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.

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

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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.

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

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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.

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

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Rev Esp Quimioter 2016;29(1):8-14

Ertapenem therapy for pneumonia requiring hospital admission in elderly people     

                        

ARTURO ARTERO, ÁNGEL ATIENZA, SARA CORREA, IAN LÓPEZ, ALEJANDRA FAUS, FRANÇESC PUCHADES, MANUEL MADRAZO             

 

 

Background. Few studies examined ertapenem for the treatment of pneumonia. This study aims to compare ertapenem with other antibiotics commonly used for the treatment of pneumonia requiring hospital admission in elderly patients in daily clinical practice.
Methods. We conducted an observational, retrospective case-control study, between January 2011 and January 2014, in a university hospital. Patients ≥65 years of age admitted to the hospital with pneumonia treated with ertapenem were included as cases. A control patient treated with antibiotics other than ertapenem, matched for age and pneumonia severity index (PSI), was enrolled for each case. Hospital mortality was the primary outcome.
Results. A total of 150 patients with a mean age of 84.1 years were studied. Ninety percent of patients had pneumonia PSI grade IV-V and 82.7% had one or more comorbidities. Healthcare-associated pneumonia (HCAP) and aspiration pneumonia were significantly higher in the ertapenem group (66.7% vs. 24.0%, p < 0.001 and 73.3% vs. 54.7%, p < 0.017, respectively), whereas malignancy was most common in the control group. There was no difference in the hospital mortality rate between ertapenem and control groups (20.0% vs. 20.0%, p = 0.500), after adjusting for HCAP, aspiration pneumonia and malignancy. Transfer from hospital to hospital at home was significantly higher in the ertapenem group (25.3% vs. 9.3%, p = 0.09).
Conclusions. Ertapenem is as effective as other antibiotics commonly used for the treatment of pneumonia requiring hospital admission in elderly people. Ertapenem is associated with a higher transfer to hospital at home.

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Rev Esp Quimioter 2016, 29(4):190-194

Microbiology, antibiotic susceptibility, and bacteraemia associated factors in acute prostatitis                     

CARLES FERRÉ, FERRÁN LLOPIS, JAVIER JACOB             

Introduction. The aim of the study was to analyze the characteristics of patients with acute prostatitis presenting to the Emergency Department, the microbiological findings, antibiotic susceptibility, and bacteraemia associated factors.
Methods. Observational and cohort study with prospective follow-up including patients with acute prostatitis presenting to the Emergency Department from January-December 2012. Data were collected for demographic variables, comorbidities, microbiological findings, antibiotic treatment and outcome.
Results. Two hundred and forty one episodes of acute prostatitis were included. Mean age was 62.9 ± 16 years, a history of prostate adenoma was reported in 54 cases (22.5%) and prior manipulation of the lower urinary tract in 40 (17%). Mean symptoms duration was 3.38 ± 4.04 days, voiding symptoms were present in 176 cases (73%) and fever in 154 (64%). Seventy patients (29%) were admitted to the hospital and 3 died. From 216 urine cultures, 128 were positive (59%) and 24 (17.6%) out of 136 blood cultures. Escherichia coli was the main pathogen (58.6% of urine cultures and 64% of blood cultures) with resistant strains to fluoroquinolones, cotrimoxazole and amoxicillin/clavulanic in 27.7%, 22.9% and 27.7% of cases respectively. In the univariate analysis, only chills were associated to bacteraemia (p=0.013). At 30-day follow-up, patients with bacteraemia returned more frequently to the Emergency Department (p=0.037) and were more often admitted to the hospital (p=0.003).
Conclusions. Patients with acute prostatitis discharged from the Emergency Department need clinical follow-up and monitoring of microbiological findings in order to assure an adequate antibiotic treatment. Return to Emergency Department and admission to the hospital were significantly more frequent among patients with bacteraemia.

Rev Esp Quimioter 2016; 29(4):190-194 [pdf]

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Rev Esp Quimioter 2016, 29(Suppl. 1):10-14

Empirical therapeutic approach to infection by resistant gram positive (acute bacterial skin and skin structure infections and health care pneumonia). Value of risk factors                     

JUAN GONZÁLEZ-DELCASTILLO, MARÍA JOSÉ NÚÑEZ-ORANTOS, FRANCISCO JAVIER CANDEL, FRANCISCO JAVIER MARTÍN-SÁNCHEZ          


Antibiotic treatment inadequacy is common in these sites of infection and may have implications for the patient’s prognosis. In acute bacterial skin and skin structure infections, the document states that for the establishment of an adequate treatment it must be assessed the severity, the patient comorbidity and the risk factors for multidrug-resistant microorganism. The concept of health care-associated pneumonia is discussed and leads to errors in the etiologic diagnosis and therefore in the selection of antibiotic treatment. This paper discusses how to perform this approach to the possible etiology to guide empirical treatment.

Rev Esp Quimioter 2016; 29(Suppl. 1):10-14 [pdf]

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Rev Esp Quimioter 2016, 29(6):328-331

Evaluation of a new device for sample collection, transport and detection of Group B Streptococcus in pregnant women                     

ALBERTO TENORIO-ABREU, JOSÉ ANTONIO GÓMEZ-FERNÁNDEZ, LUIS ARROYO-PEDRERO, ESMERALDA RODRÍGUEZ-MOLINS          

We have designed a new device that combines sample collection, transportation, culture and detection of Group B Streptococcus (GBS), requiring no additional processing in the clinical laboratory. The objective was to evaluate the performance of this device for GBS detection in pregnant women. The new prototype was compared to direct plating of vaginal-rectal swabs onto Granada solid media plates. Direct plating method detected 124 positive samples out of 600 (20.6%) whereas the new device detected 10 additional positive samples (134/600, 22.3%). This new device (patent-protected) could be considered for routine GBS screening.

Rev Esp Quimioter 2016; 29(6):328-331 [pdf]

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Rev Esp Quimioter 2017, 30(2):79-83

Favipiravir, a new concept of antiviral drug against influenza viruses                     

JORDI REINA, NURIA REINA           

Favipiravir (T-705) is a new antiviral drug with strong inhibitory activity on RNA-dependent RNA polymerase of most RNA virus genome. All the influenza viruses have been shown fully sensitive to this new antiviral, including genetic strains to neuraminidase inhibitors (oseltamivir) resistance. Its mechanism of action lies in blocking viral replication and induction of lethal mutagenesis which determines the loss of infective activity of influenza viruses. Its activity is particularly intense in the respiratory tract, decreasing the viral load to non-infectious levels. Clinical trials in humans have not yet completed but have very favourable results. It seems that the best therapy would be the combination of favipiravir with oseltamivir; both antivirals are synergistic and avoid the emergence of resistance.

Rev Esp Quimioter 2017; 30(2):79-83  [pdf]

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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.

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

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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.

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

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