Genotype D occult hepatitis B virus (HBV) infections (OBIs) have a high frequency of amino acid substitutions in the major hydrophilic region of the small surface protein (S protein). This possibly reflects an escape mutation mechanism to evade detection by the host immune system. Mutations may also impact the detection of hepatitis B surface antigen (HBsAg) by commercial assays. To test these hypotheses, 20 recombinant HBV genotype D surface proteins from OBI carriers with or without antibody to hepatitis B surface antigen (anti-HBs) were expressed in yeast. Recombinant surface protein (rS protein) variants were nonreactive with autologous anti-HBs but reacted weakly with vaccine-induced anti-HBs supporting an immune escape mechanism. rS protein variants tested with a wide range of HBs antibodies, and HBsAg commercial assays showed significantly lower antigenic reactivity in anti-HBs carriers than in donors with antibody to hepatitis B core antigen (anti-HBc) only. Eight out of 10 recombinant variants from anti-HBs carriers reacted weakly or were nonreactive with antibodies to HBs as well as with qualitative and quantitative commercial HBsAg assays, whereas eight out of 10 anti-HBc–only plasmas were fully reactive. rS proteins with substitutions of wild-type cysteine at positions 121, 124, and 137 were nonreactive or showed poor reactivity. However, mutation of cysteine 147 did not alter reactivity compared with controls. Restoration of cysteines 124 and 137 by site-directed mutagenesis improved antigenic reactivity. Conclusion: Escape mutation is a mechanism associated with OBI, which also leads to decreased reactivity in HBsAg detection assays. Performance of commercial assays would be improved by the incorporation of OBI mutants in reagent development. (Hepatology 2010)

Background: Vaginal candidiasis is frequent in pregnant women and is associated with sepsis and adverse neonatal outcomes. This study determined the prevalence of candida species in symptomatic pregnant women and evaluated the antifungal susceptibility profile of the isolated Candida strains. It also aimed to explore whether Candida species predicts gestational complications and adverse neonatal outcomes. Methods: A total of 258 pregnant women with vaginal discharge at 35 to 37 week of gestation participated in this study. Vaginal swabs from these patients were collected at various obstetrics and gynecology clinics in Lebanon for a period of 14 months. Candida isolates were identified at species level and antifungal susceptibility of Candida albicans to fluconazole (FCZ), amphotericin B (AMB), itraconazole (ICZ) and voriconazole (VCZ) was determined by the agar-based E-test method. Results: Among 258 women tested, 100 (39%) were positive for Candida species. C. albicans, C. glabrata and C. krusei were isolated from 42, 41 and 17% of the women, respectively. C. albicans was significantly associated only with gestational diabetes while C. krusei or C. glabrata had significant positive associations with other gestational complications. The antifungal susceptibility tests of C. albicans isolates revealed 97.5, 90, 87.5 and 97.5% susceptibility to AMB, FCZ, ICZ and VCZ, respectively. Conclusion: The current study revealed high incidence of both C. albicans and non-C. albicans Candida strains causing vulvovaginitis among pregnant women in Beirut, Lebanon. Candida screening as antenatal follow up is advised to minimize the risk of adverse neonatal outcome or gestational complications.

Hepatitis B virus (HBV) is one of the major viruses transmissible by blood that causes chronic infection in immunocompromised individuals. The study of 61 HBV carrier blood donors from Lebanon revealed multiple patterns of spliced HBV DNA. HBV DNA splicing was examined and quantified in samples of five genotypes and in seroconversion panels. The Lebanese sample median viral load was 1.5 ×10 ² IU/ml. All strains were genotype D, serotype ayw; 35 clustered as subgenotype D1 and 7 clustered as subgenotype D2. Three splice variants (SP1, SP1A, and Pol/S) were observed in 12 high-viral-load samples. Twenty samples of each genotype, A to E, were tested for the presence of HBV spliced DNA and SP1-specific splice variant. An unspliced HBV genome was dominant, but 100% of strains with a viral load of ≥10 ⁵ copies/ml contained various proportions of spliced DNA. SP1 was detected in 56/100 (56%) samples in levels that correlated with the overall viral load. HBV DNA quantification with S (unspliced) and X (total DNA) regions provided different levels of viral load, with the difference corresponding to spliced DNA. During the highly infectious window period, the SP1 variant became detectable shortly after the hepatitis B surface antigen (HBsAg), suggesting a correlation between the initiation of splicing and the production of detectable levels of HBsAg. The quantification of HBV DNA with primers located outside and inside the spliced region might provide different estimations of viral load and differentiate between infectious and defective viral genomes. The role of splicing neoproteins in HBV replication and interaction with the host remains to be determined.

Introduction. Infections caused by extended spectrum beta lactamase (ESBL) producing bacteria continue to be a challenge for choosing the appropriate therapy since they may exhibit coresistance to many other classes of antibiotics. The aim of the study was to screen pregnant women for ESBL producing bacteria in Beirut, Lebanon, to examine their phenotypic and genotypic characterization and to study the association between ESBL colonization with adverse neonatal outcomes. Method. In this cross-sectional study, vaginal samples from 308 pregnant women at 35–37 weeks of gestation were studied during a one-year period. The samples were plated on MacConkey agar and selective MacConkey agar supplemented with ceftazidime. Phenotypic confirmation of ESBL production was performed by double-disc synergy test and all isolates were screened by PCR for the resistance genes bla_SHV, bla_TEM, and bla_CTX-M. Clonal relatedness of Escherichia coli isolates was investigated by pulsed-field gel electrophoresis. Results. In total, 59 women out of 308 (19.1%) were colonized by ESBL producing gram negative bacteria. Two babies born to mothers colonized with ESBL were diagnosed with sepsis. The susceptibility rates of isolates to other antibiotics were 39% to co-trimoxazole, 49.2% to ciprofloxacin, 91.5% to gentamicin, 18.6% to aztreonam and 35.6% to cefepime. Most of isolates were highly sensitive to meropenem and imipenem, with a susceptibility of 93.2%. PCR was performed on all E. coli isolates to detect the most common ESBL producing genes; bla_CTX-M was the predominant gene (90.7%), followed by bla_TEM (88.4%) and finally bla_SHV (44.2%). PFGE analysis of 34 E. coli isolates revealed 22 distinct clusters showing more than 85% similarity. Conclusion. In conclusion, this study showed that Lebanon has a high prevalence of ESBL carriage in pregnant women. Further studies that include a continuous screening of pregnant women and follow up of their newborn clinical status should be conducted to foresee the risk of transmission.