Characterization and subtyping of Cronobacter spp. from imported powdered infant formulae in Argentina

Fil: Terragno, R. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Salve, Angela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Pichel, Mariana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Epszteyn, Sergio. Gobierno de la Ciudad de Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria; Argentina.Fil: Brengi, Silvina P. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Binsztein, Norma. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Cronobacter spp. (Enterobacter sakazakii), have been associated with severe foodborne infections in neonates and immunocompromised infants. In Argentina, we have isolated Cronobacter spp. from three different brands of imported powdered infant formulae (PIF). The objectives of this work were to characterize the recovered isolates phenotypically and to evaluate the use of a Pulsed-Field Gel Electrophoresis (PFGE) protocol for Cronobacter spp. subtyping. Out of 23 isolates studied from three brands of PIF (20 of brand A, 1 of brand B and 2 of brand C), 22 were identified as C. sakazakii and 1 as C. malonaticus. All isolates were susceptible to twelve antimicrobial agents assayed. The 19 C. sakazakii isolates of brand A showed five XbaI-PFGE patterns and the genetic clusters revealed by XbaI were confirmed with a second restriction enzyme, SpeI. The isolate from brand B showed the same XbaI and SpeI patterns as those of a group of isolates of brand A, suggesting a possible common source of contamination. The C. sakazakii isolates of brand C exhibited two unique XbaI-PFGE patterns, unrelated to the rest. Different genetic subtypes were found among isolates of a single batch of PIF from brand A and the single C. malonaticus strain also showed a distinct XbaI-PFGE pattern

Shiga toxin-producing Escherichia coli O157 in beef and chicken burgers, and chicken carcasses in Buenos Aires, Argentina

Fil: Chinen, Isabel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Epszteyn, Sergio. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Melamed, Celia L. Departamento Laboratorio Investigación y Monitoreo, Dirección General de Higiene y Seguridad Alimentaria, Gobierno de la Ciudad de Buenos Aires, Patricias Argentinas 277, (1405) Buenos Aires; Argentina.Fil: Aguerre, Lorena. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Martínez Espinosa, Estela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Motter, Mariana M. Departamento Laboratorio Investigación y Monitoreo, Dirección General de Higiene y Seguridad Alimentaria, Gobierno de la Ciudad de Buenos Aires, Patricias Argentinas 277, (1405) Buenos Aires; Argentina.Fil: Baschkier, Ariela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Manfredi, Eduardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Miliwebsky, Elizabeth. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.Fil: Rivas, Marta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.We describe the isolation and characterization of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H7 from cooked and uncooked beef and chicken burgers and from chicken carcasses collected during sampling procedures in 2001 and 2002 in Buenos Aires City, Argentina. Of the 24 STEC O157:H7 strains isolated, 20 were recovered from 19 (6.8%) out of 279 samples of beef and chicken burgers, and 4 strains from 4 (10.3%) out of 39 chicken carcasses. The samples were analyzed following the USDA/FSIS 2002 method. The prevalent stx genotype was stx(2) and stx(2c) (12 strains, 50%). All strains were characterized as eae and ehxA-positive. By XbaI-PFGE, the strains yielded 10 different patterns. Eighteen out of 24 strains were grouped in four clusters: #1 (4 strains, AREXHX01.0043), #2 (4 strains, AREXHX01.0022), #3 (8 strains, AREXHX01.0139), and #4 (2 strains, AREXHX01.0200). Identical strains by phage typing, stx genotyping and PFGE were detected in uncooked and cooked beef and chicken burgers in different restaurants, which had been collected on the same or different sampling dates. These findings help to underline the importance of STEC O157 detection in meat products, to improve active surveillance, and to define control strategies in order to prevent new cases of STEC infection

Quantitative risk assessment of listeriosis associated with fermented sausage and dry-cured pork shoulder consumption in Argentina

The risk of acquiring listeriosis from consuming fermented sausages and dry-cured pork shoulder (capicola/bondiola) in Argentina was estimated using quantitative microbiological risk assessment. The model included data about initial prevalence and contamination level of Listeria monocytogenes, product formulation with or without a starter culture (lactic acid bacteria [LAB]), time and temperature during distribution and storage prior to consumption, and consumption patterns. The probability of listeriosis from fermented sausage consumption in at-risk populations was estimated with average values of <10−11 per portion consumed. The main factor associated with such probability was the use of LAB in fermented sausage production, which reduced the risk by at least three orders of magnitude. Meat mass pH during fermentation and water activity (aw) at the end of ripening were the factors having the greatest impact on the probability of listeriosis. Thus, LAB added during production, pH values < 5.1 at the end of fermentation and aw <0.93 during ripening indicated that the environment was not appropriate for L. monocytogenes development, suggesting that fermented sausages had an adequate safety level. On the other hand, the risk of listeriosis from dry-cured pork shoulder consumption was negligible, even in the most susceptible populations. Both aw level and the strict control of process temperature were the main risk factors for acquiring listeriosis. The level of protection given by the current Argentine microbiological criterion for fermented sausages and dry-cured pork shoulder (absence of L. monocytogenes in 25 g of product) would guarantee the safety of these products similarly to the <100 cfu/g cut used in other countries.EEA RafaelaFil: Brusa, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina.Fil: Prieto, Monica. Instituto Nacional de Enfermedades Infecciosas (INEI); ArgentinaFil: Campos, Carmen A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Tecnología de Alimentos y Procesos Químicos. Universidad de Buenos Aires. Instituto de Tecnología de Alimentos y Procesos Químicos; ArgentinaFil: Epszteyn, Sergio. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Cuesta, Alicia. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Renaud, Viviana. Instituto Nacional de Tecnología Industrial. Gerencia Operativa de Servicios Industriales. Subgerencia Operativa de Alimentos. Departamento de Tecnología de Proceso Industrial; ArgentinaFil: Schembri, Gustavo. Instituto Nacional de Tecnología Industrial. Gerencia Operativa de Servicios Industriales. Subgerencia Operativa de Alimentos. Departamento de Tecnología de Proceso Industrial; ArgentinaFil: Vanzini, Mónica. Campo Del Tesoro; ArgentinaFil: Michanie, S. Consultora de Empresas en Inocuidad de Alimentos; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Comparison of six commercial systems for the detection of non-O157 STEC in meat and vegetables

Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food that may cause severe illness in human beings. Thus, systems for STEC detection in food should have increasingly higher sensitivity and specificity. Here we compared six commercial systems for non-O157 STEC detection in meat and vegetables and determined their sensitivity, specificity and repeatability. A total of 46 samples (meat n = 23; chard n = 23) were experimentally contaminated with strains O26:H11, O45:H-, O103:H2, O111:NM, O121:H19 and O145:NM isolated in Argentina. Strain detection was confirmed by isolation according to ISO 13136:2012. Detection of the stx and eae genes in meat samples was highly satisfactory with all commercial kits, but only five had 100% sensitivity and specificity in chard. Of four kits evaluated for serogroup detection, three had 100% sensitivity and specificity, and one had 93.7% sensitivity and 100% specificity. All kits were adequate to analyze meat but not vegetable samples, and were not therefore validated for the latter matrix. The challenge for microbiology laboratories is to identify the advantages and disadvantages of the available kits for STEC detection in food based on a clear knowledge of the particular needs of each laboratory.EEA RafaelaFil: Costa, Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Sucari, Adriana. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Epszteyn, Sergio. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Oteiza, Juan Martín. Centro de Investigación y Asistencia Técnica a la Industria. Laboratorio de Microbiología de los Alimentos (Neuquén); ArgentinaFil: Gentiluomo, Jimena. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Melamed, Celia. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Figueroa, Yamila. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Mingorance, Santiago Emmanuel. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Grisaro, Agustina. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Spioussas, Silvia. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Buffoni Almeida, Mariana. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Caruso, Mailen. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Pontoni, Andrés. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin