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Introducción. El diagnóstico microbiológico de la neumonía permite optimizar el uso de antibióticos en pacientes con asistencia respiratoria mecánica. Para ello se han cultivado cuantitativamente las muestras del lavado broncoalveolar broncoscópico, procedimiento que no siempre es posible. Objetivo. Evaluar la concordancia microbiológica entre muestras respiratorias tomadas por lavado broncoalveolar broncoscópico y no broncoscópico, y establecer si el uso previo de antibióticos y el momento de presentación de la neumonía pueden afectarla. Materiales y métodos. Estudio prospectivo realizado en el Hospital Universitario San Vicente de Paúl, en 38 pacientes con sospecha de neumonía y con asistencia respiratoria mecánica. En todos se practicó el lavado broncoalveolar por fibrobroncoscopia y el lavado no broncoscópico usando un catéter telescopado de punta preformada (Balcath®). Todas las muestras fueron procesadas siguiendo protocolos microbiológicos convencionales. Resultados. Considerando el lavado broncoalveolar por fibrobroncoscopia como patrón de referencia, los cultivos permitieron identificar el agente en 60,5% de los casos. El acuerdo diagnóstico se logró en 82% de los pacientes y 79% de los aislamientos. Utilizando el índice kappa de Cohen, la concordancia general entre los dos métodos fue 0,76 [0,60-0,93]; pero en quienes habían recibido antibióticos previos fue 0,26 [0,05-0,48], versus 1,0 en quienes no lo habían hecho (p

This revision describes in detail the different diagnostic techniques of catheter-related infection, both in terms of catheter removal and preservation. Culture techniques based on catheter withdrawal are classified depending on the detection of extraluminal and/or intraluminal colonization, and new methodologies are described. In general, the most important recommendations are: (a) do not send for culture catheter tips without suspicion of infection, (b) Maki's technique is the standard for detecting extraluminal colonization, (c) take 2 pairs of peripheral blood cultures before starting antibiotic treatment, (d) use skin and connections/connectors cultures for the conservative diagnosis due to their high negative predictive value (Gram and culture), and (e) take differential quantitative blood cultures though all catheter lumens and through a peripheral vein., (Copyright © 2018 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Introduction: Catheter-related bloodstream infection (C-RBSI) can sometimes be managed without catheter removal by combining systemic therapy with catheter lock therapy. Most antiseptic lock solutions are made up of ethanol combined with an anticoagulant. However, data regarding the anti-biofilm activity of ethanol combined with enoxaparin are scarce. We aimed to assess the efficacy of ethanol at different concentrations combined with enoxaparin 60IU as a lock solution for eradication of the biofilm of different microorganisms., Methods: Using a static 96-well plate in vitro model, we tested 30%, 35%, and 40% ethanol alone and combined with 60IU of enoxaparin against 24-h-old biofilm from the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, and Candida albicans. Time of exposure was assessed during a 2-h and 24-h regimen. We analysed the percentage reduction in metabolic activity using the XTT assay. We considered therapy to be successful when metabolic activity was reduced by >90%., Results: In the 2-h regimen, the therapy was successful against all microorganisms at 35% and 40% ethanol without enoxaparin (p<0.001). In the 24-h regimen, the therapy was successful against all microorganisms at all ethanol solutions without enoxaparin (p<0.001). When ethanol was combined with enoxaparin, the therapy was only successful in the 24-h regimen in biofilms of S. epidermidis, C. albicans and E. coli at all concentrations of ethanol assessed., Conclusions: Our in vitro model demonstrated that when ethanol is combined with enoxaparin in a lock solution, it negatively affects ethanol anti-biofilm activity after both short and long exposures., (Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

The use of reusable semi-critical devices has been extended in current medical practice for both diagnostic and therapeutic purposes. However, reuse of these instruments carries the risk of cross-transmission of microorganisms from one patient to another. The process of cleaning and disinfecting these devices is complex, long, expensive and very error-prone. This paper analyses the epidemiological aspects of infections associated with the reuse of semi-critical devices and the role of the Microbiology laboratory in monitoring the cleaning and disinfecting process through microbiological controls. The recommendations of different scientific societies on the relevance of such controls are reviewed and specific recommendations are proposed for the taking and processing of the samples, interpretation of the results and measures to be taken depending on the results obtained., (Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Introducción: Las infecciones del tracto urinario (ITU) se encuentran entre las causas de consulta ambulatoria y de urgencias más frecuentes. La ausencia de pautas y consenso para el diagnóstico dadas por el laboratorio de microbiología puede dificultar la obtención de datos relevantes y confiables sobre los hallazgos microbiológicos y retrasar la toma de conductas clínicas apropiadas. Objetivo: Elaborar un algoritmo de decisión en ITU basado en la evidencia actual para el procesamiento de la muestra de orina, que incluye desde la recolección, el transporte y almacenamiento hasta su cultivo, con el fin de generar una directriz desde el laboratorio para la correcta toma de decisiones del médico. Metodología: Se lleva a cabo una búsqueda en la literatura y el concepto de expertos en Microbiología e Infectología basada en la revisión de las referencias bibliográficas disponibles en los términos de búsqueda relacionados, haciendo énfasis en estudios locales. Resultados: Se generaron recomendaciones para el diagnóstico por el laboratorio de las ITU en Colombia, que incluyen recolección, almacenamiento y transporte, siembra y pruebas de susceptibilidad antimicrobiana.

Sexually transmitted infections (STIs) are responsible for an enormous burden of morbidity and mortality. Worldwide, millions of cases of STIs, such as syphilis, chlamydia, or gonorrhoea occur every year, and there is now an increase in antimicrobial resistance in pathogens, such as gonococcus. Delay in diagnosis is one of the factors that justifies the difficulty in controlling these infections. Rapid diagnostic tests allow the introduction of aetiological treatment at the first visit, and also leads to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. The World Health Organisation includes these tests in its global strategy against STIs., (Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Introduction: Current guidelines for the microbiological diagnosis of ventilator-associated pneumonia (VAP) are imprecise. Based on data provided by intensive care specialists (ICS) and microbiologists, this study defines the clinical practices and microbiological techniques currently used for an aetiological diagnosis of VAP and pinpoints deficiencies., Methods: Eighty hospitals in the national health network with intensive care and microbiology departments were sent two questionnaires, one for each department, in order to collect data on VAP diagnosis for the previous year., Results: Out of the 80 hospitals, 35 (43.8%) hospitals participated. These included 673 ICU beds, 32,020 ICU admissions, 173,820 ICU days stay, and generated 27,048 lower respiratory tract specimens in the year. A third of the hospitals (35%) had a microbiology department available 24/7. Most samples (83%) were tracheal aspirates. Gram stain results were immediately reported in around half (47%) of the hospitals. Quantification was made in 75% of hospitals. Molecular techniques and direct susceptibility testing were performed in 12% and one institution, respectively. Mean turnaround time for a microbiological report was 1.7 (SD; 0.7), and 2.2 (SD; 0.6) days for a negative and positive result, respectively. Telephone/in-person information was offered by 65% of the hospitals. Most (89%) ICS considered microbiological information as very useful. No written procedures were available in half the ICUs., Conclusions: Both ICS and microbiologists agreed that present guidelines for the diagnosis of VAP could be much improved, and that a new set of consensus guidelines is urgently required. A need for guidelines to be more effectively implemented was also identified in order to improve outcomes in patients with VAP., (Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

The gastrointestinal tract harbors trillions of microorganisms that are indispensable for health. The gastrointestinal microbiota can be studied using culture and molecular methods. The applications of massive sequencing are constantly increasing, due to their high yield, increasingly accessible costs, and the availability of free software for data analysis. The present article provides a detailed review of a large number of studies on the gastrointestinal microbiota and its influence on human health; particular emphasis is placed on the evidence suggesting a relationship between the gastrointestinal microbial ecosystem and diverse physiological and immune/inflammatory processes. Discussion of the articles analyzed combines a medical approach and current concepts of microbial molecular ecology. The present revision aims to be useful to those interested in the gastrointestinal microbiota and its possible alteration to maintain, re-establish and enhance health in the human host., (Copyright © 2015 Elsevier España, S.L.U. y AEEH y AEG. All rights reserved.)

The normal activity in the laboratory of microbiology poses different risks - mainly biological - that can affect the health of their workers, visitors and the community. Routine health examinations (surveillance and prevention), individual awareness of self-protection, hazard identification and risk assessment of laboratory procedures, the adoption of appropriate containment measures, and the use of conscientious microbiological techniques allow laboratory to be a safe place, as records of laboratory-acquired infections and accidents show. Training and information are the cornerstones for designing a comprehensive safety plan for the laboratory. In this article, the basic concepts and the theoretical background on laboratory safety are reviewed, including the main legal regulations. Moreover, practical guidelines are presented for each laboratory to design its own safety plan according its own particular characteristics., (Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Coccidioides immitis and Coccidioides posadasii, the two recognized causes of coccidioidomicosis, may be diagnosed by direct microscopy, culture, serologic and the skin-test with mycelial coccidioidin. Identification of spherules by direct examination of secretions after addition of KOH, is more rapid and may speed diagnosis. Histopathology of infected tissue demonstrates acute and chronic granulomatous inflammation and in the section strained with hematoxylin-eosine (HE) or Grocott metamine-silver (GMS). Isolation of Coccidioides spp. by culture is not difficult, the fungus grows well on most mycologic media after 5-7 days of incubation and the laboratory should maintain a biological safety level 2 or 3. Phenotypic identification to genus level may be achieved by visualization of arthroconidia in culture. Isolates may be confirmed as Coccidioides ssp. by molecular probes, but separation of species is best achieved by specialized molecular techniques, available at the Reference Laboratory. Immune diffusion and enzyme-immune assays (EIA) are commonly used for detection of IgM and IgG antibodies in serum. Sequential complement fixations (CF) for IgG class of antibody are useful for the prognosis of coccidioidomycosis.

The most relevant activities of clinical microbiologist and the laboratory in the surveillance and the control of nosocomial infections (NI) are mainly focused on the collection, analysis and management of the information obtained in the Microbiology Laboratory; the design, development and validation of microbiological techniques, particularly rapid tests for the early detection of nosocomial pathogens, especially those multi-drug resistant ones, and the study of the genetic relationship between them. It also assists in the design of specific programs for the prevention of the NI, and the evaluation of their impact, as well as taking part in educational and training programs on topics related to NI. The management of laboratory resources, and communications with hospital information systems is also important. The most suitable tools for the control of NI include the correct identification at the species level of relevant nosocomial pathogens, analysis of the evolution of resistance to antimicrobials, monitoring sentinel organisms, active surveillance of carriers, and molecular epidemiology studies (genotyping). Prospectively typing of these pathogens, which has been achieved through advances in technology, and dissemination of molecular techniques, have a direct impact on the design of prevention and control interventions. To achieve the maximum performance with all these tools, it is essential to have a good communication strategy and an effective alert system., (Copyright © 2012 Elsevier España, S.L. All rights reserved.)

Clinical microbiology laboratories in Peru have the task to diagnose the infectious agents present in the clinical samples, for this, they have different tools available; their use depends on having material and human resources. The microbiological laboratory can perform simple and complex tests, depending on the level, the geographical location and the available resources. We mention the problems found with the available laboratory procedures and their potential diagnostic aid. We emphasize the need of having standardised procedures, the continuous education and training of the staff, and the importance of the laboratory network led by the Instituto Nacional de Salud.

The infections of the central nervous system are associated with high morbidity and mortality. Several agents including bacteria, viruses, fungi and protozoa can invade the CNS. They are different clinical presentations of these infections: meningitis, encephalitis, brain and epidural abscesses and cerebrospinal fluid shunt infections. The clinical course could be acute, subacute or chronic depending on the infecting agent and the location of the infection. The travelling entails a risk of infection by exotic agents of meningo-encephalitis such as robovirus and arbovirus, which require new diagnostic and therapeutic methods. Despite some progress in the treatment of the CNS infections, the mortality is usually high. Rapid diagnosis and emergent interventions are necessary to improve the outcome of those patients, and early and targeted antimicrobial treatment and support measures are of paramount importance for a favourable clinical patient outcome. The antigen detection techniques and particularly those of genetic diagnosis by amplification (PCR and others) have advanced, and improved the diagnostic of those diseases. In this paper the clinical signs and symptoms and diagnostic procedures of CNS infections are presented., (Copyright © 2010 Elsevier España, S.L. All rights reserved.)

The influence of new technologies in modern microbiology is directly related to their automation, the real driving force of change. Automation has occurred since the beginning of clinical microbiology, but from the 1980s has experienced huge development, which is being projected through the immediate future to all areas of the speciality. Automation has become a prime organizational tool. However, its main disadvantage is that it has no limits, which in association with the current economicallyoriented criteria, is encouraging initiatives to integrate the various laboratory specialities into one production center and, eventually, to outsource its activity. This process could significantly reduce the quality of clinical microbiology and the training of future specialists, or even worst, lead to the eventual disappearance of the speciality, at least as it is known today. The future development of highly automated and integrated laboratories is an irreversible process. To preserve the quality of the speciality and of specialist training, rather than fight directly against this process, we must, as microbiologists, actively participate with creativity and leadership., (Copyright © 2010 Elsevier España S.L. All rights reserved.)

The microbiology laboratory should be a safe, efficient, and comfortable place for those working there, and a pleasant place for visitors. According to the ISO 15189 standard, it should be spacious enough for the workload to be carried out without jeopardizing quality or the safety of the persons present, whether workers or visitors, and provide optimal comfort to all occupants. In addition, the setup should respect the privacy of patients, and provide controlled access to the different laboratory areas and a safe place for storing clinical samples, manuals, and reagents. In the design of the facilities, the needs of specialists, technicians, and other personnel must converge, without forgetting patients, their relatives, and other visitors. The clinical microbiology laboratory has certain characteristics that make it different from other diagnostic laboratories. Its main activity involves isolation, propagation, and handling of pathogenic microorganisms that pose a risk to the laboratory personnel. To minimize this risk, the laboratory must meet a certain level of biosafety. Moreover, correct interpretation of microbiological cultures depends on the capacity of the laboratory to avoid or minimize the presence of contaminants; hence, proper handling of samples and cultures (aseptic conditions, biosafety cabinet) is mandatory. A number of documents and regulations, from very general to highly specific (biosafety), affect the design of the microbiology laboratory. The aim of this report is to establish the minimum requirements and recommendations for designing clinical microbiology laboratories, based on a review of current regulations. It is contemplated as an aid to microbiology specialists who are designing or planning to reform their laboratories., (Copyright 2009 Elsevier España, S.L. All rights reserved.)

The recent increase in the practice of ocular surgery and widespread use of contact lenses have led to an increase in the incidence of severe ocular infections. Inadequate management of these infections can result in irreversible loss of vision. Microbiological diagnosis is essential when the lesions are non-specific, recurrent, or unresponsive to antibiotic therapy, but is hampered by the difficulty of analyzing limited sample volumes containing small inocula. This document presents a review of the most important ocular infections according to the structure affected, and describes the most common causes of these infections and the situations in which a microbiological diagnosis is recommended. Information is included on the sample type and sampling methods, sample transport to the laboratory, and laboratory management and processing techniques, with special attention to liquid culture media. The yield of smear examination and culture of each type of ocular specimen is specified. Lastly, the molecular methods recently developed for the diagnosis of ocular fungal infections and Acanthamoeba infections are described.

Acute gastrointestinal tract infections are among the most common infectious diseases. In the present review, the different methods of diagnosing gastrointestinal infections caused by bacteria, viruses, and parasites are examined. Stool culture is the method of choice for diagnosing bacterial intestinal infections; however, infections caused by Clostridium difficile can be diagnosed by detection of toxins A and B in stools, and infections caused by diarrheagenic Escherichia coli by PCR detection of specific virulence factor genes harbored by several E. coli pathotypes. The techniques used to diagnose viral gastrointestinal infections include detection of viral antigens and nucleic acids. Finally, gastrointestinal infections caused by parasites can be diagnosed by testing for trophozoites and cysts of protozoa, or larvae and eggs of helminths in stools by direct microscopic examination, with concentration techniques, or by specific stains.

Cystic fibrosis (CF), a condition produced by mutations in the gene that encodes the cystic fibrosis transmembrane conductance regulator, is the most prevalent autosomal-recessive hereditary disease in caucasian populations. Among other repercussions, this defect leads to an alteration of respiratory secretions and determines a predisposition for chronic bronchopulmonary colonization-infection, which is the main driver of the high morbidity and early mortality of CF patients. Colonization by Staphylococcus aureus and Haemophilus influenzae is frequent in children younger than 10 years, but mucoid Pseudomonas aeruginosa is by far the most relevant pathogen in adults with CF and is responsible for the progressive bronchopulmonary deterioration. As a consequence of repeated, long-lasting antimicrobial treatments and deterioration of lung function, colonization by multidrug-resistant Gram-negative bacilli, such as Stenotrophomonas maltophilia, Achromobacter spp. and Burkholderia cepacia complex, is also frequent in adult CF patients. The special characteristics of the pathologic process and the microorganisms implicated in CF make it advisable to consider microbiological follow-up of chronic bronchopulmonary colonization-infection in these patients a specific diagnostic entity.

Upper respiratory tract (URT) infections are common and account for more medical visits than any other type of infectious disease. Diagnostic procedures for the following syndromes are included in this report: Streptococcal and nonstreptococcal pharyngitis, laryngeal syndromes, otitis, sinusitis, and others caused by unusual and/or uncommon bacteria or fungi, including Lemierre's disease, Vincent's angina, pharyngeal and peritonsillar abscesses, diphtheria, candidiasis, and zygomycoses. Detailed information is provided on specimen collection and processing, selection of laboratory tests, interpretation of findings, reporting results, additional procedures for uncommon infections, and the use of new techniques. All the information included in this article is contained in the Standard Operating Procedures for Clinical Microbiology (http://www.seimc.org/protocolos/microbiologia/).

Together with organ rejection, infectious complications are still the most important cause of morbidity and mortality in organ transplant recipients. Many infectious complications have an exogenous origin, including those produced by organ-transmitted pathogens, whereas others are caused by latent microorganisms that become reactivated in the recipient. Accurate pre-transplantation assessment of the organ donor as well as the recipient can prevent some infectious complications or reduce their detrimental effects during the post-transplant period. A wide range of primary and opportunistic microorganisms can affect transplant recipients, and a detailed description of these pathogens is beyond the scope of this study. However, the importance of microbiology laboratories in centers with transplant programs and the need for integration and active participation of clinical microbiologists in multidisciplinary transplant teams should be emphasized. The work of these professionals is a key requisite to establish accurate diagnoses of infectious complications, which will benefit the patient and optimize the expenditure of resources.

Objective: The aim of this research was to detect the presence of genes encoding beta-lactamases which can confer cefepime resistance on Enterobacter cloacae isolates, meaning that this antibiotic may be considered an important therapeutic alternative., Materials and Methods: 28 E. cloacae isolates collected from 4 hospitals in Bogotá during 2003 were analysed. Extended spectrum beta-lactamases and cephalosporinase production were phenotypically determined. The presence of extended spectrum beta-lactamase genes was determined by PCR amplification. Mating assays were done to determine the possible transfer of bla-genes encoding cefotaximases., Results: Microbiological tests detected 57% of extended-spectrum beta-lactamase-producing isolates. blaTEM, blasHv and blacTX-M genes were detected by PCR in 82% of the isolates. 7 out of 9 isolates carrying group 1 blacTX-M genes were in the resistant or intermediate range for cefepime. These isolates produced cefotaxime-resistant transconjugants., Conclusion: A relationship was found between resistance to cefepime and the presence of cefotaximases in E. cloacae. blacTx-M genes were present in 32% of the isolates, indicating an significant spread in the hospitals being studied. The facility of these genes' transfer between other species and Enterobacteria genera becomes an important reason for detecting them and controlling their spread in hospital settings. These results suggest a cautious use of cefepime for treating infection caused by E. cloacae strains which might produce CTX-M enzymes.

Introduction: This study attempts to describe the results obtained in the HIV resistance study performed with clinical samples obtained from patients receiving "HAART" therapy and to compare the results using different interpretation algorithms., Methods: 397 samples have been analysed (TRUGENE HIV-1 GENOTYPING kit). The results were interpreted with the algorithms Visible Genetics and Retrogram. The concordance interalgorithm was done for 105 of these samples, including the virtual phenotype interpretation., Results: The samples corresponded to multi regimen failure (39%), first and second failure (30.7% and 27.1% respectively). A 27.6% of the samples were wild type. The more frequent mutations to the ITIAN were T215Y/F (37.2%) and M184V (32.9%) following by other NAMS. The 69 insertion and Q151M complex had low representativity. For the ITINN K103N (25.8%), Y181C (11.2%) and G190A (10.9%). For the IP: key mutations L90M (26.1%), M46I (18.1%) and V82AFTS (12.9%); and accessory mutations L63P (50.5%), A71V (27.2%), L10I (25.2%) and M36I (19.2%). Low correlation was observed between interpretation systems, mainly for ITIAN and IP, being the virtual phenotype more flexible in the assignation of resistance., Conclusions: The requests for HIV resistance testing were similar for the three groups of patients. Many of the failures were the consequence of a poor adherence to the therapy. The mutation pattern found corresponded with the "TARGA" therapy. The low correlation found between interpretation systems, makes necessary the elaboration of a consensus algorithm.

Between February and September 1997, 6588 blood cultures at the Instituto de Cardiología y Cirugía Cardiovascular and Hospital de Niños Ricardo Gutiérrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3%) were monomicrobial episodes and 14 (4.7%) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10% CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7% to 4.7%. Taking into account the total number of bacteremias, only in 3 out of 294 (1%), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

Stereum hirsutum BAFC 2234 was tested for growth kinetics and ligninolytic enzyme production. The strain showed weak coincidences with widely studied organisms (Phanerochaete chrysosporium, Pleurotus ostreatus) when the response to nitrogen sources was assayed. This could be interpreted as a different regulation to nitrogen metabolism for S. hirsutum BAFC 2234. Alternative carbon sources and the addition of veratryl alcohol and wood extracts were also tested showing partial correspondence with other ligninolytic fungi. On the basis of the high enzymatic activities observed, S. hirsutum BAFC 2234 could be a suitable source of lignin degrading system aiming techological processes.

Aims: Francisella tularensis is a facultative intracellular gramnegative aerobic coccobacilli which is difficult to isolate. The appearance of an epidemic outbreak of tularemia in Castilla y Leon (Spain) during the first months of 1998 led bur microbiology laboratory to develop the diagnostic methods of this disease which, up to then, were unknown by the authors., Methods: During the months of January and February, 1998, 25 samples were processed for culture (17, adenopathy pus and 8 necrotic skin ulcers) using enriched culture mediums. In 20, direct immunofluorescence was performed on the sample spread. Serologic study was carried out in 352 patients by the agglutination technique in tubes, with titers > or = 1/160 being considered as positive. Susceptibility tests were performed by the disk plate technique in chocolate agar., Results: Three isolates of F. tularensis were achieved (12%). Seven samples (38.8%) were positive by direct immunofluorescence. By serology 149 negative (42%) and 203 positive (58%) results were obtained. Seroconversion was observed in 53 patients (increase in titer value 4-fold above the basal determination). The strains isolated were sensitive to third generation cephalosporins, aminoglycosides, macrolides and quinolones., Conclusions: F. tularensis is a microorganism which is highly demanding of its culture. Serology and direct immunofluorescence are more effective techniques for the diagnosis of tularemia than cultures. The strains presented high sensitivity to the antibiotics tested. Since the appearance of this outbreak, tularemia should be included in the differential diagnosis of the infectious processes observed in Spain.

Infectious endocarditis is caused by a wide variety of microorganisms. Etiological diagnosis depends either on direct methods, directed to the detection and isolation of the causative organisms, or serological methods. Blood cultures remain as the best method for the diagnosis of bacterial endocarditis. Blood culture technology has changed due to the appearance of new automatic continuous monitoring systems which shorten the detection time. Endocarditis with a negative blood culture has decreased below 5% because of new blood culture systems, new serological methods and molecular technology. The control of antimicrobial therapy in endocarditis must be performed by expert laboratories. A minimal bactericidal concentration, serum levels of antimicrobials and the serum bactericidal test are the most useful parameters. Their execution requires the use of strict protocols and interpretation must be carried out with an expert in clinical microbiology and infectious diseases.

Background: The efficiency of a novel differential culture medium, CHROM-agar Candida, is evaluated in order to differentiation and presumptive identification of clinically important yeasts., Methods: We studied 600 clinical yeast strains, pertaining to 8 genera (Candida, Cryptococcus, Geotrichum, Rhodotorula, Trichosporon, Kluyveromyces, Pichia and Saccharomyces) and 27 species. Strains were previously identified by conventional methods and by commercial system ATB ID32C (Bio-Mérieux)., Results: Four species (C. albicans, C. krusei, C. tropicalis and t. beigelii) were presumptive recognized after 48-72 hours of incubation, regarding their colonial morphology and color. Colony color of other species showed low specificity., Conclusion: CHROM-agar Candida medium is recommended for recognition of mixed yeast cultures and differentiation of the common clinically yeast species.

Background: Candida albicans infections are frequent in immunocompromised patients and a prompt diagnosis could favor an early and proper antifungal treatment. The rapid identification of clinical yeast isolates facilitate this diagnosis., Methods: The utility of Fluoroplate Candida ready-to-use plates for Candida albicans rapid identification was evaluated with 653 clinical isolates from 23 yeast species, including 307 C. albicans plated onto Fluoroplate Candida agar (Merck, Germany). Rapid identification of C. albicans was based on the hydrolysis of 4-methylumbelliferyl-N-acetyl-beta-D-galactosaminide by the galactosaminidase activity of C. albicans producing white fluorescent colonies under ultraviolet light. Identification on Fluoroplate Candida was confirmed by germ tube, chlamydoconidia formation and API-ATB ID 32C assays., Results: Three hundred and five of 306 isolates showing fluorescent colonies were C. albicans and one was Candida glabrata (false positive). The rest of the isolates showed colonies without fluorescence and with the exception of two false negatives, these isolates were identified as non-C. albicans by other methods., Conclusions: Fluoroplate Candida allows a rapid and excellent identification of C. albicans showing a sensitivity and specificity of 99.3 and 99.7%, respectively.

Due to lack of evidence of infection in patients for ovarian punction for ovular capture, the hypothesis of possible antibacterial action that could exist in follicular fluid, was evaluated. One hundred and ten samples of such fluid, were taken for antibacterial analysis, 37 of which, were studied, as they were the clearest ones and not contaminated. Such samples were obtained from hyperstimulated patients, ready for ovular capture through vagina by ultrasonographic guide. A bacterial inoculum, was prepared, in order to evaluate antimicrobial activity of follicular fluid against E. coli, P. aeruginosa, S. agalactiae, L. monocytogenes and C. albicans. Counting of bacterial colonies, at 2, 4, 6, 12 and 24 hours. Results summary shows bacteriostatic activity in all studied colonies, and E. coli and S. agalactiae seem to be the most sensitive, followed by P. aeruginosa, S. aureus and L. monocytogenes; and still present in C. albicans. It is concluded that follicular fluid has an antibacterial action, probably selective; and that keeping this research line will confirm this finding, and possibly will determine the concerned factors.

Potential contamination of nutritional mixtures during preparation in the Pharmacy Services has led to the need for microbiological controls. In our study, we set out the techniques used in the Son Dureta Hospital between 1986 and 1991. During those six years 11,023 nutritional mixtures were prepared, and 1,714 bacteriological controls were carried out, representing 15.5% of the total. Between January 1986 and June 1989, the simple culture technique was used (culture of 10 ml of the prepared mixture). The contamination rate was 1.27%. Between July 1989 and December 1991, the double sample technique was applied, involving a culture of 10 ml of the mixture, keeping a further 10 ml for subsequent verification culture. With this technique, the contamination rate was fixed at 0.34%. The advantages and drawbacks of the techniques used are described, along with the problem of initial false positives, and a review is made of the 39 germs isolated during the period of study.

Background: With the aim of knowing the etiology of infectious peritonitis in patients undergoing continuous ambulatory peritoneal dialysis in our Hospital and the yield of our method of culture, we have made a revision of cases recorded during a five years period., Methods: The peritoneal fluids of 105 patients with peritonitis was processed as following: 10 ml of uncentrifuged liquid was placed in hemocultures bottles, aerobe and anaerobe (Hemoline, Biomérieux) and incubated for up to 15 days at 37 degrees C. An additional 50 ml of peritoneal fluid was centrifuged and the sediment used for Gram stain and placed on enriched chocolate agar. Plates were incubated for up to two days at 37 degrees C in 5% of CO2. During the last year of the review the sediment of 50 ml resuspended in sterile distilled water was placed, too, in hemoculture bottles. In 18 cases we had only the hemoculture bottles inoculated by the nurse of the Nephrology Service (those patients came at a time when the laboratory was closed). Subcultures were identified with routine methodology., Results: 96 (91.43%) of the 105 dialysis effluents processed were culture positive; 91.67% were bacterial and 8.33% fungal peritonitis. 64 (69.56%) of the bacterial isolates were Gram positive and 28 (30.43%) Gram negative., Conclusion: We remark the good yield of a simple culture method and the high rate of Gram negative and fungal peritonitis.

Food industries use a great variety of enzymes as additives. The main percentage of them are produced by species of filamentous fungi. In this review we present the strategies to purify and overproduce this kind of enzymes using recombinant DNA techniques.

Working with highly passaged MRC-5 fibroblast monolayers in a shell-vial culture-centrifugation assay for rapid detection of cytomegalovirus (CMV), a direct toxic effect of the urine on the monolayer was observed in as many as 44% of cases when vials were inoculated with undiluted specimens. This toxicity was reduced to only 6% by inoculation of shell-vials with samples diluted 1:1 with viral transport medium. The recovery of CMV in shell-vials was not significantly affected by the dilution factor, since five cases detected in conventional culture in tubes and not in vials were compensated by seven cases detected in vials and not in tubes.

The multiple applications and advantages of the ultramicro analytical system in the serodiagnosis of different diseases produced by viruses, bacteria, and parasites are briefly reported. Also, perspectives in the use of this technology, not only for the diagnosis, but for the detection of microbial antigens are pointed out.

Quantitative evaluation of bacteria in bronchoalveolar lavage fluid from 15 patients with pneumonia was compared to that in 29 healthy controls. Aerobic and anaerobic cultures were used as well as cultures and staining for fungi and mycobacteria. A total of 1000 colony forming units per ml was considered a cutoff mark between colonization and infection. A positive result was obtained in 13 of 15 patients with pneumonia, allowing the identification of the causing agent. Counts below the indicated level were observed in 23 of 29 controls. There was no morbidity associated to the procedure. Thus, an 85% sensitivity and 87% specificity for bronchoalveolar lavage in the etiologic diagnosis of pneumonia may be estimated from this study.