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Nature Jul 2020Animals coexist in commensal, pathogenic or mutualistic relationships with complex communities of diverse organisms, including microorganisms. Some bacteria produce...
Animals coexist in commensal, pathogenic or mutualistic relationships with complex communities of diverse organisms, including microorganisms. Some bacteria produce bioactive neurotransmitters that have previously been proposed to modulate nervous system activity and behaviours of their hosts. However, the mechanistic basis of this microbiota-brain signalling and its physiological relevance are largely unknown. Here we show that in Caenorhabditis elegans, the neuromodulator tyramine produced by commensal Providencia bacteria, which colonize the gut, bypasses the requirement for host tyramine biosynthesis and manipulates a host sensory decision. Bacterially produced tyramine is probably converted to octopamine by the host tyramine β-hydroxylase enzyme. Octopamine, in turn, targets the OCTR-1 octopamine receptor on ASH nociceptive neurons to modulate an aversive olfactory response. We identify the genes that are required for tyramine biosynthesis in Providencia, and show that these genes are necessary for the modulation of host behaviour. We further find that C. elegans colonized by Providencia preferentially select these bacteria in food choice assays, and that this selection bias requires bacterially produced tyramine and host octopamine signalling. Our results demonstrate that a neurotransmitter produced by gut bacteria mimics the functions of the cognate host molecule to override host control of a sensory decision, and thereby promotes fitness of both the host and the microorganism.
Topics: Animals; Avoidance Learning; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Feeding Behavior; Gastrointestinal Microbiome; Intestines; Metabolomics; Mutation; Neurotransmitter Agents; Octanols; Octopamine; Providencia; Receptors, Biogenic Amine; Receptors, G-Protein-Coupled; Sensory Receptor Cells; Smell; Tyramine; Tyrosine Decarboxylase
PubMed: 32555456
DOI: 10.1038/s41586-020-2395-5 -
Emerging Microbes & Infections Dec 2023as an opportunistic pathogen can cause serious infection, and moreover the emergence of multi-drug-resistant strains poses a potentially life-threatening risk to...
as an opportunistic pathogen can cause serious infection, and moreover the emergence of multi-drug-resistant strains poses a potentially life-threatening risk to public health. However, a comprehensive genomic study to reveal the population structure and dissemination of is still lacking. In this study, we conducted a genomic epidemiology analysis on the 580 global sequenced isolates, including 257 ones sequenced in this study (42 ones were fully sequenced). We established a genome sequence-based species classification scheme for , redefining the conventional 11 species into seven genocomplexes that were further divided into 18 genospecies, providing an extensively updated reference for species discrimination based on the largest genome dataset to date. We then dissected the profile of antimicrobial resistance genes and the prevalence of multi-drug-resistant strains among these genocomplexes/genospecies, disclosing the presence of diverse and abundant antimicrobial resistance genes and high resistance ratios against multiple classes of drugs in . We further dissected the genetic basis for the spread of in . genes were mainly carried by five incompatible (Inc) groups of plasmids: IncC, IncW, Inc, Inc, and Inc, and the last three were newly designated in this study. By tracking the spread of -carrying plasmids, IncC, Inc, Inc, and Inc plasmids were found to be highly involved in parallel horizontal transfer or vertical clonal expansion of among . Overall, our study provided a comprehensive genomic view of species differentiation, antimicrobial resistance prevalence, and plasmid-mediated dissemination in .
Topics: Providencia; Anti-Bacterial Agents; Plasmids; beta-Lactamases; Genomics; Microbial Sensitivity Tests
PubMed: 37874004
DOI: 10.1080/22221751.2023.2275596 -
The American Journal of Tropical... Aug 2019is a member of the family Enterobacteriaceae that has been commonly implicated as a causative agent of diarrheal infection in humans and animals. Recent outbreaks of... (Review)
Review
is a member of the family Enterobacteriaceae that has been commonly implicated as a causative agent of diarrheal infection in humans and animals. Recent outbreaks of in both developing and developed countries have raised public health concerns. Several studies have suggested that can cause diarrhea by invading the intestinal mucosa, although its pathogenicity has not been well established. Often routine laboratory investigations that seek etiological agents of diarrhea do not actively pursue detection. Therefore, routine laboratory diagnosis should be given more attention for better understanding the epidemiology and pathogenicity of .
Topics: Animals; Diarrhea; Disease Outbreaks; Enterobacteriaceae Infections; Feces; Foodborne Diseases; Providencia
PubMed: 31218997
DOI: 10.4269/ajtmh.18-0376 -
New Microbes and New Infections Sep 2018species are Gram-negative bacteria that belong to the family. They have intrinsic resistance to colistin and tigecycline, which makes treatment of the... (Review)
Review
species are Gram-negative bacteria that belong to the family. They have intrinsic resistance to colistin and tigecycline, which makes treatment of the multidrug-resistant strains of challenging. Carbapenem-resistant species are increasingly reported. In this review, patients' characteristics, resistance mechanisms, treatment and infection control measures of carbapenem-resistant species in the literature are described.
PubMed: 29983987
DOI: 10.1016/j.nmni.2018.05.009 -
BMC Genomic Data Sep 2023Providencia is a genus of gram-negative bacteria within the order Enterobacterales, closely related to Proteus and Morganella. While ubiquitous in the environment, some...
OBJECTIVES
Providencia is a genus of gram-negative bacteria within the order Enterobacterales, closely related to Proteus and Morganella. While ubiquitous in the environment, some species of Providencia, such as P. rettgeri and P. stuartii, are considered emerging nosocomial pathogens and have been implicated in urinary tract infection, gastrointestinal illness, and travelers' diarrhea. Given their intrinsic resistance to many commonly used antibiotics, this study aimed to isolate and sequence bacteriophages targeting a clinical P. rettgeri isolate.
DATA DESCRIPTION
Here we report the complete genome sequence of three novel Providencia phages, PibeRecoleta, Stilesk and PatoteraRojo, which were isolated against a clinical P. rettgeri strain sourced from a patient in a metropolitan hospital in Victoria, Australia. The three phages contain dsDNA genomes between 60.7 and 60.9 kb in size and are predicted to encode between 72 and 73 proteins. These three new phages, which share high genomic similarity to two other Providencia phages previously isolated on P. stuartii, serve as important resources in our understanding about Providencia bacteriophages and the potential for future phage-based biotherapies.
Topics: Humans; Diarrhea; Providencia; Travel; Bacteriophages; Dysentery; Hospitals, Urban; Victoria
PubMed: 37658299
DOI: 10.1186/s12863-023-01153-2 -
Journal of the Association of Medical... Sep 2023There is a paucity of studies investigating the population-based epidemiology of (MPP) group infections. Our objective was to determine the incidence, risk factors, and...
BACKGROUND
There is a paucity of studies investigating the population-based epidemiology of (MPP) group infections. Our objective was to determine the incidence, risk factors, and outcome of MPP group bloodstream infections (BSI), and explore species-specific differences.
METHODS
Population-based surveillance was conducted in the western interior of British Columbia, Canada, between April 1, 2010 and March 30, 2020.
RESULTS
Sixty-two incident MPP group BSI occurred for an annual incidence of 3.4 per 100,000 residents; rates for , , and species were 0.5, 2.6, and 0.3 per 100,000 population, respectively. The median year of age was 72.5 and was different ( = 0.03) among the groups. Most (92%) MPP group BSIs were of community-onset. Significant differences were observed in the distribution of clinical focus of infection, with most notably 81% of BSI due to genitourinary focus as compared to 60% and 22% for species and , respectively. Comorbid illnesses that increased the risk for development of MPP group BSI (incidence rate ratio; 95% CI) were HIV infection (37.0; 4.4-139.6), dementia (11.5; 6.1-20.7), cancer (6.4; 3.2-11.9), stroke 6.5 (2.8-13.3), and diabetes 2.7 (1.3-5.0). Thirteen, one, and none of the cases with , , and species BSI died within 30 days of index culture for respective all cause case-fatalities of 27%, 11%, and 0% ( = 0.1).
CONCLUSIONS
Although collectively responsible for a substantial burden of illness, the epidemiology of MPP group BSI varies significantly by species.
PubMed: 38250289
DOI: 10.3138/jammi-2022-0038 -
Journal of Clinical and Diagnostic... Aug 2015Purple urine bag syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in...
Purple urine bag syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in patients who are on urinary catheters for a long time. Purple coloured urine occurs due to the accumulation of indigo and indirubin, which are the end products of tryptophan metabolism due to the action of sulfatases and phosphatases formed by bacteria like Providencia, Citrobacter, Enterobacter, Klebsiella etc. We present this interesting phenomenon of purple urine in a young male who was on prolonged urinary catheterization. The urine culture was positive for Providencia and constipation was an added risk factor for the purple urine. The urinary catheter and tubing was changed along with a course of antibiotics which lead to the normalization of the urine colour.
PubMed: 26435987
DOI: 10.7860/JCDR/2015/14736.6304 -
BMC Biology May 2022Metazoan guts are in permanent contact with microbial communities. However, the host mechanisms that have developed to manage the dynamic changes of these microorganisms...
BACKGROUND
Metazoan guts are in permanent contact with microbial communities. However, the host mechanisms that have developed to manage the dynamic changes of these microorganisms and maintain homeostasis remain largely unknown.
RESULTS
Serotonin (5-hydroxytryptamine [5-HT]) was found to modulate gut microbiome homeostasis via regulation of a dual oxidase (Duox) gene expression in both Bactrocera dorsalis and Aedes aegypti. The knockdown of the peripheral 5-HT biosynthetic gene phenylalanine hydroxylase (TPH) increased the expression of Duox and the activity of reactive oxygen species, leading to a decrease in the gut microbiome load. Moreover, the TPH knockdown reduced the relative abundance of the bacterial genera Serratia and Providencia, including the opportunistic pathogens, S. marcescens and P. alcalifaciens in B. dorsalis. Treatment with 5-hydroxytryptophan, a precursor of 5-HT synthesis, fully rescued the TPH knockdown-induced phenotype.
CONCLUSIONS
The findings reveal the important contribution of 5-HT in regulating gut homeostasis, providing new insights into gut-microbe interactions in metazoans.
Topics: Animals; Gastrointestinal Microbiome; Homeostasis; Insecta; Serotonin; Serratia
PubMed: 35550116
DOI: 10.1186/s12915-022-01319-x -
Medicina (Kaunas, Lithuania) Feb 2022: and are related genera of opportunistic pathogens belonging to the family, often a cause of infections in the immunocompromised hosts, such as diabetic patients.... (Observational Study)
Observational Study
: and are related genera of opportunistic pathogens belonging to the family, often a cause of infections in the immunocompromised hosts, such as diabetic patients. Their clinical significance has increased due to their intrinsic resistance to polymyxins, which is often associated with acquired resistance mechanisms. In this study we evaluated the infections caused by and in two groups of patients, with diabetes (group 1) and without diabetes (group 2) admitted to the intensive care unit and surgical wards. The infections were investigated in terms of infection type, risk factors, clinical course, predictive factors for unfavourable outcomes and antibiotic resistance profile. : An observational, retrospective, cross-sectional study was conducted, comprising all patients infected with these pathogens. Bacterial identification and antibiotic sensitivity testing were performed using the Vitek2C automated system. : Comparison of the two groups showed that the statistically significant common infectious risk factors were found less frequently among diabetic patients when compared with non-diabetic patients, and that antimicrobial resistance was significantly lower in the diabetic patient group. However, survival rates did not differ between the two groups, drawing attention to the implications of diabetes as comorbidity. Additionally, with regard to the antibiotic resistance profile, 38.89% of strains isolated from diabetic patients belonged to the difficult-to-treat (DTR) phenotype, contributing to the severity of these infections compared with those caused by , of which 32% were wild type strains and 0% were DTR phenotype. The DTR/extended spectrum beta-lactamase producing isolates more than doubled the risk of mortality, while the presence of nasogastric nutrition tripled the risk. : infections that occurred in diabetic patients proved to be more difficult to treat, the majority of them being healthcare-associated bacteremias.
Topics: Cross-Sectional Studies; Diabetes Mellitus; Enterobacteriaceae Infections; Humans; Proteus Infections; Proteus mirabilis; Providencia; Retrospective Studies
PubMed: 35208593
DOI: 10.3390/medicina58020271 -
MSphere Mar 2024Members of , although typically opportunistic, can cause severe infections in immunocompromised hosts. Recent advances in genome sequencing provide an opportunity for...
UNLABELLED
Members of , although typically opportunistic, can cause severe infections in immunocompromised hosts. Recent advances in genome sequencing provide an opportunity for more precise study of this genus. In this study, we first identified and characterized a novel species named sp. nov. It has ≤88.23% average nucleotide identity (ANI) and ≤31.8% DNA-DNA hybridization (dDDH) values with all known species, which fall significantly below the species-defining thresholds. Interestingly, we found that and actually fall under the same species, evidenced by an ANI of 98.59% and a dDDH value of 90.4%. By fusing ANI with phylogeny, we have reclassified 545 genomes within this genus into 20 species, including seven unnamed taxa (provisionally titled Taxon 1-7), which can be further subdivided into 23 lineages. Pangenomic analysis identified 1,550 genus-core genes in , with coenzymes being the predominant category at 10.56%, suggesting significant intermediate metabolism activity. Resistance analysis revealed that most lineages of the genus (82.61%, 19/23) carry a high number of antibiotic-resistance genes (ARGs) and display diverse resistance profiles. Notably, the majority of ARGs are located on plasmids, underscoring the significant role of plasmids in the resistance evolution within this genus. Three species or lineages (, Taxon 3, and L12) that possess the highest number of carbapenem-resistance genes suggest their potential influence on clinical treatment. These findings underscore the need for continued surveillance and study of this genus, particularly due to their role in harboring antibiotic-resistance genes.
IMPORTANCE
The genus, known to harbor opportunistic pathogens, has been a subject of interest due to its potential to cause severe infections, particularly in vulnerable individuals. Our research offers groundbreaking insights into this genus, unveiling a novel species, sp. nov., and highlighting the need for a re-evaluation of existing classifications. Our comprehensive genomic assessment offers a detailed classification of 545 genomes into distinct species and lineages, revealing the rich biodiversity and intricate species diversity within the genus. The substantial presence of antibiotic-resistance genes in the genus underscores potential challenges for public health and clinical treatments. Our study highlights the pressing need for increased surveillance and research, enriching our understanding of antibiotic resistance in this realm.
Topics: Humans; Providencia; Plasmids; Anti-Bacterial Agents; Genomics; DNA
PubMed: 38412041
DOI: 10.1128/msphere.00731-23