Antibacterial effect of essential oils and their components against Xanthomonas arboricola pv. pruni revealed by microdilution and direct bioautographic assays.

Bacterial spot of stone fruits caused by Xanthomonas arboricola pv. pruni (Xap) is one of the most significant diseases of several Prunus species. Disease outbreaks can result in severe economic losses while the control options are limited. Antibacterial efficacy of essential oils (EOs) of thyme, cinnamon, clove, rosemary, tea tree, eucalyptus, lemon grass, citronella grass, and lemon balm was assessed against two Hungarian Xap isolates. The minimal inhibitory concentration (MIC) was determined by broth microdilution assay and for the identification of active EOs' components a newly introduced high-performance thin-layer chromatography (HPTLC)-Xap (direct bioautography) method combined with solid-phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) was applied. All EOs inhibited both bacterium isolates, but cinnamon proved to be the most effective EO with MIC values of 31.25 µg/mL and 62.5 µg/mL, respectively. Compounds in the antibacterial HPTLC zones were identified as thymol in thyme, trans-cinnamaldehyde in cinnamon, eugenol in clove, borneol in rosemary, terpinen-4-ol in tea tree, citral (neral and geranial) in lemon grass and lemon balm, and citronellal and nerol in citronella grass. Regarding active compounds, thymol had the highest efficiency with a MIC value of 50 µg/mL. Antibacterial effects of EOs have already been proven for several Xanthomonas species, but to our knowledge, the studied EOs, except for lemon grass and eucalyptus, were tested for the first time against Xap. Furthermore, in case of Xap, this is the first report demonstrating that direct bioautography is a fast and suitable method for screening anti-Xap components of complex matrices, like EOs.

Antimicrobial Diterpenes from Rough Goldenrod (Solidago rugosa Mill.).

Solidago rugosa is one of the goldenrod species native to North America but has sporadically naturalized as an alien plant in Europe. The investigation of the root and leaf ethanol extracts of the plant using a bioassay-guided process with an anti-Bacillus assay resulted in the isolation of two antimicrobial components. Structure elucidation was performed based on high-resolution tandem mass spectrometric and one- and two-dimensional NMR spectroscopic analyses that revealed (-)-hardwickiic acid (Compound 1) and (-)-abietic acid (Compound 2). The isolates were evaluated for their antimicrobial properties against several plant pathogenic bacterial and fungal strains. Both compounds demonstrated an antibacterial effect, especially against Gram-positive bacterial strains (Bacillus spizizenii, Clavibacter michiganensis subsp. michiganensis, and Curtobacterium flaccumfaciens pv. flaccumfaciens) with half maximal inhibitory concentration (IC50) between 1 and 5.1 µg/mL (5-20 times higher than that of the positive control gentamicin). In the used concentrations, minimal bactericidal concentration (MBC) was reached only against the non-pathogen B. spizizenii. Besides their activity against Fusarium avenaceum, the highest antifungal activity was observed for Compound 1 against Bipolaris sorokiniana with an IC50 of 3.8 µg/mL.

[Considerations on the treatment of IgA nephropathy on the basis of the results of the latest studies (STOP-IgAN, TESTING, NEFIGAN)]. / Terápiás megfontolások IgA-nephropathiában a legutolsó vizsgálatok (STOP-IgAN, TESTING, NEFIGAN) eredményei alapján.

IgA nephropathy is an immune-mediated chronic glomerulonephritis with a great variability in clinical presentation and outcome. The disease can progress to end-stage renal failure in 25% of patients. For this reason we should identify patients with potential to progress. Most important risk factors for progression are persistent proteinuria, hypertension, decreased renal function and some histological lesions. The actually suggested treatment is summarized in KDIGO Clinical Practice Guideline from 2012. They suggest to give firstly non-specific supportive treatment (especially renin-angiotensin system blocking agents). Recommendation about steroid/immunosuppression treatment is based on low level of evidence. Recently three studies were organised concerning benefits and risk of steroid/immunosuppressive treatment added together with specific supportive treatment. In the STOP-IgAN study, systemic steroid/immunosuppressive treatment significantly decreased proteinuria but did not stop progression. In the TESTING study, systemic steroid treatment significantly decreased proteinuria and progression. However, the study was recently discontinued due to several severe side effects of steroid treatment. Involvement of intestinal mucosal immunity in the pathogenesis of IgA nephropathy suggested the NEFIGAN study with budesonide treatment. Budesonide releases corticosteroid in distal small intestine and colon. Proteinuria was significantly decreased and renal function remained stabile. High number of withdrawals owing to adverse effects is a major concern implying a substantial systemic effect of budesonide. We need further information on the characteristics of patients who most likely benefit from steroid/immunosuppressive treatment given after or together with specific supportive treatment. Orv Hetil. 2017; 158(49): 1946-1952.

[The effect of low-protein diet supplemented with ketoacids in patients with chronic renal failure]. / Ketosavakkal kiegészített fehérjeszegény diéta hatásának vizsgálata krónikus veseelégtelenségben szenvedo betegeken.

It is known that dietary protein restriction slows the progression of chronic renal disease. If daily protein intake is less than 0.5-0.6 g/kgbw, the diet has to be supplemented with essential aminoacids/ketoacids. In this study the authors evaluate the long-term effect of low-protein diet supplemented with ketoacids on the progression of chronic renal failure, calcium and phosphorus metabolism, nutritional status, the compliance of patients and the permanent dietary education for the compliance. 51 predialysis patients have been treated with ketoacids supplemented low-protein diet during 12-57 months (mean treatment period: 26 months). Serum creatinine raised from 349.72+/-78.04 micromol/l to 460.66+/-206.66 micromol/l (27 micromol/l/year or 2.3 micromol/l/month), glomerular filtration rate (GFR) decreased from 21.52+/-7.84 ml/min to 18.22+/-7.76 ml/min (0.83 ml/min/year or 0.07 ml/min/month). The slope of 1/serum creatinine versus time was 0.0018 by linear regression analysis. Serum parathormon decreased significantly, but serum calcium and phosphorus did not change. Nutritional status of patients did not change significantly during the follow-up period. Protein intake decreased significantly and remained at this lower level during the treatment period. According to results: low-protein diet supplemented with ketoacids was effective in slowing progression of chronic renal failure, decreased PTH, did not change nutritional status. With permanently and good education it was possible to keep patients on low-protein diet for a long period.

[Acute renal failure caused by plant extract]. / Növényi kivonat okozta akut veseelégtelenség.

The authors review the case of a 30 years old female patient presenting with a 48 hours-standing anuria, who permanently used products of grist of a virtuous plant, Guarana and occasionally used a parenteral non-steroid painkiller. The clinical history and laboratory results showed acute renal and hepatic failure. The histological picture of the renal biopsy specimen verified an acute tubular necrosis. After temporary dialysis treatment, her renal function recovered progressively with compensatory polyuria. The authors would like to draw the attention to the risks of the use of over-the-counter marketed paramedicinal products, per se or in combination with pharmaceutically registered products, sold in pharmacies and nutrition supplement stores.