Antimicrobial Activity of Selected Essential Oils against Bacteria Isolated from Freshwater Fish

The aim of study was to determine the antimicrobial activity of ten essential oils against ten microorganisms isolated from fish. The following essential oils were tested: Cymbopogon nardus Rendle, Citrus limon, Leptospermum petersonii Bailey, Gaultheria procumbens, Pelargonium graveolens, Citrus paradisi, Citrus aurantifolia, Litsea cubeba Pers., Citrus reticulata Blanko, Vetiveria zizanoides. The disc diffusion method and microdilution method were used for determination of antimicrobial activity. Rhodotorula spp., Aerococcus spp., Aerococcus viridans, Enterococcus faecium, Enterococcus moraviensis, Aeromonas spp., Delftia acidovorans, Pseudomonas gessardii, Yersinia spp., Yersinia ruckeri, Yersinia enterocolitica were tested in the present study. The best antimicrobial activity of Leptospermum petersonii Bailey were found against Aerococcus spp., Enterococcus faecium, E. moraviensis, Delftia acidovorans, Pseudomonas gessardii, Yersinia ruckeri and Y. enterocolitica. Litsea cubeba Pers. was effective against Delftia acidovorans, Yersinia enterocolitica, Enterococcus faecium using the disc diffusion method. The best minimal inhibition concentration (MIC 50 - 1.5 µL/mL resp. MIC 90 - 1.6 µL/mL) was found for Litsea cubeba Pers. against Aerococcus spp. and Yersinia spp. using microdilution method.

Transcriptomics reveal core activities of the plant growth-promoting bacterium Delftia acidovorans RAY209 during interaction with canola and soybean roots

The plant growth-promoting rhizobacterium Delftia acidovorans RAY209 is capable of establishing strong root attachment during early plant development at 7 days post-inoculation. The transcriptional response of RAY209 was measured using RNA-seq during early (day 2) and sustained (day 7) root colonization of canola plants, capturing RAY209 differentiation from a medium-suspended cell state to a strongly root-attached cell state. Transcriptomic data was collected in an identical manner during RAY209 interaction with soybean roots to explore the putative root colonization response to this globally relevant crop. Analysis indicated there is an increased number of significantly differentially expressed genes between medium-suspended and root-attached cells during early soybean root colonization relative to sustained colonization, while the opposite temporal pattern was observed for canola root colonization. Regardless of the plant host, root-attached RAY209 cells exhibited the least amount of differential gene expression between early and sustained root colonization. Root-attached cells of either canola or soybean roots expressed high levels of a fasciclin gene homolog encoding an adhesion protein, as well as genes encoding hydrolases, multiple biosynthetic processes, and membrane transport. Notably, while RAY209 ABC transporter genes of similar function were transcribed during attachment to either canola or soybean roots, several transporter genes were uniquely differentially expressed during colonization of the respective plant hosts. In turn, both canola and soybean plants expressed genes encoding pectin lyase and hydrolases – enzymes with purported function in remodelling extracellular matrices in response to RAY209 colonization. RAY209 exhibited both a core regulatory response and a planthost-specific regulatory response to root colonization, indicating that RAY209 specifically adjusts its cellular activities to adapt to the canola and soybean root environments. This transcriptomic data defines the basic RAY209 response as both a canola and soybean commercial crop and seed inoculant.

Orbita-Infektion mit Delftia acidovorans nach Katzenkratzer

Zusammenfassung Anamnese und klinischer Befund Die 60-jährige Patientin wurde vor 34 Monaten von ihrer Katze am linken Augenlid gekratzt. Danach kam es zu chronischen, langsam progredienten Hautveränderungen mit sich verstärkenden Kopfschmerzen. Therapieversuche mit Kortison, Pimecrolimus, Pregabalin und Metamizol waren erfolglos. Nach 24 Monaten klagte sie über starken Bulbus-Schmerz am linken Auge, zunehmende Schmerzen bei Augenbewegungen und große Lichtempfindlichkeit. Es zeigten sich granulomatöse Papeln im Bereich des Auges. Untersuchungen und Diagnose Die interdisziplinären Untersuchungsbefunde und klinisch-chemischen Parameter waren unauffällig. Eine Biopsie aus dem Lidbereich erbrachte den Nachweis von Delftia acidovorans mittels bakterieller 16S-rRNA-PCR. Therapie und Verlauf Unter der Therapie mit Piperacillin/Tazobactam 3-mal 4,5 g/d i. v. für 10 Tage kam es zu einer raschen klinischen Besserung, sodass die Patientin nach 11 Tagen entlassen werden konnte. Nach weiteren 10 Monaten war sie rezidiv- und beschwerdefrei. Folgerung D. acidovorans ist bislang nicht als zoonotischer Erreger in Erscheinung getreten, sollte aber bei Verletzungen durch Tiere in die differenzialdiagnostischen Erwägungen einbezogen werden.

Delftia Acidovorans pneumonia with lung cavities formation

Case Description: A 52-year-old female patient was admitted to our clinic with complaints of cough, sputum, fever and fatigue. The patient has been receiving immunosuppressive therapy for thrombocytopenic purpura for 5 years. Clinical Finding: Inspiratory crackles were heard on both hemithorax. Oxygen saturation measured with the pulse oximeter was 97%. Chest X-ray showed diffuse reticular opacities that were more prominent in the upper zones of both lungs. WBC counts were 17600/mm3 and Platelet counts were 29000/mm3. Thorax CT showed that there were many thin-walled cavities and millimetric nodules accompanied by ground-glass infiltrates in the upper and middle lobes. Gram staining of bronchial fluid, taken by bronchoscopy, revealed Gram-negative bacilli and intense polymorphonuclear leukocytes. The bacteria were defined as Delftia acidovorans by BD Phoenix automated system. Treatment and outcomes: The patient was hospitalized with suspicion of opportunistic pulmonary infections and cavitary lung disease. After the empirical treatment of intravenous piperacillin-tazobactam and oral clarithromycin, her clinical and radiological findings significantly regressed, and she was discharged with outpatient follow-up. Clinical Relevance: This is the first example of cavitary pneumonia due to Delftia acidovorans in an immunocompromised patient. We would like to emphasize that Delftia pneumonia should be considered in the differential diagnosis of pulmonary cavitary involvement in such patients.