Impact of SARS-CoV-2 Mu variant on vaccine effectiveness: A comparative genomics study at the peak of the third wave in Bogota, Colombia.

We assessed the circulation of severe acute respiratory syndrome coronavirus-2 variants amongst vaccinated military personnel in Bogotá, Colombia to evaluate the mutations of certain variants and their potential for breakthrough infection in vaccinated subjects. We observed that in vaccinated individuals the most frequent infecting lineage was Mu (B.1.621 and B.1.621.1). The above is possibly associated with specific mutations that confer it with vaccine-induced immune escape ability. Our findings highlight the importance of how genomic tracking coupled with epidemiological surveillance can assist in the study of novel emerging variants (e.g., Omicron) and their impact on vaccination efforts worldwide.

Volume staging for arteriovenous malformation SRS treatment using VMAT.

Volume staging involves dividing the target volume into smaller parts and treating each part separately. In this study, the feasibility of volume-staged stereotactic radiosurgery (VS-SRS) on a linear accelerator using volumetric modulated arc therapy (VMAT) and a frameless patient positioning system is investigated. Ten patients, previously treated with hypofractionated stereotactic radiotherapy with arteriovenous malformation (AVM) sized from 1.6 to 4.0 cm in diameter, were selected. VS-SRS plans were created with the VMAT technique on the Varian Eclipse treatment planning system (TPS) using the TrueBeam STx linear accelerator. For each patient, an AVM-VMAT set was planned with the AVM as the target and a PTV-VMAT set using the (PTV = AVM+1 mm) as the target. All targets were divided into two sub-volumes. The TPS data from the AVM-VMAT plans was compared to Gamma Knife (GK) VS-SRS plan data available in the literature. The AVM-VMAT and PTV-VMAT plans were compared to investigate the effect of a 1 mm PTV margin on normal brain (NB) dose. End-to-end testing was performed using a GaFchromic EBT3 film and point-dose measurements. Dosimetric effects of multiple setups were investigated through film-to-film comparisons. Median target dose coverage, NB V12Gy , and conformity index for the AVM-VMAT plans were 97.5%, 17 cm3 , and 0.8, respectively. PTV-VMAT plans attained comparable target dose coverage, but the average NB V12Gy increased by 48.9% when compared to the AVM-VMAT plans. Agreement of point-dose measurements with TPS calculations was -0.6% when averaged over all patients. Gamma analysis passing rates were above 90% for all film-to-film comparisons (2%/1 mm criteria), and for the film to TPS comparison (5%/1 mm). This work suggests that VMAT is capable of producing VS-SRS plans with similar dose falloff characteristics as GK plans. NB dose depends on PTV margin size, and two-stage treatment setups do not appear to contribute additional uncertainty to treatment delivery.

Distribution, treatment outcome and genetic diversity of Leishmania species in military personnel from Colombia with cutaneous leishmaniasis.

BACKGROUND: Leishmaniasis is one of the most important infectious diseases affecting the Colombian National Army due to the high number of reported cases and exposure throughout military operations in endemic areas. The main aim of this study was to estimate the geographical distribution along with the genetic diversity and treatment outcome of Leishmania species in Colombian military personnel. METHODS: Skin lesion samples by smear and aspirate were collected in 136 patients having parasitological cutaneous leishmaniasis (CL) diagnosis. DNA was extracted, the nuclear marker heat shock protein 70 (HSP70) was amplified by PCR and sequenced. Leishmania species were identified by BLASTn. The geo-spatial distribution of the identified parasites was determined according to the possible site of infection. Gene tree was constructed by maximum likelihood (ML), diversity indices (π, h) were estimated and haplotype network was constructed under the Templeton-Crandall-Sing algorithm in order to determine the geographic relationships of the genetic variants of Leishmania species circulating in Colombian military population. RESULTS: The species were identified in 77.94% of the samples, with a predominance of L. braziliensis (65.09%), followed by L. panamensis (31.13%), L. naiffi by the first time reported in Colombia in two patients (1.89%) as well as L. lindenbergi in a single patient (0.945%) with possible infection in the municipality of Miraflores, Guaviare and L. infantum in a single patient (0.945%) notified with CL in the municipality of Tumaco, Nariño. The phylogenetic analysis was consistent according to bootstrap, showing four strongly differentiated clades. CONCLUSIONS: The geo-spatial distribution suggested that L. braziliensis has a greater abundance, while L. panamensis has a greater dispersion. The phylogenetic relationships of Leishmania species in Colombian military personnel was estimated with the confirmation of two new species circulating without prior report in the country and a species with no background for CL in the Colombian army. A substantial genetic diversity of Leishmania braziliensis was defined. This study contributes through the understanding of the molecular epidemiology to the CL transmission in Colombia.

Emergency treatment for a venomous snakebite accident in rural southern Mexico.

In Latin America, 51 995 emergencies and 337 deaths are caused by snakebites yearly. Prompt and adequate treatment is crucial after an envenomation. We here report the case of a 40-year-old male agriculturalist, who was bitten by a venomous snake. Hours after the bite, he was admitted at the nearest clinic, diagnosed with type IV envenomation. After initial antivenom treatment he was transported to an urban hospital. Hemorrhage persisted and the patient developed compartmental syndrome and renal failure. The patient died 3 days after the accident. To reduce fatalities from snakebite envenomation, such as the case we here presented, there is a need for coordinated and multilevel approach, collaborative work and continual medical training.

Papel de las alteraciones del sueño durante la gestación en la programación del feto para el desarrollo de obesidad y enfermedades crónicas degenerativas.

Sleep disturbances are common in the third trimester of pregnancy and generate changes in the secretion of melatonin in pregnant women who sleep less than eight hours or have sleep disturbances, which promote various physiological changes in the mother that in turn result in low birth weight (LBW) in the fetus. LBW is associated with a phenomenon known as "metabolic programming," in which the fetus is subjected to a stressful situation that results in irreversible metabolic alterations that predispose it to the development of obesity in adulthood.

En el tercer trimestre del embarazo son frecuentes las alteraciones del sueño, las cuales generan cambios en la secreción de melatonina en mujeres gestantes que duermen menos de ocho horas o presentan alteraciones de sueño, promoviendo diversos cambios fisiológicos en la madre, que a su vez derivan en bajo peso al nacimiento (BPN) en el producto. El bajo peso al nacimiento está asociado con un fenómeno conocido como "programación metabólica", en la que el feto es sometido a estrés que tiene como resultado alteraciones metabólicas irreversibles que lo predisponen al desarrollo de obesidad en la edad adulta.

[Chagasic Cardiopathy in a child: Case report]. / Cardiopatía Chagásica en un escolar: Reporte de caso.

Chagas disease also known as American Trypanosomiasis is mainly caused by haematophagous insects widely distributed from Mexico to Argentina. According to the Panamerican Health Organization, 7.7 to 10 million people are living with chronic infection. Chagas disease is caused by Trypanosoma cruzi, a protozoan transmitted by triatomine vectors. After an initial acute phase, Chagas is followed by a silent phase that lasts 15-20 years before debuting with cardiac, neurological or gastrointestinal manifestations. OBJECTIVE: To analyze the atypical clinical course of chagasic cardiopathy in a pediatric patient from southern Mexico. CASE REPORT: The patient was treated by a chagoma in his left leg. Five months later an electrocardiogram showed evidence of sinus tachycardia and left atrium distension with P wave enlargement and prolonged QT interval. The thorax radiography showed cardiomegaly (Cardio-thoracic index = 0.52); the trans-thoracic echocardiogram showed left atrial and ventricular dilation. CONCLUSION: It is important to develop early cardiac evaluations even in pediatric patients with Chagas disease, it should not be assumed that the patients will undergo a long asymptomatic phase or that they will not develop an early cardiopathy.

Batch production of coenzyme Q10 by recombinant Escherichia coli containing the decaprenyl diphosphate synthase gene from Sphingomonas baekryungensis.

Coenzyme Q10 (CoQ10) is an important antioxidant used in medicine, dietary supplements, and cosmetic applications. In the present work, the production of CoQ10 using a recombinant Escherichia coli strain containing the decaprenyl diphosphate synthase from Sphingomonas baekryungensis was investigated, wherein the effects of culture medium, temperature, and agitation rate on the production process were assessed. It was found that Luria-Bertani (LB) medium was superior to M9 with glucose medium. Higher temperature (37 °C) and higher agitation rate (900 rpm) improved the specific CoQ10 content significantly in LB medium; on the contrary, the use of M9 medium with glucose showed similar values. Specifically, in LB medium, an increase from 300 to 900 rpm in the agitation rate resulted in increases of 55 and 197 % in the specific CoQ10 content and COQ10 productivity, respectively. Therefore, the results obtained in the present work are a valuable contribution for the optimization of CoQ10 production processes using recombinant E. coli strains.

Detection of FLASH-radiotherapy tissue sparing in a 3D-spheroid model using DNA damage response markers.

PURPOSE: The oxygen depletion hypothesis has been proposed as a rationale to explain the observed phenomenon of FLASH-radiotherapy (FLASH-RT) sparing normal tissues while simultaneously maintaining tumor control. In this study we examined the distribution of DNA Damage Response (DDR) markers in irradiated 3D multicellular spheroids to explore the relationship between FLASH-RT protection and radiolytic-oxygen-consumption (ROC) in tissues. METHODS: Studies were performed using a Varian Truebeam linear accelerator delivering 10 MeV electrons with an average dose rate above 50 Gy/s. Irradiations were carried out on 3D spheroids maintained under a range of O2 and temperature conditions to control O2 consumption and create gradients representative of in vivo tissues. RESULTS: Staining for pDNA-PK (Ser2056) produced a linear radiation dose response whereas γH2AX (Ser139) showed saturation with increasing dose. Using the pDNA-PK staining, radiation response was then characterised for FLASH compared to standard-dose-rates as a function of depth into the spheroids. At 4 °C, chosen to minimize the development of metabolic oxygen gradients within the tissues, FLASH protection could be observed at all distances under oxygen conditions of 0.3-1 % O2. Whereas at 37 °C a FLASH-protective effect was limited to the outer cell layers of tissues, an effect only observed at 3 % O2. Modelling of changes in the pDNA-PK-based oxygen enhancement ratio (OER) yielded a tissue ROC g0-value estimate of 0.73 ± 0.25 µM/Gy with a km of 5.4 µM at FLASH dose rates. CONCLUSIONS: DNA damage response markers are sensitive to the effects of transient oxygen depletion during FLASH radiotherapy. Findings support the rationale that well-oxygenated tissues would benefit more from FLASH-dose-rate protection relative to poorly-oxygenated tissues.

Overwhelmed by beauty and faith: review on artistic and religious travelers' syndromes.

Traveling with the intention of encountering art or seeking purification of the spirit involves retribution of intangible nature and therefore can be expected to be a positive experience; nevertheless, among susceptible travelers, there is also a possibility of experiencing pathological conditions. Although it is colloquially known that beauty lies in the eyes of the beholder, it is necessary to mention that the appreciation of beauty, immensity, or mysticism contained in masterpieces is not perceived only through the eyes but through other sense organs as well. Additionally, this is understood within a cultural framework and through previous knowledge. The reaction triggers a series of somatosensory responses of diverse nature, with a wide range of responses that together constitute a pathological phenomenon that can be defined as syndromic by eliciting signs and symptoms of a physical, physiological, and psychotic nature. Both Stendhal and Jerusalem syndromes are travelers' syndromes that may occur in response to objectively aesthetic elements saturated with meaning linked to the cultural heritage of contemporary humanity. While Stendhal syndrome evokes physical and psychoemotional symptoms from the contemplation of art, Jerusalem syndrome goes beyond perception, adding delusions of being a religious or prophetic protagonist pursuing individual or collective salvation.

A phase II multicenter randomized study to evaluate the safety and efficacy of combining thermotherapy and a short course of miltefosine for the treatment of uncomplicated cutaneous leishmaniasis in the New World.

BACKGROUND: Systemic pentavalent antimonials, mainly meglumine antimoniate, continue to be the first-choice drugs for treatment of cutaneous leishmaniasis (CL) despite their toxicity, difficulty of administration and high cost. In the search for therapeutic alternatives, combining two treatment interventions has emerged as a potential alternative to either reduce the use of antimonials with the associated toxicities, or to increase efficacy. Here, we report the results of a recently completed trial assessing the efficacy and safety of a combination of thermotherapy (TT) plus a short course of miltefosine (MLT) for the treatment of uncomplicated CL in Colombia and Peru. METHODS: A multicenter, randomized, evaluator-blinded, phase II, controled clinical trial was conducted. Adult volunteers with a parasitologically confirmed diagnosis of uncomplicated CL were randomly allocated to receive either a single session of TT or a combination of TT plus a short course of MLT (3 weeks). Therapeutic response outcomes and safety were assessed. RESULTS: 130 subjects were included in the study, of whom 64 were randomly assigned to the TT arm and 66 to the TT + MLT arm. Cure at 3 months' follow-up was achieved in 57.8% (n = 37) and 80.3% (n = 53) in the TT and TT + MLT groups, respectively, in the intention to treat analysis. The TT + MLT regimen was better that TT alone (p = 0.0055). The presence of vesicles at the site of heat application was the most common adverse event reported associated with the use of TT; while vomiting (31.8%) and elevation of liver enzymes (28.8%) were the most frequent adverse events reported associated with the use of MLT. CONCLUSION: The combination of TT plus a short course of MLT was shown to be significantly better than TT alone for the treatment of uncomplicated CL in the New World. TRIAL REGISTRATION: Registered in clinicaltrials.gov NCT02687971.

Epidemiological Dynamics of SARS-CoV-2 Variants During Social Protests in Cali, Colombia.

Background: The third wave of the global health crisis attributed to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus reached Colombia in March 2021. Over the following 6 months, it was interpolated by manifestations of popular disapproval to the actual political regime-with multiple protests sprouting throughout the country. Large social gatherings seeded novel coronavirus disease 2019 (COVID-19) variants in big cities and propagated their facile spread, leading to increased rates of hospitalizations and deaths. Methods: In this article, we evaluate the effective reproduction number (Rt) dynamics of SARS-CoV-2 in Cali, Colombia, between 4 April 2021 and 31 July 2021 based on the analysis of 228 genomes. Results: Our results showed clear contrast in Rt values between the period of frequent protests (Rt > 1), and the preceding and following months (Rt < 1). Genomic analyses revealed 16 circulating SARS-CoV-2 lineages during the initial period-including variants of concern (VOCs) (Alpha, Gamma, and Delta) and variants of interest (VOIs) (Lambda and Mu). Furthermore, we noticed the Mu variant dominating the COVID-19 distribution schema as the months progressed. We identified four principal clusters through phylogenomic analyses-each one of potentially independent introduction to the city. Two of these were associated with the Mu variant, one associated with the Gamma variant, and one with the Lambda variant. Conclusion: Our results chronicle the impact of large group assemblies on the epidemiology of COVID-19 during this intersection of political turmoil and sanitary crisis in Cali, Colombia. We emphasize upon the effects of limited biosecurity strategies (which had characterized this time period), on the spread of highly virulent strains throughout Cali and greater Colombia.

Management of congenital lobar overinflation in an adult.

Congenital lobar overinflation is characterized by disruption of bronchopulmonary development which produces lobar or segmental bronchial abnormalities and overinflation of normal lung tissue. This is a 44-year old man, never smoker, who presents dyspnea every time he arrived in highlands, marked decreased breathing sounds and hyperresonance in the left hemithorax. Imaging studies suggested left upper lobe overinflation. The affected area was resected resulting in symptoms improvement. Accepted treatment is resection, however conservative management has been proposed for asymptomatic patients because cases of spontaneous improvement have been described. We recommend close monitoring and resection if symptoms or overinflation progress.

The potential risk of enzootic Trypanosoma cruzi transmission inside four training and re-training military battalions (BITER) in Colombia.

BACKGROUND: Colombia's National Army is one of the largest military institutions in the country based on the number of serving members and its presence throughout the country. There have been reports of cases of acute or chronic cases of Chagas disease among active military personnel. These may be the result of military-associated activities performed in jungles and other endemic areas or the consequence of exposure to Trypanosoma cruzi inside military establishments/facilities located in endemic areas. The aim of the present study was to describe the circulation of T. cruzi inside facilities housing four training and re-training battalions [Battalions of Instruction, Training en Re-training (BITERs)] located in municipalities with historical reports of triatomine bugs and Chagas disease cases. An entomological and faunal survey of domestic and sylvatic environments was conducted inside each of these military facilities. METHODS: Infection in working and stray dogs present in each BITER location was determined using serological and molecular tools, and T. cruzi in mammal and triatomine bug samples was determined by PCR assay. The PCR products of the vertebrate 12S rRNA gene were also obtained and subjected to Sanger sequencing to identify blood-feeding sources. Finally, we performed a geospatial analysis to evaluate the coexistence of infected triatomines and mammals with the military personal inside of each BITER installation. RESULTS: In total, 86 specimens were collected: 82 Rhodnius pallescens, two Rhodnius prolixus, one Triatoma dimidiata and one Triatoma maculata. The overall T. cruzi infection rate for R. pallescens and R. prolixus was 56.1 and 100% respectively, while T. dimidiata and T. maculata were not infected. Eight feeding sources were found for the infected triatomines, with opossum and humans being the most frequent sources of feeding (85.7%). Infection was most common in the common opossum Didelphis marsupialis, with infection levels of 77.7%. Sylvatic TcI was the most frequent genotype, found in 80% of triatomines and 75% of D. marsupialis. Of the samples collected from dogs (n = 52), five (9.6%; 95% confidence interval: 3.20-21.03) were seropositive based on two independent tests. Four of these dogs were creole and one was a working dog. The spatial analysis revealed a sympatry between infected vectors and mammals with the military population. CONCLUSIONS: We have shown a potential risk of spillover of sylvatic T. cruzi transmission to humans by oral and vectorial transmission in two BITER installations in Colombia. The results indicate that installations where 100,000 active military personnel carry out training activities should be prioritized for epidemiological surveillance of Chagas disease.

Development of an Amplicon-Based Next-Generation Sequencing Protocol to Identify Leishmania Species and Other Trypanosomatids in Leishmaniasis Endemic Areas.

Trypanosomatid infections are an important public health threat affecting many low-income countries across the tropics, particularly in the Americas. Trypanosomatids can infect many vertebrate, invertebrate, and plant species and play an important role as human pathogens. Among these clinically relevant pathogens are species from the genera Leishmania and Trypanosoma. Mixed trypanosomatid infections remain a largely unexplored phenomenon. Herein, we describe the application of an amplicon-based next-generation sequencing (NGS) assay to detect and identify trypanosomatid species in mammalian reservoirs, human patients, and sand fly vectors throughout regions of Leishmania endemicity. Sixty-five samples from different departments of Colombia, including two samples from Venezuela, were analyzed: 49 samples from cutaneous leishmaniasis (CL) patients, 8 from sand flies, 2 from domestic reservoirs (Canis familiaris), and 6 from wild reservoirs (Phyllostomus hastatus). DNA from each sample served to identify the presence of trypanosomatids through conventional PCR using heat shock protein 70 (HSP70) gene as the target. PCR products underwent sequencing by Sanger sequencing and NGS, and trypanosomatid species were identified by using BLASTn against a reference database built from trypanosomatid-derived HSP70 sequences. The alpha and beta diversity indexes of amplicon sequence variants were calculated for each group. The results revealed the presence of mixed infections with more than two Leishmania species in 34% of CL samples analyzed. Trypanosoma cruzi was identified in samples from wild reservoirs, as well as in sand fly vectors. Coinfection events with three different Leishmania species were identified in domestic reservoirs. These findings depose the traditional paradigm of leishmaniasis as being a single-species-driven infection and redraw the choreography of host-pathogen interaction in the context of multiparasitism. Further research is needed to decipher how coinfections may influence disease progression. This knowledge is key to developing an integrated approach for diagnosis and treatment. IMPORTANCE Traditionally, there has been a frequent, yet incorrect assumption that phlebotomine vectors, animal reservoirs, and human hosts are susceptible to Leishmania infection by a single parasite species. However, current evidence supports that these new vector-parasite-reservoir associations lend vectors and reservoirs greater permissiveness to certain Leishmania species, thus promoting the appearance of coinfection events, particularly in disease-endemic regions. The present study describes the application of an amplicon-based next-generation sequencing (NGS) assay to detect and identify trypanosomatid species in mammalian reservoirs, human patients, and sand fly vectors from regions of endemicity for leishmaniasis. This changes our understanding of the clinical course of leishmaniasis in areas of endemicity.

Phylogenomic Evidence of Reinfection and Persistence of SARS-CoV-2: First Report from Colombia.

The continuing evolution of SARS-CoV-2 and the emergence of novel variants have raised concerns about possible reinfection events and potential changes in the coronavirus disease 2019 (COVID-19) transmission dynamics. Utilizing Oxford Nanopore technologies, we sequenced paired samples of three patients with positive RT-PCR results in a 1-2-month window period, and subsequent phylogenetics and genetic polymorphism analysis of these genomes was performed. Herein, we report, for the first time, genomic evidence of one case of reinfection in Colombia, exhibiting different SARS-CoV-2 lineage classifications between samples (B.1 and B.1.1.269). Furthermore, we report two cases of possible viral persistence, highlighting the importance of deepening our understanding on the evolutionary intra-host traits of this virus throughout different timeframes of disease progression. These results emphasize the relevance of genomic surveillance as a tool for understanding SARS-CoV-2 infection dynamics, and how this may translate effectively to future control and mitigations efforts, such as the national vaccination program.

Epidemiological Indicators of SARS-CoV-2 (COVID-19) and Vaccination Effectiveness on the Report of Positive Cases in the Colombian Army.

The description of the epidemiological indicators of SARS-CoV-2 (COVID-19), such as the mortality rate (MR), the case fatality rate (CFR), and the attack rate (AR), as well as the geographical distribution and daily case reports, are used to evaluate the impact that this virus has had within the Colombian Army and its health system. As military forces around the world represent the force that defends sovereignty, independence, the integrity of the national territory, and the constitutional order, while maintaining migration controls in blocked border areas during this critical pandemic times, they must carry out strict epidemiological surveillance to control the situation among the servicemen. Up to date, the Colombian Army has faced a very high attack rate (AR = 8.55%) due, among others, to living conditions where active military personnel share bedrooms, bathrooms, and dining facilities, which facilitate the spread of the virus. However, being a mainly young and healthy population, the MR was 1.82 deaths/1,000 ha, while the CFR = 2.13% indexes consistently low if compared with those values reported for the national population. In addition, the effectiveness of vaccination is shown in daily cases of COVID-19, where, for the third peak, the active military population presented a decrease of positive patients compared to the dynamics of national transmission and the total population of the military forces (active, retired, and beneficiaries).

High antibody level: an accurate serologic marker of viremia in asymptomatic people with hepatitis C infection.

BACKGROUND: The screening and diagnosis of hepatitis C virus (HCV) infection is initiated by testing for antibody to HCV (anti-HCV). A positive anti-HCV test in blood donors represents ongoing infection in only a variable proportion of individuals. Because a high anti-HCV level has been associated with viremia, a study was conducted to determine whether a high antibody level is an accurate serologic marker for viremia in asymptomatic anti-HCV-positive persons. STUDY DESIGN AND METHODS: In a diagnostic test study, we included 856 anti-HCV-positive blood donors in a blood bank at Guadalajara, Jalisco, Mexico, between 2002 and 2007. A third-generation amplified chemiluminescence assay (ChLIA HCV) was used to detect anti-HCV. A positive result of the qualitative nucleic acid test (HCV RNA) was considered the gold standard for viremia. RESULTS: By receiver operating characteristic analysis, the signal-to-cutoff (S/CO) ratio of 20 or more was chosen as optimal to identify viremia and so was defined as high anti-HCV level. There was a significant difference in the proportion of viremia between subjects with high antibody level and those with lower levels (93.7% vs. 1.8%, respectively; p < 0.001). A high antibody level showed a sensitivity for viremia of 96.6% (95% confidence interval [CI], 93.8%-98.1%), a specificity of 96.6% (95% CI, 94.8%-97.8%), and a likelihood ratio of 28.6 (95% CI, 18.4%-44.6%). CONCLUSION: A high antibody level (S/CO ratio >/=20 by ChLIA HCV) clearly divides the viremic from the nonviremic blood donors and functions as an accurate serologic marker to guide the use of routine HCV RNA testing to confirm hepatitis C infection.

Intraspecific Genomic Divergence and Minor Structural Variations in Leishmania (Viannia) panamensis.

Leishmania (Viannia) panamensis is one of the most important Leishmania species associated with cutaneous leishmaniasis (CL) in Latin America. Despite its wide geographic distribution and pathogenic potential in humans and animals, the genomic variability of this species is low compared with other Leishmania species circulating in the same geographical area. No studies have reported a detailed analysis of the whole genome of L. panamensis from clinical isolates using DNA high-throughput sequencing to clarify its intraspecific genomic variability or plausible divergence. Therefore, this study aimed to evaluate the intraspecific genomic variability of L. panamensis from Colombia and Panama. A total of 22 genomes were analyzed, 19 from Colombian patients with CL and three genomes from Panama obtained from public databases. The phylogenomic analysis revealed the potential existence of three well-supported clades as evidence of intraspecific divergence. Additionally, the whole-genome analysis showed low structural variations in terms of ploidy, copy number variations, and single-nucleotide polymorphisms (SNPs). SNPs shared among all clades were identified, revealing their importance in different biological processes of L. panamensis. The findings not only expand our knowledge of intraspecific genomic variability of one of the most important Leishmania species in South America but also highlights the possible existence of different clades/lineages/subpopulations across a geographic scale.

Development of a Digital Droplet Polymerase Chain Reaction (ddPCR) assay to detect Leishmania DNA in samples from Cutaneous Leishmaniasis patients.

AIM: Here, we evaluate the ddPCR platform using an evaluated qPCR-based diagnostic assay for the detection of Leishmania infection in Cutaneous Leishmaniasis patients. METHODS: A standard curve of cultured Leishmania parasite material and clinical samples of CL patients were tested with ddPCR to determine the analytical and diagnostic performance. RESULTS: The limit of detection of the assay on the ddPCR platform was much higher than the published limit of detection of the same assay on the qPCR platform (100 vs 1 parasites/mL, respectively). CONCLUSION: While the performance of this assay in ddPCR format was acceptable for research purposes, it is not sufficient for clinical diagnostic purposes. The assay is more suited to the qPCR platform.

Major changes in chromosomal somy, gene expression and gene dosage driven by SbIII in Leishmania braziliensis and Leishmania panamensis.

Leishmania braziliensis and Leishmania panamensis are two species clinically and epidemiologically important, among others because of their relative resistance to first-line drugs (antimonials). The precise mechanism underlying the ability of these species to survive antimony treatment remains unknown. Therefore, elucidating the pathways mediating drug resistance is essential. We herein experimentally selected resistance to trivalent antimony (SbIII) in the reference strains of L. braziliensis (MHOM/BR75/M2904) and L. panamensis (MHOM/COL/81L13) and compared whole genome and transcriptome alterations in the culture promastigote stage. The results allowed us to identify differences in somy, copy number variations in some genes related to antimony resistance and large-scale copy number variations (deletions and duplications) in chromosomes with no somy changes. We found mainly in L. braziliensis, a direct relation between the chromosomal/local copy number variation and the gene expression. We identified differentially expressed genes in the resistant lines that are involved in antimony resistance, virulence, and vital biological processes in parasites. The results of this study may be useful for characterizing the genetic mechanisms of these Leishmania species under antimonial pressure, and for clarifying why the parasites are resistant to first-line drug treatments.