The Resistance Mechanism and Clonal Distribution of Tigecycline-Nonsusceptible Klebsiella pneumoniae Isolates in Korea

PURPOSE: Tigecycline is one of the drugs used to treat multi-drug resistant Klebsiella pneumoniae (K. pneumoniae) infections, including complicated skin and soft tissue infections, complicated intra-abdominal infection, and community-acquired pneumonia in the Republic of Korea. However, since its commercial release, K. pneumoniae resistance against tigecycline has been reported, and there is a serious concern about the spread of tigecycline resistant bacteria. MATERIALS AND METHODS: In this study, we collected and analyzed 342 isolates from 23 hospitals in the Republic of Korea to determine the mechanisms of tigecycline susceptibility and their clonal types. The hospitals include several from each province in the Republic of Korea, except Jeju, an island province, and nonsusceptibility among the isolates was tested by the disk diffusion method. In our lab, susceptibility was checked again using the broth dilution method, and clonal types were determined using the multilocus sequence typing protocol. Real-time PCR was performed to measure the ramR mutation in the isolates nonsusceptible to tigecycline, which would suggest an increased expression of the AcrAB multidrug pump. RESULTS: Fifty-six K. pneumoniae isolates were found to be nonsusceptible, 16% of the 342 collected. Twenty-seven and nine isolates of the tigecycline nonsusceptible isolates had mutations in the ramR and rpsJ genes, respectively; while 18 nonsusceptible isolates harbored the tetA gene. Comparison of isolates with and without ramR mutation showed a significant statistical difference (p<0.05) for expression of AcrAB. Moreover, the most common clonal types, as observed in our study, appear to be ST11 and ST789. CONCLUSION: Several dominate clonal types infer tigecycline resistance to K. pneumoniae, including ST11, ST768, ST15, ST23, ST48, and ST307. There does not seem to be a transferrable medium, such as plasmid, for the resistance yet, although mutation of the ramR gene may be a common event, accounting for 48% of the nonsusceptibility in this study.

Surgical Treatment of Mirizzi Syndrome / 한국간담췌외과학회지

BACKGROUND/AIMS: Mirizzi syndrome is a rare complication of longstanding gallstone disease which resulting in obstructive Jaundice. It is benign stricture of common hepatic duct because of stone impacted with in the cystic duct or Hartmann pouch of the gallbladder. The aim of this study is to evaluate our experience of Mirizzi syndrome and consider its surgical treatment. METHODS: During the years 1994 to 2001 at Asan medical center, 23 cases of Mirizzi syndrome were diagnosed on the basis of preoperative and postoperative findings and they were retrospectively reviewed. RESULTS: There were 12 patients with Csendes type I, 6 patients with type II, and 5 patients with Type III. Average age was 61 years (range: 31 to 83 years) For preoperative evaluation Endoscopic retrograde cholangiopancreatography (ERCP) and Ultrasonography were performed in all cases. Laparoscopic cholecystectomy was tried in 7 type I cases. 5 were successfully treated and 2 conversions were reported, all because of unclear anatomy. In 6 type II cases open cholecystrctomy, CHD repair and T tube insertion were performed. 5 patients with type III were required hepaticojejunostomy. CONCLUSIONS: High index of suspicion is required for diagnosis of Mirizzi syndrome and laparoscopic approach is permissible in specialized center especially in the case of suspected Mirizzi type I, under the recognition of biliary anatomy through preoperative imaging studies. If there is fistula or unclear anatomy, we recommend open operative techniques for the safety and the efficiency.