Polymorphisms in the ACE I/D (4646994) and ACE2 G8790A (2285666) in Young Children Living in the Amazon Region and SARS-CoV-2 Infection.

COVID-19 infection caused by SARS-CoV-2 continues to cause significant mortality and morbidity. ACE2 is a key regulator of the renin-angiotensin-aldosterone system (RAAS). Differences in COVID-19 severity are thought to be due to the imbalance of RAAS/ACE mutations.

First molecular detection of adenoviruses in bats from an urban Atlantic Forest in Rio de Janeiro, Brazil.

Bats comprise one of the most diverse and abundant groups of mammals in the world and host a significant viral diversity with zoonotic potential. Bat adenoviruses (bat AdVs), members of the family Adenoviridae, have been detected in several bat species, suggesting that bats are natural reservoirs. Here, faeces and rectal/anal-swabs were collected from 321 bats of an urban Atlantic Forest remnant from Rio de Janeiro, during 2019-2022, and screened for bat AdV nucleic acid with PCR.

Association between detection rate of norovirus GII and climatic factors in the Northwest Amazon region.

Unlabelled: Worldwide, approximately one fifth of all cases of diarrhea are associated with norovirus, mainly in children, with a defined seasonality in temperate climates, but seasonal dynamics are less known in tropical climates. The objective was to investigate the impact of external clinical, epidemiological, and climatic factors on norovirus detection rates in samples from children under 5 years of age from Roraima, the Amazon region of Brazil. A total of 941 samples were included.

Prevalence of Human Norovirus GII.4 Sydney 2012 [P31] between 2019 and 2021 among Young Children from Rural Communities in South Africa.

Acute gastroenteritis (AGE) accounts for considerable morbidity and mortality in the paediatric population worldwide, especially in low-income countries. Human norovirus (HNoV), particularly GII.4 strains, are important agents of AGE.

G6P[8] Rotavirus a Possessing a Wa-like VP3 Gene from a Child with Acute Gastroenteritis Living in the Northwest Amazon Region.

The introduction of rotavirus A (RVA) vaccines has considerably reduced the RVA-associated mortality among children under 5 years of age worldwide. The ability of RVA to reassort gives rise to different combinations of surface proteins G (glycoprotein, VP7) and P (protease sensitive, VP4) RVA types infecting children. During the epidemiological surveillance of RVA in the Northwest Amazon region, an unusual rotavirus genotype G6P[8] was detected in feces of a 2-year-old child with acute gastroenteritis (AGE) that had been vaccinated with one dose of Rotarix (RV1).

Circulation of Vaccine-derived Rotavirus G1P[8] in a Vulnerable Child Cohort in Rio de Janeiro.

Background: The expansion of rotavirus (RV) immunization in several countries reduced the burden of acute diarrheal disease (ADD) and diarrhea-associated mortality. Although community transmission of live attenuated monovalent rotavirus vaccine (G1P[8] RV1) virus has been demonstrated in children and household contacts, fecal shedding of these strains in neonates and infants under six weeks of age has never been demonstrated. The objective of the study was to assess ADD and rotavirus vaccine strain shedding before and after immunization through 24 months of age.

Molecular Epidemiology of Sapovirus in Children Living in the Northwest Amazon Region.

Sapovirus is an important etiological agent of acute gastroenteritis (AGE), mainly in children under 5 years old living in lower-income communities. Eighteen identified sapovirus genotypes have been observed to infect humans. The aim of this study was to identify sapovirus genotypes circulating in the Amazon region.

Epidemiology of enteric virus infections in children living in the Amazon region.

Objectives: To verify the frequency of viruses causing acute gastroenteritis (AGE) in association with the histo-blood group antigen (HBGA) and Rotarix™ vaccination coverage in children from the Amazon region.

Design: Fecal and saliva samples were collected from children with AGE (n = 485) and acute respiratory infection (ARI) (n = 249) clinical symptoms. Rotavirus A (RVA), norovirus, human adenovirus (HAdV), and sapovirus (SaV) were verified in feces by molecular detection.

First report of human astrovirus MLB2 in Brazil detected in feces of children with acute gastroenteritis living in the state of Roraima, Northern Brazil.

Human astrovirus (HAstV) 1-8 and highly divergent HAstVMLB1-3 genotypes have been detected in children both with and without acute gastroenteritis (AGE). One hundred and seventy fecal samples from children (≤5 years old) living in the Amazon region were evaluated for the presence of HAstV1-8, HAstV MLB1-3 and HAstVVA1-3, using an usual RT-PCR protocol and a new protocol with specific primers designed to detect HAstVMLB1-3. HAstVMLB1 and HAstV MLB2, as well as the HAstV3 and 5 genotypes were detected.

Rotavirus A shedding and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil, 2014-2018.

Recent studies have investigated whether the human histo-blood group antigen (HBGAs) could affect the effectiveness of the oral rotavirus vaccines, suggesting secretor positive individuals develop a more robust response. We investigated the Rotavirus A (RVA) shedding in association with the host susceptibility profile in children from a birth community-cohort in Rio de Janeiro, Brazil, from 2014 to 2018. A total of 132 children were followed-up between 0 to 11-month-old, stool samples were collected before/after the 1/2 RV1 vaccination doses and saliva samples were collected during the study.

Human Bocavirus genotypes 1 and 2 detected in younger Amazonian children with acute gastroenteritis or respiratory infections, respectively.

Objectives: This study aimed to verify the frequency, genotypes, and etiological role of Human Bocavirus (HBoV) in younger Amazonian children with either acute gastroenteritis (AGE) or respiratory infections (ARI). The influence of Rotarix™ vaccination and co-infection status was also investigated.

Design: HBoV quantitative polymerase chain reaction (qPCR) testing was done on both fecal and saliva (1468 samples) from 734 children < 5 months old living in the Amazon (Brazil, Guyana, and Venezuela).

Norovirus infection and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil.

Norovirus has emerged as an important viral agent of acute pediatric gastroenteritis, with a growing genetic diversity reported in the last decades. Histo-blood group antigens (HBGAs) present on the surface of enterocytes are susceptibility factors for norovirus infection and differ between populations which could affects the epidemiology and evolution of these viruses. This study investigated the frequency, incidence and genetic diversity of noroviruses in a cohort of rotavirus A vaccinated children in association to the host HBGA (Secretor/Lewis) genetic susceptibility profile.

High genetic diversity of noroviruses in children from a community-based study in Rio de Janeiro, Brazil, 2014-2018.

We report on the occurrence and diversity of noroviruses in children (younger than 5 years old of age) from a low-income urban area in Rio de Janeiro, Brazil. Sixty-one stool specimens collected from children between 1 and 4 years old with acute diarrhoeic episodes (ADE) and non-ADE were investigated. RT-qPCR and sequencing of PCR products after conventional RT-PCR analysis were performed.

Phenotyping of Lewis and secretor HBGA from saliva and detection of new FUT2 gene SNPs from young children from the Amazon presenting acute gastroenteritis and respiratory infection.

The Histo-blood group antigens (HBGA) are host genetic factors associated with susceptibility to rotavirus (RV) and human norovirus (HuNoV), the major etiological agents of viral acute gastroenteritis (AGE) worldwide. The FUT2 gene expressing the alpha-1, 2-L- fucosyltransferase enzyme is important for gut HBGA expression, and also provides a composition of the phenotypic profile achieved through mutations occurring in populations with different evolutionary histories; as such, it can be considered a genetic population marker. In this study, Lewis and secretor HBGA phenotyping was performed using 352 saliva samples collected from children between three months and five years old born in the Amazon (Brazil, Venezuela and English Guyana) presenting AGE or acute respiratory infection (ARI), the latter considered as control samples.

Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections.

An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys.

Phylogeography and evolutionary history of hepatitis B virus genotype F in Brazil.

Background: Hepatitis B virus (HBV) genotype F (HBV/F) is considered to be indigenous to the Americas, but its emergence and spread in the continent remain unknown. Previously, only two HBV/F complete genome sequences from Brazil were available, limiting the contribution of Brazilian isolates to the phylogenetic studies of HBV/F. The present study was carried out to assess the proportion and geographic distributions of HBV/F subgenotypes in Brazil, to determine the full-length genomic sequences of HBV/F isolates from different Brazilian geographic regions, and to investigate the detailed evolutionary history and phylogeography of HBV/F in Brazil.

A Theiler's virus BeAn strain shows a persistent profile of BHK-21 cell infection as determined by genome detection using real-time RT-PCR and expression of L* protein.

Cells from various tissues and species are able to bind to Theiler's virus strain DA and allow it to replicate to some extent. Meanwhile, permissiveness in vitro to BeAn strains has not been well investigated. In this paper, the BeAn 8386 virus was subjected to five passages in BHK-21 cells and showed a persistent profile.

Comparison of two eukaryotic systems for the expression of VP6 protein of rotavirus specie A: transient gene expression in HEK293-T cells and insect cell-baculovirus system.

The VP6 protein of rotavirus A (RVA) is a target antigen used for diagnostic assays and also for the development of new RVA vaccines. We have compared the expression of VP6 protein in human embryonic kidney (HEK293-T) cells with results obtained using a well-established insect cell-baculovirus system. The recombinant VP6 (rVP6) expressed in HEK293-T cells did not present degradation and also retained the ability to form trimers.

Leishmania (Viannia) braziliensis: insights on subcellular distribution and biochemical properties of heparin-binding proteins.

Leishmaniasis is a vector-borne disease and an important public health issue. Glycosaminoglycan ligands in Leishmania parasites are potential targets for new strategies to control this disease. We report the subcellular distribution of heparin-binding proteins (HBPs) in Leishmania (Viannia) braziliensis and specific biochemical characteristics of L.

Establishment and validation of an ELISA for the quantitation of HBsAg in recombinant hepatitis B vaccines.

Commercial enzyme-linked immunosorbent assay (ELISA) kits for the determination of the in vitro potency of recombinant hepatitis B vaccines, which detect hepatitis B surface antigen (HBsAg), have been used frequently as an alternative for traditional in vivo potency tests. With the constant need for validation procedures, an ELISA that could be employed to determine the in vitro potency of five recombinant hepatitis B vaccines simultaneously was established using two monoclonal antibodies. The use of two monoclonal antibodies produced "in house" specific for the small envelope protein S of the hepatitis B virus (HBV) resulted in the production of a highly specific, sensitive and stable ELISA.

Expression of Hepatitis B virus surface antigen (HBsAg) from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection.

The impact of hepatitis B virus (HBV) genotypes on the sensitivity of surface antigen (HBsAg) detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay.

Generation of monoclonal antibodies against human recombinant interferon beta using genetic immunization with simultaneous expression of IgM and IgG isotypes.

Monoclonal antibodies (MAbs) against human recombinant interferon beta (hrIFNbeta) were generated by genetic immunization (GI). In order to test two viral promoters frequently used in mammalian expression plasmid vectors, mice were inoculated four times by intramuscular injection, without adjuvant, with 100 microg of either pcDNA 3.1hrIFNbeta or pZeoSV2IFNbeta containing the entire human interferon beta gene and under the control of, respectively, human cytomegalovirus (HCMV) immediate-early promoter or early SV-40 enhancer/promoter.

Development of a rapid and sensitive latex agglutination-based method for detection of group A rotavirus.

Considering the background of morbidity and mortality caused by human rotavirus, detection methods that use rotavirus group antigen (VP6) in either enzyme immunoassay (EIA) or latex agglutination test (LAT) has been employed routinely in clinical diagnostic and epidemiological studies. In order to develop a rapid and sensitive rotavirus group A LAT, part of segment 6 corresponding to conserved N-terminal portion of the VP6 (1-245 aa) was cloned in Escherichia coli expression pGEX vector (glutathione S-transferase-GST gene fusion system) that has been modified previously containing a histidine tail at C-terminus. The immunological propriety of the recombinant VP6 having a total molecular weight of 52 kDa was evaluated by Western blot and by the ability of inducing anti-recombinant VP6 polyclonal antibodies in rabbit.

The presence of qacA/B gene in Brazilian methicillin-resistant Staphylococcus aureus.

A total of 74 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from three government hospitals in 2002 and 2003 were examined concerning the distribution of qacA/B gene, which is the determinant of resistance to quaternary ammonium compounds largely employed in hospital disinfection. By polymerase chain reaction the qacA/B gene was found in 80% of the isolates, which is a significant result considering it is the first time that qacA/B gene is being reported for Brazilian MRSA strains and it is presented at a high rate.