Control of Fusarium sp. on pineapple by megasonic cleaning with electrolysed oxidising water

The effects of megasonication (MS) with electroly sed oxidising (EO) water (MS/EO treatment) on Fusarium sp. which causes postharvest decay of pineapple cv. Phu Lae were investigated. Spore suspensions containing 105conidia mL -1 and 1 cm mycelium discs of Fusarium sp. were subjected to MS (1 MHz) in EO water with available free chlorine at 100 ppm for 10 min., and compared with non-treated control samples. The MS/EO treatment completely inhibited spore germination and mycelial growth for 3 days and reduced fruit decay. Development of Fusarium sp. on de-crowned pineapple fruit was also investigated by scan ning electron microscopy. The fungal growth was restricted on de-crowned pineapple fruit for 72 hr, following MS/EO treatment. The MS/EO treatment also enhanced the activity of two enzymes: phenylalanine ammonia lyase (PAL) and peroxidase (POD), which play important roles in plant defense responses

Characteristics of Antibiotic Resistance and Tolerance of Environmentally Endemic <i>Pseudomonas aeruginosa</i>

Antibiotic-resistant bacteria remain a serious public health threat. In order to determine the percentage of antibiotic-resistant and -tolerant Pseudomonas aeruginosa cells present and to provide a more detailed infection risk of bacteria present in the environment, an isolation method using a combination of 41 °C culture and specific primers was established to evaluate P. aeruginosa in the environment. The 50 strains were randomly selected among 110 isolated from the river. The results of antibiotic susceptibility evaluation showed that only 4% of environmental strains were classified as antibiotic-resistant, while 35.7% of clinical strains isolated in the same area were antibiotic-resistant, indicating a clear difference between environmental and clinical strains. However, the percentage of antibiotic-tolerance, an indicator of potential resistance risk for strains that have not become resistant, was 78.8% for clinical strains and 90% for environmental strains, suggesting that P. aeruginosa, a known cause of nosocomial infections, has a high rate of antibiotic-tolerance even in environmentally derived strains. It suggested that the rate of antibiotic-tolerance is not elicited by the presence or absence of antimicrobial exposure. The combination of established isolation and risk analysis methods presented in this study should provide accurate and efficient information on the risk level of P. aeruginosa in various regions and samples