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1.
Int J Mol Sci ; 24(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36675151

RESUMO

Apicomplexan infections, such as giardiasis and cryptosporidiosis, negatively impact a considerable proportion of human and commercial livestock populations. Despite this, the molecular mechanisms of disease, particularly the effect on the body beyond the gastrointestinal tract, are still poorly understood. To highlight host-parasite-microbiome biochemical interactions, we utilised integrated metabolomics-16S rRNA genomics and metabolomics-proteomics approaches in a C57BL/6J mouse model of giardiasis and compared these to Cryptosporidium and uropathogenic Escherichia coli (UPEC) infections. Comprehensive samples (faeces, blood, liver, and luminal contents from duodenum, jejunum, ileum, caecum and colon) were collected 10 days post infection and subjected to proteome and metabolome analysis by liquid and gas chromatography-mass spectrometry, respectively. Microbial populations in faeces and luminal washes were examined using 16S rRNA metagenomics. Proteome-metabolome analyses indicated that 12 and 16 key pathways were significantly altered in the gut and liver, respectively, during giardiasis with respect to other infections. Energy pathways including glycolysis and supporting pathways of glyoxylate and dicarboxylate metabolism, and the redox pathway of glutathione metabolism, were upregulated in small intestinal luminal contents and the liver during giardiasis. Metabolomics-16S rRNA genetics integration indicated that populations of three bacterial families-Autopobiaceae (Up), Desulfovibrionaceae (Up), and Akkermanasiaceae (Down)-were most significantly affected across the gut during giardiasis, causing upregulated glycolysis and short-chained fatty acid (SCFA) metabolism. In particular, the perturbed Akkermanasiaceae population seemed to cause oxidative stress responses along the gut-liver axis. Overall, the systems biology approach applied in this study highlighted that the effects of host-parasite-microbiome biochemical interactions extended beyond the gut ecosystem to the gut-liver axis. These findings form the first steps in a comprehensive comparison to ascertain the major molecular and biochemical contributors of host-parasite interactions and contribute towards the development of biomarker discovery and precision health solutions for apicomplexan infections.


Assuntos
Criptosporidiose , Cryptosporidium , Microbioma Gastrointestinal , Giardíase , Microbiota , Camundongos , Animais , Humanos , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Regulação para Cima , Proteoma/metabolismo , Criptosporidiose/metabolismo , Camundongos Endogâmicos C57BL , Cryptosporidium/metabolismo , Metabolômica , Metaboloma , Fígado/metabolismo , Oxirredução
2.
Health Promot Int ; 37(3)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35853153

RESUMO

Treated recreational water facilities, including swimming pools and water play parks, have often been implicated in infectious disease outbreaks. Addressing this problem is complex due to the multiple and interrelated factors contributing to outbreaks in these settings. These factors may relate to inappropriate behaviours of users and operators, lack of and inconsistent regulation of these facilities, insufficient facility maintenance, and problems associated with the design of these facilities. Given the complexity of this issue, we argue that the Socio-Ecological Model (SEM) provides a useful framework to help identify the multi-level influences and factors that have implications for designing interventions to prevent this public health problem, whilst assisting in guiding future research in this area. We apply the SEM to the current literature to help identify the influences and factors contributing to infectious disease outbreaks in treated recreational water facilities to support this argument. We also identify several gaps in the existing research that would benefit from further examination to help prevent infectious disease outbreaks in treated recreational water facilities such as public swimming pools and water play parks.


Assuntos
Água , Doenças Transmitidas pela Água , Surtos de Doenças/prevenção & controle , Humanos , Microbiologia da Água , Poluição da Água , Doenças Transmitidas pela Água/epidemiologia , Doenças Transmitidas pela Água/prevenção & controle
3.
Int J Mol Sci ; 23(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36233149

RESUMO

SARS-CoV-2 is the cause of the COVID-19 pandemic which has claimed more than 6.5 million lives worldwide, devastating the economy and overwhelming healthcare systems globally. The development of new drug molecules and vaccines has played a critical role in managing the pandemic; however, new variants of concern still pose a significant threat as the current vaccines cannot prevent all infections. This situation calls for the collaboration of biomedical scientists and healthcare workers across the world. Repurposing approved drugs is an effective way of fast-tracking new treatments for recently emerged diseases. To this end, we have assembled and curated a database consisting of 7817 compounds from the Compounds Australia Open Drug collection. We developed a set of eight filters based on indicators of efficacy and safety that were applied sequentially to down-select drugs that showed promise for drug repurposing efforts against SARS-CoV-2. Considerable effort was made to evaluate approximately 14,000 assay data points for SARS-CoV-2 FDA/TGA-approved drugs and provide an average activity score for 3539 compounds. The filtering process identified 12 FDA-approved molecules with established safety profiles that have plausible mechanisms for treating COVID-19 disease. The methodology developed in our study provides a template for prioritising drug candidates that can be repurposed for the safe, efficacious, and cost-effective treatment of COVID-19, long COVID, or any other future disease. We present our database in an easy-to-use interactive interface (CoviRx that was also developed to enable the scientific community to access to the data of over 7000 potential drugs and to implement alternative prioritisation and down-selection strategies.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Antivirais/farmacologia , Antivirais/uso terapêutico , COVID-19/complicações , Reposicionamento de Medicamentos , Humanos , Pandemias , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda
4.
Curr Microbiol ; 77(10): 3065-3075, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696237

RESUMO

The elimination of spore-forming bacteria is not guaranteed by current pasteurisation processes and is a challenging problem for the dairy industry. Given that Bacillus cereus sensu lato (B. cereus group) is an important foodborne pathogen and spoiler in the dairy industry, this study aimed at evaluating the prevalence and characteristics of B. cereus group in raw and pasteurised milk samples collected in Victoria, Australia. Isolated B. cereus group were tested for antimicrobial susceptibility, biofilm formation and virulence properties. Genetic diversity was assessed using ERIC-PCR. Proteomic profiling using MALDI-TOF MS and chemical profiling using Fourier-transform infrared (FTIR) spectroscopy were also applied for clustering of the isolates. Results showed 42.3% of milk samples contained B. cereus group, with a higher contamination level for pasteurised milk. Virulence studies identified genes nheA, nheB, hblA and nheC in most isolates and cyk gene in 46% of all isolates. Antimicrobial susceptibility testing showed a high prevalence of resistance towards ampicillin, ceftriaxone and penicillin. The biofilm-forming capacity of our isolates showed that most (53.7%) had the ability to form a biofilm. Genetic profiling using ERIC-PCR placed most B. cereus group isolates from pasteurised milk in the same cluster, indicating that they probably originated from a similar source. Raw milk isolates showed greater diversity indicating various sources. FTIR spectroscopy showed high agreement with genetic profiling. In contrast, low agreement between proteomic (MALDI-TOF MS) and genetic typing was observed. The present study showed that the FTIR spectroscopy could be adopted as a rapid tool for the typing of B. cereus group. Overall, the virulence and antimicrobial resistance characteristics, together with the ability of isolates to produce biofilm, indicate the importance of B. cereus group in the Australian dairy industry.


Assuntos
Bacillus , Leite , Animais , Austrália , Bacillus cereus/genética , Enterotoxinas , Microbiologia de Alimentos , Prevalência , Proteômica
5.
Int J Mol Sci ; 21(22)2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33207639

RESUMO

Antimicrobial peptides (AMPs) often exhibit wide-spectrum activities and are considered ideal candidates for effectively controlling persistent and multidrug-resistant wound infections. PuroA, a synthetic peptide based on the tryptophan (Trp)-rich domain of the wheat protein puroindoline A, displays strong antimicrobial activities. In this work, a number of peptides were designed based on PuroA, varying in physico-chemical parameters of length, number of Trp residues, net charge, hydrophobicity or amphipathicity, D-versus L-isomers of amino acids, cyclization or dimerization, and were tested for antimicrobial potency and salt and protease tolerance. Selected peptides were assessed for effects on biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and selected mammalian cells. Peptide P1, with the highest amphipathicity, six Trp and a net charge of +7, showed strong antimicrobial activity and salt stability. Peptides W7, W8 and WW (seven to eight residues) were generally more active than PuroA and all diastereomers were protease-resistant. PuroA and certain variants significantly inhibited initial biomass attachment and eradicated preformed biofilms of MRSA. Further, P1 and dimeric PuroA were cytotoxic to HeLa cells. The work has led to peptides with biocidal effects on common human pathogens and/or anticancer potential, also offering great insights into the relationship between physico-chemical parameters and bioactivities, accelerating progress towards rational design of AMPs for therapeutics.


Assuntos
Antineoplásicos , Biofilmes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Proteínas Citotóxicas Formadoras de Poros , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Camundongos , Células NIH 3T3 , Proteínas Citotóxicas Formadoras de Poros/síntese química , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Ovinos
6.
Metabolomics ; 15(3): 33, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30830484

RESUMO

INTRODUCTION: Influenza is a highly contagious respiratory disease that causes high global morbidity and mortality each year. The dynamics of an influenza infection on the host metabolism, and how metabolism is altered in response to neuraminidase inhibitor drug therapy, is still in its infancy but of great importance. OBJECTIVES: We aim to investigate the suitability of ferret nasal wash samples for metabolomics-based analysis and characterization of influenza infections and oseltamivir treatment. METHODS: Virological and metabolic analyses were performed on nasal wash samples collected from ferrets treated with oseltamivir or a placebo. Untargeted metabolomics was performed using a gas chromatography coupled with mass spectrometery (GC-MS) based protocol that comprised a retention time (RT) locked method and the use of a commercial metabolomics library. RESULTS: Ferret activity was reduced at 2-3 days post infection, which coincided with the highest influenza viral titre. The metabolomics data indicated a shift in metabolism during various stages of infection. The neuraminidase inhibitor oseltamivir created considerable downregulation of energy center metabolites (glucose, sucrose, glycine and glutamine), which generated high levels of branched amino acids. This further increased branched amino acid degradation and deregulation via glycerate-type intermediates and biosynthesis of fatty acids in oseltamivir-treated animals where abrogated weight loss was observed. CONCLUSION: Metabolomics was used to profile influenza infection and antiviral drug treatment in ferrets. This has the potential to provide indicators for the early diagnosis of influenza infection and assess the effectiveness of drug therapies.


Assuntos
Furões/metabolismo , Infecções por Orthomyxoviridae/metabolismo , Infecções Respiratórias/metabolismo , Animais , Antivirais/farmacologia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Vírus da Influenza A/metabolismo , Vírus da Influenza A/patogenicidade , Metabolômica , Oseltamivir/farmacologia , Sistema Respiratório
7.
Microbiology (Reading) ; 164(9): 1087-1097, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29993359

RESUMO

Bacterial biofilms can cause serious health care complications associated with increased morbidity and mortality. There is an urge to discover and develop new biofilm inhibitors from natural products or by modifying natural compounds or understanding the modes of action of existing compounds. Cinnamaldehyde (CAD), one of the major components of cinnamon oil, has been demonstrated to act as an antimicrobial agent against a number of Gram-negative and Gram-positive pathogens, including Pseudomonas aeruginosa, Helicobacter pylori and Listeria monocytogenes. Despite the mechanism of action of CAD against the model organism P. aeruginosa being undefined, based on its antimicrobial properties, we hypothesized that it may disrupt preformed biofilms of P. aeruginosa. The minimum inhibitory concentration (MIC) of CAD for planktonic P. aeruginosa was determined to be 11.8 mM. Membrane depolarization assays demonstrated disruption of the transmembrane potential of P. aeruginosa. CAD at 5.9 mM (0.5 MIC) disrupted preformed biofilms by 75.6 % and 3 mM CAD (0.25 MIC) reduced the intracellular concentrations of the secondary messenger, bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), which controls P. aeruginosa biofilm formation. The swarming motility of P. aeruginosa was also reduced by CAD in a concentration-dependent manner. Collectively, these findings show that sub-MICs of CAD can disrupt biofilms and other surface colonization phenotypes through the modulation of intracellular signalling processes.


Assuntos
Acroleína/análogos & derivados , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Acroleína/farmacologia , Biofilmes/crescimento & desenvolvimento , Potenciais da Membrana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/fisiologia , Metabolismo Secundário/efeitos dos fármacos
8.
Nature ; 543(7643): 40, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28252076
9.
World J Microbiol Biotechnol ; 34(4): 62, 2018 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-29651655

RESUMO

Antimicrobial peptides (AMPs) have been established over millennia as powerful components of the innate immune system of many organisms. Due to their broad spectrum of activity and the development of host resistance against them being unlikely, AMPs are strong candidates for controlling drug-resistant pathogenic microbial pathogens. AMPs cause cell death through several independent or cooperative mechanisms involving membrane lysis, non-lytic activity, and/or intracellular mechanisms. Biochemical determinants such as peptide length, primary sequence, charge, secondary structure, hydrophobicity, amphipathicity and host cell membrane composition together influence the biological activities of peptides. A number of biophysical techniques have been used in recent years to study the mechanisms of action of AMPs. This work appraises the molecular parameters that determine the biocidal activity of AMPs and overviews their mechanisms of actions and the diverse biochemical, biophysical and microscopy techniques utilised to elucidate these.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Fenômenos Biofísicos , Membrana Celular/química , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Peptídeos/metabolismo , Conformação Proteica
10.
J Proteome Res ; 16(6): 2188-2203, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28418253

RESUMO

Identification of psychrotrophic pathogenic and spoilage Gram-negative bacteria using rapid and reliable techniques is important in commercial milk processing, as these bacteria can produce heat-resistant proteases and act as postprocessing contaminants in pasteurized milk. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a proven technology for identification of bacteria in food, however, may require optimization for identification of pathogenic and spoilage bacteria in milk and dairy products. The current study evaluated the effects of various culture conditions and sample preparation methods on assigning of raw milk isolates to the species level by MALDI-TOF MS. The results indicated that culture media, incubation conditions (temperature and time), and sample preparation significantly affected the identification rates of bacteria to the species level. Nevertheless, the development of spectral libraries of isolates grown on different media using a web tool for hierarchical clustering of peptide mass spectra (SPECLUST) followed by a ribosomal protein based bioinformatics approach significantly enhanced the assigning of bacteria, with at least one unique candidate biomarker peak identified for each species. Phyloproteomic relationships based on spectral profiles were compared to phylogenetic analysis using 16S rRNA gene sequences and demonstrated similar clustering patterns with significant discriminatory power. Thus, with appropriate optimization, MALDI-TOF MS is a valuable tool for species-level discrimination of pathogenic and milk spoilage bacteria.


Assuntos
Microbiologia de Alimentos/métodos , Bactérias Gram-Negativas/isolamento & purificação , Leite/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Bovinos , Biologia Computacional/métodos , Bases de Dados de Proteínas , Proteômica/métodos , Psychrobacter , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
11.
Fungal Genet Biol ; 102: 22-30, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27599392

RESUMO

To increase the efficiency of winery-derived biomass biodegradation, grape pomace was ultrasonicated for 20min in the presence of 0.25M, 0.5Mand1.0MKOH and 1.0MNaOH. This was followed by treatment with a 1:1 (v/v) mix of crude enzyme preparation derived from Phanerochaete chrysosporium and Trametes versicolor for 18h and a further 18h treatment with a 60:14:4:2 percent ratio combination of enzymes derived from Aspergillus niger: Penicillium chrysogenum: Trichoderma harzianum: P. citrinum, repsectively. Process efficiency was evaluated by its comparison to biological only mixed fungal degradation over 16days. Ultrasonication treatment with 0.5MKOH followed by mixed enzyme treatment yielded the highest lignin degradation of about 13%. Cellulase, ß-glucosidase, xylanase, laccase and lignin peroxidase activities of 77.9, 476, 5,390.5, 66.7 and 29,230.7U/mL, respectively, were observed during biomass degradation. Gas chromatography-mass spectrometry (GC-MS) analysis of the degraded material identified commercially important compounds such as gallic acid, lithocholic acid, glycolic acid and lactic acid which were generated in considerable quantities. Thus, the combination of sonication pre-treatment and enzymatic degradation has the potential to considerably improve the breakdown of agricultural biomass and produce commercially useful compounds in markedly less time (<40h) with respect to biological only degradation (16days).


Assuntos
Biodegradação Ambiental , Biomassa , Fungos/enzimologia , Hidrolases/metabolismo , Lignina/metabolismo , Oxirredutases/metabolismo , Sonicação , Vitis/metabolismo , Aspergillus niger/enzimologia , Aspergillus niger/metabolismo , Celulase/metabolismo , Fermentação/efeitos dos fármacos , Fungos/metabolismo , Ácido Gálico/análise , Ácido Gálico/metabolismo , Glicolatos/análise , Glicolatos/metabolismo , Lacase/metabolismo , Metabolômica , Penicillium chrysogenum/enzimologia , Penicillium chrysogenum/metabolismo , Peroxidases/metabolismo , Vinho
12.
J Nat Prod ; 80(4): 1178-1181, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28257200

RESUMO

Two new antimicrobial agents, neryl ferulate (1) and neryl p-coumarate (2), were identified using bioassay-guided isolation from the leaves of Eremophila longifolia, which is a medicinal plant used by some Australian Aboriginal communities. Although gradual autoxidation of the nerol subunit hindered the initial attempts to purify and characterize 1 and 2, it was found that the autoxidation could be stopped through storage under argon at -20 °C. Biological evaluation showed that neryl ferulate (1) had moderate activity against various Gram-positive bacteria, while neryl p-coumarate (2) was active only against Enterococcus faecium.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Ácidos Cumáricos/isolamento & purificação , Ácidos Cumáricos/farmacologia , Eremophila (Planta)/química , Plantas Medicinais/química , Monoterpenos Acíclicos , Antibacterianos/química , Anti-Infecciosos/química , Austrália , Cinamatos/química , Ácidos Cumáricos/química , Bactérias Gram-Positivas/efeitos dos fármacos , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Folhas de Planta/química , Terpenos/química , Terpenos/isolamento & purificação , Terpenos/farmacologia
13.
J Dairy Res ; 84(1): 92-101, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28252354

RESUMO

Refrigerated storage of raw milk is a prerequisite in dairy industry. However, temperature abused conditions in the farming and processing environments can significantly affect the microbiological quality of raw milk. Thus, the present study investigated the effect of different refrigeration conditions such as 2, 4, 6, 8, 10 and 12 °C on microbiological quality of raw milk from three different dairy farms with significantly different initial microbial counts. The bacterial counts (BC), protease activity (PA), proteolysis (PL) and microbial diversity in raw milk were determined during storage. The effect of combined heating (75 ± 0·5 °C for 15 s) and refrigeration on controlling those contaminating microorganisms was also investigated. Results of the present study indicated that all of the samples showed increasing BC, PA and PL as a function of temperature, time and initial BC with a significant increase in those criteria ≥6 °C. Similar trends in BC, PA and PL were observed during the extended storage of raw milk at 4 °C. Both PA and PL showed strong correlation with the psychrotrophic proteolytic count (PPrBC: at ≥4 °C) and thermoduric psychrotrophic count (TDPC: at ≥8 °C) compared to total plate count (TPC) and psychrotrophic bacterial count (PBC), that are often used as the industry standard. Significant increases in PA and PL were observed when PPrBC and TDPC reached 5 × 104 cfu/ml and 1 × 104 cfu/ml, and were defined as storage life for quality (S LQ), and storage life for safety (S LS) aspects, respectively. The storage conditions also significantly affected the microbial diversity, where Pseudomonas fluorescens and Bacillus cereus were found to be the most predominant isolates. However, deep cooling (2 °C) and combination of heating and refrigeration (≤4 °C) significantly extended the S LQ and S Ls of raw milk.


Assuntos
Conservação de Alimentos/métodos , Leite/microbiologia , Refrigeração/métodos , Animais , Bacillus cereus/isolamento & purificação , Carga Bacteriana , Indústria de Laticínios/métodos , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Temperatura Alta , Peptídeo Hidrolases/metabolismo , Proteólise , Pseudomonas fluorescens/isolamento & purificação , Temperatura , Fatores de Tempo
14.
Langmuir ; 32(25): 6496-505, 2016 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-27281288

RESUMO

Antimicrobial peptides are promising therapeutic alternatives to counter growing antimicrobial resistance. Their precise mechanism of action remains elusive, however, particularly with respect to live bacterial cells. We investigated the interaction of a fluorescent melittin analogue with single giant unilamellar vesicles, giant multilamellar vesicles, and bilamellar Gram-negative Escherichia coli (E. coli) bacteria. Time-lapse fluorescence lifetime imaging microscopy was employed to determine the population distribution of the fluorescent melittin analogue between pore state and membrane surface state, and simultaneously measure the leakage of entrapped fluorescent species from the vesicle (or bacterium) interior. In giant unilamellar vesicles, leakage from vesicle interior was correlated with an increase in level of pore states, consistent with a stable pore formation mechanism. In giant multilamellar vesicles, vesicle leakage occurred more gradually and did not appear to correlate with increased pore states. Instead pore levels remained at a low steady-state level, which is more in line with coupled equilibria. Finally, in single bacterial cells, significant increases in pore levels were observed over time, which were correlated with only partial loss of cytosolic contents. These observations suggested that pore formation, as opposed to complete dissolution of membrane, was responsible for the leakage of contents in these systems, and that the bacterial membrane has an adaptive capacity that resists peptide attack. We interpret the three distinct pore dynamics regimes in the context of the increasing physical and biological complexity of the membranes.


Assuntos
Membrana Celular/química , Escherichia coli/química , Meliteno/química , Lipossomas Unilamelares/química , Membrana Celular/metabolismo , Escherichia coli/metabolismo , Meliteno/farmacologia
15.
J Pept Sci ; 22(7): 492-500, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27238815

RESUMO

The broad-spectrum activity of antimicrobial peptides (AMPs) and low probability of development of host resistance make them excellent candidates as novel bio-control agents. A number of AMPs are found to be cationic, and a small proportion of these are tryptophan-rich. The puroindolines (PIN) are small, basic proteins found in wheat grains with proposed roles in biotic defence of seeds and seedlings. Synthetic peptides based on their unique tryptophan-rich domain (TRD) display antimicrobial properties. Bacterial endospores and biofilms are highly resistant cells, with significant implications in both medical and food industries. In this study, the cationic PIN TRD-based peptides PuroA (FPVTWRWWKWWKG-NH2 ) and Pina-M (FSVTWRWWKWWKG-NH2 ) and the related barley hordoindoline (HIN) based Hina (FPVTWRWWTWWKG-NH2 ) were tested for effects on planktonic cells and biofilms of the common human pathogens including Pseudomonas aeruginosa, Listeria monocytogenes and the non-pathogenic Listeria innocua. All peptides showed significant bactericidal activity. Further, PuroA and Pina-M at 2 × MIC prevented initial biomass attachment by 85-90% and inhibited >90% of 6-h preformed biofilms of all three organisms. However Hina, with a substitution of Lys-9 with uncharged Thr, particularly inhibited Listeria biofilms. The PIN based peptides were also tested against vegetative cells and endospores of Bacillus subtilis. The results provided evidence that these tryptophan-rich peptides could kill B. subtilis even in sporulated state, reducing the number of viable spores by 4 log units. The treated spores appeared withered under scanning electron microscopy. The results establish the potential of these tryptophan-rich peptides in controlling persistent pathogens of relevance to food industries and human health. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Sequência de Aminoácidos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/ultraestrutura , Biofilmes/crescimento & desenvolvimento , Hordeum/química , Hordeum/imunologia , Listeria/efeitos dos fármacos , Listeria/crescimento & desenvolvimento , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos , Plâncton/crescimento & desenvolvimento , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/ultraestrutura , Triticum/química , Triticum/imunologia , Triptofano/química
16.
Int J Mol Sci ; 18(1)2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-28025547

RESUMO

The application of metabolomics to biological samples has been a key focus in systems biology research, which is aimed at the development of rapid diagnostic methods and the creation of personalized medicine. More recently, there has been a strong focus towards this approach applied to non-invasively acquired samples, such as saliva and exhaled breath. The analysis of these biological samples, in conjunction with other sample types and traditional diagnostic tests, has resulted in faster and more reliable characterization of a range of health disorders and diseases. As the sampling process involved in collecting exhaled breath and saliva is non-intrusive as well as comparatively low-cost and uses a series of widely accepted methods, it provides researchers with easy access to the metabolites secreted by the human body. Owing to its accuracy and rapid nature, metabolomic analysis of saliva and breath (known as salivaomics and breathomics, respectively) is a rapidly growing field and has shown potential to be effective in detecting and diagnosing the early stages of numerous diseases and infections in preclinical studies. This review discusses the various collection and analyses methods currently applied in two of the least used non-invasive sample types in metabolomics, specifically their application in salivaomics and breathomics research. Some of the salient research completed in this field to date is also assessed and discussed in order to provide a basis to advocate their use and possible future scientific directions.


Assuntos
Biomarcadores/análise , Expiração , Metaboloma , Técnicas de Diagnóstico Molecular/métodos , Saliva/química , Animais , Cromatografia/métodos , Humanos , Espectrometria de Massas/métodos
17.
World J Microbiol Biotechnol ; 32(2): 31, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26748808

RESUMO

Drug-resistant microorganisms ('superbugs') present a serious challenge to the success of antimicrobial treatments. Subsequently, there is a crucial need for novel bio-control agents. Many antimicrobial peptides (AMPs) show a broad-spectrum activity against bacteria, fungi or viruses and are strong candidates to complement or substitute current antimicrobial agents. Some AMPs are also effective against protozoa or cancer cells. The tryptophan (Trp)-rich peptides (TRPs) are a subset of AMPs that display potent antimicrobial activity, credited to the unique biochemical properties of tryptophan that allow it to insert into biological membranes. Further, many Trp-rich AMPs cross bacterial membranes without compromising their integrity and act intracellularly, suggesting interactions with nucleic acids and enzymes. In this work, we overview some archetypal TRPs derived from natural sources, i.e., indolicidin, tritrpticin and lactoferricin, summarising their biochemical properties, structures, antimicrobial activities, mechanistic studies and potential applications.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Triptofano/química , Triptofano/farmacologia , Animais , Resistência Microbiana a Medicamentos , Humanos , Lactoferrina/química , Lactoferrina/farmacologia , Modelos Moleculares , Oligopeptídeos/química , Oligopeptídeos/farmacologia
18.
Avian Dis ; 59(3): 447-51, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26478166

RESUMO

Three outbreaks of necrotic enteritis-like disease associated with Clostridium sordelii were diagnosed in commercial broiler chicken flocks with 18,000 to 31,000 birds between 18 and 26 days old. Clinical signs in the affected flocks included high mortality up to 2% a day, depression, and diarrhea. The main gross changes included segmental dilation of the small intestine with watery contents, gas, mucoid exudate, and roughened and uneven mucosa, occasionally covered with a pseudomembrane. Microscopic lesions in the small intestine were characterized by extensive areas of coagulative necrosis of the villi, fibrinous exudate in the lumen, and high numbers of large, Gram-positive rods, occasionally containing subterminal spores, seen in the necrotic tissue and lumen. These rods were identified as C. sordellii by immunohistochemistry. Clostridium sordellii was isolated in an almost pure culture from the intestine of affected birds. A retrospective study of commercial broiler chicken and turkey submissions to the California Animal Health and Food Safety Laboratory System revealed that C. sordellii had been isolated from intestinal lesions in outbreaks of necrotic enteritis-like disease in 8 of 39 cases, 5 times together with Clostridium perfringens and 3 times alone. The latter three cases are reported here.


Assuntos
Galinhas , Infecções por Clostridium/veterinária , Clostridium sordellii/isolamento & purificação , Enterite/veterinária , Doenças das Aves Domésticas/microbiologia , Animais , Infecções por Clostridium/microbiologia , Infecções por Clostridium/patologia , Surtos de Doenças/veterinária , Enterite/microbiologia , Enterite/patologia , Doenças das Aves Domésticas/patologia
19.
BMC Complement Altern Med ; 15: 8, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25652009

RESUMO

BACKGROUND: Plant-derived compounds have been used clinically to treat type 2 diabetes for many years as they also exert additional beneficial effects on various other disorders. The aim of the present study was to investigate the possible mechanism of anti-diabetic activity of twelve (seven Australian Aboriginal and five Indian Ayurvedic) plant extracts. METHODS: The ethanolic plant extracts were investigated for glucose uptake and adipogenesis in murine 3T3-L1 adipocytes. Cytotoxicity studies were also carried out against two cancerous cell lines, HeLa and A549, to investigate the potential anti-cancer activities of the extracts. RESULTS: Of the seven Australian Aboriginal plant extracts tested, only Acacia kempeana and Santalum spicatum stimulated glucose uptake in adipocytes. Among the five Indian Ayurvedic plant extracts, only Curculigo orchioides enhanced glucose uptake. With respect to adipogenesis, the Australian plants Acacia tetragonophylla, Beyeria leshnaultii and Euphorbia drumondii and the Indian plants Pterocarpus marsupium, Andrographis paniculata and Curculigo orchioides reduced lipid accumulation in differentiated adipocytes. Extracts of Acacia kempeana and Acacia tetragonophylla showed potent and specific activity against HeLa cells. CONCLUSIONS: The findings suggest that the plant extracts exert their anti-diabetic properties by different mechanisms, including the stimulation of glucose uptake in adipocytes, inhibition of adipogenesis or both. Apart from their anti-diabetic activities, some of the extracts have potential for the development of chemotherapeutic agents for the treatment of cervical cancer.


Assuntos
Adipócitos/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Magnoliopsida , Extratos Vegetais/farmacologia , Células 3T3-L1 , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Austrália , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Células HeLa , Humanos , Hipoglicemiantes/uso terapêutico , Índia , Metabolismo dos Lipídeos/efeitos dos fármacos , Ayurveda , Medicina Tradicional , Camundongos , Fitoterapia , Extratos Vegetais/uso terapêutico
20.
J Clin Microbiol ; 52(11): 4075-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25187633

RESUMO

We compared the diagnostic accuracy of the Carba NP test with that of a straightforward matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method for detecting carbapenemase-producing Enterobacteriaceae (CPE). Using PCR as the reference method, both tests demonstrated a sensitivity of 87% and a specificity of 100%. MALDI-TOF MS offers a potential alternative for the rapid detection of CPE in the clinical laboratory setting.


Assuntos
Proteínas de Bactérias/análise , Técnicas Bacteriológicas/métodos , Enterobacteriaceae/enzimologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , beta-Lactamases/análise , Humanos , Sensibilidade e Especificidade
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