Clinical Features and Courses of Adenovirus Pneumonia in Healthy Young Adults during an Outbreak among Korean Military Personnel.

BACKGROUND: The number of pneumonia patients increased suddenly in Korean military hospitals in late December 2014, indicating the urgent need for an epidemic outbreak investigation. METHODS: We conducted a prospective study of pneumonia etiology among immunocompetent young adults admitted to Daejeon Armed Forces hospital. Patient blood and sputum samples were subjected to conventional culture, serology, and polymerase chain reaction tests for respiratory viruses and atypical pathogens. RESULTS: From January to May 2015, we enrolled 191 (189 male) adults with pneumonia; the mean age was 20.1 ± 1.3 years. Five patients had severe pneumonia, and one died. Pathogenic human adenoviruses were most common (HAdV, 153/191 [80.1%]), indicating a HAdV pneumonia outbreak. Genotyping of 35 isolates indicated that 34 matched HAdV-55 and one matched HAdV-2. HAdV pneumonia infected recruit trainees most frequently. High and prolonged fever, nasal congestion, sore throat, and pharyngeal inflammation were significantly more common in the HAdV pneumonia group, compared to patients with other or unknown causes of pneumonia. Only 12% of HAdV pneumonia patients displayed leukocytosis, whereas febrile leukopenia (62.7%) and thrombocytopenia (41%) were commonly observed. HAdV pneumonia patient chest CT scans displayed ground glass opacity (with or without septal thickness) with consolidation in 50.0% of patients. CONCLUSIONS: An outbreak of HAdV respiratory infection occurred at the Korean military training center. HAdV pneumonia exhibited specific laboratory and clinical features, and although most patients were cured without complication, some progressed to respiratory failure and fatality. Therefore, HAdV vaccine should be provided to military trainees in Korea.

Therapeutic and prophylactic activity of itraconazole against human rhinovirus infection in a murine model.

Human rhinovirus (HRV) is the most common viral infectious agent in humans and is the predominant cause of the common cold. There is a need for appropriate vaccines or therapeutic agents to treat HRV infection. In this study, we investigated whether itraconazole (ICZ) can protect cells from HRV-induced cytotoxicity. Replication of HRV1B was reduced by ICZ treatment in the lungs of HRV1B- as compared to vehicle-treated mice. The numbers of immune cells, including granulocytes and monocytes, were reduced in bronchoalveolar lavage fluid (BALF) by ICZ administration after HRV1B infection, corresponding to decreased pro-inflammatory cytokine and chemokine levels in BALF. A histological analysis of lung tissue showed that ICZ suppressed inflammation caused by HRV1B infection. Interestingly, pretreatment of mice with ICZ in the form of a nasal spray had potent prophylactic antiviral activity. Cholesterol accumulation in the plasma membrane was observed upon HRV infection; ICZ blocked cholesterol trafficking to the plasma membrane, as well as resulted in its accumulation in subcellular compartments near the nucleus. These findings suggest that ICZ is a potential antiviral agent for the treatment of HRV infection, which can be adopted preventatively as well as therapeutically.

Complete Genome Sequence of Rotavirus Group C Isolated in South Korea.

Rotavirus group C is the major etiological agent associated with acute gastroenteritis in all human age groups. Here, we report the complete genome sequence of human group C rotavirus (GpC-RV) isolated in South Korea.

Anti-human rhinovirus 2 activity and mode of action of quercetin-7-glucoside from Lagerstroemia speciosa.

Human rhinoviruses (HRVs) are a major cause of the common cold, but there is currently, no registered clinically effective antiviral chemotherapeutic agent for treatment of diseases caused by HRVs. In this study, we examined the antiviral activity of quercetin 7-glucoside (Q7G) from Lagerstroemia speciosa against human rhinovirus 2 (HRV2) using a cytopathic effect (CPE) reduction method. Furthermore, to elucidate the action of Q7G on HRV2 multiplication in more detail, we investigated the effect of Q7G on the infection cycle of HRV2 through time-of-addition study, reverse transcription-polymerase chain reaction analysis, and effects of Q7G on the infectivity of HRV2 particles. Q7G potently showed anti-HRV2 activity by reducing the formation of a visible CPE. Q7G also inhibited virus replication in the initial stage of virus infection by indirect interaction with virus particles, and ribavirin had a relative weaker efficacy compared to Q7G. Therefore, these data suggest that Q7G exerted its anti-HRV2 effect via the inhibition of virus replication in the early stage and these findings provide important information for the utilization of Q7G for HRV2 treatment.

Enterovirus infection in Korean children and anti-enteroviral potential candidate agents.

Although most enterovirus infections are not serious enough to be life threatening, several enteroviruses such as enterovirus 71 are responsible for severe, potentially life-threatening disease. The epidemic patterns of enteroviruses occur regularly during the year, but they may change due to environmental shifts induced by climate change due to global warming. Therefore, enterovirus epidemiological studies should be performed continuously as a basis for anti-viral studies. A great number of synthesized antiviral compounds that work against enteroviruses have been developed but only a few have demonstrated effectiveness in vivo. No proven effective antiviral agents are available for enterovirus disease therapy. The development of a new antiviral drug is a difficult task due to poor selective toxicity and cost. To overcome these limitations, one approach is to accelerate the availability of other existing antiviral drugs approved for antiviral effect against enteroviruses, and the other way is to screen traditional medicinal plants.

Evaluation of peptide nucleic acid probe-based real-time PCR for detection of Mycobacterium tuberculosis complex and nontuberculous mycobacteria in respiratory specimens.

BACKGROUND: A peptide nucleic acid (PNA) probe-based real-time PCR (PNAqPCR™ TB/NTM detection kit; PANAGENE, Korea) assay has been recently developed for the simultaneous detection of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) in clinical specimens. The study was aimed at evaluation of the performance of PNA probe-based real-time PCR in respiratory specimens. METHODS: To evaluate potential cross-reactivity, the extracted DNA specimens from Mycobacterium species and non-mycobacterial species were tested using PNA probe-based real-time PCR assay. A total of 531 respiratory specimens (482 sputum specimens and 49 bronchoalveolar washing fluid specimens) were collected from 230 patients in July and August, 2011. All specimens were analyzed for the detection of mycobacteria by direct smear examination, mycobacterial culture, and PNA probe-based real-time PCR assay. RESULTS: In cross-reactivity tests, no false-positive or false-negative results were evident. When the culture method was used as the gold standard test for comparison, PNA probe-based real-time PCR assay for detection of MTBC had a sensitivity and specificity of 96.7% (58/60) and 99.6% (469/471), respectively. Assuming the combination of culture and clinical diagnosis as the standard, the sensitivity and specificity of the new real-time PCR assay for detection of MTBC were 90.6% (58/64) and 99.6% (465/467), respectively. The new real-time PCR for the detection of NTM had a sensitivity and specificity of 69.0% (29/42) and 100% (489/489), respectively. CONCLUSIONS: The new real-time PCR assay may be useful for the detection of MTBC in respiratory specimens and for discrimination of NTM from MTBC.

Evaluation of a new immunochromatographic assay kit for the rapid detection of norovirus in fecal specimens.

Rapid and accurate detection of norovirus is essential for the prevention and control of norovirus outbreaks. This study compared the effectiveness of a new immunochromatographic assay kit (SD BIOLINE Norovirus; Standard Diagnostics, Korea) and real-time reverse transcription-PCR (RT-PCR) for detecting norovirus in fecal specimens. Compared with real-time RT-PCR, the new assay had sensitivity, specificity, positive predictive value, and negative predictive value of 76.5% (52/68), 99.7% (342/343), 98.1% (52/53), and 95.5% (342/358), respectively. The sensitivity of the assay was 81.8% (18/22) for GII.3 and 75.7% (28/37) for GII.4. None of the 38 enteric virus-positive specimens (3 for astrovirus, 5 for enteric adenovirus, and 30 for rotavirus) tested positive in the cross-reactivity test performed by using this assay. The new immunochromatographic assay may be a useful screening tool for the rapid detection of norovirus in sporadic and outbreak cases; however, negative results may require confirmatory assays of greater sensitivity.

Evaluation of peptide nucleic acid array for the detection of hepatitis B virus mutations associated with antiviral resistance.

A major problem of long-term antiviral therapy in chronic hepatitis B patients is the emergence of hepatitis B virus (HBV) mutations associated with drug resistance. Recently, a new array using peptide nucleic acids (PNAs), which are synthetic nucleic acid analogues, was developed for the detection of HBV mutations at six different codon positions associated with lamivudine (LAM) and adefovir (ADV) resistance. We compared the PNA array with direct sequencing and reverse hybridization (INNO-LiPA) in 73 samples obtained from chronic hepatitis B patients. The PNA array detected mutations associated with LAM and/or ADV resistance in 60 (82.2%) of the 73 samples. The overall concordance rate of PNA array and INNO-LiPA compared with direct sequencing was 99.5% and 98.2%, respectively. The rate of complete concordance between PNA array and INNO-LiPA was 92.7%. The PNA array assay results were comparable with INNO-LiPA for detection of HBV mutations associated with antiviral resistance.

Comparative analysis of the multiple test methods for the detection of Pandemic Influenza A/H1N1 2009 virus.

Accurate and rapid diagnosis of Pandemic Influenza A/H1N1 2009 virus (H1N1 2009) infection is important for the prevention and control of influenza epidemics and the timely initiation of antiviral treatment. This study was conducted to evaluate the performance of several diagnostic tools for the detection of H1N1 2009. Flocked nasopharyngeal swabs were collected from 254 outpatients of suspected H1N1 2009 during October 2009. This study analyzed the performances of RealTime ready Inf A/H1N1 Detection Set (Roche), Influenza A (H1N1) Real-Time Detection Kit (Bionote), Seeplex Influenza A/B OneStep Typing set (Seeplex reverse transcriptase PCR [RT-PCR]), BinaxNow Influenza A & B test kit (Binax rapid antigen test [RAT]) and SD BIOLINE Influenza Ag kit (SD RAT). Roche and Bionote real-time RT-PCR showed identical results for the H1N1 2009 hemagglutinin gene. Compared with real-time RT-PCR, the sensitivities and specificities were 83.7% and 100% for Seeplex RT-PCR, 64.5% and 94.7% for Binax RAT, and 69.5% and 100% for SD RAT. The sensitivities of Seeplex RT-PCR, Binax RAT and SD RAT in patients aged over 21 years were 73.7%, 47.4% and 57.9%, respectively. The sensitivities of Seeplex RT-PCR, Binax RAT and SD RAT on the day of initial symptoms were mostly lower (68.8%, 56.3% and 31.3%, respectively). In conclusion, multiplex RT-PCR and RAT for the detection of H1N1 2009 were significantly less sensitive than real-time RT-PCR. Also, a negative RAT may require more sensitive confirmatory assays, because it cannot be ruled out from influenza infection.

Molecular characterization of echovirus 30-associated outbreak of aseptic meningitis in Korea in 2008.

Evaluation of the primary etiologic agents that cause aseptic meningitis outbreaks may provide valuable information regarding the prevention and management of aseptic meningitis. In Korea, an outbreak of aseptic meningitis caused by echovirus type 30 (E30) occurred from May to October in 2008. In order to determine the etiologic agent, CSF and/or stool specimens from 140 children hospitalized for aseptic meningitis at Soonchunhyang University Cheonan Hospital between June and October of 2008 were tested for virus isolation and identification. E30 accounted for 61.7% (37 cases) and echovirus 6 accounted for 21.7% (13 cases) of all the human enteroviruses (HEVs) isolates (60 cases in total). For the molecular characterization of the isolates, the VP1 gene sequence of 18 Korean E30 isolates was compared pairwise using the MegAlign with 34 reference strains from the GenBank database. The pairwise comparison of the nucleotide sequences of the VP1 genes demonstrated that the sequences of the Korean strains differed from those of lineage groups A, B, C, D, E, F and G. Reconstruction of the phylogenetic tree based on the complete VP1 nucleotide sequences resulted in a monophyletic tree, with eight clustered lineage groups. All Korean isolates were segregated from other lineage groups, thus suggesting that the Korean strains were a distinct lineage of E30, and a probable cause of this outbreak. This manuscript is the first report, to the best of our knowledge, of the molecular characteristics of E30 strains associated with an aseptic meningitis outbreak in Korea, and their respective phylogenetic relationships.

Inhibitory effects of quercetin 3-rhamnoside on influenza A virus replication.

Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. The lack of effective therapeutical treatment underlines the importance of research for new antiviral compounds. Flavonoids widely exist in the plant kingdom, and their antiviral activities against various viruses have been recently reported. In this study, the anti-influenza A/WS/33 virus of quercetin 3-rhamnoside (Q3R) from Houttuynia cordata was evaluated using a cytopathic effect (CPE) reduction method, the assay results demonstrated that Q3R possessed strong anti-influenza A/WS/33 virus reducing the formation of a visible CPE. Q3R also did inhibit virus replication in the initial stage of virus infection by indirect interaction with virus particles. However, oseltamivir has relative weaker efficacy compared to Q3R. Therefore, these findings provide important information for the utilization of Q3R for influenza treatment.

Identification of enteroviruses by using monoclonal antibodies against a putative common epitope.

A common epitope region of enteroviruses was identified by sequence-independent single-primer amplification (SISPA), followed by immunoscreening of 11 cDNA libraries from two Korean enterovirus isolates (echoviruses 7 and 30) and a coxsackievirus B3 (ATCC-VR 30). The putative common epitope region was localized in the N terminus of VP1 when the displayed recombinant proteins from the phages were chased by the convalescent-phase sera. The genomic region encoding the common epitope region was amplified and then expressed by using the vector pGEX-5X-1. The antigenicity of the expressed recombinant protein was identified by Western blotting with guinea pig antisera for six different serotypes of enteroviruses. After successive immunization of mice with the recombinant common epitope protein, splenocytes were extracted and hybridized with P3X63-Ag8-653 cells. A total of 24 hybridomas that produced monoclonal antibodies (MAbs) against the putative common epitope of enteroviruses were selected. Four of these were immunoglobulin G1 isotypes with a kappa light chain. These MAbs recognized 15 Korean endemic serotypes and prototypes of enteroviruses in an indirect immunofluorescence assay. These results suggest that the expressed protein might be a useful antigen for producing group common antibodies and that the use of the MAbs against the putative common epitope of enteroviruses might be a valuable diagnostic tool for rapidly identifying a broad range of enteroviruses.