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 explore a simplified and economical method to isolate the murine primary pancreatic acinar cells.Methods The collagenase and trypsin inhibitor dissolving in DMEM solution were used to digest the murine pancreas,and 4％ BSA dissolving in DMEM solution was used to purify and isolate primary pancreatic acinar cells from pancreas.CCK-8 method was applied to check the ability of pancreatic acinar cells to secret amylase.Results After digestion,shaking in the water bath,resuspension,filtration and precipitation,murine primary pancreatic acinar cells could be obtained within 2 hours.Pancreatic acinar cells in good conditions appeared in clusters,and their basolateral domains were round and devoid of blebs,and the cytoplasm appeared clear.Their apical domain were surrounded by hundreds of zymogen granules which looked darker.The nucleus was located in the basal area of the vesicular region.The basal level of amylase release as a percent of total release from pancreatic acinar cells was around 2.5％ in CCK8-unstimulated group.This rate started to increase after CCK-8 stimulation and reached its peak [(12.83 ± 1.04) ％] at a concentration of 50 pmol/L of CCK-8,but the ratio of the amylase level secreted by the pancreatic acinar cells to the total amylase level displayed a decreasing trend with the increase of CCK-8 concentration.Conclusions This optimized method had the advantage of being fast and simple,low technical difficulty and good repetition.It was a new simplified and cheap method for isolating murine pancreatic acinar cells.
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Objective To investigate the alternations in gene/amino acid sequence of penicillin-binding protein (PBP) 2b from clinical isolates of penicillin-nonsusceptible Streptococcus pneumonia(PNSP) in this region.Methods 24 strains of Streptococcus pneumonia were collected from January to December 2006.The antibiotics susceptibility of these strains was detected.PCR amplification and direct sequencing of pbp2b genes were performed.The sequence variations of PBP genes of the PNSP in this region were studied with sequence BLAST analysis.Results Three prominent substitutions were common tO 13 PNSP isolates with minimal inhibitory concentration(MIC) at least 0.1 mg/L.These included the replacement of Thr445→Ala following the conservative motif SSN,Glu475→Gly and Thr488→Ala/Ser.The exchange of Glu332→Gly was identified in 12 PNSP isolates of which the MIC was at least 0.25 mg/L.Seven penicillin resistant Streptococcus pneumonia (PRSP) isolates (MIC≥3 mg/L)shared the amino acid substitution Ala618→Gly adiacent to third conserved (KTG) motif and the PBP2b sequences of seven PRSP isolates were classified within Back's group Ⅱ and were very similar to those of the Korean J77 isolate.Novel gene and amino acid sequence variants in isolate 14,15,8,11 and 24 was identified in this study and these gene sequences have been deposited in the GenBank database and assigned accession no.EU035970,EU056919,EU056920,EU056921 and EU106886.Conclusion Analysis of pbp2b genes revealed highly similar patterns of nucleotide and amino acid sequence variation among most resistant isolates.while penicillin intermediate Streptococcus pneumonia might be associated with novel gene sequence variants.
ABSTRACT
OBJECTIVE To observe the clinical efficacy of cefminox for the treatment of bacterial liver abscess. METHODS Totally 118 patients with bacterial liver abscess were treated with cefminox 2 g iv drip 12 h or 8 h for(5-10 d),then with cefminox 1 g in drip 12 h for 21-35 d. RESULTS The total cure rate was 89.4%,the overall efficacy rate was 97.6%,and side effect rate was 2.4%. CONCLUSIONS Cefminox is an effective antibiotic in treating bacterial liver abscess.
