Volume 99, Issue 2
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



serovar Varillal, a group II intermediate pathogen species/serovar discovered in the Peruvian Amazon city of Iquitos, is commonly recognized in this region by sera from humans (at least 40% seroprevalence) without a known clinical history of leptospirosis. This high frequency of human seroreactivity remains unexplained. To test the hypothesis that the oral route of infection might explain the high rate of human seroreactivity against , an experimental infection model using was developed, given that rats were one of the original reservoir hosts identified as being colonized by this leptospire. Sprague–Dawley rats were experimentally exposed via mucosa, direct gastric gavage, or parenteral inoculation with nine different isolates of originally isolated from Peruvian humans, peridomiciliary rodents, and wildlife. As shown by quantitative polymerase chain reaction of kidney tissue, infection via these routes of infection was equally successful. Importantly, the data show that infects via the oral route, leading to renal colonization. Not only do these findings confirm the infectiousness of group II , but also they underscore the potential importance of oral as well as mucosal and transcutaneous routes of infection.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...



  1. Ko AI, Goarant C, Picardeau M, , 2009. Leptospira: the dawn of the molecular genetics era for an emerging zoonotic pathogen. Nat Rev Microbiol 7: 736747. [Google Scholar]
  2. Calderon A, Rodriguez V, Mattar S, Arrieta G, , 2014. Leptospirosis in pigs, dogs, rodents, humans, and water in an area of the Colombian tropics. Trop Anim Health Prod 46: 427432. [Google Scholar]
  3. Levett PN, , 2001. Leptospirosis. Clin Microbiol Rev 14: 296326. [Google Scholar]
  4. Bharti AR, Peru-United States Leptospirosis Consortium , 2003. Leptospirosis: a zoonotic disease of global importance. Lancet Infect Dis 3: 757771. [Google Scholar]
  5. Matthias MA, 2008. Human leptospirosis caused by a new, antigenically unique Leptospira associated with a Rattus species reservoir in the Peruvian Amazon. PLoS Negl Trop Dis 2: e213. [Google Scholar]
  6. Ricaldi JN, 2012. Whole genome analysis of Leptospira licerasiae provides insight into leptospiral evolution and pathogenicity. PLoS Negl Trop Dis 6: e1853. [Google Scholar]
  7. Fouts DE, 2016. What makes a bacterial species pathogenic?: Comparative genomic analysis of the genus Leptospira. PLoS Negl Trop Dis 10: e0004403. [Google Scholar]
  8. Patra KP, Choudhury B, Matthias MM, Baga S, Bandyopadhya K, Vinetz JM, , 2015. Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species. BMC Microbiol 15: 244. [Google Scholar]
  9. Morey RE, Galloway RL, Bragg SL, Steigerwalt AG, Mayer LW, Levett PN, , 2006. Species-specific identification of Leptospiraceae by 16S rRNA gene sequencing. J Clin Microbiol 44: 35103516. [Google Scholar]
  10. Costa F, Hagan JE, Calcagno J, Kane M, Torgerson P, Martinez-Silveira MS, Stein C, Abela-Ridder B, Ko AI, , 2015. Global morbidity and mortality of leptospirosis: a systematic review. PLoS Negl Trop Dis 9: e0003898. [Google Scholar]
  11. Petersen AM, Boye K, Blom J, Schlichting P, Krogfelt KA, , 2001. First isolation of Leptospira fainei serovar Hurstbridge from two human patients with Weil’s syndrome. J Med Microbiol 50: 96100. [Google Scholar]
  12. Levett PN, Morey RE, Galloway RL, Steigerwalt AG, , 2006. Leptospira broomii sp. nov., isolated from humans with leptospirosis. Int J Syst Evol Microbiol 56: 671673. [Google Scholar]
  13. Tsuboi M, Koizumi N, Hayakawa K, Kanagawa S, Ohmagari N, Kato Y, , 2017. Imported Leptospira licerasiae infection in traveler returning to Japan from Brazil. Emerg Infect Dis 23: 548549. [Google Scholar]
  14. Chappel RJ, Khalik DA, Adler B, Bulach DM, Faine S, Perolat P, Vallance V, , 1998. Serological titres to Leptospira fainei serovar hurstbridge in human sera in Australia. Epidemiol Infect 121: 473475. [Google Scholar]
  15. Zuerner RL, Alt DP, Palmer MV, , 2012. Development of chronic and acute golden Syrian hamster infection models with Leptospira borgpetersenii serovar Hardjo. Vet Pathol 49: 403411. [Google Scholar]
  16. Zhang Y, Lou XL, Yang HL, Guo XK, Zhang XY, He P, Jiang XC, , 2012. Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route. BMC Infect Dis 12: 20. [Google Scholar]
  17. Nally JE, Fishbein MC, Blanco DR, Lovett MA, , 2005. Lethal infection of C3H/HeJ and C3H/SCID mice with an isolate of Leptospira interrogans serovar copenhageni. Infect Immun 73: 70147017. [Google Scholar]
  18. Viriyakosol S, Matthias MA, Swancutt MA, Kirkland TN, Vinetz JM, , 2006. Toll-like receptor 4 protects against lethal Leptospira interrogans serovar Icterohaemorrhagiae infection and contributes to in vivo control of leptospiral burden. Infect Immun 74: 887895. [Google Scholar]
  19. Perolat P, Chappel RJ, Adler B, Baranton G, Bulach DM, Billinghurst ML, Letocart M, Merien F, Serrano MS, , 1998. Leptospira fainei sp. nov., isolated from pigs in Australia. Int J Syst Bacteriol 48: 851858. [Google Scholar]
  20. Arzouni JP, Parola P, La Scola B, Postic D, Brouqui P, Raoult D, , 2002. Human infection caused by Leptospira fainei. Emerg Infect Dis 8: 865868. [Google Scholar]
  21. Asoh T, Saito M, Villanueva SY, Kanemaru T, Gloriani N, Yoshida S, , 2014. Natural defense by saliva and mucosa against oral infection by Leptospira. Can J Microbiol 60: 383389. [Google Scholar]
  22. Levett PN, , 2003. Leptospira and Leptonema. Murray PR, ed. Manual of Clinical Microbiology. Washington, DC: ASM Press, 929–936.
  23. American Veterinary Medical Association, 2013. AVMA Guidelines for the Euthanasia of Animals. Schaumberg, IL: AVMA.
  24. Thibeaux R, Iraola G, Ferres I, Bierque E, Girault D, Soupe-Gilbert ME, Picardeau M, Goarant C, , 2018. Deciphering the unexplored Leptospira diversity from soils uncovers genomic evolution to virulence. Microb Genom 4: 110. [Google Scholar]
  25. Pappas CJ, Benaroudj N, Picardeau M, , 2015. A replicative plasmid vector allows efficient complementation of pathogenic Leptospira strains. Appl Environ Microbiol 81: 31763181. [Google Scholar]
  26. Lourdault K, Cerqueira GM, Wunder EA, Jr. Picardeau M, , 2011. Inactivation of clpB in the pathogen Leptospira interrogans reduces virulence and resistance to stress conditions. Infect Immun 79: 37113717. [Google Scholar]
  27. Croda J, Figueira CP, Wunder EA, Jr. Santos CS, Reis MG, Ko AI, Picardeau M, , 2008. Targeted mutagenesis in pathogenic Leptospira species: disruption of the LigB gene does not affect virulence in animal models of leptospirosis. Infect Immun 76: 58265833. [Google Scholar]
  28. Katoh K, Standley DM, , 2013. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol Biol Evol 30: 772780. [Google Scholar]

Data & Media loading...

  • Received : 30 Oct 2017
  • Accepted : 07 May 2018
  • Published online : 25 Jun 2018

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error