Ετικέτες

Τρίτη 28 Μαΐου 2019

Virus Diseases

Molecular characterization of peste-des-petits ruminants virus from Nepal, 2005 to 2016

Abstract

Outbreaks of peste-des-petits ruminants (PPR) has been reported regularly in Nepal since 1994. Despite this, there has been limited molecular characterization of circulating virus in the country. In this study a 351 bp segment of the nucleoprotein gene of the PPR virus (PPRV) was amplified and sequenced from ten samples collected between 2005 and 2016. Phylogenetic trees were estimated from these sequences using the maximum likelihood method confirming that all of the PPRV from the samples analysed belonged to the sub-clade IV of clade I of lineage IV and that they shared a common origin with other PPRV isolates in the region.



A mini outbreak of human metapneumovirus infection with severe acute respiratory symptoms in a selected group of children presented to a teaching hospital in Sri Lanka

Abstract

Human metapneumovirus (hMPV) of the family Paramyxoviridae is a relatively new virus causing severe acute respiratory tract infections (SARI) in children. Data on hMPV infection in Asia including Sri Lanka is limited. We aimed to detect respiratory viruses including hMPV in a selected group of children affected by a small outbreak of SARI presented to the Teaching Hospital, Peradeniya (THP), Sri Lanka in 2014. Nasopharyngeal aspirates (NPA) were obtained from 21 children with SARI and tested for hMPV, influenza A and B, parainfluenza 1, 2 and 3 (PIV 1–3), adenovirus and respiratory syncytial virus (RSV) antigens using an immunofluorescence assay (IFA). In addition, a one step RT-PCR was done for the detection of hMPV from the viral RNA extracts. Of the 21 NPA samples tested for respiratory viral antigens by IFA, two were positive for RSV (9.5%), one was positive for influenza A (4.8%) and one was positive for both adenovirus and PIV-2 (4.8%). Of the 21 NPA viral RNA extracts tested by RT-PCR, 18 (86%) were positive for hMPV, in which 2 were co-infected with RSV and influenza A virus, respectively. hMPV was the predominant cause of SARI outbreak (2014) in children presented to the THP, Sri Lanka.



First report of cucumber mosaic virus infecting antamul vine ( Tylophora indica ) in India

Abstract

Tylophora indica (Burm f.) Merrill; commonly known as antamul, is an important medicinal herb. Typical yellow rings or irregular yellow spot and in severe condition necrotic rings were observed on the leaves of the crop. The examination of symptomatic leaf samples under transmission electron microscopy revealed the presence of spherical virions confirmed the association of cucumo like virus group. A novel degenerate primers pair was designed by multiple sequence alignment of RdRP region and used in RT-PCR to amplify a ~ 410 bp genomic fragment. The sequence of the amplified fragment shared 97–98% sequence identity with cucumber mosaic virus (CMV). This study is the first report of the association of CMV with the yellow ring symptom of antamul in India.



Human papillomavirus in Ethiopia

Abstract

Over 99% of cervical cancer cases are associated with genital infection by certain types of human papillomaviruses (HPVs). To outline optimal vaccination strategies and HPV based cervical cancer screening, synthesized data on the genotype distribution of HPV is fundamental that is otherwise missed in Ethiopia. The aim of this study is to compile the findings on HPV genotyping in Ethiopia. Published articles were systematically searched using comprehensive search strings from PubMed/Medline and SCOPUS. Further, Google Scholar and the Google databases were also searched manually for grey literature. The included studies in the review employed 859 women (age range 15–85 years) with different kinds of cervical abnormalities. A total of 534 HPV sequences were reported; the proportion of high risk HPVs was varied 80.4–100%. The top five identified genotypes were HPV 16 (45.3%; 95% CI 41.1–49.6%), HPV 52 (9.4%; 95% CI 7.2–12.1%), HPV 18 (8.2%; 95% CI 6.2–10.9%), HPV 58 (6.9%; 95% CI 5.1–9.4%) and HPV 45 (5.2%; 95% CI 3.7–7.5%). The combined prevalence of HPV 16/18 was at 53.6% (95% CI 49.3–57.8%). In this review, HPV 16 in particular, but also HPV 52 and 18, warrant exceptional consideration in vaccination and HPV based screening programs in Ethiopia. To the best of our knowledge, this study represents the first of its kind to establish the genotype distribution of HPV from different kinds of cervical lesions in Ethiopia although it was synthesized out of few studies. Hence, additional nationwide data are needed to strengthen our finding.



Prevalence of poliovirus vaccine strains in randomized stool samples from 2010 to 2018: encompassing transition from the trivalent to bivalent oral poliovirus vaccine

Abstract

Global eradication of poliovirus (PV) has previously relied on the live attenuated oral poliovirus vaccine (OPV). However, in order to eliminate the risk of vaccine-associated paralytic poliomyelitis, the use of OPV will soon be discontinued. Thailand has introduced inactivated polio vaccine since December 2015 and replaced trivalent with bivalent OPV since April 2016. To provide crucial surveillance data during this polio vaccine transition period, poliovirus shedding in stool was performed. A total of 7446 stool samples between 2010 and September 2018 were tested for poliovirus using reverse-transcription polymerase chain reaction. Approximately 0.44% (33/7446) of the samples tested were positive for PV. All positive specimens had more than 99% homology with the Sabin vaccine strain, based on complete VP1 nucleotide sequences. Although trivalent OPV use has been discontinued in Thailand since April 2016, PV type 2 could be detected in stool samples collected in May 2016 but has not been found afterwards. The use of bivalent OPV was able to reduce PV type 2 shedding in stools and could contribute to the reduction of vaccine-associated paralytic poliomyelitis in Thai children.



Performance evaluation of TRUPCR ® HBV Real-time PCR assay for Hepatitis B virus DNA quantification in clinical samples: report from a tertiary care liver centre

Abstract

Quantitative Real-time PCR (qPCR) based Hepatitis B virus (HBV) DNA load estimation is crucial for the initiation of treatment and serves as a strong predictor of liver disease progression in HBV infected individuals. HBV DNA quantification has been ever evolving with the addition of new qPCR based kits on a regular basis. The study was carried with an objective to evaluate the performance characteristics of a commercially available qPCR kit (TRUPCR®, 3B Black Bio Biotech, India Ltd.) and compare with CE approved qPCR kit (Artus HBV Real-time PCR, Qiagen, Germany). 121 HBV infected patients were prospectively enrolled from July to December 2016. Aliquots of serum samples were tested in parallel by TRUPCR® and Artus for HBV DNA levels. Genotype D was most predominant genotype in 36.9% (38/121) of patients followed by genotype A in 14.6% (15/121) patients. Median viral load as seen by Artus was log10IU/ml 3.37 (interquartile range log10IU/ml 2.10–10.89) as compared to TRUPCR® where it was log10IU/ml 3.54 (interquartile range log10IU/ml 2.67–11.52). A very good correlation was seen between the two assays (R2 = 0.964) with a concordance rate of 92.6% (112/121). The TRUPCR® qPCR HBV kit is capable of providing reliable and rapid HBV DNA quantitation and together with its much lower costs, presents itself as a good alternative.



Isolation and recombinant analysis of variants of porcine epidemic diarrhea virus strains from Beijing, China

Abstract

Porcine epidemic diarrhea virus (PEDV) is a highly infectious virus infecting pigs with high morbidity, especially for newborn piglets. Several PEDV strains were isolated from the intestinal tracts of diarrheic piglets from the Beijing area, China. Sequencing of the whole-genome of the PEDV isolates (GenBank numbers MG546687-MG546690) yielded sequences of 28033–28038 nt. The phylogenetic tree revealed that these strains from the Beijing area belonged to group II, while the vaccine strain, CV777, belonged to group I. We also determined the genetic correlation between these strains and CV777 strain. However, it showed that these strains in the Beijing area had unique mutations. The sequence identity of PEDV strains showed that these strains are most similar to these strains LZW, CH/JX-1/2013, USAIllinois972013, USAKansas1252014, CH/GDZQ/2014, SHQPYM2013, AJ1102, CHZMDZY11, KoreaK14JB01, and CHYJ130330, respectively. The possible recombination events indicate that PEDV in this studies were possibly recombinant strain formed by parent strains USAIllinois972013, KoreaK14JB01, CHYJ130330, and CHZMDZY11. These PEDV strains has been genetic recombination and mutations. The variant strains characterized in this study help to the evolutionary analysis of PEDV.



siRNA intervention inhibiting viral replication and delivery strategies for treating herpes simplex viral infection

Abstract

The effective treatment of herpes simplex virus (HSV) infections generally involves the use of antiviral nucleoside drugs, but with increasing reports of antiviral resistance, the use of these drugs is challenged. Hence, a need arises to explore alternate treatment options. In this review we have discussed various targets that have been explored to control the HSV replication using siRNA therapeutics. We have also discussed the advantages of targeting a less explored UL10 gene to develop an alternate therapeutic intervention. Gene silencing can induce an inhibitory activity to virus spread and infection. The capacity and suitability of UL10 gene as siRNA induced silencing target in eliciting the desired antiviral effect in patients is identified and particularly discussed. The major challenge associated with the siRNA therapeutics is their delivery. The various viable delivery options, that are being explored in the recent times is summarized and different delivery pathways and strategies are reviewed as a part of the study.



Dicer 1 of Candida albicans cleaves plant viral dsRNA in vitro and provides tolerance in plants against virus infection

Abstract

Most of the viral diseases of plants are caused by RNA viruses which drastically reduce crop yield. In order to generate resistance against RNA viruses infecting plants, we isolated the dicer 1 protein (CaDcr1), a member of RNAse III family (enzyme that cleaves double stranded RNA) from an opportunistic fungus Candida albicans. In vitro analysis revealed that the CaDcr1 cleaved dsRNA of the coat protein gene of cucumber mosaic virus (genus Cucumovirus, family Bromoviridae). Furthermore, we developed transgenic tobacco plants (Nicotiana tabacum cv. Xanthi) over-expressing expressing CaDcr1 by Agrobacterium mediated transformation. Transgenic tobacco lines were able to suppress infection of an Indian isolate of potato virus X (genus Potexvirus, family Alphaflexiviridae). The present study demonstrates that CaDcr1 can cleave double stranded replicative intermediate and provide tolerance to plant against RNA viruses.



Hepatitis B virus reverse transcriptase polymorphisms between treated and treatment-naïve chronically infected patients

Abstract

The aim of this study was investigation of variation(s) in the Hepatitis B virus (HBV) reverse transcriptase domain. 120 patients with chronic HBV infection recruited. 104 patients were received nucleos(t)ide analogs treatments. DNA extractions were done from plasma samples. Direct sequencing and alignment of Polymerase Chain Reaction products were applied for further analysis. HBV genotypes determined by NCBI's Genotyping Tool. Polymorphism(s) were detected by using DnaSP software. Of 120 samples, 98 were sequenced. All of products were HBV genotype D. 13/98 (13.27%) of patients had M539I/V substitutions corresponding to YMDD motif. FLLAQ to FLMAQ was observed among 22/98 (22.98) patients. Two substitutions N459Y and L515M were significantly correlated (R2 = 0.486 and R2 = 0.941 respectively) with FLLAQ motif variation. Mutation ratio among treatment-received patients to treatment-naïve patients was 0.2–0.6. Drug resistance conferring substitutions (DRCSs) were rtL180M (22/98), rtA194V (11/98), rtM204V (1/98), and rtM204I (11/98). Furthermore, six variants were observed among all patients. Appearance of DRCSs in HBV polymerase is a major obstacle to the virus treatments. In the present study, it was shown that DRCSs are more prevalent among treated patients. Therefore, replacement of current anti-viral regimen with novel anti-HBV drugs is warranted in the future.



Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου

Αναζήτηση αυτού του ιστολογίου