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1.
J Prosthet Dent ; 131(5): 935.e1-935.e8, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38431509

RESUMEN

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) materials have become popular for dental restorations; however, which materials should be preferred in terms of surface properties after biofilm formation is unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of biofilm formation on the discoloration properties of resin-infiltrated ceramic and glass-ceramic CAD-CAM materials and human teeth and to examine the effect of the brushing procedure on color change. MATERIAL AND METHODS: One hundred and six 2-mm-thick specimens were prepared from IPS e.max CAD and Cerasmart, and a total of 53 intact human teeth were used. Five specimens from each group were used to measure the amount of live biomass in the biofilm. The remaining 48 specimens in each group were divided into 4 subgroups: kept in distilled water without the formation of dental biofilm (DW), kept in tea without the formation of dental biofilm (T), kept in distilled water after the formation of dental biofilm (DWB), and kept in tea after the formation of dental biofilm (TB) (n=12). After finishing and polishing the materials, initial color measurements were made using a spectrophotometer, and surface roughness measurements were made using noncontact profilometer. After creating a biofilm layer in DWB and TB, all specimens were kept in their solutions at 37 °C for 24 hours, and the color measurements were repeated. After the biofilm layer had been removed by brushing, a third color measurement was made. The data were statistically analyzed with one-way analysis of variance (ANOVA) and two-way ANOVA (α=.05). RESULTS: The lowest roughness value was observed in Cerasmart. Tooth-IPS e.max CAD gave similar results. The Cerasmart material had the most viable biomass, whereas the IPS e.max CAD material had the least. TB had the highest ΔE1 value for all materials and DW had the lowest (P<.05). The brushing procedure caused the materials to return to their initial colors or reduce the color change in most groups. CONCLUSIONS: The presence of biofilm on CAD-CAM materials immersed in distilled water caused an unacceptable degree of discoloration (ΔE>1.8), and immersion in tea led to greater color change. The adhesion of biofilm to restorative dental materials plays an important role in the coloring of these dental materials.


Asunto(s)
Biopelículas , Cerámica , Color , Diseño Asistido por Computadora , Porcelana Dental , Propiedades de Superficie , Cerámica/química , Humanos , Ensayo de Materiales , Técnicas In Vitro , Materiales Dentales/química , Cepillado Dental , Resinas Sintéticas
2.
Int J Environ Health Res ; : 1-15, 2023 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-37805703

RESUMEN

Podologists are exposed to many occupational hazards, including volatile organic compounds (VOCs) from insole manufacturing and noise/vibration during nail or tissue grinding. In this study, VOCs, noise, and vibration were measured in five podiatry clinics and three offices. Questionnaires were administered to 23 podologists and 19 office workers to inquire about their pain, ocular, skin and respiratory complaints. The results showed that the podologists' exposure to the total VOC concentrations was approximately twice as high as that of the office workers. The podologists' complaints regarding pain were found to be correlated with ambient noise and hand-arm vibration levels. Ocular, skin, and respiratory complaints were also found to be correlated with total VOC concentrations. These results suggest that VOCs, noise and vibration in the working environment may impair podologists' health and that they have an intensifying effect on each other, increasing the severity of health issues.

3.
J Infect Chemother ; 28(2): 192-198, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34711509

RESUMEN

INTRODUCTION: Carbapenems are frequently used in the treatment of multidrug-resistant infections caused by Klebsiella pneumoniae. The aim of the study is to definition and incidence of transferable carbapenemase genes of carbapenem resistant K. pneumoniae (CRKP) and to determine clonal relatedness of these strains in tertiary care hospital in Turkey. METHODS: Identification of all 100 K. pneumoniae isolates and low sensitivity to any of the carbapenem group antibiotics were determined by Vitek-2 (BioMérieux, France). The frequency of carbapenemase genes (blaOXA-48, blaNDM, blaKPC, blaVIM,blaIMP) and extended spectrum beta-lactamase (ESBL) genes (blaCTX-M, blaSHV, blaTEM) which frequently detected in Turkey, have been investigated by multiplex polymerase chain reaction (PCR). Clonal relatedness was determined using Pulsed-field gel electrophoresis(PFGE). RESULTS: Ninety five isolates carried at least one of the carbapenemase genes (81.05% blaOXA-48, 38.9% blaNDM, 9.47% blaKPC,1.05% blaVIM). One isolate was carried the blaOXA-48+KPC and the two isolates were carried the blaKPC+NDM. PFGE demonstrated the presence of 24 pulse types and 63.09% of the isolates were in four main pulse types. CONCLUSIONS: This study demonstrated the incidence of blaNDM is beginning to reach endemic levels, in addition to blaOXA-48 found endemic in Turkey. To our knowledge, this is the first report of the co-production of these two genes (blaKPC + NDM and blaOXA-48 + KPC) in CRKP isolates.


Asunto(s)
Infecciones por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Electroforesis en Gel de Campo Pulsado , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa Multiplex , Turquía/epidemiología , beta-Lactamasas/genética
4.
Mikrobiyol Bul ; 48(2): 191-200, 2014 Apr.
Artículo en Turco | MEDLINE | ID: mdl-24819257

RESUMEN

Although Salmonella enterica serotype Paratyphi B is the less frequently isolated serotype worldwide and in Turkey, it is the most common serotype in our hospital, with a marked increase in 2007. The purpose of this study was to investigate the antibiotic susceptibility and the extended spectrum beta-lactamase (ESBL) profile, and molecular epidemiology of S. Paratyphi B isolates detected in our hospital microbiology laboratory. Seventy isolates identified as S. Paratyphi B from 109 Salmonella isolates obtained from clinical specimens from different patients between October 2005 and December 2012, were included in the study. In addition to conventional methods, isolates were identified using the Phoenix automated microbiology system (Becton Dickinson, USA). Serotyping of the isolates was performed on the basis of slide agglutination and the Kauffmann-White scheme. The antibiotic susceptibility of the isolates was determined using the BD Phoenix' automated system and disk diffusion test. ESBL enzymes were investigated using the combined disk test, isoelectric focusing, polymerase chain reaction (PCR) and sequence analysis. The molecular epidemiology of the 51 isolates obtained between October 2005 and August 2008 was examined with pulsed-field gel electrophoresis (PFGE) using the XbaI enzyme. S. Paratyphi B isolates were obtained from 70 specimens (46 blood, 16 fecal, 4 bone marrow, 2 urine and 2 wound) each from different patients. Resistance to nalidixic acid was determined in 18.6%, resistance to ampicillin, cefotaxime and cefepime in 2.9% and to ceftazidime and co-trimoxazole in 1.4% of the isolates. ESBL production was detected only in two isolates; in one TEM-1 was accompanied by CTX-M-15 and in the other isolate CTX-M-3 was found. Forty-six of the 51 isolates (90%) were found to be genetically related by PFGE and were placed in cluster A. The distribution of the isolates in cluster A revealed six subtypes as A1 (n= 7), A2 (n= 11), A3 (n= 7), A4 (n= 18), A5 (n= 2) and A6 (n= 1). Three different patterns not related to the cluster A were determined in the remaining five isolates (two were B, one of each was C, D and E). In conclusion, although the rate of antibiotic resistance was low in the S. Paratyphi B isolates in our hospital, rare types of ESBLs such as CTX-M-3 and CTX-M-15 were detected in Salmonellae. As far as the current literature is considered, this is the first report in Turkey of blaCTX-M-15 in Salmonella spp. and blaCTX-M-3 genes in S. Paratyphi B. The results may indicate a possible future threat to the treatment of Salmonella infections. Since most of the isolates were genetically related, this might suggest an epidemic in our region.


Asunto(s)
Fiebre Paratifoidea/microbiología , Salmonella paratyphi B/aislamiento & purificación , beta-Lactamasas/metabolismo , Pruebas de Aglutinación , Análisis por Conglomerados , Desoxirribonucleasas de Localización Especificada Tipo II , Pruebas Antimicrobianas de Difusión por Disco , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Humanos , Focalización Isoeléctrica , Pruebas de Sensibilidad Microbiana/métodos , Fiebre Paratifoidea/epidemiología , Reacción en Cadena de la Polimerasa , Salmonella paratyphi B/clasificación , Salmonella paratyphi B/efectos de los fármacos , Salmonella paratyphi B/enzimología , Análisis de Secuencia , Serotipificación , Turquía/epidemiología , beta-Lactamasas/genética
5.
Cureus ; 16(4): e58368, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38756251

RESUMEN

Introduction: Oral diseases affect billions worldwide, with dental caries being a significant concern. Silver-copper nanoparticles (Ag-Cu NPs) synthesized from pitaya plant extract offer a potential solution due to their antimicrobial properties. This study aimed to evaluate the inhibitory effects of Ag-Cu NPs on Streptococcus mutans (S. mutans), a major contributor to dental caries. METHODOLOGY: Ag-Cu NPs were synthesized using a green chemical method and characterized using a scanning electron microscope (SEM), ultraviolet-visible (U-vis) spectrophotometer, and Fourier Transform Infrared Spectroscopy (FT-IR). The minimum inhibitory concentration (MIC) against S. mutans was determined using the broth microdilution method, while the antibiofilm effect was assessed by the crystal violet method. RESULTS: The synthesized Ag-Cu NPs demonstrated antimicrobial activity with an MIC of 128 µg/ml, significantly inhibiting S. mutans biofilm formation by up to 94% at a concentration of 256 µg/ml. Characterization studies confirmed the successful synthesis of Ag-Cu NPs with spherical morphology. CONCLUSIONS:  These findings highlight the potential of Ag-Cu NPs as a novel approach for combating dental caries by targeting S. mutans biofilms. Further research is warranted to explore their safety and efficacy in clinical settings.

6.
J Enzyme Inhib Med Chem ; 28(5): 990-6, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22845331

RESUMEN

CONTEXT: Isolation and characterization of OXA-162, a novel variant of OXA-48. OBJECTIVES: Klebsiella pneumoniae isolate with decreased susceptibility to carbapenems was recovered from a Turkish patient. This study aimed at characterizing the carbapenem resistance determinants of this isolate. MATERIALS AND METHODS: Antibiotic susceptibility tests, analytic isoelectric focusing (IEF), cloning and sequencing were performed. Cloned ß-lactamase was purified by means of preparative gel electrophoresis and the kinetic constants were determined under initial rate conditions. RESULTS: The identified bla(OXA-162) gene was located on a ca. 45-kb plasmid carrying a transposon consisted of two IS1999-2 elements. OXA-162 differed from OXA-48 by a single amino acid substitution (Thr213Ala) which increased the catalytic efficiency (k(cat)/K(M)) of OXA-162 towards imipenem and meropenem. Also this substitution caused a gain of hydrolysis ability towards doripenem. Analysis of OXA-162 model implied that the amino acid change might generate an extension in the opening of the substrate entry site and might cause extended hydrolytic activity towards imipenem, meropenem and doripenem. DISCUSSION AND CONCLUSION: OXA-162, a derivative of OXA-48 has enhanced catalytic properties.


Asunto(s)
Biocatálisis , Carbapenémicos/metabolismo , Farmacorresistencia Bacteriana/genética , Imipenem/metabolismo , Klebsiella pneumoniae/enzimología , Tienamicinas/metabolismo , beta-Lactamasas/metabolismo , Carbapenémicos/química , Clonación Molecular , Elementos Transponibles de ADN/genética , Doripenem , Humanos , Hidrólisis , Imipenem/química , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Meropenem , Modelos Moleculares , Plásmidos/genética , Tienamicinas/química , beta-Lactamasas/química , beta-Lactamasas/aislamiento & purificación
7.
Turk Arch Pediatr ; 58(4): 371-375, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37357451

RESUMEN

OBJECTIVE: Congenital cytomegalovirus infection is the most common congenital infection. Although screening of congenital cytomegalovirus infection with polymerase chain reaction studies in blood, urine, and saliva samples has been developed in recent years, it is not yet in routine use in any country. MATERIALS AND METHODS: In our study, cytomegalovirus deoxyribonucleic acid analysis was per- formed by real-time polymerase chain reaction method in saliva samples taken before the first feeding during the first day following birth in neonates born in a university hospital between January 2021 and January 2022. To support the diagnosis, additionally, cytomegalovirus deoxy- ribonucleic acid positivity in urine and blood samples was investigated in newborns with cyto- megalovirus deoxyribonucleic acid positivity in saliva. RESULTS: Cytomegalovirus deoxyribonucleic acid was investigated in saliva samples of 545 neonates by real-time polymerase chain reaction method in 1-year period and positiv- ity was found in 6 neonates. Since cytomegalovirus deoxyribonucleic acid was found nega- tive by the real-time polymerase chain reaction method in the urine and blood samples of 5 of these neonates, the positivity in the saliva sample was interpreted as false positivity. In 1 case, cytomegalovirus deoxyribonucleic acid positivity was detected in urine and blood samples 5 weeks later. As a result, definite congenital cytomegalovirus infection could not be diagnosed in 545 cases, while possible congenital cytomegalovirus infection was diag- nosed in 1 case. CONCLUSION: It has been concluded that the frequency of congenital cytomegalovirus infection is low in our study group and studying saliva samples showed high false-positive rates. It is seen that saliva is not a suitable sample for detecting cytomegalovirus deoxyribonucleic acid by real-time polymerase chain reaction method.

8.
Mikrobiyol Bul ; 46(2): 332-4, 2012 Apr.
Artículo en Turco | MEDLINE | ID: mdl-22639323

RESUMEN

Helicobacter pylori strains isolated from different regions of the world or human ethnic groups exhibit some differences at certain loci. The aim of this study was to determine allelic differences of H.pylori strains isolated from two countries, Turkey and Germany. A total of 72 H.pylori isolates, of which 37 strains were from Kocaeli province of Turkey and 35 strains from Hamburg, Germany were included in this study. H.pylori strains had been isolated from gastric biopsies of the patients. Genomic DNA was extracted with phenol-chloroform-isoamyl alcohol procedure and vacA alleles and cagA regions were identified by polymerase chain reaction (PCR) using specific primer sets. The rates of cagA positivity in Kocaeli and Hamburg strains were found as 75.7% (28/37) and 71.4% (25/35), respectively. VacA s1a allele was predominant both in Turkey and Germany isolates. There were five vacA mosaicisms in Hamburg strains, including 14 for s1a/m1a (40%), nine for s1a/m2 (25.7%), eight for s2/m2 (17.1%), three for s1a/m1 (8.5%) and three for s1b/m2 (8.5%). There were four vacA mosaicisms in Kocaeli strains, including 22 for s1a/m2 (59.4%), eight for s2/m2 (21.6%), four for s1a/m1a (10.8%), and three for s1a/m1 (8.1%). In this study, Hamburg and Kocaeli strains did not reveal significant differences regarding cagA status and vacA s1 allele. Whereas vacA s1a/m1a, cagA(+) type was the most frequent in Hamburg strains and s1a/m2, cagA (+) type in Kocaeli strains.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Alelos , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , Alemania/epidemiología , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/aislamiento & purificación , Humanos , Turquía/epidemiología
9.
Ann Clin Microbiol Antimicrob ; 9: 1, 2010 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-20067633

RESUMEN

BACKGROUND: We studied the beta-lactamases of an E. aerogenes isolate recovered from the blood of a two-year-old patient. The isolate demonstrated a disk-diffusion phenotype typical for an AmpC-ESBL co-producer. METHODS: Microbiology studies were performed according to standard protocols. The resistance gene was identified by transconjugation and cloning experiments. RESULTS: By transconjugation only a narrow spectrum beta-lactamase (TEM-1) encoded on a small plasmid was transmitted. The ESBL was cloned and expressed in an E. coli host. Sequence analysis of the recombinant plasmid revealed blaSHV-12 associated to the insertion sequence, IS26. CONCLUSION: This is the first study demonstrated the occurrence of SHV-12 in Nigeria.


Asunto(s)
Enterobacter aerogenes/enzimología , Infecciones por Enterobacteriaceae/microbiología , beta-Lactamasas/metabolismo , Antibacterianos/farmacología , Secuencia de Bases , Preescolar , Farmacorresistencia Bacteriana/genética , Enterobacter aerogenes/efectos de los fármacos , Enterobacter aerogenes/aislamiento & purificación , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Nigeria , beta-Lactamasas/genética
10.
FEMS Microbiol Lett ; 282(2): 214-8, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18371065

RESUMEN

An intensive care unit (ICU)-based OXA-23-producing multiple-drug resistant Acinetobacter baumannii (MDRAB) outbreak was detected between October 2005 and October 2006. A total of 47 patients were infected/colonized with the outbreak strain. Clinical data were available from 37 patients. The all-cause mortality rate among the patients exposed to the epidemic strain was 35% (13/37). The outbreak strain and the resistance determinants were characterized both by microbiological methods and by molecular techniques. Cloning and sequencing experiments identified ISAbaI-associated bla(oxa-23) on the chromosome. Screening of imipenem-resistant Acinetobacter isolated from the ICU during the outbreak period with PCR identified 97 isolates as positive for the ISAbaI-bla(oxa-23) structure. Pulsed-field gel electrophoresis and plasmid analyses with selected nonrepetitive isolates revealed the clonality. Disk diffusion on cloxacillin-supplemented agar media and the real-time PCR experiments showed that outbreak isolates are overexpressing the ampC enzyme. This study highlights the occurrence of OXA-23-producing and ampC-overexpressing MDRAB in ICUs.


Asunto(s)
Infecciones por Acinetobacter/epidemiología , Acinetobacter baumannii/genética , Carbapenémicos/farmacología , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/enzimología , Electroforesis en Gel de Campo Pulsado , Humanos , Unidades de Cuidados Intensivos , Turquía/epidemiología
11.
Biomed Mater ; 13(2): 025013, 2018 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-29061917

RESUMEN

In this study, the mechanical, antibacterial properties and cell toxicity response of Ti-5Al2.5Fe alloy with different copper contents were investigated. The alloys were prepared by high-energy ball milling using elemental Ti, Al, Fe, and Cu powders and consolidated by a uniaxial vacuum hot press. Staphylococcus aureus strain ATCC 29213 and Escherichia coli strain ATCC 25922 were used to determine the antibacterial properties of the sintered alloys. The in vitro cytotoxicity of the samples was evaluated with HeLa (ATTC, CCL-2) cells using thiazolyl blue tetrazolium bromide. The mechanical behavior of the samples was determined as a function of hardness and bending tests and analyzed by scanning electron microscopy, energy dispersive x-ray spectroscopy, optical microscopy and x-ray diffraction (XRD). The results showed that the Cu content significantly improved the antibacterial properties. Cu addition prevented the formation of E. coli and S. aureus colonies on the surface of the samples. All samples exhibited very good cell biocompatibility. The alloys with different copper contents showed different mechanical properties, and the results were correlated by microstructural and XRD analyses in detail. Our results showed that Cu has a great effect on the Ti5Al2.5Fe alloy and the alloy is suitable for biomedical applications with enhanced antibacterial activity.


Asunto(s)
Aleaciones/química , Antibacterianos/química , Materiales Biocompatibles/química , Cobre/química , Fuerza Compresiva , Corrosión , Escherichia coli , Dureza , Células HeLa , Calor , Humanos , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Polvos , Staphylococcus aureus , Estrés Mecánico , Sales de Tetrazolio/química , Tiazoles/química , Difracción de Rayos X
12.
FEMS Microbiol Lett ; 249(2): 241-5, 2005 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-16006075

RESUMEN

PER-1 type beta-lactamases were screened among ceftazidime-resistant clinical isolates of Acinetobacter spp. and Pseudomonas aeruginosa. A total of 176 non-repetitive isolates (84 Acinetobacter spp. and 92 P. aeruginosa) were collected during a three month surveillance period. Isolates were obtained from seven intensive care units of seven university hospitals. All strains were screened for bla(PER-1) alleles by PCR. Of the strains, 31% and 55.4% of Acinetobacter spp. and P. aeruginosa were positive for bla(PER-1) type genes, respectively.


Asunto(s)
Acinetobacter/enzimología , Pseudomonas aeruginosa/enzimología , beta-Lactamasas/análisis , Acinetobacter/genética , Acinetobacter/aislamiento & purificación , Hospitales Universitarios , Unidades de Cuidados Intensivos , Reacción en Cadena de la Polimerasa , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , Turquía , beta-Lactamasas/genética
13.
New Microbiol ; 28(3): 231-6, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16240695

RESUMEN

An outbreak of extended-spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae (ESBL-Kp) in a neonatal intensive care unit prompted a prospective surveillance study between 12th September and 6th October 2003. Surveillance was carried out by obtaining stool samples twice a week. The DNA relatedness of the isolates was shown by random amplified polymorphic DNA comparison (ERIC-PCR). ESBL production was identified by clavulanate synergy, isoelectric focusing, PCR and sequence analysis. During the study period, 49 neonates were hospitalized in the neonatal intensive care unit (NICU). In the first 20-day period, five neonates were infected with ESBL-Kp. The first patient treated with third generation cephalosporin and the second patient treated with meropenem died. While all three infected survivors were clinically improving, the digestive tracts were being colonized by SHV-5 producing Klebsiella. In the next period of the study, five neonates were colonized by ESBL-Kp as well. Univariate comparison of risk factors between colonized and non-colonized neonates was not significant. A total of 24 colonally related ESBL-Kp have been recovered from clinical materials and stool samples. This study demonstrated that parenterally applied meropenem, though successful in treating the systemic illness, might fail to protect the digestive tract from colonization of ESBL-Kp.


Asunto(s)
Infección Hospitalaria/epidemiología , Heces/microbiología , Unidades de Cuidado Intensivo Neonatal , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Tienamicinas/uso terapéutico , beta-Lactamasas/biosíntesis , Antibacterianos/uso terapéutico , Cefalosporinas/uso terapéutico , Estudios de Cohortes , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Infección Hospitalaria/prevención & control , Dermatoglifia del ADN , ADN Bacteriano/análisis , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , Brotes de Enfermedades , Femenino , Genes Bacterianos , Humanos , Recién Nacido , Focalización Isoeléctrica , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/prevención & control , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/crecimiento & desarrollo , Masculino , Meropenem , Epidemiología Molecular , Reacción en Cadena de la Polimerasa , Técnica del ADN Polimorfo Amplificado Aleatorio , Análisis de Secuencia de ADN , beta-Lactamasas/aislamiento & purificación , beta-Lactamasas/metabolismo
14.
J Med Microbiol ; 53(Pt 9): 915-920, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15314200

RESUMEN

The effects of imipenem and meropenem on the transcriptional expression of resistance-related genes oprD, oprM and oprN in Pseudomonas aeruginosa were studied by quantitative real-time PCR. Four strains were examined: the type strain PT5 (PAO1), its derivatives M7 and PT149, and a clinical isolate, PaKT3. The derivative M7 is a nalB mutant, overexpressing the MexAB-OprM pump, and the derivative PT149 is a nfxC-type mutant, overexpressing the MexEF-OprN pump while it is down-regulated for the OprD protein. After 18 h incubation in broth, the cultures were divided into three portions. Two were supplemented with antibiotics and the other was left antibiotic-free as the control. After a further 45 min incubation, total RNA was isolated from the strains by guanidine denaturation and acid-phenol/chloroform extraction. DNA-free total RNAs were immediately reverse-transcribed by MMuLV reverse transcriptase. Concentrations of mRNAs obtained by quantitative PCR were expressed relative to uninduced portions of the strains. The results showed that oprD was relatively stable against carbapenem antibiotics. oprM was induced significantly by imipenem in only one strain and oprN was induced by imipenem in most of the strains. The responses at the mRNA level found here were unexpected and suggested a chaotic, unpredictable regulatory mechanism.


Asunto(s)
Antibacterianos/farmacología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Farmacorresistencia Bacteriana , Regulación Bacteriana de la Expresión Génica , Imipenem/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Tienamicinas/farmacología , Transcripción Genética/efectos de los fármacos , Proteínas de la Membrana Bacteriana Externa/genética , Humanos , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Meropenem , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Porinas/genética , Porinas/metabolismo , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
15.
J Med Microbiol ; 52(Pt 5): 403-408, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12721316

RESUMEN

Constantly expressed genes are used as internal controls in relative quantification studies. Suitable internal controls for such studies have not yet been defined for Pseudomonas aeruginosa. In this study, the genes ampC, fabD, proC, pbp-2, rpoD and rpoS of P. aeruginosa were compared in terms of expression stability by real-time quantitative RT-PCR. A total of 23 strains with diverse resistance phenotypes were studied. Stability of expression among the housekeeping genes was assessed on the basis of correlation coefficients, with the best-correlated pair accepted as being the most stable one. Eventually, proC and rpoD formed the most stable pair (r = 0.958; P < 0.001). Next, in four ciprofloxacin-selected nfxC-like mutants, levels of oprD, oprM and oprN mRNA were compared with those of their wild-type counterparts. The comparison was made after correcting the raw values by the geometric mean of the internal control genes proC and rpoD. The level of oprN mRNA was significantly up-regulated, while the oprD gene was down-regulated (although this difference was statistically insignificant), in the mutants. This expression pattern was consistent with that of the expected expression profile of nfxC-type mutants; this experiment therefore lends further support to the use of proC and rpoD genes simultaneously as internal controls for such studies.


Asunto(s)
Proteínas Portadoras , Muramoilpentapéptido Carboxipeptidasa , Pseudomonas aeruginosa/genética , S-Maloniltransferasa de la Proteína Transportadora de Grupos Acilo , Aciltransferasas/genética , Antiinfecciosos/farmacología , Proteínas Bacterianas/genética , Ciprofloxacina/farmacología , Cartilla de ADN/química , ADN Bacteriano/análisis , ARN Polimerasas Dirigidas por ADN/genética , Farmacorresistencia Bacteriana/genética , Regulación Bacteriana de la Expresión Génica , Hexosiltransferasas/genética , Humanos , Pruebas de Sensibilidad Microbiana , Complejos Multienzimáticos/genética , Mutación , Proteínas de Unión a las Penicilinas , Peptidil Transferasas/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/enzimología , Pirrolina Carboxilato Reductasas/genética , ARN Mensajero/metabolismo , Técnica del ADN Polimorfo Amplificado Aleatorio , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor sigma/genética , beta-Lactamasas/genética
16.
J Infect Dev Ctries ; 7(5): 424-31, 2013 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-23669434

RESUMEN

In this report, a case of community-acquired acute bacterial meningitis (CA-ABM) caused by CTX-M-15-producing Escherichia coli in an elderly male patient was presented in the light of literature. Cultures of cerebrospinal fluid, blood, ear discharge, and stool samples yielded CTX-M-15-producing E. coli in-vitro, which was resistant to the extended-spectrum cephalosporins and ciprofloxacin and susceptible to imipenem, meropenem and amikacin. Meningitis was treated with parenteral meropenem plus parenteral and intraventricular amikacin administration. Since bacterial meningitis is a life-threatening infection, empiric antibiotic therapy with carbapenem can be started before the culture results are obtained, mainly in areas where the ESBL epidemiology is well known.


Asunto(s)
Infecciones Comunitarias Adquiridas/microbiología , Escherichia coli/enzimología , Meningitis por Escherichia coli/microbiología , beta-Lactamasas/metabolismo , Anciano de 80 o más Años , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Sangre/microbiología , Líquido Cefalorraquídeo/microbiología , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Escherichia coli/aislamiento & purificación , Heces/microbiología , Humanos , Masculino , Meningitis por Escherichia coli/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana , Otitis Media con Derrame/microbiología , Resultado del Tratamiento , Resistencia betalactámica , beta-Lactamas/farmacología , beta-Lactamas/uso terapéutico
17.
Biofouling ; 23(1-2): 63-71, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17453730

RESUMEN

It has been proposed that the virulence of nosocomial Staphylococcus infections associated with indwelling medical devices is related to the ability of the bacterium to colonise these materials by forming a biofilm composed of multilayered cell clusters embedded in a slime matrix. However, the pathogenic role of exopolysaccharide biofilms is not fully understood. A new method was sought for differentiating the structure of slime from two closely related bacterial strains, Staphylococcus aureus and Staphylococcus epidermidis. Using PCR it was confirmed that these strains were positive for the icaA and icaD genes and the complete ica operon (2.7 kb). Monosaccharide analysis by thin-layer chromatography revealed an identical profile for both strains, with xylose and glucose present among the four visible bands. Using Fourier-transformed infrared spectroscopy and hierarchical cluster analysis, three of four S. aureus samples (75%), and four of five S. epidermidis samples were grouped according to species. A novel FTIR approach in classifying slime produced by S. aureus and S. epidermidis is reported.


Asunto(s)
Polisacáridos Bacterianos/clasificación , Staphylococcus aureus/química , Staphylococcus epidermidis/química , Técnicas Bacteriológicas , Secuencia de Bases , Biopelículas/crecimiento & desarrollo , Infección Hospitalaria/etiología , ADN Bacteriano/genética , Genes Bacterianos , Humanos , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/genética , Especificidad de la Especie , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Infecciones Estafilocócicas/etiología , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad , Staphylococcus aureus/fisiología , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/patogenicidad , Staphylococcus epidermidis/fisiología , Virulencia/genética
18.
J Antimicrob Chemother ; 58(3): 537-42, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16816400

RESUMEN

OBJECTIVES: This study was designed to demonstrate the prevalence of the newly discovered carbapenem-hydrolysing class D enzymes, OXA-51-type and OXA-58, among clinical isolates of Acinetobacter spp. METHODS: A total of 72 isolates from six centres were studied. Isolates were screened by PCR with specific primers for bla(OXA-51-type) and bla(OXA-58). PCR products were sequence-analysed. Plasmids were digested with EcoRV and genomic DNAs were digested with PvuII. Hybridization experiments were done with digoxigenin-labelled specific probes. Macro-restriction analysis was done on SmaI-digested genomic DNAs. RESULTS: A total of 56 (77.8%) isolates were positive for bla(OXA-51-type) genes. Sequence analysis of the products from 23 selected isolates revealed the occurrence of multiple alleles in all contributing centres. The bla(OXA-58) gene was detected among 10 isolates from five centres. All were also positive for bla(OXA-51-type) genes. Among the bla(OXA-58)-positive isolates, two from the same centre were positive for a novel OXA-51 allele (OXA-86). Southern hybridization of plasmids and of genomic DNAs suggested that bla(OXA-51-type) genes are located on chromosomes whereas bla(OXA-58) genes are plasmid borne in these 10 isolates. Plasmid profiles and pulsed-field gel electrophoresis patterns indicated the spread of the bla(OXA-58) gene among multiple clones. The bla(OXA-51-type) and bla(OXA-58) co-carrier strains were mostly associated with a pandrug-resistant phenotype. CONCLUSIONS: This study indicated that bla(OXA-58)-bearing plasmids are readily spreading among multiple clones of the bla(OXA-51-type)-bearing clinical isolates of Acinetobacter spp. Since these isolates are highly resistant to antibiotics this finding indicates the existence of a significant problem in Turkish hospitals.


Asunto(s)
Infecciones por Acinetobacter/epidemiología , Acinetobacter/aislamiento & purificación , Antibacterianos/farmacología , Ceftazidima/farmacología , Infección Hospitalaria/epidemiología , Resistencia betalactámica , beta-Lactamasas/genética , Acinetobacter/efectos de los fármacos , Acinetobacter/enzimología , Acinetobacter/genética , Infecciones por Acinetobacter/microbiología , Alelos , Southern Blotting , Infección Hospitalaria/microbiología , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Genes Bacterianos , Hospitales Universitarios , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Prevalencia , Turquía/epidemiología , Resistencia betalactámica/genética
19.
Scand J Infect Dis ; 37(10): 712-6, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16191887

RESUMEN

Tularaemia was diagnosed by TaqMan RT-PCR and microagglutination tests in 5 patients, all from a new settlement constructed after the earthquake of 1999. During the follow-up, 129 more cases were found in this settlement (data from the local Health Care Authority). In this study, clinical features of 5 cases are presented briefly, and the Turkish literature on past outbreaks of tularaemia is reviewed.


Asunto(s)
Brotes de Enfermedades , Francisella tularensis/aislamiento & purificación , Tularemia/epidemiología , Adulto , Pruebas de Aglutinación , Femenino , Francisella tularensis/genética , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Polimerasa Taq , Tularemia/diagnóstico , Turquía/epidemiología
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