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Simple Summary: This research represents the first analysis of the population genetics of the diplectanid monogenean Lamellodiscus echeneis, sampled from wild and cage-reared gilthead seabream Sparus aurata across fifteen locations in the Southern (Tunisia) and Northern (Italy and Spain) regions of the Mediterranean Sea. The comparison of the newly obtained dataset to previously published sequences of L. echeneis, and the phylogenetic trees based on the analysis of ITS rDNA, confirmed the presence of only one species in the Mediterranean Sea. The star-like haplotype network inferred by COI sequences suggested a recent population expansion of L. echeneis. This study provides insights into the genetic variation among L. echeneis populations and did not reveal a clear genetic structure throughout Tunisian, Italian, and Spanish localities, possibly due to significant gene flow between the populations facilitated by the dispersion potential of hosts. The diplectanid monogenean Lamellodiscus echeneis (Wagener, 1857) is a specific and common gill parasite of the gilthead seabream Sparus aurata Linnaeus, 1758, in the Mediterranean Sea. Few isolated molecular studies of this monogenean have been conducted, and its population structure and genetic diversity are poorly understood. This study represents the first analysis of the population genetics of L. echeneis, isolated from wild and cage-reared gilthead seabream from fifteen localities in both the Southern (Tunisia) and Northern (Italy and Spain) regions of the Mediterranean Sea, using nuclear ITS rDNA markers and a partial fragment of the mitochondrial gene cytochrome oxidase subunit I (COI). The phylogenetic trees based on the newly obtained dataset and the previously published sequences of L. echeneis corroborated the spread of only a single species throughout the Mediterranean Sea. The star-like haplotypes network, inferred by COI sequences, suggested a recent population expansion of L. echeneis. This is supported by the observed high haplotype diversity (Hd = 0.918) and low nucleotide diversity (Pi = 0.01595). Population structure-based AMOVA for two groups (the Adriatic Sea and the rest of the Mediterranean Sea) attributed 35.39% of the total variation to differences within populations, 16.63% to differences among populations within groups, and 47.99% to differences among groups. Fixation indices were significant, with a high FST value (0.64612), likely related to the divergence of the parasite populations from the Adriatic Sea and other Mediterranean regions. Phylogenetic analyses grouped all samples into the main clade corresponding to L. echeneis from several localities. This study provides insight into the genetic variation between L. echeneis populations, and did not show a clear genetic structure between populations of L. echeneis throughout Tunisian, Italian, and Spanish localities, which can be attributed to the considerable gene flow between the populations favoured by the potential for host dispersion within the Mediterranean Sea. Finally, haplotypes shared between wild and cage-reared hosts provided evidence for the potential for cross-infection between wild and farmed hosts in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

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The Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) is an endemic virus in dromedaries. Annually, Saudi Arabia imports thousands of camels from the Horn of Africa, yet the epidemiology of MERS-CoV in these animals is largely unknown. Here, MERS-CoV prevalence was compared in imported African camels and their local counterparts. A total of 1399 paired sera and nasal swabs were collected from camels between 2016 and 2018. Imported animals from Sudan (n = 829) and Djibouti (n = 328) were sampled on incoming ships at Jeddah Islamic seaport before unloading, and local camels were sampled from Jeddah (n = 242). Samples were screened for neutralizing antibodies (nAbs) and MERS-CoV viral RNA. The overall seroprevalence was 92.7% and RNA detection rate was 17.2%. Imported camels had higher seroprevalence compared to resident herds (93.8% vs 87.6%, p <0.01) in contrast to RNA detection (13.3% vs 35.5%, p <0.0001). Seroprevalence significantly increased with age (p<0.0001) and viral RNA detection rate was ~2-folds higher in camels <2-year-old compared to older animals. RNA detection was higher in males verses females (24.3% vs 12.6%, p<0.0001) but seroprevalence was similar. Concurrent positivity for viral RNA and nAbs was found in >87% of the RNA positive animals, increased with age and was sex-dependent. Importantly, reduced viral RNA load was positively correlated with nAb titers. Our data confirm the widespread of MERS-CoV in imported and domestic camels in Saudi Arabia and highlight the need for continuous active surveillance and better prevention measures. Further studies are also warranted to understand camels correlates of protection for proper vaccine development. [ABSTRACT FROM AUTHOR]

Heterakis gallinarum is one of the most recurrently diagnosed nematodes within the gastrointestinal tract of galliform birds. In the present study, we investigated the genetic diversity of 96 H. gallinarum collected from free-range chickens from different localities in Tunisia. We assessed phylogeny and genetic variability using the internal transcribed spacers (ITS) of the nuclear ribosomal DNA and the mitochondrial cytochrome c oxidase subunit I gene. Haplotype and nucleotide diversities indicate that H. gallinarum is a species with extremely low genetic diversity. Based on the networks and phylogenetic trees, there was strong support for the absence of significant geographical structuring among the H. gallinarum populations in different localities in Tunisia. Mismatch distributions and neutrality tests of both genetic markers suggest that at least one expansion event occurred in the population demographic history of H. gallinarum. Our data showed a lack of population structure using the pairwise fixation index (FST) and an extensive gene flow. It indicated that the most likely major contributor to the low genetic diversity and gene flow is the movement of the parasitized birds; in other words, the frequency of the poultry trade considerably affects patterns of worm gene flow. [ABSTRACT FROM AUTHOR]

A high percentage of camel handlers in Saudi Arabia are seropositive for Middle East respiratory syndrome coronavirus. We found that 12/100 camel handlers and their family members in Pakistan, a country with extensive camel MERS-CoV infection, were seropositive, indicating that MERS-CoV infection of these populations extends beyond the Arabian Peninsula. [ABSTRACT FROM AUTHOR]

The article compares the sequence of a mitochondrial gene, cytochrome b, in North African green frog Pelophylax saharicus specimens collected from several Tunisian localities to characterize their genetic variation and to pinpoint geographical patterns in their molecular variation. Results show that P. saharicus demonstrates little genetic differentiation. The intraspecific pairwise divergence was slow. Analyses of molecular variance (AMOVA) suggest that there is no proof of genetic structuring associated with the three studied groups, namely, north, center, and south Tunisia.

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. Samples identified morphologically as Fasciola sp. in Equus caballus host species from the city of Tunis (north of Tunisia) were genetically characterized, for the first time, by sequences of the 1st (ITS-1), the 5.8S and 2nd (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the Tunisian samples with sequences of Fasciola spp. from GenBank showed that the specimens examined had sequences identical to those of F. hepatica sequences selected as reference. The nucleotide sequencing of ITS rDNA showed no nucleotide variation in the ITS-1, 5.8S, or ITS-2 rDNA sequences among all F. hepatica samples parasitizing horses from Tunis, versus 2 ITS-2 haplotypes in standard F. hepatica, showing a substitution C/T in position 859, reported previously from Tunisia, Algeria, and Spain. The present study is the first demonstration of the existence of the most frequent haplotype (FhITS-H1) of F. hepatica species in horses from Tunis (north of Tunisia) by the genetic approach using ITS rDNA as genetic marker, providing a foundation for further studies on Fasciola sp. in North African countries. [ABSTRACT FROM AUTHOR]

Morphometric variation of Pelophylax saharicus was analysed using univariate and multivariate statistics, with both traditional and geometric morphometrics, based on 148 specimens from four different geographical localities in Tunisia and Algeria. The results show the existence of three morphotypes in Tunisia and one in Algeria, and indicate a significant degree of variation in morphometric characters between regions. Specimens from the southernmost region have the smallest body size and the greatest morphometric divergence from other populations. This pattern of morphometric variation probably results from phenotypic plasticity in response to local environmental factors. The results of our chromosomal study (C-, Ag-NOR-, endonuclease digestion, DAPI, CMA3 and Q-banding) reveal this species to exhibit the plesiomorphic Pelophylax karyotype of 2n = 26 biarmed chromosomes and NORs on the eleventh pair. Similarities and differences of the North African green frog are discussed in relation to the different forms of data collected (chromosomal, morphometric, ecological). [ABSTRACT FROM AUTHOR]

The intraspecific variation of mitochondrial cytochrome b sequence was analysed for two widely distributed Tunisian anuran species, Discoglossus pictus and Pelophylax saharicus. We observed low genetic variation within both species (D. p. auritus 0.6% uncorrected genetic distances, P. saharicus 0.2%) and the absence of genetic structure within both species in the studied region. There is no correspondence between previously described morphotypes of P saharicus in Tunisia and our genetic data. Our results show a lack of phylogeographic structure in both species despite their fragmented distribution across Tunisia. [ABSTRACT FROM AUTHOR]

Rana saharica is the most widely distributed anuran in Tunisia. We examined morphological variation in 124 specimens as a function of their geographical origin, using univariate and multivariate statistics with traditional morphometrics. Our results supported the existence of three morphotypes of this species, correctly classified 84.7% of specimens, and indicated significant degrees of variation in morphometric characteristics between regions. No significant differences were found between sexes among populations. We observed an increase in body size and a decrease in body mass as a function of latitude. Specimens from the southernmost region had the smallest body size and the greatest morphometric divergence. The pattern of morphometric variation probably results from phenotypic plasticity correlated with local environmental factors. [ABSTRACT FROM AUTHOR]

We present the results of a chromosomal study (C-, Ag-NOR-, endonuclease digestion, DAPI and CMA3 banding) carried out on four Tunisian species of amphibians: Burg mauritanicus, B. viridis, Rana saharica and Discoglossus pictus auritus. For comparative purposes, our cytogenetic analysis was also extended to Moroccan specimens of B. mauritanicus and D. pictus scovazzi. Tunisian specimens of B. viridis display chromosome and chromatin characters very similar to those found in other specimens, both North African and Euro-Asian. By contrast, chromosomes of Tunisian specimens of B. mauritanicus differed from the Moroccan specimens in presenting a different Q-banding phenotype. Tunisian specimens of R. saharica displayed the plesiomorphic Pelophylax karyotype of 2n = 26 biarmed chromosomes and NORs on the eleventh pair. The Tunisian specimens of D. pictus auritus had the typical D. pictus 2n = 28 karyotype with the 13th pair of telocentric elements, in contrast to the Spanish auritus specimens that display the chromosomes of this pair shaped as metacentric. Similarities and differences of the four studied Tunisians anuran taxa are discussed with references to published data on their relatives. [ABSTRACT FROM AUTHOR]