Genotype diversity and molecular evolution of noroviruses: A 30-year (1982-2011) comprehensive study with children from Northern Brazil

A chronologically comprehensive 30-year study was conducted that involved children living in Belém, in the Amazon region of Northern Brazil, who participated in eight different studies from October 1982 to April 2011. The children were followed either in the community or in health units and hospitals in order to identify the norovirus genotypes involved in infections during this time. A total of 2,520 fecal specimens were obtained and subjected to RT-PCR and nucleotide sequencing for regions A, B, C, D and P2 of the viral genome. An overall positivity of 16.9% (n = 426) was observed, and 49% of the positive samples were genotyped (208/426), evidencing the presence of several genotypes as follows: Polymerase gene (GI.P4, GII.Pa, GII.Pc, GII.Pe, GII.Pg, GII.Pj, GII.P3, GII.P4, GII.P6, GII.P7, GII.P8, GII.P12, GII.P13, GII.P14, GII.P21, GII.P22), and VP1 gene (GI.3, GI.7, GII.1, GII.2, GII.3, GII.4, GII.6, GII.7, GII.8, GII.10, GII.12, GII.14, GII.17, GII.23). The GII.P4/GII.4 genotype determined by both open reading frames (ORFs) (partial polymerase and VP1 genes) was found for 83 samples, and analyses of the subdomain P2 region showed 10 different variants: CHDC (1970s), Tokyo (1980s), Bristol_1993, US_95/96, Kaiso_2003, Asia_2003, Hunter_2004, Yerseke_2006a, Den Haag_2006b (subcluster “O”) and New Orleans_2009. Recombination events were confirmed in 47.6% (n = 20) of the 42 samples with divergent genotyping by ORF1 and ORF2 and with probable different breakpoints within the viral genome. The evolutionary analyses estimated a rate of evolution of 1.02 x 10⁻² and 9.05 x 10⁻³ subs./site/year using regions C and D from the VP1 gene, respectively. The present research shows the broad genetic diversity of the norovirus that infected children for 30 years in Belém. These findings contribute to our understanding of noroviruses molecular epidemiology and viral evolution and provide a baseline for vaccine design.

Detection and genetic characterization of the emergent GII.17_2014 norovirus genotype among children with gastroenteritis from Northern Brazil

Norovirus is the most important cause of viral gastroenteritis outbreaks worldwide. Recently, a novel GII.17 norovirus variant emerged and caused epidemics in Asian countries, replacing the GII.4 Sydney 2012 strain in hospitalized cases. In this study we describe the emergence of this novel NoV GII.17_2014 strain in Brazil.

Caliciviruses in hospitalized children, São Luís, Maranhão, 1997-1999: detection of norovirus GII.12

Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p<0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n=1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p=0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão.

Epidemiological and molecular investigation of norovirus and astrovirus infections in Rio Branco, Acre, Northern Brazil: A retrospective study

Norovirus (NoV) is a major cause of nonbacterial acute gastroenteritis (AGE) outbreaks worldwide, with infections reported in semiclosed environments, particularly in hospitals and nursing homes. Astrovirus (HAstV) is prevalent worldwide, especially in developing countries. We aimed to determine the prevalence, spatial distribution, and genetic diversity of NoV and HAstV in children under 5 years of age in Rio Branco city, Acre State, Amazon Region, Brazil. Stool samples from children with (n = 240) and without (n = 248) AGE were collected from January to December 2012 from seven neighborhoods. The overall NoV prevalence was 12.3% (60 of 488); representing 15.8% (38 of 240) of the symptomatic samples and 8.9% (22 of 248) of the controls. HAstVs infection was observed in 4.7% (23 of 488) of the samples tested, 6.2% (15 of 240) of AGE cases, and 2.4% (6 of 248) of the controls (plus two without information about feces consistency). Infections were found in all age groups with higher frequency in children less than two years of age, for both viruses. NoV was detected in all neighborhoods, with a higher concentration in the fourth (30%; 18 of 60). NoV nucleotide sequencing performed in 86.7% (52 of 60) of the positive samples showed the circulation of the strains GII.4 (57.7%; 30 of 52), GIIPe/GII.4 (19.2%; 10 of 52), GII.7, GII.Pg/GII.1, and GII.Pc (3.8%; 2 of 52 for each), GII.6 and GII.Pg (1.9%; 1 of 52 for each), and GI.3 (7.7%; 4 of 52). Three GII.4 variants were detected: Den Haag_2006b (n = 1), New Orleans_2009 (n = 1), and Sydney_2012 (n = 14). HAstV types HAstV-1a (81.8%; 9 of 11) and HAstV-2c (18.2%; 2 of 11) were observed in the 47.8% (11 of 23) of characterized samples. This is the first data obtained in Acre State regarding the prevalence of these viruses and provides epidemiological and molecular information for a better understanding of their role among children with and without AGE.

Norovirus genogroups I and II in environmental water samples from Belém city, Northern Brazil

This study investigated the presence of norovirus (NoV) GI and GII in environmental samples from the northern region of Brazil. Water samples were collected monthly (November 2008/October 2010) from different sources and sewage and concentrated by the adsorption-elution method. The NoV investigation used molecular methods followed by sequencing reactions. The general positivity for NoV was 33.9% (57/168). Considering the results obtained only in the semi-nested RT-PCR (reverse transcription polymerase chain reaction) and only in the TaqMan^® real-time PCR, the rates were 26.8% (45/168) and 27.4% (46/168), respectively, being for NoV GI 22.2% (10/45) and 19.6% (9/46); for GII 17.8% (8/45) and 15.2% (7/46); and for GI + GII 60% (27/45) and 65.2% (30/46), respectively. Different GI (GI.1, GI.4, GI.7 and GI.8) and GII (GII.4, GII.6, GII.9, GII.12 and GII.14) genotypes were detected. These results demonstrated the NoV was disseminated in the waters of Belém city due to a lack of sanitation that allowed the discharge of contaminated effluents into these aquatic ecosystems.

SAPOVIRUSES IN CHILDREN WITH ACUTE GASTROENTERITIS FROM MANAUS , AMAZON REGION, BRAZIL, 2010-2011

Sapoviruses (SaVs) are responsible for acute gastroenteritis in humans, especially children and the elderly. In Brazil, data on SaVs infections are very limited, especially in Northern Brazil. Here, we investigated the occurrence of SaVs in samples from hospitalized children under ten years old that presented acute gastroenteritis. Positive samples were genotyped and phylogenetic analysis was performed using prototype strains sequences obtained from GenBank database. In total, 156 fecal samples were screened by RT-PCR for SaVs. A positivity rate of 3.8% (6/156) was found in children under three years of age. Four genotypes were detected: GI.I, GI.2 and GII.2?-GII.4?/GII.4, suggesting a possible inter-genotypes recombination. Most infections (83.3%) occurred between August and September. The positivity was similar to that found in other countries and genotyping demonstrated the presence of distinct genotypes. To our knowledge, this is the first study reporting the circulation of SaVs in Manaus, state of Amazonas, Amazon region, Brazil.

Molecular and evolutionary characterization of norovirus GII.17 in the northern region of Brazil

Background

Currently, norovirus (NoV) is associated with one-fifth of all acute gastroenteritis (AGE) cases worldwide. The NoV GII.17_2014 variant has been associated with gastroenteritis outbreaks in several Asian countries, replacing the previously dominant Sydney 2012 variant. There is limited data about circulation of this new strain in Brazil. This study aimed to describe the phylogenetic and evolutionary characteristics of the GII.17_2014 strains in the Northern region of Brazil.

Methods

NoV was detected by enzyme immunoassay (EIA) in 645 stool samples of AGE cases that were reported in Pará and Amazonas states during 2015–2016. All positive samples were tested for NoV GI and GII by reverse transcription polymerase chain reaction (RT-PCR) and the amplicons were subjected to genome sequencing. The GII.17-positive samples were retested by PCR using different sets of designed primers, which target a highly conserved capsid gene region. Next, the amplicons were sequenced and phylogenetically analyzed using Bayesian inferences.

Results

Of the 645 samples tested, 208 (32.2%) tested were positive for NoV by EIA, among which 95 (45.7%) were genotyped. Among the genotyped samples, 12 (12.6%) were characterized as GII.17_2014 with the first case detected in November 2015 (1/30, 3.3%) and the others in 2016 (11/65, 16.9%). All strains found in our study were clustered in clade D (epidemic strain). The uncorrelated log-normal model estimations calculated the rate of evolution for GII-17 strains as 1.95 × 10^− 3 (1.28 × 10^− 3–2.63 × 10^− 3). In total, 36 nucleotide changes were observed after analyzing the VP1 sequence, among which 28 occurred in the P2 region.

Conclusions

These data demonstrate the evolutionary dynamics in NoV GII.17_2014 strains, which indicated high mutation rates with nucleotide substitutions and indels that are related to the elevated levels of antigenic diversity. This partly explains the increase in viral prevalence.

Ocurrence of rotavirus and picobirnavirus in wild and exotic avian from amazon forest

The present study reports the occurrence of rotavirus A (RVA), rotavirus D (RVD), rotavirus F (RVF), rotavirus G (RVG), and picobirnavirus (PBV) in fecal specimens of wild (n = 22), and exotic birds (n = 1) from different cities of Pará state. These animals were hospitalized at Veterinary Hospital of the Federal University of Pará, Brazil, in a period from January 2018 to June 2019. The animals exhibited different clinical signs, such as diarrhea, malnutrition, dehydration, and fractures. The results showed 39.1% (9/23) of positivity for RVA by RT-qPCR. Among these, one sample (1/9) for the NSP3 gene of T2 genotype was characterized. About 88.9% (8/9) for the VP7 gene belonging to G1, G3 equine like and G6 genotypes, and 55.5% (5/9) for the VP4 gene of P[2] genotype were obtained. In the current study, approximately 4.5% of the samples (1/23) revealed coinfection for the RVA, RVD and RVF groups. Furthermore, picobirnavirus (PBV) was detected in one of the 23 samples tested, and was classified in the Genogroup I. The findings represent the first report of RVA, RVD, RVF, RVG, and PBV genotypes in wild birds in Brazil, and due to wide distribution it can implies potential impacts of RVs, and PBVs on avian health, and other animals contributing to construction of new knowledge, and care perspectives.

Occurrence of norovirus genogroups I and II in recreational water from four beaches in Belém city, Brazilian Amazon region

This study aimed to investigate the presence of norovirus (NoV) in recreational waters of four estuarine beaches located in Mosqueiro Island, Belém city, Brazilian Amazon, during two years of monitoring (2012 and 2013). NoV particles were concentrated on filtering membrane by the adsorption-elution method and detected by semi-nested RT-PCR (reverse transcription polymerase chain reaction) and sequencing. NoV positivity was observed in 37.5% (39/104) of the surface water samples, with genogroup GI (69.2%) occurring at a higher frequency than GII (25.7%), with a cocirculation of both genogroups in two samples (5.1%). This virus was detected in all sampling points analyzed, showing the highest detection rate at the Paraíso Beach (46.2%). Statistically, there was a dependence relationship between tide levels and positive detection, with a higher frequency at high tide (46.7%) than at low tide (25%) periods. Months with the highest detection rates (April 2012 and April/May 2013) were preceded by periods of higher precipitation (March 2012 and February/March 2013). Phylogenetic analysis showed the circulation of the old pandemic variant (GII.4-US_95-96) and GI.8. The NoV detection demonstrated viral contamination on the beaches and evidenced the health risk to bathers, mainly through recreational activities such as bathing, and highlighted the importance of including enteric viruses research in the recreational water quality monitoring.

Detection of a novel species A, DS-1-like, G4P[6] rotavirus strain from a Brazilian child with gastroenteritis

Rotaviruses belonging to species A (RVA) remain among the most common causes of severe gastroenteritis in children aged <5 years, leading to substantial morbidity and mortality worldwide. Genome reassortment events between two human strains or human and animal strains represent one of the mechanisms which appear to generate the broad genetic variability of circulating. According to a nucleotide, sequence-based classification system, RVA strains are currently classified into three genotype constellations including Wa-like (genogroup I), DS-1-like (genogroup II), and AU-like (genogroup III). The present study reports the detection of an unusual RVA G4P[6] strain (coded as strain HSE005), which might have originated from a natural reassortment event between human and animal RVA strains. Molecular characterization of this isolate showed that it belonged to genogroup II, genotype G4P[6]. In addition, two genes (VP3 and NSP4) of this strain denoted evidence of reassortment events involving strains of distinct zoonotic evolutionary origins. Therefore, we propose that a new G4P[6] strain was identified, highlighting a possible first zoonotic transmission including a reassortment event that involved the VP3 gene.

Systematic review and meta-analysis of the potential effects of endophytic bacteria Klebsiella on plant growth promotion and biocontrol of pathogens

Klebsiella is a bacterial genus widely recognized in the medical field but with underexplored potential in agriculture. This study employed a systematic review and meta-analysis to investigate scientific articles on plant growth promotion effects associated with endophytic bacteria Klebsiella species. A total of 39 relevant studies, published between 2012 and 2024, were identified based on strict inclusion and exclusion criteria. The analysis revealed that Klebsiella sp., K. pneumoniae, and K. variicola are cosmopolitan species that have functional versatility in phytohormone production, nutrient solubilization, and pathogen control in agricultural systems in both tropical and temperate zones. The data showed a significant correlation between the use of Klebsiella sp. and plant growth, highlighting the positive impact of these species in controlling aggressive pathogens. These findings underscore the potential of Klebsiella as a biotechnological tool for sustainable agricultural practices, enhancing plant growth and reducing the reliance on chemical inputs. The study further emphasizes the need for future research to deepen genomic characterization and expand the agricultural applications of these bacteria.

Analysis of viral diversity in dogs with acute gastroenteritis from Brazilian Amazon

Viral gastroenteritis is commonly reported in dogs and involves a great diversity of enteric viruses. In this research, viral diversity was investigated in dogs with diarrhea in Northern Brazil using shotgun metagenomics. Furthermore, the presence of norovirus (NoV) was investigated in 282 stool/rectal swabs of young/adult dogs with or without diarrhea from two public kennels, based on one-step reverse transcription polymerase chain reaction (RT-PCR) for genogroup VI and VII (GVI and GVII) and real-time RT-PCR for GI, GII, and GIV. Thirty-one viral families were identified, including bacteriophages. Phylogenetic analyses showed twelve complete or nearly complete genomes belonging to the species of Protoparvovirus carnivoran1, Mamastrovirus 5, Aichivirus A2, Alphacoronavirus 1, and Chipapillomavirus 1. This is the first description of the intestinal virome of dogs in Northern Brazil and the first detection of canine norovirus GVII in the country. These results are important for helping to understand the viral groups that circulate in the canine population.