Different Morphologies of Leishmania major Amastigotes with No Molecular Diversity in a Neglected Endemic Area of Zoonotic Cutaneous Leishmaniasis in Iran

The Geographical Distribution of Human Cutaneous and Visceral Leishmania Species Identified by Molecular Methods in Iran: A Systematic Review With Meta-Analysis

Leishmaniasis is one of the most common vector-borne parasitic diseases in Iran. Leishmania species identification is necessary for epidemiological aspects, precise prognosis, control and treatment of the disease. We systematically searched all the studies, reports, and documentation related to species identification and geographical distribution of causative agents of cutaneous (CL), mucosal (ML), and visceral leishmaniasis (VL) using DNA-based molecular diagnostic techniques in Iran. International databases including PubMed, ScienceDirect, Embase, Google Scholar, Scopus, and Web of Science were systemically searched for English articles and Iran's databases including SID, IranMedex and Magiran were searched for Persian reports and articles. Searches were performed from 1999 to 2019 (20 years). The current review was conducted using the keywords: cutaneous leishmaniasis, visceral leishmaniasis, Leishmania species, Human, Molecular, PCR, and Iran. The study quality was evaluated using the NOS checklist. This meta-analysis procedure was accomplished using STATA, version 2.7.9. Of the 3,426 records identified in the initial search, 154 articles met inclusion criteria and qualified for the systematic review and meta-analysis. In subgroup analysis, the pooled frequency of causative agents of CL isolates was 67.3% (95% CI: 59.51–74.67%) for L. major and 32.1% (95% CI: 24.72–39.87%) for L. tropica. In addition, the pooled frequency of causative agents of VL isolates was 97.1% (95% CI: 94.6–98.8%) for L. infantum and 2.9% (95% CI: 1.12–5.37%) for L. tropica. The findings of this study showed that the main causative agents of CL and VL in Iran are L. major and L. infantum, respectively. Moreover, kinetoplast DNA (kDNA) and internal transcriber spacer (ITS) were the most used markers for identifying Leishmania species. The current study provides valuable data to encourage and direct researchers as well as public health managers in the comprehensive leishmaniasis control and prevention planning in Iran.

Intra-Species Diversity of Leishmania major and L. tropica from Clinical Isolates of Cutaneous Leishmaniasis in Southwest Iran Inferred by ITS1-rDNA

BACKGROUND

Cutaneous leishmaniasis (CL) as a public health concern is increasingly circulating by causative agents of Leishmania tropica and L. major in Iran. As regard to recent treatment failure and controlling problems, the accurate elucidation of heterogeneity traits and taxonomic status of Leishmania spp. should be broadly addressed by policymakers. This study was designed to determine the genetic variability and molecular characterization of L. major and L. tropica from Iranian CL patients.

METHODS

One hundred positive Giemsa-stained slides were taken from clinical isolates of CL at Pol-e-Dokhtar County, Southwest Iran, from May 2014 to Sep 2016. DNAs were directly extracted and amplified by targeting ribosomal internal transcribed spacer (ITS) gene following microscopic observation. To identify Leishmania spp. amplicons were digested by restriction enzyme HaeIII subsequent PCR-RFLP technique. To reconfirm, the isolates were directly sequenced to conduct diversity indices and phylogenetic analysis.

RESULTS

Based upon the RFLP patterns, 84 and 16 isolates were explicitly identified to L. tropica and L. major respectively. No co-infection was found in clinical isolates. The high genetic diversity of L. tropica (Haplotype diversity 0.9) was characterized compared to L. major isolates (Hd 0.476). The intra-species diversity for L. tropica and L. major isolates corresponded to 3%-3.9% and 0%-0.4%, respectively.

CONCLUSION

Findings indicate the L. tropica isolates with remarkable heterogeneity than L. major are predominantly circulating at Pol-e-Dokhtar County. Occurrence of high genetic variability of L. tropica may be noticed in probable treatment failure and/or emerging of new haplotypes; however, more studies are warranted from various geographic regions of Southwest Iran, using large sample size.

Evaluative Assay of Nuclear and Mitochondrial Genes to Diagnose Leishmania Species in Clinical Specimens

BACKGROUND

Leishmaniasis as an emerging and reemerging disease is increasing worldwide with high prevalence and new incidence in recent years. For epidemiological investigation and accurate identification of Leishmania species, three nuclear and mitochondrial genes (ITS-rDNA, Hsp70, and Cyt b) were employed and analyzed from clinical samples in three important Zoonotic Cutaneous Leishmaniasis (ZCL) foci of Iran.

METHODS

In this cross-sectional/descriptive study conducted in 2014-15, serous smears of lesions were directly prepared from suspected patients of ZCL in Turkmen in northeast, Abarkouh in center and Shush district in southwest of Iran. They were directly prepared from suspected patients and DNA was extracted. Two nuclear genes of ITS-rDNA, Hsp70 and one mitochondrial gene of Cyt b within Leishmania parasites were amplified. RFLP was performed on PCR-positive samples. PCR products were sequenced, aligned and edited with sequencher 4.1.4 and phylogenic analyses performed using MEGA 5.05 software.

RESULTS

Overall, 203 out of 360 clinical samples from suspected patients were Leishmania positive using routine laboratory methods and 231 samples were positive by molecular techniques. L. major L. tropica, and L. turanica were firmly identified by employing different molecular genes and phylogenic analyses.

CONCLUSION

By combining different molecular genes, Leishmania parasites were identified accurately. The sensitivity and specificity three genes were evaluated and had more advantages to compare routine laboratory methods. ITS-rDNA gene is more appropriate for firm identification of Leishmania species.

Diagnostic Accuracy of Loop-mediated Isothermal Amplification Assay as a Field Molecular Tool for Rapid Mass Screening of Old World Leishmania Infections in Sand Flies and In Vitro Culture

BACKGROUND

We employed a highly sensitive loop-mediated isothermal amplification (LAMP) by targeting 18S rRNA gene to identify the rapid mass screening of Leishmania infections in captured sand flies of southwest Iran and In vitro culture.

METHODS

One hundred fifty sand flies were collected from 11 sites adjacent to Iraqi's borders in southern parts of Khuzestan Province by using sticky sheets of paper and CDC miniature light traps during late May 2014 to Nov 2015. Following morphological identification of sand flies species, the DNA of infected samples was extracted and amplified by PCR and LAMP assays by targeting ITS-rDNA and 18S rRNA genes. The PCR amplicons were directly sequenced to conduct the phylogenetic analysis.

RESULTS

Ten (6.6%) Leishmania infections were identified by LAMP assay (detection limit 0.01 parasites DNA) among infected Sergentomyia baghdadis, S. sintoni and Phlebotomus papatasi sand flies that was more sensitive than PCR (n=6.4%; (detection limit 10¹ parasites DNA). LAMP can identify 10¹-10⁶ promastigotes/100 μl RPMI 1640 while PCR recognized 10⁴-10⁶ promastigotes. The majority infection rate of sand flies was confirmed to L. major inferred by phylogenetic analysis.

CONCLUSION

This is the first exploration characterized the Old World Leishmania infections by LAMP technique in both infected sand flies and In vitro conditions. The LAMP method because of its shorter reaction time, robustness, more sensitivity, lack of requirement of complicated equipment and visual discriminatory of positivity can be appeared a promising tool instead of PCR to identify low Leishmania loads and entomological monitoring of leishmaniasis in resource-limited endemic of the world.

Control of Cutaneous Leishmaniasis Using Geographic Information Systems from 2010 to 2014 in Khuzestan Province, Iran

Background

Cutaneous leishmanisis (CL) is found worldwide and is considered to be endemic in 88 countries such as Iran. Geographic information system (GIS) is a method that can create, archive, analyze traditional map and place data of the disease distribution. The aim of this study was to produce distributional maps of CL over five years and evaluate the role of GIS in control of CL in Khuzestan province where an endemic area of CL in Iran is.

Methods

CL epidemiological data on the District and village levels for the period 2010–2013 were provided as census by health surveillance system in all counties and in control diseases center (CDC) of Khuzestan province. After collection of CL data, the collected data of CL from 2010 to 2013 were analyzed using GIS. The collected data of CL from 2010 to 2013 was analyzed using GIS. The endemic areas of CL during 2010–2013 were recognized using GIS maps and the control programs of CL were done in these regions based on epidemiological situation and the stratification of risk areas.

Results

During the study period, there were 4672 recorded cases of clinical cases of CL by Khuzestan Health Center. Data of GIS referring to CL patients showed that center and eastern districts of Khuzestan had a significant number of cases. In 2014 that control program was done, ten distinct of Khuzestan Province didn’t show any cases of the disease.

Conclusion

In conclusion, analyses of data distributed in the geographic spaces are increasingly appreciated in leishmaniasis control management. GIS tools promoted greater efficiency in making decisions and planning activities in the control of vector born disease such as leishmaniasis.