ABSTRACT
@#Objective To develop and verify a multiplex fluorescent quantitative PCR method for detection of common bacterial and fungal contaminants in cell culture medium.Methods According to NUC gene of Staphylococcus aureus,COLA gene of Clostridium spore,ITS-2 segment sequence of Candida albicans,a set of primers and probes were designed for each respectively,and using UBI3 gene of capsicum introduced as external standard gene,a triple reaction system of Staphylococcus aureus,Clostridium spore and external standard gene and a double reaction system of Candida albicans and external standard gene were established.The primer specificity,linear range,limit of detection,specificity,anti-interference performance and precision of the method were verified.Finally,100 samples of 293T cell culture medium were detected by using the developed method,which was compared with the common PCR method.Results Three pairs of primers all amplified about 100 bp specific gene bands corresponding to the three strains at different annealing temperatures(56,57,58 and59 ℃),and the size was consistent with the expected.In the range of 5.80 × 10~6 — 5.80 × 10~2 copies/μL,the standard plasmids of the three strains showed a good linear relationship with the Ct values.The standard curve equations were:Y=-3.373 X+37.48,Y=-3.557X+36.59 and Y=-3.536 X+39.78,each R~2> 0.99,respectively,and the amplification efficiency was in the range of 90%—110%.All the limits of detection of the three strains were 10~1 CFU/mL.The primers and probes of the three strains showed no specific amplification on the genomic DNA of six kinds of cells that were prone to cross-reaction.The genomic DNA of 293T cells,Yeast,Escherichia coli and Mycoplasma sp.had no effect on the detection.The CVs of repeatability and intermediate precision verification were both less than 15%.Among 100 cell culture medium samples,14 positive and 86 negative samples were detected,and the results of common PCR method for three positive and two negative samples randomly selected were consistent with the developed method.Conclusion The multiplex fluorescent quantitative PCR method developed in this study for the detection of bacteria and fungi in cell culture medium has good specificity,anti-interference performance and precision,and is simple to operate with low cost and high sensitivity,which can quickly detect the contaminants during cell culture.
ABSTRACT
@#Objective To develop and verify a multiplex fluorescent quantitative PCR method for detection of common bacterial and fungal contaminants in cell culture medium.Methods According to NUC gene of Staphylococcus aureus,COLA gene of Clostridium spore,ITS-2 segment sequence of Candida albicans,a set of primers and probes were designed for each respectively,and using UBI3 gene of capsicum introduced as external standard gene,a triple reaction system of Staphylococcus aureus,Clostridium spore and external standard gene and a double reaction system of Candida albicans and external standard gene were established.The primer specificity,linear range,limit of detection,specificity,anti-interference performance and precision of the method were verified.Finally,100 samples of 293T cell culture medium were detected by using the developed method,which was compared with the common PCR method.Results Three pairs of primers all amplified about 100 bp specific gene bands corresponding to the three strains at different annealing temperatures(56,57,58 and59 ℃),and the size was consistent with the expected.In the range of 5.80 × 10~6 — 5.80 × 10~2 copies/μL,the standard plasmids of the three strains showed a good linear relationship with the Ct values.The standard curve equations were:Y=-3.373 X+37.48,Y=-3.557X+36.59 and Y=-3.536 X+39.78,each R~2> 0.99,respectively,and the amplification efficiency was in the range of 90%—110%.All the limits of detection of the three strains were 10~1 CFU/mL.The primers and probes of the three strains showed no specific amplification on the genomic DNA of six kinds of cells that were prone to cross-reaction.The genomic DNA of 293T cells,Yeast,Escherichia coli and Mycoplasma sp.had no effect on the detection.The CVs of repeatability and intermediate precision verification were both less than 15%.Among 100 cell culture medium samples,14 positive and 86 negative samples were detected,and the results of common PCR method for three positive and two negative samples randomly selected were consistent with the developed method.Conclusion The multiplex fluorescent quantitative PCR method developed in this study for the detection of bacteria and fungi in cell culture medium has good specificity,anti-interference performance and precision,and is simple to operate with low cost and high sensitivity,which can quickly detect the contaminants during cell culture.
ABSTRACT
Objective @#To understand the epidemiological characteristics of notifiable respiratory infectious diseases in Huzhou City, Zhejiang Province from 2017 to 2022, so as to provide insights into formulation of respiratory infectious disease prevention and control strategies.@*Methods@#The data pertaining to notifiable respiratory infectious disease in Huzhou City from 2017 to 2022 were collected through the Infectious Disease Report Information System of Chinese Disease Prevention and Control Information System. Epidemiological characteristics of notifiable respiratory infectious disease was analyzed using a descriptive epidemiological method.@*Results@#@*Conclusions@#A total of 31 314 cases of notifiable respiratory infectious diseases were reported in Huzhou City from 2017 to 2022, with an average annual reported incidence of 169.12/105. The reported incidence of notifiable respiratory infectious diseases appeared a tendency towards a rise in Huzhou City from 2017 to 2022 (P<0.05). The top six reported diseases in terms of case numbers were influenza (20 048 cases), tuberculosis (6 920 cases), COVID-19 (1 893 cases), mumps (1 413 cases), pertussis (475 cases) and scarlet fever (442 cases), accounting for 99.61% of the total cases. The incidence of influenza, COVID-19 and pertussis showed a tendency towards a rise, the incidence of mumps and tuberculosis showed a tendency towards a decline (all P<0.05), and scarlet fever remained at a low-level incidence (P>0.05). Respiratory infectious diseases were mainly reported in winter (January, February and December), with 14 644 cases accounting for 46.77%. There were 15 068 cases reported in schools and kindergartens, accounting for 48.12%. The incidence showed a U-shaped variation with age, with the highest incidence in residents at ages of 10 years and below (987.68/105), and showing a tendency towards a rise in residents at ages of 60 years and above. @*@#The incidence of respiratory infectious diseases in Huzhou City from 2017 to 2022 increased significantly. Influenza, tuberculosis, COVID-19, mumps and pertussis are key notifiable respiratory infectious diseases. Residents at ages of 10 years and below and 60 years and above should be given a high priority for respiratory infectious disease control.
ABSTRACT
Objective@#To investigate the trends in incidence and epidemiological characteristics of notifiable infectious diseases in Huzhou City, Zhejiang Province from 2005 to 2023, so as to provide insights into optimizing infectious disease surveillance and control.@*Methods@#Data of notifiable infectious disease cases in Huzhou City from 2005 to 2023 were collected from the Infectious Disease Report Information System of Chinese Disease Prevention and Control Information System. Trends in incidence were analyzed using annual percent change (APC) and average annual percent change (AAPC). The population distribution and seasonal characteristics were descriptively analyzed.@*Results@#From 2005 to 2023, a total of 504 283 cases of notifiable infectious diseases were reported in Huzhou City, with an annual crude incidence rate of 892.65/105 and a standardized incidence rate of 989.21/105. The incidence rate of notifiable infectious diseases in Huzhou City showed an upward trend (AAPC=8.886%, P<0.05), of which there was an obvious upward trend from 2021 to 2023 (APC=95.996%, P<0.05). After the removal of COVID-19 incidence, the incidence trend was basically unchanged (AAPC=7.970%, P<0.05). From 2005 to 2023, the incidence rate of class A and B notifiable infectious diseases showed no obvious trend (P>0.05), and the incidence rate of class A and B respiratory infectious diseases showed an upward trend (AAPC=6.958%, P<0.05). After the removal of COVID-19 incidence, the two showed a downward trend (AAPC=-7.680% and -8.660%, both P<0.05). The incidence rate of class A and class B intestinal infectious diseases, blood-borne and sexually transmitted infectious diseases showed a downward trend (AAPC=-14.849% and -5.977%, both P<0.05), while the incidence rates of natural and insect-borne infectious diseases did not show a significant trend (P>0.05). The overall incidence rate of class C infectious diseases showed an upward trend (AAPC=13.058%, P<0.05). The incidence rate ratio (IRR) of notifiable infectious diseases between males and females was 1.26 (95%CI: 1.25-1.27). A total of 204 043 cases under 10 years were reported, accounting for 40.46%. The peak incidence of class A and B respiratory infectious diseases was in January, May and June, while that of class A and B intestinal infectious diseases was from June to October. The peak incidence of class C respiratory infectious diseases was in January, March, April and December, while that of class C intestinal infectious diseases was from May to August and from November to December.@*Conclusions@#The incidence rate of notifiable infectious diseases in Huzhou City showed an upward trend from 2005 to 2023, which was more obvious from 2021 to 2023. Men and children under 10 years were the high-risk population. The incidence of respiratory and intestinal infectious diseases had obvious seasonal characteristics.
ABSTRACT
Objective@#To analyze the epidemiological characteristics of pertussis in Huzhou City, Zhejiang Province from 2012 to 2022, so as to provide insights into formulation of pertussis control measures.@*Methods@#The data of reported pertussis cases in Huzhou City from 2012 to 2022 were collected through the Infectious Disease Report Information System of Chinese Disease Prevention and Control Information System. The temporal, spatial and population distributions of pertussis cases in Huzhou City from 2012 to 2022 were analyzed using a descriptive epidemiological method.@*Results@#A total of 499 pertussis patients were reported in Huzhou City from 2012 to 2022, with mean annual reported incidence of 1.508/105, and no death was reported. The reported incidence of pertussis remained at a low level in Huzhou City from 2012 to 2021, all below 1/105, and increased to 12.625/105 in 2022. The reported incidence of pertussis appeared an overall tendency towards a rise in Huzhou City from 2012 to 2021 (Z=-29.261, P<0.001). The incidence of pertussis peaked from June to July, and a relatively higher incidence rate of pertussis was reported in Deqing (6.359/105) and Anji counties (1.725/105), while higher incidence was found among children at ages of <1 year (30.566/105), 4 years (31.896/105) and 5 years (29.485/105). @*Conclusion@#The reported incidence of pertussis was at a low level in Huzhou City from 2012 to 2021, and increased sharply in 2022. The incidence of pertussis peaked from June to July, was concentrated in Deqing and Anji counties and higher among infants under one year of age and preschool children at ages of 4 to 5 years.
ABSTRACT
Background: Banana (Musa spp.) is an important staple food, economic crop, and nutritional fruit worldwide. Conventional breeding has been seriously hampered by their long generation time, polyploidy, and sterility of most cultivated varieties. Establishment of an efficient regeneration and transformation system for banana is critical to its genetic improvement and functional genomics. Results: In this study, a vigorous and repeatable transformation system for banana using direct organogenesis was developed. The greatest number of shoots per explant for all five Musa varieties was obtained using Murashige and Skoog medium supplemented with 8.9 µM benzylaminopurine and 9.1 µM thidiazuron. One immature male flower could regenerate 380456, 310372, 200240, 130156, and 100130 well-developed shoots in only 240270 d for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Longitudinal sections of buds were transformed through particle bombardment combined with Agrobacterium-mediated transformation using a promoterless ß-glucuronidase (GUS) reporter gene; the highest transformation efficiency was 9.81% in regenerated Gongjiao plantlets in an optimized selection medium. Transgenic plants were confirmed by a histochemical assay of GUS, polymerase chain reaction, and Southern blot. Conclusions: Our robust transformation platform successfully generated hundreds of transgenic plants. Such a platform will facilitate molecular breeding and functional genomics of banana.