Indian Journal of Microbiology最新文献

Our study offers a comprehensive Monkeypox virus (MPXV) analysis, utilizing innovative protocols to uncover potential vulnerabilities. We examine MPXV's epidemiology, link to smallpox, genomics, mutation landscape, clinical features, diagnostics, therapeutics, FDA-approved drugs, clinical trials, and preventive strategies. We used various analytical methods to analyse genome data from the NCBI database (2019-2023) to assess sequence alignment, protein identification, and genome diversity. The phylogenomic analysis identified unique lineages and a mutation associated with human transmission, revealing that 24 MPXV proteins are particularly mutation-prone. Domain analysis confirmed conserved Ortho-poxvirus genes and critical regions, providing insights into MPXV's structure, diversity, and host interaction. Additionally, we integrated clinical data, geospatial mapping, statistical analysis, and AI/ML for predictive insights on MPXV progression. We also explored bioinformatics tools and plant-based treatments, conducting in-silico studies to identify potential drug targets. Our research integrates epidemiological and genomic data to inform real-time preventive measures and optimize public health responses to MPXV.

Acinetobacter baumannii has been associated with severe clinically acquired infections. The prevalence of non-A. baumannii-linked diseases is now equivalent to that of A. baumannii-associated illnesses. Hence, this study intends to explore the genomic linkage of virulence and antibiotic resistance amongst the five Acinetobacter spp. (A. baumannii, A. haemolyticus, A. johnsonni, and A. nosocomialis) using pan genome analysis. The results revealed open pan genome in Acinetobacter sp. with increase in number of additional genes in pan genome. The resistance gene identifier revealed that A. baumannii was resistant to macrolides, fluoroquinolone, lincosamide, carbapenem, cephalosporin, tetracycline, rifamycin, diaminopyrimidine, phenicol antibiotics, and penem. Non-A. baumannii sp. A. haemolyticus had the Oxa beta lactamase gene (Oxa) with resistance to carbapenem, cephalosporin, penem. A. johnsonii had no perfect hits for resistance but showed weak similarity to Oxa. A. nosocomialis had resistance genes to fluoroquinoids. The prevalence of Acinetobacter baumannii AbaQ gene was found with A. calcoaceticus and A. nosocomialis sequences used in this study supporting the transformation of resistance genes between Acinetobacter sp. This comparative research underlines the need of differentiating between distinct Acinetobacter sp. infections with their genetic profile for accurate diagnosis and management based on their anti microbial resistance.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-024-01411-6.

Pseudomonas aeruginosa is a major cause of nosocomial infection which at times causes a grim situation in clinical setups. There is a dire need to develop strategies to overcome the increasing incidence of drug resistance in this organism. The protective outer membrane and over expressed efflux pumps serve as a major survival weapon for this pathogen, making it to resist present day antibiotics. The present review dwells on some of these strategies, with emphasis on tagging to existing antibiotics with siderophore as a carrier employing a Trojan horse strategy so that an antibiotic can creep into bacterial cell through the iron acquisition pathway. These hybrid drugs, defined as synthetic structures are likely to overcome drug resistance due to their ability to evade resistance mediated by multiple antibiotic resistance operon. The advances and challenges of siderophore-antibiotic conjugates are elaborated in this article. Moreover, several xeno-siderophore-antibiotic conjugates, currently in clinical trials, have been discussed. The present review provides insights into repurposing of fluroquinolones through siderophore targeted delivery to increase the biological activity of antibiotics. In the near future, siderophore-based Trojan horse antibiotics indeed will not only help in altering the potency of antibiotics, hence decreasing antimicrobial resistance, but also will lead to disarming the pathogen of its virulence.

Gluconic acid is a mild organic acid produced by the dehydrogenation of glucose catalyzed by glucose oxidase. It has wide applications across food, pharmaceutical, chemical industries, etc. The growing demand has made it necessary for the isolation and characterization of potent organisms capable of enhanced production of gluconic acid using agro-industrial waste contributing to waste valorization. Therefore, an attempt was made to isolate, screen, and characterize the gluconic acid producing microorganisms from potato waste, a potential inexpensive substrate for bioconversion processes. Using the enrichment method, 15 fungal and 15 bacterial isolates were obtained. It was found that all the fungal and bacterial isolates showed positive for acid production when glucose (1%) was used as a carbon source, which is indicated by increased titrable acidity. Acid tolerance tests at different pH levels, such as 3, 4, and 5 showed that the isolates, especially fungi, exhibited greater tolerance at pH 5 and also showed slow growth at pH 3. Also, the statistical analysis using one-way ANOVA for the quantitative estimation of gluconic acid revealed that VDF 11 was producing the highest gluconic acid with 72.13 ± 1.82 g/L. Further, the molecular characterization using NCBI BLAST_N of ITS ribosomal DNA and maximum likelihood method revealed VDF 11 as Penicillium oxalicum. Therefore, these outcomes highlight that the isolates can be utilized for the sustainable production of gluconic acid contributing to waste valorization.

The antimicrobial compound psilocybin possesses psychoactive properties with therapeutic applications. Psilocybin is the main component naturally present in psychedelic mushrooms and has been utilized in the treatment of depression and neurological disorders. In this study, psychedelic mushrooms were collected from Kodaikanal, Tamil Nadu. They underwent solvent extraction using High Performance Thin Layer Chromatography (HPTLC) and Liquid Chromatography-Mass Spectrometry (LC-MS). Psilocybin, the primary compound, was extracted and evaluated. The extracted psilocybin was then assessed for antimicrobial activity against bacterial and fungal strains using the well diffusion method. Furthermore, HPTLC and LC-MS were employed for the identification of the psilocybin compound. The Rf values of psilocybin were found to be 0.73 and 0.77. Psilocybin inhibited the growth of bacterial and fungal pathogens including Staphylococcus epidermidis, Pseudomonas aeruginosa, Candida tropicalis, and Trichophyton rubrum. The bacterial culture was inhibited at a minimum inhibitory concentration of 12.5 µg/mL, whereas fungal pathogens were inhibited at 6.25 µg/mL. Thus, the findings conclude that in addition to its psychoactive properties, psilocybin could be utilized to develop antimicrobial drugs in future studies with in vivo efficacy and toxicity assays.

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Penicillium oxalicum PBG30 produced an extracellular phytase in solid-state fermentation and maximum production was obtained (200 ± 6.01 U/g DMR) at 30 °C after 5 days. The optimal temperature and pH for enzyme were 70 °C and 3.0, respectively. The phytase is thermostable with T_1/2 of 1 h at 70 °C and showed broad-substrate specificity with K_m and V_max values of 4.42 mM and 909.1 U/ml, respectively with calcium phytate. Phytase activity was enhanced in the existence of metal ions and surfactants and retarded by SDS, EDTA, sodium molybdate, DTT, and ß-ME. Phytase exhibited resistance against trypsin and pepsin with better storage stability at 4 °C and -20 °C. Insoluble phytates (metal and protein) were efficiently hydrolyzed by fungal phytase showing liberation of inorganic phosphate in a time-dependent manner. Also, the phytic acid reduction was observed in phytase-treated fish feed with the lowest phytic acid occurring in a diet supplemented with 1500 FTU/kg dose of phytase. Furthermore, phytase was converted into vanadium-dependent peroxidase. Fungal phytase, due to its thermostability, protease resistance, broad substrate specificity, and ability to hydrolyze phytate forms, has the potential to serve as an additive for improving nutrient digestibility in the food and feed industry.

Uricase holds significant pharmaceutical applications, particularly in treating diseases associated with elevated uric acid levels and serving as a diagnostic enzyme to detect uric acid in biological fluids. Enhancing uricase production is crucial to meet the demands of large-scale applications. This study focuses on optimizing process parameters for uricase production using advanced statistical methods, namely Response Surface Methodology (RSM) and Artificial Neural Network-Genetic Algorithm (ANN-GA). Seven key process parameters were investigated: temperature, pH, medium volume, incubation time, inoculum size, inoculum age, and rpm. Conformational experimental studies at the ANN-GA predicted optimal conditions revealed a significant uricase activity of 63.92 ± 0.06 U/mL. The purified uricase exhibited specific activity of 92.48 U/mg and a molecular weight of approximately 32 kDa. Itdemonstrated remarkable stability, withstanding a wide pH range (6.0 to 10.0) and temperatures up to 50 °C, with an optimum pH of 9.0 and temperature of 30 °C. This broad pH and temperature tolerance of the purified uricase from Pseudomonas mosselii DSS002 underscores its potential as a valuable source for industrial-scale production, catering to various pharmaceutical applications. This study's findings pave the way for efficient and scalable uricase production, offering promising implications for the pharmaceutical industry.

Salmonella Typhimurium is an important serovar causing non-typhoidal salmonellosis in humans. Poultry products are a common source of infection. In the present study, we used 46 isolates of S. Typhimurium, which were isolated from poultry eggs. Isolates were screened for their virulence, virulence factors (genes and plasmids), presence of ampicillin-resistant bla PSE-1 gene and Minimum Inhibitory Concentration (MIC) for ampicillin. Out of 46 isolates, bla PSE-1 gene was present in all 46 isolates and MIC ranged from 2.0 to 64 µg/ml. In mice inoculation test, out of 46 isolates, three isolates were found to be avirulent. Among virulence genes, stn, inv A, pef and spv C genes were detected in 45 (97.82%), 44(95.65%),13(28.26%), 4 (8.6%) isolates, respectively. Plasmids were detected in 37 isolates (80.43%). Plasmids, stn and inv A gene were more closely associated with virulence as compared to pef and spv C genes. As these isolates were virulent and exhibited resistance to ampicillin, the spread of such isolates may result in a serious threat to human and animal health.

Streptococcus mutans, primarily responsible for dental caries, results in tooth demineralization due to plaque buildup and high sugar consumption. Glucosyltransferases produced by S. mutans synthesize virulent extracellular polysaccharides, enhancing cariogenic biofilms. Sucrose activates glucosyltransferase, leading to glucan synthesis, a key factor in caries formation. This study analyzed the effect of biosurfactant-producing bacteria extracted from the oral microbiota on Streptococcus mutans MTCC 497 targeting glucosyltransferase and ATPase. Oral swabs from healthy individuals from different states in India were screened for biosurfactant production using various assays such as oil drop collapse, CTAB methylene blue agar, and emulsification activity. The inhibitory effect of biosurfactants on S. mutans MTCC 497 were analyzed with minimum inhibitory broth concentration, sucrose dependent and sucrose independent adhesion and biofilm formation assays. Of 100 oral swabs, 40 bacterial isolates demonstrated antagonistic activity against S. mutans MTCC 497. From that, 17 biosurfactant-producing bacteria were identified. Ten bacteria, including DMTMM46, were assessed through various assays. DMTMM46 exhibited significant activity against Streptococcus mutans MTCC 497. Biosurfactants demonstrated efficacy in glucan synthesis, adhesion, biofilm formation, and ATPase activity at 75 µg/mL. Identification through 16SrRNA sequencing revealed DMTMM46 as Bacillus pumilus. The results indicate that biosurfactant produced by the bacteria Bacillus pumilus MMLN01 have therapeutic potential for dental caries.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-024-01393-5.

Pyrene is a ubiquitous, high molecular weight organic pollutant known for its high recalcitrance and toxicity. The Pyrene degrading bacterium, C7 was isolated from coal deposited soil samples by using selective enrichment culture technique, and its ability of Bacillus cereus C7 to degrade pyrene was determined by a 2,6-DCPIP assay. The bacterial isolate was characterized by 16S-rDNA sequencing as Bacillus cereus. B. cereus efficiently degraded 82.62% of the pyrene and concomitant increases in growth and protein concentration with an associated decrease in pyrene concentration were observed during the course of incubation. GC-MS analysis revealed that B. cereus degraded pyrene into seven metabolites viz. 4,5-dihydroxy pyrene, phenanthrene-4-carboxylic acid, 1-hydroxy-2-naphthaldehyde, 1-hydroxy-2-naphthoic acid, 1,2-dihydroxy naphthalene, salicylic acid and catechol. This study is the first to report salicylic acid and catechol as terminal end products of pyrene catabolism. Plasmid curing studies performed to determine the role of plasmids in pyrene degradation found drastic reduction in cell growth and pyrene degradation in cured culture. Thus, pyrene degradation in B. cereus is certainly plasmid-associated. The isolated plasmid has a molecular size of 11.27 kbp and contains restriction sites for the SmaI, StuI, NotI, BglII, PuvII and EcoRI enzymes. The plasmid encoding pyrene degradation in B. cereus C7 may have practical application in bioremediation and construction of genetically engineered strains with improved PAH degradation efficiency.