Emergence of Infections Caused by Vancomycin-resistant Susceptibility, and Molecular Epidemiology

為了了解本院萬古黴素抗藥性之腸球 菌(VRE)流行情形。當我們分析了12 位病 患分離之25 株VRE，其臨床特徵菌株之藥 物感受性，van A，B 和C 基因和分子生物 學分型。所有之菌株均只含van A 基因， 有一病患有肛門口膿瘍，且由此傷口分離 出12 株VRE（分別是4 株E. faecalis，7 株E. faecium，和1 株E. casseliflavus）。 分子生物學分型之結果顯示，多種species 之VRE 和多種clones 之VRE 可同時存在 於住院病人之身上，且同一clone 之VRE 方可長期存活於病人之下腸胃道內。To understand the epidemiology of vancomycin-resistant enterococci (VRE) in a university hospital in Taipei, Taiwan. A retrospective review over a 27-month period, from March 1996 to May 1998 was performed. Patients with VRE isolated from any body site were identified through hospital microbiology and infection control records. Patient charts were reviewed for clinical and epidemiology data, including age, gender, previous hospital admissions, underlying diseases, types of infection, and recent antibiotic use. Twenty-five isolates of VRE recovered from 12 patients were identified. One patient with a perianal abscess had 12 isolates of VRE (four isolates of Enterococcus faecalis, seven of E faecium, and one of E casseliflavus) recovered from perianal lesions. Among three patients who were hospitalized in the same room, one had a community-acquired cellulitis over the left leg caused by E faecalis and the other two patients both had anal colonization with two isolates of E faecalis. The other eight patients had one E faecalis isolate each from various clinical specimens. All isolates possessed vanA resistance phenotype and vanA genes. Multiple species of VRE (E faecalis, E faecium. and E casseliflavus) and multiple clones of E faecium could colonize in and/or infect hospitalized patients. In addition, same clones of VRE can persist long-term in patients’ lower gastrointestinal tract. Different antibiotypes and RAPD patterns of the isolates from different patients excluded the possibility of nosocomial spread at the hospital. These results extend our knowledge of the coexistence and the persistence of multiple species and multiple clones of VRE in hospitalized patients

Dissemination of A Clone of Unusual Phenotype of Pandrug-Resistant Acinetobacter baumannii at a Univer sity Hospital in Taiwan

From December 2002 to February 2003, 15 isolates of pandrug-resistant unidentified Acinetobacter species were recovered from seven patients with nosocomial infections or colonizations treated at different wards or intensive care units at the National Taiwan Univer sity Hospital. These isolates, which were glucose- and lactose-non-acidifier s, failed to recognize to the species level using three commercial identification systems: the Vitek GNI, API 20NE system (bioMerieux, Marcy L’Etoile, France) and the Phoenix System (Becton-Dickinson, Sparks, Md.), and 16S rRNA gene sequence analysis. However , 16S-23S rRNA intergenic spacer PCR-restr iction fragment length polymorphism profiles and the sequence analysis of these isolates both identified as A. baumannii. All these isolates were uniformly resistant to ampicillin-sulbactam (MICs, 128->128 mg/ml), ceftazidime (MICs, 64->128 mg/ml), piperacillin-tazobactam (MICs, 128->128 mg/ml), cefepime (MICs, 16-32 mg/ml), aztreonam (MICs, 64-128 mg/ml), ciprofloxacin (MICs, 64-128 mg/ml), trovafloxacin (MICs, 8-16 mg/ml), moxifloxacin (MICs, 4 mg/ml), garenoxacin (MICs, 16-32 mg/ml), amikacin (MICs, >128 mg/ml), imipenem (MICs, 8-16 mg/ml), and meropenem (MICs, 128->128 mg/ml). The identity of the pulsed-field gel electrophoresis patterns and antibiotypes among these isolates from the same patients with an interval of 4-8 weeks and different patients indicated that this pandrug-resistant A.baumannii with unusual phenotype could have long-term per sistence in humans and has widely disseminated at the hospital