Electroforesis de campo eléctrico pulsado en la tipificación molecular de cepas aisladas de un brote de Salmonelosis ocasionado por consumo de queso contaminado con Salmonella Javiana / Pulse Field Gel Electrophoresis in molecular typification of strains isolated from a Salmonellosis outbreak caused by consumption of Salmonella Javiana contaminated cheese

El objetivo de este trabajo fue confirmar por Electroforesis de Campo Electrico Pulsado (PFGE) que la Salmonella aislada del alimento implicado en el brote (queso blanco) fue la responsable del evento.La muestra de queso blanco presento elevado recuento de coliformes, E. coli y S. aureus,ademas, presencia de Salmo nella spp., lo que indico condiciones sanitarias inadecuadas y posible contaminacion de origen fecal. Para la confirmacion de las cepas sospechosas de Sal monella spp, aisladas de los pacientes y del alimento, se utilizaron tecnicas bioquimicas convencionales, la serotipificacion se realizo siguiendo el esquema de White-kauffmann-LeMinor y la sensibilidad a los antimicrobianos (Ampicilina, Trimetroprim-Sulfametoxazole, Ciprofloxacina, Amoxicilina, Ac.Clavulanico, Cloranfenicol, Ceftriaxone y Tetraciclina) por la tecnica kirby-Bauer. Las cepas bacterianas de Salmonella spp aisladas fueron identificadas como Salmonella Javiana [1,9,12:l, z28:1,5] y resultaron sensibles a todos los antibioticos probados.La Tipificacion Molecular de las cepas, se realizo por PFGE, se gun protocolo estandarizado de PulseNet para Salmonella y el analisis de los patrones se estudio utilizando el programa BioNumerics, version 4.0, lo cual mostro que los aisla dos de Salmonella Javiana procedentes tanto de pacientes como del alimento tenian identico patron de restriccion, en tamano y numero de fragmentos. La ocurrencia de un patron unico de PFGE (Coeficiente de similitud 100%) entre los aislados permitio demostrar que el queso contaminado con Salmonella Javiana fue el responsable del brote familiar.

The aim of this work was confirmation through Pulse Field Gel Electrophoresis (PFGE) that Salmonella isolated from the food implicated in the outbreak (white cheese) was responsible for the event. The white cheese sample showed a high count of Coli orms,f E. coli and S. aureus. Moreover, Salmonella was pre ent,s which indicated inadequate sanitary conditions and possible fecal contamination. The suspected Salmonella strains isolated from patients and the food sample, were confirmed using conventional biochemical techniques, serotyping according to the White-kauffmann-Le Minor scheme and antibiotics sensibility (Am picillin, Trimetroprim-Sulfametoxazole, Ciprofloxacin, Amoxicillin, Clavulanic Acid, Cloranfenicol, Ceftriaxone and tetraciclin) following kirby-Bauer’s technique. The Salmonella strains were identified as Salmonella Javiana [1,9,12:I, z28:1,5]and were sensitive to all the antibiotics tested. The molecular typing of the strains was performed using PFGE, according to the PulseNet standardized protocol for Salmonella. The pattern analysis was studied using Bionunella merics program, version 4.0, which showed that the Sal monella Javiana isolates from patients as the food sample had an identical restriction pattern in size and fragments number. The incidence of a unique pattern of PFGE (similarity coefficient 100%) between isolates demonstrated that the cheese contaminated with Salmonella Javiana was responsible for the family outbreak.