Septic arthritis complicating Streptobacillus moniliformis rat bite fever: a case report and review of its pathophysiology and diagnosis.

Rat bite fever is characterized by a clinical triad of symptoms, fever, rash and arthritis. It is transmitted by rodents and mainly due to infection by Streptobacillus moniliformis, a fastidious bacterium carried by Rattus norvegicus. This case report presents the case of a patient who developed septic arthritis and fever after a wild rat bite, with subsequent isolation of S. moniliformis from the joint fluid. Upon reviewing 45 other published case reports of S. moniliformis osteoarticular infections following contact with either a rat or its secretions, it was firstly observed that the rat bite fever clinical triad was incomplete in over half of the cases, mainly because rash was infrequently observed among adult patients. Secondly, the clinical presentation of rat bite fever is quite non-specific and rodent exposure is not mentioned by patients in a third of cases upon admission. Altogether, diagnosing rat bite fever is a significant clinical challenge suggesting that it might be significantly underdiagnosed. In addition to these clinical aspects, no evidence was found supporting immunological mechanisms, as suggested in some literature. Instead, when excluding five improperly performed cultures, S. moniliformis was cultured in 25 reported cases and identified twice by direct PCR sequencing amounting to a detection rate of 90% (n = 27/30) on joint fluids. Cultures should be performed in medium containing yeast extract, complete peptic digest of animal tissue and at least 5% blood. Knowing that S. moniliformis is very sensitive to many antibiotics thereby making the culture negative, direct 16S rRNA gene sequencing on joint fluid is an alternative method in the case of clinical and cytological evidence of osteoarticular infections with sterile culture of joint fluid.

Systematic review and meta-analysis of diagnostic test accuracy in chronic wound's microbiology.

PURPOSE: This study aims to assess the diagnostic accuracy of non-culture-based methodologies for detecting microorganisms in chronic wounds. METHODS: We systematically reviewed studies that evaluated the diagnostic accuracy of alternative tests in chronic wound samples, excluding studies focused on animal samples or unrelated conditions. The search encompassed PubMed, CINAHL, Scopus and Web of Science databases, employing the QUADAS-2 tool for risk of bias assessment. Our search included the PubMed, CINAHL, Scopus and Web of Science databases, and we assessed the risk of bias using the QUADAS-2 tool. A meta-analysis was conducted on polymerase chain reaction (PCR) and colorimetric methods to determine sensitivity, specificity, diagnostic odds ratio, and summary receiver-operating characteristic (sROC) curves using a random-effects model. For methods not suitable for quantitative synthesis, a narrative synthesis was performed. RESULTS: Nineteen studies involving various types of chronic wounds were analysed, revealing diverse diagnostic methods including fluorescence, PCR, colorimetry, voltammetry, electronic nose, biosensors, enzymatic methods, staining and microscopy. Combining fluorescence with clinical signs and symptoms (CSS) versus culture showed significant accuracy. Colorimetry demonstrated low sensitivity but high specificity, with a diagnostic odds ratio of 6.3. PCR generally exhibited good accuracy, although significant heterogeneity was noted, even in subgroup analyses. CONCLUSIONS: This study identified a broad spectrum of diagnostic approaches, highlighting the superior diagnostic accuracy achieved when microbiological analysis is combined with clinical assessments. However, the heterogeneity and methodological variations across studies present challenges in meta-analysis. Future research should aim for standardized and homogeneous study designs to enhance the assessment of diagnostic accuracy for alternative methods.

A review of the value of point-of-care testing for community-acquired pneumonia.

INTRODUCTION: Community-acquired pneumonia (CAP) is an infectious disease associated with high mortality worldwide. Although Streptococcus pneumoniae remains the most frequent pathogen in CAP, data from recent studies using molecular tests have shown that respiratory viruses play a key role in adults with pneumonia. The impact of difficult-to-treat pathogens on the outcomes of pneumonia is also important even though they represent only a small proportion of overall cases. Despite improvements in the microbiological diagnosis of CAP in recent decades, the identification of the causative pathogen is often delayed because of difficulties in obtaining good-quality sputum samples, issues in transporting samples, and slow laboratory processes. Therefore, the initial treatment of CAP is usually empirical. Point-of-care testing (POCT) was introduced to avoid treatment delays and reduce reliance on empirical antibiotics. AREAS COVERED: This review summarizes the main scientific evidence on the role of POCT in the diagnosis and management of patients with CAP. The authors searched for articles on POCT in pneumonia on PubMed from inception to 20 January 2024. The references in the identified articles were also searched. EXPERT OPINION: POCT involves rapid diagnostic assays that can be performed at the bedside especially in cases of severe CAP and immunocompromised patients. These tests can produce results that could help guide initial therapy and management.

The presence of Trichomonas vaginalis in urogenital samples can affect the sensitivity of Mycoplasma hominis identification techniques, leading to an underestimation of bacterial infections.

Trichomonas vaginalis and Mycoplasma hominis, two microorganisms causing infections of the urogenital tract, are closely associated in that they establish an endosymbiosis relationship, the only case among human pathogens. As a result, the presence of one microorganism may be considered a sign that the other is present as well. Identification of the two pathogens in clinical samples is based on cultivation techniques on specific media, even though in recent years, new sensitive and rapid molecular techniques have become. Here, we demonstrate that the concomitant presence of T.vaginalis in urogenital swabs may lead to a delay in the identification of M.hominis, and thus to an underestimation of bacterial infections when cultural techniques are used.

A meta-analysis on the role of sonication in the diagnosis of cardiac implantable electronic device-related infections.

Introduction: One of the biggest obstacles in diagnosing Implant-Associated Infections is the lack of infection criteria and standardized diagnostic methods. These infections present a wide range of symptoms, and their diagnosis can be hampered by the formation of microbial biofilms on the surface of implants. This study aimed to provide insight into the performance of sonication in the diagnosis of infections associated with Cardiac Implantable Electronic Devices, to help define a consensus on the algorithm for the microbial diagnosis of these infections. Methods: We carried out a systematic review with meta-analysis. The PRISMA methodology guidelines were followed, and an advanced search was carried out in PubMed and Web of Science, which enabled 8 articles to be included in the review, in which a meta-analysis was also carried out. QUADAS-2 was used to assess the risk of bias and effect measures were calculated to assess publication bias. Results: The overall sensitivity of the method was 0.823 (95% CI: 0.682-0.910) and the specificity was 0.632 (95% CI: 0.506-0.743). Discussion: These results suggest that sonication may offer advantages in diagnosing these infections. However, it is essential to approach these findings carefully and take into account the recommendations provided in the EHRA 2019 guidelines. This study highlights the importance of more effective diagnostic approaches for implantable medical device-associated infections to improve the quality of treatment and minimize the risks associated with these challenging medical conditions.

Expert consensuses on the application of nanopore sequencing technology in the detection of pathogenic micro-organisms / 中国药房

OBJECTIVE To improve the diagnosis and treatment level of critically ill infectious diseases， standardize the clinical application of nanopore sequencing and promote the sound development of the technology. METHODS Division of Therapeutic Drug Monitoring of Chinese Pharmacological Society and Expert Committee of Precision Medicine for Clinical Treatment of Guangdong Pharmaceutical Association initiated and organized multidisciplinary experts to discuss and determine the consensus writing outline by using the nominal group method， forming a preliminary consensus draft； expert consultation was performed by using Delphi method， and then experts’ opinions were analyzed and revised to form consensus. RESULTS & CONCLUSIONS Consensuses of Experts on the Application of Nanopore Sequencing Technology in the Detection of Pathogenic Microorganisms covers targeted sequencing， metagenomic sequencing and whole genome sequencing， and is standardized in terms of sample collection and storage， detection process， bioinformatics analysis and report interpretation； the recommendations are provided for the key issues.

Tuberculosis in Spain: An opinion paper / Tuberculosis en España: Un documento de opinión

This document is the result of the deliberations of the Committee on Emerging Pathogens and COVID-19 of the Il lustrious Official College of Physicians of Madrid (ICOMEM) regarding the current situation of tuberculosis, particularly in Spain. We have reviewed aspects such as the evolution of its incidence, the populations currently most exposed and the health care circuits for the care of these patients in Spain. We have also discussed latent tuberculosis, the reality of extrapul monary disease in the XXI century and the means available in daily practice for the diagnosis of both latent and active forms. The contribution of molecular biology, which has changed the perspective of this disease, was another topic of discussion. The paper tries to put into perspective both the classical drugs and their resistance figures and the availability and indications of the new ones. In addition, the reality of direct observa tion in the administration of antituberculosis drugs has been discussed. All this revolution is making it possible to shorten the treatment time for tuberculosis, a subject that has also been reviewed. If everything is done well, the risk of relapse of tuberculosis is small but it exists. On the other hand, many special situations have been discussed in this paper, such as tuberculosis in pediatric age and tuberculosis as a cause for concern in surgery and intensive care. The status of the BCG vaccine and its present indications as well as the future of new vaccines to achieve the old dream of eradicating this disease have been discussed. Finally, the ethical and medicolegal impli cations of this disease are not a minor issue and our situation in this regard has been reviewed (AU)

El presente documento es el resultado de las deliberacio nes del Comité sobre Patógenos Emergentes y COVID-19 del Ilustre Colegio Oficial de Médicos de Madrid (ICOMEM) en re lación a la situación actual de la tuberculosis, particularmente en España. Hemos revisado aspectos tales como la evolución de su incidencia, las poblaciones actualmente más expuestas y los circuitos sanitarios para la atención a estos pacientes en España. Se ha discutido también la tuberculosis latente, la rea lidad de la enfermedad extrapulmonar en el siglo XXI y los me dios de que en la práctica diaria se dispone para el diagnóstico tanto de las formas latentes como de las activas. La aportación de la biología molecular que ha cambiado la perspectiva de es ta enfermedad ha constituido otro de los temas de debate. El documento trata de poner en perspectiva tanto los fármacos clásicos y sus cifras de resistencia como la disponibilidad e in dicaciones de los nuevos. Junto a esto, se ha discutido la rea lidad de la observación directa en la administración de fárma cos antituberculosos. Toda esta revolución está posibilitando el acortamiento del tiempo de tratamiento de la tuberculosis tema que ha sido igualmente revisado. Si todo se hace bien, el riesgo de recaída de la tuberculosis es pequeño pero existen te. Por otra parte, muchas situaciones especiales han merecido discusión en este documento como por ejemplo la tuberculosis en edad pediátrica y la tuberculosis como causa de preocupa ción en cirugía y cuidados intensivos. Se ha discutido tanto la situación de la vacuna BCG y sus indicaciones presentes, co mo el futuro de nuevas vacunas que permitan alcanzar el viejo sueño de erradicar esta enfermedad. Finalmente, las implica ciones éticas y medicolegales que esta enfermedad plantea no son un tema menor y se ha revisado nuestra situación en este particular (AU)

[Diagnosis and antibiotic therapy of nosocomial pneumonia in adults: from recommendations to real practice. A review].

Nosocomial pneumonia is a healthcare-associated infection with significant consequences for the patient and the healthcare system. The efficacy of treatment significantly depends on the timeliness and adequacy of the antibiotic therapy regimen. The growth of resistance of gram-negative pathogens of nosocomial pneumonia to antimicrobial agents increases the risk of prescribing inadequate empirical therapy, which worsens the results of patient treatment. Identification of risk factors for infection with multidrug-resistant microorganisms, careful local microbiological monitoring with detection of resistance mechanisms, implementation of antimicrobial therapy control strategy and use of rational combinations of antibacterial drugs are of great importance. In addition, the importance of using new drugs with activity against carbapenem-resistant strains, including ceftazidime/aviabactam, must be understood. This review outlines the current data on the etiology, features of diagnosis and antibacterial therapy of nosocomial pneumonia.

Tuberculosis in Spain: An opinion paper.

This document is the result of the deliberations of the Committee on Emerging Pathogens and COVID-19 of the Illustrious Official College of Physicians of Madrid (ICOMEM) regarding the current situation of tuberculosis, particularly in Spain. We have reviewed aspects such as the evolution of its incidence, the populations currently most exposed and the health care circuits for the care of these patients in Spain. We have also discussed latent tuberculosis, the reality of extrapulmonary disease in the XXI century and the means available in daily practice for the diagnosis of both latent and active forms. The contribution of molecular biology, which has changed the perspective of this disease, was another topic of discussion. The paper tries to put into perspective both the classical drugs and their resistance figures and the availability and indications of the new ones. In addition, the reality of direct observation in the administration of antituberculosis drugs has been discussed. All this revolution is making it possible to shorten the treatment time for tuberculosis, a subject that has also been reviewed. If everything is done well, the risk of relapse of tuberculosis is small but it exists. On the other hand, many special situations have been discussed in this paper, such as tuberculosis in pediatric age and tuberculosis as a cause for concern in surgery and intensive care. The status of the BCG vaccine and its present indications as well as the future of new vaccines to achieve the old dream of eradicating this disease have been discussed. Finally, the ethical and medicolegal implications of this disease are not a minor issue and our situation in this regard has been reviewed.

Metagenomics for the microbiological diagnosis of hospital-acquired pneumonia and ventilator-associated pneumonia (HAP/VAP) in intensive care unit (ICU): a proof-of-concept study.

BACKGROUND: Hospital-acquired and ventilator-associated-pneumonia (HAP/VAP) are one of the most prevalent health-care associated infections in the intensive care unit (ICU). Culture-independent methods were therefore developed to provide faster route to diagnosis and treatment. Among these, metagenomic next-generation sequencing (mNGS) has shown considerable promise. METHODS: This proof-of-concept study describes the technical feasibility and evaluates the clinical validity of the mNGS for the detection and characterization of the etiologic agents causing hospital-acquired and ventilator-associated pneumonia. We performed a prospective study of all patients with HAP/VAP hospitalized in our intensive care unit for whom a bronchoalveolar lavage (BAL) was performed between July 2017 and November 2018. We compared BAL fluid culture and mNGS results of these patients. RESULTS: A total of 32 BAL fluids were fully analyzed. Of these, 22 (69%) were positive by culture and all pathogens identified were also reported by mNGS. Among the culture-positive BAL samples, additional bacterial species were revealed by mNGS for 12 patients, raising the issue of their pathogenic role (colonization versus coinfection). Among BALF with culture-negative test, 5 were positive in mNGS test. CONCLUSIONS: This study revealed concordant results for pneumonia panel pathogens between mNGS and culture-positive tests and identified additional pathogens potentially implicated in pneumonia without etiologic diagnosis by culture. mNGS has emerged as a promising methodology for infectious disease diagnoses to support conventional methods. Prospective studies with real-time mNGS are warranted to examine the impact on antimicrobial decision-making and clinical outcome.

Abiotrophia defectiva endocarditis - Diagnostic and therapeutic challenge: Case report.

Belonging to the normal oral, gastrointestinal, and urogenital flora, Abiotrophia defectiva is responsible for 1-2 % of all infective endocarditis (IE) cases. The manifestation of A.defectiva endocarditis may by atypical, without fever. Difficult to isolate pathogen requires special culture media. A 45-year-old female was admitted due to anemia and progressive weight loss (8 kg in 6 months). She had a history of benign mitral valve (MV) prolapse and non-stenotic bicuspid aortic valve (BAV). In echocardiography, large vegetations on MV and small vegetation on BAV were found. An enriched medium for fastidious pathogens was used. A. defectiva was identified using biochemical analysis with VITEK-2 Compact. In the fourth week of antibiotic therapy, she required urgent MV replacement due to MV regurgitation progression while vegetation on BAV disappeared. Although patient's frailty and underweight caused prolonged postoperative wound healing, she was transferred to rehabilitation in good conditions. No relapse of IE was observed during five-month follow-up.

Next-generation sequencing: what are the needs in routine clinical microbiology? A survey among clinicians involved in infectious diseases practice.

Background: The translation of Next-Generation Sequencing (NGS) from research to clinical microbiology is increasing rapidly, but its integration into routine clinical care struggles to catch-up. A challenge for clinical laboratories is that the substantial investments made in the required technologies and resources must meet both current and forthcoming needs. Methods: To get a clinical perspective of these needs, we have sent a survey to infectious diseases clinicians of five hospitals, covering the following topics: NGS knowledge, expected syndromes and patients foreseen to benefit from NGS, and expected impact on antimicrobial prescription. Results: According to clinicians, benefits of NGS are mostly expected in neurological and respiratory infections diagnostics. Conclusion: A better dialog between microbiologists and clinicians about hopes and limits of NGS in microbiology may help identifying key investments needed for clinical laboratories, today and tomorrow.

The importance of morphological changes in neutrophils in the diagnosis of bacterial infections in dogs with confirmed urinary tract infections in a Veterinary Care Service, Rio de Janeiro, Brazil.

Neutrophils (PMNs) are cellular markers used for diagnosing inflammation and/or infections. In this study, the objective was to highlight the importance of recording the toxic morphological alterations of the PMNs as markers of infection in 10 cases, positive bacterial isolation by culture due to dysuria, hematuria and/or fetid urine, as manifestations of urinary tract disease. Smear observations were performed by immersion for counting and morphological evaluations of 3,000 leukocytes in smears and in leukocyte concentrate. One (10.0%) of the dogs had leukocytosis, and two (20.0%) dogs had leukopenia. All animals showed toxic PMNs with positive bacterial culture. None of the cases in the study showed any quantitative alterations in PMNs such as: neutropenia or neutrophilia, where 100% had nuclear displacement of the regenerative type of PMNs to the left. 100% cases had toxic morphological changes: 90.0% had PMNs with toxic granulations, 80.0% had giant rod neutrophils, 70.0% had target PMNs, in 50.0% of those with vacuolation in the cytoplasm, in 40.0% of the animals, the presence of giant PMNs, 10.0% with Döhle bodies, and another animal 10.0% with karyorrhexis. All case studies had at least one association of two types of toxic changes. Toxic morphological alterations observed in PMNs through cystoscopy proved to be more reliable and sensitive in evidencing the diagnosis of infections than the quantitative alterations of absolute values of total leukocytes; therefore, they were essential in the laboratory diagnosis by blood count in the course of infections in dogs.

Os neutrófilos (PMNs) são marcadores celulares para o diagnóstico de inflamação e/ou infecções. Neste estudo, o objetivo foi apresentar a importância das alterações morfológicas tóxicas dos PMNs envolvidos como marcadores de infecção, em 10 casos com isolamento bacteriano positivo por cultura devido à disúria, hematúria e/ou urina fétida, como manifestações clínicas de doença do trato urinário. As observações de esfregaço foram realizadas para contagens e avaliações morfológicas de 3.000 leucócitos, em esfregaços e em concentrado de leucócitos. Um (10,0%) dos cães teve leucocitose e dois (20,0%) cães apresentaram leucopenia. Todos os animais tiveram alterações tóxicas em PMNs (100% dos casos) e com cultura bacteriana positiva. Nenhum dos casos do estudo apresentou qualquer alteração quantitativa nos PMNs como: neutropenia ou neutrofilia onde 10 (100%) tiveram deslocamento nuclear do tipo regenerativo de PMNs para a esquerda. 10 (100%) casos apresentaram alterações morfológicas tóxicas: nove (90,0%) tinham PMNs com granulações tóxicas, oito (80,0%) tinham neutrófilos de bastonetes gigantes, sete (70,0%) tinham PMNs-alvo, em cinco (50,0%) daqueles com vacuolização no citoplasma, em quatro (40,0%) dos animais a presença de PMNs gigantes, um (10,0%) com corpos de Döhle e outro animal (10,0%) com cariorrexia. Todos os casos observados tiveram pelo menos uma associação de dois tipos de alterações tóxicas. As alterações morfológicas tóxicas, observadas nos PMNs através da cistoscopia, foram mais confiáveis, e sensíveis em evidenciar o diagnóstico de infecções, do que as alterações dos valores absolutos de leucócitos totais e mesmo de PMNs em exames de rotina no curso de infecções em cães.

Characterizing Actinotignum schaalii infections in a large Canadian healthcare region.

Aims: We characterize the epidemiology of Actinotignum schaalii within a large Canadian region after implementation of improved identification methods. Patients & methods: Positive cultures for A. schaalii from a centralized microbiology laboratory in Canada were analyzed. Clinical data were retrieved through administrative databases and chart reviews. Primary outcome was incidence of A. schaalii infections; secondary outcomes included mortality, hospital admission and length of stay. Results & conclusions: 86 unique isolates were studied, 37 bloodstream infections (BSI) and 49 non-BSIs. Patients with BSIs were older with more comorbidities, with urinary tract infections implicated as the most frequent source; skin abscesses caused the most non-BSIs. Hospitalization and 90-day mortality was higher in the BSI group. A. schaalii is an important community-acquired pathogen with the potential to cause invasive infections.

Actinotignum schaalii bacteria require special conditions and substances for their growth. Normally, A. schaalii reside in the urogenital tract without causing harm; however, they can be associated with urinary tract infections. Severe infections are increasingly identified with improved identification methods. This retrospective study included all positive cultures for A. schaalii from a centralized microbiology laboratory in Canada from 2012 to 2019. Eighty-six unique isolates were studied, including 37 bloodstream infections (BSIs) and 49 non-BSIs. The mean incidence rate of infections increased during the study. BSIs were seen in older men with other medical comorbidities and were associated with high hospitalization and mortality. Skin and soft-tissue infections comprised the majority of non-BSIs, occurring in younger patients and who had better clinical outcomes. Our population-based study of A. schaalii infections highlights the potential of this pathogen to cause severe infections.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in the diagnosis of microorganisms.

Microbiology culture is the gold standard method for identifying microorganisms. This identification protocol takes several days to complete. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a technique that can identify different microorganisms quickly and accurately. The objective of this work was to evaluate the use of MALDI-TOF MS in the routine of clinical laboratories to identify microorganisms and to identify their resistance to antimicrobials. This study evaluated the relevance of the MALDI-TOF MS technique for microbiological diagnosis through a literature review. The authors found that MALDI-TOF MS can identify bacteria, fungi, viruses and parasites, even in blood cultures, and also serves to assess antimicrobial resistance. Thus, MALDI-TOF MS can become an indispensable tool in laboratory diagnosis.

Procesamiento de muestras osteoarticulares para diagnóstico microbiológico: resultados de una encuesta multicéntrica nacional / Processing of osteoarticular samples for microbiological diagnosis: Results of a national multi-center survey

Introducción: Nuestro objetivo fue evaluar la variabilidad en el procesamiento de muestras osteoarticulares para el diagnóstico microbiológico entre distintos centros nacionales. Métodos: Se diseñó una encuesta online con 13 preguntas y se difundió a través de la SEIMC a los servicios de microbiología de los distintos centros. Resultados: Obtuvimos 72 respuestas. En más de la mitad de los centros, de tercer nivel, se reciben al menos 5 muestras. Aproximadamente la mitad de los centros agitan con vórtex las muestras de hueso/implante, utilizándose la sonicación sobre todo en centros de tercer nivel. Se realizan cultivos para bacterias aerobias y anaerobias durante 6-10 días de incubación, pero con diferencias en los medios de cultivo líquidos. El diagnóstico molecular se realiza en menos del 50% de los centros, siendo la PCR universal (ARNr 16S) la técnica más empleada. Conclusiones: Existe heterogeneidad fundamentalmente en el empleo de sonicación, los medios líquidos de cultivo o el diagnóstico molecular, probablemente en relación directa con los recursos y capacidades de cada centro.(AU)

Introduction. Our aim was to evaluate the variability in the processing of osteoarticular samples for microbiological diagnosis between different national centers. Methods: An online survey with 13 questions was designed and it was sent through SEIMC to the Microbiology Departments of the different centers. Results: We obtained 72 answers. In more than half of the tertiary-care centers, at least 5 samples are received. Approximately half of the centers vortex bones/implant samples. Sonication is used mostly in tertiary-care centers. Cultures for aerobic and anaerobic bacteria are performed during 6-10 days of incubation but with differences in liquid culture media. Molecular diagnosis is performed in less than 50% of the centers. Universal PCR (16S rRNA) is the most widely used technique. Conclusion: We found heterogeneity especially in the use of sonication, liquid culture media or molecular diagnosis, probably in direct relation to the resources and capacities of each center.(AU)

Utilidad del panel de PCR multiplex en el diagnóstico microbiológico temprano y adecuación antimicrobiana en pacientes críticos con neumonía / Usefulness of the multiplex PCR panel in the early microbiological diagnosis and antimicrobial suitability in critical patients with pneumonia / Utilidade do painel de PCR multiplex no diagnóstico microbiológico precoce e adequação antimicrobiana em pacientes críticos com pneumonia

Resumen: Introducción: el inicio temprano de la antibioticoterapia adecuada en infecciones graves se asocia con reducción de la mortalidad. La identificación precoz del microorganismo es fundamental para realizar un tratamiento dirigido y disminuir la terapéutica inicial inapropiada. Objetivo: valorar la utilidad de una técnica de biología molecular por amplificación de ácidos nucleicos mediante reacción en cadena de polimerasa en tiempo real para diagnóstico microbiológico temprano y adecuación de la antibioticoterapia en pacientes con neumonías graves. Metodología: estudio retrospectivo observacional llevado a cabo en la unidad de cuidados intensivos del Hospital Maciel. Se analizaron muestras respiratorias de pacientes con diagnóstico o sospecha de neumonía. Se compararon los resultados microbiológicos obtenidos por técnicas convencionales y por biología molecular multiplex (panel neumonía). Resultados: se incluyeron 53 muestras obtenidas de 51 pacientes. El multiplex detectó al menos un microorganismo en 38 (71,7%) muestras frente a 30 (56.6%) desarrollos en cultivos tradicionales. La mayoría de las muestras se obtuvieron bajo antibioticoterapia previa (86.8%). El panel neumonía mostró un porcentaje de concordancia positiva combinado de 100% y un porcentaje de concordancia negativa del 94% para la identificación bacteriana en comparación con los métodos microbiológicos tradicionales. En 27 (51%) casos el resultado del panel de neumonía determinó un cambio en la conducta terapéutica. Conclusiones: la técnica de PCR permite la identificación temprana de microorganismos causantes de neumonía optimizando la terapéutica empírica inicial y racionalizando el uso de antimicrobianos. Un panel negativo aleja el planteo de infección respiratoria a gérmenes habituales y permite considerar diagnósticos diferenciales en cuanto a foco y/o etiología.

Summary: Introduction: the early initiation of the adequate antibiotic therapy in severe infections is associated to a reduction in mortality. Early identification of the microorganism is essential to define directed therapy and decrease the initial inadequate treatment. Objective: to assess usefulness of a molecular biology technique by nucleic acid amplification through a polymerase chain reaction in real time for an early microbiological diagnosis and correction of the antibiotic therapy in patients with severe pneumonias. Method: retrospective, observational study conducted in the intensive care unit of Maciel Hospital. The respiratory samples of patients with a diagnosis of pneumonia or suspicious to have pneumonia were analyzed. The microbiological results obtained were compared using conventional techniques and multiplex molecular biology (pneumonia panel). Results: 53 samples obtained from 51 patients were included in the study. Multiplex detected at least one microorganism in 38 (71.7%) samples compared to 30 (56.6%) in traditional cultures. Most samples were obtained under the previous antibiotic therapy (86.8%). The pneumonia panel showed a combined positive agreement percentage of 100% and a negative agreement of 94% for the identification of bacteria when compared to the traditional microbiological methods. In 27 cases (51%) the pneumonia panel results determined changing the therapeutic behavior. Conclusions: the PCR technique allows for the early identification of microorganisms causing pneumonia, thus optimizing initial empirical therapy and rationalizing the use of antibiotics. A negative panel reduces the suspicion of a respiratory infection caused by the usual germs and enables considering differential diagnosis in terms of etiology or cause.

Resumo: Introdução: o início precoce da antibioticoterapia adequada em infecções graves está associado à redução da mortalidade. A identificação precoce do microrganismo é essencial para realizar o tratamento dirigido e reduzir o uso inicial inadequado de antimicrobianos. Objetivo: avaliar a utilidade de uma técnica de biologia molecular para amplificação de ácidos nucleicos por reação em cadeia da polimerase em tempo real para diagnóstico microbiológico precoce e adequação da antibioticoterapia em pacientes com pneumonia grave. Metodologia: estudo observacional retrospectivo realizado na unidade de terapia intensiva do Hospital Maciel. Amostras respiratórias de pacientes com diagnóstico ou suspeita de pneumonia foram analisadas. Os resultados microbiológicos obtidos por técnicas convencionais e por biologia molecular multiplex (painel de pneumonia) foram comparados. Resultados: foram incluídas 53 amostras obtidas de 51 pacientes. O multiplex detectou pelo menos um microrganismo em 38 (71,7%) amostras em comparação com 30 (56,6%) usando culturas tradicionais. A maioria das amostras foi obtida com antibioticoterapia prévia (86,8%). O painel de pneumonia mostrou uma concordância percentual positiva combinada de 100% e uma concordância percentual negativa de 94% para identificação bacteriana em comparação com métodos microbiológicos tradicionais. Em 27 (51%) casos, o resultado do painel de pneumonia determinou mudança no comportamento terapêutico. Conclusões: a técnica de PCR permite a identificação precoce de microrganismos causadores de pneumonia, otimizando a terapia empírica inicial e racionalizando o uso de antimicrobianos. Um painel negativo afasta a suspeita de infecção respiratória pelos germes usuais e permite considerar diagnósticos diferenciais em termos de foco e/ou etiologia.

Processing of osteoarticular samples for microbiological diagnosis: Results of a national multi-center survey.

INTRODUCTION: Our aim was to evaluate the variability in the processing of osteoarticular samples for microbiological diagnosis between different national centers. METHODS: An online survey with 13 questions was designed and it was sent through SEIMC to the Microbiology Departments of the different centers. RESULTS: We obtained 72 answers. In more than half of the tertiary-care centers, at least 5 samples are received. Approximately half of the centers vortex bones/implant samples. Sonication is used mostly in tertiary-care centers. Cultures for aerobic and anaerobic bacteria are performed during 6-10 days of incubation but with differences in liquid culture media. Molecular diagnosis is performed in less than 50% of the centers. Universal PCR (16S rRNA) is the most widely used technique. CONCLUSION: We found heterogeneity especially in the use of sonication, liquid culture media or molecular diagnosis, probably in direct relation to the resources and capacities of each center.

Periprosthetic joint infection: Comparison of automated multiplex-PCR Unyvero i60 ITI cartridge system with bacterial culture and real-time PCR.

BACKGROUND: In the past, various efforts have been made to investigate diagnostic tools for periprosthetic-joint-infection (PJI). It is little-known about the diagnostic utility of polymerase-chain-reaction (PCR) in this context, especially concerning the role of multiplex-PCR assays comparing with conventional tissue culture. OBJECTIVE: Evaluation of an automated-multiplex-PCR cartridge system for patients with suspicion of PJI in comparison with conventional microbiological culture and 16S-rDNA-PCR. METHODS: On suspicion of PJI synovial fluid specimen were taken preoperatively or periprosthetic tissue was collected intraoperatively. Microbiological analysis included conventional culture, 16S-rDNA-PCR and automated-multiplex-PCR (Unyvero-i60-ITI®). The European-Bone-and-Joint-Infection-Society (EBJIS) criteria were used for PJI diagnosis. Positive and negative percent agreement was calculated. Total percentage agreement and Cohen's kappa coefficient were calculated. Sensitivity, specificity and positive predictive value of conventional culture, 16S-rDNA-PCR and multiplex-PCR were calculated. Ten specimens of proved PJI were used as control group. RESULTS: Fifty specimen were suitable for culture. 14 (28%) were classified as PJI, 36 (72%) were aseptic. Coagulase-negative staphylococci was the most frequent detected pathogen. Concordance-rate between mPCR and culture results was 75.6% with a Cohen's kappa of 0.28. Concordance-rate between mPCR and 16S-rDNA was 82.9%, Cohen's kappa was 0.13. Concordance analysis between culture results and 16S-rDNA lead to a concordance-rate of 88.9%. Cohen's kappa was calculated with 0.6. With regard to the microbiological culture as reference, sensitivity of the mPCR was 0.33 and specificity was 0.91. Sensitivity and specificity of the 16S-rDNA-PCR was 0.55 and 0.97. The positive predictive value was 0.57 for the mPCR and 0.83 for the 16S-rDNA-PCR. CONCLUSIONS: Due to fair agreement between mPCR and conventional microbiological culture, the tested multiplex-PCR could be an additional instrument for the detection of PJI but is not superior over the conventional culture.