Genome-wide sequence divergence of satellite DNA could underlie meiotic failure in male hybrids of bighead catfish and North African catfish (Clarias, Clariidae).

Hybrid sterility, a hallmark of postzygotic isolation, arises from parental genome divergence disrupting meiosis. While chromosomal incompatibility is often implicated, the underlying mechanisms remain unclear. This study investigated meiotic behavior and genome-wide divergence in bighead catfish (C. macrocephalus), North African catfish (C. gariepinus), and their sterile male hybrids (important in aquaculture). Repetitive DNA analysis using bioinformatics and cytogenetics revealed significant divergence in satellite DNA (satDNA) families between parental species. Notably, one hybrid exhibited successful meiosis and spermatozoa production, suggesting potential variation in sterility expression. Our findings suggest that genome-wide satDNA divergence, rather than chromosome number differences, likely contributes to meiotic failure and male sterility in these catfish hybrids.

Influence of COVID-19 on the emergence of stone-tool use behavior in a population of common long-tailed macaques (Macaca fascicularis fascicularis) in Thailand.

Stone tool use is a rare behavior across nonhuman primates. Here we report the first population of common long-tailed macaques (Macaca fascicularis fascicularis) who customarily used stone tools to open rock oysters (Saccostrea forskali) on a small island along the Thai Gulf in Koh Ped (KPE), eastern Thailand. We observed this population several times during the past 10 years, but no stone-tool use behavior was observed until our survey during the coronavirus disease 2019 (COVID-19) pandemic in July 2022. KPE is located in Pattaya City, a hotspot for tourism in Thailand. Tourists in this area frequently provided large amounts of food for the monkeys on KPE. During the COVID-19 curfew, however, tourists were not allowed to access the island, and monkeys began to face food scarcity. During this time, we observed stone-tool use behavior for the first time on KPE. Based on our observations, the first tool manipulation was similar to stone throwing (a known precursor of stone tool use). From our observations in March 2023, we found 17 subadult/adult animals performing the behavior, 15 of 17 were males and mostly solitary while performing the behavior. The M. f. fascicularis subspecies was confirmed by distribution, morphological characteristics, and mtDNA and SRY gene sequences. Taken together, we proposed that the stone tool use behavior in the KPE common long-tailed macaques emerged due to the COVID-19 food scarcity. Since traveling is no longer restricted many tourists have started coming back to the island, and there is a high risk for this stone tool-use behavior to disappear within this population of long-tailed macaques.

Development of a simplified and cost-effective sample preparation method for genotyping of human papillomavirus by next-generation sequencing.

High-risk human papillomavirus (HPV) infection is the most common cause of cervical cancer, but low-risk HPV strains can sometimes also be involved. Although HPV genotyping techniques used in clinical diagnosis cannot detect low-risk HPV, next-generation sequencing (NGS) can detect both types. However, DNA library preparation is complicated and expensive. The aim of this study was to develop a simplified, cost-effective sample preparation procedure for HPV genotyping based on next-generation sequencing (NGS). After DNA extraction, a first round of PCR was performed using modified MY09/11 primers specific for the L1 region of the HPV genome, followed by a second round of PCR to add the indexes and adaptors. Then, the DNA libraries were purified and quantified, and high-throughput sequencing was performed using an Illumina MiSeq platform. The sequencing reads were compared with reference sequences for HPV genotyping. The limit of detection for HPV amplification was 100 copies/µl. Analysis of the correlation of pathological cytology with the HPV genotype in individual clinical samples showed that HPV66 was the most common genotype found in the normal stage, whereas HPV16 was the main genotype found in low-grade squamous intraepithelial lesions, high-grade squamous intraepithelial lesions, and cervical cancer. This NGS method can detect and identify several HPV genotypes with 92% accuracy and 100% reproducibility, and it shows potential as a simplified and cost-effective technique for large-scale HPV genotyping in clinical samples.

Clinical characteristics and drug susceptibility profiles of Mycobacterium abscessus complex infection at a medical school in Thailand.

OBJECTIVES: This study investigated the differences in epidemiological and clinical data, and antimicrobial susceptibilities among different subspecies of Mycobacterium abscessus complex (MABSC) clinical isolates at a medical school in Thailand. METHODS: A total of 143 MABSC clinical isolates recovered from 74 patients were genotypically analyzed for erm(41), rrl, and rrs mutations, and antimicrobial susceptibilities were determined using a broth microdilution method. Patient characteristics and clinical outcomes were reviewed from the medical records. RESULTS: Seventy-four patients were infected with 28/74 (37.8%) M. abscessus subspecies abscessus (MAB), 43/74 (58.1%) M. abscessus subsp. massiliense (MMA), and 3/74 (4.1%) M. abscessus subsp. bolletii (MBO). The clinical findings and outcomes were generally indistinguishable between the three subspecies. All three subspecies of MABSC clinical isolates exhibited high resistance rates to ciprofloxacin, doxycycline, moxifloxacin, TMP/SMX, and tobramycin. MAB had the highest resistance rates to clarithromycin (27.8%, 20/72) and amikacin (6.9%, 5/72) compared to MBO and MMA, with p < 0.001 and p = 0.004, respectively. In addition, the rough morphotype was significantly associated with resistance to amikacin (8.9%, 5/56), clarithromycin (26.8%, 15/56), and imipenem (76.8%, 43/56) (p < 0.001), whereas the smooth morphotype was resistant to linezolid (57.1%, 48/84) (p = 0.002). In addition, T28 of erm(41), rrl (A2058C/G and A2059C/G), and rrs (A1408G) mutations were detected in 87.4% (125/143), 16.1% (23/143), and 9.1% (13/143) of MABSC isolates, respectively. CONCLUSIONS: Three MABSC subspecies caused a variety of infections in patients with different underlying comorbidities. The drug susceptibility patterns of the recent circulating MABSC strains in Thailand were different among the three MABSC subspecies and two morphotypes.

Adverse childhood experiences and reoccurrence of illness impact the gut microbiome, which affects suicidal behaviours and the phenome of major depression: towards enterotypic phenotypes.

The first publication demonstrating that major depressive disorder (MDD) is associated with alterations in the gut microbiota appeared in 2008 (Maes et al., 2008). The purpose of the present study is to delineate a) the microbiome signature of the phenome of depression, including suicidal behaviours (SB) and cognitive deficits; the effects of adverse childhood experiences (ACEs) and recurrence of illness index (ROI) on the microbiome; and the microbiome signature of lowered high-density lipoprotein cholesterol (HDLc). We determined isometric log-ratio abundances or prevalences of gut microbiome phyla, genera, and species by analysing stool samples from 37 healthy Thai controls and 32 MDD patients using 16S rDNA sequencing. Six microbiome taxa accounted for 36% of the variance in the depression phenome, namely Hungatella and Fusicatenibacter (positive associations) and Butyricicoccus, Clostridium, Parabacteroides merdae, and Desulfovibrio piger (inverse association). This profile (labelled enterotype 1) indicates compositional dysbiosis, is strongly predicted by ACE and ROI, and is linked to SB. A second enterotype was developed that predicted a decrease in HDLc and an increase in the atherogenic index of plasma (Bifidobacterium, P. merdae, and Romboutsia were positively associated, while Proteobacteria and Clostridium sensu stricto were negatively associated). Together, enterotypes 1 and 2 explained 40.4% of the variance in the depression phenome, and enterotype 1 in conjunction with HDLc explained 39.9% of the variance in current SB. In conclusion, the microimmuneoxysome is a potential new drug target for the treatment of severe depression and SB and possibly for the prevention of future episodes.

Comparison of Malassezia spp. colonization between human skin exposed to high- and low-ambient air pollution.

The skin microbiota is essential for human health; altered skin microbiome colonization and homeostasis may be associated with several inflammatory skin conditions and other inflammatory diseases. Malassezia spp. are commensal fungi commonly found on the human skin, and they also play a pathogenic role in various skin diseases. It is hypothesized that the exposure of human skin to air pollution might be associated with Malassezia spp. colonization. The aim of this study was to compare Malassezia spp. colonization on healthy human skin between people living in two major cities in Thailand with different air qualities: one city with highly polluted ambient air and the other with less polluted air. Skin microbiome samples from 66 participants were collected using swabbing and scraping techniques. The skin fungal composition was analysed using high-throughput sequencing based on internal transcribed spacer 2 (ITS2) rDNA. A significant difference was found in alpha and beta diversities and the relative abundance of fungal profiles between the groups. The relative abundance of Malassezia spp. was found to be significantly higher in the highly polluted area than in the less polluted area. This study demonstrates that high-ambient air pollution may alter Malassezia spp. colonization on healthy human skin, which could lead to dysbiosis of the cutaneous ecosystem and eventually result in some skin disorders.

Alteration of gut microbiota during narrowband ultraviolet B therapy in psoriasis: A preliminary study.

Gut microbiome dysbiosis is associated with psoriasis development. A relationship between gut microbiota and psoriasis treatment response has been reported. No study has reported the effect of narrowband ultraviolet B (NBUVB) therapy, a standard treatment of psoriasis, on gut microbiota. This study aimed to evaluate gut microbiota change during NBUVB therapy. Stool samples from 22 participants, including 13 patients with chronic plaque psoriasis and nine healthy controls, were recruited. Faecal microbiota composition was analysed using 16S rRNA sequencing before and after NBUVB therapy. Serum 25-OH vitamin D of patients with psoriasis was evaluated simultaneously. The most abundant phyla of gut microbiota in patients with psoriasis were Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria in all participants. Bilophila, Paraprevotella, Alistipes, Sutterella, Romboutsia, Clostridium sensu stricto and Agathobacter are significantly more enriched in healthy controls. Lactobacillales and Ruminococus torques appeared more enriched after NBUVB treatment in responders but not non-responders. Serum vitamin D levels significantly increased after NBUVB treatment. The present study revealed that gut microbiota altered after NBUVB treatment. The change might be treatment-specific and influence the treatment response.

Identification of genes associated with Kikuchi-Fujimoto disease using RNA and exome sequencing.

Kikuchi-Fujimoto disease (KFD) is an extremely rare disease, and although it is reported to have a worldwide distribution, young Asian women are most likely to be affected. Although this disease is generally benign and self-limiting, distinguishing it from other diseases that cause lymphadenopathy (e.g., leukemia, lymphoma, and infectious diseases) is challenging. A lymph node biopsy is a definitive diagnostic technique for KFD and only requires skillful pathologists. There are no specific symptoms or laboratory tests for KFD, and more than 50% of KFD patients have suffered from being misdiagnosed with lymphoma, which leads to improper treatment. In this study, lymph node tissue samples from KFD patients were used to reveal their exomes and transcriptomes using a high-throughput nucleotide sequencer. Fourteen single nucleotide polymorphisms (SNPs) were identified as candidate KFD markers and were compared with a healthy lymph node exome dataset. The mutation of these genes caused disruptive impact in the proteins. Several SNPs associated with KFD involve genes related to human cancers, olfaction, and osteoblast differentiation. According to the transcriptome data, there were 238 up-regulated and 1,519 down-regulated genes. RANBP2-like and ribosomal protein L13 were the most up-regulated and down-regulated genes in KFD patients, respectively. The altered gene expression involved in the human immune system, chromatin remodeling, and gene transcription. A comparison of KFD and healthy datasets of exomes and transcriptomes may allow further insights into the KFD phenotype. The results may also facilitate future KFD diagnosis and treatment.

Oral-fecal mycobiome in wild and captive cynomolgus macaques (Macaca fascicularis).

Cynomolgus macaque (Macaca fascicularis) is currently a common animal model for biomedical research. The National Primate Research Center of Thailand, Chulalongkorn University (NPRCT-CU) translocated wild-borne macaques to reared colony for research purposes. At present, no studies focus on fungal microbiome (Mycobiome) of this macaque. The functional roles of mycobiome and fungal pathogens have not been elucidated. Thus, this study aimed to investigate and compare oral and fecal mycobiome between wild and captive macaques by using high-throughput sequencing on internal transcribed spacer 2 (ITS2) rDNA. The results showed that the mycobiome of wild macaque has greater alpha diversity. The fecal mycobiome has more limited alpha diversity than those in oral cavity. The community is mainly dominated by saprophytic yeast in Kasachstania genus which is related to aiding metabolic function in gut. The oral microbiome of most captive macaques presented the Cutaneotrichosporon suggesting the fungal transmission through skin-oral contact within the colony. The potential pathogens that would cause harmful transmission in reared colonies were not found in either group of macaques but the pathogen prevention and animal care is still important to be concerned. In conclusion, the results of gut mycobiome analysis in Thai cynomolgus macaques provide us with the basic information of oral and fecal fungi and for monitoring macaque's health status for animal care of research use.

Serum miRNA125a-5p, miR-125b-5p, and miR-433-5p as biomarkers to differentiate between posterior circulation stroke and peripheral vertigo.

BACKGROUND: Acute vertigo is a common presentation of inner ear disease. However, it can also be caused by more serious conditions, especially posterior circulation stroke. Differentiating between these two conditions by clinical presentations and imaging studies during the acute phase can be challenging. This study aimed to identify serum microRNA (miRNA) candidates that could differentiate between posterior circulation stroke and peripheral vertigo, among patients presenting with acute vertigo. METHODS: Serum levels of six miRNAs including miR-125a-5p, miR-125b-5p, miR-143-3p, miR-342-3p, miR-376a-3p, and miR-433-5p were evaluated. Using quantitative reverse-transcription polymerase chain reaction (RT-qPCR), the serum miRNAs were assessed in the acute phase and at a 90 day follow-up visit. RESULTS: A total of 58 patients with posterior circulation stroke (n = 23) and peripheral vertigo (n = 35) were included in the study. Serum miR-125a-5p (P = 0.001), miR-125b-5p (P <  0.001), miR-143-3p (P = 0.014) and miR-433-5p (P = 0.0056) were present at significantly higher levels in the acute phase, in the patients with posterior circulation infarction. Based on the area under the receiver operating characteristic curve (AUROC) only miR-125a-5p (0.75), miR-125b-5p(0.77), and miR-433-5p (0.71) had an acceptable discriminative ability to differentiate between the central and peripheral vertigo. A combination of miRNAs revealed no significant improvement of AUROC when compared to single miRNAs. CONCLUSION: This study demonstrated the potential of serum miR-125a-5p, miR-125b-5p, and miR-433-5p as biomarkers to assist in the diagnosis of posterior circulation infarction among patients presenting with acute vertigo.

Association of NTCP polymorphisms with clinical outcome of hepatitis B infection in Thai individuals.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in the sodium taurocholate co-transporting polypeptide (NTCP) have been showed to be associated with natural history of hepatitis B virus (HBV) infection. However, it is unclear whether the SNPs are related to the clinical outcome of HBV infection in Thai individuals. METHODS: The rs2296651 and rs4646287 polymorphisms of NTCP were determined by allelic discrimination using commercial TaqMan probes in blood samples of 1021 Thai individuals. These subjects included 610 patients with chronic HBV infection [CHB, 305 with hepatocellular carcinoma (HCC) and 305 without HCC], 206 subjects with spontaneous HBV clearance and 205 healthy controls who were age and gender-matched. RESULTS: The frequencies of rs2296651 A minor allele in the CHB group, the HBV clearance group and healthy controls were 7.8, 7.3 and 13.9%, respectively. For rs4646287, the frequencies of T minor allele of the corresponding groups were 10.4, 8.0 and 9.5%, respectively. Compared with healthy controls, the frequencies of rs2296651 GA + AA genotypes were significantly lower in the CHB group (P < 0.001) and in the HBV clearance group (P = 0.001). There was no difference in their distribution between the HBV clearance and CHB groups. Among the CHB group, the distribution of GA + AA genotypes in patients with HCC were significantly lower than in patients without HCC (P = 0.014). The frequencies of HBeAg positivity in patients harboring GG and GA + AA genotypes were 39.8 and 23.5%, respectively (P = 0.004). Among patients with HCC, the mean HBV DNA of the corresponding genotypes were 4.9 ± 1.3 vs. 2.7 ± 1.0 log10 IU/mL, respectively (P < 0.001). There was no difference in genotype and allele frequencies of rs4646287 polymorphism among all studied groups. CONCLUSIONS: Our results showed that rs2296651 polymorphism was associated with a decreased risk of susceptibility to HBV infection and the development of HCC. These data suggest that the NTCP polymorphism might have an influence on natural history of HBV infection in Thai individuals. This abstract was partly presented at the American Association for the Study of Liver Diseases (AASLD) Meeting 2018, November 9-13, 2018, in San Francisco, CA, USA and was published in Hepatology 2018; 68:1237A-1238A.

Hepatitis E virus infection in Thai blood donors.

BACKGROUND: Hepatitis E virus (HEV) infection in several industrialized and developing countries is associated with the consumption of pork and other meat products, an exposure risk among the majority of blood donors. We aimed to evaluate the prevalence of HEV in plasma from healthy blood donors in Thailand. STUDY DESIGN AND METHODS: We screened blood samples collected between October and December 2015, from 30,115 individual blood donors in 5020 pools of six, for HEV RNA using in-house real-time reverse-transcription polymerase chain reaction (RT-PCR). Thrice-reactive samples were subjected to a commercial real-time RT-PCR (cobas HEV test) and evaluated for anti-HEV immunoglobulin M and immunoglobulin G antibodies. Genotyping using nested RT-PCR, nucleotide sequencing, and phylogenetic analysis was performed. RESULTS: Twenty-six donors were positive for HEV RNA by the in-house assay, nine of whom were also positive by cobas test. None of the latter were reactive for anti-HEV immunoglobulin M or immunoglobulin G antibodies. Six samples were successfully genotyped and found to be HEV genotype 3. Thus, the frequency of HEV infection among healthy Thai blood donors is 1 in 1158. CONCLUSION: The presence of HEV RNA in the Thai blood supply was comparable to the rates reported in western European countries, but higher than in North America and Australia.

Next generation sequencing identifies baseline viral mutants associated with treatment response to pegylated interferon in HBeAg-positive chronic hepatitis B.

Current data of hepatitis B virus (HBV) variants associated with treatment outcome identified by next generation sequencing (NGS) are limited. This study was aimed at determining the role of baseline sequence variations in the enhancer II (EnhII), basal core promotor (BCP) and pre-core (PC) regions of HBV genotype C in patients treated with pegylated interferon (PEG-IFN). Patients with HBeAg-positive chronic hepatitis B (CHB) treated with 48-week PEG-IFN were enrolled. Combined response (CR) at week 96 was defined by HBeAg seroconversion plus HBV DNA < 2000 IU/mL and HBsAg < 1000 IU/mL. Pre-treatment viral mutations were characterized by Sanger sequencing and NGS (Miseq Illumina platform). Among 47 patients (32 male, mean age 32.4 years), CR was achieved in 12 (25.5%) individuals. Overall, NGS was superior to Sanger sequencing in detecting mutations (61.7% vs. 38.3%, P < 0.001). Based on NGS, the prevalence of T1753V (T1753C/A/G) and A1762T/G1764A variants were significantly lower in responders compared to non-responders (8.3% vs. 51.4%, P = 0.009 and 33.3% vs. 68.6%, P = 0.032, respectively). No significant difference between groups was found regarding C1653T and G1896A mutants. The absence of T1753V and A1762T/G1764A mutations were factors associated with CR (OR 11.65, 95%CI 1.36-100.16, P = 0.025, and OR 4.36, 95%CI 1.08-17.63, P = 0.039, respectively). The existence of pre-treatment T1753V, A1762T/G1764A mutations and their combination yielded negative predictive values of 94.7%, 85.7% and 93.8%, respectively. The presence of HBV mutants in the BCP region determined by NGS at baseline was associated with poor treatment outcome in patients with HBeAg-positive CHB receiving PEG-IFN.

Prevalence and molecular characterization of human rhinovirus in stool samples of individuals with and without acute gastroenteritis.

Human rhinovirus (RV) most often causes mild upper respiratory tract infection. Although RV is routinely isolated from the respiratory tract, few studies have examined RV in other types of clinical samples. The prevalence of RV was examined in 1,294 stool samples collected mostly from children with acute gastroenteritis residing in Bangkok and Khon Kaen province of Thailand between January 2010 and October 2014. In addition, 591 samples from hand-foot-mouth disease (HFMD) or herpangina patients who do not have gastroenteritis served as a comparison group. Samples were initially screened by semi-nested PCR for the RV 5'UTR through the VP2 capsid region. RV genotyping and phylogenetic analysis were performed on the VP4/VP2 regions. Among children with acute gastroenteritis, RV was found in 2.3% (30/1,294) of stool samples, which comprised 47% (14/30) RV-A, 17% (5/30) RV-B, and 37% (11/30) RV-C. In the comparison group, 0.8% (5/591) was RV-positive and RV-C (3/5) was the major species found. Interestingly, RV was recovered more often from children with acute gastroenteritis than from those with HFMD or herpangina. As many as 31 RV types were present in the gastroenteritis stools, which were different than the types found in those with HFMD or herpangina. J. Med. Virol. 89:801-808, 2017. © 2016 Wiley Periodicals, Inc.

Kinetics of serum HBsAg and intrahepatic cccDNA during pegylated interferon therapy in patients with HBeAg-positive and HBeAg-negative chronic hepatitis B.

This study was aimed at comparing clinical applicability of serum HBsAg quantification in relation to intrahepatic covalently closed-circular DNA (cccDNA) in patients with HBeAg-positive and HBeAg-negative chronic hepatitis B (CHB) treated with pegylated interferon (PEG-IFN) monotherapy for 48 weeks. Overall, 32 and 36 patients with HBeAg-positive and HBeAg-negative CHB, respectively were recruited. Paired liver biopsies at baseline and end of therapy were analyzed for cccDNA. Virological response (VR) at 48 weeks post-treatment was defined as HBeAg clearance (for HBeAg-positive CHB) and HBV DNA <2,000 IU/ml (for both groups). The results demonstrated that baseline levels of all viral markers were higher in the HBeAg-positive group than the HBeAg-negative group. Baseline HBsAg correlated with cccDNA in the HBeAg-positive group (r = 0.452, P = 0.009) but not in the HBeAg-negative group (r = 0.018, P = 0.919). However, the magnitude of cccDNA and HBsAg decline at end of treatment was not different between groups. The reduction of HBsAg showed a positive correlation with cccDNA decline in HBeAg-positive and HBeAg-negative CHB (r = 0.544, P = 0.001 and r = 0.364, P = 0.029, respectively). Overall, responders had more decline in cccDNA and HBsAg levels compared with non-responders. Patients with serum HBsAg decline of >1.0 log10 IU/ml during treatment archived VR and HBsAg clearance of 80% and 30%, respectively. In conclusion, serum HBsAg represented a better surrogate marker of intrahepatic cccDNA in patients with HBeAg-positive CHB compared to those with HBeAg-negative CHB. On-treatment, HBsAg reduction of 1.0 log10 IU/mL was associated with a high probability of subsequent VR and HBsAg clearance in patients receiving PEG-IFN therapy. J. Med. Virol. 89:130-138, 2017. © 2016 Wiley Periodicals, Inc.

Serum hepatitis B core-related antigen as a treatment predictor of pegylated interferon in patients with HBeAg-positive chronic hepatitis B.

BACKGROUND & AIMS: The role of quantitative serum hepatitis B core-related antigen (HBcrAg) in patients with chronic hepatitis B (CHB) receiving pegylated interferon (PEG-IFN) is unclear. This study was aimed at comparing its usefulness with quantitative HBsAg in patients with HBeAg-positive CHB receiving PEG-IFN therapy. METHODS: A total 46 patients treated with PEG-IFN for 48 weeks were retrospectively analysed. Intrahepatic covalently closed circular DNA (cccDNA) from paired liver biopsies and serial serum HBsAg and HBcrAg during therapy were assessed. RESULTS: Virological response (VR), defined as HBeAg clearance and HBV DNA <2000 IU/ml at 24 weeks post treatment, was achieved in 15 (32.6%) patients. Responders had significantly higher cccDNA decline from baseline compared with non-responders. Baseline HBsAg and HBcrAg were correlated with cccDNA (r = 0.424, P = 0.020 and r = 0.564, P = 0.001, respectively), and changes in the corresponding markers during therapy were correlated with cccDNA reduction (r = 0.579, P = 0.001 and r = 0.503, P = 0.005, respectively). Responders showed more rapid decline of both markers during therapy compared with non-responders. In multivariate analysis, serum HBcrAg at week 12 was identified as a predictor of VR. The optimal cut-off value for HBcrAg (log10 8.0 U/ml) provided negative predictive value (NPV) of achieving VR at weeks 12 and 24 of 94.4 and 100%, respectively, while using HBsAg > 20 000 IU/ml provided NPV of 80 and 100% respectively. CONCLUSIONS: The convenient quantitative HBcrAg represented a reliable marker of intrahepatic cccDNA. Monitoring HBcrAg levels during PEG-IFN therapy may help identify patients with a very low probability of response comparable to, if not better than, quantitative HBsAg.

Lineage-specific detection of influenza B virus using real-time polymerase chain reaction with melting curve analysis.

Influenza B viruses comprise two lineages, Victoria (B/Vic) and Yamagata (B/Yam), which co-circulate globally. The surveillance data on influenza B virus lineages in many countries often underestimate the true prevalence due to the lack of a rapid, accurate, and cost-effective method for virus detection. We have developed a real-time PCR with melting curve analysis for lineage-specific differential detection of influenza B virus. By amplifying a region of the hemagglutinin gene using real-time PCR with SYBR Green I dye, B/Vic and B/Yam could be differentiated based on their melting temperature peaks. This method was efficient (B/Vic = 93.2 %; B/Yam 97.7 %), sensitive (B/Vic, 94.6 %; B/Yam, 96.3 %), and specific (B/Vic, 97.7 %; B/Yam, 97.1 %). The lower detection limit was 10(2) copies per microliter. The assay was evaluated using 756 respiratory specimens that were positive for influenza B virus, obtained between 2010 and 2015. The incidence of influenza B virus was approximately 18.9 % of all influenza cases, and the percentage was highest among children aged 6-17 years (7.57 %). The overall percentage of mismatched influenza B vaccine was 21.1 %. Our findings suggest that real-time PCR with melting curve analysis can provide a rapid, simple, and sensitive lineage-specific influenza B virus screening method to facilitate influenza surveillance.

Human norovirus genogroup II recombinants in Thailand, 2009-2014.

Norovirus (NoV) is a major cause of nonbacterial acute gastroenteritis worldwide. New strains emerge partly due to viral recombination. In Thailand, there is a lack of data on NoV recombinants among clinical isolates. We screened stool samples from pediatric diarrheal patients for norovirus by RT-PCR and found GII.4 to be the most prevalent genotype. Phylogenetic and SimPlot analyses detected seven intra-genogroup recombinant strains: three GII.21/GII.3, two GII.12/GII.3, and two GII.12/GII.1 recombinants. Maximum chi-square analysis indicated that all had similar breakpoints near the ORF1/ORF2 junction (p < 0.001), either slightly upstream within the C-terminus of RdRp or downstream within the N-terminal domain of VP1.

A conserved RNA structural element within the hepatitis B virus post-transcriptional regulatory element enhance nuclear export of intronless transcripts and repress the splicing mechanism.

Hepatitis B virus (HBV) infection is a primary cause of hepatocellular carcinoma and liver cirrhosis worldwide. To develop novel antiviral drugs, a better understanding of HBV gene expression regulation is vital. One important aspect is to understand how HBV hijacks the cellular machinery to export unspliced RNA from the nucleus. The HBV post-transcriptional regulatory element (HBV PRE) has been proposed to be the HBV RNA nuclear export element. However, the function remains controversial, and the core element is unclear. This study, therefore, aimed to identify functional regulatory elements within the HBV PRE and investigate their functions. Using bioinformatics programs based on sequence conservation and conserved RNA secondary structures, three regulatory elements were predicted, namely PRE 1151-1410, PRE 1520-1620 and PRE 1650-1684. PRE 1151-1410 significantly increased intronless and unspliced luciferase activity in both HepG2 and COS-7 cells. Likewise, PRE 1151-1410 significantly elevated intronless and unspliced HBV surface transcripts in liver cancer cells. Moreover, motif analysis predicted that PRE 1151-1410 contains several regulatory motifs. This study reported the roles of PRE 1151-1410 in intronless transcript nuclear export and the splicing mechanism. Additionally, these results provide knowledge in the field of HBV RNA regulation. Moreover, PRE 1151-1410 may be used to enhance the expression of other mRNAs in intronless reporter plasmids.

NOROVIRUS OUTBREAK AT A DAYCARE CENTER IN BANGKOK, 2014.

Norovirus is a leading cause of acute non-bacterial gastroenteritis worldwide, affecting developing and developed countries, both children and adults. This study describes an outbreak of acute gastroenteritis at a daycare center of a tertiary level hospital in Bangkok, Thailand during October 2014. Although none of the staff became symptomatic, 8 of 11 children attending the center and 4 of their household contacts developed acute gastroenteritis. No pathogenic bacteria or rotavirus were detected in their evaluation; however, 3 out of 7 stool samples from the cases were positive for norovirus GII.17. Reverse transcriptase polymerase chain reaction analysis with sequence and phylogenetic analysis revealed the viral strain was the same strain reported from Taiwan in 2013. Because norovirus is a frequent cause of outbreaks in crowded conditions, early detection and preventive measures are important to control outbreaks.