ABSTRACT
At present, many infectious pathogens, especially emerging/re-emerging pathogens, exist in the blood of voluntary blood donors and may be transmitted through blood transfusions. However, most of Chinese blood centers only routinely screen for HBV, HCV, HIV, and syphilis. We employed metagenomic next-generation sequencing (mNGS) to investigate the microbiome in healthy voluntary blood donors to help assess blood safety in China by identifying infectious pathogens presented in donations that could lead to transfusion-acquired infections. We collected 10,720 plasma samples from voluntary blood donors from seven blood centers in different cities during 2012-2018 in China. A total of 562 GB of clean data was obtained. By analyzing the sequencing data, it was found that the most commonly identified bacteria found in the healthy blood were Serratia spp. (5.0176%), Pseudomonas spp. (0.6637%), and Burkholderia spp. (0.5544%). The principal eukaryote were Leishmania spp (1.3723%), Toxoplasma gondii (0.6352%), and Candida dubliniensis (0.1848%). Among viruses, Human Parvovirus B19 (B19V) accounts for the highest proportion (0.1490%), followed by Torque teno midi virus (0.0032%) and Torque teno virus (0.0015%). Since that B19V is a non-negligible threat to blood safety, we evaluated the positive samples for B19V tested by mNGS using quantitative polymerase chain reaction, Sanger sequencing, and phylogenetic analysis to achieve a better understanding of B19V in Chinese blood donors. Subsequently, 9 (0.07%) donations were positive for B19V DNA. The quantitative DNA levels ranged from 5.58 × 102 to 7.24 × 104 IU/ml. The phylogenic analyses showed that prevalent genotypes belonged to the B19-1A subtype, which disclosed previously unknown regional variability in the B19V positivity rate. The investigation revealed that many microbes dwell in the blood of healthy donors, including some pathogens that may be dormant in the blood and only cause disease under specific conditions. Thus, investigating the range and nature of potential pathogens in the qualified donations provided a framework for targeted interventions to help prevent emerging and re-emerging infectious diseases.
ABSTRACT
【Objective】 To analyze the metagenomics and microbiology of voluntary blood donors in China, so as to assess the potential threats of emerging infectious diseases to the safety of blood transfusion. 【Methods】 12 300 plasma samples (10 mL each) collected by central blood stations in Chongqing, Liuzhou, Urumqi, Mianyang, Wuhan, Nanjing, Mudanjiang, and Dehong Prefecture area from 2012 to 2018 were subjected to total DNA extraction after ultracentrifugation (32 000 rpm/min, centrifugal radius 91.9 mm) in minipools of 160 donations. The metagenomic library was constructed, and deep sequencing was conducted by Illumina Hiseq 4 500. By comparing with reference sequences of bacteria, fungi, parasites and viruses, metagenomic data were analyzed, classification of microbes were identified, and potentially harmful pathogens were evaluated. 【Results】 A total of 632 GB clean data were obtained by deep sequencing, and the top three pathogens were Pseudomonas(0.561 1%), Burkholderia(0.468 7%) and Serratia(4.242 0%). Pathogens with potential threat which could be transmitted by blood transfusion or blood products were found, such as human parvovirus B19(0.126 6%), Leishmania spp(1.348 5%) and Toxoplasma gondii(0.615 8%). 【Conclusion】 Our study analyzed metagenomics of voluntary blood donors in parts of China and revealed pathogens that may cause potential harm to blood safety, which were helpful for targeted prevention and control of emerging infectious diseases.
ABSTRACT
OBJECTIVE：To study the prepar ation technology of gastric floating tablets of Schisandra chinensis total lignans （SCTL），and evaluate the quality of prepared tablets. METHODS ：Based on single factor test ，the orthogonal experiment was conducted to optimize the formulation of SCTL gastric floating tablets with the contents of hydroxypropylmethylcellulose （HPMC） K15M，NaHCO3 and microcrystalline cellulose as the factors ，using starting time ，holding time and cumulative release rate of gastric floating tablets as evaluation indexes. The properties ，weight difference ，floatability and accumulative release rate of the prepared SCTL gastric floating tablets were determined. The gastric floating tablets were qualitatively identified by TLC ，and the contents of schisandrin A and total lignans were determined by HPLC and UV spectrophotometry. RESULTS ：The optimal formulation of SCTL gastric floating tablets was made up of 23％ SCTL extract ，20％ HPMC K 15M，40％ microcrystalline cellulose，15％ sodium bicarbonate ，1％ octadecyl alcohol and 1％ polyvinylpyrrolidone. The results of detection of this preparation were in line with the related provisions of “0101 tablet”stated in 2015 edition of Chinese Pharmacopoeia （part Ⅳ）. TLC indicated that the chromatogram of the test sample showed the main spots of same color as the corresponding positions of the chromatogram of schizandrol A control ，Schisandra chinensis reference substance and raw material ，while the negative control has no interference. Content determination results shows that the average content of schizandrol A and total lignans in SCTL gastric floating tablets is 3.187，19.617 mg. It was preliminarily formulated that the content limitation of schizandrol A in one tablet should not be less than 2.50 mg，and the content of total lignans （calculated by schizandrol A ）should not be less than 15.50 mg. CONCLUSIONS：The preparation technology of SCTL gastric floating tablets is stable ，feasible and controllable in quality.