Virginia Pereira

Dr. Virginia Pereira

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Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2013 in Journal of Dairy Science
Verified
Journal Article
Closed access
FGFelipe Guimarães
Felipe Guimarães
DNDiego Nobrega
Diego Nobrega
VPVirginia Pereira
Virginia Pereira
PMPâmela Merlo Marson
Pâmela Merlo Marson
JPJosé Carlos de Figueiredo Pantoja
José Carlos de Figueiredo Pantoja
Helio LangoniHelio Langoni
Helio Langoni
The objective of this study was to isolate and identify the main staphylococcal species causing bovine mastitis in 10 Brazilian dairy herds and study their capability to produce enterotoxins. Herds were selected based on size and use of milking technology, and farms were visited once during the study. All mammary glands of all lactating cows were screened using the California Mastitis Test (CMT) and a strip cup. A single aseptic milk sample (20 mL) was collected from all CMT-positive quarters. Identification of Staphylococcus spp. was performed using conventional microbiology, and PCR was used to determine the presence of enterotoxin-encoding genes (sea, seb, sec, and sed). Of the 1,318 CMT-positive milk samples, Staphylococcus spp. were isolated from 263 (19.9%). Of these isolates, 135 (51%) were coagulase-positive staphylococci (CPS) and 128 (49%) were coagulase-negative staphylococci (CNS). Eighteen different species of CNS were isolated, among which S. warneri, S. epidermidis and S. hyicus were the most frequent. The distribution of Staphylococcus species was different among herds: S. epidermidis was found in 8 herds, S. warneri was found in 7 herds, and S. hyicus in 6 herds. Some of the CNS species (S. saprophyticus ssp. saprophyticus, S. auricularis, S. capitis, and S. chromogenes) were isolated in only one of the farms. Genes related to production of enterotoxins were found in 66% (n=85) of all CNS and in 35% of the CPS isolates. For both CNS and CPS isolates, the most frequently identified enterotoxin genes were sea, seb, and sec; the prevalence of sea differed between CPS (9.5%) and CNS (35.1%) isolates. Staphylococcus warneri isolates showed a greater percentage of sea than seb, sec, or sed, whereas S. hyicus isolates showed a greater percentage of sea than sec. Over 60% of CNS belonged to 3 major species, which carried 62.2 to 81.3% of the enterotoxin genes. The high prevalence highlights the potential for food poisoning caused by these species. For possible high-risk situations for food poisoning, such as milk produced with total bacterial counts greater than regulatory levels and stored under inappropriate temperatures, monitoring contamination with CNS could be important to protect human health. Because the prevalence of CNS intramammary infections in dairy herds is usually high, and these species can be found in great numbers in bulk milk, identification of risk factors for production of staphylococcal enterotoxins should be considered in future studies.

1 September 2012 in Journal of Microbiological Methods
Verified
Journal Article
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FFFelipe Fornazari
Felipe Fornazari
RSRodrigo Costa da Silva
Rodrigo Costa da Silva
VPVirginia Pereira
Virginia Pereira
HBHugo Enrique Orsini Beserra
Hugo Enrique Orsini Beserra
MLMaria Cecília Rui Luvizotto
Maria Cecília Rui Luvizotto
Helio LangoniHelio Langoni
Helio Langoni

1 January 2017 in Journal of Dairy Science
Verified
Journal Article
Closed access
FGFelipe Guimarães
Felipe Guimarães
MMM.P. Manzi
M.P. Manzi
SSSâmea Aguiar Joaquim Soares
Sâmea Aguiar Joaquim Soares
VPVirginia Pereira
Virginia Pereira
Helio LangoniHelio Langoni
Helio Langoni
Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk.

22 October 2007 in BMC Microbiology
Verified
Journal Article
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GTGisela Ramos Terçarioli
Gisela Ramos Terçarioli
EBEduardo Bagagli
Eduardo Bagagli
GRGabriela Martins Reis
Gabriela Martins Reis
RTRaquel Cordeiro Theodoro
Raquel Cordeiro Theodoro
SBSandra de Moraes Gimenes Bosco
Sandra de Moraes Gimenes Bosco
VPVirginia Pereira
Virginia Pereira
Background: Paracoccidioides brasiliensis ecology is not completely understood, although several pieces of evidence point to the soil as its most probable habitat. The present study aimed to investigate the fungal growth, conidia production and molecular pathogen detection in different soil conditions. Methods: Soils samples of clayey, sandy and medium textures were collected from ground surface and the interior of armadillo burrows in a hyperendemic area of Paracoccidioidomycosis. P. brasiliensis was inoculated in soil with controlled humidity and in culture medium containing soil extracts. The molecular detection was carried out by Nested PCR, using panfungal and species specific primers from the ITS-5.8S rDNA region. Results: The soil texture does not affect fungus development and the growth is more abundant on/in soil saturated with water. Some soil samples inhibited the development of P. brasiliensis, especially those that contain high values of Exchangeable Aluminum (H+Al) in their composition. Some isolates produced a large number of conidia, mainly in soil-extract agar medium. The molecular detection was positive only in samples collected from armadillo burrows, both in sandy and clayey soil. Conclusion: P. brasiliensis may grow and produce the infectious conidia in sandy and clayey soil, containing high water content, mainly in wild animal burrows, but without high values of H+Al.

1 May 2011 in Veterinary Parasitology
Verified
Journal Article
Closed access
LCL.G. Camossi
L.G. Camossi
HGH. Greca-Júnior
H. Greca-Júnior
ACA.P.F.L. Corrêa
A.P.F.L. Corrêa
VPVirginia Pereira
Virginia Pereira
RSRodrigo Costa da Silva
Rodrigo Costa da Silva
Helio LangoniHelio Langoni
Helio Langoni

1 January 2008 in Medical Mycology
Verified
Journal Article
Open access
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VPVirginia Pereira
Virginia Pereira
SBSandra de Moraes Gimenes Bosco
Sandra de Moraes Gimenes Bosco
JGJuliana Griese
Juliana Griese
RTRaquel Cordeiro Theodoro
Raquel Cordeiro Theodoro
SMSeverino Assis Da Graça Macoris
Severino Assis Da Graça Macoris
EBEduardo Bagagli
Eduardo Bagagli
Paracoccidioides brasiliensis infections have been little studied in wild and/or domestic animals, which may represent an important indicator of the presence of the pathogen in nature. Road-killed wild animals have been used for surveillance of vectors of zoonotic pathogens and may offer new opportunities for eco-epidemiological studies of paracoccidiodomycosis (PCM). The presence of P. brasiliensis infection was evaluated by Nested-PCR in tissue samples collected from 19 road-killed animals; 3 Cavia aperea (guinea pig), 5 Cerdocyon thous (crab-eating-fox), 1 Dasypus novemcinctus (nine-banded armadillo), 1 Dasypus septemcinctus (seven-banded armadillo), 2 Didelphis albiventris (white-eared opossum), 1 Eira barbara (tayra), 2 Gallictis vittata (grison), 2 Procyon cancrivorus (raccoon) and 2 Sphiggurus spinosus (porcupine). Specific P. brasiliensis amplicons were detected in (a) several organs of the two armadillos and one guinea pig, (b) the lung and liver of the porcupine, and (c) the lungs of raccoons and grisons. P. brasiliensis infection in wild animals from endemic areas might be more common than initially postulated. Molecular techniques can be used for detecting new hosts and mapping ‘hot spot’ areas of PCM.