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1.
J Photochem Photobiol B ; 202: 111699, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31756585

RESUMO

In this work, we propose a novel application of ERIC-PCR technique to study DNA damage after ultraviolet radiation (UV) and peracetic acid (PAA) treatment for water disinfection purpose. The efficacy of both treatments on E. coli suspension was evaluated by two approaches: through monitoring of inactivation by conventional culture technique, and by analyzing DNA damage with ERIC-PCR. All the experiments were carried out in a batch reactor, using three intensities of UV-C radiation (10.5, 4.2 and 2.1 mW/cm2) and different PAA concentrations (4 to 16 ppm). Both treatments produced bacterial inactivation in a dose-response fashion. Based on the results of bacterial count we obtained an index of inactivation (INACI). For each sample, DNA extraction was performed and evaluated by ERIC-PCR. Qualitative modifications were observed in ERIC-PCR band patterns for all the UV-C radiation intensities used, but no changes were detected at any of the PAA concentrations. The banding pattern modifications observed are consequence of the interruption of Taq polymerase enzyme amplification-activity, caused by the presence of alterations on the DNA structure (dimer and hydrates formation). Furthermore, an index was proposed to measure DNA damage (DNADI) regarding the changes in the relative optical density values of the amplification products. A linear correlation was obtained with a high correspondence between the inactivation index (INACI) and the DNA damage index (DNADI), that was expressed as DNADI = 0.05881×INACI. This approach proves that ERIC-PCR is a feasible and valuable tool for detecting and quantifying DNA damage and it may provide a useful strategy for bacterial identification, tracking changes in DNA and providing reliable and reproducible data.


Assuntos
Dano ao DNA , Enterobacteriaceae/genética , Purificação da Água/métodos , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , DNA Bacteriano/química , DNA Bacteriano/metabolismo , Desinfecção/métodos , Ácido Peracético/farmacologia , Reação em Cadeia da Polimerase , Raios Ultravioleta
2.
Rev. argent. microbiol ; 50(4): 359-364, Dec. 2018. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-977257

RESUMO

Helicobacter pylori is a gastric pathogen that is widely recognized as a causative agent of gastric disease. Its eradication is variable, mainly due to increased resistance to clarithromycin. Our objective was: to evaluate (i) if the biopsy specimen used for the rapid urease test is a useful sample to detect resistance to clarithromycin by PCR-RFLP and (ii) the distribution of A2142G and A2143G point mutations in the 23S rRNA gene, in relation to virulence factors in our region. Gastric specimens were collected from adult dyspeptic patients (n = 141) and H. pylori was investigated by the rapid urease test, histopathological analysis and PCR for the hsp60 gene. Clarithromycin resistance was detected by PCR-RFLP in 62 H. pylori (+) paired biopsy specimens submitted to molecular analysis and the rapid urease test. H. pylori virulence factors were analyzed by multiplex PCR using specific primers for the cagA, vacA and babA2 genes. Thirteen out of 62 strains (20.9%) were resistant to clarithromycin: 6/13 (46.2%) harbored the A2143G mutation whereas 7/13 (53.8%) carried the A2142G point mutation. vacA m1s1 was the most frequent genotype among the resistant strains. In conclusion, the biopsy specimens used for the rapid urease test were suitable samples for clarithromycin resistance detection in patients infected with H. pylori, which became especially useful in cases where the number or size of the biopsies is limited. In addition, this is the first report of a molecular analysis for clarithromycin resistance performed directly from gastric biopsies in our region.


Helicobacter pylori es un patógeno ampliamente reconocido como causante de enfermedad gástrica. Su erradicación es variable, principalmente debido al incremento de la resistencia a claritromicina. Nuestros objetivos fueron evaluar la utilidad de la biopsia usada para realizar el test rápido de ureasa en la detección de resistencia a claritromicina por PCR-RFLP y conocer la distribución de las mutaciones puntuales A2142G y A2143G en el gen ARNr 23S, en relación con los factores de virulencia en nuestra región. Se recolectaron muestras gástricas (n=141) provenientes de pacientes adultos dispépticos y se investigó la presencia de H. pylori mediante el test rápido de ureasa, análisis histopatológico y PCR para el gen hsp60. La resistencia a claritromicina se analizó por PCR-RFLP en 62 muestras pareadas de biopsias gástricas H. pylori+ destinadas al análisis molecular y al test rápido de ureasa. Los factores de virulencia de H. pylori fueron analizados mediante PCR multiplex usando oligonucleótidos específicos para los genes cagA, vacA y babA2. Trece de 62 cepas (20,9%) fueron resistentes a claritromicina, 6/13 (46,2%) llevaron la mutación A2143G, mientras que 7/13 (53,8%) presentaron la mutación A2142G. El genotipo vacA s1m1 fue el más frecuente entre las cepas resistentes a claritromicina. En conclusión, las biopsias destinadas al test rápido de ureasa fueron muestras apropiadas para la detección de la resistencia a claritromicina en pacientes infectados con H. pylori. Esto es especialmente útil en aquellos casos en los que el número o el tamaño de las muestras son limitados. Además, este es el primer reporte de estudio de resistencia a claritromicina (mediante técnicas moleculares), directamente de biopsias gástricas en nuestra región.


Assuntos
Humanos , Helicobacter pylori/efeitos dos fármacos , Infecções por Helicobacter/diagnóstico , Claritromicina/farmacologia , Fatores de Tempo , Urease/metabolismo , Polimorfismo de Fragmento de Restrição , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Helicobacter pylori/enzimologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Infecções por Helicobacter/microbiologia , Mutação Puntual , Farmacorresistência Bacteriana , Testes Diagnósticos de Rotina/métodos
3.
Rev Argent Microbiol ; 50(4): 359-364, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29602600

RESUMO

Helicobacter pylori is a gastric pathogen that is widely recognized as a causative agent of gastric disease. Its eradication is variable, mainly due to increased resistance to clarithromycin. Our objective was: to evaluate (i) if the biopsy specimen used for the rapid urease test is a useful sample to detect resistance to clarithromycin by PCR-RFLP and (ii) the distribution of A2142G and A2143G point mutations in the 23S rRNA gene, in relation to virulence factors in our region. Gastric specimens were collected from adult dyspeptic patients (n=141) and H. pylori was investigated by the rapid urease test, histopathological analysis and PCR for the hsp60 gene. Clarithromycin resistance was detected by PCR-RFLP in 62 H. pylori (+) paired biopsy specimens submitted to molecular analysis and the rapid urease test. H. pylori virulence factors were analyzed by multiplex PCR using specific primers for the cagA, vacA and babA2 genes. Thirteen out of 62 strains (20.9%) were resistant to clarithromycin: 6/13 (46.2%) harbored the A2143G mutation whereas 7/13 (53.8%) carried the A2142G point mutation. vacA m1s1 was the most frequent genotype among the resistant strains. In conclusion, the biopsy specimens used for the rapid urease test were suitable samples for clarithromycin resistance detection in patients infected with H. pylori, which became especially useful in cases where the number or size of the biopsies is limited. In addition, this is the first report of a molecular analysis for clarithromycin resistance performed directly from gastric biopsies in our region.


Assuntos
Claritromicina/farmacologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/efeitos dos fármacos , Testes Diagnósticos de Rotina/métodos , Farmacorresistência Bacteriana , Infecções por Helicobacter/microbiologia , Helicobacter pylori/enzimologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Testes de Sensibilidade Microbiana , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Fatores de Tempo , Urease/metabolismo
4.
Biomedica ; 33(1): 122-7, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23715315

RESUMO

INTRODUCTION: Staphylococcal food poisoning is the most frequent type of food poisoning around the world. Staphylococcus aureus enterotoxins cause significant loss of water in the intestinal lumen, followed by vomiting and diarrhea. OBJECTIVE: To report a fast, reliable and inexpensive strategy based on multiplex PCR for the simultaneous identification of S. aureus and detection of five classical S. aureus enterotoxin genes ( sea, seb, sec, sed, see ) in Staphylococcus spp. strains isolated from food poisoning outbreaks. MATERIALS AND METHODS: We analyzed isolates from 12 food poisoning outbreaks occurred in Santa Fe province (Argentina). Isolation and phenotypic characterization were carried out by standard procedures. Genotypic analysis was performed by multiplex PCR, using primers for nuc , sea-see and 16S rRNA genes simultaneously. RESULTS: Of all the strains tested, 58% were found to carry toxigenic genes. Sea and seb toxins were found at the same percentage (29%) while sec, sed and see genes were found in a lower and identical proportion (14%). We did not find more than one different type of S. aureus enterotoxin in the isolates analyzed. CONCLUSIONS: The multiplex PCR strategy designed in this work has enabled us to identify strains of S. aureus and detect -at the same time- their enterotoxigenic ability. At present, our efforts are devoted to the detection of genes encoding enterotoxins other than the classical ones, in order to know their impact on staphylococcal food poisoning, as well as to investigate their relevance to our country's public health.


Assuntos
DNA Bacteriano/genética , Surtos de Doenças , Enterotoxinas/genética , Microbiologia de Alimentos/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Intoxicação Alimentar Estafilocócica/microbiologia , Staphylococcus aureus/genética , Animais , Argentina/epidemiologia , Enterotoxinas/análise , Peixes/microbiologia , Genes Bacterianos , Humanos , Carne/microbiologia , Aves Domésticas/microbiologia , Intoxicação Alimentar Estafilocócica/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação
5.
Rev Argent Microbiol ; 45(1): 39-43, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23560787

RESUMO

Our goals were: a) to detect Helicobacter pylori in gastric biopsies of symptomatic adults by PCR, b) to detect the presence of the cagA gene as well as of the allelic variants of the vacA gene, and c) to correlate genotypes with the endoscopic diagnoses. H. pylori was detected in 81 % (39/48) of patients by nested PCR for hsp60. The presence of cagA was detected in 15/22 of samples and vacA s1 - m1 was the most frequent allelic combination (15/22). Gastritis, the most frequent diagnosis, was associated with genotype cagA+ in 10/13 of patients. In this group, 9/13 showed the allelic variant vacA s1- m1. The variant vacA s2 - m2 was detected in 3/3 of gastritis cases by H. pylori with the cagA- genotype. These results are the first reported in our region and provide data of epidemiological interest.


Assuntos
Gastrite/epidemiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Estômago/microbiologia , Adolescente , Adulto , Idoso , Alelos , Antígenos de Bactérias/genética , Argentina/epidemiologia , Proteínas de Bactérias/genética , Biópsia , Chaperonina 60/genética , DNA Bacteriano/genética , Doenças do Esôfago/epidemiologia , Doenças do Esôfago/microbiologia , Feminino , Gastrite/microbiologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/microbiologia , Gastroscopia , Frequência do Gene , Genótipo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/patogenicidade , Humanos , Masculino , Pessoa de Meia-Idade , Estômago/patologia , Virulência/genética , Adulto Jovem
6.
Rev. argent. microbiol ; 45(1): 39-43, mar. 2013.
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1171770

RESUMO

Our goals were: a) to detect Helicobacter pylori in gastric biopsies of symptomatic adults by PCR, b) to detect the presence of the cagA gene as well as of the allelic variants of the vacA gene, and c) to correlate genotypes with the endoscopic diagnoses. H. pylori was detected in 81


(39/48) of patients by nested PCR for hsp60. The presence of cagA was detected in 15/22 of samples and vacA s1 - m1 was the most frequent allelic combination (15/22). Gastritis, the most frequent diagnosis, was associated with genotype cagA+ in 10/13 of patients. In this group, 9/13 showed the allelic variant vacA s1- m1. The variant vacA s2 - m2 was detected in 3/3 of gastritis cases by H. pylori with the cagA- genotype. These results are the first reported in our region and provide data of epidemiological interest.


Assuntos
Estômago/microbiologia , Gastrite/epidemiologia , Helicobacter pylori/genética , Infecções por Helicobacter/epidemiologia , Adolescente , Adulto , Adulto Jovem , Alelos , Antígenos de Bactérias/genética , Argentina/epidemiologia , Biópsia , /genética , DNA Bacteriano/genética , Doenças do Esôfago/epidemiologia , Doenças do Esôfago/microbiologia , Estômago/patologia , Feminino , Frequência do Gene , Gastrite/microbiologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/microbiologia , Gastroscopia , Genótipo , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/patogenicidade , Humanos , Idoso , Infecções por Helicobacter/microbiologia , Masculino , Pessoa de Meia-Idade , Proteínas de Bactérias/genética , Virulência/genética
7.
Rev. Argent. Microbiol. ; 45(1): 39-43, 2013 Jan-Mar.
Artigo em Espanhol | BINACIS | ID: bin-133180

RESUMO

Our goals were: a) to detect Helicobacter pylori in gastric biopsies of symptomatic adults by PCR, b) to detect the presence of the cagA gene as well as of the allelic variants of the vacA gene, and c) to correlate genotypes with the endoscopic diagnoses. H. pylori was detected in 81


(39/48) of patients by nested PCR for hsp60. The presence of cagA was detected in 15/22 of samples and vacA s1 - m1 was the most frequent allelic combination (15/22). Gastritis, the most frequent diagnosis, was associated with genotype cagA+ in 10/13 of patients. In this group, 9/13 showed the allelic variant vacA s1- m1. The variant vacA s2 - m2 was detected in 3/3 of gastritis cases by H. pylori with the cagA- genotype. These results are the first reported in our region and provide data of epidemiological interest.


Assuntos
Gastrite/epidemiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Estômago/microbiologia , Adolescente , Adulto , Idoso , Alelos , Antígenos de Bactérias/genética , Argentina/epidemiologia , Proteínas de Bactérias/genética , Biópsia , Chaperonina 60/genética , DNA Bacteriano/genética , Doenças do Esôfago/epidemiologia , Doenças do Esôfago/microbiologia , Feminino , Gastrite/microbiologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/microbiologia , Gastroscopia , Frequência do Gene , Genótipo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/patogenicidade , Humanos , Masculino , Pessoa de Meia-Idade , Estômago/patologia , Virulência/genética , Adulto Jovem
8.
Rev Argent Microbiol ; 43(1): 28-32, 2011.
Artigo em Espanhol | MEDLINE | ID: mdl-21491063

RESUMO

On February 2008, a suspected foodborne outbreak was reported in Las Rosas (Santa Fe Province, Argentina). The formal procedures indicated that an undetermined number of individuals had experienced food poisoning following consumption of vegetable cannelloni bought at a local shop. The manufacturer establishment was audited. Samples from the suspected food, as well as environmental samples and swabs from food handlers were obtained and involved subjects were interviewed. Remnants of ingested food were also obtained. Routine microbiological procedures of the foodborne outbreak revealed the presence of coagulase positive S. aureus subspecies aureus in samples from ingested and raw food, and from manipulators. Indicator microorganisms did not show significant levels and no other foodborne pathogen was isolated. Presence of staphylococcal enterotoxin-producing genes was subsequently investigated, and a positive result for enterotoxin B was shown in S. aureus strains isolated from a food handler as well as from food linked to the outbreak Moreover, these isolates showed 100% similarity by SmaI-PFGE. Timely notification together with coordinated sanitary measures and the availability of appropriate laboratory tools allowed to interrupt the chain of disease transmission by identifying risk and protective factors.


Assuntos
Surtos de Doenças , Manipulação de Alimentos , Intoxicação Alimentar Estafilocócica/epidemiologia , Adulto , Argentina/epidemiologia , Criança , Coagulase/análise , Coagulase/genética , Culinária , DNA Bacteriano/genética , Enterotoxinas/genética , Humanos , Nasofaringe/microbiologia , Intoxicação Alimentar Estafilocócica/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Verduras/microbiologia
9.
Leuk Lymphoma ; 51(5): 892-6, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20141430

RESUMO

We have analyzed the co-expression of the bcr-abl and HoxA9 genes in the follow-up of patients with chronic myeloid leukemia (CML). In the present work we measured the HoxA9 and bcr-abl gene expression in sequential samples. In all patients, bcr-abl and HoxA9 were expressed at detectable levels in every sample. When the results were expressed in relation to abl, two different situations were found: (a) patients clinically stable at second sampling, with low relative risk at diagnosis (low Sokal's score), did not show significant differences in both bcr-abl and HoxA9 levels in the sequential samples analyzed, and (b) patients with poor prognosis (showing intermediate or high Sokal's score at diagnosis) had increased expression of bcr-abl as well as HoxA9 genes (p < 0.05). Since HoxA9 gene expression remains at relatively constant levels throughout adult life, our results could reflect actual changes in the expression rate of this gene associated with bcr-abl during the progression of CML.


Assuntos
Proteínas de Fusão bcr-abl/genética , Expressão Gênica , Proteínas de Homeodomínio/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adulto , Feminino , Seguimentos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Leuk Res ; 30(11): 1453-6, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16630659

RESUMO

In the present work we study the HOXA9 expression in sequential samples of patients with CML using RT-PCR. To obtain a semi-quantitative value, the HOXA9 expression was referred to the ABL gene in the same sample. The relative HOXA9 expression was higher in patients in the accelerated phase of the disease (p<0.005). Interestingly, a patient with poorer prognosis (high Sokal's score), showing the highest HOXA9/ABL ratio, quickly entered a blast crisis and died 5 months later. These first results could be considered as an evidence of an actual biological phenomenon that could provide additional information about the HOXA9 role in the CML progression.


Assuntos
Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Proteínas de Homeodomínio/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adulto , Progressão da Doença , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Pessoa de Meia-Idade , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
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