Applications of Plackett-Burman and Central Composite Design for the Optimization of Novel Brevundimonas diminuta KT277492 Chitinase Production, Investigation of its Antifungal Activity

ABSTRACT Biological control strategy which can damage chitin, a vital component of pathogenic fungi and arthropods promises a safe solution for many fungal problems. And it's more favorable than chemicals which increase health risks and environmental problems. Thus, the chitinase producers appear potential candidates of biological control of pathogenic fungi. Brevundimonus diminuta KT277492 is a new isolate that has been isolated recently from Egyptian soil. Significant factors that affecting the chitinase enzyme production were studied and optimized using Plackett-Burman and Response Surface Methodology (RSM). As a result, maximum production of chitinase enzyme was 832.87 IUL-1, this result presented about 8.767-fold increase in the enzyme production. In the last phase of the study, partially purified chitinase enzyme obtained from B. diminuta KT277492 was tested against two pathogenic fungi and the results showed good inhibitory activity against A. alternata and F. solani with IZD of 31±0.25 and 25±0.91 mm respectively. Finally, obtained results indicated the value of optimization process and the optimized chitinase enzyme could be an excellent choice in application of food and biotechnology as a biofungicide. This reflects the necessity of studying the characteristics and kinetics of the enzyme in the forthcoming study.

Brevundimonas diminuta bacteremia in a man with myelodysplastic syndromes.

Brevundimonas diminuta are ubiquitous in the environment, but are infrequently isolated from clinical samples. Here we report a case of B. diminuta bacteremia in a man with myelodysplastic syndromes (MDS) at a teaching hospital in China and review the previously reported cases. The organism was confi rmed by culture and 16s rRNA sequence analysis with highly sensitivity to broad-spectrum antibiotics. Our report and other cases demonstrated that the optimal therapeutic duration for B. diminuta infections in various situations remains to be established.

Pseudo-outbreak of Brevundimonas diminuta / 대한임상미생물학회지

Brevundimonas diminuta is a lactose non-fermenting Gram-negative rod associated with infection in immunocompromised patients. In three patients from two general wards, B. diminuta was isolated in blood culture sample. The clinical features of the patients did not coincide with the blood culture result, and pseudo-outbreak was suspected. These isolated were biochemically identified as Brevundimonas diminuta, and 16S rRNA sequencing confirmed their identification. The PFGE result showed a single pattern, and their clonality was assumed.

Artritis reactiva asociada con bacteriemia por Brevundimonas diminuta / Reactive arthritis associated with Brevundimonas diminuta bacteremia

Dentro del grupo de las espondiloartritis, la artritis reactiva se define como una inflamación articular desencadenada por una infección bacteriana extra-articular. Existen pocos reportes de artritis reactiva asociada con bacteriemia simultánea causada por patógenos diversos. Brevundimonas diminuta es un bacilo Gram negativo aislado ocasionalmente de especímenes clínicos. Reportamos el caso de una paciente, sin inmunodeficiencia conocida, con artritis reactiva y bacteriemia simultánea por B. diminuta.Palabras clave: artritis reactiva, Brevundimonas diminuta, bacteriemia.

Within the group of spondyloarthritis, reactive arthritis is defined as a joint inflammation triggered by an extra-articular bacterial infection. There are few reports of reactive arthritis associated with bacteremia caused by different pathogens. Brevundimonas diminuta is a Gram-negative bacillus isolated occasionally from clinical specimens. We report a patient with reactive arthritis and concurrent B. diminuta bacteremia, without known immune deficiency.Key words: reactive arthritis, Brevundimonas diminuta, bacteremia.