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1.
An Acad Bras Cienc ; 93(3): e20190200, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33950134

RESUMEN

Listeria monocytogenes is an opportunistic pathogen that causes listeriosis, a foodborne disease with low incidence but with high mortality rate in humans. This microorganism has been recovered from several dairy products, especially those produced with raw milk. The objective of this work was to investigate the presence of virulence genes, and also to define the antimicrobial susceptibility profile of L. monocytogenes isolates recovered from serrano artisanal cheese produced in Southern region of Brazil. Nine strains of L. monocytogenes (serotypes 1/2b and 4b) were evaluated through PCR to detect the presence of the virulence genes hly, inlA, inlC, inlJ, actA, plcB and iap, while antimicrobial susceptibility profile was determined via disk diffusion method. All strains exhibited the presence of the genes hly and plcB, whereas the other genes (iap, actA, inlA, inlC and inlJ) were only detected in eight strains. We verified that all strains were resistant to at least one antimicrobial agent and three of them showed multidrug resistance. These findings demonstrated the serrano artisanal cheese offers risks to consumers' health and point to a need of adaptations and monitoring of manufacturing process of this food, in order to prevent the dissemination of L. monocytogenes.


Asunto(s)
Queso , Listeria monocytogenes , Listeriosis , Brasil , Humanos , Listeria monocytogenes/genética , Listeriosis/tratamiento farmacológico , Virulencia/genética
2.
Environ Monit Assess ; 193(5): 294, 2021 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-33893564

RESUMEN

Aquatic environments are hotspots for the spread of antibiotic-resistant bacteria and genes due to pollution caused mainly by anthropogenic activities. The aim of this study was to evaluate the impact of wastewater effluents, informal settlements, hospital, and veterinary clinic discharges on the occurrence, antibiotic resistance profile and virulence signatures of Aeromonas spp. and Pseudomonas spp. isolated from surface water and wastewater. High counts of Aeromonas spp. (2.5 (± 0.8) - 3.3 (± 0.4) log10 CFU mL-1) and Pseudomonas spp. (0.6 (± 1.0) - 1.8 (± 1.0) log10 CFU mL-1) were obtained. Polymerase chain reaction (PCR) and MALDI-TOF characterization identified four species of Aeromonas and five of Pseudomonas. The isolates displayed resistance to 3 or more antibiotics (71% of Aeromonas and 94% of Pseudomonas). Aeromonas spp. showed significant association with the antibiotic meropenem (χ2 = 3.993, P < 0.05). The virulence gene aer in Aeromonas was found to be positively associated with the antibiotic resistance gene blaOXA (χ2 = 6.657, P < 0.05) and the antibiotic ceftazidime (χ2 = 7.537, P < 0.05). Aeromonas recovered from both wastewater and surface water displayed high resistance to ampicillin and had higher multiple antibiotic resistance (MAR) indices close to the hospital. Pseudomonas isolates on the other hand exhibited low resistance to carbapenems but very high resistance to the third-generation cephalosporins and cefixime. The results showed that some of the Pseudomonas spp. and Aeromonas spp. isolates were extended-spectrum ß-lactamase producing bacteria. In conclusion, the strong association between virulence genes and antibiotic resistance in the isolates shows the potential health risk to communities through direct and indirect exposure to the water.


Asunto(s)
Aeromonas , Aeromonas/genética , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Monitoreo del Ambiente , Pruebas de Sensibilidad Microbiana , Pseudomonas/genética , Virulencia , Aguas Residuales , Agua
3.
Int J Mol Sci ; 22(5)2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33800857

RESUMEN

Fusarium wilt of flax is an aggressive disease caused by the soil-borne fungal pathogen Fusarium oxysporum f. sp. lini. It is a challenging pathogen presenting a constant threat to flax production industry worldwide. Previously, we reported chromosome-level assemblies of 5 highly pathogenic F. oxysporum f. sp. lini strains. We sought to characterize the genomic architecture of the fungus and outline evolutionary mechanisms shaping the pathogen genome. Here, we reveal the complex multi-compartmentalized genome organization and uncover its diverse evolutionary dynamics, which boosts genetic diversity and facilitates host adaptation. In addition, our results suggest that host of functions implicated in the life cycle of mobile genetic elements are main contributors to dissimilarity between proteomes of different Fusaria. Finally, our experiments demonstrate that mobile genetics elements are expressed in planta upon infection, alluding to their role in pathogenicity. On the whole, these results pave the way for further in-depth studies of evolutionary forces shaping the host-pathogen interaction.


Asunto(s)
Lino/microbiología , Fusarium/genética , Genoma Fúngico , Enfermedades de las Plantas/microbiología , Cromosomas Fúngicos/genética , Evolución Molecular , Proteínas Fúngicas/genética , Interacciones Huésped-Patógeno/genética , Redes y Vías Metabólicas/genética , Anotación de Secuencia Molecular , Filogenia , Proteoma , Especificidad de la Especie , Virulencia/genética
4.
BMC Infect Dis ; 21(1): 361, 2021 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-33865334

RESUMEN

BACKGROUND: Urinary Tract Infection (UTI) is one of the most common bacterial infectious diseases which causes considerable morbidity and costly health problems. Uropathogenic Escherichia coli (UPEC), the most common pathogen causing UTI, is a highly heterogeneous group of extraintestinal pathogenic E. coli (ExPEC) which may carry a variety of virulence factors and belonging to different phylogenetic backgrounds. The current study aimed to investigate the frequency and association between various virulence factors (VFs) and phylogenetic groups of UPEC and commensal isolates. METHODS: UPEC and commensal E. coli strains isolated from UTI and feces of healthy humans were compared for the presence of VFs and phylogenetic groups. Association between virulence genes was investigated and cluster analysis was employed. RESULTS: According to the results, among a 30 virulence markers tested, the pathogenicity-associated island (PAI), papAH, papEF, fimH, fyuA, and traT genes prevalence were statistically significant in UPEC isolates. A strong association was found between the B2 and D phylogenetic groups and clinical isolates of UPEC; while, commensal isolates were mostly associated with phylogenetic group A. The aggregated VFs scores were more than twice higher in the UPEC isolates in comparison with the commensal isolates. Interestingly, the B2 group in both UPEC and commensal isolates had the highest VF scores. A strong positive association was found between several virulence genes. The clustering results demonstrated that UPEC or commensal E. coli isolates were highly heterogeneous due to different composition of their virulence gene pool and pathogenicity islands. CONCLUSION: Genetic structure and VFs of UPEC strains vary from region to region; therefore, to control the UTI, the epidemiological aspects and characterization of the UPEC isolates need to be investigated in different regions. Since UPEC isolates are generally originate from the commensal strains, it may be feasible to reduce the UTI burden by interfering the intestinal colonization, particularly in the highly pathogenic clonal lineages such as B2.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Infecciones Urinarias/microbiología , Escherichia coli Uropatógena , Factores de Virulencia/genética , Virulencia/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Niño , Preescolar , Infecciones por Escherichia coli/epidemiología , Proteínas de Escherichia coli/genética , Escherichia coli Patógena Extraintestinal/genética , Escherichia coli Patógena Extraintestinal/aislamiento & purificación , Escherichia coli Patógena Extraintestinal/patogenicidad , Femenino , Islas Genómicas/genética , Humanos , Lactante , Recién Nacido , Irán/epidemiología , Masculino , Persona de Mediana Edad , Filogenia , Prevalencia , Infecciones Urinarias/epidemiología , Escherichia coli Uropatógena/clasificación , Escherichia coli Uropatógena/genética , Escherichia coli Uropatógena/aislamiento & purificación , Escherichia coli Uropatógena/patogenicidad , Adulto Joven
5.
Parasite ; 28: 36, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33843581

RESUMEN

In this review, we focus on the sequenced genomes of the pathogens Naegleria fowleri, Acanthamoeba spp. and Balamuthia mandrillaris, and the remarkable discoveries regarding the pathogenicity and genetic information of these organisms, using techniques related to the various omics branches like genomics, transcriptomics, and proteomics. Currently, novel data produced through comparative genomics analyses and both differential gene and protein expression in these free-living amoebas have allowed for breakthroughs to identify genes unique to N. fowleri, genes with active transcriptional activity, and their differential expression in conditions of modified virulence. Furthermore, orthologous genes of the various nuclear genomes within the Naegleria and Acanthamoeba genera have been clustered. The proteome of B. mandrillaris has been reconstructed through transcriptome data, and its mitochondrial genome structure has been thoroughly described with a unique characteristic that has come to light: a type I intron with the capacity of interrupting genes through its self-splicing ribozymes activity. With the integration of data derived from the diverse omic sciences, there is a potential approximation that reflects the molecular complexity required for the identification of virulence factors, as well as crucial information regarding the comprehension of the molecular mechanisms with which these interact. Altogether, these breakthroughs could contribute to radical advances in both the fields of therapy design and medical diagnosis in the foreseeable future.


Asunto(s)
Acanthamoeba , Balamuthia mandrillaris , Naegleria fowleri , Acanthamoeba/genética , Balamuthia mandrillaris/genética , Genoma de Protozoos , Genómica , Naegleria fowleri/genética , Proteómica , Transcriptoma , Virulencia
6.
Front Cell Infect Microbiol ; 11: 641920, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33816347

RESUMEN

Pseudomonas aeruginosa is a biofilm-forming opportunistic pathogen which causes chronic infections in immunocompromised patients and leads to high mortality rate. It is identified as a common coinfecting pathogen in COVID-19 patients causing exacerbation of illness. In our hospital, P. aeruginosa is one of the top coinfecting bacteria identified among COVID-19 patients. We collected a strong biofilm-forming P. aeruginosa strain displaying small colony variant morphology from a severe COVID-19 patient. Genomic and transcriptomic sequencing analyses were performed with phenotypic validation to investigate its adaptation in SARS-CoV-2 infected environment. Genomic characterization predicted specific genomic islands highly associated with virulence, transcriptional regulation, and DNA restriction-modification systems. Epigenetic analysis revealed a specific N6-methyl adenine (m6A) methylating pattern including methylation of alginate, flagellar and quorum sensing associated genes. Differential gene expression analysis indicated that this isolate formed excessive biofilm by reducing flagellar formation (7.4 to 1,624.1 folds) and overproducing extracellular matrix components including CdrA (4.4 folds), alginate (5.2 to 29.1 folds) and Pel (4.8-5.5 folds). In summary, we demonstrated that P. aeuginosa clinical isolates with novel epigenetic markers could form excessive biofilm, which might enhance its antibiotic resistance and in vivo colonization in COVID-19 patients.


Asunto(s)
Adaptación Fisiológica/fisiología , Coinfección/complicaciones , Infecciones por Pseudomonas/complicaciones , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/metabolismo , Alginatos , Bacterias , Biopelículas/crecimiento & desarrollo , Metilación de ADN , Epigenómica , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica , Genoma Bacteriano , Humanos , Infecciones por Pseudomonas/inmunología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/clasificación , Percepción de Quorum/genética , Transcriptoma , Virulencia
7.
J Med Microbiol ; 70(4)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33830909

RESUMEN

Introduction. In recent years, the Herbaspirillum genus has emerged as a pathogen in healthcare-related infections and has became stablished as an opportunistic pathogen.Hypothesis/Gap Statement. Little is known about the pathogenesis induced by Herbaspirillum genus.Aim. To evaluate the cytotoxic effects of genus Herbaspirillum, its ability to adhere to lung human cells and the ability of environmental and clinical strains of Herbaspirillum to induce pneumonia in mice.Methodology. Environmental and clinical isolates of Herbaspirillum were examined for their cytotoxic effects on the Calu-3 cell lineage. Cytotoxic activity of secretome was tested using MTT/neutral red assays and cell morphology analysis. Herbaspirillum adhesion on Calu-3 cells was assessed using bright-field microscopy and cell-associated bacteria were counted. A mouse model of acute lung infection was done using a clinical and an environmental strain. Adult male mice were used, and the pneumonia was inducted by intra-tracheal inoculation of 108 or 109 bacteria. Mice weight variations were evaluated at the end of the experiment. Bronchoalveolar lavage was collected and evaluated for total and differential cytology. A histological examination of lungs was performed giving a histological score.Results. The secretomes of all the strains induced morphological alterations in cells, but only H. seropedicae SmR1 were cytotoxic in MTT and neutral red assays. Clinical strains of H. frisingense AU14459 and H. hutttiense subsp. huttiense AU11883 exhibited low adherence to lung cells, while SmR1 was non-adhesive. Following intratracheal inoculation, mice treated with 109 c.f.u. of the SmR1 and AU11883 strains lost 18 and 6% of their weight over 7 days, respectively, and presented moderate clinical signs. Infected mice showed inflammatory cell infiltration in the perivascular and peribroncheal/peribronchiolar spaces. Bronchoalveolar fluid of mice inoculated with SmR1 109 c.f.u. presented an increase in total leucocyte cells and in neutrophils population.Conclusion. These in vivo and in vitro results provide insights into how some Herbaspirillum strains cause infection in humans, providing a basis for the characterization of pathogenesis studies on this emerging infectious agent.


Asunto(s)
Exosomas/metabolismo , Infecciones por Bacterias Gramnegativas/microbiología , Herbaspirillum/patogenicidad , Neumonía/microbiología , Animales , Adhesión Bacteriana , Líquido del Lavado Bronquioalveolar/citología , Línea Celular , Supervivencia Celular , Infecciones por Bacterias Gramnegativas/patología , Herbaspirillum/aislamiento & purificación , Herbaspirillum/metabolismo , Humanos , Pulmón/microbiología , Pulmón/patología , Masculino , Ratones , Neumonía/patología , Virulencia
8.
J Med Microbiol ; 70(4)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33830910

RESUMEN

Introduction. Clostridioides difficile infection (CDI) causes toxin-mediated enteropathy, such as antibiotic-associated diarrhoea and pseudomembranous colitis. Rho-glucosylating toxin A (TcdA) and toxin B (TcdB) have been clearly implicated in pathogenesis, whereas the virulence of binary toxin (CDT) is still debated.Hypothesis statement. We hypothesized that CDT is involved in the host immune response and plays a pivotal role in establishing virulence by modulating pro-inflammatory cytokine production; this is achieved through the integral Toll-like receptor (TLR) signalling pathways.Aim. The aim of the present study was to determine whether and how CDT impacts macrophages compared to TcdA or TcdB by examining the induction of CXC chemokine ligand 2 (CXCL2) and tumour necrosis factor-α (TNF-α), both of which are crucial in mediating local and systematic inflammatory responses.Methodology. RAW264.7 cells or transfected human embryonic kidney (HEK) 293 T cells were incubated with TcdA, TcdB, or CDT. In some experiments, a neutralizing antibody against TLR2 or TLR4, or myeloid differentiation 88 inhibitory peptide were added. The amount of CXCL2 and TNF-α secreted was then measured.Results. In RAW264.7 macrophages, CXCL2 and TNF-α were produced via the Toll-like receptor 2 (TLR2) or Toll-like receptor 4 (TLR4) pathway in a TcdA, TcdB, or CDT dose-dependent manner. Interleukin-8 secretion was induced in TLR4/MD2/CD14-transfected, but not in TLR2-transfected, HEK 293 T cells following TcdB or CDT exposure.Conclusion. Our results showed that C. difficile toxins, including CDT, enhanced macrophage-mediated CXCL2 and TNF-α production via TLR2 and TLR4, indicating that CDT affects host immune responses.


Asunto(s)
Toxinas Bacterianas/farmacología , Quimiocina CXCL2/metabolismo , Macrófagos/efectos de los fármacos , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Células HEK293 , Humanos , Macrófagos/metabolismo , Ratones , Factor 88 de Diferenciación Mieloide/antagonistas & inhibidores , Factor 88 de Diferenciación Mieloide/metabolismo , Células RAW 264.7 , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 2/antagonistas & inhibidores , Receptor Toll-Like 4/antagonistas & inhibidores , Virulencia
9.
J Med Microbiol ; 70(4)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33830911

RESUMEN

Introduction. Antipathogenic or antivirulence strategy is to target a virulence pathway that is dispensable for growth, in the hope to mitigate the selection for drug resistance.Hypothesis/Gap Statment. Peroxide stress responses are one of the conserved virulence pathways in bacterial pathogens and thus good targets for antipathogenic strategy.Aim. This study aims to identify a new chemical compound that targets OxyR, the peroxide sensor required for the full virulence of the opportunistic human pathogen, Pseudomonas aeruginosa.Methodology. Computer-based virtual screening under consideration of the 'eNTRy' rules and molecular docking were conducted on the reduced form of the OxyR regulatory domain (RD). Selected hits were validated by their ability to phenocopy the oxyR null mutant and modulate the redox cycle of OxyR.Results. We first isolated three robust chemical hits that inhibit OxyR without affecting prototrophic growth or viability. One (compound 1) of those affected the redox cycle of OxyR in response to H2O2 treatment, in a way to impair its function. Compound 1 displayed selective antibacterial efficacy against P. aeruginosa in Drosophila infection model, without antibacterial activity against Staphylococcus aureus.Conclusion. These results suggest that compound 1 could be an antipathogenic hit inhibiting the P. aeruginosa OxyR. More importantly, our study provides an insight into the computer-based discovery of new-paradigm selective antibacterials to treat Gram-negative bacterial infections presumably with few concerns of drug resistance.


Asunto(s)
Antibacterianos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Transactivadores/antagonistas & inhibidores , Animales , Drosophila , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Simulación del Acoplamiento Molecular , Mutación , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/mortalidad , Pseudomonas aeruginosa/genética , Tasa de Supervivencia , Transactivadores/química , Transactivadores/genética , Transactivadores/metabolismo , Virulencia/efectos de los fármacos , Virulencia/genética
10.
Molecules ; 26(6)2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33803983

RESUMEN

Quorum sensing (QS), a sophisticated system of bacterial communication that depends on population density, is employed by many pathogenic bacteria to regulate virulence. In view of the current reality of antibiotic resistance, it is expected that interfering with QS can address bacterial pathogenicity without stimulating the incidence of resistance. Thus, harnessing QS inhibitors has been considered a promising approach to overriding bacterial infections and combating antibiotic resistance that has become a major threat to public healthcare around the globe. Pseudomonas aeruginosa is one of the most frequent multidrug-resistant bacteria that utilize QS to control virulence. Many natural compounds, including furanones, have demonstrated strong inhibitory effects on several pathogens via blocking or attenuating QS. While the natural furanones show no activity against P. aeruginosa, furanone C-30, a brominated derivative of natural furanone compounds, has been reported to be a potent inhibitor of the QS system of the notorious opportunistic pathogen. In the present study, we assess the molecular targets and mode of action of furanone C-30 on P. aeruginosa QS system. Our results suggest that furanone C-30 binds to LasR at the ligand-binding site but fails to establish interactions with the residues crucial for the protein's productive conformational changes and folding, thus rendering the protein dysfunctional. We also show that furanone C-30 inhibits RhlR, independent of LasR, suggesting a complex mechanism for the agent beyond what is known to date.


Asunto(s)
Antibacterianos/farmacología , Furanos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Percepción de Quorum/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Biopelículas/efectos de los fármacos , Farmacorresistencia Microbiana/efectos de los fármacos , Pseudomonas aeruginosa/metabolismo , Virulencia/efectos de los fármacos
11.
J Med Microbiol ; 70(4)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33909551

RESUMEN

Candida albicans is an opportunistic pathogen accounting for the majority of cases of Candida infections. Currently, C. albicans are developing resistance towards different classes of antifungal drugs and this has become a global health burden that does not spare Lebanon. This study aims at determining point mutations in genes known to be involved in resistance acquisition and correlating resistance to virulence and ergosterol content in the azole resistant C. albicans isolate CA77 from Lebanon. This pilot study is the first of its kind to be implemented in Lebanon. We carried out whole genome sequencing of the azole resistant C. albicans isolate CA77 and examined 18 genes involved in antifungal resistance. To correlate genotype to phenotype, we evaluated the virulence potential of this isolate by injecting it into BALB/c mice and we quantified membrane ergosterol. Whole genome sequencing revealed that eight out of 18 genes involved in antifungal resistance were mutated in previously reported and novel residues. These genotypic changes were associated with an increase in ergosterol content but no discrepancy in virulence potential was observed between our isolate and the susceptible C. albicans control strain SC5314. This suggests that antifungal resistance and virulence potential in this antifungal resistant isolate are not correlated and that resistance is a result of an increase in membrane ergosterol content and the occurrence of point mutations in genes involved in the ergosterol biosynthesis pathway.


Asunto(s)
Candida albicans/efectos de los fármacos , Candida albicans/genética , Farmacorresistencia Fúngica/genética , Secuenciación Completa del Genoma , Animales , Azoles/farmacología , Candida albicans/química , Candida albicans/patogenicidad , Ergosterol/análisis , Genotipo , Humanos , Líbano , Ratones , Ratones Endogámicos BALB C , Fenotipo , Proyectos Piloto , Mutación Puntual , Virulencia
12.
Nat Commun ; 12(1): 2451, 2021 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-33907187

RESUMEN

Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen.


Asunto(s)
Proteínas Fúngicas/inmunología , Hypocreales/patogenicidad , Oryza/inmunología , Enfermedades de las Plantas/inmunología , Hojas de la Planta/inmunología , Proteínas de Plantas/inmunología , Secuencia de Aminoácidos , Muerte Celular/genética , Muerte Celular/inmunología , Proteínas Fúngicas/genética , Regulación de la Expresión Génica , Glicosilfosfatidilinositoles/química , Glicosilfosfatidilinositoles/metabolismo , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Hypocreales/genética , Hypocreales/crecimiento & desarrollo , Hypocreales/inmunología , Inflorescencia/genética , Inflorescencia/inmunología , Inflorescencia/microbiología , Oryza/genética , Oryza/microbiología , Patrón Molecular Asociado a Patógenos/inmunología , Patrón Molecular Asociado a Patógenos/metabolismo , Péptidos/genética , Péptidos/inmunología , Células Vegetales/inmunología , Células Vegetales/patología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/microbiología , Proteínas de Plantas/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal , Virulencia
13.
Indian J Med Res ; 153(1 & 2): 17-25, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33818465

RESUMEN

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of fatalities globally since its origin in November 2019. The SARS-CoV-2 shares 79 and 50 per cent genome similarity with its predecessors, severe SARS-CoV and Middle East respiratory syndrome (MERS) coronavirus, all belonging to the same genus, Betacoronavirus. This relatively new virus has stymied the effective control of COVID-19 pandemic and caused huge social and economic impact worldwide. The FDA-approved drugs were re-purposed to reduce the number of fatalities caused by SARS-CoV-2. However, controversy surrounds about the efficacy of these re-purposed antiviral drugs against SARS-CoV-2.This necessitates the identification of new drug targets for SARS-CoV-2. Hence, the development of pre-clinical animal model is warranted. Such animal models may help us gain better understanding of the pathophysiology of SARS-CoV-2 infection and will be effective tools for the evaluation and licensure of therapeutic strategies against SARS-CoV-2. This review provides a summary of the attempts made till to develop a suitable animal model to understand pathophysiology and effectiveness of therapeutic agents against SARS-CoV-2.


Asunto(s)
/fisiopatología , Modelos Animales de Enfermedad , /patogenicidad , Animales , Humanos , Virulencia
14.
Int J Mol Sci ; 22(6)2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33801996

RESUMEN

Viroids are tiny single-stranded circular RNA pathogens that infect plants. Viroids do not encode any proteins, yet cause an assortment of symptoms. The following review describes viroid classification, molecular biology and spread. The review also discusses viroid pathogenesis, host interactions and detection. The review concludes with a description of future prospects in viroid research.


Asunto(s)
ARN Circular/genética , ARN Viral/genética , Viroides/genética , Replicación Viral/genética , Resistencia a la Enfermedad/genética , Interacciones Huésped-Patógeno , Modelos Genéticos , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/virología , Plantas/genética , Plantas/virología , Viroides/clasificación , Viroides/patogenicidad , Virulencia/genética
15.
BMC Infect Dis ; 21(1): 370, 2021 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-33879083

RESUMEN

BACKGROUND: Native valves infective endocarditis due to Escherichia coli is still a rare disease and a particular virulence of some E.coli isolate may be suspected. CASE PRESENTATION: A 79-year-old woman presented during the post-operative period of an orthopedic surgery a urinary tract infection following obstructive ureteral lithiasis. E. coli was isolated from a pure culture of urine and blood sampled simultaneously. After evidence of sustained E.coli septicemia, further investigations revealed acute cholecystitis with the same micro-organism in biliary drainage and a native valve mitral endocarditis. E.coli was identified as O2:K7:H6, phylogenetic group B2, ST141, and presented several putative and proven virulence genes. The present isolate can be classified as both extra-intestinal pathogenic E.coli (ExPECJJ) and uropathogenic E. coli (UPECHM). CONCLUSIONS: The relationship between the virulent factors present in ExPEC strains and some serotypes of E. coli that could facilitate the adherence to cardiac valves warrants further investigation.


Asunto(s)
Endocarditis/diagnóstico , Escherichia coli Patógena Extraintestinal/aislamiento & purificación , Anciano , Animales , Endocarditis/microbiología , Escherichia coli Patógena Extraintestinal/clasificación , Escherichia coli Patógena Extraintestinal/patogenicidad , Femenino , Humanos , Procedimientos Ortopédicos/efectos adversos , Filogenia , Periodo Posoperatorio , Infecciones Urinarias/microbiología , Infecciones Urinarias/patología , Urolitiasis/cirugía , Virulencia/genética
16.
Molecules ; 26(6)2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33801847

RESUMEN

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin's impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.


Asunto(s)
Flavonoides/farmacología , Quinolonas/metabolismo , Sistemas de Secreción Tipo III/metabolismo , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Biopelículas/efectos de los fármacos , China , Proteínas de Drosophila/efectos de los fármacos , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Femenino , Flavonoides/metabolismo , Modelos Animales , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/metabolismo , Percepción de Quorum/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Factores de Transcripción/uso terapéutico , Sistemas de Secreción Tipo III/efectos de los fármacos , Virulencia/efectos de los fármacos , Factores de Virulencia
17.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33805371

RESUMEN

As an evolutionarily conserved pathway, mitogen-activated protein kinase (MAPK) cascades function as the key signal transducers that convey information by protein phosphorylation. Here we identified PlMAPK2 as one of 14 predicted MAPKs encoding genes in the plant pathogenic oomycete Peronophythora litchii. PlMAPK2 is conserved in P.litchii and Phytophthora species. We found that PlMAPK2 was up-regulated in sporangium, zoospore, cyst, cyst germination and early stage of infection. We generated PlMAPK2 knockout mutants using the CRISPR/Cas9 method. Compared with wild-type strain, the PlMAPK2 mutants showed no significant difference in vegetative growth, oospore production and sensitivity to various abiotic stresses. However, the sporangium release was severely impaired. We further found that the cleavage of the cytoplasm into uninucleate zoospores was disrupted in the PlMAPK2 mutants, and this developmental phenotype was accompanied by reduction in the transcription levels of PlMAD1 and PlMYB1 genes. Meanwhile, the PlMAPK2 mutants exhibited lower laccase activity and reduced virulence to lychee leaves. Overall, this study identified a MAPK that is critical for zoosporogenesis by regulating the sporangial cleavage and pathogenicity of P.litchii, likely by regulating laccase activity.


Asunto(s)
Litchi/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Oomicetos/patogenicidad , Enfermedades de las Plantas , Litchi/microbiología , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Proteínas de Plantas/metabolismo , Virulencia
18.
Artículo en Inglés | MEDLINE | ID: mdl-33852710

RESUMEN

Despite the widespread use of chlorhexidine (CHX) to prevent infection, data regarding the in vitro action of CHX against methicillin-resistant Staphylococcus aureus (MRSA) are limited. Clinical isolates from Hospital das Clinicas, Sao Paulo, Brazil, identified during 2002/2003 and 2012/2013 were studied to describe the susceptibility to CHX and mupirocin, molecular characteristics, and virulence profile of MRSA. Susceptibility test to Mupirocin was performed by the disk diffusion method and to CHX by the agar dilution technique. PCR for virulence genes, mecA gene and Staphylococcal Cassette Chromosome mec (SCCmec) types were investigated as well. Mupirocin- and CHX-resistant isolates were sequenced using the IlluminaTM plataform. Two hundred and sixteen MRSA clinical isolates were evaluated: 154 from infected and 62 from colonized patients. Resistance to mupirocin was observed in four isolates assigned as SCCmec type III and STs (ST05; ST239 and ST105) carrying mupA and blaZ, two of them co-harboring the ileS gene. Only one isolate assigned as SCCmec type III was resistant to CHX (MIC of 8.0 µg.mL-1) and harbored the qacA gene. Resistance to chlorhexidine and mupirocin were found in isolates carrying qacA and mupA in our hospital. Since these genes are plasmid-mediated, this finding draws attention to the potential spread of resistance to mupirocin in our hospital.


Asunto(s)
Antibacterianos/farmacología , Clorhexidina/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Mupirocina/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Brasil , Niño , Preescolar , ADN Bacteriano/genética , Femenino , Hospitales de Enseñanza , Humanos , Lactante , Masculino , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Análisis de Secuencia de ADN , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Virulencia , Adulto Joven
19.
Cell ; 184(8): 2229-2238.e13, 2021 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-33691138

RESUMEN

The biosafety level 3 (BSL-3) requirement to culture severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a bottleneck for research. Here, we report a trans-complementation system that produces single-round infectious SARS-CoV-2 that recapitulates authentic viral replication. We demonstrate that the single-round infectious SARS-CoV-2 can be used at BSL-2 laboratories for high-throughput neutralization and antiviral testing. The trans-complementation system consists of two components: a genomic viral RNA containing ORF3 and envelope gene deletions, as well as mutated transcriptional regulator sequences, and a producer cell line expressing the two deleted genes. Trans-complementation of the two components generates virions that can infect naive cells for only one round but does not produce wild-type SARS-CoV-2. Hamsters and K18-hACE2 transgenic mice inoculated with the complementation-derived virions exhibited no detectable disease, even after intracranial inoculation with the highest possible dose. Thus, the trans-complementation platform can be safely used at BSL-2 laboratories for research and countermeasure development.


Asunto(s)
/virología , Contención de Riesgos Biológicos/métodos , Células A549 , Animales , Chlorocebus aethiops , Cricetinae , Prueba de Complementación Genética/métodos , Genoma Viral , Células HEK293 , Humanos , Masculino , Ratones , Ratones Transgénicos , ARN Viral , /patogenicidad , Células Vero , Virulencia , Replicación Viral
20.
Microbiome ; 9(1): 65, 2021 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-33743832

RESUMEN

BACKGROUND: Viruses are the most abundant biological entities on Earth, known to be crucial components of microbial ecosystems. However, there is little information on the viral community within agricultural waste. There are currently ~ 2.7 million dairy cattle in the UK producing 7-8% of their own bodyweight in manure daily, and 28 million tonnes annually. To avoid pollution of UK freshwaters, manure must be stored and spread in accordance with guidelines set by DEFRA. Manures are used as fertiliser, and widely spread over crop fields, yet little is known about their microbial composition. We analysed the virome of agricultural slurry over a 5-month period using short and long-read sequencing. RESULTS: Hybrid sequencing uncovered more high-quality viral genomes than long or short-reads alone; yielding 7682 vOTUs, 174 of which were complete viral genomes. The slurry virome was highly diverse and dominated by lytic bacteriophage, the majority of which represent novel genera (~ 98%). Despite constant influx and efflux of slurry, the composition and diversity of the slurry virome was extremely stable over time, with 55% of vOTUs detected in all samples over a 5-month period. Functional annotation revealed a diverse and abundant range of auxiliary metabolic genes and novel features present in the community, including the agriculturally relevant virulence factor VapE, which was widely distributed across different phage genera that were predicted to infect several hosts. Furthermore, we identified an abundance of phage-encoded diversity-generating retroelements, which were previously thought to be rare on lytic viral genomes. Additionally, we identified a group of crAssphages, including lineages that were previously thought only to be found in the human gut. CONCLUSIONS: The cattle slurry virome is complex, diverse and dominated by novel genera, many of which are not recovered using long or short-reads alone. Phages were found to encode a wide range of AMGs that are not constrained to particular groups or predicted hosts, including virulence determinants and putative ARGs. The application of agricultural slurry to land may therefore be a driver of bacterial virulence and antimicrobial resistance in the environment. Video abstract.


Asunto(s)
Bacteriófagos , Animales , Bacteriófagos/genética , Bovinos , Ecosistema , Estiércol , Virulencia
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