VirusDisease最新文献

The COVID-19 pandemic has taken the world by surprise and people and organisations worldwide worked in some way or the other to combat the spread; isolate from the infected and get back to normal life, as it was before the pandemic hit. In this regard, the diagnosis of COVID-19 was at the centre of control and prevention and have seen a vehement change in every aspect, especially development of point-of-care testing for better and quick diagnosis. Among different types of techniques developed, the most important was the RT-PCR method of detection which detects nucleic acid of the virus in samples. RT-PCR is a laboratory-based method requiring trained professionals and precise steps for accurate testing. With the advent and spread of the pandemic, number of RT-PCR diagnostic centres rose significantly, and the detection process became less cumbersome, easy to use, ability to handle large volume of samples, more accurate, less time-consuming, and cost-effective. Different industries developed RT-PCR kits, reducing the efforts to prepare laboratory samples. Machines were employed for labour-driven tasks in PCR testing. In addition, new age technologies such as artificial intelligence, IoT, digital systems were combined with RT-PCR for accurate and easy testing. In this review, point-of-care RT-PCR methods, when the COVID-19 started, and the methods now, has been compared on the basis of technological advancements.

Viruses adopt strategies to efficiently utilize their compact genome. Members of the family Paramyxoviridae, exhibit a cotranscriptional RNA editing mechanism wherein polymerase stuttering generates accessory proteins from Phosphoprotein (P) gene. Newcastle disease virus (NDV), an avian paramyxovirus, expresses two accessory proteins, V and W, by RNA editing. While P and V proteins are well studied, very little is known about W protein. Recent studies confirmed W protein expression in NDV and the unique subcellular localization of W proteins of virulent and avirulent NDV. We characterized the W protein of NDV strain Komarov, a moderately virulent vaccine strain. W mRNA expression ranged between 7 and 9% of total P gene transcripts similar to virulent NDV. However, W protein expression, detectable by 6 h, peaked at 24 h and dropped by 48 h post infection in DF1 cells indicating a kinetically regulated expression by the virus. The W protein localized in the nucleus and by mutations, a strong nuclear localization signal was identified in the C-terminal region of W protein. The viral growth kinetics study suggested neither supplementation of W protein nor subcellular localization pattern of the supplemented W protein influenced viral replication in vitro similar to that noticed in avirulent NDV. A cytoplasmic mutant of W protein localized in cytoplasm unlike specific mitochondrial colocalization as recorded in velogenic NDV strain SG10 indicating a possible role of W protein in determining the viral pathogenicity. This study describes for the first time, the distinct features of W protein of moderately virulent NDV.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00813-2.

Information regarding the possible carcinogenicity of human papillomaviruses (HPVs) in bladder tissue might pave the way for the prevention of bladder cancer through improving HPV vaccination of the at-risk population. To address this, this study was conducted to detect HPVs in bladder cancer tissues in the South of Iran. Bladder biopsy samples of 181 patients with bladder cancer were included in this study. The detection of HPVs was performed by nested PCR assay, targeting the L1 region of the genome, and sequencing. HPV was detected in 0.55% of the bladder cancer samples, while the non-cancerous bladder samples were negative for HPV. HPV genotype 6 was detected in this study. The HPV-positive patient was a 55-year-old man with papillary urothelial neoplasms of low malignant in stage Ta-T1. This patient was resident of Dayer city. Overall, HPV prevalence among patients with bladder cancer was not statistically associated with place of residency, gender, age, stage, and grade of the tumor (P value > 0.05). The presence of HPV is extremely rare in bladder cancer biopsy specimens in the south of Iran. Therefore, the results of our study rule out the possible role of HPVs in the etiology of bladder cancer. Due to the increasing air pollution in this region and high-risk jobs, and habits such as cigarette smoking and hookah smoking, the role of these factors alongside genetic factors seems more prominent than the role of HPVs in causing bladder cancer in the south of Iran.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00819-w.

The productivity of cabbage (Brassica oleracea var. capitata) in Ethiopia has been generally low due to several biotic and abiotic constraints among which are several viral diseases. There is a recent report indicating that this economically important vegetable is seriously affected in Ethiopia by cauliflower mosaic virus (CaMV) and turnip mosaic virus (TuMV). However, little information exists on the incidence and distribution of these viruses as the previous report is based on samples only from Addis Ababa. In this study, a total of 370 leaf samples were collected from 75 cabbage growing fields in Central Ethiopia in two rounds of survey. Two cabbage varieties locally known as "Habesha gomen" and "Tikur gomen" with virus-like symptoms were collected and tested with Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA) using polyclonal antibodies specific to CaMV and TuMV. Results from serological diagnosis were confirmed with PCR and Sanger sequencing. The results indicated a high incidence and wide distribution of both viruses in Central Ethiopia with an average of 29.5% infection for CaMV and 40% for TuMV. Biological inoculation tests for CaMV or TuMV or both on healthy cabbage seedlings gave similar symptoms as those observed in the field. Symptom severity was higher with co-infection of CaMV and TuMV followed by TuMV single infection. BLAST analysis showed that TuMV and CaMV isolates from Ethiopia have nucleotide identity of 95-98% and 93-98%, respectively to previously reported isolates. Phylogenetic analysis revealed that CaMV isolates from Ethiopia are closely related to isolates from USA and Italy within Group II clade whereas TuMV isolates have close similarities with isolates from World B clade including isolates from Kenya, UK, Japan and the Netherlands. The identification of the causative agents of the mosaic disease observed on cabbage in Central Ethiopia may lay the foundation for future management studies.

The diagnosis of Dengue and Chikungunya infections during acute phase is a priority considering emerging pattern and increasing trends of their infections. The present study describes the commercial development and validation of RT-PCR test for the simultaneous detection of of DEN and CHIK viral RNA in a single tube from human plasma samples. Multistep one step RT-PCR assay was developed and validated for detection and discrimination of DEN and CHIK along with exogenous internal control. The test was evaluated for commercial use using 3 different lots to determine analytical sensitivity, specificity, precision and stability. The external clinical evaluation was performed at NABL accredited lab with known positive and negative Chikungunya and Dengue specimens and comparator assay method. The findings showed that the test could identify CHIK and DEN viral nucleic acid in clinical samples within 80 min, without any cross-reactivity. The analytical detection limit of the test was 1.56 copies/µl for both. The clinical sensitivity and specificity was ≥ 98% and provide a high-throughput and screen up to 90 samples in a single run. It is available in a freeze-dried format and can be used in both the manual and automated platforms. This unique combo test, PathoDetect™ "CHIK DEN Multiplex PCR Kit" enables simultaneous, sensitive, specific detection of DENV and CHIKV and serves as "ready to use" platform for commercial use. It would aid the differential diagnosis as early as day 1 of the infection and facilitate screen-and-treat approach.

Mother-to-child transmission (MTCT), is an important way of acquired immune deficiency virus (AIDS) transmission. Medical and midwifery students need to have sufficient knowledge in terms of MTCT. The aim of this study was to evaluate the educational needs of these students regarding MTCT of HIV. This cross-sectional study was conducted on 120 medical (extern and intern) and midwifery Bachelor (semester 4 and above) and Master students in Gonabad University of Medical Sciences in 2019. The real needs questionnaire on MTCT AIDS and the perceived needs questionnaire on MTCT were used for need assessment evaluation. Majority of the participants were female (77.5%) and single (65%). Study participants included 48.3% medical and 51.7% midwifery students. High real educational need was reported by 63.5% of medical and 36.5% of midwifery students. More than half of the participants (59.2%) felt a great need for education on MTCT of HIV. OF the areas of real educational needs, the highest and lowest scores were related to the areas of prevention and symptoms, respectively. Students in higher semesters had the highest percentage of real need compared to other students (p = 0.015). The real need for MTCT of HIV prevention was higher among medical students compared to midwifery students (p = 0.004). The observed high real and perceived needs of students, especially in the higher semesters and the field of medicine, necessitates the re-examination of their educational curricula.

Canine parvovirus-2(CPV-2) causes a highly contagious disease of dogs characterised by acute hemorrhagic gastroenteritis, lethargy, vomiting, fever and usually bloody or mucoid diarrhoea. In the present study, 41 faecal samples collected from dogs exhibiting the signs of fever, vomition, bloody or mucoid diarrhoea in Kolkata, India were screened by haemagglutination test and PCR for detection of capsid protein coding VP2 gene. The viral genotype was detected by multiplex PCR and analysis of partial VP2 gene nucleotide sequences of selected PCR products with bioinformatics tool. Thirteen (31.71%) samples were found positive with HA titre ≥ 32 whereas 28 (68.29%) samples were positive by PCR of VP2 gene indicating higher sensitivity of PCR. Highest occurrence of CPV-2 was observed in the age group of 1-6 months (80.65%) and non-descript breeds with no history of vaccination (85%). Three samples were antigenic type CPV-2a, rest were CPV-2b/CPV 2c. Six CPV sequences were found to be highly similar to published CPV 2c sequences in BLAST analysis revealing a maximum identity of 99-100% with other CPV-2c strains and clustered together with CPV-2c strains of India and other countries in phylogenetic analysis. The present study highlights the need for continuous monitoring of samples to detect gradual changes in circulating CPV-2 genotypes in India.

Porcine circovirus type 2 (PCV2), the causative agent of porcine circovirus-associated diseases (PCVADs), has a worldwide distribution, and is considered as one of the most important emerging viral pathogens of economic importance. In Kerala, a total of 62 tissue samples were collected during post mortem from pigs suspected to have died of PCV2 infection. The animals exhibited symptoms like respiratory illness, gradual wasting, rough hair coat, polypnoea, dyspnoea, pallor, diarrhoea, icterus, etc. PCV2 was detected in 36 (58.06%) samples by PCR. Phylogenetic analyses of complete ORF2, and complete genome sequences were carried out and genotypes 2d, 2 h and 2b were detected. The genotype predominant in Kerala was 2d. It was observed that genotypes 2 h and 2b have been recently introduced into North Kerala as it was not detected in the region prior to 2016. Close relationship of Kerala sequences with sequences from Tamil Nadu, Uttar Pradesh and Mizoram were noticed in the phylogenetic tree and also at the amino acid level. A unique K243N mutation was observed in one of the samples. It was also noticed that the most variable amino acid position in ORF2 was 169 where the occurrence of three possible amino acids were observed. The results of the study indicate that multiple genotypes of PCV2 are prevalent in pigs in Kerala and that the percent positivity is higher than that recorded in the State previously.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00814-1.

The study was conducted to characterise bean common mosaic virus strain Blackeye (BCMV-BICM) and determine the likelihood of seed transmission in cowpea breeding lines. F6 cowpea lines obtained from crosses between 'Ife-Brown' and 'IT-95 K-193-12' were planted at five locations in Southwest Nigeria for multilocational evaluation. Virus symptoms were observed on leaves of the breeding lines planted in Ibadan at eight weeks after planting. Enzyme-linked immunosorbent assay (ELISA) was used to determine the presence of six viruses: BCMV-BICM, cowpea aphid-borne mosaic virus, cucumber mosaic virus, cowpea mottle virus, southern bean mosaic virus and cowpea mild mottle virus. Seed transmission tests were carried out to determine virus transmission by seeds while growth and yield components of the cowpea lines were obtained. Reverse transcription polymerase chain reaction, sequencing and phylogenetic analyses were also used to characterise the BCMV-BICM isolates. The observed symptoms, leaf curling and mosaics, were typical of BCMV-BICM infection and ELISA results confirmed the presence of only BCMV-BICM. Line 'L-22-B' had the highest yield of 1653.9 kgha^-1 followed by 'L-43-A' (1072 kgha^-1). A non-significant relationship existed between the virus and germination parameters and similarly, the relationship between virus titres and yield parameters was not significant. Sequence analysis of the virus coat protein (CP) gene revealed the presence of three isolates with 96.87-97.47% nucleotide and 98.2-98.65% amino acid similarities and a 99.10-99.55% match with BCMV-BICM CP genes in GenBank. The deduced CP gene sequences showed unique changes at specific sites, while phylogenetic inferences revealed at least two separate origins for the isolates. Seed transmission is evident in all the cowpea breeding lines and 'L-22-B' and 'L-43-A' showed significant tolerance to BCMV-BICM. Thus, it is recommended that seeds from infected fields should not be used for further planting to prevent the introduction of viruses into new areas where their effect could be devastating in susceptible lines.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00812-3.

Banana bunchy top disease is one of the major prevailing virus diseases associated with banana cultivation, spreading rapidly within a small scale of time. Till date there are only few extensive reports of completely sequenced isolates in India. A study was conducted to detect BBTV infection across 12 districts in West Bengal (WB) where extensive prevalence of the disease was ascertained. In silico characterization of the six genome components were accomplished which showed 84.90-99.86% similarity with other BBTV isolates reported worldwide. The phylogenetic analysis based upon DNA R and DNA S suggested formation of monophyletic cluster of majority of the WB isolates and its close association with Tripura, Manipur, Australia and Africa isolates indicating diversion from geographical differentiation. Dynamics of evolutionary pattern such as genetic diversity including Tajima's D test and Fu Li's Fs test, average number of nucleotide differences (K), Polymorphic sites (S); Fst distance; Mismatch distribution plot; Haplotype network, and selection pressure were performed based upon geographical distribution of the virus. Population genetics analysis of both Pacific Indian Ocean group and South East Asian group of the global BBTV population revealed low nucleotide diversity, high haplotype diversity, high gene flow within the group, and negative or purifying selection constraint indicating recent population expansion. Hence, this study portrays Indian subcontinent as the possible hotspot for rapid demographic expansion from a small virus population size, contributing valuable addition to the currently available information on BBTV worldwide.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00815-0.