Redescription and neotypification of Alexandrium minutum Halim-the type species of Alexandrium-from its type locality in Alexandria, Egypt, with insights into ribotype biogeography and toxicity.

A phylogenetic study of two parasites found on the common host species Gracilaria salicornia from Japan and Malaysia based on nuclear, plastid, and mitochondrial molecular markers was conducted. The Japanese and Malaysian parasites were placed in the same cluster in the nuclear phylogenies inferred from the LSU rRNA gene and ITS region, supporting the monophyly of these parasites despite the slight anatomical variations observed. In addition to the molecular analyses, shared morphological and reproductive features including the lack of rhizoids, similar coloration to hosts, and the presence of deep spermatangial conceptacles supported the inclusion of both the Japanese and Malaysian parasites in Congracilaria babae. Phylogenetic analyses based on ITS sequences indicated that C. babae most likely evolved directly from its current host species, G. salicornia. C. babae was shown to be a member of Gracilaria sensu stricto along with its host. C. babae growing on G. salicornia is characterized by having plastid rbcL and mitochondrial cox1 gene sequences identical to those of its host, whereas the nuclear LSU rRNA gene and ITS region sequences are different from those of its host.

The production of mucilage aggregates is commonly associated with diatoms, but the harmful events known as 'mare sporco' or dirty seas have been attributed to the dinoflagellate Gonyaulax fragilis or G. hyalina. The synonymy of these taxa has been debated for decades. We report observations of G. fragilis from the Mediterranean Sea, and Atlantic and Indian Oceans, along with its SSU- and LSU rRNA gene and ITS region sequences from cells of the open Indian Ocean. The rDNA/ITS sequences are distantly related to those identified as G. fragilis from the Mediterranean Sea and New Zealand involved in dirty sea events. Unequivocally, G. fragilis is not the culprit of the mucilage events. Gonyaulax fragilis clusters with full support alongside with Schuettiella mitra, forming a sister group to the benthic genus Carinadinium, as an earlier branching lineage with the Protoceratiaceae (Ceratocorys, Pentaplacodinium, Protoceratium). A single anterior intercalary plate (1a) characterizes these genera, while the Gonyaulacaceae possess 2a. The genus Steiniella, first described for G. fragilis and S. mitra, has historically been synonymized with Gonyaulax. We reinstate Steiniella for these two species, and S. inflata, placing Schuettiella as a junior synonym. The species responsible of the mucilage events is attributed to G. hyalina.

Detection of 16S rRNA gene for rapid identification of bacterial pathogens causing peritonitis in patients on continuous ambulatory peritoneal dialysis

Molecular epidemiology of Theileria annulata and identification of 18S rRNA gene and ITS regions sequences variants in apparently healthy buffaloes and cattle in Pakistan

A 68-year-old woman was submitted to our hospital because of erythematous and scaly skin lesions. To exclude tinea samples of stratum corneum were collected and used for mycological investigations. In this material, no fungal elements were detected microscopically, but inoculation on Sabouraud agar with cycloheximide yielded a presumptive dermatophyte fungus. Subsequent detailed investigations with conventional morphological and physiological methods and a phylogenetic analysis of the combined LSU rRNA gene (D1/D2 domains) and ITS region sequences suggested that the fungus represents a hitherto undescribed species of the genus Arthroderma. Here, we describe this species as Arthroderma chiloniense sp. nov., EMBL accession no. LT992885. This new species can be distinguished from phylogenetically related Arthroderma species using ribosomal ITS and LSU genes, and 60S L10 protein sequences; specific macroscopic, microscopic and physiological features are lacking. Our attempts to re-isolate this fungus from the patient's skin failed although her skin lesions persisted. Most likely A.chiloniense is a geophilic species that incidentally contaminated or transiently colonised the patient's skin. To avoid diagnostic misinterpretations, it is necessary to distinguish A.chiloniense from truly pathogenic dermatophytes like Trichophyton (T.) rubrum and T.interdigitale which can easily be confused with A.chiloniense based on similar mycelium morphology.

Two new species of Dulcicalothrix, D. adhikaryi sp. nov. and D. iyengarii sp. nov., were discovered in India and are characterized and described in accordance with the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN). As a result of phylogenetic analysis, Calothrix elsteri is reassigned to Brunnivagina gen. nov. During comparison with all Dulcicalothrix for which sequence data were available, we observed that the genus has six ribosomal operons in three orthologous types. Each of the three orthologs could be identified based upon indels occurring in the D1-D1' helix sequence in the ITS rRNA region between the 16S and 23S rRNA genes, and in these three types, there were operons containing ITS rRNA regions with and without tRNA genes. Examination of complete genomes in Dulcicalothrix revealed that, at least in the three strains for which complete genomes are available, there are five ribosomal operons, two with tRNA genes and three with no tRNA genes in the ITS rRNA region. Internal transcribed spacer rRNA regions have been consistently used to differentiate species, both on the basis of secondary structure and percent dissimilarity. Our findings call into question the use of ITS rRNA regions to differentiate species in the absence of efforts to obtain multiple operons of the ITS rRNA region through cloning or targeted PCR amplicons. The ITS rRNA region data for Dulcicalothrix is woefully incomplete, but we provide herein a means for dealing with incomplete data using the polyphasic approach to analyze diverse molecular character sets. Caution is urged in using ITS rRNA data, but a way forward through the complexity is also proposed.

We used a relaxed-clock program (Multidivtime) to estimate the phylogenetic relatedness and substitution rates by comparative analyses of 16S rRNA gene and ITS region sequences. Four rhizobial strains isolated from three Tunisian wild Sulla legumes were used together with reference strains to obtain the 16S rRNA gene and ITS region alignments. Bayesian inferred trees were congruent, and showed a clear split between Agrobacterium and Rhizobium species. Among the four Tunisian isolates, Hsc01 belonged to Rhizobium species and formed a monophyletic clade with Rhizobium sullae. The strain Hc04 was placed into the Agrobacterium group, but it belonged to Rhizobium species. Two remaining strains (Hc01 and Hcar01) belonged to typically Agrobacterium species. Divergence times between these four strains were earlier the existence of legumes. Using sequence alignments of the 16S rRNA genes and ITS regions, we inferred different rates of nucleotide substitutions across these two molecular markers. The ITS region evolutionary rate was 15-fold higher than the 16S rRNA gene rate, suggesting that the ITS region represented an appropriate molecular marker for inferring phylogenies and divergence times in bacteria.

Candida auris (C. auris), an emerging multidrug-resistant microorganism, with limited therapeutical options, is one of the leading causes of nosocomial infections. The current study includes 19 C. auris strains collected from King Fahd Hospital of the University and King Fahad Specialist Hospital in Dammam, identified by 18S rRNA gene and ITS region sequencing. Drug-resistance-associated mutations in ERG11, TAC1B and FUR1 genes were screened to gain insight into the pattern of drug resistance. Molecular identification was successfully achieved using 18S rRNA gene and ITS region and 5 drug-resistance-associated missense variants identified in the ERG11 (F132Y and K143R) and TAC1B (H608Y, P611S and A640V) genes of C. auris strains, grouped into 3 clades. The prophylactic and therapeutic application of hydrothermally synthesized Ag-silicalite-1 (Si/Ag ratio 25) nanomaterial was tested against the 3 clades of clinical C. auris strains. 4wt%Ag/TiZSM-5 prepared using conventional impregnation technique was used for comparative study, and nano formulations were characterized using different techniques. The antibiofilm activity of nanomaterials was tested by cell kill assay, scanning electron microscopy (SEM) and light microscopy. Across all the clades of C. auris strains, 4 wt%Ag/TiZSM-5 and Ag-silicalite-1 demonstrated a significant (p = 1.1102 × 10−16) inhibitory effect on the biofilm’s survival rate: the lowest inhibition value was (10%) with Ag-silicalite-1 at 24 and 48 h incubation. A profound change in morphogenesis in addition to the reduction in the number of C.auris cells was shown by SEM and light microscopy. The presence of a high surface area and the uniform dispersion of nanosized Ag species displays enhanced anti-Candida activity, and therefore it has great potential against the emerging multidrug-resistant C. auris.

Two Rhizoclonium strains thriving in contrasting spring types (slightly hot spring/ambient, shaded pool spring) and biogeographic areas (El-Farafra Oasis in the Western Desert of Egypt/River-Po Plain in Northern Italy) were studied in depth based on field and cultured material, bright-field and fluorescence microscopy, and phylogenetic molecular analyses (SSU and LSU rRNA gene sequences). This polyphasic approach revealed that the two Rh. strains clearly belonged to the Rhizoclonium clade but differed in some of their key diagnostic features. The Egyptian Rhizoclonium strain, isolated from the spring-fed (Ain El-Balad) agricultural ditch in El-Farafra Oasis, was described with the working name ‘Rhizoclonium sp. 10.6 μm from a desert, slightly-hot spring’ based on its smaller cell diameter, ecological and phylogenetic molecular traits compared to allied morphospecies. Moreover, it was highlighted that the L/D ratio can be more than 3.0 within this group. The Italian Rhizoclonium strain, collected from the Fontanile Valle Re-shaded, pool ambient spring (Emilia-Romagna Region), was virtually identical to other strains identified as Rh. hieroglyphicum from China and Japan, due to its highly supported congruence in morphological characteristics and phylogenetic position. This study provided the first partial LSU and SSU rRNA gene sequences for European Rh. hieroglyphicum based on available literature. Phenotypic plasticity of rhizoid formation was also observed in both Rhizoclonium strains studied using culturing approaching techniques. Our investigation also confirms that a lot of work with a variety of approaches is still needed to assess the ecological preferences, morphological plasticity, and phylogenetics of freshwater Rhizoclonium taxa worldwide.

The identity of a marine planktonic species that forms palmelloid colonies has remained enigmatic since the first observations during the Plankton Expedition in 1889. Initially identified as spores or chlorophyte cells, Gloeodinium marinum was described as an immotile coccoid dinoflagellate with Gymnodinium-like swarmers. In this study, we have reported observations of G. marinum from the Mediterranean Sea, including the type locality, the Southwest Indian Ocean, and the tropical Atlantic Ocean. The sequences of the SSU and LSU rRNA genes and the ITS rRNA region (ITS1-5.8S gene-ITS2) revealed that G. marinum is distantly related to congeneric species, the type species G. montanum, and G. viscum, while it is closely related to Prorocentrum canariense and P. compressum auct. mult., two planktonic species known to produce mucilage envelopes. These phylogenetic and morphological characteristics positioned Gloeodinium marinum as a member of Prorocentrum sensu stricto, and we have proposed to reclassify it with the new name Prorocentrum palmelloides nom. nov. This species differs from its closest relatives in its smaller size (~25 μm), roundly oval shape, and multiple mucilage envelopes. The recently divided cells showed hemispherical shape, and the flagella only appeared in naked swarmers after theca ecdysis. The morphological adaptation to a life within mucilage envelopes has contributed to its cryptic identity for more than 130 years.

Some dinoflagellate species within the genera Alexandrium, Gymnodinium and Pyrodinium are well-known producers of paralytic shellfish toxins (PST), which led to many poisoning incidents around the world. In the northern Yellow Sea, an important mariculture zone for scallop Patinopecten yessoensis, PST have been frequently detected from scallops. However, there is little knowledge concerning PST-producing microalgae in this region so far. In cruises carried out in 2011 and 2012, scallop and phytoplankton samples were collected from the northern Yellow Sea. PST were detected from scallops by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Toxin content and profile were remarkably different among the four tissues, i.e. viscera, adductor muscle, mantle and gonad, suggesting apparent toxin transfer and transformation in scallops. Viscera always had the highest content of PST dominated by low-potency N-sulfocarbamoyl toxins C1 and C2, which closely resembled the toxin profiles of net-concentrated phytoplankton samples in spring. Based on the morphological features, cells of Alexandrium spp. in net-concentrated phytoplankton samples were picked out and a partial sequence of the large subunit ribosomal RNA gene (LSU rDNA) was amplified using a single-cell polymerase chain reaction (PCR) method. Cells of both toxic A. tamarense species complex and non-toxic A. affine were identified from the phytoplankton samples based on the partial LSU rDNA sequence information. According to these findings, it is implied that A. tamarense species complex is the major toxic species related to PST contamination in scallops of the northern Yellow Sea. The presence of both toxic and non-toxic Alexandrium spp. in this region requires for a species-specific method to monitor the distribution and dynamics of A. tamarense species complex.

Non-heterocytous filamentous cyanobacteria are increasingly recognized as abundant and diverse microbial components of tropical and subtropical mangrove ecosystems. However, taxonomic studies of cyanobacteria in Thailand have largely focused on freshwater and artificial hypersaline environments, leaving mangrove-associated cyanobacterial communities understudied. In this polyphasic study, cyanobacterial mats were isolated and characterized from mangrove environments along the Andaman coastlines of Ranong and Phang-Nga provinces. Comparative analysis of morphology, salinity tolerance, habitat preference, 16S rRNA gene phylogeny and genetic similarity, 16S-23S ITS rRNA region phylogeny, secondary structure and percent dissimilarity supported the descriptions of Desertifilum andamanense sp. nov., Tigrinifilum phangngense sp. nov., Roseofilum epilithicum sp. nov., and Persinema corticola sp. nov., while justifying the continued recognition of D. fontinale and D. tharense. Two divergent ITS rRNA region operons in T. floridanum with different leader motifs, D1-D1', and D2 regions proved to be useful diagnostic markers of the ITS rRNA region for species and strain differentiation within Tigrinifilum. Our results underscore the importance of a polyphasic approach that also considers intragenomic ITS rRNA region variation to ensure robust and accurate taxonomic assessments of cyanobacteria. This study also provides records of the genera Desertifilum, Roseofilum, Tigrinifilum, and Persinema in Thailand, contributing to a more comprehensive understanding of the nation's diversity and biogeography of cyanobacteria.

Gonyaulax montresoriae sp. nov. (Dinophyceae) from the Adriatic Sea produces predominantly yessotoxin

This investigation reports the polyphasic characterization of six cyanobacterial strains that were isolated from Basantgarh village of district Udhampur in the union territory of Jammu and Kashmir, India. Morphological examination of the isolated strains indicated that the strains are members of the genus Nostoc or its morphotypes. Phylogenetic analyses using the 16S rRNA gene showed that five strains clustered in the Nostoc sensu stricto clade, whereas one strain clustered in the Desmonostoc clade. Further, comparative studies with their phylogenetically related taxa, based on morphology, folded secondary structures, phylogeny of the ITS rRNA region, and the percent genetic homology of 16S rRNA gene and ITS rRNA region clearly established the strains as novel taxa belonging to the genera Nostoc and Desmonostoc. Also, two strains 21A-PS and 2JNA-PS emerged as conspecific to each other, representing the same species of Nostoc. Hence, in accordance with the International code of Nomenclature for algae, fungi, and plants, this study describes Nostoc jammuense, Nostoc globosum, Nostoc breve, and Nostoc coriaceum, as novel species of the genus Nostoc, while Desmonostoc raii is described as a novel species of the genus Desmonostoc. This study adds novel species of Nostoc from Indian habitats and reinforces the need to explore the Nostoc sensu stricto clade for more novel taxa.

Fukuyoa species are potential producers of polyether neurotoxins that are toxic to aquatic biota and humans. A strain of Fukuyoa (CSIRCSMCRI 004) was isolated from India’s Bay of Bengal coast. The clonal culture was identified using light and scanning electron microscopy and molecular phylogenetic analysis of the LSU rRNA gene and ITS (ITS1-5.8S gene-ITS2) sequences. Its toxicity was assessed using a 48 h Artemia bioassay. The morphological features observed included globular shape, descending cingular displacement, broad pentagonal 1′ plate, and large second apical plate (2′). The identity of the strain was confirmed to be F. paulensis based on the LSU rRNA gene and ITS sequences phylogenies. Strain CSIRCSMCRI 004 shared an identical sequence with the type strain of F. paulensis and other strains reported from different locations, based on the LSU rRNA gene and ITS sequences phylogenies. Exposure of brine shrimp larvae to its cellular lysate resulted in lethality (48 h LC50 = 0.256 mg ml−1) and behavioral abnormalities. The current study provides the first evidence of F. paulensis in the Bay of Bengal. It also reveals that CSIRCSMCRI 004 is toxic to susceptible biota like the brine shrimp and could produce ciguatera-associated toxins. The findings of this study highlight the need for sampling and screening of ciguatera-related species in the Bay of Bengal region to understand the associated public and environmental health risks.