First Morphological and Molecular Characterization of Paratylenchus vandenbrandei (Rhabditida: Tylenchulidae) in Iran

Paratylenchus vandenbrandei, has been recovered from the rhizospheric soil of Euphrates poplar (Populus euphratica) in the Karkheh protected area of Khuzestan province, southwestern Iran. The species was identified as P. vandenbrandei by the presence of three lines in the lateral fields; conoid rounded lip region; presence of submedian lobes, a stylet 24.0-28.8 μm long; an excretory pore at the level of the anterior part of the pharyngeal bulb; a round-to-oval spermatheca; presence of vulval flaps; and a conoid tail, with a terminus that is rounded or slightly pointed in some specimens. Males have a conoid tail, with a rounded-to-slightly-pointed terminus. The phylogenetic relationships of the species were reconstructed and investigated using partial sequencing of the D2-D3 expansion segments of large subunits, as well as internal transcribed spacer regions (LSU D2-D3 and ITS rDNA) based on Bayesian inference (BI). P. vandenbrandei has formed a clade with P. neonanus, P. minor, P. nainianus, P. chongqinjensis, P. pedrami, P. baldaccii, P. leptos and P. rostrocaudatus with maximal support (BPP = 1.00). To the best of our knowledge, this is the first report of P. vandenbrandei in Iran and the first molecular characterization of the species worldwide.

Assessing and mapping distribution, area, and density of riparian forests in southern Iran using Sentinel-2A, Google earth, and field data

Riparian forests in Iran are valuable ecosystems which have many ecological values. Because of destruction of these forests in recent years, providing spatio-temporal information from area and distribution of these ecosystems has been receiving much attention. This study was performed for mapping distribution, area and density of riparian forests in southern Iran using Sentinel-2A, Google Earth, and field data. First Sentinel-2A satellite image of the study area was provided. The field work was performed to take the training areas and to assess the forest density of riparian forests in Khuzestan province. In the first part of this study, after selecting training areas as pixel-based samples on the Sentinel-2A satellite image, supervised classification of image was performed using support vector machine (SVM) algorithm to classify the distribution of riparian forests. After classification of Sentinel-2A satellite image, the boundary of riparian forests map was checked and corrected on Google Earth images. In the second part of this study, field data, Normalized Difference Vegetation Index (NDVI), and regression model were used to assess the density of riparian forests. Finally, the accuracy of the final riparian forest map (showing both distribution and density of riparian forests) was assessed using Google Earth images. Results showed that the final riparian forest map (showing both distribution and density of riparian forests) with overall accuracy 89% and kappa index 0.81 had a good accuracy for classifying the distribution and density of riparian forests in Khuzestan province. These results demonstrate the accuracy of SVM algorithm for classifying the distribution of riparian forests and also capability of NDVI for classifying the density of riparian forests in this study. Results also showed that regression model (R² = 0.97) is reliable for estimating riparian forest density. The results demonstrated that there are 68447.18 ha of riparian forest around the main rivers in Khuzestan province, mainly distributed in the northwest and southeast of the province. From this area, 54694.15 ha have been covered by dense forests and 13753.03 ha by sparse forests. Results of this research have created the useful data of area, distribution and density of riparian forests in 10-m spatial resolution which is necessary for conservation and management of these forests in southern Iran. It is suggested that mapping area, distribution and density of these forests would be performed using SVM algorithm and NDVI in the certain temporal periods for protective management of these ecosystems in time series.

Mineralogical, geochemical, and textural characteristics of soil and airborne samples during dust storms in Khuzestan, southwest Iran

Dust storms are frequent phenomena in Khuzestan Province, southwest Iran, leading to environmental hazards and deleterious impacts on human health. This work analyzes mineralogic and geochemical characteristics of dust sediments at the source regions and in deposition areas in southwest Iran during three dust-storm events in winter and spring 2018. Twenty soil and airborne dust samples were collected and analyzed for compositions of dust at different distances from the source regions in Iraq and southwest Iran, aiming to assess the source characterization and possible mixing processes in the atmosphere. The grain size distributions were also analyzed at specific sites. The results show that about 50 % of the volume size distribution corresponds to particle sizes of above 20 μm, indicating local/regional dust storms of coarse to giant particles. XRD analysis indicates that calcite is the dominant mineral in all the samples, with a high quartz and dolomite fraction. The most abundant major compounds are SiO₂ and CaO, while Cl, Ba, Sr, Pb, Ni, Zn, Cr, V are the main trace elements. The enrichment factor (EF) analysis showed that apart from Th, Nb, Ce, and V, all the other elements (Pb, Zn, Cr, etc.) have an anthropogenic origin or represent high amounts of pollutant contamination. High levels of elemental enrichment are attributable to intensive pollution in Khuzestan Province and at sampling sites due to fossil-fuel combustion, gas and petroleum drilling activities. Moreover, based on the geo-accumulation index (Igeo), all samples are found to be contaminated by heavy metals due to prior war-related materiel, oil and gas extraction, and emissions from polluting industries.

Effects of climate variables on the incidence of scorpion stings in Iran for five years

Background:

Although scorpionism is recorded worldwide, some regions such as Iran present a higher incidence. Due to the great prevalence of scorpion stings in Khuzestan province, southwestern Iran, the present study examined the relationship between different climate parameters and the scorpion sting rate in this area from April 2010 to March 2015.

Methods:

In this cross-sectional descriptive-analytical study, we considered all scorpion sting cases recorded in the Department of Infectious Diseases, Ahvaz Jundishapur University of Medical Sciences. Data were analyzed using statistics, frequency distribution and Pearson’s correlation coefficient.

Results:

A total of 104,197 cases of scorpion stings was recorded from 2010 to 2015. The cumulative incidence of scorpion sting was 2.23%. The spatial distribution of scorpion stings showed that most cases occurred in the Dehdez district (4,504 scorpion stings/100,000 inhabitants) and the Masjed Soleyman county (4,069 scorpion stings/100,000 inhabitants). A significant association was found between climate factors (temperature, evaporation rate, sunshine duration, humidity, and precipitation) and the scorpion sting rate. An increase in rainfall and humidity coincided with a reduction in scorpion stings whereas an increase in temperature, evaporation, and sunshine duration was accompanied by a growth of scorpion stings. No significant correlation was found between wind velocity/direction and the incidence rate of stings. Moreover, the seasonal peak incidence of scorpion stings was recorded in summer (an average of 8,838 cases) and the lowest incidence was recorded during winter (an average of 1,286 cases). The annual trend of scorpion sting cases decreased during the period from 2010 to 2015.

Conclusion:

Climate variables can be a good index for predicting the incidence of scorpion stings in endemic regions. Since they occur mostly in the hot season, designing preventive measures in the counties and districts with a high incidence of scorpion stings such as Dehdez and Masjed Soleyman can minimize mortality and other burdens.

Morphological and molecular data of two species of the rare genera Thada Thorne, 1941 and Tenunemellus Siddiqi, 1986 (Nematoda: Tylenchidae) from Iran

Thada populus n. sp. was found in the rhizosphere of Populus euphratica in the city of Dezful, south-western Iran. The new species is characterized by its 365-453 μm body length, cuticle with transverse annuli 0.9-1.2 μm wide, lateral fields with four lines, lip region low with one or two annuli, 7.0-8.5 μm wide at base, longitudinal or slightly sigmoid amphidial slit, delicate stylet 8.4-9.8 μm long with posteriorly directed knobs, dorsal pharyngeal gland opening at 1.0-1.5 μm posterior to the stylet knobs, non-muscular and valve-less median bulb, pyriform and offset basal bulb, almost oval spermatheca, posterior position of vulva (V = 75-79%) without lateral membrane, short post-vulval uterine sac and conical tail with finely to broadly rounded terminus. Morphological differences of the new species with those of the type species, Thada striata, are discussed. Molecular phylogenetic studies of the new species using partial sequences of small subunit ribosomal DNA revealed that the new species formed a clade with Malenchus spp., Filenchus facultativus, F. fungivorus and Filenchus sp. in Bayesian inference. Morphological and molecular phylogenetic studies were also performed on Tenunemellus indicus, the second recovered species, the latter analysis using partial sequences of large subunit ribosomal DNA. In the inferred Bayesian tree, T. indicus formed a clade with Labrys fuzhouensis, Lelenchus leptosoma from the Netherlands, Malenchus spp. and Filenchus discrepans.

Gill lesions and mortality in common carp (Cyprinus carpio) with a dense bloom of Heterosigma-like algae in Khuzestan province

BACKGROUND

Widespread common carp (Cyprinus carpio) mortalities have been recorded in Khuzestan province fish farms in recent years. In summer of 2017 two cases of harmful algal bloom were encountered that led to massive mortality in common carp in Khuzestan, Iran.

AIMS

The aim of this study was to identify the possible etiologic agent of two mortalities with characteristic symptoms of gill lesions due to harmful algae.

METHODS

Water samples were collected and 5 moribund fishes were examined by histophatologic, scanning electron microscopic and PCR examination.

RESULTS

In wet smear preparations, a lot of algal cells and fragments, and sloughed, necrotic epithelial cells were observed between the lamellae. In histopathologic examination of gills, hyperplasia, necrosis and algal cells surrounded by hyperplastic cells were seen in tissue sections. No inflammatory cell aggregation was noticed. In scanning electron microscopic examination the algae was found attached to the gill surface (cell diameter: 8.5 ± 4.2 µm) with 2 equal flagella.

CONCLUSION

Phytoplankton analysis using direct microscopy and electron microscopy, morphologically resembling Heterosigma was identified, however, in PCR tests, Heterosigma analysis showed negative results, therefore the causative agent was called "Heterosigma-like" algae.

Genomic analysis of Blastocystis hominis isolates in patients with HIV-positive using locus SSU-rDNA

Blastocystis hominis (B. hominis) is a protozoan zoonosis which clinical signs of infection with this parasite has been reported to be more severe in patients with weakened immune systems than healthy controls. So, the aim of the study was to evaluate genomic analysis of B. hominis isolates obtained from patients with HIV-positive using locus SSU-rDNA. At first, 268 stool samples were randomly collected from patients with HIV-positive referred to health centers of Khuzestan province, southwest of Iran. Formol-ether and direct smear techniques were used for the detection of parasitic agents. After extracting DNA, the samples were analyzed by the PCR method. Finally, the subtypes were determined by the sequencing and PCR methods. New samples were used for the preparation of positive control sample; they were cultured in coagulant-serum biphasic cultivation media. Of 268 stool samples, 33 (12.3%) cases were detected positive for B. hominis using Formol-Ether technique but 51 (19%) cases were positive using molecular method. The most common isolates were related to the subtype III with 29 positive cases (56.8%), then, genotype I with 11 (21.6%) cases, 6 cases (11.8%) with genotype II, 3 (5.9%) combined cases with genotypes I and III as well as 2 cases (3.9%) with genotype VI. There was a significant difference between two groups of HIV-positive patients (infected with the parasite and/or without the parasite) in the term of the mean of TCD4-positive cells. The results indicated a relatively high prevalence of B. hominis in HIV-positive patients as well as our findings may represent that the number reduction of TCD4-positive cells has an effective role in the increased risk of the parasitic infection in HIV-positive patients.

Description of Enchodorus yeatsi n. sp. (Dorylaimida, Nordiidae) from Southern Iran and Its Molecular Phylogenetic Study

Enchodorus yeatsi n. sp., a new species of the rare genus Enchodorus is described and illustrated based on its morphological and molecular characters. It was recovered from southern Iran. Females of the new species are characterized by having 1,511.3- to 1,792.5-µm long slender body, angular lip region having prominent papillae, 12- to 13-µm long odontostyle, double guiding ring, simple rod-like odontophore, didelphic-amphidelphic reproductive system, and 102- to 160-µm long elongate-conoid tail with rounded tip. Males of the new species are abundant and functional, characterized by 1,484- to 1,576-µm long body, 40- to 43-µm long spicules, 5 to 6 ventromedian supplements, and ventrally bent elongate conical tail. Compared to the type species, Enchodorus dolichurus, the new species has differences in its tail morphology and V value. These morphological differences and the separation of two species was further supported with basic differences in sequences of 28S rDNA D2/D3 and internal transcribed spacer 1 (ITS1) fragments. Compared to Enchodorus neodolichurus, it has basic differences in tail characters and spicule lengths. Molecular phylogenetic studies using partial sequences of 28S rDNA D2/D3 fragment of the new species and available sequences of Nordiidae members and several other dorylaim species/genera, revealed E. yeatsi n. sp. and E. dolichurus forming a clade with 0.81 Bayesian posterior probability (BPP). This clade forms a sister clade to the clade of Heterodorus sp. and Rhyssocolpus vinciguerrae, again with 0.81 BPP. In ITS1 tree, reconstructed using few available sequences, the new species and E. dolichurus formed a clade with 0.98 BPP.