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Background: Oxyclozanide and Levamisole hydrochloride compounded suspensions is a kind of compound anthelmintics widely used in the treatment of Fasciola hepatica and nematodes in cattle and sheep. In order to compare the pharmacokinetic parameters between the self-develop drug and the reference listed drug in sheep of the oxyclozanide and levamisole hydrochloride compound suspension, a rapid and sensitive LC-MS/MS analytical method was established, mebendazole was used as the internal standard (IS) in positive ion mode and niclosamide was used as the internal standard (IS) in negative ion mode. The method was validated in terms of linearity, selectivity, specificity, accuracy, precision, and matrix effect, and was successfully applied to a pharmacokinetic study of oxyclozanide and levamisole hydrochloride compounded suspensions in healthy sheep. ·Results: A simple and rapid LC-MS/MS analytical method was established and validated to quantify oxyclozanide and levamisole hydrochloride levels in sheep. The main pharmacokinetic parameters, that is, the maximum plasma concentrations (Cmax), the time to maximum concentration (Tmax), area under the time curve concentration (AUClast) and Terminal half-life (T1/2): the self-developed drug and the reference listed drug of oxyclozanide were 45.54±17.58 μg/mL, 22.5±2.07 h, 1845.43±851.92 h*μg/mL, 20.58±7.97 h; 34.60±5.65 μg/mL, 15.50±3.96 h, 1285.46±225.7 h*μg/mL, 23.12±5.04 h, respectively; The self-developed drug and the reference listed drug of Levamisole hydrochloride was : 2.25±0.90 μg/mL, 0.49±0.69 h, 9.51±2.20 h*μg/mL, 4.43±1.75 h; 2.41±1.11 μg/mL, 0.81±0.66 h, 9.09±2.12 h*μg/mL, 3.16±1.05 h. No significant differences were observed among the AUClast andT1/2 for Oxyclozanide self-developed drug compare with the reference listed drug, and there was a significant difference in Cmax and Tmax (P＜0.05). There were no significant differences in Cmax, Tmax, AUClast and T1/2 between the self-developed drug of levamisole hydrochloride and the reference listed drug (P > 0.05). The relative bioavailability of oxyclozanide and levamisole hydrochloride were 143.56% and 104.62%, respectively. Conclusions: A reliable, accurate LC-MS/MS analytical method was established in our study and successful applied to study the pharmacokinetics of oxyclozanide and levamisole hydrochloride compound suspension in sheep plasma. These results will be useful for further evaluations of the pharmacokinetic properties of oxyclozanide and levamisole hydrochloride.

Background The natural hosts of Shigella are typically humans and other primates, but it has been shown that the host range of Shigella has expanded to many animals. Although Shigella is becoming a major threat to animals, there is limited information on the genetic background of local strains. The purpose of this study was to assess the presence of virulence factors and the molecular characteristics of S. flexneri isolated from calves with diarrhea. Results Fifty-four S. flexneri isolates from Gansun, Shanxi, Qinghai, Xinjiang and Tibet obtained during 2014 to 2016 possessed four typical biochemical characteristics of Shigella. The prevalences of ipaH, virA, ipaBCD, ial, sen, set1A, set1B and stx were 100 %, 100 %, 77.78 %, 79.63 %, 48.15 %, 48.15 and 0 %, respectively. Multilocus variable number tandem repeat analysis (MLVA) based on 8 variable number of tandem repeat (VNTR) loci discriminated the isolates into 39 different MLVA types (MTs), pulsed field gel electrophoresis (PFGE) based on NotI digestion divided the 54 isolates into 31 PFGE types (PTs), and multilocus sequence typing (MLST) based on 15 housekeeping genes differentiated the isolates into 7 MLST sequence types (STs). Conclusions The findings from this study enrich our knowledge of the molecular characteristics of S. flexneri collected from calves with diarrhea, which will be important for addressing clinical and epidemiological issues regarding shigellosis.

As an opportunistic pathogen, Escherichia coli (E. coli) forms biofilm that increases the virulence of bacteria and antibiotic resistance, posing a serious threat to human and animal health. Recently, ginkgetin (Gin) has been discovered to have antiinflammatory, antioxidant, and antitumor properties. In the present study, we evaluated the antibiofilm and antibacterial synergist of Gin against E. coli. Additionally, Alamar Blue assay combined with confocal laser scanning microscope (CLSM) and crystal violet (CV) staining was used to evaluate the effect of antibiofilm and antibacterial synergist against E. coli. Results showed that Gin reduces biofilm formation, exopolysaccharide (EPS) production, and motility against E. coli without limiting its growth and metabolic activity. Furthermore, we identified the inhibitory effect of Gin on AI-2 signaling molecule production, which showed apparent anti-quorum sensing (QS) properties. The qRT-PCR also indicated that Gin reduced the transcription of curli-related genes (csgA, csgD), flagella-formation genes (flhC, flhD, fliC, fliM), and QS-related genes (luxS, lsrB, lsrK, lsrR). Moreover, Gin showed obvious antibacterial synergism to overcome antibiotic resistance in E. coli with marketed antibiotics, including gentamicin, colistin B, and colistin E. These results suggested the potent antibiofilm and novel antibacterial synergist effect of Gin for treating E. coli infections.

Drug resistance has been partly driven by the overuse of antimicrobials in agricultural animal feed. Better understanding of antibiotic resistance in bovine gut is needed to assess its potential effects based on metagenomic approach and analysis. In this study, we collected 40 fecal samples to explore drug resistance derived from antibiotic use in the bacterial community by an analysis of the diversities and differences of antibiotic-resistant genes (ARGs) in the gut microbiota from yak, beef, and dairy cattle. Overall, 1688 genes were annotated, including 734 ARG subtypes. The ARGs were related to tetracyclines, quinolones, β-lactam, and aminoglycosides, in accordance with the antibiotics widely used in the clinic for humans or animals. The emergence, prevalence, and differences in resistance genes in the intestines of yaks, beef, and dairy cattle may be caused by the selective pressure of different feeding patterns, where yaks were raised without antibiotics for growth promotion. In addition, the abundance of ARGs in yak was lower than in beef and dairy cattle, whereas the abundance of integron, a kind of mobile genetic elements (MGEs) was higher in yaks than those in beef and dairy cattle. Furthermore, the results of this study could provide the basis for a comprehensive profile of various ARGs among yak, beef, and dairy cattle in future.

Yaks and Tibetan sheep are important and renowned livestock of the Qinghai-Tibetan Plateau (QTP). Both host genetics and environmental factors can shape the composition of gut microbiota, however, there is still no consensus on which is the more dominant factor. To investigate the influence of hosts and seasons on the gut microbiome diversity component, we collected fecal samples from yaks and Tibetan sheep across different seasons (summer and winter), during which they consumed different diets. Using 16S rRNA sequencing, principal component analysis (PCoA) data showed that PCo1 explained 57.4% of the observed variance (P = 0.001) and clearly divided winter samples from summer ones, while PCo2 explained 7.1% of observed variance (P = 0.001) and mainly highlighted differences in host species. Cluster analysis data revealed that the gut microbiota composition displayed a convergence caused by season and not by genetics. Further, we profiled the gut microbial community and found that the more dominant genera in yak and Tibetan sheep microbiota were influenced by seasonal diets factors rather than genetics. This study therefore indicated that seasonal diet can trump host genetics even at higher taxonomic levels, thus providing a cautionary note for the breeding and management of these two species.

Background Myrislignan is a natural product from Myristica sp. with diverse pharmacological activities. Recently, the anti-Toxoplasma gondii (T. gondii) activity of myrislignan has been proposed, and in vivo studies of its pharmacokinetics in BALB/c mice are necessary to further evaluate the clinical effects of myrislignan. Results In this study, a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to quantify myrislignan levels in mouse plasma using dehydrodiisoeugenol as an internal standard (IS) in positive ion mode. Chromatographic separation of the analytes was achieved using an ACE Ultracore Super C18 analytical column (2.5 μm, 2.1 × 50 mm) at 30 °C. A gradient mobile phase consisting of water (0.1 % formic acid) and acetonitrile (0.1 % formic acid) was delivered at a flow rate of 0.4 mL/min. Myrislignan and the IS eluted at 1.42 and 1.71 min, respectively. A good excellent linear response across the concentration range of 1-1000 ng/mL was achieved (r2 = 0.9973). The lower limit of quantification (LLOQ) was 1 ng/mL, and the inter- and intra-day accuracy and precision of the method showed relative standard deviations (RSDs) less than 10 %. The method was applied to examine the pharmacokinetics of myrislignan in mouse plasma following a single oral administration of 200 mg/kg or intraperitoneal administration of 50 mg/kg myrislignan, and the bioavailability (F) of orally administered myrislignan was only 1.97 % of the bioavailability of intraperitoneally administered myrislignan. Conclusions A rapid and sensitive LC-MS/MS method has been was developed, validated and successfully used to determine myrislignan levels in mice after oral or intraperitoneal administration. This study is the first to report the pharmacokinetic parameters of myrislignan in mice and to compare its pharmacokinetics after oral and intraperitoneal administration, which will be useful for further research on the administration of myrislignan in animals and humans.

CTX-M extended spectrum beta-lactamase-producing

Background Porcine infectious pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one of the most serious infectious diseases in pigs and has brought huge economic losses to the world pig industry. The aim of this trial was to evaluate the effect of enteric‐coated tilmicosin granule in the treatment and control of artificial infection of App. Methods Sixty Duroc and Yorkshire crossbred pigs (50 of which were artificially infected) were divided into six groups: BCG (Blank control group), ICG (Infection‐only control group), HDG (High‐dose enteric‐coated tilmicosin granules), MDG (Medium‐dose enteric‐coated tilmicosin granules), LDG (Low‐dose enteric‐coated tilmicosin granules) and TPG (Tilmicosin premix drug control group). The cure rate, mortality, clinical respiratory score, body temperature score, weight gain, lung score and so on were recorded. Results The cure rate of HDG and MDG was as high as 90%, the mortality was 10%, and the clinical signs recovered quickly. Conclusion The results showed that enteric‐coated tilmicosin granules had obvious therapeutic effect on artificial infection, which could reduce the damage caused by the disease and reduce the mortality., The aim of this trial was to evaluate the effect of enteric‐coated tilmicosin granule in the treatment and control of artificial infection of App. The cure rate of high dose group and medium dose group was as high as 90%, the mortality was 0%, and the clinical signs recovered quickly.

Herein, a novel magnetic molecularly imprinted polymer doped with reticular graphene oxide (Fe3O4@SiO2-GO@MIPs) was synthesized for the selective recognition and extraction of 4 flavonoids (farrerol, taxifolin, kaempferol, and hyperin) from Rhododendrons species. The Fe3O4@SiO2-GO@MIPs with lamellar membranes showed outstanding adsorption capacity. The 3D cavities complementary to the “shape” of farrerol were “imprinted” on the polymer framework after removal of farrerol template. Competitive binding assays showed that the polymer has a higher selectivity for farrerol compared with other analogues and references. The Fe3O4@SiO2-GO@MIPs as solid-phase extraction adsorbents combined with liquid chromatography-tandem quadrupole mass spectrometry (LC–MS/MS) was used for selective determination of four flavonoids from Rhododendrons samples. The limits of detection (LOD) were 0.07, 0.08, 0.06, and 0.08 μg L−1 for farrerol, taxifolin, kaempferol, and hyperin, respectively. These results suggest that the prepared Fe3O4@SiO2-GO@MIPs have the potential applicability to extract, purify, and enrich flavonoids from herbs, supplements, and other natural products.

Background Oxyclozanide is an anthelmintic drug that is widely used to treat fasciolosis. However, the pharmacokinetics of oxyclozanide in cattle are not yet clearly understood. The present study was designed to develop a sensitive method to determine oxyclozanide levels in cattle plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and to study its pharmacokinetics for application in cattle. Results A simple and rapid HPLC-MS/MS analytical method was established and validated to quantify oxyclozanide levels in cattle plasma using niclosamide as the internal standard (IS) in negative ion mode. Chromatographic separation of the analytes was achieved using a C18 analytical column (75 × 4.6 mm, 2.7 μm) at 30 °C. The mobile phase comprised 0.01% v/v acetic acid (HOAc) diluted in water:acetonitrile (MeCN) (90:10% v/v) and 5 mM ammonium formate in methanol (MeOH):MeCN (75:25, v/v) at a 10:90 ratio (v/v) and was delivered at a flow rate of 0.4 mL min− 1. A good linear response across the concentration range of 0.02048–25.600 μg/mL was achieved (r2 = 0.994). The method was validated with respect to linearity, matrix effect, accuracy, precision, recovery and stability. The lower limit of quantification (LLOQ) was 0.020 μg/mL, and the extraction recovery was > 98% for oxyclozanide. The inter- and intra-day accuracy and precision of the method showed the relative standard deviation (RSD) less than 10%. The method was successfully applied to an assessment of the pharmacokinetics of oxyclozanide in cattle plasma. In healthy cattle, a single oral dose of an oxyclozanide suspension followed the one-compartment model, with a half-life (T1/2) of 64.40 ± 30.18 h, a plasma clearance rate (CL/F) of 11.426 ± 2.442 mL/h/kg, and an average area under the curve (AUC) of 965.608 ± 220.097 h*μg/mL. The peak concentration (Cmax) was 15.870 ± 2.855 μg/mL, which occurred at a peak time (Tmax) = 22.032 ± 3.343 h. Conclusions A reliable, accurate HPLC-MS/MS analytical method was established in our study and successful applied to study the pharmacokinetics of oxyclozanide in cattle plasma. These results will be useful for further evaluations of the pharmacokinetic properties of oxyclozanide or for monitoring therapeutic drugs in animals.

Background: Avian pathogenic E. coli (APEC) is the etiologic agent of serious colibacillosis and causes extensive economic losses. To examine the genetic background of APEC, we characterized the serotypes, virulence genes, phylogenetic classification and MLST of 392 APEC and 586 AFEC strains isolated from infected chickens. Results: The results showed that the most predominant serotypes were O78 (13.47%), O2 (9.16%), O18 (5.39%), O20 (4.42%) and O25 (4.09%). The major serotypes O78 (13.47%) and O2 (9.16%) were significantly higher in the APEC isolates than in the AFEC isolates. Among the 16 analyzed virulence-associated genes (VAGs), iroN (100%), ompT (100%), fimC (92.46%), iss (77.91%) and irp2 (71.98%) were the most frequently identified. Over half (54.85%) of the strains possessed > 8–13 VAGs, and 85.23% of the strains carried iroN-ompT-fimC-iss/irp2 VAG patterns. According to the phylogenetic analysis, phylogroups A (32.11%) and B2 (31.36%) proved to be the most prevalent phylogenetic groups in the AFEC and APEC isolates, respectively. The strains that belonged to phylogroup B2 were associated with more VAGs. Based on MLST, 46 STs belonging to 15 different clonal complexes were identified, and 4 were novel. ST88 (10.67%) was found to be the most dominant ST, and it possessed at least 9 VAGs and belonged to phylogroups B2 or D. Furthermore, the isolates belonging to B2-O78/O2-ST88 were the most likely APEC isolates to be associated with epidemics, and they carried more VAGs than the other strains. Conclusions: Our findings have enriched our knowledge of the molecular characteristics of APEC isolates from chickens, which will be important for the prevention and control of avian colibacillosis.

Clostridioides difficile infection (CDI) is considered a major concern of the health care system globally, with an increasing need for alternative therapies. OBP-4, a new oxazolidinone-fluoroquinolone hybrid with excellent in vitro activities and good safety, shows promising features as an antibacterial agent. Here, we further evaluated the in vitro and in vivo activities of OBP-4 against C. difficile and its absorption (A), distribution (D), and excretion (E) profiles in rats. In vitro assays indicated that OBP-4 was active against all tested C. difficile strains, with MICs ranging from 0.25 to 1 mg/liter. In addition, OBP-4 showed complete inhibition of spore formation at 0.5× MIC. In the mouse model of CDI, 5-day oral treatment with OBP-4 provided complete protection from death and CDI recurrence in infected mice. However, cadazolid (CZD) and vancomycin (VAN) showed less protection of infected mice than did OBP-4 in terms of diarrhea and weight loss, especially VAN. Subsequently, ADE investigations of OBP-4 with a reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method showed extremely low systemic exposure and predominantly fecal excretion, resulting in a high local concentration of OBP-4 in the intestinal tract-the site of CDI. These results demonstrated that OBP-4 possesses good activity against C. difficile and favorable ADE characteristics for oral treatment of CDI, which support further development of OBP-4 as a potential anti-CDI agent.

Background The widespread distribution of antimicrobial-resistant Shigella has become a recurrent challenge in many parts of the developing world. Previous studies indicate that the host of Shigella has expanded from humans to animals. This study aimed to investigate the prevalence of fluoroquinolone resistance and associated molecular characterization of S. dysenteriae 1 isolated from calves. Results All 38 unduplicated S. dysenteriae 1 isolates were collected from calves in Gansu Province from October 2014 to December 2016. According to MLST and PFGE analysis, these isolates were separated into 4 and 28 genotypes, respectively. The most common STs identified were ST228 (34.21%, 13/38) and ST229 (39.47%, 15/38), which were first found in the present study. All isolates harbored virulence genes, and the incidence of the seven virulence genes were ipaH (100%), ipaBCD (92.11%), stx (73.68%), ial (57.89%), sen (28.95%), set1A and set1B (0%). According to the results of antimicrobial susceptibilities, 76.32% (29/38) were resistant to fluoroquinolone and showed multidrug resistance. In a study on the polymorphism of quinolone resistance–determining region (QRDR) of gyrA/B and parC/E genes, we identified two mutations in gyrA (Ser83 → Leu and Asp87 → Asn) and parC (Ser80 → Ile and Ser83 → Leu), respectively. Among them, 55.17% (16/29) of resistant strains had the gyrA point mutations (Ser83 → Leu) and parC point mutation (Ser83 → Leu). Moreover, 41.38% (12/29) of isolates had all five point mutations of gyrA and parC. In addition, the prevalence of the plasmid-mediated quinolone resistance (PMQR) determinant genes was also investigated. All 29 fluoroquinolone-resistant isolates were positive for the aac (6′)-Ib-cr gene but negative for qepA, except for SD001. In addition, only 6 (20.69%, 6/29) isolates harbored the qnr gene, including two with qnrB (6.90%, 2/29) and four with qnrS (13.79%, 4/29). Conclusion Given the increased common emergence of multidrug resistant isolates, uninterrupted surveillance will be necessary to understand the actual epidemic burden and control this infection.

Additional file 3: Table S3. Primers for the detection of fluoroquinolone resistance–determining genes.

Additional file 2: Table S2. Primers for the detection of virulence genes.

Additional file 1: Table S1. Strain information of S. dysenteriae isolates from diarrheal calves in this study.

The drug resistance has been partly driven by the overuse of antimicrobials in agricultural feeding. Better understanding of the antibiotic resistance in gut of bovine is needed to assess its potential effects based on metagenomic approach and analysis. In this study, we collected 40 fecal samples to explore the drug resistance deriving from antibiotics in bacterial community by an analysis of the diversity and difference of antibiotic resistant genes (ARGs) in gut microbiota from yak, beef and dairy cattle. 1688 genes were annotated, including 734 ARG subtypes in summary. The ARGs were related with tetracycline, quinolone, β-lactam, aminoglycoside, in accordance with the antibiotics widely used in clinic for humans or animals. The emergence, prevalence and differences in resistance genes in the intestines of yaks, beef and dairy cattle may be caused by the selective pressure of different feeding patterns. Additionally, the abundance of ARGs in yak was lower than in beef and dairy cattle, while the abundance of integron, a kind of mobile genetic elements (MGEs), was higher than those in beef and dairy cattle. Furthermore, the results of this study demonstrated that a comprehensive profile of various ARGs among yak, beef and dairy cattle for providing a basic research.

Background: The natural hosts of Shigella are conventionally humans and other primates; however, the host range of Shigella has been shown to expand to many animals. Although Shigella is becoming a huge threat to animals, there is limited information on the genetic background of local strains. The purpose of this study was to assess the presence of virulence factors and the molecular characteristics of S. flexneri isolated from calves with diarrhea.Methods: From 2014 to 2016, 54 S. flexneri isolates were collected from diarrhea, and their biochemical characteristics were determined according to API20E and virulence factors via PCR. The molecular characteristics of the isolates were studied by MLST, MLVA and PFGE.Results: Fifty-four S. flexneri isolates possessed four typical biochemical characteristics of Shigella. The prevalences of ipaH, virA, ipaBCD, ial, sen, set1A, and set1B were 100%, 100%, 77.78%, 79.63%, 48.15% and 48.15%, respectively. None of the studied strains possessed the stx gene. Regarding the differences in virulence factor distributions, the 54 S. flexneri isolates fell into seven gene profile types. Among these VTs, VT4 and VT6 were the most common, accounting for 74.07% of all VTs. MLVA based on 8 VNTR loci discriminated the isolates into 39 different MTs, PFGE based on NotI digestion divided the 54 isolates into 31 PTs, and MLST based on 15 housekeeping genes differentiated the isolates into 7 STs, with 1 ST (ST227) being novel.Conclusion: Our findings provide baseline information on the distribution of virulence genes in and the molecular characteristics of S. flexneri collected from diarrheal calves, which is a potential threat to public safety. These data will be important for addressing clinical and epidemiological issues regarding Shigellosis.

Background: Antibiotic resistance genes (ARGs) have become recognized contaminants and pose a high public health risk. The animal gut microbiota is a reservoir of ARGs, but the knowledge of the origin and dissemination of ARGs remains unclear.Methods: 30 of the fecal samples were obtained from bovine and were immediately frozen in liquid nitrogen. Total metagenomic DNA was extracted by cetyltrimethylammonium bromide (CTAB) method and sequenced by Illumina HiSeq X Ten platform. After quality control and assembled, the sequence were annotated by NR, CARD and ISfinder. Statistical analysis was performed using SPSS 19.0.Results: A total of 42 ARG types were detected by annotating the metagenomic sequencing data from the Comprehensive Antibiotic Resistance Database (CARD). We found that the diversity and abundance of ARGs in individual yaks were significantly lower than those in dairy and beef cattle. The results of heat map and single-nucleotide polymorphism (SNP) clustering suggest that ARGs from dairy and beef cattle are more similar, while those from yaks cluster separately. Conclusion: The long-term use of antibiotics may contribute to this difference, suggesting that antibiotic consumption is the main cause of ARG prevalence. Furthermore, abundant insertions and integrations were also found in this study, signifying a strong potential for horizontal transfer of ARGs among microbes, especially pathogens.

A dummy molecularly imprinted polymer (d-MIP) was developed for extraction and cleanup of farrerol from Rhododendron aganniphum. The d-MIP was prepared by precipitation polymerization using quercetin as the dummy template, 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and acetonitrile as the porogen. The d-MIP was characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. Dynamic curves, adsorption isotherms, and Scatchard plots showed the d-MIP had good affinity, capacity, and selectivity for the target compound. The prepared d-MIP was used as a sorbent in solid-phase extraction cartridges and successfully applied to specific extraction and purification of farrerol from real samples. High recoveries were obtained for four spiked levels of farrerol in Rhododendron aganniphum using d-MIP solid-phase extraction coupled with high-performance liquid chromatography. The linear range was 1–100 µg mL−1, the limit of detection was 2.23 mg kg−1, the farrerol recovery range was 85.7%–104.1%, and the relative standard deviations (n = 3) were all less than 2.2% for real samples. The proposed method provides a simple, rapid, and environmentally friendly approach to the analysis of farrerol in complex herbal products.

In this study, we aimed to optimize the extraction of polysaccharides from the leaves of Rhododendron aganniphum and investigate its rheological properties and antioxidant activity. After optimizing the operating parameters using a Box-Behnken design (BBD), the results showed that the optimal ultrasound-assisted extraction conditions were as follows: extraction temperature, 55°C; liquid-solid ratio, 25:1; extraction time, 2.2h; and ultrasound treatment power, 200W. The optimized experimental yield of polysaccharides by ultrasound-assisted extraction (PUAE) was 9.428%, higher than that obtained by hot water extraction (PHWE) for 12h at the same liquid-solid ratio and extraction temperature. In the in vitro antioxidant activity tests, PUAE had higher positive radical scavenging activity for hydroxyl, superoxide and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals than PHWE. However, PUAE and PHWE solutions had similar intermolecular interactions in the steady-shear flow and dynamic viscoelasticity tests, resulting in similar macroscopic behaviour. With respect to the apparent viscosity, storage modulus (G') and loss modulus (G″) of PUAE were lower at the same shear rate or angular frequency. All PUAE solutions exhibited non-Newtonian shear-thinning pseudoplastic behaviour that was accurately described by the Carreau model but was better fit by the power-law model at high shear rates (≥1/s), which demonstrated that the variation in the apparent viscosity dependence was greater at higher concentrations and shear rates. The G' and G″ of the solutions increased as the experimental frequency increased from 0.05 to 500rad/s under all experimental concentrations, and the modulus crossover point decreased gradually with increasing PUAE concentration. The above results demonstrated that the ultrasound-assisted extraction methods gave a higher yield of polysaccharides from the leaves of R. aganniphum with a shorter extraction time than the hot water extraction method, which could affect the apparent viscosity and dynamic viscoelasticity. PUAE presented good radical scavenging activity for DPPH, superoxide and hydroxyl radicals in vitro and could be used as a natural antioxidant in the food and medical industries.

Oregano oil possesses marked antioxidant and antimicrobial activity and is widely applied in animal husbandry. In the present study, we aimed to investigate the acaricidal activities of oregano oil and its major component, carvacrol, thymol and p-cymene against Psoroptes cuniculi in vitro and in vivo. The results revealed that oregano oil exhibited significant acaricidal effects against P. cuniculi that were dose- and time-dependent response. In in vitro test, concentrations of 0.05% and 0.02% (v/v) killed all of the mites within 1h and 6h, respectively. Moreover, 0.1mg/ml (w/v) carvacrol, 0.2mg/ml (w/v) thymol and 1% p-cymene (v/v) also possessed marked acaricidal activities, and compared with the control group, elicited mean mortalities of 84.00%, 96.00% and 66% at 24h, respectively. The median lethal times (LT50) against P. cuniculi of the concentrations of 0.02%, 0.01% and 0.005% (v/v) of oregano oil, thymol, carvacrol and p-cymene were 2.171h, 11.396h, 26.102h, and 4.424h, 8.957h and 15.201h, respectively. Meanwhile, twenty naturaly infested rabbits were used to four homogeneity groups: negative control (without treatment), positive control (treated with ivermectin), group treated with 1% of oregano oil and other group with 5% of oregano oil. All the treatments were topically. After the treatment of 1% and 5% oregano oil, the P. cuniculi were completely eliminated in the rabbits, and at the end of the test (day 20), the rabbits of all treatment groups exhibited favorable mental and physical statuses. These results indicated that oregano oil could be widely applied as a potential acaricidal agent in the treatment of animal acariasis in the future.

A group of benign Theileria species, which are often referred to as T. orientalis/T. buffeli/T. sergenti group, has low pathogenicity in cattle. Herein, we report on Theileria spp. in cattle on a farm from China. Based on phylogenetic analysis of the major piroplasm surface protein gene sequences, we detected 6 genotypes that were categorized as Types 1, 2, 3, 4, and 5 as well as an additional Type 9 genotype. The new epidemiological features of the T. orientalis/T. buffeli/T. sergenti parasites in China indicate a greater diversity in the genetics of these species than had been previously thought.

The aim of this study was to determine the potential toxicity risk of an oxyclozanide suspension to the target animal, bovine. In this experiment, 32 Simmental beef cattle were fattened and fed a full-price diet without antimicrobial agents. The test cattle were divided into 4 groups, which were treated with 0, 1, 3, and 5 times the recommended dosage through continuous intermittent oral administration at intervals of 2 days. The body weight of the cattle was recorded before and after the experiment, and the weight changes were calculated. The safety of the drugs was evaluated by weight gain, observation of clinical toxicity, haematology, clinical chemistry and histopathology. The results showed that the cattle had different degrees of diarrhoea, loss of appetite and depression after administration. The results of clinicopathology had no significant effect. The results of pathological examination showed that there was a certain degree of damage in the 5 times recommended dose group. The recommended dose was safe to use. Thus, the recommended dose should be given by a single oral administration to ensure the safe use of this drug in the clinic.

Members of the genus Shigella are intestinal pathogens and a major cause of seasonal outbreaks of bacterial diarrhea worldwide. Although humans are the conventional hosts of Shigella species, expansion of the Shigella host range to certain animals was recently reported. To investigate the prevalence of Shigella sonnei (S. sonnei) in yaks and perform molecular characterization, we analyzed 1132 fresh yak diarrheal stool samples and collected a total of 44 S. sonnei isolates. We performed multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) with XbaI-digested DNA to study genetic relatedness among the 44 isolates, which were differentiated into 4 sequence types (STs) and 32 PFGE types (PTs). All isolates harbored virulence genes, and 87.36% tested positive for invasion plasmid antigen H (ipaH), invasion associated locus (ial) and the Shigella enterotoxin gene sen. According to the results of antimicrobial susceptibility tests, 45.45% (20/44) were resistant to fluoroquinolones and/or cephalosporin. By sequencing the quinolone resistance determining region (QRDR) genes, we identified double mutations in gyrA (Ser83-Leu and Asp87-Asn) and a single mutation in parC (Ser80-Ile). All 12 fluoroquinolone-resistant S. sonnei isolates tested positive for the aac(6′)-Ib-cr gene but negative for qepA. Three isolates harbored qnr genes, including two with qnrS and one with qnrB. In addition, three types of β-lactamase genes, bla TEM-1 , bla OXA-1 and bla CTX-M-14/79 , were detected in cephalosporin-resistant isolates. The findings of this study have enriched our knowledge of fluoroquinolone- and/or cephalosporin-resistant S. sonnei isolates from yaks, which has important public health significance.

Table S2. Statistical analysis of the presence of virulence genes in each S. sonnei isolate. (DOCX 39 kb)

Table S6. Primers used to detect antibiotic resistance determinant genes. (DOCX 81 kb)

Table S3. Statistical analysis of the occurrence of each virulence gene profile in different provinces. (DOCX 36 kb)

Table S1. MLST allelic profiles and ST designations of 44Â S. sonnei isolates from this study. (DOCX 45 kb)

Table S4. Primers used to detect virulence genes. (DOCX 39 kb)