Bacteriemia por Comamonas kerstersii en un joven con apendicitis aguda / Comamonas kerstersii bacteremia in a young man with acute appendicitis

Resumen Comamonas kerstersii es un bacilo gramnegativo no fermentador, asociado a infecciones intraabdominales. Comunicamos un caso clínico de una bacteriemia por C. kerstersii en un joven con una apendicitis aguda. La primera identificación, mediante el sistema Vitek2 compact (BioMerieux) desde los hemocultivos, fue Comamonas testosteroni. Sin embargo, mediante MALDI-TOF se identificó como C. kerstersii. El paciente fue tratado con ampicilina/sulbactam y luego piperacilina/tazobactam con una evolución favorable. Dentro del género Comamonas, C. testosteroni ha sido la especie más frecuentemente reportada como causa de infecciones en humanos, describiéndose solo 23 casos de C. kerstersii. Dado los problemas en la identificación fenotípica de estos microorganismos, es posible que algunos de los reportes de C. testosteroni pudieran haber correspondido a C. kerstersii. Este caso pone en evidencia el rol patógeno de C. kerstersii y la importancia de utilizar MALDI-TOF como herramienta diagnóstica en bacilos gramnegativos no fermentadores.

Abstract Comamonas kerstersii is a non-fermenting Gram-negative bacillus. It has been associated with intra-abdominal infections. We describe a clinical case of bacteremia caused by C. kerstersii in a young man with acute appendicitis. The first identification, using the Vitek2 compact system (BioMerieux) from blood cultures, was Comamonas testosteroni. However, using MALDI-TOF was identified as C. kerstersii. The patient was treated first with ampicillin sulbactam and then piperacillin tazobactam with favorable evolution. Within the genus Comamonas, C. testosteroni has been the most frequently reported species as a cause of infections in humans, only 23 cases of C. kerstersii being described. Given the problems of phenotypic identification of these microorganisms, it is possible that some C. testosteroni reports could have corresponded to C. kerstersii. This case highlights the pathogenic role of C. kerstersii and the importance of using MALDI-TOF as a diagnostic tool for non-fermenting Gram-negative bacilli identification.

Effects of Comamonas testosteroni on PAHs degradation and bacterial community structure in Leymus chinensis rhizosphere soil / 生物工程学报

To investigate the degradation of polycyclic aromatic hydrocarbons (PAHs) and the changes of rhizosphere microorganisms in the rhizosphere soil of Leymus chinensis during the remediation of PAHs contaminated soil by Comamonas testosteroni (C.t)-assisted Leymus chinensis, we evaluated the removal of PAHs in the rhizosphere of Leymus chinensis using gas chromatography-mass spectrometry (GC-MS), analyzed the bacterial community and the diversity in Leymus chinensis rhizosphere soil by high-throughput sequencing technology, characterized the correlation among PAHs degradation and bacterial community components performing redundancy analysis (RDA) and network analysis, and predicted PAHs degradation potential via PICRUSt software in this paper. The degradation of PAHs in the rhizosphere of Leymus chinensis was promoted, the abundance and diversity of bacteria and the correlation among bacteria and PAHs were changed, and the degradation potential of PAHs in Leymus chinensis rhizosphere soil was enhanced in the later stage of phytoremediation (60-120 d) due to the incorporation of C.t. The accelerated degradation of three PAHs (Nap, Phe, BaP) was accompanied by the differ abundance and correlation of Proteobacteria (Sphingomonas, MND1, Nordella), Actinomycetes (Rubrobacter, Gaiella), Acidobacteria (RB41) and Bacteroides (Flavobacterium) affected by C.t. The results provide new insight into the microorganism choices for microbial assisted plant remediation of soil PAHs and the mechanisms of enhanced PAHs degradation via the combination of Comamonas testosteroni engineering bacteria and plants.

Septic Shock due to Unusual Pathogens, Comamonas testosteroni and Acinetobacter guillouiae in an Immune Competent Patient / 대한구급학회지

Comamonas testosteroni and Acinetobacter guillouiae are gram-negative bacilli of low virulence that are widely distributed in nature and normal flora. Despite their common occurrence in environments, they rarely cause infectious disease. We experienced a case of septic shock by C. testosterone and A. guillouiae, and isolated them by 16S ribosomal RNA sequencing method from the blood cultures of a previous healthy female during postoperative supportive care. This is the first case of septic shock required ventilator care and continuous renal replacement therapy due to these organisms in Korea.

Septic Shock due to Unusual Pathogens, Comamonas testosteroni and Acinetobacter guillouiae in an Immune Competent Patient / 대한중환자의학회지

Comamonas testosteroni and Acinetobacter guillouiae are gram-negative bacilli of low virulence that are widely distributed in nature and normal flora. Despite their common occurrence in environments, they rarely cause infectious disease. We experienced a case of septic shock by C. testosterone and A. guillouiae, and isolated them by 16S ribosomal RNA sequencing method from the blood cultures of a previous healthy female during postoperative supportive care. This is the first case of septic shock required ventilator care and continuous renal replacement therapy due to these organisms in Korea.