Evaluation of cytochrome b sequence to identify Leishmania species and variants: the case of Panama

Abstract

BACKGROUND The genetic heterogeneity of Leishmania parasites is a major factor responsible for the wide variety of Leishmania-associated manifestations. Consequently, understanding the genetic make-up of Leishmania species using suitable molecular markers is an important component of realising local and regional scale disease risk. The cytochrome b (cytb) is frequently used to type New World Leishmania species. However, its potential to discriminate Leishmania species and variants requires further evaluation.OBJECTIVES To explore the capacity of cytb gene to identify New World Leishmania species and variants and to develop an approach able to type local Leishmania species and variants.METHODS We retrieved 360 partial and complete Leishmania cytb gene sequences publicly available in GenBank database to study all single nucleotide polymorphisms (SNPs) across the cytb gene that differentiate New World Leishmania species. This information was used to develop an approach based upon the polymorphisms found in a DNA segment of 948bp. We also compared the typing results found with this technique with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) profiling obtained using HSP70 gene as target. One hundred Panamanian isolates were used to both typed Leishmania species and assess local genetic variability.FINDINGS We found complete agreement between our cytb approach and the PCR-RFLP profiling method based on HSP70 for Leishmania species identification. Ninety-two isolates were identified as L. panamensis, although other Viannia species were found circulating at a lower frequency. Three L. panamensis haplotypes were identified in Panamanian provinces. We also provide an initial report of L. guyanensis haplotypes circulating in Panama.MAIN CONCLUSIONS Cytb gene sequence encompasses key main SNPs that aid to identify Leishmania species. The cytb approach developed with this information was able to identify and assess genetic variability of local Leishmania species found in this study. Key words: leishmaniasis -cytochrome b gene -haplotypes -Leishmania panamensis -Leishmania guyanensis -PanamaLeishmaniasis, a neglected tropical disease transmitted by female sandflies and caused by kinetoplastic protozoa parasites of the genus Leishmania, is endemic in 98 countries worldwide. Due to the high number of cases and its geographical expansion, the World Health Organization (WHO) considers leishmaniasis as an emerging/ reemerging vector borne parasitic disease. (1) Regarding its impact on public health, leishmaniasis has an estimated annual incidence of 2.0 million cases and an approximated prevalence of 12,000,000 cases. (2) In addition, this disease is responsible for 20,000 to 40,000 deaths occurring in rural and suburban populations all year round. (1,2) Visceral and tegumentary leishmaniasis are the main clinical forms of the disease which show different clinical expressions depending upon the species of Leishmania responsible for the disease, the genetic background and immunological status of ...

Kaurane-Type Diterpenoids as Potential Inhibitors of Dihydrofolate Reductase-Thymidylate Synthase in New World Leishmania Species

“…Studying this type of species is crucial for the control and elimination of the disease, as there is a high diversity of Leishmania species in the Americas, with high concentrations of different species found in countries such as Brazil and Colombia, leading to a significant disease burden [ 30 ]. Some of the main New World Leishmania species include Leishmania panamensis , which is the primary cause of cutaneous leishmaniasis (CL) in Panama and has been found to infect both anthropophilic vectors and mammalian reservoirs [ 31 ]; Leishmania braziliensis , a pathogenic agent of CL and mucocutaneous leishmaniasis (MCL), primarily distributed in South and Central America [ 29 , 30 , 31 , 32 ]; and Leishmania amazonensis , an etiological agent of diffuse CL and tegumentary leishmaniasis (TL) [ 33 ]. In previous research, molecular docking calculations and MD simulations using PTR1 hybrid models of L. braziliensis , L. amazonensis , and L. panamensis identified kauranes 135 , 302 , and its derivative 302a as potential multispecies agents [ 24 ].…”

Characterization of Leishmania spp. Causing Cutaneous Lesions with a Negative Parasitological Diagnosis in Panama

“…Leishmania (V.) panamensis has been the main etiologic agent of CL reported in Panamá since it was accepted as a new species in 1972 [ 16 ]. However, recent studies have confirmed that at least one genetic variant of L. (V.) panamensis is also frequently found in Panamanian patients with CL [ 17 , 18 ]. These studies have also confirmed the presence of other species circulating in the country, such as L. (V.) braziliensis , L. (V.) guyanensis , and L. (V.) naiffi at low frequencies.…”

“…These studies have also confirmed the presence of other species circulating in the country, such as L. (V.) braziliensis , L. (V.) guyanensis , and L. (V.) naiffi at low frequencies. [ 17 , 18 ]. However, there is always the possibility of greater genetic diversity in Leishmania parasites infecting humans in the country.…”