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Journal of Zhejiang University.... Mar 2016Bacteria of the genus Myroides (Myroides spp.) are rare opportunistic pathogens. Myroides sp. infections have been reported mainly in China. Myroides sp. is highly... (Review)
Review
Bacteria of the genus Myroides (Myroides spp.) are rare opportunistic pathogens. Myroides sp. infections have been reported mainly in China. Myroides sp. is highly resistant to most available antibiotics, but the resistance mechanisms are not fully elucidated. Current strain identification methods based on biochemical traits are unable to identify strains accurately at the species level. While 16S ribosomal RNA (rRNA) gene sequencing can accurately achieve this, it fails to give information on the status and mechanisms of antibiotic resistance, because the 16S rRNA sequence contains no information on resistance genes, resistance islands or enzymes. We hypothesized that obtaining the whole genome sequence of Myroides sp., using next generation sequencing methods, would help to clarify the mechanisms of pathogenesis and antibiotic resistance, and guide antibiotic selection to treat Myroides sp. infections. As Myroides sp. can survive in hospitals and the environment, there is a risk of nosocomial infections and pandemics. For better management of Myroides sp. infections, it is imperative to apply next generation sequencing technologies to clarify the antibiotic resistance mechanisms in these bacteria.
Topics: Drug Resistance, Microbial; Flavobacteriaceae; Flavobacteriaceae Infections; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Humans; Microbial Sensitivity Tests
PubMed: 26984839
DOI: 10.1631/jzus.B1500068 -
MBio Jan 2016A large amount of bacterial biomass is transferred from land to ocean annually. Most transferred bacteria should not survive, but undoubtedly some do. It is unclear what...
UNLABELLED
A large amount of bacterial biomass is transferred from land to ocean annually. Most transferred bacteria should not survive, but undoubtedly some do. It is unclear what mechanisms these bacteria use in order to survive and even thrive in a new marine environment. Myroides profundi D25(T), a member of the Bacteroidetes phylum, was isolated from deep-sea sediment of the southern Okinawa Trough near the China mainland and had high genomic sequence identity to and synteny with the human opportunistic pathogen Myroides odoratimimus. Phylogenetic and physiological analyses suggested that M. profundi recently transitioned from land to the ocean. This provided an opportunity to explore how a bacterial genome evolved to survive in a novel environment. Changes in the transcriptome were evaluated when both species were cultured under low-salinity conditions and then transferred to high-salinity conditions. Comparative genomic and transcriptomic analyses showed that M. profundi altered transcription regulation in the early stages of survival. In these stages, vertically inherited genes played a key role in the survival of M. profundi. The contribution of M. profundi unique genes, some possibly acquired by horizontal gene transfer (HGT), appeared relatively small, and expression levels of unique genes were diminished under the high-salinity conditions. We postulate that HGT genes might play an important role in longer-term adaptation. These results suggested that some human pathogens might have the ability to survive in and adapt to the marine environment, which may have important implications for public health control in coastal regions.
IMPORTANCE
Horizontal gene transfer (HGT) is considered to be important for bacteria to adapt to a different microhabitat. However, our results showed that vertically inherited genes might play more important roles than HGT genes in the nascent adaptation to the marine environment in the bacterium Myroides profundi, which has recently been transferred from land to ocean. M. profundi unique genes had low expression levels and were less regulated under high-salinity conditions, indicating that the contribution of HGT genes to survival of this bacterium under marine high-salinity conditions was limited. In the early adaptation stages, M. profundi apparently survived and adapted mainly by regulating the expression of inherited core genes. These results may explain in part why human pathogens can easily be detected in marine environments.
Topics: Bacteroidetes; China; Culture Media; Gene Expression Profiling; Gene Transfer, Horizontal; Genetic Speciation; Genome, Bacterial; Geologic Sediments; Molecular Sequence Data; Phylogeny; Salinity; Sequence Analysis, DNA
PubMed: 26758181
DOI: 10.1128/mBio.01946-15 -
Journal of Clinical and Diagnostic... Nov 2015Myroides spp., previously known as Flavobacterium odoratum, are rare clinical isolates and are often considered non-pathogenic. Natural habitat includes soil, fresh and...
Myroides spp., previously known as Flavobacterium odoratum, are rare clinical isolates and are often considered non-pathogenic. Natural habitat includes soil, fresh and marine waters, in foods and in sewage treatment plants. We present an unusual case of fatal pericardial effusion due to Myroides odoratus in a patient suffering from chronic kidney disease and undergoing maintenance haemodialysis. This case is presented to show the increasing incidence of rare isolates causing localized and systemic infections and due to their high intrinsic resistance to many antibiotics they can be fatal. Thus isolation of these pathogens is of great clinical importance.
PubMed: 26672889
DOI: 10.7860/JCDR/2015/15120.6740 -
Standards in Genomic Sciences 2015Flavobacterium rivuli Ali et al. 2009 emend. Dong et al. 2013 is one of about 100 species in the genus Flavobacterium (family Flavobacteriacae, phylum Bacteroidetes)...
Flavobacterium rivuli Ali et al. 2009 emend. Dong et al. 2013 is one of about 100 species in the genus Flavobacterium (family Flavobacteriacae, phylum Bacteroidetes) with a validly published name, and has been isolated from the spring of a hard water rivulet in Northern Germany. Including all type strains of the genus Myroides and Flavobacterium into the 16S rRNA gene sequence phylogeny revealed a clustering of members of the genus Myroides as a monophyletic group within the genus Flavobacterium. Furthermore, F. rivuli WB 3.3-2(T) and its next relatives seem more closely related to the genus Myroides than to the type species of the genus Flavobacterium, F. aquatile. The 4,489,248 bp long genome with its 3,391 protein-coding and 65 RNA genes is part of the G enomic E ncyclopedia of B acteria and A rchaea project. The genome of F. rivuli has almost as many genes encoding carbohydrate active enzymes (151 CAZymes) as genes encoding peptidases (177). Peptidases comprised mostly metallo (M) and serine (S) peptidases. Among CAZymes, 30 glycoside hydrolase families, 10 glycosyl transferase families, 7 carbohydrate binding module families and 7 carbohydrate esterase families were identified. Furthermore, we found four polysaccharide utilization loci (PUL) and one large CAZy rich gene cluster that might enable strain WB 3.3-2(T) to decompose plant and algae derived polysaccharides. Based on these results we propose F. rivuli as an interesting candidate for further physiological studies and the role of Bacteroidetes in the decomposition of complex polymers in the environment.
PubMed: 26380634
DOI: 10.1186/s40793-015-0032-y -
International Journal of Clinical and... 2015The aim of this study was to investigate the in-vitro antimicrobial activity of usage and normal concentrations of electrolyzed water in hospital. In our study, the...
The aim of this study was to investigate the in-vitro antimicrobial activity of usage and normal concentrations of electrolyzed water in hospital. In our study, the effects of different concentrations of electrolyzed water named Envirolyte® (Industries International Ltd., Estonia) on two gram positive, four gram negative standard strains and clinical isolates of four gram negative, two gram positive, one spore-forming bacillus and Myroides spp strains that lead to hospital infections were researched. The effects of different concentrations and different contact times of Envirolyte® electrolyzed water on cited strains were researched through method of qualitative suspension tests. Petri dishes fo bacteria have been incubated at 37°C 48 hours. Bactericidal disinfectant was interpreted to be effective at the end of the period due to the lack of growth. Solutions to which disinfectant were not added were prepared with an eye to control reproduction and controlcultures were made by using neutralizing agents. 1/1, 1/2, and 1/10 concentrations of Envirolyte® electrolyzed water were found to be effective on the bacteria that lead to hospital infections used during all test times. As a conclusion, based upon the results we acquired, it was observed that Envirolyte® electrolyzed water of 100% concentration would be convenient to be used for disinfection when diluted to a usage concentration of 1/10.
PubMed: 26379964
DOI: No ID Found -
New Microbes and New Infections Sep 2015The aim of the present study was to investigate the molecular mechanism of carbapenem resistance of three imipenem-resistant isolates of Myroides odoratimimus recovered...
The aim of the present study was to investigate the molecular mechanism of carbapenem resistance of three imipenem-resistant isolates of Myroides odoratimimus recovered from two livestock farms of cows and pigeons by rectal swab in Lebanon in January 2014. Investigation of imipenem resistance of these isolates using the modified Hodge test, the EDTA test, the modified CarbaNP test and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry Ultraflex assay showed a carbapenemase activity due to the presence of a chromosome-encoded β-lactamase MUS, verified by PCR. However amplification and sequencing of this chromosomal gene showed a novel variant of it designated MUS-2 by the curators of the Lahey database of β-lactamases (http://www.lahey.org/Studies/webt.asp). Cloning of the bla MUS-2 was performed, followed by protein expression in Escherichia coli TOP 10. Pulsed-field gel electrophoresis clearly showed that the three isolates belonged to the same clone. This study reports a novel variant of the chromosome-encoded bla MUS-1 associated with carbapenem resistance in Myroides odoratimimus and shows that animals may represent a reservoir of bacteria harbouring several variants of resistance genes.
PubMed: 26257915
DOI: 10.1016/j.nmni.2015.06.007 -
Transplantation Direct May 2015Immunosuppressed patients and experimental nonhuman primates are at risk of opportunistic infection. We report a infection in an immunosuppressed baboon that had...
BACKGROUND
Immunosuppressed patients and experimental nonhuman primates are at risk of opportunistic infection. We report a infection in an immunosuppressed baboon that had received a life-supporting kidney from a genetically-engineered pig.
CASE REPORT
The baboon received a costimulation blockade-based immunosuppressive regimen as well as two anti-inflammatory agents (tocilizumab and etanercept). Although the pig kidney functioned well, approximately four months after the transplant the baboon became less active and ate and drank poorly. On day 136, it collapsed and died despite inotropic and fluid support. A blood culture drawn before death grew .
DISCUSSION AND CONCLUSIONS
To our knowledge, has not been reported as a cause of opportunistic infection in either patients with organ allotransplants or experimental animals. We summarize what is known about this rare organism, and suggest it should be considered in any immunocompromised patient or animal. In the present case, we suggest the baboon died of circulatory shock following infection through an indwelling intravenous catheter.
PubMed: 26146660
DOI: 10.1097/TXD.0000000000000523 -
Molecules (Basel, Switzerland) Jun 2015The protease myroilysin is the most abundant protease secreted by marine sedimental bacterium Myroides profundi D25. As a novel elastase of the M12 family, myroilysin...
The protease myroilysin is the most abundant protease secreted by marine sedimental bacterium Myroides profundi D25. As a novel elastase of the M12 family, myroilysin has high elastin-degrading activity and strong collagen-swelling ability, suggesting its promising biotechnological potential. Because myroilysin cannot be maturely expressed in Escherichia coli, it is important to be able to improve the production of myroilysin in the wild strain D25. We optimized the culture conditions of strain D25 for protease production by using single factor experiments. Under the optimized conditions, the protease activity of strain D25 reached 1137 ± 53.29 U/mL, i.e., 174% of that before optimization (652 ± 23.78 U/mL). We then conducted small scale fermentations of D25 in a 7.5 L fermentor. The protease activity of strain D25 in small scale fermentations reached 1546.4 ± 82.65 U/mL after parameter optimization. Based on the small scale fermentation results, we further conducted pilot scale fermentations of D25 in a 200 L fermentor, in which the protease production of D25 reached approximately 1100 U/mL. These results indicate that we successfully set up the small and pilot scale fermentation processes of strain D25 for myroilysin production, which should be helpful for the industrial production of myroilysin and the development of its biotechnological potential.
Topics: Bacteroides; Culture Media; Fermentation; Marine Biology; Metalloproteases; Nitrogen; Pilot Projects; Temperature
PubMed: 26132910
DOI: 10.3390/molecules200711891 -
Proceedings (Baylor University. Medical... Jul 2015Myroides species are a rare source of human infection. Though not part of the human microbiota, Myroides species are commonly found in the environment. Myroides...
Myroides species are a rare source of human infection. Though not part of the human microbiota, Myroides species are commonly found in the environment. Myroides infections are typically attributed to contact with contaminated water; the most common presentation is in immunocompromised patients. We present a patient with a diabetic foot ulcer who subsequently developed Myroides odoratimimus bacteremia and bone abscess.
PubMed: 26130883
DOI: 10.1080/08998280.2015.11929268 -
Xenotransplantation 2015The longest survival of a non-human primate with a life-supporting kidney graft to date has been 90 days, although graft survival > 30 days has been unusual. A baboon...
The longest survival of a non-human primate with a life-supporting kidney graft to date has been 90 days, although graft survival > 30 days has been unusual. A baboon received a kidney graft from an α-1,3-galactosyltransferase gene-knockout pig transgenic for two human complement-regulatory proteins and three human coagulation-regulatory proteins (although only one was expressed in the kidney). Immunosuppressive therapy was with ATG+anti-CD20mAb (induction) and anti-CD40mAb+rapamycin+corticosteroids (maintenance). Anti-TNF-α and anti-IL-6R were administered. The baboon survived 136 days with a generally stable serum creatinine (0.6 to 1.6 mg/dl) until termination. No features of a consumptive coagulopathy (e.g., thrombocytopenia, decreased fibrinogen) or of a protein-losing nephropathy were observed. There was no evidence of an elicited anti-pig antibody response. Death was from septic shock (Myroides spp). Histology of a biopsy on day 103 was normal, but by day 136, the kidney showed features of glomerular enlargement, thrombi, and mesangial expansion. The combination of (i) a graft from a specific genetically engineered pig, (ii) an effective immunosuppressive regimen, and (iii) anti-inflammatory agents prevented immune injury and a protein-losing nephropathy, and delayed coagulation dysfunction. This outcome encourages us that clinical renal xenotransplantation may become a reality.
Topics: Animals; Animals, Genetically Modified; Antigens, Heterophile; Complement System Proteins; Galactosyltransferases; Gene Knockout Techniques; Genetic Engineering; Graft Survival; Humans; Immunosuppressive Agents; Kidney; Kidney Transplantation; Papio; Swine; Time Factors; Transplantation, Heterologous
PubMed: 26130164
DOI: 10.1111/xen.12174