Rev Esp Quimioter 2011:24(1):32-36

Rapid detection of clarithromycin resistant Helicobacter pylori strains in Spanish patients by polymerase chain reaction-restriction fragment length polymorphism 

S. AGUDO, G. PÉREZ-PÉREZ, T. ALARCÓN, M. LÓPEZ-BREA    

 

Introduction. The aim of this study was to characterize the mutations types present in the 23S rRNA gene related to H. pylori clarithromycin-resistance strains in Spain and evaluate a novel PCR-RFLP method for detection of the most frequent point mutation in our population.
Methods. Gastric biopsies were obtained by endoscopy from patients with gastric symptoms. H. pylori was cultured according to standard microbiological procedures and clarithromycin resistance was determined by E-test. DNA extraction was performed by NucliSens platform with the NucliSens magnetic extraction reagents (bioMérieux) according to the manufacturer instructions. Analyses for point mutations in 23S rRNA gene strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using BsaI enzyme to detect restriction sites that correspond to the mutation (A2143G).
Results. We found 42 out of 118 (35.6%) strains resistant to clarithromycin by E-test. E-test results were confirmed for the presence of point mutation in 34 (88.1%) of these strains. Mutation A2143G was found in 85.3% of the strains. Analyses with the restriction enzyme BsaI was able to confirm the presence of A2143G mutation. There were 8 H. pylori strains resistant to clarithromycin by E-test but without any point mutationin the 23 rRNA gene.
Conclusions. We conclude that PCR-RFLP is a reliable method to detect clarithromycin-resistance H. pylori strains in countries with a high prevalence of clarithromycin-resistance as Spain. It may be useful before choosing regimens of H. pylori eradication.    

 
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Rev Esp Quimioter 2011:24(1):37-41

Prosthetic joint infection by Candida spp 

E. GARCÍA-OLTRA, S. GARCÍA-RAMIRO, J. C MARTÍNEZ, R. TIBAU, G. BORI, J. BOSCH, J. MENSA, A. SORIANO     

 

Introduction: Fungal periprosthetic infectionis a rare entity. The aim of this report was to review our experience in two different educational hospitals.
Material and methods: patients with documented prosthetic joint infection due to Candida spp. from February 2002 to October 2010 were retrospectively reviewed. Demographics, microbiological data, treatment and outcome of each patient was recorded.
Results: Ten patients, 8 women and 2 men, with a meanage of 77.7 (range 66-92) years were identified. Nine patients had previous bacterial infection, received antibiotic treatment for more than 15 days and required multiple surgeries. The most frequent species was C. albicans with 6 cases. All patients received fluconazole and surgical treatment consisted of debridement without removing the implant in 3 cases and 2-stage exchange with a spacer in 7. The first surgical and antifungal approach failed in all cases and a second debridement was necessary in one case, a resection arthroplasty in 8 and chronic suppressive treatment with fluconazol in one. After a mean follow-up of 31 (range 2-67) months, two patients were free of infection.
Conclusion: Prosthetic joint infection was associated with long-term antibiotic treatment and multiples previous surgeries. Treatment with fluconazol and debridement or two stage replacement with a spacer was associated with a high failure rate.    

 
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Rev Esp Quimioter 2011:24(1):42-47

Clinical experience with linezolid for the treatment of neurosurgical infections  

D. SOUSA, P. LLINARES, H. MEIJIDE, J.M. GUTIÉRREZ, E. MIGUEZ, E. SÁNCHEZ, L. CASTELO, A. MENA      

 

Objectives: We sought to evaluate the clinical use of linezolid for the treatment of neurosurgical infections.
Methods: Retrospective observational study of a cohort of hospitalized patients who received linezolid for a culture-positive neurosurgical infection from July 2004 to February 2009 in a tertiary hospital in Spain.
Results: Seventeen patients were included in the study. Main comorbidities among these patients included one or more of the following: subarachnoidal or intraventricular hemorrhage (n=8), solid neurological cancer (n=7), corticosteroids(n=9) and hydrocephalus (n=6). Eight patients underwent acraniotomy and fourteen patients had an external ventriculardrainage (EVD) as predisposing factors for infection. Meningitis was the most common infection (11; 64.7%), followed by ventriculitis (4; 23.5%) and brain abscesses (2;11.8%). The main causative organisms were coagulase-negative Staphylococcus spp. (13; 76.5%). Linezolid was used as theinitial therapy in 8 episodes, after therapy failure in 6 and forother reasons in 3. The oral route was used in 9 (52.9%) episodes; linezolid was initiated orally in 2 cases. The mean duration of treatment was 26.5 days (range 15-58). No adverse events were reported. Sixteen (94.1%) patients were considered cured.There was one recurrence. The mean length of hospital stay was 45.6 (range 15-112) days and the mean duration of follow-up was 7.2 (range 0.4-32) months. No related deaths occurred during active episodes.
Conclusions: Linezolid was mainly indicated in post-neurosurgical EVD-associated infections due to coagulase-negative Staphylococcus spp. It was used as initial therapy in most cases. A high rate of clinical cure was observed and no related adverse events were reported. More than half of the patients were benefited by the advantages of the oral route of administration.    

 
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Rev Esp Quimioter 2011:24(2):57-66

Bacteraemia due to Escherichia coli producing extended-spectrum betalactamases (ESBL): clinical relevance and today’s insights  

A. M. GARCÍA-HERNÁNDEZ, E. GARCÍA-VÁZQUEZ, A. HERNÁNDEZ-TORRES, J. RUIZ, G. YAGÜE, J. A. HERRERO, J. GÓMEZ     

 

Antibiotic resistance is an old problem with new face as the rate of infections due to multidrug resistant bacteria is higher everyday and the number of new antibiotics to overwhelm the problem is becoming smaller. E. coli is the most frequent agent causing nosocomial or community-acquired bacteraemia being in our country 10% of them extended-spectrum betalactamases (ESBL) producing E. coli isolates. Nowadays the number of community- acquired or health-related infections caused by these ESBL producing E. coli is increasing. CTX-M has also become the most frequent ESBL compared to other enzymes. The role of these enzymes as a virulence factor increasing mortality in patients with bacteraemia due to E. coli is not well defined. The relevance of ESBL-E. coli seems to be related with the higher frequency of inadequate treatment and therefore the importance of identifying factors or features that might predict that the patient’s infection is due to one of these isolates. In terms of prevention and control of infection measures, the role of patient’s isolation is not clear but a proper prescription of antibiotics and antibiotic control policies are probably important to reduce the problem.    

 
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Rev Esp Quimioter 2011:24(2):67-73

Pharmaecology  

J. GONZÁLEZ, A. ORERO, V. OLMO, D. MARTÍNEZ, J. PRIETO, J. A. BAHLSEN,  F. ZARAGOZÁ,  J. HONORATO       

 

Two of the main characteristics of western societies in the last fifty years have been the medicalization of the human life and the environmental degradation. The first one has forced human being to consider medicines use related to what would be rational, reasonable and well-reasoned. The second one brought us to a new ecologist conscience.
In relation to the “human social system”, the effects of medication can be considered very positive as a whole, particularly those related to the amazing increase of expectative and quality of life. But, along with those unquestionable beneficial effects, medicines have also caused some negative effects for other biotic and abiotic systems, such as microbian alterations and their undesirable consequences which have involved the massive use of antibiotics in medicine and veterinary, the uncontrolled elimination of millions of doses of all kind of drugs, additives and excipients, etc., as well as atmospheric contamination and degradation of forests and deep oceans which can have been caused by investigation and production of determinated drugs. In this context pharmaecology appears as a scientific discipline that studies the research (R), development (D), production (P), and utilization (U) of drugs and medical substances in relation to the environment. From a farmaecologic perspective the drugs utilization has its development in three main contexts, all of them closely related: prescription quality, farmaceutical care, and patient’s active participation in his own disease and treatment. 

 
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Rev Esp Quimioter 2011:24(2):74-78

Activity of vancomycin, ciprofloxacin, daptomycin, and linezolid against coagulase-negative staphylococci bacteremia   

M. FAJARDO, R. HIDALGO, S. RODRÍGUEZ, F. F. RODRÍGUEZ-VIDIGAL, A. VERA, M. ROBLES       

 

Objective. Multiresistant coagulase-negative staphylococci (CNS) infections are mainly increased in hospitalized patients. We have studied the activity of vancomycin, ciprofloxacin, daptomycin and linezolid in methicillin-resistant CNS strains, isolated from true blood cultures.
Methods. We collected 87 strains of different CNS species from positive blood cultures. Staphylococci were identified by MicroScan Walkaway (Dade Behring, Siemens) and with the Api ID 32 Staph (BioMerieux, France). The susceptibility to oxacillin, vancomycin and ciprofloxacin was performed by automatic microdilution plate as cited above. The susceptibility to daptomycin and linezolid was performed by Etest (AB BioMerieux, Solna, Sweden). Interpretative criteria were done following the CLSI guidelines.
Results. Eighty-seven CNS strains were studied: 55 (63%) were S. epidermidis, 15 (17%) S. haemolyticus, 10 (12%) S. hominis, and 7 (8%) other species. Fifty-three (61%) strains showed loss of susceptibility to vancomycin, MIC = 2 mg/L. Ciprofloxacin resistance, MIC > 2 mg/L, was observed in 56 (64%) strains. Daptomycin resistance was not observed, with a susceptibility range between 0.032-1 mg/L and modal value of 0.25 mg/L. Ten strains (11.5%) resistant to linezolid were observed. Nine patients were in ICU, where the average length of stay was 38 days (range 16-58 days) and one belonged to Hepato-Pancreatic Surgery, where he stayed for 64 days.
Conclusions. Low susceptibility to vancomycin is frecuent in the CNS strains studied in our hospital. Daptomycin shows a high efficacy against CNS, and it could be useful for the treatment of primary bacteremia or catheter associated bacteremia. The massive and continuous use of linezolid has led to the appearance of resistance. 

 
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Rev Esp Quimioter 2011:24(1):4-12

Proton pump inhibitors and infection risk 

E. PALENCIA-HERREJÓN, B. SÁNCHEZ, I. ESCOBAR, M. L. GÓMEZ-LUS   

 

Gastric antisecretory drugs, especially proton pump inhibitors, are among the most used drugs both in ambulatory and hospital settings, and prescription does not always follows approved indications. Experimental data suggest that gastric acid inhibition and the effects of proton pump inhibitors on the immune system can promote the development of infections. In recent years a number of observational studies have found an independent association between the use of proton pump inhibitors and an increased risk of gastrointestinal infections, including those caused by Clostridium difficile, and community and nosocomial pneumonia. This review discusses the current evidence, raises the potential pathogenic mechanisms involved and makes recommendations for current clinical practice and future research.    

 
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Rev Esp Quimioter 2011:24(2):84-90

Resistance of Streptococcus pneumoniae isolated from Lebanese patients between 2005 and 2009    

Z. DAOUD, M. KOURANI, R. SAAB, M. A. NADER, M. HAJJAR        

 

Introduction: Streptococcus pneumoniae is an important organism in view of its prevalence and ability to cause serious infections; its resistance to antimicrobial agents is increasing worldwide. The purpose of this study was to evaluate the patterns of resistance of S. pneumoniae to penicillin, macrolides and various other antibiotics in strains isolated from Lebanese patients.
Methods: 121 strains isolated between January 2005 and January 2009 from two university hospitals in Beirut were identified and tested for MIC determination using the E-test method. The presence of erm(B) and mef(A/E) genes was investigated using PCR.
Results: The majority of the strains (73.5%) were isolated from respiratory tract infections, 50.4% were isolated in winter, 15.7% were invasive strains, 61.9% came from male patients, and 68.5% from adults. Out of 121 isolates, 58 were susceptible to penicillin, 61 were intermediate, and 2 were fully resistant to this antibiotic. Amoxicillin-clavunanic acid and cefpodoxime showed 100% activity on all tested isolates. In general, the MICs90 appear to fluctuate within the same range over the four years. The erm(B) gene was detected in 85.3% of the isolates, mef(A/E) in 19.5% whereas erm(A) was not detected in any of the macrolide resistant strains.

Discussion: The results of this study have important impact on the empirical antibiotic prescriptions; the increasing prevalence of resistance jeopardises the treatment choices posing a serious threat. Further surveillance and epidemiological serotyping are needed to monitor the local and regional resistance patterns and to track the spread route of resistance.  

 
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Rev Esp Quimioter 2011:24(2):91-95

Antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus strains from outpatient individuals    

L. GARCÍA-AGUDO, M. HUERTAS, M. A. ASENCIO EGEA, R. CARRANZA, P. GARCÍA-MARTOS         

 

Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged worldwide as a cause of infections among patients without risk factors. This CA-MRSA is different from nosocomial strains in terms of epidemiology, microbiology and clinical manifestations. We report the epidemiologic characteristics and resistance to antimicrobial agents of CA-MRSA strains isolated in the last three years in the Microbiology Lab of Hospital General La Mancha-Centro (Alcázar de San Juan, Ciudad Real).
Methods: We performed a retrospective analysis of microbiological cultures in patients with S. aureus diagnosed from 2007 to 2009 in La Mancha-Centro Health-Care Area, within Castilla-La Mancha Community.
Results: The distribution of CA-MRSA in the studied period was 26 out of a total of 97 S. aureus isolates in 2007 (26.8%), 40/113 in 2008 (35.4%) and 57/157 in 2009 (36.3%). The percentage from purulent skin and soft tissue infections was 63.4%. All strains were susceptible to linezolid, quinupristin/dalfopristin, and glycopeptides. The resistance was high to fluoroquinolones (94.3%), erythromycin (87.0%), tobramycin (82.9%), and clindamycin (65.3%).
Conclusions: CA-MRSA isolates percentage increased along the period of the study. The majority were obtained from skin and soft tissue specimens. The most commonly associated antimicrobial resistance was to fluoroquinolones, erythromycin, tobramycin and clindamycin. An understanding of the CAMRSA epidemiology is important to prevent these organisms from becoming endemic in the world. 

 
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Rev Esp Quimioter 2011:24(2):96-98

Results of a counselling programme in antibiotic treatment in a secundary hospital    

A. DEL ARCO, B. TORTAJADA, J. DE LA TORRE, J. OLALLA, J. L. PRADA, N. MONTIEL, J. GARCÍA-ALEGRÍA          

 

Background: The inappropriate use of antimicrobial agents may contribute to the development of bacterial resistance to the principal antimicrobial drugs. There is no provision in the immediate future of marketing of new broad-spectrum antibiotics, especially with activity against Enterobacteriaceae, so programs should be implemented to optimize antimicrobial therapy. We describe the results of a year of a counselling program in antibiotic treatment in a secondary Andalusian hospital.
Methods: We describe 276 interventions of a multidisciplinary non-compulsory counselling program of antimicrobial management on the Costa del Sol Hospital in Marbella. We evaluated the adequacy of empirical treatment, possibility of antibiotic de-escalation, duration and dose used. We analyzed the evolution of the sensitivity profile of the main microorganisms as well as a cost-effective analysis.
Results: 90% of the recommendations were accepted. The main actions were assessment of empirical therapy and deescalation in relation with the result of cultures. The main drugs tested were imipenem, meropenem, cefepime, and linezolid. The sensitivity profile of imipenem and meropenem improved slightly over previous years. It was found a considerable savings in annual drug spending.
Conclusions: The non-compulsory counselling programs are useful tools for optimization of antimicrobial therapy, can prevent an increase of antimicrobial resistance and reduce the cost of antibiotic treatment. 

 
Rev Esp Quimioter 2011:24(2):96-98 [pdf]

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