Resultado da pesquisa (2)
Termo utilizado na pesquisa Quinolones
#1 - Quinolones resistance in Salmonella spp. isolated from broilers and chickens’ carcasses under federal inspection
Abstract in English:
We analyzed 77 Salmonella spp. strains, from which 20 were isolated from broilers (cloacal swabs) and 57 from chickens from slaughterhouses under federal inspection. The following serotypes were identified: Salmonella Saint Paul (29), Salmonella Heidelberg (27), Salmonella Anatum (9), Salmonella Cerro (5), Salmonella Senftenberg (5), Salmonella enterica (O: 4,5) (1) and Salmonella enterica (O: 9.12) (1). Fifteen strains (19.5%) were resistant to enrofloxacin, six (7.8%) to ciprofloxacin, and 26 (33.8%) to nalidixic acid in the Disk Diffusion Test. The fifteen enrofloxacin resistant strains were selected for the PCR to detect the genes gyrA, gyrB, parC, and parE, and genetic sequencing to identify mutations in these genes. Five strains (33.3%) had point mutations in the gyrA gene, and one (6.7%) presented a point mutation in the parC gene. None of the 15 strains had mutations in the gyrB and parE genes, and none had more than one mutation in the gyrA gene or the other genes. The presence of point mutations in the strains studied corroborates with the phenotypic resistance observed to nalidixic acid. However, it did not explain the resistance to fluoroquinolones found in the 15 strains. Other mechanisms may be related to the fluoroquinolones resistance, highlighting the need for additional mutation screening.
Abstract in Portuguese:
Foram analisadas neste estudo 77 estirpes de Salmonella spp., 20 isoladas de frangos vivos (suabes de cloaca) e 57 isoladas de carcaças, provenientes de abatedouros frigoríficos sob Inspeção Federal. Foram identificados os seguintes sorotipos: Salmonella Saint Paul (29), Salmonella Heidelberg (27), Salmonella Anatum (9), SalmonellaC erro (5), Salmonella Senftenberg (5), Salmonella enterica (O: 4,5) (1) e Salmonella enterica (O: 9,12) (1). Do total de estirpes estudadas, 15 (19,5%) se mostraram resistentes à enrofloxacina, seis (7,8%) à ciprofloxacina e 26 (33,8%) ao ácido nalidíxico no Teste de Difusão em Disco. Foram selecionadas as 15 estirpes resistentes à enrofloxacina para a realização da PCR para detecção dos genes gyrA, gyrB, parC e parEe para sequenciamento genético do produto da PCR para identificação de mutações nesses genes. Cinco estirpes (33,3%) apresentaram mutações pontuais no gene gyrA e uma (6,7%) apresentou mutação pontual no gene parC. Nenhuma das 15 estirpes apresentou mutações nos genes gyrB e parE e nenhuma apresentou mais de uma mutação no gene gyrA ou nos outros genes. A existência apenas de mutações pontuais em alguns genes das estirpes analisadas está de acordo com a resistência fenotípica observada ao ácido nalidíxico, mas não explica a resistência às fluoroquinolonas encontrada nas 15 estirpes. Outros mecanismos de resistência podem estar relacionados à resistência encontrada às fluoroquinolonas e estudos adicionais são necessários para investigar sua presença.
#2 - Eliminação de resistência a drogas por fluorquinolonas em Staphylococcus aureus de origem bovina
Abstract in English:
Pereira M.S.V., Siqueira Júnior J.P. & Campos Takaki G.M. 2004. [Elimination of resistance to drugs by fluoroquinolones in bovine strains of Staphylococcus aureus.] Eliminação de resistência a drogas por fluorquinolonas em Staphylococcus aureus de origem bovina. Pesquisa Veterinária Brasileira 24(1):11-14. Depto Biologia Molecular, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraiba, João Pessoa, PB 58059-900, Brazil. E-mail: svieira@dbm.ufpb.br
Bovine strains of Staphylococcus aureus were submitted to treatment with four fluoro-quinolones in subinhibitory concentrations (1/2 x MICs) to evaluate their influence on the curing of plasmids. Ciprofloxacin showed to be the most efficient by eliminating resistance to streptomycin, tetracyclin, penicillin, and cadmium nitrate. Norfloxacin and pefloxacin eliminated penicillin- and tetracyclin-resistance respectively. Otherwise, plasmids elimination by ofloxacin was not evidenced. The results obtained in this study confirm the potential of fluoroquinolones to eliminate antibiotic-resistant plasmids, and showed to be a valuable contribution for the prevention of multi-resistant strains, and may even enhance their sensitivity to other chemotherapeutic agents.
Abstract in Portuguese:
Pereira M.S.V., Siqueira Júnior J.P. & Campos Takaki G.M. 2004. [Elimination of resistance to drugs by fluoroquinolones in bovine strains of Staphylococcus aureus.] Eliminação de resistência a drogas por fluorquinolonas em Staphylococcus aureus de origem bovina. Pesquisa Veterinária Brasileira 24(1):11-14. Depto Biologia Molecular, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraiba, João Pessoa, PB 58059-900, Brazil. E-mail: svieira@dbm.ufpb.br
Bovine strains of Staphylococcus aureus were submitted to treatment with four fluoro-quinolones in subinhibitory concentrations (1/2 x MICs) to evaluate their influence on the curing of plasmids. Ciprofloxacin showed to be the most efficient by eliminating resistance to streptomycin, tetracyclin, penicillin, and cadmium nitrate. Norfloxacin and pefloxacin eliminated penicillin- and tetracyclin-resistance respectively. Otherwise, plasmids elimination by ofloxacin was not evidenced. The results obtained in this study confirm the potential of fluoroquinolones to eliminate antibiotic-resistant plasmids, and showed to be a valuable contribution for the prevention of multi-resistant strains, and may even enhance their sensitivity to other chemotherapeutic agents.
