Rev Esp Quimioter 2015:28(2):92-97

Mortality among methicillin-resistant Staphylococcus aureus carriers in long-term care facilities                                  
 


ESTER VENDRELL, JOSEP A CAPDEVILA, PILAR BARRUFET, LLUÍS FORCE, GORETTI SAUCA, ENCARNA MARTÍNEZ, ELISABET PALOMERA, MATEU SERRA-PRAT, JORDI CORNUDELLA, ANNABEL LLOPIS, MªASUNCIÓN ROBLEDO, CRISÓSTOMO VÁZQUEZ              

 

Introduction. Little is known about the natural course of patients with chronic stable illnesses colonized with methicillin-resistant Staphylococcus aureus (MRSA). The aim is to determine the impact of MRSA colonization in mortality among long-term health care facility (LTHCF) residents.
Method. A multicenter, prospective, observational study was designed. Residents in 4 LTHCFs were classified according to MRSA carriage status and followed for 12 months. Treatment consisted of 5 days of nasal mupirocin in MRSA carriers.
Results. Ninety-three MRSA-carriers among 413 residents were identified. Thirty-one MRSA-colonized patients died during the study period, 11 of whom from an infectious disease. Independent predictors of their higher mortality rates included heart failure, current neoplasm, MRSA carriage and COPD at 3 months and these same factors plus stroke, Bar-thel index <40, pressure ulcers, and older age at 12 months. MRSA-persistence was 35% and 62.5% at 3 and 12 months, respectively.
Conclusions. MRSA colonization among frail LTHCFs residents is highly prevalent, and is associated with higher mortality. Despite treatment of MRSA carriers, many remained colonized. Factors that promote persistence of MRSA colonization, and the impact of their modification on mortality rates in these patients, need further investigation.

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Rev Esp Quimioter 2015:28(4):214-216

Could ceftaroline be an alternative therapy for linezolid resistant Staphylococcus epidermidis infections in Intensive Care Medicine?     

                        
FRANCISCO JAVIER CANDEL, ELVIRA BAOS, MERCEDES NIETO, JUAN JOSÉ PICAZO              

Introduction. Coagulase negative Staphylococcus continues generating interest in critically ill patients, due to their infections in extended admissions, in instrumented patients and due to their described multidrug resistance, which include glycopeptide heterorresistance and the increase in oxazolidinone resistance. Ceftaroline is a new cephalosporin with activity against resistant gram-positives, which, being betalactam, may provide adequate safety profile in the critical ill patient. The aim of this study was to determine the activity of ceftaroline and other antimicrobial agents against methicillin and linezolid-resistant Staphylococcus epidermidis.
Material and methods. We studied susceptibility of ceftaroline, tigecycline, daptomycin and vancomycin in a total of sixty-eight methicillin and linezolid-resistant S. epidermidis isolates with clinical significance from an Intensive Care Unit, using E-test.
Results. All strains were susceptible to the four antimicrobial agents, regardless of the level of resistance to linezolid.
Conclusion. Ceftaroline could be an alternative in the treatment of methicillin and linezolid-resistant S. epidermidis infections in critically ill patients.

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Rev Esp Quimioter 2015:28(5):235-241

Boosted protease inhibitor monotherapy in HIV-infected patients: results of a study in a real life setting     

                        
NICOLÁS DI BENEDETTO, MARTA MONTERO-ALONSO, MARINO BLANES, JOSÉ LACRUZ, SANDRA CUELLAR, EVA CALABUIG, JOSÉ LÓPEZ, MIGUEL SALAVERT              

Background. Boosted protease inhibitor monotherapy may offer antiviral efficacy while reducing drug interactions, costs and toxicity. The aim of this study was to assess the efficacy of darunavir/ritonavir (DRV/r) and lopinavir/ritonavir (LPV/r) monotherapy in a real life setting.
Methods. A retrospective analysis of all HIV infected patients, who had initiated DRV/r or LPV/r monotherapy, was performed. Patients whose HIV viral load had remained undetectable for at least two consecutive follow-up visits and who had no neurocognitive disorder or hepatitis B co-infection, were included.
Results. Sixty patients were included. The median (IQR) time to follow-up was 66 (33-118) weeks. The proportions (CI95%) of patients with virological failure were 6.3% (1.7- 20.2) and 25.0% (12.7-43.4), respectively, in the DRV/r and LPV/r groups (p= 0.0424). The proportions (CI95%) of patients with therapeutic success were 90.6% (80.5-100) in the DRV/r group and 60.7% (42.6-78.8) in the LPV/r group (p=0.0063). No protease inhibitor mutations were detected. During the follow-up, 6 patients with dyslipidemia normalized their lipid values. The median monthly cost was 410 (IQR 242-416) euros per person lower for the monotherapy than for the combined antiretroviral therapy.
Conclusions. Boosted protease inhibitor monotherapy was effective in a real life setting. This study showed differences in favour of DRV/r as compared with LPV/r in terms of therapeutic success; however prospective studies are needed to confirm these results. Finally, although this study was not specifically designed to detect benefits in terms of costs and lipid profile, it shows evidence of a positive impact of monotherapy in these fields.

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Rev Esp Quimioter 2015:28(2):98-100

Phenotypic methods for detection of methicillin-resistant Staphylococcus aureus                                 
 


GERTRUDIS HORNA, LIZETH ASTOCONDOR, JAN JACOBS, CORALITH GARCÍA              

 
Background.  Cefoxitin is a potent inducer of the mecA gene. It is currently as a screening recommended method for presumptive identification of isolates of methicillin resistant Staphylococcus aureus (MRSA). The aim of the study was to compare the sensitivity and specificity of the cefoxitin disc diffusion (30μg) to oxacillin agar screening from detection of the mecA gene by PCR.
Methods. Three hundred thirty-one strains of S. aureus isolated from blood cultures of patients from hospitals in Lima were used in the study. The following tests were performed: oxacillin screening agar (plates were inoculated with 4% NaCl and 6 mg/L of oxacillin), cefoxitin disc diffusion test (30 ug) and PCR to amplify the mecA gene.
Results.  The mecA gene was detected in 165 out of 331 S. aureus isolates. Thus, the frequency of detection of MRSA was 50%. The evaluation of the cefoxitin disc diffusion test showed a 96.3% and 90.9% of sensitivity and specificity, respectively.
Conclusion. Cefoxitin disc diffusion test correlated well with detection of the mecA gene by PCR. Therefore, this test can be an alternative to PCR for detection of MRSA in limited resources settings.

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Rev Esp Quimioter 2015:28(Suppl. 1):1-4

Update in Infectious Diseases 2015     

                        
FRANCISCO JAVIER CANDEL, LAURA LÓPEZ GONZÁLEZ, ANA BELÉN GARCÍA-GARCÍA, FLAVIA CHIARELLA, JUAN JOSÉ PICAZO              

Infectious disease remains current worldwide. During the second half of 2014 an outbreak of ebolavirus hit West Africa with implications in the rest of the world. In fact, Spain declared the first imported case of this infection. Multiresistant enterobacteria outbreaks are emerging all around the world in a moment on which WHO draws attention to the limited resources, coining the term “post antibiotic era”. On the other hand, 2014 went down in history as one in which hepatitis C is cured. Are also current HIV epidemiological control or strategies for antiviral and antifungal prophylaxis in immunocompromised hosts.

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Rev Esp Quimioter 2015:28(5):242-246

Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry for identifying respiratory bacterial pathogens: a fast and efficient method     

                        
Mª FÁTIMA LÓPEZ-FABAL, JOSÉ LUÍS GÓMEZ-GARCÉS, JOSÉ LUÍS LÓPEZ-HONTANGAS, NURIA SANZ, CARMEN MUÑOZ, MARTA REGODÓN              

Mass spectrometry has become a reference resource for identifying microorganisms in clinical microbiology services. One hundred and fifty one clinical isolates were selected from respiratory specimens routinely identified as Streptococcus pneumoniae (43), Haemophilus influenzae (64) and Moraxella catarrhalis (44). These identifications were compared with other phenotypical methods and mass spectrometry (MALDI-TOF-MS Vitek). Result discrepancies were assessed by 16S rRNA sequencing. Thirty-eight of the 43 strains of S. pneumoniae (86%) were identified as such using phenotypical methods and spectrometry. In 5 cases, MALDI-TOF identified 4 of them as Streptococcus pseudopneumoniae and 1 as S. mitis/oralis. Forty-eight of the 64 strains were identified as H. influenzae (75%) using biochemical identification systems and automated identification systems, whereas MALDI-TOF-MS Vitek identified 51 strains (79%) as such. Conventional methods and spectrometry identified all the 40 strains tested (100%) as M. catarrhalis. All strains with discrepant results were sequenced, and in all cases, the identification obtained by spectrometry was confirmed. The results obtained in this study show that mass spectrometry provides identification of these bacteria faster and in a more reliable way than those based on conventional phenotypical methods.

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Rev Esp Quimioter 2015:28(2):101-108

Genotypic and phenotypic diversity in Enterococcus faecalis: is agar invasion a pathogenicity score?                                 
 


FABIO CAFINI, FERNANDO GÓMEZ-AGUADO, MARÍA TERESA CORCUERA, CARMEN RAMOS, PEDRO BAS, LUIS COLLADO, MARÍA LUISA GÓMEZ-LUS, JOSÉ PRIETO              

 

Objectives. The main objective of the present study is to analyze different genotypic and phenotypic traits related to virulence in Enterococcus faecalis, as well as evaluated the agar invasion phenotype in a collection of isolates with different clinical origins. 
Material and methods. Seventy-nine E. faecalis isolates, with invasive and non-invasive clinical origins, have been used in this work. Presence of cytolysin activator (cylA), gelatinase (gelE), surface protein (esp), aggregation substance (asa1), endocarditis antigen (efaA), and collagen-binding protein (ace) have been analyzed by PCR. Phenotypic characterization included gelatinase activity, haemolysin production, biofilm formation and agar invasion. 
Results. All the isolates tested harboured at least one of the virulence determinants. The 95.5% of isolates from haematologic samples were positive for agar invasion test, significantly higher than isolates from non-invasive diseases. A significant reduction in relative invasion area was observed in three selected agar-invasive strains after 15 serial passages.
Conclusions. It has been observed a significant high prevalence of agar-invasion positive isolates among strains belonged to haematological samples. Agar invasiveness is reduced after adaptation of clinical isolates to laboratory conditions, showing that agar invasion phenotype can be modulate by culture conditions as other virulence factors observed in different bacterial species.

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Rev Esp Quimioter 2015:28(Suppl. 1):5-7

Applicability of new diagnostic techniques in microbiology; technological innovation     

                        
RAFAEL CANTÓN, ELENA LOZA, JOSÉ ROMERO              

Different new techniques have been introduced in microbiology laboratories during the last years, including mass spectrometry and next generation sequencing. These techniques, in addition to automation, microfludics, nanotechnology and informatics, have impelled innovation in the prevention and management of patients with infectious diseases. These approaches are relevant for revitalization and consolidation Clinical Microbiology laboratories.

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Rev Esp Quimioter 2015:28(5):247-255

A two-hour procedure for determining the susceptibility of enterococci and staphylococci to antibiotics by a colourimetric method     

                        
GABRIEL ALBERTO MARCH-ROSSELLÓ, MARÍA PURIFICACIÓN GUTIÉRREZ-RODRÍGUEZ, MARÍA SIMARRO-GRANDE, ANTONIO ORDUÑA-DOMINGO, MIGUEL ÁNGEL BRATOS-PÉREZA              

Introduction. Rapid determination of the antibiotic susceptibility test in bacteria remains a challenge for Clinical Microbiology laboratories.
Methods. An improvement in the colorimetric antimicrobial susceptibility testing performed with resazurin in enterococci and staphylococci has been carried out. The design of method was performed using two collection strains, which have a known susceptibility. This procedure was then validated against standard commercial methods on 15 strains of staphylococci and 15 strains of enterococci from patients.
Results. The essential agreement between the colorimetric method and commercial methods (E-test, MicroScan and VITEK2) was 100%.
Conclusion. Resazurin allows us to obtain a reliable antibiotic susceptibility test in staphylococci and enterococci in less than two hours.

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Rev Esp Quimioter 2015:28(3):116-124

Hydatidosis: epidemiological, clinical, diagnostic and therapeutic aspects                                 
 


CARLOS ARMIÑANZAS, MANUEL GUTIÉRREZ-CUADRA, MARÍA CARMEN FARIÑAS              

Hydatidosis or cystic echinococcosis (CE) is a parasitic zoonosis caused by Echinococcus granulosus. Its life cycle involves dogs, sheep and sometimes other animals. CE has a worldwide distribution, with greater prevalence in temperate zones. In Spain, Castile and León, La Rioja, Navarre, Aragón, and the Mediterranean coast are the areas where it is most commonly diagnosed, although there have also been published cases in other regions, such as Cantabria. Clinical signs and symptoms of EC may be related to the mass effect of the cyst, its superinfection or anaphylactic reactions secondary to its rupture. Because of its slow growth, diagnosis is usually made in adulthood by combining clinical symptoms with imaging and serological tests. There is no universal consensus on the management of CE. Treatment is based mainly on three pillars: medical treatment (mainly albendazole), surgery, and percutaneous drainage. The choice of the most appropriate approach is based on the patient’s symptoms and the characteristics of the cysts.

Rev Esp Quimioter 2015:28(3):116-124 [pdf]

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