Objective: To isolate Salmonella from curry samples and to evaluate the drug sensitivity of the food-borne Salmonella and its susceptibility to specific plant extracts. Methods: Salmonella was isolated from the curry samples by standard microbiological methods and was confirmed by biochemical tests. The antibiotic susceptibility test was conducted by disc diffusion method using commercially available antibiotics such as ampicillin, tetracycline, chloramphenicol, kanamycin, and penicillin. In addition, the susceptibility of the food-borne Salmonella was also evaluated against the aqueous extracts of Camelia sinensis (L.) Theaceae (tea leaves) and the Trachyspermum ammi (L.) Apiaceae ( ajwain or omum seeds). Results: Out of fifty curry samples, only seven samples were identified to have Salmonella contamination. The Salmonella isolates showed a significant drug resistance pattern except for kanamycin. The plant extracts showed a considerable antibacterial activity against the isolates, indicating the presence of antimicrobial principle which can be exploited after complete pharmacological investigations. Conclusions:The present study demonstrates the occurrence of Salmonella in the curry samples, and shows significant drug resistance against most of the commercially available antibiotics, except kanamycin. Antimicrobial effect of the plant extracts against the food-bone Salmonella suggests that dietary including medicinal herbs would be one strategy to manage food borne pathogens.

Aims: Temporary Immersion Bioreactor (TIB) system is an advanced technology for commercial mass production of potato microtubers. Despite of several advantages, this system possess a great risk of culture loss at any stage of micropropagation due to microbial contamination. The aims of this study were to identify microbial contaminants isolated during potato shoot growth in the TIB system, evaluate the efficacy of antimicrobial agents to prevent them, to investigate the effect of those agents in vitro on growth and morphology of potato plantlets. Methodology and results: Six bacteria namely Pseudomonas, Staphylococcus, Klebsiella, Corynebacterium, Proteus, Bacillus and five fungi Aspergillus, Penicillium, Mucor, Fusarium and Rhizopus were isolated from the TIB system. We examined the effect of three antibacterial (Gentamycin, Vancomycin and Tetracycline) and four antifungal agents (Mencozeb, Propiconazole, Bavistin and Copper oxychloride) on the contaminants and on potato shoot growth. Results show that Gentamycin (50 mg/L) and Propiconazole (0.15%) were most effective against the isolated bacteria (35 mm inhibition zone) and fungi (100%) respectively, whereas Gentamycin in combination with Bavistin showed better performance on potato shoot and root development. Conclusion, significance and impact of study: Present study will provide useful guidelines to reduce or eliminate the risk of contamination during micropropagation.

Aims: The purpose of this experiment was to determine the artificial symbiosis interaction of Herbaspirillum seropedicae (Z78) on oil palm embryogenic calli. Methodology and results: For this purpose, symbiotic associations were established between Z78 and embryogenic calli of oil palm tissue cultured. A total of five treatments involved, in particular: i) + 3.0 mg/L 2,4-D + 100% N MS medium (control), ii) + Z78 pellet cells (1 mL) + 25% N MS medium, iii) + Z78 supernatant (1 mL) + 25% N MS medium, iv) + Z78 broth culture (1 mL) + 25% N MS medium, and v) + Z78 sonicated cells (1 mL) + 25% N MS medium. All treatments were supplied with minimal N sources (25% N), ammonium nitrate and potassium nitrate, while the control was treated with 100% N sources. Treated samples were harvested on D80 and observed for biomass and diameter increment (%), formation of embryoids, and Z78 colonization. The results showed embryogenic calli in the inoculated treatments that contained depleted N produced similar result to the control treatment which contained 100% N nutrients. Positive interactions occurred between the diazotroph and host plant tissues as viewed under FESEM and EFTEM. Among the treatments, Z78 sonicated cell showed better growth of embryogenic calli compared to others. Conclusion, significance and impact study: The in vitro nitrogen-depleted artificial symbiosis environment allowed the diazotroph (Z78) to be expressed and provide the nitrogen sources and indole-3-acetic acid for cell growth. This study represents beneficial co-culture interaction effects of different inocula of diazotrophic bacterial cells with in vitro embryogenic calli of oil palm.

OBJECTIVETo isolate Salmonella from curry samples and to evaluate the drug sensitivity of the food-borne Salmonella and its susceptibility to specific plant extracts.

METHODSSalmonella was isolated from the curry samples by standard microbiological methods and was confirmed by biochemical tests. The antibiotic susceptibility test was conducted by disc diffusion method using commercially available antibiotics such as ampicillin, tetracycline, chloramphenicol, kanamycin, and penicillin. In addition, the susceptibility of the food-borne Salmonella was also evaluated against the aqueous extracts of Camelia sinensis (L.) Theaceae (tea leaves) and the Trachyspermum ammi (L.) Apiaceae ( ajwain or omum seeds).

RESULTSOut of fifty curry samples, only seven samples were identified to have Salmonella contamination. The Salmonella isolates showed a significant drug resistance pattern except for kanamycin. The plant extracts showed a considerable antibacterial activity against the isolates, indicating the presence of antimicrobial principle which can be exploited after complete pharmacological investigations.

CONCLUSIONSThe present study demonstrates the occurrence of Salmonella in the curry samples, and shows significant drug resistance against most of the commercially available antibiotics, except kanamycin. Antimicrobial effect of the plant extracts against the food-bone Salmonella suggests that dietary including medicinal herbs would be one strategy to manage food borne pathogens.

Anti-Bacterial Agents ; isolation & purification ; pharmacology ; Apiaceae ; chemistry ; Camellia ; chemistry ; Drug Resistance, Bacterial ; Food Microbiology ; Humans ; Microbial Sensitivity Tests ; Plant Extracts ; isolation & purification ; pharmacology ; Salmonella ; drug effects ; isolation & purification

Aims: Dendrobiums are majorly affected by Fusarium proliferatum and F. oxysporum. The aim of this research was to utilise the mycotoxin, fusaric acid (FA) on Dendrobium hybrid to produce cultivars that are resistant towards these fungi. Methodology and results: FA of concentrations 0.05, 0.10, 0.15 and 0.20 mM were transferred to sterilised half-strength Murashige and Skoog (MS) medium and inoculated with four weeks old thin cell layer (TCL) of protocorm-like bodies (PLBs) for eight weeks. It was deduced that PLBs treated with 0.10 mM of FA resulted in highest survival and shoot regeneration rate but the survival and regeneration rate began to decline as the concentrations of FA were increased. Histology and scanning electron microscopy (SEM) observation showed prominent cell damage and stomatal closure in PLBs treated with FA. Direct amplification of minisatellite DNA (DAMD) markers showed polymorphism in the FA treated PLBs compared to the control PLBs. In the leaf bridge bioassay, plantlets treated with 0.05 mM of FA showed most resistance towards both fungal species. Conclusion, significance and impact of study Therefore, this research is a preliminary screening study where the optimum concentration of FA was selected based on the reaction of treated TCL of PLBs towards these mutagens.