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1.
APMIS ; 128(2): 150-161, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32352605

RESUMO

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.


Assuntos
Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/imunologia , Fatores de Virulência/imunologia , Virulência/imunologia , Carcinogênese/imunologia , Humanos , Prognóstico , Neoplasias Gástricas/microbiologia
2.
J Appl Oral Sci ; 28: e20190578, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348446

RESUMO

Objective This study sought to analyze the gene expression of Candida albicans in sound root surface and root caries lesions, exploring its role in root caries pathogenesis. Methodology The differential gene expression of C. albicans and the specific genes related to cariogenic traits were studied in association with samples of biofilm collected from exposed sound root surface (SRS, n=10) and from biofilm and carious dentin of active root carious lesions (RC, n=9). The total microbial RNA was extracted, and the cDNA libraries were prepared and sequenced on the Illumina Hi-Seq2500. Unique reads were mapped to 163 oral microbial reference genomes including two chromosomes of C. albicans SC5314 (14,217 genes). The putative presence of C. albicans was estimated (sum of reads/total number of genes≥1) in each sample. Count data were normalized (using the DESeq method package) to analyze differential gene expression (using the DESeq2R package) applying the Benjamini-Hochberg correction (FDR<0.05). Results Two genes (CaO19.610, FDR=0.009; CaO19.2506, FDR=0.018) were up-regulated on SRS, and their functions are related to biofilm formation. Seven genes ( UTP20 , FDR=0.018; ITR1 , FDR=0.036; DHN6 , FDR=0.046; CaO19.7197 , FDR=0.046; CaO19.7838 , FDR=0.046; STT4 , FDR=0.046; GUT1 , FDR=0.046) were up-regulated on RC and their functions are related to metabolic activity, sugar transport, stress tolerance, invasion and pH regulation. The use of alternative carbon sources, including lactate, and the ability to form hypha may be a unique trait of C. albicans influencing biofilm virulence. Conclusions C. albicans is metabolically active in SRS and RC biofilm, with different roles in health and disease.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/genética , RNA Fúngico/genética , Cárie Radicular/microbiologia , Candida albicans/crescimento & desenvolvimento , Candida albicans/isolamento & purificação , Expressão Gênica , Regulação Fúngica da Expressão Gênica , Humanos , Morfogênese , RNA-Seq/métodos , Valores de Referência , Raiz Dentária/microbiologia , Regulação para Cima , Fatores de Virulência
3.
Ann Clin Microbiol Antimicrob ; 19(1): 10, 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32220258

RESUMO

BACKGROUND: Staphylococcus aureus is a primary pathogen of orthopedic infections. By mediating antimicrobial resistance, S. aureus biofilm plays an important role in the recalcitrance of orthopedic infections, especially for the intractable osteomyelitis (OM). This study investigated the relationship between biofilm production and various genetic or phenotypic characteristics among orthopedic S. aureus strains. METHODS: A total of 137 orthopedic S. aureus isolates were enrolled and divided into OM and non-OM groups. Biofilm production was evaluated using the crystal violet assay. Genetic and phenotypic characteristics including MRSA identification, MLST and spa typing, carriage of virulence genes, drug resistance, and patients' inflammatory responses indicators were characterized. The relationship between biofilm production and above-mentioned features was respectively analyzed among all isolates and compared between OM and non-OM isolates. RESULTS: Biofilm production presented no significant difference between OM (including 9 MRSA isolates) and non-OM (including 21 MRSA isolates) strains. We found that ST88, t377 and ST630-MSSA-t377 strains produced very strong biofilms, while MLST types of ST15, ST25, ST398, ST5, ST59 and spa types of t002, t2325, t437 tended to produce weaker biofilms. Strains with the following profiles produced stronger biofilms: fib(+)-hlgv(+)-lukED(+)-sei(-)-sem(-)-seo(-) for all isolates, sei(-)-sem(-)-seo(-) for OM isolates, and cna (+)-fib (+)-hlgv (+)-lukED (+)-seb(-)-sed(-) for non-OM isolates. In addition, not any single drug resistance was found to be related to biofilm production. We also observed that, among OM patients, strains with stronger biofilms caused weaker inflammatory responses. CONCLUSION: Some genetic or phenotypic characteristics of orthopedic strains were associated with biofilm production, and this association could be different among OM and non-OM strains. The results are of great significance for better understanding, evaluating and managing different kinds of biofilm-associated orthopedic infections, and provide potential targets for biofilm clearance.


Assuntos
Biofilmes , Doenças Musculoesqueléticas/microbiologia , Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Doenças Musculoesqueléticas/tratamento farmacológico , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Fenótipo , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética
4.
Wiad Lek ; 73(1): 78-82, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32124811

RESUMO

OBJECTIVE: The aim: To study the biological properties of museum and clinical strains of E.coli isolated from patients with peritonitis. PATIENTS AND METHODS: Materials and methods: It was used 94 strains (clinical, museum and reference). The ability of E. coli to adhere was investigated by hemadhezive method to formal human erythrocytes of 0 (I) Rh-positive blood group. The study measured the ability of microorganisms to produce gelatinaze, caseinase, fibrinolysin, hemolysin. To control of the enzyme activity the positive and negative control with reference strains were used. Synchronisation of cultures activity before experiments was achieved by one-time effect of low temperature (+4 С) during 30 minutes. RESULTS: Results: To investigate the pathogenic factors of E. coli we carried out determining of proteolytic, gelatinous, caseinous, fibrinolytic, haemolytic and adhesion properties. CONCLUSION: Conclusions: In our investigation pathogen icspecies of Esherihies are virtually indistinguishable from representatives of normal microflora on its morphological, biochemical and cultural properties. During investigation of serological properties of selected of E. coli strains (n = 94) 65.8% of pathogenic serotypes were revealed. Moreover, all marked E. coli isolated from the abdominal cavity of children and adults, as well as museum strains related to enteropathogenic E. coli (O127: K63, O33: K-) and 1 - to enteroinvazive Escherichia coli (O144: K-).


Assuntos
Infecções por Escherichia coli , Peritonite , Adulto , Criança , Escherichia coli , Humanos , Fatores de Virulência
5.
BMC Infect Dis ; 20(1): 223, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171281

RESUMO

BACKGROUND: Streptococcus suis is a zoonotic pathogen that causes serious systemic infections in pigs and occupation-related infections in humans who contact with pigs or pork products. In China, it has caused two outbreaks of human infection and surveillance for S.suis has been ongoing since last time. CASE PRESENTATION: Two cases of meningitis and sepsis caused by S. suis were reported in this study. Both patients work in relation to the pork trade, a risk factor for S. suis infection. The outcome was favorable after a prolonged ceftriaxone therapy but one patient was left with mild hearing loss. Two isolates were identified as sequencing type (ST) 7, S. suis serotype 2 (SS2), which is one the most prevalent and cause two outbreaks in China. Whole-genome sequencing (WGS) revealed that a high degree identity was noted in the genome organizations and sequences between two sporadic ST7 SS2 isolates in this study and representative epidemic virulent isolates. Major differences among them are two sporadic ST7 SS2 isolates lacked a virulence factor called agglutinin receptor and an 89 K pathogenicity island (PAI), which plays important role in the pathogenesis of streptococcal toxic shock syndrome (STSS). A summary about STs of human infection with S. suis in China was completed. The result showed ST1 and ST7 were still the major STs and several novel STs were successfully discovered in different provinces. CONCLUSIONS: Our results enhanced the understanding of the ability to cause life-threatening infections in humans and the distribution and evolution of the S. suis in China.


Assuntos
Epidemias , Doenças Profissionais/microbiologia , Sorogrupo , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/genética , Streptococcus suis/genética , Doenças dos Suínos/epidemiologia , Idoso , Animais , Antibacterianos/uso terapêutico , Ceftriaxona/uso terapêutico , China/epidemiologia , Genoma Bacteriano/genética , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/tratamento farmacológico , Choque Séptico/tratamento farmacológico , Choque Séptico/microbiologia , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/microbiologia , Streptococcus suis/isolamento & purificação , Suínos/microbiologia , Doenças dos Suínos/transmissão , Resultado do Tratamento , Fatores de Virulência
6.
PLoS One ; 15(3): e0221837, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32126063

RESUMO

Despite being the subject of intensive research, tuberculosis, caused by Mycobacterium tuberculosis, remains at present the leading cause of death from an infectious agent. Secreted and cell wall proteins interact with the host and play important roles in pathogenicity. These proteins are explored as candidate diagnostic markers, potential drug targets or vaccine antigens, and more recently special attention is being given to the role of their post-translational modifications. With the purpose of contributing to the proteomic and glycoproteomic characterization of this important pathogen, we performed a shotgun analysis of culture filtrate proteins of M. tuberculosis based on a liquid nano-HPLC tandem mass spectrometry and a label-free spectral counting normalization approach for protein quantification. We identified 1314 M. tuberculosis proteins in culture filtrate and found that the most abundant proteins belong to the extracellular region or cell wall compartment, and that the functional categories with higher protein abundance factor were virulence, detoxification and adaptation, and cell wall and cell processes. We could identify a group of proteins consistently detected in previous studies, most of which were highly abundant proteins. In culture filtrate, 140 proteins were predicted to contain one of the three types of bacterial N-terminal signal peptides. Besides, various proteins belonging to the ESX secretion systems, and to the PE and PPE families, secreted by the type VII secretion system using nonclassical secretion signals, were also identified. O-glycosylation was identified in 46 proteins, many of them lipoproteins and cell wall associated proteins. Finally, we provide proteomic evidence for 33 novel O-glycosylated proteins, aiding to the glycoproteomic characterization of relevant antigenic membrane and exported proteins. These findings are expected to collaborate with the research on pathogen derived biomarkers, virulence factors and vaccine candidates, and to provide clues to the understanding of the pathogenesis and survival strategies adopted by M. tuberculosis.


Assuntos
Proteínas de Bactérias/metabolismo , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/patogenicidade , Proteoma , Proteômica/métodos , Antígenos de Bactérias/metabolismo , Sistemas de Secreção Bacterianos/metabolismo , Vacinas Bacterianas , Parede Celular , Cromatografia Líquida , Glicosilação , Interações Hospedeiro-Patógeno , Proteínas de Membrana/metabolismo , Espectrometria de Massas em Tandem , Tuberculose/microbiologia , Virulência , Fatores de Virulência/metabolismo
7.
Arch Virol ; 165(5): 1141-1150, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32222822

RESUMO

Pigs are capable of harbouring influenza A viruses of human and avian origin in their respiratory tracts and thus act as an important intermediary host to generate novel influenza viruses with pandemic potential by genetic reassortment between the two viruses. Here, we show that two distinct H1N2 swine influenza viruses contain avian-like or classical swine-like hemagglutinins with polymerase acidic (PA) and nucleoprotein (NP) genes from 2009 pandemic H1N1 influenza viruses that were found to be circulating in Korean pigs in 2018. Swine H1N2 influenza virus containing an avian-like hemagglutinin gene had enhanced pathogenicity, causing severe interstitial pneumonia in infected pigs and mice. The mortality rate of mice infected with swine H1N2 influenza virus containing an avian-like hemagglutinin gene was higher by 100% when compared to that of mice infected with swine H1N2 influenza virus harbouring classical swine-like hemagglutinin. Further, chemokines attracting inflammatory cells were strongly induced in lung tissues of pigs and mice infected by swine H1N2 influenza virus containing an avian-like hemagglutinin gene. In conclusion, it is necessary for the well-being of humans and pigs to closely monitor swine influenza viruses containing avian-like hemagglutinin with PA and NP genes from 2009 pandemic H1N1 influenza viruses.


Assuntos
Vírus da Influenza A Subtipo H1N2/crescimento & desenvolvimento , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Fatores de Virulência/genética , Animais , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H1N2/isolamento & purificação , Vírus da Influenza A Subtipo H1N2/patogenicidade , Camundongos , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Proteínas de Ligação a RNA/genética , Análise de Sobrevida , Suínos , Doenças dos Suínos/patologia , Proteínas do Core Viral/genética , Virulência
8.
PLoS One ; 15(2): e0228676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32040487

RESUMO

Production of the Panton-Valentine leukocidin (PVL) by Staphylococcus aureus is mediated via the genes lukS-PV and lukF-PV which are carried on bacteriophage ϕSa2. PVL is associated with S. aureus strains that cause serious infections and clones of community-associated methicillin-resistant S. aureus (CA-MRSA) that have additionally disseminated widely. In Western Australia (WA) the original CA-MRSA were PVL negative however, between 2005 and 2008, following the introduction of eight international PVL-positive CA-MRSA, PVL-positive WA CA-MRSA were found. There was concern that PVL bacteriophages from the international clones were transferring into the local clones, therefore a comparative study of PVL-carrying ϕSa2 prophage genomes from historic WA PVL-positive S. aureus and representatives of all PVL-positive CA-MRSA isolated in WA between 2005 and 2008 was performed. The prophages were classified into two genera and three PVL bacteriophage groups and had undergone many recombination events during their evolution. Comparative analysis of mosaic regions of selected bacteriophages using the Alignments of bacteriophage genomes (Alpha) aligner revealed novel recombinations and modules. There was heterogeneity in the chromosomal integration sites, the lysogeny regulation regions, the defence and DNA processing modules, the structural and packaging modules and the lukSF-PV genes. One WA CA-MRSA (WA518751) and one international clone (Korean Clone) have probably acquired PVL-carrying ϕSa2 in WA, however these clones did not disseminate in the community. Genetic heterogeneity made it impossible to trace the source of the PVL prophages in the other WA clones. Against this background of PVL prophage diversity, the sequence of one group, the ϕSa2USA/ϕSa2wa-st93 group, was remarkably stable over at least 20 years and associated with the highly virulent USA300 and ST93-IVa CA-MRSA lineages that have disseminated globally.


Assuntos
Toxinas Bacterianas/genética , Bacteriófagos/genética , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/virologia , Linhagem da Célula , DNA Bacteriano/genética , Genótipo , Geografia , Lisogenia , Staphylococcus aureus Resistente à Meticilina/genética , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Fases de Leitura Aberta , Prófagos/genética , Fatores de Virulência/genética , Austrália Ocidental
9.
Lett Appl Microbiol ; 70(5): 365-371, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32012305

RESUMO

In the present study, a total of 100 catla (Catla catla-major South Asian carp, local name botcha) collected from local fish markets and aquaculture ponds were subjected for isolation and characterization of Arcobacter sp. In all, 21 Arcobacter sp. were isolated, of which 18 (85·7%) were Arcobacter butzleri and three (14%) were A. cryoaerophilus as identified by multiplex PCR. All 18 A. butzleri isolates were positive for mviN, ciaB and tlyA virulence genes, three of A. cryoaerophilus isolates carried mviN gene and none of the isolates were positive for cadF, irgA, cj1349, hecA and hecB genes. All isolates (n = 21) were resistant to penicillin (100%). Meanwhile, 71·43, 23·81, 23·81, 14·29 and 9·52% of the isolates showed resistance towards vancomycin, nalidixic acid, erythromycin, cefixime and kanamycin, respectively. Multidrug resistance was observed in 23·81% of the Arcobacter sp. isolates and none of the isolates were positive for any of the extended spectrum beta-lactamases either by phenotypic or by molecular identification genes (blaOXA , blaSHV , blaTEM , blaCTX-M1 , blaCTX-M2 and blaCTX-M9 groups). The results emphasize the need to implement specific control procedures to reduce the use of antibiotics in aquaculture particularly the ones which are very important in human medicine. SIGNIFICANCE AND IMPACT OF THE STUDY: Arcobacter species are emerging food- and water-borne human pathogens. In this study, Arcobacter butzleri was predominant in fish compared to A. cryoaerohilus and A. skirrowii. Higher incidence of arcobacters in fish market samples suggests cross contamination and unhygienic handling of fish in markets. Virulence genes profile and antibiotics resistance of the Arcobacter sp. isolated in current study indicate pathogenic potential of Arcobacter sp. to humans. Occurrence of multidrug-resistant Arcobacter sp. in fish is a major concern in food safety. To our knowledge, this is the first report of Arcobacter sp. from freshwater fish, catla (Catla catla) in India.


Assuntos
Arcobacter/genética , Arcobacter/patogenicidade , Carpas/microbiologia , Genes Bacterianos , Fatores de Virulência/genética , Animais , Antibacterianos , Farmacorresistência Bacteriana Múltipla , Inocuidade dos Alimentos , Índia , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase Multiplex , Virulência
10.
BMC Infect Dis ; 20(1): 108, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32033541

RESUMO

BACKGROUND: Urinary tract infection (UTI) is a common cause of morbidity worldwide. Uropathogenic Escherichia coli (UPEC) bacteria are the major cause of urinary tract infections. UPEC strains derive from different phylogenetic groups and possess an arsenal of virulence factors that contribute to their ability to overcome different defense mechanisms and cause disease. The objective of this study was to identify phylogroup and virulence genes of UPEC among urinary tract infection patients. METHODS: A cross sectional study was conducted from January 1, 2017 to October 9, 2017. E. coli bacteria were isolated from UTI patients using culture and conventional biochemical tests. Identification of phylogroup and genes that encodes for virulence factors was done using multiplex polymerase chain reaction (PCR). Data was processed and analyzed with SPSS version16.0 and Epi-info version 3.4.1 software. RESULTS: The most common urologic clinical manifestation combinations in this study were dysuria, urine urgency and urgency incontinence. The frequent UPEC virulence gene identified was fimH 164 (82%), followed by aer 109 (54.5%), hly 103 (51.5%), pap 59 (29.5%), cnf 58 (29%), sfa 50 (25%) and afa 24 (12%).There was significant association between pap gene and urine urgency (p-0.016); sfa and dysuria and urine urgency (p-0.019 and p-0.043 respectively); hly and suprapubic pain (p-0.002); aer and suprapubic pain, flank pain and fever (p-0.017, p-0.040, p-0.029 respectively). Majority of E. coli isolates were phylogroup B2 60(30%) followed by D 55(27.5%), B1 48(24%) and A 37(18.5%). There was significant association between E. coli phylogroup B2 and three virulence genes namely afa, pap, and sfa (p-0.014, p-0.002, p-0.004 respectively). CONCLUSION: In this study the most frequent E. coli virulence gene was fimH, followed by aer, hly, pap, cnf, sfa and afa respectively. There was significant association between E. coli virulence genes and clinical symptoms of UTI. The phylogenetic analysis indicates majority of uropathogenic E. coli isolates were phylogroup B2 followed by phylogroup D. Phylogroup B2 carries more virulence genes. Hence, targeting major UPEC phylogroup and virulence genes for potential vaccine candidates is essential for better management of UTI and further research has to be conducted in this area.


Assuntos
Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Genes Bacterianos , Filogenia , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica/patogenicidade , Virulência/genética , Adulto , Estudos Transversais , Etiópia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Escherichia coli Uropatogênica/isolamento & purificação , Fatores de Virulência/genética
11.
Lett Appl Microbiol ; 70(5): 372-379, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32048742

RESUMO

Pseudomonas aeruginosa is a prominent member of emerging waterborne pathogens. The environmental reservoirs of multi-resistant phenotypes and other virulence factors in this bacterium are poorly understood. Our study aimed to determine the virulence properties of P. aeruginosa isolated from Roraima Sur Cave (RSC) waters at Guayana Highlands. Based on the best identification at species level by biochemical tests, 16S rRNA sequencing and phylogenetic inferences, one RSC isolate named LG11 was characterized for virulence properties in comparison with P. aeruginosa reference strains. PCR amplification of alginate, elastase, exoenzyme S, exotoxin A, neuraminidase and Quorum-Sensing genes showed a high virulence potential in LG11. This isolate demonstrated multi-resistance to ceftriaxone, tigecycline and imipenem. Pyocyanin production was greater in LG11 (0·478 µg ml-1 ) than the strain ATCC 10145 (0·316 µg ml-1 ), but the highest pigment concentration (2·140 µg ml-1 ) was displayed by the clinical strain CVCM 937 (P = 0·000175). Pronounced biomass production on granite and glass (P < 0·05) and well-developed biofilms indicated the ability of P. aeruginosa from RSC to colonize surfaces found in human and healthcare environments. These data suggest that waters from pristine ecosystems such as RSC could be reservoirs of this opportunistic bacterium carrying important virulence properties with potential epidemiological implications. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows for the first time the occurrence of virulence genes and multi-resistance to antimicrobials in Pseudomonas aeruginosa isolated from cave waters at Guayana Highlands. These findings, together with the biofilm formation on surfaces found in human and healthcare settings, suggest public health risks and the potential of these virulence properties to be transferred from or to native populations in waters. Our results provide important insights to the current knowledge of P. aeruginosa in the environment, setting the basis for future studies driven to assess reservoirs of multi-resistant bacteria and virulence features unknown in pristine ecosystems.


Assuntos
Cavernas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Fatores de Virulência/genética , Microbiologia da Água , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana/efeitos dos fármacos , Ecossistema , Testes de Sensibilidade Microbiana , Filogenia , Pseudomonas aeruginosa/isolamento & purificação , Piocianina/biossíntese , Percepção de Quorum , RNA Ribossômico 16S/genética , Venezuela , Virulência
12.
PLoS One ; 15(2): e0228959, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084148

RESUMO

Secreted autotransporter toxin (Sat) is a 107-kDa serine protease autotransporter of Enterobacteriaceae (SPATE) presenting cytotoxic activity in renal and bladder cells. Further studies have detected the Sat-encoding gene (sat) in enteroaggregative Escherichia coli (EAEC) and in E. coli strains isolated from neonatal septicemia and meningitis. Here, we investigated the role of Sat as a cytotoxin of EAEC. Sat was purified from a strain of E. coli harboring sat (DEC/Sat+, O126:H2) and used to raise antibodies in rabbit. The presence of Sat was detected by ELISA in the supernatant of 93.7% of EAEC strains harboring sat and in none lacking the gene. The effect of Sat during infection was investigated in polarized Caco-2 cells infected with Sat-producing EAEC (CV323/77, O125ab:H21). This strain induced intense cell detachment, which was inhibited by PMSF or Sat antiserum. Also, sat transcription and Sat production were detected during infection. Here we demonstrate that Sat is internalized in polarized cells leading to F-actin disruption which preceded cell detachment. A comparative study of the toxin action in cell lines corresponding to the infection sites in which bacteria carrying the sat gene have been isolated was performed. Cells originating from the gastrointestinal tract (Caco-2), urinary (LLC-PK1) and endothelium (HUVEC) were incubated with purified Sat. The time required for observation of cell damage differed according to the cell line. HUVEC cells were more sensitive to Sat than cells derived from urinary and intestinal tracts. The intense activity of Sat on the endothelial cells suggests that Sat could also be a virulence factor for the bacteria in the bloodstream. In addition, this is the first work demonstrating that Sat induces cytotoxic effect during EAEC infection in vitro. The cell damage observed during infection indicates that Sat may be another toxin with cytotoxic role in the EAEC pathogenesis.


Assuntos
Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Toxinas Bacterianas/toxicidade , Células CACO-2 , Citotoxinas/metabolismo , Células Endoteliais/metabolismo , Células Epiteliais/metabolismo , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/toxicidade , Humanos , Serina Endopeptidases/metabolismo , Sistemas de Secreção Tipo V/metabolismo , Fatores de Virulência/metabolismo
13.
PLoS One ; 15(2): e0229416, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084241

RESUMO

Acinetobacter baumannii is a highly potent nosocomial pathogen that is associated with increased in-hospital mortality. Here, we investigated the changes in molecular characteristics of carbapenem-resistant A. baumannii (CRAB) isolated from the blood samples of patients admitted to a tertiary hospital in South Korea from January 2009 to July 2015. Whole genome sequencing using the Illumina MiSeq platform and multi-locus sequence typing (MLST) were performed for 98 CRAB clinical isolates. In silico analyses for the prediction of antimicrobial resistance and virulence factor genes were performed. Plasmid sequences, including complete forms, were reconstructed from the sequence reads. Epidemiologic data were collected from the hospital database. MLST using the Oxford scheme revealed 10 sequence types of CRAB, of which ST191 was the dominant type (n = 59). Although blaOXA-23 was shared by most analysed strains, the compositions of antimicrobial resistance determinants differed among sequence types. ST447 and ST451/ST1809 with a few resistance genes were isolated during the later years of the study period. The number of virulence genes increased, while that of ST191 did not change significantly over the investigation period. Intriguingly MLST types, compositions of antimicrobial resistance genes, and virulence genes had no association with clinical outcomes of CRAB bacteraemia. In conclusion, active changes in or accumulations of antimicrobial resistance determinants and virulence genes in CRAB were not observed during the research period. Molecular characteristics of CRAB had no association with clinical outcomes of CRAB bacteraemia.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana/genética , Genômica/métodos , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Infecção Hospitalar/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , República da Coreia/epidemiologia , Fatores de Virulência/genética
14.
J Med Microbiol ; 69(2): 218-227, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32011229

RESUMO

Introduction. Gastric cancer is a health disparity in the Alaska Native people. The incidence of Helicobacter pylori infection, a risk factor for non-cardia gastric adenocarcinoma, is also high. Gastric cancer is partially associated with the virulence of the infecting strain.Aim. To genotype the vacA s, m and i and cag pathogenicity island (cagPAI) genes in H. pylori from Alaskans and investigate associations with gastropathy.Methodology. We enrolled patients with gastritis, peptic ulcer disease (PUD) and intestinal metaplasia (IM) in 1998-2005 and patients with gastric cancer in 2011-2013. Gastric biopsies were collected and cultured and PCR was performed to detect the presence of the right and left ends of the cagPAI, the cagA, cagE, cagT and virD4 genes and to genotype the vacA s, m and i regions.Results. We recruited 263 people; 22 (8 %) had no/mild gastritis, 121 (46 %) had moderate gastritis, 40 (15%) had severe gastritis, 38 (14 %) had PUD, 30 (11 %) had IM and 12 (5 %) had gastric cancer. H. pylori isolates from 150 (57%) people had an intact cagPAI; those were associated with a more severe gastropathy (P≤0.02 for all comparisons). H. pylori isolates from 77 % of people had either the vacA s1/i1/m1 (40 %; 94/234) or s2/i2/m2 (37 %; 86/234) genotype. vacA s1/i1/m1 was associated with a more severe gastropathy (P≤0.03 for all comparisons).Conclusions. In this population with high rates of gastric cancer, we found that just over half of the H. pylori contained an intact cagPAI and 40 % had the vacA s1/i1/m1 genotype. Infection with these strains was associated with a more severe gastropathy.


Assuntos
Proteínas de Bactérias/genética , Ilhas Genômicas , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alaska , Nativos do Alasca/estatística & dados numéricos , Proteínas de Bactérias/metabolismo , Feminino , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/microbiologia , Neoplasias Gástricas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Adulto Jovem
15.
Rev Soc Bras Med Trop ; 53: e20190214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049200

RESUMO

INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.


Assuntos
Antifúngicos/farmacologia , Candida albicans/patogenicidade , Unhas/microbiologia , Onicomicose/microbiologia , Fatores de Virulência , Ácido Aspártico Proteases/biossíntese , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Farmacorresistência Fúngica , Hemólise , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Fosfolipases/biossíntese , Reação em Cadeia da Polimerase
16.
Rev Soc Bras Med Trop ; 53: e20190429, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049204

RESUMO

INTRODUCTION: Nosocomial and community acquired urinary tract infections (UTIs) are one of the most encountered infections in the world. METHODS: This study aimed to determine the antibiotic susceptibility, phylogeny, and virulence genes of 153 Escherichia coli strains isolated from UTIs. Antimicrobial susceptibility of the isolates to different classes of antimicrobials was determined by the VITEK-2 automated system. Presence of virulence genes and phylogenetic groups were investigated by PCR. RESULTS: Regarding susceptibility to antimicrobials, ampicillin resistance was most abundant (67.3%), followed by amoxicillin-clavulanic acid (50.9%); least abundant was resistance to amikacin (1.3%) and nitrofurantoin (1.3%). Multi drug resistance (MDR) was observed in 34.6% of the isolates, and all isolates were found to be susceptible to imipenem, meropenem and fosfomycine. The majority of the isolates belonged to the phylogenetic group B23 (35.9%), followed by A1 (20.9%), D1 (18.9%), D2 (12.4%), A0 (%5.9), B1 (3.9%) and B2 (1.9%). Among E. coli strains examined, 49% had iucD, 32.7% papE-F, 26.1% papC, 15% cnf2, 11.1% sfa, 7.8% cnf1, 1.3% afaE, 1.3% afaD, 1.3% hlyA, 0.7% f17a-A, 0.7% clpG and 0.7% eaeA genes. CONCLUSIONS: Our research demonstrated that virulence factors were distributed among different phylogroup/subgroups, which play a role in UTIs pathogenesis in humans. For this reason, complex and detailed studies are required to determine the relationship between virulence factors and specific E. coli strains that cause UTIs in humans.


Assuntos
Antibacterianos/farmacologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções Urinárias/microbiologia , Fatores de Virulência/genética , Escherichia coli/isolamento & purificação , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S
17.
Nat Commun ; 11(1): 760, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32029733

RESUMO

Inflammasomes are important for host defence against pathogens and homeostasis with commensal microbes. Here, we show non-haemolytic enterotoxin (NHE) from the neglected human foodborne pathogen Bacillus cereus is an activator of the NLRP3 inflammasome and pyroptosis. NHE is a non-redundant toxin to haemolysin BL (HBL) despite having a similar mechanism of action. Via a putative transmembrane region, subunit C of NHE initiates binding to the plasma membrane, leading to the recruitment of subunit B and subunit A, thus forming a tripartite lytic pore that is permissive to efflux of potassium. NHE mediates killing of cells from multiple lineages and hosts, highlighting a versatile functional repertoire in different host species. These data indicate that NHE and HBL operate synergistically to induce inflammation and show that multiple virulence factors from the same pathogen with conserved function and mechanism of action can be exploited for sensing by a single inflammasome.


Assuntos
Bacillus cereus/patogenicidade , Enterotoxinas/toxicidade , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Proteínas de Bactérias/toxicidade , Linhagem Celular , Enterotoxinas/química , Feminino , Proteínas Hemolisinas/toxicidade , Interações entre Hospedeiro e Microrganismos , Especificidade de Hospedeiro , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Piroptose/efeitos dos fármacos , Fatores de Virulência/toxicidade
18.
PLoS Negl Trop Dis ; 14(2): e0008046, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069325

RESUMO

Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains.


Assuntos
Cólera/epidemiologia , Cólera/microbiologia , Epidemias , Saúde Global , Vibrio cholerae/genética , China/epidemiologia , Análise por Conglomerados , DNA Bacteriano/genética , Regulação Bacteriana da Expressão Gênica , Variação Genética , Genômica , Humanos , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
19.
BMC Infect Dis ; 20(1): 128, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32046678

RESUMO

BACKGROUND: Coagulase-negative staphylococci belonging to S. haemolyticus, S. hominis subsp. hominis, S. simulans, and S. warneri are often described as etiological factors of infections. Staphylococci are a phylogenetically coherent group; nevertheless, there are differences among the species which may be important to clinicians. METHODS: We investigated selected virulence factors and antibiotic resistance that were phenotypically demonstrated, the presence and expression of genes encoding the virulence factors, and the type of the SCCmec cassette. RESULTS: The differences between the tested species were revealed. A great number of isolates produced a biofilm and many of them contained single icaADBC operon genes. Clear differences between species in the lipolytic activity spectrum could be related to their ability to cause various types of infections. Our studies also revealed the presence of genes encoding virulence factors homologous to S. aureus in the analysed species such as enterotoxin and pvl genes, which were also expressed in single isolates of S. simulans and S. warneri. S. haemolyticus and S. hominis subsp. hominis isolates were resistant to all clinically important antibiotics including ß-lactams. The identified SCCmec cassettes belonged to IV, V, VII, and IX type but most of the detected cassettes were non-typeable. Among the investigated species, S. hominis subsp. hominis isolates accumulated virulence genes typical for S. aureus in the most efficient way and were widely resistant to antibiotics. CONCLUSIONS: Our results clearly indicated significant differences between the tested species, which might be a result of the horizontal gene transfer (HGT) and can lead to the formation and selection of multi-drug resistant strains as well as strains with new virulence features. Such strains can have a new clinical relevance.


Assuntos
Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Antibacterianos/farmacologia , Bacteriemia/microbiologia , Proteínas de Bactérias/genética , Biofilmes , Coagulase/metabolismo , Farmacorresistência Bacteriana/genética , Enterotoxinas/genética , Regulação Bacteriana da Expressão Gênica , Hospitais , Humanos , Testes de Sensibilidade Microbiana , Staphylococcus/efeitos dos fármacos , Staphylococcus/patogenicidade , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
20.
J Med Microbiol ; 69(3): 457-464, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32100714

RESUMO

Introduction. Helicobacter pylori is associated with gastrointestinal disease, most notably gastric cancer. Cytotoxin-associated antigen A (CagA), an important virulence factor for H. pylori pathogenicity, induces host cells to release inflammatory factors, especially interleukin-8 (IL-8). The mechanism by which C-terminal CagA induces IL-8 production has been studied extensively, but little is known about the role of the N-terminus.Aim. To investigate the effect of CagA303-456aa (a peptide in the N-terminal CagA) on IL-8 production by gastric epithelial cells.Methodology. CagA303-456aa was produced by a prokaryotic expression system and purified by Strep-tag affinity chromatography. An integrin ß1 (ITGB1)-deficient AGS cell line was constructed using the CRISPR/Cas9 technique, and NCTC 11637 cagA and/or cagL knockout mutants were constructed via homologous recombination. The levels of IL-8 production were determined by enzyme-linked immunosorbent assay (ELISA), and p38 and ERK1/2 phosphorylation were examined by Western blot.Results. CagA303-456aa induced IL-8 expression by AGS cells. IL-8 induction by CagA303-456aawas specifically inhibited by ITGB1 deficiency. Notably, CagA303-456aa activated the phosphorylation of both p38 and ERK1/2, and blocking p38 and ERK1/2 activity significantly reduced IL-8 induction by CagA303-456aa. ITGB1 deficiency also inhibited the activation of p38 phosphorylation by CagA303-456aa. Finally, experiments in CagA and/or CagL knockout bacterial lines demonstrated that extracellular CagA might induce IL-8 production by AGS cells.Conclusion. Residues 303-456 of the N-terminal region of CagA induce IL-8 production via a CagA303-456-ITGB1-p38-IL-8 pathway, and ERK1/2 is also involved in the release of IL-8. Extracellular CagA might induce IL-8 production before translocation into AGS cells.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/imunologia , Integrina beta1/metabolismo , Interleucina-8/metabolismo , Peptídeos/metabolismo , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Linhagem Celular Tumoral , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Feminino , Helicobacter pylori/patogenicidade , Humanos , Sistema de Sinalização das MAP Quinases , Peptídeos/genética , Fosforilação , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
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