Navegando por Palavras-chave "pulsed-field gel electrophoresis"
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- ItemSomente MetadadadosAtypical enteropathogenic Escherichia coli genomic background allows the acquisition of non-EPEC virulence factors(Wiley-Blackwell, 2009-10-01) Bando, Silvia Y.; Andrade, Fernanda B.; Guth, Beatriz E. C. [UNIFESP]; Elias Junior, Waldir Pereira [UNIFESP]; Moreira-Filho, Carlos A.; Pestana de Castro, Antonio F.; Inst Butantan; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Atypical enteropathogenic Escherichia coli (aEPEC) has been associated with infantile diarrhea in many countries. the clonal structure of aEPEC is the object of active investigation but few works have dealt with its genetic relationship with other diarrheagenic E. coli (DEC). This study aimed to evaluate the genetic relationship of aEPEC with other DEC pathotypes. the phylogenetic relationships of DEC strains were evaluated by multilocus sequence typing. Genetic diversity was assessed by pulsed-field gel electrophoresis (PFGE). the phylogram showed that aEPEC strains were distributed in four major phylogenetic groups (A, B1, B2 and D). Cluster I ( group B1) contains the majority of the strains and other pathotypes [enteroaggregative, enterotoxigenic and enterohemorrhagic E. coli ( EHEC)]; cluster II ( group A) also contains enteroaggregative and diffusely adherent E. coli; cluster III ( group B2) has atypical and typical EPEC possessing H6 or H34 antigen; and cluster IV ( group D) contains aEPEC O55:H7 strains and EHEC O157:H7 strains. PFGE analysis confirmed that these strains encompass a great genetic diversity. These results indicate that aEPEC clonal groups have a particular genomic background - especially the strains of phylogenetic group B1 that probably made possible the acquisition and expression of virulence factors derived from non-EPEC pathotypes.
- ItemSomente MetadadadosPseudomonas aeruginosa clonal dissemination in Brazilian intensive care units(Ediciones Doyma S/l, 2005-08-01) Figueiredo-Mendes, Caio Marcio; Sinto, Sumiko; Mello-Sampaio, Jorge Luiz; Cardoso-Leao, Sylvia [UNIFESP]; Oplustil, Carmen Paz; Turner, Philip; Veiga-Kiffer, Carlos Roberto; Universidade Federal de São Paulo (UNIFESP); AstraZeneca PharmaceutOBJECTIVE. Investigate clonal dissemination of nosocomial multidrug-resistant Pseudomonas aeruginosa isolates within and between Brazilian intensive care units, which participated in the MYSTIC Program Brazil 2002.METHODS. Thirty-six P. aeruginosa isolates resistant to meropenem or imipenem plus at least two of the following drugs: ciprofloxacin, cefepime, ceftazidime or piperacillin/tazobactam were isolated during 2002 at 4 centres in São Paulo and 1 centre in Brasilia. Chromosomal restriction fragments obtained with Spel were separated by pulsed-field gel electrophoresis (PFGE). Electrophoretic patterns were analyzed with GeICompar II v. 2.5.RESULTS. Five major clones were identified (A, B, C, D, G). Clone A was constituted by 8 isolates with indistinguishable PFGE pattern present in 2 centres. Clone B was constituted by 4 indistinguishable isolates predominant in centre 6. Clone C had 3 indistinguishable isolates, with closely related clones (C1-3). Also, Clone D had 3 indistinguishable isolates, with closely related (D1) and possibly related (D2/D3) clones. Clones C and D were present in centre 1. Clone G was constituted by 2 indistinguishable isolates and was present in centre 7. Finally, 8 isolates were unique. Isolates from Centre 4 were unique.CONCLUSIONS. Clonal dissemination was detected within (clones A, B, C, D, and G) and between centres (clone A). These findings are important when analyzing surveillance data, since susceptibility rates may be significantly affected by the dissemination of a resistant clone.
- ItemSomente MetadadadosPulsed-field gel electrophoresis in the identification of the origin of bacterial keratitis caused by Pseudomonas aeruginosa(Springer, 2007-07-01) Melo, Gustavo Barreto de; Aggio, Fabio Bom; Hofling-Lima, Ana Luisa; d'Azevedo, Pedro Alves [UNIFESP]; Campos Pignatari, Antonio Carlos; Universidade Federal de São Paulo (UNIFESP)Purpose To report the use of pulsed-field gel electrophoresis (PFGE) in the investigation of the origin of infectious keratitis.Methods A 19-year-old girl presented with infectious keratitis in the left eye. She was a soft contact lens wearer, and was noncompliant with the proper cleaning methods proposed by the manufacturer. Microbiological assessment was performed by means of culture and PFGE.Results the patient was treated successfully with topical cefalotin and gentamicin drops. Cultures were positive for Pseudomonas aeruginosa in the cornea and conjunctiva, and in the contact lens, its case and the cleaning solution. PFGE showed identical patterns of banding in each.Conclusion in this case of bacterial keratitis, PFGE proved to be very useful in identifying how the contamination occurred.
- ItemSomente MetadadadosShiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in São Paulo, Brazil(Wiley-Blackwell, 2009-07-01) Vettorato, M. P.; Castro, A. F. P. de; Cergole-Novella, Maria Cecilia [UNIFESP]; Camargo, F. L. L. [UNIFESP]; Irino, K.; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Inst Adolfo Lutz RegistroAims: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent.Methods and Results: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx(1), stx(2), eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)-PCR was performed to investigate the variants of stx(1) and stx(2), and the flagellar antigen (fliC) genes in nonmotile isolates. Five isolates were eae(+) and stx(-), and belonged to serotypes O128:H2/beta-intimin (2), O145:H2/gamma, O153:H7/beta and O178:H7/epsilon. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx(1c)stx(2d-O118) (46.9%), stx(1c) (27.2%), stx(2d-O118) (23.4%), and stx(1c)stx(2dOX3a) (2.5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates.Conclusions: This study demonstrated that healthy sheep in São Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC.Significance and Impact of the Study: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.
- ItemSomente MetadadadosShiga toxin-producing Escherichia coli in drinking water supplies of north Parana State, Brazil(Wiley-Blackwell, 2013-04-01) Lascowski, K. M. S. [UNIFESP]; Guth, B. E. C. [UNIFESP]; Martins, F. H.; Rocha, S. P. D.; Irino, K.; Pelayo, J. S.; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Londrina (UEL); Adolfo Lutz InstAim To determine the occurrence and characteristics of Shiga toxin-producing Escherichia coli (STEC) in drinking water supplies treated and untreated. Methods and Results Drinking water samples (n=1850) were collected from 41 municipalities in the north of Parana State between February 2005 and January 2006. Escherichia coli isolates (n=300) were recovered from water and investigated for the presence of virulence markers related to STEC by PCR. STEC isolates recovered were then characterized for both phenotypic and genotypic traits. A total of 12 isolates (11 from untreated water and one from treated water) were positive for stx, including five positive for both stx1 and stx2, two positive for stx1 and five positive for stx2. None of the STEC isolates contained eae, but other virulence genes were observed such as ehxA (100%), saa (100%), lpfAO113 (75%), iha (42%), subAB (25%) and cdtV (8%). Multidrug resistance was identified in 25% of the STEC isolates. the 12 STEC isolates belonged to seven distinct serotypes and pulsed-field gel electrophoresis typing revealed the presence of two clusters and two clones in this region. Conclusion Drinking water, especially from untreated water supplies, can be source of STEC strains potentially pathogenic for humans. Significance and Impact of the Study the investigation of the drinking water supplies for pathogenic E.coli, as STEC, may be useful to prevent waterborne outbreaks.
- ItemAcesso aberto (Open Access)The use of molecular typing to evaluate the dissemination of antimicrobial resistance among gram-negative rods in Brazilian hospitals(Brazilian Society of Infectious Diseases, 2003-12-01) Tosin, Iraci [UNIFESP]; Silbert, Suzane [UNIFESP]; Sader, Helio Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Federal University of Santa Catarina Centre of Biological SciencesAntimicrobial resistance has increased rapidly in Brazil and worldwide during the past few years, giving rise to a growing necessity for antimicrobial resistance surveillance programs. These programs have been instituted in order to monitor bacterial resistance in various regions, and to guide empirical antimicrobial therapy. We evaluated the use of molecular typing in multicenter surveillance programs. We also studied the dissemination modes of selected resistance profiles. Antimicrobial susceptibility to various antimicrobial agents was evaluated by the reference broth microdilution method. Bacterial isolates with selected susceptibility patterns were characterized by pulsed field-gel electrophoresis (PFGE). A total of 119 Gram-negative bacteria were molecularly typed, including 22 imipenem-resistant Pseudomonas aeruginosa, 26 ESBL-producing Escherichia coli, 27 cefoxitin-resistant-ESBL-producing Klebsiella pneumoniae, 33 Enterobacter spp., 8 Citrobacter spp., and 3 S. marcescens isolates resistant to ceftazidime. The isolates were from clinically apparent bacteremia of patients hospitalized in medical centers located in 13 cities of 11 Brazilian states. Our molecular typing results revealed a great genetic diversity among isolates of the same species. However, some major PFGE patterns were found in more than one isolate. All repeated PFGE patterns were detected in only 2 isolates, which were isolated within the same institutions or in different medical centers. We conclude that the ability to characterize organisms phenotypically and genotypically is a powerful epidemiologic tool and it provides unique information that is very important for multicenter surveillance programs.