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M López-Brea

Publications and source records attributed to M López-Brea.

At least 19 recordsLinked to original sources
PubMed2006

[Susceptibility of 36 Helicobacter pylori clinical isolates to four first-line antibiotics and virulence factors].

Helicobacter pylori possess various virulence factors, including cagA and vacA genes, that are associated with more aggressive symptoms such as bleed-ing ulcer and gastric cancer. Although there are different treatment regimens, there is still a failure rate of up to 20% due to antibiotic resistance, among other causes. In our country resistance to metronidazole and clarithromycin is increasing, especially in children, although they are still susceptible to amoxicillin and tetracycline. In order to determine the susceptibility pattern to these antibiotics 36 H. pylori clinical isolates were studied. MIC was determined by agar diffusion and agar dilution, and vacA and cagA genes were detected by conventional PCR. All isolates were susceptible to amoxicillin and tetracycline. Resistance to metronidazole by diffusion or dilution tests was 35.7% and 36.1%, respectively, and to clarithromycin, 21.4% and 22.3%, respectively. There was one strain that showed intermediate resistance to clarithromycin (MIC 0.38 mg/l), using agar diffusion, and that was included among the resistant strains. Three discrepancies were observed between the diffusion and dilution methods. The vacA s1 allele was detected in 17.2% of the strains, and vacA s2 in 82.8%; 51.7% of the total were cagA+. In conclusion, all strains tested in our study were susceptible to amoxicillin and tetracycline, allowing them to be considered as first-line antibiotics, while clarithromycin and metronidazole maintain a slight increase in their resistance level. The cagA+ strains were detected in expected quantities, while the s1 allele of the vacA gene was detected in lower quantities.

Adult↗
PubMed2006

[Susceptibility pattern of Acinetobacter baumannii clinical isolates in Madrid vs. Hong Kong].

The objective of this study was to compare the susceptibility to seven antimicrobials of Acinetobacter baumannii clinical isolates from H. U. de La Princesa of Madrid vs. A. baumannii clinical isolates from Hospital Queen Mary of Hong Kong from January 2004 to March 2005. A total of 74 strains isolated from our hospital and 30 strains attended to Hospital Queen Mary were studied. The MIC (minimal inhibitory concentration) was determined by agar dilution method. NCCLS recommended breakpoints were used against imipenem, tobramycin, amikacin, ofloxacin and ceftazidime. For sulbactam the break point for ampicillin/sulbactam was used. BSAC breakpoint was considered against colistin. Colistin showed the highest susceptibility percentage in Spanish strains (98.64%), followed by imipenem (94.59%) and tobramycin (78.37%). About 50% of the clinical isolates were susceptible to sulbactam (54.05%) and amikacin (51.35%). The majority of the strains were resistant to ofloxacin (2.7% of susceptible strains) and ceftazidime (1.35% of susceptible strains). In the Hong Kong clinical isolates, high susceptibility percentages were shown for most antimicrobials: 96.66% to colistin, sulbactam, tobramycin and amikacin; lower for imipenem (93.33%) and ofloxacin (90%). Ceftazidime presented the lowest susceptibility percentage (10%). In conclusion, higher resistant percentages in Spanish strains than Chinese strains were obtained for most antimicrobials tested. To ofloxacin, 90% of Hong Kong isolates were susceptible while 93% of Madrid isolates were resistant. Geographically remote populations (such as Madrid and Hong Kong) showed important differences according to the susceptibility patterns.

Acinetobacter Infections↗
PubMed2005

[Resistance of Mycobacterium tuberculosis in a four-year period in a Madrid hospital].

Tuberculosis is considered a serious public health problem. Some factors, such as HIV infection and immigration, have had a major impact on the epidemiology of this illness in Spain. The problem has worsened in recent years due to the dissemination of multiresistant strains. Therefore, a periodic surveillance should be established with respect to the incidence and the resistances observed. In this study we collect M. tuberculosis isolates carried out in the years 2001, 2002, 2003 and 2004, and their susceptibility characteristics in patients from Area 2 in Madrid. To evaluate the isolates' susceptibilities, the MGIT 960 system was used. Of a total of 244 isolates, 15.2% were resistant to at least one antibiotic (different to streptomycin), and 29.9% of the isolates were obtained in samples from immigrant patients. In addition, the immigrant population affected showed a greater percentage of resistances (p <0.01) and a younger mean age (p <0.01) than the indigenous population.

Adult↗
PubMed2005

[In vitro activity of furazolidone and nitrofurantoin in Helicobacter pylori clinical isolates and study of mutation rate].

Clarithromycin, amoxicillin, tetracycline and metronidazole are the most frequently used antimicrobials for Helicobacter pylori infection treatment. While tetracycline and amoxicillin resistance are rare, clarithromycin and metronidazole resistance vary in different populations and are considered factors for treatment failure. The aim of this study was to determine the in vitro activity of furazolidone and nitrofurantoin in 164 H. pylori clinical isolates by agar dilution and to determine the spontaneous mutation rate. Metronidazole and clarithromycin resistance were 23.77% (CI95%: 18.96-29.14) and 16.78% (CI95%: 12.64-21.62), respectively; moreover, 1.4% (CI95%: 0.38-3.54) were intermediate to clarithromycin. All the isolates were susceptible to amoxicillin and tetracycline. Furazolidone and nitrofurantoin resistance rates were 1.82% (CI95%: 0.37-5.25) and 0.6% (CI95%: 0-3.35), respectively. The three furazolidone-resistant strains were nitrofurantoine-susceptible (MIC 4 mg/l for furazolidone and 2 mg/l for nitrofurantoin) and the nitrofurantoin-resistant strains were furazolidone-susceptible (MIC 4 mg/l for nitrofurantoin and 1 mg/l for furazolidone). These four strains were metronidazole-resistant (MIC 16 mg/l). Furazolidone or nitrofurantoin spontaneous mutants were not detected in the eight H. pylori strains tested. However, mutants with resistance to metronidazole were found with all the strains with a mutation rate of 7.4 x 10(-10) to 9.4 x 10(-10). Furazolidone and nitrofurantoin showed an excellent in vitro activity against the H. pylori clinical isolates included herein, supporting the usefulness of furazolidone as second-line antimicrobial after treatment failure or as first-line therapy in populations with low economical resources.

Anti-Infective Agents↗
PubMed2004

Community-acquired urinary tract infection caused by vancomycin-resistant Enterococcus faecalis clinical isolate.

We present a case of urinary tract infection caused by vancomycin-resistant Enterococcus faecalis. The patient is a 62-year-old woman showing no recent admittances. The isolated microorganism was identified by MicroScan (DADE) and API (BioMerieux) and susceptibility was assessed by disk diffusion, E-test and broth microdilution. The isolate was identified as Enterococcus faecalis and showed high MIC for vancomycin (>128 mg/l) and teicoplanin (8 mg/l) but was susceptible to ampicillin. The transmission routes of vancomycin-resistant enterococci in the community and their clinical implications remain uncertain. Healthy carriers have already been described in several countries but this case report represents an unusual finding.

Community-Acquired Infections↗
PubMed2003

[Detection of resistance to clarithromycin in clinical isolates of Helicobacter pylori from children and adults].

Several methods have been used to detect clarithromycin resistance. Agar dilution is now recommended by the NCCLS (susceptible to clarithromycin: MIC<=0.25 mg/l; intermediate resistance: MIC=0.5 mg/l; resistant: MIC>=1 mg/l), and the detection of mutations involved in resistance is used in many laboratories. We analyzed 36 clarithromycin-resistant strains isolated from children and 30 from adults. In vitro susceptibility to clarithromycin was determined by an agar dilution method. DNA from the isolates was extracted using the method published by Ge and Taylor. A2142G and A2143G mutations were identified by PCR-RFLP. A 1.4 Kpb of the 23S rRNA gene was amplified and digested using MboII or BsaI restriction enzymes to detect mutations. The prevalence of the A-G transition mutation at position 2143 was higher in the children (80.55%) than in the adult patients (46.66%) (p<0.05); however, the prevalence of the mutation at position 2142 was higher in adults than in children (36.66% vs. 5.55%; p<0.05). In children, a higher MIC (2-64 mg/l) was observed when the A-G mutation was detected at position 2143. However, in adult patients higher MICs were observed when the A-G mutation was detected at position 2142.

Adult↗
PubMed2003

[Susceptibility of Campylobacter jejuni clinical isolates from children to eight antibiotics].

This study aimed to identify the activity of eight antibiotics (ofloxacin, moxifloxacin, azithromycin, erythromycin, clindamycin, ampicillin, amoxicillin-clavulanic acid and tetracycline) against 80 strains of Campylobacter jejuni isolated from children. Minimal inhibitory concentrations (MIC) were determined by an agar dilution method. Resistance to azithromycin and erythromycin was considered when MIC > or =8 mg/l, to clindamycin when MIC > or =1 mg/l, to amoxicillin-clavulanic acid and ampicillin when MIC > or =32 mg/l, to ofloxacin and moxifloxacin when MIC > or =4 mg/l, and to tetracycline when MIC > or =16 mg/l. All strains tested were susceptible to amoxicillin-clavulanic acid. The lowest frequency of resistance was to azithromycin (2%), erythromycin (3.7%), clindamycin (4.4%) and ampicillin (4.9%), and the highest was to ofloxacin and tetracycline (61.7% for both), and moxifloxacin (37%). Considered the antibiotics of choice for the treatment of infections caused by this microorganism, macrolides showed excellent activity with MIC(90)=0.5 mg/l for azithromycin and MIC(90)=0.5 mg/l for erythromycin.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed2002

Comparison of the E test and agar dilution method for antimicrobial suceptibility testing of Helicobacter pylori.

A multicentre study was carried out in order to validate the E test in comparison with the reference agar dilution method for testing the susceptibility of Helicobacter pylori to amoxicillin, clarithromycin, and metronidazole. Ten clinical isolates and one control collection isolate ( Helicobacter pylori ATCC 43504) were tested blindly at four centres according to a uniform methodology. The E test showed excellent intra- and inter-laboratory correlations with the agar dilution method for amoxicillin and clarithromycin (>98% agreement within 2 log(2) dilution steps). For metronidazole, however, the E test revealed significantly higher minimum inhibitory concentration values (>2 log(2)) against 5 of the 10 Helicobacter pylori strains tested. Overall, neither method was found reliable for testing the susceptibility of Helicobacter pylori to metronidazole, since both tended to lack reproducibility.

Amoxicillin↗
PubMed2002

Clinical pattern and therapeutic results achieved in 1490 patients with germ-cell tumours of the testis: the experience of the Spanish Germ-Cell Cancer Group (GG).

OBJECTIVE: To describe the clinical characteristics and treatment results obtained with the application of a homogeneous treatment protocol in 1490 patients with germ-cell tumours (GCT) registered in the 55 hospitals belonging to the Spanish Germ-Cell Cancer Group (GG) during the period between January 1994 and April 2001. METHODS: In general, surveillance was the common policy for stage I patients without local poor prognosis factors, whereas they received adjuvant chemotherapy in case those factor were present. Chemotherapy schedules used in advanced cases were cisplatin and etoposide (EP) for seminoma and BEP or BOMP-EPI in non-seminoma, according to whether the patient was in the good or poor prognosis IGCCCG (International Germ-Cell Cancer Collaborative Group) group. Excision of residual masses was mandatory in non-seminomatous germ-cell tumour (NSGCT). RESULTS: Initial local symptomatology was increased testis size in 90% of cases. Sonography was an excellent diagnostic tool to suggest tumour. Non-seminoma (64.2%) was more frequent than seminoma (35.8%). Approximately 10% had the antecedent of cryptorchidism. Non-seminoma patients were 7 years younger than seminoma. Right testis was involved predominantly. Pre-orchidectomy tumour markers were elevated in 21% of seminoma (betaHGC) and 79% in non-seminoma (alphaFP and/or betaHGC). Scrotum violation occurred in only 1.8%. There were significant differences among stage I and the IGCCCG prognosis groups related to a longer interval between the first symptom and orchiectomy. Eighteen percent of non-seminomatous germ-cell tumour belonged to the poor prognosis IGCCCG group. With a median follow-up to 33 months, this series has achieved a 3 year overall survival of 98% for seminoma and 94% for non-seminoma. Only 10% of excised residual masses present after chemotherapy contained malignant cells. CONCLUSION: Spanish GCT have a similar clinical pattern to that described in the other occidental countries except for a slight increased proportion of non-seminoma upon seminoma. Co-operative groups as GG are unique structures to obtain quick and wide experience on the treatment of testis tumours, contributing to achieve a high cure rate.

Adolescent↗
PubMed2002

[Present perspectives on Creutzfeldt-Jakob disease: pathogenesis, diagnosis and treatment].

In recent years, interest in the group of diseases generically known as "transmissible spongiform encephalopathies" has reemerged, mainly due to the socioeconomic implications of one of its variants: bovine spongiform encephalopathy. Transmissible spongiform encephalopathies seem to be caused by proteinaceous particles called prions, isoforms of a membrane protein which can be found in humans as well as in several animal species. Their precise function is still unknown. Although investigation into transmissible spongiform encephalopathies has clarified some uncertainties about its pathogenesis and epidemiology, many important questions remain. This is especially true or treatment, since no effective curative therapy exists as yet.

Creutzfeldt-Jakob Syndrome↗
PubMed2002

[In vitro activity of clarithromycin and metronidazole against Helicobacter pylori in different incubation atmospheres].

The aim of this study was to determine the in vitro activity of clarithromycin and metronidazole using an agar dilution method to compare two different incubation atmospheres: a CO2 incubator and a jar with a microaerobic gas-generating system. Antibiotics were placed on plates in twofold dilutions ranging from 128 to 0.064 mg/l in Mueller-Hinton agar supplemented with 7% horse blood. The inoculum was prepared from 31 Helicobacter pylori isolates and was inoculated using a Steers replicator. Plates were incubated for 3 to 5 days and MICs were recorded as the lowest concentration of antibiotic inhibiting visible growth. Two different incubation atmospheres were used: a CO2 incubator set at 95% humidity and 10% CO2, and a jar with a gas-generating envelope that produces 7-10% O2 and 14% CO2 (BioMerieux). Clarithromycin resistance was found in 19% of strains both in the gas-generating system and the CO2 incubator. Metronidazole resistance was 23% in both atmospheres. MICs for clarithromycin in both atmospheres showed two dilutions of difference for 100% of the strains, and were slightly higher in the jar with a gas-generating envelope. However, MICs for metronidazole were higher when it was incubated in the CO2 incubator, and in 86.7% of strains the MICs showed < or = 2 dilutions of difference. No great discrepancies were found for either metronidazole or clarithromycin using the two methods.

Anti-Bacterial Agents↗
PubMed2001

Granulocyte colony-stimulating factor in the treatment of high-risk febrile neutropenia: a multicenter randomized trial.

BACKGROUND: Granulocyte colony-stimulating factors (G-CSFs) have been shown to help prevent febrile neutropenia in certain subgroups of cancer patients undergoing chemotherapy, but their role in treating febrile neutropenia is controversial. The purpose of our study was to evaluate-in a prospective multicenter randomized clinical trial-the efficacy of adding G-CSF to broad-spectrum antibiotic treatment of patients with solid tumors and high-risk febrile neutropenia. METHODS: A total of 210 patients with solid tumors treated with conventional-dose chemotherapy who presented with fever and grade IV neutropenia were considered to be eligible for the trial. They met at least one of the following high-risk criteria: profound neutropenia (absolute neutrophil count <100/mm(3)), short latency from previous chemotherapy cycle (<10 days), sepsis or clinically documented infection at presentation, severe comorbidity, performance status of 3-4 (Eastern Cooperative Oncology Group scale), or prior inpatient status. Eligible patients were randomly assigned to receive the antibiotics ceftazidime and amikacin, with or without G-CSF (5 microg/kg per day). The primary study end point was the duration of hospitalization. All P values were two-sided. RESULTS: Patients randomly assigned to receive G-CSF had a significantly shorter duration of grade IV neutropenia (median, 2 days versus 3 days; P = 0.0004), antibiotic therapy (median, 5 days versus 6 days; P = 0.013), and hospital stay (median, 5 days versus 7 days; P = 0.015) than patients in the control arm. The incidence of serious medical complications not present at the initial clinical evaluation was 10% in the G-CSF group and 17% in the control group (P = 0.12), including five deaths in each study arm. The median cost of hospital stay and the median overall cost per patient admission were reduced by 17% (P = 0.01) and by 11% (P = 0.07), respectively, in the G-CSF arm compared with the control arm. CONCLUSIONS: Adding G-CSF to antibiotic therapy shortens the duration of neutropenia, reduces the duration of antibiotic therapy and hospitalization, and decreases hospital costs in patients with high-risk febrile neutropenia.

Aged↗
PubMed2001

A 9 year study of clarithromycin and metronidazole resistance in Helicobacter pylori from Spanish children.

The evolution of clarithromycin, metronidazole and amoxycillin resistance in 246 Spanish Helicobacter pylori clinical isolates, obtained from paediatric patients during a 9 year period, was determined by an agar dilution technique. Clarithromycin resistance (MIC 1 mg/L) was 2.27% (IC95 0.05-12.02) in 1991-1993, 20.98% (IC95 12.72-31.46) in 1994-1996 and 28.33% (IC95 20.48-37.28) in 1997-1999 (P < 0.01). Metronidazole resistance (MIC 8 mg/L) was 7.14% (IC95 1.49-19.48) in 1991-1993, 20.25% (IC95 12.04-30.79) in 1994-1996 and 43.90% (IC95 32.95-55.30) in 1997-1999 (P < 0.01). Amoxycillin resistance was not found (all strains showed MICs < 2 mg/L).

Anti-Bacterial Agents↗