Isolation and characterization of Listeria monocytogenes and other Listeria species in foods of animal origin in Addis Ababa, Ethiopia
ABSTRACT Listeriosis is a disease of humans and animals, in which it is one of the important emerging bacterial zoonotic diseases worldwide. Among the different species of the genus Listeria, Listeria monocytogenes (L. monocytogenes) is known to cause listeriosis in humans and animals with low incidence but high case fatality rate. Information on the occurrence and distribution of L. monocytogenes and other Listeria species is very limited both in the veterinary and public health sectors in Ethiopia. The objective of this study was to isolate and characterize L. monocytogenes and other Listeria species from foods of animal origin (cottage cheese, raw beef, raw milk and liquid whole egg) in Addis Ababa, Ethiopia. A total of 391 food samples of animal origin were collected randomly, using a cross-sectional study design from November 2008 to March 2009. L. monocytogenes isolation and characterization were performed according to mainly the United States Food and Drug Administration procedures. Of the samples examined, 102 (26.1%) were found to be positive for Listeria. Listeria species were isolated in 39 (51.3%), 37 (32.2%), 22 (22%) and 4 (4%) of the raw beef, liquid whole egg, raw milk and cottage cheese samples respectively. L. monocytogenes was detected in 5.4% of the samples analyzed. It was isolated mainly from raw milk (13%) and liquid whole egg (4.3%) followed by raw beef (2.6%) and cottage cheese (1%). In addition to L. monocytogenes, other Listeria species were identified as L. innocua (60.8%), L. welshimeri (6.9%), L. seeligeri (3.9%), L. murrayi (2.9%) and L. grayi (2.9%) and L. ivanovii (1.9%). It was shown that L. monocytogenes and other Listeria species are widely spread in occurrence in foods of animal origin in Addis Ababa, Ethiopia.
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- "L. monocytogenes was detected in 5.4% of the samples analyzed. It was isolated mainly from raw milk (13%) (Gebretsadik et al., 2010). "
ABSTRACT: Milk and milk products serve as important source of many disease producing microbes including Listeria monocytogenes, which is a Gram-positive, motile, psychotropic bacterium, and is the principal cause of listeriosis in humans and in a wide variety of animals including birds. The disease occurs in sporadic as well as in epidemic form, following the ingestion of food contaminated by this organism. In the world, it is becoming an important food-borne bacterial disease, with low incidence but high case fatality rate. L. monocytogenes primarily affects older, pregnant women, newborns, and adults with weakened immune systems; and it has been recovered from the soil, dust, water, sewage, decaying vegetation, etc. Raw or inadequately pasteurized milk (or milk contaminated post-pasteurization), soft cheeses, ice cream and other dairy products are important sources of L. monocytogenes in humans. The disease has two forms, one febrile gastroenteritis and other inva-sive systemic disease. The control of Listeria in foods relies largely on a HACCP approach and the establishment of effective critical control points in the process. As milk and milk products are important vehicles of L. monocytogenes and clear risk factors, it is emphasized that people susceptible for acquiring listeriosis should not consume unpasteurized milk and milk products.
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- "), from 19% of beef in Jordan (Awaisheh, 2010), from 32% of the chicken meats in Spain (Capita et al., 2001), from 52% of the beef meat and from 34% of chicken meats in Canada (Bohaychuk et al., 2006), from 2.6% of raw beef in Ethiopia (Gebretsadik et al., 2011), from 30.2% of the chicken meat in Korea (Baek et al., 2000). In the present study, L. monocytogenes was isolated from 17.8% in the chicken meat samples and from 7.2% in the ground beef samples collected from commercial market in and around the eastern part of Turkey. "
ABSTRACT: The present work aimed to investigate the prevalence of Listeria monocytogenes in ground beef and chicken samples put into the market during the period of April to September 2011 in the eastern part of Turkey. A total of 360 food samples consisting of 180 ground beef and 180 chicken meat samples were examined in terms of the presence of Listeria species. L. monocytogenes was isolated from 7.2 % ground beef samples and 17.8 % of chicken meat samples. While in 15.5% of the ground beef samples L. innocua was detected, L. welshimeri was detected in 6.1% of them. As for chicken meat samples, L. innocua was detected in 36.7% of them while L. welshimeri was detected in 5.5%, L. seeligeri was detected in 4.4% and L. murrayi was detected in 1.1% of them. Out of 45 L. monocytogenes isolates, 28 were type 1, while 17 of them were type 4. These results indicated that L. monocytogenes and other Listeria species are widely distributed in the ground beef and chicken meat samples in the eastern part of Turkey. Thus, meat products may be a potential food safety concern in Turkey.Pakistan Veterinary Journal 01/2012; 32(3):456-458. · 1.39 Impact Factor
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ABSTRACT: Milk of dairy cows can harbor a variety of microorganisms including Listeria monocytogenes, the first to be identified as an important foodborne pathogen. This pilot survey aimed to assess the presence of L. monocytogenes in raw whole milk in 15 provinces of China between June 2009 and October 2010. All 5211 analyzed samples were compliant using polymerase chain reaction (PCR) detection. A total of 19 samples were positive in 9 provinces, while no PCR-positive samples were obtained in the other 6 provinces. The prevalence of L. monocytogenes in raw milk was 0.36% in the 15 Chinese provinces, while the prevalence of positive areas within these dates was 0.23–1.2% among the nine provinces. Among the investigated 24 herds, rates of L. monocytogenes positivity were 0.17–2.89% in 13 herds, whereas they were 0% in the other 11 herds. There was a significant difference (p < 0.05) in PCR-positive data between organized farms (0.19%) and private herds (1.83%). These results indicate that there is a lower risk of contamination in the milking process in China when more attention is paid to maintaining good milking and strict hygiene practices, especially in private herds.Food Control 05/2013; 31(1):176–179. DOI:10.1016/j.foodcont.2012.09.026 · 2.82 Impact Factor