Comparative analysis of commercially available kits for optimal DNA extraction from bovine fecal samples.

In the field of metagenomic research, the choice of DNA extraction methods plays a pivotal yet often underestimated role in shaping the reliability and interpretability of microbial community data. This study delves into the impact of five commercially available DNA extraction kits on the analysis of bovine fecal microbiota. Recognizing the importance of accurate DNA extraction in elucidating microbial community dynamics, we systematically assessed DNA yield, quality, and microbial composition across these kits using 16S rRNA gene sequencing. Notably, the FastDNA spin soil kit yielded the highest DNA concentration, while significant variations in quality were observed across kits. Furthermore, differential abundance analysis revealed kit-specific biases that impacted taxa representation. Microbial richness and diversity were significantly influenced by the choice of extraction kit, with QIAamp DNA stool minikit, QIAamp Power Pro, and DNeasy PowerSoil outperforming the Stool DNA Kit. Principal-coordinate analysis revealed distinct clustering based on DNA isolation procedures, particularly highlighting the unique microbial community composition derived from the Stool DNA Kit. This study also addressed practical implications, demonstrating how kit selection influences the concentration of Gram-positive and Gram-negative bacterial taxa in samples. This research highlights the need for consideration of DNA extraction kits in metagenomic studies, offering valuable insights for researchers striving to advance the precision and depth of microbiota analyses in ruminants.

Genomic investigation unveils high-risk ESBL producing Enterobacteriaceae within a rural environmental water body.

Antimicrobial resistance is regarded as a global threat to public health, animals, and the environment, emerging in response to extensive utilization of antimicrobials. The determinants of antimicrobial resistance are transported to susceptible bacterial populations through genetic recombination or through gene transfer, mediated by bacteriophages, plasmids, transposons, and insertion sequences. To determine the penetration of antimicrobial resistance into the bacterial population of the Thiruvandarkoil Lake, a water body located in the rural settings of Puducherry, India, culture-based microbiological and genomic approaches were used. Resistant bacterial isolates obtained from microbiological screening were subjected to whole genome sequencing and the genetic determinants of antimicrobial resistance were identified using in silico genomic tools. Cephalosporin-resistant isolates were found to produce extended spectrum beta lactamases, encoded by blaVEB-6 (in Proteus mirabilis PS01), blaSHV-12 and ompK36 mutation (in Klebsiella quasipneumoniae PS02) and blaSHV-12, blaACT-16, blaCTX-M and blaNDM-1 in (Enterobacter hormaechei PS03). Genes encoding heavy metal resistance, virulence and resistance to detergents were also detected in these resistant isolates. Among ESBL-producing organisms, one mcr-9-positive Enterobacter hormaechei was also identified in this study. To our knowledge, this is the first report of mcr-9 carrying bacterium in the environment in India. This study seeks the immediate attention of policy makers, researchers, government officials and environmental activists in India, to develop surveillance programs to monitor the dissemination of antimicrobial resistance in the environment.

Genomic insights into plasmid-mediated antimicrobial resistance in the bacterium Bhargavaea beijingensis strain PS04.

The dissemination of antimicrobial-resistant bacteria through environment is a major health concern for public health. Pathogenic bacteria in natural environment can mediate the transfer of antimicrobial-resistant genes via horizontal gene transfer to naturally occurring bacteria in the soil. Bhargavaea beijingensis is a Gram-negative bacterium that is commonly found in soil and water. In recent years, there has been an emergence of antibiotic-resistant strains of environmental bacteria, which pose a significant threat to human health. One mechanism of antibiotic resistance in bacteria is through the acquisition of plasmids, which can carry genes that confer resistance to various antibiotics. In this study, a novel plasmid of repUS12 replicon type was identified in the strain PS04 of B. beijingensis, which carried the ermT and tet(L) genes, encoding resistance to macrolides, lincosamides, and tetracycline. The plasmid was found to be the first of its kind in B. beijingensis and was thought to have been acquired through horizontal gene transfer. The emergence of plasmid-mediated resistance in B. beijingensis highlights the need for continued surveillance and monitoring of antibiotic resistance in environmental bacteria.

The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread.

Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed. Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.

Gut microbiome responses in the metabolism of human dietary components: Implications in health and homeostasis.

The gut microbiome and its link with human health and disease have gained a lot of attention recently. The microbiome executes its functions in the host by carrying out the transformation of dietary components and/or de novo synthesis of various essential nutrients. The presence of complex microbial communities makes it difficult to understand the host-microbiome interplay in the metabolism of dietary components. This review attempts to uncover the incredible role of the gut microbiome in the metabolism of dietary components, diet-microbiome interplay, and restoration of the microbiome. The in silico analysis performed in this study elucidates the functional description of essential/hub genes involved in the amino acid degradation pathway, which are mutually present in the host and its gut microbiome. Hence, the computational model helps comprehend the inter-and intracellular molecular networks between humans and their microbial partners.

Delineating the impact of COVID-19 on antimicrobial resistance: An Indian perspective.

The COVID-19 pandemic has shattered millions of lives globally and continues to be a challenge to public health due to the emergence of variants of concern. Fear of secondary infections following COVID-19 has led to an escalation in antimicrobial use during the pandemic, while some antimicrobials have been repurposed as treatments for SARS-CoV-2, further driving antimicrobial resistance. India is one of the largest producers and consumers of antimicrobials globally, hence the task of curbing antimicrobial resistance is a huge challenge. Practices like empirical antimicrobial prescription and repurposing of drugs in clinical settings, self-medication and excessive use of antimicrobial hygiene products may have negatively impacted the prevalence of antimicrobial resistance in India. However, the expanded production of antimicrobials and disinfectants during the pandemic in response to increased demand may have had an even greater impact on the threat of antimicrobial resistance through major impacts on the environment. The review provides an outline of the impact COVID-19 can have on antimicrobial resistance in clinical settings and the possible outcomes on the environment. This review calls for the upgrading of existing antimicrobial policies and emphasizes the need for research studies to understand the impact of the pandemic on antimicrobial resistance in India.

Promising treatment strategies to combat Staphylococcus aureus biofilm infections: an updated review.

Staphylococcus aureus is a leading cause of nosocomial and community-acquired infections. The formation of biofilm by this pathogen renders it resilient to antimicrobial agents, which complicates the treatment of such infections. S. aureus can form biofilms with other pathogens and cause polymicrobial infections recalcitrant to antimicrobial agents. Therefore, anti-biofilm agents against which this bacterium cannot develop resistance are a highly desirable treatment strategy. Nanoparticles and some non-antimicrobial drugs proposed for various clinical purposes have proven to be excellent antibacterial and anti-biofilm agents to control S. aureus biofilm infections. A variety of chemically distinct compounds capable of acting as anti-biofilm agents against S. aureus have been extracted from microbial sources. This review explains the characteristics of S. aureus biofilms, emphasizing the therapeutic potential of nanoparticles, repurposed drugs, and anti-biofilm agents from microbial sources to combat S. aureus biofilm infections.

Intra-abdominal follicular dendritic cell tumor: report of two cases.

Follicular dendritic cell (FDC) tumor is an uncommon entity described mainly in the lymph nodes. We report two men with intra-abdominal FDC tumors--one arising from the colon and other presenting as a mesenteric mass. Both patients underwent successful surgical excision of the tumor.