Prevalence and genetic diversity analysis of human coronaviruses among cross-border children.

BACKGROUND: More than a decade after the outbreak of human coronaviruses (HCoVs) SARS in Guangdong province and Hong Kong SAR of China in 2002, there is still no reoccurrence, but the evolution and recombination of the coronaviruses in this region are still unknown. Therefore, surveillance on the prevalence and the virus variation of HCoVs circulation in this region is conducted. METHODS: A total of 3298 nasopharyngeal swabs samples were collected from cross-border children (<6 years, crossing border between Southern China and Hong Kong SAR) showing symptoms of respiratory tract infection, such as fever (body temperature > 37.5 °C), from 2014 May to 2015 Dec. Viral nucleic acids were analyzed and sequenced to study the prevalence and genetic diversity of the four human coronaviruses. The statistical significance of the data was evaluated with Fisher chi-square test. RESULTS: 78 (2.37%; 95%CI 1.8-2.8%) out of 3298 nasopharyngeal swabs specimens were found to be positive for OC43 (36;1.09%), HKU1 (34; 1.03%), NL63 (6; 0.18%) and 229E (2;0.01%). None of SARS or MERS was detected. The HCoVs predominant circulating season was in transition of winter to spring, especially January and February and NL63 detected only in summer and fall. Complex population with an abundant genetic diversity of coronaviruses was circulating and they shared homology with the published strains (99-100%). Besides, phylogenetic evolutionary analysis indicated that OC43 coronaviruses were clustered into three clades (B,D,E), HKU1 clustered into two clades(A,B) and NL63 clustered into two clades(A,B). Moreover, several novel mutations including nucleotides substitution and the insertion of spike of the glycoprotein on the viral surface were discovered. CONCLUSIONS: The detection rate and epidemic trend of coronaviruses were stable and no obvious fluctuations were found. The detected coronaviruses shared a conserved gene sequences in S and RdRp. However, mutants of the epidemic strains were detected, suggesting continuous monitoring of the human coronaviruses is in need among cross-border children, who are more likely to get infected and transmit the viruses across the border easily, in addition to the general public.

Differential expression of long non-coding RNAs in patients with tuberculosis infection.

Tuberculosis (TB) remains a major worldwide health problem and has caused millions of deaths in the past few years. Current diagnostic methods, such as sputum smear microscopy and sputum culture, are time-consuming and cannot prevent the rapid spreading of TB during the diagnostic period. In this connection, detecting biomarkers specific to TB at molecular level in plasma of patients will provide a rapid means for diagnosis. In this study, we first evaluated the differential expression of the long non-coding RNAs (lncRNAs) in the plasma from patients with TB (TB positive), community acquired pneumonia (CAP) and healthy individuals (CG) using lncRNA microarray scanning. It was found that there were 2116 specific lncRNAs differentially expressed in the TB positive samples (1102 up-regulated and 1014 down-regulated), which accounted for 6.96% of total lncRNAs. Twelve differentially expressed lncRNAs discovered in microarray were subsequently validated by using real-time quantitative PCR (RT-qPCR). Two lncRNAs (ENST00000354432 and ENST00000427151) were further validated with more Tuberculosis samples. These results suggested the expression level of lncRNAs and the two validated lncRNAs in plasma could be the potential molecular biomarkers for the rapid diagnosis of Tuberculosis.

Surveillance of mosquito-borne infectious diseases in febrile travelers entering China via Shenzhen ports, China, 2013.

BACKGROUND: About 100 million passengers enter China via Shenzhen ports every year and such huge populations increase the risk of various infectious diseases, particularly mosquito-borne diseases, entering China. This paper reports the testing and monitoring of mosquito-borne diseases in febrile travelers through Shenzhen ports in 2013. METHODS: The blood samples of 619 febrile cases were collected and the serum of each sample was used for the specific gene amplification and IgM antibody detection of five typical mosquito-borne pathogens: Dengue virus (DENV), Japanese encephalitis virus (JEV), Chikungunya virus (CHIKV), yellow fever virus (YFV), and West Nile Virus (WNV). Additionally, malaria was diagnosed by rapid diagnostic tests (RDTs). RESULTS: In total, 34 cases were detected of DENV infection (serotype I to IV), 17 cases of JEV infection, 2 cases of CHIKV infection, and 3 cases of malaria infection. No virus genes or IgM antibodies of YFV or WNV were detected in the samples. DENV, JEV and CHIKV cases were mainly from Southeast Asia, while malaria cases from Africa. CONCLUSIONS: DENV, JEV and CHIKV were the primary pathogens imported via Shenzhen ports. International travelers with mosquito-borne infections would accelerate the spread of these diseases, thus reinforcing the need for surveillance of mosquito-borne infections at ports should become a high priority.

Identification of microRNAs in Throat Swab as the Biomarkers for Diagnosis of Influenza.

BACKGROUND: Influenza is a serious worldwide disease that captures global attention in the past few years after outbreaks. The recent discoveries of microRNA (miRNA) and its unique expression profile in influenza patients have offered a new method for early influenza diagnosis. The aim of this study was to examine the utility of miRNAs for the diagnosis of influenza. METHODS: Thirteen selected miRNAs were investigated with the hosts' throat swabs (25 H1N1, 20 H3N2, 20 influenza B and 21 healthy controls) by real-time quantitative polymerase chain reaction (RT-qPCR) using U6 snRNA as endogenous control for normalization, and receiver operating characteristic (ROC) curve/Area under curve (AUC) for analysis. RESULTS: miR-29a-3p, miR-30c-5p, miR-34c-3p and miR-181a-5p are useful biomarkers for influenza A detection; and miR-30c-5p, miR-34b-5p, miR-205-5p and miR-449b-5p for influenza B detection. Also, use of both miR-30c-5p and miR-34c-3p (AUC=0.879); and miR-30c-5p and miR-449b-5p (AUC=0.901) are better than using one miRNA to confirm influenza A and influenza B infection, respectively. CONCLUSIONS: Given its simplicity, non-invasiveness and specificity, we found that the throat swab-derived miRNAs miR-29a-3p, miR-30c-5p, miR-34b-5p, miR-34c-3p, miR-181a-5p, miR-205-5p and miR-449b-5p are a useful tool for influenza diagnosis on influenza A and B.

Multiplex biomarker analysis biosensor for detection of hepatitis B virus.

In this paper, we report the development of a protein microarray-based biosensor for the detection of the hepatitis B virus (HBV) serological markers using surface plasmon resonance (SPR Printing buffer, protein immobilization time and concentration of the capture protein were optimized systematically to determine the best performance of the biosensor. Under optimal conditions, five hepatitis B markers in 20 µL human serum can be simultaneously detected within 30 minutes, whereas other methods such as ELISA and PCR can detect only one marker within four hours. This platform has been validated by analysis of 35 patients known to have hepatitis B, with 85% agreement between the test platform and analysis by commercial enzyme-linked immunosorbent assay (ELISA) kits. The results demonstrate that the protein microarray with SPR displayed a sensitivity of 0.1 ng mL(-1) for HBsAg. In addition to high sensitivity, it also shows excellent specificity, reproducibility and stability. This integrated protein microarray technique combined with SPR is a promising candidate for hepatitis B diagnosis with high-throughput.

Development of SPR biosensor for simultaneous detection of multiplex respiratory viruses.

A surface plasmon resonance (SPR)-based biosensor was developed for specific detection of nine common respiratory virus, including influenza A and influenza B, H1N1, respiratory syncytial virus (RSV), parainfluenza virus 1-3 (PIV1, 2, 3), adenovirus, and severe acute respiratory syndrome coronavirus (SARS). The SPR biosensor was developed by immobilizing nine respiratory virus-specific oligonucleotides in an SPR chip. To increase the biosensor sensitivity, biotin was used to label the PCR primer and further amplify the signal by introducing streptavidin after hybridization. Throat swab specimens representing nine common respiratory viruses were tested by the innovative SPR-based biosensor to evaluate the sensitivity, specificity and reproducibility of this method. Results suggest that this biosensor has the potential to simultaneously identify common respiratory viruses.

Development of a smart dynamic surface chemistry for surface plasmon resonance-based sensors for the detection of DNA molecules.

We report the design of a polyrotaxane surface for biosensor applications. The results show that a three-fold improvement in immobilization and hybridization efficiency has been achieved compared to PEG SAM. The results confirm that polyrotaxane is a very promising platform candidate for biosensor applications.

[Preparation and performance assessment of Gamma-peptide nucleic acid gene chip detection system based on surface plasmon resonance].

The aim of this study was to build a gene chip system with surface plasmon resonance (SPR) technique, for which Gamma-peptide nucleic acid (Gamma-PNA) functioned as a probe, in order to improve sensitivity and its specificity. With the use of self-assembled monolayer (SAM) technology, surface chemistry of two-dimensional structure was used. Gamma-PNA was designed according to the bioinformatics, and was plated on the SPR chip modified by SAM. Subsequently, relevant parameters of the experiment were ensured and optimized. The results showed that the performances of Gamma-PNA probe was little affected by the ion concentration of buffer, and it had a strong light signal in a stable state. As the ion concentration was 0, there were still good hybrid reactions; pH value had less influence upon Gamma-PNA probe, and acid environment of buffer could be better. Gamma-PNA probe combined with sensor technologies achieved made the probe with dispensable labels and real-time detection. It also improved the efficiency of the hybridization and the stability, providing the foundation for clinical application.