THE OCCURRENCE AND SEASONAL-CHANGES IN THE ISOLATION OF LISTERIA SPP IN SHOP BOUGHT FOOD STUFFS, HUMAN FECES, SEWAGE AND SOIL FROM URBAN SOURCES

Eight hundred and twenty-two shop-bought food specimens, 136 soil and 692 faecal specimens were cultured for Listeria spp. in a regular, yea r round survey. 19.7% (162/822) of the foods, 93.9% (108/115) of the s ewage, 14.7% (20/136) soils and 1% (7/692) of faeces yielded Listeria spp. with 10.5% foods, 60.0% sewage, 0.7% soils and 0.6% faeces contai ning L. monocytogenes. No seasonal variation was noted in isolates fro m either sewage or foods, with L. monocytogenes and L. innocua being t he commonest species in both. L. ivanovii when isolated from foods was strongly associated with mutton. Poultry was most likely to contain L . monocytogenes (65.6%, 21/32) and in the greatest numbers. A high per centage of beef (34.6%, 9/26), lamb (40%, 8/20), pork (28.1%, 9/32) an d sausages (34.7%, 8/23) also contained L. monocytogenes. L. monocytog enes was rarely isolated from pate (1/40) or soft cheeses (1/251), bot h of which have been involved with foodborne listeriosis outbreak in t he UK Listeria spp. were commonest in faeces and soils in July to Sept ember but the predominant species isolated were different with L. mono cytogenes and L. innocua the commonest from faeces and L. ivanovii and L. seeligeri the most common from soil.