ABSTRACT
This study addresses the pressing issue of high arsenic (As) contaminations, which poses a severe threat to various life forms in our ecosystem. Despite this prevailing concern, all organisms have developed some techniques to mitigate the toxic effects of As. Certain plants, such as bryophytes, the earliest land plants, exhibit remarkable tolerance to wide range of harsh environmental conditions, due to their inherent competence. In this study, bryophytes collected from West Bengal, India, across varying contamination levels were investigated for their As tolerance capabilities. Assessment of As accumulation potential and antioxidant defense efficiency, including SOD, CAT, APX, GPX etc. revealed Marchantia polymorpha as the most tolerant species. It exhibited highest As accumulation, antioxidative proficiency, and minimal damage. Transcriptomic analysis of M. polymorpha exposed to 40 µM As(III) for 24 and 48 h identified several early responsive differentially expressing genes (DEGs) associated with As tolerance. These includes GSTs, GRXs, Hsp20s, SULTR1;2, ABCC2 etc., indicating a mechanism involving vacuolar sequestration. Interestingly, one As(III) efflux-transporter ACR3, an extrusion pump, known to combat As toxicity was found to be differentially expressed compared to control. The SEM-EDX analysis, further elucidated the operation of As extrusion mechanism, which contributes added As resilience in M. polymorpha. Yeast complementation assay using Δacr3 yeast cells, showed increased tolerance towards As(III), compared to the mutant cells, indicating As tolerant phenotype. Overall, these findings significantly enhance our understanding of As tolerance mechanisms in bryophytes. This can pave the way for the development of genetically engineered plants with heightened As tolerance and the creation of improved plant varieties.
Subject(s)
Arsenic , Bryophyta , Marchantia , Resilience, Psychological , Arsenic/toxicity , Marchantia/genetics , Ecosystem , Saccharomyces cerevisiaeABSTRACT
INTRODUCTION: In endodontics, despite careful instrumentation and antimicrobial irrigation, root canals still harbor cultivable microorganisms. Such cases require intra canal medicament that eliminates the microbial inhabitants from the canals. Recent trend advocates the use of herbal extracts due to easy availability, cost-effectiveness, low toxicity, and lack of microbial resistance. Hence, in the present study, Neem, Tulsi, and Guduchi extracts were used as intracanal medicaments. AIM: This study aimed to evaluate and compare the antibacterial efficacy of Neem, Tulsi, Guduchi extracts, and chlorhexidine against Enterococcus faecalis, when used as intracanal medicaments. MATERIALS AND METHODS: One hundred and twenty-five extracted human teeth, inoculated with E. faecalis, were divided into four experimental groups and a control group (n = 25 in each group). The experimental groups were treated with chlorhexidine, Neem, Tulsi, and Guduchi extracts and their antibacterial property was evaluated by estimating microbial counting (CFU/ml). RESULTS: The reduction in bacterial count for chlorhexidine, Neem, Tulsi, and Guduchi groups was 60.76%, 51.98%, 37.73%, and 34.93%, respectively. Statistically significant difference in reduction of bacterial count was observed in all the groups, when compared with the control group. CONCLUSION: Among all the herbal extracts, Neem was found to be the most potent medicament followed by Tulsi and Guduchi. However, chlorhexidine was found to be at epic.
ABSTRACT
BACKGROUND: AmpC beta lactamases are cephalosporinases that confer resistance to a wide range of beta lactam drugs thereby causing serious therapeautic problem. As there are no CLSI guidelines for detection of AmpC mediated resistance in Gram negative clinical isolates and it may pose a problem due to misleading results, especially so in phenotypic tests. Although cefoxitin resistance is used as a screening test, it does not reliably indicate AmpC production. MATERIALS AND METHODS: We planned a study to determine the occurrence of AmpC beta lactamase in hospital and community, clinical isolates of Escherichia coli and simultaneously evaluate different phenotypic methods for detection of AmpC beta lactamases. RESULTS: It was observed that 82.76% isolates were ESBL positive and 59% were cefoxitin screen positive. Using phenotypic confirmatory tests the occurrence of Amp C beta lactamases was found to be 40% and 39% by inhibitor based method using boronic acid (IBM) and modified three dimensional test (M3D) respectively. CONCLUSION: Both the test showed concordant result. Co-production was observed in 84.62% isolates Screening of ESBL and Amp C can be done in routine clinical microbiology laboratory using aztreonam and IBM respectively as it is a simple, rapid and technically less demanding procedure which can be used in all clinical laboratories.
