Isolation and Molecular Characterization of Leptospira interrogans and Leptospira borgpetersenii Isolates from the Urban Rat Populations of Kuala Lumpur, Malaysia

Abstract

Abstract. Rats are considered the principal maintenance hosts of Leptospira. The objectives of this study were isolation and identification of Leptospira serovars circulating among urban rat populations in Kuala Lumpur. Three hundred urban rats (73% Rattus rattus and 27% R. norvegicus) from three different sites were trapped. Twenty cultures were positive for Leptospira using dark-field microscopy. R. rattus was the dominant carrier (70%). Polymerase chain reaction (PCR) confirmed that all isolates were pathogenic Leptospira species. Two Leptospira serogroups, Javanica and Bataviae, were identified using microscopic agglutination test (MAT). Pulsed-field gel electrophoresis (PFGE) identified two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (85%) and L. interrogans serovar Bataviae (15%). We conclude that these two serovars are the major serovars circulating among the urban rat populations in Kuala Lumpur. Despite the low infection rate reported, the high pathogenicity of these serovars raises concern of public health risks caused by rodent transmission of leptospirosis.

Survey for zoonotic pathogens in Norway rat populations from Europe

“…Varying infection risks among populations have long been associated with intrinsic factors such as demographic functional groups. In various pathogen/host systems, a higher prevalence has been found in males than in females, which has been linked to more aggressive behaviour among males . In the present study, sex was not of importance for the Leptospira and rat PyV prevalences in the population.…”

“…Weight (as an approximation for age) was the only demographic factor associated with Leptospira and rat PyV prevalence. This has often been reported for Leptospira and other infections in rat populations and could reflect increased exposure time through environmental transmission or aggressive behaviour of adult rats . Analysis of infection risk related to human population density revealed higher prevalences in rural areas compared with urban areas.…”

Urban Leptospirosis in Africa: A Cross-Sectional Survey of Leptospira Infection in Rodents in the Kibera Urban Settlement, Nairobi, Kenya

“…The use of Sherman traps may provide one explanation for the relatively low prevalence in the Rattus population sampled in this study. These traps may select for smaller (and younger) Rattus rodents, in which the Leptospira infection prevalence in kidneys may be lower than in adults 38–40. The mass of the R. norvegicus and R. rattus rodents trapped in this study ranged from 25 to 194 grams and from 12.5 to 122 grams, respectively, indicating that all of the Rattus rodents trapped were juveniles 39,40.…”

Rodent-borne health risks in farming systems

“…Other studies confirm the relation between R. exulans and L. interrogans (Cosson et al, 2014;Perez et al, 2011), and in Thailand, R. exulans was also found to be infected with both L. interrogans and L. borgpetersenii (Kositanont, Naigowit, Imvithaya, Singchai, & Puthavathana, 2003;Wangroongsarb et al, 2002). These findings are in line with the fact that Leptospira species, borgpetersenii and interrogans, contribute a great deal to human disease in Asia (Benacer et al, 2013;Cosson et al, 2014;Laras et al, 2002;Thaipadungpanit et al, 2007). Also, in Europe, L. borgpetersenii and L. interrogans are the most observed Leptospira genomospecies present in rodents; however, in Europe, a third genomospecies is Chapter 4 (Saravanan et al, 2000) Bandicota indica 4% (n = 75)…”

“…Moreover, in our study, there was no correlation between Leptospira prevalence and the gender of the animals for five of the six rodent species, which was also demonstrated in other earlier studies (Krøjgaard et al, 2009;Nuttall, 1929). Some studies have shown that in Norway rats (R. rattus), both in South-East Asia and in the United States of America, male specimens have a higher infection rate than females (Benacer, Mohd Zain, Amran, Galloway, & Thong, 2013;Cosson et al, 2014;Easterbrook et al, 2007). However, in the current study, it was found that female R. rattus were significantly more prone to a Leptospira infection than males.…”