Detection and characterization of shiga toxin producing Escherichia coli, Salmonella spp., and Yersinia strains from human, animal, and food samples in San Luis, Argentina

Shiga toxin producing Escherichia coli (STEC), Salmonella spp., and Yersinia species was investigated in humans, animals, and foods in San Luis, Argentina. A total of 453 samples were analyzed by culture and PCR. The antimicrobial susceptibility of all the strains was studied, the genomic relationships among isolates of the same species were determined by PFGE, and the potencial virulence of Y. enterocolitica strains was analyzed. Yersinia species showed higher prevalence (9/453, 2.0%, 95% CI, 0.7–3.3%) than STEC (4/453, 0.9%, 95% CI, 0–1.8%) and Salmonella spp. (3/453, 0.7%, 95% CI, 0–1.5%). Y. enterocolitica and Y. intermedia were isolated from chicken carcasses (6/80, 7.5%, 95% CI, 1.5–13.5%) and porcine skin and bones (3/10, 30%, 95% CI, 0–65%). One STEC strain was recovered from human feces (1/70, 1.4%, 95% CI, 0–4.2%) and STEC stx1/stx2 genes were detected in bovine stools (3/129, 2.3%, 95% CI, 0–5.0%). S. Typhimurium was isolated from human feces (1/70, 1.4%, 95% CI, 0–4.2%) while one S. Newport and two S. Gaminara strains were recovered from one wild boar (1/3, 33%, 95% CI, 0–99%). The knowledge of prevalence and characteristics of these enteropathogens in our region would allow public health services to take adequate preventive measures.Fil: 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: 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; ArgentinaFil: Cortiñas, Teresa I. . Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; Argentin

The trypanocidal activity of the alkaloid oliverine involves inhibition of DNA synthesis

The Trypanosoma cruzi parasite is an etiologic agent of the American trypanosomiasis called Chagas disease. This pathology affects more than 24 million persons and represents one of the most important public health problems in Latin America. Taking into account this, it is necessary the search of new antitrypanosomal agents that show a major level of efficacy and minor indexes of toxicity in affected patients. Vast source of them are the natural products from plants with enormous structural diversity. A particular type of these compounds is represented by aporphinoid alkaloids. In our experiments, anonaine (2), oliverine (3) and guatterine (5) displayed antitrypanosomal activity. The compound 3 showed the most important activity with an IC50 = 12.00 ± 0.36 μM. Its mechanism of action may include inhibition of DNA synthesis.Fil: Garro, Hugo Alejandro. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Juri Ayub, Maximiliano. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Fundación Instituto Leloir; ArgentinaFil: Nieto, M.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; ArgentinaFil: Pungitore, Carlos Rodolfo. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Tonn, Carlos Eugenio. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; Argentin

Detection and survival of Yersinia enterocolitica in goat cheese produced in San Luis, Argentina

Detection limits and the survival of Yersinia enterocolitica in goat cheese were determined by culture and by nested polymerase chain reaction (PCR). Thirty goat cheese samples inoculated with 104 to 101 cfu/g Y. enterocolitica O:9 or O:3 strains were enriched for 0, 3 and 18h in trypticase soy broth (TSB), modified Rappaport broth and a formulated in our laboratory broth (FLB). The lowest detection limits were 1×103cfu/g by culture on Mac Conkey agar after 3h TSB and FLB enrichments, and 1×102cfu/g by nested PCR at 3h from all enrichment broths. Y. enterocolitica survival was studied in 20 goat cheese samples contaminated at levels of 1×106cfu/g and stored at 4° and 22C for 120 days. Y. enterocolitica was detected during 7 and 30 days at 22C and 4C, respectively. Total and fecal coliforms were recovered from microflora of goat cheese, but indigenous Y. enterocolitica was not detected.Fil: Lazarte Otero, Valeria Sabrina. 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: 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: Favier, Gabriela Isabel. 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. 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: Stefanini de Guzman, Ana Maria Teresa Valentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin

Depletion of Dendritic Cells Enhances Innate Anti-Bacterial Host Defense through Modulation of Phagocyte Homeostasis

Dendritic cells (DCs) as professional antigen-presenting cells play an important role in the initiation and modulation of the adaptive immune response. However, their role in the innate immune response against bacterial infections is not completely defined. Here we have analyzed the role of DCs and their impact on the innate anti-bacterial host defense in an experimental infection model of Yersinia enterocolitica (Ye). We used CD11c-diphtheria toxin (DT) mice to deplete DCs prior to severe infection with Ye. DC depletion significantly increased animal survival after Ye infection. The bacterial load in the spleen of DC-depleted mice was significantly lower than that of control mice throughout the infection. DC depletion was accompanied by an increase in the serum levels of CXCL1, G-CSF, IL-1α, and CCL2 and an increase in the numbers of splenic phagocytes. Functionally, splenocytes from DC-depleted mice exhibited an increased bacterial killing capacity compared to splenocytes from control mice. Cellular studies further showed that this was due to an increased production of reactive oxygen species (ROS) by neutrophils. Adoptive transfer of neutrophils from DC-depleted mice into control mice prior to Ye infection reduced the bacterial load to the level of Ye-infected DC-depleted mice, suggesting that the increased number of phagocytes with additional ROS production account for the decreased bacterial load. Furthermore, after incubation with serum from DC-depleted mice splenocytes from control mice increased their bacterial killing capacity, most likely due to enhanced ROS production by neutrophils, indicating that serum factors from DC-depleted mice account for this effect. In summary, we could show that DC depletion triggers phagocyte accumulation in the spleen and enhances their anti-bacterial killing capacity upon bacterial infection

Evaluation of physical-sanitary conditions in butcher shops of Justo Daract, San Luis

Foodborne 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

Biogenic silver nanoparticles affect motility and eradicate the biofilm in yersinia enterocolitica

Yersinia 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

An overview of Yersinia enterocolitica and related species in samples of different origin from San Luis, Argentina

This 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 inhibit biofilm formation of Yersinia enterocolitica isolated from sausages

Aims of the study: The ability of Yersinia enterocolitica strains to form biofilms and the capacity of different alkaloids to inhibit biofilm formation were investigated. Methods and Results: The capacity to form biofilm on polystyrene of 31 Y. enterocolitica strains was evaluated. Biofilm and quorum sensing (QS) inhibition of 17 alkaloids were assayed; furthermore, minimum biofilm inhibitory concentration (MBIC) was determined. The capacity to form biofilms among the examined strains seemed to be a strain-related feature. The best biofilm inhibitors at 100 µmol l−1 were oliverine (1), guatterine (3), liriodenine (4), oliveridine (5) and pachypodanthine (6), which showed biofilm inhibition higher than 87%. Pachypodanthine (6) was the most effective compound with MBIC value of 12·5 µmol l−1 at subinhibitory concentration and also was able to inhibit QS system and reduce yenR expression at this concentration. Conclusion: This is the first study to demonstrate that oliverine, liriodenine, and pachypodanthine are able to inhibit biofilm formation of Y. enterocolitica without critically disturbing its growing capacity. At MBIC, pachypodanthine inhibited biofilm formation and QS. Significance and Impact of the Study: The use of aporphinoid alkaloids as biofilms inhibitory agents might potentially be useful to treat biofilm-associated infections in the future.Fil: Di Marco Pellegrini, Natalia Indira. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Área de Química Orgánica; Argentina. 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: 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; 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; Argentin

Aporphinoid alkaloids as antimicrobial agents against Yersinia enterocolitica

Foodborne 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

Effects of organic acids, nisin, lyzozyme and edta on the survival of Yersinia enterocolitica population in inoculated orange beverages

Inactivation 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