Identification and antifungal susceptibility testing of Candida haemulonii complex isolated from clinical samples.

Candida haemulonii complex (Candida haemulonii [I], Candida duobushaemulonii [II], and Candida haemulonii var. vulnera [III]) has become relevant in recent times, not so much because of a high incidence in human clinical sample cultures but because of its remarkable antifungal resistance. The objective of this study was to evaluate several methods for the identification of this uncommon species of Candida. Ten isolates of C. haemulonii were identified by biochemical and proteomic methods, and their antifungal susceptibility testing was performed by both commercial and reference methods. MALDI-TOF MS (Vitek MS and Vitek MS PRIME) and Vitek2 correctly identified these genera but API method did not. There was a good correlation between the commercial methods and the reference methods for the AST. In conclusion Vitek MS, Vitek MS PRIME, and Vitek2 systems, but not API32C, are reliable for identification of C. haemulonii complex. Furthermore, MALDI-TOF MS systems could identify to the subspecies level. Commercial methods for antifungal susceptibility testing are valid for the study of this species and confirm amphotericin B and to azole resistance.

Outbreak of Arcobacter butzleri? An emerging enteropathogen.

BACKGROUND: Arcobacter butzleri is a gram-negative rod, with microaerobic growth at an optimal temperature of 37°C. It was reported to be the fourth most common Campylobacter-like organism isolated from patients with diarrhoea. OBJECTIVE: Characterise a potential outbreak of A. butzleri detected in a short period of time in the University Hospital Marqués de Valdecilla. METHODS: Eight strains of A. butzleri were detected in our hospital in only two months. Isolates were identified by MALDI-TOF MS system and 16S rDNA sequencing. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and Pulsed Field Gel Electrophoresis (PFGE) were carried out to assess clonal relationship. Gradient strips (Etest) were used to determine susceptibility by agar diffusion. RESULTS: ERIC-PCR and PFGE confirmed the lack of clonal relationship between strains. Erythromycin or ciprofloxacin might be appropriate for antibiotic treatment of infections. CONCLUSIONS: A. butzleri is an emerging pathogen with increasing incidence, and may be underestimated.

Outbreak of Arcobacter butzleri? An emerging enteropathogen / Brote de Arcobacter butzleri? Un enteropatógeno emergente

Background: Arcobacter butzleri is a gram-negative rod, with microaerobic growth at an optimal temperature of 37°C. It was reported to be the fourth most common Campylobacter-like organism isolated from patients with diarrhoea. Objective: Characterise a potential outbreak of A. butzleri detected in a short period of time in the University Hospital Marqués de Valdecilla. Methods: Eight strains of A. butzleri were detected in our hospital in only two months. Isolates were identified by MALDI-TOF MS system and 16S rDNA sequencing. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and Pulsed Field Gel Electrophoresis (PFGE) were carried out to assess clonal relationship. Gradient strips (Etest) were used to determine susceptibility by agar diffusion. Results: ERIC-PCR and PFGE confirmed the lack of clonal relationship between strains. Erythromycin or ciprofloxacin might be appropriate for antibiotic treatment of infections. Conclusions: A. butzleri is an emerging pathogen with increasing incidence, and may be underestimated.(AU)

Antecedentes: Arcobacter butzleri es un bacilo gramnegativo, con crecimiento microaerófilo a una temperatura óptima de 37°C. Ha sido descrito como el cuarto organismo asociado a Campylobacter más frecuentemente aislado de pacientes con diarrea. Objetivo: Caracterizar un potencial brote de A. butzleri detectado en el Hospital Universitario Marqués de Valdecilla. Métodos: Se detectaron 8 cepas de A. butzleri en nuestro hospital en solo 2 meses. Los aislamientos fueron identificados con MALDI-TOF MS y secuenciación del ARNr 16S. Se llevó a cabo la PCR basada en secuencia de consenso intergénica repetitiva de enterobacterias(ERIC-PCR) y electroforesis en campo pulsado (PFGE) para asegurar la relación clonal. Para determinar la sensibilidad se usaron tiras de gradiente (Etest®) por difusión en agar. Resultados: ERIC-PCR y PFGE confirmaron la falta de relación clonal entre las cepas. Eritromicina o ciprofloxacino podrían ser apropiados para el tratamiento antibiótico de estas infecciones. Conclusiones: A. butzleri es un patógeno emergente con un aumento en la incidencia, y podría estar subestimado.(AU)

Characterization, antifungal susceptibility and virulence of Candida parapsilosis complex isolates in a tertiary hospital in Cantabria, Northern Spain.

INTRODUCTION: The correct identification of the species within the Candida parapsilosis complex has become relevant due to the resistance of Candida metapsilosis to antifungals. We describe the characteristics of the Candida parapsilosis complex isolates, with respect to antifungal resistance and biofilm formation. METHODS: We perform a descriptive cross-sectional study in 30 strains, collected in a tertiary hospital. All strains, were identified by Vitek2, Vitek-MS™ systems and by ITS sequencing. The antifungal susceptibility profile was obtained with Sensititre™ panels, while biomass production and metabolic activity were quantified by means of crystal violet and XTT reduction assay, respectively. RESULTS: There was a 100% correlation between Vitek-MS™ and ITS sequencing. All isolates were susceptible to the nine antifungals tested. The metabolic activity and biomass production tests did not show any difference among the subtypes. CONCLUSIONS: The Vitek-MS™ system provides acceptable identification. We did not find significant differences neither in azole resistance nor in biofilm formation.

Characterization, antifungal susceptibility and virulence of Candida parapsilosis complex isolates in a tertiary hospital in Cantabria, Northern Spain / Caracterización, sensibilidad antifúngica y virulencia de aislamientos del complejo Candida parapsilosis en un hospital terciario en Cantabria, norte de España

Introduction: The correct identification of the species within the Candida parapsilosis complex has become relevant due to the resistance of Candida metapsilosis to antifungals. We describe the characteristics of the Candida parapsilosis complex isolates, with respect to antifungal resistance and biofilm formation. Methods: We perform a descriptive cross-sectional study in 30 strains, collected in a tertiary hospital. All strains, were identified by Vitek2, Vitek-MS™ systems and by ITS sequencing. The antifungal susceptibility profile was obtained with Sensititre™ panels, while biomass production and metabolic activity were quantified by means of crystal violet and XTT reduction assay, respectively. Results: There was a 100% correlation between Vitek-MS™ and ITS sequencing. All isolates were susceptible to the nine antifungals tested. The metabolic activity and biomass production tests did not show any difference among the subtypes. Conclusions: The Vitek-MS™ system provides acceptable identification. We did not find significant differences neither in azole resistance nor in biofilm formation.(AU)

Introducción: La correcta identificación del complejo Candida parasilopsis es relevante debido a la resistencia antifúngica de Candida metasilopsis. Describimos las características de aislados del complejo Candida parapsilosis respecto a la resistencia antifúngica y formación de biopelícula. Métodos: Se realiza un estudio descriptivo transversal de 30 cepas recolectadas en un hospital terciario. Todas se identificaron por los sistemas Vitek2, MALDI-TOF MS Vitek-MSTM y por secuenciación de las regiones ITS. La sensibilidad antifúngica se realizó con paneles SensititreTM. Para la producción de biomasa y la actividad metabólica se emplearon la medición de cristal violeta y el ensayo de reducción de XTT, respectivamente. Resultados: Hubo una correlación del 100% entre Vitek-MSTM y la secuencia de ITS. Todos los aislados fueron sensibles a los 9 antifúngicos evaluados. Los ensayos de actividad metabólica y producción de biomasa no arrojaron diferencias entre los subtipos. Conclusiones: El sistema Vitek-MSTM proporciona una identificación aceptable. No encontramos diferencias significativas ni en la resistencia a azoles ni en la formación de biopelículas.(AU)

Evaluation of Vitek-MS(TM) and Microflex LT(TM) commercial systems for identification of Acinetobacter calcoaceticus-baumannii complex / Evaluación de los sistemas comerciales Vitek(R) MS y Microflex(R) LT para la identificación del complejo Acinetobacter calcoaceticus-baumannii

INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS(TM) and Microflex LT(TM) systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS(TM) and Microflex LT(TM) proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them

INTRODUCCIÓN: Acinetobacter es un género que comprende un grupo de patógenos oportunistas responsables de varias infecciones nosocomiales. El complejo Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) reúne algunas especies de importancia clínica, principalmente A. baumannii, A. pittii y A. nosocomialis, que comparten similitudes fenotípicas que hacen muy difícil poder discriminar entre ellas utilizando un enfoque fenotípico. El objetivo de este estudio fue evaluar 2 sistemas comerciales de espectrometría de masas de ionización por láser asistido con una matriz (MALDI-TOF MS) para la identificación de diferentes especies de Acinetobacter, con un enfoque especial entre los que pertenecen al complejo Acb. MÉTODOS: Analizamos 156 cepas clínicas de Acinetobacter spp., identificadas mediante análisis de restricción de ADN ribosomal amplificado (ARDRA) y secuenciación del gen rpoB, por 2 sistemas diferentes de MALDI-TOF. RESULTADOS: Teniendo en cuenta solo las 144 cepas del complejo Acb evaluadas en este estudio, los sistemas Vitek(R) MS y Microflex(R) LT identificaron correctamente 129 (89,6%) y 143 (99,3%) cepas, respectivamente. CONCLUSIÓN: Después de analizar 156 cepas pertenecientes a Acinetobacter spp., Vitek(R) MS y Microflex(R) LT demostraron ser sistemas rápidos y precisos para la identificación de especies del complejo Acb mostrando una buena correlación. Sin embargo, ambos fabricantes deberían mejorar sus bases de datos incluyendo nuevas especies en ellas

Evaluation of Vitek-MS™ and Microflex LT™ commercial systems for identification of Acinetobacter calcoaceticus-baumannii complex.

INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS™ and Microflex LT™ systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS™ and Microflex LT™ proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them.

Evaluation of the Vitek-MS™ system in the identification of Candida isolates from bloodstream infections.

BACKGROUND: Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) represents a revolution in the identification of microorganisms of clinical interest. Many studies have confirmed the accuracy and fastness of this tool with routine strains. AIMS: To identify clinical isolates of Candida from patients diagnosed with candidemia. METHODS: Vitek-MS™ system was used with a collection of 298 blood isolates of the genus Candida represented by 9 different species. Sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA cluster was used as the reference method. RESULTS: The results of Vitek-MS™ were concordant with those obtained with the reference method for 279 (93.62%) isolates (Kappa coefficient (κ)=0.91). Vitek-MS™ misidentified 10 (3.36%) isolates and did not identify 9 (3.02%) isolates. CONCLUSIONS: This study determines the potential of Vitek-MS™ in yeast identification, being a reliable and fast alternative in the clinical laboratory, with an acceptable sensitivity of 82% (IC 95%: 70-90.6%), in comparison with a 100% (IC 95%: 92.9-100%) sensitivity of the conventional methods.

Evaluation of the Vitek-MS(TM) system in the identification of Candida isolates from bloodstream infections / Evaluación del sistema VITEK(R) MS(TM) en la identificación de aislamientos de Candida de pacientes con candidemia

Background: Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) represents a revolution in the identification of microorganisms of clinical interest. Many studies have confirmed the accuracy and fastness of this tool with routine strains. Aims: To identify clinical isolates of Candida from patients diagnosed with candidemia. Methods: Vitek-MS(TM) system was used with a collection of 298 blood isolates of the genus Candida represented by 9 different species. Sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA cluster was used as the reference method. Results: The results of Vitek-MS(TM) were concordant with those obtained with the reference method for 279 (93.62%) isolates (Kappa coefficient (κ)=0.91). Vitek-MS(TM) misidentified 10 (3.36%) isolates and did not identify 9 (3.02%) isolates. Conclusions: This study determines the potential of Vitek-MS(TM) in yeast identification, being a reliable and fast alternative in the clinical laboratory, with an acceptable sensitivity of 82% (IC 95%: 70-90.6%), in comparison with a 100% (IC 95%: 92.9-100%) sensitivity of the conventional methods

Antecedentes: La espectrometría de absorción de masas mediante láser asistido por una matriz (MALDI-TOF MS) representa una revolución en la identificación de microorganismos de interés clínico. Muchos estudios han confirmado la exactitud y rapidez de esta herramienta con aislamientos de la rutina clínica diaria. Objetivos: Identificar aislamientos clínicos del género Candida procedentes de pacientes con un diagnóstico de candidemia. Métodos: Se utilizó el sistema VITEK(R) MS con un grupo de 298 aislamientos sanguíneos del género Candida, representado por 9 especies diferentes. Se utilizó como método de referencia la secuenciación de la región del espaciador de transcripción interno (ITS, por sus siglas en inglés) del ADN ribosómico. Resultados: Los resultados de VITEK(R) MS coincidieron con aquellos obtenidos por el método de referencia en 279 (93,62%) de los aislamientos (coeficiente Kappa [κ]=0,91), mientras que clasificó erróneamente a 10 (3,36%) aislamientos y no identificó otros 9 (3,02%). Conclusiones: VITEK(R) MS es una alternativa fiable y rápida en la identificación de levaduras en el laboratorio clínico, con una sensibilidad aceptable del 82% (IC 95%:70-90,6%) en comparación con una sensibilidad del 100% (IC 95%:92,9-100%) de los métodos convencionales

Correlación entre el sistema de MALDI-TOF Vitek-MSTM y los métodos convencionales de identificación de bacterias causantes de infección gastrointestinal / Correlation between MALDI-TOF Vitek-MSTM system and conventional identification methods of gastrointestinal infection causing bacteria

Introducción. La identificación rápida de patógenos es esencial para el diagnóstico de las infecciones gastrointestinales. La espectrometría de masas matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) ha demostrado ser eficaz y rápida en la identificación de microorganismos. El objetivo de este estudio fue evaluar la correlación entre Vitek-MSTM y los métodos convencionales para la identificación de bacterias causantes de infección gastrointestinal. Material y métodos. Se han identificado un total de 329 patógenos gastrointestinales empleando, simultáneamente, Vitek-MSTM (v2 SARAMIS MS-ID, BioMérieux, Marcy-I´Étoile, Francia) y métodos diagnósticos convencionales. En los casos de discrepancia se realizó secuenciación del gen 16SrRNA. Resultados. La correlación entre Vitek-MSTM y los métodos diagnósticos convencionales fue del 100% excepto para Yersinia enterocolitica (94,1%), Helicobacter pylori (10%) y Aeromonas veronii (0%). Conclusiones. Vitek-MSTM es un método rápido y útil en la identificación de bacterias enteropatógenas. Es necesario mejorar las prestaciones del sistema para H. pylori y A. veronii (AU)

Introduction. Rapid identification of pathogens is essential for the diagnosis of gastrointestinal infections. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry has shown to be effective and fast for the identification of microorganisms. The objective of this study was to evaluate the correlation between Vitek-MSTM and conventional methods for bacterial identification causing gastrointestinal infection. Material and methods. A total of 329 gastrointestinal pathogens were identified using Vitek-MSTM (v2 SARAMIS MS -ID, bioMérieux, Marcy-I´Étoile, France) and routine diagnostic methods simultaneously. In cases of discrepancy 16SrRNA gene sequencing was performed. Results. The correlation between Vitek-MSTM and diagnostic methods was 100% except for Yersinia enterocolitica (94.1%), Helicobacter pylori (10%) and Aeromonas veronii (0 %). Conclusions. Vitek-MSTM is a quick and useful method for identification of enterophatogenic bacteria. It is necessary to improve the performance of the system for the identification of H. pylori and A. veronii (AU)

Expression and function of toll-like receptors in peripheral blood mononuclear cells of patients with polymyalgia rheumatica and giant cell arteritis.

OBJECTIVE: To investigate the expression and function of the Toll-like receptor (TLR) family in peripheral blood mononuclear cells (PBMCs) of patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). METHODS: The authors analysed 70 patients with PMR, 20 with GCA, and 24 healthy controls (HC). TLR expression was assessed by flow cytometry. TLR function was assessed by stimulating PBMCs with specific ligands. RESULTS: A significantly increased expression of TLR7 in PBMCs of patients with active disease compared with HC was found. Despite increased expression of TLR7, circulating monocytes from patients showed a significantly lower in vitro response to TLR7 agonists. No amino acid substitutions predicted to be functionally damaging were found in TLR7. A normal response to specific TLR7 agonists in patients in complete remission eliminated a genetic defect. TLR expression and function were also affected to some degree in other diseases characterised by a strong acute phase response. CONCLUSION: These data suggest activation of TLR7 during the active phase of PMR and GCA which resolves with complete disease remission. Whether this finding is the consequence of the marked inflammatory process in these disorders or activation by natural ligands remains to be explored.

[Outbreak of streptococcal toxic shock syndrome in a day care center in Cantabria, Spain, 2006]. / Brote de síndrome de shock tóxico estreptocócico en una guardería de Cantabria en 2006.

BACKGROUND: Beta hemolytic group A streptococcus only exceptionally produces aggressive disease with high lethality. Even more uncommon is the occurrence of an outbreak. In Spain, no outbreak in child care center has been previously described. METHODS: Descriptive study of an outbreak of streptococcal toxic shock syndrome (3 cases, one lethal) in a child care center, which motivated the health care intervention with chemoprophylaxis, the closure of the child care center and the study of contacts. We analyzed the determinants of infection in the invasive and non-invasive cases, and the results of the pharyngeal culture of contacts. RESULTS: We identified 3 invasive and 14 non-invasive cases between 40 children attending the child care center (attack rate 42.5%). We studied 19 possible determinants of the infection, finding only an association with being over the age of 24 months and the assistance to the handouts classroom (that of the oldest children). It was not associated with chickenpox. All children attending the child care center, its staff (4 women) and 258 contacts were microbiologically investigated. In 12 children the emm 4 strain was isolated, including 2 of 3 cases with invasive disease. In 13 of 258 contacts other strains of beta hemolytic group A streptococcus were isolated, but in none of them the strain responsible of the outbreak was found. Azytromicin chemoprophylaxis was implemented for all children and contacts, and in those with a positive isolation, the culture was repeated until negative. CONCLUSIONS: The invasive strain circulated only in the child care center. Azytromicin chemoprophylaxis eradicated effectively the infection.

Brote de síndrome de shock tóxico estreptocócico en una guardería de Cantabria en 2006 / Outbreak of streptococcal toxic shock syndrome in a day care center in Cantabria, Spain, 2006

Fundamento: Las infecciones por estreptococo beta-hemolítico grupo A (EGA) sólo excepcionalmente son agresivas y con letalidad alta. Más infrecuente aún es la ocurrencia de un brote. El objetivo de este estudio es la descripción de un brote epidémico por estreptococo beta-hemolítico grupo A en una guardería de Cantabria. Métodos: Estudio descriptivo de un brote de síndrome de shock tóxico estreptocócico (3 casos, uno letal) en una guardería, que motivó una intervención de salud pública con quimioprofilaxis, cierre de la guardería y estudio de los contactos. Se analizan los determinantes de la infección en los casos invasivos y no invasivos, y los resultados de los cultivos faríngeos de los contactos. Resultados: Se identificaron 3 casos invasivos y 14 no invasivos entre los 40 niños de la guardería (tasa de ataque 42,5%). Se estudiaron 19 posibles determinantes de la infección, asociándose sólo la edad mayor de 24 meses y la asistencia al aula de fichas (la de los niños más mayores). No se asoció a la varicela. Se investigaron microbiológicamente todos los niños de la guardería y su personal (4 cuidadoras) y 258 personas de contacto. En 12 de los niños se aisló el estreptococo emm 4, incluyendo 2 de los 3 casos con enfermedad invasiva. En 13 de los 258 contactos se aislaron otras cepas de estreptococo, pero en ninguno la causante del brote. Se hizo quimioprofilaxis con azitromicina a todos los niños y contactos, y a los positivos se les repitió el tratamiento hasta su negativización. Conclusiones: La cepa invasiva circuló sólo en la guardería. La quimioprofilaxis erradicó efectivamente la infección (AU)

Background: Beta hemolytic group A streptococcus only exceptionally produces aggressive disease with high lethality. Even more uncommon is the occurrence of an outbreak. In Spain, no outbreak in child care center has been previously described. Methods: Descriptive study of an outbreak of streptococcal toxic shock syndrome (3 cases, one lethal) in a child care center, which motivated the health care intervention with chemoprophylaxis, the closure of the child care center and the study of contacts. We analyzed the determinants of infection in the invasive and non-invasive cases, and the results of the pharyngeal culture of contacts. Results: We identified 3 invasive and 14 non-invasive cases between 40 children attending the child care center (attack rate 42.5%). We studied 19 possible determinants of the infection, finding only an association with being over the age of 24 months and the assistance to the handouts classroom (that of the oldest children). It was not associated with chickenpox. All children attending the child care center, its staff (4 women) and 258 contacts were microbiologically investigated. In 12 children the emm 4 strain was isolated, including 2 of 3 cases with invasive disease. In 13 of 258 contacts other strains of beta hemolytic group A streptococcus were isolated, but in none of them the strain responsible of the outbreak was found. Azytromicin chemoprophylaxis was implemented for all children and contacts, and in those with a positive isolation, the culture was repeated until negative. Conclusions: The invasive strain circulated only in the child care center. Azytromicin chemoprophylaxis eradicated effectively the infection (AU)

[Hepatitis B and C virus antiviral resistance]. / Resistencias a los antivirales en los virus de las hepatitis B y C.

Infection by the hepatitis B (HBV) and C (HCV) viruses is a major cause of morbidity and mortality world-wide. The clinical outcomes of infection by these viruses (e.g., chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma) depend on several factors related to the host and the viral agent. Among the latter, factors associated with the response to current antiviral therapies, such as the emergence of resistance mutants and the genotype responsible for the infection, are gaining increasing importance. As has been established for human immunodeficiency virus (HIV), the presence of resistance mutations in the viral polymerase constitutes the main problem for treating HBV infection with approved drugs and those recently applied. Methods have been developed to detect these mutations, as well as algorithms to predict the response to treatment. The outcome of treatment for HCV infection is highly influenced by the viral genotype, however, and our understanding of the molecular basis for the response to interferon in these patients has grown considerably in recent years.

Resistencias a los antivirales en los virus de las hepatitis B y C / Hepatitis B and C virus antiviral resistance

Los virus de las hepatitis B (VHB) y C (VHC) son responsables de una elevada morbimortalidad de distribución mundial. Las consecuencias clínicas de las infecciones por estos virus (hepatitis crónica, cirrosis, hepatocarcinoma) van a depender de factores relacionados con el huésped y con el agente viral. Entre estos últimos, cada vez cobran más importancia aquellos que se relacionan con la respuesta al tratamiento antiviral, como son la aparición de mutantes de resistencia y la infección asociada a genotipos específicos del virus. En el caso del VHB, al igual que lo establecido para el virus de la inmunodeficiencia humana (VIH), es de vital importancia la presencia y acumulación de mutaciones responsables de la resistencia a los antivirales aprobados para el tratamiento de la infección, o de otros de reciente aplicación. Se han desarrollado técnicas para la detección de dichas mutaciones, así como algoritmos para predecir la respuesta al tratamiento. En los pacientes infectados por el VHC, sin embargo, la respuesta al tratamiento se encuentra más relacionada con la infección por genotípicos específicos, aunque en los últimos años se ha ampliado notablemente el conocimiento sobre los mecanismos moleculares de la respuesta al interferón en dichos pacientes (AU)

Infection by the hepatitis B (HBV) and C (HCV) viruses is a major cause of morbidity and mortality world-wide. The clinical outcomes of infection by these viruses (e.g., chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma) depend on several factors related to the host and the viral agent. Among the latter, factors associated with the response to current antiviral therapies, such as the emergence of resistance mutants and the genotype responsible for the infection, are gaining increasing importance. As has been established for human immunodeficiency virus (HIV), the presence of resistance mutations in the viral polymerase constitutes the main problem for treating HBV infection with approved drugs and those recently applied. Methods have been developed to detect these mutations, as well as algorithms to predict the response to treatment. The outcome of treatment for HCV infection is highly influenced by the viral genotype, however, and our inderstanding of the molecular basis for the response to interferon in these patients has grown considerably in recent years (AU)

Development of a new PCR assay to identify Brucella abortus biovars 5, 6 and 9 and the new subgroup 3b of biovar 3.

One hundred twenty-nine Brucella field strains isolated from cattle in Cantabria, Spain, from March 1999 to February 2003, were analysed by using the AMOS-ERY PCR assay and by Southern blot hybridisation with a probe from insertion sequence IS711. Most of the field isolates produced only the ery band in the AMOS-ERY assay and showed a hybridisation pattern identical to that exhibited by reference strains of biovars 5, 6 and 9 of Brucella abortus, but different from strain Tulya, belonging to biovar 3 of B. abortus. However, typing of these strains by standard methods demonstrated that they belonged to biovar 3 of B. abortus. These results indicated that B. abortus biovar 3 was not genetically homogeneous and at least could be divided in two. In one class, that we called biovar 3a, would be the Tulya strain, while the local field strains would belong to biovar 3b. Cloning and nucleotide sequencing of a DNA fragment containing an IS711 copy exclusive of the B. abortus field strains from biovar 3b and reference strains from biovars 5, 6 and 9, revealed the existence of a 5.4 kb deletion close to an IS711 copy. Based on these data, we designed a new primer, which together with the IS711 AMOS primer produced a PCR fragment of 1.7 kb only from the isolates of biovars 3b, 5, 6 and 9 of B. abortus. No amplification products were produced with these primers from strains of the rest of species and biovars of Brucella and from bacteria phylogenetically close to Brucella analysed in this work. Addition of this primer to the AMOS-ERY PCR primer cocktail allows the positive distinction of B. abortus biovars 3b, 5, 6 and 9 from the rest of Brucella species and biovars.