Assessment of SARS-CoV-2 RNA shedding in semen of 36 males with symptomatic, asymptomatic, and convalescent infection during the first and second wave of COVID-19 pandemic in Italy
: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), has been identified in the human testis, but the risk of transmission of SARS-CoV-2 through sexual intercourse still needs to be defined. The goal of our study was to determine if SARS-CoV-2 is detectable in the semen of patients suffering or recovering from coronavirus disease-19 (COVID-19), still testing positive at nasopharyngeal swabs but showing mild or no symptoms at the time of sampling. Detection of SARS-CoV-2 RNA in semen was performed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR targeting open reading frame (ORF) 1ab. Medical …
Clinical and Epidemiologic Features of Viral Gastroenteritis in Hospitalized Children: An 11-Year Surveillance in Palermo (Sicily)
In order to acquire information regarding viral agents and epidemiologic features of severe paediatric Viral Acute Gastroenteritis (VAGE) across multiple seasons in the pre-rotavirus-vaccine era, the epidemiologic characteristics of VAGE were investigated among paediatric patients hospitalized in a major Sicilian paediatric hospital from 2003 to 2013. Overall, 4725 children were observed and 2355 (49.8%) were diagnosed with a viral infection: 1448 (30.6%) were found positive to rotavirus, 645 (13.7%) to norovirus, 216 (4.6%) to adenovirus, and 46 (0.97%) to astrovirus. Viral infections showed different patterns of hospitalization in terms of age at risk (younger for rotavirus and adenovirus…
Italian males recovering from mild COVID-19 show no evidence of SARS-CoV-2 in semen despite prolonged nasopharyngeal swab positivity.
Analysis of early strains of the norovirus pandemic variant GII.4 Sydney 2012 identifies mutations in adaptive sites of the capsid protein.
AbstractGlobal surveillance for norovirus identified in 2012 the emergence of a novel pandemic GII.4 variant, termed Sydney 2012. In Italy, the novel pandemic variant was identified as early as November 2011 but became predominant only in the winter season 2012–2013. Upon sequencing and comparison with strains of global origin, the early Sydney 2012 strains were found to differ from those spreading in 2012–2013 in the capsid (ORF2) putative epitopes B, C and D, segregating into a distinct phylogenetic clade. At least three residues (333, 340 and 393, in epitopes B, C and D, respectively) of the VP1 varied among Sydney 2012 strains of different clades. These findings suggest that the spread …
Nationwide surveillance study of human astrovirus infections in an Italian paediatric population
SUMMARYThe study investigated the genetic diversity of human astroviruses (HAstVs) detected in children hospitalized with gastroenteritis in Italy in 2008–2009. A total of 1321 faecal samples were collected in Parma (northern Italy), Bari (southern Italy), and Palermo (Sicily) and screened for the presence of HAstVs. RT–PCR amplification of a portion at the 5′-end of ORF2 allowed the detection of HAstVs in 3·95% of the patients. Four different genotypes (HAstV-1, HAstV-2, HAstV-4, HAstV-5) were found to be circulating during the study period, with HAstV-1 being the predominant type. Interestingly, a novel lineage, proposed as HAstV-2d, was found to have emerged in Parma in 2009. Investigati…
Extended Validation of Dynamic Irreversible Thermoporation: A Novel Thermal Process for Microbial Inactivation
A novel thermal treatment for microorganism inactivation, characterized by a very rapid temperature increase (up to 30°C/s) and a low final temperature (up to 65°C) maintained for a relatively short holding time, has been recently presented and tested by the authors, showing microbial load reduction greater than 5 log units against several common bacteria and yeasts. With the aim of extending the possible use of the new thermal treatment to a wider microorganisms class, in this work the dynamic irreversible thermoporation (DIT) treatment was further tested on a well-known thermoresistant strain, the Enterococcus hirae: The results of these new experimental tests confirmed the reliability of…
Evaluation of the diagnostic performances of two commercially available assays for the detection of enteric adenovirus antigens
The performance of 2 antigenic commercial assays for enteric adenovirus (AdV) infection, bioNexia Rota-Adeno ImmunoChromatographic Tests (ICT) and LIAISON® Adenovirus ChemiLuminescence Immuno Assays (CLIA), was evaluated on 321 stools from children hospitalized for acute gastroenteritis in Palermo, Italy, using a Real time-PCR (Rt-PCR) as reference method. The CLIA showed higher sensitivity (77% vs 60%), accuracy (94.4 vs 90.9) and concordance (k: 0.81 vs 0.67) with respect to ICT, despite equivalent specificity (98.8%). Using the Ct values of the Rt-PCR as a proxy of the fecal viral load, similar Ct values (mean 9.32 vs 9.89) were observed among the true positive samples, whilst a signific…
Recombinant GII.P16 genotype challenges RT-PCR-based typing in region A of norovirus genome
Abstract Objectives In latest years GII.4[P16] and GII.2[P16] noroviruses have become predominant in some temporal/geographical settings. In parallel with the emergence of the GII.P16 polymerase type, norovirus surveillance activity in Italy experienced increasing difficulties in generating sequence data on the RNA polymerase genomic region A, using the widely adopted JV12A/JV13B primer set. Two sets of modified primers (Deg1 and Deg2) were tested in order to improve amplification and typing of the polymerase gene. Methods Amplification and typing performance of region A primers was assessed in RT-PCR on 452 GII norovirus positive samples obtained from 2194 stool samples collected in 2016–2…
Is Italian population protected from Poliovirus? Results of a seroprevalence survey in Florence, Italy
ABSTRACT Objectives: Periodical assessments of population susceptibility to polioviruses (PV) is essential for evaluating population protection and planning appropriate vaccination strategies. The aim of the current work was to assess serological protective titers against all three polioviruses in the general population of Florence. Methods: A convenience sample of 328 sera, collected in 2009 in Florence (Central Italy) was analyzed. Samples were considered protective if neutralizing antibodies were detected at dilutions ≥1:8, according to the WHO protocols. Results: The immune coverage was 75.3%, 69.2% and 46% for PV1, PV2 and PV3, respectively. The protective titers of neutralizing antibo…
Sentinel hospital-based surveillance for norovirus infection in children with gastroenteritis between 2015 and 2016 in Italy
Noroviruses are one of the leading causes of gastro-enteric diseases worldwide in all age groups. Novel epidemic noroviruses with GII.P16 polymerase and GII.2 or GII.4 capsid type have emerged worldwide in late 2015 and in 2016. We performed a molecular epidemiological study of the noroviruses circulating in Italy to investigate the emergence of new norovirus strains. Sentinel hospital-based surveillance, in three different Italian regions, revealed increased prevalence of norovirus infection in children (<15 years) in 2016 (14.4% versus 9.8% in 2015) and the emergence of GII.P16 strains in late 2016, which accounted for 23.0% of norovirus infections. The majority of the strains with a GII.…
Neutralizing Antibodies Response against SARS-CoV-2 Variants of Concern Elicited by Prior Infection or mRNA BNT162b2 Vaccination.
In order to determine the humoral protective response against SARS-CoV-2, the vaccine-induced and naturally induced neutralizing antibodies (NtAbs) responses against SARS-CoV-2 variants circulating in Italy through in vitro live virus neutralization assay were evaluated. A total of 39 SARS-CoV-2 recovered subjects (COVID-19+) and 63 subjects with a two-dose cycle of the BNT16262 vaccine were enrolled. A single serum sample was tested for COVID-19+ at 35–52 days post-positive swab, while vaccinees blood samples were taken at one (V1) and at three months (V3) after administration of the second vaccine dose. Significantly higher NtAb titers were found against B.1 and Alpha in both COVID-19+ an…
Performance evaluation of a newly developed molecular assay for the accurate diagnosis of gastroenteritis associated with norovirus of genogroup II
The performance of a newly proposed fully automated cassette-based sample-to-results solution for norovirus (NoV) detection, InGenius Norovirus ELITe MGB®, was evaluated. A total of 120 selected archival stool samples from children hospitalized for acute gastroenteritis were used to compare the results to a reference real-time RT-PCR. The InGenius NoV assay showed optimal diagnostic accuracy (sensitivity, 100%; specificity, 95.7%) and was able to correctly detect the entire wide panel of epidemiologically relevant genotypes tested. These preliminary results suggest that the InGenius NoV assay can be recommended as a valuable method for accurate diagnosis of NoV GII infection in epidemic and…
VALUTAZIONE DI DUE TEST IMMUNOCROMATOGRAFICI PER LA DIAGNOSI DI INFEZIONE DA ROTAVIRUS
Obiettivo dello studio: Valutare l’efficienza diagnostica di due tecniche immunocromatografiche (IC) utilizzate per la ricerca di antigeni di Rotavirus di gruppo A (RVA) nei campioni fecali: CerTest Rotavirus+Adenovirus (Biotec) e Vikia Rota+Adeno (bioMérieux). relazione Entrambe le tecniche IC sono state confrontate con la PCR RealTime, considerata il gold standard per la diagnosi delle enteriti da RVA. I RVA sono i principali agenti eziologici di gastroenterite acuta (AGE) nei bambini al di sotto dei 5 anni di età, con elevati tassi di morbilità e mortalità nelle diverse aree geografiche. Metodi impiegati: Uno studio retrospettivo è stato eseguito su 2096 campioni fecali, raccolti dal 200…
Waterborne Norovirus outbreak at a seaside resort likely originating from municipal water distribution system failure
AbstractIn May 2016 a Norovirus (NoV) gastroenteritis outbreak involved a high school class visiting a seaside resort near Taormina (Mascali, Sicily). Twenty-four students and a teacher were affected and 17 of them showed symptoms on the second day of the journey, while the others got ill within the following 2 days. Symptoms included vomiting, diarrhoea and fever, and 12 students required hospitalisation. Stool samples tested positive for NoV genome by Real-Time polymerase chain reaction assay in all 25 symptomatic subjects. The GII.P2/GII.2 NoV genotype was linked to the outbreak by ORF1/ORF2 sequence analysis. The epidemiological features of the outbreak were consistent with food/waterbo…
Evidence for recombination between the pandemic GII.4 norovirus strains New Orleans 2009 and Sydney 2012
ABSTRACT During 2012, a novel pandemic GII.4 norovirus variant, Sydney 2012, emerged worldwide. A signature of the variant was a GII.Pe ORF1, in association with GII.4 Apeldoorn 2008-like ORF2-ORF3 genes. We report the detection of recombinant GII.4 Sydney 2012 strains, possessing the ORF1 gene of the former pandemic variant New Orleans 2009.
Performance analysis of two immunochromatographic assays for the diagnosis of rotavirus infection
Group A rotaviruses (RVAs) are the primary cause of acute gastroenteritis (AGE) in young children worldwide. Several commercial tests including latex agglutination, enzyme-linked assays (ELISA) and immunochromatographic tests (ICT) have been developed for the diagnosis of RVA infection. In the present study, the performance of two commercially available one-step chromatographic immunoassays, CerTest Rotavirus + Adenovirus (Biotec S.L, Zaragoza, Spain) and Vikia Rota-Adeno (bioMerieux SA, Lyon, France) were retrospectively evaluated using Real-time PCR as reference test. Re-testing by Real-time PCR of 2096 stool samples of children hospitalized with AGE previously screened by ICTs (1467 by C…
Identification of a multi-reassortant G12P[9] rotavirus with novel VP1, VP2, VP3 and NSP2 genotypes in a child with acute gastroenteritis.
The G12 rotavirus genotype is globally emerging to cause severe gastroenteritis in children. Common G12 rotaviruses have either a Wa-like or DS-1-like genome constellation, while some G12 strains may have unusual genome composition. In this study, we determined the full-genome sequence of a G12P[9] strain (ME848/12) detected in a child hospitalized with acute gastroenteritis in Italy in 2012. Strain ME848/12 showed a complex genetic constellation (G12-P[9]-I17-R12-C12-M11-A12-N12-T7-E6-H2), likely derived from multiple reassortment events, with the VP1, VP2, VP3 and NSP2 genes being established as novel genotypes R12, C12, M11 and N12, respectively. Gathering sequence data on human and anim…
Antibodies Responses to SARS-CoV-2 in a Large Cohort of Vaccinated Subjects and Seropositive Patients
COVID-19 is a current global threat, and the characterization of antibody response is vitally important to update vaccine development and strategies. In this study we assessed SARS-CoV-2 antibody concentrations in SARS-CoV-2 positive patients (N = 272) and subjects vaccinated with the BNT162b2 m-RNA COVID-19 vaccine (N = 1256). For each participant, socio-demographic data, COVID-19 vaccination records, serological analyses, and SARS-CoV-2 infection status were collected. IgG antibodies against S1/S2 antigens of SARS-CoV-2 were detected. Almost all vaccinated subjects (99.8%) showed a seropositivity to anti-SARS-COV-2 IgG and more than 80% of vaccinated subjects had IgG concentrations >
Epidemiological dynamics of norovirus GII.4 variant New Orleans 2009.
Norovirus (NoV) is one of the major causes of diarrhoeal disease with epidemic, outbreak and sporadic patterns in humans of all ages worldwide. NoVs of genotype GII.4 cause nearly 80–90 % of all NoV infections in humans. Periodically, some GII.4 strains become predominant, generating major pandemic variants. Retrospective analysis of the GII.4 NoV strains detected in Italy between 2007 and 2013 indicated that the pandemic variant New Orleans 2009 emerged in Italy in the late 2009, became predominant in 2010–2011 and continued to circulate in a sporadic fashion until April 2013. Upon phylogenetic analysis based on the small diagnostic regions A and C, the late New Orleans 2009 NoVs circulati…
Emergence in 2017-2019 of novel reassortant equine-like G3 rotavirus strains in Palermo, Sicily.
Rotavirus A (RVA) is a major etiologic agent of gastroenteritis in children worldwide. Hospital-based surveillance of viral gastroenteritis in paediatric population in Palermo (Italy) from 2017 onwards revealed a sharp increase in G3P[8] RVAs, accounting for 71% of all the RVAs detected in 2019. This pattern had not been observed before in Italy, with G3 RVA usually being detected at rates lower than 3%. In order to investigate this unique epidemiological pattern, the genetic diversity of G3 RVAs identified during a 16-year long surveillance (2004-2019) was explored by systematic sequencing of the VP7 and VP4 genes and by whole genome sequencing of selected G3 strains, representative of the…
Genetic heterogeneity and recombination in human type 2 astroviruses
ABSTRACT Novel lineages of human astrovirus (HAstV) types 2, 2c, and 2d have been identified. Upon sequencing of the 3′ end of the genome, the type 2c and 2d HAstVs were found to be open reading frame 1b (ORF1b)-ORF2 recombinant, with ORF1b being derived from type 3 and type 1 HAstVs, respectively. An ORF2 interlineage recombinant strain, 2c/2b, was also identified.
Differing kinetics of anti-spike protein IgGs and neutralizing antibodies against SARS-CoV-2 after Comirnaty (BNT162b2) immunization
Abstract Aims Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has had a serious worldwide impact on human health. On December 2020, an immunization campaign with a COVID-19 mRNA vaccine (Comirnaty-BNT162b2 Pfizer-BioNTech) was started in Italy, first targeting healthcare workers (HCWs). This study aims to investigate the antibodies that are response against SARS-CoV-2 vaccine. Methods and Results The kinetics and the persistence of both anti-S1/S2 IgGs and neutralizing antibodies (Nt-Abs) were investigated in 76 HCWs through a 4-month follow-up with multiple testing points starting at the first dose. Temporal analysis of SARS-CoV-2 Abs titre kinetics showed three diff…
Evolution of DS-1-like human G2P[4] rotaviruses assessed by complete genome analyses
Group A rotaviruses (RVAs) are a leading cause of viral gastroenteritis in children, with G2P[4] RVA being one of the most common human strain worldwide. The complete genome sequences of nine G2P[4] RVA strains, selected from a 26-year archival collection (1985-2011) established in Palermo/Italy, were determined. A strain associated with a peak of G2P[4] RVA activity in 1996 resembled a reassortant strain identified in Kenya in 1982 and completely differed in the genomic make up from more recent strains that circulated during 2004-2011. Conversely, the 2004-2011 G2P[4] RVAs were genetically more similar to contemporary RVA strains circulating globally. Recent G2P[4] strains possessed either…
Impact of Vaccination on Rotavirus Genotype Diversity: A Nearly Two-Decade-Long Epidemiological Study before and after Rotavirus Vaccine Introduction in Sicily, Italy
Sicily was the first Italian region to introduce rotavirus (RV) vaccination with the monovalent G1P[8] vaccine Rotarix® in May 2012. In this study, the seasonal distribution and molecular characterization of RV strains detected over 19 years were compared to understand the effect of Rotarix® on the evolutionary dynamics of human RVs. A total of 7846 stool samples collected from children < 5 years of age, hospitalized with acute gastroenteritis, were tested for RV detection and genotyping. Since 2013, vaccine coverage has progressively increased, while the RV prevalence decreased from 36.1% to 13.3% with a loss of seasonality. The local distribution of RV genotypes changed over th…
Assessing the burden of viral co-infections in acute gastroenteritis in children: An eleven-year-long investigation.
Abstract Background Acute gastroenteritis is an important cause of childhood morbidity and mortality worldwide. A number of pathogens are responsible for human acute gastroenteritis. The recent introduction of syndromic assays for the diagnosis of enteric infections, including a wide panel of enteric pathogens, has unveiled the frequency of mixed infections. This study was carried out to assess the burden of viral co-infections and the genetic diversity of the viruses detected in children hospitalized with acute gastroenteritis in Italy. Methods A total of 4161 stool samples collected from diarrheic children over 11 years, from January 2008 to December 2018, were investigated for the presen…
Introduction and prolonged circulation of G12 rotaviruses in Sicily
SUMMARYGenotype G12 strains are now considered to be the sixth most prevalent human rotaviruses worldwide. In two Sicilian cities, Palermo and Messina, surveillance of rotavirus circulation performed since 1985 and 2009, respectively, did not detect G12 strains until 2012. From 2012 to 2014 rotavirus infection was detected in 29·7% of 1647 stool samples collected from children admitted for acute gastroenteritis to three Sicilian hospitals in Palermo, Messina and Ragusa. In 2012, G12P[8] was first detected in Palermo and then in Messina where it represented the second most frequent genotype (20% prevalence) after G1P[8]. Thereafter, G12 strains continued to circulate in Sicily, showing a mar…
Data mining from a 27-years rotavirus surveillance in Palermo, Italy.
Uninterrupted surveillance conducted in Palermo, Sicily, for 27 years (1985–2012) detected rotavirus infection in 32.7% of 6522 children <5 years of age, hospitalised at the “G. Di Cristina” Children’s Hospital of Palermo. Increased rotavirus activity usually occurred from the beginning of winter to mid-spring. G1P[8] rotaviruses were the prevalent strains in most of the years and were only occasionally overcome by G9P[8], G4P[8] or G2P[4]. The circulation of non-G1P[8] strains was discontinuous and fluctuating. Phylogenetic analyses revealed an heterogeneous population of viruses within each genotype, with different lineages and sublineages emerging over the time. Amino acid substitutions …
Sporadic detection in children during a 25-year surveillance in Palermo, Italy, clarifies the zoonotic potential of G6 rotavirus strains
Analysis of T and NK cell subsets in Sicilian population from young to supercentenarian: the role of age and gender
Summary Ageing dramatically affects number and function of both innate and adaptive arms of immune system, particularly T cell subsets, contributing to reduced vaccination efficacy, decreased resistance to infections and increased prevalence of cancer in older people. In the present paper, we analysed the age‐related changes in the absolute number of lymphocytes in 214 Sicilian subjects, and in the percentages of T and natural killer (NK) cells in a subcohort of donors. We compared these results with the immunophenotype of the oldest living Italian supercentenarian (aged 111 years). The results were also sorted by gender. The correlation between number/percentage of cells and age in all ind…
PREVALENCE OF ANTIBODIES ANTI-BARTONELLA HENSELAEIN WESTERN SICILY: CHILDREN, BLOOD DONORS, AND CATS
To evaluate seroprevalence of B. henselae infection both in Sicilian children and healthy blood donors. Furthermore, circulation of Bartonella in the natural reservoir was also studied. Two hundred forty-three children, living in Sicily (Palermo), affected by various diseases, without clinical features suggesting B. henselae infection, together with 122 healthy blood donors were serologically investigated for IgG and IgM antibodies by indirect fluorescent antibody test (IFAT). One hundred twenty stray and 62 pet cats were also analyzed only for IgG. Among children 25.1% had IgG antibodies to B. henselae; 18.5% showed a titer 1:64, 2.4% 1:128, 2.4% 1:256, 0.8% 1:512, 0.4% 1:1024, and 0.4% 1:…
Temporal variation in the distribution of type-1 human astrovirus lineages in a settled population over 14 years.
Human astroviruses (HAstVs) are important enteric pathogens that are genetically and antigenically heterogeneous and can be classified into eight sero/genotypes (HAstV-1 to -8) and different lineages within each HAstV type. This study describes the genetic diversity of HAstVs circulating in southern Italy over 14 years. Molecular analysis of HAstV-1 strains showed that three different lineages (1a, 1b and 1d) of the predominant genotype were circulating during the study period. The study of an archival collection of HAstV strains offers a unique opportunity to evaluate the patterns of variation of HAstV infections over the years and to correlate the observed epidemiological changes to the g…
Complete genome analysis of contemporary G12P[8] rotaviruses reveals heterogeneity within Wa-like genomic constellation
G12 rotaviruses are globally emergent rotaviruses causing severe childhood gastroenteritis. Little is known about the evolution and diversity of G12P[8] rotaviruses and the possible role that widespread vaccine use, globally, has had on their emergence. In Sicily, Italy, surveillance activity for rotaviruses has been conducted uninterruptedly since 1985, thus representing a unique observatory for the study of human rotaviruses in the pre- and post-vaccine era. G12 rotaviruses were first detected only in 2012 and between 2012 and 2014 they accounted for 8.7% of all rotavirus-associated infections among children, with peaks of 27.8% in 2012/2013 and 21% in 2014. We determined and analyzed the…
Antibodies Responses to SARS-CoV-2 in a Large Cohort of Vaccinated Subjects and Seropositive Patients
Background: COVID-19 is a current global threat and characterisation of antibody response to SARS-CoV-2 is vitally important to update vaccine development and strategies. Methods: In this study we assessed SARS-CoV-2 antibody concentrations in SARS-CoV-2 positive patients (N=272) and subjects vaccinated with BNT162b2 m-RNA Covid-19 vaccine (N=1,256). For each participant socio-demographic data, COVID-19 vaccination records, serological analyses and SARS-CoV-2 infection status have been collected. IgM and IgG antibodies against S1/S2 antigens of SARS-CoV-2 were detected. Findings: Almost all vaccinated subjects (99·8%) showed a seropositivity to anti-SARS-COV-2 IgG and more than 80% vaccinat…
Norovirus GII.17 as Major Epidemic Strain in Italy, Winter 2015–16
In winter 2015-16, norovirus GII.17 Kawasaki 2014 emerged as a cause of sporadic gastroenteritis in children in Italy. Median patient age was higher for those with GII.17 than GII.4 infection (55 vs. 24 months), suggesting limited cross-protection for older children.
Lineage diversification and recombination in type-4 human astroviruses.
Abstract Human astroviruses (HAstVs) are important enteric pathogens and can be classified genetically and antigenically into eight types. During surveillance of HAstVs in Italy, type-4 HAstVs were detected only sporadically and found to cluster into two distinct genetic groups. Upon sequence analysis of the 3′ end of the polymerase gene (ORF1b) and of the full-length ORF2, the 2008 type-4 HAstV strains were characterised as a novel ORF2 genetic lineage, designated as 4c. The 2008 type-4 HAstVs also shared the ORF1b gene with similar HAstV-4c strains detected globally, thus displaying a conserved ORF1b/ORF2 asset. By interrogation of the databases, this novel lineage 4c accounted for 60.8% …
Performance evaluation of gastrointestinal viral ELIte panel multiplex RT-PCR assay for the diagnosis of rotavirus, adenovirus and astrovirus infection.
Rotavirus, adenovirus, norovirus and astrovirus are considered to be among the major causes of sporadic cases and outbreaks of acute gastroenteritis globally. Rapid and accurate identification of enteric viruses is still a challenge for the clinical laboratory. Recently, several molecular platforms for the detection of viral enteric pathogens have become available. In this study, the diagnostic accuracy of InGenius Gastrointestinal Viral (GV) Elite Panel, a newly developed one-step multiplex real-time RT-PCR assay simultaneously detecting rotavirus, adenovirus and astrovirus, was evaluated retrospectively analyzing an archival collection of 128 stool samples of children hospitalized with ac…
Analysis of GII.P7 and GII.6 noroviruses circulating in Italy during 2011-2016 reveals a replacement of lineages and complex recombination history.
Noroviruses are important human enteric pathogens and monitoring their genetic diversity is important for epidemiological surveillance, vaccine development, and understanding of RNA viruses evolution. Epidemiological investigations have revealed that genogroup II, genotype 6 noroviruses (GII.6) are common agents of gastroenteritis. Upon sequencing of the ORF2 (encoding the viral capsid), GII.6 viruses have been distinguished into three variants. Sentinel hospital-based surveillance in Italy revealed that GII.6 noroviruses were the second most common capsid genotype in 2015, mostly in association with a GII.P7 ORF1 (encoding the viral polymerase). Upon molecular characterization of the ORF1 …
Recombinant norovirus GII.g/GII.12 gastroenteritis in children.
Recombinant GII.g/GII.12 norovirus (NoV) strains emerged in 2008 in Australia and subsequently have been associated with gastroenteritis outbreaks worldwide. In the winter season 2009-2010 GII.12 strains caused 16% of the NoV outbreaks in the United States. During 2009-2010 we also identified GII.g/GII.12 strains during surveillance of sporadic cases of gastroenteritis in Italian children. Severity scores were calculated for the GII.g/GII.12 NoV infections using the Vesikari scale and in two out of three paediatric cases they exceeded the median value calculated for concomitant GII.4 infections. Upon sequence analysis, the Italian strains were found to be recombinant viruses and displayed d…
Molecular characterization of genotype G6 human rotavirus strains detected in Italy from 1986 to 2009.
Group A human rotavirus (HRV) strains with a bovine-like (G6) major outer capsid protein VP7 were first detected in Palermo, Italy, in the late 1980s, and subsequently worldwide. During a 25-year rotavirus surveillance period, additional HRV G6 strains, associated with either a P[9] or P[14] VP4 genotype, have been detected sporadically, but repeatedly, in Palermo. Whether these G6 HRVs were transmitted to humans directly from an animal reservoir or could have circulated at low prevalence in susceptible individuals is uncertain. Upon sequence analyses of the VP7, VP4, VP6, NSP4 and NSP5 gene segments, all the Italian HRV strains displayed a conserved genotype constellation, G6-P[9]/[14]-I2-…
Molecular evolutionary analysis of type-1 human astroviruses identifies putative sites under selection pressure on the capsid protein
Human astroviruses (HAstV) are important enteric pathogens that can be classified into eight sero/genotypes (HAstV-1 to -8). Although the various HAstV types show global spread, type-1 strains tend to be predominant. Molecular analysis of the genomic region encoding the capsid protein (ORF2) has revealed discrete sequence variation, with different lineages within each HAstV type and at least three major lineages have been identified within HAstV-1. Longitudinal epidemiological surveillance has revealed temporal shift of the various HAstV-1 lineages. Metadata analysis of HAstV-1 sequences available in the databases also revealed temporal shifts of the circulation of HAstV-1 lineages, suggest…