Rev Esp Quimioter 2010:23(2):81-86

Activity of daptomycin, ciprofloxacin, clindamycin and cotrimoxazole against coagulase-negative Staphylococcus strains with diminished susceptibility to vancomycin

M. FAJARDO, R. HIDALGO, S. RODRÍGUEZ, E. GARDUNO, F. F. RODRÍGUEZ, M. ROBLES 

 

Introduction. Coagulase Negative Staphylococci (CNS) have become one of the most common nosocomial pathogens and it has a high mortality rate due to the increased of seriously ill patients survival, long states immunosuppression and presence of foreign bodies, such as catheters, prostheses, pacemakers, etc. In addition, there is a significant increase in resistance to antimicrobial drugs, especially beta-lactams, and the increase in the MIC for vancomycin leads to a loss of clinical efficacy. This necessitates the search for new therapeutic alternatives, such as daptomycin. The aim of this paper is to study the activity of daptomycin, ciprofloxacin, clindamycin and cotrimoxazole in two groups of clinically significant CNS. a MIC90 with vancomycin ≤ 1 mg/L and the other with MIC90 2 mg/L.
Methods. We identified and studied MIC90 to ciprofloxacin, clindamycin and cotrimoxazole from 54 strains of clinically significant by the CNS Combo 22 Microscan panels (Dade Behring, Siemens). The MIC90 for daptomycin was performed using Etest (AB BioMérieux, Solna, Sweden) on Mueller Hinton plates (BioMérieux, France).

Results. In Group I (vancomycin MIC90 ≤ 1 mg/L) were 19 strains whereas in Group II (vancomycin MIC90 = 2 mg/L) were 35 strains. Expressed in mg/L, MIC90 ranges for daptomycin were 0.047-0.5 in Group I and 0.064-0.5 in Group II. For ciprofloxacin were 8 sensitive strains and 11 resistant in Group I and 10 sensitive and 25 resistant in Group II. For clindamycin were 7 sensitive strains and 12 resistant in Group I and 16 sensitive and 19 resistant in Group II. Finally, for cotrimoxazole were 10 sensitive strains and 9 resistant in Group I and 19 sensitive and 16 resistant in Group II.
Conclusions. The MIC levels to daptomycin were not influenced by the increase in the MIC for vancomycin. There was no statistically significant difference for the sensitivity of ciprofloxacin between the two groups of vancomycin. Regardless of vancomycin, there were a clear relationship between the sensitivity of ciprofloxacin with clindamycin and cotrimoxazole.

 
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Rev Esp Quimioter 2010:23(4):201-205

Impact of the consumption of ophthalmic topical antibiotics   

S. GARCÍA, P. MORI, A. LÓPEZ, L. ALOU, D. MARTINEZ, C. RAMOS, M. L. GÓMEZ-LUS    

 

Introduction. The aim of the study was to value the impact of the consumption of the topical antibiotics used in ophthalmology and to lay the foundations for their prudent use.

Material and methods. A descriptive study about antibiotic use in Spain between 1st January 2004 and 31th December 2008 was carried out. Drugs used in the study had to follow the next criteria: topical administration and ophthalmic antibiotics only or in association. Data of the number of vials and nosocomial consumption were provided by Intercontinental Marketing Services (IMS) and  Health National System, respectively.

Results. Nosocomial and community ophthalmologic antiinfectives in 2008 mean a cost of 4.9 and 24.4 millions of euros, respectively increasing a 5.5% respect to the previous year. Six millions of vials were used, 65% were antibiotics alone and 35% antibiotics in association. The most used ophthalmic antibiotics in monoterapy were the aminoglycosides(tobramycin and gentamicin), followed by the quinolones while the most used ophthalmic antibiotic in association were gramicidine plus neomycine plus polimixin B.

Conclusions.The ophthalmic antiinfectives market, alone and in association, used in the nosocomial and community context means 30 millions of euros and shows an increase about 6%. Strict measures in the antibiotic use are not taken incount in the context of the ophthalmic topical antibiotics.    

 
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Rev Esp Quimioter 2011:24(2):107-111

Methicillin-resistant Staphylococcus aureus: changes in the susceptibility pattern to daptomycin during a 10-year period (2001-2010)  

J. J. PICAZO, C. BETRIU, E. CULEBRAS, I. RODRÍGUEZ-AVIAL, M. GÓMEZ, F. LÓPEZ-FABAL AND VIRA GROUP           

 

Introduction. The objective of this study was to evaluate the activity of daptomycin and other agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from 2001 to 2010, in order to determine changes and to detect resistance trends.
Methods. The study included a total of 1,130 MRSA isolates collected as part of a multicenter surveillance program for antibiotic resistance, Estudio de Vigilancia de Resistencia a los Antimicrobianos (VIRA study), from 51 medical centers throughout Spain between 2001 and 2010. Broth microdilution test was performed according to the Clinical Laboratory Standards Institute guidelines.
Results. Daptomycin showed excellent activity and maintained its activity over time; only one MRSA isolate collected in 2001 was nonsusceptible to this agent (MIC=2 mg/L). Based on the MIC90, daptomycin was 2-4 dilutions more active than vancomycin, teicoplanin and linezolid. Daptomycin retained activity against MRSA isolates that were resistant to linezolid, to quinupristin-dalfopristin, or showed intermediate susceptibility to vancomycin.
Conclusions. Our data and those of other studies, coupled with daptomycin’s rapid bactericidal activity, suggest that this antimicrobial could be an alternative in the treatment of severe infections caused by multiresistant S. aureus.

 
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Rev Esp Quimioter 2011:24(4):223-232

Antimicrobial susceptibility of Gram-negative organisms from intraabdominal infections and evolution of isolates with extended spectrum β-lactamases in the SMART study in Spain (2002-2010)           


R. CANTÓN, E. LOZA, J. AZNAR, J. CALVO, E. CERCENADO, R. CISTERNA, F. GONZÁLEZ, J. L. LÓPEZ, C. RUBIO, A. I. SUÁREZ, F. TUBAU, I. WEBER, P. YUSTE, R. CAVANILLAS y grupo de trabajo SMART-España                   

Introduction. The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study records the antimicrobial susceptibility of Gram-negative bacilli obtain from intraabdominal infections with special focus in isolates with extended spectrum β-lactamases (ESBLs).
Material and Methods. The antimicrobial susceptibility of 8,869 isolates was analyzed by microdilution during the SMART study performed in Spain from 2002 to 2010. Isolates were recovered in 16 centres.
Results. Escherichia coli was the most prevalent pathogen (60.9% from intraabdominal infections acquired in the community and 49.9% in those from nosocomial origin) followed by Klebsiella pneumoniae (8.9% vs 9.2%). Pseudomonas aeruginosa was more common in intraabdominal infections from nosocomial origin (5.6% community and 8.6% nosocomial). Frequency of ESBL-producing isolates was: E. coli, 8.7%; K. pneumoniae, 8.4%; Klebsiella oxytoca, 1.4%; and Proteus mirabilis, 1.6%. Overall, ESBL-producing isolates were more frequently isolated from elderly patients (6.8% >60 years). Ertapenem and meropenem were the most active antimicrobials (susceptibility range with EUCAST criteria, 89.0-100%) when considering all Enterobacteriaceae isolates and also against ESBL producers (95.5-100%). Susceptibility of amoxicillin/clavulanic acid and piperacillin/tazobactam was lower, particularly among ESBL-producing isolates. Nevertheless, ertapenem maintained a good activity (susceptibility >95%) in ESBL-producers that were resistant to amoxicillin/clavulanic acid, piperacillin/tazobactam or fluoroquinolones.
Conclusions. Antimicrobial susceptibility data from the SMART-Spain study reinforce current therapeutic guidelines of intraabdominal infections that include ertapenem as the empirical choice for treatment. This is also supported by the high frequency of ESBL-producers in our geographic area. 

 
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Rev Esp Quimioter 2012:25(2):122-128

Plasmid-mediated AMPc producing Proteus mirabilis in the Health Care Area of Santiago de Compostela: molecular and epidemiological analysis by rep-PCR and MALDI-TOF 
           

M. TREVIÑO, D. NAVARRO, G. BARBEITO, P. ARESES, C. GARCÍA-RIESTRA, B. J. REGUEIRO                                                               

 
Introduction: Proteus mirabilis is an important pathogen isolated from both community-acquired and health-care associated infections. Acquired AmpC-type beta-lactamases represent an important mechanism of resistance to extended-spectrum cephalosporins and are emerging in several European countries. The objective of this work was to know the prevalence of acquired AmpC beta-lactamase producing P. mirabilis over the last three years and eight months and their clonal relationships comparing MALDI-TOF and automated rep-PCR results.
Methods: P. mirabilis isolates (n= 1,396) were obtained from routine cultures at the University Hospital Complex of Santiago de Compostela from January 2006 to August 2009. Identification to the species level and antimicrobial susceptibility testing were achieved with Vitek 2. The isolates showing intermediate or total resistance to amoxicillin-clavulanic and cefoxitin, cefotaxime or ceftazidime were selected for AmpC phenotypic detection by double-disk synergy test, and molecular confirmation by multiplex PCR. Molecular typing of the isolates was performed by automated rep-PCR and MALDI-TOF.
Results: For the last three years and eight months, the prevalence of AmpC-producing P. mirabilis increased from 0.17% to 4.5%, mainly associated with urinary tract infection in elderly outpatients. In all cases, plasmidic AmpC belonging to LAT/CMY lineage were detected. A high genetic variability was seen with both, rep-PCR and MALDI-TOF MS.
Conclusions: AmpC-producing P. mirabilis is an emergent pathogen. The high genetic variability detected suggests that the spread of the resistance mechanism is more probable than a clone dispersion. Automated rep-PCR and MALDI-TOF MS show as fast and decisive methods for bacterial strain typing in clinical microbiology laboratories.
  

 

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Rev Esp Quimioter 2012:25(4):252-255

Is it necessary to know which workers are carriers of MRSA in contact with cancer patients?                   

T. GARCÍA-LOZANO, A. EGIDO, E. CONTEL, M. I. PICÓN, M. A. MARTÍNEZ, E. AZNAR                                                                               

Our objective was to determine the prevalence of methicillin-resistant Staphylococcus aureus in workers who had direct contact with oncologic patients infected with MRSA and admitted to the intensive care unit of the Valencian Institute of Oncology. A study of prevalence of MRSA colonization of 62 workers was performed. Samples were taken from nose and pharynx in each of the workers. After 24 hours of incubation in Amies transport medium Viscose (Eurotubo®), 124 samples were seeded (N = 124) in chocolate agar agar, MRSA II and BHI broth (Brain Heart Infusion). Those colonies that were identified by Gram stain gram-positive cocci in clusters available, catalase positive and coagulase positive were processed for study of sensitivity by Kirby-Bauer method and screening test for methicillin (10μg of Oxoid®) on Mueller-Hinton (Becton-Dickinson®, BD), supplemented with NaCl (2%). Those confirmed MRSA isolates, he returned to perform sensitivity study by microdilution (MicroScan®, Siemens) to determine the MIC (mg/L). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was 1.61% (1) and 12.90% (8) for methicillin-sensitive Staphylococcus aureus (MSSA), from nostrils. The measures implemented were: nasal application of mupirocin to the worker colonized control isolation measures in infected patients and indoctrination of the personnel involved.  

 

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Rev Esp Quimioter 2010:23(2):87-92

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

J. L. GÓMEZ-GARCÉS, F. LÓPEZ-FABAL, A. BURILLO, Y. GIL 

 

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.

 

 
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Rev Esp Quimioter 2010:23(4):206-209

Rapid identification of Mycobacterium tuberculosis complex from broth cultures by immunochromatographic assay   

P. GARCÍA-MARTOS, L. GARCÍA-AGUDO, M. J. RODRÍGUEZ-JIMÉNEZ, M. RODRÍGUEZ-IGLESIAS    

 

Background: Recently, a simple and rapid commercial assay (BD MGIT TBc ID) has been developed using a monoclonal antibody anti-MPT64 for the differentiation of Mycobacterium tuberculosis complex from other mycobacteria by immunochromatography.

Methods: We evaluate in this work the clinical usefulness of the test for the identification of 51 strains of M. tuberculosis complex and 24 strains of other mycobacteria belonging to 14 different species, compared with the method of hybridization with DNA probes.

Results: Immunochromatographic method performance was excellent, with sensitivity, specificity, positive and negative predictive values of 98, 100, 96.1, and 98.7%, respectively.

Conclusions: These results indicate that immunochromatographic assay can be safely used for rapid identification of M. tuberculosis complex in combination with culture in liquid media. The test is extremely simple, provides results in just 15 minutes, requires no complex equipment or specialized personnel and may be a good alternative to molecular methods, especially in small laboratories.    

 
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Rev Esp Quimioter 2011:24(3):117-122

Empirical antifungal treatment: a valid alternative for invasive fungal infection  

C. VALLEJO, J. BARBERÁN           

 

Empirical antifungal therapy refers to initiation of an antifungal agent at the first possible clinical evidence of fungal infection. It is frequently recommended in neutropenic highrisk hematological patients of invasive fungal infection in order to guarantee an early approach. An extensive review is made of therapeutic advances and scientific evidence in this setting. Specific recommendations for use and criteria for selection of antifungal agents are discussed.

 
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Rev Esp Quimioter 2013:26(1):51-55

Candida sp endocarditis. Experience in a third level hospital and review of the literature 
                                  

A.HERNÁNDEZ-TORRES, E. GARCÍA-VÁZQUEZ, A. LASO-ORTIZ, J. A. HERRERO-MARTÍNEZ, J. GÓMEZ-GÓMEZ                      

Despite the relative high frequency of Candida bloodstream infection, Candida endocarditis is a rare entity. We report five cases of Candida endocarditis admitted to our hospital in the period between 2005 and 2011. Two cases were caused by C. albicans, two cases were caused by C. parapsilosis and in the last one, we didn´t identify the species of Candida. All but one had clear risk factors for candidemia. Treatment consisted of amphotericin B with / without flucytosine in four patients, and they all underwent surgery for valve replacement and / or removal of intravascular devices. Overall mortality was 60% (40% of mortality was directly related to endocarditis). All patients who survived were given suppressive therapy with fluconazole for a minimum of two years. After stopping fluconazole there was a case of recurrence.

Rev Esp Quimioter 2013:26(1):51-55 [pdf]

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