Development of Aptamer-Functionalized Gold Nanoparticles as Probes in Point-of-Care Diagnostic Device for Rapid Detection of Multidrug-Resistant Bacteria in Bombyx mori L. .

The sericulture industry suffers severe crop losses due to various silkworm diseases, necessitating the development of further technologies for rapid pathogen detection. Here, we report an all-in-one portable biosensor that combines conjugated gold nanoparticles (Au NPs) with an aptamer-based lateral flow assay (LFA) platform for the real-time analysis of Mammaliicoccus sp. and Pseudomonas sp. Our platform enables sample-to-answer naked eye detection within 5 min without any cross-reactivity with other representatives of the silkworm pathogenic bacterial group. This assay was based on the sandwich-type format using a bacteria-specific primary aptamer (Apt1) conjugated with 23 nm ± 1.27 nm Au NPs as a signal probe and another bacteria-specific secondary aptamer (Apt2)-coated nitrocellulose membrane as a capture probe. The hybridization between the signal probe and the capture probe in the presence of bacteria develops a red band in the test line, whose intensity is directly proportional to the bacterial concentration. Under the optimal experimental conditions, the visual limit of detection of the strip for Mammaliicoccus sp. and Pseudomonas sp. was 1.5 × 104 CFU/mL and 1.5 × 103 CFU/mL, respectively. Additionally, the performance of the LFA device was validated by using a colorimetric assay, and the results from the colorimetric assay are consistent with those obtained from the LFA. Our findings indicate that the developed point-of-care diagnostic device has significant potential for providing a cost-effective, scalable alternative for the rapid detection of silkworm pathogens.

Multifunctional silver nanoparticle embedded eri silk cocoon scaffolds against burn wounds-associated infection.

Antimicrobial wound dressings offer enhanced efficacy compared to conventional dressing platforms by limiting bacterial infections, expediting the healing process, and creating a barrier against additional wound contamination. The use of silk derived from silkworm cocoons in wound healing applications is attributed to its exceptional characteristics. Compared to mulberry silk, sericin from non-mulberry cocoons has higher water exchange mobility and moisture retention. Eri, a non-mulberry silkworm, is an unexplored source of silk with an eco-friendly nature of production where the natural life cycle of silkworms is not disrupted, and no moths are sacrificed. This work reports on an eri silk cocoon-based scaffold decorated with silver nanoparticles as a wound dressing material effective against burn-wound-associated multiple-drug-resistant bacteria. The UV-vis spectroscopy showed maximum absorbance at 448 nm due to the surface plasmon resonance of silver nanoparticles. FT-IR spectra exhibited the functional groups in the eri silk proteins accountable for the reduction of Ag+ to Ag0 in the scaffold. SEM-EDX analysis revealed the presence of elemental silver, and XRD analysis confirmed their particle size of 5.66-8.82 nm. The wound dressing platform showed excellent thermal stability and hydrophobicity, fulfilling the criteria of a standard waterproof dressing material, and anticipating the prevention of bacterial biofilm formation in chronic wounds. The scaffold was found to be effective against both Staphylococcus aureus (MTCC 87) and Pseudomonas aeruginosa (MTCC 1688) multiple-drug-resistant pathogens. Electron microscopy revealed the bacterial cell damage, suggesting its bactericidal property. The results further revealed that the scaffold was both hemocompatible and cytocompatible, suggesting its potential application in chronic wounds such as burns. As an outcome, this study presents a straightforward, cost-effective, and sustainable way of developing a multifunctional wound dressing platform, suggesting its significant therapeutic potential in clinical and biomedical sectors and facile commercialization.

Recent advances in the biosensors application for reviving infectious disease management in silkworm model: a new way to combat microbial pathogens.

Silkworms are an essential economic insect but are susceptible to diseases during rearing, leading to yearly losses in cocoon production. While chemical control is currently the primary method to reduce disease incidences, its frequent use can result in loss of susceptibility to pathogens and, ultimately, antibiotic resistance. To effectively prevent or control disease, growers must accurately, sensitively, and quickly detect causal pathogens to determine the best management strategies. Accurate recognition of diseased silkworms can prevent pathogen transmission and reduce cocoon loss. Different pathogen detection methods have been developed to achieve this objective, but they need more precision, specificity, consistency, and promptness and are generally unsuitable for in-situ analysis. Therefore, detecting silkworm diseases under rearing conditions is still an unsolved problem. As a consequence of this, there is an enormous interest in the development of biosensing systems for the early and precise identification of pathogens. There is also significant room for improvement in translating novel biosensor techniques to identify silkworm pathogens. This study explores the types of silkworm diseases, their symptoms, and their causal microorganisms. Moreover, we compare the traditional approaches used in silkworm disease diagnostics along with the latest sensing technologies, with a precise emphasis on lateral flow assay-based biosensors that can detect and manage silkworm pathogens.

Genomic dataset of a multiple-drug resistant Pseudomonas sp. strain RAC1 isolated from a flacherie infected Nistari race of Bombyx mori L.

Species belonging to the genus Pseudomonas is a rod shaped Gram-negative bacteria emerged as an important silkworm pathogen with broad-level multi-drug resistance. The extensive usage of antimicrobials in sericulture farming is gradually leading to the emergence of multi-drug resistance (MDR) strains, posing a significant threat to the well-being of both Bombyx mori L. and serifarmers. Pseudomonas spp. with MDR level may gets transmitted from the infected silkworm to human handlers either via direct contact or through contaminated feces. To understand the emerging concern of antimicrobial resistance (AMR) in Pseudomonas spp. provides insights into their genomic information. Here, we present the draft genome sequence data of Pseudomonas sp. strain RAC1 isolated from a flacherie infected Nistari race of Bombyx mori L. from the silkworm rearing house of Raiganj University, India and sequenced using the Illumina NovaSeq 6000 platform. The estimated genome size of the strain was 4494347 bp with a G + C content of 63.5%. The de novo assembly of the genome generated 38 contigs with an N50 of 200 kb. Our data might help to reveal the genetic diversity, underlying mechanisms of AMR and virulence potential of Pseudomonas spp. This draft-genome shotgun project has been deposited under the NCBI GenBank accession number NZ_JAUTXS000000000.