Infección bacteriana/fúngica en pacientes con COVID-19 ingresados en un hospital de tercer nivel de Castilla y León, España / Bacterial/fungal infection in hospitalized patients with COVID-19 in a tertiary hospital in the Community of Castilla y León, Spain

IntroducciónLa coinfección/sobreinfección bacteriana/fúngica contribuye al incremento de la morbimortalidad de las infecciones respiratorias (IRs) virales. El objetivo de este trabajo es conocer la incidencia de estas infecciones en los pacientes hospitalizados por COVID-19.MétodoEstudio retrospectivo observacional de todos los pacientes ingresados por COVID-19 e infección bacteriana/fúngica en el Hospital Clínico de Valladolid (1 marzo-31 mayo, 2020). Comparación de datos demográficos, clínicos y microbiológicos en función del ingreso en UCI e identificación de los factores predictores de mortalidad mediante regresión logística multivariante.ResultadosDe 712 pacientes con COVID-19, 113 (16%) presentaron coinfección/ sobreinfección bacteriana/fúngica. Mediana de edad 73 años (RIQ 57-89), 59% de ellos hombres. Perfil del paciente de UCI (44%): hombre con neumonía por SARS-CoV-2, leucocitosis, interleucina-6 elevada, con interferón β-1b y tocilizumab y sobreinfección (p < 0,05). El 5% (39/712) de los pacientes presentaron una coinfección. Streptococcus pneumoniae (6) y Staphylococcus aureus (6) fueron los principales patógenos de las coinfecciones respiratorias (18). El 11% (80/712) se sobreinfectaron. Las infecciones más frecuentes fueron las urinarias (53) e IRs (39). Acinetobacter baumannii multirresistente fue el principal agente de la IR y la bacteriemia. Un brote por A. baumannii contribuyó a este resultado. Tres pacientes se diagnosticaron como probable aspergilosis pulmonar. La mortalidad fue superior en los pacientes de UCI (50 vs. 29%; p = 0,028). Factores predictores de mortalidad: hombre con varias comorbilidades, neumonía por SARS-CoV-2, bacteriemia y sobreinfectado por A. baumannii.ConclusiónEl brote por A. baumannii fue determinante en la incidencia de la infección y en la morbimortalidad de los pacientes de UCI.

IntroductionBacterial/fungal coinfection and superinfections contribute to the increased morbi-mortality of viral respiratory infections (RIs). The main objective of this study was to determine the incidence of these infections in hospitalized patients with COVID-19.MethodRetrospective observational study of all patients admitted for COVID-19 and bacterial/fungal infections at the Hospital Clínico Universitario of Valladolid, Spain (March 1-May 31, 2020). Demographic, clinical and microbiological data were compared based on Intensive Care Unit (ICU) admission and predictors of mortality by were identified using multivariate logistic regression analyses.ResultsOf the 712 COVID-19 patients, 113 (16%) presented bacterial/fungal coinfections or superinfections. Their median age was 73 years (IQR 57-89) and 59% were men. The profiles of ICU patients (44%) included male, SARS-CoV-2 pneumonia, leukocytosis, elevated inteleukin-6, with interferon β-1b and tocilizumab and superinfection (p < 0.05). Coinfections were diagnosed in 5% (39/712) patients. Most common pathogens of respiratory coinfection (18) were Streptococcus pneumoniae (6) and Staphylococcus aureus (6). Superinfections were detected in 11% (80/712) patients. Urinary (53) and RIs (39) constituted the majority of superinfections Acinetobacter baumannii multidrug-resistant was the main agent of IR and bacteremia. An outbreak of A. baumannii contributed to this result. Three patients were considered to have probable pulmonary aspergillosis. Mortality was higher in UCI patients (50 vs. 29%; p = 0.028). The predictive factors of mortality included being a male with various comorbidities, SARS-CoV-2 pneumonia, bacteremia and superinfections from A. baumannii.ConclusionThe outbreak of A. baumannii was a determining factor in the increases of the incidence of infection and the morbi-mortality of ICU patients.

Bacterial/fungal infection in hospitalized patients with COVID-19 in a tertiary hospital in the Community of Castilla y León, Spain.

INTRODUCTION: Bacterial/fungal coinfection and superinfections contribute to the increased morbi-mortality of viral respiratory infections (RIs). The main objective of this study was to determine the incidence of these infections in hospitalized patients with COVID-19. METHOD: Retrospective observational study of all patients admitted for COVID-19 and bacterial/fungal infections at the Hospital Clínico Universitario of Valladolid, Spain (March 1-May 31, 2020). Demographic, clinical and microbiological data were compared based on Intensive Care Unit (ICU) admission and predictors of mortality by were identified using multivariate logistic regression analyses. RESULTS: Of the 712 COVID-19 patients, 113 (16%) presented bacterial/fungal coinfections or superinfections. Their median age was 73 years (IQR 57-89) and 59% were men. The profiles of ICU patients (44%) included male, SARS-CoV-2 pneumonia, leukocytosis, elevated inteleukin-6, with interferon ß-1b and tocilizumab and superinfection (p < 0.05). Coinfections were diagnosed in 5% (39/712) patients. Most common pathogens of respiratory coinfection (18) were Streptococcus pneumoniae (6) and Staphylococcus aureus (6). Superinfections were detected in 11% (80/712) patients. Urinary (53) and RI (39) constituted the majority of superinfections Acinetobacter baumannii multidrug-resistant was the main agent of IR and bacteremia. An outbreak of A. baumannii contributed to this result. Three patients were considered to have probable pulmonary aspergillosis. Mortality was higher in UCI patients (50% vs. 29%, p = 0.028). The predictive factors of mortality included being a male with various comorbidities, SARS-CoV-2 pneumonia, bacteremia and superinfections from A. baumannii. CONCLUSION: The outbreak of A. baumannii was a determining factor in the increases of the incidence of infection and the morbi-mortality of ICU patients.

Infección bacteriana/fúngica en pacientes con COVID-19 ingresados en un hospital de tercer nivel de Castilla y León, España / Bacterial/fungal infection in hospitalized patients with COVID-19 in a tertiary hospital in the Community of Castilla y León, Spain

INTRODUCCIÓN: La coinfección/sobreinfección bacteriana/fúngica contribuye al incremento de la morbimortalidad de las infecciones respiratorias (IRs) virales. El objetivo de este trabajo es conocer la incidencia de estas infecciones en los pacientes hospitalizados por COVID-19. MÉTODO: Estudio retrospectivo observacional de todos los pacientes ingresados por COVID-19 e infección bacteriana/fúngica en el Hospital Clínico de Valladolid (1 marzo-31 mayo, 2020). Comparación de datos demográficos, clínicos y microbiológicos en función del ingreso en UCI e identificación de los factores predictores de mortalidad mediante regresión logística multivariante. RESULTADOS: De 712 pacientes con COVID-19, 113 (16%) presentaron coinfección/ sobreinfección bacteriana/fúngica. Mediana de edad 73 años (RIQ 57-89), 59% de ellos hombres. Perfil del paciente de UCI (44%): hombre con neumonía por SARS-CoV-2, leucocitosis, interleucina-6 elevada, con interferón β-1b y tocilizumab y sobreinfección (p < 0,05). El 5% (39/712) de los pacientes presentaron una coinfección. Streptococcus pneumoniae (6) y Staphylococcus aureus (6) fueron los principales patógenos de las coinfecciones respiratorias (18). El 11% (80/712) se sobreinfectaron. Las infecciones más frecuentes fueron las urinarias (53) e IRs (39). Acinetobacter baumannii multirresistente fue el principal agente de la IR y la bacteriemia. Un brote por A. baumannii contribuyó a este resultado. Tres pacientes se diagnosticaron como probable aspergilosis pulmonar. La mortalidad fue superior en los pacientes de UCI (50 vs. 29%; p = 0,028). Factores predictores de mortalidad: hombre con varias comorbilidades, neumonía por SARS-CoV-2, bacteriemia y sobreinfectado por A. baumannii. CONCLUSIÓN: El brote por A. baumannii fue determinante en la incidencia de la infección y en la morbimortalidad de los pacientes de UCI

INTRODUCTION: Bacterial/fungal coinfection and superinfections contribute to the increased morbi-mortality of viral respiratory infections (RIs). The main objective of this study was to determine the incidence of these infections in hospitalized patients with COVID-19. METHOD: Retrospective observational study of all patients admitted for COVID-19 and bacterial/fungal infections at the Hospital Clínico Universitario of Valladolid, Spain (March 1-May 31, 2020). Demographic, clinical and microbiological data were compared based on Intensive Care Unit (ICU) admission and predictors of mortality by were identified using multivariate logistic regression analyses. RESULTS: Of the 712 COVID-19 patients, 113 (16%) presented bacterial/fungal coinfections or superinfections. Their median age was 73 years (IQR 57-89) and 59% were men. The profiles of ICU patients (44%) included male, SARS-CoV-2 pneumonia, leukocytosis, elevated inteleukin-6, with interferon beta-1b and tocilizumab and superinfection (p < 0.05). Coinfections were diagnosed in 5% (39/712) patients. Most common pathogens of respiratory coinfection (18) were Streptococcus pneumoniae (6) and Staphylococcus aureus (6). Superinfections were detected in 11% (80/712) patients. Urinary (53) and RIs (39) constituted the majority of superinfections Acinetobacter baumannii multidrug-resistant was the main agent of IR and bacteremia. An outbreak of A. baumannii contributed to this result. Three patients were considered to have probable pulmonary aspergillosis. Mortality was higher in UCI patients (50 vs. 29%; p = 0.028). The predictive factors of mortality included being a male with various comorbidities, SARS-CoV-2 pneumonia, bacteremia and superinfections from A. baumannii. CONCLUSION: The outbreak of A. baumannii was a determining factor in the increases of the incidence of infection and the morbi-mortality of ICU patients

Bacterial/fungal infection in hospitalized patients with COVID-19 in a tertiary hospital in the Community of Castilla y León, Spain. / Infección bacteriana/fúngica en pacientes con COVID-19 ingresados en un hospital de tercer nivel de Castilla y León, España.

INTRODUCTION: Bacterial/fungal coinfection and superinfections contribute to the increased morbi-mortality of viral respiratory infections (RIs). The main objective of this study was to determine the incidence of these infections in hospitalized patients with COVID-19. METHOD: Retrospective observational study of all patients admitted for COVID-19 and bacterial/fungal infections at the Hospital Clínico Universitario of Valladolid, Spain (March 1-May 31, 2020). Demographic, clinical and microbiological data were compared based on Intensive Care Unit (ICU) admission and predictors of mortality by were identified using multivariate logistic regression analyses. RESULTS: Of the 712 COVID-19 patients, 113 (16%) presented bacterial/fungal coinfections or superinfections. Their median age was 73 years (IQR 57-89) and 59% were men. The profiles of ICU patients (44%) included male, SARS-CoV-2 pneumonia, leukocytosis, elevated inteleukin-6, with interferon ß-1b and tocilizumab and superinfection (p < 0.05). Coinfections were diagnosed in 5% (39/712) patients. Most common pathogens of respiratory coinfection (18) were Streptococcus pneumoniae (6) and Staphylococcus aureus (6). Superinfections were detected in 11% (80/712) patients. Urinary (53) and RIs (39) constituted the majority of superinfections Acinetobacter baumannii multidrug-resistant was the main agent of IR and bacteremia. An outbreak of A. baumannii contributed to this result. Three patients were considered to have probable pulmonary aspergillosis. Mortality was higher in UCI patients (50 vs. 29%; p = 0.028). The predictive factors of mortality included being a male with various comorbidities, SARS-CoV-2 pneumonia, bacteremia and superinfections from A. baumannii. CONCLUSION: The outbreak of A. baumannii was a determining factor in the increases of the incidence of infection and the morbi-mortality of ICU patients.

Métodos rápidos para la detección de la resistencia bacteriana a antibióticos / Rapid methods for detection of bacterial resistance to antibiotics

Los métodos más frecuentemente utilizados en Microbiología Clínica para la determinación de la sensibilidad de las bacterias a los antibióticos se basan en un estudio fenotípico, observando el crecimiento bacteriano de una cepa incubada en presencia del antibiótico a estudiar. Estos métodos requieren normalmente un tiempo de unas 24h para la obtención de resultados. En esta revisión se exponen el fundamento y los resultados de las principales técnicas instrumentales que proporcionan un antibiograma rápido. De manera pormenorizada se exponen datos relativos a técnicas moleculares, microarrays, métodos comerciales utilizados en el trabajo de rutina, técnicas inmunocromatográficas, métodos colorimétricos, métodos de imagen, nefelometría, espectrometría de masas MALDI-TOF, citometría de flujo, quimioluminiscencia y bioluminiscencia, microfluidos y métodos de lisis bacteriana

The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24hours to obtain results. Here we review the main techniques for rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, microarrays, commercial methods used in work routine, immunochromatographic methods, colorimetric methods, image methods, nephelometry, MALDI-TOF mass spectrometry, flow cytometry, chemiluminescence and bioluminescence, microfluids and methods based on cell disruption are analysed in detail

Rapid methods for detection of bacterial resistance to antibiotics. / Métodos rápidos para la detección de la resistencia bacteriana a antibióticos.

The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24hours to obtain results. Here we review the main techniques for rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, microarrays, commercial methods used in work routine, immunochromatographic methods, colorimetric methods, image methods, nephelometry, MALDI-TOF mass spectrometry, flow cytometry, chemiluminescence and bioluminescence, microfluids and methods based on cell disruption are analysed in detail.

A two-hour antibiotic susceptibility test by ATP-bioluminescence / Antibiograma en dos horas mediante la medición de ATP por bioluminiscencia

The antibiotic susceptibility test (AST) in Clinical Microbiology laboratories is still time-consuming, and most procedures take 24 h to yield results. In this study, a rapid antimicrobial susceptibility test using ATP-bioluminescence has been developed. The design of method was performed using five ATCC collection strains of known susceptibility. This procedure was then validated against standard commercial methods on 10 strains of enterococci, 10 staphylococci, 10 non-fermenting gram negative bacilli, and 13 Enterobacteriaceae from patients. The agreement obtained in the sensitivity between the ATP-bioluminescence method and commercial methods (E-test, MicroScan and VITEK2) was 100%. In summary, the preliminary results obtained in this work show that the ATP-bioluminescence method could provide a fast and reliable AST in two hours

La mayoría de procedimientos diagnósticos para el estudio de la sensibilidad de las bacterias a los antibióticos en Microbiología Clínica requieren unas 24 horas para la obtención de resultados. En este estudio se propone una metodología para llevar a cabo un antibiograma rápido mediante la medición de ATP por bioluminiscencia. El diseño del antibiograma se realizó mediante el uso de cinco cepas de colección ATCC, las cuales presentan una sensibilidad conocida. Este diseño fue posteriormente validado frente a los métodos comerciales de antibiograma mediante el procesamiento de 10 cepas de enterococos, 10 de estafilococos, 10 de bacilos gramnegativos no fermentadores y 13 de Enterobacteriaceae aisladas de pacientes. El acuerdo obtenido entre la sensibilidad obtenida mediante bioluminiscencia y la obtenida mediante los métodos comerciales (E-test, MicroScan and VITEK2) fue del 100%. Por lo tanto, los resultados preliminares obtenidos en este trabajo indican que las medidas de ATP mediante bioluminiscencia podrían proporcionar, en dos horas, un antibiograma rápido y seguro

Anti-infectives for systemic use prescribed in a Spanish hospital between 2009-2013.

The overuse and misuse of antimicrobials contribute to the emergence of antibiotic-resistant bacteria. The aim of this work was to analyse all the anti-infectives for systemic use (J ATC group) prescribed at the University Clinic Hospital of Valladolid (Spain) for the years 2009-2013. Amounts of anti-infectives (antibacterials, antifungals and antivirals) used in the period 2009-2013 were expressed as defined daily doses (DDDs) and as total expenditure, and the significance of the difference in consumption of anti-infectives and the relevant expenditure between years was evaluated from the overlapping of the corresponding confidence intervals at 95% confidence level of DDDs and expenditure. The results obtained showed that DDDs and expenditure of antibacterials decreased in the period 2009-2013. Antimycotics showed an upward trend in expenditure and DDDs in the five-year study period, but with major oscillations. The consumption of antivirals was practically constant in the period 2009-2011; in 2012, a significant reduction was observed and this reduction was conserved in 2013, although their expenditure increased year by year. In conclusion, in the period 2009-2013, expenditure on anti-infectives increased year to year. However, this increase in expenditure resulted in a downward trend of DDDs.

Antibiograma rápido en Microbiología Clínica / Rapid antibiotic susceptibility test in Clinical Microbiology

Los métodos más frecuentemente utilizados en Microbiología Clínica para la determinación de la sensibilidad de las bacterias a los antibióticos se basan en un estudio fenotípico, observando el crecimiento bacteriano de la cepa incubada en presencia del antibiótico a estudiar. Estos métodos requieren normalmente un tiempo de unas 24 h para la obtención de resultados. El objetivo de este trabajo es revisar el fundamento y los resultados de las principales técnicas instrumentales que proporcionan un antibiograma rápido. De manera pormenorizada se exponen datos relativos a técnicas moleculares, citometría de flujo, quimioluminiscencia, espectrometría de masas, métodos comerciales utilizados en el trabajo de rutina, métodos colorimétricos, nefelometría, microarrays, microfluidos y métodos de lisis bacteriana

The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24 hours to obtain results. A review is presented here of recently developed techniques for the rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, flow cytometry, chemiluminescence, mass spectrometry, commercial methods used in routine work, colorimetric methods, nephelometry, microarrays, microfluids, and methods based on cell disruption and sequencing, are analyzed and discussed in detail

A two-hour antibiotic susceptibility test by ATP-bioluminescence.

The antibiotic susceptibility test (AST) in Clinical Microbiology laboratories is still time-consuming, and most procedures take 24h to yield results. In this study, a rapid antimicrobial susceptibility test using ATP-bioluminescence has been developed. The design of method was performed using five ATCC collection strains of known susceptibility. This procedure was then validated against standard commercial methods on 10 strains of enterococci, 10 staphylococci, 10 non-fermenting gram negative bacilli, and 13 Enterobacteriaceae from patients. The agreement obtained in the sensitivity between the ATP-bioluminescence method and commercial methods (E-test, MicroScan and VITEK2) was 100%. In summary, the preliminary results obtained in this work show that the ATP-bioluminescence method could provide a fast and reliable AST in two hours.

[Rapid antibiotic susceptibility test in Clinical Microbiology]. / Antibiograma rápido en Microbiología Clínica.

The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24hours to obtain results. A review is presented here of recently developed techniques for the rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, flow cytometry, chemiluminescence, mass spectrometry, commercial methods used in routine work, colorimetric methods, nephelometry, microarrays, microfluids, and methods based on cell disruption and sequencing, are analyzed and discussed in detail.

A two-hour procedure for determining the susceptibility of enterococci and staphylococci to antibiotics by a colourimetric method.

INTRODUCTION: Rapid determination of the antibiotic susceptibility test in bacteria remains a challenge for Clinical Microbiology laboratories. METHODS: An improvement in the colorimetric antimicrobial susceptibility testing performed with resazurin in enterococci and staphylococci has been carried out. The design of method was performed using two collection strains, which have a known susceptibility. This procedure was then validated against standard commercial methods on 15 strains of staphylococci and 15 strains of enterococci from patients. RESULTS: The essential agreement between the colorimetric method and commercial methods (E-test, MicroScan and VITEK2) was 100%. CONCLUSION: Resazurin allows us to obtain a reliable antibiotic susceptibility test in staphylococci and enterococci in less than two hours.

A two-hour procedure for determining the susceptibility of enterococci and staphylococci to antibiotics by a colourimetric method / Un procedimiento de dos horas para determinar la sensibilidad de estaficolococos y enterococos a los antibióticos en dos horas mediante un método colorimétrico

Introduction. Rapid determination of the antibiotic susceptibility test in bacteria remains a challenge for Clinical Microbiology laboratories. Methods. An improvement in the colorimetric antimicrobial susceptibility testing performed with resazurin in enterococci and staphylococci has been carried out. The design of method was performed using two collection strains, which have a known susceptibility. This procedure was then validated against standard commercial methods on 15 strains of staphylococci and 15 strains of enterococci from patients. Results. The essential agreement between the colorimetric method and commercial methods (E-test, MicroScan and VITEK2) was 100%. Conclusion. Resazurin allows us to obtain a reliable antibiotic susceptibility test in staphylococci and enterococci in less than two hours (AU)

Introducción. La realización de un antibiograma rápido sigue siendo un reto para los laboratorios de Microbiología Clínica. Métodos. Se ha realizado una mejora en el antibiograma colorimétrico realizado mediante resazurina en estafilococos y enterococos. El diseño del método se realizó mediante el uso de dos cepas de colección que presentan una sensibilidad conocida. Este procedimiento se validó posteriormente frente a los métodos comerciales mediante el procesamiento de 15 cepas de estafilococos y 15 de enterococos aisladas de pacientes. Resultados. Se ha obtenido un 100% de concordancia entre la sensibilidad obtenida mediante resazurina y la obtenida mediante los métodos comerciales (E-test, MicroScan and VITEK2). Conclusión. Mediante el uso de resazurina es posible obtener un antibiograma en estafilococos y enterococos en menos de dos horas de forma fiable (AU)

New procedure for rapid identification of microorganisms causing urinary tract infection from urine samples by mass spectrometry (MALDI-TOF)

INTRODUCTION: Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry is widely established as a technique in clinical microbiology laboratories for the identification of microorganisms. Using this technique, it is also possible to obtain the identification of microorganisms from untreated urine samples. METHODS: In this study, a differential centrifugation protocol and a criterion for validation of the results in order to achieve microbial identification from untreated urine samples are proposed. Additionally, the sensitivity of the analytical procedure in monobacterial urine samples has beenevaluated. RESULTS: A 90% sensitivity (confidence interval of 81.96%-94.84%) was obtained in urine samples with bacterial counts of ≥ 1×105 CFU/ml, and it was possible to improve the percentages of direct identifications from urine samples with bacterial counts of < 1 × 105 CFU/ml. CONCLUSIÓN: It is concluded that the MALDI-TOF system is both fast and reliable in the identification of individual microorganisms from untreated urine samples with counts of ≥ 1 × 105 CFU/mll

INTRODUCCIÓN: El uso de la espectrometría de masas Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) es una técnica implantada en los laboratorios de Microbiología Clínica que permite llevar a cabo la identificación de microorganismos. Una de las aplicaciones de esta técnica es la identificación a partir de muestra directa de orina. MÉTODOS: En este estudio se propone un protocolo de centrifugación diferencial y un criterio de validación de los resultados para alcanzar la identificación microbiana a partir de muestra directa de orina. Adicionalmente se estudia la sensibilidad del procedimiento analítico en muestras de orina monomicrobianas. RESULTADOS: Las orinas con recuentos ≥ 1×105 UFC/ml mostraron un 90% de sensibilidad (Intervalo de Confianza de 81.96%-94.84%) y se logró mejorar los porcentajes de identificación directa a partir de orinas con recuentas bacterianos < 1×105 UFC/ml. CONCLUSIONES: La espectrometría de masas MALDI-TOF es un sistema rápido y fiable para la identificación de microorganismos a partir de orinas monomicrobianas con recuentos ≥ 1 × 105 UFC/ml

New procedure for rapid identification of microorganisms causing urinary tract infection from urine samples by mass spectrometry (MALDI-TOF).

INTRODUCTION: Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry is widely established as a technique in clinical microbiology laboratories for the identification of microorganisms. Using this technique, it is also possible to obtain the identification of microorganisms from untreated urine samples. METHODS: In this study, a differential centrifugation protocol and a criterion for validation of the results in order to achieve microbial identification from untreated urine samples are proposed. Additionally, the sensitivity of the analytical procedure in monobacterial urine samples has been evaluated. RESULTS: A 90% sensitivity (confidence interval of 81.96%-94.84%) was obtained in urine samples with bacterial counts of ≥1×10(5)CFU/ml, and it was possible to improve the percentages of direct identifications from urine samples with bacterial counts of <1×10(5)CFU/ml. CONCLUSION: It is concluded that the MALDI-TOF system is both fast and reliable in the identification of individual microorganisms from untreated urine samples with counts of ≥1×10(5)CFU/ml.

[How to fight parasitic infectious diseases with bacteria. The case of Wolbachia pipientis]. / Cómo combatir con bacterias a las enfermedades infecciosas parasitarias. El caso de Wolbachia pipientis.

In Nature, no individual can live in isolation; hence, living organisms are forced to interact with each other. This necessity has led many organisms to establish heterogeneous relations to enhance their ability to adapt to the environment, thus acquiring evolutionary advantages. These relationships are sometimes so intense, that on the long term the organisms may lose their individual identity. An example of these associations is the endosymbiotic ones, where eukaryote organisms generally harbor different prokaryote organisms. The endosymbiotic bacterium Wolbachia pipientis is a species described by Hertig and Wolbach in 1924. This microorganism can be isolated in a large variety of eukaryote organisms, with which it maintains different links. Until now, this species has only been described with 11 serogroups numbered from A to K within the Wolbachia genus. This work is intended to illustrate the relationship of Wolbachia pipientis with human pathogenic filaria and with arthropods, as well as to describe the implications of this bacterium in the treatment of filariasis. Finally, this work tries to describe recent studies that have targeted the use of artificially-created Wolbachia pipientis virulent strains that, once inoculated in infectious diseases-transmitting vectors, develop negative effects within them in order to, in this way, erradicate mosquito-transmitted infectious diseases for which no treatment is available at the moment or the prevention of its transmissibility has not been achieved.

En la naturaleza ningún individuo puede vivir de forma aislada, de tal forma que los organismos vivos se ven obligados a interactuar unos con otros. Esta necesidad ha llevado a que diferentes organismos establezcan relaciones heterogéneas para mejorar su capacidad de adaptación al medio, obteniendo así ventajas evolutivas. Estas relaciones a veces son tan intensas que a la larga los organismos pueden perder su identidad individual. Un ejemplo de estas asociaciones son las endosimbióticas, en las cuales generalmente organismos eucariotas albergan a diferentes organismos procariotas. La bacteria endosimbiótica Wolbachia pipientis es una especie descrita en 1924 por Hertig y Wolbach. Este microorganismo se puede aislar en gran variedad de organismos eucariotas, con los que mantiene diferentes vínculos. Hasta el momento solo se ha descrito esta especie con 11 serogrupos enumerados de la A a la K dentro del género Wolbachia. En este trabajo se pretende ilustrar la relación de Wolbachia pipientis con las filarias patógenas humanas y con los artrópodos, así como describir las implicaciones de esta bacteria en el tratamiento de las filariasis. Finalmente, se pretende exponer los estudios recientes que han apuntado el uso de cepas virulentas de Wolbachia pipientis creadas artificialmente que una vez inoculadas en los vectores transmisores de enfermedades desarrollan efectos negativos en estos, para de esa forma lograr la erradicación de enfermedades infecciosas transmitidas por mosquitos para las cuales de momento no existe tratamiento o no se ha logrado impedir su transmisibilidad.

[Quorum sensing in bacteria and yeast]. / Quorum sensing en bacterias y levaduras.

Bacterial sets are complex dynamic systems, which interact with each other and through the interaction, bacteria coexist, collaborate, compete and share information in a coordinated manner. A way of bacterial communication is quorum sensing. Through this mechanism the bacteria can recognize its concentration in a given environment and they can decide the time at which the expression of a particular set of genes should be started for developing a specific and simultaneous response. The result of these interconnections raises properties that cannot be explained from a single isolated bacterial cell.