[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.

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.

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.

Pulmonary infection by Mycobacterium gordonae in an immunocompromised patient.

Mycobacterium gordonae, a scotochromogenic organism, is considered a saprophyte and isolation of this organism in sputum cultures is not generally considered clinically significant. We report the case of 70-yr-old man with Hodgkin's disease and pulmonary infection caused by Mycobacterium gordonae. The clinical and radiographic findings in this case and the course are outlined. Mycobacterium gordonae isolated from patients with debilitating diseases should not automatically be rejected as a contaminant.

Bacteriologic characteristics and antimicrobial susceptibility of 70 clinically significant isolates of Streptococcus milleri group.

The phenotypical characteristics of 70 clinical isolates of Streptococcus milleri group were analyzed. Association of the three species with particular sites of isolation could not be demonstrated in all cases, but S. anginosus strains predominated in abdominal area, while S. intermedius was isolated mainly in hepatic abscesses. Penicillin G and other beta-lactams showed good in vitro activity against these streptococci, whereas > 10% exhibited resistance to erythromycin and clindamycin. Resistance to tetracycline reached almost 40%. All of the isolates were uniformly susceptible to vancomycin, chloramphenicol, and trimethoprim.

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.

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.

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.

[The prevalence of Escherichia coli susceptibility to quinolones and other antibiotics in community-acquired bacteriurias in Madrid]. / Prevalencia de susceptibilidad de Escherichia coli a quinolonas y otros antibióticos en bacteriurias extrahospitalarias de Madrid.

BACKGROUND: The empiric treatment of extrahospitalary urinary infections must keep in mind the patterns of susceptibility of the potentially causative bacteria. The consumption of antibiotics is one of the most important causes of change in the susceptibility of the bacteria. The recent introduction of fluorquinolones and the widespread use of those antibiotics makes knowledge of new patterns of sensitivity necessary in order to determine whether there are changing sensitive pattern among the different geographic zones. METHODS: During a period of two weeks randomly chosen 379 strains of Escherichia coli isolated from extrahospitalary bacteria were collected in 11 laboratories in 4 health areas in Madrid. Sensitivity to 11 antibiotics, including four of the quinolone group was determined by the agar dilution method. The existence of significant differences of sensitivity among the different areas was analyzed by the chi 2 test. RESULTS: The prevalence of sensitivity to ampicillin and cotrimoxazol was 42 and 73% respectively. Nineteen percent of the strains were resistant to amoxycillin/clavulanic acid. No strain was found to be resistant to cefotaxime. Four percent of the sample studied was not sensitive to the new fluorquinolones and almost 10% were resistant to nalidixic acid latter having decreased sensitivity to the fluorquinolones. No significant differences were observed in sensitivity among the areas, except with amoxycillin/clavulanic acid and cotrimoxazole. CONCLUSIONS: The high prevalence of the resistance of E. coli to ampicillin recently leads to the recommendation of its use in empiric treatments of urinary infections. In the zone in Madrid studied a high prevalence of resistance and decreased sensitivity of E. coli to fluoroquinolones was observed. It is therefore advisable to moderate their use to thereby prolong use over time.

[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.