Luciana Helena Antoniassi da Silva

Genetic variability in the G protein gene of human respiratory syncytial virus isolated from the Campinas metropolitan region, Brazil.

Human respiratory syncytial virus (hRSV) is recognized as the most important viral agent of serious respiratory tract diseases in the pediatric population worldwide. A prospective study for hRSV was conducted in children ageing less than 1 year admitted in two university hospitals in Campinas, São Paulo, Brazil. The aim of the present study was to investigate the genetic variability of both A and B subgroups of hRSV isolated during an epidemic period in the Campinas metropolitan region, Brazil, by sequencing a variable region of the G protein gene. Phylogenetic trees were constructed from alignments of sequences available in the GenBank database and Brazil isolates for hRSV A and B. The data demonstrate that Brazilian isolates clusters together with A and B viruses from Kenya, New Zealand, South Africa, West Virginia, United States (CH, Rochester), and other Brazilian isolates. Phylogenetic analysis of subgroup A isolates showed that the sequences obtained on the present study falls on three clusters, namely GA2, GA5, and SAA1 that co‐circulate during the analyzed period. Subgroup B isolates detected belongs to three genotypes, GB3 (SAB3) and BA (BAIII). Different subgroup B genotypes were detected and BA isolates present in our samples showed some degree of genetic variability. This is one of the first reports on the molecular epidemiology of hRSV strains from the Campinas metropolitan region, São Paulo state, Brazil. And is also the first description of the circulation pattern of hRSV genotypes in two university hospitals, revealing interesting differences between the two subgroups of the virus. J. Med. Virol. 80:1653–1660, 2008.

Variant isolates of human metapneumovirus subgroup B genotype 1 in Campinas, Brazil

BACKGROUND Human metapneumovirus (HMPV) is a paramyxovirus associated with respiratory illness. The genotypes of HMPV isolates in Brazil have not been well characterized. OBJECTIVES To investigate the presence of HMPV in clinical samples collected from pediatric patients of two university hospitals in the region of Campinas (São Paulo, Brazil) and to genotype them by partial sequencing of the HMPV F gene. STUDY DESIGN Nasopharyngeal aspirates were collected from children hospitalized between April and September, 2004 because of acute respiratory infections (ARI). RESULTS We identified HMPV in 8 of 142 (5.6%) clinical samples. We determined through phylogenetic analysis that HMPV isolates in Campinas during the study were clustered within subgroup B genotype 1. Two of the isolates analyzed showed significant differences from previously isolated B1 viruses, when compared to HMPV isolated in South Africa and Canada, and clustered in a separate branch within this genotype. CONCLUSIONS In 2004 in our geographic region all HMPV isolates from pediatric patients were in the B1 HMPV genetic group, with two variant isolates.

Detection of and phylogenetic studies with avian metapneumovirus recovered from feral pigeons and wild birds in Brazil

The aim of the present study was to determine whether avian metapneumovirus (aMPV)-related viruses were present in wild and synanthropic birds in Brazil. Therefore, we analysed samples from wild birds, feral pigeons and domestic chickens in order to perform a phylogenetic comparison. To detect the presence of aMPV, a nested reverse transcriptase-polymerase chain reaction was performed with the aim of amplifying a fragment of 270 bases for subtype A and 330 bases for subtype B, comprising the gene coding the G glycoprotein. Positive samples for aMPV subtypes A and B were found in seven (13.2%) different asymptomatic wild birds and pigeons (50%) that had been received at the Bosque dos Jequitibás Zoo Triage Center, Brazil. Also analysed were positive samples from 15 (12.9%) domestic chickens with swollen head syndrome from several regions of Brazil. The positive samples from wild birds, pigeons and domestic chickens clustered in two major phylogenetic groups: some with aMPV subtype A and others with subtype B. The similarity of the G fragment nucleotide sequence of aMPV isolated from chickens and synanthropic and wild avian species ranged from 100 to 97.5% (from 100 to 92.5% for the amino acids). Some positive aMPV samples, which were obtained from wild birds classified in the Orders Psittaciformes, Anseriformes and Craciformes, clustered with subtype A, and others from the Anas and Dendrocygma genera (Anseriformes Order) with subtype B. The understanding of the epizootiology of aMPV is very important, especially if this involves the participation of non-domestic bird species, which would add complexity to their control on farms and to implementation of vaccination programmes for aMPV.

Brazilian avian metapneumovirus subtypes A and B: experimental infection of broilers and evaluation of vaccine efficacy

Avian metapneumovirus (aMPV) is a respiratory pathogen associated with the swollen head syndrome (SHS) in chickens. In Brazil, live aMPV vaccines are currently used, but subtypes A and, mainly subtype B (aMPV/A and aMPV/B) are still circulating. This study was conducted to characterize two Brazilian aMPV isolates (A and B subtypes) of chicken origin. A challenge trial to explore the replication ability of the Brazilian subtypes A and B in chickens was performed. Subsequently, virological protection provided from an aMPV/B vaccine against the same isolates was analyzed. Upon challenge experiment, it was shown by virus isolation and real time PCR that aMPV/B could be detected longer and in higher amounts than aMPV/A. For the protection study, 18 one-day-old chicks were vaccinated and challenged at 21 days of age. Using virus isolation and real time PCR, no aMPV/A was detected in the vaccinated chickens, whereas one vaccinated chicken challenged with the aMPV/B isolate was positive. The results showed that aMPV/B vaccine provided a complete heterologous virological protection, although homologous protection was not complete in one chicken. Although only one aMPV/B positive chicken was detected after homologous vaccination, replication in vaccinated animals might allow the emergence of escape mutants.

Cloning of the transmembrane glycoproteins G and F from a Brazilian isolate of bovine respiratory syncytial virus in a prokaryotic system

The aim of this work was the cloning of those transmembrane glycoproteins G and F from an isolate bovine respiratory syncytial viruses (BRSV) - a Brazilian isolate of BRSV, named BRSV-25-BR in previous studies, in a prokaryotic system to proceed the sequencing of larger genomic fragments. The nucleotide substitutions were confirmed and these clones may also be used in further studies regarding the biological effects of those proteins in vitro and in vivo.