Indian Journal of Microbiology最新文献

The COVID-19 outbreak began in December 2019 and has affected people worldwide. It was declared a pandemic in 2020 by the World Health Organization. Developing rapid and reliable diagnostic techniques is crucial for identifying COVID-19 early and preventing the disease from becoming severe. In addition to conventional diagnostic techniques such as RT-PCR, computed tomography, serological assays, and sequencing methods, biosensors have become widely accepted for identifying and screening COVID-19 infection with high accuracy and sensitivity. Their low cost, high sensitivity, specificity, and portability make them ideal for diagnostics. The use of nanomaterials improves the performance of biosensors by increasing their sensitivities and limiting detection by several orders of magnitude. This manuscript briefly reviews the COVID-19 outbreak and its pathogenesis. Furthermore, it comprehensively discusses the currently available biosensors for SARS-CoV-2 detection, with a special emphasis on nanomaterials-based biosensors developed to detect this emerging virus and its variants efficiently.

The current study is focused on the screening and isolation of a bioactive pigment producing actinomycete from paddy fields of Kerala, India. Among the five-pigment producing isolates obtained, a red colour pigmented actinomycetes was selected for further extraction and analysis. Optimization of production media enhanced the production of pigmented biomass. Glucose and beef extract was found to have a significant effect in the pigment production. The isolated actinomycetes was identified as Streptomyces griseorubiginosus by using 16 s r-DNA sequencing. Streptomyces griseorubiginosus cells were ruptured using ultrasonication and pigment was extracted using methanol as solvent. Different bio active compounds present in the extract were determined using Gas Chromatography Mass Spectrometry (GCMS) analysis and functional groups were identified using Fourier Transform Infrared (FT-1R) spectroscopy. Bioactive compounds present in the pigment showed significant antioxidant and antibacterial activities. The extracted red coloured pigment was used as a natural colorant to formulate a bio-lip balm. Preliminary analysis confirmed the stability of the synthesised bio-lip balm. Further, the extracted pigment can be used as a safer alternative for synthetic chemical pigments in various cosmetics, personal care products and pharmaceuticals.

This study provides a comprehensive analysis of pathogenesis-related (PR) proteins, focusing on PR1, PR5, and PR10, in three plant species: Arabidopsis thaliana (At), Solanum lycopersicum (Sl), and Solanum tuberosum (St). We investigated various physico-chemical properties, including protein length, molecular weight, isoelectric point (pI), hydrophobicity, and structural characteristics, such as RMSD, using state-of-the-art tools like AlphaFold and PyMOL. Our analysis found that the SlPR10-StPR10 protein pair had the highest sequence identity (80.00%), lowest RMSD value (0.307 Å), and a high number of overlapping residues (160) among all other protein pairs, indicating their remarkable similarity. Additionally, we used bioinformatics tools such as Cello, Euk-mPLoc 2.0, and Wolfpsort to predict subcellular localization, with AtPR1, AtPR5, and SlPR5 proteins predicted to be located in the extracellular space in both Arabidopsis and S. lycopersicum, while AtPR10 was predicted to be located in the cytoplasm. This comprehensive analysis, including the use of cutting-edge structural prediction and subcellular localization tools, enhances our understanding of the structural, functional, and localization aspects of PR proteins, shedding light on their roles in plant defense mechanisms across different plant species.

 The evolution of nanotechnology-driven lipid and metalloid-based nanoformulations has garnered significant attention for developing effective drug delivery systems with position/time precision and efficacy. This study focuses on challenges of blood-brain barrier (BBB) and their pivotal role in drug targeting in chronic diseases such as brain tumors (BTs). These formulations encapsulate therapeutic agents within lipidic matrices, enhancing drug solubility, bioavailability, and targeted delivery. The diverse lipid materials used in these nanoformulations highlight their biocompatibility and versatility, covering a wide range of drugs. Emphasis is placed on metal nanoparticles, liposomes, ethosomes, quantum dots, carbon nanotubes, nanorobots, and micelles. The analysis explores their drug loading, stability, release characteristics, and bioavailability modulation. It also delves into the enhanced-permeability and retention (EPR) effect, crucial for passive targeting of tumors. Recent nanocarrier systems enable better penetration of therapeutic compounds through the BBB, addressing treatment failures in invasive BTs.This review highlights the latest nanotechnology developments and potential therapeutic approaches, serving as a valuable resource for researchers, clinicians, and pharmaceutical scientists.

Vaccines signify one of the economical and reasonable means to prevent and eradicate the important infectious diseases. Conventional vaccines like live attenuated and inactivated vaccines comprise of whole pathogen either in attenuated or killed form. While, new generation vaccines have been designed to elicit immune response by genetically modifying only the nucleic acid portion of that pathogen. These new generation therapeutics include mRNA vaccines, DNA plasmid vaccines, chimeric vaccines and recombinant viral vector-based vaccines. Nucleic acid based vaccines use genetic material itself thus, they are highly stable and potent in nature to induce long-lasting immune response. Amongst these novel vaccine platforms, viral vector-based vaccines is one such emerging field which has proven to be extremely effective and potent. Nowadays, veterinary medicine has also accepted this innovative vectored vaccine platform to develop an effective control strategy against certain important viral diseases of animals. Viral vector-based vaccine uses various DNA and RNA viruses of human or animal origin to carry an immunogenic transgene of target pathogen. These vaccines enhance both humoral and cell mediated immune response without use of any accessory immune-stimulants. Till today, several viruses have been modified to be characterized as vaccine vectors. Currently, large number of research programs are going on to develop vectored vaccines and novel viral vector for veterinary use. In the present review, different kinds of viral vectored vaccines having veterinary importance have been discussed.

This study depicts the antimicrobial resistance (AMR) pattern of E. coli (n: 503) isolated from cloacal swabs collected from chicks and duck in the six agroclimatic (hill, tarai, red & laterite, old alluvial, new alluvial and coastal saline) zones of West Bengal, India. Resistance to ampicillin (47.1%), ceftriaxone (27.0%), aztreonam (25.2%), tetracycline (20.0%), enrofloxacin (19.6%), and nalidixic acid (18.8%) was quite frequent, however, majority of the isolates were sensitive to amoxicillin-clavulanic acid (97%), chloramphenicol (97.5%) and imipenem (> 98%). In general, duck isolates demonstrated a higher level of antibiotic resistance while resistance was negligible for the isolates from the red & laterite zones. This study identified considerable number of extended-spectrum (n: 120) and A mpC type β-lactamase producers (n: 95). Phylotype A (285) was the most abundant followed by B1 (40) and C (87), while the other groups consisted of 91 isolates—B2 (25), D (31). F (34), and clade-1 (1). Logistic regression analysis demonstrated that the isolates of duck origin (OR: 4.44 (95% CI 2.5, 7.8), p < 0.001) and those belonging to virulent phylotypes (OR: 1.79 (95% CI 1.16, 2.75), P < 0.001) were more likely to be an ESBL producer. Likewise, the isolates from old alluvial zone were significantly and more frequently associated with ESBL production (OR: 2.04 (95% CI 1.04, 4.02), p < 0.001), ceftazidime (OR: 2.06 (95% CI 1.06, 4.04), p < 0.001) and quinolone [NAL: (OR: 2.42 (95% CI 1.23, 4.73), p < 0.01); ENR: (OR: 3.72 (95% CI 1.30, 6.72), p < 0.001)] resistance. The current study provided a first-ever thorough examination of the factors influencing antimicrobial resistance in poultry and the potential influence of variables such as agroclimatic zones, bird types [(broiler (chicken), layer (chicken), duck (mainly as layer)], and phylotypes on resistance pattern. Our findings highlight that there might be other factors contributing to AMR, in addition to the usage of antibiotics, in a particular sector. Therefore, a comprehensive approach through enhanced biosecurity and identification of loopholes that permit resistant elements to expand is needed, to tackle AMR in poultry sector.

The phyllosphere harbours a distinctive microbial community that is influenced by plant species, geological locations, and biotic and abiotic environmental factors. Organophosphates represent a significant category of pesticides that are applied to plant surfaces for pest management. Despite substantial research into phyllosphere microorganisms, little is known about the influence of pesticides on the phyllosphere bacterial ecosystem. In the present study, the effect of chlorpyrifos, monocrotophos, and malathion was studied on the phyllosphere bacterial community of Solanum melongena. The plant-inhabitant bacterial population was explored using culturable and high-throughput 16S rRNA gene amplicon sequencing, with and without pesticide application. A total of 165 genera belonging to 14 phyla were observed in the control and 108 genera belonging to 11 phyla in the treated sample. In total, 28 morphologically distinct bacteria were isolated from the abaxial and adaxial surfaces of leaf, and 4 bacteria were found tolerant to pesticides. An increased abundance of Psychrobacter, Janthinobacterium, Sphingomonas, Flavobacterium, and Pedobacter were observed from the pesticide-treated phyllosphere. Overall pesticide impacted the evenness and diversity of the bacterial communities colonizing the S. melongena phyllosphere.

Polyhydroxyalkanoates (PHAs) constitute a principal group of bio-degradable polymers that are produced by certain microbes under limited supply of nutrients. PHA is a linear polyester that comprises of 3-hydroxy fatty acid monomers. Triacylglycerol acylhydrolases are known to catalyze the hydrolysis of ester linkages and in turn they are beneficial in the degradation of PHA. In present study, lipase-catalyzed degradation of PHA synthesized by Priestia megatarium POD1 was monitored. A gene from thermotolerant Bacillus subtilis TTP-06 that was capable of expressing lipase enzyme was amplified by PCR, cloned into a pTZ57R/T-vector, transferred to an expression vector pET-23a (+) and expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme purified to 19.37-fold had a molecular weight of 30 kDa (SDS-PAGE analysis). Scanning Electron Microscopy (SEM) revealed changes in the surface morphology of native and treated PHA films. Further, changes in molecular vibrations were confirmed by Fourier Transform Infrared Spectroscopy.

Extensive research over the years has revealed the remarkable potential of gold nanoparticles (AuNPs) for detecting biomarkers in osteoarthritis (OA). AuNPs are a promising class of nanomaterials offering a wide range of diagnostic and clinical applications. It provides an effective and robust framework for qualitative and quantitative analysis of biomarkers present in the biological fluids of OA patients. AuNPs as theranostics have gained significant attention due to their discrete physical and optical characteristics, including localized surface plasmon resonance (LSPR), fluorescence, surface-enhanced Raman scattering, and quantized charging effect. These unique properties provide AuNPs as an excellent scaffold for ligand multiplexing, allowing accrued sensitivity for biomarker detection. Several reports have delved into the LSPR properties of the kinetics of biological interactions between the ligand and analyte. Tuneable radiative properties of AuNPs coupled with surface engineering allow facile detection of biomarkers in biological fluids. Herein, we have presented a comprehensive summary of distinct biomarkers generated from different molecular pathological processes in OA. An armamentarium of diagnostic methodologies such as aptamer conjugation, antibody coupling, ligand anchoring, and peptide decoration on the surface of AuNPs facilitates the identification and quantification of biomarkers. Additionally, a diverse range of sensing strategies for biomarker spotting, along with current challenges and future perspectives, have also been well delineated in the present manuscript.

Graphical Abstract

The eastern sub-Himalayan region of India (which belongs to the Cwa zone in Koppen’s classification) experiences severe cold waves during winter which causes a loss in seed vigor. Though most of the studies on cold stress deal with atmospheric temperatures, the seed vigor is majorly affected by the temperature of the soil. Therefore, the vigor loss of tomato and green gram were investigated under low-temperature stress. The analysis of locally available soil temperature showed a median value of 20.3 ± 0.1 °C. When the seeds were subjected to this temperature in vitro, a loss in vigor (70–75%) was observed. This was due to the reduced fluidity of the membrane which caused electrolyte leakage. In this regard, the indigenous polysaccharides-producing microbes act as an eco-friendly priming agent to recover the lost vigor. However, seed treatment with Bacillus and Pseudomonas strains didn’t affect the germination-related factors but aided in recovering 30–70% of the lost vigor by enhancing the growth of seedlings. The mode of vigor recovery was the production of indole-acetic acid. This approach can be used to quicken the nursery period of tomato and green gram exposed to low soil temperatures prevalent in the sub-Himalyan terai region.