Ramananda College

This study characterizes two bacterial isolates Enterobacter mori ASP8 and Bacillus stercoris ASP10, derived from the stinging catfish (Heteropneustes fossilis) and evaluates in vitro probiotic efficacy for enhancing sustainability in freshwater aquaculture. Rigorous biosafety assessments confirmed that both strains were non-hemolytic, were non-blood coagulant, lack DNase/RNase activity, and were non-biogenic amine producers. Both isolates exhibited high gastrointestinal resilience and survival under stimulated stomach duodenum passage (SSDP) with a value of 81.98% for E. mori ASP8 and 84.89% for B. stercoris ASP10. The isolates also showed strong tolerance to bile, phenol, and lysozyme. Functional assays revealed robust hydrocarbon adherence up to 84.83% and significant co-aggregation with fish pathogens varied between 50.5 and 72.69%. Notably, it was found that B. stercoris ASP10 exhibited biofilm-forming capabilities on Congo red agar. E. mori ASP8 and B. stercoris ASP10 showed strong antibacterial activity against seven pathogens by producing bacteriocin, siderophore production. In addition, the isolates exhibited cholesterol lowering, antioxidant potentially and multi-enzymatic (amylase, protease, cellulase, and lipase) activities. Overall findings concluded both strains are effective, but B. stercoris ASP10 emerged as superior probiotic candidate for future aquaculture application.

The Mycobacterium avium complex (MAC) houses several pathogens that cause diseases in humans, ruminants, and birds. They are widely distributed in soils and water worldwide. In immunocompromised humans, MAC is responsible for nodular bronchiectasis and fibrocavitary lung diseases. The treatment of lung diseases induced by MAC remains difficult owing to antibiotic intolerance and disease recurrence. In this study, we compared the genome sequences of 90 complete MAC genomes and explored the factors shaping codon usage bias in the bacteria within MAC. Additionally, we studied the relationship between codon bias and pathogenic adaptation. The genome sizes ranged from 4.7 to 6.5 Mb. Variation in the mobile genetic elements and the number of CRISPR candidates was observed amongst the bacteria within MAC. Synonymous codon usage analysis divulged variations among subspecies, high codon usage bias, substantial heterogeneity in codon usage patterns, and moderate use of optimal codons. High GC3 content and elevated levels of CAI (a metric for gene expression levels) in all probability assisted the bacteria within MAC in adjusting to different host environments. Translational selection pressure prevailed over compositional bias and mutational selection in these organisms. Our analysis revealed differences in the tRNA content amongst the bacteria in MAC. The translational selective pressure enabled the adaptation of these pathogenic bacteria to competitive pressure in diverse environments and niches by maintaining a lesser number of tRNAs and lower tAI values.

Mycobacterium abscessus infections exacerbate lung conditions in individuals with cystic fibrosis, bronchiectasis, or low immunity. The existing treatment options are unreliable, owing to the high antibiotic resistance of the bacterium. Isocitrate lyase is an important enzyme in mycobacteria linked with the glyoxylate cycle, facilitating persistent infections within the host. Isocitrate lyase is considered a promising drug target because its inhibition diminishes mycobacterial growth and persistence. The dearth of effective treatment highlighted the need for in silico screening for antimicrobials with improved efficacy and safety. Through literature review, ADMET profiling, and molecular docking, eight natural products were shortlisted based on drug-like properties and Lipinski’s rule. AlphaFold generated high-quality structures of isocitrate lyase. Subsequently, the docking of the eight compounds with the 3D structures of isocitrate lyase was carried out. Binding energies ranged from –5.2 to –8.8 kcal/mol, with bonianic acid A and demethoxycurcumin showing the strongest affinities (–8.8 and –8 kcal/mol) against M. abscessus subsp. bolletii BD and M. abscessus subsp. abscessus ATCC 19977. Bisdemethoxycurcumin exhibited a –7.9 kcal/mol binding energy with M. abscessus subsp. abscessus ATCC 19977. Normal mode analysis confirmed their robustness. These findings support further exploration of bonianic acid A, demethoxycurcumin, and bisdemethoxycurcumin targeting isocitrate lyase, paving the way for future in vitro and in vivo studies.

Mycobacterium abscessus is a rapidly growing non-tuberculous mycobacterium that infects the human respiratory tract. It is associated with complicated lung diseases in vulnerable individuals, especially those with weakened immune systems. The intrinsic resistance of the bacterium to common antibiotics, along with its ability to persist within the host, makes it difficult to treat. Currently, there is no effective vaccine, and the increasing incidence of M. abscessus infections has been a public health concern. Hence, there is a demand for devising effective strategies to control the pathogen. This study employed an immunoinformatic strategy to design a suitable multi-epitope construct. To this end, the potential linear B-cell, cytotoxic T lymphocyte, and helper T lymphocyte epitopes were predicted and coupled with cholera toxin adjuvant and linkers. Physicochemical and structural analyses indicated that the multi-epitope construct had satisfactory stability, solubility, and antigenic properties. Moreover, it was non-allergenic and non-toxic. Interferon-gamma–inducing and conformational B-cell epitopes were predicted from the construct. Molecular docking analysis revealed a strong binding affinity of the construct with human Toll-like receptors 2 and 4, signifying its potential to elicit immune responses. Molecular simulation using normal mode analysis confirmed the stability and flexibility of the docked complexes. Additionally, codon optimization and in silico cloning illustrated effective expression in a microbial host. Immune simulation analysis confirmed the immunogenic profile of the construct. Our findings support the ability of the construct to regulate immune responses against M. abscessus infections. However, in vitro and in vivo studies are required to ensure its efficacy.

Aphelenchoides confusus Thorne & Malek, 1968, was isolated and described during a survey on the east coast mangroves from Odisha, India. The females characterized by a short body (596.6 ± 20.1 µm), a short stylet (9.7 ± 0.3 µm) with small basal knobs, a vulva at 64.7–69.6% of body length with an unmodified lip, a well-developed post-uterine sac, and a conoid, rounded tail without a mucro. Morphometrics closely agree with the original description and other populations. Principal component analysis explained 91.67% of total variation and clustered the present population with previously reported populations, indicating morphometric congruence. This record extends the known host association of the species to mangrove plants.