title: Determination of Leptospira borgpetersenii serovar Javanica and Leptospira interrogans serovar Bataviae as the persistent Leptospira serovars circulating in the urban rat populations in Peninsular Malaysia.
abstract: BACKGROUND
  Leptospirosis is an emerging infectious disease of global significance, and is endemic in tropical countries, including Malaysia. Over the last decade, a dramatic increase of human cases was reported; however, information on the primary vector, the rat, and the Leptospira serovars circulating among the rat population is limited. Therefore, the present study was undertaken to isolate Leptospira and characterise the serovars circulating in the urban rat populations from selected main cities in Peninsular Malaysia.
  
  
  METHODS
  Rat trappings were carried out between October 2011 to February 2014 in five urban cities which were chosen as study sites to represent different geographical locations in Peninsular Malaysia. Microscopic agglutination test (MAT) and PCR were carried out to identify the Leptospiral serogroup and determine the pathogenic status of the isolates, respectively while pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD)-PCR were used to characterize the isolates.
  
  
  RESULTS
  Three rat species were identified from the three hundred and fifty seven rats captured with Rattus rattus, being the dominant rat species (285, 80 %) followed by Rattus norgevicus (53, 15 %) and Rattus exulans (19, 5 %). Only 39 samples (11.0 %) were positive by culture and further confirmed as pathogenic Leptospira by PCR. Significant associations were shown between host infection with locality, season, host-age and species. Based on MAT, two serogroups were identified in the population namely; L. borgpetersenii serogroup Javanica (n = 16) and L. interrogans serogroup Bataviae (n = 23). Pulsed-field gel electrophoresis (PFGE) distinguished the two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (41 %), and L. interrogans serovar Bataviae (59 %). RAPD-PCR yielded 14 distinct patterns and was found to be more discriminative than PFGE.
  
  
  CONCLUSIONS
  This study confirms two Leptospira serovars circulating among the urban rats population in Peninsular Malaysia namely; L. borgpetersenii serovar Javanica and L. interrogans serovars Bataviae. Despite the low number of isolates obtained from the rat population, this study suggests that rodent control programs and disease surveillance may help to reduce the possible risk of disease transmission.
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. benacer.dvt@gmail.com.
authors.forename: Douadi
authors.initials: D
authors.lastname: Benacer
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. nsheena@um.edu.my.
authors.forename: Siti Nursheena
authors.initials: SN
authors.lastname: Mohd Zain
authors.affiliation: Institute of Mathematical Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. simsz@um.edu.my.|Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kuala Lumpur, Malaysia. simsz@um.edu.my.
authors.forename: Shin Zhu
authors.initials: SZ
authors.lastname: Sim
authors.affiliation: Bacteriology Unit, Institute for Medical Research, Ministry of Health, Kuala Lumpur, Malaysia. mknizam@imr.gov.my.
authors.forename: Mohd Khairul Nizam
authors.initials: MK
authors.lastname: Mohd Khalid
authors.affiliation: Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia. zul0@cdc.gov.
authors.forename: Renee L
authors.initials: RL
authors.lastname: Galloway
authors.affiliation: UMR_D 190 "Emergence des Pathologies Virales", IRD Aix- Marseille University EHESP, Marseille, France. Marc.Souris@ird.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Souris
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. thongkl@um.edu.my.
authors.forename: Kwai Lin
authors.initials: KL
authors.lastname: Thong
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D002947:Cities; D004199:Disease Vectors; D016521:Electrophoresis, Gel, Pulsed-Field; D007919:Leptospira / Q000145:classification / Q000302:isolation & purification*; D007922:Leptospirosis / Q000382:microbiology / Q000662:veterinary*; D008296:Malaysia; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D051381:Rats; D012376:Rodent Diseases / Q000382:microbiology*; D065288:Serogroup