Genotyping and sero-virological characterisation of hepatitis B virus-infected blood donors in Central Eritrea

Aim To determine serological markers and genotypes profiles of HBV isolates in Central Eritrea. Materials & methods A total of 191 HBsAg sero-positive samples were randomly selected for the study from 23,232 screened blood donors from 2015 to 2017. Enzyme-linked immunosorbent assay was used to perform HBV serological markers screening, while genotypes were determined using type-specific primer-based multiplex-nested PCR. Results The median age of infected blood donors was 28.9 ± 10.26 years. Of 191 HBsAg reactive serum samples, 77.5% (148/191) were sero-positive for HBcAb-total, among which 99.3% (147/148) and 0.7% (1/148) were sero-positive for HBsAg and HBsAb, respectively. Interestingly, among 147 HBcAb-total/HBsAg reactive samples, 16 (10.9%) and 131 (77.9%) were sero-positive for HBeAg and HBeAb, respectively. For genotyping, 73 HBV isolates were successfully amplified and genotyped, with 59 (80.8%) had a mono-genotype and 14 (19.2%) had a mixed-genotype infection. Among HBV isolates with mono-genotypes: 39 (53.4%) D; 10 (13.7%) E; 6 (8.2%) A and 4 (5.5%) C. While five mixed-genotypes comprised: 6 (8.2%) C/D; 3 (4.1%) C/D/E; 2 (2.7%) each with genotype A/D and D/E; and 1 (1.4%) genotype B/D. Conclusion HBV genotype D is the predominant genotype, either as a HBV mono- or mixed-genotype infection, among blood donors in Eritrea.

Distribution of Hepatitis C virus genotypes among chronic Hepatitis C patients in Kuantan Pahang

Introduction: Hepatitis C virus (HCV) has been classified into seven genotypes with more than 80 subtypes isolated worldwide. HCV genotypes are an important parameter in determining the right antiviral dosage, duration and monitoring the response of that treatment. The main aim of this study was to determine the distribution of HCV genotypes, their association with demographic variables and to investigate the presence of uncommon mixed-genotype infection case. Methods: This cross sectional study was performed in Hospital Tengku Ampuan Afzan, Kuantan, Pahang from January to July 2014. The sera samples from 40 HCV seropositive patients were analyzed using reversetranscription PCR (RT-PCR) and direct DNA sequencing assays. Results: More than half of study patients were from male patients (32/40; 80%), below the age of 45 (27/40; 67.5%) and Malays (34/40; 77.5%). Thirty one out 40 (77.5%) samples were successfully sequenced for genotyping with genotype 3 (24/31; 77.4%) predominate the study, followed by genotype 1 (6/31; 19.3%). There is no significant association established between the demographic factors and HCV genotypes. Majority of the HCV RNA positive samples were identified as mono genotype HCV infection. There was one isolate with mixed-genotype infection. Conclusions: The findings of the study showed that genotype 3 and 1 are still the commonest genotypes found among the study population. No association can be established from HCV genotypes and basic demographic factors. The finding of mixed HCV genotype infection from this study requires further investigation to evaluate the clinical role of this type of infection in treatment outcome.

Two Xylella fastidiosa Genotypes Associated with Almond Leaf Scorch Disease on the Same Location in California

Almond leaf scorch disease (ALSD) has recently reemerged in the San Joaquin Valley of California threatening almond production. ALSD is caused by Xylella fastidiosa, a nutritionally fastidious bacterium. Single nucleotide polymorphisms (SNPs) in the 16S rRNA gene (16S rDNA) of X. fastidiosa strains were identified to characterize the bacterial population in infected trees. Genotype-specific SNPs were used to design primers for multiplex polymerase chain reaction assays of early passage cultures. Two genotypically distinct types of X. fastidiosa strains, G-type and A-type, coexist simultaneously in the same infected almond orchard. This was substantiated by restriction fragment length polymorphism analysis of a different genetic locus, RST31-RST33, which has previously been used to identify and differentiate X. fastidiosa strains. Furthermore, unique bacterial colony morphology was consistently associated with the A-type X. fastidiosa strains. To our knowledge, this is the first report of a mixed genotype infection of X. fastidiosa disease on the same location under natural environmental conditions. The concept of mixed genotype infection could affect the current epidemiological study based on the assumption that one genotype causes ALSD on one location and, therefore, the disease management strategy.