Metal and antibiotic-resistance in psychrotrophic bacteria from Antarctic marine waters

• Main Authors: DeSouza, M.J.B.D., Nair, S., LokaBharathi, P.A., Chandramohan, D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2006
• Subjects: psychrotrophic bacteria; Antibiotic-resistance; Antarctic; Southern Ocean; The Antarctic; Austral; Indian; Antarc*
• Online Access: http://drs.nio.org/drs/handle/2264/206

In the wake of the findings that Antarctic krills concentrate heavy metals at ppm level, (Yamamoto et al., 1987), the Antarctic waters from the Indian side were examined for the incidence of metal and antibiotic-resistant bacteria during the the austral summer (13th Indian Antarctic expedition) along the cruise track extending from 50°S and 18°E to 65°S and 30°E. The bacterial isolates from these waters showed varying degrees of resistance to antibiotics (Chloramphenicol, ampicillin, streptomycin, tetracycline and kanamycin) and metals (K2CrO4, CdCl2, ZnCl2 and HgCl2) tested. Of the isolates screened, about 29% and 16% were resistant to 100ppm of cadmium and chromium salt respectively. Tolerance to lower concentration (10ppm) of mercury (Hg) was observed in 68% of the isolates. Depending on the antibiotics the isolates showed different percentage of resistance. Multiple drug and metal-resistance were observed. High incidence of resistance to both antibiotics and metals were common among the pigmented bacterial isolates. Increased resistance decreased the ability of bacteria to express enzymes. The results reiterate previous findings by other researchers that the waters of southern ocean may not be exempt from the spread of metal and antibioticresistance.