Estimation of genetic diversity of the exotic Indian trout populations by using microsatellite markers.

Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) are popular salmonid species that are reared for sport and recreational activities worldwide. In India, they were introduced and successfully established in the late 19th and early 20th centuries by the European settlers. However, until now, no studies have analysed the genetic integrity of wild trout populations in India. Therefore, this study aimed to analyse the genetic integrity of the wild rainbow trout populations from south India, one wild rainbow trout population from north India, and one wild brown trout population from north India. Genetic diversity studies revealed low genetic diversity in all the population with genetic bottlenecks in two trout populations from south India and disruption of alleles in the populations from north India. The results showed that the south Indian trout populations are in a comparatively poor condition than the north Indian trout populations, and stocking efforts have recently been carried out to enhance the genetic diversity of south Indian trout populations.

Isolation and identification of high fluoride resistant bacteria from water samples of Dindigul district, Tamil Nadu, South India.

Fluoride (F - ) pollution is one of the major issues in India and worldwide. Water samples were collected, and analyse the physicochemical characteristics. From the results, acceptable limit pH ranges, low and high electrical conductivity (EC) values, high-level of TDS (total dissolved solids) and chloride (Cl-) values, less than desirable and higher than permissible F - concentrations (4.7 and 11 ppm) were found. At first, ninety-three colonies were screened using rapid hicoliform agar plates. After that, sixty-six F - resistant colonies were picked up from 50  mM NaF (Sodium fluoride) containing LB agar plates. Finally, eight isolates were showing a high degree of F - resistance (200--300 mM NaF) and selected for further studies. High F - resistance isolates exhibited ß and γ-haemolytic activities were determined in blood agar plates. F - resistant isolates showed their salt tolerances ranged from 4% to 7% NaCl and resistant to multiple antibiotics. Biochemical and 16S rRNA sequencing results showed that the F - resistant isolates were identified as Enterobacter cloacae strain 3, E. hormaechei strain 14, Enterobacter sp. strain 21, E. hormaechei strain 22, E. coli strain S2-9, Aeromonas caviae strain 31, A. caviae strain 32, A. caviae strain 34. All strains were submitted in the NCBI database with the accession numbers (MW131637, MW131639; MW131650-655). The F - resistant gene 'crcB' gene was successfully amplified from the resistant isolates using gene-specific primers. These results have demonstrated that fluoride resistant bacteria would be useful for bacterial fluoride bioremediation near future.

Isolation of Lactic Acid Bacteria from Intestine of Freshwater Fishes and Elucidation of Probiotic Potential for Aquaculture Application.

Probiotics play significant roles in enhancing systemic immunity, improving intestinal balance and feed value, enhancing enzymatic digestion, and inhibiting pathogenic microorganisms of freshwater fish. Probiotics from an identical organism's gastrointestinal system promote effective colonization and provide greater benefits than other sources. This study aimed to evaluate the usefulness of probiotic bacteria isolated from the intestines of freshwater fishes for a dietary supplement of freshwater aquaculture. A total of 120 isolates were collected from freshwater fishes of Channa striata, Puntius filamentosus, Oreochromis mossambicus, Cirrhinus mrigala, and Rasbora daniconius. Seven of these isolates exhibited antagonistic activity against fish pathogens: Aeromonas hydrophila, Staphylococcus epidermidis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa. Using 16S rRNA gene sequencing analysis, the isolates were identified as Enterococcus sp., Lactococcus lactis, Weissella cibaria, and Limosilactobacillus fermentum. Of these tolerates, L. fermentum URLP18 isolated from C. mrigala exhibited high tolerance to low acidic (pH 2.0) and high bile salt (2%) concentrations, exhibiting a significant hydrophobicity and extracellular enzyme secretions like amylase, protease, and lipase. In vitro evaluations on intestinal mucus indicate that L. fermentum URLP18 have strong adherence capacity, and its survival rate increased after being administered to Artemia nauplii. The results suggest that L. fermentum URLP18 has high probiotic potential and is an effective dietary supplement for freshwater aquaculture.

High fluoride resistance and virulence profile of environmental Pseudomonas isolated from water sources.

In our previous study, all Pseudomonas strains THP6, THP41, and OHP5 were identified as fluoride-resistant bacteria isolated from Dindigul district, Tamilnadu, India. The selected strains exhibiting a high level of fluoride resistance was determined in Luria broth (LB) medium and LB agar plates. In a further effort, fluoride-resistant organisms were tested for hemolytic activity and showed ß-hemolysis on blood agar plates. The virulence factors such as gyrB, toxA, algD and lasB, plcH, rhlC and biofilm response genes (pslA, pelA, ppyR) were detected by PCR analysis. The putative genus-specific and species-specific PCR also confirmed that the selected fluoride-resistant strains were belonging to Pseudomonas aeruginosa species. Fluoride-resistance gene crcB was amplified by gene-specific primers. The crcB gene was cloned in TA vector and transformed into E. coli DH5α. Comparative and blast analysis of THP6, THP41, and OHP5 strains crcB gene sequences were high homology with P. aeruginosa fluoride efflux transporter crcB and P. aeruginosa putative fluoride ion transporter crcB. The recombinants were efficiently growing in the NaF containing LB agar plates. The fluoride tolerance of these strains was also associated with resistance to multiple antibiotics. These results can lead to the use of the fluoride resistance gene of P. aeruginosa for the development of a biosensor for fluoride detection.

Influence of anti-inflammatory irrigant on substance P expression for single-visit root canal treatment of teeth with irreversible pulpitis.

One of the main objectives of root canal treatment is to alleviate the pain associated with irreversibly inflamed pulps. However, some patients may have moderate to severe pain following treatment. The aim of this study was to compare and assess the effect of ketorolac tromethamine on substance P expression in the pulp and periapical tissues when used as a root canal irrigant for single-visit root canal treatment in teeth with irreversible pulpitis. Thirty-six patients were randomly allotted to three irrigant groups - saline (n = 14), 3% sodium hypochlorite (n = 11) and ketorolac tromethamine (n = 11). Pulp blood samples (S1) were collected on gaining access to the pulp, and periapical blood samples (S2) were collected after root canal preparation. Quantification of substance P was done by ELISA test. The ketorolac tromethamine group had greater reduction in substance P expression (S2). Post-operative pain levels were not significantly influenced by the different root canal irrigants.

Influence of different irrigants on substance P and IL-8 expression for single visit root canal treatment in acute irreversible pulpitis.

The aim of this study was to assess the influence of ketorolac tromethamine and dexamethasone on substance P and IL-8 expression when used as a root canal irrigant for single visit root canal treatment for acute irreversible pulpitis. A total of 42 patients with pain due to acute irreversible pulpitis in carious premolar and molar teeth were included in this study. The four irrigation groups were as follows: saline (n = 11), 3% sodium hypochlorite (n = 11), ketorolac tromethamine (n = 10) and dexamethasone (n = 10). Blood samples S1 and S2 were collected upon access opening and after canal preparation, respectively. Quantification of substance P and IL-8 were done using ELISA test. Post-operative pain was assessed by questioning the patients. The difference between S1 and S2 sample values for the four different irrigant groups was not significant. The sodium hypochlorite group had a higher mean expression of substance P and IL-8 values. Dexamethasone irrigation was more effective in controlling post-operative pain.

A study on the impact of water quality on the murrel fish Channa striata and Channa punctata from three major Southern Tamilnadu rivers, India.

Rivers are one of the natural fresh water resources that satisfy the domestic, agricultural and industrial needs of people. The Cauvery, Vaigai and Thamirabarani are the three major rivers flowing through the Southern Tamil Nadu region of India. In this study, the Water Quality Index (WQI) and heavy metal concentrations of river water during the pre- and post-monsoon periods in 2015 were recorded and the impact of heavy metal accumulation in two important murrel fish species, Channa striata and Channa punctata, was analysed using micronuclei and histology assays. The results revealed that the WQI was greater than 50 in most sites, indicating poor water quality for the sustainability of living organisms. The Heavy metal Pollution Index (HPI) was critical with values >100 in a few sites along the Cauvery and the Vaigai. The bioaccumulation of heavy metals was higher in the C. punctata than in the C. striata in most instances. Cd, Cu and Pb showed higher bioaccumulation in the pre-monsoon samples whereas As, Cr and Zn exhibited higher bioaccumulation during the post monsoon period. The Ni bioconcentration was consistent in both of the periods. The accumulation of heavy metals in the fish organs was as follows: gills > liver > kidney > muscle. The muscles exhibited Hazard Quotient (HQ) values 0.05-3.3 × 10-6 times lower than the Reference Dose (RfD) level, indicating no significant health risk from the intake of these metals through the consumption of their muscle tissues. The MN% was 0.19-0.22% in the C. striata, 0.15-0.25% in the C. punctata from heavily polluted sites and less polluted sites showed 0.05% and 0.07% MN in the C. striata and C. punctata, respectively. The MN% in the pre-monsoon samples was higher than that of the post-monsoon samples and the C. punctata had a higher MN% than the C. striata. The gills of the fish with high bioaccumulation showed severe lamellar fusion, hyperplasia, hypertrophy and epithelial lifting, their liver hepatocytes showed necrosis of the parenchymal cells and vacuolation, their Kidney tubules were dilated and vacuolated glomeruli with no Bowman's space were observed. Their muscles had normal myotomes with equally spaced muscle bundles. The C. punctata showed more severe histopathological changes than the C. striata. Thus, the present study defines a warning alarm for the proper remediation steps to be taken to safeguard the natural water resources as well as the aquatic ecosystem.