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1.
Pestic Biochem Physiol ; 165: 104522, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32359549

RESUMEN

Two sterol 14α-demethylase genes from Penicillium digitatum, PdCYP51A and PdCYP51B, were evaluated and revealed that 95% of Imazalil (IMZ)-resistant isolates carried a 195-bp insertion in the PdCYP51B promoter. We functionally characterized both sterol 14α-demethylases by overexpression. Molecular analysis of overexpression mutants showed that the introduction of PdCYP51B insertion is more stable than the five-tandem repeat PdCYP51A sequence previously described that confers DMI fungicide resistance. The both enhancers can coexist in P. digitatum isolates that initially contained the 195-bp PdCYP51B insertion but the introduction of 195-bp PdCYP51B enhancer promoted the loss of the five-tandem repeat of PdCYP51A. The incorporation of 195-bp PdCYP51B resulted in an increase of DMI fungicide resistance in mutants from already resistant isolates and confers resistance to DMIs in mutants from sensitive isolates. Transcription evaluation of the both genes showed noticeable induction in all overexpression mutants, except for those coming from the five-tandem repeat PdCYP51A sequence, whereas PdCYP51A expression dropped dramatically. Only PdCYP51B exhibited up-regulation during citrus infection compared to axenic growth, and the role of PdCYP51B in fungal virulence was further reinforced since strains with low virulence showed increased infectivity in overexpression mutants. This study suggested the predominant role of the PdCYP51B enhancer in the acquisition of DMI resistance and fungal virulence, by replacing homologues genes with same putative function.


Asunto(s)
Citrus , Fungicidas Industriales , Penicillium , Farmacorresistencia Fúngica , Virulencia
2.
APMIS ; 128(2): 150-161, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32352605

RESUMEN

Infection with Helicobacter pylori is associated with the development of gastric cancer. Although the prevalence of gastric cancer has declined throughout years due to improvement in early screening strategy, mortality due to gastric cancer has not changed. Incidence and mortality due to gastric cancer are higher in developing countries as compared to developed countries. Diagnosis and prognosis of gastric cancer are still poor with patients usually diagnosed with cancer at an advanced stage. Eradication of H. pylori is pertinent for the prevention of gastric cancer. However, the rise in antimicrobial resistance among H. pylori isolates has complicated the prevention strategy. H. pylori express multiple virulence factors for survival in the hostile acid gastric environment. The expression of oncogenic protein cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and outer inflammatory protein is essential for H. pylori to exert pathogenesis towards the host. Interestingly, <3% of H. pylori-infected subjects develop gastric cancer, suggesting a unique way of interaction between the host's immune response and H. pylori virulence factors. This article is aimed to review the epidemiology and role of H. pylori in gastric carcinogenesis. A better understanding of the interaction between H. pylori virulence factors and host is required for better gastric cancer prevention.


Asunto(s)
Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Neoplasias Gástricas/etiología , Neoplasias Gástricas/inmunología , Factores de Virulencia/inmunología , Virulencia/inmunología , Carcinogénesis/inmunología , Humanos , Pronóstico , Neoplasias Gástricas/microbiología
3.
Phytochemistry ; 174: 112341, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32240851

RESUMEN

Eight undescribed terpenoids, namely, odongrossins A-H, together with two known terpenoids were isolated from Odontoschisma grosseverrucosum Stephani (Cephaloziaceae). Their structures were established based on NMR data, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction measurements. Odongrossin A and odongrossin G displayed moderate anti-virulence activities against CDR1-and CDR2-efflux-pump-deficient Candida albicans DSY654. Further investigation of odongrossin A revealed that it inhibited adhesion and biofilm formation on C. albicans DSY654. The results regarding the transcription levels of genes demonstrated that odongrossin A could regulate the expression of genes that are associated with the virulence of C. albicans DSY654.


Asunto(s)
Antifúngicos , Hepatophyta , Biopelículas , Candida albicans , Proteínas Fúngicas , Terpenos , Virulencia
4.
Emerg Microbes Infect ; 9(1): 837-842, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32301390

RESUMEN

The emergence of SARS-CoV-2 has led to the current global coronavirus pandemic and more than one million infections since December 2019. The exact origin of SARS-CoV-2 remains elusive, but the presence of a distinct motif in the S1/S2 junction region suggests the possible acquisition of cleavage site(s) in the spike protein that promoted cross-species transmission. Through plaque purification of Vero-E6 cultured SARS-CoV-2, we found a series of variants which contain 15-30-bp deletions (Del-mut) or point mutations respectively at the S1/S2 junction. Examination of the original clinical specimen from which the isolate was derived, and 26 additional SARS-CoV-2 positive clinical specimens, failed to detect these variants. Infection of hamsters shows that one of the variants (Del-mut-1) which carries deletion of 10 amino acids (30bp) does not cause the body weight loss or more severe pathological changes in the lungs that is associated with wild type virus infection. We suggest that the unique cleavage motif promoting SARS-CoV-2 infection in humans may be under strong selective pressure, given that replication in permissive Vero-E6 cells leads to the loss of this adaptive function. It would be important to screen the prevalence of these variants in asymptomatic infected cases. The potential of the Del-mut variants as an attenuated vaccine or laboratory tool should be evaluated.


Asunto(s)
Infecciones por Coronavirus/patología , Modelos Animales de Enfermedad , Mesocricetus , Neumonía Viral/patología , Virus del SRAS/genética , Virus del SRAS/patogenicidad , Eliminación de Secuencia , Glicoproteína de la Espiga del Coronavirus/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Chlorocebus aethiops , Infecciones por Coronavirus/virología , Femenino , Especificidad del Huésped , Humanos , Pulmón/patología , Masculino , Pandemias , Neumonía Viral/virología , Virus del SRAS/crecimiento & desarrollo , Virus del SRAS/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/química , Células Vero , Virulencia
5.
Crit Rev Microbiol ; 46(2): 182-193, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32282268

RESUMEN

The last century has witnessed several assaults from RNA viruses, resulting in millions of death throughout the world. The 21st century appears no longer an exception, with the trend continued with escalated fear of SARS coronavirus in 2002 and further concern of influenza H5N1 in 2003. A novel influenza virus created the first pandemic of the 21st century, the pandemic flu in 2009 preceded with the emergence of another deadly virus, MERS-CoV in 2012. A novel coronavirus "SARS-CoV-2" (and the disease COVID-19) emerged suddenly, causing a rapid outbreak with a moderate case fatality rate. This virus is continuing to cause health care providers grave concern due to the lack of any existing immunity in the human population, indicating their novelty and lack of previous exposure. The big question is whether this novel virus will be establishing itself in an endemic form or will it eventually die out? Endemic viruses during circulation may acquire mutations to infect naïve, as well as individual with pre-existing immunity. Continuous monitoring is strongly advisable, not only to the newly infected individuals, but also to those recovered individuals who were infected by SARS-CoV-2 as re-infection may lead to the selection of escape mutants and subsequent dissemination to the population.


Asunto(s)
Betacoronavirus/patogenicidad , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Neumonía Viral/epidemiología , Neumonía Viral/virología , Betacoronavirus/genética , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/mortalidad , Brotes de Enfermedades , Enfermedades Endémicas , Humanos , Mutación , Pandemias , Neumonía Viral/inmunología , Neumonía Viral/mortalidad , Virulencia/genética
6.
Dis Aquat Organ ; 138: 237-246, 2020 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-32270764

RESUMEN

In this study, spontaneous swim bladder mycosis was documented in a farmed fingerling rainbow trout from a raceway culture system. At necropsy, the gross lesions included a thickened swim bladder wall, and the posterior portion of the swim bladder was enlarged due to massive hyperplasia of muscle. A microscopic wet mount examination of the swim bladder contents revealed abundant septate hyphae, and histopathological examination showed periodic acid-Schiff-positive mycelia in the lumen and wall of the swim bladder. Histopathological examination of the thickened posterior swim bladder revealed muscle hyperplasia with expansion by inflammatory cells. The causative agent was identified as Phoma herbarum through morphological analysis and DNA sequencing. The disease was reproduced in rainbow trout fingerlings using intraperitoneal injection of a spore suspension. Necropsy in dead and moribund fish revealed extensive congestion and haemorrhages in the serosa of visceral organs and in liver and abdominal serosanguinous fluid. Histopathological examination showed severe hepatic congestion, sinusoidal dilatation, Kupffer cell reactivity, leukostasis and degenerative changes. Fungi were disseminated to the liver, pyloric caeca, kidney, spleen and heart. Although infections caused by Phoma spp. have been repeatedly reported in fish, species identification has been hampered by extensive taxonomic changes. The results of this study confirmed the pathogenicity of P. herbarum in salmonids by using a reliably identified strain during experimental fish infection and provides new knowledge regarding the course of infection.


Asunto(s)
Enfermedades de los Peces , Micosis , Oncorhynchus mykiss , Animales , Vejiga Urinaria , Virulencia
8.
Arch Virol ; 165(6): 1367-1375, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32285201

RESUMEN

Sequencing of the VP2 region was carried out to identify amino acid mismatches between vaccine strains and field isolates of infectious bursal disease virus (IBDV). Viruses were isolated in chicken embryo fibroblast (DF-1) cells using pooled samples of bursa collected from nine outbreaks, which affected 30,250 chickens in five localities, with an overall mortality of 47.87%. Virus strains were identified by comparing the deduced amino acid sequence between positions 232 and 446 of the immunodominant VP2 epitope. All of the pooled samples were positive for IBDV. RT-PCR yielded a 645-bp DNA fragment of the VP2 gene. Phylogenetic analysis of this fragment revealed clustering of these isolates with very virulent IBDV strains. The amino acid sequences of these isolates were identical to those of the European very virulent strains UK 661 and DV 86, except at position 222, but differed from the vaccine strains used in Ethiopia, suggesting the possible introduction of virulent virus strains to Ethiopia from Europe. Our study demonstrates the widespread presence of very virulent strains of IBDV on poultry farms in Ethiopia and demonstrates the need to evaluate the protective level of existing vaccines against circulating field viruses.


Asunto(s)
Infecciones por Birnaviridae/veterinaria , Pollos/virología , Enfermedades de las Aves de Corral/virología , Proteínas Estructurales Virales/genética , Vacunas Virales/inmunología , Secuencia de Aminoácidos , Animales , Infecciones por Birnaviridae/virología , Cartilla de ADN , Brotes de Enfermedades/veterinaria , Etiopía , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Filogenia , ARN Viral/genética , Análisis de Secuencia de ARN/veterinaria , Virulencia
9.
Respir Physiol Neurobiol ; 277: 103443, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32333993

RESUMEN

In the present study we analyze the epidemiological data of COVID-19 of Tibet and high-altitude regions of Bolivia and Ecuador, and compare to lowland data, to test the hypothesis that high-altitude inhabitants (+2,500 m above sea-level) are less susceptible to develop severe adverse effects in acute SARS-CoV-2 virus infection. Analysis of available epidemiological data suggest that physiological acclimatization/adaptation that counterbalance the hypoxic environment in high-altitude may protect from severe impact of acute SARS-CoV-2 virus infection. Potential underlying mechanisms such as: (i) a compromised half-live of the virus caused by the high-altitude environment, and (ii) a hypoxia mediated down regulation of angiotensin-converting enzyme 2 (ACE2), which is the main binding target of SARS-CoV-2 virus in the pulmonary epithelium are discussed.


Asunto(s)
Betacoronavirus/fisiología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Neumonía Viral/epidemiología , Neumonía Viral/virología , Altitud , Betacoronavirus/patogenicidad , Bolivia/epidemiología , Susceptibilidad a Enfermedades , Ecuador/epidemiología , Humanos , Oxígeno , Pandemias , Tibet/epidemiología , Virulencia
10.
Life Sci ; 250: 117541, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32169520

RESUMEN

AIM: Nontuberculous mycobacterial (NTM) infection such as endophthalmitis, dacryocystitis, and canaliculitis are pervasive across the globe and are currently managed by antibiotics. However, the recent cases of Mycobacteroides developing drug resistance reported along with the improper practice of medicine intrigued us to explore its genomic and proteomic canvas at a global scale and develop a chimeric vaccine against Mycobacteroides. MAIN METHODS: We carried out a vivid genomic study on five recently sequenced strains of Mycobacteroides and explored their Pan-core genome/proteome in three different phases. The promiscuous antigenic proteins were identified via a subtractive proteomics approach that qualified for virulence causation, resistance and essentiality factors for this notorious bacterium. An integrated pipeline was developed for the identification of B-Cell, MHC (Major histocompatibility complex) class I and II epitopes. KEY FINDINGS: Phase I identified the shreds of evidence of reductive evolution and propensity of the Pan-genome of Mycobacteroides getting closed soon. Phase II and Phase III produced 8 vaccine constructs. Our final vaccine construct, V6 qualified for all tests such as absence for allergenicity, presence of antigenicity, etc. V6 contains ß-defensin as an adjuvant, linkers, Lysosomal-associated membrane protein 1 (LAMP1) signal peptide, and PADRE (Pan HLA-DR epitopes) amino acid sequence. Besides, V6 also interacts with a maximum number of MHC molecules and the TLR4/MD2 (Toll-like receptor 4/Myeloid differentiation factor 2) complex confirmed by docking and molecular dynamics simulation studies. SIGNIFICANCE: The knowledge harnessed from the current study can help improve the current treatment regimens or in an event of an outbreak and propel further related studies.


Asunto(s)
Vacunas Bacterianas/química , Infecciones por Bacterias Grampositivas/prevención & control , Mycobacteriaceae/genética , Vacunología , Alelos , Linfocitos B/inmunología , Bacteriófagos , Sistemas CRISPR-Cas , Biología Computacional , Farmacorresistencia Bacteriana , Epítopos , Epítopos de Linfocito T/genética , Microbioma Gastrointestinal , Genoma Bacteriano , Genómica , Antígenos de Histocompatibilidad Clase I/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Inmunoterapia , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Mycobacteriaceae/patogenicidad , Proteoma , Virulencia
11.
Plant Dis ; 104(5): 1378-1389, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32181722

RESUMEN

Leaf spot diseases caused by Alternaria species have been reported worldwide in plants in the Brassicaceae family. However, there is little information on Alternaria species causing diseases in horseradish. In the present study, 89 Alternaria spp. isolates from Armoracia rusticana, sampled from nine districts in Serbia, were characterized based on their morphology, physiology, and molecular markers. Morphological characterization and molecular analyses based on ITS, GAPDH, Alt a 1, and PM-ATP sequences identified three distinct species associated with the disease: Alternaria brassicae, A. brassicicola, and A. alternata. For all species, growth and sporulation rates at 0, 5, 10, 15, 20, 25, 30, 35, and 40°C showed a quadratic response, with A. alternata having the widest temperature optimum (20 to 30°C) while A. brassicicola had higher optimum temperatures (20 to 25°C) than A. brassicae (15 to 20°C). To gain a better understanding of the pathogenicity of these species, the influence of leaf age, host susceptibility, and ability to infect artificially wounded and nonwounded leaves were tested. The pathogenicity test identified A. brassicicola and A. brassicae as the main causal agents of horseradish leaf spot disease. Results indicated that young and intact leaves of horseradish and cabbage were less susceptible to infection and also suggested the potential for cross-infection between these two hosts. Haplotype networks showed haplotype uniformity for A. brassicae, two haplotype groups of A. brassicicola, and eight haplotype groups of A. alternata in Serbia and suggest the possible association of some haplotypes with the geographic area. This study is the first to investigate Alternaria leaf spot disease on A. rusticana in Serbia and is the first record of A. brassicicola on horseradish in this country.


Asunto(s)
Alternaria , Brassica , Armoracia , Serbia , Virulencia
12.
Plant Dis ; 104(5): 1358-1368, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32196416

RESUMEN

Walnut (Juglans regia L.) is an economically important woody nut and edible oil tree all over the world. However, walnut production is limited by walnut anthracnose, which is a disastrous disease that causes significant yield losses. Studying the etiology of anthracnose on walnut and the pathogens' virulence and sensitivities to fungicides would be beneficial for effective control. This study was conducted to identify the pathogen of walnut anthracnose and reveal the population diversity of pathogens through virulence, sensitivities to fungicides, and genetic variation. A total of 13 single-spore Colletotrichum isolates were collected from walnut anthracnose-diseased fruits and leaves from 13 walnut commercial orchards in Henan, Hubei, Shandong, and Shaanxi provinces in China. The isolates were identified as Colletotrichum gloeosporioides sensu stricto (s.s.) according to multilocus phylogenetic analyses (internal transcribed spacer, actin, glyceraldehyde-3-phosphate dehydrogenase, and chitin synthase), morphological as well as cultural characters, and pathogenicity. When the same walnut tissue was inoculated with different isolates, the disease lesion size was different. The results showed that the virulence of all isolates was considerably different, and the differences were not correlated with geographic origins. The virulence to walnut leaves and fruits inoculated with the same isolate was significantly different. Based on the virulence to walnut leaves and fruits, the 13 isolates were divided into three groups. Virulence of 69.2% of the isolates to walnut fruits was higher than that to leaves; 15.4% of isolates had no difference in pathogenicity, and the virulence to walnut leaves was higher for 15.4% of isolates. Tebuconazole, difenoconazole, flusilazole, and carbendazim inhibited the growth of fungal mycelia, and the concentration for 50% of maximal effect (EC50) values were 0.4 to 20.5, 0.6 to 2.6, 0.2 to 1.6, and 0.002 to 0.2 µg/ml, respectively, with average values of 6.5 ± 6.9, 1.5 ± 0.6, 0.9 ± 0.4, and 0.1 ± 0.05 µg/ml, respectively. All isolates were more sensitive to difenoconazole, flusilazole, and carbendazim than tebuconazole (P < 0.01). Isolate sensitivities to the same fungicide were different. Isolates SL-31 and TS-09 were the least sensitive to carbendazim and tebuconazole, respectively, and the resistance ratios were 87.3 and 51.6, respectively. Sensitivities to difenoconazole and flusilazole were largely consistent among all isolates, and the resistance ratios were from 1 to 4.6 and from 1 to 7, respectively. Therefore, difenoconazole and flusilazole could be chosen for disease control. The differences of pathogenicity and fungicide sensitivity were not correlated with geographic regions. These results indicated that there was high intraspecific diversity of populations in C. gloeosporioides s.s. that caused walnut anthracnose. For effective management, the targeted control strategy should be implemented based on the different geographic regions.


Asunto(s)
Colletotrichum , Fungicidas Industriales , Juglans , China , Nueces , Filogenia , Enfermedades de las Plantas , Virulencia
13.
Gene ; 741: 144566, 2020 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-32171826

RESUMEN

Bacteria of the genusGlutamicibacterare considered ubiquitous because they can be found in soil, water and air. They have already been isolated from different habitats, including different types of soil, clinical samples, cheese and plants. Glutamicibacter creatinolyticus is a Gram-positive bacterium important to various biotechnological processes, however, as a pathogen it is associated to urinary tract infections and bacteremia. Recently,Glutamicibacter creatinolyticusLGCM 259 was isolated from a mare, which displayed several diffuse subcutaneous nodules with heavy vascularization. In this study, sequencing, genomic analysis ofG. creatinolyticusLGCM 259 and comparative analyseswere performedamong 4representatives of different members of genusfromdifferent habitats, available in the NCBI database. The LGCM 259 strain's genome carries important factors of bacterial virulence that are essential in cell viability, virulence, and pathogenicity. Genomic islands were predicted for 4 members of genusGlutamicibacter,showing ahigh number of GEIs,which may reflect a high interspecific diversity and a possible adaptive mechanism responsible for the survival of each species in its specific niche. Furthermore,G. creatinolyticusLGCM 259 sharessyntenicregions, albeit with a considerable loss of genes, in relation to the other species. In addition,G. creatinolyticusLGCM 259 presentsresistancegenes to 6 differentclasses ofantibiotics and heavy metals, such as: copper, arsenic, chromium and cobalt-zinc-cadmium.Comparative genomicsanalysescouldcontribute to the identification of mobile genetic elements particular to the speciesG. creatinolyticuscompared to other members of genus. The presence of specific regions inG. creatinolyticuscould be indicative of their rolesin host adaptation, virulence, and the characterization ofastrain that affects animals.


Asunto(s)
Absceso/genética , Adaptación Fisiológica/genética , Variación Genética , Micrococcaceae/genética , Absceso/microbiología , Absceso/veterinaria , Animales , Genoma Bacteriano , Islas Genómicas/genética , Genómica , Caballos/microbiología , Masculino , Micrococcaceae/patogenicidad , Filogenia , Virulencia/genética
14.
PLoS Negl Trop Dis ; 14(3): e0008166, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32203536

RESUMEN

Flaviviruses such as yellow fever, dengue or Zika viruses are responsible for significant human and veterinary diseases worldwide. These viruses contain an RNA genome, prone to mutations, which enhances their potential to emerge as pathogens. Bamaga virus (BgV) is a mosquito-borne flavivirus in the yellow fever virus group that we have previously shown to be host-restricted in vertebrates and horizontally transmissible by Culex mosquitoes. Here, we aimed to characterise BgV host-restriction and to investigate the mechanisms involved. We showed that BgV could not replicate in a wide range of vertebrate cell lines and animal species. We determined that the mechanisms involved in BgV host-restriction were independent of the type-1 interferon response and RNAse L activity. Using a BgV infectious clone and two chimeric viruses generated as hybrids between BgV and West Nile virus, we demonstrated that BgV host-restriction occurred post-cell entry. Notably, BgV host-restriction was shown to be temperature-dependent, as BgV replicated in all vertebrate cell lines at 34°C but only in a subset at 37°C. Serial passaging of BgV in Vero cells resulted in adaptive mutants capable of efficient replication at 37°C. The identified mutations resulted in amino acid substitutions in NS4A-S124F, NS4B-N244K and NS5-G2C, all occurring close to a viral protease cleavage site (NS4A/2K and NS4B/NS5). These mutations were reverse engineered into infectious clones of BgV, which revealed that NS4B-N244K and NS5-G2C were sufficient to restore BgV replication in vertebrate cells at 37°C, while NS4A-S124F further increased replication efficiency. When these mutant viruses were injected into immunocompetent mice, alongside BgV and West Nile virus chimeras, infection and neurovirulence were enhanced as determined by clinical scores, seroconversion, micro-neutralisation, viremia, histopathology and immunohistochemistry, confirming the involvement of these residues in the attenuation of BgV. Our studies identify a new mechanism of host-restriction and attenuation of a mosquito-borne flavivirus.


Asunto(s)
Infecciones por Flavivirus/virología , Flavivirus/genética , Flavivirus/patogenicidad , Mutación , Proteínas no Estructurales Virales/genética , Animales , Encéfalo/patología , Encéfalo/virología , Línea Celular , Chlorocebus aethiops , Culicidae/virología , Modelos Animales de Enfermedad , Endorribonucleasas/metabolismo , Femenino , Flavivirus/fisiología , Infecciones por Flavivirus/metabolismo , Infecciones por Flavivirus/patología , Células HEK293 , Humanos , Masculino , Ratones , Mosquitos Vectores/virología , Células Vero , Virulencia/genética , Replicación Viral , Virus del Nilo Occidental/genética
15.
Am J Pathol ; 190(4): 862-873, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32200972

RESUMEN

Group A streptococcus (GAS) is a major pathogen that impacts health and economic affairs worldwide. Although the oropharynx is the primary site of infection, GAS can colonize the female genital tract and cause severe diseases, such as puerperal sepsis, neonatal infections, and necrotizing myometritis. Our understanding of how GAS genes contribute to interaction with the primate female genital tract is limited by the lack of relevant animal models. Using two genome-wide transposon mutagenesis screens, we identified 69 GAS genes required for colonization of the primate vaginal mucosa in vivo and 96 genes required for infection of the uterine wall ex vivo. We discovered a common set of 39 genes important for GAS fitness in both environments. They include genes encoding transporters, surface proteins, transcriptional regulators, and metabolic pathways. Notably, the genes that encode the surface-exclusion protein (SpyAD) and the immunogenic secreted protein 2 (Isp2) were found to be crucial for GAS fitness in the female primate genital tract. Targeted gene deletion confirmed that isogenic mutant strains ΔspyAD and Δisp2 are significantly impaired in ability to colonize the primate genital tract and cause uterine wall pathologic findings. Our studies identified novel GAS genes that contribute to female reproductive tract interaction that warrant translational research investigation.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas de la Membrana/metabolismo , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidad , Enfermedades Vaginales/microbiología , Animales , Proteínas Bacterianas/genética , Modelos Animales de Enfermedad , Femenino , Regulación Bacteriana de la Expresión Génica , Macaca fascicularis , Proteínas de la Membrana/genética , Infecciones Estreptocócicas/metabolismo , Streptococcus pyogenes/metabolismo , Enfermedades Vaginales/patología , Virulencia
16.
J Insect Sci ; 20(2)2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32112650

RESUMEN

Nine strains of five species of entomopathogenic hypocrealean fungi were tested against adults of the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky). These strains have been developed as commercial biopesticide products in the United States, Brazil, South Korea, or the European Union (EU). Metarhizium anisopliae (Metschnikoff) (Hypocreales: Clavicipitaceae) ESALQ E-9 and Metarhizium brunneum (Petch) F52 (formerly M. anisopliae F52) (Hypocreales: Clavicipitaceae) killed 100% of treated beetles with the shortest survival times. Virulence differed among the five strains of Beauveria bassiana (Balsamo) (Hypocreales: Cordycipitaceae) tested, ranging from 0 to 77.3% mortality within 28 d. Two Isaria fumosorosea (Wize, 1904) (Hypocreales: Cordycipitaceae) (formerly Paecilomyces fumosoroseus) strains and the Lecanicillium muscarium (Petch) Zare & Gams (Hypocreales: Cordycipitaceae) strain used in Mycotal were not pathogenic to A. glabripennis adults. Within the entomopathogenic fungi tested, the Metarhizium strains may be the most appropriate for further evaluation.


Asunto(s)
Beauveria/patogenicidad , Escarabajos/microbiología , Metarhizium/patogenicidad , Control Biológico de Vectores/métodos , Animales , Hypocreales/patogenicidad , Virulencia
17.
Trends Plant Sci ; 25(4): 315-317, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32191865

RESUMEN

Phage cocktails have emerged as precision tools for controlling plant bacterial diseases. Wang et al. now report that phage cocktails decreased the occurrence of tomato bacterial wilt disease efficiently by infecting and destroying bacterial pathogens, selecting phage-resistant but slow-growing pathogen strains, and fostering bacterial species that are antagonistic to the pathogens.


Asunto(s)
Bacteriófagos , Lycopersicon esculentum , Bacterias , Enfermedades de las Plantas , Virulencia
18.
Mil Med Res ; 7(1): 11, 2020 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-32169119

RESUMEN

An acute respiratory disease, caused by a novel coronavirus (SARS-CoV-2, previously known as 2019-nCoV), the coronavirus disease 2019 (COVID-19) has spread throughout China and received worldwide attention. On 30 January 2020, World Health Organization (WHO) officially declared the COVID-19 epidemic as a public health emergency of international concern. The emergence of SARS-CoV-2, since the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, marked the third introduction of a highly pathogenic and large-scale epidemic coronavirus into the human population in the twenty-first century. As of 1 March 2020, a total of 87,137 confirmed cases globally, 79,968 confirmed in China and 7169 outside of China, with 2977 deaths (3.4%) had been reported by WHO. Meanwhile, several independent research groups have identified that SARS-CoV-2 belongs to ß-coronavirus, with highly identical genome to bat coronavirus, pointing to bat as the natural host. The novel coronavirus uses the same receptor, angiotensin-converting enzyme 2 (ACE2) as that for SARS-CoV, and mainly spreads through the respiratory tract. Importantly, increasingly evidence showed sustained human-to-human transmission, along with many exported cases across the globe. The clinical symptoms of COVID-19 patients include fever, cough, fatigue and a small population of patients appeared gastrointestinal infection symptoms. The elderly and people with underlying diseases are susceptible to infection and prone to serious outcomes, which may be associated with acute respiratory distress syndrome (ARDS) and cytokine storm. Currently, there are few specific antiviral strategies, but several potent candidates of antivirals and repurposed drugs are under urgent investigation. In this review, we summarized the latest research progress of the epidemiology, pathogenesis, and clinical characteristics of COVID-19, and discussed the current treatment and scientific advancements to combat the epidemic novel coronavirus.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus , Brotes de Enfermedades , Neumonía Viral , Adulto , Anciano , Alphacoronavirus/genética , Animales , Betacoronavirus/genética , Betacoronavirus/patogenicidad , China/epidemiología , Quirópteros , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/terapia , Infecciones por Coronavirus/transmisión , Tos/etiología , Diarrea/etiología , Reservorios de Enfermedades , Fatiga/etiología , Femenino , Fiebre/etiología , Humanos , Masculino , Persona de Mediana Edad , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Coronavirus del Síndrome Respiratorio de Oriente Medio/patogenicidad , Peptidil-Dipeptidasa A , Neumonía Viral/diagnóstico , Neumonía Viral/epidemiología , Neumonía Viral/terapia , Neumonía Viral/transmisión , Virus del SRAS/genética , Virus del SRAS/patogenicidad , Proteínas del Envoltorio Viral , Virulencia , Replicación Viral
19.
Emerg Microbes Infect ; 9(1): 631-638, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32183606

RESUMEN

Clostridioides difficile infection (CDI) is a common cause of nosocomial diarrhea and can sometimes lead to pseudo-membranous colitis and toxic megacolon. We previously reported that the PCR ribotype 002 was a common C. difficile ribotype in Hong Kong that was associated with increased mortality. In this study, we assessed in vitro bacteriological characteristics and in vivo virulence of ribotype 002 compared to other common ribotypes, including ribotypes 012, 014 and 046. We observed significantly higher toxin A (p < 0.05) and toxin B (p < 0.05) production, sporulation (p < 0.001) and germination rates (p < 0.0001) in ribotype 002 than other common ribotypes. In a murine model of C. difficile infection, ribotype 002 caused significantly more weight loss (p < 0.001) and histological damage (p < 0.001) than other common ribotypes. These findings may have contributed to the higher prevalence and mortality observed, and provided mechanistic insights that can help public surveillance and develop novel therapeutics to combat against this infection.


Asunto(s)
Clostridiales/patogenicidad , Infecciones por Bacterias Grampositivas/microbiología , Animales , Hong Kong , Masculino , Ratones Endogámicos C57BL , Ribotipificación , Virulencia
20.
Mem Inst Oswaldo Cruz ; 115: e190398, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32187326

RESUMEN

BACKGROUND: Streptococcus agalactiae capsular type III strains are a leading cause of invasive neonatal infections. Many pathogens have developed mechanisms to escape from host defense response using the host membrane microdomain machinery. Lipid rafts play an important role in a variety of cellular functions and the benefit provided by interaction with lipid rafts can vary from one pathogen to another. OBJECTIVES: This study aims to evaluate the involvement of membrane microdomains during infection of human endothelial cell by S. agalactiae. METHODS: The effects of cholesterol depletion and PI3K/AKT signaling pathway activation during S. agalactiae-human umbilical vein endothelial cells (HUVEC) interaction were analysed by pre-treatment with methyl-ß-cyclodextrin (MßCD) or LY294002 inhibitors, immunofluorescence and immunoblot analysis. The involvement of lipid rafts was analysed by colocalisation of bacteria with flotillin-1 and caveolin-1 using fluorescence confocal microscopy. FINDINGS: In this work, we demonstrated the importance of the integrity of lipid rafts microdomains and activation of PI3K/Akt pathway during invasion of S. agalactiae strain to HUVEC cells. Our results suggest the involvement of flotillin-1 and caveolin-1 during the invasion of S. agalactiae strain in HUVEC cells. CONCLUSIONS: The collection of our results suggests that lipid microdomain affects the interaction of S. agalactiae type III belonging to the hypervirulent ST-17 with HUVEC cells through PI3K/Akt signaling pathway.


Asunto(s)
Células Endoteliales/virología , Lípidos de la Membrana , Microdominios de Membrana/virología , Streptococcus agalactiae/patogenicidad , Virulencia , Humanos , Recién Nacido , Streptococcus agalactiae/genética
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