Miniaturized most probable number for the enumeration of Salmonella sp in artificially contaminated chicken meat

Salmonella is traditionally identified by conventional microbiological tests, but the enumeration of this bacterium is not used on a routine basis. Methods such as the most probable number (MPN), which utilize an array of multiple tubes, are time-consuming and expensive, whereas miniaturized most probable number (mMPN) methods, which use microplates, can be adapted for the enumeration of bacteria, saving up time and materials. The aim of the present paper is to assess two mMPN methods for the enumeration of Salmonella sp in artificially-contaminated chicken meat samples. Microplates containing 24 wells (method A) and 96 wells (method B), both with peptone water as pre-enrichment medium and modified semi-solid Rappaport-Vassiliadis (MSRV) as selective enrichment medium, were used. The meat matrix consisted of 25g of autoclaved ground chicken breast contaminated with dilutions of up to 10(6) of Salmonella Typhimurium (ST) and Escherichia coli (EC). In method A, the dilution 10-5 of Salmonella Typhimurium corresponded to >57 MPN/mL and the dilution 10-6 was equal to 30 MPN/mL. There was a correlation between the counts used for the artificial contamination of the samples and those recovered by mMPN, indicating that the method A was sensitive for the enumeration of different levels of contamination of the meat matrix. In method B, there was no correlation between the inoculated dilutions and the mMPN results.

Interference of Salmonella typhimurium lipopolysaccharide on performance and biological parameters of broiler chickens

This study was conducted to determine the interference of Salmonella typhimurium lipopolysaccharide (sLPS) on the performance, biological parameters, and histological evaluations of 198 one-day-old male broiler chickens divided into three treatments according to sLPS dose (0, 250, or 500 µg/application/bird) that was applied to the birds every other day, from 15 to 27 days of age. At the end of the experiment (28 days), significant effects were observed on body weight (R= -0.17 and P=0.05), total cholesterol serum levels(R=0.43 and p 0.01), phosphorus (R=0.53 and P 0.01), uric acid (R= -0.38 and P 0.01), C-reactive protein (R=0.68 and p 0.01), serum activity of aspartate aminotransferase (R=0.39 and p 0.01) and alkaline phosphatase (R= -0.39 and p 0.01). According to these results, sLPS mainly affect broiler biological parameters, but also their live performance.

Interference of Salmonella typhimurium lipopolysaccharide on performance and biological parameters of broiler chickens

This study was conducted to determine the interference of Salmonella typhimurium lipopolysaccharide (sLPS) on the performance, biological parameters, and histological evaluations of 198 one-day-old male broiler chickens divided into three treatments according to sLPS dose (0, 250, or 500 µg/application/bird) that was applied to the birds every other day, from 15 to 27 days of age. At the end of the experiment (28 days), significant effects were observed on body weight (R= -0.17 and P=0.05), total cholesterol serum levels(R=0.43 and p 0.01), phosphorus (R=0.53 and P 0.01), uric acid (R= -0.38 and P 0.01), C-reactive protein (R=0.68 and p 0.01), serum activity of aspartate aminotransferase (R=0.39 and p 0.01) and alkaline phosphatase (R= -0.39 and p 0.01). According to these results, sLPS mainly affect broiler biological parameters, but also their live performance.

Miniaturized most probable number for the enumeration of Salmonella sp in artificially contaminated chicken meat

Salmonella is traditionally identified by conventional microbiological tests, but the enumeration of this bacterium is not used on a routine basis. Methods such as the most probable number (MPN), which utilize an array of multiple tubes, are time-consuming and expensive, whereas miniaturized most probable number (mMPN) methods, which use microplates, can be adapted for the enumeration of bacteria, saving up time and materials. The aim of the present paper is to assess two mMPN methods for the enumeration of Salmonella sp in artificially-contaminated chicken meat samples. Microplates containing 24 wells (method A) and 96 wells (method B), both with peptone water as pre-enrichment medium and modified semi-solid Rappaport-Vassiliadis (MSRV) as selective enrichment medium, were used. The meat matrix consisted of 25g of autoclaved ground chicken breast contaminated with dilutions of up to 10(6) of Salmonella Typhimurium (ST) and Escherichia coli (EC). In method A, the dilution 10-5 of Salmonella Typhimurium corresponded to >57 MPN/mL and the dilution 10-6 was equal to 30 MPN/mL. There was a correlation between the counts used for the artificial contamination of the samples and those recovered by mMPN, indicating that the method A was sensitive for the enumeration of different levels of contamination of the meat matrix. In method B, there was no correlation between the inoculated dilutions and the mMPN results.

Isolamento de Salmonella Heidelberg em diferentes pontos da tecnologia de abate de frangos de corte

Bacteria of the genus Salmonella are part of the normal flora of poultry, and its occurrence in poultry products varies with the production management methods and slaughter technology, representing risks to the consumer and difficulties in exports. S. Heidelberg appears to be more invasive and to cause more severe disease than other non-typhoidal serovars. The objective of the present study was to search for Salmonella at different points of the slaughterhouse and to report on the isolation of S. Heidelberg in a slaughterhouse under federal inspection. S. Heidelberg was isolated in poultry soon after feathering-out and in the chiller water, indicating that, although it was not isolated at another sampled points, the bacteria was present in the environment and could contaminate carcasses ready for consumption, with an impact on public health. This concern is underscored by the fact that S. Heidelberg is a proven causative agent of foodborne infections.

Bactérias do gênero Salmonella fazem parte da flora normal das aves e sua ocorrência em produtos avícolas varia com o manejo na criação e tecnologia de abate, representando riscos para o consumidor final e dificuldades nas exportações. A S. Heidelberg parece ser mais invasiva e causar doenças com maior gravidade que outros sorovares paratíficos. Este trabalho teve por objetivos pesquisar Salmonella em diferentes pontos da tecnologia de abate de frangos e relatar o isolamento de S. Heidelberg em um abatedouro sob inspeção federal. S. Heidelberg foi isolada em frangos logo após a depenagem e na água do chiller indicando que, embora não tenha sido realizado o isolamento em outros pontos amostrados, a bactéria estava presente no ambiente e poderia contaminar carcaças prontas para consumo, com reflexos na saúde pública. O isolamento de S. Heidelberg reforça esta preocupação uma vez que este sorovar tem se destacado como causador de doenças transmitidas por alimentos.

Isolamento de Salmonella Heidelberg em diferentes pontos da tecnologia de abate de frangos de corte

Bacteria of the genus Salmonella are part of the normal flora of poultry, and its occurrence in poultry products varies with the production management methods and slaughter technology, representing risks to the consumer and difficulties in exports. S. Heidelberg appears to be more invasive and to cause more severe disease than other non-typhoidal serovars. The objective of the present study was to search for Salmonella at different points of the slaughterhouse and to report on the isolation of S. Heidelberg in a slaughterhouse under federal inspection. S. Heidelberg was isolated in poultry soon after feathering-out and in the chiller water, indicating that, although it was not isolated at another sampled points, the bacteria was present in the environment and could contaminate carcasses ready for consumption, with an impact on public health. This concern is underscored by the fact that S. Heidelberg is a proven causative agent of foodborne infections.

Bactérias do gênero Salmonella fazem parte da flora normal das aves e sua ocorrência em produtos avícolas varia com o manejo na criação e tecnologia de abate, representando riscos para o consumidor final e dificuldades nas exportações. A S. Heidelberg parece ser mais invasiva e causar doenças com maior gravidade que outros sorovares paratíficos. Este trabalho teve por objetivos pesquisar Salmonella em diferentes pontos da tecnologia de abate de frangos e relatar o isolamento de S. Heidelberg em um abatedouro sob inspeção federal. S. Heidelberg foi isolada em frangos logo após a depenagem e na água do chiller indicando que, embora não tenha sido realizado o isolamento em outros pontos amostrados, a bactéria estava presente no ambiente e poderia contaminar carcaças prontas para consumo, com reflexos na saúde pública. O isolamento de S. Heidelberg reforça esta preocupação uma vez que este sorovar tem se destacado como causador de doenças transmitidas por alimentos.

Effect of acidified drinking water on the recovery of Salmonella enteritidis from broiler crops

Crop is a known source of Salmonella contamination during broiler carcass processing. The effect of drinking water acidification by lactic acid or citric acid or a combination of those with cupric sulfate and d-limonene in the reduction of Salmonella Enteritidis (SE) recovered from the crop of broilers was evaluated. Treatments were administered during 8 hours of preslaughter fasting period (Experiments I and II) and during the last 32 hours of preslaughter (Experiment III). It was observed that acidification reduced water intake when treatments began at preslaughter feed withdrawal, and affected the possible reducing effect of these acids on SE recovering (Experiments I and II). Water intake during preslaughter feed withdrawal was not affected when treatment began 32 hours before slaughter (Experiment III). Treatments reduced SE recovering from crop (p 0.05). In Experiment III, 0.470% of lactic acid reduced the number of recovered SE in 99%. This study suggested that the addition of organic acids in the drinking water 24 hours before beginning the preslaughter feed withdrawal might reduce crop SE colonization and might be an important strategy to reduce SE contamination of broiler products during processing.

Effect of acidified drinking water on the recovery of Salmonella enteritidis from broiler crops

Crop is a known source of Salmonella contamination during broiler carcass processing. The effect of drinking water acidification by lactic acid or citric acid or a combination of those with cupric sulfate and d-limonene in the reduction of Salmonella Enteritidis (SE) recovered from the crop of broilers was evaluated. Treatments were administered during 8 hours of preslaughter fasting period (Experiments I and II) and during the last 32 hours of preslaughter (Experiment III). It was observed that acidification reduced water intake when treatments began at preslaughter feed withdrawal, and affected the possible reducing effect of these acids on SE recovering (Experiments I and II). Water intake during preslaughter feed withdrawal was not affected when treatment began 32 hours before slaughter (Experiment III). Treatments reduced SE recovering from crop (p 0.05). In Experiment III, 0.470% of lactic acid reduced the number of recovered SE in 99%. This study suggested that the addition of organic acids in the drinking water 24 hours before beginning the preslaughter feed withdrawal might reduce crop SE colonization and might be an important strategy to reduce SE contamination of broiler products during processing.