An experiment was carried out with 630 oneday-old chicks to evaluate the effects of organic acids when birds were experimentally inoculated with Salmonella Typhimurium. Liver damage and the persistence of the bacterium in the organs were evaluated as well. Broilers were distributed in a completely randomised experimental design in a 3×2 factorial arrangement of six treatments with seven replicates of 15 birds each. Birds were inoculated with saline solution or the bacterium via gavage at 1 day of age, or were offered a feed containing or not the organic acid blend for the period of 7 to 14 days of age. A dose of 5.0x10 2 colony-forming units (CFU)/0.5 mL of Salmonella Typhimurium was used for inoculation both via gavage and feed. The parameters evaluated are weight, liver histopathology, liver and serum biochemistry, and bacteriological analyses of the caeca, crop, spleen, and liver and heart pool. At 21 and 28 days of age, the liver of the non-inoculated groups was significantly lighter as compared to the other treatments. Birds fed organic acids presented lower bacterial isolation rates in all organs tested. Birds inoculated in the crop and treated with organic acids presented lower E. coli CFU counts (P<0.05). Birds inoculated with Salmonella presented significant changes (P<0.05) in liver enzymes, as detected by serum biochemistry, and in liver histopathology. It was concluded that organic acids effectively controlled Salmonella Typhimurium and did not cause any liver damage.

BACTERIOLOGICAL QUALITY OF WASHED AND UNWASHED EGGS STORED UNDER ROOM TEMPERATURE AND REFRIGERATION AND CONTAMINATED WITH Pseudomonas aeruginosa ABSTRACTThe aim of this study was to evaluate the effect of sanitization and storage temperature on the quality of commercial eggs inoculated with Pseudomonas aeruginosa. We used 240 large eggs, without cracks, from Dekalb White laying hens at 30 to 40 weeks of age. The experimental design used was two blocks in a 2 x 2 factorial arrange (washed/non-washed and refrigerated/non-refrigerated) with twelve replicates. The eggs were contaminated by handling, with 1.5 x 10 5 colony-forming units (CFU) of Pseudomonas aeruginosa and stored at 5 °C and 25 °C for 30 days. Each ten days the eggshell and contents were submitted to bacteriological analyses. Variance analyses were performed and the data were compared by Tukey test. The results showed that Pseudomonas aeruginosa were isolated from the shells and contents of all eggs. Therefore, when the eggs were sanitized and stored at 5 ºC the contamination was less intense. The correlation between the presences of Pseudomonas aeruginosa in the shell and contents was high, when the eggs were not sanitized nor refrigerated. The conclusion of this study was that the egg must be sanitized and refrigerated when the stored for more than 30 days.

RESUMOA avicultura industrial tem o desafio de aumentar a produção de aves e manter a sanidade do plantel. A artrite infecciosa em frangos de corte é uma enfermidade que causa inúmeros prejuízos econômicos, pois além de desvalorizar o lote, as aves deixam de se alimentar, constitui uma das causas de condenação em abatedouros, pois as carcaças doentes são condenadas total ou parcialmente. Entretanto, as perdas econômicas são contabilizadas apenas dentro dos abatedouros e não há contabilização das perdas ocorridas nas granjas. Para controlar essa enfermidade, medidas de biossegurança devem ser estabelecidas, com base nos seus agentes etiológicos, formas de transmissão e de controle. Os principais agentes etiológicos envolvidos na patogenia das artrites infecciosas são Mycoplasma, Ortheoreovirus aviário, Pasteurella spp., Salmonella sp., Escherichia coli e Staphylococcus spp.. O conhecimento desses patógenos se faz necessário para diminuir as perdas econômicas, pois conhecer o agente possibilitará a implantação de medidas preventivas e corretivas nas granjas, estabelecendo programas de controle para diminuir o risco de disseminação em níveis aceitáveis, bem como oferecer alimento de qualidade aos consumidores. Com base no exposto, foi realizada uma revisão de literatura com o intuito de trazer informações relacionadas aos principais agentes etiológicos envolvidos na gênese da artrite infecciosa em frangos.

-The objective of this experiment was to evaluate the influence of lactulose on performance as well as its ability to prevent colonization by Salmonella Typhimurium in broilers orally inoculated with this pathogen. The design adopted was completely randomized, with 630 one-day-old male chicks distributed into six treatments, with seven replications and 15 birds per experimental unit. The treatments comprised the following procedures: T1 (control group) -no S.Typhimurium inoculation or supply of lactulosis; T2 -only inoculation of S. Typhimurium; T3 -only lactulosis supply; T4 -supply of lactulosis and S. Typhimurium inoculation on the first day of life; T5 -supply of lactulosis 48 hours before S.Typhimurium inoculation; and T6 -supply of lactulosis 48 hours after inoculation of S. Typhimurium. Performance variables were evaluated on the seventh, 14th, 21st and 28th days of age; fragments of the duodenum and jejunum were collected and sent to histomorphometric assessment at 14 days of age, and S. Typhimurium excretion was verified in cloacal swabs on the 10th, 24th and 35th days of age. Performance data were analyzed by ANOVA and Tukey's test (5%) and fecal excretion data were assessed by non-parametric chi-square test. Better weight gain and feed conversion were observed in groups fed lactulosis with or without challenge of S. Typhimurium up to 21 days of age. Reduced duodenum villous height was verified on the 14th day in groups challenged with the pathogen. Reduction of S. Typhimurium fecal excretion was verified in broilers fed lactulosis from the first day of life on and 48 hours before receiving S. Typhimurium directly into the crop. Lactulosis increases broiler performance up to one week after its inoculation, influences duodenum villous height and reduces the fecal excretion of Salmonella Typhimurium.

RESUMO: Objetivou-se verificar o efeito da sanitização, contaminação experimental bacteriana e da refrigeração na perda de peso de ovos, durante o período de armazenamento de 30 dias. Foram utilizados 96 ovos, os quais pesados a cada três dias. O delineamento utilizado foi em blocos casualizados em esquema fatorial 2 x 2 x 2 (sanitização x contaminação x temperatura de armazenamento), com seis repetições e um ovo a unidade experimental. A sanitização dos ovos foi realizada com a lavagem com água morna contendo clorhexidina 20% e teor ativo 8% de cloro. Após, os ovos foram contaminados na casca, pelo manuseio por 10 segundos, com 1,5 x 10 5 unidades formadoras de colônias (UFCs) de Pseudomonas aeruginosa/mL de solução e permaneceram armazenados a 5 o C ou 25 o C por 30 dias. Constatou-se que a refrigeração manteve a qualidade interna dos ovos, mesmo quando houve contaminação na casca com inóculo de Pseudomonas aeruginosa. Concluiu-se que a refrigeração retarda a perda de peso e proporciona melhor qualidade interna, física e química de ovos, durante os 30 dias de armazenamento, independente da contaminação e do processo de sanitização.