[Filamentous fungal infection in burned patients: retrospective study.] / Infección por hongos filamentosos en pacientes quemados: estudio retrospectivo.

Introduction: Infections are the most frequent complications in burn patients. Filamentous fungi have an uncertain place within the statistics, since in our media data regarding their prevalence, causal agents and outcome of those who suffer them remain scarce. The aim of this study was to evaluate the prevalence of fungal infection by filamentous fungi (IHF) in patients hospitalized in burn intensive care unit (BICU), and to review clinical, epidemiological, microbiological and evolutionary characteristics of these patients and to know the frequency and distribution of the isolated fungi. Materials and methods: Retrospective and descriptive study. It includes all individuals admitted in burns intensive care unit (2012-2015), with positive culture for filamentous fungi in skin biopsies and bedsores. Results: A total of 168 patients were admitted in the BICU in a period of 3 years. 90% were major burned and 17% of them developed IHF (29/168). Aspergillus spp (24%), Fusarium sp (14%), Mucor spp (3%) and various black fungus genera (58%) were the main genera found in cultives. About 24% of the patients with IHF died and Fusarium spp was found in 50% of the cases. The cause of death was irreversible cardiogenic shock with multiorgan failure. Conclusions: Filamentous fungal infection was present in 17% of burned patients. The main isolatte fungi in samples were dematiaceous mould. Mortality among patients was 24%, with Fusarium being the fungus found in the highest number of deaths (50%).

Antecedentes: Las infecciones son las complicaciones más frecuentes en los pacientes quemados. Los hongos filamentosos ocupan un lugar incierto dentro de las estadísticas nosocomiales; existen escasos datos sobre la prevalencia de las mismas, los agentes causales y el desenlace de los que las padecen. Objetivos: El objetivo fue evaluar prevalencia de la infección por hongos filamentosos (IHF) en pacientes internados en la unidad terapia intensiva de quemados (UTIQ), revisar algunas características clínicas, epidemiológicas, microbiológicas y evolución de estos pacientes; conocer la frecuencia y distribución de las especies fúngicas aisladas. Materiales y métodos: Estudio retrospectivo y descriptivo. Se incluyeron todos los individuos que ingresaron a la terapia intensiva de pacientes quemados (2012-2015), con cultivo positivo para hongos filamentosos en biopsias de piel y escaras. Resultados: Un total de 168 de pacientes ingresaron en la unidad intensiva de quemados en un período de 3 años. El 17% desarrolló IHF (29/168) y el 90% fueron grandes quemados. Se recuperaron 29 hongos filamentosos (93% de exámenes microscópicos positivos): Aspergillus spp (24%), Fusarium spp (14%), Mucor spp (3%) y diversos géneros de hongos negros (58%). El 95% presentó entre 1 y 4 infecciones bacterianas además de la infección fúngica en piel. El 24% de los pacientes con IHF falleció. La causa de la muerte fue shock cardiogénico irreversible con falla multiorgánica. Conclusiones: La infección por hongos filamentosos se presentó en el 17% de los pacientes quemados. Los principales hongos causantes de infección fúngica fueron dematiáceos. La mortalidad entre los pacientes fue del 24%, siendo Fusarium el hongo hallado en el mayor número de muertes (50%).

CARB-9, a carbenicillinase encoded in the VCR region of Vibrio cholerae non-O1, non-O139 belongs to a family of cassette-encoded beta-lactamases.

The gene bla(CARB-9) was located in the Vibrio cholerae super-integron, but in a different location relative to bla(CARB-7). CARB-9 (pI 5.2) conferred beta-lactam MICs four to eight times lower than those conferred by CARB-7, differing at Ambler's positions V97I, L124F, and T228K. Comparison of the genetic environments of all reported bla(CARB) genes indicated that the CARB enzymes constitute a family of cassette-encoded beta-lactamases.

New carbenicillin-hydrolyzing beta-lactamase (CARB-7) from Vibrio cholerae non-O1, non-O139 strains encoded by the VCR region of the V. cholerae genome.

In a previous study, an analysis of 77 ampicillin-nonsusceptible (resistant plus intermediate categories) strains of Vibrio cholerae non-O1, non-O139, isolated from aquatic environment and diarrheal stool, showed that all of them produced a beta-lactamase with a pI of 5.4. Hybridization or amplification by PCR with a probe for bla(TEM) or primers for bla(CARB) gene families was negative. In this work, an environmental ampicillin-resistant strain from this sample, ME11762, isolated from a waterway in the west region of Argentina, was studied. The nucleotide sequence of the structural gene of the beta-lactamase was determined by bidirectional sequencing of a Sau3AI fragment belonging to this isolate. The gene encodes a new 288-amino-acid protein, designated CARB-7, that shares 88.5% homology with the CARB-6 enzyme; an overall 83.2% homology with PSE-4, PSE-1, CARB-3, and the Proteus mirabilis N29 enzymes; and 79% homology with CARB-4 enzyme. The gene for this beta-lactamase could not be transferred to Escherichia coli by conjugation. The nucleotide sequence of the flanking regions of the bla(CARB-7) gene showed the occurrence of three 123-bp V. cholerae repeated sequences, all of which were found outside the predicted open reading frame. The upstream fragment of the bla(CARB-7) gene shared 93% identity with a locus situated inside V. cholerae's chromosome 2. These results strongly suggest the chromosomal location of the bla(CARB-7) gene, making this the first communication of a beta-lactamase gene located on the VCR island of the V. cholerae genome.