Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Clin Infect Dis ; 61(7): 1107-15, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26084844

RESUMO

BACKGROUND: Necrotizing enterocolitis (NEC) is the most common and serious gastrointestinal disorder among preterm neonates. We aimed to assess a specific gut microbiota profile associated with NEC. METHODS: Stool samples and clinical data were collected from 4 geographically independent neonatal intensive care units, over a 48-month period. Thirty stool samples from preterm neonates with NEC (n = 15) and controls (n = 15) were analyzed by 16S ribosomal RNA pyrosequencing and culture-based methods. The results led us to develop a specific quantitative polymerase chain reaction (qPCR) assay for Clostridium butyricum, and we tested stool samples from preterm neonates with NEC (n = 93) and controls (n = 270). We sequenced the whole genome of 16 C. butyricum strains, analyzed their phylogenetic relatedness, tested their culture supernatants for cytotoxic activity, and searched for secreted toxins. RESULTS: Clostridium butyricum was specifically associated with NEC using molecular and culture-based methods (15/15 vs 2/15; P < .0001) or qPCR (odds ratio, 45.4 [95% confidence interval, 26.2-78.6]; P < .0001). Culture supernatants of C. butyricum strains from preterm neonates with NEC (n = 14) exhibited significant cytotoxic activity (P = .008), and we identified in all a homologue of the ß-hemolysin toxin gene shared by Brachyspira hyodysenteriae, the etiologic agent of swine dysentery. The corresponding protein was secreted by a NEC-associated C. butyricum strain. CONCLUSIONS: NEC was associated with C. butyricum strains and dysbiosis with an oxidized, acid, and poorly diversified gut microbiota. Our findings highlight the plausible toxigenic mechanism involved in the pathogenesis of NEC.


Assuntos
Clostridium butyricum/genética , Disbiose/complicações , Disbiose/microbiologia , Enterocolite Necrosante/complicações , Enterocolite Necrosante/microbiologia , Sobrevivência Celular , Estudos de Coortes , Disbiose/epidemiologia , Enterocolite Necrosante/epidemiologia , Fezes/microbiologia , França/epidemiologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Células Jurkat
2.
J Med Virol ; 87(8): 1389-96, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25908062

RESUMO

Better understanding of the correlation between high-risk HPV DNA testing, viral load quantitation, and E6/E7 mRNA detection is required. The aim of this study was to assess the relationship between these markers and the severity of cervical lesions. One-hundred and fifty one directed cervical specimens were analysed (normal, cervical intraepithelial neoplasia, and cancer). HPV types 16, 18, 31, 33, and 45 DNA detection and quantititation and E6/E7 mRNA detection were performed. DNA was detected in 87 (57.6%) samples and increased from 0% (normal) to 93.9% (cancer). E6/E7 mRNA was detected in 65 (43%) samples and increased with the severity of the lesions from 0% (normal) to 78.8% (26/33) (cancers) (P < 0.001). HPV DNA and E6/E7 mRNA detection were compared in the 141 samples harbouring HPV16, 18, 31, 33, or 45 infection: 45.4% (64/141) of specimens were DNA-/mRNA-, 46% (65/141) were DNA + /mRNA+ and 8.5% (12/141) were DNA + /mRNA-. The proportion of DNA + /mRNA+ specimens increased with the severity of the lesions (P < 0.001). All normal cervix specimens were DNA-/mRNA-. Among grade 2 cervical intraepithelial neoplasia, prevalence of DNA was higher than that of mRNA: 41.6% (5/12) versus 25% (3/12), whereas it was 79.3% (46/58) versus 62% (36/58) among grade 3 cervical intraepithelial neoplasia. Full concordance was observed in cancers as all the 26 DNA+ specimens were mRNA +. Median overall HPV load was higher in DNA + /mRNA+ than in DNA + /mRNA- specimens (1.41 × 10(6) vs. 9.1 × 10(2) copies per million cells, P < 0.001). Both E6/E7 mRNA detection and concordant DNA + /mRNA+ detection increases with the severity of the lesions and with the HPV DNA load.


Assuntos
Proteínas Oncogênicas Virais/biossíntese , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , RNA Mensageiro/análise , Índice de Gravidade de Doença , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , Estudos Transversais , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , RNA Mensageiro/genética , RNA Viral/análise , RNA Viral/genética , Neoplasias do Colo do Útero/virologia
3.
PLoS Negl Trop Dis ; 7(1): e2042, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23390560

RESUMO

BACKGROUND: In Africa, relapsing fever borreliae are neglected arthropod-borne pathogens causing mild to deadly septicemia and miscarriage. The closely related Borrelia crocidurae, Borrelia duttonii, Borrelia recurrentis and Borrelia hispanica are rarely diagnosed at the species level, hampering refined epidemiological and clinical knowledge of the relapsing fevers. It would be hugely beneficial to have simultaneous detection and identification of Borrelia to species level directly from clinical samples. METHODOLOGY/PRINCIPAL FINDINGS: We designed a multiplex real-time PCR protocol targeting the 16S rRNA gene detecting all four Borrelia, the glpQ gene specifically detecting B. crocidurae, the recN gene specifically detecting B. duttonii/B. recurrentis and the recC gene specifically detecting B. hispanica. Compared to combined 16S rRNA gene and flaB gene sequencing as the gold standard, multiplex real-time PCR analyses of 171 Borrelia-positive and 101 Borrelia-negative control blood specimens yielded 100% sensitivity and specificity for B. duttonii/B. recurrentis and B. hispanica and 99% sensitivity and specificity for B. crocidurae. CONCLUSIONS/SIGNIFICANCE: The multiplex real-time PCR developed in this study is a rapid technique for both molecular detection and speciation of relapsing fever borreliae from blood in Africa. It could be incorporated in point-of-care laboratory to confirm diagnosis and provide evidence of the burden of infection attributed to different species of known or potentially novel relapsing fever borreliae.


Assuntos
Borrelia/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Febre Recorrente/diagnóstico , África , Técnicas Bacteriológicas/métodos , Sangue/microbiologia , Borrelia/classificação , Borrelia/genética , Humanos , Sensibilidade e Especificidade , Fatores de Tempo
4.
Mol Biol Evol ; 30(2): 369-83, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23071100

RESUMO

Here, we sequenced the 5,419,609 bp circular genome of an Enterobacter aerogenes clinical isolate that killed a patient and was resistant to almost all current antibiotics (except gentamicin) commonly used to treat Enterobacterial infections, including colistin. Genomic and phylogenetic analyses explain the discrepancies of this bacterium and show that its core genome originates from another genus, Klebsiella. Atypical characteristics of this bacterium (i.e., motility, presence of ornithine decarboxylase, and lack of urease activity) are attributed to genomic mosaicism, by acquisition of additional genes, such as the complete 60,582 bp flagellar assembly operon acquired "en bloc" from the genus Serratia. The genealogic tree of the 162,202 bp multidrug-resistant conjugative plasmid shows that it is a chimera of transposons and integrative conjugative elements from various bacterial origins, resembling a rhizome. Moreover, we demonstrate biologically that a G53S mutation in the pmrA gene results in colistin resistance. E. aerogenes has a large RNA population comprising 8 rRNA operons and 87 cognate tRNAs that have the ability to translate transferred genes that use different codons, as exemplified by the significantly different codon usage between genes from the core genome and the "mobilome." On the basis of our findings, the evolution of this bacterium to become a "killer bug" with new genomic repertoires was from three criteria that are "opportunity, power, and usage" to indicate a sympatric lifestyle: "opportunity" to meet other bacteria and exchange foreign sequences since this bacteria was similar to sympatric bacteria; "power" to integrate these foreign sequences such as the acquisition of several mobile genetic elements (plasmids, integrative conjugative element, prophages, transposons, flagellar assembly system, etc.) found in his genome; and "usage" to have the ability to translate these sequences including those from rare codons to serve as a translator of foreign languages.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Enterobacter aerogenes/genética , Genoma Bacteriano , Rizoma/genética , Composição de Bases , Códon , Enterobacter aerogenes/classificação , Enterobacter aerogenes/efeitos dos fármacos , Perfilação da Expressão Gênica , Ordem dos Genes , Genes Essenciais , Humanos , Klebsiella/classificação , Klebsiella/genética , Dados de Sequência Molecular , Fenótipo , Plasmídeos/genética , Proteoma , RNA Ribossômico 16S
5.
APMIS ; 120(10): 773-7, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22958284

RESUMO

A 16S rDNA sequence-based investigation of methanogenic Archaea in the human stools found Methanobrevibacter smithii in 99.2% and Methanosphaera stadtmanae in 32.6%. The recently described Methanomassiliicoccus luminyensis found by others to be representative of a new order of methanogenic Archaea was found in 4% of stool specimens. The prevalence of M. luminyensis significantly increased with age, contrary to M. smithii and M. stadtmanae.


Assuntos
Trato Gastrointestinal/microbiologia , Metagenoma , Methanobacteriaceae/genética , Methanobrevibacter/genética , RNA Ribossômico 16S/genética , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Primers do DNA , DNA Arqueal/análise , Fezes/microbiologia , Humanos , Lactente , Recém-Nascido , Methanobacteriaceae/classificação , Methanobacteriaceae/isolamento & purificação , Methanobrevibacter/classificação , Methanobrevibacter/isolamento & purificação , Pessoa de Meia-Idade , Filogenia , Reação em Cadeia da Polimerase em Tempo Real
6.
J Med Virol ; 84(6): 964-72, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22499020

RESUMO

Management of patients infected with high-risk HPV (hrHPV) despite normal colposcopy following abnormal cytology remains a clinical challenge. The aim of this study was to evaluate if, in that specific population, initial HPV 16 and HPV 18 viral loads are predictive of infection clearance over a 24-month follow-up. A total of 67 women infected with hrHPV having normal colposcopy following equivocal or low-grade cytological abnormalities were recruited and attended regular follow-ups based on repeat colposcopies and HPV testing. HPV16 and HPV18 infection were diagnosed in 36 (53.7%) and 7 (10.4%) cases, respectively. Viral load was quantified using the quantitative duplex real-time PCR method. Although this was not observed for HPV 18, initial HPV 16 viral load was highly associated to HPV 16 infection outcome (receiver operating characteristic curve analysis, area under curve: 0.90). Thus, women who had cleared their HPV 16 infection had significantly lower median initial HPV 16 viral load than those with persistent HPV 16 infection: 1.5 × 10(3) copies per million cells (CPMC) versus 3.8 × 10(6) CPMC, respectively (P = 0.006). The best prediction of HPV 16 clearance was obtained with an initial HPV 16 viral load of <7.5 × 10(4) CPMC: 86.7% specificity and 85.7% sensitivity. Finally, six patients were diagnosed with grade 2 or 3 cervical or vaginal intraepithelial neoplasia. Although all had a persistent hrHPV infection, neither HPV 16 nor 18 viral loads were found to be predictive of the risk of cervical or vaginal intraepithelial neoplasia. HPV16 viral load quantitation could represent a clinically useful marker in that very specific population.


Assuntos
Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/isolamento & purificação , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Displasia do Colo do Útero/epidemiologia , Carga Viral , Adulto , Idoso , Colposcopia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/complicações , Prognóstico , Medição de Risco , Sensibilidade e Especificidade , Resultado do Tratamento , Adulto Jovem , Displasia do Colo do Útero/patologia
7.
J Med Virol ; 84(2): 306-13, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22170552

RESUMO

The clinical utility of HPV 16 and 18 viral loads remains debated. The aim of this study was to assess the clinical significance of HPV 16 and 18 viral load and to determine a cut-off for optimal prediction of grade 2 or higher cervical intraepithelial neoplasia among patients referred to colposcopy. A total of 186 cervico-vaginal specimens harboring HPV 16 and/or 18 obtained at the time of colposcopy from patients without previous cervical neoplasia were tested for HPV 16 and 18 detection and quantitation using quantitative duplex real-time PCR method. Grade 2 or higher cervical intraepithelial neoplasia was diagnosed in 87 (46.8%) cases. Only HPV 16 median viral load increased significantly with the lesion grade: 9.1 × 10(4) in normal cervix or grade 1 cervical intraepithelial lesion versus 4.0 × 10(6) copies per million cells in grade 2 or higher cervical intraepithelial lesion (P < 0.001). The highest predictive value for grade 2 or higher cervical intraepithelial lesion was observed with a HPV 16 viral load cut-off of 3.0 × 10(6) copies per million cells (91% specificity, 58.2% sensitivity). Using this cut-off, the highest predictive value of HPV 16 viral load was observed among those referred for previous low-grade abnormal cervical cytology (96.4% specificity, 88% sensitivity). HPV 18 quantitation showed very poor predictive value. Specific attention should be given when performing colposcopic examination of women with an HPV 16 viral load higher than 3.0 × 10(6) copies per million cells, especially among those referred after a low-grade abnormal cytology.


Assuntos
Colposcopia , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/isolamento & purificação , Carga Viral , Adolescente , Adulto , Idoso , DNA Viral/análise , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
8.
BMC Res Notes ; 4: 423, 2011 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-22011383

RESUMO

BACKGROUND: Identification of the Mycobacterium tuberculosis complex organisms to the species level is important for diagnostic, therapeutic and epidemiologic perspectives. Indeed, isolates are routinely identified as belonging to the M. tuberculosis complex without further discrimination in agreement with the high genomic similarity of the M. tuberculosis complex members and the resulting complex available identification tools. FINDINGS: We herein develop a pyrosequencing assay analyzing polymorphisms within glpK, pykA and gyrB genes to identify members of the M. tuberculosis complex at the species level. The assay was evaluated with 22 M. tuberculosis, 21 M. bovis, 3 M. caprae, 3 M. microti, 2 M. bovis BCG, 2 M. pinnipedii, 1 M. canettii and 1 M. africanum type I isolates. The resulted pyrograms were consistent with conventional DNA sequencing data and successfully identified all isolates. Additionally, 127 clinical M. tuberculosis complex isolates were analyzed and were unambiguously identified as M. tuberculosis. CONCLUSION: We proposed a pyrosequencing-based scheme for the rapid identification of M. tuberculosis complex isolates at the species level. The assay is robust, specific, rapid and can be easily introduced in the routine activity.

9.
J Med Virol ; 83(4): 637-43, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21328378

RESUMO

The persistence of high-risk HPV (HR-HPV) infection is necessary for the development of cervical intraepithelial neoplasia. The aim of this study was to evaluate if HR-HPV typing and HPV16, 18, 31, and 33 quantitation are predictive for type-specific infection persistence and/or the development of CIN in women under 30 with normal cervical cytology. Young women (under 30) attending a family planning clinic who were HPV positive with normal cervical cytology were included. HPV genotyping was assessed by MY09/MY11 PCR, sequencing, phylogenetic analysis, and cloning when necessary. HR-HPV viral load was quantified using duplex real-time PCR. Study patients were offered for a second smear and HR-HPV detection and quantitation after 12 months. HR-HPV was identified in 43 (21.9%) of the 199 included women. Of these, 39 patients had a second cervical sample taken within a mean interval of 11.7 months (8.8-18.3 months). The mean HR-HPV 16, 18, 31, and 33 initial viral load was 1.9 × 10(6) copies/million cells. The level of viral load did not reveal any significant association with type-specific HR-HPV persistence or the subsequent development of cervical intraepithelial neoplasia. Only HPV16 infection was significantly more likely to persist (91.7% vs. 33.1%, P=0.001) and to develop CIN (33.3% vs. 3.7%, P=0.025). In women under 30 with normal cytology, HR-HPV viral load is common and is not predictive of HPV persistence or the development of cervical intraepithelial neoplasia. HPV16 positive women are significantly more likely to have persistent infection and to develop cervical intraepithelial neoplasia.


Assuntos
Colo do Útero/fisiologia , Colo do Útero/virologia , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Carga Viral , Adolescente , Adulto , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Genótipo , Humanos , Papillomaviridae/genética , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Prevalência , Análise de Sequência de DNA , Adulto Jovem
10.
J Food Sci ; 76(8): M568-72, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22417598

RESUMO

Probiotic food is manufactured by adding probiotic strains simultaneously with starter cultures in fermentation tanks. Here, we investigate the accuracy and feasibility of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for bacterial identification at the species level in probiotic food and yoghurts. Probiotic food and yoghurts were cultured in Columbia and Lactobacillus specific agar and tested by quantitative real-time PCR (qPCR) for the detection and quantification of Lactobacillus sp. Bacterial identification was performed by MALDI-TOF analysis and by amplification and sequencing of tuf and 16S rDNA genes. We tested 13 probiotic food and yoghurts and we identified by qPCR that they presented 10(6) to 10(7) copies of Lactobacillus spp. DNA/g. All products contained very large numbers of living bacteria varying from 10(6) to 10(9) colony forming units/g. These bacteria were identified as Lactobacillus casei, Lactococcus lactis, Bifidobacterium animalis, Lactobacillus delbrueckii, and Streptococcus thermophilus. MALDI-TOF MS presented 92% specificity compared to the molecular assays. In one product we found L. lactis, instead of Bifidus spp. which was mentioned on the label and for another L. delbrueckii and S. thermophilus instead of Bifidus spp. MALDI-TOF MS allows a rapid and accurate bacterial identification at the species level in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified. Practical Application: MALDI-TOF MS is rapid and specific for the identification of bacteria in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified.


Assuntos
Microbiologia de Alimentos , Probióticos/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Iogurte/microbiologia , Bifidobacterium/classificação , Bifidobacterium/isolamento & purificação , Contagem de Colônia Microbiana , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Fermentação , Alimento Funcional/microbiologia , Lacticaseibacillus casei/classificação , Lacticaseibacillus casei/isolamento & purificação , Lactobacillus delbrueckii/classificação , Lactobacillus delbrueckii/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Streptococcus thermophilus/classificação , Streptococcus thermophilus/isolamento & purificação
11.
J Med Virol ; 82(8): 1431-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20572091

RESUMO

Self-sampling using vaginal swabs could be a valuable alternative to screen for cervical cancer for women who do not attend regular cytological screening. The aim of this study was to determine the prevalence of high and low-risk HPV types and of HPV type 16 and 18 DNA load in self-collected vaginal swabs from 35- to 69-year-old Southern French women of low socioeconomic level or migrant populations who do not attend regular cervical screening. A good concordance (93.1%) was found between cervical brush and vaginal swabs in 29 samples. Self-collected vaginal swabs were examined from 120 women. HPV infection was found in 28 women (23.3%; median age 48 years), 17 (14.1%) of whom harbored high-risk HPV types. HPV type 16 was the high risk type found most frequently, followed by types 53, 31, 18, 58, and 66. The low-risk type detected most frequently was HPV type 6, followed by types 61, 70, and 81. The mean HPV 16 and 18 load was 6.3 log(10) copies/10(6) cells and 2.4 log(10) copies/10(6) cells, respectively. These results suggest that vaginal self-swabs can be a reliable tool for cervical cancer screening in non-attending and inadequately screened elderly women.


Assuntos
Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/isolamento & purificação , Programas de Rastreamento/métodos , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Autoadministração , Vagina/virologia , Adulto , Idoso , Feminino , França/epidemiologia , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/virologia , Prevalência , Carga Viral
12.
BMC Res Notes ; 2: 239, 2009 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-19951445

RESUMO

BACKGROUND: The worldwide expanding Mycobacterium tuberculosis W-Beijing family is associated with treatment failure and relapse. Its identification currently relies on spoligotyping and conventional sequencing. We developed pyrosequencing as an alternative method for its identification. FINDINGS: Pyrosequencing found a G/A substitution in the Rv0927c-pstS3 intergenic spacer and a RD105 deletion, identifying 8/104 M. tuberculosis isolates as W-Beijing isolates. In addition, pyrosequencing found a previously unreported TGC deletion in the Rv0927c gene of W-Beijing isolates. Total concordance was found between the pyrosequencing data and conventional sequencing, as well as reference molecular identification. Multispacer Sequence Typing assigned the W-Beijing isolates to the Asian lineage and the 96 non-W-Beijing isolates to the Euro-American lineage (P < 10-5). The W-Beijing isolates were all susceptible to streptomycin, rifampin, isoniazid, ethambutol, and pyrazinamide; no resistance-associated mutations were detected in these eight W-Beijing isolates. There were no statistically significant differences in the antibiotic susceptibility of W-Beijing and non-W-Beijing isolates (p = 0.2, X2 test). Pyrosequencing correctly identified M. tuberculosis organisms in 26/26 sputum specimens exhibiting acid-fast bacilli. Pyrosequencing results were obtained within four hours, incurring an estimated cost of 1.86 euro/test. CONCLUSION: Pyrosequencing of the Rv0927c gene and adjacent intergenic spacer is an efficient, low-cost technique for the rapid identification of W-Beijing isolates.

13.
PLoS One ; 4(9): e7063, 2009 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-19759898

RESUMO

BACKGROUND: The low and variable prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae DNA in human stool contrasts with the paramount role of these methanogenic Archaea in digestion processes. We hypothesized that this contrast is a consequence of the inefficiencies of current protocols for archaeon DNA extraction. We developed a new protocol for the extraction and PCR-based detection of M. smithii and M. stadtmanae DNA in human stool. METHODOLOGY/PRINCIPAL FINDINGS: Stool specimens collected from 700 individuals were filtered, mechanically lysed twice, and incubated overnight with proteinase K prior to DNA extraction using a commercial DNA extraction kit. Total DNA was used as a template for quantitative real-time PCR targeting M. smithii and M. stadtmanae 16S rRNA and rpoB genes. Amplification of 16S rRNA and rpoB yielded positive detection of M. smithii in 95.7% and M. stadtmanae in 29.4% of specimens. Sequencing of 16S rRNA gene PCR products from 30 randomly selected specimens (15 for M. smithii and 15 for M. stadtmanae) yielded a sequence similarity of 99-100% using the reference M. smithii ATCC 35061 and M. stadtmanae DSM 3091 sequences. CONCLUSIONS/SIGNIFICANCE: In contrast to previous reports, these data indicate a high prevalence of the methanogens M. smithii and M. stadtmanae in the human gut, with the former being an almost ubiquitous inhabitant of the intestinal microbiome.


Assuntos
DNA Arqueal/análise , Regulação Bacteriana da Expressão Gênica , Infecções/epidemiologia , Infecções/microbiologia , Intestinos/microbiologia , Methanobacteriaceae/metabolismo , Methanobrevibacter/metabolismo , Técnicas Microbiológicas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Fezes , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/metabolismo
14.
PLoS One ; 4(9): e7125, 2009 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-19774074

RESUMO

BACKGROUND: Studies of the bacterial communities of the gut microbiota have revealed a shift in the ratio of Firmicutes and Bacteroidetes in obese patients. Determining the variations of microbial communities in feces may be beneficial for the identification of specific profiles in patients with abnormal weights. The roles of the archaeon Methanobrevibacter smithii and Lactobacillus species have not been described in these studies. METHODS AND FINDINGS: We developed an efficient and robust real-time PCR tool that includes a plasmid-based internal control and allows for quantification of the bacterial divisions Bacteroidetes, Firmicutes, and Lactobacillus as well as the methanogen M. smithii. We applied this technique to the feces of 20 obese subjects, 9 patients with anorexia nervosa, and 20 normal-weight healthy controls. Our results confirmed a reduction in the Bacteroidetes community in obese patients (p<0.01). We found a significantly higher Lactobacillus species concentration in obese patients than in lean controls (p=0.0197) or anorexic patients (p=0.0332). The M. smithii concentration was much higher in anorexic patients than in the lean population (p=0.0171). CONCLUSIONS: Lactobacillus species are widely used as growth promoters in the farm industry and are now linked to obesity in humans. The study of the bacterial flora in anorexic patients revealed an increase in M. smithii. This increase might represent an adaptive use of nutrients in this population.


Assuntos
Anorexia Nervosa/microbiologia , Intestinos/microbiologia , Lactobacillus/metabolismo , Methanobrevibacter/metabolismo , Obesidade/microbiologia , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , Fezes , Humanos , Pessoa de Meia-Idade , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
J Med Virol ; 81(10): 1750-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19697419

RESUMO

The present study aimed to assess whether hepatitis E virus (HEV) is present in domestic pigs in Southern France, and to determine the relationship between HEV sequences detected from pigs and from humans. Two hundred fifteen sera, 207 stools, and 107 bile samples were collected from 3- or 6-month-old pigs from different regions of Southern France. Pig IgG anti-HEV antibodies testing was performed using a commercial ELISA kit with minor modifications. Pig HEV RNA was tested by real-time PCR and sequencing assays using "in-house" protocols. Forty percent of pigs were HEV-seropositive. Sixty-five percent of 3-month-old pigs and none of 6-month-old pigs were HEV RNA-positive. HEV RNA was significantly more frequently detected from stools than from sera (65% vs. 22%; P < 0.001). Phylogenetic analysis showed that pig HEV sequences belonged to genotype 3 and formed two clusters of genotype 3f and 3e. Nucleotide homology between pig HEV sequences of each cluster was high (>97%), and clusters were correlated with the geographical origin of pigs and with their repartition into pens and buildings in the pig farm. Based on analysis of 331 nucleotides, pig HEV sequences were close genetically to HEV sequences found from humans or pigs in Europe, and one showed complete nucleotide identity with an HEV sequence obtained in France from a human. The present data indicate that 3-month-old pigs from Southern France might represent a potential source of HEV transmission to humans, and stress the potential of HEV to cause epizootic infections in population of farm pigs.


Assuntos
Vírus da Hepatite E/isolamento & purificação , Hepatite E/veterinária , Doenças dos Suínos/virologia , Animais , Bile/virologia , Análise por Conglomerados , Ensaio de Imunoadsorção Enzimática/métodos , Fezes/virologia , França , Genótipo , Geografia , Anticorpos Anti-Hepatite/sangue , Hepatite E/transmissão , Humanos , Imunoglobulina G/sangue , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência , Soro/virologia , Suínos
16.
Microbiology (Reading) ; 155(Pt 7): 2384-2389, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19389783

RESUMO

The laboratory diagnosis of pulmonary tuberculosis mainly relies on the detection of Mycobacterium tuberculosis complex (MTC) organisms in the sputum. In patients who do not give sputum, alternative respiratory tract specimens can be obtained only by invasive procedures. Based on the known survival of MTC organisms in the gastric fluid, we hypothesized that swallowed MTC organisms would be detectable in stool samples. We compared the presence of MTC organisms in respiratory tract specimens and stool specimens collected in parallel from the same patients. MTC was detected in cultures grown on egg-based medium after appropriate decontamination, by microscopic examination after Ziehl-Neelsen staining and by real-time PCR detection of IS6110 using internal controls. A case of pulmonary tuberculosis was defined by the presence of (i) clinical and radiological signs and symptoms suggestive of pulmonary tuberculosis, and (ii) culture of MTC organisms from at least one respiratory tract specimen or (iii) the presence of acid-fast bacilli in the sputum that were subsequently identified as MTC organisms by real-time PCR. The observation of 134 patients suspected to be suffering pulmonary tuberculosis led to the identification of 24 cases and 110 non-infected control patients. Cases and controls did not significantly differ with respect to sex but cases were significantly younger than controls. The sensitivity/specificity was 37.5%/100% for the microscopic examination of stools, 54.2%/100% for culturing and 100%/97.3% for real-time PCR. The positive predicted value was 100%, 100% and 88.9%, respectively, and the negative predicted value was 88%, 90.9% and 100%, respectively. In four patients, a stool specimen initially yielded the correct diagnosis of pulmonary tuberculosis before evaluation of the respiratory tract specimen confirmed the diagnosis. These data indicate that stools could be used in conjunction with sputum testing or as an alternative specimen upon which to base the diagnosis of pulmonary tuberculosis by molecular identification of acid-fast bacilli and culture. This non-invasive alternative procedure is of particular interest for patients who cannot expectorate.


Assuntos
Fezes/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Pulmonar/diagnóstico , Adulto , Sequência de Bases , DNA Bacteriano/análise , DNA Bacteriano/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Análise de Sequência de DNA , Escarro/microbiologia , Tuberculose Pulmonar/microbiologia
17.
J Clin Virol ; 44(4): 314-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19269245

RESUMO

BACKGROUND: Despite HAART, the prevalence and incidence of anal cancer in HIV-infected individuals have increased. Recently, the relationship between the severity of cervical lesions and oncogenic HPV load was demonstrated; however, few studies have assessed the level and the significance of oncogenic HPV load in patients at risk for anal neoplasia. OBJECTIVES: To assess HPV genotypes and HPV 16/18 DNA load in HIV-1 infected patients at risk for anal neoplasia. STUDY DESIGN: Cross-sectional pilot study from male and female HIV-1 infected individuals at risk for anal neoplasia in an outpatient HIV Clinical Unit of Marseilles university Hospitals. RESULTS: Anal HPV was found in 79% of the patients whereas high-risk (HR) HPV types and infection with multiple HPV types were found in 83% and 61% of the patients, respectively. Using a sensitive real-time PCR, median HPV 16 and 18 DNA load were 5 x 10(6) copies/10(6) cells and 3.2 x 10(5) copies/10(6) cells, respectively. Notably, there were no significant differences in the HPV 16/18 viral loads with respect to the anoscopic results. CONCLUSIONS: Longitudinal studies are needed to evaluate the link between high anal HPV DNA load and progression to anal squamous intraepithelial lesions and anal cancer.


Assuntos
Canal Anal/virologia , DNA Viral/isolamento & purificação , Infecções por HIV/complicações , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Adulto , Estudos Transversais , Feminino , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/virologia , Prevalência
18.
Clin Infect Dis ; 47(1): 33-43, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18513147

RESUMO

BACKGROUND: Bacterial vaginosis (BV) is a poorly detected public health problem that is associated with preterm delivery and for which no reliable diagnostic tool exists. METHODS: Molecular analysis of 231 vaginal samples, classified by Gram stain-based Nugent score, was used to propose molecular criteria for BV; these criteria were prospectively applied to 56 new samples. A quantitative molecular tool targeting 8 BV-related microorganisms and a human gene was developed using a specific real-time polymerase chain reaction assay and serial dilutions of a plasmid suspension. The targeted microorganisms were Gardnerella vaginalis, Lactobacillus species, Mobiluncus curtisii, Mobiluncus mulieris, and Candida albicans (which can be identified by Gram staining), as well as Atopobium vaginae, Mycoplasma hominis, and Ureaplasma urealyticum (which cannot be detected by Gram staining). RESULTS: With use of the Nugent score, 167 samples were classified as normal, 20 were classified as BV, and 44 were classified as intermediate. Except for U. urealyticum, M. mulieris, and Lactobacillus species, DNA of the tested bacteria was detected more frequently in samples demonstrating BV, but the predictive value of such detection was low. The molecular quantification of A. vaginae (DNA level, > or = 10(8) copies/mL) and G. vaginalis (DNA level, > or = 10(9) copies/mL) had the highest predictive value for the diagnosis of BV, with excellent sensitivity (95%), specificity (99%), and positive (95%) and negative (99%) predictive values; 25 (57%) of the samples demonstrating intermediate flora had a BV profile. When applied prospectively, our molecular criteria had total positive and negative predictive values of 96% and 99%, respectively. CONCLUSIONS: We report a highly reproducible, quantitative tool to objectively analyze vaginal flora that uses cutoff values for the concentrations of A. vaginae and G. vaginalis to establish the molecular diagnosis of BV.


Assuntos
Actinobacteria/isolamento & purificação , Contagem de Colônia Microbiana/métodos , Gardnerella vaginalis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Vaginose Bacteriana/diagnóstico , Actinobacteria/genética , Candida albicans/genética , Candida albicans/isolamento & purificação , Primers do DNA/genética , Feminino , Gardnerella vaginalis/genética , Humanos , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Mobiluncus/genética , Mobiluncus/isolamento & purificação , Mycoplasma hominis/genética , Mycoplasma hominis/isolamento & purificação , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Ureaplasma urealyticum/genética , Ureaplasma urealyticum/isolamento & purificação
19.
Pediatr Infect Dis J ; 27(3): 278-80, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18277921

RESUMO

We report the first case of mother-to-child transmission of human immunodeficiency virus type 1 strains harboring multiple mutations including the Q151M multinucleoside reverse transcriptase inhibitor resistance mutation. Sustained virologic success was obtained in the infant with postnatal antiretroviral therapy optimized according to genotypic drug resistance testing and therapeutic drug monitoring.


Assuntos
Farmacorresistência Viral/genética , Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV-1/genética , Transmissão Vertical de Doenças Infecciosas , Adulto , Substituição de Aminoácidos/genética , Antirretrovirais/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , HIV-1/isolamento & purificação , Humanos , Recém-Nascido , Gravidez
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...