Antimicrobial susceptibility of bacteria isolated from pinnipeds stranded in central and northern California.

Abstract

Over a 2-yr period (1994-1995), the antimicrobial susceptibilities of 129 bacterial isolates recovered from live stranded California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) were studied. Nineteen genera of bacteria were isolated from various sites of inflammation; abscesses and umbilici were the most common sites. Seventy-two percent of the bacterial isolated were gram negative, and the Enterobacteriaceae (Escherichia coli, Proteus spp., Klebsiella spp., Salmonella spp.) accounted for 75% of the gram-negative isolates. All of the gram-positive isolates were either Enterococcus spp. or Staphylococcus aureus. Multiple drug resistance was present in all but one of the bacterial isolates. The gram-positive bacteria were most susceptible to amoxicillin-clavulanic acid (77% of 36 isolates) and least susceptible to lincomycin (18% of 11 isolates). The gram-negative bacteria were most susceptible to amikacin (91% of 91 isolates) and least susceptible to clindamycin (3% of 109 isolates).