title: Leptospira-rat-human relationship in Luzon, Philippines.
abstract: Leptospirosis is a zoonotic infection that is caused by the pathogenic species of Leptospira. Rats are the most important reservoirs of these organisms. Our study aimed to characterize Leptospira isolates from humans and rats and elucidate the Leptospira-rat-human relationship in Luzon, Philippines. Forty strains were isolated from humans and rats. The isolates were confirmed to be Leptospira and pathogenic through rrl- and flaB-PCR, respectively. Around 73% of the isolates were found to be lethal to hamsters. Serotyping showed that there were mainly three predominant leptospiral serogroups in the study areas namely Pyrogenes, Bataviae, and Grippotyphosa. Gyrase B gene sequence analysis showed that all the isolates belonged to Leptospira interrogans. Most had 100% similarity with serovar Manilae (15/40), serovar Losbanos (8/40), and serogroup Grippotyphosa (8/40). Strains from each group had highly identical pulsed-field gel electrophoresis patterns and were further grouped as A (Pyrogenes, 14), B (Bataviae, 8), and C (Grippotyphosa, 10). Results further revealed that similar serotypes were isolated from both humans and rats in the same areas. It is suggested that these three predominant groups with highly similar intra-group PFGE patterns may have been primarily transmitted by rats and persistently caused leptospirosis in humans particularly in the Luzon islands.
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan. Electronic address: svillan@bact.med.kyushu-u.ac.jp.
authors.forename: Sharon Yvette Angelina M
authors.initials: SY
authors.lastname: Villanueva
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Rubelia A
authors.initials: RA
authors.lastname: Baterna
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Crystal Amiel M
authors.initials: CA
authors.lastname: Estrada
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Ana Kriselda B
authors.initials: AK
authors.lastname: Rivera
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Micaella C
authors.initials: MC
authors.lastname: Dato
authors.affiliation: College of Medicine, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Pia Regina Fatima C
authors.initials: PR
authors.lastname: Zamora
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Segawa
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Lolita L
authors.initials: LL
authors.lastname: Cavinta
authors.affiliation: Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, Chiba Institute of Science, Chiba 288-0025, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, Chiba Institute of Science, Chiba 288-0025, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Masuzawa
authors.affiliation: College of Medicine, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Yanagihara
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Manila 1000, Philippines.
authors.forename: Nina G
authors.initials: NG
authors.lastname: Gloriani
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004195:Disease Models, Animal; D004197:Disease Reservoirs; D018562:Disease Transmission, Infectious; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D007921:Leptospira interrogans / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007922:Leptospirosis / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D008297:Male; D008647:Mesocricetus; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058889:Molecular Typing; D010679:Philippines / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D051381:Rats; D012376:Rodent Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D017422:Sequence Analysis, DNA; D065288:Serogroup; D016019:Survival Analysis; D015047:Zoonoses / Q000382:microbiology / Q000635:transmission
chemical_list: D004269:DNA, Bacterial
keywords: Geographic information system (GIS); Human; Leptospira; PFGE; Pathogenicity; Rat; gyrB sequence analysis