Evaluation of Methods for Storage of Marine Macroorganisms with Optimal Recovery of Bacteria

Marine macroorganisms are a potential source for new bioactive substances. In many cases marine microorganisms—especially bacteria—associated with these macroorganisms are actually producing the bioactive substances. One often is not able to immediately isolate microorganisms from collected macroorganismic materials; we therefore evaluated different methods for storage of such material, e.g., on board research vessels. These methods were the following: storage of macerates in sintered glass beads and 5% trehalose at −20°C (SGT method); storage of sections in 5% dimethyl sulfoxide at −70°C (SD method); storage of macerates at −20°C using the commercial ROTI-STORE system (RS method); storage of macerates at −20°C in 50% glycerol (GC method); and storage of macerates covered by mineral oil at 4°C (MO method). The SGT and SD methods resulted in numbers of and especially diversity of recoverable bacteria that were higher than for the other methods. Data for the RS method indicated its potential usefulness, too. The MO method resulted in growth during storage, thereby enriching a few selected microorganisms; the GC method resulted in a survival and diversity of recovered bacteria that was too low

Incidence of Virulence Factors and Antibiotic Resistance among Enterococci Isolated from Food

The incidence of virulence factors among 48 Enterococcus faecium and 47 Enterococcus faecalis strains from foods and their antibiotic susceptibility were investigated. No strain was resistant to all antibiotics, and for some strains, multiple resistances were observed. Of E. faecium strains, 10.4% were positive for one or more virulence determinants, compared to 78.7% of E. faecalis strains. Strains exhibiting virulence traits were not necessarily positive for all traits; thus, the incidence of virulence factors may be considered to be strain specific