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Dive into the research topics where Ayrton Sydnei Cavalheiro is active.

Publication


Featured researches published by Ayrton Sydnei Cavalheiro.


Antimicrobial Agents and Chemotherapy | 2008

In Vitro Activities of Voriconazole, Itraconazole, and Terbinafine Alone or in Combination against Pythium insidiosum Isolates from Brazil

Juliana Siqueira Argenta; Janio Morais Santurio; Sydney Hartz Alves; Daniela Isabel Brayer Pereira; Ayrton Sydnei Cavalheiro; Andréia Spanamberg; Laerte Ferreiro

ABSTRACT We evaluated the in vitro activities of voriconazole, itraconazole, and terbinafine against 30 clinical isolates of Pythium insidiosum using a checkerboard macrodilution method. The combined activity of terbinafine plus itraconazole or plus voriconazole was synergic against 17% of the strains. Antagonism was not observed.


Antimicrobial Agents and Chemotherapy | 2009

In Vitro Activity of Terbinafine Combined with Caspofungin and Azoles against Pythium insidiosum

Ayrton Sydnei Cavalheiro; Grazieli Maboni; Maria Isabel de Azevedo; Juliana Siqueira Argenta; Daniela Isabel Brayer Pereira; Tatiana Spader; Sydney Hartz Alves; Janio Morais Santurio

ABSTRACT In this text we evaluated the in vitro antifungal activities of terbinafine combined with caspofungin, miconazole, ketoconazole, and fluconazole against 17 Pythium insidiosum strains by using the microdilution checkerboard method. Synergistic interactions were observed with terbinafine combined with caspofungin (41.2% of the strains), fluconazole (41.2%), ketoconazole (29.4%), and miconazole (11.8%). No antagonistic effects were observed. The combination of terbinafine plus caspofungin or terbinafine plus fluconazole may have significant therapeutic potential for treatment of pythiosis.


Veterinary Microbiology | 2009

In vitro activity of terbinafine associated to amphotericin B, fluvastatin, rifampicin, metronidazole and ibuprofen against Pythium insidiosum.

Ayrton Sydnei Cavalheiro; Régis Adriel Zanette; Tatiana Spader; Luciane Teresinha Lovato; Maria Isabel de Azevedo; Sônia de Avila Botton; Sydney Hartz Alves; Janio Morais Santurio

We evaluated the in vitro activities of terbinafine alone and in combination with amphotericin B, fluvastatin, rifampicin, metronidazole or ibuprofen against 17 clinical isolates of Pythium insidiosum. The assays were based on technique M38-A2, as well as the checkerboard microdilution method. The main synergism observed was by combination of terbinafine plus amphotericin B (41.18%). Antagonisms were observed in combinations of terbinafine with fluvastatin (35.30%) or rifampicin (5.88%).


Veterinary Record | 2008

Granulomatous rhinitis associated with Pythium insidiosum infection in sheep.

Janio Morais Santurio; J. S. Argenta; S. E. Schwendler; Ayrton Sydnei Cavalheiro; Daniela Isabel Brayer Pereira; Régis Adriel Zanette; Sydney Hartz Alves; Valéria Dutra; M. C. Silva; L. P. Arruda; Luciano Nakazato; Edson Moleta Colodel

Pythium insidiosum is an aquatic organism classified in the kingdom Stramenopila, class Oomycetes ([De Cock and others 1987][1]). It is the aetiological agent of pythiosis in mammals; the occurrence of this disease is associated with contact between traumatic lesions in animals or human beings and


Veterinary Microbiology | 2012

In vitro and in vivo susceptibility of two-drug and three-drug combinations of terbinafine, itraconazole, caspofungin, ibuprofen and fluvastatin against Pythium insidiosum.

Juliana Siqueira Argenta; Sydney Hartz Alves; Flávio Silveira; Grazieli Maboni; Régis Adriel Zanette; Ayrton Sydnei Cavalheiro; Patrique de Lima Pereira; Daniela Isabel Brayer Pereira; Elisa Simone V. Sallis; Luciana Pötter; Janio Morais Santurio; Laerte Ferreiro

The present study investigated the in vitro inhibitory activity of terbinafine, itraconazole, caspofungin, fluvastatin and ibuprofen against 15 isolates of Pythium insidiosum in double and triple combinations and determined in vivo correlations using rabbits with experimental pythiosis. The minimal inhibitory concentration (MIC) was determined in accordance with the Clinical and Laboratory Standards Institute M 38-A2 protocol (2008), and the in vitro interactions were evaluated using a checkerboard microdilution method. For the in vivo study, 20 rabbits inoculated with P. insidiosum zoospores were divided into four groups: group 1 was treated with terbinafine and itraconazole; group 2 was treated with terbinafine, itraconazole and fluvastatin; group 3 was treated with terbinafine and caspofungin; and group 4 was the control group. Combinations of terbinafine with caspofungin or ibuprofen were synergistic for 47% of the isolates, and antagonism was not observed in any of the double combinations. The triple combinations were mostly indifferent, but synergism and antagonism were also observed. In the in vivo study, the histological aspect of the lesions was similar among the groups, but group 2 showed the lowest amount of hyphae and differed significantly from the other groups.


Ciencia Rural | 2008

Zoosporogênese in vitro entre isolados do oomiceto Pythium insidiosum

Daniela Isabel Brayer Pereira; Janio Morais Santurio; Sydney Hartz Alves; Juliana Siqueira Argenta; Ayrton Sydnei Cavalheiro; Laerte Ferreiro

Pythium insidiosum is an aquatic oomycete and the etiology of a chronic disease called pythiosis, commonly found in the skin of horses. The production of mobile zoospores by this microorganism is the determinant factor of this disease. This study evaluated the zoosporogenesis and quantification of zoospores in 32 samples of Pythium insidiosum isolated from horses with pythiosis. The assay used culture of the Pythium insidiosum in Corn Meal Agar plus grass blades for 5 days at 37°C. The grass blades were incubated in Induction Medium at 37°C for 24 hours. The findings showed 16 samples (50%) yielded 20,000 zoospores mL-1, 12 (37.5%) samples yielded over 20,000 zoospores mL-1 and 4 samples (12.5%) yielded less than 20,000 zoospores mL-1. The zoospores production was higher between 6 and 8 hours of incubation. The protocol used in the zoosporogenesis induction was efficient and represents an important tool for Pythium insidiosum identification and the attainment of zoospores in adequate amounts for inoculation in experimental animals and application in the development of susceptibility tests.


Ciencia Rural | 2008

Diagnóstico de criptococose canina pela citologia aspirativa por agulha fina

Danieli Brolo Martins; Anna Laeticia da Trindade Barbosa; Ayrton Sydnei Cavalheiro; Sonia Terezinha dos Anjos Lopes; Janio Morais Santurio; João Eduardo Wallau Schossler; Alexandre Mazzanti

This paper aimed to described a 1.5 year-old Labrador male, diagnosed with cryptococcosis using fine-needle aspiration cytology (FNAC). The dog was showing signs of depression and hyporexia. Peripheral lymph nodes and a mass situated between the submandibular lymph nodes were aspirated. The cytology showed yeast-like structures resembling Cryptococcus sp. in all samples examined. These findings were confirmed by culture (C. neoformans, serotype D). The FNAC technique allowed a quick, safe and easy diagnosis in this case.


Ciencia Rural | 2006

Surto de Trichophyton equinum var. equinum em eqüinos no sul do Brasil

Daniela Isabel Brayer Pereira; Luiz Sergio Segala de Oliveira; Andressa Bueno; Ayrton Sydnei Cavalheiro; Stela Elisangela Schwendler; Maria Isabel de Azevedo; João Carlos Eckhardt Júnior; Leila Cristiane Aguiar; Deise Flores Santurio; Janio Morais Santurio; Sydney Hartz Alves

One outbreak of dermatophytosis in horses is described in south Brazil. Fifty eight young animals (55.2%) presented clinical signs of the disease. The mycological diagnosis was realized through the presence of fungus in the hair, associated with the macro and micromorphologic characteristics of the isolated colonies in agar also allowed the dermatophyte´s classification as Trichophyton equinum var. equinum.


Acta Scientiae Veterinariae | 2006

Dermatophytes isolated from dogs and cats suspected of dermatophytosis in Southern Brazil

Marina Venturini Copetti; Janio Morais Santurio; Ayrton Sydnei Cavalheiro; Ana Aurea Boeck; Juliana Siqueira Argenta; Leila Canabarro Aguiar; Sydney Hartz Alves


Acta Scientiae Veterinariae | 2009

Comparison of different culture media for mycological evaluation of commercial pet food

Marina Venturini Copetti; Janio Morais Santurio; Ayrton Sydnei Cavalheiro; Sydney Hartz Alves; Laerte Ferreiro

Collaboration


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Janio Morais Santurio

Universidade Federal de Santa Maria

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Sydney Hartz Alves

Universidade Federal de Santa Maria

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Juliana Siqueira Argenta

Universidade Federal do Rio Grande do Sul

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Laerte Ferreiro

Universidade Federal do Rio Grande do Sul

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Marina Venturini Copetti

Universidade Federal de Santa Maria

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Maria Isabel de Azevedo

Universidade Federal de Santa Maria

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Régis Adriel Zanette

Universidade Federal do Rio Grande do Sul

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Tatiana Spader

Universidade Federal de Santa Maria

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