Recovery of metallo-tolerant and antibiotic resistant psychrophilic bacteria from Siachen glacier, Pakistan

Cultureable bacterial diversity of previously unexplored Siachen glacier, Pakistan, was studied. Out of 50 isolates 33 (66%) were Gram negative and 17 (34%) Gram positive. About half of the isolates were pigment producers and were able to grow at 4-37°C. 16S rRNA gene sequences revealed Gram negative bacteria dominated by Proteobacteria (especially γ-proteobacteria and β-proteobacteria) and Flavobacteria. The genus Pseudomonas (51.51%, 17) was dominant among γ- proteobacteria. β-proteobacteria constituted 4 (12.12%) Alcaligenes and 4 (12.12%) Janthinobacterium strains. Among Gram positive bacteria, phylum Actinobacteria, Rhodococcus (23.52%, 4) and Arthrobacter (23.52%, 4) were the dominating genra. Other bacteria belonged to Phylum Firmicutes with representative genus Carnobacterium (11.76%, 2) and 4 isolates represented 4 genera Bacillus, Lysinibacillus, Staphylococcus and Planomicrobium. Most of the Gram negative bacteria were moderate halophiles, while most of the Gram positives were extreme halophiles and were able to grow up to 6.12 M of NaCl. More than 2/3 of the isolates showed antimicrobial activity against multidrug resistant S. aureus, E. coli, Klebsiella pneumonia, Enterococcus faecium, Candida albicans, Aspergillus flavus and Aspergillus fumigatus and ATCC strains. Gram positive bacteria (94.11%) were more resistant to heavy metals as compared to Gram negative (78.79%) and showed maximum tolerance against iron and least tolerance against mercury

Antibiotic resistance, mutliple antibiotic resistant (MAR) index and antimicrobial activity of Gram positive bacterial isolates.

<p>Antibiotic resistance, mutliple antibiotic resistant (MAR) index and antimicrobial activity of Gram positive bacterial isolates.</p

Phylogenetic tree of the study isolates HTS (15°C) by Maximum Likelihood method constructed in MEGA 6 software.

<p>Phylogenetic tree of the study isolates HTS (15°C) by Maximum Likelihood method constructed in MEGA 6 software.</p

Antibiotic resistance and production of antimicrobial compounds in Gram negative bacteria isolated from Siachen Glacier.

<p>Antibiotic resistance and production of antimicrobial compounds in Gram negative bacteria isolated from Siachen Glacier.</p

Phylogenetic relationship analysis of study isolates (LTS) by Maximum Likelihood method in MEGA 6 software.

<p>Phylogenetic relationship analysis of study isolates (LTS) by Maximum Likelihood method in MEGA 6 software.</p

Comparative study of bacteria isolates resistant to different antibiotics.

<p>Comparative study of bacteria isolates resistant to different antibiotics.</p

Viable count of study samples in term CFU/gm or ml.

<p>Viable count of study samples in term CFU/gm or ml.</p

Tolerance of Gram negative and Gram positive bacteria to varying concentrations of metal ions.

<p>Tolerance of Gram negative and Gram positive bacteria to varying concentrations of metal ions.</p