Antimicrobial susceptibility of Erysipelothrix rhusiopathiae isolated from pigs in Southern Japan with a modified agar dilution method.

The determination of antimicrobial minimum inhibitory concentration (MIC) in Erysipelothrix rhusiopathiae by using the agar dilution method has not been covered by the Clinical and Laboratory Institute (CLSI). Only the broth microdilution method has been outlined. This report describes a modification of the agar dilution procedure for E. rhusiopathiae using Trypto-soy agar supplemented with 0.1% Tween 80 and incubation in ambient air at 37 degrees C for 24 hr. The MICs of the assay were in agreement with those of the broth microdilution method recommended by the CLSI. Antimicrobial susceptibility test was performed using this method for 149 E. rhusiopathiae isolates from 2 meat processing plants in Kagoshima Prefecture during the period of April 2004 to March 2005. The number of strains resistant to oxytetracycline, erythromycin, lincomycin, ofloxacin and enrofloxacin were 56 (37.6%), 4 (2.7%), 18 (12.1%), 21 (14.1%) and 19 (12.8%), respectively. All strains were susceptible to ampicillin.

The evaluation of trifloxystrobin in protection of Calendula officinalis (Pot marigold) against Erysiphe cichoracearum DC.

The aim of the two-years field's examinations was the evaluation of the fungicide Zato 50 WG (biologically active substances BAS--trifloxystrobin 50%) in protection of Calendula officinalis (Pot marigold) against Erysiphe cichoracearum. Mentioned fungicide was applied at three concentrations: 0.1, 0.15 and 0.2%. As the standard fungicide Amistar 250 SC (biologically active substances BAS - azoxystrobin 250 g/dm3) was used. In every year of research work the four protective treatments were carried out. The estimation of infestation degree of Calendula officinalis leafs by the Erysiphe cichoracearum was made 5 times. Before each treatment four analysis were done, whereas the last analysis--the fifth one was executed after 10 days from the last protective spraying. According to the results, it was found that investigated preparations significant reduced the mean infestation degree of Calendula officinalis leafs by the Erysiphe cichoracearum compared to the control. The results pointed, that in protection of the mentioned plant by the powdery mildew the 0.2% dose of Zato 50WG showed the best suitability.

Effects of tamoxifen, melatonin, coenzyme Q10, and L-carnitine supplementation on bacterial growth in the presence of mycotoxins.

The involvement of toxic oxygen intermediates in the bacteriostatic effects of mycotoxins (T-2 toxin, deoxynivalenol, ochratoxin A, aflatoxin B1, and fumonisin B1) was investigated by producing bacterial growth curves using turbidimetry assays in the presence and absence of oxygen radical-scavenging substances. The strains used in this study included Escherichia coli (FT 101), Streptococcus agalactiae (FT 311, FT 313, FT 315), Staphylococcus aureus (FT 192), Yersinia enterocolitica (FT 430), Salmonella infantis (FT 431), Erysipelothrix rhusiopathiae (FT 432), Lactobacillus plantarum (FT234) and Lactobacillus casei (FT 232). Tamoxifen, melatonin, l-carnitine and coenzyme Q10 were used as radical scavengers against oxygen toxicity to the strains studied. Tamoxifen was the most effective in inhibiting bacterial growth when used at a high concentration, whereas melatonin and l-carnitine were less effective. A combination of l-carnitine and coenzyme Q10 provided better protection against oxygen toxicity caused by the mycotoxins growth than they did individually. It was concluded that oxygen radicals are involved in the killing of bacteria and that there is endogenous formation of toxic oxygen products by mycotoxins. The objective of this study was to determine whether the antioxidants were able to counteract the toxic effects of the mycotoxins. The data obtained indicate that bacterial growth can be inhibited especially by T-2 toxin, aflatoxin B1 and ochratoxin A and that this effect can be partially counteracted by antioxidants such as coenzyme Q10 plus l-carnitine.