M D Díaz

Evolution of susceptibilities of Campylobacter spp. to quinolones and macrolides.

Erythromycin, new macrolides, and quinolones are alternatives for the treatment of Campylobacter infections. Concerns related to the emergence of resistance to both groups of drugs have been raised. We studied the evolution of antimicrobial susceptibilities of 275 clinical isolates of microorganisms of the genus Campylobacter isolated in our institution during a 5-year period (1988 to 1992). The microorganisms studied were C. jejuni (n = 230), C. coli (n = 42), and C. fetus (n = 3). The overall resistance rates (determined by the agar dilution method and the recommendations of the National Committee for Clinical Laboratory Standards) were as follows: erythromycin, 2.3%; clarithromycin, 2.3%; azithromycin, 1.9%; ciprofloxacin, 28.5%; norfloxacin, 31%; ofloxacin, 26.3%; and nalidixic acid, 36.8%. The evolution of resistance (percent resistance in 1988 versus percent resistance in 1992) was as follows: erythromycin, 2.6 versus 3.1; clarithromycin, 2.6 versus 3.1; azithromycin, 2.6 versus 3.1; ciprofloxacin, 0 versus 49.5; norfloxacin, 2.6 versus 55.5; ofloxacin, 0 versus 45.6; nalidixic acid, 2.6 versus 56.8. Our data show stable macrolide activity against Campylobacter spp. and the rapid development of quinolone resistance over the last 5 years.

In Vitro Activities of Six Fluoroquinolones against 250 Clinical Isolates of Mycobacterium tuberculosis Susceptible or Resistant to First-Line Antituberculosis Drugs

ABSTRACT Two hundred fifty isolates of Mycobacterium tuberculosis were evaluated for susceptibility to ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, trovafloxacin, and gemifloxacin (SB-265805). Levofloxacin, ciprofloxacin, and grepafloxacin showed the greatest activity (MIC for 90% of strains tested [MIC90] 1 μg/ml), although ofloxacin also showed good activity, with an MIC90 of 2 μg/ml. Trovafloxacin and gemifloxacin showed lower in vitro activity, with MIC90s of 64 and 8 μg/ml, respectively.

Antimicrobial resistance of Salmonella isolates in a Spanish hospital.

We studied 961 clinical Salmonella isolates (one per patient) seen in one Spanish hospital from 1988 to 1991. The incidence of non-Salmonella typhi Salmonella infections per 100,000 admissions increased from 3.93 to 5.98. Overall rates of resistance to ampicillin, chloramphenicol, and co-trimoxazole were 32, 11, and 2%, respectively. Resistance to chloramphenicol increased from 9 to 16% during the study period, while resistance to each of the other drugs remained stable. Variations related to serogroups were observed.

Utility of the BACTEC Myco/F lytic medium for the detection of mycobacteria in blood

This study aims to evaluate the performance of a new vial (Myco/F Lytic) for the detection of mycobacteria from blood specimens. This vial is monitored in the BACTEC 9000 blood culture system. We compared it with the traditional method routinely used in our laboratory, which is a lysis-centrifugation based procedure. Of 275 samples tested in parallel by both methods, 23 from 20 patients grew mycobacteria (18 Mycobacterium avium complex, 4 M. tuberculosis and 1 M. simiae); 11 isolates were recovered using both systems, 12 were isolated with the Myco/F Lytic medium only, and none were isolated using the traditional method only (p < 0.05). Blood was the diagnostic sample for 12 patients with the Myco/F Lytic system and only 7 with the traditional system. The mean time to detection of mycobacteria with Myco/F Lytic medium was 17 days, whereas it was 44 days with the traditional method (p < 0.001). Identification by DNA probes was performed directly from the Myco/F Lytic bottle. Myco/F Lytic is a rapid, simple, safe and highly reliable diagnostic method for the detection of mycobacteria in blood.

Enhanced activity of the combination of penicillin G and gentamicin against penicillin-resistant viridans group streptococci.

We evaluated the effects of the combination of penicillin G and gentamicin against 10 penicillin-resistant bacteremic isolates of viridans group streptococci for which the MICs of penicillin were 4 to 64 micrograms/ml. In time-kill studies, the combination resulted in more killing of eight isolates for which the MICs of penicillin were from 8 to 64 micrograms/ml than any of the antimicrobial agents tested alone. In general, clearly enhanced antimicrobial activity was observed with the combination.

Mujer de 33 años con colitis ulcerosa que presenta fiebre prolongada y hepatoesplenomegalia

espanolMujer de 33 anos de edad, con antecedentes de colitis ulcerosa diagnosticada un ano antes, en tratamiento con azatioprina (100 mg al dia) y 5-amino-salicilico, que acude por presentar, desde hace 10 dias, un cuadro de fiebre diaria de hasta 40 °C, sin claro ritmo circadiano, acompanado de escalofrios, astenia, anorexia, quebrantamiento general y cefalea. No refiere sintomatologia de organo especifica, asi como tampoco cuadro diarreico, dolor abdominal ni emision de sangre por el ano. Entre los antecedentes epidemiologicos resenar, tan solo, que tenia contacto ocasional con un perro. En la exploracion, la enferma tiene aspecto toxico, esta febril, normotensa, con 90 latidos por minuto (lpm), no se palpan adenopatias en ningun territorio; ausencia de signos meningeos, orofaringe normal, auscultacion cardiaca y pulmonar normal, hepatomegalia blanda a 3 cm y esplenomegalia a 4 cm de reborde costal izquierdo en linea medioclavicular. No presentaba lesiones cutaneas, las extremidades eran normales, al igual que la exploracion neurologica. Los estudios de imagen (radiografia de torax y tomografia axial computarizada [TAC] abdominal) no demostraron alteraciones significativas. espanolEn los datos analiticos iniciales destacaban: sistematico de sangre: leucocitos 1.650 (73 N, 19 L, 3M); hemoglobina 9,7 g/l, hematocritos 28,6%; volumen corpuscular medio (VCM) 95; concentracion de hemoglobina corpuscular media (CHCM) 34; plaquetas 157.000. Velocidad de sedimentacion globular (VSG) 47 mm a la primera hora. Frotis: ausencia de hemoparasitos. Linfocitos activados. Coagulacion sin alteraciones, salvo fibrinogeno de 140 mg/dl. Sistematico de orina normal. Bioquimica: ALT 88 UI/l (normal hasta 37), AST 126 UI/l (normal hasta 32), LDH 431 UI/l (normal hasta 190), proteinas 5,4 g/dl, calcio 8,1 mg/dl, albumina 2,7 g/dl.