Isolation and characterization of Staphylococcus argenteus strains from retail foods and slaughterhouses in Japan.

Staphylococcus argenteus has been recently established as a novel species of Staphylococcus aureus complex. It is known to cause various human diseases, such as skin and soft-tissue infections, sepsis, and staphylococcal food poisoning, although the source of infection has not been clearly described. In food poisoning cases, the source of bacterial contamination in food is unknown. This study examined the prevalence of S. argenteus among retail fresh food and poultry slaughterhouses in Japan. Among 642 food samples examined, successful isolation of S. argenteus was achieved in 21 of 151 (13.9%) chicken samples. No isolations from pork, beef, fish, or vegetables in retail markets were confirmed. Multiple-locus sequence typing revealed that the 21 isolates were classified into four sequence types (ST) that were divided into 14 subtypes using spa-typing. All food isolates were susceptible to methicillin and did not show positivity for the Panton-Valentine leukocidin gene. When bacteria were isolated from two poultry slaughterhouses in the same region, 14 S. argenteus strains were successfully isolated from only one slaughterhouse. Thirteen of 14 strains were isolated from a poultry carcass and slaughterhouse environments during a certain sampling period and were all classified as ST5961 with identical spa-type. Also, the number of single nucleotide variants (SNVs) detected on the core genomes of the same 13 strains were between 0 and 17, suggesting a long-term inhabitation of an S. argenteus strain inside the facility. Furthermore, one isolate from chicken meat was also genetically linked with the same lineage of slaughterhouse isolates, with ≤15 SNVs being detected. Additionally, one slaughterhouse isolate from chiller water and three chicken isolates were classified into the same cluster by phylogenetic analysis, although the number of pairwise SNVs ranged from 62 to 128. To the best of the authors' knowledge, this is the first study that demonstrated S. argenteus in a food processing facility and the possible bacterial contamination on food during food processing.

A possible involvement of 3-monoglucuronyl-glycyrrhetinic acid, a metabolite of glycyrrhizin (GL), in GL-induced pseudoaldosteronism.

Glycyrrhizin (GL), a major ingredient of Glycyrrhiza Radix (licorice), is widely used to treat various disorders or as a sweetener. It is also known that GL occasionally induces pseudoaldosteronism. It is conceivable that the active form of GL in pseudoaldosteronism induction is glycyrrhetinic acid (GA). Although it is reported that 3-monoglucuronyl-glycyrrhetinic acid (3MGA) is detectable specifically in the plasma of patients with GL-induced hypokalemia, pharmacokinetics and a hypokalemia induction mode of action for 3MGA have not been clarified. We investigated the toxicokinetics of GL, GA and 3MGA in a single or multiple oral administration of GL. The results suggested that higher blood concentrations of 3MGA were maintained by the multiple administration compared to the single dose, whereas the concentrations of GA and GL showed no difference. We injected 3MGA intravenously and found that it can decrease the plasma potassium level (PPL) in vivo. It is clinically recommended to avoid a combination treatment of GL and furosemide. While treatment with a low dosage of furosemide had no effect on PPL, the multiple administration of GL and furosemide markedly decreased PPL compared to the effect of administering GL alone. In the single dosage regime, there was no difference between PPL after the combination treatment and after administering GL alone. Collectively, these findings suggested that accumulation of 3MGA may be involved in the pathogenesis of pseudoaldosteronism induced by chronic GL treatment.

Pharmacokinetics of TJ-8117(Onpi-to), a drug for renal failure (II): effects of food, repeated administration and renal failure to plasma concentration of [3H]-(-)epicatechin 3-O-gallate in rats.

TJ-8117 (Onpi-to) is a herbal medicine extracted from mixture of five crude drugs (Rhei Rhizoma, Glycyrrhizae Radix, Ginseng Radix, Zingiberis Rhizoma and Aconiti Tuber), which has been developed as a drug for chronic renal failure. (-)Epicatechin 3-O-gallate (ECG), one of the active compounds of TJ-8117, was labeled with tritium and spiked to TJ-8117. Effects of food, renal failure and repeated administration to pharmacokinetics of ECG-related radioactivity in the plasma were investigated after oral administration of TJ-8117 containing [3H]ECG ([3H]TJ-8117) in male rats. After oral administration of [3H]TJ-8117, the radioactivity in the plasma in non-fasted rats was higher than that in fasted rats. AUC(0-72 h) and Cmax in the non-fasted was 123% and 248% of those in the fasted. After oral administration of [3H]TJ-8117, the radioactivity in the plasma in 5/6 nephrectomized rats was higher than that in sham-operated rats. AUC(0-72 h) and Cmax in 5/6 nephrectomized was 332% and 236% of those in sham-operated. After repeated administration of TJ-8117 for 6 days, [3H]TJ-8117 was administered on 7th day. Radioactivity in plasma in first day was similar to that in 7th day. The pharmacokinetic parameters were not significantly different between single and repeated administration.