer between CTC and PMS. In addition, the full-scale zebrafish toxicology assays have indicated that antibiotic chlortetracycline exerted significantly toxic effects on zebrafish, while the biotoxicity of the chlortetracycline degradation products has been dramatically reduced. This work provides an interesting dual-decontamination strategy: First, chemical pollutant RB19 is entirely transformed into carbon nanopinnacles, Second, this carbon nanopinnacles has been successfully used as an efficient metal-free catalyst for CTC removal.

Evaluation of tetracycline antibiotics residues in chicken tissues using the four-plate test, ELISA, and HPLC methods in Iran

ABSTRACT Nowadays, various antibiotics are widely used for preventing and treating several diseases and for promoting growth in food-producing animals in different countries of the world. In this assay, edible chicken meat from local markets of Hamadan, a Province of Iran, was examined for residues of tetracycline antibiotics (tetracycline, oxytetracycline and chlortetracycline). In total, 150 samples of breast, wings and thigh tissue were randomly obtained from the local markets of the city of Hamadan. Four-plate tests (FPT), the enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) were used to analyse tetracycline antibiotic (TC) residues, respectively. Results showed that out of 150 samples, 30 samples (24.00%) and 22 samples (14.71%) of carcases were positive or “suspect by antibiotic residues by FPT and ELISA screening method, respectively. The HPLC assay indicated in 7 samples of wings and 12 samples of breast and 18 samples of thigh, residues of TCs were detected. The study revealed that the TCs levels in one sample of wings and three samples of breast and five samples of thigh exceeded the maximum residue level (MRL) reported by the EU. To reduce the TC residues found in edible chicken meat, regulatory authorities should ensure that the chicken would undergo the proper withdrawal period from TCs before slaughtering.

Heterostructure coal-bearing strata kaolinite/MnFe2O4 composite for activation of peroxydisulfate to efficiently degrade chlortetracycline hydrochloride

The excessive discharge of the antibiotic chlortetracycline hydrochloride (CTC·HCl) directly threatens human life and health. Different from previous studies on MnFe2O4 (MFO) combined with bulk BT or disc-shaped DE in the treatment of antibiotic wastewater, in this study, layered coal-bearing strata kaolinite (CK) was used as a carrier to prepare MnFe2O4/coal-bearing strata kaolinite (MFO/CK) catalyst, and used to evaluate the effect of activated peroxodisulfate (PDS) in the removal of CTC·HCl in wastewater under visible light. Compared with MFO and CK, the specific surface area of MnFe2O4/coal-bearing strata kaolinite-40% (MFO/CK-40%) was significantly increased, the reactive sites increased, and the PDS activation and CTC·HCl degradation were better. After 60 min of reaction under visible light, the removal rate of CTC·HCl can reach 85.1%. In addition, the influence of various factors on the degradation of CTC·HCl was investigated. It is concluded that the most effective removal of CTC·HCl occurs when there is an additional 25 mg of MFO/CK-40%, the concentration of CTC·HCl is 50 mg/L, pH= 4, and PDS is 1.5 mL. Then, through electron spin resonance and radical trapping experiments, it was determined that h+ and ·O2− were the main active species for removing CTC·HCl. The mechanism of CTC·HCl degradation by the MFO/CK-40%/PDS/Vis system was discussed. Finally, the stability and reusability of the MFO/CK-40% composite material were tested. After 3 cycles of experiments, the removal rate of CTC·HCl is still more than 70%, indicating that the MFO/CK-40% composite material has good stability and catalytic activity. Therefore, the MFO/CK catalyst can be used as a new and efficient PDS activator, which is widely used in the photocatalytic degradation of organic matter in wastewater. Data AvailabilityNot applicable.

Enhanced adsorption and degradation of antibiotics by doping corncob biochar/PMS with heteroatoms at different preparation temperatures: Mechanism, pathway, and relative contribution of reactive oxygen species

Antibiotics in the water environment pose harm to animals, plants, and humans. In this study, biochar doped with sulfur (S), nitrogen (N), and NS was used to adsorb and activate peroxymonosulfate (PMS) to degrade the antibiotics chlortetracycline, ofloxacin, and sulfadiazine in an aqueous solution. The adsorption capacity of the biochar doped with single atoms increased significantly, and the maximum saturated adsorption capacities of undoped, N-doped, S-doped, and NS-doped biochar were 40.7, 85.5, 63.3, and 40.7 mg/g, respectively. The increase in specific surface area and the number of functional groups was the main cause for the increase in the adsorption capacity of heteroatom-doped biochar. The antibiotic degradation process involved the use of biochar to activate PMS and produce reactive oxygen species (ROS) for complete removal. The concentration of environmentally persistent free radicals (EPFRs) increased in response to heteroatom-doped biochar, and the type of EPFRs changed, which enhanced the ability of biochar to degrade antibiotics. At the 500 °C preparation temperature, the degradation rates of antibiotics by the undoped, N-doped, S-doped, and NS-doped biochar were 73.83%, 84.32%, 79.60%, and 74.10%, respectively, whereas the degradation rates at 900 °C were 82.38%, 93.78%, 91.11%, and 81.55%, respectively. The sulfate radical was produced during the activation process and made the largest relative ROS contribution to the increased adsorption capacity, followed by singlet oxygen, hydroxyl radical, and superoxide radical. Recycling experiments confirmed that the heteroatom-doped biochar was highly reusable and that the removal rates of N-doped biochar and S-doped biochar were high (81.94% and 78.06%, respectively).

Chlortetracycline, a Novel Arf Inhibitor That Decreases the Arf6-Dependent Invasive Properties of Breast Cancer Cells.

Breast cancer is a major disease for women worldwide, where mortality is associated with tumour cell dissemination to distant organs. While the number of efficient anticancer therapies increased in the past 20 years, treatments targeting the invasive properties of metastatic tumour cells are still awaited. Various studies analysing invasive breast cancer cell lines have demonstrated that Arf6 is an important player of the migratory and invasive processes. These observations make Arf6 and its regulators potential therapeutic targets. As of today, no drug effective against Arf6 has been identified, with one explanation being that the activation of Arf6 is dependent on the presence of lipid membranes that are rarely included in drug screening. To overcome this issue we have set up a fluorescence-based high throughput screening that follows overtime the activation of Arf6 at the surface of lipid membranes. Using this unique screening assay, we isolated several compounds that affect Arf6 activation, among which the antibiotic chlortetracycline (CTC) appeared to be the most promising. In this report, we describe CTC in vitro biochemical characterization and show that it blocks both the Arf6-stimulated collective migration and cell invasion in a 3D collagen I gel of the invasive breast cancer cell line MDA-MB-231. Thus, CTC appears as a promising hit to target deadly metastatic dissemination and a powerful tool to unravel the molecular mechanisms of Arf6-mediated invasive processes.

Radiated temperature of weaned piglets and the response to in-feed antibiotics with correction for ambient conditions

Growth performance, health status, and the radiated thermal temperatures of groups of piglets consuming non-medicated feed and in-feed antibiotics (chlortetracycline hydrochloride and tiamulin) were monitored continuously for up to 35 d, from weaning at 28 d of age until moving to commercial pens at approximately 63 d of age. There was a trend (P = 0.1) for body weight at the time of moving to be higher for the medicated animals. The average daily gain was higher in medicated piglets (P = 0.03). Radiated temperature variables were the maximum (Tmax) and the average (Tmean) pig temperatures, and both were higher for the medicated piglets (P < 0.0001). A threshold temperature was derived to partition the image and derive the background radiated temperature that was used to obtain the expected radiated temperature of the pigs. Temperature data were adjusted for environmental effects by expressing the residual temperature. The residual for Tmax (TmaxRes) and for Tmean (TmeanRes) were higher in medicated piglets (P < 0.0001). In-feed antibiotics were associated with increased growth rates and with an increase in radiated temperature variables, particularly those corrected for environmental conditions, possibly mediated through increased metabolic activity related to growth.

PSV-4 Direct-fed microbial program improved survivability of nursery pigs in commercial production

Abstract A total of 2,304 newly weaned pigs (5.8±0.06 Kg BW, ~21-day old, DNA Genetics) were used in a RCBD to evaluate the effect of a direct-fed microbial (DFM) program on pig performance and survivability, under commercial pig production. Pigs were housed in 2 barns (blocking factor) with 36 pens each (32 pigs/pen, mixed-sex), and pens randomized to treatments: Control or DFM program (36 pens/treatment). The program consisted of a DFM (blend 1) delivered through drinking water (1.32x108 CFU/pig/day) from day 0 to 7, followed by another DFM (blend 2) in feed (1.5x105 CFU/g of feed) from day 7 through 49. Those DFM consisted of spore-forming Bacillus sp. selected to inhibit enterotoxigenic E. coli growth (blend 1) and reduce local inflammation (blend 2). The feeding program included phases 1 and 2 (7 days each) in pellet, and phases 3 (11 days) and 4 (24 days) in meal. Phase 1 feeds included antibiotics Chlortetracycline and Tiamulin; both phase 4 feeds included Carbadox. A severe diarrhea outbreak was observed in week 3; antibiotic therapy (Neomycin, Sulfadiazine or Trimethoprim) throughout drinking water was used in both treatments alike between days 19 and 28. Pig and feed weight were recorded by pen; ADG and ADFI were calculated on pig-days. Pigs removed included mortality and those ill, nonresponsive to antibiotics. Performance data were analyzed by ANOVA, using the GLM procedure. Pigs removed did not follow normal distribution and was analyzed using a parametric survival option with days as time variable (JMP v14.2.0). No differences were detected through day 25. Pigs in DFM consumed less feed (923 vs. 951 g/d; SEM=10.33; P=0.05) and were more efficient (0.61 vs. 0.59 kg/kg; SEM=0.004; P< 0.05) from days 25 to 49. Total pigs removed were reduced (P< 0.05) by 23% in DFM vs. Control (Table 1). In conclusion, the DFM program improved nursery pig survivability and late performance, under commercial pig production that included a diarrhea outbreak and antibiotic therapy.

Effect of chloretracycline and albendazole on alkaline phosphatase activity of carp gill (Cyprinus carpio L.)

The effect of the antibiotic chlortetracycline and the anthelmintic albendazole on morphological features, internal organs, alkaline phosphatase activity and protein content in the gills of two-year-old carp was studied. It was found that chlortetracycline and albendazole at the studied concentrations in water and short-term action do not affect the morphological features, behavior and internal organs, but change the alkaline phosphatase activity of the gills of two-year-old carp. The antibiotic chlortetracycline at concentrations of 1.10, 3.15, and 6.30 mg/dm3 of water and fish exposure for 72 h reduced the alkaline phosphatase activity of gills in carp of the first experimental group by 2.5 times, in the second – by 2.8 times and in the third – by 2.7 times regard the control; it did not affect the protein content in the gills, morphological features and internal organs of fish. We registered an increase in alkaline phosphatase activity of gills in two-year-old carp under effect of anthelmintic albendazole at at the concentration of 1.0 mg/dm3 by 28.2%, while albendazole concentration of 0.2 and 0.5 mg/dm3 did not affect the alkaline phosphatase activity as well as the level of protein in fish body. Our results indicate an important role of gill alkaline phosphatase in assessing the negative effects of antibiotics and water anthelmintics in freshwater fish.

Dissipation of chlorothalonil in the presence of chlortetracycline and ciprofloxacin and their combined effects on soil enzyme activity.

The long-term application of substantial amounts of fungicides and antibiotic-polluted organic manure (OM) in greenhouse has caused the co-existence of fungicides and antibiotics in soils. However, little is known about the effects of antibiotics on the persistence of fungicides in soils or their combined effects on soil enzyme activity. In this study, fungicide chlorothalonil (CTL) alone and in combination with antibiotic chlortetracycline (CTC) or ciprofloxacin (CIP) were repeatedly added to OM-amended soil to investigate the changes in the residual characteristics of CTL and in soil dehydrogenase and urease activity. The results showed that CTL rapidly dissipated in soils with the corresponding half-lives of 0.9-3.2, which initially increased, then decreased and finally stabilized with an increased treatment frequency. The dissipation of CTL was inhibited by CTC and CIP during the first several treatments. The soil dehydrogenase and urease activity in CTL-treated soils was inhibited during the first six treatments and then recovered afterwards. Compared with the OM-amended soil+CTL treatment, the OM-amended soil+CTL+CTC and OM-amended soil+CTL+CIP treatments had stronger inhibitory effects on soil enzyme activity during the first six repeated treatments but exhibited slight stimulating effects afterwards. Therefore, the results obtained in this study suggested that the long-term co-existence of CTL, CTC, and CIP altered the dissipation characteristics of CTL in soil and affected the soil enzyme activity levels. The prudent application of large and frequent of fungicides and OM-containing antibiotic residues in greenhouses should therefore be carefully considered in order to reduce the long-term combined pollution in soils.

Simultaneous extraction of antibiotic and estrogen from animal blood serum using aqueous two-phase systems as predictor of environmental impact.

Efficient analytical methods are required for optimizing dosage of veterinary antibiotics and hormones in order to reduce toxicity and antimicrobial resistance in the environment. Thus, the objective of this work was to develop a rapid and low-cost method for determination of hormone estradiol and antibiotic chlortetracycline in bovine and porcine blood serum by aqueous two-phase system (ATPS) extraction and capillary electrophoresis quantification. ATPS based on ionic liquid cholinium alaninate and citrate salt along with mixtures of protic and aprotic polar solvents were evaluated in terms of recovery of extraction (%R). The liquid-liquid equilibrium, phase diagrams, and tie lines are discussed. Antibiotic migrated to solvent-rich phase (R ≈ 89.0%) to all systems. Estradiol migrates to ionic liquid-rich phase; however, addition of 10% methanol changed partition to solvent-rich phase (R ≈ 89.7%). The method has high recovery and cleanliness, is cost-efficient, scalable, and hence is adequate for screening of antibiotics and hormones tested in animal blood serum for dosage optimization and to predict their environment.

Preliminary Study on the Effect of Bacillus amyloliquefaciens TL on Cecal Bacterial Community Structure of Broiler Chickens.

Probiotics can promote the health and growth performance of animals through modulation of intestinal microbiota. When used as a feed additive, they have the potential to minimize or abolish the use of antibiotics. In this study, we investigated the effect of the probiotic strain Bacillus amyloliquefaciens TL on the growth performance and cecum microflora composition in Cobb 500 broiler chickens. In total, 180 broilers were randomly divided into three groups—each group comprised 4 pens, and each pen contained 15 chickens. The three groups were fed either a control diet, or a diet supplemented with either the antibiotic chlortetracycline or B. amyloliquefaciens TL. Broilers were weighed, and cecum contents were collected on days 7, 14, 21, and 35, respectively. The broilers in both the antibiotic and probiotic groups exhibited significant weight gain compared with controls, exhibiting increases of 16.02% and 13.40%, respectively, after 35 days (P < 0.01). Similarly, the feed conversion ratio (FCR, 1–35 days) of broilers in the chlortetracycline and B. amyloliquefaciens TL groups was lower than that of the controls. HiSeq high-throughput sequencing of 16S rRNA of the cecal microbiota was performed on days 7, 14, 21, and 35, respectively. The Firmicutes/Bacteroidetes ratio was higher in the chlortetracycline and B. amyloliquefaciens TL groups than in the control group on days 14, 21, and 35, and especially on day 21. The prevalence of genera Oscillospira, Ruminococcus, Butyricicoccus, and Faecalibacterium (Firmicutes) was higher in the antibiotic and probiotic groups, while that of Bacteroides, Parabacteroides (Bacteroidetes), and Lactobacillus was higher in the control group. In this study, the changes in the microbiota of the probiotic group were similar to those in the antibiotic group. These results suggest that the probiotic strain B. amyloliquefaciens TL can modulate the cecal microbiota of broilers similar to chlortetracycline.

Chlortetracycline and florfenicol induce expression of genes associated with pathogenicity in multidrug-resistant Salmonella enterica serovar Typhimurium

BackgroundMultidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Typhimurium) is a serious public health threat as infections caused by these strains are more difficult and expensive to treat. Livestock serve as a reservoir for MDR Salmonella, and the antibiotics chlortetracycline and florfenicol are frequently administrated to food-producing animals to treat and prevent various diseases. Therefore, we evaluated the response of MDR S. Typhimurium after exposure to these two antibiotics.ResultsWe exposed four MDR S. Typhimurium isolates to sub-inhibitory concentrations of chlortetracycline (16 and 32 µg/ml) or florfenicol (16 µg/ml) for 30 min during early-log phase. Differentially expressed genes following antibiotic treatment were identified using RNA-seq, and genes associated with attachment and those located within the Salmonella pathogenicity islands were significantly up-regulated following exposure to either antibiotic. The effect of antibiotic exposure on cellular invasion and motility was also assessed. Swimming and swarming motility were decreased due to antibiotic exposure. However, we observed chlortetracycline enhanced cellular invasion in two strains and florfenicol enhanced invasion in a third isolate.ConclusionsChlortetracycline and florfenicol exposure during early-log growth altered the expression of nearly half of the genes in the S. Typhimurium genome, including a large number of genes associated with virulence and pathogenesis; this transcriptional alteration was not due to the SOS response. The results suggest that exposure to either of these two antibiotics may lead to the expression of virulence genes that are typically only transcribed in vivo, as well as only during late-log or stationary phase in vitro.

Фракційний склад білків крові коропа за дії хлортетрацикліну, нандролону та альбендазолу

&lt;p&gt;The influence of xenobiotics, in particular, the antibiotic chlortetracycline, anabolic steroid nandrolone and anthelmintic albendazole, on carp fish depends on their concentration in water and is associated with a change in a number of morphological indices and physiological and biochemical mechanisms in the process of their adaptation to the action of xenobiotics of water, and as shown by the study - total content and fractional composition of blood plasma proteins. In model experiments carried out on the bogs of carp, the main objective of which was to investigate the influence of xenobiotics of anthropogenic origin on the fractional composition of plasma proteins, it was established that for a short exposure (72 hours) and low concentrations of nandrolone 0.1 mg / dm3 (the first experimental group) and (0.5 mg / dm3 second experimental group), only slight changes in the protein content with a molecular weight of 25, 35-50 and 100-140 kDa in the water of the aquariums are observed at constant values of the parameters of other fractions. With an increase in the concentration of nandrolone in aquarium water up to 1.0 mg / dm3, the protein content with a molecular weight of 450 kDa and above increased by 91%, 340 kDa by 78%, 260 kDa by 101%, 70 kDa by 149%, 50 kDa - 111%, 25-50 kDa - 35-62% compared to control. Consequently, anabolic steroids, getting into the water at low concentrations do not affect, and in high stimulate biosynthesis processes of proteins in tissues, two decades of carp.&lt;/p&gt;&lt;p&gt;The intolerance (12 hours) of carps in an aquarium with an anthelmintic concentration of albendazole in water of 0.2 mg / L varied only with individual fractions of blood plasma proteins of fish. The increase in the concentration of albendazole in water to 0.5 mg / L and especially to 1.0 mg / L affects the protein spectrum of blood plasma fish to a large extent, reducing the content of most proteins of low and high molecular weight fractions. It was found that chlortetracycline in the concentration of 1.10 mg / dm3 did not affect, and when it increased in water to 3.15 and 6.30 mg / dm3, it reduced the level of proteins in the blood plasma of the carp in 3 days, with a molecular weight of 340-450 kDa, and higher and contributed to the appearance of protein fractions with a molecular weight of 140 - 200 and 70 - 90 kDa. Investigated xenobiotics chlortetracycline, nandrolone and albendazole, in the above-mentioned concentrations in water and short-term exposure of fish, did not affect their behavior, the number of respiratory movements and the tomographic indices of the internal organs. The state of the external body covers, as well as the organoleptic indices of the internal organs of fish of experimental groups for the effects of various concentrations of the studied xenobiotics, did not differ from the similar characteristics of the control group carps. The obtained results testify to the important role of blood plasma proteins in the mechanisms of their adaptation to the action of xenobiotics of water, in particular anabolic steroid nandrolone, antibiotic chlortetracycline and anthelmintic albendazole. &lt;/p&gt;

A Randomised Non-inferiority Trial on the Effect of an Antibiotic or Non-antibiotic Topical Treatment Protocol for Digital Dermatitis in Dairy Cattle

Objective: Investigation of the therapeutic effect of a protocol using non-antibiotic Intra Epidine (IE) spray containing copper and zinc chelate on M2 digital dermatitis (DD) lesions compared to a treatment protocol using antibiotic chlortetracycline (CTC) spray for non-inferiority testing. Background: Digital dermatitis (DD) is an infection in dairy cattle which frequently results in lameness. A common individual treatment for DD in Europe is a topical administration of antibiotic CTC spray. Given the important objective to minimise antibiotic use in order to prevent selection for antibiotic resistance, there is a need for effective non-antibiotic treatments for common animal diseases. Evidentiary value: This clinical trial on commercial farms with registered products is valuable for all veterinary practitioners interested in the quantitative curative effects of treatments forDD. Methods: Professional hoof trimmers trimmed hind legs of 944 cows from nine dairy herds. All legs with DD M2 lesions were included and randomly assigned to a treatment protocol with IE spray or CTC spray according to the label instructions from the manufacturers. At the end of the study 231 individual legs, one per cow, in seven herds were eligible for analysis. Clinical improvement was defined as the transition of the clinical most relevant ulcerative M2 lesion to any other less severe lesion stage at 10 days after the start of the treatment. Results: The overall individual leg clinical improvement rate of IE spray (86.8%) was higher compared to CTC spray (47.9%). The herd adjusted odds ratio for clinical improvement was 8.2 (95% CI 4.2 – 15.7) for IE spray versus CTC spray with an estimated Relative Risk of 1.9. Conclusion: In conclusion, the IE treatment protocol was non-inferior but more effective than the CTC treatment protocol to clinically improve DD M2 lesions.

Impact of Saccharomyces cerevisiae boulardii CNCMI-1079 and Lactobacillus acidophilus BT1386 on total lactobacilli population in the gastrointestinal tract and colon histomorphology of Holstein dairy calves

There is interest in the use of direct-fed microbials (DFM) as substitutes for antibiotic growth promoters in farm animal production. However, little information exists on their effects in dairy calves. The aims of this study were to: 1) determine the viability of supplemental DFM in feed and throughout the gastrointestinal tract (GIT) of calves; 2) evaluate the effect of DFM on total lactobacilli population in the digestive tract and in feces of calves; and 3) examine the influence of DFM on colon histomorphology and overall calf performance. Forty eight calves (2–7days old) were randomly allocated to four treatments as follows: 1) Control (CTRL) fed milk replacer (MR) followed by starter feed (SF); 2) CTRL supplemented with Saccharomyces cerevisiae boulardii CNCMI-1079 (SCB; 7.5×108 colony forming units (CFU)/L MR+3×109 CFU/kg SF); 3) CTRL supplemented with Lactobacillus acidophilus BT1386 (LA; 2.5×108 CFU/L MR+1×109 CFU/kg SF); and 4) CTRL supplemented with antibiotics (ATB) chlortetracycline and neomycin (528 and 357mg/L MR, respectively), and chlortetracycline (55mg/kg SF). Four calves per treatment were euthanized on day 33 (pre-weaning) and an additional four calves per treatment on day 96 (post-weaning) to sample different sections of the GIT. The effects of treatments were analyzed following a completely randomized design with repeated measures and Tukey adjustments for multiple comparisons. The DFM (SCB and LA) remained viable in the commercial product throughout the period of the experiment. Viable SCB was recovered throughout the GIT and in the feces pre- and post-weaning. There was no effect of DFM on total lactobacilli population in the GIT of calves. However, feces of SCB-treated calves showed a greater lactobacilli population compared with CTRL (P<0.01) around weaning. In the pre-weaning period, the distribution of lactobacilli population differed along the digestive tract (colon > ileum content > rumen > ileum mucosa; P<0.001). The lactobacilli population was significantly reduced in all compartments (P=0.02) post-weaning compared to pre-weaning, except in the rumen. Crypts depth and width of the colon decreased (P<0.01) whereas number of goblet cells containing neutral mucins tended to increase (P=0.058) while acidic mucins increased (P<0.05) in SCB- and ATB-treated calves compared with CTRL and LA-treated calves. Overall, growth performances were not affected by treatment. Feeding SCB stimulated total lactobacilli population around weaning and altered colon morphology with potential beneficial effects during the early period of growth in calves. Our findings suggest that SCB would deserve more attention as a modulator of the gastrointestinal health in young dairy calves.

Effects of chlortetracycline, Cu and their combination on the performance and microbial community dynamics in swine manure anaerobic digestion

Swine manure was typical for the combined pollution of heavy metals and antibiotics. The effects of widely used veterinary antibiotic chlortetracycline (CTC), Cu and their combination on swine manure anaerobic digestion performance and microbial community have never been investigated. Thus, four 2L anaerobic digestion reactors were established including reactor A (control), B (CTC spiked by 0.5g/kg dry weight, dw), C (Cu spiked by 5g/kg dw) and D (combination of CTC, 0.5g/kg dw, and Cu, 5g/kg dw), and dynamics of bacterial and archaeal community structure was investigated using high throughput sequencing method. Results showed that addition of CTC and Cu separately could increase the total biogas production by 21.6% and 15.8%, respectively, while combination of CTC and Cu severely inhibited anaerobic digestion (by 30.3%). Furthermore, corresponding to different stages and reactors, four kinds of microbes including bacteria and archaea were described in detail, and the effects of CTC, Cu and their combination mainly occurred at hydrolysis and acidification phases. The addition of Cu alone changed the dynamics of archaeal community significantly. It was genus Methanomassiliicoccus that dominated at the active methane production for A, B and D, while it was genus Methanobrevibacter and Methanoculleus for C.

High-Throughput Chemical Screening Identifies Compounds that Inhibit Different Stages of the Phytophthora agathidicida and Phytophthora cinnamomi Life Cycles.

Oomycetes in the genus Phytophthora are among the most damaging plant pathogens worldwide. Two important species are Phytophthora cinnamomi, which causes root rot in thousands of native and agricultural plants, and Phytophthora agathidicida, which causes kauri dieback disease in New Zealand. As is the case for other Phytophthora species, management options for these two pathogens are limited. Here, we have screened over 100 compounds for their anti-oomycete activity, as a potential first step toward identifying new control strategies. Our screening identified eight compounds that showed activity against both Phytophthora species. These included five antibiotics, two copper compounds and a quaternary ammonium cation. These compounds were tested for their inhibitory action against three stages of the Phytophthora life cycle: mycelial growth, zoospore germination, and zoospore motility. The inhibitory effects of the compounds were broadly similar between the two Phytophthora species, but their effectiveness varied widely among life cycle stages. Mycelial growth was most successfully inhibited by the antibiotics chlortetracycline and paromomycin, and the quaternary ammonium salt benzethonium chloride. Copper chloride and copper sulfate were most effective at inhibiting zoospore germination and motility, whereas the five antibiotics showed relatively poor zoospore inhibition. Benzethonium chloride was identified as a promising antimicrobial, as it is effective across all three life cycle stages. While further testing is required to determine their efficacy and potential phytotoxicity in planta, we have provided new data on those agents that are, and those that are not, effective against P. agathidicida and P. cinnamomi. Additionally, we present here the first published protocol for producing zoospores from P. agathidicida, which will aid in the further study of this emerging pathogen.

Uptake of the veterinary antibiotics chlortetracycline, enrofloxacin, and sulphathiazole from soil by radish

Veterinary antibiotics are available for uptake by the plants through sources such as manure, irrigation, and atmospheric interaction. The present study was conducted to estimate the half-lives of three veterinary antibiotics, chlortetracycline (CTC), enrofloxacin (ENR), and sulphathiazole (STZ), in soil and experimentally explore their uptake from contaminated soil to radish roots and leaves. Samples were extracted using a modified citrate-buffered version of the quick, easy, cheap, effective, rugged, and safe “QuEChERS” method followed by liquid chromatography coupled with tandem mass spectrometric analysis (LC–MS/MS) in the positive ion mode. Good linearity was observed for the three tested antibiotics in soil and plants (roots and leaves) with high coefficients of determination (R2≥0.9922). The average recovery rates at two spiking levels with three replicates per level ranged between 77.1 and 114.8%, with a relative standard deviation (RSD)≤19.9% for all tested drugs. In a batch incubation experiment (in vitro study), the half-lives of CTC, ENR, and STZ ranged from 2.0–6.1, 2.2–4.5, and 1.1–2.2days, respectively. Under greenhouse conditions, the half-lives of the three target antibiotics in soil with and without radishes were 2.5–6.9 and 2.7–7.4; 4.7–16.7 and 10.3–14.6; and 4.4–4.9 and 2.5–2.8days, respectively. Trace amounts of the target antibiotics (CTC, ENR, and STZ) were taken up from soil via roots and entered the leaves of radishes. The concentration of CTC was lower than 2.73%, ENR was 0.08–3.90%, and <1.64% STZ was uptaken. In conclusion, the concentrations of the tested antibiotics decreased with time and consequently lower residues were observed in the radishes. The rapid degradation of the tested antibiotics in the present study might have only little impact on soil microorganisms, fauna, and plants.