[Evaluation of a PCR-multiplex technique for the rapid diagnosis of bacteriemia]. / Valoración de una técnica de PCR-múltiple en el diagnóstico rápido de la bacteriemia.

OBJECTIVE: Rapid and safe diagnosis of bacteremia is a continuous challenge in clinical microbiology. In this work, we evaluated a multiple PCR system that identifies 23 common pathogens as well as the production of 3 resistance mechanisms potentially present in them. METHODS: During a period of 2 months the positive blood cultures were processed in the usual way for identification and determination of their antimicrobial sensitivity. At the same time were incorporated into FilmArray panels. RESULTS: The agreement between two methods for bacterial identification was 100%. The time of obtaining the results by the molecular technique did not exceed 1 hour 15 minutes and in 7 cases of the 21 studied (33%) a modification of the empirical therapy was carried out. CONCLUSIONS: The implementation of rapid techniques such as multiple PCR offers a fast, reliable and easy to perform diagnosis in the therapeutic management of sepsis.

Coupling of conformational and ionization equilibria in linear poly(ethylenimine): a study based on the site binding/rotational isomeric state (SBRIS) model.

The conformational and ionization properties of linear poly(ethylenimine) are studied by combining the site binding model (SB) with the rotational isomeric state (RIS) model, developed by Flory to calculate the conformational properties of neutral linear molecules. The resulting approach (the SBRIS model) is used to rationalise the experimental poly(ethylenimine) titration curves. By fitting the experimental macroconstants, conformational and binding parameters are obtained. The obtained values are consistent with previous binding and structural information. The emergence of triplet interaction between protonated sites is explained as a natural consequence of the coupling between binding and conformational equilibria. When only nearest neighbour interactions are considered, transfer matrix techniques are used in the calculations. In order to account for excluded volume and long-range electrostatic interactions, Monte Carlo simulations are performed. The results indicate that at high ionic strengths, long-range interactions have a very limited impact on the titration curves. However, for long chains, they have a significant influence on the radius of gyration.

[Comparative study of the susceptibility to daptomycin and other antimicrobials against Staphylococcus spp. resistant to methicillin and Enterococcus spp. using Wider, E-test, and microdilution methods]. / Estudio comparativo de Wider, E-test y microdilución para la determinación de la sensibilidad a daptomicina y otros tres antimicrobianos de aislamientos clínicos de Staphylococcus spp. resistentes a meticilina y Enterococcus spp.

The human and material costs of inappropriate antimicrobial therapy are high. This study was designed to search for a rapid, simple and effective antimicrobial susceptibility test capable of identifying the best treatment strategy against microorganisms causing hospital infections showing resistance or reduced susceptibility to the more traditional antibiotics. The tests compared were the E-test, an automated test (Wider) and broth microdilution ( as the reference test), to determine the susceptibility to vancomycin, teicoplanin, linezolid and daptomycin of clinical isolates of methicillin resistant Staphylococcus aureus (MRSA), methicillin resistant coagulase negative Staphylococcus spp. and Enterococccus spp. The E-test and Wider methods showed good agreement with the reference method indicating their reliability for routine susceptibility testing of staphylococci and enterococci against vancomycin, teicoplanin, linezolid and daptomycin. Notwithstanding, when faced with a serious enterococcal infection, the MIC of daptomycin should be more accurately determined using a reference technique such as broth microdilution.

Susceptibility of 228 non-fermenting gram-negative rods to tigecycline and six other antimicrobial drugs.

The aim of the study was to determine the in vitro activity of tigecycline and 6 other antimicrobial drugs used in clinical practice against 228 clinical isolates of nonfermenting Gram-negative rods (NFGNRs) including Acinetobacter spp., Stenotrophomonas maltophilia, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MICs) were determined according to the recommendations of the Clinical and laboratory Standards institute. for tigecycline, we used the criteria approved by the fDA. Almost 50% of the clinical isolates of Acinetobacter spp. were resistant to piperacillin/tazobactam, ciprofloxacin, gentamicin, and ceftazidime. Strains of this microorganism were more susceptible to imipenem, and even more susceptible to colistin and tigecycline; no strains were resistant to tigecycline. Stenotrophomonas maltophilia showed even greater resistance to the drugs tested. Thus, all strains were resistant to imipenem and a large percentage (82.6%) were resistant to piperacillin/tazobactam. Resistance to the other agents tested was also high, with the exception of tigecycline, with only 3 resistant strains (MIC >8 microg/ml). Tigecycline, on the other hand, was scarcely active against Pseudomonas aeruginosa, which bears efflux pump systems such as MexXy-OprM. Almost 90% of strains were resistant to ciprofloxacin; only 8% were resistant to gentamicin; over half were colistin-intermediate or -resistant, and finally, approximately half of the strains were susceptible to the 3 beta-lactams studied. In conclusion, NFGNRs present variable susceptibility patterns, although they are generally highly resistant to antimicrobial agents including those considered more specific. Tigecycline, which showed good activity against most of the strains examined, broadens the spectrum of drugs available for the treatment of infections caused by these complex microorganisms.

Activity of ertapenem and other antimicrobials against ESBL-producing enterobacteria isolated from urine in patients from Madrid.

The objective of this study was to evaluate the activity of ertapenem and other antimicrobials against extended-spectrum beta-lactamase (ESBL)-producing enterobacteria isolated from patients' urine samples at 4 community healthcare centers in the Madrid (Spain) area and to determine the prevalence of ESBL-producing enterobacteria in community-acquired urinary tract infections. The antibiotic susceptibility results were compared by patient age and sex. A total of 293 strains were studied. The minimum inhibitory concentration (MIC) for each antibiotic was determined using the agar dilution method. The tested carbapenems were the antibiotics with the greatest activity (ertapenem MIC(90)=0.06 mg/l; imipenem MIC(90)=0.5 mg/l), with no intermediate or resistant strains being observed. High rates of resistance to ciprofloxacin (80.9%) and cotrimoxazole were observed (62.1%). The global prevalence of ESBL-producing enterobacteria was 3.6% (293/8,139). Prevalence according to areas was 5.3% in Getafe, 3.45% in Arguelles, 3.02% in Alcala de Henares and 3.56% in Mostoles. The global prevalence of ESBL-producing Escherichia coli was 4.15% (279/6,721). The analysis of resistance according to patient sex (males versus females) showed no significant differences. The analysis of resistance according to patient age (<50 years versus > or = 50 years) showed statistically significant differences (more resistance among subjects > or = 50 years old) for cotrimoxazole (OR=0.43, 95%CI: 0.20-0.93, p=0.018) and ciprofloxacin (OR=0.32, 95%CI: 0.14-0.74, p=0.0027). In view of the good activity shown by ertapenem, and the continuous increase in the prevalence of ESBL strains, this antibiotic and some of the others could be a good choice for the treatment of community-acquired urinary tract infections produced by such bacteria in Spain.

Activity of ertapenem and other antimicrobials against ESBL-producing enterobacteria isolated from urine in patients from Madrid

El objetivo de nuestro estudio fue evaluar la actividad del ertapenem y de otros antimicrobianos frente a cepas de enterobacterias productoras de BLEE aisladas de orina de pacientes de la comunidad en cuatro áreas sanitarias de Madrid, así como establecer la prevalencia de enterobacterias productoras de BLEE en este tipo de infecciones. Los resultados de sensibilidad antibiótica se compararon por edad y sexo. Se estudiaron 293 cepas. La CMI de cada antibiótico se determinó por el método de dilución en agar. Los carbapenemes probados fueron los antibióticos con mayor actividad (ertapanem CMI90=0,06 mg/l; imipenem CMI90=0,5 mg/l), sin que se observara ninguna cepa con sensibilidad intermedia o resistente. Se encontraron altas tasas de resistencia a ciprofloxacino (80,9%) y a cotrimoxazol (62,1%). La prevalencia global de enterobacterias productoras de BLEE fue del 3,6% (293/8139). La prevalencia según el área de salud fue del 5,3% en Getafe, del 3,45% en Argüelles, del 3,02% en Alcalá de Henares y del 3,56% en Móstoles. La prevalencia global de Escherichia coli productoras de BLEE fue del 4,15% (279/6721). En el análisis de la resistencia por sexo (hombres frente a mujeres) no se encontraron diferencias significativas. En el análisis por edad (<50 años frente a ≥ 50 años) se encontraron diferencias estadísticamente significativas (más resistencia en ≥50 años) para el cotrimoxazol (OR=0.43, IC95%: 0,20-0,93, p=0.018) y el ciprofloxacino (OR=0.32, IC95%: 0,14-0,74, p=0.0027). Considerando la buena actividad mostrada por el ertapenem y el continuo aumento en la prevalencia de cepas productoras de BLEE, este antibiótico y algún otro podrían ser una buena elección para el tratamiento de las infecciones del tracto urinario adquiridas en la comunidad producidas por cepas productoras de BLEE en España

The objective of this study was to evaluate the activity of ertapenem and other antimicrobials against extended-spectrum β-lactamase (ESBL)- producing enterobacteria isolated from patients’ urine samples at 4 community healthcare centers in the Madrid (Spain) area and to determine the prevalence of ESBL-producing enterobacteria in community-acquired urinary tract infections. The antibiotic susceptibility results were compared by patient age and sex. A total of 293 strains were studied. The minimum inhibitory concentration (MIC) for each antibiotic was determined using the agar dilution method. The tested carbapenems were the antibiotics with the greatest activity (ertapenem MIC90=0.06 mg/l; imipenem MIC90=0.5 mg/l), with no intermediate or resistant strains being observed. High rates of resistance to ciprofloxacin (80.9%) and cotrimoxazole were observed (62.1%). The global prevalence of ESBL-producing enterobacteria was 3.6% (293/8,139). Prevalence according to areas was 5.3% in Getafe, 3.45% in Argüelles, 3.02% in Alcalá de Henares and 3.56% in Móstoles. The global prevalence of ESBL-producing Escherichia coli was 4.15% (279/6,721). The analysis of resistance according to patient sex (males versus females) showed no significant differences. The analysis of resistance according to patient age (<50 years versus ≥ 50 years) showed statistically significant differences (more resistance among subjects ≥ 50 years old) for cotrimoxazole (OR=0.43, 95%CI: 0.20-0.93, p=0.018) and ciprofloxacin (OR=0.32, 95%CI: 0.14-0.74, p=0.0027). In view of the good activity shown by ertapenem, and the continuous increase in the prevalence of ESBL strains, this antibiotic and some of the others could be a good choice for the treatment of community-acquired urinary tract infections produced by such bacteria in Spain

Resistance to macrolides, clindamycin and telithromycin in Streptococcus pyogenes isolated in Spain during 2004.

OBJECTIVES: To study the antimicrobial susceptibility and prevalence of the different phenotypes and genotypes of macrolide resistance in group A streptococci isolated in Spain in 2004, and to compare the results with those obtained in 1998 and 2001 using the same methodology and centres. METHODS: A total of 530 unique isolates of Streptococcus pyogenes collected in 21 laboratories from 16 geographic areas (regions) in Spain were used. Antimicrobial susceptibility testing was performed using the agar dilution method. Discs containing erythromycin or clindamycin were used to recognize the phenotypes of macrolide-lincosamide-streptogramin (MLS) resistance. Genes encoding macrolide-lincosamide resistance were detected by PCR. RESULTS: Resistance to erythromycin was 21.7% [95% confidence interval (CI) 16.5-26.3]. The resistance to azithromycin was 21.5%, whereas the resistance to miocamycin and to clindamycin was 6.6% (95% CI 3.0-8.9). Thirty-one (5.8%) of the isolates were resistant to telithromycin. Of the 115 erythromycin-resistant isolates, 67.8% had the M phenotype, representing 14.7% of all the isolates tested. Thirty-five isolates (30.5% of the erythromycin-resistant strains and 6.6% of all the isolates) had the MLS(B) constitutive phenotype. There was a high prevalence of resistance to telithromycin (88.6%) among the 35 strains with the MLS(B) constitutive phenotype. When we compared these results with those from previous studies (1998 and 2001), we found a significant increase in the MLS(B) constitutive phenotype (P < 0.001), and a significant decrease in the M phenotype (P < 0.005) was noted. CONCLUSIONS: The significant increase in the prevalence of resistance to clindamycin and miocamycin, and the prevalence of resistance to telithromycin reached in a short period of time from the introduction of its use, underscore the need for continuous surveillance of antimicrobial resistance in S. pyogenes in Spain.

Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections in relation to demographic and clinical data.

This prospective study determined the antibiotic susceptibility of 164 isolates of Escherichia coli from the urine of 164 patients (112 female, 52 male; mean age of 54.12 years) with community-acquired urinary tract infection (UTI). Half of the isolates were from uncomplicated UTI and half from complicated UTI (52 males and 34 females). Overall, 57.3% of isolates were resistant to ampicillin, 25% to co-trimoxazole, 20.1% to nalidixic acid, 14% to norfloxacin and ciprofloxacin, and 0% to fosfomycin and nitrofurantoin. Of the 82 isolates from complicated UTI, 16 (19.5%) were resistant to norfloxacin and ciprofloxacin, compared with seven (8.5%) from uncomplicated UTI (p 0.043). Isolates from patients aged >50 years were significantly more resistant than those from patients aged <50 years for nalidixic acid (p 0.007) and the fluoroquinolones tested (p 0.015). Resistance to fluoroquinolones was 25% (13/52) in males and 9% (10/112) in females (p 0.006). For patients with and without previous antimicrobial therapy, there was a significant difference only for resistance to nalidixic acid (p < 0.001) and the fluoroquinolones (p 0.011). There were adequate susceptibility rates to fosfomycin, nitrofurantoin and the fluoroquinolones for empirical use in the treatment of acute uncomplicated UTI. In order to interpret cumulative susceptibility data from the primary healthcare setting, it is necessary to take into account the type of UTI (uncomplicated vs. complicated), previous antimicrobial therapy, and the sex and age of each patient.

Acute and chronic otitis media and Turicella otitidis: a controversial association.

Turicella otitidis is a non-fermenting Gram-positive bacillus isolated almost exclusively from ear exudates. Its significance in acute or chronic otitis media is controversial. Over a 12-month period, T. otitidis was isolated from nine ear exudates from seven patients. Most of these were cases of spontaneous drainage following recurrence of otitis media after antimicrobial therapy that was ineffective against T. otitidis. The MICs of penicillin, levofloxacin, linezolid and vancomycin were very low for all the isolates studied, but most isolates displayed high resistance to macrolides and lincosamides.

In vitro susceptibility of recent antibiotic-resistant urinary pathogens to ertapenem and 12 other antibiotics.

BACKGROUND: The treatment of complicated urinary tract infections may require the use of a parenteral antibiotic with potent activity against the most common urinary pathogens. Ertapenem is a broad-spectrum 1beta-methyl carbapenem with a long plasma half-life that allows administration of a single daily dose. METHODS: The purpose of this work was to test the in vitro susceptibility to ertapenem, ampicillin, cefazolin, cefuroxime, cefotaxime, co-amoxiclav, piperacillin/tazobactam, imipenem, gentamicin, amikacin, fosfomycin, ciprofloxacin and co-trimoxazole of 482 strains of urinary pathogens of the family Enterobacteriaceae isolated from patients in the community of Madrid (40% from males). The distribution was as follows: Escherichia coli (n = 315), Proteus mirabilis (n = 42), Klebsiella spp. (n = 14) and AmpC-producing Enterobacteriaceae (n = 111). The strains studied were selected based on their resistance to quinolones and aminoglycosides, and their production of extended-spectrum beta-lactamases (ESBLs) or AmpC-type beta-lactamases. RESULTS: All the strains were susceptible to ertapenem, imipenem and amikacin. The MIC(90) of ertapenem ranged from a minimum of 0.03 mg/L for Proteus vulgaris and a maximum of 1 mg/L for Enterobacter spp. Ertapenem was the most active of all drugs tested in all cases. On comparing antibiotic resistance among ESBL-producing strains of E. coli (n = 35) and E. coli strains not producing ESBLs (n = 280), statistically significant differences were obtained for ciprofloxacin (P = 0.002) and gentamicin (P = 0.011). Regarding ertapenem, only a slight increase in MIC(50) was seen, the value being 0.015 mg/L for strains not producing ESBLs versus 0.03 mg/L for ESBL-producing strains. CONCLUSIONS: In view of its significant antibiotic potency against antibiotic-resistant Enterobacteriaceae, ertapenem may constitute a good therapeutic alternative in urinary infections caused by these pathogens.

Nosocomial bacteremia and catheter infection by Bacillus cereus in an immunocompetent patient.

We present a case of Bacillus cereus bacteremia and catheter infection in an immunocompetent patient subjected to abdominal surgery, who recovered following central catheter removal and treatment with piperacillin/tazobactam.

Utilidad de una prueba treponémica rápida para el serodiagnóstico de sífilis / Evaluation of a rapid treponemal test for the serodiagnosis of syphilis

Evaluar una nueva prueba treponémica, Syphilis Fast, para el serodiagnóstico rápido de sífilis en comparación con otras pruebas serológicas. Pacientes y métodos. Un total de 287 sueros de 280 pacientes fueron analizados mediante una prueba no treponémica, RPR (Rapid Plasma Reagin test) y dos pruebas treponémicas (Syphilis Fast y Mercia Syphilis Total EIA). Todos los sueros reactivos fueron confirmados mediante FTA Abs. La población incluida en el estudio comprendía: inmigrantes y viajeros procedentes de África subsahariana, pacientes con prácticas de riesgo para enfermedades de transmisión sexual y VIH (homosexuales o bisexuales, adictos a drogas por vía parenteral, pacientes con múltiples parejas sexuales), inmigrantes que ejercían la prostitución, niños adoptados, mujeres embarazadas y pacientes con síntomas neurológicos o con lesiones cutáneas genitales. Resultados. De los 280 pacientes, 28 (10 por ciento) eran VIH+. La concordancia del FTA Abs, considerada la prueba de referencia o gold standard en serodiagnóstico de sífilis, con Syphilis Fast y Mercia Syphilis Total EIA fue de 98,3 por ciento (282/"287, tres resultados falsos positivos y dos falsos negativos) y de 976 por ciento (280/287, siete resultados falsos negativos), respectivamente. Comparativamente Syphilis Fast fue más sensible que Mercia Syphilis Total EIA para la detección de sífilis (98,4 vs. 94,3 por ciento) y ligeramente menos específico (98,2 por ciento vs. 100 por ciento). Conclusiones Syphilis Fast es una prueba rápida, coste-efectiva, fácil de usar y precisa. Los resultados de este estudio indican que Syphilis Fast puede ser una alternativa a otras pruebas treponémicas para el serodiagnóstico de sífilis en los laboratorios clínicos (AU)

Significant increase in the prevalence of erythromycin-resistant, clindamycin- and miocamycin-susceptible (M phenotype) Streptococcus pyogenes in Spain.

In 1998 we conducted a multicentre study in Spain on the susceptibility of Streptococcus pyogenes isolates to different 14-, 15- and 16-membered macrolides and clindamycin, in which the number of strains examined was proportional to the number of inhabitants in each geographical area. The aim of the present work was to re-examine the antimicrobial susceptibility of S. pyogenes in 2001, using the same methodology and centres as in 1998, to determine the different susceptibility phenotypes to macrolides-lincosamides, and to compare the results from the 2 years by statistical tests. A total of 529 unique isolates of S. pyogenes, collected in 21 laboratories, were studied. Throat swabs provided 417 isolates (78.8%), and the remaining 112 were from other sources. Four hundred and thirty-five (82.2%) were isolated from children and 94 (17.8%) from adults. One hundred and fifty-seven (29.7%) of the isolates were resistant to erythromycin and azithromycin, whereas resistance to miocamycin, a 16-membered macrolide, was 1.5%. The prevalence of resistance to clindamycin was 1.3%. The majority (98.7%) of the 157 erythromycin-resistant strains presented the M phenotype. When we compared the results obtained in 1998 and 2001, we observed a statistically significant increase in resistance to erythromycin and azithromycin (P = 0.02, chi(2) test), but not to clindamycin or miocamycin (P = 0.47, chi(2) test with Yates' correction). The significant increase in the prevalence of resistance to some macrolides of S. pyogenes in Spain underscores the need for continuous surveillance of antimicrobial resistance in this species.

Susceptibility of strains of Streptococcus agalactiae to macrolides and lincosamides, phenotype patterns and resistance genes.

The Group B streptococcus (Streptococcus agalactiae) is a pathogen of increasing importance in human disease. We therefore studied the susceptibility of clinical isolates of S. agalactiae to penicillin G, erythromycin, azithromycin and clindamycin using National Committee for Clinical Laboratory Standards methodology, and we also determined the phenotypes of macrolide-lincosamide susceptibility and the resistance genes implicated in a group of selected isolates of the different phenotypes. We used 221 isolates collected between 1997 and 1999 in two Health Authority Areas in Móstoles and Granada, Spain. The minimal concentration for 90% inhibition (MIC90) for penicillin G was 0.12 mg/L and all the isolates tested were susceptible. One hundred and eighty-five (83.7%) were susceptible to erythromycin and azithromycin and 191 (86.4%) were susceptible to miocamycin and clindamycin. Twenty-three isolates (10.4%) had a constitutive MLSB phenotype, seven (3.2%) an inducible phenotype, and six (2.7%) an M phenotype. All except one of the MLSB phenotype isolates tested (n = 23) carried erm genes; in two strains with the mef (A) gene, all the M phenotype (n = 6) isolates tested carried mef genes, while erm and mef (A) genes were absent in all the macrolide-lincosamide-susceptible (n = 12) isolates tested. In our environment, resistance to macrolide and lincosamide in S. agalactiae was present in 10-16% of the isolates. The majority of resistant strains had the MLSB phenotype.

Fracaso terapéutico con ceftriaxona en una exacerbación de bronquitis crónica por neumococo altamente resistente a betalactámicos / Therapeutic failure with ceftriaxone in a case of esarcebation of chronic bronchitis by pneumococcus highly resistant to beta-lactams

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