Predictors of Candida spp. as causative agents of catheter-related bloodstream infections.

We conducted this study to identify risk factors that may predict whether Candida spp. are causative agents of suspected catheter-related bloodstream infections (CRBSIs). All patients with laboratory-confirmed CRBSIs at Kyoto University Hospital between 2009 and 2011 were included. We compared the clinical features of candidal CRBSIs (78 cases) and non-candidal CRBSIs (258 cases). According to a multivariate analysis, a solid tumor (odds ratio [OR], 3.11; 95% confidence interval [CI], 1.75-5.53), total parental nutrition (OR, 2.65; 95% CI, 1.39-5.06), and the administration of anti-anaerobic agents (OR, 2.22; 95% CI, 1.03-4.79) were significantly more common among candidal CRBSIs. The (1,3)-ß-D-glucan (BDG) test was positive among 94.6% (35/37) of candidal CRBSI patients and 9.4% (10/106) of non-candidal CRBSI cases. The administration of antifungal agents may be considered for patients with these risk factors, especially when the BDG test is positive.

[Risk factors and clinical charasteristics of Stenotrophomonas maltophilia bacteremia: a comparison with bacteremia due to other glucose-non fermenters].

Stenotrophomonas maltophilia (SM) is an important nosocomial pathogen. Due to its intrinsic resistance to various therapeutic drugs, the optimal antimicrobial therapy is often delayed. From January 2005 to September 2012, we retrospectively compared drug susceptibilities, clinical backgrounds, and outcome of SM bacteremic patients (SM group) with these of other non fermentative gram negative bacilli bacteremic patients (non-SM group), at a tertiary-care hospital in Kyoto, Japan. Among the SM group, risk factors of 30-day mortality were evaluated. The SM group and non-SM group included 54 and 237 cases, respectively. Among the non-SM group, bacteremic patients due to Pseudomonas aeruginosa, Acinetobacter species, and other non-fermentative gram negative bacilli included 156, 68, and 13 patients, respectively. SM isolates were susceptible to trimethoprim-sulfamethoxazole and minocycline (82.0% and 100%, respectively). Non-SM isolates were susceptible to meropenem (88.6%), ceftazidime (88.6%), cefepime (85.2%), and amikacin (97.0%). Both SM and non-SM isolates were susceptible to levofloxacin (87.5% and 82.0%, respectively). The use of carbapenems, antipseudomonal cephalosporins, and isolation of SM within 30 days represented an independent risk factor for SM bacteremia. The 30 day mortality rate among the SM group was significantly higher compared with the non-SM group (35% vs 18%, odds ratio: 2.2, 95% CI: 1.2-4.3 p = 0.012). Among the SM group, an independent factor which was associated with 30-day mortality was the SOFA score. SM bacteremia showed a worse outcome compared with bacteremia due to non-SM. For the patients who present risk factors for SM bacteremia, empirical antimicrobial therapy including trimethoprim-sulfamethoxazole, minocycline or levofloxacin should be considered.

Clinical characteristics and risk factors of non-Candida fungaemia.

BACKGROUND: The incidence of fungaemia has been increasing worldwide. It is important to distinguish non-Candida fungaemia from candidaemia because of their different antifungal susceptibilities. The aims of this study were to investigate the clinical characteristics of non-Candida fungaemia and identify the clinical factors that differentiate it from candidaemia. METHODS: We investigated the clinical manifestations and mortality of non-Candida fungaemia in Kyoto University Hospital from 2004 to 2009. RESULTS: There were 110 episodes of fungaemia during the study period. There were 11 renal replacement therapy episodes of fungaemia due to non-Candida yeasts (10.0%), including 6 episodes with Cryptococcus neoformans, 4 with Trichosporon asahii, and 1 with Kodamaea ohmeri, in addition to 99 episodes of candidaemia (90.0%). The presence of collagen disease [odds ratio (OR) 9.00; 95% confidence interval (CI) 1.58-51.4; P=0.01] or renal replacement therapy (OR 15.0; 95% CI 3.06-73.4; P<0.01) was significantly more common in non-Candida fungaemia patients than in candidaemia patients. Prior colonisation by the species may be a predictor of non-Candida fungaemia. Non-Candida fungaemia had a higher mortality than candidaemia (54.5% versus 21.2%, P=0.03). CONCLUSIONS: Although Candida species frequently cause fungaemia, we should also be aware of non-Candida yeasts because of their high mortality, particularly among high-risk patients, such as those with collagen disease and those under renal replacement therapy. Prior colonisation by the causative organisms may be an important predictor of non-Candida fungaemia.

Emergence and spread of B2-ST131-O25b, B2-ST131-O16 and D-ST405 clonal groups among extended-spectrum-ß-lactamase-producing Escherichia coli in Japan.

OBJECTIVES: The increasing prevalence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has been associated with the emergence of the CTX-M-producing sequence type 131 (ST131) pandemic clonal group, a member of the O25b serogroup and the B2 phylogenetic group. To assess the clonal spread of ESBL-producing E. coli in Japan, a regional surveillance programme was conducted. METHODS: A total of 581 ESBL-producing clinical specimen E. coli isolates were collected between 2001 and 2010. Clonal groups, including ST131, D-ST405, D-ST393 and D-ST69, were determined using the PCR O type, phylogenetic grouping by triplex PCR, allele-specific PCR and multilocus sequence typing (MLST). A subset of clonal groups underwent PFGE. RESULTS: Among clonal strains, 215 isolates (37%) were identified as belonging to the ST131 group, 185 as B2-ST131-O25b (32%), 26 as B2-ST131-O16 (4%), 3 as B1-ST131-O25b (0.5%) and 1 as B2-ST131-O-non-typeable (0.1%). Forty-one isolates (7%) were identified as belonging to the D-ST405 clonal group, seven (1%) as D-ST69 and two (0.3%) as D-ST393. The B2-ST131-O16 clonal group was characterized by CTX-M-14 and a significantly lower ciprofloxacin resistance rate than the B2-ST131-O25b clonal group. The B2-ST131-O16 and B2-ST131-O25b clonal groups each made up a single PFGE cluster, with 65% similarity. The rate of ESBL-producing E. coli increased over the years (0.2% in 2001 to 9.7% in 2010) and corresponded to increases in the numbers of the B2-ST131-O25b, B2-ST131-O16 and D-ST405 clonal groups. CONCLUSIONS: The B2-ST131-O25b, B2-ST131-O16 and D-ST405 clonal groups have contributed to the spread of ESBL-producing E. coli in Japan.

Prevalence of plasmid-mediated AmpC ß-lactamase-producing Escherichia coli and spread of the ST131 clone among extended-spectrum ß-lactamase-producing E. coli in Japan.

In 2010, a total of 1327 clinical Escherichia coli isolates from five hospitals in the Kyoto and Shiga regions of Japan were analysed by PCR. The prevalences of plasmid-mediated AmpC ß-lactamase (pAmpC)-producers, extended-spectrum ß-lactamase (ESBL)-producers and co-producers of pAmpC and ESBL were 1.7%, 9.7% and 0.3%, respectively. Less than one-half of the pAmpC-producers were reported to be resistant to third-generation cephalosporins, cephamycins and ß-lactam/ß-lactam inhibitors using the old 2009 Clinical and Laboratory Standards Institute (CLSI) breakpoints. CMY-2 was the most prevalent pAmpC type (95%), and CTX-M-14 (38%), CTX-M-15 (26%) and CTX-M-27 (19%) were the most prevalent ESBL types. The worldwide O25b-ST131-B2 clone accounted for 11% of pAmpC-producers and 41% of ESBL-producers. The O25b-ST131-B2 clone was characterised by a CTX-M-27- or CTX-M-15-type ESBL and ciprofloxacin-non-susceptibility with quadruple mutations in the quinolone resistance-determining regions (S83L and D87N in GyrA and S80I and E84V in ParC). A significant proportion of pAmpC-producers and the O25b-ST131-B2 clone were found in Japan by a recent regional surveillance programme.

Molecular characterization of IMP-type metallo-ß-lactamases among multidrug-resistant Achromobacter xylosoxidans.

OBJECTIVES: To analyse the metallo-ß-lactamase (MBL) genes and their genetic environments in clinical isolates of Achromobacter xylosoxidans. METHODS: From January 2004 to December 2010, four MBL-producing, multidrug-resistant (MDR) A. xylosoxidans strains were isolated and analysed at a tertiary care university hospital in Japan. Species-level identification was confirmed by 16S ribosomal RNA gene sequencing. Molecular typing was performed using PFGE, the presence of MBL genes was detected using PCR, and integron gene cassettes were examined by cloning and sequence analysis of integron PCR products. The plasmids obtained from individual isolates were analysed based on EcoRI restriction patterns, Southern hybridizations using digoxigenin-labelled probes for bla(IMP-1) and bla(IMP-19) as well as conjugation and transformation experiments. RESULTS: No clonal relationship was found among the four A. xylosoxidans isolates. Three isolates harboured bla(IMP-1) and one isolate harboured bla(IMP-19). These MBL genes were carried on class 1 integrons. Four different class 1 integron gene cassette arrays were found, including orf1-bla(IMP-1)-aacA4, bla(IMP-1)-bla(IMP-1)-nit1/nit2-catB3-bla(IMP-1)-bla(IMP-1), aacA4-bla(IMP-1) and bla(IMP-19). The restriction pattern of the plasmid DNA obtained from each isolate was unique and the hybridization analyses revealed the presence of each MBL gene within a plasmid. Moreover, all of the plasmids carrying an MBL gene could be transformed into Escherichia coli HST08. CONCLUSIONS: This study provides genetic evidence for the existence of IMP-type MBL genes in MDR A. xylosoxidans isolates. Moreover, the present findings provide evidence that A. xylosoxidans can receive IMP-type MBL genes via plasmid-mediated transfer, which contributes to their carbapenem resistance.

Clinical characteristics and risk factors of ocular candidiasis.

Ocular candidiasis is a major complication of Candida bloodstream infection (BSI). This study was performed to reveal the clinical characteristics of ocular candidiasis. Of the 220 patients with Candida BSI, 204 cases received ophthalmology consultations between January 2005 and December 2011 at 2 teaching hospitals. Fifty-four (26.5%) cases had findings consistent with the diagnosis of ocular candidiasis. Of these 54 cases, 43 (79.6%) were diagnosed within 7 days after a positive blood culture. Among ocular candidiasis cases, more cases were due to Candida albicans (P =0.034 odds ratio [OR]; 3.68 95% confidence interval [CI] 1.11-12.2) and had higher ß-d-glucan values (P = 0.001 OR; 9.99 95% CI 2.60-21.3). We need to consider fundoscopic examination to be performed within the first 7 days of therapy, especially for those patients who have C. albicans BSIs and higher ß-d-glucan values. Additionally, follow-up fundoscopic examination should be considered before stopping therapy for high-risk patients.