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Id: biblio-1249214
Autor: Verma, Kanika; Mahalapbutr, Panupong; Suriya, Utid; Somboon, Tuanjai; Aiebchun, Thitinan; Shi, Liyi; Maitarad, Phornphimon; Rungrotmongkol, Thanyada.
Título: In Silico Screening of DNA Gyrase B Potent Flavonoids for the Treatment of Clostridium difficile Infection from PhytoHub Database
Fonte: Braz. arch. biol. technol;64:e21200402, 2021. tab, graf.
Idioma: en.
Resumo: Abstract Clostridium difficile infection (CDI) is the most common hospital acquired diarrheal disease with its increasing incidence and mortality rate globally. DNA Gyrase B (GyrB) is a key component of DNA replication process across all bacterial genera; thus, this offers a potential target for the treatment of CDI. In the present study, several virtual screening approaches were employed to identify a novel C. difficile GyrB inhibitor. The 139 known metabolites were screened out from the 480 flavonoids in PhytoHub database. Molinspiration and PROTOX II servers were used to calculate the ADME properties and oral toxicity of the metabolites, whereas mutagenicity, tumorigenicity, irritant, and reproductive effect were predicted using DataWarrior program. The binding mode and the binding efficiency of the screened flavonoids against the GyrB were studied using FlexX docking program. From virtual screening of 139 metabolites, we found 25 flavonoids with no mutagenicity, tumorigenicity, irritant, and reproductive effect. Docking study suggested that flavonoids 1030 ((-)-epicatechin 3'-O-sulfate), 1032 ((-)-epicatechin 4'-O-sulfate), 1049 (3'-O-methyl-(-)-epicatechin 4-O-sulfate), 1051 (3'-O-methyl-(-)-epicatechin 7-O-sulfate), 1055 (4'-O-methyl-(-)-epicatechin 7-O-sulfate) and 1317 (quercetin sulfate) have significantly higher binding affinity than the known GyrB inhibitor novobiocin. The results from molecular dynamics simulation and free energy calculations based on solvated interaction energy suggested that (-)-epicatechin 3'-O-sulfate could be a potential drug candidate in the management of CDI.
Descritores: Flavonoides/uso terapêutico
Infecções por Clostridium/terapia
DNA Girase/uso terapêutico
-Ensaios de Triagem em Larga Escala
Responsável: BR1.1 - BIREME


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Id: biblio-828207
Autor: Nouri, Roghayeh; Ahangarzadeh Rezaee, Mohammad; Hasani, Alka; Aghazadeh, Mohammad; Asgharzadeh, Mohammad.
Título: The role of gyrA and parC mutations in fluoroquinolones-resistant Pseudomonas aeruginosa isolates from Iran
Fonte: Braz. j. microbiol;47(4):925-930, Oct.-Dec. 2016. tab.
Idioma: en.
Projeto: Infectious and Tropical Diseases Research Center.
Resumo: Abstract The aim of this study was to examine mutations in the quinolone-resistance-determining region (QRDR) of gyrA and parC genes in Pseudomonas aeruginosa isolates. A total of 100 clinical P. aeruginosa isolates were collected from different university-affiliated hospitals in Tabriz, Iran. Minimum inhibitory concentrations (MICs) of ciprofloxacin and levofloxacin were evaluated by agar dilution assay. DNA sequences of the QRDR of gyrA and parC were determined by the dideoxy chain termination method. Of the total 100 isolates, 64 were resistant to ciprofloxacin. No amino acid alterations were detected in gyrA or parC genes of the ciprofloxacin susceptible or ciprofloxacin intermediate isolates. Thr-83 → Ile substitution in gyrA was found in all 64 ciprofloxacin resistant isolates. Forty-four (68.75%) of them had additional substitution in parC. A correlation was found between the number of the amino acid alterations in the QRDR of gyrA and parC and the level of ciprofloxacin and levofloxacin resistance of the P. aeruginosa isolates. Ala-88 → Pro alteration in parC was generally found in high level ciprofloxacin resistant isolates, which were suggested to be responsible for fluoroquinolone resistance. These findings showed that in P. aeruginosa, gyrA was the primary target for fluoroquinolone and additional mutation in parC led to highly resistant isolates.
Descritores: Pseudomonas aeruginosa/efeitos dos fármacos
Pseudomonas aeruginosa/genética
Infecções por Pseudomonas/microbiologia
Infecções por Pseudomonas/epidemiologia
Fluoroquinolonas/farmacologia
DNA Girase/genética
DNA Topoisomerase IV/genética
Farmacorresistência Bacteriana
Mutação
-Pseudomonas aeruginosa/isolamento & purificação
Testes de Sensibilidade Microbiana
Análise de Sequência de DNA
Irã (Geográfico)/epidemiologia
Antibacterianos/farmacologia
Limites: Humanos
Responsável: BR1.1 - BIREME


  3 / 16 LILACS  
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Moreira, Beatriz Meurer
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Id: biblio-839355
Autor: Rodrigues, Naiara Miranda Bento; Bronzato, Greiciane França; Santiago, Gabrielli Stefaninni; Botelho, Larissa Alvarenga Batista; Moreira, Beatriz Meurer; Coelho, Irene da Silva; Souza, Miliane Moreira Soares de; Coelho, Shana de Mattos de Oliveira.
Título: The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) identification versus biochemical tests: a study with enterobacteria from a dairy cattle environment
Fonte: Braz. j. microbiol;48(1):132-138, Jan.-Mar. 2017. tab.
Idioma: en.
Projeto: National Council for Scientific and Technological Development.
Resumo: Abstract Mastitis adversely affects milk production and in general cows do not regain their full production levels post recovery, leading to considerable economic losses. Moreover the percentage decrease in milk production depends on the specific pathogen that caused the infection and enterobacteria are responsible for this greater reduction. Phenotypic tests are among the currently available methods used worldwide to identify enterobacteria; however they tend to misdiagnose the species despite the multiple tests carried out. On the other hand The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique has been attracting attention for its precise identification of several microorganisms at species level. In the current study, 183 enterobacteria were detected in milk (n = 47) and fecal samples (n = 94) from cows, and samples from water (n = 23) and milk lines (n = 19). All these samples were collected from a farm in Rio de Janeiro with the specific purpose of presenting the MALDI-TOF MS technique as an efficient methodology to identify Enterobacteriaceae from bovine environments. The MALDI-TOF MS technique results matched the biochemical test results in 92.9% (170/183) of the enterobacteria species and the gyrB sequencing confirmed 100% of the proteomic technique results. The amino acid decarboxylation test made the most misidentifications and Enterobacter spp. was the most misidentified genus (76.9%, 10/13). These results aim to clarify the current biochemical errors in enterobacteria identification, considering isolates from a bovine environment, and show the importance for more careful readings of phenotypic tests which are often used in veterinary microbiology laboratories.
Descritores: Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
Enterobacteriaceae/classificação
Enterobacteriaceae/metabolismo
-Fenótipo
Bovinos
Análise de Sequência de DNA
DNA Girase/genética
Proteômica/métodos
Leite/microbiologia
Enterobacteriaceae/isolamento & purificação
Genes Bacterianos
Mastite Bovina/diagnóstico
Mastite Bovina/microbiologia
Limites: Animais
Feminino
Responsável: BR1.1 - BIREME


  4 / 16 LILACS  
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Id: lil-771616
Autor: Álvarez-Hernández, Diego Abelardo; Garza-Mayén, Gilda Sofía; Vázquez-López, Rosalno.
Título: Quinolonas: Perspectivas actuales y mecanismos de resistencia / Quinolones: Nowadays perspectives and mechanisms of resistance
Fonte: Rev. chil. infectol;32(5):499-504, oct. 2015. tab.
Idioma: es.
Resumo: Quinolones are a family of synthetic broad-spectrum antimicrobial drugs whose target is the synthesis of DNA. They directly inhibit DNA replication by interacting with two enzymes; DNA gyrase and topoisomerase IV. They have been widely used for the treatment of several community and hospital acquired infections, in the food processing industry and in the agricultural field, making the increasing incidence of quinolone resistance a frequent problem associated with constant exposition to diverse microorganisms. Resistance may be achieved by three non-exclusive mechanisms; through chromosomic mutations in the Quinolone Resistance-Determining Regions of DNA gyrase and topoisomerase IV, by reducing the intracytoplasmic concentrations of quinolones actively or passively and by Plasmid-Mediated Quinolones-Resistance genes, [Qnr determinant genes of resistance to quinolones, variant gene of the aminoglycoside acetyltransferase (AAC(6')-Ib-c)] and encoding genes of efflux pumps (qepA and oqxAB)]. The future of quinolones is uncertain, however, meanwhile they continue to be used in an irrational way, increasing resistance to quinolones should remain as an area of primary priority for research.

Las quinolonas son un grupo de antimicrobianos sintéticos de amplio espectro, cuyo objetivo es la síntesis del ADN. Inhiben directamente su replicación al interactuar con dos enzimas; ADN girasa y topoisomerasa IV. Se han utilizado ampliamente para el tratamiento de infecciones intra y extra-hospitalarias, en el campo de la agricultura y en el procesamiento de alimentos, lo que hace que el incremento de resistencia a quinolonas sea un problema cada vez más frecuente, asociado a la constante exposición de diversos microorganismos. La resistencia puede alcanzarse mediante tres mecanismos no excluyentes entre sí; a través de mutaciones cromosómicas en genes codificantes que afectan las regiones determinantes de resistencia a quinolonas de ADN girasa y topoisomerasa IV, al reducir las concentraciones intracitoplásmicas de quinolonas de manera activa o pasiva y por genes de resistencia a quinolonas mediados por plásmidos [genes de resistencia a quinolonas determinates de qnr, gen variante de la aminoglucósido acetil transferasa (AAC(6’)-lb-cr) y genes codificadores de bombas de eflujo (qepAy oqxAB)]. El futuro de las quinolonas es incierto; sin embargo, mientras continúen empleándose para el manejo de infecciones en el ser humano, el incremento de resistencia a quinolonas debe permanecer como un área de importancia primaria para la investigación.
Descritores: Antibacterianos/farmacologia
Enterobacteriaceae/efeitos dos fármacos
Quinolonas/farmacologia
-Acetiltransferases/genética
DNA Girase/genética
DNA Topoisomerase IV/genética
Farmacorresistência Bacteriana/genética
Enterobacteriaceae/enzimologia
Enterobacteriaceae/genética
Limites: Humanos
Tipo de Publ: Revisão
Responsável: CL1.1 - Biblioteca Central


  5 / 16 LILACS  
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Id: lil-762905
Autor: Yassien, M.A.M.; Elfaky, M.A..
Título: Overexpression of Salmonella enterica serovar Typhi recA gene confers fluoroquinolone resistance in Escherichia coli DH5α
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;48(11):990-995, Nov. 2015. tab, graf.
Idioma: en.
Projeto: Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah, Saudi Arabia.
Resumo: A spontaneous fluoroquinolone-resistant mutant (STM1) was isolated from its parent Salmonella enterica serovar Typhi (S. Typhi) clinical isolate. Unlike its parent isolate, this mutant has selective resistance to fluoroquinolones without any change in its sensitivity to various other antibiotics. DNA gyrase assays revealed that the fluoroquinolone resistance phenotype of the STM1 mutant did not result from alteration of the fluoroquinolone sensitivity of the DNA gyrase isolated from it. To study the mechanism of fluoroquinolone resistance, a genomic library from the STM1 mutant was constructed in Escherichia coli DH5α and two recombinant plasmids were obtained. Only one of these plasmids (STM1-A) conferred the selective fluoroquinolone resistance phenotype to E. coli DH5α. The chromosomal insert from STM1-A, digested with EcoRI and HindIII restriction endonucleases, produced two DNA fragments and these were cloned separately into pUC19 thereby generating two new plasmids, STM1-A1 and STM1-A2. Only STM1-A1 conferred the selective fluoroquinolone resistance phenotype to E. coli DH5α. Sequence and subcloning analyses of STM1-A1 showed the presence of an intact RecA open reading frame. Unlike that of the wild-type E. coli DH5α, protein analysis of a crude STM1-A1 extract showed overexpression of a 40 kDa protein. Western blotting confirmed the 40 kDa protein band to be RecA. When a RecA PCR product was cloned into pGEM-T and introduced into E. coli DH5α, the STM1-A11 subclone retained fluoroquinolone resistance. These results suggest that overexpression of RecA causes selective fluoroquinolone resistance in E. coli DH5α.
Descritores: Farmacorresistência Bacteriana/efeitos dos fármacos
Escherichia coli
Fluoroquinolonas/farmacologia
Recombinases Rec A/genética
Salmonella enterica
Sorogrupo
-Western Blotting
Clonagem Molecular
DNA Girase/efeitos dos fármacos
Escherichia coli/classificação
Escherichia coli/efeitos dos fármacos
Escherichia coli/metabolismo
Biblioteca Genômica
INHIBITORY CONCENTRATION ACADEMIES AND INSTITUTES
Testes de Sensibilidade Microbiana
Fases de Leitura Aberta/genética
Reação em Cadeia da Polimerase
Fatores R/metabolismo
Salmonella enterica/classificação
Salmonella enterica/efeitos dos fármacos
Salmonella enterica/genética
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-755834
Autor: Ugwu, Clifford C.; Gomez-Sanz, Elena; Agbo, Ifeoma C.; Torres, Carmen; Chah, Kennedy F..
Título: Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria
Fonte: Braz. j. microbiol;46(3):885-892, July-Sept. 2015. tab, ilus.
Idioma: en.
Resumo:

This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains), Staphylococcus lentus (6 strains), Staphylococcus cohnii (3 strains) and Staphylococcus haemolyticus (one strain). All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%), tetracycline (75%), streptomycin (65%), ciprofloxacin (65%), and trimethoprim/sulphamethoxazole (60%). In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K), tet(M), tet(L), erm(B), erm(C), aacA-aphD, aphA3, str, dfrK, dfrG, catpC221, and catpC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain) and Glu88Asp and Asp96Thr (2 strains). A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA ...

Descritores: Farmacorresistência Bacteriana Múltipla/genética
Fermentação/fisiologia
Manitol/metabolismo
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação
Staphylococcus aureus Resistente à Meticilina/metabolismo
Staphylococcus haemolyticus/isolamento & purificação
Staphylococcus haemolyticus/metabolismo
-Antibacterianos/farmacologia
Proteínas de Bactérias/genética
DNA Girase/genética
DNA Bacteriano/genética
Genes Bacterianos/genética
Testes de Sensibilidade Microbiana
Staphylococcus aureus Resistente à Meticilina/genética
Staphylococcus aureus Resistente à Meticilina/patogenicidade
Nigéria
Proteínas de Ligação às Penicilinas/genética
Infecções Estafilocócicas/microbiologia
Staphylococcus haemolyticus/genética
Staphylococcus haemolyticus/patogenicidade
Suínos/microbiologia
Limites: Animais
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  7 / 16 LILACS  
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Id: lil-755797
Autor: Gomig, Franciane; Galvão, Carolina Weigert; Freitas, Denis Leandro de; Labas, Larissa; Etto, Rafael Mazer; Esmerino, Luiz Antonio; Lima, Marcelo Andrade de; Appel, Marcia Helena; Zanata, Silvio Marques; Steffens, Maria Berenice Reynaud; Nader, Helena Bonciani; Silveira, Rafael Bertoni da.
Título: Quinolone resistance and ornithine decarboxylation activity in lactose-negative Escherichia coli
Fonte: Braz. j. microbiol;46(3):753-757, July-Sept. 2015. tab, ilus.
Idioma: en.
Resumo:

Quinolones and fluoroquinolones are widely used to treat uropathogenic Escherichia coli infections. Bacterial resistance to these antimicrobials primarily involves mutations in gyrA and parC genes. To date, no studies have examined the potential relationship between biochemical characteristics and quinolone resistance in uropathogenic E. coli strains. The present work analyzed the quinolone sensitivity and biochemical activities of fifty-eight lactose-negative uropathogenic E. coli strains. A high percentage of the isolates (48.3%) was found to be resistant to at least one of the tested quinolones, and DNA sequencing revealed quinolone resistant determining region gyrA and parC mutations in the multi-resistant isolates. Statistical analyses suggested that the lack of ornithine decarboxylase (ODC) activity is correlated with quinolone resistance. Despite the low number of isolates examined, this is the first study correlating these characteristics in lactose-negative E. coli isolates.

.
Descritores: Farmacorresistência Bacteriana Múltipla/genética
Infecções por Escherichia coli/tratamento farmacológico
Fluoroquinolonas/uso terapêutico
Lactose/metabolismo
Ácido Nalidíxico/uso terapêutico
Ornitina Descarboxilase/genética
Infecções Urinárias/tratamento farmacológico
Escherichia coli Uropatogênica/genética
-Antibacterianos/uso terapêutico
Brasil
DNA Girase/genética
DNA Topoisomerase IV/genética
Descarboxilação/genética
Descarboxilação/fisiologia
Infecções por Escherichia coli/microbiologia
Testes de Sensibilidade Microbiana
Ornitina/metabolismo
Infecções Urinárias/microbiologia
Escherichia coli Uropatogênica/efeitos dos fármacos
Escherichia coli Uropatogênica/enzimologia
Escherichia coli Uropatogênica/isolamento & purificação
Limites: Humanos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


  8 / 16 LILACS  
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Id: lil-716086
Autor: Sousa, Rafaela Rogério Floriano de.
Título: Pesquisa de genes de resistência a quinolonas em bacilos Gram negativos de origem clínica e ambiental / Research for genes of quinolone resistance in Gram negative bacilli from clinical and environmental origin.
Fonte: São Paulo; s.n; 2014. 97 p.
Idioma: pt.
Tese: Apresentada a Universidade de São Paulo. Faculdade de Saúde Pública. Departamento de Serviço de Saúde Pública para obtenção do grau de Mestre.
Resumo: Introdução. Quinolonas são antimicrobianos sintéticos que inibem as enzimas DNA-girase e topoisomerase IV resultando na morte bacteriana. São altamente eficazes no tratamento de infecções bacterianas, especialmente causadas por bactérias Gram negativas, e portanto amplamente utilizados na medicina humana e veterinária, na qual também são empregados como profiláticos. Porém, o uso indiscriminado e inadequado levou ao aumento de bactérias resistentes a estes compostos. Esta resistência pode ocorrer devido a mutações nas enzimas DNA-girase e topoisomerase IV, e também por genes contidos em plasmídeos. Estes últimos são os principais responsáveis pela disseminação e circulação da resistência entre o meio ambiente e o ambiente hospitalar. Objetivos. Pesquisar genes de resistência a antimicrobianos do grupo das quinolonas em bactérias Gram negativas de origem clínica e ambiental que apresentam resistência fenotípica a este grupo. Material e Métodos. 73 cepas de Enterobacteriaceae e Aeromonas sp. de origem clínica e ambiental foram selecionadas para o estudo, e avaliadas quanto à sensibilidade aos antimicrobianos do grupo das quinolonas e à pesquisa de genes de resistência a este mesmo grupo e mutações no gene que codifica a enzima DNA-girase por meio de PCR e sequenciamento. Resultados. Das 73 cepas previamente selecionadas para compor o estudo, 65 foram utilizadas, devido à exclusão de perfis clonais similares. Nestas, foram observados os genes, qnrS1 (1,5 por cento ), qnrS2 (26,2 por cento ), qnrB1 (3,1 por cento ), qnrB19 (12,3 por cento ), qnrD1 (1,5 por cento ), aac(6)-Ib-cr (10,8 por cento ), oqxA (43,1 por cento ) e oqxB (41,5 por cento ), e duas variantes determinadas qnrB-like (3,1 por cento ) e qnrB69-like (1,5 por cento ). Os genes qnrA, qnrC e qepA não foram identificados. Mutações na enzima DNA-girase foram observadas em 97,9 por cento das cepas positivas para algum dos genes pesquisados...

Introduction. Quinolones are synthetic antimicrobial agents that inhibit DNA gyrase and topoisomerase IV enzymes resulting in bacterial death. They are highly effective in the treatment of bacterial infections, especially the ones caused by Gram negative bacteria, as well as for prophylaxy. Therefore they are widely used in human and veterinary medicine. However, indiscriminate and improper use led to an increase of bacteria resistance to these compounds. This resistance can be due to mutations in DNA gyrase and topoisomerase IV enzymes and also by genes contained in plasmids, which are mainly responsible for the spread and transmission of resistance between the environment and the hospital set. Objectives. To search for genes of resistance to quinolone antimicrobial agents in Gram-negative bacteria from clinical and environmental strains that present phenotypic resistance to this group. Material and Methods. 73 strains of Enterobacteriaceae and Aeromonas spp., from clinical and environmental origin, were selected for this study, and evaluated for antimicrobial susceptibility of quinolone and search of resistance genes in this same group and also for mutations in the gene encoding the enzyme DNA gyrase by PCR and sequencing. Results. Of the 73 strains previously selected to compose this study, 65 were used, due to the exclusion of similar clonal profiles. In these, genes qnrS1 (1.5 per cent ), qnrS2 (26.2 per cent ) qnrB1 (3.1 per cent ), qnrB19 (12.3 per cent ) qnrD1 (1.5 per cent ) aac(6')-Ib-cr (10.8 per cent ) oqxA (43.1 per cent ) and oqxB (41.5 per cent ) were observed, and two variants were named as qnrB-like (3.1 per cent ) and qnrB69-like (1.5 per cent ). The qnrA, qnrC and qepA genes were not identified. Mutations in DNA gyrase enzyme were observed in 97.9 per cent of the positive strains for at least one of the genes studied. It was possible to establish the association of aac(6')-Ib-cr with class 1 integron gene in four strains...
Descritores: Bactérias Gram-Negativas/química
Farmacorresistência Bacteriana/genética
Quinolonas/uso terapêutico
Fatores R
-DNA Girase/genética
Mutação/genética
Reação em Cadeia da Polimerase
Análise de Sequência de DNA
Responsável: BR67.1 - CIR - Biblioteca - Centro de Informação e Referência
BR67.1; MTR, 2046. CM. 54997/2014


  9 / 16 LILACS  
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Id: lil-709485
Autor: Dong-Ya, Meng; Chang-Jian, Sun; Jing-Bo, Yu; Jun, Ma; Wen-Cheng, Xue.
Título: Molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis clinical isolates
Fonte: Braz. j. microbiol;45(1):239-242, 2014. tab.
Idioma: en.
Resumo: To evaluate the molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis (MH) clinical strains isolated from urogenital specimens. 15 MH clinical isolates with different phenotypes of resistance to fluoroquinolones antibiotics were screened for mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) in comparison with the reference strain PG21, which is susceptible to fluoroquinolones antibiotics. 15 MH isolates with three kinds of quinolone resistance phenotypes were obtained. Thirteen out of these quinolone-resistant isolates were found to carry nucleotide substitutions in either gyrA or parC. There were no alterations in gyrB and no mutations were found in the isolates with a phenotype of resistance to Ofloxacin (OFX), intermediate resistant to Levofloxacin (LVX) and Sparfloxacin (SFX), and those susceptible to all three tested antibiotics. The molecular mechanism of fluoroquinolone resistance in clinical isolates of MH was reported in this study. The single amino acid mutation in ParC of MH may relate to the resistance to OFX and LVX and the high-level resistance to fluoroquinolones for MH is likely associated with mutations in both DNA gyrase and the ParC subunit of topoisomerase IV.
Descritores: Antibacterianos/farmacologia
Farmacorresistência Bacteriana
Fluoroquinolonas/farmacologia
Mutação de Sentido Incorreto
Infecções por Mycoplasma/microbiologia
Mycoplasma hominis/efeitos dos fármacos
Infecções do Sistema Genital/microbiologia
-DNA Girase/genética
DNA Topoisomerase IV/genética
Mycoplasma hominis/genética
Mycoplasma hominis/isolamento & purificação
Limites: Humanos
Responsável: BR1.1 - BIREME


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Id: lil-683130
Autor: Rushdy, Abeer Ahmed; Mabrouk, Mona Ibrahim; Abu-Sef, Ferialla Abdel-Hamid; Kheiralla, Zeinab Hassan; Abdel -All, Said Mohamed; Saleh, Neveen Mohamed.
Título: Contribution of different mechanisms to the resistance to fluoroquinolones in clinical isolates of Salmonella enterica
Fonte: Braz. j. infect. dis;17(4):431-437, July-Aug. 2013. ilus, tab.
Idioma: en.
Resumo: OBJECTIVES: To study the potential factors include gene mutation, efflux pump and alteration of permeability associated with quinolone-resistance of Salmonella enterica strains isolated from patients with acute gastroenteritis and to evaluate the degree of synergistic activity of efflux pump inhibitors when combined with ciprofloxacin against resistant isolates. METHODS: Antimicrobial resistance patterns of fifty-eight Salmonella isolates were tested. Five isolates were selected to study the mechanism of resistance associated with quinolone group, including mutation in topoisomerase-encoding gene, altered cell permeability, and expression of an active efflux system. In addition, the combination between antibiotics and efflux pump inhibitors to overcome the microbial resistance was evaluated. RESULTS: Five Salmonella isolates totally resistant to all quinolones were studied. All isolates showed alterations in outer membrane proteins including disappearance of some or all of these proteins (Omp-A, Omp-C, Omp-D and Omp-F). Minimum inhibitory concentration values of ciprofloxacin were determined in the presence/absence of the efflux pump inhibitors: carbonyl cyanide m-chlorophenylhydrazone, norepinephrin and trimethoprim. Minimum inhibitory concentration values for two of the isolates were 2-4 fold lower with the addition of efflux pump inhibitors. All five Salmonella isolates were amplified for gyrA and parC genes and only two isolates were sequenced. S. Enteritidis 22 had double mutations at codon 83 and 87 in addition to three mutations at parC at codons 67, 76 and 80 whereas S. Typhimurium 57 had three mutations at codons 83, 87 and 119, but no mutations at parC. CONCLUSIONS: Efflux pump inhibitors may inhibit the major AcrAB-TolC in Salmonella efflux systems which are the major efflux pumps responsible for multidrug resistance in Gramnegative clinical isolates.
Descritores: Antibacterianos/farmacologia
Fluoroquinolonas/farmacologia
Salmonella enterica/efeitos dos fármacos
-DNA Girase/genética
DNA Topoisomerase IV/genética
Farmacorresistência Bacteriana/genética
Testes de Sensibilidade Microbiana
Proteínas de Membrana Transportadoras/efeitos dos fármacos
Salmonella enterica/genética
Salmonella enterica/isolamento & purificação
Limites: Humanos
Responsável: BR1.1 - BIREME



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