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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

En jämförande studie mellan tre selektiva agarplattors förmåga att detektera β-laktamas producerande bakterier / A comparative study between three selective agar-plates' ability to detect β-lactamase-producing bacteria.

Naser, Rafal, Jacob, Amir January 2015 (has links)
Betalaktamaser med utvidgat spektrum så kallade Extended Spectrum Beta-Lactamase (ESBL) är enzymer som produceras av bakterier och som har en avgörande roll ur kliniskt perspektiv då de blir resistenta mot de flesta antibiotika vilket leder till begränsade behandlingsalternativ. För att selektera fram dessa bakterier användes kromogena agarplattor vid odling, vilka selekterade bort jästsvampar och grampositiva bakterier och underlättar detektionen av ESBL-positiva stammar. Syftet med studien var att jämföra tre olika selektiva agarplattor CHROMagar ESBL, ChromID ESBL och CHROMagar C3GR genom att utvärdera deras specificitet och sensitivitet. Totalt användes 130 olika patientprover från feces, blod, sår och urin, vilka valdes ut slumpmässigt ur den rutinmässiga diagnostiken. Proverna odlades på de tre agarplattor. De bakteriestammar som växte fram artidentifierades med IVD Maldi Biotyper och resistensbestämdes med VITEK. Den totala sensitiviteten för ESBL, med ett 95 % konfidensintervall, efter 16 timmars aerob inkubering i 37° C var 96,7 % (KI 95% 81,0 – 99,9 %) för de tre agarplattorna. Specificiteten var 94,0 % (KI 95%  86,9 – 97,5%) för CHROMagar ESBL, 93,1 % (KI 95%  85,6– 96,9%) för ChromID ESBL och 73,0 % (KI 95% 63, 0- 81,2 %) för CHROMagar C3GR. De tre agarplattor uppvisade jämförbar sensitivitet men skillnaden i specificitet där ansåg CHROMagar ESBL och ChromID ESBL erhöll likvärdiga resultat. / Bacteria that produce enzymes with extended spectrum, Extended Spectrum Beta-Lactamase (ESBLs), have a major role in a clinical perspective since they became resistant to most antibiotics, leading to limited treatment options. In order to detect the bacteria, chromogenic agar plates were used for culture in order to inhibit growth of yeast and gram positive bacteria and enables the detection of ESBL-positive strains. The aim of this study was to compare three chromogenic agar plates CHROMagar ESBL, ChromID ESBL and CHROMagar C3GR regarding their specificity and sensitivity. A total of 130 different samples from faeces, blood, wounds and urine were randomly selected for the routine diagnosis. The samples were grown on the three chromogenic agar plates and were species identified by IVD Maldi biotypes and resistance determined with VITEK. The overall sensitivity for ESBLs with 95% confidence interval, after 16 hours of aerobic incubation at 37° C was 96.7 % (CI 81.0-99.9 %) for the three agar plates. The specificity showed 94.0 % (CI 86.9-97.5 %) for CHROMagar ESBL, 93.1 % (CI 85,6- 96.9 %) for ChromID ESBL and 73.0 % (CI 63, 0- 81 , 2 %) for CHROMagar C3GR. All three chromogenic agar plates were equally sensitive but the specificity differed. CHROMagar ESBL and ESBL ChromID were considered equivalent.
2

Characterization of Escherichia coli and Klebsiella pneumoniae with resistance or reduced susceptibility to carbapenems isolated from Canadian hospitals from 2007-2010

Tailor, Franil 01 September 2011 (has links)
Escherichia coli and Klebsiella pneumoniae isolates were obtained from the Canadian Ward Surveillance Study (CANWARD) and underwent in vitro susceptibility testing to determine prevalence and antimicrobial resistance patterns. The prevalence was found to be relatively stable over the years although there was an increase in prevalence among the K. pneumoniae isolates; 1.1% to 1.3% to 2.5% to 2.6% in 2007, 2008, 2009, and 2010, respectively. Genotypic characterization was conducted on ESBL, AmpC, carbapenemase genes, and outer membrane porins. The highest proportion of isolates were found to produce CTX-M-15 β-lactamase. Only 1 of each KPC-producing E. coli and K. pneumoniae was found. Porin alteration was found to be a factor leading to carbapenem reduced susceptibility among isolates. Genetic relatedness of CRS/CIR E. coli and K. pneumoniae was determined using pulsed-field gel electrophoresis. The spread of these organisms was mainly due to polyclonal spread rather than one specific clone.
3

The Utility of Admission Screening for the Prevention of Nosocomial Transmission of Extended-spectrum β-Lactamase Producing Enterobacteriaceae

Lowe, Christopher 15 November 2013 (has links)
Background: The efficacy of interventions to prevent in-hospital transmission of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) is poorly defined, particularly for admission screening. Methods: Variability in ESBL-E infection control practices was evaluated with a survey of 15 hospitals. All ESBL-E positive clinical and screening specimens at 12 hospitals (6 screening and 6 non-screening) from 2005-2009 were included and defined as hospital-onset or community-onset using standard definitions. ESBL-E incidence and susceptibility were studied. Screening efficacy was evaluated with a negative binomial model, adjusting for study year and incidence of community-onset cases. Results: Diverse practices in infection control for ESBL-E were found with 53.3% of hospitals utilizing admission screening. Overall incidence and hospital-onset cases increased 4-fold and 2-fold, respectively. Fluoroquinolone susceptibility for E. coli (12.8%) and K. pneumoniae (9.0%) was low. Hospital-onset cases were 49.1% lower in screening compared to non-screening hospitals (p<0.001). Conclusion: Admission screening can reduce the incidence of hospital-onset ESBL-E cases.
4

The Utility of Admission Screening for the Prevention of Nosocomial Transmission of Extended-spectrum β-Lactamase Producing Enterobacteriaceae

Lowe, Christopher 15 November 2013 (has links)
Background: The efficacy of interventions to prevent in-hospital transmission of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) is poorly defined, particularly for admission screening. Methods: Variability in ESBL-E infection control practices was evaluated with a survey of 15 hospitals. All ESBL-E positive clinical and screening specimens at 12 hospitals (6 screening and 6 non-screening) from 2005-2009 were included and defined as hospital-onset or community-onset using standard definitions. ESBL-E incidence and susceptibility were studied. Screening efficacy was evaluated with a negative binomial model, adjusting for study year and incidence of community-onset cases. Results: Diverse practices in infection control for ESBL-E were found with 53.3% of hospitals utilizing admission screening. Overall incidence and hospital-onset cases increased 4-fold and 2-fold, respectively. Fluoroquinolone susceptibility for E. coli (12.8%) and K. pneumoniae (9.0%) was low. Hospital-onset cases were 49.1% lower in screening compared to non-screening hospitals (p<0.001). Conclusion: Admission screening can reduce the incidence of hospital-onset ESBL-E cases.
5

Characterization of Escherichia coli and Klebsiella pneumoniae with resistance or reduced susceptibility to carbapenems isolated from Canadian hospitals from 2007-2010

Tailor, Franil 01 September 2011 (has links)
Escherichia coli and Klebsiella pneumoniae isolates were obtained from the Canadian Ward Surveillance Study (CANWARD) and underwent in vitro susceptibility testing to determine prevalence and antimicrobial resistance patterns. The prevalence was found to be relatively stable over the years although there was an increase in prevalence among the K. pneumoniae isolates; 1.1% to 1.3% to 2.5% to 2.6% in 2007, 2008, 2009, and 2010, respectively. Genotypic characterization was conducted on ESBL, AmpC, carbapenemase genes, and outer membrane porins. The highest proportion of isolates were found to produce CTX-M-15 β-lactamase. Only 1 of each KPC-producing E. coli and K. pneumoniae was found. Porin alteration was found to be a factor leading to carbapenem reduced susceptibility among isolates. Genetic relatedness of CRS/CIR E. coli and K. pneumoniae was determined using pulsed-field gel electrophoresis. The spread of these organisms was mainly due to polyclonal spread rather than one specific clone.
6

Estudo genético e molecular da disseminação da resistência aos beta-lactâmicos em Pseudomonas aeruginosa / Genetic and molecular study of beta-lactams resistance dissemination in Pseudomonas aeruginosa

Galetti, Renata 06 November 2014 (has links)
A presença de plasmídeos conjugativos como IncP, IncU e IncFII carreando genes de resistência em Pseudomonas aeruginosa é de grande importância, pois podem ser trocados entre diferentes bactérias gram-negativas, disseminando a resistência aos antibióticos. Conhecer estes genes de resistência bem como os elementos genéticos que os carreiam é importante para entender os fatores que contribuem para a disseminação da resistência, auxiliando no controle da disseminação da resistência aos antibióticos. Ainda hoje não existe esquema para a tipagem de plasmídeos de P. aeruginosa, e são encontrados poucos trabalhos sobre estes plasmídeos. O objetivo deste estudo foi identificar os genes de resistência a antibióticos, o ambiente genético em que estes genes estão inseridos e a clonalidade dos isolados produtores de genes bla. No período do estudo, foram estudados 293 isolados de P. aeruginosa resistentes às cefalosporinas de 3ª e/ou 4ª gerações e/ou aos carbapenêmicos isoladas de pacientes de hospitais de Ribeirão Preto-SP, Belo Horizonte-MG, Franca-SP, Cuiabá-MT, de Barretos-SP e de Rio Branco-AC. Genes de resistência foram pesquisados por PCR. O perfil clonal dos isolados produtores de genes bla foi determinado por PFGE e MLST. A tipagem de plasmídeos foi feita por PFGE-S1 nuclease, hibridações com sondas específicas e tipagem de replicons (PBRT). Foram identificados 12 isolados carreando o gene blaSPM-1, 16 isolados carreando o gene blaCTX-M-2 e 3 isolados carreando o gene blaKPC-2. Em todos os 12 isolados produtores de SPM-1 foram identificadas duas cópias do elemento de inserção ISCR4, sendo uma cópia upstream e uma cópia downstream ao gene blaSPM-1 inseridos no cromossomo bacteriano. Em 13 dos 16 isolados produtores de CTX-M-2 o gene blaCTX-M-2 foi encontrado associado ao elemento de inserção ISCR1 e em 3 ao elemento de inserção ISEcp1 também inseridos no cromossomo bacteriano. Em 2 isolados o gene blaKPC-2 é carreado por um plasmídeo de ~3kb não tipável por PBRT e um em está inserido no cromossomo bacteriano. O ambiente genético do gene blaKPC-2 nos isolados estudados é diferente daqueles encontrados na literatura. Os isolados produtores de genes bla citados apresentaram diversidade clonal, tanto por PFGE quanto MLST demonstrando que vários clones estão envolvidos na disseminação desses genes. Este trabalho identificou e caracterizou 31 isolados produtores de ?-lactamases, o ambiente genético destes genes e a clonalidade de isolados de várias cidades do Brasil e em períodos diferenciados, demonstrando a disseminação desses genes em diferentes hospitais brasileiros. Esses dados auxiliam no conhecimento dos fatores que estão envolvidos na disseminação da resistência aos antibióticos e podem auxiliar as CCIHs dos hospitais a definirem estratégias para controlar a disseminação desses microrganismos prevenindo surtos de bactérias multirresistentes. / The presence of conjugative plasmids as IncP, IncU and Inc FII carrying resistance genes in Pseudomonas aeruginosa is very important because t these plasmids can be shared among different bacteria, spreading antibiotic resistance. Knowledge of these genes as well as genetic elements carrying these genes it is important to understend the factors that contribute to the spread of resistance, helping to control the spread of antibiotic resistance. Today there is no plasmid typing scheme to P. aeruginosa and few papers are found about this subject. The purpose of this study was to investigate resistance genes, genetic environment of these genes and clonal relationship of the isolates carrying these resistance genes. In the period of this study was studied 293 P. aeruginosa resistant to third and fourth generations of cephalosporins and/or carbapenens isolated of patients from hosptital from Ribeirão Preto, Belo Horizonte-MG, Franca-SP, Cuiabá-MT, Barretos-SP and Rio Branco-AC. Resistance genes were investigated by PCR. Twelve isolates were identified carrying blaSPM-1 gene, 16 isolates carrying blaCTX-M-2 gene and 3 isolates carrying blaKPC-2 gene. Clonal profiles of isolates producing resistance genes were investigated by PFGE and MLST. Plasmid typing was performed by PFGE-S1 nuclease, specific hybridizations and PCR replicon typing (PBRT). Two isolates presented a 3kb plasmid non-typeable by PBRT carrying blaKPC-2 gene. In all isolates SPM-1-producers were identified two copies of insertion sequence ISCR4, a copy upstream and a copy downstream to blaSPM-1 gene inserted in chromosomal DNA. In 13 of 16 isolates CTX-M-2-producers the blaCTX-M-2 gene was found associated to insertion sequence ISCR1 and in 3 isolates was associated to insertion sequence ISEcp1 also inserted in chromosomal DNA. Genetic environment of blaKPC-2 gene in the isolates studied it is different from those found in the literature. Isolates producing bla genes are clonally diversified using both PFGE and MLST showing that various clones are responsible to spread these resistance genes. This work identified and characterized 31 P. aeruginosa-?-lactamase-producing, the genetic environment of these genes and the clonal relationship of isolates collected from different periods from different cities of Brazil. These data can help us to understand the factors that are involved in the spread of antibiotics resistance and to help the Hospital Infection Control Committee to define strategies to control the spread of these microorganisms preventing outbreaks of resistant.
7

Caracterização molecular de plasmídeos carreadores de genes codificadores de beta-lactamases de espectro estendido em Enterobactereaceas isoladas de suínos / Molecular characterization of plasmids carrying extended-spectrum beta-lactamases coding genes from Enterobactereaceas isolated from swine

Silva, Ketrin Cristina da 21 March 2016 (has links)
A produção de beta-lactamases de espectro estendido (ESBL) tornou-se um desafio em saúde pública por restringir as opções terapêuticas para o tratamento de infecções causadas por bactérias gram-negativas. O objetivo desse estudo foi avaliar a ocorrência de estirpes produtoras de ESBL nas granjas de suínos brasileiras, bem como caracterizar os plasmídeos carreadores dos genes blaESBL quanto ao grupo de incompatibilidade, tamanho e presença de genes de resistência adicionais. As estirpes foram isoladas em meio MacConkey e identificadas por MALDI-TOF. Posteriormente, os valores de concentração inibitória mínima foram determinados por microdiluição e/ou ágar diluição para aminoglicosídeos, carbapenens, cefalosporinas, fluoroquinolonas, tetraciclinas, sulfas e cefalosporinas associadas a inibidores competitivos. Os genes codificadores de beta-lactamases foram identificados por PCR assim como o grupo de incompatibilidade dos respectivos plasmídeos carreadores e o grupo filogenético das estirpes de E. coli. A análise de clonalidade foi realizada por ERIC-PCR e MLST. Finalmente, o ambiente genético do gene blaCTX-M-15 foi determinado por PCR e/ou sequenciamento, sendo que os plasmídeos carreando genes blaESBL foram transferidos às estirpes receptoras E. coli TOP10 e C600 por transformação e conjugação, respectivamente, e parcialmente sequenciados. As estirpes de Escherichia coli produtoras de CTX-M-2 foram as mais prevalentes, sendo endêmicas no estado de Minas Gerais. Além disso, é relatada a presença da enzima CTX-M-15 em estirpes de E. coli (ST224, ST410, ST1284), Klebsiella pneumoniae, Enterobacter cloacae e Pseudomonas aeruginosa (ST3201). O gene blaCTX-M-15 esteve associado a plasmídeos IncF e foi transferido com sucesso para a estirpe receptora E.coli TOP10, plasmídeos IncF também foram associados a presença do gene blaCTX-M-2. O gene blaCTX-M-8 foi detectado em quatro novos STs de E. coli (ST5845, ST5847, ST5848 e ST5350) e não foi adquirido pelas estirpes receptoras. Estes dados indicam que a vigilância de fenótipos resistentes na produção suína deve de ser considerada uma prioridade, assim como a preferência ao uso de antimicrobianos de espectro estrito a fim de evitar a disseminação desses fenótipos nas granjas e sua possível transmissão para população humana. / Extended-spectrum beta-lactamase production (ESBL) became a great challenge regarding public health because limit the therapeutic options to treat infections by gram-negative bacteria. The aim of this study were evaluate the occurrence of ESBL producers in Brazilian swine farms and characterize blaESBL-carrying plasmids by sizing and incompatibility group and presence of additional resistance genes. Strains were isolated in MacConkey agar and identified by Maldi-Tof. Next, the minimal inhibitory concentration values were determined by microdilution and/or agar dilution to aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, tetracyclines, sulfas and cephalosporin/inhibitors association. Betalactamase encoding genes, plasmid incompatibility group and Escherichia coli phylogenetic group were determined by PCR. Clonal relatedness was evaluated by ERIC-PCR and MLST. Finally, the blaCTX-M-15 genetic environment was determined by PCR and/or sequencing and blaESBL-carrying plasmids transferred to E. coli TOP10 and C600 receptor strains by transformation and conjugation, respectively, and partially sequenced. CTX-M-2-producing E. coli were the most prevalent phenotype, which were endemic in Minas Gerais State. Moreover, the CTX-M-15 enzyme emerged among E. coli (ST224, ST410, ST1284), Klebsiella pneumoniae, Enterobacter cloacae e Pseudomonas aeruginosa (ST3201) strains. The blaCTX-M-15 was associated with IncF plasmids, which were successfully transferred to E.coli TOP10, similarly, IncF plasmids were found harboring the blaCTX-M-2. The blaCTX-M-8, detected in four novel E. coli sequence types (ST5845, ST5847, ST5848 e ST5350), was not acquired by receptor strains. Thus, the surveillance of resistant phenotypes in swine production must be established as a priority as well as narrow spectrum antimicrobials prescription antimicrobial instead broad spectrum to prevent the dissemination of these phenotypes in farms and their transmission to human population.
8

Caracterização molecular de plasmídeos carreadores de genes codificadores de beta-lactamases de espectro estendido em Enterobactereaceas isoladas de suínos / Molecular characterization of plasmids carrying extended-spectrum beta-lactamases coding genes from Enterobactereaceas isolated from swine

Ketrin Cristina da Silva 21 March 2016 (has links)
A produção de beta-lactamases de espectro estendido (ESBL) tornou-se um desafio em saúde pública por restringir as opções terapêuticas para o tratamento de infecções causadas por bactérias gram-negativas. O objetivo desse estudo foi avaliar a ocorrência de estirpes produtoras de ESBL nas granjas de suínos brasileiras, bem como caracterizar os plasmídeos carreadores dos genes blaESBL quanto ao grupo de incompatibilidade, tamanho e presença de genes de resistência adicionais. As estirpes foram isoladas em meio MacConkey e identificadas por MALDI-TOF. Posteriormente, os valores de concentração inibitória mínima foram determinados por microdiluição e/ou ágar diluição para aminoglicosídeos, carbapenens, cefalosporinas, fluoroquinolonas, tetraciclinas, sulfas e cefalosporinas associadas a inibidores competitivos. Os genes codificadores de beta-lactamases foram identificados por PCR assim como o grupo de incompatibilidade dos respectivos plasmídeos carreadores e o grupo filogenético das estirpes de E. coli. A análise de clonalidade foi realizada por ERIC-PCR e MLST. Finalmente, o ambiente genético do gene blaCTX-M-15 foi determinado por PCR e/ou sequenciamento, sendo que os plasmídeos carreando genes blaESBL foram transferidos às estirpes receptoras E. coli TOP10 e C600 por transformação e conjugação, respectivamente, e parcialmente sequenciados. As estirpes de Escherichia coli produtoras de CTX-M-2 foram as mais prevalentes, sendo endêmicas no estado de Minas Gerais. Além disso, é relatada a presença da enzima CTX-M-15 em estirpes de E. coli (ST224, ST410, ST1284), Klebsiella pneumoniae, Enterobacter cloacae e Pseudomonas aeruginosa (ST3201). O gene blaCTX-M-15 esteve associado a plasmídeos IncF e foi transferido com sucesso para a estirpe receptora E.coli TOP10, plasmídeos IncF também foram associados a presença do gene blaCTX-M-2. O gene blaCTX-M-8 foi detectado em quatro novos STs de E. coli (ST5845, ST5847, ST5848 e ST5350) e não foi adquirido pelas estirpes receptoras. Estes dados indicam que a vigilância de fenótipos resistentes na produção suína deve de ser considerada uma prioridade, assim como a preferência ao uso de antimicrobianos de espectro estrito a fim de evitar a disseminação desses fenótipos nas granjas e sua possível transmissão para população humana. / Extended-spectrum beta-lactamase production (ESBL) became a great challenge regarding public health because limit the therapeutic options to treat infections by gram-negative bacteria. The aim of this study were evaluate the occurrence of ESBL producers in Brazilian swine farms and characterize blaESBL-carrying plasmids by sizing and incompatibility group and presence of additional resistance genes. Strains were isolated in MacConkey agar and identified by Maldi-Tof. Next, the minimal inhibitory concentration values were determined by microdilution and/or agar dilution to aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, tetracyclines, sulfas and cephalosporin/inhibitors association. Betalactamase encoding genes, plasmid incompatibility group and Escherichia coli phylogenetic group were determined by PCR. Clonal relatedness was evaluated by ERIC-PCR and MLST. Finally, the blaCTX-M-15 genetic environment was determined by PCR and/or sequencing and blaESBL-carrying plasmids transferred to E. coli TOP10 and C600 receptor strains by transformation and conjugation, respectively, and partially sequenced. CTX-M-2-producing E. coli were the most prevalent phenotype, which were endemic in Minas Gerais State. Moreover, the CTX-M-15 enzyme emerged among E. coli (ST224, ST410, ST1284), Klebsiella pneumoniae, Enterobacter cloacae e Pseudomonas aeruginosa (ST3201) strains. The blaCTX-M-15 was associated with IncF plasmids, which were successfully transferred to E.coli TOP10, similarly, IncF plasmids were found harboring the blaCTX-M-2. The blaCTX-M-8, detected in four novel E. coli sequence types (ST5845, ST5847, ST5848 e ST5350), was not acquired by receptor strains. Thus, the surveillance of resistant phenotypes in swine production must be established as a priority as well as narrow spectrum antimicrobials prescription antimicrobial instead broad spectrum to prevent the dissemination of these phenotypes in farms and their transmission to human population.
9

Estudo genético e molecular da disseminação da resistência aos beta-lactâmicos em Pseudomonas aeruginosa / Genetic and molecular study of beta-lactams resistance dissemination in Pseudomonas aeruginosa

Renata Galetti 06 November 2014 (has links)
A presença de plasmídeos conjugativos como IncP, IncU e IncFII carreando genes de resistência em Pseudomonas aeruginosa é de grande importância, pois podem ser trocados entre diferentes bactérias gram-negativas, disseminando a resistência aos antibióticos. Conhecer estes genes de resistência bem como os elementos genéticos que os carreiam é importante para entender os fatores que contribuem para a disseminação da resistência, auxiliando no controle da disseminação da resistência aos antibióticos. Ainda hoje não existe esquema para a tipagem de plasmídeos de P. aeruginosa, e são encontrados poucos trabalhos sobre estes plasmídeos. O objetivo deste estudo foi identificar os genes de resistência a antibióticos, o ambiente genético em que estes genes estão inseridos e a clonalidade dos isolados produtores de genes bla. No período do estudo, foram estudados 293 isolados de P. aeruginosa resistentes às cefalosporinas de 3ª e/ou 4ª gerações e/ou aos carbapenêmicos isoladas de pacientes de hospitais de Ribeirão Preto-SP, Belo Horizonte-MG, Franca-SP, Cuiabá-MT, de Barretos-SP e de Rio Branco-AC. Genes de resistência foram pesquisados por PCR. O perfil clonal dos isolados produtores de genes bla foi determinado por PFGE e MLST. A tipagem de plasmídeos foi feita por PFGE-S1 nuclease, hibridações com sondas específicas e tipagem de replicons (PBRT). Foram identificados 12 isolados carreando o gene blaSPM-1, 16 isolados carreando o gene blaCTX-M-2 e 3 isolados carreando o gene blaKPC-2. Em todos os 12 isolados produtores de SPM-1 foram identificadas duas cópias do elemento de inserção ISCR4, sendo uma cópia upstream e uma cópia downstream ao gene blaSPM-1 inseridos no cromossomo bacteriano. Em 13 dos 16 isolados produtores de CTX-M-2 o gene blaCTX-M-2 foi encontrado associado ao elemento de inserção ISCR1 e em 3 ao elemento de inserção ISEcp1 também inseridos no cromossomo bacteriano. Em 2 isolados o gene blaKPC-2 é carreado por um plasmídeo de ~3kb não tipável por PBRT e um em está inserido no cromossomo bacteriano. O ambiente genético do gene blaKPC-2 nos isolados estudados é diferente daqueles encontrados na literatura. Os isolados produtores de genes bla citados apresentaram diversidade clonal, tanto por PFGE quanto MLST demonstrando que vários clones estão envolvidos na disseminação desses genes. Este trabalho identificou e caracterizou 31 isolados produtores de ?-lactamases, o ambiente genético destes genes e a clonalidade de isolados de várias cidades do Brasil e em períodos diferenciados, demonstrando a disseminação desses genes em diferentes hospitais brasileiros. Esses dados auxiliam no conhecimento dos fatores que estão envolvidos na disseminação da resistência aos antibióticos e podem auxiliar as CCIHs dos hospitais a definirem estratégias para controlar a disseminação desses microrganismos prevenindo surtos de bactérias multirresistentes. / The presence of conjugative plasmids as IncP, IncU and Inc FII carrying resistance genes in Pseudomonas aeruginosa is very important because t these plasmids can be shared among different bacteria, spreading antibiotic resistance. Knowledge of these genes as well as genetic elements carrying these genes it is important to understend the factors that contribute to the spread of resistance, helping to control the spread of antibiotic resistance. Today there is no plasmid typing scheme to P. aeruginosa and few papers are found about this subject. The purpose of this study was to investigate resistance genes, genetic environment of these genes and clonal relationship of the isolates carrying these resistance genes. In the period of this study was studied 293 P. aeruginosa resistant to third and fourth generations of cephalosporins and/or carbapenens isolated of patients from hosptital from Ribeirão Preto, Belo Horizonte-MG, Franca-SP, Cuiabá-MT, Barretos-SP and Rio Branco-AC. Resistance genes were investigated by PCR. Twelve isolates were identified carrying blaSPM-1 gene, 16 isolates carrying blaCTX-M-2 gene and 3 isolates carrying blaKPC-2 gene. Clonal profiles of isolates producing resistance genes were investigated by PFGE and MLST. Plasmid typing was performed by PFGE-S1 nuclease, specific hybridizations and PCR replicon typing (PBRT). Two isolates presented a 3kb plasmid non-typeable by PBRT carrying blaKPC-2 gene. In all isolates SPM-1-producers were identified two copies of insertion sequence ISCR4, a copy upstream and a copy downstream to blaSPM-1 gene inserted in chromosomal DNA. In 13 of 16 isolates CTX-M-2-producers the blaCTX-M-2 gene was found associated to insertion sequence ISCR1 and in 3 isolates was associated to insertion sequence ISEcp1 also inserted in chromosomal DNA. Genetic environment of blaKPC-2 gene in the isolates studied it is different from those found in the literature. Isolates producing bla genes are clonally diversified using both PFGE and MLST showing that various clones are responsible to spread these resistance genes. This work identified and characterized 31 P. aeruginosa-?-lactamase-producing, the genetic environment of these genes and the clonal relationship of isolates collected from different periods from different cities of Brazil. These data can help us to understand the factors that are involved in the spread of antibiotics resistance and to help the Hospital Infection Control Committee to define strategies to control the spread of these microorganisms preventing outbreaks of resistant.
10

Molecular epidemiology of klebsiellae with extended-spectrum #beta#-lactamases and multiple drug resistances

Yuan, Meifang January 1999 (has links)
No description available.

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