Isolation and Identification of Listeria Species

Isolation and Identification of Listeria SpeciesAlesha Coleman-McCallum statute titleIsolation and Identification of Listeria species from whiner stress employ Palcam ancestry (pre-enrichment), UVM 11 broth ( discriminating enrichment), Palcam and Oxford nutrient agars (selective plating) also plump foration using biochemical tests.ObjectivesTo isolate Listeria species from crybaby sampleTo observe the reaction of listeria on selective mediumTo confirm the Listeria species using biochemical testsIntroductionListeria is a genus of aerobic parasitic, grand prescribed rod-shaped bacterium (Define, n.d). This genus has more than than 10 species with the commonly encountered being Listeria monocytogenes, Listeria innocua, Listeria ivanovii, Listeria welshimeri, Listeria seeligeri, Listeria grayi, Listeria murrayi. Members of this genus atomic number 18 extensively spread in the environment and by chance found in soil, plants, gastrointestinal tract of animal and earthly concer n. Listeria monocytogenes species is of great concern because it is pathogenic to humans and causes Listeriosis. Listeriosis is a foodborne illness (Hardy Diagnostics, 1996).Listeria monocytogenes is different from most bacteria since it disregard enhance in the cold, salt, acid and air-tight conditions. The increased demand of lay down to eat foods especially in first world countries has the potential of listeriosis more eminent. Pregnant women, older adults, young children and immunocompromised persons are more susceptible to Listeriosis infections. Therefore cooking, pasteurization/applying heating steps to food, avoiding mad meat and milk/ moist or processed food and dry wash hands regularly may reduce the risk of infections. (FDA, 2004). According to viands woodland Safety USA 4 a dry and clean head for the hills environment is crucial in avoiding listeria outbreaks in the food industry.Methods for IdentificationMethods apply in BI208 lab for identification of Liste ria were Palcam broth (pre-enrichment) then UVM 11 broth for selective enrichment step, Palcam (selective agent) and Oxford agars (selective and differential agent). For confirmation of species organism was plated on a melody agar to check for hemolysis. Biochemical test included SIM tube for motility, mannitol, D Xylose and L Rhamnose reactions obtained. Other methods that could be used to identify listeria species are Polymerase Chain Reaction (PCR), Rapid Identification Kits and Serological tests (MFHPB-07, 2012).ResultsTable showing results obtained from Listeria media reactionMediaObservationsReactionPalcam nutrient agarShiny, smooth, circular, convex colonies.No fermentationNo HydrolsisOxford AgarBlack colour around coloniesEsculin Reduction beginningCream, hilly,glistening coloniesNo Beta-hemolysisMannitolTransparent colonies banishD XyloseTransparent colonies nixL RhamnoseLight yellow fermentation around coloniesPositiveSIM organ pipeUmbrella shaped growthPositiveGram Sta in one thousand positive rodsAssuming Listeria monocytogenes control was usedMediaExpected ResultsPalcam Broth denseUVM 11CloudyPalcam AgarNo fermentationPositive HydrolysisOxford AgarEsculin ReductionBloodBeta-hemolysisMannitolNegativeD XyloseNegativeL RhamnosePositiveSIM TubePositiveDiscussionListeria innocua was marooned from the moaner sample. Listeria innocua is not usually implicated in food born-illnesses however an isolated death in an elderly patient was reported (Perrin, Bemer and Delamare, 2003).Portions of chicken sample were first placed in pre-enrichment broth in order for punctuate cells to become viable and all other bacterial cells to multiply. Enrichment stage is to partly suppress unwanted organisms and allow listeria to thrive. Oxford agar (OXA) is both selective and differential. The selective properties of OXA agar will not allow gram negative organisms to grow while suppressing most gram positive organisms (Oxoid, n.d). The different property of OXA agar will allow some species of Listeria to be totally inhibited, growth with or without blackened colonies (MFHPB-07, 2012). Palcam agar utilizes two indicator systems esculin and mannitol. Listeria monocytogenes changes esculin to a black involved around colonies but does not ferment mannitol. Therefore some gram positive organisms such as enterococci and staphylococci will ferment mannitol hence can be ruled out as contaminants (Oxoid, n.d). Blood agar was used to determine if the organism is beta-hemolytic. Other Biochemical tests were mannitol, D Xylose, L Rhamnose and SIM Tube to differentiate and confirm the species. Since Listeria monocytogenes is pathogenic to humans a 2 Class Sampling Plan would be used to asses if the chicken is fit for consumption. Different species of an organism may exhibit variable characteristics and maybe mistaken. Listeria species were found and should be deemed unacceptable for consumption. Further testing such as PCR which is very specific could be used to conclusively identify the species present.Conclusionsestablish on the objectives previously outlined, isolation and Identification of Listeria species from chicken sample using Palcam broth method was very effective.ReferencesDefine,n.d. Listeria Genus. Retrieved February 22, 2017 from http//www.dictionary.com/browse/listeriaHardy Diagnostics, 1996. solid food Borne-illneses Retrieved February 22, 2017 from https//catalog.hardydiagnostics.com/cp_prod/ issue/hugo/Listeria.htmFDA, 2004. Food-Borne Pathogenic Microorganisms and Natural Toxins Handbook The Bad Bug Book U.S. FDA/CFSAN. pith for Food Safety and Applied Nutrition, Food and Drug Administration, College park, MD.Food Quality Safety (formerly Food Quality),2007. Retrieved February 20, 2017 from http//www.foodqualityandsafety.com/article/prevent-and-control-listeriaJay, J.M.,Loessner, M.J. Golden, D. A. (2005). Modern Food Microbiology Indicator of Food Microbial Quality and Safety, 476-477. join States of America Springer Science+ business organisation Media LLC .MFHPB-07 Method, November, 2012. The isolation of Listeria monocytogenes and other listeria species from food and environment samples using Palcam broth. Retrieved February 20, 2017 fromhttp//www.hc-sc.gc.ca/fn-an/res-rech/analy-meth/microbio/volume2-eng.phpMonique Perrin, Michel Bemer and Catherine Delamare, 2003. Fatal human face of Listeria innocua Bacteremia Journal of Clinical MicrobiologyOxoid, n.d. Enrichment Media for Listeria. Retrieved February 20, 2017 fromhttp//www.oxoid.com/uk/blue/prod_detail/prod_detail.asp?pr=CM0856org=91c=uklang=ENUS Government, n.d. Retrieved February 20, 2017 from https//www.foodsafety.gov/poisoning/causes/bacteriaviruses/listeria/Zimbro, M.J., Power D.A., Miller,M.M., Wilson, G.E., Johnson, J.A., (Revised 2009). Difco BBL Manual Palcam and Oxford Agar, Culture Media for Specific Groups of Microorganisms. United States of America Becton, Dickinson and Company.