Leptomonas seymouri Co-infection in Cutaneous Leishmaniasis Cases Caused by Leishmania donovani From Himachal Pradesh, India.

Lovlesh Thakur,Hemant Ritturaj Kushwaha,Aklank Jain,Manju Jain,Ajeet Negi

doi:10.3389/fcimb.2020.00345

Abstract

Himachal Pradesh in India is a newer endemic state with co-existence of cutaneous and visceral leishmaniasis. The cutaneous leishmaniasis cases are on an increase in the region and reported to be unusually caused by Leishmania donovani with limited molecular validation. In order to molecularly characterize the causative parasite of the cutaneous disease, parasite specific Internal-Transcribed Spacer 1 (ITS1) PCR RFLP and sequence analysis was performed on skin lesional biopsies from cutaneous leishmaniasis patients. Interestingly, we found the presence of Leptomonas seymouri in 38.5% (22/57) of the patients along with L. donovani detected in all the samples. L. seymouri is a monoxenous insect trypanosomatid, generally incapable of infecting humans. In recent years, the parasite is also reported to co-infect humans with L. donovani in visceral and post kala-azar dermal leishmaniasis (PKDL) cases prevalent in northeastern India. The finding of L. seymouri-L. donovani co-infection in unusual cutaneous cases from Himachal Pradesh is the first ever to our knowledge and imply a newer disease paradigm. There is an urgent need to understand the biology of Leptomonas co-infection with L. donovani and its possible role in visceral and/or dermotropic disease outcome. Importantly, L. seymouri co-infection in cutaneous cases and previously reported visceral and PKDL cases needs to be recognized as a newer phenomenon by the leishmaniasis surveillance program in India.

Highlights

Leishmaniasis is a disease complex caused by Leishmania parasite with a digenetic life cycle in the sandfly vector and the mammalian host
We report for the first time the presence of L. seymouri co-infection in the unusual cutaneous leishmaniasis (CL) cases in Himachal Pradesh (HP) caused by L. donovani variants
This is the firstever report of L. seymouri co-infection in CL patients, typed with unusual cutaneous manifestation by L. donovani with no visceral features, detailed in a recent communication from our laboratory. Our study concludes another instance of L. seymouri as a L. donovani co-infectant in leishmaniasis patients from HP, a newer endemic region in India in line with earlier reports of L. seymouri co-infection in visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) patients from the northeastern VL zone (Srivastava et al, 2010; Ghosh et al, 2012; Singh et al, 2013)

Summary

Introduction

Leishmaniasis is a disease complex caused by Leishmania parasite with a digenetic life cycle in the sandfly vector and the mammalian host. Adaption of the parasite to dixenous life cycle has been reported under specific conditions such that L. seymouri can exist as a co-infectant with other pathogens in immunocompromised subjects (Dedet and Pratlong, 2000; Kraeva et al, 2015; Selvapandiyan et al, 2015; Kaufer et al, 2017). In this context, our finding re-affirms the limited but significant emerging evidence on the newer parasitic capability of Leptomonas sp. This is in line with the previous reports on L. seymouri as a co-infectant in clinical isolates as well as direct clinical specimens from VL and PKDL cases from northeast India (Srivastava et al, 2010; Ghosh et al, 2012; Singh et al, 2013)

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