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Resumen:
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Background : Cutaneous leishmaniasis (CL) may present with an inflammatory phenotype, characterized by pain, erythema, and purulent exudate, which is typically treated with antibiotics prior to anti-Leishmania treatment. Although the inflammatory phenotype suggests secondary bacterial infection, bacterial contribution to the pathogenesis of inflammatory CL has yet to be elucidated. The objective of this study was to document the spectrum of bacteria present in inflammatory and non-inflammatory ulcers of CL in order to understand the relationship between disease phenotype and bacterial pathogens. Methods & Materials : Filter paper lesion impressions (FPLIs) from 34 patients with CL (18 inflammatory and 16 non-inflammatory CL) were evaluated via real-time PCR (qPCR) and end-point PCR targeting organisms implicated in skin- and soft-tissue infections, including: Staphylococcus aureus, Enterobacter cloacae, Streptococcus pyogenes, Enterococcus spp. , Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia , as well as 16S rDNA. Positive specimens were Sanger sequenced for species confirmation. Results : Of 34 specimens, 26 (76%) (14 inflammatory and 12 non-inflammatory) had at least one bacterial species detected, and this did not differ by phenotype. Represented species detected include: Staphylococcus aureus (n = 14, 41%), Pseudomonas aeruginosa (n = 9, 26%), Enterobacter cloacae (n = 8, 24%) , Citrobacter freundii (n = 8, 24%) , Enterococcus spp. (n = 6, 18%) , Streptococcus pyogenes (n = 4, 12%) , Klebsiella pneumonia (n = 1, 3%) and Proteus mirabilis (n = 1, 3%). No ulcers were found to harbour Escherichia coli. Prevalence of individual bacterial species did not differ by CL phenotype (p > 0.15). In particular, S. aureus was detected in 6 (37.5%) non-inflammatory ulcers and 8 (44.4%) inflammatory ulcers (p = 1.00). Conclusion : Our findings do not support that bacterial prevalence or individual species composition differs by phenotype of CL ulcers. Further prospective analysis, including WGS of CL ulcers, is warranted to determine the role of empiric antibiotic therapy for those with an inflammatory phenotype of CL.
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