Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generate...Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generated 3 recombinant rabies viruses(RABV),rERAG_(333E)/S6P,rERAG_(333E)/DS6P and rERAG_(333E)/BA2S6P,expressing the prefusion-stabilized SARS-CoV-2 spike protein of wild-type(S6P),δ(DS6P)or BA.2(BA2S6P)strain based on an oral rabies vaccine candidate(rERAG_(333E)).Oral or inactivated immunization of the 3 RABVs monovalent or trivalent were safe,and induced robust RABV neutralizing antibody and cross-antibody responses against the three SARS-CoV-2 in mice and minks.The challenge tests showed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts,and largely prevented viral replication and lung damage caused by wild-type SARS-CoV-2infection in minks.Notably,we also confirmed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine can largely protect minks against wild-type SARS-CoV-2 transmission via respiratory droplets.Our findings suggest that rERAG_(333E)-based COVID-19 vaccines appear to be suitable oral candidates to protect minks from SARS-CoV-2infection and transmission,and may serve as inactivated vaccines for further investigation in humans.展开更多
Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-strand...Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014;Ge et al. 2018).展开更多
Growth curves of Minghua black minks at 0-180 days old were fitted and analyzed by using two growth models Logistic and Gompertz. The results showed that the growth curves of Minghua black minks could be fitted very w...Growth curves of Minghua black minks at 0-180 days old were fitted and analyzed by using two growth models Logistic and Gompertz. The results showed that the growth curves of Minghua black minks could be fitted very well by Logistic model and Gompertz model (the degree of fitting FF≥0.99), but Gompertz model was better at fitting and predicting their weight.展开更多
[Objective] This study aimed to test the sensitivity of Eperythrozoon from mink to various drugs in vitro. [Method] The red blood cells isolated from Eperythro- zoon positive mink was cultured in complete medium (70%...[Objective] This study aimed to test the sensitivity of Eperythrozoon from mink to various drugs in vitro. [Method] The red blood cells isolated from Eperythro- zoon positive mink was cultured in complete medium (70% RPMI-1640 medium and 30% calf serum), supplemented with bernier, oxytetracycline, trichlorfon, tylosin, imi- docarb, florfenicol, Fuhongjuesha or primaquine phosphate at the working concentra- tions of 12, 24, 36, 48 and 96 μL/ml, incubated at 37.3 ℃, 5% CO2. [Result] Fuhongjuesha was most efficient for killing Eperythrozoon, followed by trichiorfon and primaquine phosphate, but trichlorfon is toxic. Bernier, imidocarb and florfenicol are efficient. [Conclusion] The study provides a scientific reference for clinical treatment of eperythrozoonosis.展开更多
[Objective] The paper was to diagnose and treat hemorrhagic pneumonia of mink. [Method] The diseased minks bred by one raiser in Huangtian Village of Changli County in Qinhuangdao City were used as experimental materi...[Objective] The paper was to diagnose and treat hemorrhagic pneumonia of mink. [Method] The diseased minks bred by one raiser in Huangtian Village of Changli County in Qinhuangdao City were used as experimental materials. It was necropsied, and its tissues such as liver, kidney, spleen and lung were taken under aseptic condition, then inoculated into general nutrition agar and blood agar. The bacteria were isolated and purified, and the strains obtained were carried out animal inoculation test and drug sensitivity test. Finally, the relevant treatment and preven- tive measures were put forward. [Conclusion] The bacteria isolated were detected to be negative by Gram staining; it formed hemolysis ring in blood agar; the bacteria could ferment glucose and xylose, which could not ferment sucrose, lactose, maltose and esculin; it was positive in catalase and oxidase test, and negative in urease test and hydrogen sulfide test; so the strain was indentified to be Pseudomonas aerugi- nosa. Drug sensitivity test showed that the bacteria were highly sensitive to ciprofloxacin, which had tolerance to cefoxitin. [Conclusion] The study laid foundation for diagnosis and treatment of hemorrhagic pneumonia of mink.展开更多
AIM: To establish a new, reliable vomit model of minks METHODS: Adult male minks were randomly divided into 8 groups (n=6): cisplatin (7.5 mg/kg) intraperitoneal injection (ip) group, copper sulfate (40 mg/k...AIM: To establish a new, reliable vomit model of minks METHODS: Adult male minks were randomly divided into 8 groups (n=6): cisplatin (7.5 mg/kg) intraperitoneal injection (ip) group, copper sulfate (40 mg/kg) intragastric injection (ig) group, apomorphine (1.6 mg/kg) subcutaneous injection (sc) group, and 18 Gy whole-body X-irradiation group, ondansetron injection group (2 mg/kg ip) 30 min later followed by cisplatin (7.5 mg/kg) ip, normal saline (NS) ip injection control group, metoclopramide injection group (4 mg/kg ip) 30 rain later followed by apomorphine (1.6 mg/kg) sc, NS ig control group. The frequency of retching and vomiting was calculated. After behavioral experiment, distribution of 5-HT in the ileum was detected by immunohistologic method. RESULTS: Cisplatin, apomorphine, copper sulfate and X-irradiation administered to minks evoked a profound emetic response in the animals. However, retching and vomiting were significantly inhibited by pretreatment with ondansetron and metoclopramide in cisplatin and copper sulfate groups (P=0.018). Immunohistologic result showed that 5-HT released from enterochromaffin cells (EC cells) was involved in vomiting mechanism. CONCLUSION: Mink vomit model has a great value in studying the vomiting mechanism and screening new antiemetic drugs.展开更多
A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five grou...A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five groups of 14 minks each. The minks were fed in five kinds of experiment diets (HP, LP, LP+M1, LP+M2 and LP+M3). The dietary protein levels, expressed as percentage of dry matter (DM), were 32% (high protein, HP) and 24% (low protein, LP). LP was supple- mented with Met 0.4% (M1), 0.8% (M2) and 1.2% (M3) DM. From mid of September to December 10, apparent digestibility of CP (crude pro- tein), N intake and urinary N excretion were decreased with declining dietary protein levels (p 〈 0.05) and N retained was the highest in treat- ment LP+M2. No significant difference was found in total serum protein (TP) and serum urea nitrogen (SUN) among all treatment groups (p 〉 0.05). Skin length of treatment HP and LP^M2 was higher than that of other groups (p 〈 0.05). Body length, skin weight, length of guard hair and under hair were not affected by different dietary protein levels (p〉0.05). The best performance could be observed in treatment LP+M2. In diet, 24% (DM) protein level with 1.54% Met supplementing was enough for minks during growing-farring period. Dietary protein lowered from 32% to 24% with supplementing Met in diets would result in a37.9% decrease in urinary N excretion. Furthermore, addition of Met in diets for minks would be beneficial in terms of reducing feed expenses and lessening nitrogen emissions to the environment.展开更多
Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAP...Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAPD method to analyze a molecular genetic marker linked with self-biting trait in mink group. The molecular marker was converted into sequence-characterized amplified regions (SCAR) marker for rapid detection of this disease. A single RAPD marker A8 amplified a specific band of 263bp in self-biting minks, which was designated as SRA8-250, and non-specific band of 315bp in both self-biting and healthy minks. The sequences of the bands exhibited 75% and 88% similarity to Canis familiarizes major histocompatibility complex (MHC) class II region and Macaca mulatta MHC class I region, respectively. A SCAR marker SCAR-A8 was designed for the specific fragment SRA8-250 and validated in 30 self-biting minks and 30 healthy minks. Positive amplification of SCAR-A8 was detected in 24 self-biting minks and 12 healthy minks. χ2 test showed significant difference (p〈0.01) in the detection rate between the two groups. This indicated that SRA8-250 can be used as a positive marker to detect self-biting disease in minks. Furthermore, the finding that self-biting disease links with MHC genes has significant implications for the mechanism of the disease.展开更多
Inter-simple Sequence Repeat (ISSR) analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers p...Inter-simple Sequence Repeat (ISSR) analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers produced 35 discernible bands, with 30 (85.71%) being polymorphic, indicating high genetic diversity at the species level. The highest genetic diversity was observed in the brown mink population, whereas the lowest diversity was found in the standard-pitchy mink population. Based on genetic distance (1972), a dendrogram was constructed by using UPGMA algorithm, and five populations were divided into two major groups. Group I consisted of only the standard-pitchy mink population, and Group II included other four populations, in Group II, sapphire mink was close to brown mink population. The results of genetic differentiation indicated that the genetic differentiation degree between populations was lower and the genetic variation primarily came from within populations. This paper showed that ISSR technique was a reliable tool that could be used to study genetic diversity in the mink.展开更多
[Objective] This paper aimed to study the mechanism of diarrhea of mink caused by Escherichia coil [Method] Through the detection of K88 fimbriae gene of E. coli, cloning of gene fragments and identification, then PCR...[Objective] This paper aimed to study the mechanism of diarrhea of mink caused by Escherichia coil [Method] Through the detection of K88 fimbriae gene of E. coli, cloning of gene fragments and identification, then PCR amplification was used to detect adhesion factor K88 gene, which was connected to T-vector and transformed into competent cells, and positive clones were selected. [ Results] E. coli 078, 029 and 038 were isolated from organs and feces of mink died of diarrhea in 3 mink farms, respectively, the 3 serotypes of E. coliwere detected in carrying K88 fimbriae gene and 3 positive clones were screened, respectively. [ Conclusion] The E. coli causing mink diarrhea carry K88 fimbriae gene.展开更多
There were 4 Acinetobacter lwoffii obtained from soil samples.The antimicrobial susceptibility of the strains to 16 antimicrobial agents was investigated using K-B method.Three isolates showed the multi-drug resistanc...There were 4 Acinetobacter lwoffii obtained from soil samples.The antimicrobial susceptibility of the strains to 16 antimicrobial agents was investigated using K-B method.Three isolates showed the multi-drug resistance.The presence of resistance genes and integrons was determined using PCR.The aadA 1,aac(3')-IIc,aph(3')-VII,aac(6')-Ib,sul2,cat2,floR,and tet(K)genes were detected,respectively.展开更多
This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks...This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks at the age of 60 d were randomly assigned into six groups with 15 replicates per group and one mink per replicate. The minks were fed six experimental diets with two protein levels (32% and 36% ) and three fat levels ( 10% , 20% and 30% ) for a 7-day preliminary period and then for 60-day experimental period. The results showed that the final body weight and average daily weight gain (ADWG) were significantly higher in low-protein, middle-fat group and low-protein, high-fat group than those in low-protein, low-fat group and high-protein, low-fat group (P 〈 0. O1 ). The final weight and ADWG were increased with dietary fat level increasing, and the two indices of 20% and 30% fat groups were significantly higher than those of 10% fat groups ( P 〈 0. O1 ). The ratio of feed intake to weight gain (F/G) in low-protein, high-fat group was the lowest, which was significantly lower than that in low- protein, low-fat group and high-protein, high-fat group (P 〈 0.05 ). Serum urea nitrogen (UN) in low-protein, high-fat group was significantly lower than that in other groups (P 〈 0. 01 ). Serum alanine transaminase (ALT) activity in 32% protein groups was significantly higher than that in 36% protein groups (P 〈 O. 05). Serum triglyceride (TG) content in low-protein, high-fat group and high-protein, high-fat group was significantly higher than that in low-protein, low-fat group and high-protein, low-fat groups (P 〈 0.05 ). Serum TG, total cholesterol (TCHO) and high-density lipoprotein (HDL) contents increased with the increase in dietary fat level, and they were all the highest in low-protein, high-fat group. The growth performance and serum biochemical parameters of minks were not affected by the interaction between dietary protein and fat levels (P 〉 O. 05 ). Considering all the factors, when the dietary protein is 32% and the fat level is 20% to 30% under the condition of this experiment, the dietary protein and fat utilization rates are higher, and the male minks during the growing period can get a better growth performance.展开更多
基金supported by the National Key Research and Development Program of China(2021YFC2301700)the Natural Science Foundation of Heilongjiang Province,China(YQ2022C040)。
文摘Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generated 3 recombinant rabies viruses(RABV),rERAG_(333E)/S6P,rERAG_(333E)/DS6P and rERAG_(333E)/BA2S6P,expressing the prefusion-stabilized SARS-CoV-2 spike protein of wild-type(S6P),δ(DS6P)or BA.2(BA2S6P)strain based on an oral rabies vaccine candidate(rERAG_(333E)).Oral or inactivated immunization of the 3 RABVs monovalent or trivalent were safe,and induced robust RABV neutralizing antibody and cross-antibody responses against the three SARS-CoV-2 in mice and minks.The challenge tests showed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts,and largely prevented viral replication and lung damage caused by wild-type SARS-CoV-2infection in minks.Notably,we also confirmed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine can largely protect minks against wild-type SARS-CoV-2 transmission via respiratory droplets.Our findings suggest that rERAG_(333E)-based COVID-19 vaccines appear to be suitable oral candidates to protect minks from SARS-CoV-2infection and transmission,and may serve as inactivated vaccines for further investigation in humans.
基金financially supported by the National Key Research and Development Program of China (No. 2017YFD0500103)the National Natural Science Foundation of China (No. 31772747)+2 种基金the Science and Technology Development Project of Jilin Province (No. 20170623043TC)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, No. 2017TD-28)the Fundamental Research Funds for the Central Universities
文摘Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014;Ge et al. 2018).
基金Supported by Foundation for Innovation Team of Special Animal Genetic Resources of Chinese Academy of Agricultural Sciences~~
文摘Growth curves of Minghua black minks at 0-180 days old were fitted and analyzed by using two growth models Logistic and Gompertz. The results showed that the growth curves of Minghua black minks could be fitted very well by Logistic model and Gompertz model (the degree of fitting FF≥0.99), but Gompertz model was better at fitting and predicting their weight.
基金Supported by Fund of Hebei Science and Technology Department(10960408D01)~~
文摘[Objective] This study aimed to test the sensitivity of Eperythrozoon from mink to various drugs in vitro. [Method] The red blood cells isolated from Eperythro- zoon positive mink was cultured in complete medium (70% RPMI-1640 medium and 30% calf serum), supplemented with bernier, oxytetracycline, trichlorfon, tylosin, imi- docarb, florfenicol, Fuhongjuesha or primaquine phosphate at the working concentra- tions of 12, 24, 36, 48 and 96 μL/ml, incubated at 37.3 ℃, 5% CO2. [Result] Fuhongjuesha was most efficient for killing Eperythrozoon, followed by trichiorfon and primaquine phosphate, but trichlorfon is toxic. Bernier, imidocarb and florfenicol are efficient. [Conclusion] The study provides a scientific reference for clinical treatment of eperythrozoonosis.
基金Supported by Science and Technology Support Program of Qinhuagndao City~~
文摘[Objective] The paper was to diagnose and treat hemorrhagic pneumonia of mink. [Method] The diseased minks bred by one raiser in Huangtian Village of Changli County in Qinhuangdao City were used as experimental materials. It was necropsied, and its tissues such as liver, kidney, spleen and lung were taken under aseptic condition, then inoculated into general nutrition agar and blood agar. The bacteria were isolated and purified, and the strains obtained were carried out animal inoculation test and drug sensitivity test. Finally, the relevant treatment and preven- tive measures were put forward. [Conclusion] The bacteria isolated were detected to be negative by Gram staining; it formed hemolysis ring in blood agar; the bacteria could ferment glucose and xylose, which could not ferment sucrose, lactose, maltose and esculin; it was positive in catalase and oxidase test, and negative in urease test and hydrogen sulfide test; so the strain was indentified to be Pseudomonas aerugi- nosa. Drug sensitivity test showed that the bacteria were highly sensitive to ciprofloxacin, which had tolerance to cefoxitin. [Conclusion] The study laid foundation for diagnosis and treatment of hemorrhagic pneumonia of mink.
基金Supported by the Health Department of Shandong Province,No,1999CA1CBA3
文摘AIM: To establish a new, reliable vomit model of minks METHODS: Adult male minks were randomly divided into 8 groups (n=6): cisplatin (7.5 mg/kg) intraperitoneal injection (ip) group, copper sulfate (40 mg/kg) intragastric injection (ig) group, apomorphine (1.6 mg/kg) subcutaneous injection (sc) group, and 18 Gy whole-body X-irradiation group, ondansetron injection group (2 mg/kg ip) 30 min later followed by cisplatin (7.5 mg/kg) ip, normal saline (NS) ip injection control group, metoclopramide injection group (4 mg/kg ip) 30 rain later followed by apomorphine (1.6 mg/kg) sc, NS ig control group. The frequency of retching and vomiting was calculated. After behavioral experiment, distribution of 5-HT in the ileum was detected by immunohistologic method. RESULTS: Cisplatin, apomorphine, copper sulfate and X-irradiation administered to minks evoked a profound emetic response in the animals. However, retching and vomiting were significantly inhibited by pretreatment with ondansetron and metoclopramide in cisplatin and copper sulfate groups (P=0.018). Immunohistologic result showed that 5-HT released from enterochromaffin cells (EC cells) was involved in vomiting mechanism. CONCLUSION: Mink vomit model has a great value in studying the vomiting mechanism and screening new antiemetic drugs.
基金supported by Special Fund for Public Welfare Technology Research of Agricultural Industry (200903014)
文摘A study was conducted to evaluate production performance of minks in growing-furring period with supplementing DL-Methinnine (Met) in low protein diet. Seventy healthy male minks were randomly divided into five groups of 14 minks each. The minks were fed in five kinds of experiment diets (HP, LP, LP+M1, LP+M2 and LP+M3). The dietary protein levels, expressed as percentage of dry matter (DM), were 32% (high protein, HP) and 24% (low protein, LP). LP was supple- mented with Met 0.4% (M1), 0.8% (M2) and 1.2% (M3) DM. From mid of September to December 10, apparent digestibility of CP (crude pro- tein), N intake and urinary N excretion were decreased with declining dietary protein levels (p 〈 0.05) and N retained was the highest in treat- ment LP+M2. No significant difference was found in total serum protein (TP) and serum urea nitrogen (SUN) among all treatment groups (p 〉 0.05). Skin length of treatment HP and LP^M2 was higher than that of other groups (p 〈 0.05). Body length, skin weight, length of guard hair and under hair were not affected by different dietary protein levels (p〉0.05). The best performance could be observed in treatment LP+M2. In diet, 24% (DM) protein level with 1.54% Met supplementing was enough for minks during growing-farring period. Dietary protein lowered from 32% to 24% with supplementing Met in diets would result in a37.9% decrease in urinary N excretion. Furthermore, addition of Met in diets for minks would be beneficial in terms of reducing feed expenses and lessening nitrogen emissions to the environment.
文摘Self-biting disease occurred in most farmed fur animals in the world. The mechanism and rapid detection method of this disease has not been reported. We applied bulked sergeant analysis (BSA) in combination with RAPD method to analyze a molecular genetic marker linked with self-biting trait in mink group. The molecular marker was converted into sequence-characterized amplified regions (SCAR) marker for rapid detection of this disease. A single RAPD marker A8 amplified a specific band of 263bp in self-biting minks, which was designated as SRA8-250, and non-specific band of 315bp in both self-biting and healthy minks. The sequences of the bands exhibited 75% and 88% similarity to Canis familiarizes major histocompatibility complex (MHC) class II region and Macaca mulatta MHC class I region, respectively. A SCAR marker SCAR-A8 was designed for the specific fragment SRA8-250 and validated in 30 self-biting minks and 30 healthy minks. Positive amplification of SCAR-A8 was detected in 24 self-biting minks and 12 healthy minks. χ2 test showed significant difference (p〈0.01) in the detection rate between the two groups. This indicated that SRA8-250 can be used as a positive marker to detect self-biting disease in minks. Furthermore, the finding that self-biting disease links with MHC genes has significant implications for the mechanism of the disease.
文摘Inter-simple Sequence Repeat (ISSR) analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers produced 35 discernible bands, with 30 (85.71%) being polymorphic, indicating high genetic diversity at the species level. The highest genetic diversity was observed in the brown mink population, whereas the lowest diversity was found in the standard-pitchy mink population. Based on genetic distance (1972), a dendrogram was constructed by using UPGMA algorithm, and five populations were divided into two major groups. Group I consisted of only the standard-pitchy mink population, and Group II included other four populations, in Group II, sapphire mink was close to brown mink population. The results of genetic differentiation indicated that the genetic differentiation degree between populations was lower and the genetic variation primarily came from within populations. This paper showed that ISSR technique was a reliable tool that could be used to study genetic diversity in the mink.
基金China Postdoctoral Sustentation Fund(NO.20100470565)Hebei Sustain Program of Science and Technology(NO.10960408D)Qinhuangdao Scientific and Technological Development Program(NO.201101A182)
文摘[Objective] This paper aimed to study the mechanism of diarrhea of mink caused by Escherichia coil [Method] Through the detection of K88 fimbriae gene of E. coli, cloning of gene fragments and identification, then PCR amplification was used to detect adhesion factor K88 gene, which was connected to T-vector and transformed into competent cells, and positive clones were selected. [ Results] E. coli 078, 029 and 038 were isolated from organs and feces of mink died of diarrhea in 3 mink farms, respectively, the 3 serotypes of E. coliwere detected in carrying K88 fimbriae gene and 3 positive clones were screened, respectively. [ Conclusion] The E. coli causing mink diarrhea carry K88 fimbriae gene.
基金supported by the Innovation Project Foundation of Chinese Academy of Agricultural Sciences(20140204066NY)Development Plan of Science and Technology in Jilin Province(20150520128JH)the Special Fund for Agro-Scientific Research in the Public Interest from the Ministry of Agriculture,China(201303042)
文摘There were 4 Acinetobacter lwoffii obtained from soil samples.The antimicrobial susceptibility of the strains to 16 antimicrobial agents was investigated using K-B method.Three isolates showed the multi-drug resistance.The presence of resistance genes and integrons was determined using PCR.The aadA 1,aac(3')-IIc,aph(3')-VII,aac(6')-Ib,sul2,cat2,floR,and tet(K)genes were detected,respectively.
基金Supported by Natural Foundation of Jilin Provincial Department of Science and Technology(20150101112JC)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences
文摘This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks at the age of 60 d were randomly assigned into six groups with 15 replicates per group and one mink per replicate. The minks were fed six experimental diets with two protein levels (32% and 36% ) and three fat levels ( 10% , 20% and 30% ) for a 7-day preliminary period and then for 60-day experimental period. The results showed that the final body weight and average daily weight gain (ADWG) were significantly higher in low-protein, middle-fat group and low-protein, high-fat group than those in low-protein, low-fat group and high-protein, low-fat group (P 〈 0. O1 ). The final weight and ADWG were increased with dietary fat level increasing, and the two indices of 20% and 30% fat groups were significantly higher than those of 10% fat groups ( P 〈 0. O1 ). The ratio of feed intake to weight gain (F/G) in low-protein, high-fat group was the lowest, which was significantly lower than that in low- protein, low-fat group and high-protein, high-fat group (P 〈 0.05 ). Serum urea nitrogen (UN) in low-protein, high-fat group was significantly lower than that in other groups (P 〈 0. 01 ). Serum alanine transaminase (ALT) activity in 32% protein groups was significantly higher than that in 36% protein groups (P 〈 O. 05). Serum triglyceride (TG) content in low-protein, high-fat group and high-protein, high-fat group was significantly higher than that in low-protein, low-fat group and high-protein, low-fat groups (P 〈 0.05 ). Serum TG, total cholesterol (TCHO) and high-density lipoprotein (HDL) contents increased with the increase in dietary fat level, and they were all the highest in low-protein, high-fat group. The growth performance and serum biochemical parameters of minks were not affected by the interaction between dietary protein and fat levels (P 〉 O. 05 ). Considering all the factors, when the dietary protein is 32% and the fat level is 20% to 30% under the condition of this experiment, the dietary protein and fat utilization rates are higher, and the male minks during the growing period can get a better growth performance.