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1.
J Hosp Infect ; 100(1): 40-46, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29330015

RESUMO

BACKGROUND: Preterm infants are at high risk for extended-spectrum-beta-lactamase-producing Enterobacteriaceae (ESBL-E) sepsis and neonatal intensive care unit (NICU) outbreaks. Maternal colonization with ESBL-E may be precursory to mother-to-child transmission. However, there is no consensus regarding surveillance of pregnant women for ESBL-E colonization. AIM: To identify pairs of mothers and infants harbouring same-strain ESBL-E colonization and to determine whether maternal transmission may play a role in increasing ESBL-E carriage in preterm infants. METHODS: This was a one-year analysis from an ongoing, prospective ESBL-E surveillance of mothers of premature infants and their offspring. Mother-infant pairs colonized with the same bacteria underwent strain analysis using pulsed-field gel electrophoresis (PFGE). Clinical parameters were collected from the hospital computerized records. FINDINGS: Between January 2015 and January 2016, 313/409 (76.5%) mothers and all 478 (100%) infants were screened for ESBL-E colonization; carriage rates were 21.5% and 14.8%, respectively. Four (5.6%) colonized infants developed late-onset sepsis and two (2.8%) died. Twenty-five mother-infant pairs colonized with the same bacterial strain were identified; a subgroup of 10 pairs of isolates underwent PFGE, and 70% displayed an identical PFGE fingerprint. No similarities were found between isolates recovered from unrelated neonates and mothers. ESBL-E colonization was found significantly earlier in infants of mothers colonized at birth (P<0.001) compared with infants of non-colonized mothers. CONCLUSIONS: ESBL-E carriage rates in mothers and NICU infants with non-negligible maternal-neonatal ESBL-E transmission in the study region indicate that maternal colonization surveillance and/or further infection control interventions should be considered.


Assuntos
Portador Sadio/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/transmissão , Enterobacteriaceae/enzimologia , Enterobacteriaceae/isolamento & purificação , Transmissão Vertical de Doenças Infecciosas , beta-Lactamases/metabolismo , Portador Sadio/microbiologia , Eletroforese em Gel de Campo Pulsado , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Tipagem Molecular , Gravidez , Estudos Prospectivos , Estudos Retrospectivos
2.
Int J Infect Dis ; 17(9): e702-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23522635

RESUMO

OBJECTIVE: To assess the epidemiological and microbiological characteristics of pneumococcal acute otitis media (AOM) in children in Brasov, Central Romania, before the introduction of pneumococcal conjugate vaccine (PCV) into the routine national immunization program. METHODS: All AOM patients aged <5 years who underwent tympanocentesis or presented with purulent otorrhea of ≤24h duration during 2009-2011 were enrolled. RESULTS: Two hundred and twelve consecutive AOM patients had a middle ear fluid (MEF) culture performed; 99 (46.6%) episodes occurred in patients <12 months of age. One hundred and eleven (52.4%) episodes were culture-positive. Tympanocentesis was performed in 142 patients and spontaneous otorrhea cultures in 70 patients. Overall, 114 pathogens were recovered: Streptococcus pneumoniae was the most common isolate (81 isolates, 70.3% of all culture-positive episodes), followed by non-typeable Haemophilus influenzae (26, 20.7%), Streptococcus pyogenes (5, 4.5%), and Moraxella catarrhalis (2, 1.8%). Antibiotic susceptibility and serotyping were performed for 48 (59.3%) S. pneumoniae isolates: 45 (93.8%) were non-susceptible to penicillin (minimal inhibitory concentration (MIC) ≥2.0µg/ml in 24, 53.3%) and 37 (77.1%) isolates had ceftriaxone MIC values ≥0.5µg/ml (16 with MIC >2.0µg/ml). S. pneumoniae non-susceptibility rates to trimethoprim-sulfamethoxazole, erythromycin, and clindamycin were 75.0%, 58.3%, and 35.4%, respectively. All isolates were susceptible to chloramphenicol. Multidrug resistance was found in 33 (68.7%) isolates. The most common S. pneumoniae serotypes were 19F (14, 29.2%), 6B (8, 16.7%), 23F (8, 16.7%), and 14 (6, 12.5%). Serotype 19A was found in three (6.2%) patients and 6A in two (4.1%). Non-PCV13 serotypes represented six (12.6%) of all serotypes (four of them non-susceptible to penicillin). Thirty-six (75.0%) isolates were potentially covered by PCV7, 37 (77.0%) by PCV10, and 42 (87.5%) by PCV13. CONCLUSIONS: (1) S. pneumoniae was the most prevalent pathogen, with frequent antibiotic resistance and multi-resistance patterns; (2) most pneumococcal AOM and multidrug-resistant episodes could be prevented by PCVs.


Assuntos
Otite Média/epidemiologia , Infecções Pneumocócicas/epidemiologia , Streptococcus/isolamento & purificação , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Otite Média/microbiologia , Otite Média/prevenção & controle , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Estudos Prospectivos , Romênia/epidemiologia , Sorotipagem , Streptococcus/classificação , Vacinas Conjugadas/imunologia
3.
Eur J Clin Microbiol Infect Dis ; 32(8): 1049-53, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23479041

RESUMO

The purpose of this study was to investigate the prevalence of ß-lactamase and the genomic clonality of a large collection of Kingella kingae isolates from Israeli patients with a variety of invasive infections and asymptomatic pharyngeal carriers. ß-lactamase production was studied by the nitrocefin method and the minimum inhibitory concentrations (MICs) of penicillin and amoxicillin-clavulanate were determined by the epsilon (Etest) method. The genotypic clonality of isolates was investigated by pulsed-field electrophoresis (PFGE). ß-lactamase was found in 2 of 190 (1.1 %) invasive isolates and in 66 of 429 (15.4 %) randomly chosen carriage organisms (p < 0.001). Overall, 73 distinct PFGE clones were identified (33 among invasive organisms and 56 among carriage isolates). ß-lactamase production was found to be limited to four distinct PFGE clones, which were common among carriage strains but rare among invasive strains, and all organisms in the collection belonging to these four clones expressed ß-lactamase. The penicillin MIC of ß-lactamase-producing isolates ranged between 0.094 and 2 mcg/mL (MIC50: 0.25 mcg/mL; MIC90: 1.5 mcg/mL) and that of amoxicillin-clavulanate between 0.064 and 0.47 mcg/mL (MIC50: 0.125 mcg/mL; MIC90: 0.125 mcg/mL). The penicillin MIC of ß-lactamase non-producing isolates ranged between <0.002 and 0.064 mcg/mL (MIC50: 0.023 mcg/mL; MIC90: 0.047 mcg/mL). Although ß-lactamase production is prevalent among K. kingae organisms carried by healthy carriers, the low invasive potential of most colonizing clones results in infrequent detection of the enzyme in isolates from patients with clinical infections. The exceptional presence of ß-lactamase among invasive organisms correlates with the favorable response of K. kingae infections to the administration of ß-lactamase-susceptible antibiotics.


Assuntos
Bacteriemia/microbiologia , Portador Sadio/microbiologia , Kingella kingae/enzimologia , Infecções por Neisseriaceae/microbiologia , Adulto , Antibacterianos/farmacologia , Bacteriemia/epidemiologia , Proteínas de Bactérias/metabolismo , Portador Sadio/epidemiologia , Distribuição de Qui-Quadrado , Criança , Humanos , Israel/epidemiologia , Kingella kingae/classificação , Kingella kingae/efeitos dos fármacos , Kingella kingae/isolamento & purificação , Testes de Sensibilidade Microbiana , Infecções por Neisseriaceae/epidemiologia , beta-Lactamases/metabolismo
4.
Int J Qual Health Care ; 25(2): 188-96, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23335057

RESUMO

QUALITY PROBLEM: Medication administration is one of the most potentially dangerous tasks in hospitals. In recent years, the medical establishment has gained insight into the importance of environmental and ergonomic factors on patient safety. Limited data are available on how a standard designed medication room (MR) supports safety medication administration. INITIAL ASSESSMENT: Proactive observations were conducted at a tertiary care facility, the Hadassah University Medical Center, Jerusalem, Israel, to determine if safety principles were being implemented in the medication preparation and storage environment. These observations revealed that no designated MRs existed in the hospitals wards and safety systemic weaknesses in medication preparation. CHOICE OF SOLUTION: Guidelines for planning and designing MRs, based on safety and human engineering principles, were established to promote safer medication administration in hospital wards. IMPLEMENTATION: The purpose of the survey was to compare the implementation of safety principles among hospital wards before and after MR renovation and among hospital wards with and without a MR. Structured observations in medication preparation areas and storage were designed. Selected safety indicators were measured (e.g. ordering and labeling; storage of intravenous infusions). Each category was subdivided into indicators that were design dependent only (DD), design and behavior dependent (DBD) and behavior dependent only (BD). EVALUATION: Indicators that were both DD and DBD showed significant improvement before and after renovation of MRs. Most of the results were not significant for BD indicators. A similar trend was observed in departments with and without a MR. A trend of improvement could be seen in BD-positive indicators, regardless of the presence or absence of a dedicated MR. LESSONS LEARNED: A standard design MR can improve environmental aspects of safety medication administration.


Assuntos
Decoração de Interiores e Mobiliário/normas , Erros de Medicação/prevenção & controle , Sistemas de Medicação no Hospital/organização & administração , Segurança do Paciente , Pesquisas sobre Atenção à Saúde , Humanos , Israel , Inquéritos e Questionários
5.
J Oral Rehabil ; 38(12): 929-39, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21707697

RESUMO

The periodontal ligament is a viscoelastic soft tissue that connects the tooth to the alveolar bone. This tissue should be simulated in numerical as well as in laboratory models. The mechanical properties of this tissue were previously determined ex vivo and in vivo. The aim of the study was to analyse the appropriateness of impression and reline materials used in dentistry to simulate viscoelastic behaviour of the periodontal ligament. Two reline [Durabase (Reliance Dental MFG, Co.) and Soft Liner (GC Corporation)] and two impression [President Plus (Coltene) and Prestige L (Vanini Dental Industry)] materials were examined in recovery and tensile relaxation tests. Recovery: This experiment simulated in vivo test. Roots of a pair of plastic maxillary premolar teeth were covered with each test material and embedded in acryl while maintaining the contact point. A 0·1-mm stainless steel strip, inserted at the contact point and maintained for 10 s, was used to tip the teeth. After removal, the tightness of dental contact point was measured over 30 min by determining the force needed to insert a 0·05-mm metal strip. Tensile relaxation: strips were elongated to 120%, 140% and 160% of their initial length and maintained at that length for 30 min. Two-phase decay function was applied. The results showed that elastic modulus and relaxation behaviour were significantly different between materials. Elastic modulus values were in the same range of those reported in the literature. However, the recovery values and behaviour showed that impression materials, especially President, are the materials of choice for this purpose because they simulated better the in vivo test.


Assuntos
Elasticidade , Ligamento Periodontal/fisiologia , Resistência à Tração , Fenômenos Biomecânicos , Força de Mordida , Elasticidade/fisiologia , Humanos , Resistência à Tração/fisiologia
6.
Br Poult Sci ; 52(1): 58-65, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21337199

RESUMO

1. Birds, especially nestlings, are generally difficult to sex by morphology and early detection of chick gender in ovo in the hatchery would facilitate removal of unwanted chicks and diminish welfare objections regarding culling after hatch. 2. We describe a method to determine chicken gender without the need for PCR via use of Thymine-DNA Glycosylase (TDG). TDG restores thymine (T)/guanine (G) mismatches to cytosine (C)/G. We show here, that like DNA Polymerase, TDG can recognise, bind and function on a primer hybridised to chicken genomic DNA. 3. The primer contained a T to mismatch a G in a chicken genomic template and the T/G was cleaved with high fidelity by TDG. Thus, the chicken genomic DNA can be identified without PCR amplification via direct and linear detection. Sensitivity was increased using gender specific sequences from the chicken genome. 4. Currently, these are laboratory results, but we anticipate that further development will allow this method to be used in non-laboratory settings, where PCR cannot be employed.


Assuntos
Galinhas/genética , DNA/química , Análise para Determinação do Sexo/métodos , Timina DNA Glicosilase/análise , Animais , Proteínas Aviárias/genética , Proteínas de Ligação a DNA/genética , Transferência Ressonante de Energia de Fluorescência , Marcadores Genéticos , Genoma , Reação em Cadeia da Polimerase
7.
Qual Saf Health Care ; 18(6): 505-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19955466

RESUMO

PROBLEM: Labelling of high-risk drug infusions and lines is a well-recognised safety strategy to prevent medication errors. Although hospital wards characterised by multiple high-risk drug infusions use different types of labelling, little is known about the contribution of a colour-coded label (CCL) to patient safety. SETTING: A quality improvement programme audit at a tertiary care facility, the Hadassah University Medical Center Ein Kerem, Jerusalem, Israel. STRATEGY FOR CHANGE: A CCL for intravenous (IV) high-risk medications and lines was designed to promote safer medication administration at the intensive care unit bedside and in other acute wards. METHODS: The purpose of the study was to compare a new CCL method (intervention) with the current labelling method (control). Laboratory simulation, imitating an intensive care unit, was designed. Safety of the medication treatment and overall duration of nurses' orientation with drugs and lines at the patient's bedside were measured. EFFECTS OF CHANGE: The use of the new CCL improved proper identification of IV bags (p<0.0001), reduced the time required for description of overall drugs and lines (p = 0.04), improved identification of errors at the treatment setting-drugs and lines (p = 0.03) and reduced the average performance time for overall tasks (p<0.0001). LESSONS LEARNT: The use of CCLs for IV high-risk medications and lines can improve patient safety and improve medical staff efficiency.


Assuntos
Rotulagem de Medicamentos , Infusões Intravenosas/instrumentação , Erros de Medicação/prevenção & controle , Gestão de Riscos/métodos , Cor , Humanos , Garantia da Qualidade dos Cuidados de Saúde , Gestão da Segurança
8.
J Hosp Infect ; 67(2): 149-55, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17900759

RESUMO

The prevalence of skin colonisation with Acinetobacter baumannii (ACBA) on admission to the medical intensive care unit (MICU) was studied in an institution endemic for ACBA bloodstream infections (BSIs). The impact of 4% chlorhexidine gluconate (4% CG) whole-body washing on the patients' ACBA skin colonisation was also determined. A prospective cohort trial in a MICU during March 2002 to December 2003 was performed, with a comparison between the prevalence and incidence of ACBA-BSIs obtained after intervention and retrospectively. During the intervention period, ACBA skin-screening swabs were taken from all patients on admission and periodically until discharge. Patients underwent whole-body disinfection with 4% CG immediately after obtaining the initial cultures. Disinfection was carried out on a daily basis until discharge, regardless of colonisation status. Of the 320 patients at ward admission, 55 (17%) yielded ACBA. The prevalence of ACBA colonisation among the remaining MICU patients was 5.5% at 24h and 1% at 48h following the disinfection regimen (P=0.002, OR: 2.4). Following a second screen, 80% of colonised patients were decolonised. Prevalence of ACBA-BSIs decreased from 4.6 to 0.6 per 100 patients (P < or = 0.001; OR: 7.6) and incidence decreased from 7.8 to 1.25 (85% reduction). We conclude that daily whole-body disinfection with 4% CG significantly reduced ACBA skin colonisation. This regimen may be considered in addition to well-known infection control measures, particularly in institutions with endemic rates of multidrug-resistant ACBA-BSIs.


Assuntos
Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/isolamento & purificação , Clorexidina/análogos & derivados , Infecção Hospitalar/prevenção & controle , Desinfecção/métodos , Farmacorresistência Bacteriana Múltipla , Pele/microbiologia , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/efeitos dos fármacos , Clorexidina/uso terapêutico , Estudos de Coortes , Humanos , Incidência , Unidades de Terapia Intensiva , Prevalência , Estudos Prospectivos
9.
Biopolymers ; 83(4): 434-42, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16858697

RESUMO

Fourier transform infrared (FTIR) spectroscopy has shown remarkable ability in distinguishing between bacterial species and identifying bacterial colony structures, when used in tandem with methods such as cluster analysis, principal component analysis, or linear discriminant analysis. The present work was aimed to evaluate the potential of FTIR-microscopy (FTIR-MSP) to distinguish between different serotypes and capsular quantities of Streptococcus pneumoniae. In general, the results obtained have consistently proven that the spectral information at the region 900-1,185 cm(-1) was sufficient to distinguish between various pneumococcal serotypes. Moreover, the method was able to differentiate between S. pneumoniae phase variants on the basis of their relative carbohydrate content. The unsupervised cluster analysis of the samples showed differences, not only in the carbohydrate content, but also in the region 1,350-1,480 cm(-1), which is dominated by absorptions due to lipids and phospholipids. This approach proved to be useful for the distinction between S. pneumoniae serotypes and between phase variants, which were shown to acquire different pathogenic capacity.


Assuntos
Cápsulas Bacterianas/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Streptococcus pneumoniae/metabolismo , Cápsulas Bacterianas/classificação , Análise por Conglomerados , Sorotipagem/métodos , Streptococcus pneumoniae/classificação
10.
Gene Ther ; 13(13): 1057-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16511518

RESUMO

Following gene therapy of SCID-X1 using murine leukemia virus (MLV) derived vector, two patients developed leukemia owing to an activating vector integration near the LMO2 gene. We found that these integrations reside within FRA11E, a common fragile site known to correlate with chromosomal breakpoints in tumors. Further analysis showed that fragile sites attract a nonrandom number of MLV integrations, shedding light on its integration mechanism and risk-to-benefit ratio in gene therapy.


Assuntos
Sítios Frágeis do Cromossomo , Terapia Genética/efeitos adversos , Vetores Genéticos/efeitos adversos , Vírus da Leucemia Murina/genética , Imunodeficiência Combinada Severa/terapia , Integração Viral/genética , Células Cultivadas , Fragilidade Cromossômica , Terapia Genética/métodos , Vetores Genéticos/genética , Células HeLa/virologia , Humanos , Leucemia/imunologia , Leucemia/virologia , Mutagênese Insercional , Medição de Risco , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Linfócitos T/virologia
11.
FEMS Microbiol Lett ; 233(1): 147-52, 2004 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15043881

RESUMO

Mice were inoculated intranasally with Streptococcus pneumoniae isolates of serotype 14 with different genetic backgrounds (14R, 14DW) and a capsular switch of 14R, strain 9VR (serotype 9V). Inoculation of the mice with 14R and 9VR resulted in 60% mortality. All the mice survived 14DW inoculation. No differences in lungs' bacterial loads were found 3 h following inoculation. Bacterial clearance of 5 logs was observed 48 h after inoculation with 14DW versus within 1 log 48 h after inoculation with 14R and 9VR. No significant differences in bacterial size or the capsular amount could be found between 14R and 14DW. We conclude that factor(s) in addition to the capsule, contribute to disease outcome.


Assuntos
Cápsulas Bacterianas , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/patogenicidade , Virulência , Animais , Cápsulas Bacterianas/química , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Polissacarídeos Bacterianos , Análise de Sobrevida
12.
J Hosp Infect ; 53(1): 31-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12495683

RESUMO

We describe an outbreak of Acinetobacter baumannii in a neonatal intensive care unit (NICU), and our investigation to determine the source and mode of transmission and identify the population at risk. A case (infected infant) was defined as a patient hospitalized in the NICU during the outbreak period, with clinical signs of sepsis and isolation of A. baumannii. In colonized infants, A. baumannii was isolated from body surfaces without signs of infection. Infected infants were separated and treated by a different medical team. Cultures were taken from working surfaces and along the infant's admission passage from the delivery room to the NICU. The outbreak strain was identified by pulsed-field gel electrophoresis (PFGE). Nine cases and eight colonized infants met the definition criteria. Cases were younger than colonized infants with regard to gestational age and age of diagnosis and had lower birthweights (P<0.01). The outbreak strain was only isolated from hygroscopic bandages used on skin under the ventilation tube and umbilical catheters. Discontinuing the use of the bandages put an end to the outbreak. We conclude that a rapid and thorough investigation of the environment during an outbreak of A. baumannii is essential to finding the source of the infection, and that hygroscopic bandages may be a source of such outbreaks.


Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/isolamento & purificação , Infecção Hospitalar/etiologia , Infecção Hospitalar/prevenção & controle , Controle de Infecções/métodos , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Infecções por Acinetobacter/etiologia , Técnicas Bacteriológicas , Bandagens/microbiologia , Transmissão de Doença Infecciosa/prevenção & controle , Farmacorresistência Bacteriana Múltipla , Monitoramento Ambiental/métodos , Monitoramento Epidemiológico , Contaminação de Equipamentos , Humanos , Recém-Nascido
13.
Eur J Clin Microbiol Infect Dis ; 21(5): 368-72, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12072921

RESUMO

The annual incidence of gonorrhea in Israel has sharply increased during the past 2 years. At the end of 1999, high-level ciprofloxacin-resistant strains of Neisseria gonorrhoeae (MIC90, > or =32 mcg/ml) also exhibiting decreased susceptibility to penicillin and tetracycline were isolated for the first time in southern Israel, as well as in other regions of the country. The incidence of male gonococcal urethritis in the south increased in a 1.5-year period from 3/100,000 to 12/100,000 ( P<0.05) in correlation with increased isolation of ciprofloxacin-resistant organisms. A marked increase in the incidence of gonorrhea was also encountered in Jerusalem, where ciprofloxacin resistance affected 54.5% of the isolates in 2000. Pulsed-field gel electrophoresis typing of gonococci from different areas of Israel indicated that all of the ciprofloxacin-resistant isolates belonged to identical or related strains. Since fluoroquinolone-resistant gonococci may emerge and disseminate extensively over a short period of time, continuous surveillance of antibiotic susceptibility among gonococcal isolates should be performed to guide empiric therapy.


Assuntos
Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana , Gonorreia/epidemiologia , Gonorreia/microbiologia , Neisseria gonorrhoeae/efeitos dos fármacos , Adulto , Técnicas de Tipagem Bacteriana , Eletroforese em Gel de Campo Pulsado , Feminino , Gonorreia/tratamento farmacológico , Humanos , Incidência , Israel/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificação
14.
Carcinogenesis ; 22(12): 2009-16, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11751433

RESUMO

Glutathione synthesis and growth properties were studied in the gamma-glutamyl transpeptidase(GGT)-negative, non-tumorigenic rat liver oval cell line OC/CDE22, and in its GGT-positive, tumorigenic counterpart line M22. gamma-Glutamylcysteine synthetase (GGCS) activities were comparable. Growth rates of M22 cells exceeded those of OC/CDE22 cells at non-limiting and limiting exogenous cysteine concentrations. A monoclonal antibody (Ab 5F10) that inhibits the transpeptidatic but not the hydrolytic activity of GGT did not affect the growth rates of OC/CDE22, and decreased those of M22 to the OC/CDE22 level. In GSH-depleted M22, but not in OC/CDE22 cells, the rate and extent of GSH repletion with exogenous cysteine and glutamine exceeded those obtained with exogenous cysteine and glutamate. With Ab 5F10, repletion with cysteine/glutamine was similar to that obtained with cysteine/glutamate. Repletion with exogenous GSH occurred only in M22 cells, and was abolished by the GGT inhibitor acivicin. Repletion with gamma-glutamylcysteine (GGC) in OC/CDE22 was resistant to acivicin whereas that in M22 was inhibited by acivicin. Repletion with exogenous GSH or cysteinylglycine (CG) required aminopeptidase activity and was lower than that obtained with cysteine. Unless reduced, CG disulfide did not support GSH repletion. The findings are compatible with the notions that (i) GGT-catalyzed transpeptidation was largely responsible for the growth advantage of M22 cells at limiting cysteine concentration, and for their high GSH content via the formation of GGC from a gamma-glutamyl donor (glutamine) and cyst(e)ine, and (ii) aminopeptidase/dipeptidase activity is rate-limiting in GSH repletion when GSH or CG serve as cysteine sources.


Assuntos
Glutationa/biossíntese , Fígado/citologia , gama-Glutamiltransferase/metabolismo , Aminopeptidases/antagonistas & inibidores , Aminopeptidases/metabolismo , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Cistina/metabolismo , Inibidores Enzimáticos/farmacologia , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Glutationa/metabolismo , Glutationa/farmacologia , Cinética , Fígado/efeitos dos fármacos , Fígado/enzimologia , Ratos , Células Tumorais Cultivadas , gama-Glutamiltransferase/antagonistas & inibidores
15.
Clin Infect Dis ; 33(4): 436-44, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11462177

RESUMO

Although antibiotic-resistant pneumococci have been frequently detected among day care center (DCC) attendees, the transmission of these organisms to other members of the community has not been adequately studied. Nasopharyngeal cultures were obtained from 152 children and 244 adult members of a closed community (a kibbutz) in Israel. Serotyping, antibiogram, and pulsed-field gel electrophoresis were performed to determine the relatedness of isolated pneumococci. Twenty (30%) of the 66 isolates from children showed decreased susceptibility to penicillin and 9 isolates (14%) were resistant to > or =3 drugs. Of the 16 isolates from adults, 5 (31%) were intermediately resistant to trimethoprim-sulfamethoxazole. Resistant strains carried by DCC attendees were not isolated either from their parents or from other adult members of the community. Despite the high degree of interpersonal contact occurring in a closed community, resistant pneumococcal strains carried by DCC attendees do not appear to be easily transmitted to the adult population, which suggests the existence of an immunological barrier.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Portador Sadio/transmissão , Streptococcus pneumoniae/efeitos dos fármacos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Resistência Microbiana a Medicamentos , Eletroforese em Gel de Campo Pulsado , Humanos , Lactente , Israel , Nasofaringe/microbiologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/transmissão , Fatores de Risco , População Rural , Sorotipagem , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação
16.
J Clin Microbiol ; 39(5): 1827-32, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11325998

RESUMO

We conducted a study to examine the clonal distribution of invasive serotype 1 and 5 isolates as representatives of serotypes that are rarely carried by healthy individuals compared to that of invasive serotype 6B and 23F isolates as representatives of serotypes often carried by young children for prolonged periods. All invasive serotype 1, 5, 6B, and 23F isolates recovered from blood cultures during January 1995 to May 1999 were analyzed; these included 66 serotype 1, 30 serotype 5, 11 serotype 6B, and 15 serotype 23F isolates. One hundred thirty-three nasopharyngeal (NP) isolates of the indicated four serotypes from healthy children were also studied. The strains were characterized using serotyping, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis profiling. We found that both invasive and NP serotype 1 and 5 isolates were susceptible to penicillin and that each serotype showed only one clonal type. In contrast, serotype 6B and 23F strains showed different phenotypic characteristics as well as multiple clonal types; 10 clones were identified among 6B isolates, and 11 clones were identified among 23F isolates.


Assuntos
Nasofaringe/microbiologia , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/patogenicidade , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Portador Sadio/microbiologia , Criança , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Humanos , Lactente , Recém-Nascido , Israel , Testes de Sensibilidade Microbiana , Penicilinas/farmacologia , Sorotipagem , Infecções Estreptocócicas/microbiologia , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética
17.
J Infect Dis ; 183(6): 880-6, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11237804

RESUMO

Antibiotic-resistant pneumococci are difficult to eradicate from middle ear fluid (MEF) and the nasopharynx (NP). Bacteriologic eradication from the NP and MEF during acute otitis media (AOM) by 3 common antibiotic drugs was prospectively evaluated. In 19 (16%) of 119 MEF culture-positive patients, an organism susceptible to the treatment drug (Haemophilus influenzae, Streptococcus pneumoniae, or both) was isolated from the initial MEF, whereas resistant S. pneumoniae was present in the NP; in 9 (47%) patients, the initial resistant NP organism (identified by serotyping, resistance to the administered drug, and pulsed-field gel electrophoresis) replaced the susceptible MEF organism within only a few days after initiation of treatment. In regions where resistant pneumococci are prevalent, antibiotics may not only fail to eradicate the organisms, but they may often induce MEF superinfection with resistant pneumococci initially carried in the NP. This is an important mechanism by which, in recently treated patients, AOM infections often become refractory to treatment.


Assuntos
Resistência Microbiana a Medicamentos , Otite Média/tratamento farmacológico , Infecções Pneumocócicas/tratamento farmacológico , Streptococcus pneumoniae/efeitos dos fármacos , Superinfecção/tratamento farmacológico , Doença Aguda , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Criança , Quimioterapia Combinada/uso terapêutico , Orelha Média/microbiologia , Feminino , Humanos , Masculino , Nasofaringe/microbiologia , Otite Média/microbiologia , Infecções Pneumocócicas/microbiologia , Sorotipagem , Streptococcus pneumoniae/isolamento & purificação , Superinfecção/microbiologia , Fatores de Tempo , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
18.
Int J Antimicrob Agents ; 16(3): 219-24, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11091039

RESUMO

In 1996, 19 isolates of serotype 6B Streptococcus pneumoniae with a unique resistance pattern were found in carriers attending daycare centres in Patras, Southwestern Greece. These isolates were penicillin susceptible but resistant to chloramphenicol, tetracycline, erythromycin, clindamycin and trimethoprim-sulphamethoxazole. Subsequently, isolates with the same characteristics were found in 23 additional carriers in central and southern Greece in 1997-98 as well as in 19 carriers in central Italy in 1997, and in seven carriers in southern Israel in 1998. Carriers were all children under 6 years of age, attending daycare centres or outpatient hospital visits. The relatedness of the isolates was determined on representative isolates from the three countries by pulsed-field gel electrophoresis of SmaI digests of chromosomal DNA. Most Greek isolates were identical to each other, while isolates from Italy and Israel showed one to three band differences, with all isolates being closely related to each other as well as to the isolates from Greece. We have therefore documented the presence of this unique clone of S. pneumoniae in these three countries and have named this the 'Mediterranean' clone. While isolates appear to have a common origin, their source and direction of spread are unknown. However, isolates from Italy showed the most diversity, suggesting that this clone had been present in that country for a longer period than it had been in Greece.


Assuntos
Resistência a Múltiplos Medicamentos/genética , Penicilinas/farmacologia , Streptococcus pneumoniae/genética , DNA Bacteriano , Resistência a Múltiplos Medicamentos/imunologia , Eletroforese em Gel de Campo Pulsado , Grécia , Humanos , Israel , Itália , Região do Mediterrâneo , Sorotipagem , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/imunologia , Streptococcus pneumoniae/isolamento & purificação
19.
Harefuah ; 138(9): 758-62, 805, 2000 May 01.
Artigo em Hebraico | MEDLINE | ID: mdl-10883231

RESUMO

Amplification of specific DNA sequences by polymerase chain reaction (PCR), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. Studies in recent years have reported identification of several enteropathogens directly from stool samples by PCR. The amplification process includes the use of primers complementary to the DNA sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on which identification by the methods of classical microbiology were based. We have developed PCR protocols for the differential identification of enteropathogens resembling the normal flora (enterotoxigenic E. coli (ETEC), E. coli O-157), Shigella spp, and the detection of enteropathogens that can not be grown on classic growth media (Norwalk virus). The amplification process is inhibited by several substrates present in fecal material (phenol, hemoglobin), limiting DNA extraction by phenol. The protocols we have developed for direct detection of Shigella spp and ETEC in stools circumvent inhibition of PCR by the use of a 4-hour pre-enrichment step in brain-heart infusion broth. Rapid and accurate identification of enteropathogens is important for prompt and focused intervention to stop the chain of transmission in outbreaks of gastroenteritis in military and civilian populations.


Assuntos
Infecções por Enterobacteriaceae/diagnóstico , Enterobacteriaceae/isolamento & purificação , Disenteria Bacilar/diagnóstico , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/diagnóstico , Humanos , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Shigella/isolamento & purificação
20.
Mol Microbiol ; 36(5): 1059-70, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10844691

RESUMO

In the present study, we show that Neisseria gonorrhoeae lipooligosaccharide (LOS) can bind to the asialoglycoprotein receptor (ASGP-R) on human sperm. This work demonstrates the presence of ASGP-R on human sperm. Binding of purified ASGP-R ligand decreased in the presence of gonococci. Binding of purified iodinated gonococcal LOS identified a protein of molecular weight corresponding to that of human ASGP-R. The presence of excess unlabelled LOS blocked binding of iodinated gonococcal LOS. Binding of wild-type gonococcal LOS to sperm was higher than that of mutant LOS lacking the galactose ligand for ASGP-R. These data suggest that the ASGP-R on human sperm cells recognizes and binds wild-type gonococcal LOS. This interaction may contribute to the transmission of gonorrhea from infected males to their sexual partners.


Assuntos
Lipopolissacarídeos/metabolismo , Neisseria gonorrhoeae/metabolismo , Espermatozoides/metabolismo , Receptor de Asialoglicoproteína , Humanos , Radioisótopos do Iodo , Marcação por Isótopo , Ligantes , Masculino , Neisseria gonorrhoeae/genética , Receptores de Superfície Celular , Transferases/genética
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