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1.
Acta Odontol Latinoam ; 33(2): 104-111, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920612

RESUMO

Candida dubliniensis (Cd) and Candida albicans (Ca) are the most frequently isolated yeasts in HIV+ patients. Some of the enzymes produced by these yeasts are considered virulence factors since they contribute to pathogenicity of Candida spp. The aim of the present study was to compare production of enzymes such as phospholipase (Ph), proteinase (P), and hemolysin (H) by Cd and Ca strains isolated from periodontal HIV-positive patients receiving and not receiving highly active antiretroviral therapy (HAART). Subgingival biofilm samples were obtained using paper points, and a sample of oral mucosa was taken using a swab. Phenotypic and molecular methods were used to isolate 39 strains of Candida, including 25 strains of Cd and 14 strains of Ca, obtained from 33 periodontal pocket samples and 6 oral mucosa samples collected from 15 HIV+ patients (8 receiving and 7 not receiving HAART). Malt egg-yolk agar, albumin agar and blood agar were used to evaluate pH, P and H production respectively. The strains were inoculated in duplicate and incubated at 37 ºC. Colony and halo diameters were measured. A greater proportion of Ca was observed in patients not receiving HAART, and a higher proportion of Cd was observed in those under HAART, Chi2 p< 0.001. Phospholipase production was observed in 92.9% percent of isolated Ca strains but in none of the isolated Cd strains. Proteinase production was high in Ca and Cd strains isolated from patients not receiving HAART. Hemolysin production was observed in all the studied strains, though it was significantly higher (p=0.04) in Ca and Cd strains isolated from patients not receiving HAART. To sum up, the proportion of Candida dubliniensis strains was highest in the subgingival biofilm of patients receiving HAART, and Cd strains were found to express fewer virulence factors than Ca strains.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Biofilmes/crescimento & desenvolvimento , Candida albicans/enzimologia , Candida albicans/isolamento & purificação , Candida/enzimologia , Candida/isolamento & purificação , Candidíase Bucal/microbiologia , Gengiva/microbiologia , Infecções por HIV/complicações , Candida/classificação , Candida/genética , Candida albicans/genética , Candidíase Bucal/complicações , Genótipo , Infecções por HIV/microbiologia , Humanos , Mucosa Bucal/microbiologia , Fenótipo , Reação em Cadeia da Polimerase , Fatores de Virulência/genética
2.
PLoS Pathog ; 16(8): e1008822, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866204

RESUMO

Shigella flexneri invades host cells by entering within a bacteria-containing vacuole (BCV). In order to establish its niche in the host cytosol, the bacterium ruptures its BCV. Contacts between S. flexneri BCV and infection-associated macropinosomes (IAMs) formed in situ have been reported to enhance BCV disintegration. The mechanism underlying S. flexneri vacuolar escape remains however obscure. To decipher the molecular mechanism priming the communication between the IAMs and S. flexneri BCV, we performed mass spectrometry-based analysis of the magnetically purified IAMs from S. flexneri-infected cells. While proteins involved in host recycling and exocytic pathways were significantly enriched at the IAMs, we demonstrate more precisely that the S. flexneri type III effector protein IpgD mediates the recruitment of the exocyst to the IAMs through the Rab8/Rab11 pathway. This recruitment results in IAM clustering around S. flexneri BCV. More importantly, we reveal that IAM clustering subsequently facilitates an IAM-mediated unwrapping of the ruptured vacuole membranes from S. flexneri, enabling the naked bacterium to be ready for intercellular spread via actin-based motility. Taken together, our work untangles the molecular cascade of S. flexneri-driven host trafficking subversion at IAMs to develop its cytosolic lifestyle, a crucial step en route for infection progression at cellular and tissue level.


Assuntos
Disenteria Bacilar , Shigella flexneri , Transdução de Sinais , Vacúolos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Disenteria Bacilar/genética , Disenteria Bacilar/metabolismo , Células HeLa , Humanos , Shigella flexneri/genética , Shigella flexneri/metabolismo , Shigella flexneri/patogenicidade , Vacúolos/genética , Vacúolos/metabolismo , Vacúolos/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
3.
Nat Commun ; 11(1): 4894, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994400

RESUMO

Identification of the complete set of translated genes of viruses is important to understand viral replication and pathogenesis as well as for therapeutic approaches to control viral infection. Here, we use chemical proteomics, integrating bio-orthogonal non-canonical amino acid tagging and high-resolution mass spectrometry, to characterize the newly synthesized herpes simplex virus 1 (HSV-1) proteome in infected cells. In these infected cells, host cellular protein synthesis is shut-off, increasing the chance to preferentially detect viral proteomes. We identify nine previously cryptic orphan protein coding sequences whose translated products are expressed in HSV-1-infected cells. Functional characterization of one identified protein, designated piUL49, shows that it is critical for HSV-1 neurovirulence in vivo by regulating the activity of virally encoded dUTPase, a key enzyme that maintains accurate DNA replication. Our results demonstrate that cryptic orphan protein coding genes of HSV-1, and probably other large DNA viruses, remain to be identified.


Assuntos
Encefalite por Herpes Simples/virologia , Herpesvirus Humano 1/patogenicidade , Pirofosfatases/metabolismo , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo , Animais , Encéfalo/patologia , Encéfalo/virologia , Chlorocebus aethiops , Replicação do DNA , Modelos Animais de Doenças , Encefalite por Herpes Simples/patologia , Feminino , Genes Virais/genética , Células HEK293 , Células HeLa , Herpesvirus Humano 1/genética , Humanos , Camundongos , Biossíntese de Proteínas , Proteômica/métodos , Células Vero , Proteínas Virais/genética , Fatores de Virulência/genética , Replicação Viral
4.
PLoS Genet ; 16(8): e1008992, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32797092

RESUMO

Bacterial virulence factors facilitate host colonization and set the stage for the evolution of parasitic and mutualistic interactions. The Sodalis-allied clade of bacteria exhibit striking diversity in the range of both plant and animal feeding insects they inhabit, suggesting the appropriation of universal molecular mechanisms that facilitate establishment. Here, we report on the infection of the tsetse fly by free-living Sodalis praecaptivus, a close relative of many Sodalis-allied symbionts. Key genes involved in quorum sensing, including the homoserine lactone synthase (ypeI) and response regulators (yenR and ypeR) are integral for the benign colonization of S. praecaptivus. Mutants lacking ypeI, yenR and ypeR compromised tsetse survival as a consequence of their inability to repress virulence. Genes under quorum sensing, including homologs of the binary insecticidal toxin PirAB and a putative symbiosis-promoting factor CpmAJ, demonstrated negative and positive impacts, respectively, on tsetse survival. Taken together with results obtained from experiments involving weevils, this work shows that quorum sensing virulence suppression plays an integral role in facilitating the establishment of Sodalis-allied symbionts in diverse insect hosts. This knowledge contributes to the understanding of the early evolutionary steps involved in the formation of insect-bacterial symbiosis. Further, despite having no established history of interaction with tsetse, S. praecaptivus can infect reproductive tissues, enabling vertical transmission through adenotrophic viviparity within a single host generation. This creates an option for the use of S. praecaptivus in the biocontrol of insect disease vectors via paratransgenesis.


Assuntos
Percepção de Quorum/genética , Moscas Tsé-Tsé/genética , Fatores de Virulência/genética , 4-Butirolactona/análogos & derivados , 4-Butirolactona/biossíntese , 4-Butirolactona/genética , Animais , Enterobacteriaceae/genética , Enterobacteriaceae/patogenicidade , Humanos , Insetos Vetores/genética , Insetos Vetores/microbiologia , Insetos/genética , Simbiose/genética , Moscas Tsé-Tsé/microbiologia
6.
PLoS One ; 15(8): e0237714, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804961

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious public health problem. There is limited information regarding the genetics of MRSA strains among the native Iraqi and incoming Syrian refugee communities. We aimed to characterize the genotypes and different virulence factors of MRSA in strains isolated from these two communities. Frozen MRSA strains (125) isolated from the native Iraqi and Syrian refugee communities were used in this study. PCR (singleplex and multiplex) and agr typing was used for the genotypic analysis of different virulence genes. We tested for the presence of virulence genes including pvl, arcA, tst, lukE/lukD, hla, hlb, eta, etb and agr. Prevalence of arcA MRSA in the Iraqi community (56.58%) was significantly higher (p = 0.008) than that in the Syrian refugee community (32.66%). Prevalence of lukE-lukD was also significantly higher (p = 0.001) in the Iraqi (82.89%) compared to that in the Syrian refugee community (57.14%). Further, prevalence of hla MRSA in the Iraqi community was (93.4%) and in the Syrian refugee community was (71.4%); (p = 0.0008). No significant differences were observed in the prevalence of pvl, tst, eta, etb and hlb. The most dominant agr types in both Iraqi (76.1% and 10.5%) and Syrian refugee (44.9% and 18.37%) communities were I and III. To sum up, no significant differences were observed between the groups for a majority of virulence factors. This is the first investigation of MRSA genotypes and virulence in both these communities. These results could be useful for further studies that assess the genetic relatedness of strains in the region for epidemiological and monitoring purposes, which would be crucial to limiting the spread of MRSA.


Assuntos
Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Refugiados , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Cidades/epidemiologia , Exotoxinas/genética , Exotoxinas/isolamento & purificação , Genes Bacterianos/genética , Técnicas de Genotipagem , Humanos , Iraque/epidemiologia , Meticilina/farmacologia , Meticilina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Prevalência , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Síria , Transativadores/genética , Transativadores/isolamento & purificação , Fatores de Virulência/isolamento & purificação
7.
PLoS Pathog ; 16(8): e1008835, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32785253

RESUMO

Hyaloperonospora arabidopsidis (Hpa) is an oomycete pathogen causing Arabidopsis downy mildew. Effector proteins secreted from the pathogen into the plant play key roles in promoting infection by suppressing plant immunity and manipulating the host to the pathogen's advantage. One class of oomycete effectors share a conserved 'RxLR' motif critical for their translocation into the host cell. Here we characterize the interaction between an RxLR effector, HaRxL21 (RxL21), and the Arabidopsis transcriptional co-repressor Topless (TPL). We establish that RxL21 and TPL interact via an EAR motif at the C-terminus of the effector, mimicking the host plant mechanism for recruiting TPL to sites of transcriptional repression. We show that this motif, and hence interaction with TPL, is necessary for the virulence function of the effector. Furthermore, we provide evidence that RxL21 uses the interaction with TPL, and its close relative TPL-related 1, to repress plant immunity and enhance host susceptibility to both biotrophic and necrotrophic pathogens.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Interações Hospedeiro-Patógeno/imunologia , Oomicetos/fisiologia , Doenças das Plantas/imunologia , Imunidade Vegetal/imunologia , Fatores de Virulência/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/microbiologia , Virulência , Fatores de Virulência/genética
8.
PLoS Pathog ; 16(8): e1008781, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810179

RESUMO

Chagas disease is caused by Trypanosoma cruzi, a protozoan parasite that has a heterogeneous population composed of a pool of strains with distinct characteristics, including variable levels of virulence. In previous work, transcriptome analyses of parasite genes after infection of human foreskin fibroblasts (HFF) with virulent (CL Brener) and non-virulent (CL-14) clones derived from the CL strain, revealed a reduced expression of genes encoding parasite surface proteins in CL-14 compared to CL Brener during the final steps of the intracellular differentiation from amastigotes to trypomastigotes. Here we analyzed changes in the expression of host genes during in vitro infection of HFF cells with the CL Brener and CL-14 strains by analyzing total RNA extracted from cells at 60 and 96 hours post-infection (hpi) with each strain, as well as from uninfected cells. Similar transcriptome profiles were observed at 60 hpi with both strains compared to uninfected samples. However, at 96 hpi, significant differences in the number and expression levels of several genes, particularly those involved with immune response and cytoskeleton organization, were observed. Further analyses confirmed the difference in the chemokine/cytokine signaling involved with the recruitment and activation of immune cells such as neutrophils upon T. cruzi infection. These findings suggest that infection with the virulent CL Brener strain induces a more robust inflammatory response when compared with the non-virulent CL-14 strain. Importantly, the RNA-Seq data also exposed an unexplored role of fibroblasts as sentinel cells that may act by recruiting neutrophils to the initial site of infection. This role for fibroblasts in the regulation of the inflammatory response during infection by T. cruzi was corroborated by measurements of levels of different chemokines/cytokines during in vitro infection and in plasma from Chagas disease patients as well as by neutrophil activation and migration assays.


Assuntos
Doença de Chagas/metabolismo , Fibroblastos , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Ativação de Neutrófilo , Neutrófilos , Trypanosoma cruzi/metabolismo , Doença de Chagas/genética , Doença de Chagas/patologia , Fibroblastos/metabolismo , Fibroblastos/parasitologia , Fibroblastos/patologia , Humanos , Neutrófilos/metabolismo , Neutrófilos/parasitologia , Neutrófilos/patologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/patogenicidade , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
9.
PLoS One ; 15(8): e0236713, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750089

RESUMO

Coagulase-negative staphylococci (CoNS) are the most common isolates from blood culture in neonates resulting in high mortality and morbidity. This study investigated CoNS obtained from blood cultures of neonates for antibiotic resistance and virulence factors, and possible association with inflammatory response (C-reactive protein). A total of 93 CoNS isolates were collected from 76 blood cultures of neonates at the Maternity hospital in Kuwait in a six-month period and investigated for susceptibility to antibiotics, carriage of staphylococcal cassette chromosome mec (SCCmec), and virulence-associated genes. The 93 CoNS isolates consisted of S. epidermidis (76; 81.7%), S. capitis (12; 12.9%), S. hominis (2; 2.1%), S. warneri (2; 2.1%) and S. haemolyticus (1; 1.0%). Eighty-six (92.4%) of the isolates were resistant to cefoxitin (MR-CoNS) while 49 (52.7%) expressed multi-antibiotic resistance. The methicillin-resistant isolates (MR-CoNS) carried SCCmec III, SCCmec IVa and four combinations of SCCmec types including SCCmec types I+IVa (one S. warneri and 25 S. epidermidis isolates), types I+III (one S. epidermidis isolate), types III+IVa (six S. epidermidis isolates) and types I+III+IVa (one S. epidermidis isolate). The most common virulence-related genes were icaC, seb, arc detected in 69.7%, 60.5%, 40.8% of the isolates respectively. Two isolates were positive for tst1. No association between C-reactive protein and antibiotic resistance or virulence factors was established. This study revealed that S. epidermidis carrying different SCCmec genetic elements, was the dominant CoNS species isolated from neonatal blood cultures with 90.3% and 36.6% of the isolates positive for genes for biofilm and ACME production respectively.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Recém-Nascido Prematuro , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Toxinas Bacterianas/genética , Biofilmes , Coagulase/metabolismo , Feminino , Genes Bacterianos , Humanos , Recém-Nascido , Kuweit , Masculino , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Staphylococcus/enzimologia , Staphylococcus/isolamento & purificação , Staphylococcus/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
10.
BMC Infect Dis ; 20(1): 453, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600258

RESUMO

INTRODUCTION: Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the biofilm forming capability, presence of virulence genes and antimicrobial susceptibility pattern of Uropathogenic E. coli isolates in Uganda. METHODS: This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (> 105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers. RESULTS: In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant (MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%). CONCLUSIONS: We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.


Assuntos
Antibacterianos/uso terapêutico , Biofilmes/crescimento & desenvolvimento , Infecções por Escherichia coli/epidemiologia , Infecções Urinárias/epidemiologia , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/patogenicidade , Estudos Transversais , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Uganda/epidemiologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica/efeitos dos fármacos , Escherichia coli Uropatogênica/isolamento & purificação , Virulência/genética , Fatores de Virulência/genética
11.
Rev Chilena Infectol ; 37(1): 37-44, 2020 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-32730398

RESUMO

BACKGROUND: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. AIM: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". METHODS: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. RESULTS: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. CONCLUSION: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Estudos Transversais , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , México/epidemiologia , Testes de Sensibilidade Microbiana , Prevalência , Estudos Prospectivos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética
12.
Nucleic Acids Res ; 48(14): 7681-7689, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32619234

RESUMO

Genome-enabled approaches to molecular epidemiology have become essential to public health agencies and the microbial research community. We developed the algorithm STing to provide turn-key solutions for molecular typing and gene detection directly from next generation sequence data of microbial pathogens. Our implementation of STing uses an innovative k-mer search strategy that eliminates the computational overhead associated with the time-consuming steps of quality control, assembly, and alignment, required by more traditional methods. We compared STing to six of the most widely used programs for genome-based molecular typing and demonstrate its ease of use, accuracy, speed and efficiency. STing shows superior accuracy and performance for standard multilocus sequence typing schemes, along with larger genome-scale typing schemes, and it enables rapid automated detection of antimicrobial resistance and virulence factor genes. STing determines the sequence type of traditional 7-gene MLST with 100% accuracy in less than 10 seconds per isolate. We hope that the adoption of STing will help to democratize microbial genomics and thereby maximize its benefit for public health.


Assuntos
Algoritmos , Sequenciamento de Nucleotídeos em Larga Escala , Tipagem de Sequências Multilocus/métodos , Resistência Microbiana a Medicamentos/genética , Genes Microbianos , Genômica/métodos , Software , Fatores de Virulência/genética
13.
PLoS One ; 15(7): e0222747, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639982

RESUMO

Physiology-based differentiation of SH genes and Hemileia vastatrix races is the principal method employed for the characterization of coffee leaf rust resistance. Based on the gene-for-gene theory, nine major rust resistance genes (SH1-9) have been proposed. However, these genes have not been characterized at the molecular level. Consequently, the lack of molecular data regarding rust resistance genes or candidates is a major bottleneck in coffee breeding. To address this issue, we screened a BAC library with resistance gene analogs (RGAs), identified RGAs, characterized and explored for any SH related candidate genes. Herein, we report the identification and characterization of a gene (gene 11), which shares conserved sequences with other SH genes and displays a characteristic polymorphic allele conferring different resistance phenotypes. Furthermore, comparative analysis of the two RGAs belonging to CC-NBS-LRR revealed more intense diversifying selection in tomato and grape genomes than in coffee. For the first time, the present study has unveiled novel insights into the molecular nature of the SH genes, thereby opening new avenues for coffee rust resistance molecular breeding. The characterized candidate RGA is of particular importance for further biological function analysis in coffee.


Assuntos
Café/genética , Resistência à Doença/genética , Genoma de Planta , Sequência de Aminoácidos , Basidiomycota/fisiologia , Sítios de Ligação , Café/classificação , Biblioteca Gênica , Lycopersicon esculentum/classificação , Lycopersicon esculentum/genética , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polimorfismo Genético , Alinhamento de Sequência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Vitis/classificação , Vitis/genética
14.
Nat Commun ; 11(1): 3571, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678094

RESUMO

Pathogenic bacteria of the genus Bartonella can induce vasoproliferative lesions during infection. The underlying mechanisms are unclear, but involve secretion of an unidentified mitogenic factor. Here, we use functional transposon-mutant screening in Bartonella henselae to identify such factor as a pro-angiogenic autotransporter, called BafA. The passenger domain of BafA induces cell proliferation, tube formation and sprouting of microvessels, and drives angiogenesis in mice. BafA interacts with vascular endothelial growth factor (VEGF) receptor-2 and activates the downstream signaling pathway, suggesting that BafA functions as a VEGF analog. A BafA homolog from a related pathogen, Bartonella quintana, is also functional. Our work unveils the mechanistic basis of vasoproliferative lesions observed in bartonellosis, and we propose BafA as a key pathogenic factor contributing to bacterial spread and host adaptation.


Assuntos
Bartonella/patogenicidade , Neovascularização Patológica/metabolismo , Transdução de Sinais , Sistemas de Secreção Tipo V/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo , Fatores de Virulência/metabolismo , Animais , Bartonella/classificação , Bartonella/genética , Proliferação de Células , Perfilação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/microbiologia , Humanos , Camundongos , Neovascularização Patológica/genética , Neovascularização Patológica/microbiologia , Domínios Proteicos , Sistemas de Secreção Tipo V/química , Sistemas de Secreção Tipo V/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fatores de Virulência/química , Fatores de Virulência/genética
15.
PLoS One ; 15(7): e0235771, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658912

RESUMO

Bacillus cereus commonly causes catheter-related bloodstream infections (BSIs) in hospital settings, and occasionally occurs fatal central nervous system (CNS) complications. B. cereus harboring Ba813, a specific chromosomal marker of Bacillus anthracis, has been found in patients with severe infection and nosocomial BSI. However, the bacteriological profile and clinical feature of Ba813 (+) B. cereus are unclear. Fifty-three patients with B. cereus BSI were examined. Isolates were evaluated for Ba813, B. anthracis-related and food poisoning-related virulence, multilocus sequencing typing, and biofilm formation. Patients' clinical records were reviewed retrospectively. The 53 isolates were comprised of 29 different sequence types in two distinct clades. Seventeen of the 53 (32%) B. cereus isolates including five sequence types possessed Ba813 and were classified into Clade-1/Cereus-III lineage which is most closely related to Anthracis lineage. No B. cereus possessed B. anthracis-related virulence genes. Ba813 (+) strains showed a lower prevalence of enterotoxin genes than Clade-2 strains (n = 4), but no difference from Clade-1. Ba813 (+) strains showed significantly lower biofilm formation than Clade-1/non-Cereus-III (n = 22) and Clade-2 strains, respectively. Compared to Clade-1/non-Cereus-III and Clade-2 B. cereus, Ba813 (+) strains were isolated more frequently from elderly patients, patients with indwelling central venous catheter rather than peripheral venous catheter, and patients who remained in the hospital for longer before BSI onset. No significant differences in disease severity or mortality were observed. Though two of the ten Ba813 (-) strains in Clade-1/Cereus III were isolated from the patients with CNS complication, no significant difference was observed in the bacterial profile and clinical characteristics among Clade-1/Cereus III strains. In conclusion, our report suggested that Ba813-harboring B. cereus strains, genetically closely related to B. anthracis, were abundant among B. cereus strains in the hospital setting, and might cause catheter-related nosocomial BSI. However, it did not affect the clinical outcomes.


Assuntos
Infecções por Bacillaceae/microbiologia , Bacillus anthracis/genética , Bacillus cereus/genética , Infecção Hospitalar/microbiologia , Fatores de Virulência/genética , Adulto , Idoso , Infecções por Bacillaceae/sangue , Infecção Hospitalar/sangue , Feminino , Genes Bacterianos , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Estudos Retrospectivos
16.
PLoS One ; 15(7): e0235873, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32687505

RESUMO

This study evaluates whole-genome sequence of Lactobacillus reuteri PNW1 and identifies its safety genes that may qualify it as a putative probiotic. It further extracted the bacteriocin produced by the strain and tested its effectiveness against pathogenic STEC E. coli O177. The genomic DNA was sequenced on illuminal Miseq instrument and the sequenced data was assessed for quality reads before assembled with SPAdes. The draft assembly was annotated with Prokaryotic Genome Annotation Pipeline (PGAP) and Rapid Annotations using Subsystems Technology (RAST). Further downstream analyses were carried out using appropriate bioinformatic tools. Production of biogenic amines was biochemically confirmed through HPLC analysis. The assembled genome was 2,430,215 bp long in 420 contigs with 39% G+C content. Among all known genes, putatively responsible for the production of toxic biochemicals, only arginine deiminase (EC3.5.3.6) was spotted. Coding sequences (CDS) putative for D-lactate dehydrogenase (EC1.1.1.28), L-lactate dehydrogenase (EC1.1.1.27) and bacteriocin helveticin J were found within the genome together with plethora of other probiotic important genes. The strain harbours only resistant genes putative for Lincosamide (lnuC) and Tetracycline resistant genes (tetW). There was no hit found for virulence factors and probability of the strain being a human pathogen was zero. Two intact prophage regions were detected within the genome of L. reuteri PNW1 and nine CDS were identified for insertion sequence by OASIS which are belong to seven different families. Five putative CDS were identified for the CRISPR, each associated with Cas genes. Maximum zone of inhibition exhibited by the bacteriocin produced L. reuteri PNW1 is 20.0±1.00 mm (crude) and 23.3±1.15 mm (at 0.25 mg/ml) after being partially purified. With the strain predicted as non-human pathogen, coupled with many other identified desired features, L. reuteri PNW1 stands a chance of making good and safe candidates for probiotic, though further in-vivo investigations are still necessary.


Assuntos
Genoma Bacteriano , Lactobacillus reuteri/genética , Probióticos/efeitos adversos , Proteínas de Bactérias/genética , Bacteriocinas/genética , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Escherichia coli/efeitos dos fármacos , Hidrolases/genética , L-Lactato Desidrogenase/genética , Lactobacillus reuteri/patogenicidade , Anotação de Sequência Molecular , Fatores de Virulência/genética
17.
Proc Natl Acad Sci U S A ; 117(29): 17228-17239, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32616573

RESUMO

The ability of Staphylococcus aureus to infect many different tissue sites is enabled, in part, by its transcriptional regulatory network (TRN) that coordinates its gene expression to respond to different environments. We elucidated the organization and activity of this TRN by applying independent component analysis to a compendium of 108 RNA-sequencing expression profiles from two S. aureus clinical strains (TCH1516 and LAC). ICA decomposed the S. aureus transcriptome into 29 independently modulated sets of genes (i-modulons) that revealed: 1) High confidence associations between 21 i-modulons and known regulators; 2) an association between an i-modulon and σS, whose regulatory role was previously undefined; 3) the regulatory organization of 65 virulence factors in the form of three i-modulons associated with AgrR, SaeR, and Vim-3; 4) the roles of three key transcription factors (CodY, Fur, and CcpA) in coordinating the metabolic and regulatory networks; and 5) a low-dimensional representation, involving the function of few transcription factors of changes in gene expression between two laboratory media (RPMI, cation adjust Mueller Hinton broth) and two physiological media (blood and serum). This representation of the TRN covers 842 genes representing 76% of the variance in gene expression that provides a quantitative reconstruction of transcriptional modules in S. aureus, and a platform enabling its full elucidation.


Assuntos
Regulação Bacteriana da Expressão Gênica , Redes Reguladoras de Genes/genética , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Transcriptoma , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Redes e Vias Metabólicas , Proteínas Repressoras/genética , Análise de Sequência de RNA , Fator sigma/genética , Infecções Estafilocócicas , Virulência/genética , Fatores de Virulência/genética
18.
Parasitol Res ; 119(9): 2907-2916, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32686022

RESUMO

The protozoan parasite Toxoplasma gondii secretes a number of dense granule proteins (GRAs) from the dense granule organelle to manipulate the host cell. Two of these effector proteins (GRA17 and GRA23) are involved in the trafficking of molecules between the parasitophorous vacuole (PV) and the host cell cytoplasm. However, their roles in establishing chronic infection remain obscured. In this study, CRISPR-Cas9 was used to delete gra17 or gra23 gene in T. gondii Pru strain (type II). The growth, the virulence, the ability to establish chronic infection, and the immunogenicity of the constructed mutant strains were investigated in Kunming mice. Pru:Δgra17 and Pru:Δgra23 mutants developed PVs with abnormal morphology and exhibited reduced growth rate, compared with the wild-type Pru strain. Deletion of gra17 abrogated acute infection and blocked cyst formation. Although the deletion of gra23 caused slight attenuation of the parasite virulence in mice, it caused a significant reduction in cyst formation. Immunization with Pru:Δgra17 induced high levels of IgG (IgG1 and IgG2a) antibodies and cytokines (interleukin-2 [IL-2], IL-10, IL-12, and interferon gamma [IFN-γ]), which conferred significant protection in mice challenged with virulent type I (RH), ToxoDB#9 (PYS) strains, or less virulent type II (Pru) strain of T. gondii. These findings show that GRA17 and GRA23 play important roles in T. gondii chronic infection and that irreversible deletion of gra17 in T. gondii type II Pru strain can be a viable option for stimulating protective immunity to T. gondii infection.


Assuntos
Antígenos de Protozoários/imunologia , Citocinas/metabolismo , Proteínas de Protozoários/genética , Toxoplasma , Fatores de Virulência/genética , Animais , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Feminino , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Toxoplasma/genética , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/imunologia , Toxoplasma/patogenicidade , Toxoplasmose Animal/parasitologia , Virulência/genética
20.
PLoS Negl Trop Dis ; 14(6): e0008373, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32479541

RESUMO

BACKGROUND: Atypical enteropathogenic Escherichia coli (aEPEC) are one of the most frequent intestinal E. coli pathotypes isolated from diarrheal patients in Brazil. Isolates of aEPEC contain the locus of enterocyte effacement, but lack the genes of the bundle-forming pilus of typical EPEC, and the Shiga toxin of enterohemorrhagic E. coli (EHEC). The objective of this study was to evaluate the phylogeny and the gene content of Brazilian aEPEC genomes compared to a global aEPEC collection. METHODOLOGY: Single nucleotide polymorphism (SNP)-based phylogenomic analysis was used to compare 106 sequenced Brazilian aEPEC with 221 aEPEC obtained from other geographic origins. Additionally, Large-Scale BLAST Score Ratio was used to determine the shared versus unique gene content of the aEPEC studied. PRINCIPAL FINDINGS: Phylogenomic analysis demonstrated the 106 Brazilian aEPEC were present in phylogroups B1 (47.2%, 50/106), B2 (23.6%, 25/106), A (22.6%, 24/106), and E (6.6%, 7/106). Identification of EPEC and EHEC phylogenomic lineages demonstrated that 42.5% (45/106) of the Brazilian aEPEC were in four of the previously defined lineages: EPEC10 (17.9%, 19/106), EPEC9 (10.4%, 11/106), EHEC2 (7.5%, 8/106) and EPEC7 (6.6%, 7/106). Interestingly, an additional 28.3% (30/106) of the Brazilian aEPEC were identified in five novel lineages: EPEC11 (14.2%, 15/106), EPEC12 (4.7%, 5/106), EPEC13 (1.9%, 2/106), EPEC14 (5.7%, 6/106) and EPEC15 (1.9%, 2/106). We identified 246 genes that were more frequent among the aEPEC isolates from Brazil compared to the global aEPEC collection, including espG2, espT and espC (P<0.001). Moreover, the nleF gene was more frequently identified among Brazilian aEPEC isolates obtained from diarrheagenic patients when compared to healthy subjects (69.7% vs 41.2%, P<0.05). CONCLUSION: The current study demonstrates significant genomic diversity among aEPEC from Brazil, with the identification of Brazilian aEPEC isolates to five novel EPEC lineages. The greater prevalence of some virulence genes among Brazilian aEPEC genomes could be important to the specific virulence strategies used by aEPEC in Brazil to cause diarrheal disease.


Assuntos
Hibridização Genômica Comparativa/métodos , Escherichia coli Enteropatogênica/classificação , Escherichia coli Enteropatogênica/genética , Genoma Bacteriano , Filogenia , Fatores de Virulência/genética , Brasil , Infecções por Escherichia coli , Proteínas de Escherichia coli/genética , Humanos , Tipagem de Sequências Multilocus , Sorotipagem , Virulência
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