A comparison of fish tissue mercury concentrations from homogenized fillet and nonlethal biopsy plugs.

The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs.

In vitro activity of ceftriaxone plus tazobactam against members of Enterobacteriaceae.

AIMS: To study the in vitro activity of ceftriaxone alone and in combination with the beta-lactamase inhibitor tazobactam against bacterial isolates belonging to the Family Enterobacteriaceae. METHODS: One hundred and five consecutive isolates of Escherichia coli and Klebsiella spp. that had been recovered from various high-risk areas of the hospital were included in the study. MIC estimation to ceftriaxone and a combination of ceftriaxone and tazobactam was performed by the agar dilution method. RESULTS: By the MIC studies, 88.6% of the strains appeared to be resistant to ceftriaxone with the MIC90 value being > 256 microg/ml. When the MIC were done to ceftriaxone in combination with tazobactam, the resistance rate dropped to 4.8% with the MIC90 value being 4.0 microg/ml. CONCLUSION: The combination of ceftriaxone and tazobactam appears to be an excellent therapeutic alternative with 94.6% of ceftriaxone resistant strains being susceptible in vitro to this combination.