Revista Argentina de microbiologia最新文献

{"title":"Comparison of two MALDI-TOF MS systems for the identification of clinically relevant anaerobic bacteria in Argentina","authors":"Mirta Litterio ,&nbsp;Liliana Castello ,&nbsp;María Elena Venuta ,&nbsp;Sofía Abel ,&nbsp;Liliana Fernández-Canigia ,&nbsp;María Cristina Legaria ,&nbsp;Raquel Rollet ,&nbsp;Daniela Vaustat ,&nbsp;Natalia Azula ,&nbsp;Bárbara Fox ,&nbsp;Silvina Otero ,&nbsp;María Laura Maldonado ,&nbsp;Natalia Alejandra Mangieri ,&nbsp;María Adelaida Rossetti ,&nbsp;Silvia Carla Predari ,&nbsp;Daniela Cejas ,&nbsp;Claudia Barberis","doi":"10.1016/j.ram.2023.12.001","DOIUrl":"10.1016/j.ram.2023.12.001","url":null,"abstract":"<div><p>The aim of this study was to compare the performance of two MALDI-TOF MS systems in the identification of clinically relevant strict anaerobic bacteria. The 16S rRNA gene sequencing was the gold standard method when discrepancies or inconsistencies were observed between platforms. A total of 333 isolates were recovered from clinical samples of different centers in Buenos Aires City between 2016 and 2021. The isolates were identified in duplicate using two MALDI-TOF MS systems, BD Bruker Biotyper (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMèrieux, Marcy-l’Etoile, France). Using the Vitek MS system, the identification of anaerobic isolates yielded the following percentages: 65.5% (n: 218) at the species or species–complex level, 71.2% (n: 237) at the genus level, 29.4% (n: 98) with no identification and 5.1% (n: 17) with misidentification. Using the Bruker Biotyper system, the identification rates were as follows: 85.3% (n: 284) at the species or species–complex level, 89.7% (n: 299) at the genus level, 14.1% (n: 47) with no identification and 0.6% (n: 2) with misidentification. Differences in the performance of both methods were statistically significant (<em>p</em>-values &lt;0.0001). In conclusion, MALDI-TOF MS systems speed up microbial identification and are particularly effective for slow-growing microorganisms, such as anaerobic bacteria, which are difficult to identify by traditional methods. In this study, the Bruker system showed greater accuracy than the Vitek system. In order to be truly effective, it is essential to update the databases of both systems by increasing the number of each main spectrum profile within the platforms.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 33-61"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754124000014/pdfft?md5=45b1a1e5771b1bc7a5e801f40875798a&pid=1-s2.0-S0325754124000014-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139898192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute viral hepatitis: What we do know and still do not know about hepatitis A and E in Argentina","authors":"Maria Laura Minassian","doi":"10.1016/j.ram.2024.03.001","DOIUrl":"https://doi.org/10.1016/j.ram.2024.03.001","url":null,"abstract":"","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 1-3"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754124000257/pdfft?md5=b4f4c1a7f2244d7fd789e7dc7e48cfa7&pid=1-s2.0-S0325754124000257-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140141685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential diagnosis of human Entamoeba infections: Morphological and molecular characterization of new isolates in Argentina","authors":"Andrea Servián,&nbsp;María Lorena Zonta,&nbsp;Graciela T. Navone","doi":"10.1016/j.ram.2023.05.003","DOIUrl":"10.1016/j.ram.2023.05.003","url":null,"abstract":"<div><p><em>Entamoeba</em> infections occur worldwide, with higher frequency in countries of low socioeconomic status and poor public health. Since <em>Entamoeba histolytica</em> has long been recognized as the only pathogenic species, making a differential diagnosis of other morphologically identical <em>Entamoeba</em> is important. This study aimed to determine the prevalence of <em>Entamoeba</em> species in two populations from Argentina, make a differential diagnosis by PCR and characterize <em>Entamoeba</em> isolates at the SSU rRNA gene. A total of 493 serial fecal samples were obtained from individuals in the provinces of Buenos Aires (n<!--> <!-->=<!--> <!-->210) and Misiones (n<!--> <!-->=<!--> <!-->283). Samples were examined by conventional methods (formalin–ethyl acetate and Willis flotation) and specific PCRs to differentiate <em>Entamoeba</em> species. <em>Entamoeba</em> isolates were characterized by sequencing a fragment of the SSU rRNA gene. The overall prevalence of <em>Entamoeba</em> infection was 12.4%, being more prevalent in Buenos Aires than in Misiones (14.8% vs. 10.6%). A case of <em>E. histolytica</em> confirmed by PCR and sequence analysis was reported for the first time in Buenos Aires. Moreover, new genetic data on <em>Entamoeba coli</em> and <em>Entamoeba dispar</em> were recorded. The phylogenetic analysis revealed a congruence between morphological characteristics and SSU rRNA gene sequences. This study increases the amount of information on the distribution of these species in Argentina and the region of the Americas.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 16-24"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000494/pdfft?md5=dc09ae222767376b944da776d9391c63&pid=1-s2.0-S0325754123000494-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9812039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction in the incidence of invasive infections caused by encapsulated bacteria after the onset of the COVID-19 pandemic","authors":"Leda Guzzi ,&nbsp;Juan Manuel Sambade ,&nbsp;Martin Diego Christin ,&nbsp;Federico Rodriguez Cairoli ,&nbsp;Alejandra Rodriguez ,&nbsp;Silvia Vicario ,&nbsp;Miriam Hinojosa Del Carpio ,&nbsp;Juan Molinos ,&nbsp;Pablo Dimitroff","doi":"10.1016/j.ram.2023.06.003","DOIUrl":"10.1016/j.ram.2023.06.003","url":null,"abstract":"<div><p>Interaction between severe acute respiratory coronavirus 2 (SARS-CoV-2) and IIEB remains under investigation. Objective: to compare IIEB incidence before and during COVID-19 pandemic, and assess incidence of coinfection with COVID-19 and case fatality. A cross-sectional study was performed on data from a centralized microbiology laboratory serving a network of healthcare centers comprising 713 pediatric and adult inpatient beds, expanded by 20% during the pandemic. Three periods were evaluated: (1) pre-pandemic: March 1, 2019–February 29, 2020; (2) pandemic year 1: March 1, 2020–February 28, 2021; (3) pandemic year 2: March 1, 2021–July 31, 2021. Descriptive statistical analysis was performed. 56 502 samples (96% blood cultures) from 27<!--> <!-->224 patients were analyzed. Of these, 54 samples (from 54 patients) were positive for encapsulated bacteria. IIEB incidence was: 167.4, 32.6, and 50.4 per 100<!--> <!-->000 samples for periods 1, 2, and 3, respectively. Twelve IIEB episodes occurred during the pandemic period: 10 <em>Streptococcus pneumoniae</em>, and 2 <em>Haemophilus influenzae</em>, of which 7 were SARS-CoV-2/<em>S. pneumoniae</em> coinfections, with an incidence of 5.68 per 10<!--> <!-->000 COVID-19-related hospitalizations (0.056%). IIEB case fatality was 31%, 29%, and 60% for each period, respectively, 3/7 patients with coinfection died (43%). Case fatality for invasive pneumococcal disease (IPD) in patients without COVID-19, was 32.5%. Significant reduction in IIEB incidence was observed during the pandemic, coinciding with implementation of containment measures. The incidence of SARS-CoV-2/<em>S. pneumoniae</em> coinfection was low, with higher case fatality than IPD patients without COVID-19.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 62-68"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000548/pdfft?md5=a1ef15702a02c0cb98c609084862a029&pid=1-s2.0-S0325754123000548-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9888224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of Demodex spp. in patients with chronic blepharitis","authors":"Viviana Flores ,&nbsp;Marina Ruf ,&nbsp;Silvia Paola Abad Farfan ,&nbsp;Andrea Vanessa Suárez Echávez ,&nbsp;Dolores Pilar Bastard ,&nbsp;Maria Celeste Puga ,&nbsp;Luis Daniel Mazzuoccolo","doi":"10.1016/j.ram.2023.05.005","DOIUrl":"10.1016/j.ram.2023.05.005","url":null,"abstract":"<div><p>Blepharitis is a very common disease in ophthalmology, dermatology and allergy practice. It generally follows a chronic course and is frequently associated with objective and/or subjective symptoms such as epiphora, red eye, dandruff, gritty sensation, itching, burning, photophobia, and blurred vision. The purpose of this study is to analyze the prevalence of <em>Demodex</em> spp. in patients with symptoms of chronic blepharitis. An analytical cross-sectional study was conducted in the period between 2016 and 2020. All patients with symptoms of chronic blepharitis who underwent a parasitological test of eyelashes (Rapitest) in the Dermatology Department of the <em>Hospital Italiano de Buenos Aires</em> were included. Those with previously established blepharitis due to another infectious cause were excluded. We analyzed 972 patients. Sixty percent (n<!--> <!-->=<!--> <!-->585) underwent a positive Rapitest for the presence of <em>Demodex</em> spp. Seventy five percent (n<!--> <!-->=<!--> <!-->728) were women. There were no significant differences in the prevalence associated with sex (<em>p</em> <!-->=<!--> <!-->0.38). Among the patients positive for <em>Demodex</em> spp., 65% (n<!--> <!-->=<!--> <!-->628) were older than 60 years old. The most frequently associated symptom was itching, present in 35% (n<!--> <!-->=<!--> <!-->342). A statistically significant decrease in the number of consultations was observed during the cold months of the year (May–June–July–August). Our results show a high prevalence of <em>Demodex</em> spp. in patients with chronic blepharitis. As its presence reveals a direct association with age, we recommend looking for this parasite in this age group.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 74-78"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S032575412300055X/pdfft?md5=9580a5c6d93a63f3525313c2f6843ac5&pid=1-s2.0-S032575412300055X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9940067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of plasma anti-lipopolysaccharide (LPS) antibodies against enterohemorrhagic Escherichia coli (EHEC) in asymptomatic kindergarten teachers from Buenos Aires province","authors":"Romina J. Fernandez-Brando ,&nbsp;Flavia Sacerdoti ,&nbsp;María M. Amaral ,&nbsp;Alan M. Bernal ,&nbsp;Marcelo Da Rocha ,&nbsp;Marcela Belardo ,&nbsp;Marina S. Palermo ,&nbsp;Cristina A. Ibarra","doi":"10.1016/j.ram.2023.05.006","DOIUrl":"10.1016/j.ram.2023.05.006","url":null,"abstract":"<div><p>In Argentina, hemolytic uremic syndrome (HUS) caused by EHEC has the highest incidence in the world. EHEC infection has an endemo-epidemic behavior, causing 20–30% of acute bloody diarrhea syndrome in children under 5 years old. In the period 2016–2020, 272 new cases per year were notified to the National Health Surveillance System. Multiple factors are responsible for HUS incidence in Argentina including person-to-person transmission. In order to detect possible EHEC carriers, we carried out a preliminary study of the frequency of kindergarten teachers with anti-LPS antibodies against the most prevalent EHEC serotypes in Argentina. We analyzed 61 kindergarten teachers from 26 institutions from José C. Paz district, located in the suburban area of Buenos Aires province, Argentina. Fifty-one percent of the plasma samples had antibodies against O157, O145, O121 and O103 LPS: 6.4% of the positive samples had IgM isotype (n<!--> <!-->=<!--> <!-->2), 61.3% IgG isotype (n<!--> <!-->=<!--> <!-->19) and 32.3% IgM and IgG (n<!--> <!-->=<!--> <!-->10). Given that antibodies against LPS antigens are usually short-lived specific IgM detection may indicate a recent infection. In addition, the high percentage of positive samples may indicate a frequent exposure to EHEC strains in the cohort studied, as well as the existence of a large non-symptomatic population of adults carrying pathogenic strains that could contribute to the endemic behavior through person-to-person transmission. The improvement of continuous educational programs in kindergarten institutions could be a mandatory measure to reduce HUS cases not only in Argentina but also globally.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 25-32"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000561/pdfft?md5=d85b90f8e9aa64cd342e2669c9a1f6a0&pid=1-s2.0-S0325754123000561-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10229462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Caracterización molecular de Escherichia coli diarreogénica proveniente de población pediátrica ambulatoria con diarrea, atendida en dos hospitales de Buenos Aires, Argentina","authors":"Nora Beatriz Molina ,&nbsp;Sebastián Oderiz ,&nbsp;Marisa Ana López ,&nbsp;Juan Ángel Basualdo ,&nbsp;Mónica Delfina Sparo","doi":"10.1016/j.ram.2023.06.002","DOIUrl":"10.1016/j.ram.2023.06.002","url":null,"abstract":"<div><p>Diarrheagenic <em>Escherichia coli</em> comprises a heterogeneous group of pathotypes or pathogenic variants that share phenotypic characteristics with marked differences in virulence genes, colonization sites, pathogenesis, clinical presentation, and epidemiology of infection. The most studied pathotypes are Shiga toxin-producing <em>E.</em> <em>coli</em> (STEC), enterotoxigenic <em>E.</em> <em>coli</em> (ETEC), enteropathogenic <em>E.</em> <em>coli</em> (EPEC), enteroaggregative <em>E.</em> <em>coli</em> (EAEC), and enteroinvasive <em>E.</em> <em>coli</em> (EIEC). The objective of the study was to characterize the isolates of diarrheagenic <em>E.</em> <em>coli</em> from an outpatient pediatric population with diarrhea attended in two public hospitals from Buenos Aires, Argentina. Diarrheagenic <em>E.</em> <em>coli</em> pathotypes were investigated by amplifying characteristic virulence gene fragments: intimin (<em>eae</em>), heat-labile toxin (<em>lt</em>), heat-stable toxins (<em>stp</em>, <em>sth</em>), invasion plasmid antigen H (<em>ipaH</em>), transcriptional activator R (<em>aggR</em>) and Shiga toxins (<em>stx1</em>, <em>stx2</em>). Molecular subtyping of isolates was performed using PFGE (XbaI). Diarrheagenic <em>E.</em> <em>coli</em> was detected in 14% (84/601) of cases. The EAEC pathotype was prevalent, while ETEC, STEC, EPEC and EIEC were found in a lower proportion. EAEC isolates exhibited a high degree of genetic diversity. All pathotypes were found in children under 5<!--> <!-->years of age, while only EAEC, EIEC and ETEC were detected in the older population. Future studies that include the characterization of isolates from a greater number of genes and populations from other geographical areas will be necessary to determine the relevance of diarrheagenic <em>E.</em> <em>coli</em> in Argentina.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 8-15"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000536/pdfft?md5=78f54a484a5c420995c5c6ecfb040477&pid=1-s2.0-S0325754123000536-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9886098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feline sporotrichosis due to Sporothrix globosa in the Metropolitan region of Buenos Aires: A case study","authors":"Alejandro N. Etchecopaz ,&nbsp;Katherine Hermida Alava ,&nbsp;Miguel Scarpa ,&nbsp;Adriana Duchene ,&nbsp;Diego García Re ,&nbsp;María Luján Cuestas","doi":"10.1016/j.ram.2023.07.001","DOIUrl":"10.1016/j.ram.2023.07.001","url":null,"abstract":"<div><p>We describe here the first case of feline sporotrichosis caused by <em>Sporothrix globosa</em>, occurring outside the epizootic area of Buenos Aires province, Argentina. Unlike cases reported with <em>Sporothrix brasiliensis</em>, on this occasion there was no clinical or serological evidence of zoonotic transmission through scratches or bites from the sick cat to the attending veterinarian or the person responsible for its care. This report aimed to improve the knowledge about the pathogenic profile of <em>S. globosa</em>.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 4-7"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000573/pdfft?md5=42b8b97cc09797198665ea00ece37acc&pid=1-s2.0-S0325754123000573-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10406304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth, tolerance, and enzyme activities of Trichoderma strains in culture media added with a pyrethroids-based insecticide","authors":"Caliope Mendarte-Alquisira,&nbsp;Alejandro Alarcón,&nbsp;Ronald Ferrera-Cerrato","doi":"10.1016/j.ram.2023.06.004","DOIUrl":"10.1016/j.ram.2023.06.004","url":null,"abstract":"<div><p>The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as <em>Trichoderma</em>, which contribute to the biocontrol of several fungal phytopathogens. This research evaluated the tolerance of several strains of <em>Trichoderma</em> to a selected culture medium contaminated with a commercial insecticide (H24®) composed of pyrethroids, permethrin and prallethrin, and carbamate propoxur, and determined the influence of this insecticide on the release of enzymes such as chitinases, peroxidases, and endoglucanases by a consortium of selected <em>Trichoderma</em> strains grown in liquid culture medium. Four out of 10 <em>Trichoderma</em> strains showed tolerance to 200<!--> <!-->ppm (∼48.3% of growth) of the commercial insecticide after 96<!--> <!-->h of exposure to a contaminated solid medium. After eight days of growth in liquid culture, the insecticide enhanced extracellular protein content and peroxidase activities in the <em>Trichoderma</em> consortium but decreased both chitinase and glucanase activities. These fungal responses should be considered when implementing strategies that combine alternative pesticides and fungal biocontrollers for managing fungal phytopathogens.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 79-89"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000597/pdfft?md5=4feb8875011e336f3a3fbce993f62818&pid=1-s2.0-S0325754123000597-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10466689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macroencapsulation of Limosilactobacillus reuteri DSPV002C as nutritional supplement for piglets: Storage stability and survival in gastrointestinal conditions","authors":"Jorge Alberto Zimmermann ,&nbsp;Noelí Sirini ,&nbsp;Carolina Raquel Olivero ,&nbsp;María Sol Renna ,&nbsp;Marcelo Lisandro Signorini ,&nbsp;María Virginia Zbrun ,&nbsp;Laureano Sebastián Frizzo ,&nbsp;Lorena Paola Soto","doi":"10.1016/j.ram.2023.07.005","DOIUrl":"10.1016/j.ram.2023.07.005","url":null,"abstract":"<div><p>The aim of this study was to evaluate the protective effect of the encapsulation of <em>Limosilactobacillus reuteri</em> DSPV002C in macrocapsules made from industrial materials during production, storage and under simulated gastrointestinal conditions <em>in vitro</em> and <em>in vivo</em>. The production of macrocapsules involved the evaluation of different wall materials (matrix), namely, gelatin and pregelatinized starch, different inoculums, matrix ratios, and diverse cryoprotectants (whey permeate and maltodextrin). The different macrocapsules were arranged in molds of similar size to pig pelleted food and lyophilized. Then, the viability of the macrocapsules was assessed over time during storage at different temperatures (freezing, refrigeration and room temperature) and atmospheres (vacuum and non-vaccum). The macrocapsules with 10% w/v gelatin<!--> <!-->+<!--> <!-->5% w/v pregelatinized starch, permeated (10%, w/v), with a 9:1 inoculum:matrix ratio (GS7.5P9), stored under freezing conditions and vacuum, exhibited the highest viability of <em>L. reuteri</em> DSPV002C (9.3 log CFU/cap until 210 d). Under simulated gastrointestinal conditions, the encapsulated inoculum showed less viability loss (0.58<!--> <!-->±<!--> <!-->0.09 log CFU/ml, 26.53%), compared to the free culture (1.56<!--> <!-->±<!--> <!-->0.16 log CFU/ml, 2.85%). Finally, by administering GS7.5P9 to pigs, the tolerance of the bacteria to the gastrointestinal environment was verified, with viable counts equal to or greater than 3.72 log CFU/g of fecal matter throughout the trial. In this study, a high-density carrier probiotic macrocapsule of <em>L. reuteri</em> DSPV002C was obtained, which displayed a long shelf life, a suitable shape to be included in pig feed and an adequate survival of viable cells at the site of action.</p></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"56 1","pages":"Pages 90-101"},"PeriodicalIF":1.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0325754123000822/pdfft?md5=c6ecab413d42605d383ba4cb98193446&pid=1-s2.0-S0325754123000822-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71485530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}