Pub Date : 2025-10-07DOI: 10.1016/j.ram.2025.09.001
Patricia Olga Andres, Elizabeth Madsen, Analía Laura Fernández
Tuberculosis in solid organ transplant (SOT) recipients is a clinical challenge. This opportunistic infection has atypical presentations and raises concerns due to both the toxicity of antifimic drugs and their interaction with immunosuppressive therapy that may result in graft loss or death. This retrospective review of cases of active tuberculosis after SOT describes the management of this infection in a hospital in Argentina. Between January 2006 and June 2022, 27 transplanted patients had positive cultures for the Mycobacterium tuberculosis complex. Their median age was 56 years; 78% were male. Ten (37%) patients had extra-pulmonary or disseminated tuberculosis. Twenty-five (93%) patients required invasive procedures to reach a diagnosis. In 17 (63%) patients, the initial diagnosis was based on a positive Ziehl-Neelsen smear. Twenty-four patients received a four-drug induction treatment without rifampin. Clinical cure was 80% and crude mortality was 20%.
{"title":"Tuberculosis after solid organ transplantation: Clinical experience in a tertiary hospital from Argentina.","authors":"Patricia Olga Andres, Elizabeth Madsen, Analía Laura Fernández","doi":"10.1016/j.ram.2025.09.001","DOIUrl":"https://doi.org/10.1016/j.ram.2025.09.001","url":null,"abstract":"<p><p>Tuberculosis in solid organ transplant (SOT) recipients is a clinical challenge. This opportunistic infection has atypical presentations and raises concerns due to both the toxicity of antifimic drugs and their interaction with immunosuppressive therapy that may result in graft loss or death. This retrospective review of cases of active tuberculosis after SOT describes the management of this infection in a hospital in Argentina. Between January 2006 and June 2022, 27 transplanted patients had positive cultures for the Mycobacterium tuberculosis complex. Their median age was 56 years; 78% were male. Ten (37%) patients had extra-pulmonary or disseminated tuberculosis. Twenty-five (93%) patients required invasive procedures to reach a diagnosis. In 17 (63%) patients, the initial diagnosis was based on a positive Ziehl-Neelsen smear. Twenty-four patients received a four-drug induction treatment without rifampin. Clinical cure was 80% and crude mortality was 20%.</p>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145252491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-06DOI: 10.1016/j.ram.2025.08.001
Melisa G Fossaroli, Mariana Biscia, Melisa V Spadaro, Lilian M Anthony, Paula S Tugores, Javier E Sarradell
Aujeszky's disease virus infects pigs and causes latency in the absence of clinical signs, making its diagnosis very difficult. Due to the huge economic losses related to this disease, the Argentinian government has created and implemented a control and eradication plan to manage it. As part of the monitoring plan to assess the progress of the control and eradication plan for a positive status farm, oral fluid samples were obtained from animals at 40, 70, 90,120 and 130-160days of age, after one year of vaccination with a deleted and inactivated vaccine. These samples were processed using an antigen-PCR technique and positive results were obtained from 130-160day-old animals. Recovering DNA from Aujeszky's disease virus in oral fluids from field samples could enable the use of this technique for epidemiological surveillance in Aujeszkýs control and eradication programs.
{"title":"[Oral fluid PCR monitoring for Aujeszky's disease virus detection in a swine farm].","authors":"Melisa G Fossaroli, Mariana Biscia, Melisa V Spadaro, Lilian M Anthony, Paula S Tugores, Javier E Sarradell","doi":"10.1016/j.ram.2025.08.001","DOIUrl":"https://doi.org/10.1016/j.ram.2025.08.001","url":null,"abstract":"<p><p>Aujeszky's disease virus infects pigs and causes latency in the absence of clinical signs, making its diagnosis very difficult. Due to the huge economic losses related to this disease, the Argentinian government has created and implemented a control and eradication plan to manage it. As part of the monitoring plan to assess the progress of the control and eradication plan for a positive status farm, oral fluid samples were obtained from animals at 40, 70, 90,120 and 130-160days of age, after one year of vaccination with a deleted and inactivated vaccine. These samples were processed using an antigen-PCR technique and positive results were obtained from 130-160day-old animals. Recovering DNA from Aujeszky's disease virus in oral fluids from field samples could enable the use of this technique for epidemiological surveillance in Aujeszkýs control and eradication programs.</p>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2025.05.001
Elisa Crespi , Bárbara Ghiglione , Ximena Blanco Crivelli , Cecilia Cundon , Roque Figueroa Espinosa , Pedro Penzotti , Ezequiel Nuske , Alicia Broglio , Luis Ambros , María Valeria Rumi , Gabriela Albarellos , José Di Conza , Adriana Bentancor
Escherichia coli contamination in minced meat poses a significant public health concern and may serve as a reservoir for antimicrobial-resistant strains. This study investigated the presence of E. coli resistant to ciprofloxacin and/or gentamicin in minced meat samples from Tierra del Fuego, Argentina. Resistant E. coli isolates were identified using MALDI-TOF. A total of 109 samples were analyzed, yielding 97 E. coli isolates (23 from AMC-CIP and 74 from AMC-GEN). Twenty-three isolates carried the ant(2″) gene, ten the ant(3″) gene, and one the blaCTX-M gene. Resistance was observed to gentamicin (6/25), streptomycin (1/25), ceftazidime (1/25), and cefotaxime (4/25). Eleven isolates carried the aggR gene, and another three were identified as biofilm producers. Although phenotypic resistance was low, we detected genetic potential for resistance which, combined with biofilm formation, represents a risk to food safety.
{"title":"Analysis of Escherichia coli isolated from minced meat: Implications for public health in Tierra del Fuego, Argentina","authors":"Elisa Crespi , Bárbara Ghiglione , Ximena Blanco Crivelli , Cecilia Cundon , Roque Figueroa Espinosa , Pedro Penzotti , Ezequiel Nuske , Alicia Broglio , Luis Ambros , María Valeria Rumi , Gabriela Albarellos , José Di Conza , Adriana Bentancor","doi":"10.1016/j.ram.2025.05.001","DOIUrl":"10.1016/j.ram.2025.05.001","url":null,"abstract":"<div><div><em>Escherichia coli</em> contamination in minced meat poses a significant public health concern and may serve as a reservoir for antimicrobial-resistant strains. This study investigated the presence of <em>E. coli</em> resistant to ciprofloxacin and/or gentamicin in minced meat samples from Tierra del Fuego, Argentina. Resistant <em>E. coli</em> isolates were identified using MALDI-TOF. A total of 109 samples were analyzed, yielding 97 <em>E. coli</em> isolates (23 from AMC-CIP and 74 from AMC-GEN). Twenty-three isolates carried the ant(2″) gene, ten the ant(3″) gene, and one the blaCTX-M gene. Resistance was observed to gentamicin (6/25), streptomycin (1/25), ceftazidime (1/25), and cefotaxime (4/25). Eleven isolates carried the aggR gene, and another three were identified as biofilm producers. Although phenotypic resistance was low, we detected genetic potential for resistance which, combined with biofilm formation, represents a risk to food safety.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 399-407"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2024.08.002
María Carolina Artuso , Vanina Daniela Marchione , Estefanía Benedetti , Paula Bonastre , Ana María Alvarez , Luana Piccini , Angeles Ponde , Evelyn Barrios Benito , Marcos Fabeiro , Karen Waisman , Luciano Coppola , Tomás Poklepovich , Ariana Chamorro , Martín Avaro , Diego Ariel Riva , Andrea Pontoriero , María Eugenia Ferrer , Andrea Marcos , Lorena Dassa , Daniel Caria , Ana María Nicola
In 2021, avian influenza A (H5N1) clade 2.3.4.4b virus spread to North America and then to Central and South America in October 2022, extending from Colombia to Chile in three months. During 2023, several countries, mostly in the Americas, reported outbreaks in poultry, wild birds and mammals, as well as the emergence of two cases in humans (one in Ecuador in January and one in Chile in March). As of September 20th, 2023, 17 countries in the Americas Region have recorded cases of A (H5N1) in birds and mammals. On February 14th, 2023, Argentina confirmed the first case of avian influenza in wild birds, which was later detected in backyard and commercial poultry, and in the South-American sea lion (Otaria flavescens) in Tierra del Fuego, in the south of the country. So far, 21 suspected cases have been recorded in humans; however, all of them tested negative for Influenza A virus. Hemagglutinin sequence data of animal viruses analyzed in this report showed that Argentinian viruses clustered together with those isolated in other countries of the region. Epidemiological data suggested the possibility of multiple simultaneous entries of the avian virus, highlighting the role of migratory avian populations in the introduction and dissemination of the disease in Argentina. Continued comprehensive surveillance of these viruses in animals and people worldwide, along with ongoing preparedness efforts, are critical to determine the public health risk.
{"title":"Detection and characterization of highly pathogenic avian influenza A (H5N1) clade 2.3.4.4b virus circulating in Argentina in 2023","authors":"María Carolina Artuso , Vanina Daniela Marchione , Estefanía Benedetti , Paula Bonastre , Ana María Alvarez , Luana Piccini , Angeles Ponde , Evelyn Barrios Benito , Marcos Fabeiro , Karen Waisman , Luciano Coppola , Tomás Poklepovich , Ariana Chamorro , Martín Avaro , Diego Ariel Riva , Andrea Pontoriero , María Eugenia Ferrer , Andrea Marcos , Lorena Dassa , Daniel Caria , Ana María Nicola","doi":"10.1016/j.ram.2024.08.002","DOIUrl":"10.1016/j.ram.2024.08.002","url":null,"abstract":"<div><div>In 2021, avian influenza A (H5N1) clade 2.3.4.4b virus spread to North America and then to Central and South America in October 2022, extending from Colombia to Chile in three months. During 2023, several countries, mostly in the Americas, reported outbreaks in poultry, wild birds and mammals, as well as the emergence of two cases in humans (one in Ecuador in January and one in Chile in March). As of September 20th, 2023, 17 countries in the Americas Region have recorded cases of A (H5N1) in birds and mammals. On February 14th, 2023, Argentina confirmed the first case of avian influenza in wild birds, which was later detected in backyard and commercial poultry, and in the South-American sea lion (<em>Otaria flavescens</em>) in Tierra del Fuego, in the south of the country. So far, 21 suspected cases have been recorded in humans; however, all of them tested negative for Influenza A virus. Hemagglutinin sequence data of animal viruses analyzed in this report showed that Argentinian viruses clustered together with those isolated in other countries of the region. Epidemiological data suggested the possibility of multiple simultaneous entries of the avian virus, highlighting the role of migratory avian populations in the introduction and dissemination of the disease in Argentina. Continued comprehensive surveillance of these viruses in animals and people worldwide, along with ongoing preparedness efforts, are critical to determine the public health risk.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 327-335"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142627160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2024.12.005
Néstor D. Portela , Cristian Mena , Mauricio G. Martín , Verónica L. Burstein , Laura S. Chiapello , Susana A. Pesoa
Understanding the gut mycobiota composition and its impact on health requires reliable methods for fungal community assessment. This study explores the influence of DNA extraction methods in GM analysis. Three protocols were evaluated: Qiagen DNeasy blood and tissue kit with mechanical glass bead lysis (DNgb), Thermofisher MagMax Microbiome ultra-nucleic isolation kit automated method (MM), and MM combined with glass beads lysis (MMgb). Fecal samples from healthy volunteers were collected, DNA extracted and ITS2 amplicon library preparation and sequencing performed. Results showed that DNA yields did not significantly differ among methods and the addition of glass bead beating favored the recovery of DNA more appropriate for fungal analysis. Beta diversity revealed distinct clusters, with MMgb showing the most pronounced variation in mycobiota composition, exposing particularly the low abundance taxa. LEfSe analysis identified significant differences in the abundance of fungal species among the extraction methods. Samples extracted with bead beating were enriched in filamentous species, while those without this step showed higher relative abundance of yeast fungi. This study underscores the importance of selecting appropriate DNA extraction methods for accurate characterization of the gut mycobiota, emphasizing the need for standardized methodologies to ensure reproducibility and reliability in microbial data acquisition.
{"title":"Effect of DNA extraction method in gut fungal community assessment","authors":"Néstor D. Portela , Cristian Mena , Mauricio G. Martín , Verónica L. Burstein , Laura S. Chiapello , Susana A. Pesoa","doi":"10.1016/j.ram.2024.12.005","DOIUrl":"10.1016/j.ram.2024.12.005","url":null,"abstract":"<div><div>Understanding the gut mycobiota composition and its impact on health requires reliable methods for fungal community assessment. This study explores the influence of DNA extraction methods in GM analysis. Three protocols were evaluated: Qiagen DNeasy blood and tissue kit with mechanical glass bead lysis (DNgb), Thermofisher MagMax Microbiome ultra-nucleic isolation kit automated method (MM), and MM combined with glass beads lysis (MMgb). Fecal samples from healthy volunteers were collected, DNA extracted and ITS2 amplicon library preparation and sequencing performed. Results showed that DNA yields did not significantly differ among methods and the addition of glass bead beating favored the recovery of DNA more appropriate for fungal analysis. Beta diversity revealed distinct clusters, with MMgb showing the most pronounced variation in mycobiota composition, exposing particularly the low abundance taxa. LEfSe analysis identified significant differences in the abundance of fungal species among the extraction methods. Samples extracted with bead beating were enriched in filamentous species, while those without this step showed higher relative abundance of yeast fungi. This study underscores the importance of selecting appropriate DNA extraction methods for accurate characterization of the gut mycobiota, emphasizing the need for standardized methodologies to ensure reproducibility and reliability in microbial data acquisition.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 309-317"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143371147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2025.01.001
Julia Brignone , Carina Sen , María Laura Martin , Natalia Fernandez , Gabriela Delgado , Anabel Sinchi , Yael Nazar , María Cecilia Monzani , María Laura Cisneros , Patricia Clua , Rocío Coronel , Jorge García
The confirmation of two cases of hantavirus pulmonary syndrome (HPS) in the city of San Miguel de Tucuman, province of Tucuman, is described in the present study. In 2021, the diagnosis of two patients with HPS with no history of travel outside the province was confirmed. The infection was determined by serology in both cases. Case 1 had an unfavorable outcome, was confirmed by the detection of specific IgM antibodies for orthohantavirus and the identification in a serum sample from three days of evolution of a viral genotype, which was previously unreported to be in circulation in Argentina. In Case 2, specific IgM and IgG type antibodies were detected in two serum samples, with no amplification of the viral genome. Due to the recreational habits of the patients, it is possible to infer exposure to infected rodent fluids during outdoor activities in their areas of residence. In conclusion, the circulation of a new viral genotype of orthohantavirus in Argentina is confirmed.
{"title":"Report of a novel pathogenic orthohantavirus in Tucuman, Argentina","authors":"Julia Brignone , Carina Sen , María Laura Martin , Natalia Fernandez , Gabriela Delgado , Anabel Sinchi , Yael Nazar , María Cecilia Monzani , María Laura Cisneros , Patricia Clua , Rocío Coronel , Jorge García","doi":"10.1016/j.ram.2025.01.001","DOIUrl":"10.1016/j.ram.2025.01.001","url":null,"abstract":"<div><div>The confirmation of two cases of hantavirus pulmonary syndrome (HPS) in the city of San Miguel de Tucuman, province of Tucuman, is described in the present study. In 2021, the diagnosis of two patients with HPS with no history of travel outside the province was confirmed. The infection was determined by serology in both cases. Case 1 had an unfavorable outcome, was confirmed by the detection of specific IgM antibodies for orthohantavirus and the identification in a serum sample from three days of evolution of a viral genotype, which was previously unreported to be in circulation in Argentina. In Case 2, specific IgM and IgG type antibodies were detected in two serum samples, with no amplification of the viral genome. Due to the recreational habits of the patients, it is possible to infer exposure to infected rodent fluids during outdoor activities in their areas of residence. In conclusion, the circulation of a new viral genotype of orthohantavirus in Argentina is confirmed.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 336-340"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143568027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2024.12.010
Silvana Ramadán , Lucía Bulacio , Hernán Dalmaso , Graciela Sepúlveda , Maximiliano Sortino , Fabián Fay , Claudia Misto , María Fernanda Salvador , Alejandro Etchecopaz , María Luján Cuestas
Protothecosis is an infectious disease caused by microalgae of the genus Prototheca. Prototheca can be found in soil and water and transiently colonize animals. Cutaneous protothecosis can involve not only the skin but also the underlying subcutaneous tissue and lymph nodes. This can lead to clinical signs and a microscopic tissue image that closely resembles a fungal infection. Treatment typically involves antifungal medications. We report the first case of fatal disseminated protothecosis caused by Prototheca wickerhamii in the city of Rosario, Argentina in a 5-year-old female poodle dog. The dog exhibited ocular signs of uveitis and lymphadenitis. To reach a clinical and etiological diagnosis, imaging studies, routine laboratory tests and serological tests were performed. A mycological analysis was conducted on the material obtained by puncturing three lymph nodes. Additionally, morphological, metabolic, and molecular analyses were performed. Antifungal susceptibility testing was also conducted using broth microdilution and diffusion methods. Phenotypic, metabolic, and sequencing techniques identified the isolated organism as P. wickerhamii. This isolate displayed susceptibility to amphotericin, variable susceptibility to itraconazole and voriconazole, and resistance to fluconazole and caspofungin. The frequent presence of pets in our homes highlights the need for a more comprehensive diagnostic approach. This is important because, from a public health perspective, dogs could serve as indicators of algal presence in the environments they frequently share with humans.
{"title":"First report of canine protothecosis caused by Prototheca wickerhamii in Argentina. Brief literature review","authors":"Silvana Ramadán , Lucía Bulacio , Hernán Dalmaso , Graciela Sepúlveda , Maximiliano Sortino , Fabián Fay , Claudia Misto , María Fernanda Salvador , Alejandro Etchecopaz , María Luján Cuestas","doi":"10.1016/j.ram.2024.12.010","DOIUrl":"10.1016/j.ram.2024.12.010","url":null,"abstract":"<div><div>Protothecosis is an infectious disease caused by microalgae of the genus <em>Prototheca</em>. <em>Prototheca</em> can be found in soil and water and transiently colonize animals. Cutaneous protothecosis can involve not only the skin but also the underlying subcutaneous tissue and lymph nodes. This can lead to clinical signs and a microscopic tissue image that closely resembles a fungal infection. Treatment typically involves antifungal medications. We report the first case of fatal disseminated protothecosis caused by <em>Prototheca wickerhamii</em> in the city of Rosario, Argentina in a 5-year-old female poodle dog. The dog exhibited ocular signs of uveitis and lymphadenitis. To reach a clinical and etiological diagnosis, imaging studies, routine laboratory tests and serological tests were performed. A mycological analysis was conducted on the material obtained by puncturing three lymph nodes. Additionally, morphological, metabolic, and molecular analyses were performed. Antifungal susceptibility testing was also conducted using broth microdilution and diffusion methods. Phenotypic, metabolic, and sequencing techniques identified the isolated organism as <em>P. wickerhamii</em>. This isolate displayed susceptibility to amphotericin, variable susceptibility to itraconazole and voriconazole, and resistance to fluconazole and caspofungin. The frequent presence of pets in our homes highlights the need for a more comprehensive diagnostic approach. This is important because, from a public health perspective, dogs could serve as indicators of algal presence in the environments they frequently share with humans.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 341-348"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143433585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2024.11.006
Esteban C. Nannini , Matías Lahitte , Pablo Scapellato , Corina Nemirosvky , Marcelo Zylberman , Andrea Vila , Viviana Rodríguez , Roman Zucchi , Analia Mykietiuk , Valeria David , Adriana Limansky , Patricia Marchiaro , Mariángel Rinaudo
Cryptogenic liver abscesses (CLA) caused by hypervirulent Klebsiella pneumoniae (hvKP) strains are emerging in Western countries. The aim of the study was to describe the clinical characteristics of patients from Argentina with hvKP-related CLA as well as the molecular analysis of isolated strains. A retrospective chart review of 15 patients hospitalized in 8 hospitals of Argentina between October 2015 and November 2018 was performed. PCR assays for genes associated with capsular and multilocus sequence typing (MLST) determination and virulence factors were conducted in 8 hvKP isolates from these patients. We found that the mean age of patients was 60 years, 73% of them were men and 40% suffered from diabetes. Bacteremia was detected in 60% of them and 73% had ≥1 metastatic foci of infection. There were no in-hospital deaths, but two patients with endophthalmitis required eye enucleation. Of the 8 studied isolates, 4 belonged to K1 and 4 to K2 serotypes, with the rpmA and iroB genes being present in all of them, and isolates 7 and 5 also harboring the iucA and the rmpA2 genes, respectively. MSLT analysis showed that most of the K1 serotypes belonged to ST23 while a diverse MLST pattern was observed among the K2 strains. In addition, the four hvKP strains associated with metastatic complications and belonging to three distinct sequence types, exhibited the rpmA, iroB and iuc virulence genes. We were able to demonstrate important morbidity associated with this syndrome, a significant diversity in the hvKP clones causing CLA in Argentina, and the potential utility of the rpmA and iroB genes as predictors of virulence.
{"title":"Diversity of hypervirulent Klebsiella pneumoniae clones causing cryptogenic liver abscesses and metastatic complications in Argentina","authors":"Esteban C. Nannini , Matías Lahitte , Pablo Scapellato , Corina Nemirosvky , Marcelo Zylberman , Andrea Vila , Viviana Rodríguez , Roman Zucchi , Analia Mykietiuk , Valeria David , Adriana Limansky , Patricia Marchiaro , Mariángel Rinaudo","doi":"10.1016/j.ram.2024.11.006","DOIUrl":"10.1016/j.ram.2024.11.006","url":null,"abstract":"<div><div>Cryptogenic liver abscesses (CLA) caused by hypervirulent <em>Klebsiella pneumoniae</em> (hvKP) strains are emerging in Western countries. The aim of the study was to describe the clinical characteristics of patients from Argentina with hvKP-related CLA as well as the molecular analysis of isolated strains. A retrospective chart review of 15 patients hospitalized in 8 hospitals of Argentina between October 2015 and November 2018 was performed. PCR assays for genes associated with capsular and multilocus sequence typing (MLST) determination and virulence factors were conducted in 8 hvKP isolates from these patients. We found that the mean age of patients was 60 years, 73% of them were men and 40% suffered from diabetes. Bacteremia was detected in 60% of them and 73% had ≥1 metastatic foci of infection. There were no in-hospital deaths, but two patients with endophthalmitis required eye enucleation. Of the 8 studied isolates, 4 belonged to K1 and 4 to K2 serotypes, with the <em>rpmA</em> and <em>iroB</em> genes being present in all of them, and isolates 7 and 5 also harboring the <em>iucA</em> and the <em>rmpA2</em> genes, respectively. MSLT analysis showed that most of the K1 serotypes belonged to ST23 while a diverse MLST pattern was observed among the K2 strains. In addition, the four hvKP strains associated with metastatic complications and belonging to three distinct sequence types, exhibited the <em>rpmA</em>, <em>iroB</em> and <em>iuc</em> virulence genes. We were able to demonstrate important morbidity associated with this syndrome, a significant diversity in the hvKP clones causing CLA in Argentina, and the potential utility of the <em>rpmA</em> and <em>iroB</em> genes as predictors of virulence.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 356-363"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2024.12.013
Juan Leandro Pellegrini , María de los Ángeles González , Liliana Silvina Lösch , Luis Antonio Merino , José Alejandro Di Conza
The emergence and spread of multidrug-resistant Escherichia coli carrying mcr-1 is recognized as a threat to public health. The aim of this study was to determine the prevalence of the mcr-1 gene in colistin-resistant E. coli isolates from commercial pig farms in Chaco, Argentina from 2020 to 2021. A total of 140 rectal swab samples were collected from pigs in six different pig production farms. Antimicrobial susceptibility was determined by broth microdilution. mcr-1 to mcr-5 genes were identified by multiplex PCR and clonality was assessed by ERIC and REP-PCR. The prevalence of mcr-1 was 16.4% and mcr-2, mcr-3, mcr-4 and mcr-5 genes were not detected. Colistin MIC values showed a bimodal distribution with a MIC50, MIC90 and a range of 4, 8 and 4–8 μg/ml, respectively. The resistance profile to other antimicrobials was: ampicillin, 87% (20); ampicillin–sulbactam, 47.8% (11); amoxicillin–clavulanic, 13% (3); chloramphenicol, 82.6% (19); ciprofloxacin, 60.9% (14); minocycline, 26.1% (5) and trimethoprim/sulfamethoxazole, 43.5% (10). Eighty-seven percent (87%) of the strains were categorized as MDR and 12 phenotypic resistance patterns with different clonality profiles were observed. A high prevalence of mcr-1 is demonstrated in colistin-free pig farms from Chaco, Argentina. The mcr-1 positive E. coli isolates showed an alarming level of multidrug resistance and high clonal diversity. It is necessary to continuously monitor the presence of the mcr-1 gene not only in pig production, but also in humans and the environment.
{"title":"Colistin-resistant Escherichia coli mediated by the mcr-1 gene from pigs in northeastern Argentina","authors":"Juan Leandro Pellegrini , María de los Ángeles González , Liliana Silvina Lösch , Luis Antonio Merino , José Alejandro Di Conza","doi":"10.1016/j.ram.2024.12.013","DOIUrl":"10.1016/j.ram.2024.12.013","url":null,"abstract":"<div><div>The emergence and spread of multidrug-resistant <em>Escherichia coli</em> carrying <em>mcr-1</em> is recognized as a threat to public health. The aim of this study was to determine the prevalence of the <em>mcr-1</em> gene in colistin-resistant <em>E. coli</em> isolates from commercial pig farms in Chaco, Argentina from 2020 to 2021. A total of 140 rectal swab samples were collected from pigs in six different pig production farms. Antimicrobial susceptibility was determined by broth microdilution. <em>mcr-1</em> to <em>mcr-5</em> genes were identified by multiplex PCR and clonality was assessed by ERIC and REP-PCR. The prevalence of <em>mcr-1</em> was 16.4% and <em>mcr-2</em>, <em>mcr-3</em>, <em>mcr-4</em> and <em>mcr-5</em> genes were not detected. Colistin MIC values showed a bimodal distribution with a MIC50, MIC90 and a range of 4, 8 and 4–8<!--> <!-->μg/ml, respectively. The resistance profile to other antimicrobials was: ampicillin, 87% (20); ampicillin–sulbactam, 47.8% (11); amoxicillin–clavulanic, 13% (3); chloramphenicol, 82.6% (19); ciprofloxacin, 60.9% (14); minocycline, 26.1% (5) and trimethoprim/sulfamethoxazole, 43.5% (10). Eighty-seven percent (87%) of the strains were categorized as MDR and 12 phenotypic resistance patterns with different clonality profiles were observed. A high prevalence of <em>mcr-1</em> is demonstrated in colistin-free pig farms from Chaco, Argentina. The <em>mcr-1</em> positive <em>E. coli</em> isolates showed an alarming level of multidrug resistance and high clonal diversity. It is necessary to continuously monitor the presence of the <em>mcr-1</em> gene not only in pig production, but also in humans and the environment.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 349-355"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143472899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.ram.2025.07.004
Nidia del C. Ríos-De León , Miguel Á. Salas-Marina , Vidal Hernández-García , Brenda del R. Saldaña-Morales , Luis A. Rodríguez-Larramendi , Rubén Martínez-Camilo , Claudio Ríos-Velasco , Daniel A. Pérez-Corral , Sergio Casas-Flores
Fungal diseases in agricultural crops cause economic losses, with chemical control being the conventional method to manage them. However, this approach negatively impacts both the environment and human health. This study focused on endophytic fungi isolated from the roots of Ceratozamia mirandae in the Mexican locality of Juan Sabines (Villa Corzo, Chiapas). These fungi were identified morphologically and molecularly, biochemically characterized, and evaluated for their antagonistic activity against Colletotrichum karstii, Neopestalotiopsis sp. and Fusarium oxysporum. Their potential for promoting growth in Arabidopsis thaliana and tomato, as well as protecting against Botrytis cinerea, was also assessed. Fourteen fungal isolates were identified and grouped into six genera: Fusarium, Pestalotiopsis, Trichoderma, Umbelopsis, Nectria and Podospora. Among these Fusarium proliferatum JS311 and F. oxysporum JS239 exhibited strong inhibitory effects against the tested pathogens. Eight isolates were found to produce indole-3-acetic acid, promoting the growth of A. thaliana and tomato plants. Notably, F. oxysporum JS439 and F. solani (JS240, JS256 and JS4101) exhibited additional capabilities, including siderophore production and growth in nitrogen-free media. All Fusarium endophytic isolates induced systemic resistance against B. cinerea in tomato. Endophytic fungi from C. mirandae show promising potential as biofertilizers due to their combined mechanisms of anti-phytopathogenic activity, plant growth promotion, and systemic resistance induction through the production of beneficial metabolites.
{"title":"Endophytic Fusarium isolates from Ceratozamia mirandae enhance tomato growth, suppress pathogenic fungi, and induce protection against Botrytis cinerea","authors":"Nidia del C. Ríos-De León , Miguel Á. Salas-Marina , Vidal Hernández-García , Brenda del R. Saldaña-Morales , Luis A. Rodríguez-Larramendi , Rubén Martínez-Camilo , Claudio Ríos-Velasco , Daniel A. Pérez-Corral , Sergio Casas-Flores","doi":"10.1016/j.ram.2025.07.004","DOIUrl":"10.1016/j.ram.2025.07.004","url":null,"abstract":"<div><div>Fungal diseases in agricultural crops cause economic losses, with chemical control being the conventional method to manage them. However, this approach negatively impacts both the environment and human health. This study focused on endophytic fungi isolated from the roots of <em>Ceratozamia mirandae</em> in the Mexican locality of Juan Sabines (Villa Corzo, Chiapas). These fungi were identified morphologically and molecularly, biochemically characterized, and evaluated for their antagonistic activity against <em>Colletotrichum karstii</em>, <em>Neopestalotiopsis</em> sp. and <em>Fusarium oxysporum</em>. Their potential for promoting growth in <em>Arabidopsis thaliana</em> and tomato, as well as protecting against <em>Botrytis cinerea</em>, was also assessed. Fourteen fungal isolates were identified and grouped into six genera: <em>Fusarium</em>, <em>Pestalotiopsis</em>, <em>Trichoderma</em>, <em>Umbelopsis</em>, <em>Nectria</em> and <em>Podospora</em>. Among these <em>Fusarium proliferatum</em> JS311 and <em>F. oxysporum</em> JS239 exhibited strong inhibitory effects against the tested pathogens. Eight isolates were found to produce indole-3-acetic acid, promoting the growth of <em>A. thaliana</em> and tomato plants. Notably, <em>F. oxysporum</em> JS439 and <em>F. solani</em> (JS240, JS256 and JS4101) exhibited additional capabilities, including siderophore production and growth in nitrogen-free media. All <em>Fusarium</em> endophytic isolates induced systemic resistance against <em>B. cinerea</em> in tomato. Endophytic fungi from <em>C. mirandae</em> show promising potential as biofertilizers due to their combined mechanisms of anti-phytopathogenic activity, plant growth promotion, and systemic resistance induction through the production of beneficial metabolites.</div></div>","PeriodicalId":21163,"journal":{"name":"Revista Argentina de microbiologia","volume":"57 4","pages":"Pages 380-390"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145016126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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