RESUMO
Sortase-assembled pili contribute to virulence in many Gram-positive bacteria. In Enterococcus faecalis, the endocarditis and biofilm-associated pilus (Ebp) is polymerized on the membrane by sortase C (SrtC) and attached to the cell wall by sortase A (SrtA). In the absence of SrtA, polymerized pili remain anchored to the membrane (i.e. off-pathway). Here we show that the high temperature requirement A (HtrA) bifunctional chaperone/protease of E. faecalis is a quality control system that clears aberrant off-pathway pili from the cell membrane. In the absence of HtrA and SrtA, accumulation of membrane-bound pili leads to cell envelope stress and partially induces the regulon of the ceftriaxone resistance-associated CroRS two-component system, which in turn causes hyper-piliation and cell morphology alterations. Inactivation of croR in the OG1RF ΔsrtAΔhtrA background partially restores the observed defects of the ΔsrtAΔhtrA strain, supporting a role for CroRS in the response to membrane perturbations. Moreover, absence of SrtA and HtrA decreases basal resistance of E. faecalis against cephalosporins and daptomycin. The link between HtrA, pilus biogenesis and the CroRS two-component system provides new insights into the E. faecalis response to endogenous membrane perturbations.
Assuntos
Aminoaciltransferases , Proteínas de Bactérias , Biofilmes , Cisteína Endopeptidases , Enterococcus faecalis , Fímbrias Bacterianas , Chaperonas Moleculares , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo , Aminoaciltransferases/genética , Aminoaciltransferases/metabolismo , Enterococcus faecalis/genética , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Biofilmes/crescimento & desenvolvimento , Membrana Celular/metabolismo , Regulação Bacteriana da Expressão Gênica , Virulência/genética , Antibacterianos/farmacologia , Ceftriaxona/farmacologiaRESUMO
Group B Streptococcus (GBS) is a major human and animal pathogen that threatens public health and food security. Spill-over and spill-back between host species is possible due to adaptation and amplification of GBS in new niches but the evolutionary and functional mechanisms underpinning those phenomena are poorly known. Based on analysis of 1,254 curated genomes from all major GBS host species and six continents, we found that the global GBS population comprises host-generalist, host-adapted and host-restricted sublineages, which are found across host groups, preferentially within one host group, or exclusively within one host group, respectively, and show distinct levels of recombination. Strikingly, the association of GBS genomes with the three major host groups (humans, cattle, fish) is driven by a single accessory gene cluster per host, regardless of sublineage or the breadth of host spectrum. Moreover, those gene clusters are shared with other streptococcal species occupying the same niche and are functionally relevant for host tropism. Our findings demonstrate (1) the heterogeneity of genome plasticity within a bacterial species of public health importance, enabling the identification of high-risk clones; (2) the contribution of inter-species gene transmission to the evolution of GBS; and (3) the importance of considering the role of animal hosts, and the accessory gene pool associated with their microbiota, in the evolution of multi-host bacterial pathogens. Collectively, these phenomena may explain the adaptation and clonal expansion of GBS in animal reservoirs and the risk of spill-over and spill-back between animals and humans.
Assuntos
Genoma Bacteriano , Infecções Estreptocócicas , Streptococcus agalactiae , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/genética , Animais , Humanos , Bovinos , Especificidade de Hospedeiro/genética , Genômica , Peixes/microbiologia , FilogeniaRESUMO
Despite dramatic advances in genomics, connecting genotypes to phenotypes is still challenging. Sexual genetics combined with linkage analysis is a powerful solution to this problem but generally unavailable in bacteria. We build upon a strong negative selection system to invent mass allelic exchange (MAE), which enables hybridization of arbitrary (including pathogenic) strains of Escherichia coli. MAE reimplements the natural phenomenon of random cross-overs, enabling classical linkage analysis. We demonstrate the utility of MAE with virulence-related gain-of-function screens, discovering that transfer of a single operon from a uropathogenic strain is sufficient for enabling a commensal E. coli to form large intracellular bacterial collections within bladder epithelial cells. MAE thus enables assaying natural allelic variation in E. coli (and potentially other bacteria), complementing existing loss-of-function genomic techniques.
Assuntos
Infecções por Escherichia coli , Proteínas de Escherichia coli , Infecções Urinárias , Escherichia coli Uropatogênica , Humanos , Escherichia coli Uropatogênica/genética , Infecções Urinárias/microbiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Virulência/genética , Fatores de Virulência/genéticaRESUMO
DNA methylation is a common epigenetic mark that influences transcriptional regulation, and therefore cellular phenotype, across all domains of life. In particular, both orphan methyltransferases and those from phasevariable restriction modification systems (RMSs) have been co-opted to regulate virulence epigenetically in many bacteria. We now show that three distinct non-phasevariable Type I RMSs in Escherichia coli have no measurable impact on gene expression, in vivo virulence, or any of 1190 in vitro growth phenotypes. We demonstrated this using both Type I RMS knockout mutants as well as heterologous installation of Type I RMSs into two E. coli strains. These data provide three clear and currently rare examples of restriction modification systems that have no impact on their host organism's gene regulation. This leads to the possibility that other such nonregulatory methylation systems may exist, broadening our view of the potential role that RMSs may play in bacterial evolution.
Assuntos
Metilação de DNA , Enzimas de Restrição-Modificação do DNA , Escherichia coli/genética , Animais , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Regulação Bacteriana da Expressão Gênica , Camundongos , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/crescimento & desenvolvimento , Escherichia coli Uropatogênica/metabolismo , Escherichia coli Uropatogênica/patogenicidadeRESUMO
The outer membrane (OM) is an essential component of the Gram-negative bacterial envelope that protects the cells against external threats. To maintain a functional OM, cells require distinct mechanisms to ensure balance of proteins and lipids in the membrane. Mutations in OM biogenesis and/or homeostasis pathways often result in permeability defects, but how molecular changes in the OM affect barrier function is unclear. Here, we seek potential mechanism(s) that can alleviate permeability defects in Escherichia coli cells lacking the Tol-Pal complex, which accumulate excess PLs in the OM. We identify mutations in enterobacterial common antigen (ECA) biosynthesis that re-establish OM barrier function against large hydrophilic molecules, yet did not restore lipid homeostasis. Furthermore, we demonstrate that build-up of biosynthetic intermediates, but not loss of ECA itself, contributes to the rescue. This suppression of OM phenotypes is unrelated to known effects that accumulation of ECA intermediates have on the cell wall. Finally, we reveal that an unusual diacylglycerol pyrophosphoryl-linked lipid species also accumulates in ECA mutants, and might play a role in the rescue phenotype. Our work provides insights into how OM barrier function can be restored independent of lipid homeostasis, and highlights previously unappreciated effects of ECA-related species in OM biology.
Assuntos
Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Membrana Externa Bacteriana/fisiologia , Escherichia coli/genética , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Permeabilidade da Membrana Celular , Parede Celular/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Homeostase , Mutação , Proteínas Periplásmicas/genética , Proteínas Periplásmicas/metabolismoRESUMO
Movement of patients in a health care network poses challenges for the control of carbapenemase-producing Enterobacteriaceae (CPE). We aimed to identify intra- and interfacility transmission events and facility type-specific risk factors of CPE in an acute-care hospital (ACH) and its intermediate-term and long-term-care facilities (ILTCFs). Serial cross-sectional studies were conducted in June and July of 2014 to 2016 to screen for CPE. Whole-genome sequencing was done to identify strain relatedness and CPE genes (blaIMI, blaIMP-1, blaKPC-2, blaNDM-1, and blaOXA-48). Multivariable logistic regression models, stratified by facility type, were used to determine independent risk factors. Of 5,357 patients, half (55%) were from the ACH. CPE prevalence was 1.3% in the ACH and 0.7% in ILTCFs (P = 0.029). After adjusting for sociodemographics, screening year, and facility type, the odds of CPE colonization increased significantly with a hospital stay of ≥3 weeks (adjusted odds ratio [aOR], 2.67; 95% confidence interval [CI], 1.17 to 6.05), penicillin use (aOR, 3.00; 95% CI, 1.05 to 8.56), proton pump inhibitor use (aOR, 3.20; 95% CI, 1.05 to 9.80), dementia (aOR, 3.42; 95% CI, 1.38 to 8.49), connective tissue disease (aOR, 5.10; 95% CI, 1.19 to 21.81), and prior carbapenem-resistant Enterobacteriaceae (CRE) carriage (aOR, 109.02; 95% CI, 28.47 to 417.44) in the ACH. For ILTCFs, presence of wounds (aOR, 5.30; 95% CI, 1.01 to 27.72), respiratory procedures (aOR, 4.97; 95% CI, 1.09 to 22.71), vancomycin-resistant enterococcus carriage (aOR, 16.42; 95% CI, 1.52 to 177.48), and CRE carriage (aOR, 758.30; 95% CI, 33.86 to 16,982.52) showed significant association. Genomic analysis revealed only possible intra-ACH transmission and no evidence for ACH-to-ILTCF transmission. Although CPE colonization was predominantly in the ACH, risk factors varied between facilities. Targeted screening and precautionary measures are warranted.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Estudos Transversais , Atenção à Saúde , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/epidemiologia , Hospitais , Humanos , Singapura , beta-Lactamases/genéticaRESUMO
OBJECTIVES: To estimate the transmission rate of carbapenemase-producing Enterobacteriaceae (CPE) in households with recently hospitalized CPE carriers. METHODS: We conducted a prospective case-ascertained cohort study. We identified the presence of CPE in stool samples from index subjects, household contacts and companion animals and environmental samples at regular intervals. Linked transmissions were identified by WGS. A Markov model was constructed to estimate the household transmission potential of CPE. RESULTS: Ten recently hospitalized index patients and 14 household contacts were included. There were seven households with one contact, two households with two contacts, and one household with three contacts. Index patients were colonized with blaOXA-48-like (nâ=â4), blaKPC-2 (nâ=â3), blaIMP (nâ=â2), and blaNDM-1 (nâ=â1), distributed among divergent species of Enterobacteriaceae. After a cumulative follow-up time of 9.0 years, three family members (21.4%, 3/14) acquired four different types of CPE in the community (hazard rate of 0.22/year). The probability of CPE transmission from an index patient to a household contact was 10% (95% CI 4%-26%). CONCLUSIONS: We observed limited transmission of CPE from an index patient to household contacts. Larger studies are needed to understand the factors associated with household transmission of CPE and identify preventive strategies.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Estudos de Coortes , Infecções por Enterobacteriaceae/epidemiologia , Humanos , Estudos Prospectivos , beta-Lactamases/genéticaRESUMO
To determine the duration of carbapenemase-producing Enterobacteriaceae (CPE) carriage, we studied 21 CPE carriers for ¼1 year. Mean carriage duration was 86 days; probability of decolonization in 1 year was 98.5%, suggesting that CPE-carriers' status can be reviewed yearly. Prolonged carriage was associated with use of antimicrobial drugs.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Proteínas de Bactérias/genética , Infecções por Enterobacteriaceae/epidemiologia , Hospitais , Humanos , beta-Lactamases/genéticaRESUMO
MOTIVATION: Stirling numbers enter into the calculation of several population genetics statistics, including Fu's Fs. However, as alignments become large (≥50 sequences), the Stirling numbers required rapidly exceed the standard floating point range. Another recursive method for calculating Fu's Fs suffers from floating point underflow issues. RESULTS: I implemented an estimator for Stirling numbers that has the advantage of being uniformly applicable to the full parameter range for Stirling numbers. I used this to create a hybrid Fu's Fs calculator that accounts for floating point underflow. My new algorithm is hundreds of times faster than the recursive method. This algorithm now enables accurate calculation of statistics such as Fu's Fs for very large alignments. AVAILABILITY AND IMPLEMENTATION: An R implementation is available at http://github.com/swainechen/hfufs. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Genética Populacional , Software , Algoritmos , Alinhamento de SequênciaRESUMO
Notonesomycin A is a 32-membered bioactive glycosylated macrolactone known to be produced by Streptomyces aminophilus subsp. notonesogenes 647-AV1 and S. aminophilus DSM 40186. In a high throughput antifungal screening campaign, we identified an alternative notonesomycin A producing strain, Streptomyces sp. A793, and its biosynthetic gene cluster. From this strain, we further characterized a new more potent antifungal non-sulfated analogue, named notonesomycin B. Through CRISPR-Cas9 engineering of the biosynthetic gene cluster, we were able to increase the production yield of notonesomycin B by up to 18-fold as well as generate a strain that exclusively produces this analogue.
Assuntos
Antifúngicos/isolamento & purificação , Macrolídeos/isolamento & purificação , Streptomyces/genética , Antifúngicos/metabolismo , Clonagem Molecular , Macrolídeos/metabolismo , Família Multigênica , Streptomyces/metabolismoRESUMO
BACKGROUND: Phomafungin is a recently reported broad spectrum antifungal compound but its biosynthetic pathway is unknown. We combed publicly available Phoma genomes but failed to find any putative biosynthetic gene cluster that could account for its biosynthesis. RESULTS: Therefore, we sequenced the genome of one of our Phoma strains (F3723) previously identified as having antifungal activity in a high-throughput screen. We found a biosynthetic gene cluster that was predicted to synthesize a cyclic lipodepsipeptide that differs in the amino acid composition compared to Phomafungin. Antifungal activity guided isolation yielded a new compound, BII-Rafflesfungin, the structure of which was determined. CONCLUSIONS: We describe the NRPS-t1PKS cluster 'BIIRfg' compatible with the synthesis of the cyclic lipodepsipeptide BII-Rafflesfungin [HMHDA-L-Ala-L-Glu-L-Asn-L-Ser-L-Ser-D-Ser-D-allo-Thr-Gly]. We report new Stachelhaus codes for Ala, Glu, Asn, Ser, Thr, and Gly. We propose a mechanism for BII-Rafflesfungin biosynthesis, which involves the formation of the lipid part by BIIRfg_PKS followed by activation and transfer of the lipid chain by a predicted AMP-ligase on to the first PCP domain of the BIIRfg_NRPS gene.
Assuntos
Antifúngicos/química , Depsipeptídeos/química , Proteínas Fúngicas/genética , Saccharomycetales/genética , Sequência de Aminoácidos , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Vias Biossintéticas , Depsipeptídeos/biossíntese , Depsipeptídeos/farmacologia , Genômica , Estrutura Molecular , Família Multigênica , Saccharomycetales/metabolismo , Sequenciamento Completo do GenomaRESUMO
Type 1 pili (T1P) are major virulence factors for uropathogenic Escherichia coli (UPEC), which cause both acute and recurrent urinary tract infections. T1P expression therefore is of direct relevance for disease. T1P are phase variable (both piliated and nonpiliated bacteria exist in a clonal population) and are controlled by an invertible DNA switch (fimS), which contains the promoter for the fim operon encoding T1P. Inversion of fimS is stochastic but may be biased by environmental conditions and other signals that ultimately converge at fimS itself. Previous studies of fimS sequences important for T1P phase variation have focused on laboratory-adapted E coli strains and have been limited in the number of mutations or by alteration of the fimS genomic context. We surmounted these limitations by using saturating genomic mutagenesis of fimS coupled with accurate sequencing to detect both mutations and phase status simultaneously. In addition to the sequences known to be important for biasing fimS inversion, our method also identifies a previously unknown pair of 5' UTR inverted repeats that act by altering the relative fimA levels to control phase variation. Thus we have uncovered an additional layer of T1P regulation potentially impacting virulence and the coordinate expression of multiple pilus systems.
Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/genética , Fímbrias Bacterianas/genética , Mutagênese , Regiões Promotoras Genéticas , Bexiga Urinária/microbiologia , Escherichia coli/patogenicidade , RNA Mensageiro/genéticaRESUMO
Infections due to clonal expansion of highly virulent bacterial strains are clear and present threats to human and animal health. Association of genetic changes with disease is now a routine, but identification of causative mutations that enable disease remains difficult. Campylobacter jejuni is an important zoonotic pathogen transmitted to humans mainly via the foodborne route. C. jejuni typically colonizes the gut, but a hypervirulent and rapidly expanding clone of C. jejuni recently emerged, which is able to translocate across the intestinal tract, causing systemic infection and abortion in pregnant animals. The genetic basis responsible for this hypervirulence is unknown. Here, we developed a strategy, termed "directed genome evolution," by using hybridization between abortifacient and nonabortifacient strains followed by selection in an animal disease model and whole-genome sequence analysis. This strategy successfully identified SNPs in porA, encoding the major outer membrane protein, are responsible for the hypervirulence. Defined mutagenesis verified that these mutations were both necessary and sufficient for causing abortion. Furthermore, sequence analysis identified porA as the gene with the top genome-wide signal of adaptive evolution using Fu's Fs, a population genetic metric for recent population size changes, which is consistent with the recent expansion of clone "sheep abortion." These results identify a key virulence factor in Campylobacter and a potential target for the control of this zoonotic pathogen. Furthermore, this study provides general, unbiased experimental and computational approaches that are broadly applicable for efficient elucidation of disease-causing mutations in bacterial pathogens.
Assuntos
Proteínas de Bactérias/genética , Infecções por Campylobacter/genética , Campylobacter jejuni/genética , Porinas/genética , Doenças dos Ovinos/genética , Animais , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/transmissão , Campylobacter jejuni/patogenicidade , Humanos , Mutação Puntual , Ovinos , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/transmissãoRESUMO
Urinary tract infections (UTIs) are a major infection of humans, particularly affecting women. Recurrent UTIs can cause significant discomfort and expose patients to high levels of antibiotic use, which in turn contributes to the development of higher antibiotic resistance rates. Most UTIs are caused by uropathogenic Escherichia coli, which is able to form intracellular collections (termed intracellular bacterial communities [IBCs]) within the epithelial cells lining the bladder lumen. IBCs are seen in both infected mice and humans and are a potential cause of recurrent UTI. Genetic and molecular studies of IBCs have been hampered both by the low number of bacteria in IBCs relative to the number extracellular bacteria and by population bottlenecks that occur during IBC formation. We now report the development of a simple and rapid technique for isolating pure IBCs from experimentally infected mice. We verified the specificity and purity of the isolated IBCs via microscopy, gene expression, and culture-based methods. Our results further demonstrated that our isolation technique practically enables specific molecular studies of IBCs. In the first such direct measurement, we determined that a single epithelial cell containing an early IBC typically contains 103 viable bacteria. Our isolation technique complements recent progress in low-input, single-cell genomics to enable future genomic studies of the formation of IBCs and their activation pathways during recurrent UTI, which may lead to novel strategies to eliminate them from the bladder.
Assuntos
Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Linhagem Celular , Modelos Animais de Doenças , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Feminino , Camundongos , Células RAW 264.7RESUMO
Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing Enterobacter cloacae complex to determine the flanking regions of blaIMI-type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The blaIMI-type genes were all found on Xer-dependent integrative mobile elements (IMEX). The IMEX elements of 5 isolates were similar to those described in Canada, while the remainder were novel. Five isolates had IMEX elements lacking a resolvase and recombinase.
Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/genética , Sequências Repetitivas Dispersas/genética , beta-Lactamases/genética , Enterobacter cloacae/isolamento & purificação , Genoma Bacteriano/genética , Humanos , Tipagem de Sequências Multilocus , Singapura , Sequenciamento Completo do GenomaRESUMO
Burkholderia pseudomallei (Bp) is the causative agent of the infectious disease melioidosis. To investigate population diversity, recombination, and horizontal gene transfer in closely related Bp isolates, we performed whole-genome sequencing (WGS) on 106 clinical, animal, and environmental strains from a restricted Asian locale. Whole-genome phylogenies resolved multiple genomic clades of Bp, largely congruent with multilocus sequence typing (MLST). We discovered widespread recombination in the Bp core genome, involving hundreds of regions associated with multiple haplotypes. Highly recombinant regions exhibited functional enrichments that may contribute to virulence. We observed clade-specific patterns of recombination and accessory gene exchange, and provide evidence that this is likely due to ongoing recombination between clade members. Reciprocally, interclade exchanges were rarely observed, suggesting mechanisms restricting gene flow between clades. Interrogation of accessory elements revealed that each clade harbored a distinct complement of restriction-modification (RM) systems, predicted to cause clade-specific patterns of DNA methylation. Using methylome sequencing, we confirmed that representative strains from separate clades indeed exhibit distinct methylation profiles. Finally, using an E. coli system, we demonstrate that Bp RM systems can inhibit uptake of non-self DNA. Our data suggest that RM systems borne on mobile elements, besides preventing foreign DNA invasion, may also contribute to limiting exchanges of genetic material between individuals of the same species. Genomic clades may thus represent functional units of genetic isolation in Bp, modulating intraspecies genetic diversity.
Assuntos
Burkholderia pseudomallei/genética , Epigênese Genética , Genoma Bacteriano , Recombinação Genética , Transcriptoma , Animais , Primers do DNA , DNA Bacteriano/genética , Escherichia coli/genética , Feminino , Deleção de Genes , Estudos de Associação Genética , Genômica , Haplótipos , Humanos , Melioidose/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Tipagem de Sequências Multilocus , Filogenia , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
OBJECTIVES: To examine the impact on quality of life of recurrent acute uncomplicated urinary tract infection among premenopausal Singaporean women, and to determine the risk factors for lower quality of life among these patients. METHODS: A total of 85 patients with recurrent acute uncomplicated urinary tract infection who were referred to the Urology Department at the National University Hospital, Singapore, were prospectively recruited over a 3-year period to complete the validated Short Form 36 Health Survey version 1. In addition, demographic and clinical details including symptomology and medical history were analyzed for factors impacting quality of life. Short Form 36 Health Survey version 1 results were compared with published population norms. RESULTS: After adjusting for age, gender and race, recurrent acute uncomplicated urinary tract infection patients had significantly lower quality of life on seven out of eight Short Form 36 Health Survey version 1 domains when compared with age-, gender- and race-adjusted population norms for Singapore. Among those with recurrent acute uncomplicated urinary tract infection, those who also reported caffeine consumption had significantly lower Short Form 36 Health Survey version 1 scores than those who did not. Those who reported chronic constipation also had consistently lower Short Form 36 Health Survey version 1 scores across all domains. CONCLUSIONS: Recurrent acute uncomplicated urinary tract infection has a negative impact on the quality of life of premenopausal, otherwise healthy women. Recurrent acute uncomplicated urinary tract infection patients who also have chronic constipation or consume caffeine have lower quality of life than those who do not. More studies are required to understand the relationships between these common problems and risk factors.
Assuntos
Constipação Intestinal/psicologia , Qualidade de Vida , Infecções Urinárias/psicologia , Doença Aguda/epidemiologia , Doença Aguda/terapia , Adulto , Antibacterianos/uso terapêutico , Cafeína/efeitos adversos , Café/efeitos adversos , Comorbidade , Constipação Intestinal/epidemiologia , Comportamento Alimentar , Feminino , Humanos , Pré-Menopausa , Recidiva , Fatores de Risco , Singapura/epidemiologia , Inquéritos e Questionários/estatística & dados numéricos , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , Infecções Urinárias/patologiaRESUMO
BACKGROUND: Streptococcus agalactiae (group B Streptococcus [GBS]) has not been described as a foodborne pathogen. However, in 2015, a large outbreak of severe invasive sequence type (ST) 283 GBS infections in adults epidemiologically linked to the consumption of raw freshwater fish occurred in Singapore. We attempted to determine the scale of the outbreak, define the clinical spectrum of disease, and link the outbreak to contaminated fish. METHODS: Time-series analysis was performed on microbiology laboratory data. Food handlers and fishmongers were screened for enteric carriage of GBS. A retrospective cohort study was conducted to assess differences in demographic and clinical characteristics of patients with invasive ST283 and non-ST283 infections. Whole-genome sequencing was performed on human and fish ST283 isolates from Singapore, Thailand, and Hong Kong. RESULTS: The outbreak was estimated to have started in late January 2015. Within the study cohort of 408 patients, ST283 accounted for 35.8% of cases. Patients with ST283 infection were younger and had fewer comorbidities but were more likely to develop meningoencephalitis, septic arthritis, and spinal infection. Of 82 food handlers and fishmongers screened, none carried ST283. Culture of 43 fish samples yielded 13 ST283-positive samples. Phylogenomic analysis of 161 ST283 isolates from humans and fish revealed they formed a tight clade distinguished by 93 single-nucleotide polymorphisms. CONCLUSIONS: ST283 is a zoonotic GBS clone associated with farmed freshwater fish, capable of causing severe disease in humans. It caused a large foodborne outbreak in Singapore and poses both a regional and potentially more widespread threat.
Assuntos
Epidemias , Peixes/microbiologia , Microbiologia de Alimentos , Alimentos Crus/microbiologia , Análise de Sequência de DNA , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae/genética , Idoso , Animais , Estudos de Coortes , Surtos de Doenças , Feminino , Água Doce/microbiologia , Genoma Bacteriano , Hong Kong/epidemiologia , Humanos , Masculino , Meningoencefalite/etiologia , Meningoencefalite/microbiologia , Pessoa de Meia-Idade , Filogenia , Estudos Retrospectivos , Singapura/epidemiologia , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/isolamento & purificação , Tailândia/epidemiologia , ZoonosesRESUMO
We assessed microbial safety and quality of raw fish sold in Singapore during 2015-2016 to complement epidemiologic findings for an outbreak of infection with group B Streptococcus serotype III sequence type (ST) 283 associated with raw fish consumption. Fish-associated group B Streptococcus ST283 strains included strains nearly identical (0-2 single-nucleotide polymorphisms) with the human outbreak strain, as well as strains in another distinct ST283 clade (57-71 single-nucleotide polymorphisms). Our investigations highlight the risk for contamination of freshwater fish (which are handled and distributed separately from saltwater fish sold as sashimi) and the need for improved hygienic handling of all fish for raw consumption. These results have led to updated policy and guidelines regarding the sale of ready-to-eat raw fish dishes in Singapore.
Assuntos
Surtos de Doenças , Peixes/microbiologia , Manipulação de Alimentos , Doenças Transmitidas por Alimentos/etiologia , Infecções Estreptocócicas/etiologia , Streptococcus agalactiae , Animais , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Filogenia , Restaurantes , Singapura/epidemiologia , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae/genéticaRESUMO
Recurrent urinary tract infections (UTIs) caused by uropathogenic E. coli (UPEC) are common and morbid infections with limited therapeutic options. Previous studies have demonstrated that persistent intracellular infection of bladder epithelial cells (BEC) by UPEC contributes to recurrent UTI in mouse models of infection. However, the mechanisms employed by UPEC to survive within BEC are incompletely understood. In this study we aimed to understand the role of host vesicular trafficking proteins in the intracellular survival of UPEC. Using a cell culture model of intracellular UPEC infection, we found that the small GTPase Rab35 facilitates UPEC survival in UPEC-containing vacuoles (UCV) within BEC. Rab35 plays a role in endosomal recycling of transferrin receptor (TfR), the key protein responsible for transferrin-mediated cellular iron uptake. UPEC enhance the expression of both Rab35 and TfR and recruit these proteins to the UCV, thereby supplying UPEC with the essential nutrient iron. Accordingly, Rab35 or TfR depleted cells showed significantly lower intracellular iron levels and reduced ability to support UPEC survival. In the absence of Rab35, UPEC are preferentially trafficked to degradative lysosomes and killed. Furthermore, in an in vivo murine model of persistent intracellular infection, Rab35 also colocalizes with intracellular UPEC. We propose a model in which UPEC subverts two different vesicular trafficking pathways (endosomal recycling and degradative lysosomal fusion) by modulating Rab35, thereby simultaneously enhancing iron acquisition and avoiding lysosomal degradation of the UCV within bladder epithelial cells. Our findings reveal a novel survival mechanism of intracellular UPEC and suggest a potential avenue for therapeutic intervention against recurrent UTI.