Thermal requirements for growth, survival and aerobic performance of weatherfish larvae Misgurnus fossilis.

Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27° C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27° C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15° C resulted in severe declines in survival (to <10%). Growth of larvae (expressed as dry mass and total length) was highest at 19 and 23° C, but significantly decreased at 27° C. Routine metabolic rate of 3 days post-hatch larvae was estimated as oxygen consumption rate (MO2 ) during acute exposure (30 min to 1 h) to seven temperatures (11, 15, 19, 23, 27, 31 and 35° C). Larval oxygen uptake increased with each consecutive temperature step from 11 to 27° C, until a plateau was reached at temperatures >27° C. All larvae of the 35° C regime, however, died within the MO2 measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re-introduction activities for endangered M. fossilis.

Nosocomial outbreak due to Enterococcus faecium highly resistant to vancomycin, penicillin, and gentamicin.

In October 1990, Enterococcus faecium that was highly resistant to glycopeptides, penicillins, and aminoglycosides was isolated from the peritoneal dialysis fluid from a patient in an intensive care unit. Over the following 6 months, multiresistant E. faecium organisms were isolated from cultures of blood, urine, or surgical wound specimens from eight additional patients. Surveillance cultures of groin and/or rectal swabs were positive for eight of 37 patients and four of 62 employees at risk. Restriction endonuclease digestion of chromosomal DNA from outbreak isolates was consistent with dissemination of a single strain throughout the intensive care unit. Strict infection control interventions contained the outbreak after several weeks. Review of patient charts suggested that renal insufficiency, length of hospital stay, duration of antibiotic treatment, and prior treatment with vancomycin were risks for infection due to multiresistant E. faecium. The emergence of multiple-drug-resistant enterococci presents serious infection control and therapeutic dilemmas.