Deciphering the Cold Adaptive Mechanisms in Pseudomonas psychrophila MTCC12324 Isolated from the Arctic at 79° N.

Psychrophiles, host of cold environments, have been successfully undergoing the process of evolution by which they have acquired innate adaptations to withstand the unfavorable effects of low temperature. Psychrophiles renders immense opportunity to explore the underlying mechanisms of cold adaptation. The present study focused to explore the cold adaptive mechanisms of Pseudomonas psychrophila MTCC12324, a facultative psychrophilic bacterium isolated from the Ny-Alesund, an island in the Svalbard Archipelago (79°55' N, 11°56' E) in the Arctic. Whole genome sequencing of P. psychrophila MTCC12324 and its analysis revealed the redundant nature of genome and identified several cold acclimation genes including cold shock proteins, and chaperones involved in the adaptive mechanism to thrive in the cold environment. Comparative proteome analysis of P. psychrophila MTCC12324 at 4 °C and 25 °C has thrown lights on the metabolic pathways and cellular processes adopted to withstand the cold environment. Basic survival pathways and factors involved in energy metabolism were found to be unaltered whereas stress response factors, enzymes involved in fatty acid elongation and cold-adapted chaperones were found to be enhanced towards cold stress. The present study facilitates recognition of crucial factors including polyunsaturated fatty acid biosynthesis, mRNA chaperones, and other cold-inducible proteins which favors the bacteria in conferring cold adaptation.

Draft Genome Sequence of Pseudomonas psychrophila MTCC 12324, Isolated from the Arctic at 79°N.

Pseudomonas psychrophila MTCC 12324 is a facultatively psychrophilic bacterium isolated from the Arctic fjord Ny-alesund in the Svalbard Archipelago. Here, we present a 5.2-Mb draft genome sequence of P. psychrophila MTCC 12324, reported for the first time, from the Arctic. This enables a study of the cold adaptation mechanisms to survive under the extreme cold conditions.

Multiresistant Vibrio cholerae non-O1/non-O139 from waters in South India: resistance patterns and virulence-associated gene profiles.

From different aquatic locations in Alleppey district, Kerala, South India a number (n = 36) of multiresistant non-O1, non-O139 V. cholerae strains were isolated. Water samples were filtered through 0.22 mum membrane filters, enriched in alkaline peptone water and plated onto thiosulfate-citrate-bile salts-sucrose (TCBS) agar. The isolates were resistance to cefotaxime (50%), nalidixic acid (44.4%), streptomycin and tetracycline (41.6%), trimethoprim (38.8%), co-trimoxazole (33.3%), furazolidone (27.7%), neomycin and ofloxacin (19.4%), ciprofloxacin, norfloxacin and spectinomycin (16.6%), gentamicin (8.3%) and chloramphenicol (2.7%). To our knowledge, this is the first report from Kerala, South India on the emergence of multiple drug resistance in V. cholerae isolates belonging to serogroup other than O1 and O139. Virulence-associated gene profiling of the isolates by PCR revealed the presence of toxR (100%), rtxA (61.1%), hlyA (50%), mshA (33.3%), tcpA-acfB (13.8%) and st (2.7%) genes. The virulence gene clusters ctxA, ompU, ace, and zot were not detected. This study demonstrates the presence of a wide array of critical virulence factors in diverse strains of Vibrio cholerae non-O1/non-O139. Hence, this serogroup can no longer be ignored as an environmental reservoir of virulence genes.

Phenotypic and molecular identification of Cellulosimicrobium cellulans isolated from Antarctic snow.

We report for the first time the isolation of Cellulosimicrobium cellulans from Antarctic snow. This strain demonstrated physiological traits that were markedly different from that of the mesophilic C. cellulans type strain DSM 43879(T). The dominant cell wall sugars in C. cellulans were glucose, galactose and mannitol whereas rhamnose was the only major sugar in the type strain. Cellular fatty acid patterns were dominated by 12-methyltetradecanoic acid (ai-C(15:0)), hexadecanoic acid (C(16:0)) and 14-methylhexadecanoic acid (ai-C(17:0)) but lacked iso fatty acids unlike the type strain. The ability of C. cellulans to survive in Antarctic snow could be due to these modified physiological properties that distinguish it from its mesophilic counterpart. Carbon utilization studies demonstrated that C. cellulans preferred complex carbon substrates over simple ones suggesting that it could play a potential role in carbon uptake in snow. Our study shows that this genus could be more cosmopolitan than hitherto thought of and is capable of living in extreme cold environments.