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1.
Artículo en Inglés | MEDLINE | ID: mdl-38563675

RESUMEN

Strain LB-N7T, a novel Gram-negative, orange, translucent, gliding, rod-shaped bacterium, was isolated from water samples collected from an open system of Atlantic salmon (Salmo salar) smolts in a fish farm in Chile during a flavobacterial infection outbreak in 2015. Phylogenetic analysis based on 16S rRNA sequences (1337 bp) revealed that strain LB-N7T belongs to the genus Flavobacterium and is closely related to the type strains Flavobacterium ardleyense A2-1T (98.8 %) and Flavobacterium cucumis R2A45-3T (96.75 %). The genome size of strain LB-N7T was 2.93 Mb with a DNA G+C content 32.6 mol%. Genome comparisons grouped strain LB-N7T with Flavobacterium cheniae NJ-26T, Flavobacterium odoriferum HXWNR29T, Flavobacterium lacisediminis TH16-21T and Flavobacterium celericrescens TWA-26T. The calculated digital DNA-DNA hybridization values between strain LB-N7T and the closest related Flavobacterium strains were 23.3 % and the average nucleotide identity values ranged from 71.52 to 79.39 %. Menaquinone MK-6 was the predominant respiratory quinone, followed by MK-7. The major fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The primary polar lipids detected included nine unidentified lipids, two amounts of aminopospholipid and phospholipids, and a smaller amount of aminolipid. Phenotypic, genomic, and chemotaxonomic data suggest that strain LB-N7T (=CECT 30406T=RGM 3221T) represents as a novel bacterial species, for which the name Flavobacterium psychraquaticum sp. nov. is proposed.


Asunto(s)
Flavobacterium , Salmo salar , Animales , Flavobacterium/genética , Chile , Filogenia , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana
2.
Artículo en Inglés | MEDLINE | ID: mdl-37010890

RESUMEN

Strain I-SCBP12nT, a novel Gram-stain-negative, aerobic, non-spore-forming, motile-by-gliding and rod-shaped bacterium, was isolated from a chinstrap penguin chick (Pygoscelis antarcticus) during a 2015 expedition to the Chilean Antarctic territory. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain I-SCBP12nT belonged to the genus Flavobacterium, being closely related to strains Flavobacterium chryseum P3160T (98.52 %), Flavobacterium hercynium WB 4.2-33T (98.47 %) and Flavobacterium chilense LM-19-FpT (98.47 %). The genome size of strain I-SCBP12nT was 3.69 Mb with DNA G+C content 31.95 mol%. Genomic comparisons of strain I-SCBP12nT with type species in the genus Flavobacterium were performed, with obtained average values near 75.17 and 84.33 % for the blast and MUMer analyses of average nucleotide identity, respectively, and 0.86 for the tetranucleotides frequency analysis. These values are far from the accepted species cut-off values. Strain I-SCBP12nT contained MK-6 as the predominant menaquinone and the major polar lipids were aminophospholipid, an unidentified aminolipid and unidentified lipids. The predominant fatty acids (> 5 %) were iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C16 : 1, iso-C16 : 0 3-OH, C15 : 1 ω6c and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c). Phenotypic, chemotaxonomic and genomic data supported the assignment of strain I-SCBP12nT (=CECT 30404T=RGM 3223T) to a novel species of Flavobacterium, for which the name Flavobacterium pygoscelis sp. nov.is proposed.


Asunto(s)
Ácidos Grasos , Spheniscidae , Animales , Ácidos Grasos/química , Flavobacterium , Filogenia , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Análisis de Secuencia de ADN , Composición de Base , Técnicas de Tipificación Bacteriana , Vitamina K 2
3.
Environ Res ; 196: 110344, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33068585

RESUMEN

The air humidity in Antarctica is very low and this peculiar weather parameter make the use of flame retardants in research facilities highly needed for safety reasons, as fires are a major risk. Legacy and novel flame retardants (nFRs) including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), Dechlorane Plus (DP), and other nFRs were measured in indoor dust samples collected at research Stations in Antarctica: Gabriel de Castilla, Spain (GCS), Julio Escudero, Chile (JES), and onboard the RRS James Clark Ross, United Kingdom (RRS JCR). The GC-HRMS and LC-MS-MS analyses of dust samples revealed ∑7PBDEs of 41.5 ± 43.8 ng/g in rooms at GCS, 18.7 ± 11.6 ng/g at JES, and 27.2 ± 37.9 ng/g onboard the RRS JCR. PBDE pattern was different between the sites and most abundant congeners were BDE-183 (40%) at GCS, BDE-99 (50%) at JES, and BDE-153 (37%) onboard the RRS JCR. The ∑(4)HBCDs were 257 ± 407 ng/g, 14.9 ± 14.5 ng/g, and 761 ± 1043 ng/g in indoor dust collected in rooms at GCS, JES, and RRS JCR, respectively. The ∑9nFRs were 224 ± 178 ng/g at GCS, 14.1 ± 13.8 ng/g at JES, and 194 ± 392 ng/g on the RRS JCR. Syn- and anti-DP were detected in most of the samples and both isomers showed the highest concentrations at GCS: 163 ± 93.6 and 48.5 ± 61.1 ng/g, respectively. The laboratory and living room showed the highest concentration of HBCDs, DPs, BTBPE. The wide variations in FR levels in dust from the three research facilities and between differently used rooms reflect the different origin of furnishing, building materials and equipment. The potential health risk associated to a daily exposure via dust ingestion was assessed for selected FRs: BDEs 47, 99, and 153, α-, ß-, and γ-HBCD, BTBPE, syn- and anti-DP. Although the estimated exposures are below the available reference doses, caution is needed given the expected increasing use of novel chemicals without a comprehensive toxicological profile.


Asunto(s)
Contaminación del Aire Interior , Retardadores de Llama , Contaminación del Aire Interior/análisis , Regiones Antárticas , Chile , Polvo/análisis , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Retardadores de Llama/análisis , Éteres Difenilos Halogenados/análisis , Humanos , España , Reino Unido
4.
Int J Syst Evol Microbiol ; 70(3): 1963-1968, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31985393

RESUMEN

A Gram-stain positive, pleomorphic, oxidase-negative, non-motile isolate from the ulcer of a farmed Atlantic salmon (Salmo salar), designated strain T11bT, was subjected to a comprehensive taxonomic investigation. A comparative analysis of the 16S rRNA gene sequence showed highest similarities to the type strains of Pseudarthrobacter siccitolerans (98.1 %) and Arthrobacter methylotrophus and Pseudarthrobacter phenanthrenivorans (both 98.0 %). The highest ANI value observed between the assembled genome of T11bT and the publicly available Pseudarthrobacter and Arthrobacter type strain genomes were 81.15 and 80.99 %, respectively. The major respiratory quinone was menaquinone MK-9(H2). The polyamine pattern contained predominantly spermidine. The polar lipid profile consisted of the major lipids diphosphatidylglycerol, phosphatidylglycerol, monogalactosyl-diacylglycerol and dimannosylglyceride. Minor amouts of trimannosyldiacylglycerol and phosphatidylinositol were also detected. The peptidoglycan was of the type A3α l-Lys-l-Ser-l-Thr-l-Ala (A11.23). In the fatty acid profile, anteiso and iso branched fatty acids predominated (anteiso C15 : 0, iso C16 : 0, anteiso C17 : 0). Moderate to low DNA-DNA similarities, physiological traits as well as unique traits in the fatty acid pattern distinguished strain T11bT from the next related species. All these data point to the fact that strain T11bT represents a novel species of the genus Arthrobacter for which we propose the name Arthrobacter ulcerisalmonis sp. nov. The type strain is T11bT (=CIP 111621T=CCM 8854T=LMG 30632T=DSM 107127T).


Asunto(s)
Arthrobacter/clasificación , Enfermedades de los Peces/microbiología , Filogenia , Salmo salar/microbiología , Úlcera/microbiología , Animales , Acuicultura , Arthrobacter/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Peptidoglicano/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
Int J Syst Evol Microbiol ; 70(1): 211-219, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31617840

RESUMEN

One slightly beige-white pigmented, Gram-stain-negative, rod-shaped bacterium, strain I-STPP5bT, was isolated from the trachea of a Gentoo penguin chick individual (Pygoscelin papua) investigated in Fildes Bay, Chilean Antarctic (62° 12' S, 58° 57' W). I-STPP5bT consists of a 3.4 Mb chromosome with a DNA G+C content of 44.4 mol%. Of the 3056 predicted genes, 1206 were annotated as hypothetical proteins and 51 were tRNAs. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared a 16S rRNA gene sequence identity to the type strains of Psychrobacter phenylpyruvicus (98.8 %), Psychrobacter arenosus and Psychrobacter pasteurii (both 98.3 %), Psychrobacter piechaudii (98.2 %) and Psychrobacter sanguinis (98.1 %), but 16S rRNA gene sequence similarities to all other Psychrobacter species were ≤98.0 %. Partial gyrB nucleotide and amino acid sequence similarities among strain STPP5bT and the next related type strains were all below 81.8 and 92.9%, respectively. DNA-DNA hybridisation (DDH) with P. phenylpyruvicus LMG 5372T, P. arenosus DSM 15389T and P. sanguinis DSM 23635T also showed low values (all below 30 %). The main cellular fatty acids of the strain were C18 : 1ω9c and C16 : 1ω7c and/or C16 : 1ω6c. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a new species of the genus Psychrobacter, with the name Psychrobacter pygoscelis sp. nov. and strain I-STPP5bT (=CIP 111410T= CCM 8799T=LMG 30301T) as type strain.


Asunto(s)
Filogenia , Psychrobacter/clasificación , Spheniscidae/microbiología , Tráquea/microbiología , Animales , Regiones Antárticas , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Psychrobacter/aislamiento & purificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
6.
Antonie Van Leeuwenhoek ; 113(8): 1201-1211, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32436126

RESUMEN

The bacterial strain M7D1T was isolated from samples of the rhizosphere of desert bloom plants on the Atacama region located in northern Chile as part of a study intended to isolate nitrifying bacteria in this adverse environment. It was previously identified as belonging to the Pseudomonas fluorescens group. In this study, the phylogenetic analysis of the 16s RNA, gyrA, rpoB and rpoD genes confirmed that this strain belongs to this group, especially Sub Group (SG) Koreensis, but it represents a potential new species. Additionally, the average nucleotide identity confirmed this as the highest identity value (0.92) with Pseudomonas moraviensis LMG 24280, which is lower than the 0.94 threshold established to classify two strains within the same species. The strain M7D1T shared a similar fatty acids methyl ester profile than the type strains of other Pseudomonas spp. previously described. Furthermore, it can be differentiated phenotypically from other related species of SG P. koreensis. Based on these results, the existence of a new species of Pseudomonas is demonstrated, for which the name Pseudomonas atacamensis is proposed. This strain presented a set of genes associated with plant growth-promoting rhizobacteria and it is a good candidate to be used for recovery of contaminated soils. However, more studies are required to demonstrate whether this bacterium is non-pathogenic, can survive in the presence of toxic compounds and promote growth or help to the stress management of plants.


Asunto(s)
Filogenia , Pseudomonas/clasificación , Pseudomonas/aislamiento & purificación , Rizosfera , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/análisis , Genes Bacterianos/genética , Genoma Bacteriano , Hibridación de Ácido Nucleico , Pseudomonas/citología , Pseudomonas/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
7.
J Fish Dis ; 43(5): 561-570, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32196708

RESUMEN

Flavobacterium psychrophilum is the causative agent of bacterial cold-water disease and rainbow trout syndrome in freshwater salmonid fish worldwide, generating injuries and high mortality rates. Despite several studies on this bacterium, the infection mechanism remains unknown due to limitations in the employed animal models. In this work, we propose using zebrafish (Danio rerio) as a model for studying bacterial pathogenicity. To substantiate this proposal, zebrafish infection by F. psychrophilum strain JIP 02/86 was characterized. Zebrafish larvae were infected using the bath method, and morphological changes and innate immune system activation were monitored using transgenic fish. Salmonid-like infection phenotypes were observed in 4.74% of treated larvae, as manifested by fin, muscle and caudal peduncle damage. Symptomatic and dead larvae accounted for 1.35% of all challenged larvae. Interestingly, infected larvae with no infection phenotypes showed stronger innate immune system activation than specimens with phenotypes. A failure of function assay for myeloid factor pu.1 resulted in more infected larvae (up to 43.5%), suggesting that low infection rates by F. psychrophilum would be due to the protective actions of the innate immune system against this bacterium in zebrafish larvae. Our results support the use of zebrafish as an infection model for studying F. psychrophilum. Furthermore, the percentage of infected fish can be modulated by disturbing, to varying extents, the differentiation of myeloid cells. Using this evidence as a starting point, different aspects of the infection mechanism of F. psychrophilum could be studied in vivo.


Asunto(s)
Modelos Animales de Enfermedad , Enfermedades de los Peces/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Flavobacterium/fisiología , Pez Cebra , Animales , Infecciones por Flavobacteriaceae/microbiología
8.
Int J Syst Evol Microbiol ; 69(9): 2794-2800, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31310192

RESUMEN

An 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 : 1 ω7c/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.


Asunto(s)
Riñón/microbiología , Paracoccus/clasificación , Perciformes/microbiología , Filogenia , Animales , Regiones Antárticas , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Paracoccus/aislamiento & purificación , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
9.
Antonie Van Leeuwenhoek ; 112(10): 1465-1475, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31119412

RESUMEN

A pink pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain 36B243T), was isolated from the spleen of a black rock cod (Notothenia coriiceps, Richardson 1844) in the Chilean Antarctica. Strain 36B243T has a 5.26 Mb chromosome with a DNA G + C content of 35.4 mol%. The draft genome includes the prediction and annotation of 4585 coding genes, and 46 tRNA, 1 tmRNA, and 2735 hypothetical proteins. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain 36B243T into the genus Pedobacter with high sequence similarity to the type strains of Pedobacter sandarakinus (97.5%) and Pedobacter petrophilus (97.1%). Sequence similarities to type strains of all other current Pedobacter species were below 97.1%. Predominant fatty acids are summed feature 3 (C16:1ω7c and/or C16:1ω6c) and iso-C15:0 followed by iso-C17:0 3-OH and C16:0. The major respiratory quinone was menaquinone MK-7. The polar lipid profile contained the major lipids phosphatidylethanolamine, five unidentified aminolipids, two lipids lacking a functional group and two minor glycolipids and one lipid lacking a functional group. An alkali-stable lipid was present. The polyamine pattern contained the predominant compound sym-homospermidine. Characterization by 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, polar lipid, and fatty acid composition revealed that strain 36B243T represents a new species of the genus Pedobacter. For this reason, we propose the name Pedobacter nototheniae sp. nov. with the type strain 36B243T (= LMG 30634T = CCM 8855T = CIP 111622T).


Asunto(s)
Pedobacter/clasificación , Pedobacter/aislamiento & purificación , Perciformes/microbiología , Bazo/microbiología , Animales , Regiones Antárticas , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , Análisis por Conglomerados , Citosol/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Genoma Bacteriano , Glucolípidos/análisis , Pedobacter/genética , Pedobacter/fisiología , Fosfolípidos/análisis , Filogenia , Pigmentos Biológicos/metabolismo , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análisis
10.
J Fish Dis ; 42(10): 1447-1455, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31418903

RESUMEN

Vibrio ordalii is an extracellular, Gram-negative bacterium that produces vibriosis in salmonids. While pathogenesis is not fully understood, this bacterium has numerous likely genes for adhesion, colonization, invasion factors and, as recently suggested, intracellular behaviour. Therefore, this study aimed to clarify possible intracellular behaviour for V. ordalii Vo-LM-18 and ATCC 33509T in the fish-cell lines SHK-1 and CHSE-214. Confocal microscopy revealed Vo-LM-18 and ATCC 33509T inside cytoplasm in both fish-cell lines at 4 hr post-inoculation (hpi). At 8 and 16 hpi, the proportion of fish cells invaded by both strains increased. Moreover, intracellular V. ordalii were observed after 8 hpi inside mouse embryonic fibroblasts (MEF), demonstrating that entry was not due to a cellular phagocytosis process. Flow cytometry confirmed immunocytochemistry results, with both V. ordalii evidencing statistically significant differences in the number of infected cells between 8 and 16 hpi. Interestingly, V. ordalii infection did not significantly damage fish cells, as determined by LDH liberation. Viable counts at 8 hpi detected, on average for both lines, 176 ± 47 CFU/ml of culturable intracellular Vo-LM-18 and ATCC 33509T cells. These in vitro findings support the facultative intracellular behaviour of V. ordalii and may be of importance for understanding pathogenicity and survival in aquatic environments.


Asunto(s)
Enfermedades de los Peces/microbiología , Salmón , Vibriosis/veterinaria , Vibrio/fisiología , Animales , Línea Celular , Citometría de Flujo/veterinaria , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Microscopía Confocal/veterinaria , Vibriosis/microbiología
11.
J Fish Dis ; 42(5): 667-675, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30874321

RESUMEN

Spring viraemia of carp (SVC) is an infectious disease responsible for severe economic losses for various cyprinid species, particularly common carp (Cyprinus carpio carpio). The causative agent is the SVC virus (SVCV), a member of the Sprivivirus genus, Rhabdoviridae family, and a List 1 pathogen notifiable by the World Organization for Animal Health. This study describes the diagnosis of an SVCV pathogen isolated in October 2015 from wild common carp inhabiting a natural lagoon in central Mexico. While neither an epidemic nor fish mortalities were reported, the collected killed specimens exhibited clinical signs of disease (e.g., exopthalmia, moderate abdominal distension and haemorrhaging, as well as internal haemorrhages and adhesions). Histological results of injuries were consistent with the pathology caused by SVCV. This finding was supported by the isolation of a virus in EPC and BF-2 cells and subsequent RT-PCR confirmation of SVCV. The phylogenetic analyses of partial SVCV glycoprotein gene sequences classified the isolates into the Ia genogroup. These findings make this the first report of SVCV detection in Mexico, extending the southern geographical range of SVCV within North America. However, since this pathogen was detected in fish inhabiting a natural body of water without tributaries or effluents, it is difficult to estimate the risk of SVCV for other wild/feral cohabitating cyprinid species in the lagoon. The status of this virus is also unknown for other bodies of water within this region.


Asunto(s)
Carpas , Enfermedades de los Peces/diagnóstico , Infecciones por Rhabdoviridae/veterinaria , Rhabdoviridae/aislamiento & purificación , Sepsis/veterinaria , Animales , Enfermedades de los Peces/virología , Glicoproteínas/análisis , México , Filogenia , Infecciones por Rhabdoviridae/diagnóstico , Infecciones por Rhabdoviridae/virología , Sepsis/diagnóstico , Sepsis/virología , Proteínas Virales/análisis
12.
Int J Syst Evol Microbiol ; 67(5): 1306-1311, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28109208

RESUMEN

A 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.


Asunto(s)
Gammaproteobacteria/clasificación , Filogenia , Agua de Mar/microbiología , Regiones Antárticas , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Gammaproteobacteria/genética , Gammaproteobacteria/aislamiento & purificación , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
13.
Int J Syst Evol Microbiol ; 67(3): 716-723, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27902301

RESUMEN

A group of seven Chilean isolates presumptively belonging to Vibrio tapetis was isolated from diseased fine flounders (Paralichthys adspersus) and red conger eel (Genypterus chilensis) experimentally reared in Quintay (Chile). All isolates were confirmed as members of V. tapetis on the basis of matrix-assisted laser desorption ionization time-of-flight MS, 16S rRNA gene sequencing, DNA-DNA hybridization values and G+C content. The ERIC-PCR and REP-PCR patterns were homogeneous among those isolates recovered from the same host (red conger or fine flounders), but distinct from the type strains V. tapetis subsp. tapetis CECT 4600T and V. tapetis subsp. britannicus CECT 8161T. On the basis of atpA, rpoA, rpoD, recA and pyrH gene sequence similarities (99.7-100 %) and clustering in the phylogenetic trees, the red conger isolates (Q20, Q047, Q48 and Q50) were confirmed as representing V. tapetis subsp. tapetis. However, they differed from V. tapetis subsp. tapetis CECT 4600T in their lipase, alpha quimiotripsin and non-acid phosphatase production. On the other hand, the fine flounder isolates (QL-9T, QL-35 and QL-41) showed rpoD, recA and pyrH gene sequence similarities ranging from 91.6 to 97.7 % with the type strains of the two V. tapetis subspecies (CECT 4600T and CECT 8161T) and consistently clustered together as an independent phylogenetic line within V. tapetis. Moreover, they could be differentiated phenotypically from strains CECT 4600T and CECT 8161T by nine and three different biochemical tests, respectively. In conclusion, the presence of V. tapetis in diseased red conger eel and fine flounder was demonstrated, extending the known host range and geographical location for this pathogen. Furthermore, this study demonstrates that the three isolates from fine flounder represent a novel subdivision within V. tapetis, for which the name V. tapetis subsp. quintayensis subsp. nov. is proposed and with QL-9T (=CECT 8851T=LMG 28759T) as the type strain. Although QL-9T was isolated from kidney of diseased fine flounder specimens, the challenge assays showed that it was non-pathogenic for this species.


Asunto(s)
Lenguado/microbiología , Filogenia , Urodelos/microbiología , Vibrio/clasificación , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Genes Bacterianos , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vibrio/genética , Vibrio/aislamiento & purificación
14.
Int J Syst Evol Microbiol ; 66(9): 3625-3631, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27307140

RESUMEN

One beige-pigmented, Gram-stain-negative, rod-shaped bacterium, strain E3/4T, was isolated from a zebrafish, Danio rerio. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared 98.5 % 16S rRNA gene sequence identity to the type strain of Undibacterium macrobrachii and 97.8 % to the type strain of Undibacterium seohonense. Lower 16S rRNA gene sequence similarities (<97.0 %) could be found in comparison with all other species of the genus Undibacterium. DNA-DNA hybridization with Undibacterium macrobrachiiLMG 26891T showed a low level of relatedness, <35 %. The main cellular fatty acids of the strain were summed feature 3 fatty acids (C16 : 1ω7c/C16 : 1ω8c), C10 : 0 3-OH and C16 : 0. The polyamine pattern of strain E3/4T contained predominantly putrescine and 2-hydroxyputrescine. The major quinone was ubiquinone Q-8. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. On the basis of phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a novel species of the genus Undibacterium, Undibacterium danionis, with strain E3/4T (=DSM 102221T=CCM 8677T=CIP 111017T) as the type strain.


Asunto(s)
Oxalobacteraceae/clasificación , Filogenia , Pez Cebra/microbiología , Animales , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Oxalobacteraceae/genética , Oxalobacteraceae/aislamiento & purificación , Putrescina/análogos & derivados , Putrescina/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ubiquinona/química
15.
Dis Aquat Organ ; 120(1): 27-38, 2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-27304868

RESUMEN

Vibrio ordalii, the causative agent of atypical vibriosis, is a Gram-negative, motile, rod-shaped bacterium that severely affects the salmonid aquaculture industry. V. ordalii has been biochemically, antigenically and genetically characterized. However, studies on the survival behaviour of this bacterium in aquatic environments are scarce, and there is no information regarding its disease transmission and infectious abilities outside of the fish host or regarding water as a possible reservoir. The present study investigated the survival behaviour of V. ordalii Vo-LM-06 and Vo-LM-18 in sterile and non-sterile seawater microcosms. After a year in sterile seawater without nutrients, 1% of both V. ordalii strains survived (~10(3) colony-forming units ml(-1)), and long-term maintenance did not affect bacterial biochemical or genetic properties. Additionally, V. ordalii maintained for 60 d in sterile seawater remained infective in rainbow trout Oncorhynchus mykiss. However, after 2 d of natural seawater exposure, this bacterium became non-culturable, indicating that autochthonous microbiota may play an important role in survival. Recuperation assays that added fresh medium to non-sterile microcosms did not favour V. ordalii recovery on solid media. Our results contribute towards a better understanding of V. ordalii survival behaviour in seawater ecosystems.


Asunto(s)
Enfermedades de los Peces/microbiología , Oncorhynchus mykiss , Agua de Mar/microbiología , Vibriosis/veterinaria , Vibrio/fisiología , Animales , Factores de Tiempo , Vibrio/patogenicidad , Vibriosis/microbiología , Virulencia
16.
Dis Aquat Organ ; 118(3): 217-26, 2016 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-27025309

RESUMEN

Vibrio ordalii is the causative agent of vibriosis in several cultured salmonid species worldwide. Despite its impact on aquaculture, relatively little information is available about its virulence factors. The present study demonstrates for the first time that V. ordalii possesses different systems of iron acquisition, one involving siderophore synthesis and another one that uses direct binding of heme to use iron. Using 6 strains of V. ordalii from Atlantic salmon Salmo salar and the V. ordalii type strain, we could demonstrate that all strains could grow in presence of the chelating agent 2,2'-dipyridyl and produced siderophores in solid and liquid media. Cross-feeding assays among V. ordalii strains evidenced variability in the siderophores produced. Bioassays and PCR data suggest that V. ordalii could produce a siderophore with a structure similar to piscibactin, although the production of a second siderophore in certain strains cannot be discarded. Furthermore, all strains were able to use hemin and hemoglobin as the only iron sources, although the cell yield was higher when using hemoglobin. A hemin-binding assay indicated the presence of constitutive heme-binding molecules at the cell surface of V. ordalii. Virulence tests using rainbow trout as a model of infection revealed a clear relationship between iron-uptake ability and pathogenicity in V. ordalii.


Asunto(s)
Enfermedades de los Peces/microbiología , Hierro/metabolismo , Salmo salar , Sideróforos/metabolismo , Vibriosis/veterinaria , Vibrio/metabolismo , Animales , Acuicultura , Chile/epidemiología , ADN Bacteriano/genética , Enfermedades de los Peces/epidemiología , Hemo/metabolismo , Vibriosis/epidemiología , Vibriosis/microbiología
17.
Curr Res Microb Sci ; 2: 100049, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34841340

RESUMEN

Botrytis cinerea is a phytopathogenic fungus that infects over 200 plant species and can cause significant crop losses in local and worldwide agricultural industries. However, its presence in the endemic flora in the Coquimbo Region and its impact on local flora have not been studied yet. In order to determine whether Botrytis spp is present in the native plant in the Coquimbo Region, fifty-two field-samples were analysed. A total of 30 putative Botrytis spp were isolated and phenotypic and genetically characterized. The internal transcribed spacer (ITS) analysis of these isolates revealed that it corresponded to genus Botrytis. For further confirmation, nuclear protein-coding genes (G3PDH, HSP60, and RPB2) were sequenced and showed 100% identity against B. cinerea. Complementary to this, Botrytis can also be clustered in two different groups, group I (B. pseudocinerea) and group II (B. cinerea), based on DNA polymorphism, the Botrytis isolates were identified as member of group II. On the order hand, we investigated the presence and frequency distribution of the transposable elements boty and flipper in the isolates obtained. The results indicate that 83.3% of the isolates presented both transposable elements, boty and flipper, indicating that the most prevalent genotype was transpose. In addition, 16.6% of the isolates showed substantially reduced virulence in apple fruit in comparison to B05.10 strain. According to fungicide resistance studies, the results indicate that resistance to Fenhexamid or Boscalid was observed in the 22.6% of isolates. The results show for the first time that B. cinerea has not been described before in fourteen new host plants and contributes to our fundamental understanding of the presence of B. cinerea in the native plant in the Coquimbo Region and the possible ecological impact of this disease on native and endemic plants.

18.
Microbiol Resour Announc ; 9(9)2020 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-32107298

RESUMEN

We announce the draft genome sequence of strain B2, which belongs to a potentially new Buttiauxella species, isolated from soil associated with rhizosphere of olivillo trees (Aextoxicon punctatum). Its size is 4,967,099 bp, and its G+C content is 49.1%. The genome of strain B2 carries genes related to rhizobacteria that promote the growth of plants.

19.
Microbiol Resour Announc ; 9(21)2020 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-32439667

RESUMEN

Here, we announce the draft genome sequence of Pseudomonas sp. strain AN3A02, isolated from the rhizosphere of one of the only two species of vascular plants existing in the Antarctic continent, Deschampsia antarctica Desv. This isolate, which inhibited the mycelial growth of Botrytis cinerea in dual culture, has a genome sequence of 6,778,644 bp, with a G+C content of 60.4%. These draft genome sequence data provide insight into the genetics underpinning the antifungal activity of this strain.

20.
Microbiol Resour Announc ; 8(22)2019 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-31147434

RESUMEN

We announce the draft genome sequence of Pseudomonas sp. strain M7D1, isolated from the rhizosphere of a plant in the Atacama Desert bloom event. The genome sequence had 6,170,633 bp with a G+C content of 59.9%. This draft genome sequence gives information about the presence of genes related to iron acquisition, alleviation of abiotic stress, and other essential traits of plant growth-promoting rhizobacteria.

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