Microbial drug resistance : MDR : mechanisms, epidemiology, and disease
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Microb. Drug Resist. · Jun 2011
Molecular characteristics of community-acquired methicillin-resistant Staphylococcus aureus in Hokkaido, northern main island of Japan: identification of sequence types 6 and 59 Panton-Valentine leucocidin-positive community-acquired methicillin-resistant Staphylococcus aureus.
Prevalence and molecular characteristics of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) were studied in Hokkaido, the main northern island of Japan. Among the 1,015 S. aureus isolates derived from clinical specimens of outpatients collected in 2009, methicillin resistance gene mecA was detected in 189 isolates (18.6%). The most frequent staphylococcal cassette chromosome mec (SCCmec) type in MRSA was II (83.1%), followed by IV (6.9%) and V (3.2%). ⋯ The PVL gene-positive ST6 and ST59 CA-MRSA strains were susceptible to more antimicrobials and had less virulence factor genes than the PVL-negative ST5 MRSA, including the ACME-arcA-positive strains. In the present study, ST6 was identified as a lineage of PVL-positive CA-MRSA, the ACME-arcA was first detected in ST5 MRSA with type V-SCCmec, and ST59 Taiwanese CA-MRSA strain was isolated in Hokkaido for the first time. These findings suggest a potential spread of these emerging CA-MRSA clones in Japan.
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Microb. Drug Resist. · Jun 2011
Epidemiology and clinical features of community-onset bacteremia caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae.
There is limited clinical information regarding community-onset bacteremia caused by extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae. This study was performed to evaluate risk factors and clinical outcomes of community-onset bacteremia caused by ESBL-producing K. pneumoniae. A total of 435 patients with community-onset K. pneumoniae bacteremia were included and data from patients with ESBL-producing K. pneumoniae bacteremia were compared to those with non-ESBL-producing bacteremia. ⋯ Among 16 isolates, for which the ESBL characterization was performed by PCR, the most common types of ESBLs were SHV (n = 16) and cefotaxime-M-2 (n = 5). Pulsed-field gel electrophoresis analysis of the ESBL-producing organisms showed extensive clonal diversity. ESBL-producing K. pneumoniae is a significant cause of bacteremia, even in patients with community-onset infections, particularly in patients with corticosteroid use, percutaneous tube, prior receipt of antibiotics, or healthcare-associated infections.
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Microb. Drug Resist. · Jun 2011
Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia: clinical impact of antimicrobial resistance on outcome.
Despite the high prevalence of antimicrobial resistance among Pseudomonas aeruginosa bacteremia, the clinical consequence of resistance remains unclear. The purpose of this study was to identify predictors of mortality and evaluate the clinical impact of antimicrobial resistance on outcome in P. aeruginosa bacteremia. A retrospective cohort study including patients with P. aeruginosa bacteremia was performed. ⋯ As compared with the susceptible group, ceftazidime-, piperacillin-, or imipenem-resistant groups had a higher mortality (p < 0.05). A multivariate analysis showed that resistance to ceftazidime or imipenem remained a significant factor associated with mortality (odds ratio, 2.96; 95% confidential interval, 1.20-7.31; and odds ratio, 2.74; 95% confidential interval, 1.02-7.31, respectively). Antimicrobial resistance, especially to ceftazidime or imipenem, adversely affected outcome in patients with P. aeruginosa bacteremia.