Chromium is a naturally occurring element found in rocks, animals, plants, soil, and in volcanic dust and gases. Chromium is present in the environment in several different forms. Most leather is chrome-tanned. All wastes containing chromium are considered hazardous by the U.S. Environmental Protection Agency. These irregularities have had a disastrous economic, social and health impacts. Chrome liquor is generally used for tanning purpose. When chrome liquor is discharged with effluents into the environment, they contain chrome salts in excess of the maximum permissible limits. In biological system, enrichment of chromium-resistant bacteria is formed by sludge deposition from such effluents. The present study shows the diversity of chromium resistance bacteria/strains isolated from tannery effluents in past decades by researchers. Our literature review found a high chromium tolerance among isolated bacteria ranging from 10µg/ml-45000µg/ml. CMBL Crl3 exhibited the highest resistance to chromium. Isolates were screened and characterized with biochemical and 16S rRNA based sequencing methods. There are few reports are available for characterization by using 16S rDNA sequencing methods, but 16S rDNA sequencing has played a significant role in the accurate identification of bacterial isolates (its amplicon product shows highly and less conserved region but in case of 16S rRNA amplicon shows only highly conserved stretches in bacteria) and particularly important in the case of bacteria with unusual phenotypic profiles, rare bacteria, slow-growing bacteria, uncultivable bacteria and culture-negative infections. Identification of microbes related technology might provide an alternative or addition to conventional method of metal removal or metal recovery. The identified chromium resistant bacteria would be useful for bioremediation of heavy metal contaminated tannery effluent. In transferring this technology from laboratory to a large-scale application, better understanding of all these aspects is necessary. Hence, this developing biotechnological method that encompasses fields from genetic engineering to reactor engineering demands focused research in these directions, which may lead to implementation of this technology on a larger scale and drive it toward being the most opted-for technology.

Background: Pseudomonas aeruginosa cause infections of all sites and is common cause of nosocomial infections. Objectives: Detection of resistant phenotypes of P.aeruginosa clinical isolates in rural tertiary care hospital. Materials and methods: A total of 88 P.aeruginosa were included in the study and antibiotic susceptibility of the isolates was determined by Clinical laboratory and standard institute [CLSI] guidelines. Betalactames, aminoglycosides and quinolones resistant phenotypes of P.aeruginosa are detected on the basis of antibiotic susceptibility profile. Extended spectrum betalactamases (ESBL), AmpC betalactamases and Carbapenemases are detected using standard microbiology guidelines. Result: Out of 88 P.aeruginosa isolates, majority were isolated from sputum followed by urine and endotracheal tube. Betalactams resistant phenotypes: Out of 88, 71 (81%) were natural wild strain, 4(5%) were ESBL, 3 (4%) were carbapenamase, 1 (1%) was penicilinase, oprJ, oprN, and D2 resistant phenotype. Aminoglycosides resistant phenotype: Out of 88, 64 (73%) were natural wild strain, 6 (7%) were G phenotype, 5 (6%) were impermeability phenotype, and 1 (1%) was GNtT phenotype. Quinolones resistant phenotype: Out of 88, 74 (84%) were natural wild strain, 4(5%) were IV phenotype, and 2 (2%) were efflux phenotype. Conclusion: Early identification of resistant phenotypes of P.aeruginosa based on antimicrobial susceptibility result would guide clinician to start early appropriate therapy that lead to good clinical outcome, and to reduce spread of nosocomial infections