© 2015. Volodina V.V., Dyakova S.A., Ruban E.A., Shokasheva D.I., the Caspian Research Institute of Fisheries, Russia
On conditionally pathogenic microflora in the Caspian seal (Pusa caspica)
In the 2000s, the Caspian seal was suffered from combined infection caused by viruses and pathogenic bacteria that led to mass mortality of this species, the only marine mammal in the Caspian Sea. The necessity to carry out bacteriological monitoring and reveal the level of conditionally pathogenic microorganisms in the internal organs and tissues of seals, timely information on the sanitary-microbiological status of these unique animals is currently very relevant.
The results of long-term studies (2007-2014) showed there was a broad spectrum of high-adaptive pathogenic microbial associations in the Caspian seal’s body. The examined mammals had not diseases of bacterial origin in that time, and the most part of this microflora was qualified as the resident one, but these bacteria were able to trigger infectious process in case of deterioration of environmental conditions (anthropogenic pollution, malnutrition, lack of ice fields, etc.). Composition and abundance of the conditionally pathogenic microflora depended on physiological state of seals: the animals with invasive diseases had more abundant and diverse sanitary-indicative microorganisms. Presence of highly adaptive opportunistic microorganisms in the Caspian seal’s body testifies unfavourable sanitary-microbiological status of this species and considerable persistence of sanitary-indicative microflora in the Volga-Caspian basin ecosystem, having a significant parasitizing and multiple antibiotic resistances. That is a background for high epidemiological risk.
Photo: V. Slodkevich and M. Khrisanova