TABLE 2 



Resistance of Bering Sea microorganisms of different taxonomic groups to antibiotics 

 (the proportion of resistant strains - R-strains, %). 



Multiple resistance to antibiotics was typical of the majoiity 

 of the heterotrophic microorganisms, isolated in the Bering Sea 

 basin, irrespective of their taxonomic position. The percentage 

 of such strains was 60.8%. The highest percentage found in the 

 genera Pseudomonas and Planococcus was 70.8 and 67.5%. 

 respectively (Table 3). 



TABLE 3 



Number of determinants of resistance to antibiotics with 

 microorganisms of different taxonomic groups. 



The percentage of microorganisms resistant to natural and 

 semisynthetic penicillins ranged from 12.0% for carbenicillin 

 to 26.7-41.4% forbenzylpenicillin, ampicillin, and oxacillin. 

 The tendency was typical of all taxonomic groups. However, 

 most strains were among the genus Pseudonumas (above 50% 

 in some cases). Resistance to antibiotics is characteristic of 

 Pseudomonades (Palleroni, 1975). 



Resistance of Bering Sea heterotrophic microorganisms to 

 aminoglycosides occurred much less frequently. Maximum 

 resistance to hentamycin, kanamycin. monomycin, and 

 streptomycin varied from 8.9 to 1 4. 17f. Resistance to ristomycin 

 was somewhat higher (22.2%). Among the different taxonomic 

 groups, the greatest number of strains resistant to 

 aminoglycosides occurred in the genus Planococcus. 



Analysis of resistance spectra of Bering Sea strains of the 

 main taxonomic groups revealed great diversity (42. 37, and 33 

 spectra in the genera Pseudomonas. Planococcus. and Bacillus. 

 respectively) as well as the absence of the dominating 



R-spectra. Diversity of R-spectra can probably be considered 

 as an indication of an extraordinary genetic plasticity of the 

 studied Bering Sea microorganisms. 



The study of antibiotic resistance of the strains isolated 

 from Chukchi Sea water was conducted and compared with 

 antibiotic resistance of the strains isolated from the Baltic Sea 

 — an impact region of the World Ocean (Table 4). 



TABLE 4 



Resistance of the microorganisms of the Chukchi and Baltic Seas 

 (the proportion of R-strains, %). 



In Table 2, Pseudomonades of the Chukchi Sea were 

 characterized by resistance to benzylpenicillin and methicillin, 

 kanamycin and monomycin (77.7 and 92.6%, respectively), 

 and nevigramon-nalidixic acid (63.0%). The majority of the 

 Chukchi Sea strains showed a low resistance to gentamicin 

 (11.1%) like those of the Baltic Sea. Only one-third of the 

 strains proved resistant to streptomycin (33.3 %). 



Pseudomonades from the Chukchi and Baltic Seas were 

 distinguished by the number of strains resistant to ampicillin, 

 levomycetin, kanamycin, and monomycin. The proportion of 

 the strains from the Chukchi Sea, which were resistant to the 

 first two antibiotics, were considerably less than of Baltic 

 Pseudomonades (14.8 and 33.3% versus 77.8 and 86.7%, 

 respectively). As far as resistance to kanamycin is concerned. 



105 



