Human rhinoviruses (HRV) are usually associated with mild respiratory symptoms in children. However, some studies have found that HRV can cause severe disease, especially when the patient is co-infected with a second virus. In this study, 532 nasopharyngeal aspirates (NPAs) were collected over a nine-year period from children at the Clinics Hospital of Uberlândia. The collected NPAs were then tested for HRV RNA using the reverse transcription-polymerase chain reaction. Eighty-three specimens from children diagnosed with lower respiratory tract illness (LRTI) were positive for HRV RNA and were then tested for the presence of eight other respiratory viruses. A second virus was detected in 37.3% (31/83) of the samples. The most frequent clinical diagnosis was bronchiolitis, followed by other LRTI and then pneumonia. The frequency of severe disease in children infected with more than one virus was not significantly different from the frequency of severe disease in children infected with HRV alone. Children infected with both HRV and parainfluenza virus (1.5 m.o.) were significantly younger than those infected by HRV alone (5.0 m.o.) (p = 0.0454). Overall, these results suggest that infection with a second virus does not lead to a higher frequency of severe syndromes in children presenting with LRTI.

Human adenoviruses (HAdV) are a major cause of acute respiratory diseases (ARD), gastroenteritis, conjunctivitis and urinary infections. Between November 2000-April 2007, a total of 468 nasopharyngeal aspirate samples were collected from children with ARD at the Clinics Hospital of Uberlândia. These samples were tested by immunofluorescence assay (IFA) and 3% (14/468) tested positive for the presence of HAdV. By performing polymerase chain reaction (PCR) to detect HAdV DNA in samples that tested negative or inconclusive for all viruses identifiable by IFA (respiratory syncytial virus, parainfluenza viruses 1, 2 and 3, influenza viruses A and B and HAdV), as well as negative for rhinoviruses by reverse transcription-PCR, additional 19 cases were detected, for a total of 33 (7.1%) HAdV-positive samples. Nucleotide sequences of 13 HAdV samples were analyzed, revealing that they belonged to species B, C and E. Further analyses showed that species C (HAdV-2) was the most prevalent among the sequenced samples. To our knowledge, this is the first report describing the presence of HAdV-4 in Brazil. We also detected an isolate that was 100% identical to a part of the feline adenovirus hexon gene sequence.

INTRODUÇÃO: Lamivudina é um análogo de nucleosídeo clinicamente utilizado para o tratamento da infecção crônica pela hepatite B. Entretanto, o principal problema do uso prolongado da lamivudina é o desenvolvimento de resistência viral ao tratamento. Mutações no motivo YMDD no gene da DNA polimerase do vírus da hepatite B estão associados com a resistência a terapia medicamentosa. Até o presente momento, não há muitos estudos no Brasil que descrevem o desenvolvimento genótipo-dependente da resistência à lamivudina. Assim, o intuito do trabalho aqui descrito foi determinar a possível correlação entre um determinado genótipo e o desenvolvimento aumentado da resistência à lamivudina em pacientes com hepatite B crônica. MÉTODOS: O HBV DNA foi amplificado por PCR convencional a partir de 50 amostras coletadas de pacientes submetidos ao tratamento com lamivudina no Hospital das Clínicas- FMRP- USP. Posteriormente, os produtos foram seqüenciados e a análise filogenética foi realizada. RESULTADOS: A análise filogenética mostrou que 29 (58%) pacientes foram infectados com o genótipo D, 20 (40%) com o genótipo A e 1 (2%) com o genótipo F. Mutações no motivo YMDD ocorreu em 20% dos pacientes com genótipo A e 27,6% em pacientes do genótipo D. CONCLUSÕES: Apesar do baixo número de amostras, nossos resultados indicaram que mutações no motivo YMDD são 1,38 X mais frequentes no genótipo D em relação ao genótipo A.

INTRODUCTION: Lamivudine is a nucleoside analogue that is used clinically for treating chronic hepatitis B infection. However, the main problem with prolonged use of lamivudine is the development of viral resistance to the treatment. Mutations in the YMDD motif of the hepatitis B virus DNA polymerase gene have been associated with resistance to drug therapy. So far, there have not been many studies in Brazil reporting on genotype-dependent development of resistance to lamivudine. Thus, the aim of the present study was to determine the possible correlation between a certain genotype and increased development of resistance to lamivudine among chronic hepatitis B patients. METHODS: HBV DNA in samples from 50 patients under lamivudine treatment was amplified by means of conventional PCR. Samples were collected at Hospital das Clínicas, FMRP-USP. The products were then sequenced and phylogenetic analysis was performed. RESULTS: Phylogenetic analysis revealed that 29 (58%) patients were infected with genotype D, 20 (40%) with genotype A and one (2%) with genotype F. Mutations in the YMDD motif occurred in 20% of the patients with genotype A and 27.6% of the patients with genotype D. CONCLUSIONS: Despite the small number of samples, our results indicated that mutations in the YMDD motif were 1.38 times more frequent in genotype D than in genotype A.

Apesar de evidências sorológicas da presença do vírus da hepatite E (VHE) em humanos ou outros animais, até o presente estudo o vírus não havia sido detectado e a caracterização molecular da cepa que circula no Brasil não havia sido descrita. Assim, amostras de fezes de porcos jovens foram colhidas e analizadas quanto a presença do ARN do VHE por RT-PCR, utilizando-se oligonucleotídeos para amplificação da seqüência parcial do ORF2 viral. Análise filogenética realizada com a seqüência obtida dos produtos amplificados revelou que a cepa encontrada apresentou relação próxima com cepas do genótipo 3 que são detectadas com freqüência em porcos. Análises das seqüências nucleotídicas realizadas com todo o segmento amplificado, com somente o segmento sobreposto do ORF2/ORF3 e aquele sem sobreposição do ORF2, em comparação com isolados de genótipos conhecidos, mostraram maior identidade com o isolado encontrado nos Estados Unidos (US) do genótipo 3. De maneira semelhante, análises da seqüência de aminoácidos realizadas com os mesmos segmentos também mostraram maior identidade com o isolado de genótipo 3. Presença ou não do vírus de genótipo 4, que também infecta porcos, ainda necessita ser verificada. Da mesma forma, cepas do VHE que infectam humanos ainda necessitam ser detectadas e caracterizadas.

Despite serological evidences of presence of hepatitis E virus (HEV) in humans or other animals, until this study the virus had not been detected and molecular characterization of the isolate that circulates in Brazil had not been described. Thus, we collected stool samples of young pigs and tested for presence of HEV RNA by RT-PCR, using primers for partial amplification of ORF2 sequence. Phylogenetic analysis with sequence obtained from the amplified products revealed that the HEV isolate identified here was most closely related to HEV isolates of genotype 3, which is commonly detected in HEV infected pigs. Nucleotide sequence analyses carried out with the entire amplified fragment, ORF2/ORF3 overlapping and ORF2 non-overlapping sequences showed highest identities with the US isolate of genotype 3. Similarly, amino acid sequence analyses done with the entire amplified fragment, ORF2 non-overlapping, ORF2 and ORF3 overlapping sequences also showed highest identities with the genotype 3 isolate. Presence, in Brazil, of HEV of genotype 4, which also infects pigs, as well as HEV strains that infect humans still remain to be detected and characterized.

Respiratory syncytial virus (RSV) is responsible for annual respiratory infection outbreaks in infants and young children worldwide, frequently causing bronchiolitis and pneumonia. We evaluated clinical and epidemiological features of acute respiratory infections (ARIs) caused by respiratory syncytial virus (RSV) in children less than five years old. Nasopharyngeal aspirate samples from children with ARI symptoms, attended at the 'Hospital das Clínicas' - Federal University of Uberlândia, MG, Brazil, were collected and tested for RSV by the immunofluorescence assay (IFA). Patients' clinical and epidemiological data were also obtained. From April 2000 to June 2003, 317 nasopharyngeal samples were collected from children less than 54 months old. Seventy-six samples (24.0%) were positive for RSV, with 53% (40/76) obtained from male patients. Hospitalization occurred in 50% (38/76) of the cases, with an average period of 10.6 days, in most cases (87%, 33/38) occurring in children less than 12 months of age. Although an association between this age group and the presentation of more severe clinical symptoms was observed, such as bronchiolitis in 51% (27/53) of the patients and pneumonia in 19% (10/53), no patients died. RSV was found from February to August, with the highest incidence in May. Conclusions: RSV is an important agent that causes ARIs; the clinical manifestations varied from mild to severe and patients frequently required hospitalization; RSV mostly affected children less than one year old.

Para identificar e caracterizar o agente causador de um quadro clínico sugestivo de doença de Gumboro (DG) que afetou um plantel de frangos de corte com 34 dias de idade, em Buriti Alegre (estado de Goiás, centro-oeste do Brasil), no ano de 2001, procedeu-se uma combinação de métodos virológicos clássicos e modernos. Análises histopatológicas de bursas revelaram necrose, depleção de folículos linfóides, infiltração de heterófilos, edema e formação de cistos, lesões compatíveis com DG. A inoculação em ovos embrionados de galinhas SPF (specific pathogen-free) de uma suspensão de macerado de amostras de bursas resultou em mortalidade embrionária e lesões macroscópicas compatíveis com aquelas provocadas pelo VDIB. Amostras de bursas foram submetidas à técnica de transcrição reversa-reação em cadeia da polimerase (RT-PCR), utilizando-se oligonucleotídeos específicos para amplificação da região hipervariável do gene da VP2. Essa reação produziu um fragmento do tamanho esperado, que foi digerido pelas enzimas de restrição TaqI, StyI e SspI, mas não foi digerido com SacI. Este padrão foi o mesmo observado com cepas de VDIB hipervirulentas (vvVDIB). Análise da seqüência nucleotídica revelou a presença dos aminoácidos alanina, isoleucina e isoleucina nas posições 222, 256 e 294, respectivamente, característica dessas cepas. Além disso, análise filogenética realizada agrupou a cepa encontrada, denominada de BR-GO, com outras cepas de vvVDIB.

In order to identify and characterize the agent of a suggestive clinical case of Gumboro disease (GD) that affected a 34-day-old broiler flock in Buriti Alegre (Goias State, Midwestern Brazil) in the year 2001, we carried out a combination of classic and modern virological methods. Histopathological analysis of the bursa revealed necrosis, presence of depleted follicles, some infiltration of heterophils, edema and formation of cystic cavities that are compatible with lesions observed in GD. Inoculation of embryonated eggs of specific pathogen-free (SPF) chickens with macerated bursa suspension resulted in embryo mortality and lesions which were also compatible with those caused by IBDV. A sample of bursa was submitted to a nested reverse transcriptase-polymerase chain reaction (RT-PCR) procedure to amplify the hypervariable region of the VP2 gene. The amplicon that was obtained from this sample (BR-GO) was digested with the restriction enzymes TaqI, StyI and SspI, but not with SacI, a pattern similar to that observed with very virulent IBDV (vvIBDV) strains. Furthermore, nucleotide sequence analysis revealed alanine, isoleucine, and isoleucine at amino acid positions 222, 256, and 294, respectively, which are also found in vvIBDV strains. Finally, phylogenetic analysis grouped BR-GO isolate with other vvIBDV strains.

Seqüências de DNA de adenovirus são freqüentemente encontradas em linfócitos humanos, tendo sido utilizadas para tal as técnicas de PCR e "Southern blot". Isto é possível apesar dessas células não serem permissivas à replicação de adenovírus, sugerindo persistência do genoma viral. Para investigar esse fenômeno, procuramos detectar em voluntários não sintomáticos DNA adenoviral e expressão do gene E1A. Amostras de DNA obtidas de glóbulos brancos periféricos de 51 voluntários, foram submetidas à PCR utilizando oligonucleotídeos para uma seqüência conservada do gene hexon, seguindo-se uma "nested PCR". Seqüências de adenovirus foram encontradas em 27 amostras (52,9%). Depois de mais de um ano, novas amostras desses voluntários positivos foram analisadas e em 70,8% dos casos o resultado foi mantido. Como isto poderia ser devido à persistência, decidimos verificar se o gene precoce E1A estava relacionado analisando sua expressão através de RT-PCR. Os resultados foram negativos para todas as amostras. O par de oligonucleotídeos desenvolvido para essa finalidade, que tem como alvo uma região conservada em E1A, permitiu detectar seqüências de adenovírus diretamente por PCR. A concordância encontrada entre essa análise e a pesquisa para o gene hexon foi de 84%. Nossos dados sugerem alta ocorrência e persistência de genoma adenoviral em linfócitos humanos, e indicam que uma região distinta de E1A é responsável pela persistência. Podemos também afirmar que a PCR para o gene E1A é uma boa opção quando se quer detectar adenovírus, evitando-se o alto risco de contaminação da "nested PCR" necessária para identificar a presença do gene hexon.

Human lymphoid cells frequently carry adenoviruses and DNA sequences have been identified in peripheral blood lymphocytes by Southern blot and PCR, although these cells are not permissive for virus replication, suggesting persistence of the viral genome. In order to investigate this phenomenon we screened non-symptomatic volunteers for adenovirus DNA presence and E1A gene expression. DNA samples extracted from peripheral blood mononuclear cells of 51 volunteers were submitted to PCR using primers for a conserved hexon sequence, followed by nested PCR. Adenovirus sequences were detected in 27 samples (52.9%). After more than one year, new samples of these positive volunteers were analyzed and in 70.8% of the cases the result was maintained. Since this could be due to a possible persistence we checked if the early gene E1A was involved analyzing its expression by RT-PCR. For that purpose we developed a pair of primers to target a conserved region in the E1A gene. The RT-PCR results for E1A were negative for all samples. Using these primers it was possible to detect adenovirus sequences directly by PCR in DNA samples and we found 84% agreement in comparison to the hexon analysis. Our data suggest a high occurrence and persistence of adenovirus genome sequences in human lymphoid cells, and an indication that a region other than E1A is involved in persistence. We also can say that E1A gene is a good choice for amplification as a tool in adenovirus detection, avoiding the high risk of contamination in the nested PCR procedure necessary for hexon detection.