Relatedness of Streptococcus equi subsp. zooepidemicus strains isolated from harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) of various origins of the North Sea during 1988-2005.

The present study was designed to identify 15 beta-hemolytic streptococci isolated during a period between 1988 and 2005 from nine harbour seals and six grey seals from various origins of the North Sea. All isolates were identified as Streptococcus equi subsp. zooepidemicus. The bacteria were additionally investigated for relatedness by restriction fragment length polymorphism analysis of PCR amplified 16S-23S rDNA intergenic spacer region and gene szp and by macrorestriction analysis of chromosomal DNA of the strains by pulsed field gel electrophoresis. The molecular analysis yielded identical or closely related patterns within the strains of the present study and with the S. equi subsp. zooepidemicus strains isolated from harbour seals of German North Sea which were investigated previously [Akineden, O., Hassan, A.A., Alber, J., El-Sayed, A., Estoepangestie, A.T.S., Lämmler, C., Weiss, R., Siebert, U., 2005. Phenotypic and genotypic properties of S. equi subsp. zooepidemicus isolated from harbor seals (Phoca vitulina) from the German North Sea during the phocine distemper outbreak in 2002. Vet. Microbiol. 110, 147-152]. This indicates that this single or closely related bacterial clone existed during both phocine distemper virus epidemics in 1988 and 2002 and that a direct transmission of the strains has occurred between two seal species and between seal populations of far distant regions possibly with grey seals as a vector.

Adrenocortical responsiveness in southern elephant seal mothers and pups during lactation and the effect of scientific handling.

We examined the cortisol responses to chemical and physical restraint stress in southern elephant seal Mirounga leonina females and their pups at three stages during lactation. In anaesthetised females the serum cortisol levels changed moderately during the 45-min sampling period following restraint, with average peaks at 23 min after anaesthetic administration. Overall, cortisol was relatively low 2 days postpartum and increased throughout lactation. In physically restrained pups serum cortisol increased rapidly after capture; the response was milder at age 2 days than at 11 days and 21 days. Levels were higher in female pups than in males. In order to test whether cortisol levels and/or responses became chronically (i.e. days to weeks) altered due to restraint, we compared the cortisol response at a late stage of lactation between three groups of mother-pup pairs previously given different levels of chemical (mothers) or physical (pups) restraint stress: control (not handled previously), moderate treatment (previously handled twice), and high treatment (previously handled 3-4 times). Pups of the three treatment groups showed similar adrenocortical responses suggesting no chronic effect of repeated physical restraint, despite the clear acute effects. Mothers of the control and moderate treatment groups showed similar cortisol responses; however, mothers of the high treatment group showed significantly attenuated responses. This indicated that elephant seals tolerated moderate degrees of handling disturbance; however, repeated (3-4) chemical immobilisations in lactating females may reduce their adrenocortical responsiveness for a period of days or weeks.