Development of Leishmania (Mundinia) in guinea pigs

Abstract

Background: Leishmaniasis is a human and animal disease caused by parasites of the genus Leishmania, which is now divided into four subgenera, Leishmania, Viannia, Sauroleishmania and Mundinia. Subgenus Mundinia, established in 2016, is geographically widely dispersed, its distribution covers all continents, except Antarctica. It consists of 5 species; L. enriettii and L. macropodum are parasites of wild mammals while L. martiniquensis, L. orientalis and an unnamed Leishmania sp. from Ghana are infectious to humans. There is very little information on natural reservoir hosts and vectors for any Mundinia species. Methods: Experimental infections of guinea pigs with all five Mundinia species were performed. Animals were injected intradermally with 10 7 culture-derived promastigotes into both ear pinnae. The courses of infections were monitored weekly; xenodiagnoses were performed at weeks 4 and 8 post-infection using Lutzomyia migonei. The distribution of parasites in different tissues was determined post-mortem by conventional PCR. Results: No significant differences in weight were observed between infected animals and the control group. Animals infected with L. enriettii developed temporary lesions at the site of inoculation and were infectious to Lu. migonei in xenodiagnoses. Animals infected with L. martiniquensis and L. orientalis developed temporary erythema and dry lesions at the site of inoculation, respectively, but were not infectious to sand flies. Guinea pigs infected by L. macropodum and Leishmania sp. from Ghana showed no signs of infection during experiments, were not infectious to sand flies and leishmanial DNA was not detected in their tissue samples at the end of experiments at week 12 post-inoculation. Conclusions: According to our results, guinea pigs are not an appropriate model organism for studying Mundinia species other than L. enriettii. We suggest that for better understanding of L. (Mundinia) biology it is necessary to focus on other model organisms.

Experimental infection of Leishmania (Mundinia) martiniquensis in BALB/c mice and Syrian golden hamsters

“…Appropriate animal models would facilitate understanding of the biology of the parasite, clinical presentation and progression of the disease. So far, a few studies regarding animal infection of L. martiniquensis have been reported (Garin et al 2001;Somboonpoonpol 2016;Becvar et al 2020). Garin et al (2001) have infected BALB/c mice with two strains of a presumed monoxenous trypanosomatid isolated from humans (MHOM/MQ/92/MARl from an HIV patient and MHOM/MQ/97/MAR2 from an immunocompetent patient) that are later identified as L. martiniquensis (Desbois et al 2014).…”

“…In another study, guinea pigs (Cavia porcellus) have been infected with L. martiniquensis (MHOM/MQ/1992/MAR1 and MHOM/TH/2011/CU1). The infected animals develop only temporary erythema lesion at the site of inoculation and no infection to sand flies (Lutzomyia migonei) is observed indicating that guinea pigs are not an appropriate model animal for studying L. martiniquensis (Becvar et al 2020). In addition, based on previous experience (Handman 2001), different strains of L. martiniquensis might be expected to cause different progression of visceral disease.…”

Of Drugs and Trypanosomatids: New Tools and Knowledge to Reduce Bottlenecks in Drug Discovery

“…However, the outcome was different in terms of Chagasic cardiomyopathy based on the strain of parasite and mouse line chosen for infection. Among alternative rodent models, guinea pigs have also been used as a model for experimental T. cruzi infection for acute and chronic Chagas disease [77][78][79]. For T. brucei, Wistar rats have been exploited as a preclinical model for HAT-associated cardiomyopathy [80].…”

Experimental transmission of Leishmania (Mundinia) parasites by biting midges (Diptera: Ceratopogonidae)

“…Similarly, experimental models enabling research of Leishmania pathology are scarce; guinea pigs and golden hamsters were proven to be susceptible to L. enriettii [4,[23][24][25][26][27] and L. martiniquensis was reported to widely disseminate and visceralize in BALB/c mice [28][29][30]. The only previous study to systematically examine susceptibility to infection for all five Mundinia species was carried out in guinea pigs and only L. enriettii demonstrated an ability to infect this host [31].…”

“…The only previous study to systematically examine susceptibility to infection for all five Mundinia species was carried out in guinea pigs and only L . enriettii demonstrated an ability to infect this host [ 31 ].…”