Beta-lactam antibiotics and viridans group streptococci / Antibióticos beta-lactámicos y estreptococos grupo viridans

Abstract The aim of this review is to present an update on the susceptibility of viridans groupstreptococci (VGS) to -lactam antimicrobials, with emphasis on the Argentinean scenario. VGSare a heterogeneous group including five groups of species, each one exhibiting peculiar sus-ceptibility patterns to penicillin (PEN). Species of the Streptococcus mitis group are frequentlynonsusceptible to PEN. PEN resistance is associated with changes in PEN-binding proteins. InArgentina, one to two thirds of VGS are nonsusceptible to PEN. Third generation cephalosporinsand carbapenems are currently more effective in vitro than PEN against VGS. Mortality was asso-ciated to nonsusceptibility to PEN in at least two studies involving patients with bacteremiacaused by VGS. Treatment of endocarditis due to VGS should be adjusted/to the PEN suscepti-bility of the isolates. Vancomycin may be an alternative choice for treating endocarditis causedby PEN-resistant isolates (MIC 4 g/ml).

Resumen El objetivo de esta revisión es presentar una actualización sobre la sensibilidad de los estreptococos del grupo viridans (EGV) a los antimicrobianos p-lactámicos, con énfasis en el escenario argentino. Los EGV son un grupo heterogéneo que incluye cinco grupos de especies, y cada una presenta su patrón especial de sensibilidad a la penicilina (PEN). Las especies del grupo Streptococcus mitis, con mayor frecuencia, no son sensibles a la PEN. La resistencia a la PEN se asocia con cambios de las proteínas ligadoras de PEN. En la Argentina, de uno a dos tercios de los EGV no son sensibles a la PEN. Las cefalosporinas de tercera generación y los carbapenemes son actualmente más eficaces in vitro que la PEN contra los EGV. La mortalidad se asoció con la no sensibilidad a la PEN en al menos dos estudios de pacientes con bacteriemia por EGV. El tratamiento de las endocarditis por EGV debe ajustarse según la sensibilidad a la PEN de los aislados. La vancomicina podría ser una elección alternativa para el tratamiento de las endocarditis por cepas resistentes a PEN (CIM >4 ^g/ml).

Beta-lactam antibiotics and viridans group streptococci.

The aim of this review is to present an update on the susceptibility of viridans group streptococci (VGS) to ß-lactam antimicrobials, with emphasis on the Argentinean scenario. VGS are a heterogeneous group including five groups of species, each one exhibiting peculiar susceptibility patterns to penicillin (PEN). Species of the Streptococcus mitis group are frequently nonsusceptible to PEN. PEN resistance is associated with changes in PEN-binding proteins. In Argentina, one to two thirds of VGS are nonsusceptible to PEN. Third generation cephalosporins and carbapenems are currently more effective in vitro than PEN against VGS. Mortality was associated to nonsusceptibility to PEN in at least two studies involving patients with bacteremia caused by VGS. Treatment of endocarditis due to VGS should be adjusted/to the PEN susceptibility of the isolates. Vancomycin may be an alternative choice for treating endocarditis caused by PEN-resistant isolates (MIC≥4µg/ml).

Empirical benchmarks for changes in social and emotional skills over time.

This study provides empirical benchmarks that quantify typical changes in students' reports of social and emotional skills in a large, diverse sample. Data come from six cohorts of students (N = 361,815; 6% Asian, 8% Black, 68% White, 75% Latinx, 50% Female) who responded to the CORE survey from 2015 to 2018 and help quantify typical gains/declines in growth mindset, self-efficacy, self-management, and social awareness. Results show fluctuations in skills between 4th and 12th grade (changes ranging from -.33 to .23 standard deviations). Growth mindset increases in fourth grade, declines in fifth to seventh grade, then mostly increases. Self-efficacy, self-management, and social awareness decline in sixth to eighth grade. Self-management and social awareness, but not self-efficacy, show increases in 10th to 12th grade.

Resistance to ß-lactams in Streptococcus pneumoniae.

Streptococcus pneumoniae is an important causal agent of pneumonia, meningitis, sepsis, bacteremia, and otitis media. Penicillin resistance rates in S. pneumoniae have remained stable in Argentina in the last years. In the late '90s more isolates with MIC of penicillin ≥2µg/ml were observed; however, their frequency has decreased in recent years. The phenotypic expression of penicillin resistance is due to a modification in penicillin-binding proteins associated with a mosaic structure in the coding genes. The expansion of successful resistant clones varies among the different regions and is influenced by the use of antibiotics, vaccines, particularly conjugated ones, as well as population density. Parenteral treatment with high doses of penicillin G continues to be effective for the treatment of pneumonia and bacteremia, oral aminopenicillins for otitis media and sinusitis and third generation cephalosporins for meningitis.

English learners' achievement in mathematics and science: Examining the role of self-efficacy.

The goals of the current study were twofold. The first goal was to describe levels of mathematics and science self-efficacy and achievement among a sample of students with varying levels of English language proficiency. The second goal was to examine the extent to which students' self-efficacy explains the relation between their English proficiency level and mathematics and science achievement. The sample consisted of 332 fifth graders (mean age = 10.46 years, SD = 0.38) and their 63 teachers in 20 schools. The student sample was linguistically diverse with parents reporting 22 different home languages. Based on district classification procedures, each student was coded into one of three English language proficiency level categories: English proficient-speaking students (English proficient), English Learner (EL) students who are reaching proficiency, yet are still being monitored (reaching proficiency), and EL students who are receiving English for Speakers of Other Languages services (ESOL; limited English proficient). Regression analyses indicated that students identified as limited English proficient consistently demonstrated lower achievement and self-efficacy across the content areas of mathematics and science as compared to their peers who were English proficient and reaching proficiency. In addition, students' self-efficacy partially explained the relation between limited English proficiency level and achievement for science, but not for mathematics. Results indicate that educators should consider variability in students' English proficiency levels as they select supports to promote both science achievement and self-efficacy. Findings also suggest promise for practices and programs that foster self-efficacy in addition to language and content skills.

Resistencia a los β -lactámicos en enterococos / Resistance to β-lactams in enterococci

Enterococci are intrinsically resistant to several antimicrobial classes and show a great ability to acquire new mechanisms of resistance. Resistance to β-lactam antibiotics is a major concern because these drugs either alone or in combination are commonly used for the treatment of enterococcal infections. Ampicillin resistance, which is rare in Enterococcus faecium occurs in most of the hospital-associated Enterococcus faecium isolates. High-level resistance to ampicillin in E. faecium is mainly due to the enhanced production of PBP5 and/or by polymorphisms in the beta subunit of this protein. The dissemination of high-level ampicillin resistance can be the result of both clonal spread of strains with mutated pbp5 genes and resistance horizontal gene transfer.

Los enterococos son intrínsecamente resistentes a varias clases de antimicrobianos y presentan una gran capacidad para adquirir mecanismos de resistencia. La resistencia a los antibióticos p-lactámicos es preocupante porque estos fármacos solos o combinados se usan comúnmente para el tratamiento de las infecciones enterocócicas. La mayoría de los aislamientos hospitalarios de Enterococcus faecium presentan resistencia a la ampicilina, la cual es rara en Enterococcus faecalis. El alto nivel de resistencia a la ampicilina en E. faecium se debe principalmente a la hiperproducción de PBP5 y/o a polimorfismos en la subunidad beta de esta proteína. La propagación de esta resistencia puede deberse tanto a la diseminación clonal de cepas con genes pbp5 mutados como a la transferencia horizontal de genes.

Endocarditis infecciosa por Mycobacterium mageritense asociada a dispositivo cardíaco electrónico / Electronic cardiovascular device-associated to infective endocarditis caused by Mycobacterium mageritense

Las micobacterias de crecimiento rápido son una rara causa de endocarditis bacteriana. Durante las últimas décadas han aumentado las infecciones debido a este tipo de micobacterias, en especial las postraumáticas y las posquirúrgicas. Estas infecciones pueden ser localizadas o diseminadas, y también pueden producir brotes nosocomiales debido a la contaminación del equipamiento médico. Por lo general, las tinciones para bacterias ácido-alcohol resistentes no se emplean de rutina en el procesamiento de hemocultivos positivos. Sin embargo, el microbiólogo debe estar atento al ver un bacilo gram positivo, ya que podría tratarse de una micobacteria de crecimiento rápido. Describimos un caso de endocarditis por de Mycobacterium mageritense en una paciente con parche pericárdico autógeno y un catéter para medir la presión en la aurícula izquierda. La bacteria fue identificada por espectrometría de masas (MALDI-TOF MS), score 2,3, y luego confirmada por secuenciación y análisis del gen ARNr 16s con las bases de datos del NCBI y EzTaxon, con una concordancia del 99,8 y el 100%, respectivamente.

Rapidly growing non-tuberculosis mycobacteria are a rare cause of bacterial endocarditis. During the last decades, there has been an increase in infections due to rapidly growing mycobacteria, mainly after trauma and post-surgical procedures, both localized and disseminated, as well as nosocomial outbreaks due to contamination of medical equipment. Routine acid-fast staining for blood culture bottles is not always performed; however, the microbiologist should be aware of potential RGM infections especially when gram positive bacilli are observed. We describe a case of endocarditis caused by Mycobacterium mageritense in a patient with an autologous pericardial patch and a pressure catheter in the left auricle. The bacterial species was identified as Mycobacterium mageritense by mass spectrometry (MALDI-TOF MS), score 2.3, and confirmed by 16S rRNA analysis with 99.8 and 100% agreement, respectively.

[Electronic cardiovascular device-associated to infective endocarditis caused by Mycobacterium mageritense]. / Endocarditis infecciosa por Mycobacterium mageritense asociada a dispositivo cardíaco electrónico.

Rapidly growing non-tuberculosis mycobacteria are a rare cause of bacterial endocarditis. During the last decades, there has been an increase in infections due to rapidly growing mycobacteria, mainly after trauma and post-surgical procedures, both localized and disseminated, as well as nosocomial outbreaks due to contamination of medical equipment. Routine acid-fast staining for blood culture bottles is not always performed; however, the microbiologist should be aware of potential RGM infections especially when gram positive bacilli are observed. We describe a case of endocarditis caused by Mycobacterium mageritense in a patient with an autologous pericardial patch and a pressure catheter in the left auricle. The bacterial species was identified as Mycobacterium mageritense by mass spectrometry (MALDI-TOF MS), score 2.3, and confirmed by 16S rRNA analysis with 99.8 and 100% agreement, respectively.

Resistance to ß-lactams in enterococci.

Enterococci are intrinsically resistant to several antimicrobial classes and show a great ability to acquire new mechanisms of resistance. Resistance to ß-lactam antibiotics is a major concern because these drugs either alone or in combination are commonly used for the treatment of enterococcal infections. Ampicillin resistance, which is rare in Enterococcus faecalis, occurs in most of the hospital-associated Enterococcus faecium isolates. High-level resistance to ampicillin in E. faecium is mainly due to the enhanced production of PBP5 and/or by polymorphisms in the beta subunit of this protein. The dissemination of high-level ampicillin resistance can be the result of both clonal spread of strains with mutated pbp5 genes and horizontal gene transfer.

Susceptibility to β-lactams in β-hemolytic streptococci / Sensibilidad a los β-lactámicos en estreptococos β-hemolíticos

Group A (GAS), B (GBS), c (GCS) and G (GGS) β-hemolytic streptococci are important human pathogens. They cause infections of different severity and frequency. Nowadays, after 70 years of use, penicillin is still universally active against GAS, GCS and GGS. However, therapeutic failures have been recorded in 2-28% of pharyngitis cases (median: 12%) attributable to different causes. By contrast, some GBS with reduced susceptibility to penicillin have been described, especially in Japan. In this group of bacteria, it is important to highlight that confirmation by reference methods is mandatory when decreased susceptibility to penicillin is suspected as well as checked for the detection of the mechanisms involved.

Los estreptococos β-hemolíticos de los grupos A (GAS), B (GBS), C (GCS) y G (GGS) son importantes patógenos humanos. Ellos producen infecciones de diversa gravedad y frecuencia. Aún después de más de 70 años de uso, la penicilina sigue siendo activa in vitro frente al 100% de los GAS, GCS y GGS. No obstante se han producido fallas terapéuticas entre el 2-28% de los casos de faringitis (media: 12%), atribuibles a diversas causas. En cambio se han descrito aislados de GBS con sensibilidad reducida a la penicilina, especialmente en Japón. Es importante que toda sospecha de sensibilidad disminuida a la penicilina en este grupo de bacterias sea confirmada por los métodos de referencia y comprobada mediante la detección de los mecanismos involucrados.

Susceptibility to ß-lactams in ß-hemolytic streptococci.

Group A (GAS), B (GBS), C (GCS) and G (GGS) ß-hemolytic streptococci are important human pathogens. They cause infections of different severity and frequency. Nowadays, after 70 years of use, penicillin is still universally active against GAS, GCS and GGS. However, therapeutic failures have been recorded in 2-28% of pharyngitis cases (median: 12%) attributable to different causes. By contrast, some GBS with reduced susceptibility to penicillin have been described, especially in Japan. In this group of bacteria, it is important to highlight that confirmation by reference methods is mandatory when decreased susceptibility to penicillin is suspected as well as checked for the detection of the mechanisms involved.

[Mycoplasma hominis bacteremia. An underestimated etiological agent]. / Bacteriemia por Mycoplasma hominis: un agente etiológico subestimado.

Mycoplasma hominis is a fastidious bacterium, which usually colonizes the lower urogenital tract and may cause systemic infections in neonates and genital infections in adults. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects. CASE PRESENTATION: We describe a case of bacteremia caused by M. hominis in a previously healthy woman after uterine curettage due to incomplete abortion. M. hominis could be an underestimated cause of bacteremia in immunocompetent patients. Mycoplasma organisms have fastidious growth requirements, are often difficult to culture on a cell-free medium and have no cell wall. The conventional method for detection may fail. This is the first report of M. hominis isolation from a positive automated blood culture (BD BACTEC, USA).

Prevalence of cryptococcal infection among advanced HIV patients in Argentina using lateral flow immunoassay.

BACKGROUND: Globally, Latin America ranks third among regions with most cases of AIDS related cryptococcal meningitis. In 2009, a lateral flow immunoassay (LFA) for the detection of cryptococcal antigen (CrAg) was developed as a potential point-of-care test for diagnosis of cryptococcal infection. In 2011 World Health Organizations recommended on CrAg screening for HIV positive persons with CD4 below 100 cells/µL, followed by preemptive fluconazole treatment. However, in Argentina no formal recommendations for CrAg screening have been issued. METHODS: HIV positive patients > = 18 years with advanced immunosuppression (CD4 counts ≤100 cells/µL within 3 months or WHO stage III/IV), who visited the hospital between April 1, 2014 and January 31, 2015, were included. The LFA was performed according to the manufacturer's instructions on all serum samples. When CrAg detection was positive, a lumbar puncture was performed to rule out cryptococcal meningitis. Patients without evidence of meningeal involvement were treated with preemptive oral fluconazole in ambulatory care. RESULTS: We included 123 patients. Prevalence of CrAg-positivity was 8.1%. Among the 10 CrAg-positive patients, 6 had meningeal involvement detected through the CSF analysis (CSF India-ink testing, CSF CrAg and culture). The remaining 4 patients with positive CrAg received targeted preemptive treatment with oral fluconazole and were free of cryptococcal disease during the follow-up period. None of the 113 patients with a negative CrAg test result developed cryptococcal disease. CONCLUSIONS: This is the first study in Argentina, to our knowledge, describing the prevalence of cryptococcosis and usefulness of CrAg screening. LFA provided early diagnosis to determine a high prevalence of CrAg in our hospital, and that screening for subclinical infection with preemptive antifungal treatment, prevented a substantial proportion of meningeal disease.

Are All Program Elements Created Equal? Relations Between Specific Social and Emotional Learning Components and Teacher-Student Classroom Interaction Quality.

School-based social and emotional learning (SEL) programs are presented to educators with little understanding of the program components that have the greatest leverage for improving targeted outcomes. Conducted in the context of a randomized controlled trial, the present study used variation in treatment teachers' (N = 143) implementation of four core components of the Responsive Classroom approach to examine relations between each component and the quality of teachers' emotional, organizational, and instructional interactions in third, fourth, and fifth grade classrooms (controlling for pre-intervention interaction quality and other covariates). We also examined the extent to which these relations varied as a function of teachers' baseline levels of interaction quality. Indices of teachers' implementation of Morning Meeting, Rule Creation, Interactive Modeling, and Academic Choice were derived from a combination of teacher-reported surveys and classroom observations. Ratings of teacher-student classroom interactions were aggregated across five observations conducted throughout the school year. Structural path models indicated that teachers' use of Morning Meeting and Academic Choice related to higher levels of emotionally supportive interactions; Academic Choice also related to higher levels of instructional interactions. In addition, teachers' baseline interaction quality moderated several associations such that the strongest relations between RC component use and interaction quality emerged for teachers with the lowest baseline interaction quality. Results highlight the value of examining individual program components toward the identification of program active ingredients that can inform intervention optimization and teacher professional development.

Warmth and Demand: The Relation Between Students' Perceptions of the Classroom Environment and Achievement Growth.

Theory suggests that African American students benefit from warm and demanding teachers. This study examines the relation between students' perceptions of 634 teachers' warm demander characteristics and achievement growth in fourth and fifth grades (Mstudent age  = 9-11.5 years). Analyses explored whether relations were moderated by the proportion of African American students in the classroom or the ethnic match or mismatch between African American students and their teachers. Results indicated that students' perceptions of teachers' demand (challenge and control) related to student achievement growth. Findings showed a stronger relation between challenge and academic growth in classrooms with more African American students, but no significant findings were identified for ethnic match or mismatch.

Infección tuberculosa meníngea (meningitis tuberculosa) en un paciente con sida y la aplicación del GeneXpert como herramienta diagnóstica / Tuberculous meningitis in a patient with aids and the application of GeneXpert as a diagnostic too

La infección por VIH incrementa la posibilidad de contraer tuberculosis; el riesgo resulta mayor para las formas extrapulmonares y dentro de estas, la meníngea. La infección por VIH no modifica las manifestaciones neurológi-cas pero disminuye significativamente la supervivencia. El método molecu-lar GeneXpert MTB/RIF (CEPHEID, USA), implementado en 2010, es un mé-todo de amplificación del ácido nucleico para Mycobacterium tuberculosis, en tiempo real, con la determinación adicional de la resistencia a rifampicina.Caso clínico: paciente con VIH de diagnóstico reciente que manifes-tó enfermedad consuntiva. El cuadro inicial fue de compromiso pulmo-nar y luego meníngeo; en ambos casos el método GeneXpert MTB/RIF detectó Mycobacterium tuberculosis resistente a rifampicina. Se utili-zaron drogas de segunda línea, por la presunción de estar frente a una tuberculosis multiresistente, por definición resistente al menos a iso-niacida y rifampicina. Desarrolló hidrocefalia y profundas secuelas.Conclusiones: este método molecular permitió la detección rápida de la tuberculosis, la implementación de medidas de aislamiento así como con-trol de la infección y el inicio temprano de una terapéutica más eficaz, tan-to en la forma pulmonar como meníngea

HIV infection increases the risk of developing any form of tuberculosis, but the risk is greater for meningitis and the extrapulmonary form. HIV infection does not alter the neurological manifestations, but significantly decreases survival. The GeneXpert MTB / RIF (CEPHEID, USA), implemented in 2010, is a real time PCR for Mycobacterium tuberculosis, with rifampicin sensitivity.Case report: patient with recent diagnosed HIV, stating wasting disease. The original picture involved lung and then meningeal compromise: In both cases the Xpert MTB / RIF detected the presence of Mycobacterium tuberculosis rimfapicin resistant. Second-line drugs were used by the presumption of being faced with multidrug-resistant tuberculosis that, by definition, is resistant to at least isoniazid and rifampin. Patient developed hydrocephalus and was severe aftermath.Conclusions: This molecular method allowed the rapid detection of tuberculosis, implementation of isolation measures as infection control and the early onset of a more effective therapy, both in the pulmonary form and the meningeal

Do student self-efficacy and teacher-student interaction quality contribute to emotional and social engagement in fifth grade math?

This study examined (a) the contribution of math self-efficacy to students' perception of their emotional and social engagement in fifth grade math classes, and (b) the extent to which high quality teacher-student interactions compensated for students' low math self-efficacy in contributing to engagement. Teachers (n = 73) were observed three times during the year during math to measure the quality of teacher-student interactions (emotional, organizational, and instructional support). Fifth graders (n = 387) reported on their math self-efficacy at the beginning of the school year and then were surveyed about their feelings of engagement in math class three times during the year immediately after the lessons during which teachers were observed. Results of multi-level models indicated that students initially lower in math self-efficacy reported lower emotional and social engagement during math class than students with higher self-efficacy. However, in classrooms with high levels of teacher emotional support, students reported similar levels of both emotional and social engagement, regardless of their self-efficacy. No comparable findings emerged for organizational and instructional support. The discussion considers the significance of students' own feelings about math in relation to their engagement, as well as the ways in which teacher and classroom supports can compensate for students lack of agency. The work has implications for school psychologists and teachers eager to boost students' engagement in math class.

[Rapid identification of microorganisms by mass spectrometry in a blood culture system. Comparison of two procedures]. / Identificación rápida de microorganismos de frascos de hemocultivos por espectrometría de masas. Comparación de 2 procedimientos diagnósticos.

Rapid identification of microorganisms is critical in hospitalized infected patients. Blood culture is currently the gold standard for detecting and identifying microorganisms causing bacteremia or sepsis. The introduction of mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) in microbiology laboratories, especially in microorganisms growing in blood culture bottles, provides rapid identification. This study evaluates the performance of the Maldi Sepsityper Biotyper procedure (hereinafter, MS) compared to that of an in-home method (hereinafter, HF). Eight hundred and forty (840) positive blood culture bottles were processed using the HF procedure, 542 of which were also processed using MS. The organisms were identified in 670 (79.76%) and 391 (72.14%) bottles respectively (p = 0,0013). This study demonstrates the effectiveness of both procedures for identifying microorganisms directly from positive blood culture bottles. However, the HF procedure proved to be more effective than MS, especially in the presence of Gram positive organisms.

Identificación rápida de microorganismos de frascos de hemocultivos por espectrometría de masas: Comparación de 2 procedimientos diagnósticos / Rapid identification of microorganisms by mass spectrometry in a blood culture system: Comparison of two procedures

La identificación rápida de microorganismos es crítica, en especial en pacientes sépticos hospitalizados. La espectrometría de masas conocida como matrix-assisted laser desorption/ionization time-of- flight mass spectrometry (MALDI-TOF MS) permite la identificación directa desde botellas de hemocultivos positivos en forma rápida y sencilla. Este estudio evaluó el desempeño del procedimiento basado en el sistema MALDI Biotyper que utiliza el kit comercial MALDI Sepsityper de Bruker Daltonics (en adelante, MS) frente a uno artesanal (en adelante, HF). Se procesaron 840 botellas de hemocultivos positivos con HF y 542 de estas fueron evaluadas también con MS. Se logró la identificación de los microorganismos en 670 (79,76 %) y 391 (72,14 %) botellas, respectivamente (p = 0,0013). Se demostró la efectividad de ambos procedimientos para la identificación de microorganismos desde frascos de hemocultivos positivos. Sin embargo, el procedimiento HF fue superior al MS, en especial frente a bacterias gram positivas.

Rapid identification of microorganisms is critical in hospitalized infected patients. Blood culture is currently the gold standard for detecting and identifying microorganisms causing bacteremia or sepsis. The introduction of mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) in microbiology laboratories, especially in microorganisms growing in blood culture bottles, provides rapid identification. This study evaluates the performance of the Maldi Sepsityper Biotyper procedure (hereinafter, MS) compared to that of an in-home method (hereinafter, HF). Eight hundred and forty (840) positive blood culture bottles were processed using the HF procedure, 542 of which were also processed using MS. The organisms were identified in 670 (79. 76 %) and 391 (72. 14 %) bottles respectively (p = 0,0013). This study demonstrates the effectiveness of both procedures for identifying microorganisms directly from positive blood culture bottles. However, the HF procedure proved to be more effective than MS, especially in the presence of Gram positive organisms.