ABSTRACT
Objective To understand the genetic variations of neuraminidase (NA) genes of avian influenza virus H9N2 in Weining,Guizhou Province,and to provide the scientific evidence for the prevention and control of avian influenza virus.Methods Ribonucleic acids (RNA) were extracted and NA genes were amplified and sequenced from 13 randomly selected H9N2 positive samples from the live poultry market (LPM)environments in north of Weining Yi and Hui and Miao autonomous county (Weining),Guizhou Province during 2015 to 2017.Then the homology,genetic evolution,and sites of stalk deletion areas,potential N-glycosylation,receptor binding regions and drug resistance of H9N2 subtype avian influenza viruses were analyzed by a series of bioinformation software.Results Homology analysis revealed that there were 93.0％-100.0％ and 92.1％-100.0％ similarity among 13 strains H9N2 avian influenza viruses in nucleotide and amino acid of the NA gene,respectively.All strains belonged to DK/HK/Y280/97 sub-lineage,but their genetic sources were complex and diverse.Thirteen strains had a stalk deletion of 3 amino acid residues TEI at positions 63-65 and 3 isolates had mutation QN to QK at positions 39-40.The potential N-glycosylation sites at amino acid residues 86,146,200,and 234 of the NA protein of all strains were highly conserved,while other N-glycosylation sites had quantity and site mutations.There were different mutation types at the three sialic acid binding site areas,especially at 399-404 area.All NA protease activity sites and key sites of the 13 strains had no mutations associated with resistance to the neuraminidase inhibitor drugs.Conclusions All 13 strains H9N2 viruses belongs to DK/HK/Y280/97 sub-lineage in Weining,Guizhou Province during 2015-2017,and their genetic sources are complex and diverse.The mutations on sites of stalk areas,potential N-glycosylation and sialic acid binding site areas are presented at different degrees.Hence,enhancing surveillance and controlling H9N2 avian influenza virus is necessary.
ABSTRACT
Objective To analyze the serotype distribution and antibiotic resistance characteristics of food-borne Salmonella strains isolated from food and patients with gastroenteritis in Guizhou Province from 2016 to 2018. Methods Serotypes of the strains were characterised using slid agglutination method with Salmonella antisera. Minimal inhibitory concentrations (MIC) of antibiotics were determined by the broth microdilution method. Microsoft Excel 2007 and SPSS18. 0 were used for statistical analysis. Results A to-tal of 170 strains of food-borne Salmonella were detected in food and patients with gastroenteritis in Guizhou Province from 2016 to 2018. Thirty-five serotypes were identified and 6 were found in both food and pa-tients. The main serotypes in food were Salmonella Typhimurium ( 16. 67％ ) and Salmonella Stanley (8. 33％ ), and the predominant serotypes in patients were Salmonella Typhimurium (41. 79％ ), Salmonel-la Enteritidis (16. 42％ ) and Salmonella London (8. 96％ ). The rate of resistance to ampicillin, chloram-phenicol, tetracycline, ciprofloxacin, nalidixic and trimeth-sulfame were 27. 78％ -33. 33％ among the iso-lates from food, and 22. 22％ -25. 00％ to gentamicin, cefocime and ampicillin/ sulbatan. Among the isolates from patients, the highest resistance was to ampicillin ( 55. 97％ ), followed by that to tetracycline (49. 25％ ), ampicillin/ sulbatan (44. 03％ ), nalidixic acid (41. 04％ ) and cefazolin (37. 31％ ), and 20. 90％ -30. 60％ strains were resistant to chloramphenicol, ciprofloxacin, gentamicin, cefotaxime and am-picillin/ sulbatan. There were 25. 00％ isolates from food and 25. 37％ isolates from patients resistant to at least 6 antibiotics, and the main multi-resistant pattern was ampicillin-tetracyline-nalidixic-cephalosporin an-tibiotics (partial). Conclusions There were many kinds of serotypes of food-borne Salmonella in Guizhou Province from 2016 to 2018 and the predominant types were Salmonella Typhimurium, Salmonella Enteritidis and Salmonella London. Drug resistance was common in the strars and some multidrug resistant strains were detected.
ABSTRACT
Objective@#To analyze the serotype distribution and antibiotic resistance characteristics of food-borne Salmonella strains isolated from food and patients with gastroenteritis in Guizhou Province from 2016 to 2018.@*Methods@#Serotypes of the strains were characterised using slid agglutination method with Salmonella antisera. Minimal inhibitory concentrations (MIC) of antibiotics were determined by the broth microdilution method. Microsoft Excel 2007 and SPSS18.0 were used for statistical analysis.@*Results@#A total of 170 strains of food-borne Salmonella were detected in food and patients with gastroenteritis in Guizhou Province from 2016 to 2018. Thirty-five serotypes were identified and 6 were found in both food and patients. The main serotypes in food were Salmonella Typhimurium (16.67%) and Salmonella Stanley (8.33%), and the predominant serotypes in patients were Salmonella Typhimurium (41.79%), Salmonella Enteritidis (16.42%) and Salmonella London (8.96%). The rate of resistance to ampicillin, chloramphenicol, tetracycline, ciprofloxacin, nalidixic and trimeth-sulfame were 27.78%-33.33% among the isolates from food, and 22.22%-25.00% to gentamicin, cefocime and ampicillin/sulbatan. Among the isolates from patients, the highest resistance was to ampicillin (55.97%), followed by that to tetracycline (49.25%), ampicillin/sulbatan (44.03%), nalidixic acid (41.04%) and cefazolin (37.31%), and 20.90%-30.60% strains were resistant to chloramphenicol, ciprofloxacin, gentamicin, cefotaxime and ampicillin/sulbatan. There were 25.00% isolates from food and 25.37% isolates from patients resistant to at least 6 antibiotics, and the main multi-resistant pattern was ampicillin-tetracyline-nalidixic-cephalosporin antibiotics (partial).@*Conclusions@#There were many kinds of serotypes of food-borne Salmonella in Guizhou Province from 2016 to 2018 and the predominant types were Salmonella Typhimurium, Salmonella Enteritidis and Salmonella London. Drug resistance was common in the strars and some multidrug resistant strains were detected.
ABSTRACT
OBJECTIVE： To establish the quality standard of Tricyrtis maculata. METHODS： The character and microstructure of T. maculata were identified according to the method stated in 2015 edition of Chinese Pharmacopoeia. The contents of moisture， ash and extract were determined. TLC was used for qualitative identification of quercetin and nicotifiorin in samples. The contents of puerarin， p-hydroxybenzoic acid， nicotiflorin， ferulic acid， quercetin and kaempferol were determined by HPLC. RESULTS： The characters and microscopic identification had specificity. TLC spots of quercetin and nicotifiorin were clear and well-separated without interference from negative control. The water content， total ash content， acid insoluble ash content， alcohol soluble extract and water soluble extract for 10 batches of samples were 0.61％-1.89％，6.28％-8.88％，0.76％-1.79％，1.31％-2.00％ and 9.39％-14.27％， respectively. The linear range of puerarin， p-hydroxybenzoic acid， nicotiflorin， ferulic acid， quercetin and kaeniphenol were 0.031 92-0.111 7 μg （r＝0.999 6）， 0.085 3-0.298 5 μg （r＝0.999 5）， 0.010 76-0.037 66 μg （r＝0.999 8）， 0.070 08- 0.245 3 μg （r＝0.999 8），0.058 56-0.205 0 μg （r＝0.999 4），0.009 860-0.033 88 μg （r＝0.999 4）， respectively. The quantitation limits were 1.06， 0.47， 0.75， 1.40， 1.20， 0.74 ng， and the detection limits were 0.36， 0.12， 0.30， 0.53， 0.60， 0.31 ng， respectively. RSDs of precision， stability and repeatability tests were all less than 2％. The average recoveries were 101.54％， 102.10％， 101.46％， 103.35％， 99.36％ and 96.85％， respectively； RSDs were 1.76％， 1.68％， 1.56％， 1.26％， 0.91％ and 1.96％， respectively （n＝6）； the results of the content were 0.017-0.047， 0.042-0.140， 0.003 8-0.015 0， 0.049-0.180， 0.024- 0.091， 0.003 9-0.011 0 mg/g. CONCLUSIONS： The established quality standard can be used for the quality control of T. maculata.
ABSTRACT
Objective To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province.Methods RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017.Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package.Results Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8％-99.2％ and 99.2％ similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO,respectively.Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2％-99.3％ and 97.6％-98.8％ similarities with vaccine strain A/Hunan/02650/2016,respectively.Other 6 stains detected in 2017 shared 99.1％-99.4％ and 98.9％-99.3％ similarities with strain A/Guangdong/17SF003/2016,respectively.Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch,but they were derived from different small branch.PEVPKRKRTAR ↓ GLF was found in 6 of 24 strains cleavage site sequences of HA protein,indicating the characteristic of highly pathogenic avian influenza virus.Mutations A134V,G186V and Q226L at the receptor binding sites were found in the HA.All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein,and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/ 18980/2017.In addition,potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains.Condusions HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017.The mutations of key sites might enhance the virulence of the virus,human beings are more susceptible to it.Hence,the risk of infection is increasing.
ABSTRACT
Objective To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province.Methods RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017.Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package.Results Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8％-99.2％ and 99.2％ similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO,respectively.Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2％-99.3％ and 97.6％-98.8％ similarities with vaccine strain A/Hunan/02650/2016,respectively.Other 6 stains detected in 2017 shared 99.1％-99.4％ and 98.9％-99.3％ similarities with strain A/Guangdong/17SF003/2016,respectively.Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch,but they were derived from different small branch.PEVPKRKRTAR ↓ GLF was found in 6 of 24 strains cleavage site sequences of HA protein,indicating the characteristic of highly pathogenic avian influenza virus.Mutations A134V,G186V and Q226L at the receptor binding sites were found in the HA.All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein,and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/ 18980/2017.In addition,potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains.Condusions HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017.The mutations of key sites might enhance the virulence of the virus,human beings are more susceptible to it.Hence,the risk of infection is increasing.
ABSTRACT
Objective To understand the epidemic characteristics and regularity of influenza B virus in Guizhou Province, and provide scientific evidence for the control and prevention of influenza.Methods Results of reverse transcription polymerase chain reaction(PT-PCR) of influenza B virus in Guizhou Province from April 1, 2013 to March 31, 2016 were statistically analyzed.Results A total of 1 904 samples were detected influenza B virus by RT-PCR, B/Yamagata (By) lineage and B/Victoria (Bv) lineage were 1 215 and 642 respectively.In April 2013-March 2014 and April 2014-March 2015, the predominant strains of influenza B were both By lineage, in April 2015-March 2016, the predominant strains of influenza B were Bv and By lineages, the epidemic peaks were in winter and spring;there's a higher positive percentage of influenza B in male, accounting for 56.83%;the highest detection rate of influenza B virus was found in population aged <15 years(70.80%),Bv and By lineages were the highest in the 0~ (42.37%) and 5~ age groups (35.56%) respectively;the main pathogen causing mixed infection was By+Bv (67.65%),mixed infection with influenza B virus accounted for 95.59%.Conclusion There are two lineages By and Bv epidemic in Guizhou Province, the epidemic peaks of influenza B are in winter and spring, male cases are higher than female, people under 15 years old are the high-risk group for influenza B, it is of great significance to strengthen the vaccination and surveillance of influenza in low age population.