Publications by authors named "Karin Correa Scheffer"

13 Publications

  • Page 1 of 1

Evaluation of polyclonal anti-RNP IgG antibody for rabies diagnosis by indirect rapid immunohistochemistry test.

Acta Trop 2020 Jun 21;206:105340. Epub 2020 Feb 21.

Instituto Pasteur, 393, Paulista Avenue, 01311-000, São Paulo, Brazil. Electronic address:

Rabies still represents a major public health threat and estimated to cause 60,000 human deaths annually, particularly in developing countries. Thus, adequate surveillance based on rapid and reliable rabies diagnosis for both humans and animals is essential. The WHO and OIE recommended gold standard diagnostic technique for rabies is the direct immunofluorescence assay (dFAT). However, dFAT is expensive and requires a high level of expertise. As an alternative, the rapid immunohistochemistry technique is a promise to be a simple and cost effective diagnostic tool for rabies, and can be performed on field conditions prevalent in developing countries. However, no validated commercial conjugate antibody for rabies is available to meet the laboratory demand. Here, we evaluated the polyclonal anti-rabies virus ribonucleoprotein (RNP) IgG antibody for Rabies lyssavirus (RABV) detection by indirect rapid immunohistochemistry test (iRIT). We tested polyclonal anti-RNP IgG antibody against a batch of 100 brain specimens representing a wide phylogenetic origin in the State of São Paulo, Brazil. The purified IgG obtained 100% of diagnostic specificity and sensibility for RABV antigen detection in iRIT compared with the gold standard dFAT. In conclusion, our results demonstrate that the polyclonal anti-RNP IgG antibody may be used as a diagnostic reagent for rabies using iRIT, with the expectation of increase in availability and cost reduction of the epidemiological surveillance for developing countries.
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http://dx.doi.org/10.1016/j.actatropica.2020.105340DOI Listing
June 2020

A rabies virus vampire bat variant shows increased neuroinvasiveness in mice when compared to a carnivore variant.

Arch Virol 2017 Dec 22;162(12):3671-3679. Epub 2017 Aug 22.

Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo, São Paulo, SP, Brazil.

Rabies is one of the most important zoonotic diseases and is caused by several rabies virus (RABV) variants. These variants can exhibit differences in neurovirulence, and few studies have attempted to evaluate the neuroinvasiveness of variants derived from vampire bats and wild carnivores. The aim of this study was to evaluate the neuropathogenesis of infection with two Brazilian RABV street variants (variant 3 and crab-eating fox) in mice. BALB/c mice were inoculated with RABV through the footpad, with the 50% mouse lethal dose (LD) determined by intracranial inoculation. The morbidity of rabies in mice infected with variant 3 and the crab-eating fox strain was 100% and 50%, respectively, with an incubation period of 7 and 6 days post-inoculation (dpi), respectively. The clinical disease in mice was similar with both strains, and it was characterized initially by weight loss, ruffled fur, hunched posture, and hind limb paralysis progressing to quadriplegia and recumbency at 9 to 12 dpi. Histological lesions within the central nervous system (CNS) characterized by nonsuppurative encephalomyelitis with neuronal degeneration and necrosis were observed in mice infected with variant 3 and those infected with the crab-eating fox variant. However, lesions and the presence of RABV antigen, were more widespread within the CNS of variant-3-infected mice, whereas in crab-eating fox-variant-infected mice, RABV antigens were more restricted to caudal areas of the CNS, such as the spinal cord and brainstem. In conclusion, the results shown here demonstrate that the RABV vampire bat strain (variant 3) has a higher potential for neuroinvasiveness than the carnivore variant.
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http://dx.doi.org/10.1007/s00705-017-3530-yDOI Listing
December 2017

Group A rotavirus in Brazilian bats: description of novel T15 and H15 genotypes.

Arch Virol 2016 Nov 12;161(11):3225-30. Epub 2016 Aug 12.

Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine, University of São Paulo, Av. Orlando Marques de Paiva, 87, Cidade Universitária, São Paulo, SP, 05508-270, Brazil.

This study aimed to survey for group A rotaviruses (RVA) in bats from Brazil and to perform phylogenetic inferences for VP4, VP7, NSP3, NSP4 and NSP5 genes. RVA was found in 9.18 % (28/305) of tested samples. The partial genotype constellation of a Molossus molossus RVA strain was G3-P[3]-Ix-Rx-Cx-Mx-Ax-Nx-T3-E3-H6, and that of a Glossophaga soricina RVA strain was G20-P[x]-Ix-Rx-Cx-Mx-Ax-Nx-T15-Ex-H15. These findings demonstrate an important role of bats in RVA epidemiology and provide evidence of participation of bat RVA strains in interspecies transmission and reassortment events.
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http://dx.doi.org/10.1007/s00705-016-3010-9DOI Listing
November 2016

Erratum to: Alphacoronavirus in urban Molossidae and Phyllostomidae bats, Brazil.

Virol J 2016 07 7;13(1):124. Epub 2016 Jul 7.

Departament of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine, University of São Paulo, Av. Orlando Marques de Paiva, 87, São Paulo, CEP: 05508-270, Brazil.

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http://dx.doi.org/10.1186/s12985-016-0581-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4937601PMC
July 2016

Alphacoronavirus in urban Molossidae and Phyllostomidae bats, Brazil.

Virol J 2016 06 24;13:110. Epub 2016 Jun 24.

Departament of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine, University of São Paulo, Av. Orlando Marques de Paiva, 87, CEP: 05508-270, São Paulo, Brazil.

Background: Bats have been implicated as the main reservoir of coronavirus (CoV). Thus the role of these hosts on the evolution and spread of CoVs currently deserve the attention of emerging diseases surveillance programs. On the view of the interest on and importance of CoVs in bats the occurrence and molecular characterization of CoV were conducted in bats from Brazil.

Findings: Three hundred five enteric contents of 29 bat species were tested using a panCoV nested RT-PCR. Nine specimens were positive and eight was suitable for RdRp gene sequencing. RdRp gene phylogeny showed that all CoVs strains from this study cluster in Alphacoronavirus genus, with one Molossidae and one Phlyllostomidae-CoV specific groups. Phylogenetic analyses of two S gene sequences showed a large diversity within the Alphacoronavirus genus.

Conclusions: This study indicated a CoV-to-host specificity and draws attention for CoV detection in Cynomops sp, a potential new reservoir. The phylogenetic analyses indicate that diversity of CoV in bats is higher than previously known.
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http://dx.doi.org/10.1186/s12985-016-0569-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4920988PMC
June 2016

Delayed progression of rabies transmitted by a vampire bat.

Arch Virol 2016 Sep 15;161(9):2561-6. Epub 2016 Jun 15.

Laboratório de Diagnóstico da Raiva, Instituto Pasteur of São Paulo, São Paulo, SP, Brazil.

Here, we compared the growth kinetics, cell-to-cell spread, and virus internalization kinetics in N2a cells of RABV variants isolated from vampire bats (V-3), domestic dogs (V-2) and marmosets (V-M) as well as the clinical symptoms and mortality caused by these variants. The replication rate of V-3 was significantly higher than those of V-2 and V-M. However, the uptake and spread of these RABV variants into N2a cells were inversely proportional. Nevertheless, V-3 had longer incubation and evolution periods. Our results provide evidence that the clinical manifestations of infection with bat RABV variant occur at a later time when compared to what was observed with canine and marmoset rabies virus variants.
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http://dx.doi.org/10.1007/s00705-016-2927-3DOI Listing
September 2016

Monoclonal antibodies for characterization of rabies virus isolated from non-hematophagous bats in Brazil.

J Infect Dev Ctries 2015 Nov 30;9(11):1238-49. Epub 2015 Nov 30.

Instituto Pasteur, São Paulo, SP, Brasil.

Introduction: In Brazil, various isolates of rabies virus (RABV) show antigenic profiles distinct from those established by the reduced panel of eight monoclonal antibodies (MAbs) determined by the Centers for Disease Control and Prevention (CDC), utilized for the antigenic characterization of RABV in the Americas. The objective of this study was to produce MAbs from RABV isolates from insectivorous bats with an antigenic profile incompatible with the pre-established one.

Methodology: An isolate of RABV from the species Eptesicus furinalis that showed an antigenic profile incompatible with the panel utilized was selected. Hybridomas were produced utilizing the popliteal lymph nodes of mice immunized with ribonucleoproteins purified from the isolate.

Results: Two MAbs-producing clones were obtained, BR/IP1-3A7 and BR/IP2-4E10. Fifty-seven isolates of RABV from different species of animals and different regions of Brazil were analyzed utilizing the MAbs obtained. In the analysis of 23 RABV isolates from non-hematophagous bats, the MAbs cross-reacted with ten isolates, of which four were of the species Nyctinomops laticaudatus, one of the species Eptesicus furinalis, and five of the genus Artibeus. Of the nine isolates of non-hematophagous isolates that displayed an incompatible profile analyzed, characteristic of insectivorous bats, BR/IP1-3A7 reacted with five (55.55%) and BR/IP2-4E10 with four (44.44%).

Conclusions: The MAbs obtained were able to recognize epitopes common between the three genera, Artibeus, Eptesicus, and Nyctinomops, thereby allowing the antigenic characterization of RABV isolates in Brazil.
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http://dx.doi.org/10.3855/jidc.6959DOI Listing
November 2015

[Hematophagous bats as reservoirs of rabies].

Rev Peru Med Exp Salud Publica 2014 Apr;31(2):302-9

Instituto Pasteur, São Paulo, Brasil.

Rabies continues to be a challenge for public health authorities and a constraint to the livestock industry in Latin America. Wild and domestic canines and vampire bats are the main transmitter species and reservoirs of the disease. Currently, variations observed in the epidemiological profile of rabies, where the species of hematophagous bat Desmodus rotundus constitutes the main transmitting species. Over the years, knowledge has accumulated about the ecology, biology and behavior of this species and the natural history of rabies, which should lead to continuous development of methods of population control of d. Rotundus as well as prevention and diagnostic tools for rabies. Ecological relationships of this species with other hematophagous and non-hematophagous bats is unknown, and there is much room for improvement in reporting systems and surveillance, as well as creating greater awareness among the farming community. Understanding the impact of human-induced environmental changes on the rabies virus in bats should be cause for further investigation. This will require a combination of field studies with mathematical models and new diagnostic tools. This review aims to present the most relevant issues on the role of hematophagous bats as reservoirs and transmitters of the rabies virus.
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April 2014

Serosurvey for selected viral infections in free-ranging jaguars (Panthera onca) and domestic carnivores in Brazilian Cerrado, Pantanal, and Amazon.

J Wildl Dis 2013 Jul;49(3):510-21

Jaguar Conservation Fund/Instituto Onça-Pintada, Caixa Postal 193, 75830-000, Mineiros-Goiás, Brazil.

We investigated the exposure of jaguar (Panthera onca) populations and domestic carnivores to selected viral infections in the Cerrado, Amazon, and Pantanal biomes of Brazil. Between February 2000 and January 2010, we collected serum samples from 31 jaguars, 174 dogs (Canis lupus familiaris), and 35 domestic cats (Felis catus). Serologic analyses for antibodies to rabies virus, canine distemper virus (CDV), feline immunodeficiency virus (FIV), and for feline leukemia virus (FeLV) antigen were conducted. The jaguars from Cerrado and Pantantal were exposed to rabies virus, while the jaguars from the Pantanal and the dogs from all three areas were exposed to CDV. Two cats from the Amazonian site were antigen-positive for FeLV, but no jaguars had FeLV antigen or FIV antibody. Canine distemper and rabies viruses should be carefully monitored and considered potential threats to these jaguar populations. Currently FIV and FeLV do not appear to represent a health threat for jaguar populations in this area. Domestic dogs and cats in these areas should be vaccinated, and the movement of domestic animals around protected areas should be restricted.
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http://dx.doi.org/10.7589/2012-02-056DOI Listing
July 2013

Phylogenetic analysis of partial RNA-polymerase blocks II and III of Rabies virus isolated from the main rabies reservoirs in Brazil.

Virus Genes 2012 Aug 18;45(1):76-83. Epub 2012 Apr 18.

Pasteur Institute, Av. Paulista 393, São Paulo, Brazil.

This study describes the results of the sequencing and analysis of segments of Blocks II and III of the RNA polymerase L gene of Rabies virus isolates from different reservoir species of Brazil. The phylogenetic relations of the virus were determined and a variety of species-specific nucleotides were found in the analyzed areas, but the majority of these mutations were found to be synonymous. However, an analysis of the putative amino acid sequences were shown to have some characteristic mutations between some reservoir species of Brazil, indicating that there was positive selection in the RNA polymerase L gene of Rabies virus. On comparing the putative viral sequences obtained from the Brazilian isolates and other Lyssavirus, it was determined that amino acid mutations occurred in low-restriction areas. This study of the L gene of Rabies virus is the first to be conducted with samples of virus isolates from Brazil, and the results obtained will help in the determination of the phylogenetic relations of the virus.
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http://dx.doi.org/10.1007/s11262-012-0743-8DOI Listing
August 2012

Rabies virus in insectivorous bats: implications of the diversity of the nucleoprotein and glycoprotein genes for molecular epidemiology.

Virology 2010 Sep 6;405(2):352-60. Epub 2010 Jul 6.

Instituto Pasteur of São Paulo, CEP 01311-000, São Paulo, SP, Brazil.

Insectivorous bats are the main reservoirs of rabies virus (RABV) in various regions of the world. The aims of this study were to (a) establish genealogies for RABV strains from different species of Brazilian insectivorous bats based on the nucleoprotein (N) and glycoprotein (G) genes, (b) investigate specific RABV lineages associated with certain genera of bats and (c) identify molecular markers that can distinguish between these lineages. The genealogic analysis of N and G from 57 RABV strains revealed seven genus-specific clusters related to the insectivorous bats Myotis, Eptesicus, Nyctinomops, Molossus, Tadarida, Histiotus and Lasiurus. Molecular markers in the amino acid sequences were identified which were specific to the seven clusters. These results, which constitute a novel finding for this pathogen, show that there are at least seven independent epidemiological rabies cycles maintained by seven genera of insectivorous bats in Brazil.
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http://dx.doi.org/10.1016/j.virol.2010.05.030DOI Listing
September 2010

Antigenic and genetic characterization of the first rabies virus isolated from the bat Eumops perotis in Brazil.

Rev Inst Med Trop Sao Paulo 2008 Mar-Apr;50(2):95-9

Pasteur Institute, São Paulo, SP, Brasil.

Although the main transmitters of rabies in Brazil are dogs and vampire bats, the role of other species such as insectivorous and frugivorous bats deserves special attention, as the rabies virus has been isolated from 36 bat species. This study describes the first isolation of the rabies virus from the insectivorous bat Eumops perotis. The infected animal was found in the city of Ribeirão Preto, São Paulo. The virus was identified by immunofluorescence antibody test (FAT) in central nervous system (CNS) samples, and the isolation was carried out in N2A cell culture and adult mice. The sample was submitted to antigenic typing using a panel of monoclonal antibodies (CDC/Atlanta/USA). The DNA sequence of the nucleoprotein gene located between nucleotides 102 and 1385 was aligned with homologous sequences from GenBank using the CLUSTAL/W method, and the alignment was used to build a neighbor-joining distance-based phylogenetic tree with the K-2-P model. CNS was negative by FAT, and only one mouse died after inoculation with a suspension from the bat's CNS. Antigenic typing gave a result that was not compatible with the patterns defined by the panel. Phylogenetic analysis showed that the virus isolated segregated into the same cluster related to other viruses isolated from insectivorous bats belonging to genus Nyctinomops ssp. (98.8% nucleotide identity with each other).
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http://dx.doi.org/10.1590/s0036-46652008000200006DOI Listing
August 2008

[Rabies virus in naturally infected bats in the State of São Paulo, Southeastern Brazil].

Rev Saude Publica 2007 Jun;41(3):389-95

Instituto Pasteur de São Paulo, São Paulo, SP, Brasil.

Objective: To identify the species of bats involved in maintaining the rabies cycle; to investigate the distribution of the rabies virus in the tissues and organs of bats and the time taken for mortality among inoculated mice.

Methods: From April 2002 to November 2003, bats from municipalities in the State of São Paulo were screened for the presence of the rabies virus, by means of direct immunofluorescence. The virus distribution in the bats was evaluated by inoculating mice and N2A cells with 20% suspensions prepared from fragments of different organs and tissues, plus the brain and salivary glands. The time taken for mortality among the mice was monitored daily, following intracerebral inoculation.

Results: Out of the 4,395 bats received, 1.9% were found positive for the rabies virus. They belonged to ten genera, with predominance of insectivores. The maximum mean times taken for mortality among the mice following inoculation with brain and salivary gland material were 15.33+/-2.08 days and 11.33+/-2.30 days for vampire bats, 16.45+/-4.48 days and 18.91+/-6.12 days for insectivorous bats, and 12.60+/-2.13 days and 15.67+/-4.82 days for frugivorous bats, respectively.

Conclusions: The species infected with the rabies virus were: Artibeus lituratus, Artibeus sp., Myotis nigricans, Myotis sp., Eptesicus sp., Lasiurus ega, Lasiurus cinereus, Nyctinomops laticaudatus, Tadarida brasiliensis, Histiotus velatus, Molossus rufus, Eumops sp. and Desmodus rotundus. Virus investigation in the different tissues and organs showed that the brain and salivary glands were the most suitable sites for virus isolation.
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http://dx.doi.org/10.1590/s0034-89102007000300010DOI Listing
June 2007