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Applied Microbiology Jan 1974A genetic transformation assay for unequivocal identification of strains of Moraxella osloensis is described. In this assay a stable tryptophan auxotroph is transformed...
A genetic transformation assay for unequivocal identification of strains of Moraxella osloensis is described. In this assay a stable tryptophan auxotroph is transformed to prototrophy by deoxyribonucleic acid (DNA) samples from other strains of M. osloensis but not by DNA samples from unrelated bacteria. The test is simple to perform and definitive results can be obtained in less than 24 h. The procedure, which is suitable for routine diagnosis in a clinical laboratory, involves a rapid method for preparation of crude transforming DNA from small quantities of bacterial cells and permits simultaneous examination of large numbers of isolated cultures. The assay was shown to correctly identify 27 strains previously classified as M. osloensis. Forty-five other gram-negative, oxidase-positive, nonmotile coccobacilli, which might be confused with M. osloensis unless subject to more extensive testing, were shown to be unrelated genetically to M. osloensis. The transformation assay clearly distinguishes M. osloensis from Acinetobacter. Although most strains of M. osloensis are nonfastidious, being able to grow in a mineral medium supplemented with a single organic carbon source, one of the strains tested was only able to grow on fairly complex media and could not be transformed to grow on simple media. Inability to alkalize Simmons citrate agar was shown not to be characteristic of all strains of M. osloensis.
Topics: Acinetobacter; Alcaligenes; Bacteriological Techniques; Culture Media; DNA, Bacterial; Methods; Micrococcus; Moraxella; Mutagens; Mutation; Nitrosoguanidines; Transformation, Genetic; Tryptophan
PubMed: 4589126
DOI: 10.1128/am.27.1.16-24.1974 -
Scientific Reports Jul 2017The built environment (BE) and in particular kitchen environments harbor a remarkable microbial diversity, including pathogens. We analyzed the bacterial microbiome of...
The built environment (BE) and in particular kitchen environments harbor a remarkable microbial diversity, including pathogens. We analyzed the bacterial microbiome of used kitchen sponges by 454-pyrosequencing of 16S rRNA genes and fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH-CLSM). Pyrosequencing showed a relative dominance of Gammaproteobacteria within the sponge microbiota. Five of the ten most abundant OTUs were closely related to risk group 2 (RG2) species, previously detected in the BE and kitchen microbiome. Regular cleaning of sponges, indicated by their users, significantly affected the microbiome structure. Two of the ten dominant OTUs, closely related to the RG2-species Chryseobacterium hominis and Moraxella osloensis, showed significantly greater proportions in regularly sanitized sponges, thereby questioning such sanitation methods in a long term perspective. FISH-CLSM showed an ubiquitous distribution of bacteria within the sponge tissue, concentrating in internal cavities and on sponge surfaces, where biofilm-like structures occurred. Image analysis showed local densities of up to 5.4 * 10 cells per cm, and confirmed the dominance of Gammaproteobacteria. Our study stresses and visualizes the role of kitchen sponges as microbiological hot spots in the BE, with the capability to collect and spread bacteria with a probable pathogenic potential.
Topics: Acinetobacter; Chryseobacterium; Cluster Analysis; DNA, Bacterial; DNA, Ribosomal; Environmental Microbiology; In Situ Hybridization, Fluorescence; Microbiota; Microscopy, Confocal; Moraxella; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 28725026
DOI: 10.1038/s41598-017-06055-9 -
Genome Announcements Jan 2018Here, we present the complete whole-genome sequences of three strains with octylphenol polyethoxylate-degrading abilities. These strains were isolated from human skin.
Here, we present the complete whole-genome sequences of three strains with octylphenol polyethoxylate-degrading abilities. These strains were isolated from human skin.
PubMed: 29348360
DOI: 10.1128/genomeA.01509-17 -
Frontiers in Microbiology 2022To understand the role of the skin commensal bacterial community in skin health and the spread of pathogens, it is crucial to identify genetic differences in the...
To understand the role of the skin commensal bacterial community in skin health and the spread of pathogens, it is crucial to identify genetic differences in the bacterial strains corresponding to human individuals. A culture-independent genomics approach is an effective tool for obtaining massive high-quality bacterial genomes. Here we present a single-cell genome sequencing to obtain comprehensive whole-genome sequences of uncultured skin bacteria from skin swabs. We recovered 281 high-quality (HQ) and 244 medium-quality single-amplified genomes (SAGs) of multiple skin bacterial species from eight individuals, including cohabiting group. Single-cell sequencing outperformed in the genome recovery from the same skin swabs, showing 10-fold non-redundant strain genomes compared to the shotgun metagenomic sequencing and binning approach. We then focused on the abundant skin bacteria and identified intra-species diversity, especially in 47 derived HQ SAGs, characterizing the strain-level heterogeneity at mobile genetic element profiles, including plasmids and prophages. Even between the cohabiting individual hosts, they have unique skin bacterial strains in the same species, which shows microdiversity in each host. Genetic and functional differences between skin bacterial strains are predictive of competition to adapt bacterial genome to utilize the sparse nutrients available on the skin or produce molecules that inhibit the colonization of other microbes or alter their behavior. Thus, single-cell sequencing provides a large number of genomes of higher resolution and quality than conventional metagenomic analysis and helps explore the skin commensal bacteria at the strain level, linking taxonomic and functional information.
PubMed: 35992707
DOI: 10.3389/fmicb.2022.955404 -
The Journal of Antimicrobial... Oct 2017To determine the occurrence of mcr-1 and mcr-2 genes in Gram-negative bacteria isolated from healthy pigs in Great Britain.
OBJECTIVES
To determine the occurrence of mcr-1 and mcr-2 genes in Gram-negative bacteria isolated from healthy pigs in Great Britain.
METHODS
Gram-negative bacteria (n = 657) isolated from pigs between 2014 and 2015 were examined by WGS.
RESULTS
Variants of mcr-1 and mcr-2 were identified in Moraxella spp. isolated from pooled caecal contents of healthy pigs at slaughter collected from six farms in Great Britain. Other bacteria, including Escherichia coli from the same farms, were not detected harbouring mcr-1 or mcr-2. A Moraxella porci-like isolate, MSG13-C03, harboured MCR-1.10 with 98.7% identity to MCR-1, and a Moraxella pluranimalium-like isolate, MSG47-C17, harboured an MCR-2.2 variant with 87.9% identity to MCR-2, from E. coli; the isolates had colistin MICs of 1-2 mg/L. No intact insertion elements were identified in either MSG13-C03 or MSG47-C17, although MSG13-C03 harboured the conserved nucleotides abutting the ISApl1 composite transposon found in E. coli plasmids and the intervening ∼2.6 kb fragment showed 97% identity. Six Moraxella osloensis isolates were positive for phosphoethanolamine transferase (EptA). They shared 62%-64.5% identity to MCR-1 and MCR-2, with colistin MICs from 2 to 4 mg/L. Phylogenetic analysis indicated that MCR and EptA have evolved from a common ancestor. In addition to mcr, the β-lactamase gene, blaBRO-1, was found in both isolates, whilst the tetracycline resistance gene, tetL, was found in MSG47-C17.
CONCLUSIONS
Our results add further evidence for the mobilization of the mcr-pap2 unit from Moraxella via composite transposons leading to its global dissemination. The presence of mcr-pap2 from recent Moraxella isolates indicates they may comprise a reservoir for mcr.
Topics: Animals; Anti-Bacterial Agents; Colistin; DNA Transposable Elements; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Proteins; Farms; Gene Transfer, Horizontal; Genes, Bacterial; Genetic Variation; Humans; Membrane Proteins; Microbial Sensitivity Tests; Moraxella; Moraxellaceae Infections; Phylogeny; Sus scrofa; Swine; Swine Diseases; United Kingdom; beta-Lactamases
PubMed: 29091227
DOI: 10.1093/jac/dkx286 -
Frontiers in Immunology 2022Nematodes and bacteria are prevalent in soil ecosystems, and some have evolved symbiotic relationships. In some cases, symbionts carry out highly specialized functions:...
Nematodes and bacteria are prevalent in soil ecosystems, and some have evolved symbiotic relationships. In some cases, symbionts carry out highly specialized functions: a prime example being entomopathogenic nematodes (EPNs), which vector bacteria ( or ) into insect hosts, killing them to provide a food source for the nematodes. It is thought that the commercially available malacopathogenic (kills slugs and snails) biocontrol nematode vectors a bacterium () into slugs to kill them. To investigate this further we used a metagenomic approach to profile the bacteria present in the commercial strain of , a wild strain of and two other species ( and ), after they had killed their slug host (). We show that these nematodes do not exclusively associate with one bacterium but a range of species, with members of the phyla Pseudomonadota, Bacillota, Actinobacteriota and Bacteroidota the most prevalent. The commercial strain of had the least diverse bacterial community. Furthermore, we found that the bacterium has been cultured on for 25 years is not the expected species but is spp. and the only strain of the species to associate with spp. was the commercial strain of . In summary, we found no evidence to show that rely exclusively on one bacterium to cause host mortality but found variable and diverse bacterial communities associated with these nematodes in their slug hosts.
Topics: Animals; Microbiota; Nematoda; Rhabditoidea; Snails; Soil
PubMed: 35515005
DOI: 10.3389/fimmu.2022.878783 -
Journal of Insect Science (Online) Jul 2021The gut microbiota of insects usually plays an important role in the development and reproduction of their hosts. The fecundity of Henosepilachna vigintioctopunctata...
The gut microbiota of insects usually plays an important role in the development and reproduction of their hosts. The fecundity of Henosepilachna vigintioctopunctata (Fabricius) varies greatly when they develop on different host plants. Whether and how the gut microbiota regulates the fecundity of H. vigintioctopunctata was unknown. To address this question, we used 16S rRNA sequencing to analyze the gut microbiomes of H. vigintioctopunctata adults fed on two host plant species (Solanum nigrum and Solanum melongena) and one artificial diet. The development of the ovaries and testes was also examined. Our results revealed that the diversity and abundance of gut microorganisms varied significantly in insects reared on different diets. The gut microbiota of H. vigintioctopunctata raised on the two host plants was similar, with Proteobacteria being the dominant phylum in both groups, whereas Firmicutes was the dominant phylum in the group reared on the artificial diet. The predominant microbiota in the S. nigrum group were Acinetobacter soli and Acinetobacter ursingii (Acinetobacter, Moraxellaceae); Moraxella osloensis (Enhydrobacter, Moraxellaceae); and Empedobacter brevis (Empedobacter, Weeksellaceae). The microbiota in this group are associated with high lipid metabolism. In addition, the beetles' ovaries and testes were more highly developed in the S. nigrum group than in the other two groups. These findings provide valuable information for elucidating the complex roles the gut microbiota play in the fecundity of H. vigintioctopunctata, and may also contribute to developing future novel control strategies involving this economically important pest.
Topics: Animals; Bacteria; Coleoptera; DNA, Bacterial; Diet; Female; Fertility; Gastrointestinal Microbiome; Lipid Metabolism; Male; Metagenomics; Ovary; Pest Control; RNA, Ribosomal, 16S; Testis
PubMed: 34415303
DOI: 10.1093/jisesa/ieab061 -
Applied and Environmental Microbiology Nov 2001Moraxella osloensis, a gram-negative bacterium, is associated with Phasmarhabditis hermaphrodita, a nematode parasite of slugs. This bacterium-feeding nematode has...
Moraxella osloensis, a gram-negative bacterium, is associated with Phasmarhabditis hermaphrodita, a nematode parasite of slugs. This bacterium-feeding nematode has potential for the biological control of slugs, especially the grey garden slug, Deroceras reticulatum. Infective juveniles of P. hermaphrodita invade the shell cavity of the slug, develop into self-fertilizing hermaphrodites, and produce progeny, resulting in host death. However, the role of the associated bacterium in the pathogenicity of the nematode to the slug is unknown. We discovered that M. osloensis alone is pathogenic to D. reticulatum after injection into the shell cavity or hemocoel of the slug. The bacteria from 60-h cultures were more pathogenic than the bacteria from 40-h cultures, as indicated by the higher and more rapid mortality of the slugs injected with the former. Coinjection of penicillin and streptomycin with the 60-h bacterial culture reduced its pathogenicity to the slug. Further work suggested that the reduction and loss of pathogenicity of the aged infective juveniles of P. hermaphrodita to D. reticulatum result from the loss of M. osloensis from the aged nematodes. Also, axenic J1/J2 nematodes were nonpathogenic after injection into the shell cavity. Therefore, we conclude that the bacterium is the sole killing agent of D. reticulatum in the nematode-bacterium complex and that P. hermaphrodita acts only as a vector to transport the bacterium into the shell cavity of the slug. The identification of the toxic metabolites produced by M. osloensis is being pursued.
Topics: Animals; Anti-Bacterial Agents; Colony Count, Microbial; Mollusca; Moraxella; Penicillins; Pest Control, Biological; Rhabditoidea; Streptomycin; Virulence
PubMed: 11679319
DOI: 10.1128/AEM.67.11.5010-5016.2001 -
Swiss Medical Weekly 2015We report two cases of endocarditis due to Moraxella osloensis. Only one previous case of such infection has been described. These infections occurred in...
We report two cases of endocarditis due to Moraxella osloensis. Only one previous case of such infection has been described. These infections occurred in immunocompromised patients (B-cell chronic lymphocytic leukaemia and kidney graft associated with Hodgkin's disease) and both patients had a favourable outcome with a complete cure of their infectious endocarditis. This bacterium could be an emerging pathogen revealed by MALDI-TOF. Indeed, its characterisation within the Moraxella group by use of biochemistry-based methods is difficult. Moreover, this strain could be particularly involved in immunocompromised patients.
Topics: Aged; Endocarditis, Bacterial; Humans; Immunocompromised Host; Male; Middle Aged; Moraxella; Moraxellaceae Infections
PubMed: 26376092
DOI: 10.4414/smw.2015.14185 -
Journal of Veterinary Research Sep 2023Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be...
INTRODUCTION
Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be taken. The identification of many bacteria simultaneously facilitates the determination of the characteristics of the accompanying microbiota and/or the microbiological complexity of a given environment.
MATERIAL AND METHODS
The effectiveness of the VITEK2 Compact automated microbial identification system and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), analytical profile index (API) and Remel RapID tests were compared in identification of bacteria isolated from the alpaca gastrointestinal tract.
RESULTS
Most isolates were Gram-positive, such as and and , , and ; ; ; ; ; , , and (the last only isolated manually by API Coryne and the VITEK2 system and (CBC) card). was misidentified by MALDI-TOF MS as (currently ). Gram-positive and Gram-variable were also isolated. Gram-negative , , and ; ; subsp. ; and ; , and ; subsp. ; ; ; ; ; and were also found. The yeasts and were also present.
CONCLUSION
MALDI-TOF MS enabled the identification of pathogens and opportunistic pathogens from the alpaca gut which may represent a high risk to human and animal health.
PubMed: 37786852
DOI: 10.2478/jvetres-2023-0051