Brazilian Journal of Microbiology最新文献

{"title":"Associations between epidemiological and laboratory parameters and disease severity in hospitalized patients with COVID-19 during first and second epidemic waves in middle south Mato Grosso.","authors":"Thais Campos Dias da Cruz, Janeth Aracely Ramirez Pavon, Francisco Scoffoni Kennedy de Azevedo, Edila Cristina de Souza, Bergman Morais Ribeiro, Renata Dezengrini Slhessarenko","doi":"10.1007/s42770-024-01379-x","DOIUrl":"10.1007/s42770-024-01379-x","url":null,"abstract":"<p><strong>Background: </strong>COVID-19 is a multisystemic disease characterized by respiratory distress. Disease severity is associated with several factors. Here we characterize virological findings and evaluate the association of laboratorial, epidemiological, virological findings and clinical outcomes of 251 patients during the first and second epidemic waves of COVID-19.</p><p><strong>Methods: </strong>This transversal study used biological samples and data from patients hospitalized with COVID-19 between May 2020 and August 2021 in the metropolitan region of Cuiabá, Mato Grosso Brazil. Biological samples were subjected to RT-qPCR and MinION sequencing. Univariate and multivariate logistic regression and Odds ratio were used to correlate clinical, laboratorial, epidemiological data.</p><p><strong>Findings: </strong>Patients were represented by males (61.7%) with mean age of 52.4 years, mild to moderate disease (49,0%), overweight/obese (69.3%), with comorbidities (66.1%) and evolving to death (55.38%). Severe cases showing symptoms for prolonged time, ≥ 25% of ground-glass opacities in the lungs and fatality rate increased significantly in second wave. Fatality was statistically associated to > 61 years of age,>25% ground-glass opacities in the lungs, immune, cardiac, or metabolic comorbidities. Higher viral load (p < 0.01/p = 0.02 in each wave), decreased erythrocyte (p < 0.01), hemoglobin (p < 0.05/p < 0.01), hematocrit (p < 0.01), RDW (p < 0.01), lymphocyte (p < 0.01), increased leucocyte (p < 0.01), neutrophil (p < 0.01) and CRP levels (p < 0.01) showed significant association with fatality in both waves, as did Neutrophil/Platelet (NPR; p < 0.01), Neutrophil/Lymphocyte (NLR; p < 0.01) and Monocyte/Lymphocyte ratio (MLR; p < 0.01). SARS-CoV-2 genomes from lineage B.1.1.33(n = 8) and Gamma/P.1(n = 15) shared 6/7 and 20/23 lineage-defining mutations, respectively.</p><p><strong>Main conclusions: </strong>Severity and mortality of COVID-19 associated with a panel of epidemiological and laboratorial findings, being second wave, caused by Gamma variant, more severe in this in-hospital population.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141247191","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":"Different light intensity on Messastrum gracile growth under phototrophic cultivation in laboratory.","authors":"Lúcia Helena Sipaúba-Tavares, Jesaias Ismael da Costa, Débora Cristina Fenerick","doi":"10.1007/s42770-024-01389-9","DOIUrl":"10.1007/s42770-024-01389-9","url":null,"abstract":"<p><p>The present research evaluates the effects of three different lighting intensities, 60 (control), 30 and 120 µmol photons m^- 2 s^- 1 on Messastrum gracile growth. The observations indicated that a light intensity of 60 µmol photons m^- 2 s^- 1 resulted in higher cell density during experimental period. The light intensity of 120 µmol photons m^- 2 s^- 1 had a strong negative impact on M. gracile growth. Parameters such as lipid and protein content, cell density, chlorophyll-a and biomass were lower compared to the other light intensities. On the 14th and 21st growth days, the biomass, lipid and protein content were higher at 60 µmol photons m^- 2 s^- 1 with 800 mg L^- 1, 5.7% and 34.4% biomass dry weight, respectively. The study also highlighted the economic aspects of M. gracile cultivation. The light intensities 30 and 60 µmol photons m^- 2 s^- 1 were found to be more advantageous than 120 µmol photons m^- 2 s^- 1 in terms of biomass, unit cost, lipid and protein content. Based on these findings, it was concluded that the light intensities of 30 and 60 µmol photons m^- 2 s^- 1 are more viable for M. gracile cultivation in laboratory under conditions used.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405606/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141261212","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":"Revolutionizing food safety with electrochemical biosensors for rapid and portable pathogen detection.","authors":"Brígida D' Ávila Oliveira, Raíssa Soares Gomes, Alice Mendes de Carvalho, Emília Maria França Lima, Uelinton Manoel Pinto, Luciana Rodrigues da Cunha","doi":"10.1007/s42770-024-01427-6","DOIUrl":"10.1007/s42770-024-01427-6","url":null,"abstract":"<p><p>Foodborne diseases remain a worldwide concern, despite the advances made in sanitation, pathogen surveillance and food safety management systems. The methods routinely applied for detecting pathogens in foods are time consuming, labor intensive and usually require trained and qualified individuals. The objective of this review was to highlight the use of biosensors, with a focus on the electrochemical devices, as promising alternatives for detecting foodborne pathogens. These biosensors present high speed for obtaining results, with the possibility of evaluating foods in real time, at low cost, ease of use, in addition to being compact and portable. These aspects are considered advantageous and suitable for use in food safety management systems. This work also shows some limitations for the application of biosensors, and we present perspectives with the development and use of nanomaterials.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405362/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141449661","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":"Evaluating climate-dependent distribution of orthohantaviruses with monitoring wild rodents: One Health Perspective^†.","authors":"Ceylan Polat, Mert Erdin, Şaban Orçun Kalkan, Sercan Irmak, Ortaç Çetintaş, Faruk Çolak, Kürşat Kenan Kalkan, Muhsin Çoğal, Kirami Ölgen, Mustafa Sözen, Ferhat Matur, İbrahim Mehmet Ali Öktem","doi":"10.1007/s42770-024-01447-2","DOIUrl":"10.1007/s42770-024-01447-2","url":null,"abstract":"<p><p>Orthohantaviruses, cause hemorrhagic fever with renal syndrome, nephropathia epidemica, and hantavirus pulmonary syndrome, are major public health problems all over the world. Wild rodent surveillance for orthohantaviruses is of great importance for the preparedness against these human infections and the prediction of possible outbreak regions. Thus, we aimed to screen orthohantaviruses in wild rodents in Southern Anatolia, where the area has some of the glacial period refugia in the Mediterranean Basin, and interpret their current epidemiology with climatic biovariables in comparison with previously positive regions.We trapped muroid rodents between 2015 and 2017, and screened for orthohantaviruses. Then, we evaluated the relationship between orthohantavirus infections and bioclimatic variables. In spite of the long-term and seasonal sampling, we found no evidence for Orthohantavirus infections. The probable absence of orthohantaviruses in the sampling area was further evaluated from the climatic perspective, and results led us suggest that Orthohantavirus epidemiology might be relatively dependent on precipitation levels in driest and warmest quarters, and temperature fluctuations.These initial data might provide necessary perspective on wild rodent surveillance for orthohantaviruses in other regions, and help to collect lacking data for a such habitat suitability study in a bigger scale in the future.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405598/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141619300","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":"Phenotypic and molecular characterization of clinically isolated antibiotics-resistant S. aureus (MRSA), E. coli (ESBL) and Acinetobacter 1379 bacterial strains.","authors":"Daraksha Iram, Manish Singh Sansi, Anil Kumar Puniya, Kamal Gandhi, Sunita Meena, Shilpa Vij","doi":"10.1007/s42770-024-01347-5","DOIUrl":"10.1007/s42770-024-01347-5","url":null,"abstract":"<p><p>Antibiotic-resistant bacteria causing nosocomial infections pose a significant global health concern. This study focused on examining the lipid profiles of both non-resistant and clinically resistant strains of Staphylococcus aureus (MRSA 1418), E. coli (ESBL 1384), and Acinetobacter 1379. The main aim was to investigate the relationship between lipid profiles, hydrophobicity, and antibiotic resistance so as to identify the pathogenic potential and resistance factors of strains isolated from patients with sepsis and urinary tract infections (UTIs). The research included various tests, such as antimicrobial susceptibility assays following CLSI guidelines, biochemical tests, biofilm assays, and hydrophobicity assays. Additionally, gas chromatography mass spectrometry (GC-MS) and GC-Flame Ionization Detector (GC-FID) analysis were used for lipid profiling and composition. The clinically isolated resistant strains (MRSA-1418, ESBL-1384, and Acinetobacter 1379) demonstrated resistance phenotypes of 81.80%, 27.6%, and 63.6%, respectively, with a multiple antibiotic resistance index of 0.81, 0.27, and 0.63. Notably, the MRSA-1418 strain, which exhibited resistance, showed significantly higher levels of hemolysin, cell surface hydrophobicity, biofilm index, and a self-aggregative phenotype compared to the non-resistant strains. Gene expression analysis using quantitative real-time PCR (qPCR). Indicated elevated expression levels of intercellular adhesion biofilm-related genes (icaA, icaC, and icaD) in MRSA-1418 (pgaA, pgaC, and pgaB) and Acinetobacter 1379 after 24 h compared to non-resistant strains. Scanning electron microscopy (SEM) was employed for structural investigation. These findings provide valuable insights into the role of biofilms in antibiotic resistance and suggest potential target pathways for combating antibiotic-resistant bacteria.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141075249","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":"Isolation, screening, and characterization of the newly isolated osmotolerant yeast Wickerhamomyces anomalus BKK11-4 for the coproduction of glycerol and arabitol.","authors":"Jesnipit Thammaket, Piroonporn Srimongkol, Paweena Ekkaphan, Sitanan Thitiprasert, Sorapat Niyomsin, Thanyalak Chaisuwan, Suwabun Chirachanchai, Nuttha Thongchul","doi":"10.1007/s42770-024-01383-1","DOIUrl":"10.1007/s42770-024-01383-1","url":null,"abstract":"<p><p>This study explored the isolation and screening of an osmotolerant yeast, Wickerhamomyces anomalus BKK11-4, which is proficient in utilizing renewable feedstocks for sugar alcohol production. In batch fermentation with high initial glucose concentrations, W. anomalus BKK11-4 exhibited notable production of glycerol and arabitol. The results of the medium optimization experiments revealed that trace elements, such as H₃BO₃, CuSO₄, FeCl₃, MnSO₄, KI, H₄MoNa₂O₄, and ZnSO₄, did not increase glucose consumption or sugar alcohol production but substantially increased cell biomass. Osmotic stress, which was manipulated by varying initial glucose concentrations, influenced metabolic outcomes. Elevated glucose levels promoted glycerol and arabitol production while decreasing citric acid production. Agitation rates significantly impacted the kinetics, enhancing glucose utilization and metabolite production rates, particularly for glycerol, arabitol, and citric acid. The operational pH dictated the distribution of the end metabolites, with glycerol production slightly reduced at pH 6, while arabitol production remained unaffected. Citric acid production was observed at pH 6 and 7, and acetic acid production was observed at pH 7. Metabolomic analysis using GC/MS identified 29 metabolites, emphasizing the abundance of sugar/sugar alcohols. Heatmaps were generated to depict the variations in metabolite levels under different osmotic stress conditions, highlighting the intricate metabolic dynamics occurring post-glucose uptake, affecting pathways such as the pentose phosphate pathway and glycerolipid metabolism. These insights contribute to the optimization of W. anomalus BKK11-4 as a whole-cell factory for desirable products, demonstrating its potential applicability in sustainable sugar alcohol production from renewable feedstocks.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405736/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141075308","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":"Antimicrobial resistance, virulence genes, and ESBL (Extended Spectrum Beta-Lactamase) production analysis in E. coli strains from the Rio Grande/Rio Bravo River in Tamaulipas, Mexico.","authors":"Rocío Requena-Castro, María Guadalupe Aguilera-Arreola, Ana Verónica Martínez-Vázquez, Wendy Lizeth Cruz-Pulido, Gildardo Rivera, Virgilio Bocanegra-García","doi":"10.1007/s42770-024-01376-0","DOIUrl":"10.1007/s42770-024-01376-0","url":null,"abstract":"<p><p>The Rio Grande/Rio Bravo River is used as a major water supply for diverse recreational, household, and industrial activities in Northeast Tamaulipas, Mexico, and South Texas. In this study, we sampled surface water from 38 sites along Rio Grande/Rio Bravo River (Díaz Ordaz, Reynosa and Matamoros). We isolated 105 E. coli strains that were molecularly and phenotypically characterized. The percentage of virulence genes detected in E. coli were: hlyA (15.23%), stx2 (11.42%), stx1 (9.52%), bfp (0.95%), and eae (0.0) and combinations of stx1/stx2 (2.85%), stx2/hlyA (1.90%), stx1/bfp (0.95%) and stx2/bfp (0.95%) were detected in these strains. Resistance to more than one antibiotic was detected in 85.71%, and 5.71% of strains were extended-spectrum β-lactamase-E. coli (ESBL-EC). These results indicate the presence of potentially pathogenic E. coli strains in the Rio Grande/Rio Bravo River; therefore, it can be considered a reservoir of pathogenic strains and represents a health risk for the population.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405568/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140956158","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":"Investigating the interaction of zno nanoparticles with flagellum and fimbriae in multi-drug resistant uropathogenic bacteria encoding fli and fim genes.","authors":"Maryam Bagheri Mohammadgholi Pour, Monir Doudi, Ali Mohammad Ahadi, Gholam Reza Amiri","doi":"10.1007/s42770-024-01445-4","DOIUrl":"10.1007/s42770-024-01445-4","url":null,"abstract":"<p><p>Due to the increasing occurrence of drug resistant urinary tract infections (UTI) among children, there is a need to investigate alternative effective treatment protocols such as nanoparticles. Flagella and fimbriae are primary factors contributing the virulence of urinary tract infecting bacteria. The aim of this study was to assess the antibacterial effects of zinc oxide nanoparticles which have been synthesized using both chemical and green methods on multi-drug resistant (MDR) uropathogenic bacteria encoding fli and fim genes and investigating their binding ability to bacterial appendage proteins. A total of 30 urine culture samples were collected from children under 2 years old diagnosed with urinary tract infection. The isolates underwent antibiotic suseptibility assessment and the isolates demonstrating MDR were subjected to molecular amplification of fimG (fimbrial) and fliD and fliT (flagellal) genes. The confirmation of cellular appendages was achieved through silver nitrate staining. The antibacterial efficacy of the synthetized nanoparticles was assessed using the micro and macrodilution methods. The successful binding of nanoparticles to bacterial appendage proteins was confirmed through mobility shift and membrane filter assays. The dimensions of chemically synthesized ZnO nanoparticles and green nanoparticles were measured at 30 nm and 85 nm, respectively, with the exhibition of hexagonal geometries. The nanoparticles synthesized through chemical and green methods exhibited minimum inhibitory concentrations (MIC) of 0.0062-0.025 g/L and 0.3 g/L, respectively. The ability of ZnO nanoparticles to bind bacterial appendage proteins and to combat MDR uropathogenic bacteria are promising for new treatment protocols against UTI in children in future.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405561/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142104245","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":"Biofilm formation by Listeria monocytogenes from the meat processing industry environment and the use of different combinations of detergents, sanitizers, and UV-A radiation to control this microorganism in planktonic and sessile forms.","authors":"Larissa Siqueira Lima, Taís Nunzio Müller, Rafaela Ansiliero, Marcia Bär Schuster, Bruna Louise Silva, Itiane Barcellos Jaskulski, Wladimir Padilha da Silva, Liziane Schittler Moroni","doi":"10.1007/s42770-024-01361-7","DOIUrl":"10.1007/s42770-024-01361-7","url":null,"abstract":"<p><p>This study aimed to evaluate the ability of biofilm formation by L. monocytogenes from the meat processing industry environment, as well as the use of different combinations of detergents, sanitizers, and UV-A radiation in the control of this microorganism in the planktonic and sessile forms. Four L. monocytogenes isolates were evaluated and showed moderate ability to form biofilm, as well as carried genes related to biofilm production (agrB, agrD, prfA, actA, cheA, cheY, flaA, sigB), and genes related to tolerance to sanitizers (lde and qacH). The biofilm-forming isolates of L. monocytogenes were susceptible to quaternary ammonium compound (QAC) and peracetic acid (PA) in planktonic form, with minimum inhibitory concentrations of 125 and 75 ppm, respectively, for contact times of 10 and 5 min. These concentrations are lower than those recommended by the manufacturers, which are at least 200 and 300 ppm for QAC and PA, respectively. Biofilms of L. monocytogenes formed from a pool of isolates on stainless steel and polyurethane coupons were subjected to 14 treatments involving acid and enzymatic detergents, QAC and PA sanitizers, and UV-A radiation at varying concentrations and contact times. All treatments reduced L. monocytogenes counts in the biofilm, indicating that the tested detergents, sanitizers, and UV-A radiation exhibited antimicrobial activity against biofilms on both surface types. Notably, the biofilm formed on polyurethane showed greater tolerance to the evaluated compounds than the biofilm on stainless steel, likely due to the material's surface facilitating faster microbial colonization and the development of a more complex structure, as observed by scanning electron microscopy. Listeria monocytogenes isolates from the meat processing industry carry genes associated with biofilm production and can form biofilms on both stainless steel and polyurethane surfaces, which may contribute to their persistence within meat processing lines. Despite carrying sanitizer tolerance genes, QAC and PA effectively controlled these microorganisms in their planktonic form. However, combinations of detergent (AC and ENZ) with sanitizers (QAC and PA) at minimum concentrations of 125 ppm and 300 ppm, respectively, were the most effective.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405597/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064741","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":"Co-infection of Lactococcus garvieae and Aeromonas hydrophila in cultured Nile Tilapia in Kerala, India.","authors":"Reshma Rajeev Nair, Kollanoor Riji John, Preenanka Rajan, Rahul Krishnan, Muhammed Puratheparampilchira Safeena","doi":"10.1007/s42770-024-01415-w","DOIUrl":"10.1007/s42770-024-01415-w","url":null,"abstract":"<p><p>Co-infection of Lactococcus garvieae and Aeromonas hydrophila, has been confirmed from diseased Nile Tilapia (Oreochromis niloticus), Chithralada strain cultured in a freshwater rearing pond of Alappuzha district of Kerala, India. The aetiological agents behind the disease outbreak were bacteriologically proven and confirmed by 16SrRNA sequencing and phylogenetic analysis. PCR detection of the virulent genes, showed existence of adhesin and hemolysin in L. garvieae and aerolysin in A. hydrophila strain obtained. To fulfil Koch's postulates, challenge experiments were conducted and median lethal dose (LD₅₀) of L. garvieae and A. hydrophila was calculated as 1 × 10^5.91 CFU per mL and 1 × 10^5.2 CFU per mL respectively. Histopathologically, eyes, spleen, and kidney were the predominantly infected organs by L. garvieae and A. hydrophila. Out of the 13 antibiotics tested to check antibiotic susceptibility, L. garvieae showed resistance to almost 7 antibiotics tested, with a resistance to Ciprofloxacin while A. hydrophila was found resistant to Streptomycin and Erythromycin. Understanding the complex interaction between Gram-positive and Gram-negative bacteria in the disease process and pathogenesis in fish host will contribute to efficient treatment strategies. As a preliminary investigation into this complex interaction, the present study is aimed at phenotypic and genotypic characterization, pathogenicity evaluation, and antibiotic susceptibility of the co-infecting pathogens in a diseased sample of freshwater-farmed Nile tilapia.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11405729/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141431289","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}