MicrobiologyOpen

Gene expression in Haloarcula hispanica cells infected with the gammapleolipovirus His2 was studied using a custom DNA microarray. Temporal and differential expression in both host and viral genes was observed. This study facilitates the  characterization of many hypothetical viral genes and provides insights into the interaction between His2 and its host.

MRSA has been reported as the main pathogen involved in osteomyelitis and prosthetic joint infections. The host/pathogen interaction is dynamic and requires several changes to promote bacterial survival. Here, we focused on the internalization and persistence behavior of Staphylococcus aureus invasive strains belonging to the major MRSA clones, within human MG-63 osteoblasts. We used imaging flow cytometry, a technique able to analyze living host cells. We demonstrated that the intracellular persistence process is different among clones and depends on the total number of infected cells instead of the number of intracellular bacteria.

Study question: What is the intralaboratory reliability of microbiome sequencing of infant stool samples and how do results differ with the various collection, handling, and processing extraction protocols? What is already known: Various protocols are used in human microbiome research. Studies of the reliability of these methods have been conducted largely among adults in whom the microbiome is relatively stable. What this study adds: Large-scaled epidemiologic studies of the human microbiome are beginning to emerge. This study adds to evidence of the reliability of methods used to assess the early developing microbiome during the time of the greatest interperson variability.

Biosurfactants such as rhamnolipids are emerging as a sustainable and environmentally friendly alternative to synthetic surfactants. The production of the mono-rhamnolipid Rha-C10-C10 by a novel nonpathogenic and easily engineerable host, Pantoea sp. P37 was investigated. Analysis of the genome suggested that the strain has evolved into an epiphytic rather than a pathogenic lifestyle. Functional heterologous expression of the mono-rhamnolipid operon rhlAB derived from a Pseudomonas aeruginosa strain was established.

We applied molecular epidemiology and population genetics to obtain insights in to the population structure, host-species relationships, gene flow and evolution of Campylobacter jejuni in urban ducks and starlings.

The microbial communities of the different parts of the Mongolian horse gastrointestinal tracts were significantly different, and there was greater diversity between the lower gut and upper gut. Direct sampling of the different segments of gastrointestinal tracts provided a more complete diagram of the gut microbiota than fecal analysis. The vegetarian diets and adaptability of Mongolian horses were likely related not only to their stable and complicated gastrointestinal microbiota but also to their special herbivorous digestive physiology.

Pseudomonas aeruginosa biofilm formation is a primary cause of chronic infections and has been a highly active area of research over the past two decades. This study evaluates global trends in the dynamic and rapidly evolving field of P. aeruginosa biofilm research through bibliometric and visualized analyses.

Leptonycteris yerbabuenae is a bat species found in Mexico in two separate populations, one in the Pacific and the other in the Central region. With the analysis of its fecal microbiota, we found differentiation between the two populations. However, these populations share a core microbiota of 359 Amplicon Sequences Variants, accounting for 75% of abundance, and suggesting stability over time. The microbiota differs between reproductive stages within the populations, suggesting that factors such as geographic separation and physiological variation drive changes in the microbiota.

A reusable water bottle was swabbed as part of the citizen science project “Swab and Send,” and a Klebsiella grimontii isolate was recovered on chromogenic agar and designated SS141. Whole-genome sequencing of SS141 showed it has the potential to be a human pathogen as it contains the biosynthetic gene cluster for the potent cytotoxin, kleboxymycin, and genes for other virulence factors and antibiotic resistance. We have also shown that SS141 is a potent biofilm former, providing a reasonable explanation for its ability to colonize a reusable water bottle.

A set of 23 new shuttle plasmid vectors for use in actinomycetes has been developed using the modular SEVA architecture. The figure shows a trimodular structure of these new conjugative shuttle vectors for actinomycetes and E. coli, based on the pSEVA backbone, showing the replication module, the antibiotic selection region, and the cargo sector.

The alpha diversity of gut microbiomes in the wild group was significantly higher than that in the captive group. The content of pathogenic bacteria increased in the captive group. The health level of the captive kiang was lower than that of the wild kiang.

This study investigated the microbiota of larvae and pupae of Aedes albopictus exposed to different ampicillin concentrations and the bacterial composition of adult females. Results demonstrate that the microbial community showed obvious stage-specific characteristics, whereas differences were observed between adult females that were exposed to different ampicillin concentrations in immature stages. Antibiotics might cause dysbiosis rather than excluding bacteria from mosquitoes, and the accumulated disturbing effect of ampicillin has emerged in adults.

This article proposes a protocol for image analysis of electrophoresis gels that allows the quantification of unknown proteins using the molecular weight markers in SDS-PAGE gels as protein standards. The periplasmic production of the nanobody CH10-12 was obtained through fed-batch strategy and quantified using the band of 50 kDa in the marker as a reference for 750 ng of recombinant protein. The molecular weight marker was used as a sole protein standard for protein quantification in SDS-PAGE gel images.

In this study, we reported a novel strain isolated from the desert soil in the Qinghai–Tibetan Plateau. According to an analysis of phenotypic, phylogenetic, and chemotaxonomic characteristics, strain Y74T was determined to be a new member within the genus Planococcus. Therefore, it was named as Planococcus antioxidans sp. nov. Y74T. Strain Y74T was found to have potent antioxidant activity via its hydrogen peroxide tolerance and its 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity.

The apo-forms of [NiFe]-hydrogenase large subunits are usually synthesized with a C-terminal peptide extension that is proteolytically cleaved off upon incorporation of the catalytic metal center. Although to a limited amount, an artificially precleaved large subunit, which was deleted for the C-terminal extension by genetic engineering, still received the active site components delivered by the dedicated maturation machinery. This suggests that the C-terminal extension optimizes metal center incorporation, but is not essential for the formation of catalytically active [NiFe]-hydrogenase.

In this study, we describe the microbial communities in the floral nectar of seven Epipactis species. Despite previous claims that the floral nectar of orchids is characterized by the presence of several antimicrobial substances that possibly limit microbial growth, we found a wide variety of both bacterial and yeast species.

A multianalytical approach based on culture-dependent methods, high-throughput sequencing, and scanning electron microscopy was implemented to characterize the microbiota on stone of the Convent of Christ (Tomar, Portugal). The biocolonizer agents detected induce aesthetic damages and structural alterations on these materials, promoting the appearance of stains, biofilms, and detachment of stone fragments. These findings are a starting point for the implementation of a long-term monitoring plan to prevent the decay of this monument and promote its safeguard.

The abundance and distribution of virioplankton were investigated in the Caroline seamount of Western Pacific. Three to four distinct viral subclusters with similar side scatter but different green fluorescence intensity were identified. The interactions of shallow seamount and local current could sustain a significant enhancement of virus standing stock, causing a so-called “seamount effect” for virioplankton.

We address an unresolved question regarding the source of Escherichia coli that causes community-acquired urinary tract infection (CA-UTI)—whether E. coli strains that cause UTI represent members of the intestinal commensal E. coli or a distinct subgroup of pathogenic E. coli. Our results based on multilocus sequence type (MLST) analysis of E. coli isolates from healthy volunteers versus urine isolates from patients with UTI indicate that uropathogenic E. coli has a source outside of the human intestine.

Rhodobacter capsulatus fixes nitrogen from air by a molybdenum-dependent and an iron-only nitrogenase. Here, we present evidence that the transcriptional activator AnfA is required for AnfHDGK production, but dispensable for biosynthesis of the Fe-only cofactor and electron delivery.