Search results for " BAC"
showing 10 items of 2829 documents
The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae)
2016
Termite gut is host to a complex microbial community consisting of prokaryotes, and in some cases flagellates, responsible for the degradation of lignocellulosic material. Here we report data concerning the analysis of the gut microbiota of Reticulitermes lucifugus (Rossi), a lower termite species that lives in underground environments and is widespread in Italy, where it causes damage to wood structures of historical and artistic monuments. A 16S rRNA gene clone library revealed that the R. lucifugus gut is colonized by members of five phyla in the domain Bacteria: Firmicutes (49 % of clones), Proteobacteria (24 %), Spirochaetes (14 %), the candidatus TG1 phylum (12 %), and Bacteroidetes (…
Human milk and mucosa-associated disaccharides impact on cultured infant fecal microbiota
2020
Human milk oligosaccharides (HMOs) are a mixture of structurally diverse carbohydrates that contribute to shape a healthy gut microbiota composition. The great diversity of the HMOs structures does not allow the attribution of specific prebiotic characteristics to single milk oligosaccharides. We analyze here the utilization of four disaccharides, lacto-N-biose (LNB), galacto-N-biose (GNB), fucosyl-α1,3-GlcNAc (3FN) and fucosyl-α1,6-GlcNAc (6FN), that form part of HMOs and glycoprotein structures, by the infant fecal microbiota. LNB significantly increased the total levels of bifidobacteria and the species Bifidobacterium breve and Bifidobacterium bifidum. The Lactobacillus genus levels wer…
Metabolic and process engineering for biodesulfurization in Gram-negative bacteria
2017
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Conjugative ESBL plasmids differ in their potential to rescue susceptible bacteria via horizontal gene transfer in lethal antibiotic concentrations.
2017
Conjugative ESBL plasmids differ in their potential to rescue susceptible bacteria via horizontal gene transfer in lethal antibiotic concentrations
Whole genome sequences reveal Vibrio hemicentroti Kim et al. 2013 as a later heterotypic synonym of Vibrio splendidus (Beijerinck 1900) Baumann et al…
2017
The synonymy between Vibrio hemicentroti Kim et al. 2013 and Vibrio splendidus (Beijerinck 1900) Baumann et al. 1981 was suggested after a recent multilocus sequence analysis of the Splendidus clade, which included the type strains of both species. To clarify their status, we have determined genomic indexes from whole genome sequences of strains V. hemicentroti CECT 8714T and V. splendidus NCCB 53037T. Average Nucleotide Identities of 96.0–96.7 % and an in silico DNA–DNA hybridization value of 70.2 %, as well as similarity levels of selected housekeeping gene sequences support the consideration of V. hemicentroti as a later heterotypic synonym of V. splendidus .
Chance and necessity in the genome evolution of endosymbiotic bacteria of insects.
2017
An open question in evolutionary biology is how does the selection–drift balance determine the fates of biological interactions. We searched for signatures of selection and drift in genomes of five endosymbiotic bacterial groups known to evolve under strong genetic drift. Although most genes in endosymbiotic bacteria showed evidence of relaxed purifying selection, many genes in these bacteria exhibited stronger selective constraints than their orthologs in free-living bacterial relatives. Remarkably, most of these highly constrained genes had no role in the host–symbiont interactions but were involved in either buffering the deleterious consequences of drift or other host-unrelated function…
High prevalence and moderate diversity of Pseudomonas aeruginosa in the U-bends of high-risk units in hospital
2017
The presence of P. aeruginosa in water supply is clearly identified as a risk factor for P. aeruginosa infection in critical care units, even if routes of transmission are often unclear and remain a matter of debate. We determined here the frequency of U-bends contaminated with P. aeruginosa in high-risk units and described the population structure of this opportunistic pathogen in a non-outbreak situation. Eighty-seven U-bends from sinks of rooms in five wards were sampled 3 times and P. aeruginosa was detected in 121 of the 261 (46.4%) U-bend samples. We genotyped 123 P. aeruginosa isolates with pulsed-field gel electrophoresis and multilocus sequence typing and found 41 pulsotypes distri…
Role of mucosal immune response and histopathological study in European eel (Anguilla anguilla L.) intraperitoneal challenged by Vibrio anguillarum o…
2021
Abstract The external mucus layer that covers fish skin contains numerous immune substances scarcely studied that act as the first line of defence against a broad spectrum of pathogens. This study aimed to characterize and describe for the first time several humoral immune defence parameters in the skin mucus of the European eel (Anguilla anguilla) after intraperitoneal injection with Vibrio anguillarum or Tenacibaculum soleae. This study evaluated several immune-related enzymes and bactericidal activity against fish pathogenic bacteria in the skin mucus of European eels at 24, 48, and 72 h post-challenge. The results demonstrated that European eel skin mucus showed significant increments i…
Genetic Diversity of O-Antigens in Hafnia alvei and the Development of a Suspension Array for Serotype Detection.
2016
Hafnia alvei is a facultative and rod-shaped gram-negative bacterium that belongs to the Enterobacteriaceae family. Although it has been more than 50 years since the genus was identified, very little is known about variations among Hafnia species. Diversity in O-antigens (O-polysaccharide, OPS) is thought to be a major factor in bacterial adaptation to different hosts and situations and variability in the environment. Antigenic variation is also an important factor in pathogenicity that has been used to define clones within a number of species. The genes that are required to synthesize OPS are always clustered within the bacterial chromosome. A serotyping scheme including 39 O-serotypes has…
Rapid detection of carbapenem resistance: Targeting a zero level of inadequate empiric antibiotic exposure
2016
Resistance to carbapenems is an increasingly encountered phenomenon in the ICU, complicating empiric and targeted antimicrobial therapy. Infections due to carbapenem-resistant microorganisms are characterized by high morbidity and mortality [1, 2]. Recently, there has been an increasing interest in rapid detection techniques, based on real time on-demand easy-to-use PCR, to detect genes responsible for carbapenem resistance. One of these techniques is the Cepheid Xpert Carba-R assay, which is able to detect and differentiate five of the most frequent genes associated with non-susceptibility to carbapenems in Gram-negative bacteria (bla KPC, bla VIM, bla OXA-48, bla IMP-1, bla NDM). The diag…