RESUMEN
Bacterial phospholipases and sphingomyelinases are lipolytic esterases that are structurally and evolutionarily heterogeneous. These enzymes play crucial roles as virulence factors in several human and animal infectious diseases. Some bacterial phospholipases C (PLCs) have both phosphatidylcholinesterase and sphingomyelinase C activities. Among them, Listeria monocytogenes PlcB, Clostridium perfringens PLC, and Pseudomonas aeruginosa PlcH are the most deeply understood. In silico predictions of substrates docking with these three bacterial enzymes provide evidence that they interact with different substrates at the same active site. This review discusses structural aspects, substrate specificity, and the mechanism of action of those bacterial enzymes on target cells and animal infection models to shed light on their roles in pathogenesis.
Asunto(s)
Esfingomielina Fosfodiesterasa/metabolismo , Esfingomielina Fosfodiesterasa/fisiología , Fosfolipasas de Tipo C/metabolismo , Fosfolipasas de Tipo C/fisiología , Animales , Clostridium perfringens/enzimología , Clostridium perfringens/patogenicidad , Humanos , Listeria monocytogenes/enzimología , Listeria monocytogenes/patogenicidad , Fosfolipasas , Pseudomonas aeruginosa/enzimología , Pseudomonas aeruginosa/patogenicidad , Fosfolipasas de Tipo C/genéticaRESUMEN
ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum) were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine) and/or a histone deacetylase inhibitor (suberohydroxamic acid). Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%), when compared to the control extract (39.62 ± 3.76%). Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control) to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.
Asunto(s)
Antibacterianos/farmacología , Inhibidores de la Colinesterasa/farmacología , Penicillium/química , Talaromyces/química , Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/metabolismo , Cromatina/metabolismo , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/enzimología , Listeria monocytogenes/crecimiento & desarrollo , Penicillium/metabolismo , Talaromyces/metabolismoRESUMEN
Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum) were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine) and/or a histone deacetylase inhibitor (suberohydroxamic acid). Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66±5.98% and 15.38±1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%), when compared to the control extract (39.62±3.76%). Similarly, inhibition of acetylcholinesterase activity increased from 20.91±3.90% (control) to 92.20±3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.
Asunto(s)
Antibacterianos/farmacología , Inhibidores de la Colinesterasa/farmacología , Penicillium/química , Talaromyces/química , Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/metabolismo , Cromatina/metabolismo , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/enzimología , Listeria monocytogenes/crecimiento & desarrollo , Penicillium/metabolismo , Talaromyces/metabolismoRESUMEN
The effects of the addition of nitrite at 200 ppm (N), sodium lactate 1.5% (L) and thyme essential oil at 100 ppm (T1) on Listeria monocytogenes behaviour and ATPase activity inhibition were evaluated, as well as lipid oxidation through the quantification of malonaldehydes, in sausage stored at 8 â for 41 days and at 30 â for 14 days. The changes in the colour profile were performed during storage time at 8 â. Quantitative descriptive sensory analyses were performed after two days at 4 â. At 8 â, the treatments with the highest inhibition on L. monocytogenes were L and N, without significant differences. In turn, at 30 â, the bacterium was most inhibited with treatment L, followed by T1 and N, without significant differences. A 44.1% and 19% inhibition of ATPase activity was detected in L and T1 treatments, respectively. At 8 â and 30 â, malonaldehydes content was not different between the treatments. N presented the highest values of a* and concentration of metmyoglobin after 41 days at 8 â. The panel detected differences between T1 and N for the aroma in the descriptors spices and herbal.
Asunto(s)
Conservación de Alimentos/métodos , Conservantes de Alimentos/farmacología , Listeria monocytogenes/fisiología , Productos de la Carne/microbiología , Aceites Volátiles/farmacología , Lactato de Sodio/farmacología , Nitrito de Sodio/farmacología , Thymus (Planta)/química , Adenosina Trifosfatasas/efectos de los fármacos , Animales , Bovinos , Microbiología de Alimentos , Embalaje de Alimentos , Calidad de los Alimentos , Lípidos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/enzimología , Productos de la Carne/análisis , Porcinos , GustoRESUMEN
Listeria monocytogenes is the causative agent of listeriosis, a very serious food-borne human disease. The analysis of the proteins coded by the L. monocytogenes genome reveals the presence of two eukaryotic-type Ser/Thr-kinases (lmo1820 and lmo0618) and a Ser/Thr-phosphatase (lmo1821). Protein phosphorylation regulates enzyme activities and protein interactions participating in physiological and pathophysiological processes in bacterial diseases. However in the case of L. monocytogenes there is scarce information about biochemical properties of these enzymes, as well as the physiological processes that they modulate. In the present work the catalytic domain of the protein coded by lmo1820 was produced as a functional His(6)-tagged Ser/Thr-kinase, and was denominated PrkA. PrkA was able to autophosphorylate specific Thr residues within its activation loop sequence. A similar autophosphorylation pattern was previously reported for Ser/Thr-kinases from related prokaryotes, whose role in kinase activity and substrate recruitment was demonstrated. We studied the kinase interactome using affinity chromatography and proteomic approaches. We identified 62 proteins that interact, either directly or indirectly, with the catalytic domain of PrkA, including proteins that participate in carbohydrates metabolism, cell wall metabolism and protein synthesis. Our results suggest that PrkA could be involved in the regulation of a variety of fundamental biological processes.
Asunto(s)
Listeria monocytogenes/enzimología , Unión Proteica , Proteínas Serina-Treonina Quinasas/metabolismo , Proteómica , Proteínas Bacterianas , Dominio Catalítico , Humanos , Metabolismo , Fosforilación , Proteómica/métodos , Especificidad por SustratoRESUMEN
This work describes for the first time a model of Purine Nucleoside Phosphorylase from Listeria monocytogenes (LmPNP). We modeled the complexes of LmPNP with ligands in order to determine the structural basis for specificity. Comparative analysis of the model of LmPNP allowed identification of structural features responsible for ligand affinities.
Asunto(s)
Biología Computacional , Listeria monocytogenes/enzimología , Purina-Nucleósido Fosforilasa/química , Secuencia de Aminoácidos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Apoenzimas/antagonistas & inhibidores , Apoenzimas/química , Apoenzimas/metabolismo , Sitios de Unión , Diseño de Fármacos , Humanos , Ligandos , Listeria monocytogenes/efectos de los fármacos , Listeriosis/tratamiento farmacológico , Modelos Moleculares , Estructura Terciaria de Proteína , Purina-Nucleósido Fosforilasa/antagonistas & inhibidores , Purina-Nucleósido Fosforilasa/metabolismo , Especificidad por SustratoRESUMEN
Com o proposito de avaliar a producao de lecitinase e a capacidade de adsorcao do corante vermelho Congo como marcadores de patogenicidade, foram estudadas 130 amostras de Listeria. Estas amostras foram identificadas segundo a producao de acido a partir de acucares aliada ao teste CAMP, correlacionando-se estes dados a capacidade de producao de ceratoconjuntivite em cobaia. As culturas de L. monocytogenes apresentaram taxas de positividade para a adsorcao do corante e producao de lecitinase de 51,8 e 88,8 por cento, respectivamente, enquanto 80,8 e 100 por cento das culturas de L. innocua foram negativas para os referidos testes.
Asunto(s)
Animales , Cobayas , Conjuntivitis Bacteriana/etiología , Proteínas Hemolisinas/clasificación , Listeria monocytogenes/enzimología , Medios de Cultivo , Listeria monocytogenes/genética , Marcadores Genéticos/inmunologíaRESUMEN
A total of 130 Listeria strains were tested in order to evaluate lecithinase production and capacity for Congo red adsorption as markers of pathogenicity. The strains were identified according to acid production from sugars and by the CAMP test and the data were correlated with the ability to produce keratoconjunctivitis in guinea pigs. L. monocytogenes cultures presented 51.8% and 88.8% positivity rates for Congo red adsorption and lecithinase production, respectively, whereas 80.8% and 100% for L. innocua cultures were negative for the two test, respectively.
Asunto(s)
Listeria monocytogenes/genética , Listeria monocytogenes/patogenicidad , Animales , Cobayas , Humanos , Listeria monocytogenes/enzimología , Fenotipo , Fosfolipasas/metabolismo , VirulenciaRESUMEN
Listeria monocytogenes is a model intracellular pathogen which escapes from a host cell vacuole, grows intracytoplasmically, and spreads cell to cell without an extracellular phase. A number of genes necessary for pathogenicity have been discovered, two of which encode phospholipases C, a PI-PLC and a broad-range PLC. Single and double mutants were constructed with in-frame deletions in one or both PLCs. Characterization of the strains indicated that the two PLCs may have overlapping function as the double mutant was 500-fold less virulent while the single mutants had a negligible effect on virulence. The role of the PLCs appears to be multifactorial as PI-PLC has a role in escaping from the initial host vacuole and the broad-range PLC appears to have a role in cell to cell spreading.