Examinando por Autor "Irgang, Rute"
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Ítem Collective behavior and virulence arsenal of the fish pathogen Piscirickettsia salmonis in the biofilm realm(Frontiers in Cellular and Infection Microbiology, 2022-12-05) Levipan, Héctor A.; Irgang, Rute; Opazo, L. Felipe; Araya-León, Henry; Avendaño-Herrera, RubenPiscirickettsiosis is a fish disease caused by the Gram-negative bacterium Piscirickettsia salmonis. This disease has a high socio-economic impact on the Chilean salmonid aquaculture industry. The bacterium has a cryptic character in the environment and their main reservoirs are yet unknown. Bacterial biofilms represent a ubiquitous mechanism of cell persistence in diverse natural environments and a risk factor for the pathogenesis of several infectious diseases, but their microbiological significance for waterborne veterinary diseases, including piscirickettsiosis, have seldom been evaluated. This study analyzed the in vitro biofilm behavior of P. salmonis LF-89T (genogroup LF-89) and CA5 (genogroup EM-90) using a multi-method approach and elucidated the potential arsenal of virulence of the P. salmonis LF-89T type strain in its biofilm state. P. salmonis exhibited a quick kinetics of biofilm formation that followed a multi-step and highly strain-dependent process. There were no major differences in enzymatic profiles or significant differences in cytotoxicity (as tested on the Chinook salmon embryo cell line) between biofilm-derived bacteria and planktonic equivalents. The potential arsenal of virulence of P. salmonis LF-89T in biofilms, as determined by whole-transcriptome sequencing and differential gene expression analysis, consisted of genes involved in cell adhesion, polysaccharide biosynthesis, transcriptional regulation, and gene mobility, among others. Importantly, the global gene expression profiles of P. salmonis LF-89T were not enriched with virulence-related genes upregulated in biofilm development stages at 24 and 48 h. An enrichment in virulence-related genes exclusively expressed in biofilms was also undetected. These results indicate that early and mature biofilm development stages of P. salmonis LF-89T were transcriptionally no more virulent than their planktonic counterparts, which was supported by cytotoxic trials, which, in turn, revealed that both modes of growth induced important and very similar levels of cytotoxicity on the salmon cell line. Our results suggest that the aforementioned biofilm development stages do not represent hot spots of virulence compared with planktonic counterparts. This study provides the first transcriptomic catalogue to select specific genes that could be useful to prevent or control the (in vitro and/or in vivo) adherence and/or biofilm formation by P. salmonis and gain further insights into piscirickettsiosis pathogenesis. Copyright © 2022 Levipan, Irgang, Opazo, Araya-León and Avendaño-Herrera.Ítem Draft Genome Sequence of Tenacibaculum haliotis Strain RA3-2T, Isolated from Korean Wild Abalone (Haliotis discus hannai)(American Society for Microbiology, 2023-03) Avendaño-Herrera, Ruben; Saldarriaga-Córdoba, Mónica; Araya-León, Henry; Irgang, RuteHere, we present the draft genome sequence of Tenacibaculum haliotis strain RA3-2T (i.e., KCTC 52419T and NBRC 112382T), isolated from Korean wild abalone (Haliotis discus hannai). As the only strain for this Tenacibaculum species worldwide, the information is of use for comparative genomic analyses delineating Tenacibaculum species. Copyright © 2023 Avendaño-Herrera et al.Ítem Draft Genome Sequence of Tenacibaculum ovolyticum To-7Br, Recovered from a Farmed Atlantic Salmon (Salmo salar)(American Society for Microbiology, 2022-07) Avendaño Herrera, Ruben; Saldarriaga Córdoba, Mónica; Irgang, RuteWe present the draft genome sequence of Tenacibaculum ovolyticum isolate To-7Br, recovered from a gill of a farmed specimen of Atlantic salmon (Salmo salar) showing signs of tenacibaculosis. This study provides the first detailed insights into the genomic characteristics of T. ovolyticum isolated for the first time from fish farmed in Chile. © 2022 Avendaño-Herrera et al.Ítem First identification and characterization of lactococcus garvieae isolated from rainbow trout (Oncorhynchus mykiss) cultured in México(Animals, 2020-09-15) Ortega, Cesar; Irgang, Rute; Valladares-Carranza, Benjamín; Collarte, Constanza; Avendaño-Herrera, RubenLactococcosis is a hyperacute hemorrhagic septicemia disease caused by Lactococcus garvieae, which is an emerging pathogen in global fish farming. Between 2016 and 2018, rainbow trout (Oncorhynchus mykiss) from five farms that presented outbreaks were sampled as part of a Mexican surveillance program for the detection of fish diseases. Fourteen L. garvieae isolates were recovered from sampled fish, as confirmed by biochemical tests, 16S rRNA gene sequencing, and clinical and histological insights. The biochemical and protein profiles of the isolates obtained were homogeneous. Repetitive extragenic palindromic—(REP)—and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) analyses established weak genetic heterogeneity. Rainbow trout challenged with two of the isolates used at different bacterial concentrations (10−2 and 10−4 CFU/mL) showed melanosis, and hemorrhages were observed in the fins, liver, kidney, and spleen. Isolates were obtained from all of the organs sampled, including from surviving fish, as either pure or mixed cultures. The present study is the first to confirm the presence of L. garvieae as the agent of severe lactococcosis outbreaks in the two primary Mexican states for trout farming.Ítem New salmonid hosts for Tenacibaculum species: Expansion of tenacibaculosis in Chilean aquaculture(Blackwell Publishing Ltd, 2020-09) Avendaño-Herrera, Ruben; Collarte, Constanza; Saldarriaga-Córdoba, Mónica; Irgang, RuteThe success and sustainability of Chilean aquaculture largely depends on the control of endemic and emerging pathogens, including several species of the genus Tenacibaculum. Tenacibaculum dicentrarchi and “Tenacibaculum finnmarkense” have been detected and confirmed in Chilean Atlantic salmon (Salmo salar). However, no outbreaks of tenacibaculosis in rainbow trout (Oncorhynchus mykiss) or coho salmon (Oncorhynchus kisutch) have been reported, either in Chile or globally. The aims of this study were to determine whether the mortalities recorded for rainbow trout and coho salmon from five marine fish farms located in the Los Lagos, Aysén, and Magallanes Regions could be caused by Tenacibaculum spp. The diseased fish exhibited cutaneous haemorrhages, tail and peduncle rots, and damage on the mouth and tongue. Microbiological analysis of infected external tissues yielded 13 bacterial isolates. The isolates were identified as members of the genus Tenacibaculum through biochemical analysis (e.g. Gram-stain negative, straight rods, filamentous cells and motile by gliding), but differences existed in biochemical results, making species-level identification through biomolecular tools essential. The 16S rRNA analysis found that the majority of isolates were more closely related to “T. finnmarkense” than T. dicentrarchi, while the phylogenetic trees resulting from multilocus sequence data recovered the four main clades (clades I to IV) identified by Olsen et al. (2017, Veterinary Microbiology, 205, 39). This is the first documented occurrence of clinical tenacibaculosis in farmed rainbow trout and coho salmon globally, and it extends the known host distribution of this pathogen in Chile. Moreover, we confirm the presence of Tenacibaculum species in the Chilean Patagonia. These findings highlight the importance of establishing preventative measures to minimize the spread of this disease within the Chilean marine aquaculture industry, as well as the need for monitoring initiatives worldwide in these farmed fish species. © 2020 John Wiley & Sons LtdÍtem Paracoccus nototheniae sp. nov., isolated from a black rock cod fish (Notothenia coriiceps) from the Chilean Antarctic(International Journal of Systematic and Evolutionary Microbiology, 2019) Kampfer, Peter; Irgang, Rute; Poblete-Morales, Matías; Fernandez-Negrete, Guillermo; Glaeser, Stefanie P.; Fuentes-Messina, Derie; Avendaño-Herrera, RubenAn orange-pigmented, oxidase-positive bacterial strain (I-41R45T), isolated from the kidney of a black rock cod fish sampled in the Chilean Antarctic was studied in a polyphasic taxonomic investigation. Cells of the isolate were coccoid and stained Gram-negative. A comparison of the 16S rRNA gene sequence of strain I-41R45T with sequences of type strains of most closely related Paracoccus species showed highest sequence similarities to Paracoccus hibiscisoli (98.4 %), Paracoccus marcusii (98.3 %), Paracoccus haeundaensis and Paracoccus carotinifaciens (both 98.2 %). 16S rRNA gene sequence similarities to all other Paracoccus species were below 97 %. The draft genome of strain I-41R45T had a size of 4.59 Mb with a DNA G+C content of 65.26 mol% and included the prediction and annotation of 4426 coding genes, 1973 protein-coding genes and 46 tRNAs. The fatty acid profile of strain I-41R45T consisted mainly of the major fatty acids C18: 1ω7c/ω9t/ω12t and C18:0, typical of the genus Paracoccus. DNA–DNA hybridizations between I-41R45T and type strains of P. hibiscisoli, P. marcusiiand P. haeundaensis resulted in similarity values of 45 % (reciprocal 26 %), 66 % (reciprocal 61 %), and 29 % (reciprocal 36 %), respectively. DNA–DNA hybridization results, together with the differentiating biochemical and chemotaxonomic properties, showed that strain I-41R45T represents a novel Paracoccus species, for which the name Paracoccus nototheniae sp. nov. (type strain I-41R45T=CCM 8875T=CIP 111632T), is proposed.Ítem Pseudoduganella danionis sp. nov., isolated from zebrafish (Danio rerio)(Microbiology Society, 2016-10) Kämpfer, Peter; Irgang, Rute; Busse, Hans-Jürgen; Poblete-Morales, Mathías; Kleinhagauer, Tanita; Glaeser, Stefanie P.; Avendaño-Herrera, RubenOne beige-pigmented, Gram-staining-negative, rod-shaped bacterium, strain E3/2T , was isolated from a zebrafish, Daniorerio. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared 97.7 % 16S rRNA gene sequence similarity to the species Pseudoduganella violaceinigra and between 97.4 to 97.0 % to some species of the genera Duganella and Massilia, including Duganella radicis, Duganella phyllosphaerae, Massilia dura, Massilia lutea, Duganella sacchari, Duganella zoogloeoides, Massilia albidiflava and Massilia umbonata. Sequence similarities to all other species were below 97 %. The main cellular fatty acids of the strain were summed feature 3 fatty acids (C16 : 1!7c/iso-C15 : 0 2-OH), C10 : 0 3-OH, C16 : 0 and C12 : 0. The polyamine pattern of strain E3/2T contained predominantly putrescine and 2-hydroxyputrescine. The major quinone was ubiquinone Q-8. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a novel species of the genus Pseudoduganella named Pseudoduganella danionis sp. nov., with strain E3/2T (=LMG 29678T=CCM 8698T ) as the type strain.Ítem Psychromonas aquatilis sp. nov., isolated from seawater samples obtained in the Chilean Antarctica(Microbiology Society, 2017-05) Kämpfer, Peter; Irgang, Rute; Poblete-Morales, Matías; Glaeser, Stefanie P.; Martín, Marcelo Cortez-San; Avendaño-Herrera, RubenA slightly beige-white pigmented, Gram-staining-negative, rod-shaped bacterium, strain M1A1T, was isolated from seawater samples obtained in Fildes Bay, Antarctica (62°12′ S 58° 57′ W). Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared 98.4% 16S rRNA gene sequence identity to the type strain of Psychromonas arctica, but less than 97% 16S rRNA gene sequence similarities to all other species of the genus Psychromonas. DNA–DNA hybridization with Psychromonas arctica DSM 14288T showed low values (21%, reciprocal 27%). The main cellular fatty acid of strain M1A1T was summed feature 3 fatty acids (C16: 1ω7c/C16: 1ω8c), followed by C16: 0. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses, we propose a novel species of the genus Psychromonas with the name Psychromonas aquatilis sp. nov. and the strain M1A1T (=CIP 111183T=CCM 8710T=LMG 29766T) as type strain. © 2017 IUMS.