1 |
The Effectiveness of Potassium Lactate and Lactic Acid Against Campylobacter Species and Psychrotrophic BacteriaRasmussen, David Dean 08 October 1999 (has links)
This study examined the efficacy of potassium lactate and lactic acid to control Campylobacter sp. and psychrotrophic bacteria on chicken. The objectives of the two studies conducted were to determine the optimal combination of potassium lactate and lactic acid to inhibit Campylobacter sp. in a challenge study and to inhibit naturally occurring Campylobacter sp. and psychrotrophic bacteria in a shelf life study.
Boneless, skinless chicken breasts were injected with three levels of potassium lactate (0,1.5,2%), in conjunction with four levels of lactic acid. Lactic acid was injected (0, 0.1, 0.2, 0.3%) as well as applied directly to the surface (0.1% of weight of chicken breast). The chicken breasts were surface inoculated with a mixture of Campylobacter sp. and sampled over a period of 28 days at 11oC. The greatest inhibition was found using 2% potassium lactate in conjunction with any level of lactic acid (injected) or 0.1% lactic acid (surface application). Results of this study indicate that potassium lactate and lactic acid can be used to control the growth and/or survival of Campylobacter sp. on boneless chicken breasts.
The second study eliminated the 1.5% potassium lactate and 0.2% and 0.3% lactic acid treatments and chicken breasts were not inoculated with Campylobacter sp.. This 4oC shelf life study occurred over 32 days, testing for Campylobacter species, psychrotrophic bacteria, as well as testing for sensory perceptions of color and odor changes in the chicken. The most effective treatment was the 2% potassium lactate-0.1% lactic acid surface treatment, demonstrating the most inhibition against both target populations. This treatment also had the greatest impact upon the odor of the chicken breasts. This treatment had the greatest difference from control samples, which was achieved by the inhibition of spoilage organisms on the chicken breasts. / Master of Science
|
2 |
Transmissão vertical de Campylobacter sp em um sistema de produção avícola / Vertical transmission of Campylobacter sp in a poultry production systemFonseca, Belchiolina Beatriz 14 July 2007 (has links)
Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Campylobacter sp is recognized as one of the main causes of human
gastroenteritis of food origin. Among the foods that circulate these microorganism, chicken
is the meat most involved. Existent studies about the vertical transmission of
Campylobacter sp are scarce and inconclusive. The aim of this study was to verify the
vertical transmission of Campylobacter sp from heavy matrixes to the progeny. With the
use of the traditional culture method, cloacal swabs of 279 heavy matrix samples were
analyzed from the follow sits: 6 bed, 4 nest, 11 ovary and oviduct, 11 liver, spleen and
heart and 11 intestine. In 11 cloacal swab samples polymerase chain reaction (PCR) was
also performed, using the automated BAX® system. In progeny samples, the following
were analyzed: 78 and 44 fresh eggs, disinfected and not disinfected, respectively, 12
infertile eggs, 45 unhatched eggs, 13 hatching environment samples, 121 meconium
samples and 36 organ samples (heart, liver, spleen) and 36 intestines from one-day old
chickens. The analyses were performed by the traditional culture method. In another 10
meconium samples, analysis was performed by the BAX® method. The positivity in the
cloacal swab samples by the traditional culture method was 13.97% and by the BAX®
methodology it was 54.54%. The bed samples, positivity was 83.33% and in the nest
samples it was 0.25%. In matrix organs, Campylobacter sp was only isolated in 27.27% of
samples and only in the intestines. There was no positivity in any of the samples of fresh
eggs, infertile eggs, embryonic eggs, chicken organs or from the hatching environment.
By the traditional culture method there was no positivity in the meconium, but with the use
of the BAX® system, positivity was 80%. Although the physiological characteristics of the
matrixes, the eggs and Campylobacter sp are favorable to the entry and survival of
bacteria in the eggs, and consequently in the one-day old chickens, in this study, positivity
in the progeny was only found with the use of the BAX® system. These findings suggest
that further studies with the use of molecular techniques should be conducted to verify
vertical transmission. / Campylobacter sp é reconhecida como uma das principais causas de
gastroenterite humana de origem alimentar e dentre os alimentos veiculadores desses
microrganismos, a carne de frango é a mais implicada. As pesquisas existentes sobre a
transmissão vertical da Campylobacter sp são escassas e não conclusivas. O objetivo
desse estudo foi verificar a transmissão vertical da Campylobacter sp de matrizes
pesadas para a progênie. Utilizando o método de cultura tradicional, foram analisados
suabes cloacais de 279 amostras matrizes pesadas, 6 de cama, 4 de ninho, 11 de ovário
e oviduto, 11 de fígado, baço e coração e 11 de intestino. Em 11 amostras de suabe
cloacal, também foi realizada a reação da polimerase em cadeia (PCR) utilizando o
sistema automatizado BAX®. Em amostras da progênie foram analisadas: 78 e 44 ovos
frescos desinfetados e não desinfetados, respectivamente, 12 ovos inférteis, 45 ovos não
eclodidos, 13 amostras ambientais de nascedouro, 121 de mecônio e 36 amostras de
órgãos (coração, fígado, baço) e 36 intestinos de pintainhos de um dia. As análises foram
realizadas pelo método de cultura tradicional e em outras 10 amostras de mecônio, pelo
método BAX®. A positividade em amostras de suabe cloacal pelo método de cultura
tradicional foi de 13,97% e pela metodologia BAX® 54,54%. Nas de cama, a positividade
foi de 83,33% e nas de ninho, 25%. Em órgãos de matrizes, Campylobacter sp foi isolada
em 27,27% das amostras e somente em intestinos. Não houve positividade em nenhuma
das amostras de ovos frescos, inférteis, ovos embrionados, órgãos de pintainhos ou
ambiente de nascedouro. Pelo método de cultura tradicional, não houve positividade em
mecônio, embora com o uso do sistema BAX® a positividade foi de 80%. Apesar das
características fisiológicas das matrizes, dos ovos e da Campylobacter sp serem
favoráveis à entrada e sobrevivência da bactéria nos ovos, e conseqüentemente, nos
pintainhos de 1 dia de idade, nesse estudo, as positividades na progênie foram apenas
encontradas com a utilização do sistema BAX®. Esses achados sugerem que outros
estudos com utilização de técnicas moleculares devem ser aplicados para verificação da
transmissão vertical. / Mestre em Ciências Veterinárias
|
Page generated in 0.0797 seconds