Samuel Bernal

In vitro activity of voriconazole, itraconazole, caspofungin, anidulafungin (VER002, LY303366) and amphotericin B against aspergillus spp

Voriconazole, anidulafungin (VER002, LY303366) and caspofungin are promising antifungal agents which provide a good protection against a variety of fungi, including yeasts and filamentous fungi. In this study, we tested the in vitro efficacy of voriconazole, itraconazole, caspofungin, anidulafungin (VER002, LY303366) and amphotericin B, against different species of Aspergillus spp. isolated from clinical specimens, using a microdilution broth method and following the NCCLS guidelines (document M38-P). We also evaluated the effect that time readings have on MIC results. For caspofungin, we determined the minimun effective concentration (MEC), defined like the lowest concentration of caspofungin causing abnormal hyphal growth. Anidulafungin (VER002, LY303366) was the most active antifungal agent tested with MIC(90) of < or =0,03 mg/L. The activity of voriconazole, and itraconazole very similar with MIC(90) of 0,12 mg/L, 0,12 mg/L respectively. For caspofungin the MEC(90) was of 0,25 mg/L. Amphotericin B was the lest active antifungal agent studied with MIC(90) of 1 mg/L. There were no differences between MIC values at 48 and 72 h. These data demonstrate promising activity of voriconazole, anidulafungin (VER002, LY303366) and caspofungin against Apergillus spp.

Evaluation of CHROMagar candida medium for the isolation and presumptive identification of species of candida of clinical importance

CHROMagar candida is a new differential culture medium that allows the isolation and presumptive identification of species of yeast of clinical importance. We tested 618 strains of yeast, including 128 direct isolates from clinical specimens. After two days of incubation at 37 degrees C, 339 of 341 Candida albicans, 98 of 99 Candida glabrata, all the Candida tropicalis, and all the Candida krusei were identified correctly. The sensitivity and specificity in these cases were both superior to 99%. Easy to prepare, with low cost, CHROMagar Candida proves to be a useful medium for the identification of species of yeast that are isolated with greater frequency in clinical material and for the identification of mixed cultures.

Evaluation of the new API candida system for identification of the most clinically important yeast species

The API Candida system (bioMérieux) a new yeast identification system, was evaluated for its reliability in identifying 198 clinical yeast isolates in comparison with the API 20C system (bioMérieux) that was used as reference standard. The API Candida system correctly identified 91.4% and 71.7% of the isolates, with and without additional tests, respectively. The API Candida system identified 96.3% of common isolates studied, and 66.6% of uncommon isolates. We think that API Candida system is an easy and good yeast identification system and it could be used in a routine clinical microbiology laboratory.

Evaluation of the cobas 4800 CT/NG Test for detecting Chlamydia trachomatis and Neisseria gonorrhoeae DNA in urogenital swabs and urine specimens

We have evaluated 696 samples (488 swabs and 208 urine specimens) with the cobas 4800 (c4800) CT/NG Test for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae DNA in swab and urine specimens. c4800 results were compared with those obtained from COBAS AMPLICOR (CAM) CT/NG Test. Discordant results were reanalyzed with the MultiNA system and compared with clinical data. For C. trachomatis detection by both methods, we obtained 93.8%, 100%, 100%, and 99.1% for sensitivity, specificity, and positive and negative predictive values, respectively. For urine specimens analyzed in c4800, our results were 96.6%, 100%, 100%, and 99.4%, respectively. For N. gonorrhoeae detection, swab results were:88.0%, 100%, 100%, and 99.4%. For urine specimen, results obtained were 100%, 100%, 100%, and 100%. Reanalyses were all concordant between both methods. c4800 results were comparable with those obtained with the CAM system. We had an excellent correlation between swab and urine specimens analyzed by c4800.

Response to fluconazole and itraconazole of Candida spp. in denture stomatitis

Summary. The significance of Candida albicans in the development of denture stomatitis (DS), as well as the clinical and microbiological efficacy of treatment with fluconazole and itraconazole was studied in 115 patients affected with DS and 200 controls (100 healthy patients with dental prosthesis and 100 healthy patients without prosthesis).

Comparison of urine and cervical samples for detecting human papillomavirus (HPV) with the Cobas 4800 HPV test

BACKGROUND Human papillomavirus (HPV) is the main cause of cervical cancer. The development of non-invasive self-sample collection methods would have the potential advantage of increasing the acceptance of the screening procedures. OBJECTIVES To compare human papillomavirus (HPV) DNA detection and genotyping with the Cobas 4800 HPV test (Roche Diagnostic, Spain) on paired cervical and first voided urine. STUDY DESIGN Paired urine and cervical samples were collected from 125 women referred for evaluation of abnormal Pap smear results. RESULTS The overall percent agreement between HPV detection in urine and cervical samples was 88%. A substantial concordance rate of HPV DNA detection in both samples was observed (κ=0.76; 95% IC: 64-87). In this high prevalence population the sensitivity, specificity, NPV and PPV for detection of HPV DNA from urine versus cervical samples were 90.5% (95% IC: 80-95%), 85%, (95% IC: 74-92%), 89.8% (95% IC: 79.5-95.3) and 86.4% (95% IC: 76.1-92.7) respectively. Compared to histologically confirmed CIN 2/3 disease, the clinical sensitivity and specificity for the detection of high-risk HPV in urine samples were 95% (95% IC: 76-97%) and 52.4% (95% IC: 40-64%) respectively. CONCLUSIONS These results suggest that urine samples processed with Cobas 4800 HPV test may be useful for clinical management of HPV infection.

Molecular diagnosis of Aspergillus fumigatus endocarditis

A 66-year-old male with ischaemic cardiomyopathy and chronic lymphocytic leukemia developed signs of severe systemic inflammatory response syndrome. Serial blood cultures were negative and a SeptiFast test detected the presence of Aspergillus fumigatus DNA. Afterwards, detection of galactomannan and 1,3-β-D-glucan showed a positive result. Autopsy revealed the presence of branched fungal structures suggestive of Aspergillus.

Prevalencia de los marcadores de infección de los virus de las hepatitis en pacientes portadores del VIH en el sur de España

OBJECTIVES To determine: (a) The prevalence of active infection by the hepatitis C virus (HCV) and hepatitis B virus (HBV) in HIV-infected patients, as well as previous exposure to hepatitis A virus (HAV), HBV and HCV. (b) The proportion of patients who have been vaccinated against HAV and/or HBV. (c) The HCV genotype distribution and the percentage of patients who have started treatment against HCV infection. METHODS All HIV-infected patients who attended the Infectious Diseases Unit of a tertiary care hospital in Southern Spain between September 2008 and February 2009 were included in a prospective cross-sectional study. RESULTS A total of 520 patients were included. Three hundred and fifty-eight (69%) patients had positive HCV antibody, while 71% of them showed detectable HCV-RNA. The HCV genotype distribution was: 153 (62%) genotype 1, 49 (20%) genotype 3, and 45 (18%) genotype 4. One hundred and thirteen (36.5%) subjects had received treatment against HCV. The prevalence of active HBV infection was 4.4%, while the exposure to HBV was 54.8%. Four hundred and thirty-seven (84%) patients had positive markers of infection of HAV. Of the patients eligible to be vaccinated, 25.6% and 22.3% patients were vaccinated against HAV and HBV, respectively. CONCLUSIONS The current prevalence of active HCV infection remains high in our area. There were no changes in the HCV genotype distribution. The number of patients with indication for HBV and HAV vaccination and receive these vaccines is low.

Comparison of the Sensititre YeastOne Colorimetric Microdilution Panel and the NCCLS Broth Microdilution Method for Antifungal Susceptibility Testing against Candida Species

We evaluated the commercially prepared Sensititre YeastOne colorimetric antifungal panel to determine the susceptibility of 170 Candida spp isolates to amphotericin B, fluconazole, itraconazole, and flucytosine. The NCCLS reference microdilution method (M27-A document) was used as reference method. The YeastOne panel was performed according to the manufacturer’s instructions. For the colorimetric method, MICs were determined at 24 h of incubation. MICs for the NCCLS reference method were read at 48 h of incubation. The overall agreement within ±2 dilutions by both methods was calculated against the four antifungal agents. This agreement was 92.9, 68.2, 77.6 and 80% for amphotericin B, fluconazole, itraconazole, and flucytosine, respectively. Thirteen isolates (7.6%) showed very major discrepancies for fluconazole and 12 (7%) for itraconazole. We found that the reading of MIC with the YeastOne panel was somewhat easier than the reading of reference MIC, although the determination of endpoint was sometimes difficult, especially for azoles, because the trailing effect appeared in a high percentage of isolates.

Estudio de resistencia mediante el sistema de genotipificación TRUGENE HIV-1 y análisis de concordancia entre algoritmos basados en reglas y el fenotipo virtual

Introduccion. Describir los resultados obtenidos en el estudio de resistencia en enfermos con virus de la inmunodeficiencia humana (VIH) en tratamiento antirretroviral de gran actividad (TARGA) y comparar los resultados obtenidos empleando dos algoritmos de interpretacion genotipica y el fenotipo virtual. Metodos. Se han estudiado 397 muestras (TRUGENE HIV-1 GENOTYPING kit), interpretando los resultados con los algoritmos Visible Genetics y Retrogram®. Se realizo el estudio de concordancia entre algoritmos de 105 de estas muestras incluyendo tambien la interpretacion por el fenotipo virtual. Resultados. Pacientes en multifracaso (39%), primer fracaso (30,7%) y segundo fracaso (27,1%). El 27,6% de las muestras fueron cepas salvajes. Las mutaciones a los inhibidores de la transcriptasa inversa analogos de nucleosidos (ITIAN) mas frecuentes fueron T215Y/F (37,2%) y M184V (32,9%) seguida por otras mutaciones asociadas a los analogos de nucleosidos (NAMS). La insercion 69 y el complejo Q151M (1,5%) tuvieron poca representacion. Para los inhibidores de la transcriptasa inversa no nucleosidos (ITINN) K103N (25,8%), Y181C (11,2%) y G190A (10,9%). Para los inhibidores de la proteasa (IP): mutaciones primarias L90M (26,1%), M46I (18,1%) y V82AFTS (12,9%); y mutaciones secundarias L63P (50,5%), A71V (27,2%), L10I (25,2%) y M36I (19,2%). Detectamos baja correlacion entre sistemas de interpretacion para ITIAN e IP, mostrandose el fenotipo virtual mas flexible en la asignacion de resistencia. Conclusiones. Las peticiones de estudios de resistencia fueron similares para los tres grupos de pacientes. Muchos fracasos son el resultado de falta de adherencia al tratamiento. El patron de mutaciones halladas se corresponde con los tratamientos TARGA. La baja correlacion entre los sistemas de interpretacion hace necesaria la elaboracion de un algoritmo consensuado en funcion de la eficacia clinica.