Aplicación del análisis de los polimorfismos de los tamaños de los fragmentos de restricción del gen flaA amplificado por reacción en cadena de la polimerasa y resistotipo para identificar potenciales brotes de campilobacteriosis no diagnosticados en España

Introduction

Outbreaks of campylobacteriosis are infrequent and usually involve a low number of patients, although it is estimated that many more remain undiagnosed. The most successful techniques for outbreak investigation in Campylobacter spp. (PFGE, MLST) have the drawback of being laborious and not available in many laboratories.

Methods

During the year 2008, 352 isolates of C. jejuni and C. coli from 16 hospitals were received in our laboratory. All strains were genotyped by RFLP-PCR-flaA (flaA type) and phenotyped with their resistotype. It was established that the strains of the same species from the same hospital, isolated over a period of up to 11 days, with MIC values of ± 1 dilution with the same flaA type could belong to an outbreak. Strains that met these criteria would be later subtyped by KpnI-PFGE and MLST.

Results

A total of 23 out of 352 isolates, distributed in 10 groups, met the criteria for being associated with putative undiagnosed outbreaks. The similarity of the PFGE-profiles in 8 groups was greater than 95% among the isolates from each group. In 7 of the groups, the sequence types (MLST) were coincident.

Conclusions

The use of 2 easy markers (resistotype and RFLP-PCR-flaA) may detect isolates probably belonging to an undiagnosed outbreak of campylobacteriosis. Accurate diagnosis requires other molecular markers and epidemiological data of each isolate. The study suggests that, as in other countries, the number of outbreaks of campylobacteriosis in Spain is probably underestimated.     

Caracterización molecular de aislados humanos de Cryptosporidium spp. procedentes de 2 diferentes localizaciones de España

Molecular PCR based diagnostic techniques have enabled us to distinguish between the different, morphologically identical, Cryptosporidium species that can infect humans. Of the 23 recognized species in the genus, at least 9 are able to infect humans. As the intensity of the clinical manifestations, pathogenicity, excretion of oocysts, and incidence, are different between this species, molecular studies are crucial for a better understanding of the epidemiology of human cryptosporidiosis.     

Mutaciones de la región precore,promotor basal del core y polimerasa viral en pacientes con hepatitis B crónica

Background

Variations of C gene give rise to precore and basal core mutations, which influence HBeAg expression The antiviral treatment failure is due to the presence of variations in the gene P, which cause mutations in the viral polymerase.

Methods

We performed genotyping of HBV P gene by sequencing, and gene C in patients with chronic hepatitis B over a period of five years.

Results

A total of 75 % of the patients had some mutation in precore or in basal core promoter regions, and 37 % demonstrated resistance mutations to antiviral treatment. The most frequent genotypes were A and D.

Conclusions

The presence of mutations in core/precore regions in patients with chronic hepatitis has led to tighter control of these patients. Detecting for resistance should be done as quickly as possible before there is an increase in viral load.     

Significado clínico del aislamiento de Staphylococcus aureus en muestras de orina

Introduction

To evaluate the clinical significance of the isolation of Staphylococcus aureus in urine samples.

Methods

A retrospective study was performed on adult patients identified from a microbiology database in a 200-bed general hospital between the years 2000 and 2009. The demographic data, comorbidities, and risk factors, were reviewed, particularly those associated with the concomitant isolation of S. aureus in blood cultures.

Results

The frequency of S. aureus found in urine samples was 0.63%. A total of 43 patients (mean age 68.7 years [SD ± 16], and 58.1% males) were identified in the database. A Charlson comorbidity index > 3 was observed in 20.9%. Concurrent bacteremia was seen in 48.8%. Two groups of patients were distinguished: with concomitant bacteremia (n = 21) or without (n = 22). Intervention in the urinary tract significantly predicted (P = .00004) bacteriuria without bacteremia (81.8%), compared to bacteremia cases (19%). The attributable mortality was 47.6% in patients with bacteremia compared to non-bacteremia (no deaths), even though the appropriate antibiotic treatment was more frequent among patients with bacteremia (92% and 60%, respectively).

Conclusion

The presence of S. aureus in urine was accompanied by bacteremia in half of the cases, but in patients without previous urinary tract intervention such a possibility increased to 81%. Concomitant bacteremia predicts a worse prognosis even with appropriate treatment.     

Neumonitis por hipersensibilidad a Mucor sp. en un trabajador de la industria del corcho

Suberosis is a type of hypersensitivity pneumonitis caused by exposure to cork proteins and molds such as Aspergillus fumigatus and Penicillium frequentans. We present the case of a man with suberosis caused by Mucor species, a mold that has been rarely reported to cause hypersensitivity pneumonitis. Furthermore, the patient had symptoms and lung function tests indicating bronchial obstruction—an atypical presentation of hypersensitivity pneumonitis. No imaging abnormalities were observed. A diagnosis was made on the basis of bronchoalveolar lavage and transbronchial biopsy findings. Mucor species was identified as the causative agent using a specific bronchial challenge test.     

Caracterización de cepas de Staphylococcus epidermidis y S. haemolyticus resistentes a meticilina y linezolid en un hospital español

Introduction

Linezolid resistance is mainly due to mutations in the 23S rRNA target. The aim of this study was to characterize linezolid and methicillin resistant Staphylococcus epidermidis (SE-LM^R) and S. haemolyticus (SH-LM^R) strains detected in a Spanish hospital.

Methods

SE-LM^R and SH-LM^R strains obtained in the period June 2009-August 2011 in a second level hospital were recorded along with the epidemiological characteristics of the patients. These strains were typed, and their resistance, phenotype, genotype and the factors determining their virulence were analysed.

Results

Linezolid resistance was explained by the presence of G2603T mutation (23S rRNA) and aminoacid changes in L3 and L4 ribosomal proteins. The 25 SE-LM^R strains belonged to sequence type ST2, presented SCCmec type III, and two different PFGE patterns. The two SH-LM^R strains showed non-typeable SCCmec. SE-LM^R strains harboured the resistance genes aac(6’)-aph(2”), and dfrS1. SH-LM^R strains contained these genes and the gene erm(C). No lincomycin resistance mechanism was identified in SE-LM^R strains regardless of showing lincomycin resistance and diminished susceptibility to clindamycin.

Conclusions

Linezolid resistance is of concern in hospitals, and requires continued vigilance. Several linezolid resistance mechanisms (mutation in 23S RNAr and amino acid changes in L3 and L4) were identified in this study.     

Actualización de la eficacia de la terapia triple para la infección por Helicobacter pylori y de la resistencia a claritromicina en España (2007-2012)

Introduction

Triple therapy, which remains the standard treatment for Helicobacter pylori infection, should be discouraged when its efficacy is lower than 80% or when clarithromycin resistance rates are above 15-20%.

Aim

To update the available evidence on the effectiveness of triple therapy and clarithromycin resistance rates in adults in Spain over the last 6 years.

Methods

A literature search (2007-2012) was conducted in Medline and the abstracts books of the annual meetings of several Spanish gastroenterological and microbiological congresses. The search terms were «Helicobacter pylori», «Spain» and «clarithromycin». Studies were selected if they included triple therapy consisting of a proton pump inhibitor with clarithromycin and amoxicillin or if they analyzed H. pylori clarithromycin susceptibility in treatment-naïve patients.

Results

There were five articles and nine abstracts (3147 patients) on triple therapy, which showed a mean cure rate of 70.8% (95% CI = 66-76%). When stratified by the duration of therapy, the mean cure rates were 68.8% (60-76%) for 7-day regimens and 71.76% (68-78%) for 10-day regimens. For clarithromycin resistance rates, four articles and five abstracts (1709 patients) revealed a mean resistance rate of 18.3% (13-22%).

Conclusions

The efficacy of triple therapy seems to be unacceptable in recent studies conducted in Spain, possibly associated with clarithromcyin resistance rates higher than previously reported.     

Implantación electiva de stent recubierto en la coartación y recoartación en el joven y en el adulto

Introduction and objectives

Stent implantation is an effective therapy for aortic coarctation and recoarctation. However, in adolescents and adults, aortic wall rupture and dissection can occur, as well as aneurysms during follow-up. In order to reduce these complications, we electively implant covered stents.

Methods

Since 2005, we have performed the procedure using femoral access in 17 patients (2 adolescents and 15 adults), 16 electively and 1 as a rescue procedure. We used the Mullins technique in all cases, implanting a NuMED^® covered stent.

Results

Good stent apposition was achieved in all 17 procedures; 8 patients required a distal flare. Gradient was reduced from 40 (16) mmHg to 2 (2) mmHg (P<.001) and lumen diameter increased from 4 (2) mm to 19 (3) mm (P<.001). Two exceptional cases are discussed: one patient with aortic wall rupture who underwent a rescue procedure using a stent within a covered stent and another patient with total obstruction and intercostal aneurysm in whom the outcome was fatal at 48 h postprocedure (autopsy is shown). Four-year clinical follow-up included Doppler echocardiography; an additional imaging technique was required in 13 patients. All patients recovered well and there were no complications.

Conclusions

Covered stents are effective in treating coarctation and recoarctation in adolescents and adults, are the treatment of choice in patients with complex anatomy, and must be available in the operating room as a rescue device when implanting a conventional stent.Full English text available from:www.revespcardiol.org/en     

Colonización nasal por Staphylococcus aureus en estudiantes de medicina: importancia en la transmisión hospitalaria

Background

Staphylococcus aureus is the main pathogen causing nosocomial infections. Health professionals, including medical students, could be a source of transmission. The aims of the study were to determine the rate of nasal carriage of S. aureus susceptible and resistant to methicillin (MRSA) and evaluate the knowledge and adherence that students had about hand hygiene.

Methods

The study included medical students attached to the Hospital Universitario 12 de Octubre (Madrid, Spain). We collected samples from both nasal vestibules, and the antimicrobial susceptibility was determined on all isolates. Data collection was performed using a self-administered questionnaire that included risk factors for colonization, hygiene habits and knowledge of hand hygiene protocols.

Results

Of the 140 students included, 55 (39.3%) were colonized by S. aureus, and 3 (2,1%) by MRSA. The exposure to antibiotics in the last 3 months was lower in colonized students (12.3% vs. 25.9%, P = .03). Self-assessment showed that 56.4% of students almost never washed their hands before to attending to the first patient, and only 38.6% always washed after examining patients. More than a third (35.7%) ignored the hand hygiene protocol, and 38.6% had not received specific formation.

Conclusions

Medical students should be included in hospital infection control programs. Hand hygiene training should be given to students before they begin their practices in the hospital.     

Efectos protectores del aceite de Nigella sativa en la lesión pulmonar inducida por hiperoxia

Background

Oxygen-induced lung injury is believed to lead to the development of bronchopulmonary dysplasia in premature infants. We have evaluated the beneficial effects of Nigella sativa oil (NSO) on rats with hyperoxia-induced lung injury.

Methods

Thirty newborn Sprague-Dawley rats were randomly divided into 3 groups as hyperoxia (95% O₂), hyperoxia + NSO and control (21% O₂). Pups in the hyperoxia + NSO group were administered intraperitoneal NSO at a dose of 4 ml/kg daily during the study period. Histopathologic, immunochemical, and biochemical evaluations (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], malonaldehyde [MDA] and myeloperoxidase [MPO]) were performed.

Results

In the histopathologic and immunochemical evaluation, severity of lung damage was significantly lower in the hyperoxia + NOS group (P < .05). Tissue GSH-Px and SOD levels were significantly preserved, and MDA, MPO levels were significantly lower in the hyperoxia + NSO group (P < .05).

Conclusion

NSO significantly reduced the severity of lung damage due to hyperoxia.     

Caracterización molecular de cepas de Staphylococcus aureus resistentes a meticilina ST398 en pacientes con infecciones cutáneas y sus familiares

Introduction

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) of sequence type ST398 is a genetic lineage also described in human infections.

Methods

Cutaneous infections related with MRSA ST398 are described in 3 patients, two of them pig farmers. The MRSA nasal carriage by patients and their relatives was also studied. MRSA ST398 strains were typed (SCCmec, spa, agr and MLST) and the antimicrobial resistance pattern and virulence genes were determined.

Results

Twenty MRSA ST398 isolates were recovered in lesions of three patients, and in nasal samples of two patients and five relatives. Isolates were typed: spa-type t011 or t108; agr-type I and SCCmec IVa or V. MRSA strains were tetracycline-resistant and 15 of them showed a phenotype and genotype of multi-resistance, but they were free of tested virulence genes.

Conclusions

LA-MRSA ST398 is an emergent problem in our country, mainly associated with skin and soft tissue infections in people with professional relationships with pig farms. Tetracycline resistance is an important marker for MRSA ST398 detection.     

Asociación en un mismo plásmido de blaVIM-1 y qnrS2 en Klebsiella pneumoniae y Klebsiella oxytoca aisladas en Sevilla

Background

Combined resistance to quinolones and β-lactams is common in Enterobacteriaceae. The appearance in enterobacteria coding for metallo-β-lactamases and determinants of plasmid-mediated quinolone resistance are an emerging problem in our country.

Methods

The susceptibility was determined by E-test. The resistance genes were detected by PCR and the corresponding plasmids were characterised.

Results

This study describes 2 strains (1 Klebsiella oxytoca, 1 Klebsiella pneumoniae) carrying the genes qnrS2 and blaVIM-1 in a transferable plasmid of 70-Kb isolated in surveillance cultures at the University Hospital Virgen Macarena in Seville.

Conclusion

This is the first combination of qnrS2 and bla_VIM-1 on the same non-typeable plasmid isolated in our centre.     

Enterococcus faecium resistente a glucopéptidos. Análisis del genotipo de resistencia,virulencia y líneas genéticas

Objective

The objective of this study was to analyse the genotypic characteristics of all Enterococcus isolates with acquired vancomycin resistance (VRE) recovered in the Hospital Clinic (Barcelona, Spain) in a period of three years and two months.

Methods

All VRE isolated in the referred Hospital in the period January 2004-March 2007 were included in the study. The vancomycin resistance mechanism was investigated, as well as other antibiotic resistance mechanisms. Isolates were also typed by pulsed-field-gel-electrophoresis (PFGE) and multi-locus-sequence-typing (MLST).

Results

Thirty-nine VRE were recovered, all being identified as E. faecium, representing 2% of total enterococci obtained in that period. Thirty-eight of them carried the vanA gene, and one isolate the vanB2 gene. The 39 VRE were classified into 13 different pulsotypes (A-M), with one main pulsotype, A, which included 13 isolates. The sequence type was identified by MLST in 24 VRE (with unrelated or closely-related PFGE patterns), and they were ascribed to the clonal complex CC17, but two classified as CC9. All VRE showed a multiresistance phenotype, including, in most cases ampicillin, ciprofloxacin, erythromycin, streptomycin, gentamicin, kanamycin and chloramphenicol, harbouring multiple antibiotic resistance genes. The presence of esp and/or hyl genes was identified in 37 VRE.

Conclusion

All VRE, but one, showed the vanA genotype and they were mostly ascribed to the high-risk clonal complex CC17.     

Efecto de la infección por Clostridium difficile sobre la estancia hospitalaria. Estudio de cohortes

Introduction

Clostridium difficile is responsible for a spectrum of diseases known as “Clostridium difficile infection” (CDI). It is currently the leading cause of nosocomial diarrhea in developed countries. This infection has been associated with both increased hospital stay and mortality, and to a greater likelihood of readmission. In our country these undesirable effects have not yet been characterized. Our objective was to quantify the increase in hospital stay attributable to infection by C. difficile.

Methods

A retrospective cohort study matched by age, sex and admission date, was conducted in a tertiary care university hospital during an outbreak of nosocomial transmission of CDI.

Results

The cohort study included 38 infected, and 76 non-infected patients. Patients who developed CDI showed a higher proportion of malnutrition at admission (OR = 10.3; 3.6 to 29.6), were exposed to a wider range of antibiotics (mean difference = 1.5; 0.7-2.2), had a higher mortality (31.6% vs. 6.6% of controls, P < .001), and a longer hospital stay (median 31.5 days versus 5.5 days for controls, P < .001). After adjustment, infection by C. difficile was associated with an increase in hospital stay of 4 days (P < .001).

Conclusions

C. difficile infection has important consequences on the length of hospital stay, and therefore on health costs.     

Aumento significativo de la colonización por Staphylococcus aureus entre los estudiantes de medicina durante la realización de las prácticas en el hospital

Introduction

Staphylococcus aureus is a pathogen of major concern. The emergence of methicillin-resistant S. aureus (MRSA) has increasingly complicated the therapeutic approach of hospital-acquired infections. Surveillance of MRSA and control measures must be implemented in different healthcare settings, including screening programs for carriers. Our first aim was to determine the prevalence of methicillin-susceptible S. aureus (MSSA) and MRSA nasal carriage in medical students from the Clínico San Carlos Hospital (Madrid). As the MRSA carrier rate in healthcare workers is higher than in the general population, we hypothesised that carrier rate could be increased during their clinical practice in their last three years.

Methods

We performed an epidemiologic al study of the prevalence of S. aureus colonisation among a group of medical students, who were sampled in 2008 in their third-year, and in 2012 when this class was in its sixth year.

Results

We have found a significant increase in MSSA carriage, from 27% to 46%. There were no MRSA colonisations in the third-year, but one was found in the sixth-year group. The large majority of strains (89%) of strains were resistant to penicillin, and 27% to erythromycin and clindamycin. As 19 coagulase-negative Staphylococcus MR were also identified, a horizontal transfer of genes, such as mecA gene to S. aureus, could have occurred.

Conclusions

Medical students are both, at risk for acquiring, and a potential source of nosocomial pathogens, mainly MSSA. Therefore, they should take special care for hygienic precautions, such as frequent and proper hand washing, while working in the hospital.     

Estandarización de la técnica Dot-ELISA para la detección de anticuerpos anti-Trypanosoma cruzi y su comparación con ELISA y Western blot

Introduction

Chagas disease is considered endemic of Latin America. Because of migration of people from this region to non-endemic areas, such as the United States, Canada and Europe, it has become a major health problem. There are parasitology and serology tests for its diagnosis, but only the latter are useful during the chronic phase. Most of these tests require expensive equipment, which make them also inaccessible for laboratories in endemic areas. In the present work we standardize Dot-ELISA as a diagnostic test for Trypanosoma cruzi infection, since it is an easy, inexpensive and an accessible test.

Methods

A total of 360 samples were tested: 96 sera from Chagas patients and 153 from healthy people; 40 blood samples spots collected and eluted from filter paper were also tested, as well as 71 serum samples of patients with non-related infections. Sensitivity, specificity and kappa index of Dot-ELISA test were calculated, in order to determine a correlation value of this technique compared to ELISA and Western blot that are already being used for diagnosis.

Results

Dot-ELISA obtained 97% sensitivity and 89% specificity, since it showed cross-reaction mainly with Leishmania spp., and a kappa index of 0,79.

Conclusions

Dot-ELISA results correlate well with other tests that are already being used for diagnosis of Chagas disease. As it is easy and inexpensive, it may be useful as an additional diagnostic test or for field studies.     

Reconocimiento de los antígenos excretores/secretores de Anisakis tipo i y evolución de la IgE en ratas infectadas experimentalmente

Introduction

Anisakis spp., during parasitism, release excretory-secretory antigens that, in contact with the human immune system, can trigger a hypersensitivity response mediated by IgE, causing various allergic symptoms.

Objectives

To evaluate the IgE response in Wistar rats after infection with L3 larvae of the parasite Anisakis spp.

Methods

Some determining factors involved in the technique have been improved in this work, such as: the concentration of polyacrylamide used in the preparation of the gels, the antigen concentration used, and the temperature required for denaturation of proteins.

Results

Immune responses (Ag-Ab) observed by the immunoblotting technique showed a greater intensity with serum obtained after reinfection, which have recognized proteins that may correspond to the major antigen Ani s 1 and other polypeptides of interest in the diagnosis of human anisakiasis.

Conclusion

This paper concludes that immunoblotting is a useful technique to detect IgE antibodies against Anisakis proteins.