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Chromatogram from patient with diarrheic syndrome of non-parasitic aetiology (NPD) (a) and from patient with diarrheic syndrome with Giardia presence (GD) (b)
Source publication
Currently, chronic diarrhoea syndrome in children is a very common pathology whose aetiology is sometimes difficult to identify. Methodologies for the diagnosis of infections have diversified, and gas chromatography/mass spectrometry (GC/MS) is a very useful tool. The aim of this study was to identify volatile biomarkers of the presence of Giardia...
Similar publications
Giardia lamblia is one of most common protozoan cause diarrheas, and the most health problem in development countries worldwide. Our work aimed to assess activity and toxicity of metronidazole loaded silver nanoparticles in treatment of acute giardiasis in mice. After inoculated mice with Giardia cysts in a dose of 10 5 cyst for acute infection, tr...
Citations
... Furthermore, microorganisms can produce species-specific VOCs as a product of their metabolism and could also be helpful for the diagnosis of infection as an odor fingerprinting (Tait et al. 2014). Thus, the VOCs produced by microorganisms have been employed successfully to identify their presence in biological samples with Helicobacter pylori (Ulanowska et al. 2011), Giardia lamblia (Ubeda et al. 2019), and SARS-CoV-2 (Lamote et al. 2020), among several others. Specifically, the volatilomic profile of L. monocytogenes has already been studied in thioglycolate broth (Lepe-Balsalobre et al. 2022), trypticase soy broth (Chen et al. 2017), and milk samples (Tait et al. 2014). ...
Aim
Volatile organic compounds (VOCs) are being studied as potential biomarkers in many infections. Therefore, this study aimed to analyze the volatile profile of three Gram-positive bacteria of clinical relevance to identify potential volatile biomarkers that allow their differentiation.
Methods and results
L. monocytogenes, S. aureus, and E. faecalis clinical isolates were inoculated in a thioglycollate medium until grown. Then, VOCs were extracted by solid-phase microextraction, and the data obtained were subjected to multivariate analysis. According to our results, there was a high production of aldehydes in E. faecalis. In the case of alcohols, they only increased in L. monocytogenes, while ketones were produced significantly in all three bacteria, mainly due to acetoin. Acids were produced significantly in E. faecalis and L. monocytogenes.
Conclusions
Potential biomarkers of L. monocytogenes could be 1-butanol and 2-methylbutanoic acid. In the case of E. faecalis, the VOC most related to its presence was nonanal. Lastly, potential biomarkers of S. aureus could be isoamyl butanoate and methionol, although some pyrazines have also been associated with this bacterium.
Significance and impact of the study
The identification of potential biomarkers of these clinically relevant bacteria could open the way for the diagnosis of these infections through the analysis of volatile compounds.
... For example, people infected with Plasmodium falciparium, the pathogen that causes malaria transmitted by female Anopheles mosquitoes, emit VCs that in turn attract the vector insect. It has been described that this protozoan produces terpene compounds very similar to plants, which may act as signals to indicate to the vector organism the potential and preferred final hosts (Berna et al., 2020;Ubeda et al., 2019). Thus, it has been identified that the terpenes 4,5,9,10-dehydro-isolongifolene and 8,9-dehydro-9-formyl cycloisolongifolen are highly produced by Plasmodium falciparium and are detected in infected-erythrocyte. ...
... Although the main detection technique of the infection is immunoflorescence, the VCs profile of this microbe has been determined, which acts as a key biomarker in the detection of the disease, a topic that will be developed in subsequent sections. Thus, compounds such as 2,2,4,4-tetramethyloctane; acetic acid; 2,2,4,6,6-pentamethylheptane; 4-dimethoxy-2,3-butanediol and 1,3-dimethoxy-2-propanol are VOC derived from the metabolism of Giardia that can be used as an indicator of the disease (Roshidi & Arifin, 2022;Ubeda et al., 2019). ...
... There are several studies on the effects of VCs on microbiota diversity (Dalis et al., 2023;Elmassry & Piechulla, 2020;Neyrinck et al., 2022;Smolinska et al., 2018;Ubeda et al., 2019). Because of that, we cannot fail to highlight the important interaction that occurs in these environments both at the microbial level (fungi, bacteria) with the virome that resides there, as well as with animal cells. ...
... In a previous study by Bond et al., the characteristic smell of the feces of giardiasis patients with persistent diarrhea was analyzed, resulting in the identification of several important compounds, namely, 2,2,4,4-tetramethyloctane, acetic acid, and 2,2,4,6,6-pentamethylheptane, suggesting that these were potential biomarkers of giardiasis [70]. The sensitivity and specificity value of VSP5 and VSP3 on cumulative assays of IgG/IgM were 100% while the sensitivity and specificity value of IgA-VSP5 and VSP3 cumulative assays were 80% and 100%, respectively ...
Giardiasis is a common, treatable intestinal disease that adversely affects underprivileged communities living in unsanitary conditions. Giardiasis causes a wide spectrum of gastrointestinal diseases in those infected, ranging from subclinical disease that can manifest as irritable bowel syndrome with persistent abdominal symptoms. Importantly, giardiasis has been identified as a predictor of malnutrition among young children in rural areas and as a cause of waterborne mass epidemics endangering not only humans but also animals in a broad clinical, social, and economic spectrum. While the diagnosis of giardiasis is heavily dependent on the presence of cysts and/or trophozoites detected using microscopy, the intermittent cyst excretion, low infection intensity, and low sensitivity method m4akes fecal examination unrewarding, thus urging the need for an improved diagnostic method for giardiasis. Proteins are key compounds in biosynthesis, cells, tissues, and organ signaling, carrying important information related to biological and pathogenic processes, as well as pharmacological responses to therapeutic intervention, and are therefore important indicators for determining disease onset, progression, and drug treatment effectiveness. In connection with this, proteins could serve as promising biomarkers for antigen-antibody detection, as well as vaccine candidates. This article is aimed at providing a comprehensive overview of proteins, serological, molecular, inflammatory, volatile, and hormonal biomarkers associated with giardiasis and their potential for diagnostics and therapeutics.
... One potential application of this method is for the detection of complex biological samples. Studies have already shown that diabetic patients have different levels of acetone in exhaled gas than healthy individuals, which can be used as a biomarker for diabetes [60,61]; dimethyl disulphide in the feces of cholera patients can be used as a biomarker [62,63], and trimethylaminuria patients have much higher levels of trimethylamine in their urine and sweat than healthy individuals [64,65]. Samples such as exhaled gas, urine, and feces contain a large number of different volatiles from which identifying specific disease markers would be a challenge, which may be possible using deep learning. ...
High-field asymmetric ion mobility spectrometry (FAIMS) spectra of single chemicals are easy to interpret but identifying specific chemicals within complex mixtures is difficult. This paper demonstrates that the FAIMS system can detect specific chemicals in complex mixtures. A homemade FAIMS system is used to analyze pure ethanol, ethyl acetate, acetone, 4-methyl-2-pentanone, butanone, and their mixtures in order to create datasets. An EfficientNetV2 discriminant model was constructed, and a blind test set was used to verify whether the deep-learning model is capable of the required task. The results show that the pre-trained EfficientNetV2 model completed convergence at a learning rate of 0.1 as well as 200 iterations. Specific substances in complex mixtures can be effectively identified using the trained model and the homemade FAIMS system. Accuracies of 100%, 96.7%, and 86.7% are obtained for ethanol, ethyl acetate, and acetone in the blind test set, which are much higher than conventional methods. The deep learning network provides higher accuracy than traditional FAIMS spectral analysis methods. This simplifies the FAIMS spectral analysis process and contributes to further development of FAIMS systems.
... Considering that feces constitute the main media for eliminating metabolic products, these are an important source of information about the internal homeostasis (17). The reason for testing changes in VOCs in feces is based on the common assumption that any abnormality in the activity or composition of the intestinal microbiota and in the whole organism may alter the odor of this matrix (1), which is supported by studies from both human (93)(94)(95)(96) and animal medicine (97)(98)(99)(100). Consequently, examination of volatile fecal emission could be a very useful non-invasive diagnostic approach (1). ...
Volatile organic compounds (VOCs) are small molecular mass metabolites which compose the volatilome, whose analysis has been widely employed in different areas. This innovative approach has emerged in research as a diagnostic alternative to different diseases in human and veterinary medicine, which still present constraints regarding analytical and diagnostic sensitivity. Such is the case of the infection by mycobacteria responsible for tuberculosis and paratuberculosis in livestock. Although eradication and control programs have been partly managed with success in many countries worldwide, the often low sensitivity of the current diagnostic techniques against Mycobacterium bovis (as well as other mycobacteria from Mycobacterium tuberculosis complex) and Mycobacterium avium subsp. paratuberculosis together with other hurdles such as low mycobacteria loads in samples, a tedious process of microbiological culture, inhibition by many variables, or intermittent shedding of the mycobacteria highlight the importance of evaluating new techniques that open different options and complement the diagnostic paradigm. In this sense, volatilome analysis stands as a potential option because it fulfills part of the mycobacterial diagnosis requirements. The aim of the present review is to compile the information related to the diagnosis of tuberculosis and paratuberculosis in livestock through the analysis of VOCs by using different biological matrices. The analytical techniques used for the evaluation of VOCs are discussed focusing on the advantages and drawbacks offered compared with the routine diagnostic tools. In addition, the differences described in the literature among in vivo and in vitro assays, natural and experimental infections, and the use of specific VOCs (targeted analysis) and complete VOC pattern (non-targeted analysis) are highlighted. This review emphasizes how this methodology could be useful in the problematic diagnosis of tuberculosis and paratuberculosis in livestock and poses challenges to be addressed in future research.
... No volatile compound has yet proven to be of sufficient diagnostic value so far. This can be explained in terms of both the high interindividual variability [11][12][13][14] and individual daily variation 15,16 , both of which can afford opposite results from one study to another [17][18][19] . Indeed, variables such as overall health status, diet, medication intake, exercise and smoking habits can induce qualitative and quantitative changes in the patient volatolome that are unrelated to pathologies 20,21 . ...
Volatolomics allows us to elucidate cell metabolic processes in real time. In particular, a volatile organic compound (VOC) excreted from our bodies may be specific for a certain disease, such that measuring this VOC may afford a simple, fast, accessible and safe diagnostic approach. Yet, finding the optimal endogenous volatile marker specific to a pathology is non-trivial because of interlaboratory disparities in sample preparation and analysis, as well as high interindividual variability. These limit the sensitivity and specificity of volatolomics and its applications in biological and clinical fields but have motivated the development of induced volatolomics. This approach aims to overcome issues by measuring VOCs that result not from an endogenous metabolite but, rather, from the pathogen-specific or metabolic-specific enzymatic metabolism of an exogenous biological or chemical probe. In this Review, we introduce volatile-compound-based probes and discuss how they can be exploited to detect and discriminate pathogenic infections, to assess organ function and to diagnose and monitor cancers in real time. We focus on cases in which labelled probes have informed us about metabolic processes and consider the potential and drawbacks of the probes for clinical trials. Beyond diagnostics, VOC-based probes may also be effective tools to explore biological processes more generally.
... Table 2, the coupling GC-MS is the most widely employed analytical technique for the analysis of VOCs in animal feces. [15,81,82] Although it has been widely used in the diagnosis of diseases in humans, such as cholera, Crohn's disease, giardiasis, or other bacterial infections; [83][84][85] only a few studies have been published in the literature for the diagnosis of diseases in animals ( Table 2). The coupling GC-MS is advantageous since it allows the identification and quantification of unknown compounds at concentrations below ng/g levels and provides accurate determination of the compounds with high resolution [18] This analytical technique also allows the use of different extraction techniques, enabling the pre-concentration of the compounds if necessary. ...
Volatilome analysis is growing in attention for the diagnosis of diseases in animals and humans. In particular, volatilome analysis in fecal samples is starting to be proposed as a fast, easy and noninvasive method for disease diagnosis. Volatilome comprises volatile organic compounds (VOCs), which are produced during both physiological and patho-physiological processes. Thus, VOCs from a pathological condition often differ from those of a healthy state and therefore the VOCs profile can be used in the detection of some diseases. Due to their strengths and advantages, feces are currently being used to obtain information related to health status in animals. However, they are complex samples, that can present problems for some analytical techniques and require special consideration in their use and preparation before analysis. This situation demands an effort to clarify which analytic options are currently being used in the research context to analyze the possibilities these offer, with the final objectives of contributing to develop a standardized methodology and to exploit feces potential as a diagnostic matrix. The current work reviews the studies focused on the diagnosis of animal diseases through fecal volatilome in order to evaluate the analytical methods used and their advantages and limitations. The alternatives found in the literature for sampling, storage, sample pretreatment, measurement and data treatment have been summarized, considering all the steps involved in the analytical process.
Microorganisms produce a wide variety of volatile organic compounds (VOCs) as products of their metabolism and some of them can be specific VOCs linked to the microorganism's identity, which have proved to be helpful for the diagnosis of infection via odour fingerprinting. The aim of this study was to determine the VOCs produced and consumed to characterize the volatile metabolism of seven isolates of different clonal complexes (CCs) of Listeria monocytogenes. For this purpose, dichloromethane extracts from the thioglycolate broth medium were analysed by gas chromatography coupled to mass spectrometry (GC/MS). Also, multivariate analyses were applied to the data obtained. Results showed that all the isolates of L. monocytogenes produced de novo isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-(methylthio)-1-propanol, acetic acid, isobutyric acid, butanoic acid, and isovaleric acid. Significant differences were found among isolates for the production amount of these volatiles, which allowed their differentiation. Thus, CC4 (ST-219/CT-3650) and CC87 (ST-87/CT-4557) showed an active volatile compounds metabolism with high consumption nitrogen and sulphur compounds and production of alcohols and acids, and CC8 (ST-8/CT-8813) and CC3 (ST-3/CT-8722) presented a less active volatile metabolism. Moreover, within the VOCs determined, huge differences were found in the production of butanol among the seven isolates analysed, being probably a good biomarker to discriminate among isolates belonging to different CCs. Hence, the analysis of volatile profile generated by the growth of L. monocytogenes in vitro could be a useful tool to differentiate among CCs isolates.
