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1.
Eur J Clin Microbiol Infect Dis ; 19(8): 602-7, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11014622

RESUMO

In a retrospective study conducted in an Italian tertiary care hospital, the incidence of nosocomial candidemia was evaluated together with causative pathogens, treatment, and risk factors for death. Over a 6-year period (1992-1997), a total of 189 episodes of candidemia occurred in 189 patients (mean age 58+/-19 years), accounting for an average incidence of 1.14 episodes per 10,000 patient-days per year. The most common reasons for hospitalization were solid neoplasia (21%), trauma (17%), abdominal diseases requiring surgery (13%), and cardiovascular diseases (13%). No patient was neutropenic within 3 weeks prior to the onset of candidemia. One hundred thirty patients were hospitalized in intensive care units, 47 patients in surgical wards, and 12 patients in medical wards. Candida albicans was the most frequently isolated pathogen, accounting for 54% of fungal isolates, followed by Candida parapsilosis (23%), Candida glabrata (7%), Candida tropicalis (5%), Candida pelliculosa (4%), Candida lusitaniae (1%), Candida humicula (1%), and other non-albicans Candida spp. (5%). Seventy-six (41%) patients received adequate antifungal therapy. Seventy-one (58%) of the 123 evaluable patients with central venous catheters underwent line removal; 51 of them had catheter-related candidemia. The 30-day crude mortality rate was 45%. Older age, hospitalization in an intensive care unit, a longer duration of candidemia, retention of central lines, and inadequate antifungal therapy were significantly associated with poor outcome. In the present study, nosocomial candidemia was a frequent and relatively underestimated illness. Adequate antifungal therapy and central line removal independently reduced the high mortality of the disease.


Assuntos
Candidíase/epidemiologia , Infecção Hospitalar/epidemiologia , Fungemia/epidemiologia , Hospitais Universitários , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/classificação , Candida/isolamento & purificação , Candidíase/microbiologia , Causalidade , Criança , Infecção Hospitalar/microbiologia , Feminino , Fungemia/microbiologia , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Neutropenia , Estudos Retrospectivos , Fatores de Risco
2.
Cancer Genet Cytogenet ; 116(1): 6-9, 2000 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-10616524

RESUMO

The aneuploidy of autosomes 7, 10, and sex chromosomes (X and Y) was analyzed in a series of 44 primary (de novo) and 20 secondary glioblastomas using fluorescence in situ hybridization (FISH) on smear preparations of glioma tissue. The tumors were screened for trisomy 7, monosomy 10, as well as loss of the Y chromosome and disomy of the X chromosome in male subjects, and monosomy of the X chromosome in female subjects. We found that taken alone or in combination, these chromosomal abnormalities do not appear to be characteristic of a glioblastoma subtype; therefore, they do not allow the differentiation between primary and secondary glioblastomas. Also, the loss of a chromosome 10 appears to be an earlier event than a gain of a chromosome 7 for the genesis of a secondary glioblastoma.


Assuntos
Aneuploidia , Neoplasias Encefálicas/genética , Aberrações Cromossômicas , Glioblastoma/genética , Neoplasias Encefálicas/etiologia , Cromossomos Humanos Par 10 , Cromossomos Humanos Par 7 , Feminino , Glioblastoma/etiologia , Humanos , Hibridização in Situ Fluorescente , Masculino , Monossomia , Trissomia , Cromossomo X , Cromossomo Y
3.
Antimicrob Agents Chemother ; 43(8): 1856-61, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10428902

RESUMO

Cryptococcus neoformans isolates that exhibited unusual patterns of resistance to fluconazole and voriconazole were isolated from seven isolates from two different geographical regions: one isolate from an Israeli non-AIDS patient and six serial isolates from an Italian AIDS patient who had suffered six recurrent episodes of cryptococcal meningitis. Each isolate produced cultures with heterogeneous compositions in which most of the cells were susceptible, but cells highly resistant to fluconazole (MICs, >/=64 microg/ml) were recovered at a variable frequency (7 x 10(-3) to 4.6 x 10(-2)). Evidence showed that this type of resistance is innate and is unrelated to drug exposure since the Israeli patient had never been treated with azoles or any other antimycotic agents. Analysis of clonal subpopulations of these two strains showed that they exhibited heterogeneous patterns of resistance. The number of subpopulations which grew on fluconazole or voriconazole agar declined progressively with increasing azole concentration without a sharp cutoff point. For the Italian serial isolates, the number of clonal populations resistant to fluconazole (64 microg/ml) and voriconazole (1 microg/ml) increased steadily, yielding the highest number for the isolate from the last episode. Attempts to purify a sensitive subpopulation failed, but clones highly resistant to fluconazole (100 microg/ml) and moderately resistant to voriconazole (1 microg/ml) always produced a homogeneous population of resistant cells. Upon maintenance on drug-free medium, however, the majority of the homogeneously resistant cells of these subclones lost their resistance and returned to the stable initial heteroresistant phenotype. The pattern of heteroresistance was not affected by the pH or osmolarity of the medium but was influenced by temperature. The resistance appeared to be suppressed at 35 degrees C and was completely abolished at 40 degrees C. Although heterogeneity in azole resistance among subpopulations of single isolates has been reported for Candida species, the transient changes in expression of resistance under different growth conditions reported here have not been observed in fungal pathogens.


Assuntos
Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Fluconazol/farmacologia , Pirimidinas/farmacologia , Triazóis/farmacologia , Síndrome da Imunodeficiência Adquirida/microbiologia , Adulto , Anfotericina B/farmacologia , Cryptococcus neoformans/classificação , Cryptococcus neoformans/crescimento & desenvolvimento , Cryptococcus neoformans/isolamento & purificação , Resistência Microbiana a Medicamentos , Humanos , Concentração de Íons de Hidrogênio , Itraconazol/farmacologia , Masculino , Meningite Fúngica/microbiologia , Testes de Sensibilidade Microbiana , Concentração Osmolar , Fenótipo , Coloração e Rotulagem/métodos , Temperatura , Voriconazol
4.
Clin Infect Dis ; 26(2): 330-3, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9502450

RESUMO

Between September and October 1994 we observed three cases of Pseudomonas aeruginosa endophthalmitis in a single ophthalmology center. Endophthalmitis progressed rapidly following surgical intervention, and the three patients completely lost vision in the affected eye. Microbiological surveillance culture specimens were obtained from environmental sites, the operating team, intraocular lenses, irrigation fluids, and surgical equipment. P. aeruginosa was isolated from the internal tubing system of automated cataract surgical equipment. The strains of P. aeruginosa cultured from vitreous and anterior chamber specimens of case patients and from the surgical equipment were analyzed with pulsed-field gel electrophoresis. Genomic DNA typing of these isolates showed an identical banding pattern on ethidium bromide-stained gels. We believe that this is the first reported outbreak of P. aeruginosa endophthalmitis traced to automated surgical equipment. Genomic DNA typing emerged as a practical and reliable option for the epidemiological investigation of the outbreak.


Assuntos
Endoftalmite/microbiologia , Pseudomonas aeruginosa/genética , Infecção da Ferida Cirúrgica/microbiologia , Idoso , Endoftalmite/epidemiologia , Endoftalmite/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/terapia
5.
J Basic Microbiol ; 38(5-6): 313-22, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9871329

RESUMO

An electron microscopic survey of the occurrence of bacteriophages which appear spontaneously in cultures of haemolytic intestinal spirochaetes of human and animal origin was made. Excluding one isometric tailed phage particle which was observed in the form of free particle in proximity to a spirochaete of the w beta HIS strain HRM18, bacteriophages were never observed while examining cells of 21 weakly beta-haemolytic human intestinal spirochaetes (w beta HIS), swine Serpulina pilosicoli strain P43/6/78, and the avian strain 1380, although 50-100 cells of each spirochaetal strain were analysed. Isometric tailed bacteriophages were found associated with only three out of the 100 cells of strongly beta-haemolytic swine Serpulina hyodysenteriae strain P18A comparatively analysed. According to our results and previous published reports, the occurrence of bacteriophages which appear spontaneously in cultures of intestinal spirochaetes is a rare event.


Assuntos
Bacteriófagos , Spirochaetaceae/virologia , Animais , Aves/microbiologia , Brachyspira/virologia , Fezes/microbiologia , Técnica de Placa Hemolítica , Humanos , Intestinos/microbiologia , Microscopia Eletrônica , Suínos/microbiologia
6.
J Anal Toxicol ; 20(7): 547-54, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8934304

RESUMO

A gas chromatographic technique with flame ionization detection, which is based on a solid-phase extraction (SPE) procedure using mixed-mode SPE columns, for the simultaneous quantitation of dextropropoxyphene and norpropoxyphene in urine is presented. Urine is treated with sodium hydroxide in order to rearrange, by base catalysis, norpropoxyphene to norpropoxyphene amide, which is then extracted with these columns and chromatographed. The method is specific, linear over the range 0-2000 ng/mL, sensitive, and reproducible. The extracts are cleaner than those obtained with traditional liquid-liquid extraction procedure, which is an important feature in view of further mass spectrometric confirmation of narcotics and other drugs.


Assuntos
Analgésicos Opioides/urina , Cromatografia Gasosa/métodos , Dextropropoxifeno/análogos & derivados , Dextropropoxifeno/urina , Detecção do Abuso de Substâncias/métodos , Ionização de Chama , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de Tempo
7.
Acta Paediatr ; 85(5): 554-7, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8827098

RESUMO

In patients with cystic fibrosis, infection with Pseudomonas cepacia is associated with poor outcomes. However, the epidemiology of Burkholderia cepacia is still unclear. The aim of this study was to investigate the epidemiology of Burkholderia (Pseudomonas) cepacia colonization among cystic fibrosis patients attending the Verona CF Centre, a large specialized unit to which patients from different parts of Italy are admitted. We used a genome finger-printing system to analyse the nucleotidic structure of B. cepacia isolates from 60 colonized cystic fibrosis patients. Forty-two different finger-printing patterns were identified. Thirty-two patients were colonized by individual B. cepacia strains (53.3%). The remaining 28 subjects were divided into 10 different subgroups, each exhibiting a distinct strain of B. cepacia (46.7%). Nevertheless, direct, person-to-person transmission was evident in only 10 cases (16.7%). The stability up to 12 months, of the B. cepacia colonizing strain was documented in 36 individuals. Consistent with other reports, risk of B. cepacia transmission between cystic fibrosis patients through intimacy or nosocomial contact was found in our study. However, besides low contagiousness, our data suggest that the environmental reservoir of B. cepacia outside the hospital seems to play an important role in B. cepacia infection of our cystic fibrosis population.


Assuntos
Infecções por Burkholderia/microbiologia , Burkholderia cepacia/genética , Infecção Hospitalar/microbiologia , Fibrose Cística/microbiologia , Genoma Bacteriano , Mapeamento de Nucleotídeos , Infecções por Burkholderia/complicações , Burkholderia cepacia/classificação , Burkholderia cepacia/isolamento & purificação , Fibrose Cística/complicações , Humanos , Epidemiologia Molecular , Escarro/microbiologia
8.
Eur J Epidemiol ; 12(2): 149-53, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8817193

RESUMO

Genome fingerprinting by field inversion gel electrophoresis (FIGE) was utilized to typify 129 isolates of Pseudomonas cepacia (Pc) from 59 patients with cystic fibrosis (CF) and from environmental cultures in the CF ward. The aim of this study was to assess whether a segregation policy avoided colonization of CF patients by nosocomial strains and contamination of the environment by colonized individuals, whether or not an 'epidemic strain' was present in the ward and whether cross-colonization occurred in CF individuals subjected to prolonged close contact. The Pc strains of each patient remained unchanged over time; 78% of the genome finger printings (GFP) were individual, whereas the others gave rise to 9 GFP groups. A spirometer was probably contaminated by a newly colonized patient. Adequate sanitary measures and avoidance of excessive promiscuity are helpful for limiting but are unable to eliminate Pc transmission in the CF ward. Direct or indirect transmission, however seems, more frequent in CF patients in contacts outside the hospital.


Assuntos
Infecções por Burkholderia/microbiologia , Burkholderia cepacia/genética , Infecção Hospitalar/microbiologia , Fibrose Cística/complicações , DNA Bacteriano/genética , Infecções Respiratórias/microbiologia , Infecções por Burkholderia/transmissão , Infecção Hospitalar/transmissão , Impressões Digitais de DNA/métodos , Eletroforese em Gel de Campo Pulsado/métodos , Contaminação de Equipamentos , Humanos , Controle de Infecções , Infecções Respiratórias/transmissão
9.
Therapie ; 51(2): 177-84, 1996.
Artigo em Francês | MEDLINE | ID: mdl-8763053

RESUMO

Clarithromycin, azithromycin and dirithromycin have recently been introduced in France. We list the different drug-interactions with these three new drugs and with erythromycin, josamycin, roxithromycin, midecamycin and spiramycin.


Assuntos
Macrolídeos/farmacologia , Interações Medicamentosas , Humanos , Macrolídeos/classificação , Macrolídeos/farmacocinética
10.
Thromb Haemost ; 75(2): 332-8, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8815586

RESUMO

Treatment of rat C6 glioma with high doses of 13 cis-retinoic acid (cRA) was responsible for death related to haemorrhagic necrosis localized to the tumor. Our aim was to explore this adverse effect of retinoid treatment. We show that cRA-treated C6 glioma at 25 mg/kg/day for 18 days exhibits in vivo an increase T-PA activity, which is responsible for a localized tumor fibrinolytic activity. Production of t-PA is supported by specific enhancement of gene expression, as was shown by the increase in t-PA mRNA (x 2.3). This production is a direct effect of cRA when treating the tumor, since tumor cells themselves do not produce enough t-PA and treatment of control rats does not increase the t-PA level. T-PA production by rat C6 glioma is in vivo related to the specific synthesis of t-PA by the C6 cell-line. The stimulation of C6 cell-line by cRA in vitro is dose-dependent and reached a maximum for 3 and 30 microM at the 72nd h. So cRA-treated C6 glioma cells produce t-PA which appears to be the major species associated with the fibrinolytic activity-induced intra-tumoral haemorrhage after exposure to retinoid treatment.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/metabolismo , Morte Súbita/etiologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/metabolismo , Isotretinoína/farmacologia , Proteínas de Neoplasias/biossíntese , Ativador de Plasminogênio Tecidual/biossíntese , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Neoplasias Encefálicas/patologia , Hemorragia Cerebral/etiologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Fibrinólise , Glioma/patologia , Isotretinoína/uso terapêutico , Isotretinoína/toxicidade , Necrose , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Transplante de Neoplasias , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Ratos , Ratos Sprague-Dawley , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/fisiologia , Células Tumorais Cultivadas
11.
Acta Ophthalmol Scand ; 73(6): 560-2, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9019386

RESUMO

We report on a case of keratitis with hypopion by Fusarium monilinforme, in a patient with palpebral retraction and light exophthalmos caused by hyperthyroidism. We emphasize the importance of the microscopic examination of bioptic material and the identification of fungal species: the first permits an early diagnosis, the second the adoption of a targeted and effective therapy. In our case, the ocular infection was successfully treated with antimycotic drugs used topically.


Assuntos
Fusarium , Ceratite/microbiologia , Micoses , Idoso , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Córnea/microbiologia , Córnea/patologia , Feminino , Fusarium/isolamento & purificação , Humanos , Ceratite/patologia , Miconazol/uso terapêutico , Micoses/tratamento farmacológico
12.
J Clin Microbiol ; 33(11): 3070-3, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8576381

RESUMO

A 73-year old man developed an acute prosthetic aortic valve dehiscence for which emergent operation was undertaken. The intraoperative evidence of an aortic annular disruption and of a subannular abscess led to the hypothesis that an endocarditis process was involved. The aortic valve was replaced with a stentless porcine bioprosthesis. Cultures taken intraoperatively from the aortic area had a pure growth of aerobic, spore-forming, gram-positive bacilli identified as Bacillus licheniformis. The patient responded to specific antibiotic therapy with no relapse at a 20-month follow-up. The potentiality of B. licheniformis as a pathogen should be reconsidered.


Assuntos
Infecções por Bacillaceae/diagnóstico , Endocardite Bacteriana/diagnóstico , Próteses Valvulares Cardíacas/efeitos adversos , Idoso , Valva Aórtica/microbiologia , Valva Aórtica/cirurgia , Infecções por Bacillaceae/tratamento farmacológico , Infecções por Bacillaceae/etiologia , Bioprótese , Cefazolina/uso terapêutico , Cefalosporinas/uso terapêutico , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/etiologia , Humanos , Masculino
15.
Anal Biochem ; 222(1): 76-80, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7856874

RESUMO

Biotinylation and digoxigenination have been compared for labeling proteins from a total frozen tissue extract and from products of immunopurification with anti-RAR beta (retinoic acid receptor beta). The detection of biotinylated and digoxigeninated proteins was found to be easier and more sensitive than detection of silver-stained proteins after two-dimensional electrophoresis. Although biotinylated or digoxigeninated proteins can be detected with avidin conjugates or anti-digoxigenin antibodies, they can also be detected with specific antibodies such as anti-RAR beta antibodies. Previously, coimmunoprecipitates could be visualized only by radioactive amino acid incorporation in cell culture, whereas biotinylation and digoxigenination enable the study of specific protein expression in frozen tissues by immunoprecipitation and the visualization of coimmunoprecipitates. Chemolabeling presents the two major advantages of limiting the use of radioisotopes and allowing the use of frozen tissues in all types of protein expression studies.


Assuntos
Biotina/química , Química Encefálica , Digoxigenina/química , Proteínas do Tecido Nervoso/análise , Albuminas/análise , Eletroforese em Gel Bidimensional , Congelamento , Humanos , Peso Molecular , Testes de Precipitina
16.
Pathologica ; 86(2): 222-3, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7936770

RESUMO

A case of bilateral idiopathic granulomatous mastitis in a 67-year-old woman is described. The clinical presentation and mammographic findings raised strong suspicions of malignancy, excluded by the histological examination, which made it possible also to rule out possible known causes of granulomatous inflammation of the breast.


Assuntos
Neoplasias da Mama/diagnóstico , Granuloma/diagnóstico , Mastite/diagnóstico , Idoso , Diagnóstico Diferencial , Feminino , Granuloma/diagnóstico por imagem , Granuloma/cirurgia , Humanos , Mamografia , Mastite/diagnóstico por imagem , Mastite/cirurgia
17.
FEBS Lett ; 316(2): 147-51, 1993 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-8420799

RESUMO

In view of the frequent activation of the epidermal growth factor receptor (EGF-R) in gliomas and autocrine hypothesis, we searched for 'EGF-like' factor(s) in cystic fluids (CFs) associated with gliomas. Membranes of A431 cells, which overexpress EGF-R, were used to explore such activity in 20 CFs. In all cases CFs induced inhibition of EGF-R phosphorylation. Biochemical analysis revealed an anti-tyrosine kinase activity which was identified as a 18 kDa proteic factor. Effectiveness at high dilution and anti-proliferative effect on living cells in culture suggest that this factor may be involved in the negative regulation of glial oncogenesis.


Assuntos
Astrocitoma/química , Neoplasias Encefálicas/química , Proteínas Tirosina Quinases/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Receptores ErbB/metabolismo , Humanos , Fosforilação , Células Tumorais Cultivadas
18.
J Chemother ; 4(6): 338-41, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1287135

RESUMO

The inhibitory activity of cefpirome (HR 810), a new cephalosporin derivative for parenteral use, was tested by agar dilution methods against Enterococcus faecalis (100 strains), Staphylococcus aureus (40 strains) and coagulase-negative staphylococcal species (60 strains) in comparison with other beta-lactam antibiotics. For E. faecalis, the cefpirome minimum inhibitory concentration (MIC) range was 2-128 micrograms/ml, with an MIC50 of 8 micrograms/ml, and an MIC90 of 64 micrograms/ml. The optimal bactericidal activity against strains with MICs of < or = 8 micrograms/ml occurred at 2-4 times the MIC, and the reduction in the initial inoculum was 99.9-99.7% after 24 h incubation at these concentrations. Mec gene-negative staphylococci (both S. aureus and coagulase-negative species) had cefpirome MICs of 0.25-2 micrograms/ml (MIC50 0.5 microgram/ml, MIC90 1 microgram/ml). Mec gene-positive strains had MICs of 0.5-128 micrograms/ml (MIC50 2 micrograms/ml, MIC90 32 micrograms/ml). Strains with borderline resistance to oxacillin which did not harbor the mec gene and which were susceptible to cefpirome maintained their susceptibility even when high-density inocula were used and after several passages in media containing the antibiotic. These studies present some potential advantages of cefpirome over other cephalosporins in the inhibitory activity against Gram-positive cocci.


Assuntos
Cefalosporinas/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Staphylococcus/efeitos dos fármacos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Especificidade da Espécie , Vancomicina/farmacologia , Cefpiroma
19.
Clin Infect Dis ; 15(3): 486-9, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1520798

RESUMO

Enterococci are characterized by an intrinsic resistance to growth inhibition by beta-lactam antibiotics. The low susceptibility of enterococci to beta-lactam antibiotics is associated with the synthesis of a particular penicillin-binding protein (PBP) that has a low affinity for beta-lactam agents. This protein appears to be capable of taking over the function of the other PBPs when they are saturated with beta-lactam molecules or inactivated by mutations. A quantitative correlation can be established between the binding of several beta-lactam molecules to the low-affinity PBP and the minimal inhibitory concentration for enterococcal strains. In contrast, the mechanism of enterococcal resistance to the bactericidal activity of beta-lactam agents that inhibit growth at relatively low concentrations appears to be associated with an alteration in the pattern of autolytic enzyme activity. In particular, lack of or poor activity of an autolytic enzyme appears to be responsible for the paradoxical bactericidal response often exhibited by clinical isolates of Enterococcus faecalis in the presence of penicillin.


Assuntos
Antibacterianos/farmacologia , Enterococcus/efeitos dos fármacos , Hexosiltransferases , Peptidil Transferases , Proteínas de Bactérias , Proteínas de Transporte/fisiologia , Resistência Microbiana a Medicamentos/fisiologia , Enterococcus/crescimento & desenvolvimento , Enterococcus/fisiologia , Humanos , Muramilpentapeptídeo Carboxipeptidase/fisiologia , Proteínas de Ligação às Penicilinas , beta-Lactamas
20.
Antimicrob Agents Chemother ; 35(9): 1900-4, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1952864

RESUMO

The in vitro activity of BAY v 3522, a new cephalosporin with unusually good activity against enterococci, was tested on 100 clinical isolates of Enterococcus faecalis. The MIC for 86.3% of the strains was 4 micrograms/ml, whereas the MIC for 13.7% ranged from 8 to 16 micrograms/ml. No differences were found between MICs determined with low- or high-density inocula. The bactericidal activity of BAY v 3522 was tested on eight clinical strains; most strains showed a ca. 3-log decrease of the original inoculum at two to eight times the MIC. The interaction of BAY v 3522 and of other beta-lactams with penicillin-binding proteins (PBPs) was studied with a laboratory strain, E. hirae ATCC 9790, producing a discernible amount of PBP 5, a protein belonging to the family of low-affinity PBPs, responsible for the low susceptibility of enterococci to beta-lactams. PBPs 3 and 5 of ATCC 9790 showed the highest affinity for the new cephalosporin. Bay V 3522 at the MIC (8 micrograms/ml) saturated these two PBPs without any significant binding to the other PBPs. This result may explain the good antienterococcal activity of BAY v 3522.


Assuntos
Cefalosporinas/farmacologia , Enterococcus/efeitos dos fármacos , Ampicilina/farmacologia , Benzotiazóis , Testes de Sensibilidade Microbiana
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