Molecular Characterization of High and Low Virulent Clinical Strains Isolated from Patients with Urinary Tract Infections with or without Bacteremia in Southern Taiwan.

Objective: The most common extraintestinal pathogen and infection site is uropathogenic (UPEC), which causes urinary tract infections (UTIs). UPEC is also a common pathogen in bloodstream infections; in severe cases, it can lead to death. Although host and bacterial virulence factors have been demonstrated to be associated with UTI pathogenesis, the role of the related contributing factors in UTI and urinary source bacteremia is not yet fully understood.

Characterization of Hepatitis B Virus in Tenofovir-Treated and Untreated Chronically Infected Mothers and Their Immunoprophylaxis Failure Infants.

Background: Maternal tenofovir disoproxil fumarate (TDF) therapy during late pregnancy can reduce mother-to-infant transmission of hepatitis B virus (HBV). We investigated HBV mutations associated with maternal TDF therapy and their role in infant immunonophylaxis failure (IPF).

Methods: Serum samples from untreated (n = 89) and TDF-treated (n = 68), highly viremic, chronically infected mothers and their infants were analyzed for HBV DNA by nested polymerase chain reaction (PCR) and direct sequencing.

Hepatitis B virus X gene impacts on the innate immunity and immune-tolerant phase in chronic hepatitis B virus infection.

Background And Aims: The immunologic features involved in the immune-tolerant phase of chronic hepatitis B (CHB) virus (HBV) infection are unclear. The hepatitis B virus X (HBx) protein disrupts IFN-β induction by downregulating MAVS and may destroy subsequent HBV-specific adaptive immunity. We aimed to analyse the impacts of genetic variability of HBx in CHB patients on the immune-tolerant phase during long-term follow-up.

Genetic variants of NTCP gene and hepatitis B vaccine failure in Taiwanese children of hepatitis B e antigen positive mothers.

Background And Aims: Hepatitis B virus (HBV) vaccine failure remains a hurdle to the global elimination of HBV infections in the vaccination era. We aimed to elucidate the relationships between HBV entry receptor sodium taurocholate co-transporting polypeptide (NTCP) and vaccine failure in children born to highly infectious mothers.

Methods: The genetic variants rs7154439, rs4646285, rs4646287, and rs2296651 were genotyped in 170 children with chronic HBV infections and 138 control children of mothers positive for hepatitis B e antigen (HBeAg).

Occult Hepatitis B Virus Infection in Immunized Infants Born to Untreated and Tenofovir-Treated Highly Viremic Mothers.

Tenofovir disoproxil fumurate (TDF) therapy during late pregnancy in highly viremic mothers can reduce residual overt hepatitis B virus (HBV) infections of their infants that occur despite immunoprophylaxis. Occult HBV infection (OBI) has been defined as the presence of HBV DNA in liver or sera in subjects seronegative for hepatitis B surface antigen (HBsAg). OBI has been found in varying proportions of immunized infants born to HBsAg-positive mothers.

Occult hepatitis B virus and surface antigen mutant infection in healthy vaccinated cohorts and children with various forms of hepatitis and multiple transfusions.

Background And Aims: Despite the success of universal infant immunization initiated in Taiwan in 1984, occult hepatitis B virus infection (OBI) and circulating surface antigen mutants remain potential obstacles for eventual eradication of HBV infection.

Methods: From 3299 apparently healthy, neonatally-vaccinated subjects (<30 years of age ) enrolled during 2014 serosurvey, we recruited all HBsAg-positive (n = 17), all HBsAg-negative but anti-HBc-positive (n = 132) and randomly selected HBsAg-negative and anti-HBc-negative subjects (n = 411). These recruited subjects and 81 HBsAg-negative children with various forms of hepatitis and multiple transfusions were analysed for serum HBV DNA.

Universal infant immunization and occult hepatitis B virus infection in children and adolescents: a population-based study.

Unlabelled: To determine whether universal infant immunization affects occult hepatitis B virus (HBV) infection (OBI), serum samples from hepatitis B surface antigen (HBsAg)-negative subjects <18 years enrolled during six sequential seroepidemiological surveys conducted between 1984 (just before universal infant immunization) and 2009 were analyzed. Study subjects were divided into unvaccinated cohorts (born before 1984) and vaccinated cohorts (born after 1984). HBV-DNA positivity was determined by positivity of nested polymerase chain reaction in at least two of three regions (pre-S, S, and pre-core/core genes).

Long-term follow-up of children with postnatal immunoprophylaxis failure who were infected with hepatitis B virus surface antigen gene mutant.

Background: The long-term evolution and outcomes of infection with a hepatitis B virus (HBV) surface antigen (HBsAg) gene mutant (hereafter, "HBsAg-mutant HBV") among immunized children remain unclear.

Methods: Ninety-five HBsAg-positive children aged 0.5-18.

Effects of maternal screening and universal immunization to prevent mother-to-infant transmission of HBV.

Background & Aims: Mother-to-infant transmission is the major cause of hepatitis B virus (HBV) infection among immunized children. There has been much debate about screening pregnant women and administering hepatitis B immunoglobulin (HBIG) to newborns. We analyzed the rate of HBV infection among children born to hepatitis B surface antigen (HBsAg)-positive mothers and whether HBIG administration reduces transmission.

Persistent elevation of hepatocyte growth factor activator inhibitors in cholangiopathies affects liver fibrosis and differentiation.

Unlabelled: Alteration of cell surface proteolysis has been proposed to play a role in liver fibrosis, a grave complication of biliary atresia (BA). In this study we investigated the roles of hepatocyte growth factor activator inhibitor (HAI)-1 and -2 in the progression of BA. The expression levels of HAI-1 and -2 were significantly increased in BA livers compared with those in neonatal hepatitis and correlated with disease progression.

No increase in prevalence of hepatitis B surface antigen mutant in a population of children and adolescents who were fully covered by universal infant immunization.

Background: Mutants of the a determinant of hepatitis B surface antigen (HBsAg) can escape neutralization by vaccine-induced antibodies and prevail in an immunized population.

Methods: We evaluated the a mutants in a pediatric population surveyed in 2004 and compared these findings with the data of previous surveys.

Results: There were 38 children and 74 adolescents who were HBsAg positive, and serum hepatitis B virus (HBV) DNA was obtained and tested from 31 and 34 of them, respectively.

Pre-S2 deletions of hepatitis B virus and hepatocellular carcinoma in children.

The cause of early oncogenesis in hepatitis B virus (HBV)-related childhood hepatocellular carcinoma (HCC) remains unclear. This study investigated whether pre-S deletion of HBV is related to childhood HCC. By using nested polymerase chain reaction, we compared the pre-S sequence of HBV from sera of children with HCC against control children with similar chronic HBV infection.

Interferon-alpha treatment in children and young adults with chronic hepatitis B: a long-term follow-up study in Taiwan.

Background/aims: The short- and long-term benefits of interferon (IFN)-alpha therapy in young patients with chronic hepatitis B (CHB) acquiring infection perinatally or during early childhood have been questioned.

Methods: Twenty-one Taiwanese hepatitis B envelope antigen (HBeAg)-positive CHB patients aged 1.8-21.

SEN virus infection in children in Taiwan: transmission route and role in blood transfusion and liver diseases.

Background: SEN virus (SENV) is a newly discovered DNA virus. We conducted this study to evaluate potential modes of SENV transmission and the pathogenic effect of SENV on liver diseases in children.

Methods: Polymerase chain reaction was used to detect 2 SENV variant (SENV-D and SENV-H) DNA in sera from healthy individuals and diseased children.