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2022 ◽  
Author(s):  
Sirawit Ittisoponpisan ◽  
Shalip Yahangkiakan ◽  
Michael J.E. Sternberg ◽  
Alessia David

Thailand was the first country outside China to officially report COVID-19 cases. Despite the strict regulations for international arrivals, up until February 2021, Thailand had been hit by two major outbreaks. With a large number of SARS-CoV-2 sequences collected from patients, the effects of many genetic variations, especially those unique to Thai strains, are yet to be elucidated. In this study, we analysed 439,197 sequences of the SARS-CoV-2 spike protein collected from NCBI and GISAID databases. 595 sequences were from Thailand and contained 52 variants, of which 6 had not been observed outside Thailand (p.T51N, p.P57T, p.I68R, p.S205T, p.K278T, p.G832C). These variants were not predicted to be of concern. We demonstrate that the p.D614G, although already present during the first Thai outbreak, became the prevalent strain during the second outbreak, similarly to what was described in other countries. Moreover, we show that the most common variants detected in Thailand (p.A829T, p.S459F and p.S939F) do not appear to cause any major structural change to the spike trimer or the spike-ACE2 interaction. Among the variants identified in Thailand was p.N501T. This variant, which involves an asparagine critical for spike-ACE2 binding, was not predicted to increase SARS-CoV-2 binding, thus in contrast to the variant of global concern p.N501Y. In conclusion, novel variants identified in Thailand are unlikely to increase the fitness of SARS-CoV-2. The insights obtained from this study could aid SARS-CoV-2 variants prioritisations and help molecular biologists and virologists working on strain surveillance.


Author(s):  
J Bikrant Kumar Prusty ◽  
Jasashree Choudhury ◽  
Goolla Akhila ◽  
Mrutunjay Dash ◽  
Mamata Devi Mohanty ◽  
...  

Abstract Objective Diarrheal diseases are one of the most common causes of hospitalization in children under five. Rotavirus is the most common cause of acute diarrhea in younger children, and the prevalence decreases rapidly with increasing age. The objective of the study was to estimate the burden of rotavirus infection in acute gastroenteritis among under-five children admitted to a tertiary care hospital in eastern Odisha, for the clinical profile and identity of the prevalent strains. Methods This was a prospective observational study linked to the National Rotavirus Surveillance Network (NRSN), where 720 under-five children with diarrhea were enrolled. In total, 675 stool samples of eligible candidates were sent for rotavirus isolation, and identification of strains was done by identifying VP7 (G-type) and VP4 (P-type) genes by reverse transcription polymerase chain reaction. Results Categorical variables were presented as frequency and percentage, and continuous variables were expressed as mean ± standard deviation. Rotavirus was detected in 256 (37.92%) samples. Males outnumbered females. The most common affected age group was 7 to 12 months, followed by 13 to 18 months. G3P[8] was the most prevalent strain in this study. Conclusion Children between the age of 7 and 18 months were most vulnerable to rotavirus infection. The most prevalent strain varies from one region to another and continuous surveillance is needed.


2021 ◽  
Vol 12 ◽  
Author(s):  
Neha Jha ◽  
Dwight Hall ◽  
Akshay Kanakan ◽  
Priyanka Mehta ◽  
Ranjeet Maurya ◽  
...  

Globally, SARS-CoV-2 has moved from one tide to another with ebbs in between. Genomic surveillance has greatly aided the detection and tracking of the virus and the identification of the variants of concern (VOC). The knowledge and understanding from genomic surveillance is important for a populous country like India for public health and healthcare officials for advance planning. An integrative analysis of the publicly available datasets in GISAID from India reveals the differential distribution of clades, lineages, gender, and age over a year (Apr 2020–Mar 2021). The significant insights include the early evidence towards B.1.617 and B.1.1.7 lineages in the specific states of India. Pan-India longitudinal data highlighted that B.1.36* was the predominant clade in India until January–February 2021 after which it has gradually been replaced by the B.1.617.1 lineage, from December 2020 onward. Regional analysis of the spread of SARS-CoV-2 indicated that B.1.617.3 was first seen in India in the month of October in the state of Maharashtra, while the now most prevalent strain B.1.617.2 was first seen in Bihar and subsequently spread to the states of Maharashtra, Gujarat, and West Bengal. To enable a real time understanding of the transmission and evolution of the SARS-CoV-2 genomes, we built a transmission map available on https://covid19-indiana.soic.iupui.edu/India/EmergingLineages/April2020/to/March2021. Based on our analysis, the rate estimate for divergence in our dataset was 9.48 e-4 substitutions per site/year for SARS-CoV-2. This would enable pandemic preparedness with the addition of future sequencing data from India available in the public repositories for tracking and monitoring the VOCs and variants of interest (VOI). This would help aid decision making from the public health perspective.


2021 ◽  
Vol 17 (12) ◽  
pp. e1010071
Author(s):  
Bin Hu ◽  
Muhammad Junaid Rao ◽  
Xiuxin Deng ◽  
Sheo Shankar Pandey ◽  
Connor Hendrich ◽  
...  

Citrus Huanglongbing (HLB), also known as citrus greening, is one of the most devastating citrus diseases worldwide. Candidatus Liberibacter asiaticus (CLas) is the most prevalent strain associated with HLB, which is yet to be cultured in vitro. None of the commercial citrus cultivars are resistant to HLB. The pathosystem of Ca. Liberibacter is complex and remains a mystery. In this review, we focus on the recent progress in genomic research on the pathogen, the interaction of host and CLas, and the influence of CLas infection on the transcripts, proteins, and metabolism of the host. We have also focused on the identification of candidate genes for CLas pathogenicity or the improvements of HLB tolerance in citrus. In the end, we propose potentially promising areas for mechanistic studies of CLas pathogenicity, defense regulators, and genetic improvement for HLB tolerance/resistance in the future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yunhu Zhao ◽  
Yalong Liao ◽  
Ni Zhang ◽  
Suling Liu ◽  
Jiao Zhang ◽  
...  

Objectives: This study aimed to explore changes in carbapenem-resistant Klebsiella pneumoniae (CR-KP) isolates collected in Guangdong over the period of 2016–2020.Methods: Antibacterial susceptibility was quantified through VITEK 2 compact and K-B method. Carbapenemase phenotypes and genotypes were characterized by modified carbapenem inactivation method (mCIM), EDTA-carbapenem inactivation method (eCIM), and polymerase chain reaction (PCR). Molecular characteristics and evolutionary trends were analyzed by multilocus sequence typing and evolutionary tree.Results: Isolates (2,847) of K. pneumoniae were separated in 2016–2020, and the separate rate of CR-KP increased from 5.65 to 9.90% (p = 0.009). The top 3 wards were intensive care unit (ICU) (21.92%), neonatal wards (13.70%), and respiratory wards (12.33%). In 146 CR-KP strains, serine carbapenemase was the main phenotype, and KPC was the main genotype, and 57 contained two resistant genes, and 1 contained three resistant genes. Two polygenic strains were first found: IMP + GES and KPC + NDM + VIM, but all the phenotypes were metalloenzyme, which indicated that metalloenzyme was usually the first choice for CR-KP resistance. In addition, all the ST54 of metalloenzyme type contained IMP, and all the ST45, ST37, and ST76 contained OXA. ST11 was the most prevalent (42.47%); ST11 and its mutants proved the predominant sequence type making up 51.1% of the carbapenemase-producing isolates. A novel type of ST11 mutation, the rpoB was mutated from sequence 1 to sequence 146, was in an independent separate branch on the evolutionary tree and was resistant to all antibacterial agents. The other three mutants, rpoB 1–15, infB 3–148, and infB 3–80, are also resistant to all antibacteria. Of note, all the four mutants produced serine carbapenemase and contained KPC, and indicated that the prevalent strain in China, ST11, has serious consequences and potential outbreaks.Conclusion: The infection rate of CR-KP has increased, and ICU and neonatal wards have become the key infection areas. Producing serine enzyme, the KPC genotype, and ST11 are the predominant CR-KP. Polygenic strains and ST11 mutation made clinical treatment difficult and may become a potential threat.


2021 ◽  
Author(s):  
Graham Bell

The progress of an epidemic in a small closed community is simulated by an agent-based model which allows vaccination and variation. The attributes of the virus are governed by two genetic loci: the P-locus, which determines growth, and the M-locus, which determines immune characteristics. Mutation at either locus modifies the attributes of the virus and leads to evolution through natural selection. For both loci the crucial variable is the potential mutation supply UPot, because evolution is likely to happen when UPot > 1. Mutation at the P-locus causes a limited increase in virulence, which may be affected by vaccine design. Mutation at the M-locus may cause a qualitative shift of dynamic regime from a simple limited epidemic to a perennial endemic disease by giving rise to escape mutants which may themselves mutate. A broad vaccine that remains efficacious despite several mutations at the M-locus prevents this shift and provides protection despite the evolution of the virus. Escape variants may nevertheless arise through recombination after coinfection, and can be suppressed by timely revaccination, using the prevalent strain to design the vaccine.


Author(s):  
Zhenjiang Zhang ◽  
Jing Su ◽  
Xin Shen ◽  
Bing Pei ◽  
Fang Zhu ◽  
...  

Background: To evaluate the condition of antiviral therapy (ART) for individuals infected HIV-1 in Suqian district of Jiangsu Province, China. Methods: Altogether, 561 HIV-positive patients who received antiviral therapy in Suqian district in 2019 were recruited. EDTA anticoagulated blood was collected and separated to obtain the plasma samples. Viral load (VL) were tested for evaluating the outcome of ART. Then samples with VL beyond 1000IU/mL were used to conduct the molecular test in order to master the characters of HIV-1 and the prevalence of resistance strains. Results: VL results showed that the virus in 91.1% of the patients who received continuous antiviral treatment for more than 6 months were effectively inhibited (VL ≤ 1000 IU / ml). Among the 50 patients who failed in the treatment, 46 HIV-1 pol gene sequences were obtained, and the positive rate was 92.0%. The most prevalent strain was CRF_ 07bc (32.6%), and new epidemic strains, such as 67_01B、79_0107、87_cpx, were popular in this district. Drug resistance test results showed that 56.5% of the patients failed in antiviral treatment due to drug resistance, mainly resistant to the national first-line antiviral drug 3TC. Drug-resistant strains were not found in 43.5% of the patients. Conclusion: ART achieved a satisfied result in Suqian district, but the main cause resulting in ART-failure was resistant, so it is very necessary to enhance the education of adherence prior to the initiation of ART.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 393
Author(s):  
Mpho Magwalivha ◽  
Jean-Pierre Kabue Ngandu ◽  
Afsatou Ndama Traore ◽  
Natasha Potgieter

Diarrhoeal disease is considered an important cause of morbidity and mortality in developing areas, and a large contributor to the burden of disease in children younger than five years of age. This study investigated the prevalence and genogroups of human sapovirus (SV) in children ≤5 years of age in rural communities of Vhembe district, South Africa. Between 2017 and 2020, a total of 284 stool samples were collected from children suffering with diarrhoea (n = 228) and from children without diarrhoea (n = 56). RNA extraction using Boom extraction method, and screening for SV using real-time PCR were done in the lab. Positive samples were subjected to conventional RT-PCR targeting the capsid fragment. Positive sample isolates were genotyped using Sanger sequencing. Overall SV were detected in 14.1% (40/284) of the stool samples (16.7% (38/228) of diarrhoeal and 3.6% (2/56) of non-diarrhoeal samples). Significant correlation between SV positive cases and water sources was noted. Genogroup-I was identified as the most prevalent strain comprising 81.3% (13/16), followed by SV-GII 12.5% (2/16) and SV-GIV 6.2% (1/16). This study provides valuable data on prevalence of SV amongst outpatients in rural and underdeveloped communities, and highlights the necessity for further monitoring of SV circulating strains as potential emerging strains.


2021 ◽  
Author(s):  
John Onditi ◽  
Moses Nyongesa ◽  
René van der Vlugt

AbstractOver the past decades, two new strains of potato virus Y (PVYN-Wi (Wilga) and PVYNTN) have been the most widely distributed worldwide in potato crops (Solanum tuberosum L.). Effective resistance genes comprehensive against all the known strains of the virus are available in some commercial cultivars. However, not all resistance genes in cultivars have been challenged by the new PVY strains to confirm effectiveness of the resistances available. This study was set to identify PVY resistant genotypes and estimate yield losses in potato cultivars in Kenya. PVYN-Wi was used for PVY resistance screening because it was the most prevalent strain in Kenya and also was found to produce more severe infection in Kenyan potato genotypes compared with PVYO (the second most prevalent strain). Three cultivars, Kenya Karibu, Sherekea and Unica, were identified as resistant because they did not get PVY infections over three seasons of both greenhouse and field screening experiments. In addition, two early generation breeding clones were identified as resistant at 28 days post-inoculation. In susceptible cultivars Dutch Robyjn, Nyayo and Kenya Mpya, PVYN-Wi infection caused yield losses of 21.6, 39.0 and 53.1%, respectively, after three seasons. This study demonstrated the necessity to screen for PVY resistance based on the most prevalent PVY strains and to make an informed decision on the usefulness of current levels of resistance in potato cultivars.


Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
Giuseppina La Rosa ◽  
Pamela Mancini ◽  
Giusy Bonanno Ferraro ◽  
Marcello Iaconelli ◽  
Carolina Veneri ◽  
...  

The genetic diversity of Hepatitis A Virus (HAV) circulating in the Campania Region in years 2015–2018 was investigated through the monitoring of sentinel bivalve shellfish and water matrices. Overall, 463 water samples (71 sewage samples, 353 coastal discharge waters, and 39 seawaters samples), and 746 bivalve shellfish samples were analyzed. Positivity for HAV was detected in 20/71 sewage samples, 14/353 coastal discharge waters, 5/39 seawaters, and 102/746 bivalve shellfish. Sixty-one of the positive samples were successfully sequenced and were characterized as genotype IA (n = 50) and IB (n = 11). The prevalent strain circulating in 2015 in both bivalves and waters was the IA strain responsible for the outbreak occurring around the same time in the Naples area. This variant was no longer identified in subsequent years (2017–2018) when, instead, appeared two of the IA variants of the multistate outbreak affecting men who have sex with men (MSM), VRD_521_2016, and RIVM-HAV16–090, with the former prevailing in both shellfish and water environments. HAV IB isolates were detected over the years in shellfish and in water matrices, but not in clinical samples, suggesting that this genotype had been circulating silently. An integrated surveillance system (environment/food/clinical cases) can be a useful tool to monitor changes in viral variants in the population, as well as an early warning system.


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