Color-Coding of Microchip RT-PCR Test System for SARS-CoV-2 Detection

An RT-PCR based microchip test system for the detection of SARS-CoV-2 offers pre-loaded and lyophilized reagents in the microchip. However, the 30- and 48-microwell formats of the microchip being miniaturized and performing 1.2 μl reaction, seek visual attention during sample addition. Therefore, adding colorants as color indicator in the lyophilized matrix in the microchips or adding to sample or master mix can impart not only user-friendliness to the task of liquid handling but also precision, and color-codes for easy identification of multiple kits in the layout of the microchip without compromising PCR data quality. A panel of colorants was screened for their background intensity, spectral inertness towards detection channels of AriaDNATM analyzer, interference with the reporter dyes (FAM, Cy5 and ROX), and visibility of optimal concentration in the microwell. The concentration of the colorant displaying insignificant impact on the quality of the amplification (Ct, fluorescence, and sensitivity) in comparison to no-colorant control was chosen for inclusion in the test kit. Tartrazine, Acid Red, Brilliant Blue and FAST Green colorants lyophilized with the reagents in the SARS-CoV-2 microchips were found to be stable and suitable. Storage of microchips with Fast Green colorant was tested at 40°C, 22°C, 4°C, and -20°C for 70 days and was found to be suitable and compatible with different master mixes available as liquid or lyophilized. Additionally, the microchips pre-loaded with lyophilized reagents in the presence and absence of two colorants Tartrazine and Fast Green were validated with clinical samples of SARS-COV-2. No significant impact of these colorants both intra- and inter-microchips was observed on the Ct and intensity of amplification for the tested samples in comparison to no-colorant control. The data suggested that the tested colorants can be used to color the sample, or the master mix or PCR mix for user-friendly liquid handling in empty microchips. For the microchip with pre-loaded and lyophilized reagents, the colorant can be added to lyophilized mixture for precision liquid handling and color-coding of lyophilized kits in the microchips. The manufacturing quality of the lyophilized microchips can also improve with colorant loaded reagent mix.

Ocular manifestations and SARS-CoV-2 detection in tears and conjunctival scrape from non-severe COVID-19 patients

AIM:To explore the ocular features of corona virus disease(COVID)-19 and severe acute respiratory syndrome coronavirus(SARS-CoV)-2 detection in tears and conjunctival scrapes in non-severe COVID-19 patients.METHODS:This is a multicenter observational clinical study with no intervention conducted from Jan 25th to March 1st,2020.Clinical data and samples of tears and conjunctival scraping were collected in consecutive laboratory-confirmed,non-severe COVID-19 patients from three hospitals.COVID-19 virus was analyzed by real-time reverse transcriptase polymerase chain reaction(RT-PCR)kits.RESULTS:Totally 255 laboratory-confirmed,non-severe COVID-19 patients were recruited for ocular manifestation investigation.Of them,54.9%were females,with a mean age of 49.4 y.None of the patients has evidence of uveitis;11 patients(4.3%)complained of mild asthenopia;2(0.8%)had mild conjunctival congestion and serous secretion.Twenty-five of them had performed tears and conjunctival scrape for COVID-19 virus detection,with 4 yield possible positive results in the nucleoprotein gene.One of them were asymptomatic with normal chest CT and positive pharyngeal swab result.CONCLUSION:Ocular manifestations are neither common nor specific in non-severe COVID-19 patients.Meanwhile,COVID-19 virus nucleotides can be detected in the tears and conjunctival scrape samples,warranting further research on the transmissibility by the ocular route.

Evaluation of a Rapid Diagnostic Test, Boson Biotech SARS CoV-2 Ag, for the Detection of SARS-CoV-2 in Gabon

1) Background: Rapid and acurate diagnostic testing for case identification, quarantine, and contact tracing is essential for managing the COVID 19 pandemic. Rapid antigen detection tests are available, however, it is important to evaluate their performances before use. We tested a rapid antigen detection of SARS-CoV-2, based on the immunochromatography (Boson Biotech SARS-CoV-2 Ag Test (Xiamen Boson Biotech Co., Ltd., China)) and the results were compared with the real time reverse transcriptase-Polymerase chain reaction (RT-PCR) (Gold standard) results;2) Methods: From November 2021 to December 2021, samples were collected from symptomatic patients and asymptomatic individuals referred for testing in a hospital during the second pandemic wave in Gabon. All these participants attending “CTA Angondjé”, a field hospital set up as part of the management of COVID-19 in Gabon. Two nasopharyngeal swabs were collected in all the patients, one for Ag test and the other for RT-PCR;3) Results: A total of 300 samples were collected from 189 symptomatic and 111 asymptomatic individuals. The sensitivity and specificity of the antigen test were 82.5% [95%CI 73.8 - 89.3] and 97.9 % [95%CI 92.2 - 98.2] respectively, and the diagnostic accuracy was 84.4% (95% CI: 79.8 - 88.3%). The antigen test was more likely to be positive for samples with RT-PCR Ct values ≤ 32, with a sensitivity of 89.8%;4) Conclusions: The Boson Biotech SARS-CoV-2 Ag Test has good sensitivity and can detect SARS-CoV-2 infection, especially among symptomatic individuals with low viral load. This test could be incorporated into efficient testing algorithms as an alternative to PCR to decrease diagnostic delays and curb viral transmission.

PCR-HRM for Genomic Surveillance of SARS-CoV-2: A Variant Detection Tool in Côte d’Ivoire, West Africa

The rise of new viruses, like SARS-CoV-2 causing the COVID-19 outbreak, along with the return of antibiotic resistance in harmful bacteria, demands a swift and efficient reaction to safeguard the health and welfare of the global population. It is crucial to have effective measures for prevention, intervention, and monitoring in place to address these evolving and recurring risks, ensuring public health and international security. In countries with limited resources, utilizing recombinant mutation plasmid technology in conjunction with PCR-HRM could help differentiate the existence of novel variants. cDNA synthesis was carried out on 8 nasopharyngeal samples following viral RNA extraction. The P1 segment of the SARS-CoV-2 Spike S protein was amplified via conventional PCR. Subsequently, PCR products were ligated with the pGEM-T Easy vector to generate eight recombinant SARS-CoV-2 plasmids. Clones containing mutations were sequenced using Sanger sequencing and analyzed through PCR-HRM. The P1 segment of the S gene from SARS-CoV-2 was successfully amplified, resulting in 8 recombinant plasmids generated from the 231 bp fragment. PCR-HRM analysis of these recombinant plasmids differentiated three variations within the SARS-CoV-2 plasmid population, each displaying distinct melting temperatures. Sanger sequencing identified mutations A112C, G113T, A114G, G214T, and G216C on the P1 segment, validating the PCR-HRM findings of the variations. These mutations led to the detection of L452R or L452M and F486V protein mutations within the protein sequence of the Omicron variant of SARS-CoV-2. In summary, PCR-HRM is a vital and affordable tool for distinguishing SARS-CoV-2 variants utilizing recombinant plasmids as controls.

Contribution of Genomic Surveillance in the Detection and Monitoring of SARS-CoV-2 Variants during the 6 Pandemic Waves in the Central African Republic from 2020 to 2023

Objective: The COVID-19 pandemic has highlighted the need to strengthen diagnosis and genomic surveillance capacities. In 2021, Central African managed five waves of COVID-19 by integrating genomic surveillance into their health monitoring system. This study sought to report surveillance data from the National Laboratory of Clinical Biology and Public Health and describe the circulation of SARS-CoV-2 variants. Materials and Methods: This retrospective, descriptive observational study spans three years, from April 2020 to November 2023. It was conducted on a population of consenting volunteers from across the Central African Republic, who were tested using RT-PCR on nasopharyngeal samples. Data with sufficient information were obtained from the National Laboratory of Clinical Biology and Public Health (LNBCSP) databases. Sequencing was largely carried out at the National Institute of Biomedical Research (INRB) in Kinshasa until May 2023, and subsequently at the LNBCSP. Results and Discussion: Out of 97,864 RT-PCR tests performed, 9,764 were positive, resulting in a prevalence of 9.98%. The average age of the patients was 39.97 years ± 13.76, and the male-to-female sex ratio was 2.12. RT-PCR test positivity was significantly associated with age (p = 0.001), sex (p = 0.013) and clinical manifestations. Ten variants circulated during the five recorded waves, with Omicron (B.1.1.529), Delta (B.1.617.2) variants being predominant. Notably, the B.1.620 and B.640 variants were prominent during the second wave. Conclusion: This retrospective study provides key insights into the COVID-19 pandemic in the CAR. It identifies risk factors and details the circulation of various SARS-CoV-2 variants. Enhancing national genomic surveillance capacities would enable the country to better respond to future pandemic challenges.

Development of an Integrated Disposable Device for SARSCoV-2 Nucleic Acid Extraction and Detection

Objective To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods We designed,developed,and manufactured an integrated disposable device for SARS-CoV-2 nucleic acid extraction and detection.The precision of the liquid transfer and temperature control was tested.A comparison between our device and a commercial kit for SARS-Cov-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction(RT-PCR).The entire process,from SARS-CoV-2 nucleic acid extraction to amplification,was evaluated.Results The precision of the syringe transfer volume was 19.2±1.9μL(set value was 20),32.2±1.6(set value was 30),and 57.2±3.5(set value was 60).Temperature control in the amplification tube was measured at 60.0±0.0℃(set value was 60)and 95.1±0.2℃(set value was 95)respectively.SARS-Cov-2 nucleic acid extraction yield through the device was 7.10×10^(6) copies/mL,while a commercial kit yielded 2.98×10^(6) copies/mL.The mean time to complete the entire assay,from SARS-CoV-2 nucleic acid extraction to amplification detection,was 36 min and 45 s.The detection limit for SARS-CoV-2 nucleic acid was 250 copies/mL.Conclusion The integrated disposable devices may be used for SARS-CoV-2 Point-of-Care test(POCT).

Effectiveness of Wastewater-Based Epidemiology as an Early Warning Tool to Detect SARS-CoV-2 (COVID-19)

Medical diagnostic tests to detect Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) for individuals in the United States were initially limited to people who were traveling or symptomatic to track disease incidence due to the cost of providing testing for all people in a community on a routine basis. As an alternative to randomly sampling large groups of people to track disease incidence at significant cost, wastewater-based epidemiology (WBE) is a well-established and cost-effective technique to passively measure the prevalence of disease in communities without requiring invasive testing. WBE can also be used as a forecasting tool since the virus is shed in individuals prior to developing symptoms that might otherwise prompt testing. This study applied the WBE approach to understand its effectiveness as a possible forecasting tool by monitoring the SARS-CoV-2 levels in raw wastewater sampled from sewer lift stations at a large public university campus setting including dormitories, academic buildings, and athletic facilities. The WBE analysis was conducted by sampling from building-specific lift stations and enumerating target viral copies using RT-qPCR analysis. The WBE results were compared with the 7-day rolling averages of confirmed infected individuals for the following week after the wastewater sample analysis. In most cases, changes in the WBE outcomes were followed by similar trends in the clinical data. The positive predictive value of the applied WBE approach was 86% for the following week of the sample collection. In contrast, positive correlations between the two data with Spearmen correlation (rs) ranged from 0.16 to 0.36. A stronger correlation (rs = 0.18 to 0.51) was observed when WBE results were compared with COVID-19 cases identified on the next day of the sampling events. The P value of 0.007 for Dorm A suggests high significance, while moderate significance was observed for the other dormitories (B, C, and D). The outcomes of this investigation demonstrate that WBE can be a valuable tool to track the progression of diseases like COVID-19 seven days before diagnostic cases are confirmed, allowing authorities to take necessary measures in advance and also enable authorities to decide to reopen a facility after a quarantine.

Human ACE2-Functionalized Gold“Virus-Trap”Nanostructures for Accurate Capture of SARS-CoV-2 and Single-Virus SERS Detection

The current COVID-19 pandemic urges the extremely sensitive and prompt detection of SARS-CoV-2 virus.Here,we present a Human Angiotensin-converting-enzyme 2(ACE2)-functionalized gold“virus traps”nanostructure as an extremely sensitive SERS biosensor,to selectively capture and rapidly detect S-protein expressed coronavirus,such as the current SARS-CoV-2 in the contaminated water,down to the single-virus level.Such a SERS sensor features extraordinary 106-fold virus enrichment originating from high-affinity of ACE2 with S protein as well as“virus-traps”composed of oblique gold nanoneedles,and 109-fold enhancement of Raman signals originating from multi-component SERS effects.Furthermore,the identification standard of virus signals is established by machine-learning and identification techniques,resulting in an especially low detection limit of 80 copies mL^(−1) for the simulated contaminated water by SARS-CoV-2 virus with complex circumstance as short as 5 min,which is of great significance for achieving real-time monitoring and early warning of coronavirus.Moreover,here-developed method can be used to establish the identification standard for future unknown coronavirus,and immediately enable extremely sensitive and rapid detection of novel virus.

Molecular detection of SARS-CoV-2 being challenged by virus variation and asymptomatic infection

Coronavirus disease 2019(COVID-19)has been a pandemic for more than a year.With the expanding second wave of the pandemic in winter,the continuous evolution of SARS-CoV-2 has brought new issues,including the significance of virus mutations in infection and the detection of asymptomatic infection.In this review,we first introduced several major SARS-CoV-2 mutations since the COVID-19 outbreak and then mentioned the widely used molecular detection techniques to diagnose COVID-19,primarily focusing on their strengths and limitations.We further discussed the effects of viral genetic variation and asymptomatic infection on the molecular detection of SARS-CoV-2 infection.The review finally summarized useful insights into the molecular diagnosis of COVID-19 under the special situation being challenged by virus mutation and asymptomatic infection.

SARS-Cov-2 Delayed Tokyo 2020 Olympics: Very Recent Advances in COVID-19 Detection, Treatment, and Vaccine Development Useful Conducting the Games in 2021

The novel coronavirus (SARS-Cov-2) delayed the Tokyo 2020 Games. The traveling by air, rail, road, and sea inside and outside the countries has stopped to contain the virus. The amount of money lost and assistance needed to reschedule and conduct the Games in 2021 have been estimated. With more than one billion population is under the semi-locked down and movement of people is restricted, athletes cannot prepare at home and participate in the Games. The COVID-19 outbreak has spread around the world;it has already infected 5.7 million people and caused 355,000 deaths reported on May 28, 2020 and the figures increasing every day. The publication of this article is important as the postponement of the Olympics has costed Japan $6 billion and the organizers have worked very hard for seven years. If the Games are conducted in 2021, it will be the—beginning of the world recovery—from big COVID-19 pandemic. In this communication, the development in testing, treatment, and vaccine preparation for SARS-Cov-2 have occurred so far in different countries and companies have been discussed to know the possibilities if the pandemic can be overcome and the Games can be conducted in 2021.

A High-Throughput, Multi-Index Isothermal Amplification Platform for Rapid Detection of 19 Types of Common Respiratory Viruses Including SARS-CoV-2

快速、准确地诊断以及及时对感染严重急性呼吸综合征冠状病毒2(SARS-CoV-2)的患者进行隔离被认为是抗击新冠病毒肺炎(COVID-19)大流行的最有效的措施。本文介绍了一款高通量、多指标的等温扩增检测平台(RTisochip^TM-W),该平台使用离心式微流控芯片,在90min内即可完成一次运行,从16个样本中检测出包括SARS-CoV-2在内的19种常见呼吸道病毒。通过RTisochip^TM-W系统检测的所有病毒的检出限均等于或小于50拷贝·μL^-1,与常规逆转录聚合酶链反应(RT-PCR)灵敏度相当。该系统具有重复性好、鲁棒性强和特异性高的优点。最后,使用RTisochip^TM-W系统对201例临床前样本、14例COVID-19阳性临床样本、25例临床确诊样本以及614例来自呼吸道感染或疑似感染的患者的临床样本进行了测试。测试结果与临床诊断结果吻合良好,也反映出呼吸道传染病的流行特征。在对SARS-CoV-2的诊断上,RTisochip^TM-W系统与参考试剂盒的一致性达到98.15%。基于大量的测试结果,我们相信RTisochip^TM-W系统是一款抗击COV ID-19大流行的强有力工具。

CRISPR-Cas12a-Empowered Electrochemical Biosensor for Rapid and Ultrasensitive Detection of SARS-CoV-2 Delta Variant

Coronavirus disease 2019(COVID-19)is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).The gold standard method for the diagnosis of SARS-CoV-2 depends on quantitative reverse transcription-polymerase chain reaction till now,which is time-consuming and requires expensive instrumentation,and the confirmation of variants relies on further sequencing techniques.Herein,we first proposed a robust technique-methodology of electrochemical CRISPR sensing with the advantages of rapid,highly sensitivity and specificity for the detection of SARS-CoV-2 variant.To enhance the sensing capability,gold electrodes are uniformly decorated with electro-deposited gold nanoparticles.Using DNA template identical to SARS-CoV-2 Delta spike gene sequence as model,our biosensor exhibits excellent analytical detection limit(50 fM)and high linearity(R2=0.987)over six orders of magnitude dynamic range from 100 fM to 10 nM without any nucleic-acid-amplification assays.The detection can be completed within 1 h with high stability and specificity which benefits from the CRISPR-Cas system.Furthermore,based on the wireless micro-electrochemical platform,the proposed biosensor reveals promising application ability in point-of-care testing.

Highly Sensitive Poly-N-isopropylacrylamide Microgel-based Electrochemical Biosensor for the Detection of SARS-COV-2 Spike Protein

Objective Late 2019 witnessed the outbreak and widespread transmission of coronavirus disease 2019(COVID-19),a new,highly contagious disease caused by novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Consequently,considerable attention has been paid to the development of new diagnostic tools for the early detection of SARS-CoV-2.Methods In this study,a new poly-N-isopropylacrylamide microgel-based electrochemical sensor was explored to detect the SARS-CoV-2 spike protein(S protein)in human saliva.The microgel was composed of a copolymer of N-isopropylacrylamide and acrylic acid,and gold nanoparticles were encapsulated within the microgel through facile and economical fabrication.The electrochemical performance of the sensor was evaluated through differential pulse voltammetry.Results Under optimal experimental conditions,the linear range of the sensor was 10-13-10-9 mg/m L,whereas the detection limit was 9.55 fg/mL.Furthermore,the S protein was instilled in artificial saliva as the infected human saliva model,and the sensing platform showed satisfactory detection capability.Conclusion The sensing platform exhibited excellent specificity and sensitivity in detecting spike protein,indicating its potential application for the time-saving and inexpensive detection of SARS-CoV-2.

Clinical application of SARS-CoV-2 antibody detection and monoclonal antibody therapies against COVID-19

The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.

Clinical application of combined detection of SARS-CoV-2-specific antibody and nucleic acid

BACKGROUND The global outbreak of human severe acute respiratory syndrome coronavirus(SARS-CoV)-2 infection represents an urgent need for readily available,accurate and rapid diagnostic tests.Nucleic acid testing of respiratory tract specimens for SARS-CoV-2 is the current gold standard for diagnosis of coronavirus disease 2019(COVID-19).However,the diagnostic accuracy of reverse transcription polymerase chain reaction(RT-PCR)tests for detecting SARS-CoV-2 nucleic acid may be lower than optimal.The detection of SARS-CoV-2-specific antibodies should be used as a serological non-invasive tool for the diagnosis and management of SARS-CoV-2 infection.AIM To investigate the diagnostic value of SARS-CoV-2 IgM/IgG and nucleic acid detection in COVID-19.METHODS We retrospectively analyzed 652 suspected COVID-19 patients,and 206 non-COVID-19 patients in Wuhan Integrated TCM and Western Medicine Hospital.Data on SARS-CoV-2 nucleic acid tests and serum antibody tests were collected to investigate the diagnostic value of nucleic acid RT-PCR test kits and immunoglobulin(Ig)M/IgG antibody test kits.The j2 test was used to compare differences between categorical variables.A 95%confidence interval(CI)was provided by the Wilson score method.All analyses were performed with IBM SPSS Statistics version 22.0(IBM Corp.,Armonk,NY,United States).RESULTS Of the 652 suspected COVID-19 patients,237(36.3%)had positive nucleic acid tests,311(47.7%)were positive for IgM,and 592(90.8%)were positive for IgG.There was a significant difference in the positive detection rate between the IgM and IgG test groups(P<0.001).Using the RT-PCR results as a reference,the specificity,sensitivity,and accuracy of IgM/IgG combined tests for SARS-CoV-2 infection were 98.5%,95.8%,and 97.1%,respectively.Of the 415 suspected COVID-19 patients with negative nucleic acid test results,366 had positive IgM/IgG tests with a positive detection rate of 88.2%.CONCLUSION Our data indicate that serological IgM/IgG antibody combined test had high sensitivity and specificity for the diagnosis of SARS-CoV-2 infection,and can be used in combination with RT-PCR for the diagnosis of SARS-CoV-2 infection.

Detection of SARS-CoV-2 Eta VOI among international travelers using COVIDSeq-NGS

Rationale:SARS-CoV-2 has been identified as a highly infective and contagious viral infection.The SARS-CoV-2 pandemic has been spread worldwide and affected more than 210 countries.Globally,the fast spread of novel SARS-CoV-2 variants has been mostly attributed to international travel.Patient concerns:We are reporting the genomic evidence of SARSCoV-2 Eta VOI among two international travelers.Both travelers were males from Nigeria aged 24 and 34 years and both were asymptomatic.Diagnosis:The nasopharyngeal swab samples were in both travelers positive by real-time RT-PCR followed by COVIDSeq-NGS.Interventions:Paracetamol 3 times daily for 5 days.Outcomes:Patient recovered completely within 10 days and discharged after 14 days of quarantine duration.Lessons:This report highlights genomic variation of SARSCoV-2 among the travelers.For managing the present health crisis,molecular identification of viral variants present in different geographical locations will be very helpful.

Performance Evaluation of Real Time Polymerase Reaction Assay (SCODA) for Detection of SARS-CoV-2

In order to robustly detect and quantify gene expression from small amounts of RNA, amplification of the gene transcript is necessary. Real Time PCR is useful for detection and quantification of genetic constitution of pathogens. This technique amplifies a tiny DNA target million or billion times in such a way that it can be easily studied by scientists. Availability of highly sensitive and specific assay for the detection of SARS-Cov-2 and easy accessibility of such was necessary for early diagnosis and effective management of COVID-19 infection. The aim of this study was to evaluate the performance characteristic of SCODA. Validation of SCODA was performed using synthesized standards and clinical samples previously tested using a commercially approved COVID-19 RT-qPCR detection kit (LifeRiver). The assay showed a linearity of 98.2% on the ORF1ab target and 99.8% on the N-gene target. The sensitivity and specificity were both 100%. Analysis for the LoD95 produced 74.04 (CI: 25 - 1000) cp/μl on ORF1ab gene and 1.119 (CI: 1 - 1) cp/μl on N-gene target with a precision of CV ≤ 3%. SCODA showed high comparable performance in comparison with LifeRiver and other commercial COVID-19 RT-qPCR test kits.

SARS-CoV-2合并感染患者的病原微生物分布特征及耐药性分析

目的分析严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)合并感染患者病原微生物分布特点及耐药情况,为临床诊治提供依据。方法收集2022年12月至2023年2月延安大学附属医院收治的2019冠状病毒病(corona virus disease 2019,COVID-19)患者637例的临床资料,回顾性分析其临床特征及合并感染病原微生物情况。结果COVID-19患者以老年人为主,合并基础疾病患者占79.59%,好转及痊愈患者高达91.05%。培养阳性标本来源于呼吸道、血液和尿液,合并感染的病原微生物分别以肺炎克雷伯杆菌、凝固酶阴性葡萄球菌(coagulase negative staphylococci,CNS)和真菌为主。药敏试验结果显示,肺炎克雷伯杆菌对β内酰胺类抗生素及三代、四代头孢菌素类抗生素耐药率较低(14%~20%),鲍曼不动杆菌对氨基糖苷类抗生素和β内酰胺类复合物较为耐药(均>45%),大肠埃希菌对β内酰胺类抗生素及其复合物耐药率较低(14%~19%)。金黄色葡萄球菌、CNS、屎肠球菌、粪肠球菌均未发现对万古霉素、利奈唑胺、替加环素耐药。结论COVID-19合并感染病原体以革兰阴性菌及真菌为主,感染部位以呼吸道为主,主要病原菌为肺炎克雷伯杆菌。鲍曼不动杆菌对氨基糖苷类抗生素和β内酰胺类复合物耐药率高于全国细菌耐药平均水平,提示临床上应根据COVID-19患者的微生物鉴定和药敏试验结果,选择对症药物治疗,以改善患者预后。

糖尿病患者接种SARS-Cov-2疫苗后的免疫反应:系统评价

目的系统评价糖尿病患者在接种SARS-CoV-2疫苗后的体液和细胞免疫反应。方法检索Web of Science、PubMed、中国知网、万方数据知识服务平台、维普中文科技期刊全文数据库和中国生物医学文献数据库,获取国内外于2019年12月1日至2022年5月12日公开发表的有关糖尿病患者接种SARS-CoV-2疫苗后的体液和细胞免疫反应的观察性研究,经由2名研究者独立筛选文献和提取资料后,采用美国国立卫生研究质量评价工具对纳入文献进行偏倚风险评价,使用描述性统计方法进行汇总分析。结果13篇文献共纳入66651例研究对象,其中5874例(7.9%)患有糖尿病。7篇文献报道了接种第1剂疫苗后糖尿病患者和对照组的免疫反应,其中3篇文献表明,接种1剂SARS-CoV-2疫苗后,糖尿病患者血清抗体水平和阳性率低于对照组;11篇涉及接种2剂SARS-CoV-2疫苗后的免疫反应的文献中,2篇报道了糖尿病患者可产生与对照组相似的抗体反应,9篇报道了糖尿病患者的血清抗体水平、阳性率或细胞免疫反应低于对照组。结论接种SARS-CoV-2疫苗后糖尿病患者和对照组体液和细胞免疫反应均有所增加,但糖尿病患者增加幅度普遍低于对照组。

基于hACE2转导建立SARS-CoV-2 spike假病毒感染病证结合的小鼠病毒肺炎模型

目的建立与评价一种安全、经济、有效的病证结合小鼠新冠病毒感染肺炎模型。方法30只KM种小鼠随机分为空白组、对照组及实验1组、实验2组、实验3组,每组各6只。每天把KM小鼠置于模拟寒湿环境中4 h,将表达hACE2的重组腺相关病毒(pAAV-hACE2)采用改良悬挂法气管内给药转导至肺组织,继以新型冠状病毒(SARS-CoV-2)spike假病毒采用相同的气管内给药方式造模。观察各组小鼠一般情况,检测体重变化、肺指数、血清炎性因子及肺部病理变化。结果免疫组化法显示h ACE2在小鼠肺组织中有效表达;在寒湿环境中给予SARS-CoV-2 spike假病毒后,实验组小鼠表现出类似疫毒犯肺证候的体征;且同样喂养条件和时间下,与空白组和对照组小鼠比较,实验组小鼠出现体重下降;实验1、2、3组小鼠出现肺指数显著增大(P<0.05或P<0.01),血清炎性因子白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)显著升高(P<0.01),肺组织病理改变明显。结论本研究成功建立了一种安全、经济、有效的病证结合小鼠新冠病毒感染肺炎模型。