307 research outputs found
Evaluation of the pathogenicity potential, antimicrobial susceptibility and genomic relations of Yersinia enterocolitica strains from food and human origin
No full textYersinia enterocolitica is a food-borne pathogen that causes gastroenteritis with occasional postinfection sequels. This study was aimed to determinate the pathogenic potential, antimicrobial susceptibility, and genomic relationships of Y. enterocolitica strains of different bioserotypes (B/O) isolated from foods and human samples in San Luis, Argentina. Strains obtained by culture were bioserotyped and characterized by phenotypic and genotypic virulence markers, antimicrobial susceptibility, and pulsed-field gel electrophoresis (PFGE). Yersinia enterocolitica was detected in 9.2% of 380 samples, with a distribution of 10.6% (30/284) for food products and 5.2% (5/96) for human samples. Regarding the pathogenic potential, B1A strains of different serotypes were virF– ail–, of which 72.0% (13/18) were ystB+ with virulence-related phenotypic characteristics. Among B2/O:9 isolates, 75.0% (9/12) exhibited the genotype virF+ ail+ ystB– along with phenotypic traits associated with virulence; the same genotype was observed in 80.0% (4/5) of B3/O:3 and B3/O:5 strains. By PFGE, it was possible to separate Y. enterocolitica biotypes into 4 clonal groups (A to D) with 23 genomic types, generating a discriminatory index of 0.96. All isolates were susceptible to antimicrobials used for clinical treatment. This study highlights the presence of pathogenic bioserotypes and the high genomic diversity of the Y. enterocolitica strains isolated in our region.Fil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Soria, José Miguel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Favier, Gabriela Isabel. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; Argentin
Effects of organic acids, nisin, lyzozyme and edta on the survival of Yersinia enterocolitica population in inoculated orange beverages
No full textInactivation of a Yersinia enterocolitica strain by 3.4% ascorbic acid (AA), 0.5% citric acid (CA), 0.2% lactic acid, 100 IU/mL nisin, 2,400 IU/mL lysozyme and 20 mM ethylenediaminetetraacetic acid disodium salt (EDTA ), alone and combined, was studied at different temperatures (4 and 25C) in commercial and laboratory-prepared orange beverages. In laboratory-prepared juice, highest reductions (between 3.06 and 4.07 log units) were obtained with acid mixtures at 25C after 20 min of incubation. At 24 h of incubation, EDTA was bactericidal and the mixtures with nisin or lysozyme resulted in count reductions of 6.03 and 5.98 log units, respectively. In commercial orange beverage, AA and CA gave reductions of 5.43 and 4.26 log units, respectively. The three acid mixtures were bactericidal within the first 10 min. EDTA alone or mixed completely inhibited Y. enterocolitica strain at 6 and 24 h of incubation. At 4C, all the results were significantly lower than at 25C.Fil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis; ArgentinaFil: Velázquez, Lidia del Carmen. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: de Guzmán, Ana María S.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentin
Presence of enterotoxigenic Staphylococcus aureus in artisan fruit salads in the city of San Luis, Argentina
No full textAn increase in the consumption of fruit juices and minimally processed fruits salads has been observed in recent years all over the world. In this work, the microbiological quality of artisan fruit salads was analysed. Faecal coliforms, Salmonella spp, Shigella spp, Yersinia enterocolitica and Escherichia coli O157:H7 were not detected; nevertheless, eleven strains of Staphylococcus aureus were isolated. By multiplex PCR, all isolates showed positive results for S. aureus 16S rRNA gene and 63.6% of them were positive for sea gene. Furthermore, PCR sea positive strains were able to produce the corresponding enterotoxin. Finally, the inactivation of these strains in fruit salads by nisin, lysozyme and EDTA, was studied. EDTA produced a total S. aureus growth inhibition after 60 h of incubation at a concentration of 250 mg/L. The presence of S. aureus might indicate inadequate hygiene conditions during salad elaboration; however, the enterotoxigenicity of the strains isolated in this study, highlights the risk of consumers intoxication. EDTA could be used to inhibit the growth of S. aureus in artisan fruit salads and extend the shelf life of these products.Fil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alcaráz, Lucia E.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Satorres, Sara E.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Manfredi, Eduardo. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorio e Instituto de Salud ; ArgentinaFil: Velázquez, Lidia del Carmen. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin
Comparison of DNA extraction methods for pathogenic Yersinia enterocolitica detection from meat food by nested PCR
No full textThe objective of this work was to compare three different methods of DNA extraction from meat food, and to determine whether these methods removed inhibitors of nested PCR for pathogenic Yersinia enterocolitica detection. The amplification of the yadA gene from the DNA obtained from a pure Y. enterocolitica culture could be carried out with all the protocols. DNA amplification from the food samples was observed with two of the three tested protocols, which gave highly sensitive amplifications (detection limit 1 CFU/ml). These protocols detected a lower limit of 0.6 fg/μl of DNA extracted from Y. enterocolitica pure culture. We concluded that these protocols were able to eliminate satisfactorily the PCR inhibitors present in the foods. The nested PCR tested could be used satisfactorily in the investigation of pathogenic Y. enterocolitica in foods in the presence of a high background of microflora.Fil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Velázquez, Lidia del Carmen. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Di Genaro, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Stefanini de Guzman, Ana Maria Teresa Valentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin
Prevalence, antimicrobial susceptibility, and molecular characterization by PCR and pulsed field gel electrophoresis (PFGE) of Salmonella spp. isolated from foods of animal origin in San Luis, Argentina
No full textThis study was aimed to determine the prevalence of Salmonella spp. in foods of animal origin sold at retail stores over the period 2005–2011 in San Luis, Argentina. Characterization of isolates was performed by biochemical and serological tests, antimicrobial susceptibility assays, detection of invA invasion gene by PCR and comparison of genomic profiles by XbaI DNA restriction and PFGE. Twenty seven Salmonella strains were detected in 27 (6.32%) of 427 samples of foods analysed. Sixteen S. Enteritidis and one S. Montevideo strains from chicken meat (17 positive samples/115 total samples), six S. Anatum strains from pork sausages (6/90), two S. Typhimurium strains from liquid egg (2/60) and two S. Montevideo strains from chicken giblets (2/62) were isolated. No Salmonella strains were recovered from chicken carcasses (0/100). Salmonella strains were susceptible to antimicrobials commonly used for clinical treatment. All isolates carried the invA gene. DNA restriction and PFGE analysis revealed similar genomic profiles within each Salmonella serovar regardless of the food type, sampling year, or retail store where samples were purchased, suggesting the possibility of circulation and transmission of clones of limited diversity in our region.Fil: Favier, Gabriela Isabel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lazarte Otero, Valeria Sabrina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
An overview of Yersinia enterocolitica and related species in samples of different origin from San Luis, Argentina
No full textThis study is aimed at offering an overview of the prevalence of Yersinia enterocolitica and related species in San Luis, Argentina, from samples of diverse origin received in our laboratory between 1984 and 2014, and providing an analysis of the distribution of Yersinia isolates according to their isolation sources, highlighting bioserotypes and potential reservoirs and vehicles of transmission to humans. From a total of 4572 samples of human, animal, food and environmental origins analyzed by traditional culture methods and molecular techniques, 229 (5%) samples were Yersinia positive. The highest frequency of Yersinia isolates was observed in environmental specimens (14.3%), followed by animal (9.2%), food (5%) and human (0.6%) samples. A total of 255 Yersinia isolates were characterized, including 183 Y. enterocolitica and 72 isolates of other Yersinia species. Biotype 1A associated to several serotypes was identified in Y. enterocolitica isolates from environment (100%), animals (95.5%), foods (71.7%) and human samples (40%); bioserotype 2/O:9 was identified in isolates from foods (25.5%), and biotype 3 was associated with strains from humans (60%), animals (4.5%) and foods (2.8%). This biotype included three strains O:3 and six strains O:5. The data highlight animals and foods as the main Y. enterocolitica sources in our region.Fil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Favier, Gabriela Isabel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin
Aporphinoid alkaloids as antimicrobial agents against Yersinia enterocolitica
No full textFoodborne diseases have become a health issue worldwide, mainly due to the consumption of contaminated foods that are either raw, improperly heat treated or cross-contaminated after adequate heat treatment foods. A group of alkaloids extracted from plants were tested to evaluate their antimicrobial effect against different strains of Yersinia enterocolitica and other foodborne bacteria. The results obtained reveal that oliveridine and pachypodanthine inhibited Y. enterocolitica growth, with MIC values of 25 lmol l 1 and 100 lmol l 1 respectively. The results indicated that both alkaloids are good growth inhibitors, but oliveridine showed greater inhibitory effect with lower MIC values. Inhibitory alkaloids can be developed as potential antimicrobials in food system to prevent or treat foodborne diseases, thus contributing to solve the global issue of contaminated food consumption.Fil: Di Marco Pellegrini, Natalia Indira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Pungitore, Carlos Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentin
Evaluation of physical-sanitary conditions in butcher shops of Justo Daract, San Luis
No full textFoodborne diseases are caused by ingestion of foodstuffs contaminated by microorganisms or chemicals. They are considered a growing public health problem worldwide. Foodstuff manufacturing equipment and the surrounding environment may serve as potential reservoirs of contamination. Foodborne pathogens are the cause of acute and chronic diseases. Food contamination by microorganisms may occur at any stage in the process from food production to consumption, and may be the result of environmental contamination. Moreover, cross contamination of food with pathogens in the retail environment is an important problem that contributes to an increased risk of foodborne illness. Some pathogenic bacteria such as Listeria monocytogenes, Salmonella spp. or Escherichia coli O157:H7 have the ability to attach onto stainless and other food-contact surface materials; as consequence, foodstuff manufacture equipment and the surrounding environment may serve as potential reservoirs of contamination. The aim of this work was to establish possible risk variables for contamination of meat products depending on the physical-sanitary conditions of facilities, equipment, and the personal hygiene of workers of butcher shops in the city of Justo Daract, San Luis, Argentina. This city located at the east region of San Luis province has 10 butcher shops for a population of 13,130 inhabitants. A risk quantification using a checklist was applied at every butcher shop in the city during September-December 2019. The checklist included five groups of variables (total value, 100): 1) situation and conditions of the building (10.0), 2) equipment and tools (15.0); 3), handlers (25.0), 4) raw materials and products for sale (20.0), and 5) production flow (30.0). Risk assessment on a 1–100 scale was quantified as high-risk (1–40), moderate-risk (41–70), or low risk (71–100). Risk quantification in all butcher shops resulted in two (20.0%) moderate-risk and eight (80.0%) low-risk shops. Minimum-maximal values obtained for each group of the five variables were as follows: situation and conditions of construction, 6.0-9.0; equipment and tools, 10.5-15.0; handlers, 18.7-25.0; raw materials and products for sale, 6.6-20.0; and production flow, 15.1-30.0. Due to the results obtained, some changes are recommended: i) to implement programs of good hygienic and manufacturing practices that allow a strict and constant sanitary control to ensure food safety; and ii) to train butcher shop personnel through a Guide or Protocol of Good Handling Practices to improve the microbiological quality of the product and the hygienic-sanitary conditions of sale establishments and thus, minimize the disease risk that might represent the consumption of meat products.Fil: Lucero, Mariela Cristina. Universidad Nacional de Villa Mercedes. Escuela de Ingeniería; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaXXXIX Reunión Científica Anual de la Sociedad de Biología de CuyoArgentinaSociedades de Biología de Cuy
Evaluation of chlorine, benzalkonium chloride and lactic acid as sanitizers for reducing Escherichia coli O157:H7 and Yersinia enterocolitica on fresh vegetables
No full textThe effectiveness in the assurance of fresh vegetable microbiological quality of wash solutions containing 200 ppm free chlorine, 0.1 mg/ml benzalkonium chloride, 0.2% and 1% lactic acid was assessed on Escherichia coli O157:H7 and Yersinia enterocolitica contaminated lettuce and tomatoes. Y. enterocolitica reduction on tomatoes (5.08, 4.77 and 4.21 log after 0.2% lactic acid, 200 ppm chlorine and 0.1 mg/ml benzalkonium chloride treatments, respectively) were significantly higher than those for Y. enterocolitica on lettuce and E. coli O157:H7 on both vegetables. Antimicrobial treatment effects on bacterial counts and product quality after subsequent 7 day storage (4 C and 22 C) were determined. No pathogens were found in natural microflora of fresh vegetables.Fil: Velázquez, Lidia del Carmen. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Barbini, Norma Beatriz. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Stefanini de Guzman, Ana Maria Teresa Valentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin
Biogenic silver nanoparticles affect motility and eradicate the biofilm in yersinia enterocolitica
No full textYersinia enterocolitica is a Gram-negative cocobacillus, not sporulated, mobile at 25 °C but immobile at 37 °C. This pathogenic specie is widely distributed in nature and animals, being the pig the main reservoir of pathogenic strains for humans. Y. enterocolitica can cause numerous diseases, usually at gastrointestinal level but various complications can be manifested especially in immunocompromised people, being the cases where antibacterial therapy is needed. Biofilms are communities of microorganisms that grow irreversibly adhered to living or inert substrates, contained in a polymer matrix secreted by themselves. The most important property of the biofilm forms in clinical medicine is the enhanced resistance to antimicrobial agents. The flagellar motility is crucial initially for surface attachment and subsequently for biofilm formation in Y. enterocolitica. In addition, the fliA gene is a regulator gene necessary for the expression of flagella. The objective of this work was to determine if silver nanoparticles (AgNPs) phytosynthesized from the aqueous extract of Bothriochloa laguroides are capable of inhibiting motility modifying the expression of the fliA gene and eradicating mature biofilm of Y. enterocolitica. Two strains were used: Y. enterocolitica 8081 bio/serotype 1B/O:4 and Y. enterocolitica ME110 1A/O:5. The swimming and swarming motility was determined in a culture medium containing 0.3 and 0.6 % p/v of agar respectively, the fliA gene expression was carried out by RT-PCR and the mature biofilm eradication was determined by the crystal violet technique. The swimming and swarming motility was effectively reduced by AgNPs at 7.8 pM in the two tested strains. The decrease in swimming was 90.38 % for Y. enterocolitica 8081 and 74.27 % for Y. enterocolitica ME110, while for swarming it was 79.16 % and 89.28, respectively. Furthermore, AgNPs at 31.25 pM significantly reduce (p<0.05) the expression of the fliA gene in the two Y. enterocolitica strains. In addition, the AgNPs were able to eradicate mature biofilm at a concentration of 500 pM, with an eradication percentage of 99.33 % for Y. enterocolitica 8081 and 92.95 % for Y. enterocolitica ME110. The AgNPs were able to decrease the motility in Y. enterocolitica and to eradicate the mature biofilm, for which they could be used in the future not only to prevent the formation of biofilm but also to eradicate formed biofilms.Fil: Toranzo, Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Páez, Paulina Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaLVII SAIB Meeting; XVI SAMIGE MeetingBuenos AiresArgentinaSociedad Argentina De Investigación Bioquímica Y Biología MolecularSociedad Argentina de Microbiología Genera
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