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Animal hosts live in continuous interaction with bacterial partners, yet we still lack a clear understanding of the ecological drivers of animal-associated bacteria, particularly in seabirds. Here, we investigated the effect of body site in the structure and diversity of bacterial communities of two seabirds in the Strait of Magellan: the Magellanic penguin (Spheniscus magellanicus) and the king penguin (Aptenodytes patagonicus). We used 16S rRNA gene sequencing to profile bacterial communities associated with body sites (chest, back, foot) of both penguins and the nest soil of Magellanic penguin. Taxonomic composition showed that Moraxellaceae family (specifically Psychrobacter) had the highest relative abundance across body sites in both penguin species, whereas Micrococacceae had the highest relative abundance in nest soil. We were able to detect a bacterial core among 90% of all samples, which consisted of Clostridium sensu stricto and Micrococcacea taxa. Further, the king penguin had its own bacterial core across its body sites, where Psychrobacter and Corynebacterium were the most prevalent taxa. Microbial alpha diversity across penguin body sites was similar in most comparisons, yet we found subtle differences between foot and chest body sites of king penguins. Body site microbiota composition differed across king penguin body sites, whereas it remained similar across Magellanic penguin body sites. Interestingly, all Magellanic penguin body site microbiota composition differed from nest soil microbiota. Finally, bacterial abundance in penguin body sites fit well under a neutral community model, particularly in the king penguin, highlighting the role of stochastic process and ecological drift in microbiota assembly of penguin body sites. Our results represent the first report of body site bacterial communities in seabirds specialized in subaquatic foraging. Thus, we believe it represents useful baseline information that could serve for long-term comparisons that use marine host microbiota to survey ocean health.

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Bacteria of the genus Psychrobacter are known for their psychrophilic characteristics, being extremophilic organisms capable of surviving and reproducing in hostile environments of low temperature and high pressure. Among many of the genus characteristics, there is the ability to produce enzymes and molecules of industrial biotechnology importance, such as pigments and proteins related to heavy metal bioremediation. The bacterium strain Psychrobacter nivimaris LAMA 639 was isolated from sediments from the Walvis Ridge ocean crest at a depth of 4.400 m (33.40 S 2.35 E). It is a nonmotile, halotolerant, cream-colored gram-negative aerobic bacterium. Its cultivation was performed in marine agar plates and inoculated into test tubes with NaCl at an optimal temperature of 30 °C and with shaking at 100 rpm. Genome extraction was performed with the DNeasy Blood & Tissue Kit (QIAGEN®). Sequencing was performed by Macrogen using the NovaSeq® 6000 platform (Illumina) applying the whole genome shotgun (WGS) method. Thereafter, 14.712.526 reads of 151 bp were generated, totaling 2.2 G bp with a GC content of 42.9%. Assembly and mapping were performed with a CLC Genomics Workbench. The best assembly considered was the one with the lowest number of contigs and the highest base length pair. The assemblies were evaluated using QUAST, and the best resulting variant was selected for annotation. Genome annotation was performed with RAST and PATRIC; the antiSMASH tool was used for secondary metabolites; NaPDoS was used for domains; and three-dimensional structural prediction of relevant proteins was performed using Phyre2. Annotation with ClassicRAST generated 2,891 coding sequences (CDSs) distributed in 402 subsystems. Annotation with PATRIC generated 2,896 coding sequences, among them 776 hypothetical proteins. The antiSMASH tool visualized a beta-lactone cluster in contig 06. In the search for natural products with NaPDoS, two ketosynthase domains were identified. The search for relevant proteins was performed using the AMFEP list as a criterion. From these data, 34 possible enzymes with biotechnological potential were found. Finally, the organism is presented as a new reference regarding the potential of deep-sea marine bacteria, demonstrating that, from the annotated and cured genome, it is possible to find in its genetic repertory products of interest for biotechnological applications.

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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.

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Se efectuó un estudio con el empleo de la metodología de Gupta, en el Departamento de Biología y Geografía de la Universidad de Oriente en Santiago de Cuba, para determinar marcadores moleculares de tipo inserción en secuencias de las proteínas ADN polimerasa I y ADN polimerasa III (subunidad alfa), obtenidas de bases de datos internacionales y posteriormente alineadas con el programa ClustalX2. Las familias Moraxellaceae y Helicobacteraceae han sido ampliamente estudiadas, porque comprenden agentes patógenos causantes de numerosas enfermedades en humanos, pero pocas investigaciones han estado dirigidas a la identificación de las características moleculares que puedan distinguir a sus miembros de otros grupos de bacterias; de manera que los presentes resultados constituyen un aporte al conocimiento de la genética y la bioquímica de estas familias y proveen herramientas moleculares para la clasificación taxonómica y el diagnóstico de especies patógenas

A study with the use of Gupta methodology was carried out in the Biology and Geography Department of Oriente University in Santiago de Cuba, to determine molecular markers of insertion type in sequences of the DNA polimerase I proteins and DNA polimerase III (alpha subunity), obtained from international databases and later on aligned with the ClustalX2 program. The Moraxellaceae and Helicobacteraceae families have been broadly studied, because they comprise pathogen agents that cause numerous diseases in humans, but few investigations have been directed to the identification of the molecular characteristics that can distinguish their members from other groups of bacterias; so these results constitute a contribution to the knowledge of genetics and biochemistry of these families and provide molecular tools for the taxonomic classification and the diagnosis of pathogen species

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In this study, we have investigated the phylogeny and the antagonistic interactions of culturable bacteria isolated from the sea urchin Paracentrotus lividus collected from Aber and Morgat, both located in Crozon peninsula, France. Bacteria were isolated from the gastrointestinal tracts of ten specimens by using conventional culture-dependent method and then investigated by using phylogenetic analysis based on 16S rRNA gene sequence comparisons. Assays for antagonistic interactions among the bacterial strains were performed; bacteria (including at least one strain representative of each OTU identified) were screened for antimicrobial substance production. So, 367 bacterial strains were isolated on marine-agar. On the basis of morphological characteristics, 180 strains were sequenced and 94 OTUs were classified. The dominant phyla were Proteobacteria, Firmicutes and Actinobacteria, with a high abundance of the strains belonging to the genus Psychrobacter. From the antagonistic interactions assays, it could be determined that 22.7% strains were positive for at least one antagonism interaction, 18.3% of them isolated from the sea urchins collected in Morgat. We hypothesize that the bacteria isolated in this study may represent the transitory microbiota of the gastrointestinal tract of P. lividus, and that this microbiota may be related to the diet of this marine invertebrate. Furthermore, our results suggest that chemical antagonism could play a significant role in shaping the bacterial communities within gastrointestinal tract of the sea urchins. In addition, most isolated bacteria may have promising biotechnology applications.

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The genus Psychrobacter includes Gram-negative coccobacilli that are non-pigmented, oxidase-positive, non-motile, psychrophilic or psychrotolerant, and halotolerant. Psychrobacter strain ENNN9_III was isolated from water in a polluted temperate estuarine system, contaminated with hydrocarbons and heavy metals. The genome has a G + C content of 42.7%, 2618 open reading frames (ORFs), three copies of the rRNAs operon, and 29 tRNA genes. Twenty-five sequences related to the degradation of aromatic compounds were predicted, as well as numerous genes related to resistance to metals or metal(loid)s. The genome sequence of Psychrobacter strain ENNN9_III provides the groundwork for further elucidation of the mechanisms of metal resistance and aromatic compounds degradation. Future studies are needed to confirm the usefulness of this strain for bioremediation proposes.

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The genus Psychrobacter contains environmental, psychrophilic and halotolerant gram-negative bacteria considered rare opportunistic pathogens in humans. Metagenomics was performed on the cerebrospinal fluid (CSF) of a pediatric patient with meningitis. Nucleic acids were extracted, randomly amplified, and sequenced with the 454 GS FLX Titanium next-generation sequencing (NGS) system. Sequencing reads were assembled, and potential virulence genes were predicted. Phylogenomic and phylogenetic studies were performed. Psychrobacter sp. 310 was identified, and several virulence genes characteristic of pathogenic bacteria were found. The phylogenomic study and 16S rRNA gene phylogenetic analysis showed that the closest relative of Psychrobacter sp. 310 was Psychrobacter sanguinis. To our knowledge, this is the first report of a meningitis case associated with Psychrobacter sp. identified by NGS metagenomics in CSF from a pediatric patient. The metagenomic strategy based on NGS was a powerful tool to identify a rare unknown pathogen in a clinical case.

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