Characteristics of Antibiotic Resistance and Tolerance of Environmentally Endemic <i>Pseudomonas aeruginosa</i>
Seryoung Kim,
Satomi Masai,
Keiji Murakami,
Momoyo Azuma,
Keiko Kataoka,
Mayu Sebe,
Kazuya Shimizu,
Tomoaki Itayama,
Niwooti Whangchai,
Kanda Whangchai,
Ikko Ihara,
Hideaki Maseda
Affiliations
Seryoung Kim
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Osaka 563-8577, Japan
Satomi Masai
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Osaka 563-8577, Japan
Keiji Murakami
Department of Clinical Nutrition, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288 Matsushima, Okayama 701-0193, Japan
Momoyo Azuma
Department of Infection Control and Prevention, Tokushima University Hospital, 2-50-1 Kuramoto, Tokushima 770-8503, Japan
Keiko Kataoka
Department of Microbiology and Genetic Analysis, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima 770-8503, Japan
Mayu Sebe
Department of Clinical Nutrition, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288 Matsushima, Okayama 701-0193, Japan
Kazuya Shimizu
Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
Tomoaki Itayama
Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo, Nagasaki 852-8131, Japan
Niwooti Whangchai
Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai 50290, Thailand
Kanda Whangchai
Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
Ikko Ihara
Department of Agricultural Engineering and Socio-Economics, Kobe University, Kobe 657-8501, Japan
Hideaki Maseda
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Osaka 563-8577, Japan
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.
