Treatment of Donor-derived Carbapenem-resistant Klebsiella pneumoniae Infection after Renal Transplantation with Tigecycline and Extended-infusion Meropenem.

OBJECTIVE: Donor-derived carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has recently emerged as a critical early complication after renal transplantation. Although CRKP is usually sensitive to tigecycline, monotherapy with this drug is often less than effective. We investigated the efficacy of a combined regimen of tigecycline with high-dose, extended-infusion meropenem in the treatment of donor-derived CRKP infection after kidney transplantation. METHODS: From Jan. 2016 to Dec. 2017, a total of 12 CRKP isolates were detected from cultures of the organ preservation solution used for soaking the donor kidneys at our institute. Probable or possible donor-derived infection (DDI) was identified in 8 transplant recipients. Clinical data were retrospectively analyzed. RESULTS: Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing CRKP was reported to be positive in organ preservation solution cultures at 3.5±0.9 days after transplantation, leading to surgical site (n=3), urinary tract (n=4), and/or bloodstream (n=2) infections in 8 recipients. The drug susceptibility tests showed that CRKP was sensitive to tigecycline, but resistant to meropenem. In 7 patients who received tigecycline combined with high-dose extended-infusion meropenem, DDIs were successfully cured. The length of hospital stay was 31 (18-129) days, and the serum creatinine at discharge was 105.8±16.7 µmol/L. The one remaining patient who received tigecycline combined with intravenous-drip meropenem died of septic shock. A median follow-up of 43 months (33-55) showed no recurrence of new CRKP infection in the 7 surviving recipients. CONCLUSION: It was suggested that a prompt and appropriate combination therapy using tigecycline with high-dose extended-infusion meropenem is effective in treating donor-derived KPC-2-producing CRKP infection after renal transplantation.

Nature of pectin-protein-catechin interactions in model systems: pectin-protein-catechin interactions.

Apple pectins, proteins and catechins were combined in model systems, and the resulting hazes were measured by spectrophotometric method, a zeta potential and particle size analyzer and Ostwald viscosimeter. The amount of hazes formed depends on the concentrations of both protein and pectin. The cooperative hydrogen bonding between the numerous hydroxyl groups of pectins and hydrone and the gel-like structure developed by pectin induced the solvation or solubilization of polymers, and the protein molecule has a fixed number of polyphenol binding sites. The influence of pectin relative molecular mass and degree of esterification on the formation of suspended particles is prominent, and this makes the number of hydroxyl groups and charge of pectin which is concerned with combining protein and catechin to change a lot. More haze was observed when model systems were heated, suggesting that hydrophobic groups of protein are beneficial to their binding with phenols and pectins. The pH value affects the charged state of the protein and pectin, which influences the combination of pectin-gliadin-catechin.