Diverging Characteristics – Mercury Resistance and Antibiotic Susceptibility of Bacillus anthracis Isolated from Different Estuarine Environments

Abstract

The present study focused on the isolation and selection of identically similar bacteria from two different estuaries: polluted (KM186605) and marginally polluted (KM186603). The selected strains were tentatively identified as Bacillus anthracis using biochemical and molecular characteristics. The comparative assessments were performed based on their mercury and antibiotic resistance capabilities. The mercury removal percentages of KM186605 were 57.76, 40.88, 30.24 and 24.88%, while those of KM186603 were 45.92, 36.16, 28.15 and 21.69% respectively, at 25, 50, 75 and 100 mg^−l concentrations of mercury. The antibiotic profile showed that KM186605 was susceptible to erythromycin, novobiocin, oxytetracycline, vancomycin, and amikacin. On the other hand, KM186603 was susceptible to oxytetracycline, erythromycin, novobiocin, and amikacin. The notable finding of the present investigation is that the strain screened from the polluted estuary (KM186605) showed higher mercury resistance but lower antibiotic resistance. The strain screened from a marginally polluted estuary (KM186603) exhibited lower mercury resistance and higher antibiotic resistance.

HIGHLIGHTS

1. Identically similar strains (Bacillus anthracis) were isolated from two different estuary ecosystems (polluted and marginally polluted estuaries).

2. Phenotypical and genotypical similarities of the strains were characterized using biochemical analysis and genetic tools.

3. Mercury removal efficiency and antibiotic resistance of the stains were analyzed and compared.

4. The findings illustrated that the efficiency of the bacteria is influenced by the contaminant factors present in the respective environment. Based on the nature of pollutants, the resistance genes may be induced to develop their resistance capacity for their survival.

Keywords:

• Bacillus anthracis
• behavioural disparities
• mercury and antibiotic resistance

Acknowledgements

We would like to acknowledge the authorities of Annamalai University and CSIR-CLRI for providing necessary facilities.

Authors’ contributions

Kailasam Saranya: Conceptualization, investigation and writing the original manuscript; Arumugam Sundaramanickam: Writing review, Supervision and Editing; Masilamani Dineshkumar: Experimental design, Data entry and review; Muthusamy Thangaraj: Experimental review; Swarna Vinodh Kanth: Formal analysis and validation.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This study was supported by a research grant from RUSA 2.0 (Project File No. RUSA 2.0-100-E-002).