ABSTRACT
Eggs are foods with almost perfect proteins, while also containing nutrients with high biological value. The purpose of this study was to evaluate the morphological structure, physical-chemical, nutritional, and microbiological parameters of commercial and free-range eggs sold in the municipality of Santarém, State of Pará, Brazil. The two types of eggs were also compared to check for any differences in quality. The evaluations were conducted on variables such as Haugh unit, weight loss, egg width and length, specific gravity, yolk and albumen dimensions, pH, among others. A total of 240 eggs were purchased in the Brazilian municipality of Santarém (2º45'06" S and 54º70'09" W). A statistical study was also performed using the BIOESTAT 5.0 statistical program. A comparison of the industrial and free-range eggs and their various parameters is given in the tables along with the coefficient of variation. The results obtained were satisfactory and showed that the quality of eggs is affected more by environmental factors than by the source from which they are obtained. The results were also compared to previously published literature, and it was determined that this study offers a better foundation for the nutritional examination of egg quality.(AU)
Subject(s)
Animals , Commerce/methods , Eggs/analysis , BrazilABSTRACT
The identification of salmonella infection in commercial poultry has been one of the strong points of prophylaxis and consequent reduction of salmonellosis outbreaks in humans associated to consumption of eggs, considering that the analysis of the eggs can be one more point of detection of infection, which for many times appear without clinical signs. The Polymerase Chain Reaction (PCR) seems to be a useful strategy for Salmonella detection, because various authors have used the PCR to verify the presence of bacteria in meat, feces, tissues, blood, milk and eggs, with different methods of manipulation of samples. We have analyzed 360 eggs from ten farms, producers of free range-eggs, in the district of Camobi, in Santa Maria - RS - Brasil. The eggs were grouped in pools of six, totaling sixty samples. The bacteriological exam was done in compliance with the method preconized by the technical rules and the method for extraction of DNA was by phenol-chloroform. The PCR was performed for the amplification of a 284 bp DNA fragment. The analysis of the results do not show significant difference between the PCR and the bacteriological exam. All positive samples in the bacteriological exam were also positive by PCR, however the PCR detected more two samples due to higher sensitivity and specificity, specially when it is known that the eggs show a mixed population of germs that many times difficult isolation of salmonellas in the bacteriological exam because of the competition with normal flora bacteria.
A identificação de poedeiras comerciais infectadas por salmonelas tem sido um dos pontos fortes da profilaxia e conseqüente redução de surtos de salmonelose em humanos associados ao consumo de ovos, sendo que a análise dos ovos pode ser mais um dos pontos de detecção da infecção, que, muitas vezes, cursa sem sinais clínicos. A Reação em Cadeia da Polimerase (PCR) parece ser uma estratégia útil para detecção de Salmonella, pois vários autores têm utilizado a PCR para verificar a presença da bactéria em carnes, fezes, tecidos, sangue, leite e ovos, com diferentes metodologias de manipulação das amostras. Foram analisados 360 ovos, procedentes de dez propriedades rurais, produtoras de ovos tipo colonial, no distrito de Camobi, em Santa Maria - RS. Os ovos foram divididos em grupos de seis, totalizando sessenta amostras. O exame bacteriológico foi realizado conforme metodologia preconizada pelas normas técnicas e a metodologia de extração de DNA pelo fenol-clorofórmio. A PCR foi realizada para a amplificação de um fragmento de DNA de 284 pb. A análise dos resultados não demonstrou diferença significativa entre a PCR e o bacteriológico. Todas as amostras positivas ao bacteriológico foram positivas na PCR, sendo que essa última detectou duas amostras a mais, devido a sua alta sensibilidade e especificidade, especialmente quando é sabido que os ovos apresentam uma população microbiana mista que, muitas vezes, impede o isolamento adequado das salmonelas no bacteriológico pela competição com a flora bacteriana normalmente presente.
ABSTRACT
The identification of salmonella infection in commercial poultry has been one of the strong points of prophylaxis and consequent reduction of salmonellosis outbreaks in humans associated to consumption of eggs, considering that the analysis of the eggs can be one more point of detection of infection, which for many times appear without clinical signs. The Polymerase Chain Reaction (PCR) seems to be a useful strategy for Salmonella detection, because various authors have used the PCR to verify the presence of bacteria in meat, feces, tissues, blood, milk and eggs, with different methods of manipulation of samples. We have analyzed 360 eggs from ten farms, producers of free range-eggs, in the district of Camobi, in Santa Maria - RS - Brasil. The eggs were grouped in pools of six, totaling sixty samples. The bacteriological exam was done in compliance with the method preconized by the technical rules and the method for extraction of DNA was by phenol-chloroform. The PCR was performed for the amplification of a 284 bp DNA fragment. The analysis of the results do not show significant difference between the PCR and the bacteriological exam. All positive samples in the bacteriological exam were also positive by PCR, however the PCR detected more two samples due to higher sensitivity and specificity, specially when it is known that the eggs show a mixed population of germs that many times difficult isolation of salmonellas in the bacteriological exam because of the competition with normal flora bacteria.
A identificação de poedeiras comerciais infectadas por salmonelas tem sido um dos pontos fortes da profilaxia e conseqüente redução de surtos de salmonelose em humanos associados ao consumo de ovos, sendo que a análise dos ovos pode ser mais um dos pontos de detecção da infecção, que, muitas vezes, cursa sem sinais clínicos. A Reação em Cadeia da Polimerase (PCR) parece ser uma estratégia útil para detecção de Salmonella, pois vários autores têm utilizado a PCR para verificar a presença da bactéria em carnes, fezes, tecidos, sangue, leite e ovos, com diferentes metodologias de manipulação das amostras. Foram analisados 360 ovos, procedentes de dez propriedades rurais, produtoras de ovos tipo colonial, no distrito de Camobi, em Santa Maria - RS. Os ovos foram divididos em grupos de seis, totalizando sessenta amostras. O exame bacteriológico foi realizado conforme metodologia preconizada pelas normas técnicas e a metodologia de extração de DNA pelo fenol-clorofórmio. A PCR foi realizada para a amplificação de um fragmento de DNA de 284 pb. A análise dos resultados não demonstrou diferença significativa entre a PCR e o bacteriológico. Todas as amostras positivas ao bacteriológico foram positivas na PCR, sendo que essa última detectou duas amostras a mais, devido a sua alta sensibilidade e especificidade, especialmente quando é sabido que os ovos apresentam uma população microbiana mista que, muitas vezes, impede o isolamento adequado das salmonelas no bacteriológico pela competição com a flora bacteriana normalmente presente.