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Abstract Background Antibiotic‐responsive enteropathy (ARE) is diagnosed by excluding other causes of diarrhea and when there is a short‐term response to administration of antibiotics. Objectives To characterize the gut microbiota and clinical trend of dogs with suspected ARE and to evaluate the variation in microbiota before (T0), after 30 days (T30) of tylosin treatment, and 30 days after discontinuation of treatment (T60). A further objective was to evaluate whether changes in gut microbiota are related to relapses of diarrhea when the therapy is tapered. Animals Study sample (group A) was composed of 15 dogs with chronic diarrhea, group B was composed of 15 healthy dogs. Group A was given tylosin for 30 days. Methods A multicentric prospective study. Clinical Indexes, fecal score, and samples for microbiota analysis were collected at T0, T30, and T60 in group A and T0 and T30 in group B. The gut microbiota was analyzed via 16S ribosomal RNA gene. Qiime2 version 2020.2 was used to perform bioinformatic analyses, and Alpha‐ and Beta‐diversity were computed. Results Diarrhea recurred after T30 in 9 of 14 dogs, which were classified as affected by ARE. At T0, a difference was noted in the beta‐diversity between groups (Bray Curtis metric P = .006). A T0‐T30 difference in alpha‐diversity was noted in group A (Shannon index P = .001, Faith PD P = .007). Conclusions and Clinical Importance Although tylosin influences the microbiota of dogs with ARE, we failed to find any specific characteristic in the microbiota of dogs with ARE.

Mycoplasmoses of cattle and small ruminants, pigs and poultry are widely spread and the infection process is frequently associated with other diseases. Mycoplasma spp. cause inflammatory respiratory diseases, diseases of joints and meninges, keratoconjunctivitis, mastitis and endometritis, abortion and stillbirths. Etiotropic therapy of mycoplasmal infections consists in prescribing antibiotics: enrofloxacin, difloxacin, oxytetracycline, chlortetracycline, doxycycline, tylosin, tilmicosin, tylvalosin, tiamulin, florfenicol, lincomycin, spectinomycin, tulathromycin. The results of studies described in different publications show high sensitivity of Mycoplasma synoviae and Mycoplasma gallisepticum to tetracyclines, tiamulin and tylvalosin. Isolates with increased resistance to tilmicosin are also resistant to tylosin and lincomycin. Treatment of respiratory infections in lambs, the main causative agents of which are Mannheimia haemolytica and Mycoplasma, has been successful with the use of fluoroquinolones, tilmicosin, tulathromycin, chlortetracycline, enrofloxacin, doxycycline, and oxytetracycline. Isolates of Mycoplasma bovis are largely sensitive to oxytetracycline, florfenicol and tulathromycin. Enrofloxacin has a less pronounced therapeutic effect. Tilmicosin and oxytetracycline are effective in the treatment of respiratory diseases of young cattle, associated with Mycoplasma spp. Tulathromycin and tilmicosin have a significant therapeutic effect in the treatment of pneumonia in weaned piglets experimentally infected with Mycoplasma hyopneumoniae. Multiple (course) use of enrofloxacin significantly increases the therapeutic effect. Tilmicosin is effective in the control of other bacterial infections of pigs (pasteurellosis, streptococcosis, hemophilic polyserositis, infectious atrophic rhinitis).The general prophylaxis of mycoplasmal infections is to comply with veterinary and sanitary standards and to implement quarantine measures in the infection outbreak.

Abstract Background Ribosome stalling on ermBL at the tenth codon (Asp) and mRNA stabilization are believed to be mechanisms by which erythromycin (Ery) induces ermB expression. Expression of ermB is also induced by 16-membered ring macrolides (tylosin, josamycin and spiramycin), but the mechanism underlying this induction is unknown. Methods We introduced premature termination codons, alanine-scanning mutagenesis and amino acid mutations in ermBL and ermBL2. Results In this paper, we demonstrated that 16-membered ring macrolides can induce ermB expression but not ermC expression. The truncated mutants of the ermB-coding sequence indicate that the regulatory regions of ermB whose expression is induced by Ery and 16-membered ring macrolides are different. We proved that translation of the N-terminal region of ermBL is key for the induction of ermB expression by Ery, spiramycin (Spi) and tylosin (Tyl). We also demonstrated that ermBL2 is critical for the induction of ermB expression by erythromycin but not by 16-membered ring macrolides. Conclusions The translation of ermBL and the RNA sequence of the C-terminus of ermBL are critical for the induction of ermB expression by Spi and Tyl.

Mycoplasma synoviae (MS) infection is mainly controlled by pathogen-free flocks' maintenance, medication in infected flocks, and vaccination in high-risk flocks. The effective control strategy requires convenient approach for detecting and differentiating MS strains and reliable drug susceptible evidence for deciding on reasonable antimicrobial usage. This study aimed to characterize the partial vlhA gene of nine Thai MS isolates circulated in chickens in 2020, to verify the PCR-RFLP assay for strain differentiation, and to determine the eight antimicrobial susceptibility profiles using microbroth dilution method. Based on sequence analysis of the partial vlhA gene, Thai MS isolates in 2020 were classified as types E and L with 19 and 35 amino acid lengths, respectively. The developed PCR-RFLP assay could detect and differentiate vaccine and Thai field strains. Most Thai MS isolates in this study were susceptible to tylosin, tylvalosin, tiamulin, doxycycline, oxytetracycline, tilmicosin, and lincomycin-spectinomycin at MIC50 values of 0.0391, 0.0098, 0.0781, 0.1563, 0.1563, 0.625 and 0.625 μg/mL, respectively; and resistance to enrofloxacin at MIC50 value of 10 μg/mL. In conclusion, this study revealed diagnostic assays for differentiating MS strains and the antimicrobial susceptibility profiles of Thai MS, which are necessary to design suitable MS control procedures for poultry flocks. [ABSTRACT FROM AUTHOR]

Neat stallion semen can contain a variety of microorganisms, some of which may impair sperm quality and/or cause infection of the mares' reproductive tract. For this reason, antibiotics are commonly added to semen extenders. A combination of gentamicin, tylosin, lincomycin and spectinomycin (GTLS) has been recommended for use, but there are no reports on the use of this mixture in equine semen extender. Penicillin and amikacin (PA) are safe for preserving sperm quality while effectively controlling bacterial growth in equine cooled stored semen, but data on frozen semen are scarce. Therefore, a bioequivalence study was performed to assess the bactericidal activity of GTLS and PA in equine frozen semen. Nine mature, healthy stallions were used in the study. Split ejaculates were processed using media without antibiotics (Control) or with different antibiotics. For the GTLS group, centrifugation medium and freezing extender were prepared with gentamicin 250 μg/ml, tylosin 50 μg/ml, lincomycin 150 μg/ml and spectinomycin 300 μg/ml. For the PA group, the centrifugation medium was prepared with potassium penicillin G (PPG) 1200 units/ml and the freezing extender was prepared with PPG 1200 units/ml and amikacin 500 μg/ml. Semen processed in extenders without antibiotics had higher (p <.005) bacterial loads throughout all cryopreservation processing steps than semen samples processed using antibiotics. There were no differences in semen bacterial load after centrifugation, 15 and 30 min after final extension, and after thawing between GTLS and PA groups, but PA had faster (p <.05) kill‐time kinetics than GTLS. Only minor differences in sperm kinetic parameters were observed among groups. In conclusion, this study demonstrated bioequivalence between GTLS and PA in mitigating end‐point bacterial loads. Prudent concentrations of the antibiotic mixtures evaluated in this study can be considered both effective and sperm‐safe for equine frozen semen. [ABSTRACT FROM AUTHOR]

Due to its hydrophilicity, the antibiotic tylosin (TYL) was challenging to remove entirely from water through traditional techniques. The design of an efficient photocatalyst for the degradation of TYL is a matter of great urgency. Herein, carboxylated cellulose beads embedded with Au-doped TiO2 nanoparticles (Au/TiO2-CCBs) were fabricated via interfacial solid-phase chemical modification with straightforward photo-deposition and TEMPO-mediated oxidation. Morphology, structure, and optical properties of Au/TiO2-CCBs have been investigated through scanning electron microscopy, energy dispersive spectrometer, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis Diffused reflectance spectra, and electron spin resonance (ESR). The fabricated Au/TiO2-CCBs exhibited superior photocatalytic performance, by demonstrating approx. 92% of TYL was decomposed in 180 min under visible light irradiation. However, the catalyst exhibited modest adsorption behavior. The enhanced photocatalytic activity for Au/TiO2-CCBs was attributed to the separation of photoinduced electron−hole pairs. The radical capture test and ESR experiment confirmed that ∙O2−, ∙OH, and h+ radicals were formed during the TYL degradation process. In addition, the stability of the Au/TiO2-CCBs was demonstrated by a steady photocatalytic performance after five cycles during the application. Therefore, this work indicated that the Au/TiO2-CCBs catalyst had an excellent prospect for environmental remediation. [ABSTRACT FROM AUTHOR]

A pooled analysis was performed to evaluate whether corn silage fed at 15% or 45% of diet DM impacted liver abscesses prevalence at slaughter in five previous experiments. Cattle fed 15% corn silage had 7.8% abscessed livers compared to 4.1% for cattle fed 45% corn silage when all diets contained tylosin. While improved due to increased corn silage inclusion, the objective of the current finishing study was to determine the impact of silage inclusion in finishing diets with and without tylosin on performance and incidence of abscessed livers in beef cattle. A total of 640 (BW = 334 ± 25 kg) steers were used in a generalized randomized block design with a 2 × 2 factorial treatment design. Treatments included two concentrations of corn silage (15% and 45% of diet DM), with or without tylosin for liver abscesses. This study used 32 pens of cattle with 20 steers per pen and 8 pens per treatment. There was a tendency for an interaction for feed efficiency (G:F; P = 0.10) where cattle fed 15% corn silage had a 2% increase in G:F when tylosin was added to the diet, but no improvements in G:F were observed when tylosin was added to diets containing 45% silage. There was an interaction between silage and tylosin inclusion for abscessed livers (P = 0.05). Cattle fed 15% corn silage without tylosin had the greatest incidence of abscessed livers (34.5%) compared to other treatments (P = 0.05), and the incidence of abscessed livers was decreased to 19% if tylosin was fed with 15% corn silage. Feeding 45% silage was effective at lowering the incidence of abscessed livers (P = 0.05) which was 12.4%, regardless of whether tylosin was fed. Feeding corn silage at 45% of diet DM (77.5% concentrate) was as effective as feeding tylosin to cattle on a 92.5% concentrate diet. Feeding corn silage at greater inclusions decreased daily gain (P ≤ 0.01) but increased final body weight when fed to an equal fatness (cattle fed 45% CS were fed 28 d longer). Feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially as corn prices increase, provided shrink is well managed. Feeding elevated concentrations of corn silage may be an economically viable method to reduce incidence of liver abscesses without antibiotic use for smaller operations that can manage more corn silage in finishing diets. [ABSTRACT FROM AUTHOR]

This experiment compared ruminal, physiological, and productive responses of feedlot cattle receiving Yucca schidigera extract to replace or fed in conjunction with monensin + tylosin. Angus-influenced steers (n = 120) were ranked by body weight (BW ; 315 ± 3 kg) and allocated to 4 groups of 30 steers each. Groups were housed in 1 of 4 drylot pens (30 × 12 m) equipped with GrowSafe feeding systems (4 bunks/pen) during the experiment (day −14 to slaughter). On day 0, groups were randomly assigned to receive a diet containing (2 × 2 factorial): 1) no inclusion or inclusion of monensin + tylosin (360 mg and 90 mg/steer daily, respectively) and 2) no inclusion or inclusion of Y. schidigera extract (4 g/steer daily). Steers were slaughtered in 3 groups balanced by treatment combination (36 steers on day 114, 36 steers on day 142, and 48 steers on day 169). Blood was sampled on days 0, 28, 56, and 84, and the day before shipping to slaughter. On day 41, eight rumen-cannulated heifers (BW = 590 ± 15 kg) were housed with steers (1 pair/pen). Pairs rotated among groups every 21 d, resulting in a replicated 4 × 4 Latin square (n = 8/treatment combination) with 14-d washout intervals. Heifers were sampled for blood and rumen fluid at the beginning and end of each 21-d period. Monensin + tylosin inclusion decreased (P < 0.01) feed intake and improved (P = 0.02) feed efficiency of steers, but did not alter (P ≥ 0.17) steer BW gain or carcass merit traits. Inclusion of Y. schidigera extract did not impact (P ≥ 0.30) steer performance and carcass characteristics. Plasma glucose, insulin, insulin-like growth factor-I, and urea-N concentrations were not affected (P ≥ 0.16) by monensin + tylosin, nor by Y. schidigera extract inclusion in steers and heifers. Ruminal pH in heifers was increased (P = 0.04) by monensin + tylosin, and also by (P = 0.03) Y. schidigera extract inclusion. Rumen fluid viscosity was reduced (P = 0.04) by Y. schidigera extract, and rumen protozoa count was increased (P < 0.01) by monensin + tylosin inclusion. The proportion of propionate in the ruminal fluid was increased (P = 0.04) by monensin + tylosin, and tended (P = 0.07) to be increased by Y. schidigera extract inclusion. Hence, Y. schidigera extract yielded similar improvements in rumen fermentation compared with monensin + tylosin, but without increasing performance and carcass quality of finishing cattle. No complimentary effects were observed when combining all these additives into the finishing diet. [ABSTRACT FROM AUTHOR]

Pyrite affects the adsorption of tylosin (TYL) due to their coexistence in the lake system. As well as the reactivity groups of S–S-H, S-OH, and Fe-OH, defects also have the possibilities to influence the adsorption of organic contaminants. However, the role of these active sites in antibiotic adsorption on pyrite has not been deeply studied. Besides, pH, N, P, dissolved oxygen, and dissolved organic matter (DOM) fluctuate greatly in lake at different seasons, which may change the surface characteristics of pyrite. Hence, the adsorption of TYL on natural pyrite considered solution chemistry and DOM in lake water was explored in this study. The fitting results of the kinetic and isotherm models showed that the adsorption included physical and chemical interactions. The neutral initial solution pH was conductive to TYL adsorption owing to the combined result of electrostatic and cover of Fe-oxyhydroxide. NO3− and NH4+ had no effect on TYL adsorption, whereas H2PO4− promoted adsorption by forming flocculent Fe(H2PO4)3 precipitates. The dissolved oxygen increased adsorption. This is due to the co-promotion of the pyrite oxidation by oxygen and sulfur defects. The Fe(II)-DOM complex caused by pyrite surface oxidation reduced the concentration of TYL in solution by gathering. Except for the surface charge, reactivity groups on pyrite significantly influenced the adsorption of TYL. The bond fracture of S–S resulted in sulfur defects that contributed to pyrite oxidation. As a result, Fe(III)/Fe(II) on the surface of pyrite or in solution produced a complex Fe(III)/Fe(II) with anions and DOM. In addition, Fe(III)-S on sulfur defects interacted with the O–H of TYL through hydrogen bonding. Furthermore, the Fe–O-C bond is formed by the interaction of C–OH on TYL and Fe(III) (hydr)oxides on the surface of pyrite. The study provides a deep insight into the effect of pyrite surface active sites on amphoteric antibiotic adsorption. It helps to understand antibiotic migration and interactions with widespread pyrite in the real environment. [ABSTRACT FROM AUTHOR]

The study was to establish a fast spectrometric method for determination of tylosin tartrate. The intensity difference of resonance light scattering spectra before and after the reaction of tylosin tartrate with cationic dye neutral red was measured by resonance light scattering spectroscopy under the condition of pH value 6.4. The results showed that when the scanning speed was 2 000 nm/min and the excitation light and emission light bandwidth were both 5.0 nm, the charge transfer reaction occurred between tylosin tartrate and the cationic dye neutral red in Clark-Lubs buffer solution, and the charge transfer complex was formed, which weakened the resonance light scattering intensity of the system. When the resonance light scattering spectrum peak of neutral red is located at 324 nm, the intensity difference of the resonance scattering spectrum of the system reaches the maximum, with a linear relationship between 0.05 and 0.60 mg/L, and the correlation coefficient R is 0.999 6. The detection limit (3 d/k) of the test method was 0.011 5 mg/L. The study indicates that the method is simple and sensitive, and can be used to determine the content of tylosin tartrate. [ABSTRACT FROM AUTHOR]

In this study, a novel ordered multistage porous carbon (OMPC) with a micro-mesoporous structure was prepared and used for the removal of tylosin (TYL). The porous material, carbonized at 900 °C (OMPC-900), exhibited micro-mesoporous structures with pore sizes of 0.71 nm and 3.63 nm, while had a specific surface area of 1300.02 m2 g−1. OMPC-900 demonstrated a maximum adsorption capacity of 341.28 mg g−1 for TYL in water by electrostatic attraction, hydrogen bonding, π-π interactions, and pore-filling mechanisms, which is 6.41 times higher than that of activated carbon. The TYL-saturated adsorbents could be efficiently regenerated by in-situ oxidation through the activation of persulfate (PDS), achieving a regeneration rate of 94.17%, significantly higher than that of activated carbon (55.22%). The excellent regeneration performance may be attributed to the presence of -C=O and graphitic carbon in the adsorbent, which promotes the production of free radicals (•OH, SO 4 •- and •O 2 −) and non-free radicals. Among these, the non-radical pathways (1O 2 and electron transfer) played a key role in the degradation of TYL loaded on the adsorbent. OMPC-900 maintained stable regenerative adsorption performance of 80.85% after five in-situ regeneration, and the normalized adsorption capacity per unit surface area increased from 0.21 to 0.39 mg m−2, which may be due to that the increase in oxygen-carbon ratio and surface defects improved the adsorption sites activity of the regenerated adsorbent. In comparison to conventional pyrolysis and organic solvent elution, oxidative regeneration through the activation of PDS is a more efficient and sustainable method. [Display omitted] • OMPC-900 with micro-mesoporous structure exhibits superior adsorption for tylosin. • Tylosin saturated adsorbent can be in-situ oxidative regeneration by persulfate. • Effective and stable in-situ oxidative regeneration of saturated adsorbents. • 1O 2 and electron transfer played a key role in the in-situ regeneration. • Increasing surface defects and oxygen/carbon ratio lead to stable regeneration. [ABSTRACT FROM AUTHOR]

Liver abscesses (LA) pose a significant challenge to the Canadian beef industry as they are estimated to cost the industry ~ $61.2 million annually. This is likely an underestimate as it does not account for losses in animal productivity. Tylosin phosphate is widely used to reduce LA, but concerns over antimicrobial use selecting for antimicrobial resistance has created an urgency to explore alternative approaches. Understanding the impact of tylosin on the microbial ecology of LA is crucial to this. We hypothesized that altering the duration of in-feed administration of tylosin to feedlot cattle would alter the microbial community of LA. To investigate this, we collected abscessed livers from cattle fed a diet containing tylosin 1) throughout finishing, 2) during the first 78% of the feeding or 3) during the last 75% of the feeding period. We examined LA microbial ecology of purulent material, abscess capsule tissue, originating from abscesses of different sizes using a metataxonomic approach. Our findings revealed that shortening tylosin administration did not notably alter the alpha (P > 0.05) or beta-diversity (P > 0.05) of LA microbial communities. There was a significant difference in microbial richness associated with abscess capsule (P < 0.05) compared with bulk purulent material. Fusobacterium or Bacteroides ASVs dominated LA microbiomes, alongside probable opportunistic gut pathogens and other bacteria. Interestingly, classifying samples based on whether they originated from a liver with a single abscess, multiple abscesses or a very large abscess tended to differ in microbiome composition (P = 0.06). These insights contribute to our understanding of factors impacting liver abscess microbial ecology and will be valuable in identifying antibiotic alternatives. They underscore the importance of exploring varied approaches to address liver abscesses while reducing reliance on in-feed antibiotics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Smartphone-assisted portable biosensor for rapid and visualized detection of TYL. • Bimetallic CoMn-ZIF derived electroactive layered double hydroxide (CoMn-LDH) • High specific surface area, electrochemical activity, and affinity toward antibody. • Ultralow limit of detection, good practicality toward TYL in diverse real samples. The precise and rapid analysis of antibiotics containing in food stuffs is essential for guaranteeing the safety of food products and drinking water. Thus, the sensitive determination of antibiotics is highly urgent. Herein, CoMn-LDH derived from bimetallic CoMn-ZIF was utilized as the sensitive material and ink for modifying the screen-printed electrode (SPE) to manufacture the visualized amperometric immunosensor to detect tylosin (TYL) with the smartphone assistance. Benefiting to the features of CoMn-ZIF, the achieved CoMn-LDH exhibited large specific surface area and pore size, abundant oxygen vacancies, rich and exposed metal sites, high functionality, and core–shell nanostructure with thin shell thickness. Thus, CoMn-LDH illustrated the high adhesive force with the SPE, the improved affinity toward the TYL-targeted antibody and fast electronic response. Thereby, the manufactured CoMn-LDH-based amperometric immunosensor displayed the wide linear range from 1.0 fg mL−1 to 1.0 ng mL−1 with an ultralow detection limit of 0.89 fg mL−1 toward TYL. Also, the developed amperometric immunosensor has demonstrated the good sensing ability of high selectivity, good reproducibility and stability, and accepted regenerated performance, as well as the great potential for the electronic visualized analysis of TYL containing in diverse real samples. This work has provided a new amperometric immunosensing strategy for the efficient analysis of antibiotics in food samples through the visual way. [ABSTRACT FROM AUTHOR]

• No compensation of anodic H + with cathodic OH− at 50 µm at sufficiently high current. • Short distance (50 µm) could lead to high degradation yield with higher current. • With 50 µm, it still required higher energy to reach similar degradation efficiency. • A distance of 500 µm led to higher degradation, lower scaling and chlorate formation. The influence of a range of inter-electrode distances from 50 µm to 1 mm has been investigated for the first time, in order to assess to possibility to maximize the degradation and mineralization efficiency, while minimizing the cathode scaling and the inorganic by-products formation. Tylosin has been selected as representative pharmaceutical pollutant in wastewater, while the influence of Ca2+, HCO 3 −/CO 3 2− and Cl− was carried out. Advanced electro-oxidation with boron-doped diamond (BDD) anode and stainless-steel cathode was implemented to treat this synthetic effluent in a scalable filter-press reactor operated in a recirculated batch flow-by mode. The first interesting feature is that cathodic OH− and anodic H+ formations were not counterbalanced at short micro-distances (50 µm), meaning that electro-precipitation (until 50 % of CaCO 3 precipitation) and degradation/mineralization (until 100 %) could still occur at such range of distance. Secondly, the gain of mass transfer at the shorter distance (50 µm) couldn't counteract the higher energy needed to achieve similar degradation efficiency compared to the distances of 500 µm and 1 mm. Lastly, too high distances such as 1 mm suffer from lower mass transfer compared to sub-millimetric distances. Thus, an intermediate distance of 500 µm led to better performance in terms of tylosin degradation (100 % of degradation, 39 % of mineralization), while minimizing electro-precipitation (26 % of CaCO 3 cathodic precipitation) and unwanted inorganic chlorinated by-products formation (ClO 3 − = 2.8 mg L−1). This was obtained at a current density of 0.1 mA cm−2, leading to lower energy requirement (0.018 kWh g-tylosin−1). In these low-current conditions the formation of perchlorate could be avoided. [ABSTRACT FROM AUTHOR]

The removal of antibiotics from wastewater to prevent their environmental accumulation is significant for human health and ecosystems. Herein, iron (Fe)-atom-doped anatase TiO2 nanofibers (Fe-TNs) were manufactured for the photocatalytic Fenton-like decomposition of tylosin (TYL) under LED illumination. Compared with the pristine TiO2 nanofibers (TNs), the optimized Fe-TNs exhibited improved visible-light-driven photocatalytic Fenton-like activity with a TYL degradation efficiency of 98.5% within 4 h. The effective TYL degradation could be attributed to the expanded optical light absorption and accelerated separation and migration of photogenerated electrons and holes after the introduction of Fe. The photogenerated electrons were highly conducive to the generation of active SO4•− radicals as they facilitated Fe(III)/Fe(II) cycles, and to oxidizing TYL. Moreover, the holes could be involved in TYL degradation. Thus, a significant enhancement in TYL degradation could be achieved. This research verifies the use of iron-doped anatase nanofibers as an effective method to synthesize novel photocatalytic Fenton-like catalysts through surface engineering for wastewater remediation.

The aim of this study was to evaluate the in vitro cytotoxicity of different concentrations of macrolide antibiotics (tilmicosin-TILM, tylosin-TYL and spiramycin-SPI) on selected animal cell cultures. VERO cells (kidney cells from Macacus rhesus), FE cells (feline embryonal cells) and BHK 21 cells (cell line from young hamster kidneys) were used in the study and subjected to 50-1000 µg/mL macrolides, depending on the specific antibiotic and cell line. The cell viability was assessed using the metabolic mitochondrial MTT test. FE cells were the most sensitive to TILM with a significant decrease of viability at 100-150 µg/mL (P

Streptomyces fradiae sf106 is a type of actinomycete that can produce abundant secondary metabolites, making it a natural cell factory for drug synthesis. In order to comprehensively understand the genomic profile of Streptomyces fradiae sf106 and its potential for producing secondary metabolites, a combination of several methods was used to perform whole-genome sequencing of sf106. The results showed that sf106 is most closely related to Streptomyces xinghaiensis S187; the average nucleotide identity and average amino acid identity of sf106 and S187 were more than 96%. The genome size of sf106 is approximately 7300 kb, the GC content is greater than 72%, and more than 6700 coding sequences (CDS) were identified. Analysis of mobile genetic elements revealed the presence of a large number of horizontally transferred genes in Streptomyces fradiae sf106, which contribute to microbial diversity. Through antiSMASH prediction, 22 secondary metabolite gene clusters were obtained, which had great potential to generate polyketide metabolites. By examining the data, it was found that the genes contained in cluster 9 were similar to those involved in tylosin synthesis. Non-targeted metabolome sequencing revealed that a total of 1855 identifiable metabolites were produced in the fermentation broth, and the majority of metabolites showed highly significant differences in mean relative abundance between the groups. The identified metabolites were compared against the KEGG compound database to obtain metabolite classifications, mainly including Biological Roles, Phytochemical Compounds, Lipids, and Pesticides. One-way ANOVA indicated that the relative concentration of tylosin differed significantly across all the growth periods, except for the late-logarithmic and stabilization stages. This study provides important basic information on the secondary metabolite research of sf106, which will help us to understand and apply Streptomyces fradiae sf106 more comprehensively.

Abstract Background Similar to many other animals, the honey bee Apis mellifera relies on a beneficial gut microbiota for regulation of immune homeostasis. Honey bees exposed to agrochemicals, such as the herbicide glyphosate or antibiotics, usually exhibit dysbiosis and increased susceptibility to bacterial infection. Considering the relevance of the microbiota–immunity axis for host health, we hypothesized that glyphosate exposure could potentially affect other components of the honey bee physiology, such as the immune system. Results In this study, we investigated whether glyphosate, besides affecting the gut microbiota, could compromise two components of honey bee innate immunity: the expression of genes encoding antimicrobial peptides (humoral immunity) and the melanization pathway (cellular immunity). We also compared the effects of glyphosate on the bee immune system with those of tylosin, an antibiotic commonly used in beekeeping. We found that both glyphosate and tylosin decreased the expression of some antimicrobial peptides, such as apidaecin, defensin and hymenoptaecin, in exposed honey bees, but only glyphosate was able to inhibit melanization in the bee hemolymph. Conclusions Exposure of honey bees to glyphosate or tylosin can reduce the abundance of beneficial gut bacteria and lead to immune dysregulation.

A modified QuEChERS method was developed for the simultaneous analysis of tylosin (Tyl) and metronidazole (MNZ) residues in shrimp samples using LC-ESI-MS/MS. The sample extraction procedure was based on modified QuEChERS, and the cleanup method was dispersive solid-phase extraction (dSPE). Octadecyl (C18) and primary secondary amine (PSA) sorbents were used in the dSPE cleanup. Analyte chromatographic separations were carried out using a ZORBAX RRHD Eclipse Plus C18 (100 × 2.1 mm, particle size 1.8 μm) column. The mobile phase consisted of dilluting 0.1% of formic acid with water and acetonitrile. The analyte was identified with multiple reaction monitoring and positive electrospray ionization. The analyte showed good linearity in the range of 0.5–50 μg/L for both analytes, and correlation coefficients (R2) were 0.9997 and 0.9998 for Tyl and MNZ, respectively. For the recovery study, three different concentration levels were spiked in triplicate. The recovery obtained a good result in the range of 81–85 % for Tyl with relative standard deviation (RSD) ≤ ± 4.9% and in the range of 85–88% for MNZ with RSD ≤ ± 4.07 %. The limit of detection (LOD) was estimated at 0.4 μg/kg for Tyl and 0.3 μg/kg for MNZ, and the limit of quantification (LOQ) was estimated at 1 μg/kg for Tyl and 0.9 μg/kg for MNZ. The linearity and recovery study showed that the method is validated and can be used to determine the Tyl and MNZ residues in shrimp. Finally, the method was applied to 25 real samples, which were collected from local markets and super shops in Dhaka and Khulna districts of Bangladesh, and only traces of Tyl were detected in one sample. This method is suitable for the regular analysis of Tyl and MNZ antibiotic residues in shrimp samples and can be used to ensure food safety in Bangladesh.

Although many antibiotics are active against Gram-positive bacteria, fewer also show activity against Gram-negative bacteria. Here, we present a combination of in silico (electron ion-interaction potential, molecular docking, ADMET), NMR, and microbiological investigations of selected macrolides (14-membered, 15-membered, and 16-membered), aiming to discover the pattern of design for macrolides active against Gram-negative bacteria. Although the conformational studies of 14-membered and 15-membered macrolides are abundant in the literature, 16-membered macrolides, and their most prominent representative tylosin A, have received relatively little research attention. We therefore report the complete 1H and 13C NMR assignment of tylosin A in deuterated chloroform, as well as its 3D solution structure determined through molecular modelling (conformational search) and 2D ROESY NMR. Additionally, due to the degradation of tylosin A in deuterated chloroform, other species were also detected in 1D and 2D NMR spectra. We additionally studied the anti-bacterial activity of tylosin A and B against selected Gram-positive and Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

American foulbrood (AFB) is a honeybee disease caused by Paenibacillus larvae, and tylosin is used as the prophylactic in Japan. Honey contains macrolide-resistant bacteria that are a potential source of genes that may confer tylosin resistance to P. larvae. To investigate the potential risk of such genes in Japanese honey, we developed real-time PCR assays for the detection of important macrolide resistance genes, ermC and ermB, and analyzed 116 Japanese honey samples with known contamination status of P. larvae. Consequently, 91.38% of samples contained ermC and/or ermB, and 71.55% of samples contained both ermC and P. larvae, suggesting the possible emergence of tylosin-resistant P. larvae in Japan. Therefore, judicious use of the prophylactic is essential in maintaining its effectiveness. [ABSTRACT FROM AUTHOR]

The Zn,Co bimetallic organic skeleton material ZIF-11(Zn/Co) with different molar ratios was synthesized at room temperature by a one-pot method as a catalyst for the activation of persulfate (PMS) degradation of tylosin (TYL). By comparing the experimental systems of ZIF-11, ZIF-11(Zn/Co)-2, persulfate, and ZIF-11(Zn/Co)-2/PMS, the experimental system with the best effect was selected for subsequent research. X-Ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and specific surface area and porosity analyses were used to describe and characterize the properties of the catalysts. A certain concentration of TYL solution was chosen as the experimental sample, and the pollutant concentration, pH, catalyst dosage, persulfate dosage and reaction temperature were used as the experimental conditions. The influence factors of catalytic removal of TYL by ZIF-11(Zn/Co)-2/PMS were studied. The specific mechanism of catalytic degradation of TYL was investigated using the results of free radical quenching experiments. The results showed that, under acidic conditions and at higher temperatures, the removal rate of bimetal ZIF-11(Zn/Co)-2 to TYL (40 mg L−1) within 30 min reaches more than 80%. Experiments showed that the catalyst has good reusability. According to the data analysis after the addition of a free radical quenching agent in the experimental process, it can be seen that the sulfate free radical plays a leading role in the entire experimental system. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the efficacy of macrolides to eliminate intramammary infection (IMI) caused by Staphylococcus aureus (S. aureus) and Streptoccus spp. 3 weeks before calving time. Eighty Holstein dairy cows with subclinical mastitis pathogens were divided into three groups. Three weeks before expected parturition time, cows in group 1 received tilmicosin (n = 29), cows in group 2 received tylosin (n = 30) and cows in group 3 were left as negative control (n = 21). Milk samples were obtained on 3 and 7 days after calving. Randomly amplified polymorphic DNA (RAPD) method was determined for all of the S. aureus isolates that had the same isolates before and after parturition. The total cure rate was 63.33, 75.86 and 66.66% for tylosin, tilmicosin and control groups, respectively. Furthermore, cure rates were not significant, when each type of mastitis causing pathogens were considered separately. The incidence of clinical mastitis during 60 days after calving for tylosin, tilmicosin and Control groups was 23.33, 27.58 and 38.09%, respectively. Only four S. aureus isolated before drying-off were similar to post-calving isolate, according to RAPD-PCR method. In conclusion, antibiotic therapy before calving improved the cure rate numerically, however, it was not significant. [ABSTRACT FROM AUTHOR]

Purpose: Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs. Strains that are resistant to multiple drugs pose severe clinical problems and cost lives. However, systematic studies on cross-resistance of Staphylococcus xylosus have been missing. Methods: Here, we investigated various mutations in the sequence of ribosomal proteins involved in cross-resistance. To understand this effect on a molecular basis and to further elucidate the role of cross-resistance, we computationally constructed the 3D model of the large ribosomal subunit from S. xylosus as well as its complexes with both tylosin and florfenicol. Meanwhile, all-atom molecular dynamics simulations was used. In addition, the regulation of protein networks also played an essential role in the development of cross-resistance in S. xylosus. Results: We discovered that the minimum inhibitory concentration against both tylosin and florfenicol of the mutant strain containing the insertion L22 97KRTSAIN98 changed dramatically. Further, we found that unique structural changes in the β-hairpin of L22 played a central role in this variant in the development of antibiotic resistance in S. xylosus. The regulation of protein networks also played an essential role in the development of cross-resistance in S. xylosus. Conclusion: Our work provides insightful views into the mechanism of S. xylosus resistance that could be useful for the development of the next generation of antibiotics. [ABSTRACT FROM AUTHOR]

There is currently almost no poultry holding where avian eimerioses, both monoinvasions and those associated with cryptosporidioses, salmonelloses and colibacte- rioses, are not reported. In view of this, the disease control is an urgent challenge that shall be approached in its entirety, using various eimeriostats, antibiotics and probiotics. Searching for new effective products with broad-spectrum antiparasitic action is one of priorities in avian eimeriosis control. Comparative tests of different combinations of eimeriocidal products, namely solicox + chicktonic, maduvet + tylosin and eimeterm + enrofloxacin, for their treatment and protective effectiveness were carried out under production conditions in broiler chickens of a poultry factory located in the Republic of Dagestan. To perform the tests, four groups of broiler chickens (one control group and three test groups, each comprising 50 chickens) were formed based on the principle of analogues. The treatment and prevention scheme adopted in the said poultry holding was used for the control group chickens. Test group 1 chickens were given solicox at a dose of 2 ml per 1 liter of drinking water in combination with chicktonic (a feed supplement) at a dose of 1 ml per 1 liter of water during 4–5 days. Group 2 chickens were given maduvet at a dose of 3−5 mg/kg of body weight with feed twice and tylosin at a dose of 5 g of powder per 10 liters of water once a day during 5 days; where necessary, the procedure was repeated in 14–16 days. Group 3 broiler chickens were given eimeterm 2.5% at a dose of 7 mg/kg of body weight with water during 2 days in combination with enrofloxacin at a dose of 3 ml per 1 liter of drinking water during 5–6 days. It is shown that a decrease in the number of clinically diseased and dead chickens was observed in the test groups after the use of eimeriocidal products that helped to improve zootechnical parameters of reared broiler chicks. Product extenseffectiveness and intens- effectiveness in different groups of chickens were as follows: Group 1 – 89.2 and 96%, Group 2 – 87.6 and 94%, Group 3 –81.4 and 96%, respectively. The clinical signs of eimeriosis were observed in the control group chickens throughout the entire period of studies, invasion extensity and intensity were 87.6 and 42.6%, respectively.

Liposomes are the most attractive and well-known nanoparticles due to their high biocompatibility and biodegradability features which make them display less toxic effects for employing in vivo. Encapsulation of antibiotics within liposomes can provide a promising strategy for the effective treatment of resistant bacterial pathogens. This research was performed to prepare, characterize and evaluate the in vitro cytotoxicity effect of free and liposomal tylosin. Liposomal tylosin was produced by the thin-film hydration method. The characterization was performed by dynamic light scattering and high resolution transmission electron microscopy. Methylthiazol tetrazolium (MTT) assay was applied to evaluate the cytotoxicity of free and liposome-encapsulated tylosin against the NIH3T3 and NHDF. The obtained findings indicated well-formed liposome with ideal characteristics that efficiently encapsulated tylosin. The cytotoxicity data revealed cell viability of above 70% for liposomal tylosin and below 70% for free tylosin towards both NIH3T3 and NHDF at concentration of 1024 µg/mL. Therefore, liposome is a promising vehicle for an antibiotic delivery system with appropriate physicochemical, drug loading, release characteristics, and ideal biocompatibility properties.

Employing affordable and uncomplicated sample preparation techniques to recommend the most efficient antibacterial therapy could help reduce antibiotic-resistant bacteria. This study evaluated the suitability of immunoassays and microbiological assays as alternatives for liquid chromatography/mass spectrometry (LC/MS) in determining plasma tylosin concentrations after intramuscular administration at a dose of 20 mg/kg to both healthy and diseased pigs in clinical veterinary practice. The diseased pigs were confirmed using the target genes Actinobacillus pleuropneumoniae (apxIVA) and Pasteurella multocida (kmt1). The methods showed good linearity, precision, and accuracy. In both healthy and diseased pigs, a significant correlation was observed between LC/MS and the microbiological assay (Pearson correlation coefficient: 0.930, p < 0.001 vs. Pearson correlation coefficient: 0.950, p < 0.001) and between LC/MS and the enzyme-linked immunosorbent assay (ELISA) (Pearson correlation coefficient: 0.933; p < 0.001 vs. Pearson correlation coefficient: 0.976, p < 0.001). A strong correlation was observed between the microbiological assay and the ELISA in both healthy and diseased pigs (Pearson correlation coefficient: 0.911; p < 0.001 vs. Pearson correlation coefficient: 0.908, p < 0.001). A Bland-Altman analysis revealed good agreement between the methods, i.e., 95% of the differences were within the limits of agreement. Therefore, the microbiological assay and the ELISA, which demonstrated sufficient precision and accuracy, can be viable alternatives to LC/MS when it is unavailable.

Dehydrated wheat bran (DWB) prepared from wheat bran, has been used as adsorbent for Tylosin removal from aqueous solution. DWB was characterized by Fourier transform infra-Red (FT-IR), scanning electron microscopy and energy dispersive X-ray analysis (EDX). The response surface methodology (RSM) based on central composite design (CCD) was used to evaluate and optimize the effect of four parameters, including pH, DWB concentration, Tylosin (TYL) initial concentration and time of adsorption as independent variables on the adsorption removal efficiency (R %) as the response function. The optimal interaction parameters and conditions were obtained by using the MODDE 06® software. The optimal values of the operation parameters under the related constraint conditions were found at pH 5.05, DWB concentration of 0.86 g L−1, TYL initial concentration of 14.27 mg L−1, in a period time of 111 min, respectively. Under the optimized conditions, the removal efficiency of TYL approached 93.1%. Adsorption isotherm was used to interpret the process of TYL adsorption on DWB, Timken and Langmuir models were the most accurate to fit experimental data. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data. The pseudo-second-order kinetic model provided the best fitting to the experimental data. The mechanism of the adsorption process was determined from the intraparticle diffusion model. The thermodynamic parameters as ΔH° and ΔS° were calculated and the adsorption process was found to be spontaneous and exothermic. [ABSTRACT FROM AUTHOR]

Background: Antibiotic‐responsive enteropathy (ARE) is diagnosed by excluding other causes of diarrhea and when there is a short‐term response to administration of antibiotics. Objectives: To characterize the gut microbiota and clinical trend of dogs with suspected ARE and to evaluate the variation in microbiota before (T0), after 30 days (T30) of tylosin treatment, and 30 days after discontinuation of treatment (T60). A further objective was to evaluate whether changes in gut microbiota are related to relapses of diarrhea when the therapy is tapered. Animals: Study sample (group A) was composed of 15 dogs with chronic diarrhea, group B was composed of 15 healthy dogs. Group A was given tylosin for 30 days. Methods: A multicentric prospective study. Clinical Indexes, fecal score, and samples for microbiota analysis were collected at T0, T30, and T60 in group A and T0 and T30 in group B. The gut microbiota was analyzed via 16S ribosomal RNA gene. Qiime2 version 2020.2 was used to perform bioinformatic analyses, and Alpha‐ and Beta‐diversity were computed. Results: Diarrhea recurred after T30 in 9 of 14 dogs, which were classified as affected by ARE. At T0, a difference was noted in the beta‐diversity between groups (Bray Curtis metric P =.006). A T0‐T30 difference in alpha‐diversity was noted in group A (Shannon index P =.001, Faith PD P =.007). Conclusions and Clinical Importance: Although tylosin influences the microbiota of dogs with ARE, we failed to find any specific characteristic in the microbiota of dogs with ARE. [ABSTRACT FROM AUTHOR]

Antibiotics cause gut dysbiosis and bile acid dysmetabolism in dogs. The effect of fecal microbiota transplantation (FMT) on microbiome and metabolome recovery is unknown. This prospective, randomized, placebo-controlled study included sixteen healthy purpose-bred dogs. All dogs received tylosin 20 mg/kg PO once daily (days 1–7) and were randomly assigned to either receive one FMT via enema (day 8), daily oral FMT capsules (days 8–21), or daily placebo capsules (days 8–21). Fecal samples were frozen at regular intervals until day 42. Quantitative PCR for 8 bacterial taxa was performed to calculate the fecal dysbiosis index (FDI) and fecal concentrations of unconjugated bile acids (UBA) were measured using gas chromatography-mass spectrometry. Tylosin altered the abundance of most evaluated bacteria and induced a significant decrease in secondary bile acid concentrations at day 7 in all dogs. However, most parameters returned to their baseline by day 14 in all dogs. In conclusion, tylosin markedly impacted fecal microbiota and bile acid concentrations, although return to baseline values was quick after the antibiotic was discontinued. Overall, FMT did not accelerate recovery of measured parameters. Further studies are warranted to confirm the value of FMT in accelerating microbiota recovery in antibiotic-associated dysbiosis in dogs. [ABSTRACT FROM AUTHOR]

The veterinary 16-membered macrolide antibiotics tylosin (HTyl, 1a) and tilmicosin (HTilm, 1b) react with copper(II) ions in acetone at metal-to-ligand molar ratio of 1:2 to form blue (2) or green (3) metal(II) coordination species, containing nitrate or chloride anions, respectively. The complexation processes and the properties of 2–3 were studied by an assortment of physicochemical techniques (UV-Vis, EPR, NMR, FTIR, elemental analysis). The experimental data revealed that the main portion of copper(II) ions are bound as neutral EPR-silent dinuclear complexes of composition [Cu2(µ-NO3)2L2] (2a–b) and [Cu2(µ-Cl)2Cl2(HL)2] (3a–b), containing impurities of EPR-active mono-species [Cu(NO3)L] (2a'–b') and [CuCl2(HL)] (3a'–b'). The possible structural variants of the dinuclear- and mono-complexes were modeled by the DFT method, and the computed spectroscopic parameters of the optimized constructs were compared to those measured experimentally. Using such a combined approach, the main coordination unit of the macrolides, involved in the complex formation, was defined to be their mycaminosyl substituent, which acts as a terminal ligand in a bidentate mode through the tertiary nitrogen atom and the oxygen from a deprotonated (2) or non-dissociated (3) hydroxyl group, respectively. [ABSTRACT FROM AUTHOR]

Background: Ribosome stalling on ermBL at the tenth codon (Asp) and mRNA stabilization are believed to be mechanisms by which erythromycin (Ery) induces ermB expression. Expression of ermB is also induced by 16-membered ring macrolides (tylosin, josamycin and spiramycin), but the mechanism underlying this induction is unknown. Methods: We introduced premature termination codons, alanine-scanning mutagenesis and amino acid mutations in ermBL and ermBL2. Results: In this paper, we demonstrated that 16-membered ring macrolides can induce ermB expression but not ermC expression. The truncated mutants of the ermB-coding sequence indicate that the regulatory regions of ermB whose expression is induced by Ery and 16-membered ring macrolides are different. We proved that translation of the N-terminal region of ermBL is key for the induction of ermB expression by Ery, spiramycin (Spi) and tylosin (Tyl). We also demonstrated that ermBL2 is critical for the induction of ermB expression by erythromycin but not by 16-membered ring macrolides. Conclusions: The translation of ermBL and the RNA sequence of the C-terminus of ermBL are critical for the induction of ermB expression by Spi and Tyl. [ABSTRACT FROM AUTHOR]

Tylosin eliminated in animal waste, during therapeutic treatment, can be efficiently removed in anaerobic systems. The present study investigated the influence of tylosin concentration and assessed its degradation kinetics and the microorganisms involved in each stage of its anaerobic digestion (hydrolysis/acidogenesis; acetogenesis; methanogenesis). The results showed a stimulating effect on methane production with increasing tylosin concentration in the poultry litter up to 80 mg kg−1 tylosin (232.9 NL CH4 kg SV−1). As for tylosin degradation, greater removal of antibiotics was observed in the methanogenic phase (88%), followed by acetogenic (84%) and hydrolytic/acidogenic (76%) phases. The higher rate of tylosin degradation obtained in the methanogenic step, is mainly related to the co-metabolic effect exerted by the presence of acetate and its degradation by acetoclastic methanogens. Indeed, metagenomic analyses suggested a syntrophic action between archaea of ​​the genus Methanobacterium, and bacteria such as Clostridium and Flexilinea, which seemed decisive for tylosin degradation. [ABSTRACT FROM AUTHOR]

Antibiotics growth promotors (AGPs) are used for enhancing the growth performance and to reduce harmful effects of bacteria in broiler chicken. These anti-microbial agents are capable of destroying the metabolism of microbes and can alter certain properties of bacterial cellular and metabolic activity which results in impaired growth or death of these bacteria. This study was planned to find out the effect of AGPs in broiler chicken. For the purpose one day old (n=432) broiler chicks were used in the experiment. Nine groups comprising of 48 chicks with 3 replicates of sixteen broiler chicks each were formed for the trial. Control group was kept on basal diet. AGPs (Oxytetracycline and Tylosin phosphate) were supplemented solely and in combinations with different concentration. Chicks were reared in floor pens bedded with saw dust litter, optimal husbandry conditions for broiler rearing were provided to the birds and vaccinations against Newcastle disease and Infectious bursal disease (IBD) were done at 9th, 19th and 11th, 23rd day, respectively. The results of current study revealed that there was non-significant difference (P>0.05) among treatment groups in feed intake and relative visceral organ weight. Whereas, a significant difference between control and AGPs supplemented groups (solely or combination) were noted in weight gain (WG), feed conversion ratio (FCR) and average daily weight gain (ADWG). Use of AGPs in combinations of OXY-1.0+TP-0.5, OXY-2.0+TP-1.0, OXY-2.0+TP-0.5, OXY-1.0+TP-1.0 had a non-significant difference (P>0.05) for WG, FCR and ADG in starter, finisher and overall rearing phases. However a significant difference (P<0.05) was observed with other groups. It can be concluded from the results of this study that supplementation of antibiotics used in broiler chicks at sub-therapeutic level is beneficial for growth performance parameters. [ABSTRACT FROM AUTHOR]

Background and Aim: Transfer of antibiotics from raw milk to derived products is directly related to the processes involved in the manufacturing of dairy products, including East Mediterranean cheeses, since these have particular flow diagrams of production. The aim of this study was to assess the effects of skimming, pasteurization, curding, pressing, salting, cheese boiling, and whey acidification/heating on two widely used antibiotics in Lebanon, oxytetracycline (OTC) and tylosin (TYL), in the manufacture of commonly consumed cheeses in the East Mediterranean. Materials and Methods: Four hundred and fifty kilograms of full-fat bovine milk were spiked with OTC and TYL, then skimmed and pasteurized using holder and high-temperature short-time (HTST) methods. Milk was then processed to make cheeses (23 kg Baladi, 20 kg Akkawi, 20 kg Halloum, and 18 kg Double Cream). Liquid chromatography–mass-spectrometry was used to measure antibiotics. Analysis was performed using Statistical Package for the Social Sciences v25. Results: Skimming significantly (p=0.015) decreased TYL concentration by 68.6%. OTC degradation during holder (41- 54%) proved to be significant (p=0.015). HTST had a significant (p=0.012) effect on TYL with 32% degradation. Curding step in making Baladi had a significant (p=0.028) effect on OTC only with the concentration increasing by 1.5-fold. Acidification and heating of whey to produce Double Cream decreased significantly (p=0.037) OTC concentration (14.7- 46.3%), while TYL concentration increased significantly (p=0.000) by 300%. Pressing and salting in making Akkawi did not have any significant effect, while cheese boiling in making Halloum significantly decreased both antibiotics. Conclusion: OTC is transferred to Baladi and Akkawi (curd based) mainly, while double cream (whey based) has a high level of TYL transfer. Hence, people who consume these cheeses excessively could be exposed to high amounts of both antibiotics and thus be prone to their detrimental effect on health.

Livestock wastewater reused in farmland may cause tylosin to stay in farmland soil. Under the influence of some factors, such as irrigation and fertilization, tylosin may desorb and diffuse into the water environment. Batch adsorption experiments and soil column flooding experiments were set up to investigate the effects of several cations and iron reduction on the adsorption, desorption and oxidation removal of tylosin in iron-rich farmland soils (red soil). The results showed that tylosin can be adsorbed by the red soil. The coexistence of these cations significantly reduced its adsorption capacity. The order of influence was as follows: Ca2+ > Mg2+ > K+ > > Na+. This means that some agricultural farming measures, such as the application of chemical fertilizers, would release the adsorbed tylosin into the farmland. Anaerobic iron reduction and massive production of ferrous ions did not affect the adsorption and desorption of tylosin in the red soil column. Moreover, the ferrous iron could activate persulfate to generate hydroxyl radicals and sulfate radicals which oxidized and removed the tylosin adsorbed in the soil column. Therefore, the iron reduction that occurred during flooding was not a factor causing tylosin release, which provided a way for tylosin in iron-rich farmland soils to be oxidized and removed. HIGHLIGHTS All of Ca2+, Mg2+, K+, and Na+ significantly reduced the tylosin adsorption capacity.; The iron reduction did not affect the adsorption and desorption.; Persulfate largely removed the tylosin adsorbed in red soil pretreated by iron reduction.; The Fe2+ from iron reduction could activate persulfate to generate free radicals.; Horizontal flow constructed wetland (HSCW) assisted by persulfate has the potential to remove antibiotics from livestock wastewater.;

• Theoretical investigation on the noncovalent MIPs used in aqueous environment. • A modified suspension polymerization was proposed to synthesize 2,4- d -MIP. • 2,4- d -MIP has high adsorption capacity, excellent selectivity and reusability. • 2,4- d -MIP shows strong anti-protein adsorption in aqueous environment. Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4- d -imprinted polymer (2,4- d -MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4- d -MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4- d -MIP (97.75 mg g −1) was considerably higher than those of phenoxyacetic acid (35.77 mg g −1), chlorogenic acid (9.72 mg g −1), spiramycin (1.56 mg g −1) and tylosin (1.67 mg g −1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • MP fermentation was more effective at removing ARGs, especially MP2. • The dominant function of bacteria was nitrogen degradation by secreted proteases. • The uniform fermentation environment in MP2 promoted the removal of ARB and MGEs. • Antioxidant enzymes secreted by Bacillus may inhibit the horizontal transfer of ARGs. To mitigate the environmental risks posed by the accumulation of antibiotic mycelial dregs (AMDs), this study first attempted over 200 tons of mass production fermentation (MP) using tylosin and spectinomycin mycelial dregs alongside pilot-scale fermentation (PS) for comparison, utilizing the integrated-omics and qPCR approaches. Co-fermentation results showed that both antibiotics were effectively removed in all treatments, with an average removal rate of 92%. Antibiotic resistance gene (ARG)-related metabolic pathways showed that rapid degradation of antibiotics was associated with enzymes that inactivate macrolides and aminoglycosides (e.g., K06979, K07027, K05593). Interestingly, MP fermentations with optimized conditions had more efficient ARGs removal because homogenization permitted faster microbial succession, with more stable removal of antibiotic resistant bacteria and mobile genetic elements. Moreover, Bacillus reached 75% and secreted antioxidant enzymes that might inhibit horizontal gene transfer of ARGs. The findings confirmed the advantages of MP fermentation and provided a scientific basis for other AMDs. [ABSTRACT FROM AUTHOR]

Liver abscesses (LAs) are extremely prevalent in cattle and result in significant economic losses due to liver condemnation, decreased growth and production, and lower carcass quality. LAs are commonly attributed to the transition to diets high in rapidly fermentable starch which results in rumen epithelial inflammation that allows pathogenic bacteria to gain entry to liver through transport via the hepatic portal vein. The most common intervention for LAs is the inclusion of antibiotics in feedlot diets, under the supervision of a veterinarian; this treatment is associated with reduced occurrence of LAs in this and other studies. Here, through the largest LA 16S rRNA gene sequencing study to date, we demonstrate that the inclusion of tylosin and antibiotic alternatives (the essential oil limonene and Saccharomyces cerevisiae fermentation product) had little impact on LA microbial community composition. Importantly, members of Bacteroidetes (Bacteroides spp. and Porphyromonas spp.) were identified as the dominant taxa in conjunction with low proportions of Fusobacteria in nearly a quarter (61/259) of all LA communities analyzed in this study. The relative abundances of the phyla Fusobacteria and Bacteroidetes had a strongly negative correlation, and LA microbial communities rarely contained high abundances of both of these dominant phyla. Further, based on the presence of taxa discriminant of Bacteroidetes-dominated LAs within over 400 bovine gut communities, we provide evidence suggestive of Bacteroidetes-dominated abscess communities originating in more distal portions of the bovine gut. Together, these findings suggest that some LA microbial communities may originate from portions of the gut other than the rumen. [ABSTRACT FROM AUTHOR]

Two model algae, Chlorella vulgaris (C. vulgaris) and Raphidocelis subcapitata (R. subcapitata), are commonly used in registration procedures to evaluate compounds with antimicrobial capacity. However, it has been found that these two algae show considerable differences in sensitivity when exposed to antibiotics. The selection of a suitable test species plays a crucial role in assessing the environmental hazards and risks of a compound, as the balance between oxidative stress and antioxidants is a key factor for alga growth. This study was conducted to investigate the status of oxidative stress and mechanism of antioxidant defense system of algae under antibiotic stress. Different tylosin (TYN) exposure—concentrations were used for the tests in this study. Oxidative stress biomarkers (malondialdehyde (MDA)), non-enzymatic antioxidants (reduced glutathione (GSH)), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GP), glutathione S-transferase (GST)) and photosynthetic pigments were measured to determine the status of the antioxidant defense system. With increasing TYN concentration, the growth of R. subcapitata was significantly inhibited, while there was no effect on C. vulgaris. When the growth of R. subcapitata was inhibited, the content of MDA was significantly increased and the antioxidant system was activated, which indicated a significant increase in the activity of SOD and CAT. [ABSTRACT FROM AUTHOR]

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Tylosin [ABSTRACT FROM AUTHOR]

Background: Similar to many other animals, the honey bee Apis mellifera relies on a beneficial gut microbiota for regulation of immune homeostasis. Honey bees exposed to agrochemicals, such as the herbicide glyphosate or antibiotics, usually exhibit dysbiosis and increased susceptibility to bacterial infection. Considering the relevance of the microbiota–immunity axis for host health, we hypothesized that glyphosate exposure could potentially affect other components of the honey bee physiology, such as the immune system. Results: In this study, we investigated whether glyphosate, besides affecting the gut microbiota, could compromise two components of honey bee innate immunity: the expression of genes encoding antimicrobial peptides (humoral immunity) and the melanization pathway (cellular immunity). We also compared the effects of glyphosate on the bee immune system with those of tylosin, an antibiotic commonly used in beekeeping. We found that both glyphosate and tylosin decreased the expression of some antimicrobial peptides, such as apidaecin, defensin and hymenoptaecin, in exposed honey bees, but only glyphosate was able to inhibit melanization in the bee hemolymph. Conclusions: Exposure of honey bees to glyphosate or tylosin can reduce the abundance of beneficial gut bacteria and lead to immune dysregulation. [ABSTRACT FROM AUTHOR]

Background and Aim: Enrofloxacin and tylosin can be combined into an antibiotic formulation which is expected to have a broader range of antibacterial activity against various infections in broilers. Validation method analysis of the levels of these two active compounds needs to be done for future use in pharmacokinetic or residual studies. The present study aims to determine a suitable validation method of isocratic high-performance liquid chromatography (HPLC) to measure the concentration of antibiotic combinations in the broiler liver, kidney, and muscles. Materials and Methods: The combination of enrofloxacin and tylosin in the liver, kidney, and muscle was validated by HPLC method to find the procedures, processes, equipment, and systems used, consistently provides the appropriate results. The chromatography system consisted of an Octadecyl-silica column of 5 μm in diameter and 150 mm in length with a mobile phase of a mixture of 0.05 M monobasic sodium phosphate (pH 2.5) and acetonitrile (65:35 v/v). The solution was detected at a wavelength of 280 nm, 30°C, a flow rate of 1 mL/min, and an injection volume of 20 μL. The combination antibiotics powder was produced from PT Tekad Mandiri Citra, Bandung, Indonesia, and broiler tissues obtained from dayold chick broilers maintained for 30 days with free antibiotic feed. Results: Validation of a combination solution of enrofloxacin and tylosin shows the linearity values of enrofloxacin and tylosin in the liver, kidney, and muscles as r²=0.9988, r²=0.9999, r²=0.9997, r²=0.9989, r²=0.9978, and r²=0.9962. The accuracy and precision values of enrofloxacin in the liver, kidney, and muscles were 5.53, 6.23, and 6.93, respectively. The values of accuracy and precision of tylosin in the liver, kidney, and muscles were 10.43, 4.63, and 7.16%, respectively. The retention times for enrofloxacin and tylosin were 1.945-2.000 min and 4.175-4.342 min. The limit of detection (LOD) and limit of quantity (LOQ) values for enrofloxacin were 3.03 and 10.1 μg/g, respectively. In contrast, the LOD and LOQ values for tylosin were 9.05 and 30.17 μg/g, respectively. Conclusion: The value of linearity, accuracy, precision, specificity, and sensitivity of the combined solution of enrofloxacin and tylosin showed promising results. [ABSTRACT FROM AUTHOR]

Recyclable aqueous two‐phase systems with thermo‐responsive phase‐forming materials have been employed to separate macromolecules; however, these systems have achieved very limited separation efficiency for small molecules, such as antibiotics. In this study, aqueous two‐phase systems composed of the ethylene oxide/propylene oxide copolymer and water were developed to extract alkaline antibiotics from the fermentation broth. In the aqueous two‐phase systems with an ethylene oxide ratio of 20 and propylene oxide ratio of 80, the partition coefficients of tylosin and spiramycin reached 16.87 and 20.39, respectively, while the extraction recoveries were 70.67 and 86.70%, respectively. Coupled with mechanism analysis, we demonstrated the feasibility of extracting alkaline antibiotics using this aqueous two‐phase system, especially for 16‐membered macrolide antibiotics. The molecular dynamic simulation was employed to visualize the process of dual‐phase formation and the partition behavior of antibiotics in an aqueous two‐phase system. The dynamic simulation revealed the binding energy between the antibiotic and ethylene oxide/propylene oxide copolymers, which provides a simple indicator for screening suitable antibiotics in aqueous two‐phase systems. Our recyclable aqueous two‐phase systems provide a robust approach for the extraction of 16‐membered macrolide antibiotics with ease of operation and high recovery rates, which is appropriate for large‐scale extraction in the fermentation industry. [ABSTRACT FROM AUTHOR]