Características radiográficas de la neumonía adquirida en la comunidad en el adulto inmunocompetente hospitalizado según el agente causal / Radiographic characteristics of community-acquired pneumonia in the immunocompetent adult hospitalized according to the etiologic agent

Resumen En la práctica clínica, la radiografía de tórax permite confirmar el diagnóstico y la extensión de la neumonía adquirida en la comunidad (NAC). Objetivos: Examinar las características radiográficas de la NAC según el agente causal y el grado de concordancia interobservador (CI) en la descripción de los hallazgos radiográficos. Métodos: Se evaluaron las radiografías de tórax de 300 pacientes adultos inmunocompetentes hospitalizados por NAC, tres residentes de radiología consignaron el patrón de los infiltrados pulmonares, su localización anatómica y extensión, la presencia de derrame pleural y otros hallazgos radiográficos. Se realizaron cultivos de esputo, hemocultivos, pruebas serológicas y técnicas de biología molecular de hisopado nasofaríngeo para identificar los principales patógenos respiratorios. Resultados: Las manifestaciones clínicas y los hallazgos de la radiografía de tórax fueron similares en las neumonías causadas por diferentes patógenos respiratorios: bacterias clásicas, virus respiratorios y microorganismos atípicos. En las neumonías bacterianas predominó el patrón de relleno alveolar de distribución lobar, en las neumonías vírales y atípicas predominó el patrón intersticial o mixto alvéolo-intersticial con opacidades en vidrio esmerilado. La CI fue satisfactoria (kappa > 0,6) para determinar el patrón principal de los infiltrados pulmonares, su localización anatómica y la presencia de derrame pleural, su localización y extensión. La CI fue moderada (kappa 0,4-0,6) para definir la extensión de la neumonía y detectar signos radiológicos asociados a congestión pulmonar. Conclusión: Los hallazgos de la radiografía de tórax no permitieron identificar con precisión el agente causal de la neumonía, siendo útil en la caracterización de los infiltrados pulmonares y para detectar complicaciones como el derrame paraneumónico.

In a clinical setting the chest radiograph is the reference standard in establishing the diagnosis of community-acquired pneumonia (CAP). Objectives: This study aimed to assess interobserver reliability (IR) of radiographic findings and the relationship to different respiratory pathogens in CAP. Methods: Chest radiographs of 300 immunocompetent adult patients hospitalized with pneumonia, obtained from a database, were reviewed by three residents of radiology without specific clinical information. Main pattern of pulmonary infiltrates, topographic localization, extent of pneumonia, presence of pleural fluid, thickened bronchial walls, lymphadenopathy and air bronchogram were scored. Sputum and blood cultures, serological tests and nasopharyngeal swab for respiratory virus detection by molecular diagnostic techniques were performed to identify the causative pathogen. Results: Clinical manifestations and chest X-ray findings were similar in pneumonias caused by different respiratory pathogens: classic bacteria, respiratory viruses and atypical microorganisms. The alveolar pattern of lobar distribution predominated in bacterial pneumonia; meanwhile, interstitial or mixed alveolar-interstitial pattern with ground glass opacities predominated in viral and atypical pneumonias. IR was fair to good (kappa > 0.6) for determining the main pattern of infiltrates, anatomical location and the presence of pleural effusion, their anatomical location and extension. IR was moderate (kappa 0.4-0.6) for determining the extent of pneumonia and signs of congestive heart failure. Conclusion: Simple features such as main pattern description, anatomical location, identifying the involved lobes and pleural fluid recognition showed fair to excellent interobserver reliability. Chest radiographs was of limited value in predicting the causative pathogen but were of beneficial use to characterize pulmonary infiltrates and to detect complications such as parapneumonic effusion.

Clinical factors associated with composition of lung microbiota and important taxa predicting clinical prognosis in patients with severe community-acquired pneumonia / 医学前沿

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R2 = 0.033; P = 0.018), followed by acute kidney injury (AKI; R2 = 0.032; P = 0.011) and plasma MIP-1β level (R2 = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.

Neumonía por Staphylococcus aureus resistente a meticilina adquirido de la comunidad en un hospital pediátrico. Nuestra experiencia de 10 años / Community-acquired methicillin-resistant Staphylococcusaureus pneumonia in a children's hospital. Our ten-year experience

Introducción. Las infecciones por Staphylococcus aureus resistente a meticilina adquirido de la comunidad (SARM-AC) se han incrementado en los últimos años. Neumonías necrotizantes y empiemas por SARM-AC son cada vez más frecuentes en niños.Objetivos. Determinar la prevalencia de neumonías por SARM-AC y sus características clínico-epidemiológicas, en comparación con las neumonías por Streptococcus pneumoniae (SP) en la misma población.Material y métodos. Estudio descriptivo, observacional, transversal, de pacientes internados con neumonía por SARM-AC en el Hospital de Niños Víctor J. Vilela (período: 1/2008-12/2017).Resultados. De 54 neumonías por Staphylococcus aureus, 46 (el 85 %) fueron SARM-AC. El índice de neumonías por SARM-AC varió de 4,9/10 000 (2008) a 10/10 000 egresos (2017). Presentaron sepsis/shock séptico el 41 %; empiema, el 96 %; neumotórax, el 35 %; requirieron drenaje pleural el 90 % y toilette quirúrgica el 55 %. Ingresaron a Terapia Intensiva el 65 %; la mitad necesitó asistencia respiratoria mecánica. Hubo dos muertes. Resistencia de las cepas: el 17 % a gentamicina, el 13 % a eritromicina, el 11 % a clindamicina. En las neumonías por SARM-AC vs. las neumonías por SP, se observó mayor riesgo de sepsis (IC 95 %; RR 7,38; 3,32-16,38) e ingreso a Terapia Intensiva (RR 4,29; 2,70-6,83). No hubo muertes por SP.Conclusiones. La prevalencia de neumonías por SARM-AC se duplicó durante la última década. Comparadas con las neumonías por SP, las neumonías por SARM-AC se acompañaron, más frecuentemente, de cuadros de sepsis y shockséptico, ingreso a Terapia Intensiva y asistencia respiratoria.

Introduction. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have increased in recent years. CA-MRSA necrotizing pneumonia and empyema are now more common in children.Objectives. To determine the prevalence of CA-MRSA pneumonia and its clinical and epidemiological characteristics compared to Streptococcus pneumoniae (SP) pneumonia in the same population.Material and methods. Descriptive, observational, cross-sectional study of patients hospitalized due to CA-MRSA pneumonia at Hospital de Niños Víctor J. Vilela (period: January 2008-December 2017).Results. Out of 54 Staphylococcus aureus pneumonia cases, 46 (85 %) corresponded to CA-MRSA. The rate of CA-MRSA pneumonia ranged from 4.9/10 000 (2008) to 10/10 000 hospital discharges (2017). Sepsis/septic shock was observed in 41 %; empyema, in 96 %; pneumothorax, in 35 %; 90 % of cases required pleural drainage and 55 %, surgical debridement. Also, 65 % of patients were admitted to the intensive care unit (ICU); half of them required assisted mechanical ventilation. Two patients died. Strain resistance: 17 %, gentamicin; 13 %, erythromycin; and 11 %, clindamycin. Compared to SP pneumonia, CA-MRSA pneumonia showed a higher risk for sepsis (95 % confidence interval; relative risk: 7.38; 3.32-16.38) and admission to the ICU (RR: 4.29; 2.70-6.83). No patient died due to SP pneumonia.Conclusions. The prevalence of CA-MRSA pneumonia doubled in the past decade. Compared to SP pneumonia, CA-MRSA pneumonia was more commonly accompanied by sepsis and septic shock, admission to the ICU, and ventilatory support requirement

Etiología y perfil de resistencia antimicrobiana en pacientes con infección urinaria adquirida en la comunidad / Etiology and antimicrobial resistance profile in patients with community-acquired urinary infections

Las infecciones del tracto urinario afectan al ser humano a lo largo de su vida y son frecuentes tanto en el ámbito comunitario como en el nosocomial. El objetivo de este estudio fue Identificar los principales agentes etiológicos y el perfil de resistencia a los antibióticos, presentado por los microorganismos más frecuentemente aislados de los urocultivos de pacientes con infección urinaria que acudieron al Laboratorio "Luis Razetti" Mérida -Venezuela, entre enero y junio de 2015. Este estudio fue de tipo observacional, de corte transversal y descriptivo. La población y muestra estuvo conformada por 149 pacientes de ambos sexos, cuyas muestras de orina fueron procesadas utilizado el método del asa calibrada y la identificación bacteriana mediante pruebas bioquímicas convencionales. La susceptibilidad antimicrobiana se determinó a través del método de difusión del disco en agar. Escherichia coli predominó en un 84,6 %, seguido de Proteus mirabilis y Enterococcus faecalis, ambos con (4,7 %). Los porcentajes más altos de resistencia para los aislados de E. coli, se observaron para ampicilina (92,06 %), ampicilina/sulbactam (68,25 %), ácido nalidíxico (38,89 %), ciprofloxacina (38,89 %) y trimetroprim­sulfametoxazol (54,76 %); y presentaron altos niveles de sensibilidad a Nitrofurantoína (80,95 %). El 5,15 % de las cepas de E. coli se mostraron fenotípicamente productoras de belalactamasa de espectro extendido y el 35,29 % de las otras Enterobacteriaceae aisladas, presentaron un perfil fenotípico compatible con la producción de la enzima Inhibitory-resistant TEM (IRT). Es importante destacar que estos estudios permiten conocer la etiología a de infecciones urinarias en la comunidad, así como los perfiles de resistencia y sensibilidad a nivel local, datos relevantes para establecer pautas de tratamiento empírico adaptadas a cada medio.

Urinary tract infections affect the human being throughout his life and are among the most frequent in both the community and nosocomial settings. The Aim of this study was to Identify the main etiological agents and antibiotic resistance profile presented by isolated microorganisms in the urocultures of patients with urinary tract infection who attended the Laboratory "Luis Razetti" Mérida -Venezuela, between January and June 2015. This study was observational, cross-sectional and descriptive. The population and sample consisted of 149 patients of both sexes, whose urine samples were processed using the calibrated handle method and bacterial identification through conventional biochemical tests. The antimicrobial susceptibility is determined through the disk diffusion method in agar. Escherichia coli dominated by 84.6 %, followed by Proteus mirabilis and Enterococcus faecalis, both with (4.7 %). The highest percentages of resistance for E. coli were observed for ampicillin (92.06 %), ampicillin/sulbactam (68.25 %), nalidixic acid (38.89 %), ciprofloxacin (38.89 %) trimetroprim-sulfamethoxazole (54.76 %); and had high levels of sensitivity to Nitrofurantoin (80.95 %). 5.15 % of E. coli strains were phenotypically producing extended-spectrum belalactamase and 35.29 % of others Enterobacteriaceae isolated had a phenotypic profile compatible with the production of the Enzyme Inhibitoryresistant TEM (IRT). It is important to note that these studies allow knowing the etiology of urinary tract infections in the community as well as resistance and sensitivity profiles at the local level, relevant data to establish empirical processing guidelines tailored to each medium.

Clinical and microbiological characteristics of community-acquired pneumonia associated with Streptococcus pneumoniae in adult patients in Mexico / Características clínicas y microbiológicas de la neumonía adquirida en la comunidad asociada con Streptococcus pneumoniae en pacientes adultos en México

The aim of this study was to assess the risk factors and clinical and microbiological characteristics of community-acquired pneumonia (CAP) in adult patients in Mexico. Streptococcus pneumoniae classified as the causative agent of CAP in adult patients and patients with invasive S. pneumoniae isolates presented to three tertiary teaching hospitals during the 15-year study period were selected. Serotyping and susceptibility testing were performed for all included isolates. Clinical and demographic data were recorded. A total of 96 patients infected with S. pneumoniae (71 with CAP, 25 with invasive disease) were included. The CAP group involved more males (74.6%) than the invasive disease group (p = 0.03). Head trauma was more common in the CAP group (21.1%) than in the invasive disease group (4.0%; p = 0.03). The most prevalent serotype was 19A, followed by serotypes 3 and 23F. After the introduction of the heptavalent conjugated pneumococcal vaccine (PCV7), the prevalence of included serotypes declined significantly; no such change was found after the introduction of the PCV13 vaccine, including in the prevalence of serotype 19A. Susceptibility to all antimicrobials tested except vancomycin declined over the study period. In conclusion, head trauma was the most common comorbidity in the CAP group. The most prevalent serotype was 19A. Decreased susceptibility to most antimicrobials tested was observed.

El objetivo de este estudio fue evaluar los factores de riesgo y las características clínicas y microbiológicas de la neumonía adquirida en la comunidad (NAC) en pacientes adultos en México. Se seleccionaron pacientes adultos con NAC con Streptococcus pneumoniae como agente causal y pacientes con aislamientos invasivos de S. pneumoniae que concurrieron a tres hospitales de enseñanza de tercer nivel durante el período de estudio de 15 anos (2000-2015). Se realizaron pruebas de serotipificación y sensibilidad con todos los aislados incluidos. Se colectaron los datos clínicos y demográficos. Se incluyeron en total 96 pacientes infectados con S. pneumoniae (71 con NAC y 25 con enfermedad invasiva). El grupo con NAC incluía más varones (74,6%) que el grupo de enfermedad invasiva (p = 0,03). El traumatismo craneoencefálico fue más frecuente en el grupo NAC (21,1%) queen el grupo con enfermedad invasiva (4,0%; p = 0,03). El serotipo más frecuente fue 19A, seguido de los serotipos 3 y 23F. Después de la introducción de la vacuna antineumocócica conjugada heptavalente (PCV7), la prevalencia de los serotipos incluidos en aquella disminuyó significativamente; no sucedió lo mismo después de la introducción de la PCV13, incluso en relación con la prevalencia del serotipo 19A. La sensibilidad a todos los antimicrobianos evaluados, excepto la vancomicina, disminuyó durante el período de estudio. En conclusión, el traumatismo craneoencefálico fue la comorbilidad más frecuente en el grupo con NAC. El serotipo más frecuente fue el 19A, y se observó disminución de la sensibilidad a la mayoría de los antimicrobianos probados a lo largo del período considerado.

Caracterización de los pacientes con bacteriemia por Staphylococcus aureus resistente a la meticilina en un hospital militar de alta complejidad / Characterization of patients with bacteremia by methicillin-resistant Staphylococcus aureus in a high-complexity military hospital

Resumen Introducción. En las Fuerzas Militares de Colombia, cerca de 500.000 de sus miembros asisten a consulta en los establecimientos sanitarios militares. En esta población, Staphylococcus aureus resistente a la meticilina (SAMR) se ha convertido en un agente patógeno de gran incidencia. Objetivo. Caracterizar los pacientes con diagnóstico de bacteriemia por SAMR en el Hospital Militar Central entre el 2012 y el 2015. Materiales y métodos. Se llevó a cabo un estudio observacional descriptivo de revisión retrospectiva de historias clínicas de pacientes mayores de 18 años, hospitalizados y con hemocultivos positivos para S. aureus resistente a la meticilina. Para la identificación de los pacientes se empleó el sistema Whonet, version 5.6. Resultados. De los 177 cultivos positivos para S. aureus, el 24,8 % (n=44) correspondió a SAMR, con mayor prevalencia en pacientes militares activos(n=20m 45,4 %). Se observó una frecuencia similar para la bacteriemia por SAMR adquirida en la comunidad y la adquirida en el hospital, siendo más frecuente (n=37, 84 %) el fenotipo de la comunidad en ambos grupos. El principal foco infeccioso fueron los tejidos blandos, seguidos por el tejido pulmonar. Se presentaron mayores tasas de complicaciones (61%, n=13) en la bacteriemia adquirida en el hospital; 34,9 % (n=15),de los pacientes tuvieron una estancia hospitalaria prolongada atribuible a las complicaciones desencadenadas por la bacteriemia. Conclusiones. La población más afectada por SAMR fueron los pacientes militares activos (n=20, 45,4 %), con una frecuencia similar de la bacteriemia adquirida en la comunidad (n=18, 43,2 %) y la adquirida en el hospital (n=25, 56,8 %), y el principal foco infeccioso fueron los tejidos blandos. Dados estos resultados, es necesario adelantar estudios para establecer la prevalencia de infecciones por SAMR en la piel.

Abstract Introduction: In Colombia, there are about 500,000 members in the national armed forces who consult military health institutions. In this population, methicillin-resistant Staphylococcus aureus (MRSA) has become a high-incidence pathogen. Objective: The aim of this study was to characterize patients with MRSA bacteremia in the Hospital Militar Central between 2012 and 2015. Materials and methods: This was an observational descriptive study with a retrospective review of clinical histories of hospitalized patients older than 18 years of age with positive blood cultures for methicillin-resistant S. aureus. The identification of the patients was made using the Whonet system, version 5.6. Results: From cultures positive for S. aureus, 24.8% were methicillin-resistant strains, with a higher prevalence in active military personnel. A similar frequency was observed for community-acquired MRSA bacteremias and those acquired at the hospital, with the community phenotype being the most frequent in both groups. The main infectious focus related to the development of bacteremia was soft tissue, followed by pulmonary tissue. There were higher complication rates in nosocomial bacteremias; 34.9% of the patients had prolonged stays attributable to complications triggered by the bacteremia. Conclusions: Active military personnel was the most affected population by MRSA, with a similar frequency in community-acquired and nosocomial bacteremias. The main infectious focus was soft tissue. Taking into account these data, studies that establish the prevalence of skin infections by MRSA should be carried out.

Multidrug resistance and risk factors associated with community-acquired urinary tract infections caused by Escherichia coli in Venezuela / Multirresistencia a medicamentos y factores de riesgo asociados con infecciones urinarias por Escherichia coli adquiridas en la comunidad, Venezuela

Abstract Introduction: The treatment of urinary tract infections has become more challenging due to the increasing frequency of multidrug-resistant Escherichia coli in human populations. Objective: To characterize multidrug-resistant E. coli isolates causing community-acquired urinary tract infections in Cumaná, Venezuela, and associate possible risk factors for infection by extended-spectrum beta-lactamases (ESBL)-producing isolates. Materials and methods: We included all the patients with urinary tract infections attending the urology outpatient consultation and emergency unit in the Hospital de Cumaná, Estado Sucre, Venezuela, from January through June, 2014. blaTEM, blaSHV and blaCTX-M genes detection was carried out by PCR. Results: We found a high prevalence of multidrug-resistant E. coli (25.2%) with 20.4% of the isolates producing ESBL. The ESBL-producing isolates showed a high frequency (66.7%) of simultaneous resistance to trimethoprim-sulphamethoxazole, fluoroquinolones and aminoglycosides compared to non-producing isolates (2.4%). Of the resistant isolates, 65.4% carried the blaTEM gene, 34.6% the blaCTX-M and 23.1% the blaSHV. The blaCTX-M genes detected belonged to the CTX-M-1 and CTX-M-2 groups. Plasmid transfer was demonstrated by in vitro conjugation in 17 of the 26 ESBL-producing isolates. All three genes detected were transferred to the transconjugants. Age over 60 years, complicated urinary tract infections and previous use of a catheter predisposed patients to infection by ESBL-producing E. coli. Conclusions: The high frequency of multidrug-resistant ESBL-producing isolates should alert the regional health authorities to take measures to reduce the risk of outbreaks caused by these types of bacteria in the community.

Resumen Introducción. El tratamiento de las infecciones urinarias constituye un reto creciente por el aumento de Escherichia coli proveniente de la comunidad multirresistente a los medicamentos. Objetivo. Caracterizar aislamientos de E. coli multirresistente causantes de infecciones urinarias adquiridas en la comunidad en Cumaná, Venezuela, y detectar los posibles riesgos de infección por aislamientos productores de betalactamasas de espectro extendido (BLEE). Materiales y métodos. Se incluyeron todos los pacientes atendidos en la consulta externa de urología y en urgencias del Hospital de Cumaná entre enero y junio de 2014 y que evidenciaban infecciones urinarias. La detección de los genes blaTEM, blaSHV y blaCTX-M se hizo mediante la reacción en cadena de la polimerasa (PCR). Resultados. Se encontró una alta prevalencia de E. coli multirresistente a los medicamentos (25,2 %), con 20,4 % de aislamientos productores de BLEE y una gran frecuencia de resistencia simultánea a trimetoprim-sulfametoxazol, fluoroquinolonas y aminoglucósidos (66,7 %) comparados con los no productores (2,4 %). En el 65,4 % de los aislamientos resistentes, se encontró el gen blaTEM; en 34,6 %, el blaCTX-M, y en 23,1 %, el blaSHV. Los genes blaCTX-M detectados pertenecían a los grupos CTX-M-1 y CTX-M-2. Se demostró la transferencia in vitro de plásmidos por conjugación en 17 de los 26 aislamientos productores de BLEE. Los tres tipos de genes detectados se transfirieron a los transconjugantes. La edad mayor de 60 años, las infecciones urinarias con complicaciones y el uso previo de catéter, predispusieron a la infección por cepas de E. coli productoras de BLEE. Conclusiones. La gran frecuencia de aislamientos multirresistentes productores de BLEE debería alertar a las autoridades sanitarias para tomar medidas que reduzcan el riesgo de epidemias causadas por este tipo de bacterias en la comunidad.

Molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from hospital and community environments in northeastern Brazil

ABSTRACT This study characterized 30 MRSA isolates from intensive care unit (ICU) environment and equipment surfaces and healthy children. The SCCmec types I, IVa and V were detected in HA-MRSA isolates while CA-MRSA showed the SCCmec type IVa and V. Most isolates were classified as agr group II. All isolates presented the sei gene, and only HA-MRSA were positive for etb e tst genes. Three genotypes were related to Pediatric (ST5/SCCmecIV) and Berlin (ST45/SCCmecIV) clones. The present study showed molecular similarity between CA- and HA-MRSA isolates in hospital and community settings in a Brazilian region.

Características clínicas de la neumonía adquirida en la comunidad del adulto inmunocompetente hospitalizado según el agente causal / Features of community-acquired pneumonia in immunocompetent hospitalized adults according to the causal agent

Background: Molecular biological techniques allow the identification of more pathogens associated with community-acquired pneumonia (CAP). Aim: To compare clinical and laboratory parameters of patients with CAP caused by different groups of pathogens. Material and Methods: In a prospective study, immunocompetent adult patients hospitalized with CAP were tested for the presence of a broad range of possible respiratory pathogens using bacterial cultures, polymerase chain reaction, urinary antigen testing and serology. Results: Pathogens were detected in 367 of 935 patients with CAP (39.2%). Streptococcus pneumoniae (10.7%) and influenza virus (6%) were the most frequently identified bacterial and viral pathogens, respectively. Pneumococcal pneumonia predominated in older adults, with multiple comorbidities, with elevation of inflammatory parameters and hypoxemia, like other bacterial pneumonias. Viral pneumonia predominated in elderly patients with multiple comorbidities, with a shorter hospital length of stay and lower mortality. Pneumonia associated with atypical microorganisms predominated in young adults, smokers, with subacute clinical evolution. Their hospital stays and lethality was similar to other bacterial pneumonias. Viral and classical bacterial pneumonias predominated in high risk pneumonia severity index categories. Although several variables were associated with the detection of a pathogen group, substantial overlap avoided the identification of reliable clinical predictors to distinguish etiologies. Conclusions: The clinical and radiographic characteristics were similar in pulmonary infections caused by classical bacteria, respiratory viruses and atypical microorganisms. Therefore, microbial testing for common respiratory pathogens is still necessary to optimize treatment.

Molecular analysis, biofilm formation, and susceptibility of methicillin-resistant staphylococcus aureus strains causing community- and health care-associated infections in central venous catheters

Abstract INTRODUCTION: The behavior of methicillin-resistant Staphylococcus aureus (MRSA) isolated from central venous catheter-related infection was evaluated to determine its biofilm potential, antimicrobial resistance, and adhesion genes. METHODS: A total of 1,156 central venous catheters (CVC) were evaluated to screen for pathogens. Antimicrobial sensitivity, biofilm formation potential, and molecular analysis of MRSA were examined following standard guidelines. RESULTS: Of the 1,156 samples, 882 (76%) were colonized by bacteria or candida. Among the infected patients, 69% were male and 36% were female with median age of 32 years. Staphylococcus aureus infected 39% (344/882) of CVCs in patients. Of the 59% (208/344) of patients with MRSA, 57% had community acquired MRSA and 43% had hospital acquired MRSA. Linezolid and vancomycin killed 100% of MRSA; resistance levels to fusidic acid, doxycycline, clindamycin, azithromycin, amikacin, trimethoprim-sulfamethoxazole, gentamycin, tobramycin, and ofloxacin were 21%, 42%, 66%, 68%, 72%, 85%, 95%, 97%, and 98% respectively. Strong biofilm was produced by 23% of samples, moderate by 27%, and weak by 50% of MRSA. The presence of adhesion genes, sdrC and sdrD (90%), eno (87%), fnbA (80%), clfA and sdrE (67%), fnbB, sdrD (61%), and cna (51%), in most MRSA samples suggested that the adhesion genes are associated with biofilm synthesis. CONCLUSIONS: The superbug MRSA is a major cause of CVC-related infection. Antibiotic resistance to major classes of antibiotics and biofilm formation potential enhanced superbug MRSA virulence, leading to complicated infection. MRSA causes infection in hospitals, communities, and livestock.

Is community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) an emerging pathogen among children in Brazil?

ABSTRACT Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is spreading worldwide, but little is known about the epidemiology of this pathogen in Brazil. Objective: To evaluate clinical and microbiological features of children with S. aureus infections admitted to a university hospital. Methods: This was a cross-sectional study evaluating the potential risk factors for CA-MRSA, and a retrospective cohort evaluating in-hospital clinical outcomes. To include patients with both community and hospital-associated infections, we screened the results of the microbiological laboratory tests from January 1, 2012, to December 31, 2016. According to the phenotype, we classified the isolates in Methicillin-Susceptible S. aureus (MSSA), Hospital-Associated Methicillin-Resistant S. aureus (HA-MRSA), and CA-MRSA. Clinical data were collected from the patients' medical records. Results: We identified 279 cases of S. aureus infections (MSSA = 163, CA-MRSA = 69, HA-MRSA = 41). Overall, the incidence density of CA-MRSA and MSSA infections increased while the HA-MRSA incidence density decreased over the study period. CA-MRSA infected patients were more likely to present with skin and soft tissue infections (OR: 2.83, 95%CI: 1.54-5.33, p < 0.001) and osteomyelitis (OR: 4.76; 95%CI: 1.16-22.71, p = 0.014) when compared to MSSA and HA-MRSA infections. Unadjusted case fatality rates were similar between MSSA-infected patients (3.14%, 5/159) and CA-MRSA infected patients (3.80%, 3/79, p = 0.792), while HA-MRSA infected patients were more likely to die in the hospital (12.20%, 5/41, p = 0.013). Conclusions: CA-MRSA is an emergent pediatric pathogen in Brazil. Our results highlight the relevance of choosing an appropriate initial antimicrobial drug for treating children with severe S. aureus infections.

Neumonía neumocócica bacteriémica en adultos en hospital regional de Chile / Bacteremic pneumococcal pneumonia in adults admitted to a general hospital: experience in 60 cases

Background: Bacteremic pneumococcal pneumonia (BPP) is a preventable disease with high morbimortality. Aim: To evaluate clinical aspects and mortality on BPP patients admitted to a Chilean regional hospital. Patients and Methods: We looked for adult patients with Streptococcus pneumoniae isolated from blood cultures between 2010 and 2014 years and reviewed clinical records of those who were admitted with pneumonia. Results: We identified 70 BPP patients: 58% were men, mean age was 56 years, 30% were > 65 years, 70% with basic public health insurance, 26% were alcoholics, 86% had comorbidities. Only two patients were vaccinated against S. pneumoniae. CURB-65 severity index for community acquired pneumonia was > 3 in 37% of patients. Twenty-four patients were admitted to ICU, twenty required mechanical ventilation and twenty-four died (34%). Mortality was associated with an age over 65 years, presence of comorbidities and complications of pneumonia. A total of 22 serotypes of S. pneumoniae were identified, five of them (1,3,7F,14 y 9V) were present in 57% of cases. Conclusions: Elevated mortality of our BNN patients was associated with comorbidities and possibly with socio economic factors, which conditioned a late access to medical care.

A study of community-acquired Mycoplasma pneumoniae in Yantai, China / Estudio de Mycoplasma pneumoniae adquirido en la comunidad en Yantai, China

Abstract Introduction: Community-acquired pneumonia (CAP) is a global disease responsible for a large number of deaths, with significant economic impact. As diagnostic tools have increased in sensitivity, understanding of the etiology of CAP has begun to change. Mycoplasma pneumoniae is one of the major pathogens causing CAP. Macrolides and related antibiotics are first-line treatments for M. pneumoniae. Macrolide resistance has been spreading for 15 years and now occurs in worldwide. We undertook the first study on macrolide resistance of M. pneumoniae in Yantai. This may be helpful to determine the appropriate therapy for CAP in this population. Objective: To investigate the rate and mechanism of macrolide resistance in Yantai. Methods: Pharyngeal swab samples were collected from adult CAP patients. Samples were assayed by polymerase chain reaction (PCR) and cultivated to test for M. pneumoniae. Nested PCR was used to specifically amplify M. pneumoniae 23S rRNA gene fragments containing mutations, and amplicons were analyzed by CE-SSCP for macrolide resistance mutations. Results were confirmed by sequencing. Twenty-seven strains of M. pneumoniae were isolated and the activities of nine antibiotics against M. pneumoniae were tested in vitro. Results: Out of 128 samples tested, 27 were positive for M. pneumoniae. Mycoplasma 100% macrolides resistance to Mycoplasma pneumoniae. The mechanism of macrolides resistance was A2063G point mutation in the sequence directly binding to macrolides in the 23S rRNA V domain in vitro. The mean pyretolytic time for the fluoroquinolone group was 4.7 ±2.9 d, which was significantly shorter than 8.2 ±4.1 d for the azithromycin group. Conclusions: Macrolides are not the first-line treatment for M. pneumoniae respiratory tract infections in Yantai.

Resumen Introducción: Neumonía adquirida por en la comunidad (NAC) es una enfermedad responsable por un gran número de muertes y un impacto económico importante. Debido a que el diagnostico incrementó la sensibilidad, se cambió la etiología de la NAC. Adicionalmente, Mycoplasma pneumoniae es uno de los patógenos que causan la NAC. Los macrólidos y antibióticos relacionados son la primera línea de tratamiento para M. pneumoniae. La resistencia a macrólidos se aumentó en los últimos 15 años y ahora se encuentra distribuido en todo el mundo. Nosotros realizamos el primer estudio de resitencia a M. pneumoniae a los macrólidos en Yantai. Esto podría ser útil para determinar una terapia apropiada para NAC en esta población. Objetivo: Investigar la tasa y el mecanismo para la resitencia a los macrólidos en Yantai. Métodos: Se colectaron muestras faringeas usando un hisopo. Las muestras se analizaron mediante la reacción en cadena de la polimerasa (PCR) y por cultivo para M. pneumoniae. Se uso una PCR anidad para amplificar fragmentos del gen 23S rRNA especifico con las mutaciones para M. pneumoniae. Se analizaron amplicomes por CE-SSCP para determinar la resitencia a los macrólidos. Estos resultados se confirmaron por secuenciación. Se aislaron 27 cepas de M. pneumoniae y se probaron nueve antibióticos in vitro. Resultados: De 128 muestras, 27 fueron positivas para M. pneumoniae. Se determinó una resistencia a macrólidos por Mycoplasma del 100%. Los mecanismos de esta resitencia fue una mutacion punctual A2063G en la secuencia que se une directamente a los macrólidos en el dominio 23S rRNA V in vitro. El tiempo piotolítico medio para el grupo de fluoroquinolonas fue 4.7 ±2.9 d, que fue significativamente más corto que para el grupo de azitromicina: 8.2 ±4.1 d. Conclusiones: Los macrólidos no son la primera linea de tratamiento para las infecciones del tracto respiratorio contra M. pneumoniae respiratory tract infections en Yantai.

Infecciones por Staphylococcus aureus meticilino resistente adquirido en la comunidad: experiencia de 10 años en un hospital pediátrico de Rosario, Argentina / Community-acquired methicillin-resistant Staphylococcus aureus infections: 10-years' experience in a children's hospital in the city of Rosario, Argentina

Introducción: Las infecciones por Staphylococcus aureus meticilino resistente adquirido en la comunidad (SAMR-ac) son motivo de consulta frecuente en pediatría. La mayoría se presentan como infecciones de piel y partes blandas; sin embargo, en la última década, se ha constatado un aumento de las infecciones invasivas. Objetivos: El objetivo principal es describir las características clínico-epidemiológicas de las infecciones producidas por SAMR-ac. El objetivo secundario es comparar la prevalencia, presentación clínica y susceptibilidad antibiótica con un período previo de estudio (1/2004-12/2007). Material y métodos: Estudio descriptivo, prospectivo, de tipo transversal. Criterios de inclusión: niños con diagnóstico de infección por SAMR-ac admitidos en el Hospital de Niños de Rosario, período de enero de 2008 a diciembre de 2014. Criterios de exclusión: internación reciente, antibiótico o cirugía previa, comorbilidades o inmunocompromiso. Resultados: De 728 niños con infecciones por Staphylococcus aureus, 529 (73%) fueron por SAMR-ac. La tasa de incidencia de infecciones por SAMR-ac varió de 12,2/10 000 egresos hospitalarios de 2004 a 145/10 000 del 2014: 75% (391) fueron infecciones de piel y partes blandas; 8% (43), os teo articular es; 6% (30), pleuropulmonares; 5% (24), sepsis. Se observó un aumento en el número de infecciones invasivas en el 2º período sin significancia estadística (OR= 0,895; IC: 0,52-1,53). La resistencia a gentamicina, clindamicina y eritromicina se mantuvo estable en ambos períodos. Conclusión: Las infecciones por SAMR-ac fueron cada vez más frecuentes, principalmente, las de piel y partes blandas. Se observó un aumento en el número de infecciones invasivas sin significancia estadística. La resistencia antibiótica se mantuvo estable.

Introduction: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are a common reason for consultation in pediatrics. Most of them present as skin and soft tissue infections; however, invasive infections have increased during the last decade. Objectives: The main objective was to describe the clinical-epidemiological characteristics of CA-MRSA infections. The secondary objective was to compare prevalence, clinical presentation and antibiotic susceptibility with a pre-study period (1/2004-12/2007). Material and methods: This is a descriptive, prospective, cross-sectional study. Inclusion criteria: children who have been diagnosed with CA-MRSA infection and admitted to Hospital de Niños de Rosario between January 2008 and December 2014. Exclusion criteria: recent hospitalization, previous antibiotic treatment or surgery, comorbidities or immune compromise. Results: Out of 728 cases of children with Staphylococcus aureus infections, 529 (73%) were due to CA-MRSA. The incidence rate of CA-MRSA infections varied from 12.2/10 000 hospital discharges in 2004 to 145/10 000 in 2014: 75% (391) were skin and soft tissue infections; 8% (43) were osteoarticular infections; 6% (30), pleuropulmonary infections; 5% (24), sepsis. There was an increase in the number of invasive infections in the second period, with no statistical significance (OR= 0.895; CI: 0.52-1.53). Gentamicin, clindamycin and erythromycin resistance remained stable throughout both periods. Conclusion: CA-MRSA infections were increasingly more frequent, mainly skin and soft tissue infections. An increase was observed in the number of invasive infections, with no statistical significance. Antibiotic resistance remained stable.

Infection by Streptococcus pneumoniae in children with or without radiologically confirmed pneumonia / Infecção por Streptococcus pneumoniae em crianças com ou sem pneumonia radiologicamente confirmada

Abstract Objective: Community-acquired pneumonia is an important cause of morbidity in childhood, but the detection of its causative agent remains a diagnostic challenge. The authors aimed to evaluate the role of the chest radiograph to identify cases of community-aquired pneumonia caused by typical bacteria. Methods: The frequency of infection by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis was compared in non-hospitalized children with clinical diagnosis of community acquired pneumonia aged 2-59 months with or without radiological confirmation (n = 249 and 366, respectively). Infection by S. pneumoniae was diagnosed by the detection of a serological response against at least one of eight pneumococcal proteins (defined as an increase ≥2-fold in the IgG levels against Ply, CbpA, PspA1 and PspA2, PhtD, StkP-C, and PcsB-N, or an increase ≥1.5-fold against PcpA). Infection by H. influenzae and M. catarrhalis was defined as an increase ≥2-fold on the levels of microbe-specific IgG. Results: Children with radiologically confirmed pneumonia had higher rates of infection by S. pneumoniae. The presence of pneumococcal infection increased the odds of having radiologically confirmed pneumonia by 2.8 times (95% CI: 1.8-4.3). The negative predictive value of the normal chest radiograph for infection by S. pneumoniae was 86.3% (95% CI: 82.4-89.7%). There was no difference on the rates of infection by H. influenzae and M. catarrhalis between children with community-acquired pneumonia with and without radiological confirmation. Conclusions: Among children with clinical diagnosis of community-acquired pneumonia submitted to chest radiograph, those with radiologically confirmed pneumonia present a higher rate of infection by S. pneumoniae when compared with those with a normal chest radiograph.

Resumo Objetivo: Avaliar o papel do raios X de tórax na identificação de casos de pneumonia adquirida na comunidade (PAC) causada por agentes bacterianos. Métodos: A frequência de infecção por Streptococcus pneumoniae, Haemophilus influenzae e Moraxella catarrhalis em crianças com PAC não hospitalizadas foi comparada com a presença de confirmação radiológica da pneumonia (n = 249 crianças com pneumonia radiologicamente confirmada e 366 crianças com raios X de tórax normal). Infecção por S. pneumoniae foi diagnosticada com base na resposta sorológica a pelo menos uma dentre oito proteínas pneumocócicas investigadas (aumento ≥ 2 vezes nos níveis de IgG em relação a Ply, CbpA, PspA1 e 2, PhtD, StkP-C e PcsB-N ou aumento≥ 1,5 vez em relação aPcpA). Infecção por H. influenzae e M. catarrhalis foi definida por aumento ≥ 2 vezes nos níveis de IgG específica a antígenos de cada agente. Resultados: Crianças com pneumonia radiologicamente confirmada apresentaram maior taxa de infecção pelo pneumococo. Além disso, a presença de infecção pneumocócica foi um fator preditor de pneumonia radiologicamente confirmada, o que aumenta sua chance de detecção em 2,8 vezes (IC 95%: 1,8-4,3). O valor preditivo negativo do raios X normal para a infecção por S. pneumoniae foi 86,3% (IC95%: 82,4%-89,7%). Não houve diferença nas frequências de infecção por H. influenzae e M. catarrhalis entre crianças com PAC com ou sem confirmação radiológica. Conclusão: Crianças com diagnóstico clínico de PAC submetidas a um raios X de tórax que apresentam confirmação radiológica têm maior taxa de infecção por S. pneumoniae comparadas com as crianças com raios X normal.

Caracterización molecular y patrón de susceptibilidad antimicrobiana de Escherichia coli productora de β -lactamasas de espectro extendido en infección del tracto urinario adquirida en la comunidad / Molecular characterization and antimicrobial susceptibility pattern of extended-spectrum β -lactamase-producing Escherichia coli as cause of community acquired urinary tract infection

Resumen Introducción Las infecciones del tracto urinario adquiridas en la comunidad (ITUac) causadas por cepas de Escherichia coli productoras de β-lactamasas de espectro extendido (BLEE), principalmente por cepas que contienen el gen blaCTX-M-15, es un fenómeno creciente a nivel mundial. Objetivo Determinar el patrón de susceptibilidad a antimicrobianos de cepas de E. coli productoras de BLEE causantes de ITUac y conocer su patrón molecular. Materiales y Métodos Se realizó un estudio descriptivo en Oaxaca, México, donde se incluyeron 288 cepas de E. coli aisladas de pacientes adultos con posible ITUac. Para obtener los patrones de susceptibilidad antimicrobiana se siguieron los criterios del CLSI y para obtener el análisis molecular se utilizó la técnica de RPC. Resultados Del total de cepas de E. coli aisladas, 31,3% fueron productoras de BLEE, presentando una menor susceptibilidad a antimicrobianos que las cepas no productoras de estas enzimas. El 95,6% de las cepas BLEE estudiadas fueron portadoras del gen blaCTX-M. Conclusiones Un tercio de las ITUac causadas por E. coli en nuestra población fueron causadas por cepas BLEE, mostrando un alto nivel de resistencia a los antimicrobianos comúnmente utilizados en su tratamiento y disminuyendo las opciones terapéuticas para tratamientos empíricos en esta población.

Background Community acquired urinary tract infections (CaUTI) caused by strains of extended-spectrum β-lactamases (ESBL) - producing Escherichia coli, mainly by strains carrying the blaCTX-M-15 gene, is a growing phenomenon worldwide. Aim To determine the antibiotic susceptibility pattern of ESBL-producing E. coli as cause of CaUTI and to identify their molecular pattern. Methods A descriptive study was performed in the city of Oaxaca, Mexico, from where 288 strains of CaUTI-producing strains of E. coli in adults with possible UTI were isolated. The CLSI criteria was followed to determine the antimicrobial susceptibility patterns, and their molecular characterization was performed by using PCR. Results 31.3% of E. coli strains isolated in our population were ESBL producers, which presented higher levels of antibiotic resistance than those of non-producers of these enzymes. 95.6% of the studied strains were carriers of the blaCTX-M gene. Conclusions One-third of the Ca-UTI caused by E. coli in our population are caused by ESBL-producing strains, which present high levels of resistance to the antibiotics widely used in our community. This situation considerably decreases the number of antibiotics available for an empiric treatment against these infections.

Relación entre hacinamiento e infecciones comunitarias de piel y partes blandas / Relationship between crowding and community acquired skin and soft tissues infections

La asociación entre diseminación de infecciones comunitarias, pobreza y hacinamiento es bien conocida. En nuestro hospital observamos casos esporádicos de infecciones post-cesárea por cepas de Staphylococcus aureus meticilino resistente de origen comunitario (SAMRCo). En un estudio prospectivo de familias de José C. Paz atendidas en nuestro hospital, investigamos la relación entre antecedentes de infecciones de piel y partes blandas (IPPB) y hacinamiento extremo (hogares con necesidades básicas insatisfechas tipo 3, (NBI 3). Fueron incluidos 264 hogares; 109 (41.3%) tenían historia de IPPB y 59 (22.3%) eran NBI 3. El 61.0% de los hogares NBI 3 y el 35.6% de los hogares no NBI 3 refirieron IPPB (p = 0.00047). Georreferenciamos los domicilios con Google Maps y los ubicamos en un plano de José C. Paz NBI del censo nacional 2010. En barrios con un porcentaje de NBI > 9.7%, el 51.2% de los hogares tuvo antecedentes de IPPB. Cuando este porcentaje era ≤ 9.7% el porcentaje bajó al 31.1% (p = 0.0019). Estos resultados son sugestivos de diseminación comunitaria de estas infecciones asociada a hacinamiento y barrios pobres. Se debe considerar la presencia de SAMRCo en IPPB comunitarias. Por ello, en mujeres procedentes de zonas con alto porcentaje NBI o con antecedentes de IPPB se podría considerar la inclusión de la vancomicina o la clindamicina en la profilaxis de los partos por cesárea.

The association of the spread of community infections with poverty and overcrowding is well known. In our hospital, located in José C. Paz, we assist sporadic cases of post-cesarean infections caused by community acquired methicillin-resistant Staphylococcus aureus (CaMRSA). In a prospective study of families treated at our hospital, we investigated the relationship between a history of skin and soft tissue infections (SSTI) and extreme overcrowding defined as households with unsatisfied basic needs type 3 (NBI 3). A total of 264 households were included in the study; 109 (41.3%) had a history of SSTI and 59 (22.3%) were NBI 3. A total of 61.0% of the NBI 3 households and 35.6% of the non-NBI 3 households reported SSTI (p = 0.00047). Using Google Maps, we georeferenced households and identified them on a NBI map adapted from the 2010 demographic census. In neighborhoods with NBI > 9.7%, 51.2% of the households had a history of SSTI. When NBI was < 9.7%, the percentage fell to 31.1% (p = 0.0019). These results are suggestive of an association of SSTI acquired in the community with overcrowding and poverty. The presence of CaMRSA in community SSTIs should be suspected. Vancomycin or clindamycin prophylaxis could be considered when cesarean deliveries are performed in women from areas with high NBI or with a history of SSTI.

Complete genome sequence of community-associated methicillin-resistant staphylococcus aureus (strain USA400-0051), a prototype of the USA400 clone

Staphylococcus aureus subsp. aureus, commonly referred as S. aureus, is an important bacterial pathogen frequently involved in hospital- and community-acquired infections in humans, ranging from skin infections to more severe diseases such as pneumonia, bacteraemia, endocarditis, osteomyelitis, and disseminated infections. Here, we report the complete closed genome sequence of a community-acquired methicillin-resistant S. aureus strain, USA400-0051, which is a prototype of the USA400 clone.