Detection of Leishmania RNA Virus 1 in Leishmania (Viannia) panamensis Isolates, Panama.

We detected Leishmania RNA virus 1 (LRV1) in 11 isolates of Leishmania (Viannia) panamensis collected during 2014-2019 from patients from different geographic areas in Panama. The distribution suggested a spread of LRV1 in L. (V.) panamensis parasites. We found no association between LRV1 and an increase in clinical pathology.

Antibody therapies for the treatment of acute myeloid leukemia: exploring current and emerging therapeutic targets.

INTRODUCTION: Acute myeloid leukemia (AML) is the most common and deadly type of leukemia affecting adults. It is typically managed with rounds of non-targeted chemotherapy followed by hematopoietic stem cell transplants, but this is only possible in patients who can tolerate these harsh treatments and many are elderly and frail. With the identification of novel tumor-specific cell surface receptors, there is great conviction that targeted antibody therapies will soon become available for these patients. AREAS COVERED: In this review, we describe the current landscape of known target receptors for monospecific and bispecific antibody-based therapeutics for AML. Here, we characterize each of the receptors and targeted antibody-based therapeutics in development, illustrating the rational design behind each therapeutic compound. We then discuss the bispecific antibodies in development and how they improve immune surveillance of AML. For each therapeutic, we also summarize the available pre-clinical and clinical data, including data from discontinued trials. EXPERT OPINION: One antibody-based therapeutic has already been approved for AML treatment, the CD33-targeting antibody-drug conjugate, gemtuzumab ozogamicin. Many more are currently in pre-clinical and clinical studies. These antibody-based therapeutics can perform tumor-specific, elaborate cytotoxic functions and there is growing confidence they will soon lead to personalized, safe AML treatment options that induce durable remissions.

Neotropical Clavulina: Two new species from Mexico and a re-evaluation of Clavulina floridana.

Clavulina comprises ca. 90 described species distributed worldwide in both tropical and temperate regions. However, only one species (C. floridana) has been described so far from tropical North America. We used morphological and molecular data from three DNA loci (nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 [ITS], a portion of nuc 28S rDNA [28S], and a fragment of DNA-directed RNA polymerase II second largest subunit [RPB2]) from basidiomata and ectomycorrhizas collected in tropical ecosystems from three biogeographic provinces of Mexico and one tropical province in the USA to investigate the phylogenetic and taxonomic diversity of Clavulina in the region. Nine new species-level clades were discovered, two of which are proposed as new species (C. arboreiparva and C. tuxtlasana). Specimens of C. floridana recently collected in Florida were included in our analyses, for which a modern description is provided. In addition, C. floridana is a new record for Mexico. The diversity of Clavulina in tropical North America is comparable to that found in lowland tropical South America. However, some of the species found in tropical deciduous forests produce small, rare, and inconspicuous basidiomata, which easily go unnoticed, and therefore are poorly represented in collections. Many species remain undescribed in tropical regions of North America.

Genomic diversity and genetic variation of Leishmania panamensis within its endemic range.

Species belonging to the Leishmania (Viannia) subgenus are important causative agents of cutaneous and mucocutaneous leishmaniasis in Central and South America. These parasites possess several distinctive biological features that are influenced by their genetics, population structure, and genome instability. To date, several studies have revealed varying degrees of genetic diversity within Leishmania species. Particularly, in species of the L. (Viannia) subgenus, a generalized high intraspecific genetic diversity has been reported, although, conflicting conclusions have been drawn using different molecular techniques. Despite being the most common Leishmania species circulating in Panama and Colombia, few studies have analyzed clinical samples of Leishmania panamensis using whole-genome sequencing, and their restricted number of samples has limited the information they can provide to understand the population structure of L. panamensis. Here, we used next generation sequencing (NGS) to explore the genetic diversity of L. panamensis within its endemic range, analyzing data from 43 isolates of Colombian and Panamanian origin. Our results show the occurrence of three well-defined geographically correlated groups, and suggests the possible occurrence of additional phylogeographic groups. Furthermore, these results support the existence of a mixed mode of reproduction in L. panamensis, with varying frequencies of events of genetic recombination occurring primarily within subpopulations of closely related strains. This study offers important insights into the population genetics and reproduction mode of L. panamensis, paving the way to better understand their population structure and the emergence and maintenance of key eco-epidemiological traits.

Impetigo Leishmaniasis Previously Diagnosed as Crusty Impetigo: A Case Study.

Cutaneous leishmaniasis is a zoonotic disease caused by several species of protozoa of the genus Leishmania. Cutaneous leishmaniasis classically presents as an ulcer with heaped edges, but it can also appear as nodular, scabbed, or plaque-like lesions. Its diagnosis requires confirmatory laboratory tests such as a smear, culture, and polymerase chain reaction. However, atypical presentations represent a diagnostic challenge in Tropical Medicine. For instance, localized cutaneous leishmaniasis (LCL) resembles bacterial and fungal tropical dermatological infections. Atypical presentations require an experienced clinician, epidemiological knowledge, and proper diagnostic tests. We present a case of a 10-year-old male who showed classic impetigo-like symptoms, which did not improve with topical or systemic antibiotic therapy. After a thorough case review, the patient was diagnosed with LCL. Therefore, epidemiological and clinical evaluation is crucial when diagnosing, especially in patients who live or have travelled to leishmaniasis-endemic areas.

Common Dermatologic Conditions in Returning Travelers.

PURPOSE OF REVIEW: Travel medicine practitioners often are confronted with returning travelers with dermatologic disorders that could be of infectious causes or inflammatory or allergic. Some dermatologic processes are the result of exposure to insects or acquired due to environmental exposures. There is a broad range of dermatosis of infectious and non-infectious etiologies that clinicians need to consider in the differential diagnosis of dermatosis in travelers. RECENT FINDINGS: With increasing international travel to tropical destinations, many individuals may be exposed to rickettsia (i.e., African tick bite fever, scrub typhus, or Mediterranean spotted fever), parasitic infections (i.e., cutaneous larva migrans, cutaneous leishmaniasis, African trypanosomiasis, or American trypanosomiasis), viral infections (i.e., measles or Zika virus infection), bacterial (i.e., Buruli ulcer) or ectoparasites (scabies or tungiasis), and myiasis. Cutaneous lesions provide clinical clues to the diagnosis of specific exposures during travel among returned travelers. SUMMARY: Dermatologic disorders represent the third most common health problem in returned travelers, after gastrointestinal and respiratory illness. Many of these conditions may pose a risk of severe complications if there is any delay in diagnosis. Therefore, clinicians caring for travelers need to become familiar with the most frequent infectious and non-infectious skin disorders in travelers.

Environmental Conditions May Shape the Patterns of Genomic Variations in Leishmania panamensis.

Due to the absence of transcriptional regulation of gene expression in Leishmania parasites, it is now well accepted that several forms of genomic variations modulate the levels of critical proteins through changes in gene dosage. We previously observed many of these variations in our reference laboratory strain of L. panamensis (PSC-1 strain), including chromosomes with an increased somy and the presence of a putative linear minichromosome derived from chromosome 34. Here, we compared the previously described genomic variations with those occurring after exposure of this strain to increasing concentrations of trivalent antimony (SbIII), as well as those present in two geographically unrelated clinical isolates of L. panamensis. We observed changes in the somy of several chromosomes, amplifications of several chromosomal regions, and copy number variations in gene arrays after exposure to SbIII. Occurrence of amplifications potentially beneficial for the Sb-resistant phenotype appears to be associated with the loss of other forms of amplification, such as the linear minichromosome. In contrast, we found no evidence of changes in somy or amplification of relatively large chromosomal regions in the clinical isolates. In these isolates, the predominant amplifications appear to be those that generate genes arrays; however, in many cases, the amplified arrays have a notably higher number of copies than those from the untreated and Sb-treated laboratory samples.

Zoonotic Sporotrichosis Related to Cat Contact: First Case Report from Panama in Central America.

A previously healthy 34-year-old man presented with a four-week-old upper arm injury that started with a cat scratch and progressed into painless erythematous nodular ascending lesions in the left upper limb. We made the diagnosis of sporotrichosis based on the epidemiological association of the contact with a cat and culture identification. Sporotrichosis is a mycosis implantation caused by the Sporothrix schenckii complex. We present the first Central American case of sporotrichosis associated with contact with a feline.

Thelephora versatilis and Thelephora pseudoversatilis: two new cryptic species with polymorphic basidiomes inhabiting tropical deciduous and sub-perennial forests of the Mexican Pacific coast.

Thelephora is a genus of ectomycorrhizal basidiomycetes with basidiomes of varied shape which has been poorly studied in tropical ecosystems. In this paper, we present Thelephora versatilis and Thelephora pseudoversatilis, two new species collected in the same localities of deciduous and sub-perennial tropical forests of Jalisco, Mexico. Basidiomes of both species are brownish gray to violet brown with clavarioid-mesopodal, sub-resupinate or completely resupinate growth forms. In turn, phylogenetic analyses using nrDNA ITS sequences showed that these species are not closed related, nevertheless they are part of a well-supported clade conformed by several species of Thelephora, Tomentella and some undescribed Thelephorales. Morphological segregation of these species was attained by analyzing spore and hyphae characters using a wide sample. Significant statistical differences between the new species were observed regarding spore size, spine size and context hyphae width. This work exemplifies the relevance of integrating both morphological and molecular data, as well of the use of an appropriate sample size in order to discriminate among morphological cryptic species.

Phenotypic plasticity of the basidiomata of Thelephora sp. (Thelephoraceae) in tropical forest habitats.

Phenotypic plasticity in macroscopic fungi has been poorly studied in comparison to plants or animals and only general aspects of these changes have been described. In this work, the phenotypic variation in the basidiomata of Thelephora sp. (Thelephoraceae) was examined, as well as some aspects of its ecology and habitat, using 24 specimens collected in the tropical forests of the Chamela Biological Station, Jalisco, Mexico. Our observations showed that this taxon has clavarioid basidiomata that can become resupinate during development and growth if they are in contact with rocks, litter or live plants, establishing in the latter only an epiphytic relationship. This tropical species may form groups of up to 139 basidiomata over an area of 32.2m2, and in both types of vegetation (tropical sub-evergreen and deciduous forest) were primarily located on steep (>20 degree) South-facing slopes. It is found under closed canopy in both tropical forests, but its presence in sub-evergreen forests is greater than expected.

Phenotypic plasticity of the basidiomata of Thelephora sp. (Thelephoraceae) in tropical forest habitats

Phenotypic plasticity in macroscopic fungi has been poorly studied in comparison to plants or animals and only general aspects of these changes have been described. In this work, the phenotypic variation in the basidiomata of Thelephora sp. (Thelephoraceae) was examined, as well as some aspects of its ecology and habitat, using 24 specimens collected in the tropical forests of the Chamela Biological Station, Jalisco, Mexico. Our observations showed that this taxon has clavarioid basidiomata that can become resupinate during development and growth if they are in contact with rocks, litter or live plants, establishing in the latter only an epiphytic relationship. This tropical species may form groups of up to 139 basidiomata over an area of 32.2m2, and in both types of vegetation (tropical sub-evergreen and deciduous forest) were primarily located on steep (>20°) South-facing slopes. It is found under closed canopy in both tropical forests, but its presence in sub-evergreen forests is greater than expected.

La plasticidad fenotípica en hongos macroscópicos ha sido poco estudiada en comparación con la de plantas o animales y solo se conocen aspectos generales de estos cambios. En este trabajo se examinó la variación fenotípica en los basidiomas de una especie de Thelephora sp. (Thelephoraceae), así como algunos aspectos de su ecología y hábitat a partir del estudio de 24 ejemplares recolectados en bosques tropicales de la Estación de Biología de Chamela, Jalisco, México. Nuestras observaciones mostraron que este taxon presenta basidiomas en forma clavarioide, los cuales pueden modificarse a resupinados si en su proceso de desarrollo se interponen obstrucciones físicas como rocas, restos vegetales o plantas vivas, estableciendo en estas últimas solo una relación epifítica. Esta especie llega a formar conjuntos de hasta 139 basidiomas en un área de 32.2m2; con localización predominante en laderas orientadas hacia el sur, de pendientes mayores a 20°, bajo doseles cerrados y con presencia mucho más significativa de lo esperado en el bosque tropical subperennifolio.

Hepatotoxicity from ingestion of wild mushrooms of the genus Amanita section Phalloideae collected in Mexico City: two case reports.

We present two cases of acute liver injury resulting from consumption of wild mushrooms. The first case was a male who developed acute hepatitis after ingestion of diverse mushrooms including Amanita species. His clinical course was favorable with complete recovery of liver function. The second case was a male who developed acute liver failure (ALF) after ingestion of Amanita bisporigera. He required MARS therapy as a bridge to liver transplantation but transplantation was not performed because he succumbed to multiorgan failure. There are few trials demonstrating the efficacy of the different treatments for mushroom poisoning. These cases demonstrate that the consumption of wild mushrooms without proper knowledge of toxic species represents a serious and under recognized health problem.