Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Ann Dermatol Venereol ; 151(3): 103290, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003978

RESUMO

OBJECTIVE: Pseudoxanthoma elasticum (PXE) is a rare autosomal disorder with a variable phenotype that may be modulated by environmental factors. Plasma vitamin K (VK) levels may be involved in the ectopic calcification process observed in PXE. Since VK2 is predominantly produced by the gut microbiota, we hypothesized that changes in the gut microbiota of PXE patients might exacerbate the calcification process and disease symptoms. METHODS: Twenty PXE patients were included in the study and 60 gut microbiota profiles from the Biofortis laboratory database were used as controls. RESULTS: The Rhodospirillaceae family was more abundant in the PXE group while the Sphingomonadaceae family was more abundant in the control group. In a PXE severity subgroup analysis, microbiota dispersion was lower in "severe" than in "non-severe" patients, which was confirmed by permutation multivariate analysis of variance at the phylum, family and genus ranks. However, no significant association was found in a model incorporating relative abundance of bacterial families, severity score, and different blood and fecal VK species. CONCLUSION: These results suggest slight compositional changes in the gut microbiota of PXE patients. Further studies are needed to substantiate their impact on VK metabolism and the calcification process.

2.
Infect Dis Now ; 53(1): 104632, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36375765

RESUMO

OBJECTIVE: The 23 French Regional Pneumococcal Observatories (ORPs) analyzed antibiotic resistance and serotypes of Streptococcus pneumoniae strains isolated from invasive infections in France over a 12-year period. METHODS: Between 2009 and 2021, the ORPs analyzed 19,319 strains, including 1,965 in children and 17,354 in adults. Strains were assessed for their resistance to penicillin G, amoxicillin and cefotaxime. Serotypes were identified in collaboration with the National Reference Centre. RESULTS: During this period, the number of strains collected yearly decreased significantly. The decrease was particularly pronounced up until 2013, especially in children (-61.0%). However, penicillin non-susceptible strains (PNSPs) increased in children (24.7% in 2009 vs 45.0% in 2021, p < 0.0001) and in adults (27.1% in 2009 vs 31.3% in 2021, p < 0.05), as well as resistance (I + R) to amoxicillin (children: 12.5% in 2009 vs 19.4% in 2021, p < 0.05; adults: 13.4% in 2009 vs 14.5% in 2021, NS) and resistance (I + R) to cefotaxime (children: 8.0% in 2009 vs 13.1% in 2021, p < 0.05; adults: 7.1% in 2009 vs 11.9% in 2021, p < 0.0001). All in all, the proportion of strains belonging to serotypes present in the PCV13 vaccine has fallen sharply, from 64.8% in 2009 to 23.6 % in 2021. At the same time, serotypes such as 8, 10A, 11A, 15B/C and 9N, not included in PCV13, were increasing. CONCLUSION: During the study period, data collected by the network highlighted an increase of invasive PNSPs in children and non-vaccine serotypes. Surveillance of resistance and serotypes remains instrumental, particularly to monitor the evolution of vaccine efficacy.


Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Criança , Adulto , Humanos , Sorogrupo , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/epidemiologia , Resistência Microbiana a Medicamentos , Cefotaxima/farmacologia , Cefotaxima/uso terapêutico , Penicilinas , Amoxicilina/farmacologia , Amoxicilina/uso terapêutico , França/epidemiologia
3.
Infect Dis Now ; 52(7): 408-413, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36028145

RESUMO

BACKGROUND: Endocarditis due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is a rare but challenging condition. Its treatment relies on carbapenems alone or in combination, and no alternative has been described to date. The cephamycin cefoxitin has been used for treatment of mild ESBL-producing Enterobacteriaceae infections. CASE PRESENTATION: We report two patients with nosocomial endocarditis due to ESBL-producing Escherichia coli and Klebsiella pneumoniae who underwent clinical failure or adverse event, respectively, during treatment with imipenem-cilastatin. The first patient was subsequently treated with cefoxitin combined with ciprofloxacin with a favorable outcome. In the second patient, the endocarditis relapsed following a 6-week treatment with cefoxitin and fosfomycin. In time-kill assays, the cefoxitin/ciprofloxacin and cefoxitin/fosfomycin combinations showed synergistic effect. CONCLUSION: These cases illustrate that cefoxitin is an interesting alternative to carbapenems, even in severe infections such as endocarditis. Pharmacokinetic optimization and combination with another synergistic antibiotic should be considered whenever possible.


Assuntos
Endocardite , Infecções por Escherichia coli , Fosfomicina , Infecções Urinárias , Humanos , Cefoxitina/uso terapêutico , Fosfomicina/farmacologia , Fosfomicina/uso terapêutico , beta-Lactamases , Combinação Imipenem e Cilastatina/uso terapêutico , Infecções por Escherichia coli/tratamento farmacológico , Infecções Urinárias/tratamento farmacológico , Testes de Sensibilidade Microbiana , Enterobacteriaceae , Carbapenêmicos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Escherichia coli , Ciprofloxacina/farmacologia , Ciprofloxacina/uso terapêutico , Endocardite/tratamento farmacológico
4.
Expert Rev Anti Infect Ther ; 20(3): 457-461, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34469266

RESUMO

OBJECTIVES: This multicenter study aimed to assess the performances of gradient diffusion (GD) method in comparison to broth microdilution (BMD) method for susceptibility testing of dalbavancin, daptomycin, vancomycin, and teicoplanin. METHODS: Minimum Inhibitory Concentrations (MICs) were retrospectively determined concomitantly by BMD and GD methods, for 93 staphylococci and enterococci isolated from clinical samples. BMD was considered as the gold standard. Essential (EA) and categorical agreements (CA) were calculated. Discordant categorical results were categorized as major (ME) and very major errors (VME). RESULTS: EA and CA were 95.7% and 96.8%, 82.8% and 100%, 97.8% and 96.8%, and 94.6% and 95.7% for dalbavancin, daptomycin, vancomycin, and teicoplanin respectively. Concerning dalbavancin, 3 ME without any VME were observed and discrepancies were low (≤ to 2 two-fold dilutions) between both methods. VME were noted in 1 and 3 cases for vancomycin and teicoplanin, respectively, and resulted from 1 two-fold dilution discrepancy in each case. EA was lower for daptomycin. When they were discrepant, BMD MICs were systematically higher than GD ones. Nevertheless, no categorical discrepancy was noted. CONCLUSIONS: GD appears as an acceptable and convenient alternative for dalbavancin, vancomycin, and teicoplanin MICs determination. Our study also emphasizes how achieving accurate daptomycin MICs remains challenging.


Assuntos
Daptomicina , Teicoplanina , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Daptomicina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Teicoplanina/análogos & derivados , Teicoplanina/farmacologia , Vancomicina/farmacologia
5.
Rev Sci Instrum ; 92(11): 113904, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852534

RESUMO

We present a two-color Kerr microscopy system based on two electronically synchronized erbium-fiber laser oscillators with independently tunable emission energies spanning most of the visible spectrum. Combining a spatial resolution below 2 µm and sub-ps time resolution with high sensitivity and cryogenic sample temperatures, it is ideally suited for studying spin and valley dynamics in a wide range of two-dimensional materials. We illustrate its capabilities by studying a monolayer of the common semiconducting transition metal disulfide MoS2.

6.
Med Mal Infect ; 50(3): 305-307, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32014291

RESUMO

OBJECTIVE: To compare the minimum inhibitory concentrations (MIC) of the ceftazidime-avibactam (CZA) combination versus ceftazidime alone (TZ) for Stenotrophomonas maltophilia. PATIENTS AND METHODS: MIC comparison was performed by E-tests. We assumed that CZA was more effective in vitro than TZ alone when CZA led to a category change from "Resistant" with TZ alone to "Susceptible" or "Intermediate" with CZA, or if the MIC of CZA was at least 4-fold lower than the MIC of TZ for TZ-susceptible isolates. RESULTS: For the 54 clinical isolates included in the study, CZA showed better results in terms of the proportion of susceptible isolates (66.7% vs. 38.9%, P<0.01), MIC50 (2µg/mL vs. 12µg/mL, P<0.05), and MIC distribution. According to our definition, CZA was also more effective in vitro than TZ alone for 50% of the isolates. CONCLUSION: Using CZA for empirical treatments in severe or polymicrobial infections with S. maltophilia seems appropriate.


Assuntos
Compostos Azabicíclicos/farmacologia , Ceftazidima/farmacologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Stenotrophomonas maltophilia/efeitos dos fármacos , Ácidos Clavulânicos/farmacologia , Fibrose Cística/complicações , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Estudos Multicêntricos como Assunto , Ticarcilina/farmacologia
7.
J Hosp Infect ; 104(1): 53-56, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31408692

RESUMO

Sink drains of six intensive care units (ICUs) were sampled for screening contamination with extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBLE). A high prevalence (59.4%) of sink drain contamination was observed. Analysing the data by ICU, the ratio 'number of ESBLE species isolated in sink drains/total number of sink drains sampled' was highly correlated (Spearman coefficient: 0.87; P = 0.02) with the ratio 'number of hospitalization days for patients with ESBLE carriage identified within the preceding year/total number of hospitalization days within the preceding year'. Concurrently, the distribution of ESBLE species differed significantly between patients and sink drains.


Assuntos
Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/enzimologia , Unidades de Terapia Intensiva/estatística & dados numéricos , beta-Lactamases/genética , Enterobacteriáceas Resistentes a Carbapenêmicos , Portador Sadio/epidemiologia , Citrobacter/isolamento & purificação , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , França/epidemiologia , Humanos , Klebsiella pneumoniae/isolamento & purificação , Inquéritos e Questionários , beta-Lactamases/efeitos dos fármacos
8.
J Hosp Infect ; 99(3): 360-363, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29577994

RESUMO

This study assessed the characteristics of hospital-acquired Acinetobacter calcoaceticus-Acinetobacter baumannii complex bloodstream infections (BSI). From 2010 to 2017, A. calcoaceticus-A. baumannii complex BSI were investigated. Of 73 cases, 54.8% were associated with Acinetobacter pittii, 39.7% with Acinetobacter baumannii and 5.5% with Acinetobacter nosocomialis. Multi-drug-resistant isolates were significantly higher in A. baumannii BSI. Thirty-day mortality was no different between A. baumannii or non-baumannii A. calcoaceticus-A. baumannii complex BSI. In contrast with other studies, this study found that most hospital-acquired A. calcoaceticus-A. baumannii complex BSI were associated with non-baumannii A. calcoaceticus-A. baumannii complex species. This study found that these species were important hospital-acquired pathogens, and emphasizes the importance of A. calcoaceticus-A. baumannii complex species identification.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter/classificação , Acinetobacter/isolamento & purificação , Bacteriemia/microbiologia , Hemocultura , Acinetobacter/efeitos dos fármacos , Infecções por Acinetobacter/epidemiologia , Idoso , Antibacterianos/farmacologia , Bacteriemia/epidemiologia , Farmacorresistência Bacteriana Múltipla , França/epidemiologia , Hospitais , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
Clin Microbiol Infect ; 24(1): 83.e1-83.e6, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28559002

RESUMO

OBJECTIVES: Prosthetic joint infections (PJI) are responsible for significant morbidity and mortality and their number continues to rise. Their management remains complex, especially the microbiological diagnosis. Besides 'homemade' tests developed by several teams, new molecular biology methods are now available with different analytical performance and usability. METHODS: We studied the performances of one of these tests: ITI® multiplex PCR (mPCR) by the Curetis® company and compared it to either 'optimized' culture or 16S rRNA PCR. We performed a retrospective multicentre study to assess the contributions of mPCR in the diagnosis of PJI. We randomly selected 484 intraoperative specimens among 1252 of various types (biopsy, bone, tissue around the prosthesis, synovial fluid) from 251 patients in seven different hospitals. Each sample was treated according to the recommendations of the manufacturer. RESULTS: In all, 154 out of 164 (93.9%) samples negative in culture were negative with the mPCR. Among the 276 positive samples in culture, 251 (90.9%) were monomicrobial, of which 119 (47.4%) were positive with the mPCR, and 25 (9.1%) were polymicrobial, of which 12 (48%) were positive with the mPCR. The concordance rate of mPCR with culture was 58.1% (53.6%-62.7%) and the concordance rate with 16S rRNA PCR was 70.1% (65.5%-74.6%). CONCLUSION: This new standardized molecular test showed a lack of detection when the bacterial inoculum was low (number of positive media per sample and number of colonies per media) but can be useful when patients have received antibiotic therapy previously.


Assuntos
Prótese Articular/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/microbiologia , Infecções Estafilocócicas/diagnóstico , Proteínas de Bactérias/genética , Humanos , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Proteínas de Ligação às Penicilinas/genética , Infecções Relacionadas à Prótese/mortalidade , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Infecções Estafilocócicas/microbiologia
10.
New Microbes New Infect ; 12: 43-4, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27222717

RESUMO

Acinetobacter spp. have emerged as global opportunistic pathogen causing a wide range of infections. Emergence of carbapenem resistance in these organisms is a matter of great concern. We report here the first detection of Acinetobacter pittii clinical isolates in Lebanon carrying either the bla NDM-1 or the bla OXA-72 gene.

11.
New Microbes New Infect ; 9: 11-2, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26858838

RESUMO

Emergence of carbapenem-resistant Acinetobacter spp. has been increasingly reported worldwide. We report here the first detection of an Acinetobacter calcoaceticus isolate from vegetables in Lebanon carrying the bla Oxa-72 gene. These findings show that the Lebanese environment may constitute a potential reservoir for this antibiotic resistance gene.

12.
Clin Microbiol Infect ; 21(1): 35-42, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25636925

RESUMO

Streptococcus pneumoniae is an important cause of acute otitis media (AOM). The aim of this study was to evaluate trends in antibiotic resistance and circulating serotypes of pneumococci isolated from middle ear fluid of French children with AOM during the period 2001-2011, before and after the introduction of the PCV-7 (2003) and PCV-13 (2010) vaccines. Between 2001 and 2011 the French pneumococcal surveillance network analysed the antibiotic susceptibility of 6683 S. pneumoniae isolated from children with AOM, of which 1569 were serotyped. We observed a significant overall increase in antibiotic susceptibility. Respective resistance (I+R) rates in 2001 and 2011 were 76.9% and 57.3% for penicillin, 43.0% and 29.8% for amoxicillin, and 28.6% and 13.0% for cefotaxime. We also found a marked reduction in vaccine serotypes after PCV-7 implementation, from 63.0% in 2001 to 13.2% in 2011, while the incidence of the additional six serotypes included in PCV-13 increased during the same period, with a particularly high proportion of 19A isolates. The proportion of some non-PCV-13 serotypes also increased between 2001 and 2011, especially 15A and 23A. Before PCV-7 implementation, most (70.8%) penicillin non-susceptible pneumococci belonged to PCV-7 serotypes, whereas in 2011, 56.8% of penicillin non-susceptible pneumococci belonged to serotype 19A. Between 2001 and 2011, antibiotic resistance among pneumococci responsible for AOM in France fell markedly, and PCV-7 serotypes were replaced by non-PCV-7 serotypes, especially 19A. We are continuing to assess the impact of PCV-13, introduced in France in 2010, on pneumococcal serotype circulation and antibiotic resistance.


Assuntos
Farmacorresistência Bacteriana , Otite Média/epidemiologia , Otite Média/microbiologia , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/efeitos dos fármacos , Antibacterianos/farmacologia , França/epidemiologia , Humanos , Incidência , Testes de Sensibilidade Microbiana , Otite Média com Derrame/microbiologia , Vacinas Pneumocócicas , Sorogrupo
13.
Int J Infect Dis ; 29: 166-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25449252

RESUMO

We report the case of a 43-year-old man with a Mycoplasma hominis brain abscess occurring after a cranial trauma, which was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of colonies on classic blood agar plates and the use of MALDI-TOF MS, a valuable diagnostic tool that identified M. hominis due to its presence in the VITEK MS database, allowed the rapid diagnosis of this infection.


Assuntos
Abscesso Encefálico/diagnóstico , Infecções por Mycoplasma/diagnóstico , Mycoplasma hominis , Adulto , Humanos , Masculino , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Dtsch Med Wochenschr ; 139(42): 2132-5, 2014 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-25289921

RESUMO

HISTORY AND ADMISSION FINDINGS: A 55-year-old woman presented comfortable and well-nourished for a check up. The physical examination remained without pathological results. However lipase parameter in serum was conspicuously elevated we performed an ultrasound examination. EXAMINATIONS: An abdomen sonography revealed besides regular pancreas morphology a hypoechoic lesion of 11 × 10 mm in the liver and multiple hypoechoic inhomgeneous lesions in the spleen. Because of the inhomogeneous results and septa we decided to arrange an abdomen computer tomography (CT) in which the complex of cysts was stated with a size of 59 × 44 mm. As the differential diagnosis of the cysts could be an echinococcosis or amoebic infection we performed a serological analysis at the first appointment and 4 weeks later. Both test results were negative. TREATMENT AND COURSE: Eight years later we indicated a magnetic resonance tomography (MRI with MRCP) to exclude a compression of the pancreatic duct by the splenic or liver cysts because the lipase und C-reactive protein (CRP) in serum was rising up again . The MRI scan showed a progression of the splenic cysts complex to 88 × 69 mm and the liver cyst to 25 × 20 mm without signs for compression or a malignant process. A correlation between elevated lipase and splenic cysts was not evident. Despite progression of the splenic cysts we decided in view of the comfortable condition of the patient and negative serological analysis for a conservative proceeding in terms of regular check ups. CONCLUSION: From our point of view also in extended non-parasitic splenic cysts it is reasonable to follow a nonoperative regime as long as clinical complaints, parasitic genesis and malignant process can be excluded.


Assuntos
Cistos/sangue , Cistos/diagnóstico , Assistência Centrada no Paciente/métodos , Esplenopatias/sangue , Esplenopatias/diagnóstico , Biomarcadores/sangue , Diagnóstico Diferencial , Feminino , Humanos , Achados Incidentais , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
16.
Vet Microbiol ; 170(3-4): 446-50, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24613079

RESUMO

Our objective was to study the carriage of Acinetobacter baumannii (AB) in pets in Reunion Island (RI), a French territory in Indian Ocean. Overall, 138 pets were sampled (rectum, mouth, wounds if applicable) in 9 veterinary clinics (VC). The prevalence of AB carriage was 6.5% (95%CI; 2.4, 10.6) and 9 carriers were identified from 4 VC. Hospitalization in a VC and antimicrobial treatment administered within the 15 preceding days were significantly associated with AB carriage (P<0.01 and P<0.05, respectively). Despite the VC in which animals have been sampled were located all around RI, most isolates (8/9) were closely-related (>90% similarity by pulsed-field gel electrophoresis). Additional studies are needed to improve the understanding about interactions between the different reservoirs of AB in RI.


Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/genética , Hospitais Veterinários/estatística & dados numéricos , Animais de Estimação/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Gatos , Estudos Transversais , Cães , Eletroforese em Gel de Campo Pulsado , Masculino , Testes de Sensibilidade Microbiana , Filogenia , Prevalência , Reunião/epidemiologia
17.
Pathol Biol (Paris) ; 60(6): 336-9, 2012 Dec.
Artigo em Francês | MEDLINE | ID: mdl-22197193

RESUMO

Tigecycline (TGC), an antibiotic belonging to glycylcyclines, is active against Gram-positive bacteria, including multi-resistant bacteria, and most of the Gram-negative bacteria, including extended spectrum ß-lactamase-producers (ESBL) and Acinetobacter sp. TGC is not active on Pseudomonas aeruginosa. The microbiological laboratory from the university hospital of Angers participates in the Tigecycline Evaluation and Surveillance Trial (TEST) since 2006. The objective of this study is to evaluate the effectiveness of TGC and of various comparators against nosocomial and community-acquired pathogens. We also evaluated the effectiveness of TGC on a panel of strains isolated between 2006 and 2009 in the university hospital of Angers. Minimum inhibitory concentrations (MIC) were determined using the microdilution method. A total of 760 clinical strains were tested. TGC had a very good activity against Gram-positive bacteria, with 100 % of susceptibility for all the strains tested, irrespective of their resistance profile. Concerning Gram-negative bacteria, TGC was active against 93 % of Enterobacteriaceae, with a MIC 90 not exceeding 2mg/L. Whole of the 20 strains ESBL-producers tested were susceptible to TGC. Acinetobacter sp. were also inhibited at low concentrations of TGC, with a MIC 90 of 1mg/L. These results suggest that TGC can be a useful therapeutic alternative, especially for infections involving multiresistant bacteria.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Hospitais Universitários , Minociclina/análogos & derivados , Acinetobacter/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos , França , Humanos , Testes de Sensibilidade Microbiana , Minociclina/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Tigeciclina
18.
Pathol Biol (Paris) ; 59(1): 39-43, 2011 Feb.
Artigo em Francês | MEDLINE | ID: mdl-20832194

RESUMO

OBJECTIVE: It was to determine the antibacterial spectrum of JCA 250 and JCA 251, two naturally occurring compounds from Aroma Technologies research, on a bacterial population isolated from clinical infections. METHOD: Two hundred and twenty-four bacterial strains were tested. The minimum inhibitory concentrations (MIC) of JCA 250 and JCA 251 were determined by agar dilution method. Tests were performed in triplicate. RESULTS: The mean MIC was 0.20% for JCA 250 and 0.15% for JCA 251. JCA 251 regularly exhibited greater activity. All Enterobacteriaceae were inhibited at concentrations less or equal to 0.15% for JCA 250 or JCA 251. For strict aerobes, the MIC values were more spread out. Two Pseudomonas aeruginosa strains differed from the population with JCA 251 MIC of 0.25 and 0.40%. Concerning Gram-positive cocci, all the strains were inhibited with less or equal to 0.25% of compound. The most resistant population were the Enterococci and the Lactobacilli, with MIC more or equal to 0.2% for JCA 250 or JCA 251. Anaerobes showed MIC closely grouped for a heterogeneous bacterial group. One Propionibacterium sp. strain came apart from the group and was inhibited with a MIC of 0.5%. CONCLUSION: The overall results showed an interesting antibacterial activity on bacteria isolated from clinical samples. Most of the bacterial strains were inhibited at a concentration of 0.2%. The highest mean values were obtained for commensal bacteria from the flora, which is of particular interest in this study.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Técnicas In Vitro , Especificidade da Espécie
19.
Artigo em Inglês | MEDLINE | ID: mdl-21082464

RESUMO

Pyrrolizidine alkaloids (PAs) are a structurally diverse group of toxicologically relevant secondary plant metabolites. Currently, two analytical methods are used to determine PA content in honey. To achieve reasonably high sensitivity and selectivity, mass spectrometry detection is demanded. One method is an HPLC-ESI-MS-MS approach, the other a sum parameter method utilising HRGC-EI-MS operated in the selected ion monitoring mode (SIM). To date, no fully validated or standardised method exists to measure the PA content in honey. To establish an LC-MS method, several hundred standard pollen analysis results of raw honey were analysed. Possible PA plants were identified and typical commercially available marker PA-N-oxides (PANOs). Three distinct honey sets were analysed with both methods. Set A consisted of pure Echium honey (61-80% Echium pollen). Echium is an attractive bee plant. It is quite common in all temperate zones worldwide and is one of the major reasons for PA contamination in honey. Although only echimidine/echimidine-N-oxide were available as reference for the LC-MS target approach, the results for both analytical techniques matched very well (n = 8; PA content ranging from 311 to 520 µg kg(-1)). The second batch (B) consisted of a set of randomly picked raw honeys, mostly originating from Eupatorium spp. (0-15%), another common PA plant, usually characterised by the occurrence of lycopsamine-type PA. Again, the results showed good consistency in terms of PA-positive samples and quantification results (n = 8; ranging from 0 to 625 µg kg(-1) retronecine equivalents). The last set (C) was obtained by consciously placing beehives in areas with a high abundance of Jacobaea vulgaris (ragwort) from the Veluwe region (the Netherlands). J. vulgaris increasingly invades countrysides in Central Europe, especially areas with reduced farming or sites with natural restorations. Honey from two seasons (2007 and 2008) was sampled. While only trace amounts of ragwort pollen were detected (0-6.3%), in some cases extremely high PA values were detected (n = 31; ranging from 0 to 13019 µg kg(-1), average = 1261 or 76 µg kg(-1) for GC-MS and LC-MS, respectively). Here the results showed significantly different quantification results. The GC-MS sum parameter showed in average higher values (on average differing by a factor 17). The main reason for the discrepancy is most likely the incomplete coverage of the J. vulgaris PA pattern. Major J. vulgaris PAs like jacobine-type PAs or erucifoline/acetylerucifoline were not available as reference compounds for the LC-MS target approach. Based on the direct comparison, both methods are considered from various perspectives and the respective individual strengths and weaknesses for each method are presented in detail.


Assuntos
Análise de Alimentos/métodos , Mel/análise , Alcaloides de Pirrolizidina/análise , Cromatografia Líquida/métodos , Echium/química , Eupatorium/química , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Pólen/química , Senécio/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
20.
Artigo em Inglês | MEDLINE | ID: mdl-20967664

RESUMO

In recent years, there has been a steadily growing number of published data on pyrrolizidine alkaloids (PAs) in honey and pollen. This raises the question whether honey and/or pollen used as ingredients in food processing might provoke a downstream contamination in the food chain. Here we addressed two different facets in connection with PAs in honey and pollen. First, we analysed the PA content of several food types such as mead (n = 19), candy (n = 10), fennel honey (n = 9), soft drinks (n = 5), power bars and cereals (n = 7), jelly babies (n = 3), baby food (n = 3), supplements (n = 3) and fruit sauce (n = 1) that contained honey as an ingredient in the range of 5% to approximately 37%. Eight out of 60 retail samples were tested as being PA-positive, corresponding to 13%. Positive samples were found in mead, candy and fennel honey, and the average PA content was calculated to be 0.10 µg g(-1) retronecine equivalents (ranging from 0.010 to 0.484 µg g(-1)). Furthermore, we investigated the question whether and how PAs from PA pollen are transferred from pollen into honey. We conducted model experiments with floral pollen of Senecio vernalis and PA free honey and tested the influence of the quantity of PA pollen, contact time and a simulated honey filtration on the final PA content of honey. It could clearly be demonstrated that the PA content of honey was directly proportional to the amount of PA pollen in honey and that the transfer of PAs from pollen to honey was a rather quick process. Consequently, PA pollen represents a major source for the observed PA content in honey. On the other hand, a good portion remains in the pollen. This fraction is not detected by the common analytical methods, but will be ingested, and it represents an unknown amount of 'hidden' PAs. In addition, the results showed that a technically and legally possible honey filtration (including the removal of all pollen) would not be an option to reduce the PA level of the final product significantly.


Assuntos
Cadeia Alimentar , Contaminação de Alimentos/análise , Mel/análise , Pólen/química , Alcaloides de Pirrolizidina/análise , Aditivos Alimentares/análise , Análise de Alimentos , Manipulação de Alimentos/métodos , Alemanha , Humanos , Senécio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA