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Aim@#A novel endophyte, Streptomyces kebangsaanensis was isolated from the stem of a Malaysian ethnomedicinal plant, Portulaca oleracea in 2013. Studies on S. kebangsaanensis crude extract showed that it had antifungal activities and further work led to isolation of a novel compound, phenazine-1-carboxylic acid (PCA). This study investigated the combinatorial effect of PCA isolated from S. kebangsaanensis with amphotericin B on the growth of four clinical Fusarium solani isolates. @*Methodology and results@#Disk diffusion assay showed that the crude extract of S. kebangsaaneesis inhibited growth of all four F. solani isolates. Whereas, the compound PCA from this extract inhibited two of the tested F. solani isolates, UZ541/12, and UZ667/13 at minimum inhibitory concentration of 18.00 µg/mL Combinations of this compound with amphotericin B, reduced the minimum inhibitory concentration of amphotericin B for these two isolates from 8 to 0.13 µg/mL and 4 to 0.03 µg/mL respectively. Analysis of fractional inhibitory concentration index showed that a borderline synergism is present between the compound and amphotericin B. @*Conclusion, significance and impact of the study@#These results indicate PCA may be useful in improving actions of available drugs against antimicrobial resistant microorganisms.
Subject(s)
StreptomycesABSTRACT
Abstract@#An epsilometer-test method was used to determine MIC values of several antibiotics against 29 Helicobacter pylori isolated from gastric antrum of dyspepsia patients. Isolates with resistance towards antibiotics were 6.9% -65.5% but these were tetracycline-sensitive. Eight isolates showed multi-resistance towards two antimicrobial agents. The high resistance strains towards metronidazole is alarming.
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Herbal-based slimming products which are consumed orally may be contaminated with heavy metals as well as microorganisms. This study aimed to evaluate the safety level of these slimming products by determining heavy metals and microbial contamination in different batch production. Six different brands of herbal-based slimming products (A, B, C, G, H and I) with three different batch productions (1, 2 and 3) were investigated (n =18). Five heavy metals Arsenic, Cadmium, Chromium, Copper and Zinc were determined using an Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The presence of microorganisms was determined by total aerobic count and the bacteria were identified. The samples’ moisture content was determined by calculating the percentage of water loss after drying process. All batches of samples A and B had high content of zinc, over the permissible level of 5ppm while, 6 samples contained Chromium above the permissible level (1.5 ppm). All 3 batches of sample A presented with the highest total daily intake of heavy metals. Bacteria were present in all the samples tested with the highest numbers in samples G, H and A followed by B, I and C. The highest number of fungi was found in product A while product I was free from fungal contamination. Aspergillus spp. was the predominant fungus present in the samples. There was a weak correlation between moisture content and bacteria (r = 0.087) and fungal (r = 0.253) presence in the samples. As some herbal slimming products contain heavy metals as well as microorganisms, consumers need to be more vigilant and discerning when selecting products to be consumed.
Subject(s)
Metals, HeavyABSTRACT
Objective To determine ex vivo antimalarial activity and cytotoxicity of endophytic Streptomyces SUK 08 as well as the main core structure fractionated from its crude extract. Methods The activities of SUK 08 crude extract were evaluated by using the Plasmodium lactate dehydrogenase assay and synchronization test against rodent malaria parasite Plasmodium berghei, instead of human malarial parasite Plasmodium falciparum. The cytotoxicity of the crude extract was determined by MTT assay. The crude extract was analyzed by thin-layer chromatography and gas chromatography–mass spectrophotometry. Results The ethyl acetate crude extract showed very promising antimalarial activity with IC
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<p><b>OBJECTIVE</b>To genotypically characterize methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from medical and surgical wards in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) in 2009.</p><p><b>METHODS</b>MRSA strains were collected and molecularly typed by pulsed-field gel electrophoresis (PFGE).</p><p><b>RESULTS</b>PFGE typing on 180 MRSA isolated in UKMMC identified 5 pulsotypes (A-E) and 6 singletons, where pulsotypes B and C were suspected to be divergent clones originating from a single ancestor. This study also showed that most MRSA strains were isolated from swab (119 isolates), followed by blood (22 isolates), tracheal aspirate (11 isolates) and sputum (10 isolates). On the other hand, urine and bone isolates were less, which were 4 and 1 isolates, respectively. The distribution of different pulsotypes of MRSA among wards suggested that MRSA was communicated in surgical and medical wards in UKMMC, with pulsotype B MRSA as the dominant strain. Besides, it was found that most deceased patients were infected by pulsotype B MRSA, however, no particular pulsotype could be associated with patient age, underlying disease, or ward of admittance.</p><p><b>CONCLUSIONS</b>Five pulsotypes of MRSA and 6 singletons were identified, with pulsotype B MRSA as the endemic strains circulating in these wards, which is useful in establishment of preventive measures against MRSA transmission.</p>
Subject(s)
Electrophoresis, Gel, Pulsed-Field , Evolution, Molecular , Hospitals , Malaysia , Epidemiology , Methicillin-Resistant Staphylococcus aureus , Genetics , Staphylococcal Infections , Epidemiology , MicrobiologyABSTRACT
Endophytic bacteria has the potential to produce antibiotics and other secondary metabolites. The production of secondary metabolites can be enhanced through the optimization of its nutrient content such as the nitrogen source. In this study, the content of nitrogen sources such as ammonium sulphate, ammonium dihydrogen phosphate, potassium nitrate and sodium nitrate have been modified and incorporated in the International Streptomyces Project Medium 4 broth media to optimize the growth of Streptomyces SUK 02. The extraction was carried out using ethyl acetate and the antifungal activity was assayed using agar diffusion method. The test fungus used was Aspergillus fumigatus and Fusarium solani. The results showed that the maximum weight percentage (w/v) of crude extract was obtained when sodium nitrate was used (3.30%), followed by ammonium dihydrogen phosphate (2.24%), ammonium sulfate (1.46%) and potassium nitrate (1.20%). Antifungal activity was obtained from the extracts that contained ammonium sulfat. The percentage of inhibition of this extract against Aspergillus fumigatus and Fusarium solani was 33.0-35.0% and 17.4-30.0%, respectively. Nevertheless, the MIC value against Aspergillus fumigatus was 1.5 mg/ml In conclusion, natrium nitrat was a suitable nitrogen source for optimum growth of Streptomyces SUK 02 whereas the presence of ammonium sulfat was good to increase the antifungal activity.
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This study evaluated in vitro activity of 9 flavonoids in combination with vancomycin or oxacillin against vancomycin-intermediate Staphylococcus aureus [VISA] ATCC 700699 by employing the checkerboard method to obtain Minimal inhibitory concentration [MIC] and fractional inhibitory concentration [FIC] index. Six flavonoids namely hesperitin, rutin, naringenin, flavones, naringin and 3, 7-dihyroxyflavone which exhibited notable inhibitory activity [MIC values 4] were observed. In time kill studies, oxacillin-flavone combination at synergistic concentration demonstrated bactericidal effect at 24 h period with concentration-dependent manner on the VISA strain. Following 1 h exposure, the combination also produced persistent effect on the bacteria growth for 2.9 hrs at 1x sub-MIC and more than 24 h at 5x of sub-MIC and there was a significant difference between both concentrations [p<0.05]. Vancomycin-flavone combination, however, showed no concentration-dependant effect and lower PAE values [1.159 h and 2.322 h at 1x and 5x sub-MIC, respectively] on the VISA strain. In conclusion, flavone markedly intensifies the susceptibility of oxacillin against VISA and the combination can be implicated for further interaction studies at molecular level