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.

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.

Kindler syndrome in native Americans from Panama: report of 26 cases.

OBJECTIVE: To investigate the clinical, genetic, and laboratory features of 26 patients with Kindler syndrome. DESIGN: Case series of patients recruited when they were seen at outpatient consultations in the Department of Dermatology at the Changuinola Hospital in Bocas del Toro, Panama, between May 1986 and December 1990. SETTING: Clinical history, physical examination, and laboratory studies were done at a community hospital in Panama. Twelve of the patients had further studies performed at a children's hospital in Costa Rica. PATIENTS: A total of 26 patients were entered into the study. They were members of the Ngöbe-Buglé tribe and resided in isolated villages in rural Panama. RESULTS: The major findings were skin fragility with blistering (100%), poikiloderma (96%), photosensitivity (92%), severe cutaneous atrophy (89%), hyperkeratosis of the palms and soles (81%), congenital acral blisters (81%), severe periodontal disease (81%), and phimosis (80% of male subjects). In 1 large family with 10 patients, inheritance of Kindler syndrome followed that of an autosomal recessive disease. Karyotypes in 3 patients and 1 unaffected father were normal. Findings from ultrastructural studies showed replication of lamina densa in 10 patients. CONCLUSIONS: To our knowledge, this study represents the largest series to date of patients with Kindler syndrome. The clinical features confirm previously reported cases, and segregation analysis confirms its autosomal recessive inheritance. We also report severe phimosis as a complication, which has not been previously described in this syndrome.

Pesticide patch test series for the assessment of allergic contact dermatitis among banana plantation workers in panama.

BACKGROUND: Irritant contact dermatitis and allergic contact dermatitis (ACD) are frequent among agricultural workers and require targeted interventions. Patch testing is necessary for differential diagnosis, but patch testing with pesticides is uncommon. OBJECTIVE: This study explores the frequency of ACD and sensitization to pesticides among highly exposed banana plantation workers. METHODS: Frequently and recently used pesticides on banana plantations in Divala, Panama, were documented. A pesticide patch test tray specific for this population was prepared. A structured interview was administered to 366 participants, followed by a complete skin examination. The pesticide patch test series, as well as a standard patch test series, was applied to 37 workers with dermatoses likely to be pesticide related and to 23 control workers without dermatoses. RESULTS: The pesticide patch tests identified 15 cases (41%) of ACD (20 positive reactions) among the 37 workers diagnosed with pesticide dermatosis. Three controls had allergic reactions to pesticides (4 positive reactions). The pesticides were carbaryl (5 cases), benomyl (4 cases), ethoprophos (3), chlorothalonil (2), imazalil (2), glyphosate (2), thiabendazole (2), chlorpyrifos (1), oxyfluorfen (1), propiconazole (1), and tridemorph (1). Ethoprophos and tridemorph had not been previously identified as sensitizers. Thus, the prevalence of ACD was 0.03 (15 of 366). On the basis of observed prevalences of positive patch-test reactions among the subgroups with and without dermatoses, we estimated that > or = 16% of the entire population may be sensitized to pesticides. CONCLUSION: Sensitization to pesticides among banana plantation workers is a frequent occupational health problem. Pesticide patch test trays should be used in assessing skin diseases in highly exposed workers.

Loss of kindlin-1, a human homolog of the Caenorhabditis elegans actin-extracellular-matrix linker protein UNC-112, causes Kindler syndrome.

Kindler syndrome is an autosomal recessive disorder characterized by neonatal blistering, sun sensitivity, atrophy, abnormal pigmentation, and fragility of the skin. Linkage and homozygosity analysis in an isolated Panamanian cohort and in additional inbred families mapped the gene to 20p12.3. Loss-of-function mutations were identified in the FLJ20116 gene (renamed "KIND1" [encoding kindlin-1]). Kindlin-1 is a human homolog of the Caenorhabditis elegans protein UNC-112, a membrane-associated structural/signaling protein that has been implicated in linking the actin cytoskeleton to the extracellular matrix (ECM). Thus, Kindler syndrome is, to our knowledge, the first skin fragility disorder caused by a defect in actin-ECM linkage, rather than keratin-ECM linkage.

Clinical and microbiologic study of periodontitis associated with Kindler syndrome.

BACKGROUND: Little is known about the onset and prevalence of periodontal disease in patients with the rare Kindler syndrome, a genodermatological disorder. This study investigated the level of clinical periodontal attachment in relation to age and presence of putative periodontopathogenic bacteria in individuals with Kindler syndrome. METHODS: Eighteen individuals diagnosed with Kindler syndrome and 13 control subjects, aged 4 to 37 years, from rural Panama received a limited clinical periodontal examination. Subgingival samples were collected for identification of putative periodontal pathogens by polymerase chain reaction. RESULTS: Mild to severe gingivitis was a common finding in all adults of the study population. Seventy-two percent (13/18) of the Kindler patients and 46% (6/13) of the control subjects showed mild to severe periodontal disease (P = 0.001, chi-square test). The onset of periodontitis was earlier and the progression occurred at a faster rate in the Kindler group. There was a strong correlation (r = 0.83) between the level of attachment loss and age in the Kindler group and a weaker correlation (r = 0.66) in the control group. The appearance of gingival tissues suggested atypical periodontitis with spontaneous bleeding and fragile, often desquamative, gingiva. In periodontitis patients, Porphyromonas gingivallis and Diallster pneumosintes tended to occur more frequently in control individuals compared to those with Kindler syndrome. CONCLUSIONS: In the Kindler group, periodontitis had an onset in early teenage years and progressed more rapidly compared to non-Kindler individuals of the same geographic and ethnic group. Clinical and microbiological findings suggest atypical periodontitis in Kindler patients. We propose to include Kindler syndrome in the category of medical disorders predisposing to destructive periodontal disease.

Contact dermatitis caused by pesticides among banana plantation workers in Panama.

To characterize dermatitis related to pesticide exposures among banana plantation workers in Panama, the authors studied 281 workers seen at The Occupational Health Department of the Social Security Hospital of Changuinola and Puerto Armuelles between 1988-1992 and in 1993. Exposure data were collected through a standardized occupational health history. Physical examination, a standard patch test, and a pesticide patch test (PPT) were carried out. Of the 244 men (86.8%) and 37 women (13.2%), 17 and 37, respectively, were packing station workers. The other 227 men were field workers, exposed to many pesticides (propiconazole, maneb, chlorothalonil, dithane, dalaphon, ametrine; and gramoxone). The 54 packing station workers were exposed to imazalil, thiabendazole, aluminum hydroxide solutions, and formaldehyde. The hands were the most frequently affected areas (82%), followed by the thorax and abdomen (9%), legs and feet (5%), and genital area (4%). There were 78 positive PPTs (27.8%) in 281 patients. The most frequent reactions were to the fungicides chloro-thalonil (51.4%), thiabendazole (12.8%), imazalil (10.2%), and aluminum hydroxide (10.2%), which accounted for 85% of all positive tests. The majority of the cases were related to exposures to fungicides; 246 with negative PPTs were classified as irritant contact dermatitis patients; 48 controls were negatives. Contact dermatitis related to pesticide exposure is a significant occupational health problem for banana workers in Panama.

Es fácil cultivar hongos en el consultorio / It is easy to cultivate fungi in the doctor's office

Manual para ayudar a los médicos a identificar las dermatomicosis y hacer un diagnóstico correcto. Enseña cómo tomar las muestras adecuadas para frotis y cultivo