Muqadas Altaf

Vibrio parahaemolyticus is an important foodborne and aquaculture-associated pathogen, and its increasing antimicrobial resistance threatens shrimp production, seafood safety, and public health. Although bacteriophages have emerged as a potential solution to the growing challenge of antimicrobial resistance, whether antibiotic resistance is associated with phage tolerance remains unclear. This study characterized antimicrobial resistance profiles and resistance genes in Vibrio parahaemolyticus isolates from Zhanjiang shrimp aquaculture farms and evaluated their association with bacteriophage susceptibility. A total of 132 isolates were tested against 18 antibiotics, while molecular and phage-related analyses were performed on 132 isolates. High resistance was observed against kanamycin (95.5%), sulfamethoxazole (94.7%), cefazolin (78.8%), imipenem (78.8%), amoxicillin (70.5%), and ampicillin (65.2%). Multidrug resistance was detected in 131/132 isolates (99.24%), indicating an extensive resistance burden. PCR analysis showed high detection rates of aphA (100.00%), sul1 (99.24%), blaTEM (98.48%), blaOXA (73.48%), blaCTX-M (53.03%), qnrA (45.45%), tetA (37.88%), and tetB (21.21%). Phage response analysis showed that 70.45% and 68.18% of isolates were phage-resistant at 4 h and 5 h, respectively. Genes potentially associated with phage–host interactions were also detected, with luxS showing the highest frequency (85.61%). Association analysis revealed significant links between tetA, tetB, blaOXA, and bacteriophage responses. These findings suggest that antimicrobial resistance and reduced phage susceptibility can co-occur among V. parahaemolyticus isolates recovered from shrimp farms in Zhanjiang, highlighting the need for regional resistance surveillance and careful phage selection.

The widespread exposure of multidrug-resistant bacterial strains due to excessive use of antibiotics has accelerated the bacteriophage applications as highly specific antibacterial agents competent to target resistant pathogenic Vibrio through receptor-mediated adsorption and lytic infection. Vibrio pathogens are responsible for substantial economic losses, environmental instability, and foodborne infections in humans through contaminated seafood and water. However, the molecular determinants remain incompletely understood, commanding the Vibrio-phage host specificity, host range, and resistance evolution. This review highlights the comprehensive overview of structural, and functional framework of Vibrio surface receptors responsible for phage recognition, including outer membrane vesicles (OMVs), porins, lipopolysaccharides (LPS), capsular polysaccharides (CPS), flagella, and pili along with specialized bacteriophage tail spike proteins known as receptor-binding proteins (RBPs). We also explored the mechanisms against phage-mediated lysis, including receptor modification, intracellular defense systems, physiological remodeling, and structural adaptations that regulate burst size, lysis timing, and resistance evolution with emphasis on significant progress in phage biology and therapeutic development. It is critical to grasp the molecular-level interaction mechanisms due to limited marine phage ecological data, lack of standardized resistance databases, and regulatory constraints. Future perspectives emphasize the engineered phages, multi-omics integration, and artificial intelligence-driven phage design for the sustainable management of Vibriosis and improved aquaculture biosecurity.

The increased global prevalence of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), is a chronic relapsing inflammatory condition of the gastrointestinal tract that creates a substantial socioeconomic burden. Existing pharmacotherapeutic treatments primarily target inflammatory signaling cascades and have disadvantages because of the side effects of drugs, reduced long-term efficacy, and high cost, necessitating the development of safe and sustainable adjunctive therapies. This review synthesizes mechanistic advances regarding dietary polysaccharides as bioactive agents that may have the capacity to induce remodeling of inflamed gastrointestinal tract in colitis and could be an adjunctive strategy as functional food ingredients due to their various biological activities in the management of colitis. Polysaccharides alleviate colitis through several interconnected pathways. First, they correct the gut dysbiosis by enriching beneficial taxa such as Lactobacillus, Bifidobacterium, and Akkermansia muciniphila. Second, fermentation of polysaccharides produces short-chain fatty acids (SCFAs), particularly butyrate, which serve as the primary energy source for colonocytes. Third, they restore intestinal barrier integrity by upregulating tight junction proteins such as ZO-1, occludin, and claudin, also performing pro-inflammatory cascade inhibition and elimination of oxidative stress via Nrf2/HO-1 activation The relationship between structural properties of polysaccharides based on molecular weight, monosaccharide composition, and biological functions of chemically modified dietary polysaccharides in colitis is studied. Dietary polysaccharides are explored here not as replacements for pharmacotherapy but as potential adjunctive or functional food-based interventions that may complement existing treatments as safe, multitargeted, and cost-effective interventions in prevention or long-term management of colitis and IBD. This review presents dietary polysaccharides function not as passive dietary fibers but as bioactive, multi-targeted, structurally dependent agents capable of restoring intestinal homeostasis, suggesting them as potentially safe, adjunctive interventions.