Viral and Bacterial Etiology of Acute Febrile Respiratory Syndrome among Patients in Qinghai, China

Objective This study was conducted to investigate the viral and bacterial etiology and epidemiology of patients with acute febrile respiratory syndrome(AFRS) in Qinghai using a commercial routine multiplex-ligation-nucleic acid amplification test(NAT)-based assay. Methods A total of 445 nasopharyngeal swabs specimens from patients with AFRS were analyzed using the RespiFinderSmart22 kit(PathoFinder BV, Netherlands) and the LightCycler 480 real-time PCR system. Results Among the 225(225/445, 51%) positive specimens, 329 positive pathogens were detected, including 298(90.58%) viruses and 31(9%) bacteria. The most commonly detected pathogens were influenza virus(IFV;37.39%;123/329), adenovirus(AdV;17.02%;56/329), human coronaviruses(HCoVs;10.94%;36/329), rhinovirus/enterovirus(RV/EV;10.03%;33/329), parainfluenza viruses(PIVs;8.51%;28/329), and Mycoplasma pneumoniae(M. pneu;8.51%;28/329), respectively. Among the co-infected cases(17.53%;78/445), IFV/AdV and IFV/M. pneu were the most common co-infections. Most of the respiratory viruses were detected in summer and fall. Conclusion In our study, IFV-A was the most common respiratory pathogen among 22 detected pathogens, followed by AdV, HCoV, RV/EV, PIV, and M. pneu. Bacteria appeared less frequently than viruses, and co-infection was the most common phenomenon among viral pathogens. Pathogens were distributed among different age groups and respiratory viruses were generally active in July, September, and November. Enhanced surveillance and early detection can be useful in the diagnosis, treatment, and prevention of AFRS, as well as for guiding the development of appropriate public health strategies.

Full-Length Genome Sequencing of SARS-CoV-2 Directly from Clinical and Environmental Samples Based on the Multiplex Polymerase Chain Reaction Method

The new coronavirus,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is spreading worldwide with the number of confirmed cases increasing dramatically[1,2].Coronaviruses have the largest genome among RNA viruses and have caused two major outbreaks[3,4].

Detection and Identification of Six Foodborne Bacteria by Two-tube Multiplex Real Time PCR and Melting Curve Analysis

Objective This study is aimed to develop a two-tube melting curve-based multiplex real time PCR assay （MCMRT-PCR） for the simultaneous detection of six common foodborne pathogenic bacteria （diarrhoeagenic Escherichia coli, Salmonella, and 5higella in tube 1, Staphylococcus aureus, Vibrio parahaemolyticus, and Listeria monocytogenes in tube 2）. Methods A two-tube MCMRT-PCR assay was performed on 7900HT Fast Real-Time PCR System {Applied Biosystems, USA）. Amplification by PCR was optimized to obtain high efficiency. The sensitivity and specificity of assays were investigated. Results The detection limit of optimized MCMRT-PCR assay was 3.9x102 CFU/mLfor S. aureus, 4.4x102 CFU/mL for L. monocytogenes, 3.0x102 CFU/mL for Salmonella, 2.5x102 CFU/mL for Shigella, 2.1x102 CFU/mL for V. parahaemolyticus, and 1.2x102 CFU/mL for E. coll. The feasibility of MCMRT-PCR was further evaluated using artificially contaminated milk, the sensitivity was at the level of 10s CFU/mL. Conclusion A two-tube MCMRT-PCR assay using six primer sets was developed for detection of multiple pathogens. Our findings demonstrates that the proposed two-tube assay is reliable, useful and rapid for simultaneous detection of six foodborne pathogenic bacteria with an intended application in provincial Centers for Diseases Control and Prevention （CDC）.

Serological Study of An Imported Case of Middle East Respiratory Syndrome and His Close Contacts in China, 2015

The first imported Middle East respiratory syndrome （MERS） case in China was identified in May 2015. We determined the kinetics of antibody （IgG and IgM） and neutralizing antibodies against MERS-coronavirus （MERS-CoV） in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay （ELISA） of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.