During the present study on myxozoan parasites infecting gills of cyprinid carps inhabiting Ranjit Sagar Wetland, a new parasite, Myxobolus okamurae sp. nov. infecting gills of Labeo bata has been described based on morphology, histopathology and partial 18S rDNA sequencing. For M. okamurae sp. nov., hundred fish specimens were examined, out of which thirty-three had large cylindrical to round, white plasmodia in gills, each plasmodium measured 0.9-3.0 mm in diameter. The myxospore body was pyriform in shape, measuring 12.25 × 4.93 μm, with a small intercapsular process at the anterior end. The polar capsules were equal and pyriform in shape, measuring 6.06 × 1.45 μm having polar filaments forming coils up to 13-14 in number. The intensity of infection was recorded to be heavy as indicated by gill plasmodium index (GPI = 3). Sequence analysis showed that M. okamurae sp. nov. is 91% similar with M. catlae infecting gills of Catla catla from India followed by M. intimus infecting gills of Leuciscus idus from Hungary. The phylogenetic tree based on the final edited alignment (403 bp) with Maximum-Likelihood showed the high bootstrap value of 75 and formed two major clades involving M. okamurae sp. nov. with M. pendula M. catlae and M. dispar in one clade with a low bootstrap value of 23 and the rest of the species in a separate clade. The plasmodium was located in the gill lamella and typed as "intralamellar vascular type, LV3".

Urinary tract infections (UTIs) are a serious health concern worldwide. Treatment of UTIs is becoming a challenge as uropathogenic Escherichia coli (UPEC), which is the most common etiological agent, has developed resistance to the main classes of antibiotics. Small molecules that interfere with metabolic processes rather than growth are attractive alternatives to conventional antibiotics. Repurposing of already known drugs for treating infectious diseases could be an attractive avenue for finding novel therapeutics against infections caused by UPEC. Virtual screenings enable the rapid and economical identification of target ligands from large libraries of compounds, reducing the cost and time of traditional drug discovery. Moreover, the drugs that have been approved by the FDA have low cytotoxicity and good pharmacological characteristics. In this work, we targeted the HisC enzyme of the histidine biosynthetic pathway as enzymes of this pathway are absent in humans. We screened the library of FDA-approved drugs against HisC via molecular docking, and four hits (Docetaxel, Suramin, Digitoxin, and Nystatin) showing the highest binding energy were selected. These were further tested for antibacterial activity, which was observed only for Docetaxel (MIC value of 640 μg/ml); therefore, Docetaxel was further tested for its efficacy in vivo in murine catheter UTI model and antibiofilm activity using crystal violet staining and scanning electron microscopy. Docetaxel inhibited biofilm formation and reduced the bacterial load in urine, kidney, and bladder. Docking studies revealed that Docetaxel acts by blocking the binding site of HisC to the native substrate by competitive inhibition. Docetaxel may be a potential new inhibitor for UPEC with antibacterial and antibiofilm capability.

Out of the total 2600 myxozoan species reported so far, Thelohanellus Kudo, 1933 is the second most prevalent genus comprising of about 150 species after Myxobolus Butschli, 1882 infecting both freshwater and marine fishes. In general, these are mostly histozoic (within the tissues) and sometimes coelozoic (in body cavities). The present paper deals with the study of a novel Thelohanelloid T. neocyprini infecting gills of Catla catla and species complex among the member species of Thelohanellus genus from the Indian subcontinent infecting gills, fins and muscles. The species forming species complex are T. rohitae, T. catlae, T. jiroveci, T. seni, T. bifurcata, T. dykovae, T. neocyprini, T. filli, T. muscularis and T. theinensis. The phylogenetic analysis was also done on the basis of 18S rDNA. The homogeneity was found to be between 90 and 99%. The factors responsible for the species complex could be phylogeography, host reluctant, organ and tissue specificity of the these myxozoan parasites. Study of more genetic markers facilitated with morphotaxonomy can be used to sort out the occurrence of species complex among the morphologically different species having similar genetic makeup and vice-versa.

The sequences of 18S and 28S rDNA have been extensively used as molecular markers to resolve phylogenetic relationships among various myxosporeans infecting fishes. Two novel myxosporeans have been identified during the present study namely, Henneguya latiusii sp. nov. infecting gills of Crossocheilus latius and Myxobolus atkinsoni sp. nov. infecting gills of Labeo rohita inhabiting Ranjit Sagar Wetland, Punjab (India). These myxosporeans formed plasmodia in the gill arch and gill lamellae respectively and infection was moderate (gill plasmodium index, GPI: 2). Myxospores of both the species possessed distinct morphological and morphometric characteristics hence validated as new species. Phylogenetically, H. latiusii sp. nov. was closest to H. doneci infecting gill filaments of Carassius auratus gibelio, with 96% and 74% similarity in 18S and 28S rDNA respectively. Similarly, M. atkinsoni sp. nov. showed close homogeneity of 90% with M. turpisrotundus and 83% with M. nielii infecting gills of Carassius auratus. The phylogenetic analyses of species of Myxobolus and Henneguya showed a tendency to cluster according to the order or family of the host, tissue and geographical location. This study is the first report on LSU gene marker (28S rDNA) standardized on myxozoans infecting fresh water fishes from Indian subcontinent.