The microbial contamination of fish is the most important factor in assurance of food safety. The microflora on the surface of skin, gills and gut of fish is constantly under the influence of the water environment and...The microbial contamination of fish is the most important factor in assurance of food safety. The microflora on the surface of skin, gills and gut of fish is constantly under the influence of the water environment and this may cause colonization of microorganisms on fish. The goal of this study was to evaluate the bacterial contamination level on the skin, gills and gut of the European eel （Anguilla anguilla）, i.e., detecting total bacteria count （TBC） and Enterobacteriaceae counts, as well as Listeria spp, and Salmonella spp. in freshly caught fish. Among the three lakes, TBC on skin, gills and gut varied from 0.66 CFU/cm2 to 4.93 CFU/cm~, from 0.40 CFU/cm2 to 5.51 CFU/cm2 and from 0.30 CFU/cm2 to 6.37 CFU/cm2, respectively. Enterobacteriaceae count on skin, gills and gut was from 0 CFU/cm2 to 4.30 CFU/cm2, from 0 CFU/cm2 to 2.47 CFU/cm2 and from 0 CFU/cm2 to 1.72 CFU/cm2, respectively. The highest mean count of TBC on gills, skin and gut was found in samples from Sivers lake, while the lowest was in samples from Aluksne lake. Values among the lakes were significanty （P 〈 0.05） different. Also the highest mean counts of Enterobacteriaceae were found on gills and skin of eels from Sivers lake, but the highest count on gut was found in Usma lake. All tested samples were Listeria monocytogenes and Salmonella spp. negative. TBC and Enterobacteriaceae counts of skin, gills and gut were typical for wild fish in fresh water. Foodborne pathogens, such as Salmonella spp. and L. monocytogenes, have not been found in the present study, indicating that fish are safe for human consumption.展开更多
Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contaminatio...Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 （42%） hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 （15）. In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14（15） were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases （p 〈 0.05）. Data showed that 85% of consumers received hot water at a temperature below 50°C.展开更多
文摘The microbial contamination of fish is the most important factor in assurance of food safety. The microflora on the surface of skin, gills and gut of fish is constantly under the influence of the water environment and this may cause colonization of microorganisms on fish. The goal of this study was to evaluate the bacterial contamination level on the skin, gills and gut of the European eel （Anguilla anguilla）, i.e., detecting total bacteria count （TBC） and Enterobacteriaceae counts, as well as Listeria spp, and Salmonella spp. in freshly caught fish. Among the three lakes, TBC on skin, gills and gut varied from 0.66 CFU/cm2 to 4.93 CFU/cm~, from 0.40 CFU/cm2 to 5.51 CFU/cm2 and from 0.30 CFU/cm2 to 6.37 CFU/cm2, respectively. Enterobacteriaceae count on skin, gills and gut was from 0 CFU/cm2 to 4.30 CFU/cm2, from 0 CFU/cm2 to 2.47 CFU/cm2 and from 0 CFU/cm2 to 1.72 CFU/cm2, respectively. The highest mean count of TBC on gills, skin and gut was found in samples from Sivers lake, while the lowest was in samples from Aluksne lake. Values among the lakes were significanty （P 〈 0.05） different. Also the highest mean counts of Enterobacteriaceae were found on gills and skin of eels from Sivers lake, but the highest count on gut was found in Usma lake. All tested samples were Listeria monocytogenes and Salmonella spp. negative. TBC and Enterobacteriaceae counts of skin, gills and gut were typical for wild fish in fresh water. Foodborne pathogens, such as Salmonella spp. and L. monocytogenes, have not been found in the present study, indicating that fish are safe for human consumption.
文摘Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 （42%） hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 （15）. In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14（15） were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases （p 〈 0.05）. Data showed that 85% of consumers received hot water at a temperature below 50°C.
