Rev Esp Quimioter 2012:25(4):266-268

Susceptibility to fluconazole of clinical interest yeasts: new breakpoints                     

L. GARCÍA-AGUDO, P. GARCÍA-MARTOS, P. MARÍN-CASANOVA, M. RODRÍGUEZ-IGLESIAS                                                                                   

 

Introduction. Recently, Pfaller et al (Drug Resist Update 2010; 13:180-95), have proposed new breakpoints for determining the in vitro susceptibility to fluconazole of Candida albicans, C. parapsilosis and C. tropicalis. The aim of this study was to establish the variations in sensitivity of these species applying these breakpoints, in relation to those of the Clinical and Laboratory Standards Institute (CLSI).
Methods. We analyzed 112 strains of Candida: 49 C. albicans, 40 C. parapsilosis and 23 C. tropicalis. Susceptibility to fluconazole was performed by the method Sensititre YeastOne. The breakpoints used to determine the minimum inhibitory concentration (MIC) were identified by CLSI and the ones proposed by Pfaller et al.
Results. According to the CLSI criteria, all isolates were susceptible to fluconazole. MIC50 and MIC90 were 0.5 mg/L and 2 mg/L for C. albicans and C. parapsilosis, 0.5 mg/L and 1 mg/L for C. tropicalis. With the new criteria, 109 (97%) strains were susceptible. Variations were seen in C. albicans, with 3 strains (6%) susceptible dose-dependent.
Conclusions. When applying the breakpoints recommended by Pfaller et al, and EUCAST, the number of fluconazole- susceptible strains decreased according to the CLSI criteria, especially C. albicans.  

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Rev Esp Quimioter 2012:25(1):10-16

Macrolides and staphylococcal biofilms                

J. PARRA-RUIZ, C. VIDAILLAC, M. J. RYBAK                            

Medical device-associated infections represent a growing problem with limited or no therapeutic options beyond implant removal. Bacterial biofilm is the major and the final determinant of the poor prognosis of these difficult-to-treat infections. Due to the high antimicrobial resistance level of bacteria organized in biofilms, combination therapy is most often recommended, and macrolides may represent antibiotics of choice. Their anti-biofilm activity has been successfully used in-vitro and in-vivo against biofilm-associated infections caused by Pseudomonas aeruginosa and other Gram-negative bacilli. However there is only little data regarding their clinical interest against infections involving staphylococcal biofilms. Despite controversial reports, there is growing in-vitro and in-vivo evidences of anti-staphylococcal biofilm activity of macrolides that could represent a significant advance in the battle against implant-related infections. 

 
Rev Esp Quimioter 2012:25(1):10-16 [pdf]

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Rev Esp Quimioter 2012:25(2):147-154

Prospective comparison of severity scores for predicting mortality in community-acquired pneumonia              

S. LUQUE, J. GEA, P. SABALLS, O. FERRÁNDEZ, N. BERENGUER, S. GRAU                                                                      

 
Introduction. Specific prognostic models for communityacquired pneumonia (CAP) to guide treatment decisions have been developed, such us the Pneumonia Severity Index (PSI) and the Confusion, Urea nitrogen, Respiratory rate, Blood pressure and age ≥ 65 years index (CURB-65). Additionally, general models are available such as the Mortality Probability Model (MPM-II). So far, which score performs better in CAP remains controversial. The objective was to compare PSI and CURB-65 and the general model, MPM-II, for predicting 30-day mortality in patients admitted with CAP.
Methods. Prospective observational study including all consecutive patients hospitalised with a confirmed diagnosis of CAP and treated according to the hospital guidelines. Comparison of the overall discriminatory power of the models was performed by calculating the area under a receiver operator characteristic curve (AUC ROC curve) and calibration through the Goodness-of-fit test.
Results. One hundred and fifty two patients were included (mean age 73.0 years; 69.1% male; 75.0% with more than one comorbid condition). Seventy-five percent of the patients were classified as high-risk subjects according to the PSI, versus 61.2% according to the CURB-65. The 30-day mortality rate was 11.8%. All three scores obtained acceptable and similar values of the AUCs of the ROC curve for predicting mortality. Despite all rules showed good calibration, this seemed to be better for CURB-65. CURB-65 also revealed the highest positive likelihood ratio.
Conclusions. CURB-65 performs similar to PSI or MPMII for predicting 30-day mortality in patients with CAP. Consequently, this simple model can be regarded as a valid alternative to the more complex rules.

 

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Rev Esp Quimioter 2012:25(4):269-273

Discrepancy in the disk diffusion susceptibility test of Pseudomonas aeruginosa strains isolated from cystic fibrosis patients after anaerobic preincubation and its potential clinical relevance                    

F. CAFINI, C. GARCÍA REY, P. BAS, M. L. GÓMEZ-LUS, I. SÁNCHEZ, S. VÁZQUEZ, J. PRIETO                                                                                   

Introduction. In cystic fibrosis, the Pseudomonas aeruginosa cells grow inside the thick mucus layer. In spite of being an obligate aerobe, P. aeruginosa is able to grow in a limited oxygen environment. Bacterial cells could be suddenly exposed to high oxygen levels due to the movements of the mucus mass. The aim of study was to determine the impact of a previous anaerobic incubation on the antimicrobial susceptibility of P. aeruginosa strains isolated from patients with cystic fibrosis.
Materials and Methods. Four P. aeruginosa strains were used in this study (ATCC 23389 and 3 clinical isolates). The disk diffusion method was used to determine the antimicrobial susceptibility.
Results. The anaerobic pre-incubation produced changes on the susceptibility in all studied strains. All susceptible strains after an aerobic incubation remained susceptible after an anaerobic incubation except one clinical strain, which became resistant to betalactams. The response was strain-dependent and the most significant increase in susceptibility was observed in two of the three clinical isolates when ciprofloxacin was used.
Conclusions. The antimicrobial susceptibility of P. aeruginosa strains varies after their exposure to anaerobic conditions. Treatments promoting mucus fluidization could contribute to increase the antimicrobial efficacy.  

 

Rev Esp Quimioter 2012:25(4):269-273 [pdf]

 

 

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Rev Esp Quimioter 2012:25(1):17-24

Liposomal amphotericin B: a unique pharmacokinetic profile. An unfinished story                

J. R. AZANZA, J. BARBERÁN                            

La anfotericina B en su formulación liposómica continúa siendo un fármaco de referencia en el tratamiento de las infecciones fúngicas sistémicas a pesar del tiempo transcurrido desde que se desarrolló. La ausencia de resistencias de los hongos, la farmacocinética, y el mejor perfil de tolerabilidad en relación con el resto formulaciones de anfotericina B, son motivos suficientes para justificar su protagonismo, El liposoma que contiene la anfotericina B liposómica es muy estable en relación con la presencia de colesterol y los fosfolípidos no presentan termolabilidad, por ello la anfotericina B apenas está presente en forma libre (<1%) lo que explica la baja incidencia de efectos relacionados con la administración y la reducción de la incidencia de nefrotoxicidad (mitad que con la anfotericina B complejo lipidico) y que incluso en algún estudio a dosis de 1 mg/kg se ha mostrado inexistente.Este perfil justifica concentraciones plasmáticas muy elevadas y un volumen de distribución y aclaramiento reducidos, con una semivida de eliminación muy prolongada. Existen evidencias que señalan que el liposoma a través de la anfotericina B es capaz de fijarse al ergosterol presente en membrana de hongo y sólo en ese momento se produciría la liberación del antifúngico que ejercería su efecto farmacológico.

 
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Rev Esp Quimioter 2012:25(2):155-160

Pneumococcal bacteremia in adult patients at a hospital in Madrid: serotypes and susceptibility                 

M. CORREA, J. C. SANZ, C. DE LAS CUEVAS, A. GUIU, D. DOMINGO, T. ALARCÓN, M. LÓPEZ-BREA                                                                       

 
Introduction. The aim of this study is to describe the distribution of Streptococcus pneumoniae serotypes, its antimicrobial susceptibility profiles and the relation with vaccines in pneumococcal invasive strains isolated from blood cultures of adult patients.
Methods. All pneumococci isolated (67 strains) from blood cultures were serotyped by latex agglutination (Pneumotest latex) and Quellung reaction (Statens Serum Institut, Denmark). Antimicrobial susceptibility testing to penicillin (PEN), cefotaxime (CT), erythromycin (ERY) and levofloxacin (LEV) was performed by the E-test method (Biomèrieux, France).
Results. Among the 67 strains isolated, the most prevalent serotypes were 22F (11.9%) and 3 (11.9%), the second most frequent were 7F (7.5%) and 19A (7.5%). The coverage of the strains by the pneumococcal 7-valent conjugate vaccine (VNC7V), pneumococcal 13-valent conjugate vaccine (VNC13V) and pneumococcal 23-valent polysaccharide (VNP23V) were 16, 49 and 82%, respectively. Serotypes 22F and 3 were responsible for 14 of the 48 episodes of pneumonia with bacteremia (29.2%) and only 2 of the 19 episodes (10.5%) of bacteremia without pneumonia. According to the 2007 CLSI criteria, 12 strains (17.9%) were non-susceptible to penicillin. Eleven of this 12 strains (91.7%) were resistant to erythromycin, simultaneously.
Conclusions. The most common serotypes were 22F, 3, 7F y 19A. Three of them (3, 7F y 19A) are serotypes that are covered by the new VNC13V but not by VNC7V. Serotype 22F is a serotype emergent that is not covered by the VNC7V. The percentage of non-susceptibility to penicillin and resistance to erythromycin was comparable to the percentage reported in our country.

 

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Rev Esp Quimioter 2012:25(4):274-282

Efficacy and safety of caspofungin in critically ill patients. ProCAS Study                     

C. LEÓN-GIL, A. ÚBEDA-IGLESIAS, A. LOZA-VÁZQUEZ, M. V. DE LA TORRE, J. M. RAURICH-PUIGDEVALL, B. ÁLVAREZ-SÁNCHEZ, C. ORTIZ-LEYVA, J. M. DOMÍNGUEZ-ROLDÁN, L. SOCÍAS-CRESPI, J. GARNACHO-MONTERO AND THE PROCAS STUDY GROUP                                                                                   


Introduction. Caspofungin is an echinocandin with proven efficacy in invasive candidiasis (IC) and invasive aspergillosis (IA). ProCAS is a study sponsored by the Working Group of the Infectious Diseases of the Spanish Society of Intensive Care Medicine, which analyzes the effectiveness and safety of caspofungin in routine clinical practice conditions in the critically ill.
Methods. A prospective, multicenter, observational study designed to estimate the clinical effectiveness and safety of caspofungin acetate in the treatment of IC and IA in patients refractory to or intolerant of conventional antifungal therapy. The assessment of effectiveness both clinic and the microbiological was carried out at the end of the treatment with caspofungin.
Results. We included 98 patients, 62 IC proven, 25 probable and 11 IA probable, from 24 centers during 2005 and 2006. Treatment with caspofungin monotherapy was performed in 89.8% of cases and as first line therapy in 54.1%. The favorable clinical response obtained for IC, probable IC, and probable IA was 91.9, 84, and 81.8%, respectively. The microbiological response was favorable in 74.6, 68, and 54.6% for proven cases of IC, probable IC, and probable IA, respectively. No serious adverse effects were observed.
Conclusions. In routine clinical practice conditions, caspofungin is effective and safe for the treatment of invasive fungal infections (IC/IA). The efficacy and safety profile was similar to that observed in published clinical trials.  

 

Rev Esp Quimioter 2012:25(4):274-282 [pdf]

 

 

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