Detection of Vancomycin Resistance among Methicillin-Resistant Staphylococcus aureus Strains Recovered from Children with Invasive Diseases in a Reference Pediatric Hospital.

Vancomycin is the cornerstone in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. However, therapeutic failures can occur when MRSA strains with decreased susceptibility to glycopeptides (DSG) are involved. The aim of this study was to detect and characterize DSG in MRSA recovered from children with invasive diseases at a reference pediatric hospital between 2009 and 2019. Fifty-two MRSA strains were screened using agar plates with vancomycin 3 and 4 mg/L (BHI-3 and BHI-4); the VITEK2 system; and standard and macro E-tests. Suspicious hVISA were studied by population analysis profiling-area under the curve (PAP-AUC), and wall thickness was analyzed by transmission electron microscopy. Neither VRSA nor VISA were detected in this set. As only three strains met the hVISA criteria, the PAP-AUC study included 12 additional MRSA strains that grew one colony on BHI-4 plates or showed minimum inhibitory concentrations of vancomycin and/or teicoplanin ≥ 1.5 mg/L. One strain was confirmed as hVISA by PAP-AUC. The wall thickness was greater than the vancomycin-susceptible control strain; it belonged to ST30 and carried SCCmec IV. As expected, a low frequency of hVISA was found (1.9%). The only hVISA confirmed by PAP-AUC was not detected by the screening methods, highlighting the challenge that its detection represents for microbiology laboratories.

Hospitalizaciones por diarrea con sangre en un centro pediátrico de referencia en Uruguay

Introducción: La diarrea con sangre es un motivo frecuente de admisión hospitalaria en niños, con gastroenteritis aguda; en la mayoría de los casos se tratan de infecciones leves y autolimitadas, pero pueden producirse complicaciones graves. Objetivos: Describir la etiología y características clínico- evolutivas de los niños menores de 15 años hospitalizados por diarrea con sangre en el Hospital Pediátrico, Centro Hospitalario Pereira Rossell entre los años 2012- 2023. Materiales y métodos: Estudio retrospectivo mediante revisión de historias y registros de laboratorio. Variables: demográficas, estado nutricional, hidratación, motivos de hospitalización, ingreso unidades de cuidados intensivos (UCI), enteropatógenos, tratamientos, evolución. Resultados: Se incluyeron 229 niños, mediana de edad de 8 meses; sexo masculino 61%; eutróficos 88%, bien hidratados 55%, con comorbilidades 11%, prematurez 6,5%. El motivo de hospitalización fue diarrea con sangre/disentería sin otro síntoma 45%. Se solicitó coprovirológico/coprocultivo en 98% y detección por técnicas de ácidos nucleicos en materia fecal 5,2%. Se identificó al menos un agente patógeno en 34,3%: Shigella sp. 38%; Salmonella sp. 19,5%; coinfecciones en 12%. Se indicaron antibióticos a 86%; ceftriaxona 62%, azitromicina 35%. Ingresaron a UCI 6,5% (15), presentaron complicaciones 10/14, fallo renal agudo 5 y alteraciones del medio interno 3. La mayoría presentó buena evolución. Conclusiones: La diarrea con sangre/disentería continúa siendo una causa importante de hospitalización afectando en su mayoría a niños sanos menores de 5 años. Los patógenos detectados con mayor frecuencia fueron bacterias principalmente Shigella sp., Salmonella sp. y E coli diarreogénicas. Se reportó alta prescripción de antibióticos, cumpliendo en la mayoría de los casos con las recomendaciones.

Introduction: Bloody diarrhea is a common reason for hospital admission in children with acute gastroenteritis; In most cases these are mild and self-limiting infections, but serious complications can occur. Goals: To describe the etiology and clinical-evolutionary characteristics of children under 15 years of age hospitalized for bloody diarrhea at the Pediatric Hospital, Centro Hospitalario Pereira Rossell between the years 2012-2023. Materials and methods: Retrospective study through review of histories and laboratory records. Variables: demographics, nutritional status, hydration, reason for hospitalization, intensive care unit (ICU) admission, enteropathogens, treatments, evolution. Results: 229 children were included, median age 8 months; male sex 61%; eutrophic 88%, well hydrated 55%, with comorbidities 11%, prematurity 6.5%. The reason for hospitalization was bloody diarrhea/dysentery without other symptoms 45%. Coprovirological/coproculture was requested in 98% and detection by nucleic acid techniques in fecal matter was requested in 5,2%. At least one pathogenic agent was identified in 34,3%: Shigella sp. 38%; Salmonella sp 19,5%; coinfections in 12%. Antibiotics were indicated for 86%; ceftriaxone 62%, azithromycin 35%. Were admitted to the ICU 6,5% (15), 10/14 had complications, 5 had acute kidney failure and 3 had alterations in the internal environment. The majority had a good evolution. Conclusions: Bloody diarrhea/dysentery continues to be an important cause of hospitalization, affecting mostly healthy children under 5 years of age. The most frequently detected pathogens were bacteria, mainly Shigella sp., Salmonella sp. and diarrheagenic E coli. High prescription of antibiotics was reported, complying in most cases with the recommendations.

Introdução: A diarreia com sangue é um motivo comum de internação hospitalar em crianças com gastroenterite aguda; Na maioria dos casos, estas são infecções leves e autolimitadas, mas podem ocorrer complicações graves. Metas: Descrever a etiologia e as características clínico-evolutivas de crianças menores de 15 anos internadas por diarreia sanguinolenta no Hospital Pediátrico Centro Hospitalario Pereira Rossell entre os anos de 2012-2023. Materiais e métodos: Estudo retrospectivo por meio de revisão de histórias e registros laboratoriais. Variáveis: dados demográficos, estado nutricional, hidratação, motivo da internação, internação em unidade de terapia intensiva (UTI), enteropatógenos, tratamentos, evolução. Resultados: foram incluídas 229 crianças, mediana de idade 8 meses; sexo masculino 61%; eutrófico 88%, bem hidratado 55%, com comorbidades 11%, prematuridade 6,5%. O motivo da internação foi diarreia sanguinolenta/disenteria sem outros sintomas 45%. O estudo coprovirologico/coprocultivo foi solicitado em 98% e a detecção por técnicas de ácidos nucleicos em matéria fecal foi solicitada em 5,2%. Pelo menos um agente patogênico foi identificado em 34,3%: Shigella sp. 38%; Salmonella sp. 19,5%; coinfecções em 12%. Os antibióticos foram indicados para 86%; ceftriaxona 62%, azitromicina 35%. Foram internados em UTI 6,5% (15), 10/14 apresentaram complicações, 5 tiveram insuficiência renal aguda e 3 apresentaram alterações no meio interno, a maioria teve boa evolução. Conclusões: A diarreia/disenteria com sangue continua a ser uma causa importante de hospitalização, afetando sobretudo crianças saudáveis ​​com menos de 5 anos de idade. Os patógenos mais frequentemente detectados foram bactérias, principalmente Shigella sp., Salmonella sp. e E. coli diarreiogênica. Foi relatada elevada prescrição de antibióticos, cumprindo na maioria dos casos as recomendações.

Phenotypic and genotypic characterization of oxacillin-susceptible and mecA positive Staphylococcus aureus strains isolated in Uruguay / Caracterización fenotípica y genotípica de cepas de Staphylococcus aureus sensibles a oxacilina y mecA positivas aisladas en Uruguay

Abstract The aim of this study was to characterize phenotypically and genotypically 27 mecApositive Staphylococcus aureus strains with oxacillin MICs of ≤2 g/ml by Vitek 2, isolated indifferent regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient dif-fusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined.SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolateswere susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strainscarried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did notbelong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carryingSCCmec V.

Resumen El objetivo de este estudio fue caracterizar fenotípicamente y genotípicamente 27 cepas de Staphylococcus aureus positivas para mecA y con CIM de oxacilina <2 pg/ml según Vitek 2, obtenidas en diferentes regiones del país. La sensibilidad frente a la oxacilina y la cefoxitina se estudió por difusión en gradiente, por disco-difusión (cefoxitina) y por los sistemas Phoenix y MicroScan. Se analizó la portación de PBP2a, se realizó la tipificación de SCCmec y las cepas se compararon mediante PFGE. Resultaron sensibles a oxacilina por difusión en gradiente 26 cepas; una fue sensible a cefoxitina por disco-difusión y 3 lo fueron por difusión en gradiente. Los sistemas Phoenix y MicroScan detectaron resistencia a meticilina en 25 y 27 cepas, respectivamente. Asimismo, 26 cepas portaban PBP2a y 26 cepas mostraron presencia de SCCmec V, 24 correspondieron al pulsotipo A. Una portaba SCCmec IV y no perteneció al pulsotipo A. La prueba de disco-difusión con cefoxitina y la detección de PBP2a identificaron 26 de 27 cepas como MRSA. La PFGE sugiere la diseminación de un grupo MRSA con SCCmec V. © 2022 Asociación Argentina de Microbiología. Publicado por Elsevier Espana, S.L.U. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Phenotypic and genotypic characterization of oxacillin-susceptible and mecA positive Staphylococcus aureus strains isolated in Uruguay.

The aim of this study was to characterize phenotypically and genotypically 27 mecA positive Staphylococcus aureus strains with oxacillin MICs of ≤2µg/ml by Vitek 2, isolated in different regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient diffusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined. SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolates were susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3 strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in 25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strains carried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did not belong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26 of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carrying SCCmec V.

Haemophilus influenzae type b invasive infections in children hospitalized between 2000 and 2017 in a Pediatric Reference Hospital (PRH).

BACKGROUND: Uruguay incorporated the conjugate vaccine against Haemophilus influenzae b (Hib) in 1994. In 2008, the vaccine was changed from one with natural conjugated capsular polysaccharide to one with a synthetic polysaccharide component. We describe the frequency and characteristics of invasive Hib infections in children hospitalized in a Pediatric Reference Hospital (PRH) between January 1st, 2000 and December 31st, 2017. METHODS: Sterile site Hib isolations from hospitalized children were included. Clinical and microbiological characteristics were analyzed. Favorable conditions for the infection were considered: incomplete immunization, immunodeficiencies and associated pathologies. Two periods are described: 1, prior to vaccine change (1/1 st/2000- 12/31/08) and 2, post-change (1/1 st/09- 12/31st/17). RESULTS: 45 children were hospitalized: 5 in the first period and 40 in the second. The hospitalization rate per 10,000 discharges was 0.41 (95% CI 0.05-0.77) and 4.2/10,000 (95% CI 2.89-5.48), respectively (p < 0.01). The diagnoses at discharge were: meningitis/ventriculitis (20), pneumonia (16), bacteremia (3), epiglottitis (1), arthritis (1), cellulitis (3) and obstruction of the upper airway (1). Four children presented comorbidities. Twenty seven received less than 3 doses of anti-Hib vaccination and 18 were properly vaccinated (2 were immunodeficient). The median hospitalization was 14 days, 18 children required intensive therapy. CONCLUSIONS: Observed change may be due to: incomplete primary series, inhomogeneous vaccine coverage and immunogenicity of the synthetic polysaccharide. To reduce this public health problem, epidemiological surveillance.

Neumonía necrotizante en niños: 10 años de experiencia en un hospital pediátrico de referencia / Necrotizing pneumonia in children: 10 years of experience in a Pediatric Reference Hospital / Pneumonia necrosante em crianças: 10 anos de experiência em um Hospital Pediátrico de Referência

Resumen: Introducción: neumonía necrotizante (NN) es una complicación frecuente en niños hospitalizados por neumonía adquirida en la comunidad (NAC), caracterizada por importante morbilidad. En 2009, se elaboró una definición de caso, que permitió unificar criterios y racionalizar recursos en la asistencia de estos niños. Objetivo: describir características clínicas y evolutivas de niños que desarrollaron NN en los últimos 10 años. Metodología: estudio descriptivo de niños hospitalizados por NN entre 1/1/2009 y 31/12/2018. Definición de caso: neumatoceles y uno o más de los siguientes criterios: mal estado general, fiebre persistente o recurrente, leucocitosis mayor a 30.000 o menor a 5.000/mm3, proteína C reactiva mayor a 120 mg/dl, láctico deshidrogenasa en líquido pleural mayor a 2.500 UI/L y/o fístula broncopleural (FBP). Se describieron características epidemiológicas, clínicas, etiológicas y evolutivas. Resultados: se diagnosticó NN en 197 niños (7,92% de las hospitalizaciones por NAC), con número anual de casos y tasas/10.000 egresos variables. La mediana de edad fue de 25 meses; 89,8% eran sanos. La fiebre previa al diagnóstico tuvo mediana de cinco días. Tenían neumonía multilobar 58%, insuficiencia respiratoria 62%, sepsis 19%, empiema 80% y fístula bronquio-pleural 51%. Persistieron con fiebre mediana por siete días. Requirieron cuidados intensivos 46% y asistencia ventilatoria mecánica 18%. Los reactantes de fase aguda al ingreso fueron elevados. Se identificó agente etiológico en 102 casos, S. pneumoniae en 92. Fallecieron dos niños. Conclusiones: NN fue una complicación frecuente en niños hospitalizados por NAC. La presentación clínica y la evolución fueron graves. La identificación etiológica fue elevada, la mayoría correspondió a S. pneumoniae. La mortalidad fue baja.

Summary: Introduction: necrotizing pneumonia (NP) is a complication of community-acquired pneumonia (CAP) in hospitalized children, with significantly high morbidity. A case definition was devised in 2009, which enabled physicians to unify criteria and rationalize resources for the assistance of children with NP. Objective: describe clinical characteristics and evolution of children who developed NP. Methodology: descriptive study, NP hospitalized children between 1/1/2009 and 12/31/2018. Case definition: pneumatoceles and one or more of the following criteria: malaise, persistent/recurrent fever, white blood cell count over 30,000 or less than 5.000/mm3, C-reactive protein over 120 mg/dL, lactic dehydrogenase in pleural fluid over 2,500UI/L and/or bronchopleural fistula (BPF). Clinical, epidemiological, etiological and evolutionary characteristics were described. Results: NP was diagnosed in 197 children (7.92% of CAP hospitalizations), with variable annual cases and annual rate/10,000 discharges. Children had a median age of 25 months; 89.8% were previously healthy. They presented fever prior to diagnosis, median 5 days, multilobar pneumonia 58%, respiratory failure 62%, sepsis 19%, empyema 80% and BPF 51%, persistent fever median 7 days. 46% required intensive care and 18% required assisted mechanical ventilation. Acute phase reactants on admission were high. An etiological agent was identified in 102 cases, S.pneumoniae in 92. Two children died. Conclusions: NP was a frequent complication in CAP hospitalized children. Clinical presentation and evolution were severe. The etiological identification was high, most of them corresponded to S. pnuemoniae. Mortality was low.

Resumo: Introdução: a pneumonia necrosante (PN) é uma complicação da pneumonia adquirida na comunidade (PAC) em crianças hospitalizadas, com morbidade significativamente elevada. Em 2009, elaborou-se uma definição de caso, que possibilitou aos médicos unificar critérios e racionalizar recursos para o atendimento à criança com PN. Objetivo: descrever as características clínicas e evolutivas de crianças que desenvolveram PN nos últimos 10 anos. Metodologia: estudo descritivo de crianças internadas por PN entre 01/01/2009 e 31/12/2018. Definição de caso: pneumatoceles e um ou mais dos seguintes critérios: mau estado geral, febre persistente ou recorrente, leucocitose superior a 30.000 ou inferior a 5.000 / mm3, proteína C reativa superior a 120 mg / dl, desidrogenase láctica no líquido pleural superior 2.500 UI / L e / ou fístula broncopleural (BPF). Descreveram-se características epidemiológicas, clínicas, etiológicas e evolutivas. Resultados: a PN foi diagnosticada em 197 crianças (7,92% das internações por PAC), com número de casos e taxas anuais variáveis/10.000 altas. A idade média foi de 25 meses; 89,8% eram saudáveis. A febre antes do diagnóstico teve uma mediana de 5 dias. Eles tinham 58% de pneumonia multilobar, 62% de insuficiência respiratória, 19% de sepse, 80% de empiema e 51% de FBP. Eles persistiram com febre mediana por 7 dias. 46% necessitaram de cuidados intensivos e 18% de assistência ventilatória mecânica. Os reagentes de fase aguda na admissão foram elevados. Em 102 casos foi identificado um agente etiológico, S. pneumoniae em 92. 2 crianças morreram. Conclusões: NP é uma complicação frequente em crianças hospitalizadas por PAC. O quadro clínico e a evolução foram graves. A identificação etiológica foi alta, a maioria correspondeu a S. pneumoniae. A mortalidade foi baixa.