title: Clinical Specimen-Direct LAMP: A Useful Tool for the Surveillance of blaOXA-23-Positive Carbapenem-Resistant Acinetobacter baumannii.
abstract: Healthcare-associated infections are a leading cause of morbidity and mortality worldwide. Treatment is increasingly complicated by the escalating incidence of antimicrobial resistance. Among drug-resistant pathogens, carbapenem-resistant Acinetobacter baumannii (CRAb) is of increasing concern because of the limited applicable therapies and its expanding global distribution in developed countries and newly industrialized countries. Therefore, a rapid detection method that can be used even in resource-poor countries is urgently required to control this global public health threat. Conventional techniques, such as bacterial culture and polymerase chain reaction (PCR), are insufficient to combat this threat because they are time-consuming and laborious. In this study, we developed a loop-mediated isothermal amplification (LAMP) method for detecting blaOXA-23-positive CRAb, the most prevalent form of CRAb in Asia, especially in Thailand, and confirmed its efficacy as a surveillance tool in a clinical setting. Clinical samples of sputum and rectal swabs were collected from patients in a hospital in Bangkok and used for LAMP assays. After boiling and centrifugation, the supernatants were used directly in the assay. In parallel, a culture method was used for comparison purposes to evaluate the specificity and sensitivity of LAMP. As a first step, a total of 120 sputum samples were collected. The sensitivity of LAMP was 88.6% (39/44), and its specificity was 92.1% (70/76) using the culture method as the "gold standard". When surveillance samples including sputum and rectal swabs were analyzed with the LAMP assay, its sensitivity was 100.0%. This method enables the direct analysis of clinical specimens and provides results within 40 minutes of sample collection, making it a useful tool for surveillance even in resource-poor countries.
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan; Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan; Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Shigeto
authors.initials: S
authors.lastname: Hamaguchi
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan; Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Akeda
authors.affiliation: Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Pitak
authors.initials: P
authors.lastname: Santanirand
authors.affiliation: General Bacteriology Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Bangkok, Thailand.
authors.forename: Anusak
authors.initials: A
authors.lastname: Kerdsin
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Seki
authors.affiliation: Department of Microbiology and Infectious Diseases, School of Medicine, Faculty of Medicine, Toho University, Tokyo, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ishii
authors.affiliation: General Bacteriology Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Bangkok, Thailand.
authors.forename: Wantana
authors.initials: W
authors.lastname: Paveenkittiporn
authors.affiliation: Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, United States of America.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bonomo
authors.affiliation: Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Oishi
authors.affiliation: Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Kumthorn
authors.initials: K
authors.lastname: Malathum
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tomono
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D015780:Carbapenems / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D013785:Thailand; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D015780:Carbapenems; C466679:beta-lactamase OXA-23; D001618:beta-Lactamases