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In the current context of emerging drug-resistant fungal pathogens such as Candida albicans and Candida parapsilosis, discovery of new antifungal agents is an urgent matter. This research aimed to evaluate the antifungal potential of 2-chloro-N-phenylacetamide against fluconazole-resistant clinical strains of C. albicans and C. parapsilosis. The antifungal activity of 2-chloro-N-phenylacetamide was evaluated in vitro by the determination of the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), inhibition of biofilm formation and its rupture, sorbitol and ergosterol assays, and association between this molecule and common antifungal drugs, amphotericin B and fluconazole. The test product inhibited all strains of C. albicans and C. parapsilosis, with a MIC ranging from 128 to 256 µg.mL-1, and a MFC of 512-1,024 µg.mL-1. It also inhibited up to 92% of biofilm formation and rupture of up to 87% of preformed biofilm. 2-chloro-N-phenylacetamide did not promote antifungal activity through binding to cellular membrane ergosterol nor it damages the fungal cell wall. Antagonism was observed when combining this substance with amphotericin B and fluconazole. The substance exhibited significant antifungal activity by inhibiting both planktonic cells and biofilm of fluconazole-resistant strains. Its combination with other antifungals should be avoided and its mechanism of action remains to be established. Resumo No atual contexto de patógenos fúngicos resistentes emergentes tais como Candida albicans e Candida parapsilosis, a descoberta de novos agentes antifúngicos é uma questão urgente. Esta pesquisa teve como objetivo avaliar o potencial antifúngico da 2-cloro-N-fenilacetamida contra cepas clínicas de C. albicans e C. parapsilosis resistentes a fluconazol. A atividade antifúngica da substância foi avaliada in vitro através da determinação da concentração inibitória mínima (CIM), concentração fungicida mínima (CFM), ruptura e inibição da formação de biofilme, ensaios de sorbitol e ergosterol, e associação entre esta molécula e antifúngicos comuns, anfotericina B e fluconazol. O produto teste inibiu todas as cepas de C. albicans e C. parapsilosis, com uma CIM variando de 128 a 256 µg.mL-1, e uma CFM de 512-1,024 µg.mL-1. Também inibiu até 92% da formação de biofilme e causou a ruptura de até 87% de biofilme pré-formado. A 2-cloro-N-fenilacetamida não promoveu atividade antifúngica pela ligação ao ergosterol da membrana celular fúngica, tampouco danificou a parede celular. Antagonismo foi observado ao combinar esta substância com anfotericina B e fluconazol. A substância exibiu atividade antifúngica significativa ao inibir tanto as células planctônicas quanto o biofilme das cepas resistentes ao fluconazol. Sua combinação com outros antifúngicos deve ser evitada e seu mecanismo de ação deve ser estabelecido.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:56:02Z No. of bitstreams: 1 S0102-09352008000200007.pdf: 204124 bytes, checksum: 86b02f359a911d19128045a2ff0b3d4f (MD5) Made available in DSpace on 2013-08-22T18:56:02Z (GMT). No. of bitstreams: 1 S0102-09352008000200007.pdf: 204124 bytes, checksum: 86b02f359a911d19128045a2ff0b3d4f (MD5) Previous issue date: 2008-04-01 Made available in DSpace on 2013-09-30T19:49:32Z (GMT). No. of bitstreams: 2 S0102-09352008000200007.pdf: 204124 bytes, checksum: 86b02f359a911d19128045a2ff0b3d4f (MD5) S0102-09352008000200007.pdf.txt: 25205 bytes, checksum: 555d8a6e12f05be68cf720ddf25dc051 (MD5) Previous issue date: 2008-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:14:08Z No. of bitstreams: 2 S0102-09352008000200007.pdf: 204124 bytes, checksum: 86b02f359a911d19128045a2ff0b3d4f (MD5) S0102-09352008000200007.pdf.txt: 25205 bytes, checksum: 555d8a6e12f05be68cf720ddf25dc051 (MD5) Made available in DSpace on 2014-05-20T13:14:08Z (GMT). No. of bitstreams: 2 S0102-09352008000200007.pdf: 204124 bytes, checksum: 86b02f359a911d19128045a2ff0b3d4f (MD5) S0102-09352008000200007.pdf.txt: 25205 bytes, checksum: 555d8a6e12f05be68cf720ddf25dc051 (MD5) Previous issue date: 2008-04-01 Foram examinados 20 eqüinos adultos portadores de abdômen agudo e submetidos à laparotomia. Dez recuperaram-se sem intercorrência pós-operatória (G1) e 10 foram a óbito sete a 10 dias após a cirurgia, com sinais de choque séptico (G2). Avaliaram-se temperatura retal, freqüências cardíaca e respiratória, tempo de preenchimento capilar e teores plasmáticos das proteínas de fase aguda - fibrinogênio, ceruloplasmina, proteína C-reativa, antitripsina, haptoglobina e glicoproteína ácida -, antes e até sete dias após a laparotomia. As leucometrias às 72h e no sétimo dia pós-operatório dos eqüinos que foram a óbito foram, respectivamente, 34,6% e 57,1%, mais altas que a dos animais curados. Os maiores valores de proteína de fase aguda ocorreram no sétimo dia após a cirurgia; os percentuais de elevação de fibrinogênio, antitripsina, glicoproteina ácida, proteína C-reativa, ceruloplasmina e haptoglobina de eqüinos do G2 em relação ao G1 foram 46,8%, 67,9%, 91,9%, 112,2%, 126,9% e 186,2%, respectivamente. Twenty adult horses with acute abdomen were examined and submitted to treatment by laparotomy; ten had no postoperative complication (group 1), and ten showed septic shock symptom and died from seven to ten days after surgery (group 2). Body temperature, heart and respiratory rates, filling capillary time, and plasma acute phase protein concentrations - fibrinogen, ceruloplasmin, C-reactive protein, antitrypsin, haptoglobin, and acid glycoprotein - were evaluated before laparotomy and until seven days after surgery. White blood cell counts at 72h and seven days after surgery in group 2 animals were, respectively, 34.6% and 57.1%, and were higher than those measured in group 1 horses. The highest values of acute phase proteins occurred on the seventh day after surgery. The increase percentages of fibrinogen, antitrypsin, acid glycoprotein, C-reactive protein, ceruloplasmin, and haptoglobin plasma concentrations in group 2 animals in comparison to group 1 animals were 46.8%, 67.9%, 91.9%, 112.2%, 126.9%, and 186.2%, respectively. UNESP Faculdade de Ciências Agrárias e Veterinárias Universidade Federal do Tocantins (UFT) UNESP Faculdade de Ciências Agrárias e Veterinárias