Search

Tuberculosis, a re-emerging public health problem, is uncommon in infancy. Two healthy completely immunized infants presenting with manifestations compatible with osteoarticular infection required surgical debridement. The cultures of the specimens were positive for M. tuberculosis (MTB) complex comprised multiple subspecies. One case was misdiagnosed as a Bacillus Calmette-Guerin (BCG) related osteomyelitis by a polymerase chain reaction (PCR) based on detection of genes at the region of difference 1. Genome extraction and PCR using the rimM gene and sequences analysis against MTB and BCG control samples confirmed that both specimens were infected by M. tuberculosis. The lesions were successfully healed within one year. Surgical debridement of suspected lesions is warranted in infants as a definitive treatment and to obtain tissues for further evaluation. Microbiological cultures only confirm nonspecific MTB complex infection. PCR kits may yield a false positive result. Identification of the pathogen by DNA extraction and sequence analysis should be recommended.

Abstract Background Biliary atresia (BA) is a progressive inflammatory disorder of the extrahepatic bile ducts leading to the obliteration of bile flow. The purpose of this study was to determine serum adiponectin in BA patients and to investigate the relationship of adiponectin with clinical parameters and liver stiffness scores. Methods Sixty BA patients post Kasai operation and 20 controls were enrolled. The mean age of BA patients and controls was 9.6 ± 0.7 and 10.1 ± 0.7 years, respectively. BA patients were classified into two groups according to their serum total bilirubin (TB) levels (non-jaundice, TB < 2 mg/dl vs. jaundice, TB ≥ 2 mg/dl) and liver stiffness (insignificant fibrosis, liver stiffness < 7 kPa vs. significant fibrosis, liver stiffness ≥ 7 kPa). Serum adiponectin levels were analyzed by enzyme-linked immunosorbent assay. Liver stiffness scores were examined by transient elastography (FibroScan). Results BA patients had markedly higher serum adiponectin levels (15.5 ± 1.1 vs. 11.1 ± 1.1 μg/ml, P = 0.03) and liver stiffness than controls (30.1 ± 3.0 vs. 5.1 ± 0.5 kPa, P < 0.001). Serum adiponectin levels were significantly elevated in BA patients with jaundice compared with those without jaundice (24.4 ± 1.4 vs. 11.0 ± 0.7 μg/ml, P < 0.001). In addition, BA patients with significant liver fibrosis had remarkably greater serum adiponectin than insignificant fibrosis counterparts (17.7 ± 1.2 vs. 9.4 ± 1.1 μg/ml, P < 0.001). Subsequent analysis revealed that serum adiponectin was positively correlated with total bilirubin, hyaluronic acid, and liver stiffness (r = 0.58, r = 0.46, and r = 0.60, P < 0.001, respectively). Conclusions Serum adiponectin and liver stiffness values were higher in BA patients compared with normal participants. The elevated serum adiponectin levels also positively correlated with the degree of hepatic dysfunction and liver fibrosis. Accordingly, serum adiponectin and transient elastography could serve as the useful non-invasive biomarkers for monitoring the severity and progression in postoperative BA.

Abstract Background Human Rhinoviruses (HRVs) are well recognized viral pathogens associated with acute respiratory tract illnesses (RTIs) abundant worldwide. Although recent studies have phylogenetically identified the new HRV species (HRV-C), data on molecular epidemiology, genetic diversity, and clinical manifestation have been limited. Result To gain new insight into HRV genetic diversity, we determined the complete coding sequences of putative new members of HRV species C (HRV-CU072 with 1% prevalence) and HRV-B (HRV-CU211) identified from clinical specimens collected from pediatric patients diagnosed with a symptom of acute lower RTI. Complete coding sequence and phylogenetic analysis revealed that the HRV-CU072 strain shared a recent common ancestor with most closely related Chinese strain (N4). Comparative analysis at the protein level showed that HRV-CU072 might accumulate substitutional mutations in structural proteins, as well as nonstructural proteins 3C and 3 D. Comparative analysis of all available HRVs and HEVs indicated that HRV-C contains a relatively high G+C content and is more closely related to HEV-D. This might be correlated to their replication and capability to adapt to the high temperature environment of the human lower respiratory tract. We herein report an infrequently occurring intra-species recombination event in HRV-B species (HRV-CU211) with a crossing over having taken place at the boundary of VP2 and VP3 genes. Moreover, we observed phylogenetic compatibility in all HRV species and suggest that dynamic mechanisms for HRV evolution seem to be related to recombination events. These findings indicated that the elementary units shaping the genetic diversity of HRV-C could be found in the nonstructural 2A and 3D genes. Conclusion This study provides information for understanding HRV genetic diversity and insight into the role of selection pressure and recombination mechanisms influencing HRV evolution.

Abstract In January and November 2008, outbreaks of avian influenza have been reported in 4 provinces of Thailand. Eight Influenza A H5N1 viruses were recovered from these 2008 AI outbreaks and comprehensively characterized and analyzed for nucleotide identity, genetic relatedness, virulence determinants, and possible sites of reassortment. The results show that the 2008 H5N1 viruses displayed genetic drift characteristics (less than 3% genetic differences), as commonly found in influenza A viruses. Based on phylogenetic analysis, clade 1 viruses in Thailand were divided into 3 distinct branches (subclades 1, 1.1 and 1.2). Six out of 8 H5N1 isolates have been identified as reassorted H5N1 viruses, while other isolates belong to an original H5N1 clade. These viruses have undergone inter-lineage reassortment between subclades 1.1 and 1.2 and thus represent new reassorted 2008 H5N1 viruses. The reassorted viruses have acquired gene segments from H5N1, subclade 1.1 (PA, HA, NP and M) and subclade 1.2 (PB2, PB1, NA and NS) in Thailand. Bootscan analysis of concatenated whole genome sequences of the 2008 H5N1 viruses supported the reassortment sites between subclade 1.1 and 1.2 viruses. Based on estimating of the time of the most recent common ancestors of the 2008 H5N1 viruses, the potential point of genetic reassortment of the viruses could be traced back to 2006. Genetic analysis of the 2008 H5N1 viruses has shown that most virulence determinants in all 8 genes of the viruses have remained unchanged. In summary, two predominant H5N1 lineages were circulating in 2008. The original CUK2-like lineage mainly circulated in central Thailand and the reassorted lineage (subclades 1.1 and 1.2) predominantly circulated in lower-north Thailand. To prevent new reassortment, emphasis should be put on prevention of H5N1 viruses circulating in high risk areas. In addition, surveillance and whole genome sequencing of H5N1 viruses should be routinely performed for monitoring the genetic drift of the virus and new reassorted strains, especially in light of potential reassortment between avian and mammalian H5N1 viruses.

Abstract Background Influenza A virus causes severe disease in both humans and animals and thus, has a considerably impact on economy and public health. In this study, the genetic variations of the nucleoprotein (NP) gene of influenza viruses recovered from swine in Thailand were determined. Results Twelve influenza A virus specimens were isolated from Thai swine. All samples were subjected to nucleotide sequencing of the complete NP gene. Phylogenetic analysis was conducted by comparing the NP gene of swine influenza viruses with that of seasonal and pandemic human viruses and highly pathogenic avian viruses from Thailand (n = 77). Phylogenetic analysis showed that the NP gene from different host species clustered in distinct host specific lineages. The NP gene of swine influenza viruses clustered in either Eurasian swine or Classical swine lineages. Genetic analysis of the NP gene suggested that swine influenza viruses circulating in Thailand display 4 amino acids unique to Eurasian and Classical swine lineages. In addition, the result showed 1 and 5 amino acids unique to avian and human lineages, respectively. Furthermore, nucleotide substitution rates showed that the NP gene is highly conserved especially in avian influenza viruses. Conclusion The NP gene sequence of influenza A in Thailand is highly conserved within host-specific lineages and shows amino acids potentially unique to distinct NP lineages. This information can be used to investigate potential interspecies transmission of influenza A viruses. In addition, the genetic variations of the NP gene will be useful for monitoring the viruses and preparing effective prevention and control strategies for potentially pandemic influenza outbreaks.

Abstract Background Herpesviruses are not only infectious agents of worldwide distribution in humans, but have also been demonstrated in various non-human primates as well. Seventy-eight gibbons were subjected to serological tests by ELISA for herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Results The prevalence of IgG antibodies against HSV-1, HSV-2, EBV and CMV was 28.2%, 28.2%, 14.1% and 17.9%, respectively. Conclusions Antigenic cross-reactivity is expected to exist between the human herpesviruses and gibbon herpesviruses. Gibbons have antibodies to human herpesviruses that may reflect zoonotic infection with human herpesviruses or infection with indigenous gibbon herpesviruses. Therefore, it is difficult to draw concrete conclusions from serological studies alone. Identification should be based on further isolation and molecular characterization of viruses from seropositive animals.

A surveillance program for influenza A viruses (H5N1) was conducted in live bird and food markets in central Thailand during July 2006-August 2007. Twelve subtype H5N1 viruses were isolated. The [...]

Avian influenza H5N1 virus is known to cross the species barrier and infect humans and felines. We report a fatal H5N1 infection in a dog following ingestion of an H5N1-infected [...]