RESUMEN
An increasing amount of evidence implies that native microbiota is a constituent part of a healthy urinary tract (UT), making it an ecosystem on its own. What is still not clear is whether the origin of the urinary microbial community is the indirect consequence of the more abundant gut microbiota or a more distinct separation exists between these two systems. Another area of uncertainty is the existence of a link between the shifts in UT microbial composition and both the onset and persistence of cystitis symptoms. Cystitis is one of the most common reasons for antimicrobial drugs prescriptions in primary and secondary care and an important contributor to the problem of antimicrobial resistance. Despite this fact, we still have trouble distinguishing whether the primary cause of the majority of cystitis cases is a single pathogen overgrowth or a systemic disorder affecting the entire urinary microbiota. There is an increasing trend in studies monitoring changes and dynamics of UT microbiota, but this field of research is still in its infancy. Using NGS and bioinformatics, it is possible to obtain microbiota taxonomic profiles directly from urine samples, which can provide a window into microbial diversity (or the lack of) underlying each patient's cystitis symptoms. However, while microbiota refers to the living collection of microorganisms, an interchangeably used term microbiome referring to the genetic material of the microbiota is more often used in conjunction with sequencing data. It is this vast amount of sequences, which are truly "Big Data", that allow us to create models that describe interactions between different species contributing to an UT ecosystem, when coupled with machine-learning techniques. Although in a simplified predator-prey form these multi-species interaction models have the potential to further validate or disprove current beliefs; whether it is the presence or the absence of particular key players in a UT microbial ecosystem, the exact cause or consequence of the otherwise unknown etiology in the majority of cystitis cases. These insights might prove to be vital in our ongoing struggle against pathogen resistance and offer us new and promising clinical markers.
RESUMEN
For mass spectrometry-based diagnostics of microorganisms, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently routinely used to identify urinary tract pathogens. However, it requires a lengthy culture step for accurate pathogen identification, and is limited by a relatively small number of available species in peptide spectral libraries (≤3329). Here, we propose a method for pathogen identification that overcomes the above limitations, and utilizes the MALDI-TOF/TOF MS instrument. Tandem mass spectra of the analyzed peptides were obtained by chemically activated fragmentation, which allowed mass spectrometry analysis in negative and positive ion modes. Peptide sequences were elucidated de novo, and aligned with the non-redundant National Center for Biotechnology Information Reference Sequence Database (NCBInr). For data analysis, we developed a custom program package that predicted peptide sequences from the negative and positive MS/MS spectra. The main advantage of this method over a conventional MALDI-TOF MS peptide analysis is identification in less than 24 h without a cultivation step. Compared to the limited identification with peptide spectra libraries, the NCBI database derived from genome sequencing currently contains 20,917 bacterial species, and is constantly expanding. This paper presents an accurate method that is used to identify pathogens grown on agar plates, and those isolated directly from urine samples, with high accuracy.
Asunto(s)
Espectrometría de Masas en Tándem , Sistema Urinario , Secuencia de Aminoácidos , Bacterias , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
A decade ago, when the Human Microbiome Project was starting, urinary tract (UT) was not included because the bladder and urine were considered to be sterile. Today, we are presented with evidence that healthy UT possesses native microbiota and any major event disrupting its "equilibrium" can impact the host also. This dysbiosis often leads to cystitis symptoms, which is the most frequent lower UT complaint, especially among women. Cystitis is one of the most common causes of antimicrobial drugs prescriptions in primary and secondary care and an important contributor to the problem of antimicrobial resistance. Despite this fact, we still have trouble distinguishing whether the primary cause of majority of cystitis cases is a single pathogen overgrowth, or a systemic disorder affecting entire UT microbiota. There are relatively few studies monitoring changes and dynamics of UT microbiota in cystitis patients, making this field of research still an unknown. In this study variations to the UT microbiota of cystitis patients were identified and microbial dynamics has been modeled. The microbial genetic profile of urine samples from 28 patients was analyzed by 16S rDNA Illumina sequencing and bioinformatics analysis. One patient with bacterial cystitis symptoms was prescribed therapy based on national guideline recommendations on antibacterial treatment of urinary tract infections (UTI) and UT microbiota change was monitored by 16S rDNA sequencing on 24 h basis during the entire therapy duration. The results of sequencing implied that a particular class of bacteria is associated with majority of cystitis cases in this study. The contributing role of this class of bacteria - Gammaproteobacteria, was further predicted by generalized Lotka-Volterra modeling (gLVM). Longitudinal microbiota insight obtained from a single patient under prescribed antimicrobial therapy revealed rapid and extensive changes in microbial composition and emphasized the need for current guidelines revision in regards to therapy duration. Models based on gLVM indicated protective role of two taxonomic classes of bacteria, Actinobacteria and Bacteroidia class, which appear to actively suppress pathogen overgrowth.
Asunto(s)
Cistitis , Microbiota , Infecciones Urinarias , Disbiosis , Femenino , HumanosRESUMEN
BACKGROUND: Reliable high-throughput microbial pathogen identification in human urine samples is crucial for patients with cystitis symptoms. Currently employed methods are time-consuming and could lead to unnecessary or inadequate antibiotic treatment. Purpose of this study was to assess the potential of mass spectrometry for uropathogen identification from a native urine sample. METHODS: In total, 16 urine samples having more than 105 CFU/mL were collected from clinical outpatients. These samples were analysed using standard urine culture methods, followed by 16S rRNA gene sequencing serving as control and here described culture-independent MALDI-TOF/TOF MS method being tested. RESULTS: Here we present advantages and disadvantages of bottom-up proteomics, using MALDI-TOF/TOF tandem mass spectrometry, for culture-independent identification of uropathogens (e.g. directly from urine samples). The direct approach provided reliable identification of bacteria at the genus level in monobacterial samples. Taxonomic identifications obtained by proteomics were compared both to standard urine culture test used in clinics and genomic test based on 16S rRNA sequencing. CONCLUSIONS: Our findings indicate that mass spectrometry has great potential as a reliable high-throughput tool for microbial pathogen identification in human urine samples. In this case, the MALDI-TOF/TOF, was used as an analytical tool for the determination of bacteria in urine samples, and the results obtained emphasize high importance of storage conditions and sample preparation method impacting reliability of MS2 data analysis. The proposed method is simple enough to be utilized in existing clinical settings and is highly suitable for suspected single organism infectious etiologies. Further research is required in order to identify pathogens in polymicrobial urine samples.
RESUMEN
Recent study data support the role of oxidative stress in diverse psychiatric disorders. Oxidative stress results from an oxidant/antioxidant imbalance, an excess of oxidants and/or a depletion of antioxidants. There are numerous studies that indicate that free radicals (FRs) damage neurons, and then play an important role in the pathophysiology of schizophrenia and depression. Active oxygen can cause considerable damage and disrupt the important physiological functions of proteins, lipids, enzymes and DNA. The aim of our study was to investigate the possible differences in the concentration of tromboxane B2, 8-OHdG and protein carbonyls, as significant markers of oxidative damage, and urate, albumin and total protein concentrations as antioxidative molecules in PTSD patients in comparison to the healthy control group. The study included 74 male participants who were active soldiers in the Croatian armed forces from 1991 to 1995. 46 subjects with chronic and current PTSD were recruited from the Department of Psychiatry of Dubrava University Hospital during 2010, 28 healthy subjects were recruited in the same period during the regular medical examination at the Dubrava University Hospital. Study results have shown that there is no statistically significant difference in urinary concentrations of 8-OHdG, serum thromboxane B2, and serum urates between two studied groups. Statistically significant difference of the protein carbonyl concentrations was examined. Concentrations were significantly lower in the PTSD group than in the control group. The clinical significance of these results was examined using ROC analysis. The obtained ROC curves did not separate the groups in a satisfactory manner.
Asunto(s)
Estrés Oxidativo , Trastornos por Estrés Postraumático/metabolismo , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Biomarcadores , Desoxiguanosina/análogos & derivados , Desoxiguanosina/orina , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Tromboxano B2/sangreRESUMEN
Endothelins (ET) are a group of endogenous peptides, which have a strong and long-lasting vasoconstrictive effect. Three isoforms of endothelins coded by three different genes have been identified to date. Endothelin-1 (ET-1) is the most potent vasoconstrictive agent currently identified, and it was originally isolated and characterized from the culture media of aortic endothelial cells. Two other isoforms, named endothelin-2 (ET-2) and endothelin-3 (ET-3), were subsequently identified, along with structural homologues isolated from the venom ofActractapis engaddensis known as the sarafotoxins. The biological effects of endothelin production are determined via activation of one or two G-protein coupled receptors, endothelin receptors A (ETRA) and B (ETRB1 and ETRB2). Recently endothelin receptor C (ETRC) was discovered, however, its functions and distribution still remain unclear. The effects mediated by ET-1 via ETRA are vasoconstriction, bronchoconstriction and secretion of aldosterone. Agonists related to the ETRB1 activation cause vasodilatation by stimulating NO, PGI2 and endothelium-derived hyperpolarizing factor (EDHF). In contrast, coupling to ETRB2 causes vasoconstriction. Involvement of ET has been demonstrated in the pathophysiology of certain disorders. In this review, we discuss the physiological and pathophysiological role of endothelium-derived ET-1, the pharmacology of its two receptors, focusing on the role of ET-1 in the development of some pathophysiological conditions.