as nonpathogenic, and Pseudomonas aeruginosa 2-9 as 

 pathogenic. Cytopathic effect of these strains on RH ceils 

 suggested that P. fluorescence BKM-894(H) did not produce 

 an appreciable effect on the cell culture, while the aggressive 

 strain P. aeruginosa 2-9 killed laboratory animals, destroyed 

 the cell culture monolayer by 75-100% after 48 hours and 

 completely suppressed the mitotic activity of the cells. 



Analysis of cytopathic data (Table 10) showed that 44.5, 

 44.4, and 11.1% of the bacterial strains of the genus 

 Pseudomonas, isolated from the Baltic Sea, were pathogenic, 

 quasi-pathogenic (potentially pathogenic), and nonpathogenic 

 strains, respectively. Thus, both the quantitative and qualitative 

 assessment of cytopathic data suggests a high pathogenicity of 

 Baltic strains, and much higher than those of Bering strains. 

 These results support the related level of anthropogenic pollution 

 in the Baltic Sea (an impact region) and the Bering Sea (a 

 background region). In the Chukchi Sea, the proportions of 

 pathogenic, quasi-pathogenic, and nonpathogenic strains made 

 up 66.7, 1 1 .2. and 22.2% of the total number of the investigated 

 strains, respectively. 



TABLE 10 



Cytopathic effect of the strains of Pseudoinonades on the culture of 

 RH cells from the Bering, Chukchi and Baltic Seas. 



The proportion of strains with 

 cytopathic effecl, % 



Region 



Nonpathogenic 



Potentially 

 pathogenic 



Pathogenic 



BerinaSea 1984 



Chukchi Sea 1988 



Baltic Sea 1987 



42.9 



11.1 



50.0 



1.1 



44.4 



7.1 



66.7 



44.5 



The discovery of pathogenic microorganisms in the 

 Chukchi Sea is of much interest and requires a thorough study. 

 The limited information available restricts an interpretation 

 about the cause of this phenomenon. The results of parallel 

 investigations of the cytopathic effect and invasive properties 

 of 1 8 strains oi Pseudomonas and Flavobacterium-Cytophaga 

 using the culture of kidney cells of a human embryo ( RH ) and 

 fish skin cells (EPC) are shown in Table 1 1. The study of Baltic 

 and Chukchi Seas strains, using the model of fish skin cells 



(EPC) made it possible to determine their pathogenic properties 

 against fish. The comparison showed that 64. 2% of the studied 

 strains possessed cytopathic action. The results also showed 

 that a number of strains that did not manifest pathogenic 

 properties on human cells produced cytopathic effects on fish 

 cells. This confirms the different degree of pathogenicity of the 

 same strains of marine bacteria for man and fish. 



TABLE 11 



Cytopathic effect of the strains of Pseudomonades from the 

 Chukchi and Baltic Seas on the culture of RH and EPC cells. 



Proportion of strains, % 

 Number of the Pathogenic Potentially Nonpathogenic 



Region investigated pathogenic 



slrains RH EPC RH EPC RH EPC 



Chukchi 

 Sea, 1988 



18 66.7 77.8 



22 2 22.2 



Baltic 



Sea, 1987 14 50.0 71.4 50.0 28.6 



Thus, these investigations suggest that under the pressure 

 ofchemical pollutants, pathogenic properties of microorganisms 

 can change as a result of transfomiation and selection. Besides 

 an ability to decompose complex organic compounds and resist 

 the action of antibiotics, heavy metals, and xenobiotics. marine 

 microflora can acquire pathogenic properties. 



The discovered tendencies for increasing the aggressiveness 

 of marine bacteria are based on the adaptation of the bacterial 

 community to new chemical substrates, conditioned by transfer 

 of genetic determinants. The process is accompanied by the 

 selection and accumulation of strains in the polluted 

 environment. These strains contain plasmids for decomposition 

 of and resistance to xenobiotics. Based on the premise (Rochelle 

 etal. 1 989 iofconjugation in one plasmid of genes responsible 

 for decomposition and resistance to xenobiotics, with genes of 

 antibiotics resistance and pathogenic properties, we hypothesize 

 that the processes of adaptation of microorganisms to chemical 

 pollution are accompanied by selection and accumulation of 

 strains pathogenic for fish and man. This transition of 

 microorganisms from saprophytes to quasi-pathogenic 

 (potentially pathogenic ) and eventually pathogenic poses serious 

 concerns for marine mammals and man. 



110 



