Search PubMed⌕ Search

Biomedical subjects

E Bouza

Publications and source records attributed to E Bouza.

At least 37 records · Page 2Linked to original sources

Workload due to Aspergillus fumigatus and significance of the organism in the microbiology laboratory of a general hospital.

The increase in the immunocompromised population and the incidence of invasive aspergillosis (IA) are leading to an overinterpretation of the potential clinical significance of many isolates of Aspergillus fumigatus. Our work prospectively assesses the workload of the isolation of A. fumigatus and its clinical significance in the microbiology laboratory of a large teaching hospital. During a 3-year period, all patients from whom A. fumigatus was isolated were prospectively monitored and classified as having IA or "nonsignificant" disease. A point score based on the prediction of five easily obtained laboratory and clinical parameters was applied. We found 404 A. fumigatus isolates in 260 patients (1/1,000 microbiology laboratory samples; 2.1 patients/10,000 admissions). A total of 90 isolates (22.3%) were from patients with IA. Of the 260 patients, 31 (12%) had invasive disease (IA), and the remaining 229 had "nonsignificant" disease. A score based on points for five parameters was applied to our population. It was constructed as follows: "sample obtained by invasive procedures" (1 point), "presence of two or more positive samples from the same patient" (1 point), "leukemia" (2 points), "neutropenia" (5 points), and "corticosteroid treatment" (2 points). Patients with a score of 0 had only a 2.5% probability of IA. Those with a score of 1 or 2 had an increased probability of 10.3%. The probabilities rose to 40% and 70%, respectively, for patients with a score of 3 or 4 or a score of > or = 5. A simple score based on five easily available parameters may be of help to microbiologists and clinicians to predict the risk of IA.

Analysis of Variance↗

Therapeutic immunization with an inactivated HIV-1 Immunogen plus antiretrovirals versus antiretroviral therapy alone in asymptomatic HIV-infected subjects.

To determine whether the addition of an inactivated-gp120-depleted HIV-1 Immunogen to antiretrovirals (ARTs) conferred a beneficial effect on delaying time to virologic failure relative to that obtained by ARTs alone, a phase II clinical trial was performed in 243 asymptomatic, ART naïve, HIV-1 seropositive adults. The Cox model showed that HIV-1 Immunogen treatment was associated with a 34% decrease in the risk of virologic failure (P = 0.056). When the analysis incorporated baseline HIV-RNA stratification the risk of virologic failure in the HIV-1 Immunogen Arm was significantly reduced a 37% compared to the IFA placebo Arm (P = 0.034). The data suggest that therapeutic immunization plus ARTs could influence virologic control.

AIDS Vaccines↗

Semiquantitative culture of open surgical wounds for diagnosis of surgical site infection.

The aim of this study was to assess the performance of a semiquantitative culture method and traditional qualitative culture for the diagnosis of surgical site infections resulting in an open wound. Results were correlated with the definitions for the diagnosis of SSI proposed by the Centers for Disease Control and Prevention, Atlanta, Ga., USA. The sensitivity, specificity, positive and negative predictive values of the qualitative culture method were 96%, 61%, 84% and 89%, respectively. For the semiquantitative technique with a breakpoint of 15 colony forming units/plate these values were 91%, 96%, 98% and 83%, respectively. Analysis of the receiver operating characteristic curve revealed an area under the curve of 94.44% (95% confidence interval, 88.5%-99%) for the semiquantitative method. This result indicates that our easy-to-perform semiquantitative culture technique for open surgical wounds correlates better with the diagnosis of SSI than the traditional qualitative method.

Bacterial Infections↗

Nosocomial invasive aspergillosis in a heart transplant patient acquired during a break in the HEPA air filtration system.

We report a case of nosocomially acquired invasive aspergillosis (IA) in a low-risk heart transplant recipient due to a break in the air conditioning system. A high overload of Aspergillus spores in the intensive care unit room led this patient to acquire IA. Identical environmental and patient isolates allowed our hypothesis to be confirmed and a very precise incubation time to be estimated.

Air Conditioning↗

Potential use of procalcitonin as a diagnostic criterion in febrile neutropenia: experience from a multicentre study.

In order to assess the diagnostic value of procalcitonin, 158 patients with febrile neutropenia from centres across Europe were studied. Patients with fever were diagnosed on the basis of either: (1) clinical, radiological and microbiological criteria; or (2) the procalcitonin value. In the latter case, concentrations of 0.5-1.0 ng/mL were considered diagnostic of localised infection, concentrations of 1.0-5.0 ng/mL of bacteraemia, and concentrations of > 5.0 ng/mL of severe sepsis. Procalcitonin and C-reactive protein were estimated daily in serum by immunochemiluminescence and nephelometry, respectively. Overall, the sensitivity (specificity) of procalcitonin for bacteraemia was 44.2% (64.3%) at concentrations of 1.0-5.0 ng/mL, and 83.3% (100%) for severe sepsis at concentrations of > 5.0 ng/mL. It was concluded that procalcitonin is a marker strongly suggestive of severe sepsis at concentrations of > 5.0 ng/mL. Estimated concentrations of < 0.5 ng/mL indicate that infection is unlikely, but it was observed that bacteraemia associated with coagulase-negative staphylococci may fail to elevate serum procalcitonin levels.

Adult↗

Evaluation of bone marrow and blood cultures for the recovery of mycobacteria in the diagnosis of disseminated mycobacterial infections.

This study evaluated the validity of bone marrow (BM) and blood specimens for the diagnosis of disseminated mycobacterial infections (DMIs). From 1990 to February 1997, all specimens were processed with the lysis-centrifugation procedure; thereafter (until December 2001), they were processed with the BACTEC Myco/F Lytic system. Twenty-three paired BM-blood specimens with mycobacteria in at least one specimen were studied from 23 patients. The strains isolated were 14 Mycobacterium avium complex (MAC) and nine M. tuberculosis complex (MTBC). Blood specimens had a statistically significant greater sensitivity for the isolation of MAC than BM (100% vs. 57.1%, respectively), whereas sensitivity for the isolation of MTBC was equal for the two specimen types (66.7%). Although not statistically significant, the times required to detect mycobacteria from blood specimens were lower than those from BM in the MycoF/Lytic system. Overall, blood cultures represented a more sensitive and less invasive alternative to BM cultures for the diagnosis of disseminated mycobacteriosis caused by MAC, especially when the MycoF/Lytic system was used, but provided no advantage for the diagnosis of DMI caused by MTBC.

Bacteremia↗

A European perspective on intravascular catheter-related infections: report on the microbiology workload, aetiology and antimicrobial susceptibility (ESGNI-005 Study).

The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology laboratories in European (European Union (EU) and non-EU) hospitals. Also included were questions requesting retrospective information for the year 2000. In total, 151 hospitals from 26 European countries participated, of which 78.1% were teaching institutions. Overall, the estimated population served by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques. Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p < 0.0001) than non-EU centres. Of the institutions surveyed, 11.4% (7.2% in EU countries and 23.7% in non-EU countries; p 0.04) used only qualitative techniques for catheter tip sample processing. On the day of the study, 167 microorganisms were recovered from significant catheter tip cultures (122 patients), of which Gram-positive bacteria represented 70.7%, Gram-negative bacteria 22.2%, and yeasts 7.2%. The five most common microorganisms were coagulase-negative staphylococci, Staphylococcus aureus, Candida spp., Enterococcus spp. and Pseudomonas spp. Overall, 19% of catheter tip cultures were polymicrobial. In the case of S. aureus, 40% of isolates were resistant to oxacillin, as were 63.4% of coagulase-negative staphylococcus isolates. Of 37 Gram-negative isolates, 35% were resistant to cefotaxime, 31% to ceftazidime, and 27% to ciprofloxacin. Imipenem and cefepime had the lowest reported rates of resistance (11%).

Anti-Bacterial Agents↗

Clinical-epidemiological characteristics and outcome of patients with catheter-related bloodstream infections in Europe (ESGNI-006 Study).

This study analysed 89 episodes of catheter-related bloodstream infection (CR-BSI) occurring during one week in 107 hospitals from 21 European countries (1.02 episodes/1,000 admissions). Patients from European Union (EU) countries had a higher incidence of CR-BSI than patients from non-EU countries (1.55 vs. 0.33/1,000 admissions). Most (67%) catheters were non-tunneled central venous catheters, were in the jugular vein (44%), had been implanted for > 7 days (70%), were made of polyurethane (61%) and were multi-lumen (67%). In 36% of cases, catheters were implanted by physicians other than anaesthetists or surgeons, and 50% were inserted by junior staff.

Bacteremia↗

Invasive infections caused by Blastoschizomyces capitatus and Scedosporium spp.

Blastoschizomyces capitatus, Scedosporium prolificans and S. apiospermum are emerging fungal pathogens that may cause disseminated disease in neutropenic patients. They can present as fever resistant to antibiotics and to wide-spectrum antifungal agents, although they may involve almost every organ. The proportion of recovery from blood cultures is high and they are characteristically resistant to most antifungal agents. Prognosis is poor unless patients recover from neutropenia. Voriconazole has good in-vitro activity and is currently the drug of choice for these infections.

Humans↗

A needleless closed system device (CLAVE) protects from intravascular catheter tip and hub colonization: a prospective randomized study.

Hub colonization and subsequent intraluminal progression due to frequent opening and manipulation of intravenous systems is the cause of many catheter-related infections (CRI). A prospective, comparative, randomized study was performed to assess a new closed-needleless hub device (CLAVE) compared with conventional open systems (COS). End-points were hub and skin colonization, catheter tip colonization, catheter-related bloodstream infection (CRBSI) and number of accidental needlesticks. All cultures were processed following standard semiquantitative microbiological techniques. The study involved patients who underwent heart surgery over an 11-month period in a post-surgical ICU. During the study period, 352 patients underwent major heart surgery and 1774 catheters were inserted. Overall, 865 catheters in 178 patients were allocated to the CLAVE system and 909 catheters in 174 patients to COS. The groups were similar regarding underlying conditions and risk factors for infection. Comparison of endpoint results in CLAVE and COS groups was as follows: incidence density per 1000 catheter-days of tip colonization: 59.2 versus 83.6 (P=0.003); of hub colonization: 7.56 versus 24.66 (P=0.0017); of skin colonization: 41.5 versus 58.9 (P=0.038); and of CRBSI 3.78 versus 5.89 (P=0.4). There was one accidental needlestick and one catheter-related prosthetic endocarditis in the COS group. Multivariate analysis showed that CLAVE use was an independent protective factor for tip colonization. CLAVE offered significant protection from catheter-tip and hub colonization.

Aged↗

[Second consensus report on the use of antimicrobial agents in exacerbations of chronic obstructive pulmonary disease].

Aware of the importance of chronic obstructive pulmonary disease (COPD), a panel of experts belonging to the Spanish Society of Respiratory Medicine and Thoracic Surgery (SEPAR), the Spanish Society of Chemotherapy (SEQ) and the Spanish Society of Family and Community Medicine (SEMFyC) issued a statement of consensus in 2000 to serve as the basis for adequate antibiotic control of the disease. Three years later, in accordance with significant scientific progress made in this area, the statement has been thoroughly revised. The new paper in fact constitutes a second consensus statement on the use of antibiotics in COPD exacerbations. When several scientific associations expressed interest in joining the project and contributing to it the Spanish Society of Emergency Medicine (SEMES), the Spanish Society of General Medicine (SEMG) and the Spanish Society of Rural and General Medicine (SEMERGEN) their incorporation led SEPAR and SEMFyC to change the structure of the statement and certain aspects of its content. Additionally, a new group of antibiotics, the ketolides, has joined the therapeutic arsenal. Telithromycin, the single representative of the group for the moment, can be considered not only an alternative treatment but even the drug of choice in certain clinical settings that are analyzed in the new statement. Those developments, along with others, such as the increasingly recognized action of levofloxacin against Pseudomonas aeruginosa and the steady action of amoxicillin with clavulanic acid when administered at recommended doses every 8 hours, provide new antimicrobial therapeutic protocols for COPD. Finally, the statement includes a scientific analysis of other groups of antimicrobial agents (macrolides, oral cephalosporins, etc.) and guidelines for both primary care physicians and specialists to follow when prescribing them.

Anti-Bacterial Agents↗

Evolution of penicillin and erythromycin co-resistance in Streptococcus pneumoniae in Spain.

The temporal dynamics of penicillin and erythromycin co-resistance in Streptococcus pneumoniae based on two extensive multicentre Spanish surveillance SAUCE studies (1996-1997 and 1998-1999) is presented. Erythromycin resistance among penicillin non-susceptible isolates seems to have reached a limit as evidenced by a null increase between the two surveys, whereas it is growing among penicillin-susceptible pneumococci.

Drug Resistance, Bacterial↗

Antibacterial resistance in Streptococcus pneumoniae and Haemophilus influenzae from Italy and Spain: data from the PROTEKT surveillance study, 1999-2000.

Antibacterial resistance was evaluated among Streptococcus pneumoniae (n=252) and Haemophilus influenzae (n=202) from two centres in Spain (Barcelona and Madrid) and two centres in Italy (Genoa and Catania) collected during 1999-2000 as part of the ongoing PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) international surveillance program. Pneumococcal nonsusceptibility to penicillin G was found to be considerably higher in Spain (53.4%) than in Italy (15.1%), whereas erythromycin A resistance was higher in Italy (42.9%) than in Spain (28.6%). Among macrolide-resistant isolates investigated for resistance genes, the prevalence of mefA was higher among isolates from Italy (20/51, 39.2%) than among Spanish isolates (2/38, 5.3%). All other macrolide-resistant isolates possessed ermB. Telithromycin possessed good anti-pneumococcal activity against isolates from both countries (MIC90 0.03 mg/L [Spain]; 0.25 mg/L [Italy]), irrespective of resistance to other antibacterials. Beta-lactamase production among H. influenzae was low: Spain, 10.9%; Italy, 1.8%. With the exception of ampicillin and co-trimoxazole, all H. influenzae isolates were highly susceptible to the antibacterials tested, and all were inhibited by telithromycin at a concentration of < or = 2 mg/L. The findings of PROTEKT 1999-2000 highlight the importance of local resistance patterns in guiding the choice of empirical antibacterials for community-acquired respiratory tract infections.

Anti-Bacterial Agents↗

[Pseudomonas aeruginosa: a multicenter study in 136 hospitals in Spain].

A cooperative group of 136 Spanish hospitals identified 1014 isolates of P. aeruginosa in one week. It was estimated that Spanish microbiology laboratories identified 168 P. aeruginosa isolates per 100,000 inhabitants population and year (25 isolates for every 1,000 hospital admissions/year). P. aeruginosa was recovered in 5.3% of all the samples with bacterial isolates. Seventy-five percent of samples containing P. aeruginosa came from the lower respiratory tract, wound exudates, abscesses and urine. The three most common serotypes present in Spain were found to be 0:1, 0:4 and 0:11 and constituted more than 50% of all isolates. The antimicrobials active against more than 85% of all the isolates included: ceftazidime (85.2%), piperacillin-tazobactam (92.8%), imipenem (86.2%), meropenem (92.2%) amikacin (91.4%) and tobramycin (91.2%). The study showed a high rate of resistance to ciprofloxacin (22.7%) and gentamicin (31.1%). Of the 529 patients who underwent clinical follow-up, 25.5% showed P. aeruginosa colonization and the remaining 74.5% had clinical infections. We estimated an incidence rate of 88.4 patients infected with P. aeruginosa per 100,000 inhabitants and year (13.8 cases per 1000 hospital admissions and year). Overall, 42% were community acquired. The overall mortality in this study was 15%, and mortality attributable to P. aeruginosa infections was 5%. After logistical regression analysis, the two independent predictors of mortality were the presence of a rapidly fatal underlying condition and the presence of bacteremia. In Spain, P. aeruginosa is much more than a cause of severe nosocomial infections in immunocompromised patients.

Anti-Bacterial Agents↗

Catheter-related infections: diagnosis and intravascular treatment.

The diagnosis of catheter-related infections relies on the presence of clinical manifestations of infection and the evidence of colonization of the catheter tip by bacteria, mycobacteria, or fungi. The reference method to confirm the latter requires the withdrawal of the catheter for culturing, which frequently turns out to be inconvenient, unnecessary and costly. New methods try to avoid these drawbacks and to assess the presence of tip colonization without withdrawal. Comparative quantitative blood cultures with a marked increase (> or = 5) in colony counts between blood obtained from the catheter lumen and from a peripheral vein simultaneously is one of those methods. It has a high sensitivity (>80%) and specificity (94-100%) but it is cumbersome and requires both an easy backflow of blood in the catheter and the existence of bacteremia. Cytocentrifugation and acridine orange staining of blood withdrawn from an infected catheter lumen has a sensitivity and a specificity of over 90% for the diagnosis of tip colonization. 'Superficial cultures' comprise the semiquantitative culture of the hub, of the skin surrounding the catheter entrance and of the first subcutaneous portion (1 cm) of the catheter after swabbing. The sensitivity of this method is >90%, specificity is >80%, and positive and negative predictive values for catheters (considering together those with and without clinical data of infection) are 66 and 97%, respectively. Endoluminal brushing has proved to be an impractical and unreliable procedure, at least in our experience. New methods based on the speed of bacterial growth to detectable levels of micro-organisms in conventional blood cultures are a new and interesting way of assessing catheter-related infections. Moreover, as the use of antimicrobial-coated catheters becomes more prevalent, the existing definitions of catheter colonization and catheter-related infection may need to be modified, because such coatings may lead to false-negative culture results. Many catheter infections, diagnosed without catheter withdrawal, can be handled nowadays with the so-called 'antibiotic lock-in technique', which consists in 'locking' the infected catheter lumen with a solution containing antibiotics. A high proportion of infected catheters, mainly those with coagulase-negative staphylococci, can be maintained in place and sterilized with this technique, including catheters in patients with therapeutic failure after receiving conventional intravenous antibiotic therapy. New diagnostic and therapeutic techniques may avoid the unnecessary withdrawal of thousands of efficient, difficult to replace and expensive intravascular lines.

Anti-Bacterial Agents↗