Resistência antimicrobiana em Salmonella Enteritidis isoladas de amostras clínicas e ambientais de frangos de corte e matrizes pesadas Antimicrobial resistance in Salmonella Enteritidis isolated from clinical and environmental broiler chickens and breeders broiler

<abstract language="eng">The antimicrobial resistance of Salmonella Enteritidis strains isolated from clinical and environmental poultry samples in the Southern Brazil during the years of 1999, 2000 and 2001 was evaluated. Among the 79 isolated samples, 64 (81%) were resistant to at least one of the antimicrobial agents tested, showing 22 different resistance patterns. Tetracycline showed the highest percentage (64,5%) of resistance among the antimicrobial agents used. Resistance to drugs at different levels was found as the following: ampicillin (1.2%), kanamycin (1.2%), ciprofloxacin (2.5%), enrofloxacin (8.8%), gentamicin (21.5%), streptomycin (20.2%), nitrofurantoin (26.6%), and nalidixic acid (30.4%). None of the S. Enteritidis strains were resistant to chloramphenicol, norfloxacin, and polimycin B. Among the 64 S. Enteritidis strains that showed resistance, 43 (67.2%) were resistant to two or more antimicrobial agents. Twenty-one (32.8%) strains were resistant to only one of the antimicrobial agents, 14 to tetracycline, three to nalidixic acid, three to nitrofurantoin, and one to gentamycin. These antimicrobial resistance levels suggest a high occurrence of tetracycline resistant S. Enteritidis strains and resistance to two or more antimicrobial agents

Uso de microbiota cecal congelada com crioprotetores em pintos infectados experimentalmente com Salmonella enterica sorovar Enteritidis Use of frozen cecal microbiota with cryoprotectors in chicks experimentally infected with Salmonella enterica serotype Enteritidis

Pintos de corte com um dia de idade foram tratados com microbiota cecal cultivada em condição de aerobiose, nos tempos de congelamento de 90, 200, 290 e 360 dias, e associada aos crioprotetores sacarose, trealose, dimetilsulfóxido (DMSO) e glicerol. Posteriormente as aves foram desafiadas com Salmonella Enteritidis, visando determinar a eficácia dos tratamentos em relação à quantidade de bactérias viáveis da microbiota que foi maior aos 90 dias (10,58 Log10 UFC/ml), quando as aves foram tratadas com sacarose, e menor aos 290 dias, quando tratadas com glicerol (7,73 Log10 UFC/ml). No tempo zero, todas as aves apresentaram Salmonella (100%) quando tratadas com DMSO e glicerol, com colonização cecal de 4,9 e 5,2 Log10 UFC/g do conteúdo cecal, respectivamente; aos 360 dias nenhuma ave foi infectada, independente do tratamento. A microbiota cecal, independente de tratamento, sempre determinou menor quantidade de S. Enteritidis em qualquer um dos parâmetros pesquisados, quando comparada com a das aves não tratadas. O congelamento em nitrogênio líquido foi eficaz na manutenção da viabilidade da microbiota cecal até 360 dias.<br>One-day-old broiler chicks were treated with cecal microbiota cultivated under aerobiose conditions, frozen during 90, 200, 290 and 360 days and associated with different cryoprotectors such as sucrose, trehalose, DMSO and glycerol. Subsequently, the birds were challenged with Salmonella Enteritidis in order to determine the efficacy of the different treatments in relation to the quantity of viable bacteria, which was higher at 90 days when treated with sucrose (10.58 log10 CFU/ml) and lower at 290 days when treated with glycerol (7.73 log10 CFU/ml). The quantity of infected birds was 100% in 0 time, when the cecal colonization by S. Enteritidis was 4.9 and 5.2 log10 CFU/g of cecal content, respectively treated with DMSO and glycerol. No bird was infected at 360 days, irrespectively of the treatment. In all treatments, the cecal microbiota always determined a lesser quantity of S. Enteritidis for all the studied parameters compared to non-treated birds. Frozen in liquid nitrogen was effective in maintaining the viability of cecal microbiota during the experimental period of 360 days

Prevalência de sorovares de Salmonella isolados de aves no Brasil Prevalence of Salmonella serovars isolated from birds in Brazil

Foram caracterizadas antigenicamente amostras de Salmonella isoladas de aves (portadoras e doentes) provenientes de diversas regiões do país durante o período de 1962 a 1991. Nas 2123 culturas analisadas foram reconhecidos 90 sorovares, distribuídos em 14 sorogrupos com predominância dos grupos O:9 (40,0%), O:4 (33,3%), O:7 (10,6%) e O: 3,10 (6,7%). A maior diversidade de sorovares foi reconhecida no sorogrupo O:7 com 22 tipos distintos, secundado por O:4, O:3,10 e O:9, constituídos de 19, 15 e 10 sorotipos, respectivamente. No computo geral, foi determinada a média de 10,8 sorovares isolados por ano. Os sorovares classificados como muito frequentes nos três decênios, representando 65 a 67%, dos isolamentos, foram S. Gallinarum, S. Pullorum, S. Typhimurium, S. Heidelberg, S. Enteritidis e S. Infantis. Considerações de natureza bacteriológica e epidemiológica foram discutidas em relação a alguns dos sorotipos prevalentes.<br>Salmonella strains were isolated from ill and shedding birds in several regions of Brazil between 1962 and 1991. Serotyping of 2123 isolates showed 90 serovars pertaining to 14 serogroups. There was a predominance of groups O:9 (40.0%), O:4 (33.3%), O:7 (10.6%) and O:3,10 (6.7%). Major serovar diversity was found to serogroup O:7 that accounted for 22 different types, followed by serogroups O:4, O:3,10 and O:9 with 19, 15 and 10 serotypes respectively. An average of 10.8 serovars was isolated per year. S. Gallinarum, S. Pullorum, S. Typhimurium, S. Heidelberg, S. Enteritidis and S. Infantis were the most frequent serovars found over the 30 years, representing 65% to 67% of the total of isolates. Bacteriological and epidemiological aspects concerning a number of serotypes are discussed