Infección de piel y tejidos blandos por Burkholderia stabilis en un niño con quemaduras graves / Skin and soft tissue infection due to Burkholderia stabilis in a severely burned child

Resumen Las heridas por quemadura representan un grave problema, sobre todo en la población pediátrica, dada la severidad de su presentación y la morbimortalidad asociada. La infección es la complicación más frecuente y grave en el paciente quemado. Las bacterias que conforman el complejo Burkholderia cepacia (CBc) son capaces de causar enfermedades en plantas, humanos y animales. En el hombre pueden establecer infecciones crónicas y frecuentemente graves, por lo general en pacientes con fibrosis quística y en inmunocomprometidos. El CBc está compuesto por al menos 22 especies filogenéticamente muy relacionadas. El objetivo de esta publicación fue describir el primer caso de una infección de piel y partes blandas por Burkholderia stabilis, una especie poco frecuente, en un niño con grandes quemaduras en la Argentina. Las especies del CBc son intrínsecamente resistentes a la mayoría de los antimicrobianos disponibles clínicamente, como aminoglucósidos, quinolonas, polimixinas y β-lactámicos. Esto representa un serio problema en el momento de tratar las infecciones por las escasas opciones terapéuticas.

Abstract Burn wounds represent a serious problem, especially in the pediatric population, given the severity of their presentation and the associated morbidity and mortality. Infection is the most frequent and serious complication in the burned patient. Burkholderia cepacia (CBc) complex bacteria are capable of causing disease in plants, humans, and animals. In human beings they can establish chronic and frequently serious infections, generally in patients with cystic fibrosis and in immunocompromised patients. The CBc is composed of 22 phylogenetically closely related species. The objective of this publication was to describe the first report of a skin and soft tissue infection by Burkholderia stabilis, a rare species, in a child with extensive burns in Argentina. CBc species are inherently resistant to most clinically available antimicrobials, such as aminoglycosides, quinolones, polymyxins, and β-lactams. This represents a serious problem when treating infections, due to the limited therapeutic options.

Resumo As feridas por queimadura representam um grave problema, principalmente na população pediátrica, devido à gravidade de sua apresentação e morbimortalidade associada. A infecção é a complicação mais frequente e grave do paciente queimado. As bactérias que compõem o complexo Burkholderia cepacia (CBc) são capazes de causar doenças em plantas, humanos e animais. No homem, podem estabelecer infecções crônicas e freqüentemente graves, geralmente em pacientes com fibrose cística e imunocomprometidos. O CBc é composto, no mínimo, por 22 espécies filogeneticamente muito relacionadas. O objetivo desta publicação é descrever o primeiro caso de uma infecção de pele e tecidos moles por Burkholderia stabilis, uma espécie rara, em uma criança com queimaduras extensas na Argentina. As espécies do CBc são inerentemente resistentes à maioria dos antimicrobianos disponíveis clinicamente, como aminoglicosídeos, quinolonas, polimixinas e β-lactâmicos. Isso representa um problema sério na hora de tratar as infecções devido às opções terapêuticas limitadas.

Burkholderia cepacia complex: 11 years of surveillance in patients with Cystic Fibrosis in Posadas, Argentina

Abstract Cystic fibrosis patients with Burkholderia cepacia complex pulmonary infections have high morbidity and mortality. Worldwide, this disease is undergoing substantial epidemiological changes. Advances in the diagnosis and treatment have conditioned an increase in child sur-vival as well as in the proportion of affected adults. In order to know our reality, we refer to an epidemiological study in 64 CF patients during 11 years of surveillance, focusing on infections caused by Burkholderia species. Conventional and automated phenotypic tests, restriction fragment length polymorphism-recA, recA gene sequencing, and matrix-assisted laser desorp-tion ionization-time of flight (MALDI-TOF) mass spectrometry were applied. Bacterial isolates were also tested for antimicrobial susceptibility patterns. The prevalence of Burkholderia cepacia complex was 9.4%. Based on recA gene sequencing, the most common species identified were Burkholderia cenocepacia (67.3%) and Burkholderia vietnamiensis (20.3%). Ceftazidime and meropenem were the most active, inhibiting 53% and 46% of isolates, respectively. This report represents the first systematic study of Burkholderia infections in our CF population since beginning of monitoring and treatment and highlights the importance of continued longitudinal studies.

Resumen Los pacientes con fibrosis quística (FQ) con infecciones pulmonares causadas por especies del complejo Burkholderia cepacia tienen una alta morbimortalidad. En todo el mundo, esta enfermedad está experimentando cambios epidemiológicos sustanciales. Los avances en el diagnóstico y el tratamiento han condicionado un aumento en la supervivencia infantil, así como en la proporción de adultos afectados. Para conocer nuestra realidad, nos referimos a un estudio epidemiológico en 64 pacientes con FQ durante 11 años de vigilancia, focalizando las infecciones causadas por especies del género Burkholderia. Se aplicaron pruebas fenotípicas convencionales y automatizadas, polimorfismo de longitud de fragmentos de restricción-recA, secuenciación del gen recA y espectrometría de masa MALDI-TOF. Los aislados bacterianos también se analizaron para determinar los patrones de susceptibilidad antimicrobiana. La prevalencia de complejo B. cepacia fue del 9,4%. Con base en la secuenciación del gen recA, las especies más comunes identificadas fueron Burkholderia cenocepacia (67,3%) y Burkholderia vietnamiensis (20,3%). Ceftazidima y meropenem fueron los antibióticos más activos e inhibieron el 53 y el 46% de los aislamientos, respectivamente. Este informe representa el primer estudio sistemático de las infecciones por Burkholderia en nuestra población desde el comienzo de la monitorización y el tratamiento, y resalta la importancia de continuar los estudios de vigilancia longitudinales.

Burkholderia cepacia complex: 11 years of surveillance in patients with Cystic Fibrosis in Posadas, Argentina.

Cystic fibrosis patients with Burkholderia cepacia complex pulmonary infections have high morbidity and mortality. Worldwide, this disease is undergoing substantial epidemiological changes. Advances in the diagnosis and treatment have conditioned an increase in child survival as well as in the proportion of affected adults. In order to know our reality, we refer to an epidemiological study in 64 CF patients during 11 years of surveillance, focusing on infections caused by Burkholderia species. Conventional and automated phenotypic tests, restriction fragment length polymorphism-recA, recA gene sequencing, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry were applied. Bacterial isolates were also tested for antimicrobial susceptibility patterns. The prevalence of Burkholderia cepacia complex was 9.4%. Based on recA gene sequencing, the most common species identified were Burkholderia cenocepacia (67.3%) and Burkholderia vietnamiensis (20.3%). Ceftazidime and meropenem were the most active, inhibiting 53% and 46% of isolates, respectively. This report represents the first systematic study of Burkholderia infections in our CF population since beginning of monitoring and treatment and highlights the importance of continued longitudinal studies.

El controvertido complejo Burkholderia cepacia, un grupo de especies promotoras del crecimiento vegetal y patógenas de plantas, animales y humanos / The controversial Burkholderia cepacia complex, a group of plant growth promoting species and plant, animals and human pathogens

El complejo Burkholderia cepacia está formado por 22 especies conocidas como patógenos oportunistas en personas inmunocomprometidas, especialmente en aquellas con fibrosis quística. También se aíslan de infecciones nosocomiales y son difíciles de erradicar debido a su capacidad intrínseca para resistir una gran variedad de antibióticos. En general, estas especies presentan genomas de gran tamaño (hasta 9 Mpb) divididos en 2-5 replicones. Esta característica aporta una gran versatilidad metabólica, que se considera importante para habitar el suelo, el agua, las plantas, incluso los nódulos en leguminosas. Algunas especies del complejo B. cepacia exhiben actividades benéficas, como biorremediación, biocontrol y promoción del crecimiento vegetal. No obstante, debido a su papel en infecciones de humanos, su uso en la agricultura está restringido. El complejo B. cepacia es un tema constante de estudio debido a su impacto en el sector salud y su potencial en la agricultura. En este trabajo se examina la historia del complejo B. cepacia y se revisa la información reciente relacionada con este grupo de bacterias.

The Burkholderia cepacia complex is a group of 22 species, which are known as opportunistic pathogens in immunocompromised people, especially those suffering from cystic fibrosis. It is also found in nosocomial infections and is difficult to eradicate due to intrinsic resistance to several antibiotics. The species have large genomes (up to 9 Mbp), distributed into 2-5 replicons. These features significantly contribute to genome plasticity, which makes them thrive in different environments like soil, water, plants or even producing nodules in legume plants. Some B. cepacia complex species are beneficial in bioremediation, biocontrol and plant-growth promotion. However, because the B. cepacia complex is involved in human infection, its use in agriculture is restricted. B. cepacia complex is being constantly studied due to the health problems that it causes and because of its agricultural potential. In this review, the history of B. cepacia complex and the most recently published information related to this complex are revised.

[The controversial Burkholderia cepacia complex, a group of plant growth promoting species and plant, animals and human pathogens]. / El controvertido complejo Burkholderia cepacia, un grupo de especies promotoras del crecimiento vegetal y patógenas de plantas, animales y humanos.

The Burkholderia cepacia complex is a group of 22 species, which are known as opportunistic pathogens in immunocompromised people, especially those suffering from cystic fibrosis. It is also found in nosocomial infections and is difficult to eradicate due to intrinsic resistance to several antibiotics. The species have large genomes (up to 9 Mbp), distributed into 2-5 replicons. These features significantly contribute to genome plasticity, which makes them thrive in different environments like soil, water, plants or even producing nodules in legume plants. Some B. cepacia complex species are beneficial in bioremediation, biocontrol and plant-growth promotion. However, because the B. cepacia complex is involved in human infection, its use in agriculture is restricted. B. cepacia complex is being constantly studied due to the health problems that it causes and because of its agricultural potential. In this review, the history of B. cepacia complex and the most recently published information related to this complex are revised.

Prevalence of Burkholderia cepacia complex species in cystic fibrosis patients in Argentina during the period 2011-2015. / Prevalencia de especies del complejo Burkholderia cepacia en pacientes con fibrosis quística en Argentina durante el período 2011-2015.

INTRODUCTION: Burkholderia cepacia (B. cepacia) complex is composed of 20 phylogenetically closely related bacterial species. Some species have emerged as opportunistic pathogens in immunocompromised patients and are responsible for nosocomial outbreaks. The B. cepacia complex is a recognized respiratory pathogen in patients with cystic fibrosis. Burkholderia cenocepacia and Burkholderia multivorans (B. multivorans) are the most prevalent species in the world, according to the literature. However, research groups in Argentina have described a particular local epidemiology, with prevalence of Burkholderia contaminans (B. contaminans). METHODS: A total of 68 isolates of B. cepacia complex recovered of 46 cystic fibrosis patients attended at 14 hospitals distributed in 9 provinces of the country were studied. Identification was carried out by conventional phenotypic methods and was confirmed by recA gene sequencing. Sequences were analysed using the BLASTN program and comparing with B. cepacia complex type strains sequences deposited in GenBank. Antibiotic susceptibility tests were performed on isolates of the most prevalent species according to CLSI M45 guidelines. RESULTS: The prevalent specie was B. contaminans (49%, n = 33) followed by B. cenocepacia (25%; n = 17). The remaining species were Burkholderia seminalis (B. seminalis) (7%, n = 5), B. cepacia (7%, n = 5), B. multivorans (6%, n = 4), Burkholderia vietnamensis (5%, n=3) and Burkholderia pyrrocinia (1%; n = 1). The 46% of B. contaminans isolates were resistant to SXT and 76% sensitive to MIN, MEM and CAZ. The isolates of B. cenocepacia were 100% resistant to SXT and MIN and 47% to CAZ and MEM. B. seminalis showed high levels of resistance to TMS (80%), CAZ (60%) and MIN (60%), and 60% of the isolates showed intermediate sensitivity to MEM. CONCLUSION: Previous reports have described the prevalence of B. contaminans isolation from cystic fibrosis patients in Argentina, Spain and Portugal, and a case of two patients with cystic fibrosis in Ireland has recently been reported. Due to the high frequency with which B. contaminans is isolated in our country, it is necessary to promote the investigation of possible sources of infection and to understand the factors and mechanisms involved in the apparent greater transmissibility of this species. Different antimicrobial resistance profiles were detected between the species.

Evaluación de los sistemas comerciales automatizados VITEK 2 y API 20NE para la identificación de organismos del complejo Burkholderia cepacia aislados de muestras clínicas / Evaluation of commercial systems VITEK 2 and API 20NE for identification of Burkholderia cepacia complex bacteria from clinical samples

Las especies del complejo Burkholderia cepacia (CBC) son capaces de causar infecciones crónicas del tracto respiratorio en pacientes con fibrosis quística y en otros individuos inmunocomprometidos. La mayoría de estas especies exhiben alta resistencia a la terapia antibiótica, lo que genera la necesidad de una detección rápida y precisa para poder implementar estrategias de control adecuadas. En este trabajo se utilizó la técnica de reacción en cadena de la polimerasa (PCR) para amplificar el gen recA (PCR-recA), con el fin de identificar microorganismos pertenecientes al CBC. Con este método molecular como referencia, se evaluó la sensibilidad (S) y la especificidad (E) de dos sistemas de identificación comerciales automatizados, VITEK 2 y API 20NE (bioMérieux®), así como también el valor de las pruebas bioquímicas manuales más representativas para la identificación de estos microorganismos. El método VITEK 2 presentó una S del 71,1 % y una E del 100 %; para el método API 20NE, estos valores fueron 69,7 % y 90,2 %, respectivamente. En cuanto a las pruebas fenotípicas manuales, los resultados obtenidos fueron más heterogéneos, lo que posiblemente se deba a que estas bacterias podrían sufrir presión selectiva para sobrevivir en pacientes crónicos y perder factores fenotípicos característicos. La técnica de PCR-recA resultó de fácil implementación, por lo que cabe considerar a esta técnica de identificación como una opción viable, aun en laboratorios de diagnóstico clínico de mediana complejidad.

Species belonging to the Burkholderia cepacia complex (BCC) are capable of causing chronic respiratory tract infections in patients suffering from cystic fibrosis as wel as in immunocompromised individuals. Most of these species are highly resistant to antibiotic therapy, generating the need for their rapid and accurate detection for the proper treatment and clinical management of these patients. In this wok, the polymerase chain reaction (PCR) technique based on the amplification of the recA gene (PCR-recA) was applied for an accurate identification of bacteria belonging to the BCC. Sensitivity (S) and specificity (E) of two biochemically-based commercial automated systems, API 20NE and VITEK 2 (bioMérieux®), and of the most representative biochemical manual tests for the identification of the Burkholderia cepacia complex were herein evaluated. The commercial systems VITEK 2 and API 20NE showed the following sensitivity and specificity vaues for identification to the species level, S: 71.1 %, E: 100 %, S: 69.7 %, E: 90.2 %, respectively. More complex results were observed for phenotypic manual tests, since BCC bacteria can undergo selective pressure to survive in chronic patients causing the loss of their typical phenotypic characteristics. The PCR-recA technique was easy to implement even in medium-complexity clinical diagnostic laboratories.