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Higher vancomycin MIC values (≥1.5 mg/L via Etest) may be associated with vancomycin treatment failure among patients with serious methicillin-resistant Staphylococcus aureus (MRSA) infections. As there were limited similar data for teicoplanin, this retrospective cohort study intended to determine the predictive value of teicoplanin MICs for treatment failure among patients with MRSA bacteraemia.All patients with at least one blood culture positive for MRSA admitted to the hospital between January 2010 and January 2011 were reviewed. Patients with an age ≥18 years and receipt of teicoplanin therapy throughout the course or receipt of72 h of vancomycin therapy and then teicoplanin for3 days were enrolled. Teicoplanin Etest(®) MICs and treatment outcomes for MRSA bacteraemia were reviewed to identify the breakpoint of teicoplanin MICs influencing treatment outcomes.Of the 101 patients enrolled, 56 had a lower teicoplanin MIC (≤1.5 mg/L) for MRSA and 45 had a higher MIC (1.5 mg/L) for MRSA. A lower teicoplanin MIC was associated with a favourable outcome [37 (66.1%) versus 13 (28.9%); P0.001] and a lower rate of bloodstream infection-related mortality [15 (26.8%) versus 22 (48.9%); P=0.022]. Patients with chronic obstructive pulmonary disease, bacteraemic pneumonia or higher Pittsburgh bacteraemia score had an unfavourable outcome (P=0.028, 0.022 and0.001, respectively). Multivariate analysis showed that teicoplanin MIC1.5 mg/L, higher Pittsburgh bacteraemia score and bacteraemic pneumonia were independent risk factors for unfavourable outcome.A higher teicoplanin MIC value (1.5 mg/L) may predict an unfavourable outcome and higher mortality rate among teicoplanin-treated MRSA bacteraemic patients.

Objectives: In 2008, a new set of penicillin breakpoints was published in the CLSI revised guideline, M100-S18, to define the susceptibility of non-meningeal isolates of Streptococcus pneumoniae. The impact of the change is studied and discussed. Methods: Laboratory data on pneumococcal isolates collected from Chang Gung Memorial Hospital during 2000―07 were analysed using the original and modified penicillin CLSI breakpoints. Results: A total of 3729 non-duplicate isolates were identifed, including 43 (1.2%) meningeal isolates showing high rates of penicillin (79.1%) and ceftriaxone (34.9%) resistance. For non-meningeal isolates, penicillin non-susceptibility was reduced significantly from 75.1% (72.4% in 2000―03 increasing to 77.4% in 2004―07) to 16% (28.6% in 2000 decreasing to 2.4% in 2007) if the modified breakpoints were applied. However, isolates for which penicillin MICs were 1―2 mg/L increased significantly from 34.2% in 2000 to 59.8% in 2007. Ceftriaxone non-susceptibility also increased significantly from 2.8% before 2005 to 18.4% thereafter. A quarter (25.7%) of the pneumococcal isolates were recovered from patients

Objectives: The aim of the study was to characterize the genetic basis of b-lactam resistance developed in clinical isolates of Klebsiella pneumoniae after exposure to cefuroxime. Methods: Clinical features of two episodes of liver abscess caused by K. pneumoniae in a diabetic patient were reported. Four isolates (KP1/KP2 and KP3/KP4 )o fK. pneumoniae were recovered from cultures of blood/pus in the first and second episodes, respectively. Laboratory investigation of the K. pneumoniae isolates included genotyping by PFGE, resistance gene analysis by PCR amplification and DNA sequencing, and outer membrane protein analysis by SDS–PAGE. Results :K P3 and KP4 were recovered after a 21 day cefuroxime therapy and demonstrated identical genotypes to that of KP1 and KP2. However, compared with KP1 and KP2, emerging resistance to piperacillin, cefalotin, cefuroxime and cefoxitin was observed. The other antibiotics tested, except ampicillin, retained the same effectiveness against the four isolates, although increases (4- to 8-fold) in the MICs of cefotaxime, ceftriaxone, ceftazidime, cefepime, flomoxef and aztreonam were observed in KP3 and KP4. None of the isolates produced extended-spectrum b-lactamases or plasmid-mediated AmpC b-lactamases. Deficiency in the expression of an outer membrane protein (OmpK35) was observed in the cefuroxime-resistant isolates, KP3 and KP4. Conclusions: The increased resistance to cephalosporins in these clinical isolates of K. pneumoniae after exposure to cefuroxime might be related to the loss of OmpK35.

Salmonella infection is a distressing health problem worldwide. This study reports the changing epidemiology of Salmonella infections in Taiwan during 1999-2003, with emphasis on increasing ceftriaxone resistance.Records of Salmonella clinical isolates in Chang Gung Memorial Hospital during 1999-2003 were reviewed. All isolates were identified and antimicrobial susceptibility determined by standard methods. A total of 22 ceftriaxone-resistant isolates were investigated by PCR sequencing of the bla(TEM), bla(SHV), bla(CTX-M) and ampC genes. Southern-blot hybridization was used to localize the ampC gene. Infrequent-restriction-site PCR was used to genotype these isolates.A total of 3635 Salmonella isolates, including 3592 (98.8%) non-typhoid Salmonella, were identified. Serogroup B (55.6%) remained the most predominant, but the prevalence has been decreasing. In contrast, serogroup D infections have increased significantly from 13.6 to 22.8%. Overall resistance to ampicillin and chloramphenicol remained high, with the highest rate (91% to both drugs) observed in Salmonella enterica serotype Choleraesuis in 2003. A sudden upsurge of ciprofloxacin resistance from zero to 69% was found in S. Choleraesuis. Ceftriaxone resistance increased in several serogroups (0.8-2.1%; average, 1.5%). The resistance was associated with plasmid-mediated bla(CMY-2) in 14 cases and extended-spectrum beta-lactamases (ESBLs), including CTX-M-3 (n=6), SHV-2a (n=1) and SHV-12 (n=1), in others. Diverse serotypes and genotypes were found among the ceftriaxone-resistant isolates.Increasing ceftriaxone resistance in non-typhoid Salmonella appears to link to the spread of plasmid-mediated ampC or ESBL genes. Effective measures should be taken to prevent the problem worsening.