The CARBA-MAP study: national mapping of carbapenemases in Spain (2014-2018).

Introduction: Infections caused by carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa, including isolates producing acquired carbapenemases, constitute a prevalent health problem worldwide. The primary objective of this study was to determine the distribution of the different carbapenemases among carbapenemase-producing Enterobacterales (CPE, specifically Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae complex, and Klebsiella aerogenes) and carbapenemase-producing P. aeruginosa (CPPA) in Spain from January 2014 to December 2018. Methods: A national, retrospective, cross-sectional multicenter study was performed. The study included the first isolate per patient and year obtained from clinical samples and obtained for diagnosis of infection in hospitalized patients. A structured questionnaire was completed by the participating centers using the REDCap platform, and results were analyzed using IBM SPSS Statistics 29.0.0. Results: A total of 2,704 carbapenemase-producing microorganisms were included, for which the type of carbapenemase was determined in 2692 cases: 2280 CPE (84.7%) and 412 CPPA (15.3%), most often using molecular methods and immunochromatographic assays. Globally, the most frequent types of carbapenemase in Enterobacterales and P. aeruginosa were OXA-48-like, alone or in combination with other enzymes (1,523 cases, 66.8%) and VIM (365 cases, 88.6%), respectively. Among Enterobacterales, carbapenemase-producing K. pneumoniae was reported in 1821 cases (79.9%), followed by E. cloacae complex in 334 cases (14.6%). In Enterobacterales, KPC is mainly present in the South and South-East regions of Spain and OXA-48-like in the rest of the country. Regarding P. aeruginosa, VIM is widely distributed all over the country. Globally, an increasing percentage of OXA-48-like enzymes was observed from 2014 to 2017. KPC enzymes were more frequent in 2017-2018 compared to 2014-2016. Discussion: Data from this study help to understand the situation and evolution of the main species of CPE and CPPA in Spain, with practical implications for control and optimal treatment of infections caused by these multi-drug resistant organisms.

Implementation of a New Protocol for Direct Identification from Urine in the Routine Microbiological Diagnosis.

Background: The direct identification of uropathogens from urine samples, in combination with the rapid detection of resistance, would allow early adjustment of empirical antimicrobial treatment. Methods: Two hundred and ninety-eight urine samples processed between 1 June and 31 December 2020, selected with flow cytometry, with direct identification by MALDI-TOF mass spectrometry, and rapid detection of extended-spectrum beta-lactamase (ESBL) and carbapenemases-producing strains by lateral flow were analyzed. Results: The positive predictive value of the direct identification of the 86 samples that met the flow cytometry criterion (>5000 bacteria/µL) was 96.4%. Reliable direct identification was obtained in 14 of the 27 (51.8%) urinary source bacteraemias. There was 100% agreement between the lateral flow and antibiogram in the detection of ESBL and carbapenemases. Conclusion: the protocol for the direct identification and rapid detection of ESBL and carbapenemases-producing strains from urine samples is a reliable and useful tool.

Improved diagnosis of gastrointestinal infections using a semi-automated multiplex real-time PCR for detection of enteropathogens.

Introduction. The identification of enteropathogens is critical for the clinical management of patients with suspected gastrointestinal infection. The FLOW multiplex PCR system (FMPS) is a semi-automated platform (FLOW System, Roche) for multiplex real-time PCR analysis.Hypothesis/Gap Statement. FMPS has greater sensitivity for the detection of enteric pathogens than standard methods such as culture, biochemical identification, immunochromatography or microscopic examination.Aim.The diagnostic performance of the FMPS was evaluated and compared to that of traditional microbiological procedures.Methodology. A total of 10 659 samples were collected and analysed over a period of 7 years. From 2013 to 2018 (every July to September), samples were processed using standard microbiological culture methods. In 2019, the FMPS was implemented using real-time PCR to detect the following enteropathogens: Shigella spp., Salmonella spp., Campylobacter spp., Giardia intestinalis, Entamoeba histolytica, Blastocystis hominis, Cryptosporidum spp., Dientamoeba fragilis, adenovirus, norovirus and rotavirus. Standard microbiological culture methods (2013-2018) included stool culture, microscopy and immunochromatography.Results. A total of 1078 stool samples were analysed prospectively using the FMPS from July to September (2019): bacterial, parasitic and viral pathogens were identified in 15.3, 9.71 and 5.29 % of cases, respectively. During the same period of 6 years (2013-2018), the proportion of positive identifications using standard microbiological methods from 2013 to 2018 was significantly lower. A major significant recovery improvement was observed for all bacteria species tested: Shigella spp./enteroinvasive Escherichia coli (EIEC) (P <0.05), Salmonella spp. (P <0.05) and Campylobacter spp. (P <0.05). Marked differences were also observed for the parasites G. intestinalis, Cryptosporidium spp. and D. fragilis.Conclusion. These results support the value of multiplex real-time PCR analysis for the detection of enteric pathogens in laboratory diagnosis with outstanding performance in identifying labile micro-organisms. The identification of unsuspected micro-organisms for less specific clinical presentations may also impact on clinical practice and help optimize patient management.

Adult gonococcal conjunctivitis: Prevalence, clinical features and complications.

Introduction. Gonorrhoea is a sexually transmitted disease whose incidence has increased in recent years and adult gonococcal conjunctivitis (AGC) is a relatively uncommon complication.Hypothesis/Gap Statement. AGC is associated with increased incidence of genital gonorrhoea and must be treated correctly to avoid serious corneal complications.Aims. To report the prevalence, clinical features, and complications of AGC in a tertiary ophthalmology centre in Barcelona, Spain. Present epidemiological data, clinical features, ocular complications, and antibiotic susceptibility. Design: Single-centre, descriptive, retrospective case series.Methodology. Systematic case-defined search in medical records and further retrospective chart review study of microbiologically confirmed AGC attending outpatient clinic and/or emergency room from 2012 to 2020. We analysed the clinical presentation, treatments, antibiotic susceptibility, complications and ocular sequelae.Results. Thirteen patients were diagnosed of AGC. Eleven patients had unilateral presentation. Two patients had bilateral presentation. In ten cases there was abundant mucopurulent discharge, three cases presented periocular pain and periocular inflammation requiring a CT scan to rule out post-septal cellulitis. The diagnosis was confirmed by culture. In total, 100 % of strains were susceptible to ceftriaxone, 58 % were ciprofloxacin resistant and no beta-lactamase production was detected. Three patients required hospital admission. One patient developed a complication presenting with ptosis caused by superior symblepharon.Conclusion. AGC is a rare disease which is difficult to diagnose as it requires a high index of suspicion to prevent corneal perforation but in an important number of cases it may mimic orbital cellulitis. It is crucial that treatment starts as soon as possible to avoid serious corneal damage. Patients should promptly receive complete and correct treatment when admitted to the emergency room since an elevated number of patients do not attend their medical follow-up visit. Azithromycin or aminoglycoside eye drops are probably the best option to complete the treatment, due to high quinolone resistance.

Emergence of Resistance to Novel Cephalosporin-ß-Lactamase Inhibitor Combinations through the Modification of the Pseudomonas aeruginosa MexCD-OprJ Efflux Pump.

A ceftolozane-tazobactam- and ceftazime-avibactam-resistant Pseudomonas aeruginosa isolate was recovered after treatment (including azithromycin, meropenem, and ceftolozane-tazobactam) from a patient that had developed ventilator-associated pneumonia after COVID-19 infection. Whole-genome sequencing revealed that the strain, belonging to ST274, had acquired a nonsense mutation leading to truncated carbapenem porin OprD (W277X), a 7-bp deletion (nt213Δ7) in NfxB (negative regulator of the efflux pump MexCD-OprJ), and two missense mutations (Q178R and S133G) located within the first large periplasmic loop of MexD. Through the construction of mexD mutants and complementation assays with wild-type nfxB, it was evidenced that resistance to the novel cephalosporin-ß-lactamase inhibitor combinations was caused by the modification of MexD substrate specificity.

¿Es la fosfomicina una buena alternativa terapéutica para la gonorrea en nuestro medio? / Is fosfomycin a good alternative drug for gonorrhoea treatment in our setting?

No disponible

Decreased plasma phospholipid concentrations and increased acid sphingomyelinase activity are accurate biomarkers for community-acquired pneumonia.

BACKGROUND: There continues to be a great need for better biomarkers and host-directed treatment targets for community-acquired pneumonia (CAP). Alterations in phospholipid metabolism may constitute a source of small molecule biomarkers for acute infections including CAP. Evidence from animal models of pulmonary infections and sepsis suggests that inhibiting acid sphingomyelinase (which releases ceramides from sphingomyelins) may reduce end-organ damage. METHODS: We measured concentrations of 105 phospholipids, 40 acylcarnitines, and 4 ceramides, as well as acid sphingomyelinase activity, in plasma from patients with CAP (n = 29, sampled on admission and 4 subsequent time points), chronic obstructive pulmonary disease exacerbation with infection (COPD, n = 13) as a clinically important disease control, and 33 age- and sex-matched controls. RESULTS: Phospholipid concentrations were greatly decreased in CAP and normalized along clinical improvement. Greatest changes were seen in phosphatidylcholines, followed by lysophosphatidylcholines, sphingomyelins and ceramides (three of which were upregulated), and were least in acylcarnitines. Changes in COPD were less pronounced, but also differed qualitatively, e.g. by increases in selected sphingomyelins. We identified highly accurate biomarkers for CAP (AUC ≤ 0.97) and COPD (AUC ≤ 0.93) vs. Controls, and moderately accurate biomarkers for CAP vs. COPD (AUC ≤ 0.83), all of which were phospholipids. Phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins were also markedly decreased in S. aureus-infected human A549 and differentiated THP1 cells. Correlations with C-reactive protein and procalcitonin were predominantly negative but only of mild-to-moderate extent, suggesting that these markers reflect more than merely inflammation. Consistent with the increased ceramide concentrations, increased acid sphingomyelinase activity accurately distinguished CAP (fold change = 2.8, AUC = 0.94) and COPD (1.75, 0.88) from Controls and normalized with clinical resolution. CONCLUSIONS: The results underscore the high potential of plasma phospholipids as biomarkers for CAP, begin to reveal differences in lipid dysregulation between CAP and infection-associated COPD exacerbation, and suggest that the decreases in plasma concentrations are at least partially determined by changes in host target cells. Furthermore, they provide validation in clinical blood samples of acid sphingomyelinase as a potential treatment target to improve clinical outcome of CAP.

Evaluation of flow cytometry for the detection of bacteria in biological fluids.

OBJECTIVES: Conventional microbiological procedures for the isolation of bacteria from biological fluids consist of culture on solid media and enrichment broth. However, these methods can delay the microbiological identification for up to 4 days. The aim of this study was to evaluate the analytical performance of Sysmex UF500i (Sysmex, Kobe, Japan) as a screening method for the detection of bacteria in different biological fluids in comparison with direct Gram staining and the conventional culture on solid media and enrichment broth. METHODS: A total of 479 biological fluid samples were included in the study (180 ascitic, 131 amniotic, 56 synovial, 40 cerebrospinal, 36 pleural, 24 peritoneal, 9 bile and 3 pericardial fluids). All samples were processed by conventional culture methods and analyzed by flow cytometry. Direct Gram staining was performed in 339 samples. The amount of growth on culture was recorded for positive samples. RESULTS: Bacterial and white blood cell count by flow cytometry was significantly higher among culture positive samples and samples with a positive direct Gram stain compared to culture negative samples. Bacterial count directly correlated with the amount of growth on culture (Kruskall-Wallis H χ2(3) = 11.577, p = 0.009). The best specificity (95%) for bacterial count to predict culture positivity was achieved applying a cut-off value of 240 bacteria/µL. CONCLUSIONS: Bacterial and white blood cell counts obtained with flow cytometry correlate with culture results in biological fluids. Bacterial count can be used as a complementary method along with the direct Gram stain to promptly detect positive samples and perform other diagnostic techniques in order to accelerate the bacterial detection and identification.

Evaluation of the Magicplex™ Sepsis Real-Time Test for the Rapid Diagnosis of Bloodstream Infections in Adults.

Sepsis is a serious health condition worldwide, affecting more than 30 million people globally each year. Blood culture (BC) is generally used to diagnose sepsis because of the low quantity of microbes occurring in the blood during such infections. However, ~50% of bloodstream infections (BSI) give negative BC, this figure being higher for sepsis, which delays the start of appropriate antimicrobial therapy. This prospective study evaluated a multiplex real-time polymerase chain reaction, the MagicplexTM Sepsis test (MP), for the detection of pathogens from whole blood, comparing it to routine BC. We analyzed 809 blood samples from 636 adult patients, with 132/809 (16.3%) of the samples positive for one or more relevant microorganism according to BC and/or MP. The sensitivity and specificity of MP were 29 and 95%, respectively, while the level of agreement between BC and MP was 87%. The rate of contaminated samples was higher for BC (10%) than MP (4.8%) (P < 0.001). Patients with only MP-positive samples were more likely to be on antimicrobial treatment (47%) than those with only BC-positive samples (18%) (P = 0.002). In summary, the MP test could be useful in some clinical setting, such as among patients on antibiotic therapy. Nevertheless, a low sensitivity demonstrated impairs its use as a part of a routine diagnostic algorithm.

A multicentre study investigating parameters which influence direct bacterial identification from urine.

Rapid diagnosis is one of the best ways to improve patient management and prognosis as well as to combat the development of bacterial resistance. The aim of this study was to study parameters that impact the achievement of reliable identification using a combination of flow cytometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS).The study was carried out in nine hospitals in Spain and included 1,050 urine samples with bacterial counts of 5x106 bacteria/ml. MALDI-ToF-MS-based identification was performed according to a previously described protocol. Valid identification by direct MALDI-ToF-MS was obtained in 72.8% of samples, in 80.3% of samples found to be positive by culture, 32.2% of contaminated samples, and 19.7% of negative samples. Among the positives samples with a valid identification the concordance at the species level was 97.2%. The parameters related to success of direct identification were: high bacterial count, the presence of Escherichia coli as a pathogen and rod-bacteria morphology provided by flow cytometry. The parameters related to failure were a high epithelial cell (EC) count, a high white blood cell (WBC) count and urine samples obtained from in-patients. In summary, this multicentre study confirms previously published data on the usefulness and accuracy of direct MALDI-ToF-MS-based identification of bacteria from urine samples. It seems important to evaluate not only the bacterial count, but also other parameters, such as EC and WBC counts, bacterial species and morphology, and the health care setting, to decide whether the sample is suitable for direct identification.

Evaluation of a multiplex panel for the diagnosis of acute infectious diarrhea in immunocompromised hematologic patients.

INTRODUCTION: Diarrhea is a frequent complication in hematologic patients, being an infectious cause frequently suspected. Rapid and accurate detection of gastrointestinal pathogens is vital in immunocompromised hosts. The aim of this study was to compare routine diagnostic methods versus a multiplex polymerase chain reaction (PCR) assay for the diagnosis of infectious diarrhea in immunocompromised hematologic patients. MATERIAL AND METHODS: We conducted a prospective observational study from March 2015 to January 2016 to compare conventional methods for the diagnosis of infectious diarrhea with FIlmArray GI Panel (BioFire-bioMérieux, France). Samples from adult immunocompromised hematologic patients with acute diarrhea were collected. In cases with discordant results, a second multiplex assay was performed (Allplex, Seegene, Korea). The result was considered positive or negative when the same result was obtained by at least two of the methods. RESULTS: A total of 95 samples were obtained from 95 patients (median age of 52 years (46-64)). Sixty-one (64%) episodes were hospital-acquired and 34 (36%) were community-acquired diarrhea. Twenty-five (26%) patients had a positive microbiological result, being Clostridium difficile the most frequent pathogen, followed by Campylobacter spp and norovirus. The concordance between FilmArray methods was good (k = 0.79). The FilmArray GI panel showed a sensitivity of 95%, a specificity of 100% for positive results. The time required to obtain results was markedly reduced with the use of multiplex PCR methods. CONCLUSIONS: Multiplex molecular panels provide a rapid and sensitive tool for the diagnosis of infectious diarrhea, thereby allowing more timely clinical decisions in immunocompromised hematologic patients.

Time-to-positivity, type of culture media and oxidase test performed on positive blood culture vials to predict Pseudomonas aeruginosa in patients with Gram-negative bacilli bacteraemia / Tiempo de positividad, tipo de medio de cultivo y prueba de oxidasa realizada en viales de hemocultivo positivos para predecir Pseudomonas aeruginosa en pacientes con bacteriemia por bacilos gramnegativos

Introduction. The aim of this study was to determine the usefulness of oxidase test and time-to-positivity (TTP) in aerobic and anaerobic blood culture vials to detect the presence of Pseudomonas aeruginosa in patients with Gram-negative bacilli (GNB) bacteraemia. Material and methods. TTP was recorded for each aerobic and anaerobic blood culture vial of monomicrobial bacteraemia due to GNB. Oxidase test was performed in a pellet of the centrifuged content of the positive blood culture. An algorithm was developed in order to perform the oxidase test efficiently taking into account TTP and type of vial. Results. A total of 341 episodes of GNB bacteraemia were analysed. Sensitivity, specificity, positive predictive value and negative predictive value of the oxidase test performed on positive vials with GNB to predict P. aeruginosa were 95%, 99%, 91%, and 99%, respectively. When growth was first or exclusively detected in anaerobic vials, P. aeruginosa was never identified hence the performance of the oxidase test could be avoided. When growth was only or first detected in aerobic vials, a TTP≥8h predicted P. aeruginosa in 37% or cases (63 of 169), therefore oxidase test is highly recommended. Conclusions. Oxidase test performed onto positive blood culture vials previously selected by TTP and type of vials is an easy and inexpensive way to predict P. aeruginosa. In most cases, this can lead to optimization of treatment in less than 24 hours (AU)

Introducción. El objetivo del estudio fue determinar la utilidad de la prueba de oxidasa y del tiempo de positividad del hemocultivo (TPH) para detectar la presencia de Pseudomonas aeruginosa en pacientes con bacteriemia por bacilos gramnegativos (BGN). Material y métodos. Se registró el TPH de cada vial aerobio y anaerobio en todos los episodios de bacteriemia monomicrobiana por BGN. La prueba de oxidasa se realizó sobre el contenido centrifugado del hemocultivo positivo. Se diseñó un algoritmo para optimizar la realización de la prueba de oxidasa según el TPH y el tipo de vial. Resultados. Se analizaron 341 episodios de bacteriemia por BGN. La sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo de la prueba de oxidasa para predecir P. aeruginosa fueron del 95%, 99%, 91% y 99%, respectivamente. Cuando el crecimiento se detectó primero o exclusivamente en viales anaerobios, nunca se identificó P. aeruginosa pudiendo evitar la realización de la prueba de oxidasa. Cuando el crecimiento se detectó antes o exclusivamente en viales aerobios un TPH ≥8h predijo la presencia de P. aeruginosa en el 37% de los casos (63 de 169), por lo que es recomendable la realización de la prueba de oxidasa. Conclusiones. La prueba de oxidasa realizada a viales de hemocultivos positivos previamente seleccionados por el TPH y el tipo de medio es una forma fácil y económica de predecir P. aeruginosa. En la mayoría de los casos, esto puede contribuir a la optimización del tratamiento antibiótico en menos de 24h (AU)

Evaluation of a rapid immunochromatographic test for the detection of OXA-48 carbapenemase.

We evaluated the OXA-48K-Set, a rapid immunochromatographic test for the detection of Oxacillinase-48 (OXA-48) carbapenemases, among 37 strains expressing OXA-48 and OXA-48-like carbapenemases and 20 additional strains harboring other ß-lactamases. The test showed 100% sensitivity and specificity and the results were obtained in 15minutes.

Diarrea del viajero / Traveller's diarrhoea

La diarrea del viajero (DV) se adquiere principalmente a través de la ingestión de alimentos y bebidas contaminados con patógenos que causan diarrea, y que pueden ser bacterias, protozoos, helmintos y virus. A nivel mundial, las causas más comunes de DV son 2 patotipos de Escherichia coli (enterotoxigénico y enteroagregativo) y Campylobacter, aunque hay variaciones importantes según el área geográfica visitada. La mayor parte de las DV tienen lugar en viajeros a países de baja y mediana renta. El tipo de viaje, la duración de la estancia, la edad del viajero y la presencia de ciertas patologías de base son factores de riesgo importantes a considerar para la adquisición de una DV. Aunque la DV es generalmente una enfermedad leve y autolimitada, la mitad de los viajeros con DV experimentarán una cierta limitación de las actividades durante su viaje, mientras que hasta el 10% experimentarán diarrea persistente u otras complicaciones. El objetivo de este artículo es proporcionar un retrato microbiológico, epidemiológico y clínico actualizado de la DV, incluidos los factores de riesgo conocidos, y hacer recomendaciones sobre la prevención y el tratamiento de la DV

Traveller's diarrhoea (TD) is acquired primarily through ingestion of food and drinks contaminated with pathogens that cause diarrhoea. They can be bacteria, protozoa, helminths, and viruses. Globally, the most common causes of TD are two pathotypes of Escherichia coli(enterotoxigenic and enteroaggregative) and Campylobacter, although there are significant variations by geographic area visited. Most TD occurs in individuals traveling to low-middle income countries. The type of travel, length of stay, traveller's age, and the presence of certain underlying conditions are important risk factors to consider for the acquisition of TD. While TD is usually a mild and self-limiting disease, half of travellers with TD experience some limitation of activities during their trip, while up to 10% will experience persistent diarrhoea or other complications. The purpose of this article is to provide an updated microbiological, epidemiological, and clinical profile of traveller's diarrhoea, including known risk factors, as well as to make recommendations on the prevention and treatment of TD

Rapid Diagnosis of Staphylococcal Catheter-Related Bacteraemia in Direct Blood Samples by Real-Time PCR.

Catheter-related bacteremia (CRB) is an important cause of morbidity and mortality among hospitalized patients, being staphylococci the main etiologic agents. The objective of this study was to assess the use of a PCR-based assay for detection of staphylococci directly from blood obtained through the catheter to diagnose CRB caused by these microorganisms and to perform a cost-effectiveness analysis. A total of 92 patients with suspected CRB were included in the study. Samples were obtained through the catheter. Paired blood cultures were processed by standard culture methods and 4 ml blood samples were processed by GeneXpert-MRSA assay for the detection of methicillin-susceptible (MSSA) or methicillin-resistant (MRSA) Staphylococcus aureus, and methicillin-resistant coagulase-negative staphylococci (MR-CoNS). Sixteen CRB caused by staphylococci were diagnosed among 92 suspected patients. GeneXpert detected 14 out of 16 cases (87.5%), including 4 MSSA and 10 MR-CoNS in approximately 1 hour after specimen receipt. The sensitivity and specificity of GeneXpert were 87.5% (CI 95%: 60.4-97.8) and 92.1% (CI 95%: 83-96.7), respectively, compared with standard culture methods. The sensitivity of GeneXpert for S. aureus was 100%. Regarding a cost-effectiveness analysis, the incremental cost of using GeneXpert was of 31.1€ per patient while the incremental cost-effectiveness ratio of GeneXpert compared with blood culture alones was about 180€ per life year gained. In conclusion, GeneXpert can be used directly with blood samples obtained through infected catheters to detect S. aureus and MR-CoNS in approximately 1h after sampling. In addition, it is cost-effective especially in areas with high prevalence of staphylococcal CRB.

[Molecular diagnostic methods of respiratory infections. Has the scheme diagnosis changed?]. / Métodos moleculares de diagnóstico de infecciones respiratorias. ¿Ha cambiado el esquema diagnóstico?

Lower respiratory tract infections remain one of the most common causes of mortality worldwide, which is why early diagnosis is crucial. Traditionally the microbiological diagnosis of these infections has been based on conventional methods including culture on artificial media for isolation of bacteria and fungi and cell cultures for virus and antibody or antigen detection using antigen-antibody reactions. The main drawback of the above mentioned methods is the time needed for an etiological diagnosis of the infection. The techniques based on molecular biology have drawn much attention in recent decades as tools for rapid diagnosis of infections. Some techniques are very expensive, especially those that can detect various microorganisms in the same reaction, therefore the question that arises is whether the cost of such testing is justified by the information obtained and by the clinical impact that its implementation will determine. In this article we make a review of the various techniques of molecular biology applied to the diagnosis of pneumonia and focus primarily on analysing the impact they may have on the management of patients with acute respiratory tract infections.

[Future applications of mass spectrometry in microbiology]. / Perspectivas de futuro de la espectrometría de masas en microbiología.

MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry (MS) has been vigorously introduced in many clinical microbiology laboratories for the rapid and accurate identification of bacteria and fungi. In fact, the implementation of this methodology can be considered a revolution in these laboratories. In addition to microbial identification, MALDI-TOF MS is being used for the detection of some mechanisms of antibiotic resistance and for the molecular typing of bacteria. A number of current and future applications that increase the versatility of this methodology may also be mentioned. Among these are its direct application on clinical samples, the detection of toxins or specific microbial antigens, and its application in the fields of virology and parasitology.

Métodos moleculares de diagnóstico de infecciones respiratorias. ¿Ha cambiado el esquema diagnóstico? / Molecular diagnostic methods of respiratory infections. Has the scheme diagnosis changed?

Las infecciones respiratorias bajas siguen siendo una de las causas más frecuentes de mortalidad en todo el mundo, de ahí que el diagnóstico precoz sea fundamental. Tradicionalmente, el diagnóstico microbiológico de este tipo de infecciones se ha basado en métodos convencionales que incluyen cultivos en medios artificiales para aislamiento de bacterias y hongos y cultivos celulares para virus, así como en la detección antigénica o de anticuerpos mediante reacciones antígeno-anticuerpo. El principal inconveniente de las metodologías anteriormente citadas es el tiempo necesario para obtener un diagnóstico etiológico de la infección. Las técnicas basadas en la biología molecular han irrumpido con fuerza en las últimas décadas como herramientas de diagnóstico rápido de las infecciones. Algunas de estas técnicas -sobre todo aquellas que pueden detectar diversos microorganismos en la misma reacción- acostumbran a ser caras, por lo que la cuestión que se plantea es si el gasto de tales ensayos se ve justificado por la información obtenida y por el impacto clínico que su implementación determina. En este artículo se pretende hacer una revisión de las diversas técnicas de biología molecular aplicadas al diagnóstico de las infecciones respiratorias, centrándose fundamentalmente en la neumonía, y analizar el impacto que pueden tener en el manejo del paciente con infección respiratoria aguda

Lower respiratory tract infections remain one of the most common causes of mortality worldwide, which is why early diagnosis is crucial. Traditionally the microbiological diagnosis of these infections has been based on conventional methods including culture on artificial media for isolation of bacteria and fungi and cell cultures for virus and antibody or antigen detection using antigen-antibody reactions. The main drawback of the above mentioned methods is the time needed for an etiological diagnosis of the infection. The techniques based on molecular biology have drawn much attention in recent decades as tools for rapid diagnosis of infections. Some techniques are very expensive, especially those that can detect various microorganisms in the same reaction, therefore the question that arises is whether the cost of such testing is justified by the information obtained and by the clinical impact that its implementation will determine. In this article we make a review of the various techniques of molecular biology applied to the diagnosis of pneumonia and focus primarily on analysing the impact they may have on the management of patients with acute respiratory tract infections

Perspectivas de futuro de la espectrometría de masas en microbiología / Future applications of mass spectrometry in microbiology

La espectrometría de masas (EM) MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) se ha introducido con fuerza en muchos laboratorios de microbiología clínica para la identificación rápida y precisa de bacterias y hongos. De hecho, podemos considerar la implementación de esta metodología como una revolución en dichos laboratorios. Además de la identificación microbiana, la EM MALDI-TOF se está utilizando para la detección de algunos mecanismos de resistencia a los antibióticos y para la tipificación molecular de bacterias. Sin embargo, existe una serie de aplicaciones actuales y futuras que aumentan la versatilidad de esta metodología. Entre estas cabe destacar la aplicación directa a partir de muestras clínicas; la detección de toxinas o de antígenos microbianos específicos, y las aplicaciones en el campo de la virología y de la parasitología

MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry (MS) has been vigorously introduced in many clinical microbiology laboratories for the rapid and accurate identification of bacteria and fungi. In fact, the implementation of this methodology can be considered a revolution in these laboratories. In addition to microbial identification, MALDI-TOF MS is being used for the detection of some mechanisms of antibiotic resistance and for the molecular typing of bacteria. A number of current and future applications that increase the versatility of this methodology may also be mentioned. Among these are its direct application on clinical samples, the detection of toxins or specific microbial antigens, and its application in the fields of virology and parasitology