MicrobiologyOpen

Bacillus anthracis harbors two paralogs of the global transcriptional regulator of stress response, SpxA. SpxA1 and SpxA2 contribute to disulfide stress tolerance, but only SpxA1 functions in resistance to peroxide. Transcriptome analysis uncovered potential SpxA1 and SpxA2 regulon members, which include genes activated by both paralogs. However, paralog-specific gene activation was also observed. Genes encoding glutamate racemase, CoA disulfide reductase, and products functioning in bacillithiol biosynthesis, are among the genes activated by the SpxA paralogs.

We reported a newly isolated Pseudomonas koreensis strain S150, which antagonized plant pathogens, solubilized phosphates, produced siderophores and enzymes, and promoted plant growth. Genome mining showed that the strain S150 possesses 10 genomic islands coding for secondary metabolites, one of which is lokisin, an unusual cyclic lipopeptide. We generated a deletion mutant for the smallest non-ribosomal peptide synthetase gene lokA in strain S150. Antifungal activity was deficient in the lokA mutant and was restored by gene complementation.

This study investigated the occurrence of Vibrio spp. in water samples, fish and marine bivalves from the temperate Oceanic and Polar Oceanic areas around Norway. Five species, V. alginolyticus (n = 53), V. metschnikovii (n = 38), V. anguillarum (n = 21), V. antiquarius (n = 2) and V. fujianensis (n = 2) were isolated. We examined antimicrobial susceptibility, hemolytic activity and characterized antimicrobial resistance genes and virulence genes by whole genome sequencing. This study found low prevalence of multidrug resistance, and absence of virulence genes of high global concern.

The associated microbiota of marine invertebrates plays an important role in their fitness, health, and homeostasis. Cooperative as well as competitive interactions between bacteria affect the establishment and dynamics of the microbiota. Consequently, we assessed such interactions by growth inhibition and QS interference assays using isolated bacteria associated with emerging model species of the basal animal phyla Cnidaria (Aurelia aurita) and Ctenophora (Mnemiopsis leidyi).

The dominant taxon with the abundance of >1% in gut microbiota was compared between wild and captive northern grass lizards (Takydromus septentrionalis). Significant differences were found between the two groups of lizards at all levels from class down to genus. Our results provide an inference that captivity can affect the species diversity and abundance of gut microbiota in lizards.

This study focuses on the role of small noncoding RNA both in standard Streptococcus mutans and clinical strain biofilms. sRNA0426 is potentially involved in the biofilm formation of S. mutans. The results of this study provide new insights into the complex biofilm regulatory network in S. mutans, which infers a new possibility for dental caries prevention.

The present study provides an overview of the bactericidal and virucidal activity of ethanol and povidone-iodine based on a systematic literature search. Both ethanol and povidone-iodine have an inactivating effect on bacteria and viruses depending on the concentrations used. The data may help to improve the microbicidal application of ethanol and povidone-iodine in practice.

The bacterial diversity of the solar-powered sea slug, Elysia crispata (clarki ecotype), was investigated. The results showed inter-individual variability in bacterial diversity, suggesting that the bacteria live commensally with these sea slugs.

In this study, a standardized Gram stain procedure for bacteria and inflammatory cells was developed using an automated staining instrument. Favorable staining results of clinical specimens highly consistent with their cultured results were obtained. Also, an updated molecular mechanism of Gram stain for bacteria and the probable staining mechanism for inflammatory cells were proposed.

Flavour formation among twelve strains of Debaryomyces hansenii when grown on a simple cheese model mimicking a cheese surface was investigated by dynamic headspace sampling followed by gas chromatography - mass spectrometry (GC-MS). The present study confirmed that D. hansenii possess the ability to produce important cheese flavour compounds, primarily branched-chain aldehydes and alcohols, and thus important for the final cheese flavour. Even though, Debaryomyces hansenii strains differed in their production of cheese flavour compounds.

A fosmid system was used to clone a barley rhizosphere soil metagenome, which was screened for mineral phosphate solubilization (MPS). The MPS clones were analyzed by 454 Roche sequencing and annotated. A number of genes/operons with homology to P uptake, regulatory and solubilization mechanisms were identified.

Computational analysis of metagenomic and metatranscriptomic data from snow samples collected at different springtimes in Svalbard, Norway suggests that a new microbial community is metabolically active in the late spring, while early spring samples likely overwhelmingly carry genomic residue from prior seasons. Furthermore, the correlation between the sequencing-based, computationally determined metabolic pathways, and the experimentally measured organic acid concentration highlights active microbial degradation of complex organic compounds previously unreported at low temperatures.

Bacterial strains MS586^T and MS82 were isolated from soybean rhizosphere in Mississippi. Both strains exhibited striking antimicrobial activity. According to analyses of phylogenetic, phenotypic, physiological, biochemical, and chemotaxonomic characteristics, strains MS586^T and MS82 represent a novel species of the genus Pseudomonas, which belongs to the Pseudomonas koreensis subgroup. The proposed name for the new species is Pseudomonas glycinae, and the type strain is MS586^T.

The prevalence of Helicobacter pylori infection is elevated along with increasing age. Compared with the ¹³C-urea breath test, the immunochromatographic assay-based stool antigen test achieves excellent accuracy with high specificity but suboptimal sensitivity in the male elderly population before and after the eradication of H. pylori. Caution is needed when applying this test to patients with constipation, which can reduce the sensitivity of the stool antigen test.

Using a global collection of multilocus sequence typing data from Vibrio vulnificus spanning over 55 years, this study provides insights into the spatial and temporal dynamics of the species evolution. The common ancestor of all V. vulnificus populations originated in East Asia, and later evolved into two main clusters that spread with time and eventually evolved into distinct populations in North America and Western Europe.

We evaluated hexyl gallate (G6) as an alternative to copper compounds for citrus plant protection. G6 was able to protect citrus nursery trees against Xanthomonas citri infection, and it is safe for tissue culture cell lines. This study demonstrated that G6 is a promising candidate for the development and use in citrus canker management.