[Presence of Listeria monocytogenes in ready-to-eat foods available in open markets, delicatessens and supermarkets, Bogotá, 2002-2008].
BACKGROUND
The increase in diseases transmitted by foods has become a public health problem. Listeria monocytogenes, the etiological agent of listeriosis or typical food poisoning,is considered to be among the most important food borne illnesses. High risk foods for L.monocytogenes have been recognized as foods already prepared for consumption and made available in retail outlets.


OBJECTIVE
The presence of L. monocytogenes was identified in prepared foods found in open markets and delicatessens in the city of Bogotá.


METHODS
A transverse descriptive study over a 7-year period, with an analytic component, in which 600 foods were analyzed--300 from delicatessens and 300 from open market places. Reference methods were used to determine the presence or absence of L. monocytogenes in 25 grams or milliliters a food sample.


RESULTS
Of the 600 samples, 68 were positive for L. monocytogenes (11.3%). Twenty-six (38.2%) were taken from delicatessens and 42 (61.8%) from open market places. The serotype most frequently isolated was 4b, with 53 (78.0%) isolations. Fresh cheeses and matured cheeses showed greater contamination with L. monocytogenes than the other foods (p<0.001 in both cases).


CONCLUSIONS
The results indicate that prepared foods are vehicles for the transmission of the Listeria bacterium. These potentially high risk foods are candidates for control and monitoring by public health authorities. Programs must be instituted to implement surveillance norms that lead to the reduction and control of this microorganism and geared toward the prevention of food borne diseases.
Laboratorio de Microbiología de Alimentos, Subdirección de Alimentos y Bebidas Alcohólicas, Instituto Nacional de Vigilancia de Medicamentos y Alimentos, Bogotá, D.C., Colombia. amunozc@invima.gov.co
Ana Isabel
AI
Muñoz
Mercedes
M
Vargas
Ligia
L
Otero
Graciela
G
Díaz
Viviana
V
Guzmán
D000818:Animals; D002611:Cheese / Q000382:microbiology; D003105:Colombia; D003430:Cross-Sectional Studies; D005506:Food Contamination; D005511:Food Handling; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology; D012703:Serotyping; D014504:Urban Health; D014675:Vegetables / Q000382:microbiology