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Abstract: Five hundred fecal samples from 462 patients (68.4% ambulatory) (February–April, 2007) from Madrid (Spain) were screened for extended-spectrum β-lactamase (ESBL) producers using ceftazidime and cefotaxime (1 mg/L) MacConkey (MAC) agar plates and a chromogenic media (chromID ESBL; bioMérieux, Marcy-l''Etoile, France). bla ESBL, qnr, aac(6′)Ib-cr, and 16S rRNA methylase genes were assessed. A prevalence of 8.2% of ESBL fecal carriers was observed (8.9% hospitalized, 7.9% nonhospitalized patients), higher than that previously observed (1991, 0.6%; 2003, 7.0%). Sensitivity, specificity, and positive and negative predicted values were 100%, 94.8%, 63%, and 100% for chromID ESBL and 87.8%, 89.8%, 43.4%, and 98.9% for MAC, respectively. ESBL distribution was as follows: CTX-M-9-group, 40% (mainly CTX-M-14); CTX-M-1-group, 26.6% (mainly CTX-M-15); SHV-type, 29% (mainly SHV-12); and TEM-type, 4.4%. These enzymes were found in pulsed-field gel electrophoresis nonclonally related Escherichia coli and Klebsiella pneumoniae isolates. Transferable quinolone resistance was confirmed in CTX-M-9 (qnrS1), CTX-M-15 [aac(6′)Ib-cr, qnrS1], and SHV-12 (qnrB7, qnrS1) producers but not 16S rRNA methylase genes. The chromID ESBL medium was reliable to screen ESBL fecal carriers with a general decrease in the laboratory workload. Time-to-time monitoring of ESBL fecal carriers is useful to ascertain current trend of ESBL epidemiology. [Copyright &y& Elsevier]

Abstract: We report the use of tigecycline, firstly with colistin and finally alone, in a patient with a persistent breakthrough bacteremia due to a Klebsiella pneumoniae isolate harboring a metallo-β-lactamase (VIM-1) and an extended-spectrum β-lactamase (SHV-12). Time-kill studies demonstrated that the combination of both compounds was synergistic along the first 12 h, suppressing the regrowth observed after 3 to 6 h when colistin was tested alone. [Copyright &y& Elsevier]

Abstract: Despite limitations of swab transport systems (STS), many clinical samples and bacterial isolates are sent on these devices. We evaluated the performance of 4 commercial STS: M40 Transystem™ (S1, Copan Italia, Bovezzo, Italy), UNI-TER™ (S2, MEUS, Piove di Sacco, Italy), Euromed™ (S3, LAB SERVICE, Surbo, Italy), and Eurotubo™ (S4, Deltalab, Rubí, Spain). Survival of ATCC and clinical strains with characterized resistance mechanisms, stored at room temperature and using the roll-plate method (NCCLS M40-A) after holding times of 0, 6, 24, 48, and 72 h, and 7 days, was assessed. After 24 h, only S1 was able to maintain Streptococcus pneumoniae (ATCC 6305), Haemophilus influenzae (10211), and Neisseria meningitidis (13090) viability with a percentage range of recovery with respect to the baseline count at zero time of 104–184%. Neisseria gonorrhoeae (43069) was uncultivable after 6 h with all STS except S1 (46% recovery). Eighteen percent recovery after 24 h and 7% after 6 h was observed for Fusobacterium nucleatum (25586) and Peptostreptococcus anaerobius (27337), respectively, but only with S1. Resistance mechanisms in clinical isolates do not affect survival with any of the STS. [Copyright &y& Elsevier]