Sandra Soares Martins

Bio: Sandra Soares Martins is an academic researcher from State University of Campinas. The author has contributed to research in topics: Encephalomyelitis & Cardiovirus. The author has an hindex of 5, co-authored 5 publications receiving 99 citations.

Theiler's murine encephalomyelitis virus in nonbarrier rat colonies

Abstract: Theiler's murine encephalomyelitis virus (TMEV), a member of the genus Cardiovirus, is an enteric pathogen of mice that causes acute encephalomyelitis followed by persistent central nervous system infection with chronic inflammation and demyelination after intracerebral inoculation. Although TMEV is a mouse pathogen, antibodies against TMEV strain GDVII have been detected in conventional rat colonies. Natural infection of rats by Cardiovirus has not yet been described. The purpose of this study was to demonstrate TMEV infection of rat colonies by using serologic assays, reverse transcription-polymerase chain reaction (RT-PCR) analysis, and clinical characterization. Indirect immunofluorescence assay of rat serum samples demonstrated antibodies against TMEV-GDVII in 86.3% of samples analyzed, and 77.2% of the antibody-positive samples had neutralizing antibodies. To determine whether rats can be infected experimentally with TMEV-GDVII, specific pathogen-free newborn mice and rats were inoculated intracerebrally with intestinal suspensions from seropositive rats. Both species showed the typical clinical signs of TMEV infection in mice, which is characterized by flaccid hindlimb paralysis and tremor. RT-PCR in brain tissue of experimentally infected animals detected RNA sequences corresponding to the 5' noncoding region of Cardiovirus known as the 'internal ribosome entry site.' These results suggest that rats can be naturally infected with TMEV and related Cardiovirus. Therefore, continued health monitoring for TMEV infection should be included in rat colonies mainly because these animals are used for various experimental purposes.

Theiler's murine encephalomyelitis virus in nonbarrier rat colonies.

Abstract: Theiler's murine encephalomyelitis virus (TMEV), a member of the genus Cardiovirus, is an enteric pathogen of mice that causes acute encephalomyelitis followed by persistent central nervous system infection with chronic inflammation and demyelination after intracerebral inoculation. Although TMEV is a mouse pathogen, antibodies against TMEV strain GDVII have been detected in conventional rat colonies. Natural infection of rats by Cardiovirus has not yet been described. The purpose of this study was to demonstrate TMEV infection of rat colonies by using serologic assays, reverse transcription-polymerase chain reaction (RT-PCR) analysis, and clinical characterization. Indirect immunofluorescence assay of rat serum samples demonstrated antibodies against TMEV-GDVII in 86.3% of samples analyzed, and 77.2% of the antibody-positive samples had neutralizing antibodies. To determine whether rats can be infected experimentally with TMEV-GDVII, specific pathogen-free newborn mice and rats were inoculated intracerebrally with intestinal suspensions from seropositive rats. Both species showed the typical clinical signs of TMEV infection in mice, which is characterized by flaccid hindlimb paralysis and tremor. RT-PCR in brain tissue of experimentally infected animals detected RNA sequences corresponding to the 5' noncoding region of Cardiovirus known as the 'internal ribosome entry site.' These results suggest that rats can be naturally infected with TMEV and related Cardiovirus. Therefore, continued health monitoring for TMEV infection should be included in rat colonies mainly because these animals are used for various experimental purposes.

Adenovirus e rotavirus como indicadores biologicos em aguas residuarias de esgotos sanitarios apos tratamento por processo anaerobio e disposição controlada no solo

Abstract: O tratamento de esgoto sanitario em lagoa de decantacao anaerobia e disposicao controlada de agua residuaria no solo e uma alternativa de baixo custo para o reuso de aguas residuarias na agricultura. Nele, o esgoto sanitario e depositado em uma lagoa de decantacao anaerobia com retencao hidraulica de sete dias, apos o que a agua residuaria e conduzida para rampa de solo franco argilo-arenoso, com cobertura vegetal de graminia Cynodon sp, para disposicao por escoamento superficial, seguindo-se sua infiltracao e percolacao. O objetivo desse trabalho foi verificar a eficiencia desse sistema na eliminacao e/ou inativacao de adenovirus humanos (HAdV) e rotavirus (RV). Amostras de 1L de agua residuaria foram obtidas em quatro coletas, em intervalos de sete dias, na entrada do esgoto bruto (EB), no ponto de aplicacao na rampa (0m) e nos pontos da sua superficie apos 10, 20, 30, 35m e 40m. Sob a rampa, a 1m de profundidade e distantes 30m (30-1) e 35m (35 -1), dois pontos foram amostrados. Antes do ponto 0m, pontos de testemunha a 1m de profundidade e distantes 2m (T1) e 0,5m (T2) da rampa, e um ponto do lencol freatico (LF) a 3m de profundidade, tambem foram coletados.As agua residuarias foram concentradas de 1.000 a 5.000 vezes por filtracao e eluicao em membrana eletropositiva e ultracentrifugacao. Nos eluatos obtidos, apos extracao de DNA, a presenca de HAdV foi pesquisada por PCR e nested-PCR. Para a deteccao de RV usou-se RT-PCR e duplo-semi- nested-PCR. Eluatos HAdV positivos foram inoculados em celulas HEp-2 e apos ate cinco passagens a presenca de HAdV foi confirmada por PCR.. HAdV foram detectados em 29 das 35 amostras analisadas, sendo positivos todos os pontos de EB e da superficie da rampa. Em profundidade, sob a rampa, quatro amostras foram positivas, alem de outras duas em T2 e uma em LF, o que demonstra a percolacao desses virus no solo com contaminacao do LF. Quando testadas em celulas HEp-2, nas amostras do EB e dos pontos 0, 30, 35 e 40m a presenca de virions foi determinada, enquanto nos pontos 30-1m e LF os HAdV nao foram infectivos. Esses resultados permitem concluir que o sistema nao foi eficiente para remover e/ou inativar HAdV. Por outro lado, pode-se afirmar que os HAdV sao indicadores virais adequados para esse sistema, desde que mantida a metodologia aqui empregada. Uma amostra de EB foi positiva para RV (genotipos G1 e G2), resultado esse que nao permite qualquer conclusao. Para o reuso da agua residuaria advinda desse sistema impoe-se a associacao de processos de desinfeccao para a eliminacao de HAdV Abstract

FELASA recommendations for the health monitoring of mouse, rat, hamster, guinea pig and rabbit colonies in breeding and experimental units.

Abstract: The microbiological quality of experimental animals can critically influence animal welfare and the validity and reproducibility of research data. It is therefore important for breeding and experimental facilities to establish a laboratory animal health monitoring (HM) programme as an integrated part of any quality assurance system. FELASA has published recommendations for the HM of rodent and rabbit colonies in breeding and experimental units (Nicklas et al. Laboratory Animals, 2002), with the intention of harmonizing HM programmes. As stated in the preamble, these recommendations need to be adapted periodically to meet current developments in laboratory animal medicine. Accordingly, previous recommendations have been revised and shall be replaced by the present recommendations. These recommendations are aimed at all breeders and users of laboratory mice, rats, Syrian hamsters, guinea pigs and rabbits as well as diagnostic laboratories. They describe essential aspects of HM, such as the choice of agents, selection of animals and tissues for testing, frequency of sampling, commonly used test methods, interpretation of results and HM reporting. Compared with previous recommendations, more emphasis is put on the role of a person with sufficient understanding of the principles of HM, opportunistic agents, the use of sentinel animals (particularly under conditions of cage-level containment) and the interpretation and reporting of HM results. Relevant agents, testing frequencies and literature references are updated. Supplementary information on specific agents and the number of animals to be monitored and an example of a HM programme description is provided in the appendices.

The Fecal Viral Flora of Wild Rodents

Abstract: The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae, Iridoviridae, Polydnaviridae, Dicistroviriade, Bromoviridae, and Virgaviridae families followed by plant virus-related sequences in the Nanoviridae, Geminiviridae, Phycodnaviridae, Secoviridae, Partitiviridae, Tymoviridae, Alphaflexiviridae, and Tombusviridae families reflecting the largely insect and plant rodent diet. Phylogenetic analyses of full and partial viral genomes therefore revealed many previously unreported viral species, genera, and families. The close genetic similarities noted between some rodent and human viruses might reflect past zoonoses. This study increases our understanding of the viral diversity in wild rodents and highlights the large number of still uncharacterized viruses in mammals.

Group A rotavirus genotypes and the ongoing Brazilian experience: a review

Abstract: Brazil was the first Latin American country to introduce universal group A rotavirus (RV-A) vaccination in March 2006, resulting in a unique epidemiological scenario Since RV-A first identification in Brazil, 2,691 RV-A-positive stool samples, collected between 1982- 2007, were typed by independent research groups throughout the country In the pre-vaccination era, 2,492 RV-A-positive samples collected from 1982-2005 were successfully typed, while 199 samples were analyzed from 2006-2007 According to the reviewed studies, there were two important times in the pre-vaccination era: (i) the period from 1982-1995, during which the detection of G5P[8] RV-A, in addition to the classical genotypes G1-4, challenged vaccine development programs; and (ii) the period from 1996-2005, during which genotype G9P[8] emerged, following a global trend The rate of G2P[4] RV-A detection decreased from 26% (173/653) during 1982-1995 to 2% (43/1,839) during 1996-2005 The overall detection rate of RV-A genotypes from 1982-2005 was as follows: 43% (n = 1,079) G1P[8]/G1P[not typed (NT)]; 20% (n = 488) G9P[8]/G9P[NT]; 9% (n = 216) G2P[4]/G2P[NT]; 6% (n = 151) G3P[8]/G3P[NT]; 4% (n = 103) G4P[8]/G4P[NT]; and 4% (n = 94) G5P[8]/G5P[NT] Mixed infections accounted for 189 (7%) of the positive samples, while atypical G/P combinations or other genotypes, including G6, G8, G10 and G12, were identified in 172 (7%) samples The initial surveillance studies carried out in several Brazilian states with RV-A-positive samples collected in 2006 and 2007 show a predominance of G2P[4] strains (148/199 or 74%) Herein, we review RV-A typing studies carried out since the 1980s in Brazil, highlighting the dynamics of RV-A strain circulation profiles before and early after universal use of RV-A vaccine in Brazil

Viruses causing childhood diarrhoea in the developing world.

Abstract: Purpose of review Acute gastroenteritis is one of the leading causes of morbidity and mortality in children in the developing world. With improvements in hygiene and sanitation, the burden of disease due to bacterial and parasitic infections has decreased and an increasing proportion of diarrhoea hospitalizations are attributed to viruses. This review focuses on enteric viruses and their role in childhood diarrhoea in the developing world. Recent findings With the use of sensitive molecular techniques, it is evident that a significant proportion of childhood diarrhoea is attributable to enteric viruses, with at least one viral agent in nearly 43% of samples from childhood diarrhoea in developing countries. Rotaviruses remain the most common pathogens in children, followed by noroviruses in almost all countries. There is increasing evidence that both rotaviruses and caliciviruses spread beyond the gut in a large proportion of infections. Summary The review highlights the importance of viral agents of gastroenteritis in developing countries. Wider use of molecular techniques is resulting in rapid identification of new or emerging strains and in the detection of extra-intestinal spread. There is a need to better understand susceptibility and immune response to these agents to be able to design suitable interventions.

Metagenomic analysis of the turkey gut RNA virus community

Abstract: Viral enteric disease is an ongoing economic burden to poultry producers worldwide, and despite considerable research, no single virus has emerged as a likely causative agent and target for prevention and control efforts. Historically, electron microscopy has been used to identify suspect viruses, with many small, round viruses eluding classification based solely on morphology. National and regional surveys using molecular diagnostics have revealed that suspect viruses continuously circulate in United States poultry, with many viruses appearing concomitantly and in healthy birds. High-throughput nucleic acid pyrosequencing is a powerful diagnostic technology capable of determining the full genomic repertoire present in a complex environmental sample. We utilized the Roche/454 Life Sciences GS-FLX platform to compile an RNA virus metagenome from turkey flocks experiencing enteric disease. This approach yielded numerous sequences homologous to viruses in the BLAST nr protein database, many of which have not been described in turkeys. Our analysis of this turkey gut RNA metagenome focuses in particular on the turkey-origin members of the Picornavirales, the Caliciviridae, and the turkey Picobirnaviruses.