Rev Esp Quimioter 2010:23(1):12-19

Multidrug resistant Acinetobacter baumanii: clinical update and new highlights

A. HERNÁNDEZ, E. GARCÍA, G. YAGÜE, J. GÓMEZ 

 

The role of multidrug resistant Acinetobacter baumanii and its clinical relevance have been recently appreciated as a ubiquitous opportunistic nosocomial pathogen. Risk factors associated with A. baumanii infection include severe underlying diseases, previous surgery, invasive procedures, treatment with broad-spectrum antibiotics, length of hospital stay, admission to intensive care units (ICU). Carbapenem-multidrug resistant A. baumanii infections are probably associated to greater severity and more complications; in our cohort mortality was 49.3% and related mortality (within 72 hours) was 10.39%. However, severe underlying diseases probably play an important role in the clinical outcome of patients with MDR-C A. baumanii infection and controversy exists regarding the real mortality attributable to antimicrobial resistance because a high proportion of deaths took place > 7 days after diagnosis. Nevertheless, in our experience, carbapenem resistance, inappropriate therapy and monotherapy are associated to a higher mortality. Special attention should be paid to design well-controlled prospective clinical trials to determine the optimal antimicrobial therapy in critically ill patients suspected of having MDR Acinetobacter infection.

 
Rev Esp Quimioter 2010:23(1):12-19 [pdf]

Rev Esp Quimioter 2010:23(3):126-134

Critical study of spanish adult consumer profile of antibiotics on the basis of National Surveys of Health in 1993, 1995, 1997, 2001 and 2003 

J. L. BAQUERO, J. BARBERÁN, D.MARTÍNEZ   

 

Objective: The objective of this study has been to examine antibiotic consumption in Spain through the use of the National Surveys of Health (NSH) .
Material and methods: Taking the NSH, between 1993 and 2003, certain variables regarding the consumption of antibiotics have been analyzed; putting these into groups according to their typology, habits, comorbidity and the utilization of health resources. This information has been compared with published data by other authors.
Results: The consumption of antibiotics was approximately 3%, and 9-19% of this was not prescribed. Significant statistical associations have been observed between the consumption of antibiotics and other aspects such as academic and income levels, habits such as smoking, general health, certain chronic diseases, being bed-ridden due to disease; and also the use of certain medicines and the anti-influenza vaccine.
Conclusions: Consumption of antibiotics coincides with described data by other authors, and this was always higher than prescribed. The association with other variables may be limited by the inadequate NSH design in order to know the exact consumption of antibiotics.   

 
Rev Esp Quimioter 2010:23(3):126-134 [pdf]

Rev Esp Quimioter 2010:23(1):20-26

Pseudomonas aeruginosa: antimicrobial resistance in clinical isolates. Castellón 2004 -2008

F. J. PARDO, M. D. TIRADO, E. D. GARCÍA, J. GRANADOS, A. CAMPOS, R. MORENO 

 

Retrospective study of antimicrobial susceptibility of 1.943 Pseudomonas aeruginosa clinical isolates to amikacin, tobramycin, gentamicin, ceftazidime, cefepime, meropenem, piperacillin-tazobactam and ciprofloxacin during a five year period. The percentage of resistance went from 2.07% to amikacin from 15.89% to ciprofloxacin. These percentages showed differences depending on the extra or intrahospitalary origin, departments and samples. Isolates from hospital patients were significantly more resistant than the ones from ambulatory patients (p≤0.001:tobramycin, 13.74% vs 5.05%; gentamicin, 13.74% vs 8.26%; ceftazidime, 12.67% vs 4.24%; cefepime, 11.48% vs 7.07%; meropenem, 8.57% vs 2.06%),except for amikacin (1.98% vs 2.2%, p=0.74), piperacillin/tazobactam (6.07% vs 4.55%, p=0.14) and ciprofloxacin (17.17% vs 13.97%, p=0.06). Critical care department and respiratory samples showed the highest resistance percentages while surgery department and invasive samples showed the lowest. Multidrug-resistance was found in 4.8% of the isolates. When comparing our data with those from our previous study (1992-2003), we observed a significant reduction in antibiotic resistance to amikacin (7.74% vs 2.07%, p<0.001), tobramycin (13.61% vs 10.26%, p<0.001), gentamicin (30,85% vs 14.73%, p<0,001), ceftazidime (14.63% vs 9,28%, p<0.001), cefepime (12,31% vs 9.71%, p=0.005), and meropenem (7.74% vs 2.07%, p=0.001); and there were no changes in resistance to piperacillin- tazobactam (4.26% vs 5.46%, p=0,06) and ciprofloxacin (16.02% vs 15.89%, p=0.89). In the last years, the susceptibility pattern of P. aeruginosa to antimicrobial agents has changed in our health district, and it is very different from the one described in national studies so it would be very important to monitore susceptibility of clinical isolates periodically.

 
Rev Esp Quimioter 2010:23(1):20-26 [pdf]

Rev Esp Quimioter 2010:23(3):135-143

Impact factor and quality of scientific publications on Microbiology: the example of the Spanish Journal of Chemotherapy 

D. CARABANTES   

 

Introduction. The impact factor of a journal is the quantitative analysis of the number of citations obtained during a specific period of time. This currently is the standard tool to measure the quality of the publication and a way to evaluate the research trajectory of a scientist.
Methods. Search for bibliometric indicators: Journal Citation Reports, SCImago Journal Rank and Potencial Impact Factor for the Spanish Medical Journals of the Instituto de Historia de la Ciencia y Documentación López Piñero (IHCD). To identify criteria of editorial quality, of visibility and of spreading by reviewing databases such as the Online Regional Information System for Scholarly Journals from Latin America, the Caribbean, Spain and Portugal (LATINDEX), SciELO (Scientific Electronic Library Online), DIALNET and the Collective Periodical Publications Catalogue of Spanish Healthcare Science Libraries, known as C17.
Results. For the first time, the Spanish Journal of Chemotherapy appears in the 2009 edition of JCR, previously by joined the two spanish journals Clinical Microbiology and Infectious Diseases and International Microbiology, both ranked at a lower position. While calculating factors of national and international impact of the five publications included in the category of Pharmacology and Pharmacy as part of theproject initiated by the IHCD, the Spanish Journal of Chemotherapy showed the best results.
Conclusions.The Spanish Journal of Chemotherapy obtained good results in analysed bibliometric indicators, positioning it at the top of the ranking of Spanish medical journals. A good spreading helped to maintain visibility on the publication in the editorial field.   

 
Rev Esp Quimioter 2010:23(3):135-143 [pdf]

Rev Esp Quimioter 2010:23(1):27-35

Linezolid more efficacious than vancomycin to eradicate infecting organism in critically ill patients with Gram-positive infections

J. M. SIRVENT, L. PIÑEIRO, M. DE LA TORRE, M. MOTJÉ, J. DE BATLLE, A. BONET

 

Objetive: A prospective and observational study has been conducted to analyze the efficacious of linezolid compared to vancomycin to eradicate the infecting organism in critically ill patients with Gram-positive infections.
Patients and Methods: Prospective, observational and non-controlled study in a medical-surgical intensive care unit (ICU) in a university hospital. A total number of 53 critically ill patients with therapy to proven Grampositive bacterial infection were studied. Infected patients were diagnosed and treated according to international guidelines, following standard protocol for the critically ill infected patients. Microbiologic eradication of the infecting organism at the seventh day of treatment and patients’ clinical outcome were analysed.
Results: Twenty-seventh patients received linezolid and twenty-six received vancomycin. Infection-site diagnoses were: hospital-acquired pneumonia (21 cases: 39.6%), complicated surgical-site infection (19 cases: 35.8%) and catheter-related bacteraemia (13 cases: 24.5%).The most important isolated microorganism was methicillin-resistant Staphylococcus aureus (MRSA) (28 cases:52.8%). Clinical success was 20/27 (74.1%) in the linezolid group and 16/26 (61.5 %) in the vancomycin group, with p= 0.3. The adjusted logistic regression model demonstrated that the treatment with linezolid is associated to microbiologic eradication of the infecting organism at the seventh day of treatment [OR = 7.88 (95% CI 1.86-33.52)] and p = 0.005. In this model, the length of hospital stay was lower in the group with microbiologic eradication at the seventh day (p = 0.015). Drug-related adverse events were comparable in both groups of treatment.
Conclusion: Treatment with linezolid in critically ill patients with Gram-positive infections was equivalent to vancomycin in terms of efficacy and safety, but linezolid was associated to a higher rate of microbiologic eradication of the infecting organism at the seventh day of treatment.

 
Rev Esp Quimioter 2010:23(1):27-35 [pdf]

Rev Esp Quimioter 2010:23(3):144-152

Comparative activity of doripenem, meropenem, and imipenem in recent clinical isolates obtained during the COMPACT-Spain epidemiological surveillance study 

C. GIMENO, R. CANTÓN, A. GARCÍA, M. GOBERNADO Y GRUPO ESPAÑOL DE ESTUDIO DE DORIPENEM   

 

Introduction. Doripenem is a new carbapenem with broad spectrum antibacterial activity indicated for the treatment of nosocomial pneumonia and complicated urinary and intraabdominal infections.
Methods. Isolates of Pseudomonas aeruginosa, Acinetobacter and Enterobacteriaceae from patients with nosocomial pneumonia, bacteremia and complicated intraabdominal infections attended in 16 Spanish hospitals were included (October 2008–May 2009). Susceptibility to imipenem, meropenem and doripenem was studied with the Etest method, and the results were interpreted according to the EUCAST criteria.
Results. Considering all the isolates, doripenem (MIC50 0.12 mg/L) was 2- to 8-fold more active than meropenem (0.25 mg/L) and imipenem (1 mg/L). In relation to Enterobacteriaceae, the MIC50 and MIC90 values of doripenem and meropenem were similar (0.03 and 0.12 mg/L, respectively) and clearly superior to those of imipenem (0.25 and 1 mg/L). In the case of P. aeruginosa, MIC50 and MIC90 were more favorable to doripenem (0.25 and 16 mg/L) than to meropenem (0.5 and ≥64 mg/L) or imipenem (2 and ≥64 mg/L). In this species, the percentage of strains with lower MIC values for doripenem among those exhibiting intermediate susceptibility and resistance to meropenem was 63.0% (29/46) and 61.7% (63/102), respectively, versus only 4.3% (2/46) and 1.9% (2/102) with higher MIC values for doripenem.
Conclusions.The results obtained in this study are similar to those reported in other countries, and reinforce the superior in vitro activity of doripenem versus the other carbapenems and its position in the treatment guidelines regarding the nosocomial infections for which it is indicated.   

 
Rev Esp Quimioter 2010:23(3):144-152 [pdf]

Rev Esp Quimioter 2010:23(1):36-42

Changes in the antimicrobial susceptibility of Escherichia coli isolates from community diagnosed urinary tract infections during the period 2003-2007. Multicentre study in Castilla la Mancha (Spain)

D. TENA, A. GONZÁLEZ-PRAETORIUS, J. C. GONZÁLEZ, E. HEREDERO, S. ILLESCAS, C. SAINZ DE BARANDA, G. SESEÑA

 

Objective: To know the evolution of susceptibility patterns of Escherichia coli in patients with communitydiagnosed urinary tract infections (UTIs) during last years in Castilla la Mancha (Spain).
Methods: Descriptive and retrospective study performed between january 2003 and december 2007. We studied data about frequency and susceptibility of 33.651 E. coli isolates from urine cultures that were remited from primary care centres depending of 6 hospitals in Castilla la Mancha (Spain).
Results: Susceptibility rates of E. coli for most antibiotics decreased significantly during the 5-year period, especially for amoxicillin-clavulanic acid, cefuroxime and quinolones. Average rates of susceptibility for amoxicillin- clavulanic acid, ciprofloxacin, cefuroxime, fosfomycin and nitrofurantoin were: 86,7, 75,4, 87,3, 97,6 and 96,2%, respectively. We observed a significantly increase of E. coli isolates producing extended-spectrum betalactamases (ESBLs), from 1,9% in 2003 to 4,9% in 2007 (χ2 TL = 143,6, p<0,001).
Conclusions: We observed a significantly reduction of E. coli susceptibility for most antibiotics and an increase of E. coli isolates producing ESBLs. Fosfomycin and nitrofurantoin are the best choices for empiric treatment. Prospective studies should be performed in the future to confirm the results of our study.

 
Rev Esp Quimioter 2010:23(1):36-42 [pdf]

Rev Esp Quimioter 2010:23(4):158-168

Nosocomial candidemia: new challenges of an emergent problem 

J. GÓMEZ, E. GARCÍA-VAZQUEZ, A. HERNÁNDEZ, C. ESPINOSA, J. RUIZ GÓMEZ   

 

Candida spp. are currently one of the most common causes of bloodstream infections in hospitals. Over the last two decades there has been a shift towards a greater involvement of non-Candida albicans as the cause of candidemia. Several of these non-albicans spp. (e.g., C. glabrata and C.krusei) exhibit resistance to traditional triazole antifungals (fluconazole), and cross-resistance with newer triazoles (voriconazole), focusing attention on the first-line use of antifungals such as the echinocandins, which possess improved activity against fluconazole-resistant strains. Early and adequate empirical treatment as well as early removing of the central catheters are the main factors related to mortality; thus it is necessary to implement guidelines of empirical treatment (including these aspects) in patients with risk factors and possible candidemia. Recent treatment guidelines from the Infectious Diseases Society of America (IDSA) recommend an echinocandin as primary therapy for non neutropenic or neutropenic patients with moderately severe to severe candidiasis and for patients at risk for infection with a triazole-resistant strain; the increasing MIC of echinocandins in case of C. parapsilosisis also an emerging concern. Clinicians should remain vigilant to prescribe early empiric treatment of patients at risk of having candidemia.   

 
Rev Esp Quimioter 2010:23(4):158-168 [pdf]

Rev Esp Quimioter 2010:23(1):43-47

Evaluation of pharmacodynamic target attainment with vancomycin treatment of bacteremia due to Staphylococcus aureus methicillin resistant

J. A. LEPE, M. V. GIL-NAVARRO, M. D. SANTOS-RUBIO, J. BAUTISTA, J. AZNAR

 

Objective: The objective of the study is to evaluate the ability of standard vancomycin dosing strategies actually recommended to attain the pharmacodynamic target of an area under the curve of vancomycin serum concentration versus time from 0 to 24 hours (AUC24h) to minimum inhibitory concentration (MIC) ratio greater than 400:1 for patients with a suspected or documented methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia by individual analysis and Monte Carlo simulation.
Material and methods: The study included all patients admitted with suspected or proven MRSA infection during the years 2007-2008, and who were initially treated with vancomycin at a dose of 30 mg/kg/day, and underwent pharmacokinetic monitoring. The area under the curve of vancomycin serum concentration versus time from 0 to 24 hours (AUC24h) was calculated as daily dose/clearance total (D24h/CL). Additionally, we studied 45 isolates of MRSA obtained from blood cultures in the period 2007-2008. The MIC to vancomycin was determined using Epsilon-test®. The PK-PD parameter calculated was AUC24h/MIC. Microsoft
Excel was used to perform a 10.000 subject Monte Carlo simulation. An AUC24h/MIC ≥ 400 was assumed as the target attainment.
Results: In the individual study, the percentage of patients with AUC24h/MIC50/90 ≥ 400 was 50%. The probability (%) of attaining AUC24h/MIC ratio values ≥ 400 by Monte Carlo simulation was of 66%. The vancomycin MIC value from which the scenario would have to wait a suboptimal treatment (target <90%) was >1 mg/L.
Discussion: This study shows that in the population studied to achieve a vancomycin AUC24h/MIC ≥ 400 is not always attained with the standard dose. Therefore, one would expect a high probability of suboptimal vancomycin AUC24h/MIC ratios for patients infected with organisms with vancomycin MICs of >1 mg/L treated with doses of 30 mg/kg/day.

 
Rev Esp Quimioter 2010:23(1):43-47 [pdf]

Rev Esp Quimioter 2010:23(4):169-176

Antifungal agents in the treatment of systemic infections: Relevance of mechanism of action, activity profile and resistances 

M. CUENCA-ESTRELLA   

 

The availability of different therapeutic alternatives has modified the treatment of systemic fungal infections. There commendations of antifungal therapy vary according to species which causes the mycosis and its susceptibility. Consequently, the knowledge of action mechanism, activity profile and resistances to antifungal agents are essential for the clinical practice. Amphotericin B is the antifungal agent exhibiting the broadest spectrum of activity, it is a fungicidal drug and resistances have been hardly ever described. The triazoles compounds also have a broad spectrum, but their massive use for some therapeutic indications has led to emergence of strains and species of yeasts with resistance to fluconazole and of filamentous fungi itraconazole resistant.The echinocandins exhibit fungicidal effects for yeasts andafungistatic activity against moulds, and secondary resistance to these agents is uncommon.   

 
Rev Esp Quimioter 2010:23(4):169-176 [pdf]