Molecular Characterization of Leishmania Parasites in Giemsa-Stained Slides from Cases of Human Cutaneous and Visceral Leishmaniasis, Eastern Algeria

Genetic Diversity of Leishmania major Isolated from Different Dermal Lesions Using ITS2 Region

BACKGROUND AND OBJECTIVE

Cutaneous leishmaniasis (CL) is still considered to be an uncontrolled endemic disease that spreads in many countries. The current study aimed to determine intra-species relationships of L. major using ITS2 sequencing.

METHODS

The study was conducted from the beginning of March to the end of November 2022. All medical information regarding CL was collected from patients of Thi-Qar province who attended the Dermatology Department of Al-Hussein Teaching Hospital in Nasiriyah city. Seventy-three samples were selected for the molecular identification after confirming microscopy with Giemsa stain. In this study, the primers were designed using NCBI GenBank sequence database and Primer 3 plus primer design online software.

RESULTS

The results recorded 21 (28.77%) positive samples of L. major using the internal transcribed spacer 2 region (ITS2) in ribosomal RNA gene. The local L. major IQN.1-IQN.10 were submitted to NCBI GenBank database with accession numbers OM069357.1-OM069366.1, respectively. The phylogenetic analysis revealed that local isolates of L. major showed a close relationship with NCBI-BLAST L. major Iran isolate (KU680848.1).

CONCLUSION

ITS2-PCR is suitable for identifying Leishmania spp. and determining genetic diversity. A phylogenetic data analysis may provide an idea on the genetic homogeneity of local isolates and knowing the genetic origin of the dermal lesion. However, the local isolates showed genetic proximity to the KU680848.1 isolate. This signifies the possibility of infection prevalence from Iranian areas. In general, genetic variation of L. major isolates may give several clinical manifestations of the cutaneous lesion. Therefore, determination of the heterogeneity is important for detecting the infection origin, epidemiology, therapy, and control strategies.

Molecular Detection of Neglected Tropical Diseases: The Case for Automated Near-Point-of-Care Diagnosis of Leishmaniasis

Neglected tropical diseases affect those in poorer nations disproportionately across the globe. One example of these, leishmaniasis, is a debilitating and potentially fatal parasitic infection. Molecular detection of this disease can provide accurate and fast diagnosis, and with near point-of-care technologies, detection can be provided in many health-care settings. Traditionally, the perceived limitations to such detection methods have hindered their provision to resource-limited nations, but new technologies and techniques are helping to overcome these perceptions. The current pandemic offers an opportunity to maintain and develop further advances, ensuring molecular diagnostics are accessible to all.

Laboratory diagnostics for human Leishmania infections: a polymerase chain reaction-focussed review of detection and identification methods

Leishmania infections span a range of clinical syndromes and impact humans from many geographic foci, but primarily the world's poorest regions. Transmitted by the bite of a female sand fly, Leishmania infections are increasing with human movement (due to international travel and war) as well as with shifts in vector habitat (due to climate change). Accurate diagnosis of the 20 or so species of Leishmania that infect humans can lead to the successful treatment of infections and, importantly, their prevention through modelling and intervention programs. A multitude of laboratory techniques for the detection of Leishmania have been developed over the past few decades, and although many have drawbacks, several of them show promise, particularly molecular methods like polymerase chain reaction. This review provides an overview of the methods available to diagnostic laboratories, from traditional techniques to the now-preferred molecular techniques, with an emphasis on polymerase chain reaction-based detection and typing methods.

Epidemiological situation analysis of cutaneous leishmaniasis in Batna (northeast): An important focus in Algeria

Cutaneous leishmaniasis (CL) is a parasitic infection which poses a real public health problem in various countries, including Algeria. We aimed in this study to investigate the current epidemiological situation of CL in the wilaya of Batna (northeastern Algeria) during 2010-2020 and to discuss some control measures used to combat the disease in the most endemic foci. Data on CL cases and control measures were obtained from the "Direction de la Santé et de la Population (DSP) of Batna" and the "Etablissement Public de la Santé de Proximité (EPSP) of Barika". Data were analyzed and mapped using Microsoft Office Excel 2007, SPSS.21, and ArcGIS 10.3. A total of 9259 cases were notified, with a peak incidence of 1924 cases in 2010. The annual evolution of the disease showed decreasing and increasing trends during the study period. Cases were detected year-round, with a peak notification in November (1957 cases) and January (1663 cases). CL affects both genders and all age groups with predominance for males (58.6%) and infants less than 9 years old (54.4%). Most cases have occurred in western areas of the wilaya especially in the commune of Barika with 2979 cases (32.17%), followed by Abdelkader Azil (13.37%), Bitam (12.32%), Djezzar (8.67%), Ouled Ammar (7.07%), and Amdoukal (4.36%) communes. Spatiotemporal analysis showed that the highest frequencies of CL were exclusively reported in the western regions. There was no evidence of a possible relationship between Deltamethrin house spraying and leishmaniasis incidence. This study revealed that CL is highly endemic in the western areas of Batna, especially in Barika, with children less than 9 years old as the most age group at risk. The development of control measures and the selection of appropriate strategies are necessary to prevent, control, and eradicate the disease.

Bionomics and phylo-molecular analysis of Leishmania species isolated from human lesions using ITS1 genes in north-east of Iran

Leishmaniasis is a zoonotic infectious disease caused by Leishmania species. The identification of parasite species and the type of disease is beneficial for treatment and preventive modalities. Leishmania tropica and L. major have been reported as the main etiological agents of cutaneous leishmaniasis (CL) in Iran. The incidence of zoonotic CL has increased and different in distinct loci of Iran. Hence, we perused the Leishmania species and its genetic traits in the North East of Iran. The investigation was conducted on 200 positive smears prepared from patients' lesions suffering from CL referred to the health care centers of northeastern provinces in Iran from 2013 to 2019. The obtained positive microscopy samples were divided to score the ranges from + 1 to + 6, of them 40 smears exhibited low-parasitemia. Leishmania species analyzed using PCR-RFLP, genetic diversity indices evaluation, phylogenetic analysis, and sequencing comparison with other species in the GeneBank based on ITS1 gene. The isolated L. major strains were similar to other Iranian isolates in this region. Pairwise fixation index (F_ST) index was statistically significant in different L. major populations and showed the genetic differences in pairwise population of different geographical locations of Iran. The current study confirmed an old pattern endemicity of zoonotic CL in North-east of Iran. Therefore, in order to assess the hybrid formation, more epidemiological, ecological, and gene polymorphism studies are needed to understand the pathogenic role of Leishmania species in Iran.

Fish tank granuloma: An emerging skin disease in Iran mimicking Cutaneous Leishmaniasis

OBJECTIVE

Mycobacterium marinum causes a rare cutaneous disease known as fish tank granuloma (FTG). The disease manifestations resemble those associated with Cutaneous Leishmaniasis (CL). The aim of this study was to determine whether FTG was the cause of cutaneous lesions in patients who were referred to the Parasitology laboratory of Imam Reza Hospital in Mashhad to be investigated for CL.

MATERIALS/METHODS

One hundered patients, clinically diagnosed with CL between April 2014 and March 2015, were included in this study. Ziehl-Neelsen staining was performed to identify acid-fast Mycobacterium in addition to bacterial cultures using Löwenstein-Jensen medium. Skin lesion samples were also collected and kept on DNA banking cards for PCR testing.

RESULTS

Twenty-nine of the 100 individuals with skin lesions, and therefore suspected of suffering from CL, tested positive for Mycobacterium marinum by PCR. Of these, 21 (72.4%) were male and 8(27.6%) were female. In 97% of these cases the lesions were located on hands and fingers. These patients had a history of manipulating fish and had been in contact with aquarium water. A sporotrichoid appearance was observed in 58.6% of the patients with mycobacterial lesions; 67% of patients had multiple head appearance.

CONCLUSION

Patients suspected to have CL and who test negative for CL could be affected by FTG. Therefore, after obtaining an accurate case history, molecular diagnosis is recommended for cases that give a negative result by conventional methods.

A comparison of the efficiency of three sampling methods for use in the molecular and conventional diagnosis of cutaneous leishmaniasis

In human cutaneous leishmaniasis (CL), the success of positive diagnoses and species identifications depends, primarily, on how biopsies are taken and then processed and examined. The efficiency of three methods of taking skin biopsies from suspect cases of CL was compared using the classical methods of microscopy of stained smears, in vitro culture of tissue aspirate, and internal transcribed spacer region 1 (ITS1)-polymerase chain reaction in diagnosing positive cases and identifying the species of Leishmania causing them. From 1994-2014, biopsy samples from the skin lesions of 2232 CL-suspected patients were collected as unstained smears, as smears stained with Giemsa's stain and on filter paper, and compared in the diagnostic tests employed. Matched comparison based on testing biopsy samples from 100 patients, microscopy, in vitro culture and ITS1-PCR were also conducted to assess the most suitable combination of methods for diagnosing leishmaniases. In the 100-case-matched comparison, the three different types of sample proved to be equally good with no significant difference (P > 0.05). However, skin tissue imprints on filter paper revealed most cases of CL. The kappa statistic for measuring the degree of agreement among the three samples was 89%, which is considered good. Agreement was highest between imprints on filter paper and unstained smears, and lowest was for stained smears. In the overall comparison between the ITS1-PCR and conventional methods, the ITS1-PCR using samples from filter papers was the most sensitive method but the difference was insignificant (P = 0.32). The combination of microscopy together with ITS1-PCR on samples from filter papers increased the sensitivity significantly to 46%, compared to using the methods individually (P = 0.003-0.0008). On comparing the results of the tests done on the samples from the 2232 patients after applying ITS1-PCRs to their samples from filter papers, unstained smears, in vitro culture, microscopy, and stained smears showed, respectively, test sensitivities of 81, 69, 64, 57 and 48%. Of the tests and samples adjudicated, ITS1-PCRs run on skin tissue samples from filter papers proved best for the routine laboratory diagnosis of CL. Adding microscopy of stained smears to it, improved its diagnostic value significantly.