Development and preliminary evaluation toward a new tuberculosis treatment monitoring tool: the PATHFAST TB LAM Ag assay.

The PATHFAST TB LAM Ag assay is based on a chemiluminescent enzyme immunoassay to quantify lipoarabinomannan (LAM) in sputum within 1 h, and was developed as an alternative to conventional culture methods for monitoring tuberculosis (TB) treatment. This study aimed to evaluate the analytical performance and initial clinical feasibility of using five Mycobacterium tuberculosis variants, 178 non-tuberculous mycobacteria (NTM), 34 upper respiratory and oral cavity microorganisms, 100 sputum specimens from untreated patients, and potential interfering substances, including 27 drugs. The results reveled a single-site repeatability coefficient of variation (CV) of 5.2%-7.0%, and a multi-site reproducibility CV of 7.1%-8.4%. The limit of blank, limit of detection, and limit of quantification were 3.03 pg/mL, 6.67 pg/mL, and 7.44 pg/mL, respectively. Linearity was observed over the analytical measurement range (10.0 pg/mL-50,000 pg/mL), and no hook effect was observed. The assay tended to cross-react with slow-growing NTMs, but not with common upper respiratory and oral cavity microorganisms, except Nocardia asteroides, Nocardia farcinica, and Tsukamurella paurometabola. No interference was observed in the presence of mucin, blood, or major anti-TB, anti-HIV, and anti-pneumonia drugs. Regarding clinical performance, the assay had a sensitivity of 88.8% (95% CI: 80.0%-94.0%) and specificity of 100.0% (95% CI: 83.9%-100.0%) using mycobacterial culture as the reference standard, and a correlation (Spearman's r = -0.770) was observed between LAM concentration and time to detection of culture. These findings show, for the first time, that the PATHFAST TB LAM Ag assay has potential value for monitoring TB treatment.

Is Neisseria gonorrhoeae initiating a future era of untreatable gonorrhea?: detailed characterization of the first strain with high-level resistance to ceftriaxone.

Recently, the first Neisseria gonorrhoeae strain (H041) that is highly resistant to the extended-spectrum cephalosporin (ESC) ceftriaxone, the last remaining option for empirical first-line treatment, was isolated. We performed a detailed characterization of H041, phenotypically and genetically, to confirm the finding, examine its antimicrobial resistance (AMR), and elucidate the resistance mechanisms. H041 was examined using seven species-confirmatory tests, antibiograms (30 antimicrobials), porB sequencing, N. gonorrhoeae multiantigen sequence typing (NG-MAST), multilocus sequence typing (MLST), and sequencing of ESC resistance determinants (penA, mtrR, penB, ponA, and pilQ). Transformation, using appropriate recipient strains, was performed to confirm the ESC resistance determinants. H041 was assigned to serovar Bpyust, MLST sequence type (ST) ST7363, and the new NG-MAST ST4220. H041 proved highly resistant to ceftriaxone (2 to 4 µg/ml, which is 4- to 8-fold higher than any previously described isolate) and all other cephalosporins, as well as most other antimicrobials tested. A new penA mosaic allele caused the ceftriaxone resistance. In conclusion, N. gonorrhoeae has now shown its ability to also develop ceftriaxone resistance. Although the biological fitness of ceftriaxone resistance in N. gonorrhoeae remains unknown, N. gonorrhoeae may soon become a true superbug, causing untreatable gonorrhea. A reduction in the global gonorrhea burden by enhanced disease control activities, combined with wider strategies for general AMR control and enhanced understanding of the mechanisms of emergence and spread of AMR, which need to be monitored globally, and public health response plans for global (and national) perspectives are important. Ultimately, the development of new drugs for efficacious gonorrhea treatment is necessary.

Antibiotic-resistant phenotypes and genotypes of Neisseria gonorrhoeae isolates in Japan: identification of strain clusters with multidrug-resistant phenotypes.

OBJECTIVES: To determine the antibiotic susceptibility and the genotype distributions of N. gonorrhoeae isolates in Fukuoka, Japan, and to evaluate the specific associations between genotypes and antibiotic resistance. METHODS: Antibiotic susceptibility testing and N. gonorrhoeae multiantigen sequence typing (NG-MAST) were performed on 242 and 239 N. gonorrhoeae isolates, respectively, in Fukuoka, Japan in 2008. RESULTS: No isolates showed resistance to spectinomycin, ceftriaxone, or cefixime, although 34 (14.0%) and 149 (61.6%) isolates displayed decreased susceptibility to ceftriaxone (minimum inhibitory concentration range, 0.06-0.5 mg/L) and cefixime (minimum inhibitory concentration range, 0.06-0.5 mg/L), respectively. Furthermore, 171 (70.7%), 68 (28.1%), 39 (16.1%), and 1 (0.4%) isolates were resistant to ciprofloxacin, tetracycline, penicillin, and azithromycin, respectively. The 239 isolates were divided by NG-MAST into 67 sequence types (STs); the 4 most common STs were ST2958 (20.5%), ST4018 (7.5%), ST1407 (6.7%), and ST4487 (5.9%). ST2958 and ST1407 were characterized by a multidrug-resistant phenotype, whereas ST4018 and ST4487 presented a susceptible phenotype. Interestingly, ST1407, which is now common in Europe and Australia, was identified as a predominant ST in this study. CONCLUSIONS: This is the first report combining N. gonorrhoeae antibiotic susceptibility testing with molecular typing by using NG-MAST in Japan. Although a large diversity in NG-MAST was identified, based on comparisons with the international data, the ST1407 with a multidrug-resistant phenotype currently seems to be circulating worldwide.

[Nationwide antimicrobial susceptibility survey of Neisseria gonorrhoeae isolates in Japan].

In a nationwide antimicrobial susceptibility survey of 494 Nesseria gonorrhoeae isolates collected from February 2008 to December 2009 in 3 regions of Japan, 112 (22.7%) were collected from western Japan (Kinki, Chugoku, Shikoku, and Kyushu), 277 (56.1%) from mid-eastern Japan (Kanto), and 105 (21.1%) from eastern Japan (Tokai, Hokuriku, Koushinetsu, Tohoku, and Hokkaido). Resistance to ciprofloxacin (CPFX) was 72.8%, to penicillin G (PCG) 19.8%, and to tetracycline (TC) 18.2%. Intermediate resistance to CPFX was 1.8%, to PCG 73.7%, and to TC 43.7%. These results indicate that both types of resistance to the 3 agents were very high. Intermediate resistance to cefixime (CFIX) was 38.1% and to cefozidim (CDZM) 13.4%. Resistance to CFIX was only 0.4% and to CDZM 0%. Susceptibility to azithromycin was 96.6%, to ceftriaxone 99.8%, and to spectinomycin 100%. No significant difference in resistance was seen to different antimicrobial agent classes tested in the 3 regions, although intermediate resistance to CFIX in western Japan was significantly higher than in mid-eastern Japan.

[Antimicrobial susceptibility profile of Acinetobacter baumannii complex isolates in Japan].

The antimicrobial susceptibility of 93 Acinetobacter baumannii complex isolates from clinical specimens collected nationwide between May and October 2009 were measured by microdilution antimicrobial susceptibility testing based on CLSI M100-S20. Beta-lactamase genes, including classes B and D and ISAbal in meropenem nonsusceptible, including intermediate or resistant isolates, were detected using PCR. Rates of isolates nonsusceptible to meropenem were 18%, to ciprofloxacin 41% and to amikacin 14%. L7-L8: The rate of multidrug-resistant Acinetobacter (MDRA) isolates which were resistant to all 3 antimicrobial agents was 4.3%. MDRA isolates were classified into ST92 by multilocus sequence typing. No metallo-beta-lactamase producer was seen among the 17 meropenem nonsusceptible isolates. The blaoxa-51-like carbapenemase gene and ISAbal were detected in all 17 isolates. ISAba1 upstream presence of the blaOXA-51-like gene was observed in 7 of 17 isolates and the blaOXA-23 like gene in 5 of 17. Consistent with overseas reports, our results confirm the existence of MDRA isolates and isolates harboring OXA carbapenemase genes in Japan. While resistance rates were lower than reports elsewhere, it is clear that resistance trends must be carefully monitored.

[In vitro activity of sitafloxacin against clinical isolates in 2009].

In vitro activity of sitafloxacin (STFX) and various oral antimicrobial agents against bacterial isolates recovered from clinical specimens between January and December 2009, at different healthcare facilities in Japan was evaluated. A total of 1,620 isolates including aerobic and anaerobic organisms was available for the susceptibility testing using the microbroth dilution methods recommended by Clinical Laboratory Standard Institute. The minimum inhibitory concentration of STFX at which 90% of isolates (MIC90) was 0.06 microg/mL for methicillin-susceptible Staphylococcus aureus and was equal to that of garenoxacin (GRNX), 2 times lower than that of moxifloxacin (MFLX), and 8 times lower than that of levofloxacin (LVFX). STFX inhibited the growth of all the isolates of Streptococcus pneumoniae at 0.06 microg/mL or less. The MIC90s of STFX ranged from 0.03 to 0.06 microg/mL and were 1 to 2 times lower than those of GRNX, 2 to 4 times lower than those of MFLX, and 16 to 32 times lower than those of LVFX. Against Streptococcus pyogenes, the MIC90 of STFX was 0.06 microg/mL and was 2 times lower than that of GRNX, 4 times lower than that of MFLX, and 32 times lower than that of LVFX. The MIC90 of STFX was 0.25 microg/mL for Enterococcus faecalis, and was 2 times lower than those of GRNX and MFLX, and 8 times lower than that of LVFX. The MIC90 of STFX for E. coli was 2 microg/mL, and the MIC90s of other 10 species of Enterobacteriaceae which were the lowest values of the quinolones tested ranged from 0.03 to 1 microg/mL. The MIC90 of STFX for Pseudomonas aeruginosa isolates recovered from urinary infections was 8 microg/mL and was 16 times lower than those of GRNX, MFLX and LVFX. The MIC90 of STFX for P aeruginosa isolates recovered from respiratory infections was 2 microg/mL and was 32 times lower than those of GRNX and MFLX, and 16 times lower than that of LVFX. STFX inhibited the growth of all the isolates of Haemophilus influenzae at 0.004 microg/mL or less, and was 2 to 4 times lower than those of GRNX, 8 times lower than those of MFLX, and 4 times lower than those of LVFX. The MIC90 of STFX was 0.008 microg/mL for Moraxella catarrhalis, and was 2 times lower than that of GRNX, 8 times lower than those of MFLX and LVFX. The MIC90s of STFX ranged from 0.015 to 0.12 microg/mL for all the species of anaerobic bacteria and were the lowest values of all the antimicrobial agents tested. In conclusion, the activity of STFX against Gram-positive cocci was comparable or superior to those of GRNX, MFLX and LVFX. STFX showed the most potent activity against Gram-negative bacteria and anaerobic bacteria of all the antimicrobial agents tested in this study.

Sitafloxacin activity against Helicobacter pylori isolates, including those with gyrA mutations.

Sitafloxacin showed MICs of less than or equal to 0.5 microg/ml against 105 isolates of Helicobacter pylori, including 44 isolates with mutations in the gyrA gene. The highest MICs for garenoxacin and levofloxacin were 8 and 64 times, respectively, higher than the highest MICs observed for sitafloxacin.

Antimicrobial activities of piperacillin-tazobactam against Haemophilus influenzae isolates, including beta-lactamase-negative ampicillin-resistant and beta-lactamase-positive amoxicillin-clavulanate-resistant isolates, and mutations in their quinolone resistance-determining regions.

Beta-lactamase-negative ampicillin-resistant (BLNAR) isolates of Haemophilus influenzae have been emerging in some countries, including Japan. The Clinical and Laboratory Standards Institute has only a susceptible MIC breakpoint (< or = 1 microg/ml) for piperacillin-tazobactam and a disclaimer comment that BLNAR H. influenzae should be considered resistant, which was adapted without presentation of data. In addition, fluoroquinolone-resistant H. influenzae isolates have recently been occasionally reported worldwide. To address these problems, we examined susceptibilities to beta-lactams, including piperacillin-tazobactam, and ciprofloxacin by microdilution and disk diffusion (only for piperacillin-tazobactam) methods, against a total of 400 recent H. influenzae clinical isolates, including 100 beta-lactamase-negative ampicillin-susceptible, beta-lactamase-positive ampicillin-resistant, BLNAR, and beta-lactamase-positive amoxicillin-clavulanate-resistant (BLPACR) isolates each. BLNAR and BLPACR isolates were tested by PCR using primers that amplify specific regions of the ftsI gene. We also detected mutations in quinolone resistance-determining regions (QRDRs) by direct sequencing of the PCR products of DNA fragments. Among beta-lactams, piperacillin-tazobactam exhibited potent activity against all isolates of H. influenzae, with all MICs at < or = 0.5 microg/ml (susceptible). A disk diffusion breakpoint for piperacillin-tazobactam of > or = 21 mm is proposed. We confirmed that all BLNAR and BLPACR isolates had amino acid substitutions in the ftsI gene and that the major pattern was group III-like (87.5%). One ciprofloxacin-resistant isolate (MIC, 16 microg/ml) and 31 ciprofloxacin-susceptible isolates (MICs, 0.06 to 0.5 microg/ml) had amino acid changes in their QRDRs. Piperacillin-tazobactam was the most potent beta-lactam tested against all classes of H. influenzae isolates. It is possible that fluoroquinolone-resistant H. influenzae will emerge since several clinical isolates carried mutations in their QRDRs.

[Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine samples of males and females by the strand displacement amplification (SDA) method].

Urine samples collected from 422 males and 53 females visiting a clinic in Kawasaki City who were suspected to have sexually transmitted infection were tested for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by BD ProbeTecET (SDA method). The detection rates of C. trachomatis by the SDA method and polymerase chain reaction (PCR) method (control) were as high as 98.1% for C. trachomatis, and as high as 99.4% for N. gonorrhoeae, and the concordance rate of detection of both bacterial species was high. The detection sensitivity and specificity of the SDA method were 90.6 and 99.3%, respectively for C. trachomatis and 98.7% and 100% for N. gonorrhoeae, when PCR was used as the standard method. There were no differences in these results between males and females. The number of patients showing a discrepancy of the results obtained between the SDA method and the PCR method was 9 for C. trachomatis and 1 for N. gonorrhoeae, but the results of redetermination by the SDA method tended to coincide with those of the PCR method. Urine samples tested by the SDA method were positive for N. gonorrhoeae even in patients in whom the culture of secretions from the male urethra was negative for N. gonorrhoeae. Based on these results, the BD ProbeTecET (SDA method) was confirmed to have the equivalent capability to the PCR method for the detection of C. trachomatis and N. gonorrhoeae in urine samples.

Helicobacter pylori isolated from patients who later failed H. pylori eradication triple therapy readily develop resistance to clarithromycin.

In this study, the ease of selection of clarithromycin resistance was investigated in clarithromycin-susceptible Helicobacter pylori strains isolated from patients with H. pylori infection prior to the administration of triple-combination eradication therapy (clarithromycin plus amoxicillin plus a proton pump inhibitor). Clarithromycin-susceptible strains isolated from ten patients in whom the eradication therapy was successful and from six patients in whom the eradication therapy was unsuccessful were exposed serially to subinhibitory concentrations of clarithromycin. The number of transfers required for the MICs of the strains to increase by 8- and 32-fold were 6.6 and 7.2, respectively, in the successful eradication group, and as few as 2.4 and 1.5, respectively, in the unsuccessful eradication group. The number of transfers required for the A2142G or A2143G point mutation of the 23S rRNA gene to be detected in the strains were 5 and 8, respectively, for the strains in the successful eradication group, and 1 and 2, respectively, for the strains in the unsuccessful eradication group. These results suggest that patients in the unsuccessful eradication group were infected with strains of H. pylori that readily became resistant to clarithromycin on exposure to the drug.

Analysis of mutations within multiple genes associated with resistance in a clinical isolate of Neisseria gonorrhoeae with reduced ceftriaxone susceptibility that shows a multidrug-resistant phenotype.

A Neisseria gonorrhoeae strain with a reduced susceptibility to ceftriaxone (minimum inhibitory concentration (MIC) = 0.5 microg/mL) was isolated among 398 clinical isolates obtained from 2000-2001 in Fukuoka City, Japan. The N. gonorrhoeae strain was negative for penicillinase production but it showed multidrug resistance against penicillin (MIC = 8 microg/mL), tetracycline (MIC = 4 microg/mL), azithromycin (MIC = 0.5 microg/mL) and ciprofloxacin (MIC = 16 microg/mL). The molecular mechanisms of the multidrug-resistant phenotype in this strain were analysed. Polymerase chain reaction and direct DNA sequencing were performed to identify mutations within the penA, ponA, mtrR, penB, gyrA and parC genes of the gonococcal strain, which thus explain the multidrug-resistant phenotype. The N. gonorrhoeae strain contained a significantly different sequence of the penA gene from that of the ceftriaxone-susceptible strains. Some regions of the transpeptidase domain within this penA gene were closely similar to those found in other Neisseria species such as Neisseria subflava, Neisseria flavescens or Neisseria perflava/sicca. This strain also included a ponA mutation that is associated with high-level resistance to penicillin, mtrR mutations that mediate overexpression of the MtrCDE efflux pump responsible for resistance to hydrophobic agents such as azithromycin, and penB mutations that reduce porin permeability to hydrophilic agents such as tetracycline. Moreover, this strain contained gyrA and parC mutations that confer high-level resistance to ciprofloxacin. These results indicate the emergence of a N. gonorrhoeae strain with reduced susceptibility to ceftriaxone, which also showed a multidrug-resistant phenotype that can be explained by the presence of multiple loci mutations associated with antibiotic resistance.

Micro-broth dilution method with air-dried microplate for determining MICs of clarithromycin and amoxycillin for Helicobacter pylori isolates.

MICs of clarithromycin and amoxycillin for 253 isolates of Helicobacter pylori were measured by an air-dried microplate method and compared with the results obtained by the agar plate dilution method. The air-dried microplate method is performed by coating each well of a 96-well microplate with the test antibiotic and air-drying it. There were no marked differences between the air-dried microplate method and agar plate dilution methods in the MIC(50) and MIC(90) values or MIC ranges of clarithromycin obtained for the 253 isolates of H. pylori. More specifically, the MICs of clarithromycin for 114 (45.1 %) of the 253 isolates were the same by the air-dried microplate method as the agar plate dilution method, and the differences in the MICs of clarithromycin for a further 114 isolates (45.1 %) varied within one twofold dilution. The MICs of amoxycillin by the former method were in close agreement with the MICs obtained by the latter method: MICs of amoxycillin for 199 (78.7 %) of the 253 isolates were the same by both methods, and the differences in the MICs of amoxycillin for 42 isolates (16.6 %) varied within one twofold dilution. These results indicate that the air-dried microplate method is a useful method for determination of MICs, because the results obtained were in close agreement with those obtained by the standard agar plate dilution method. The air-dried microplate method is, therefore, a convenient and reliable method for determining the MICs of clarithromycin and amoxycillin for H. pylori isolates.

Antimicrobial resistance of Neisseria gonorrhoeae in Japan, 1993-2002: continuous increasing of ciprofloxacin-resistant isolates.

Susceptibility testing was conducted on 1357 isolates of Neisseria gonorrhoeae isolated from 1993 through 2002 in Japan to assess the antimicrobial resistance. Selected isolates were characterised by auxotype and analysis was done for mutations within the quinolone resistance-determining region (QRDR) in the gyrA and parC genes, which confer fluoroquinolone resistance to the organism. Isolates with ciprofloxacin resistance increased significantly from 6.6% (1993-1994) to 73.5% (2002). The proportion of plasmid-mediated penicillin-resistant isolates (PPNG) decreased significantly from 7.9% (1993-1994) to 0.9% (2002). The percentage of chromosomal-mediated resistance to penicillin decreased from 27.4% in 2000 to 12.0% in 2001 but increased to 28.9% in 2002. The proportion of isolates with any type of resistance to tetracycline decreased from 24.7% in 2000 to 13.9% in 2001 and then increased to 22.3% in 2002. The proportion of prototrophic isolates significantly decreased from 84.4% in 1992-1993 to 7.7% in 2001, while that of the proline-requiring isolates significantly increased from 4.4% in 1992-1993 and 80.8% in 1998. The proline-requiring isolates were less susceptible to ciprofloxacin than the prototrophic or arginine-requiring isolates. Of 87 isolates resistant to ciprofloxacin, 2 (2.3%) contained five amino acid substitutions within the GyrA and ParC proteins, 76 (87.4%) contained three or four amino acid substitutions and 9 (10.3%) contained one or two amino acid substitutions.

Development of an adhesive sheet for direct counting of bacteria on solid surfaces.

An adhesive sheet was developed for direct counting of microorganisms on solid surfaces. The sheet consists of a polyurethane film base and water insoluble adhesive. SYBR Green II (for total direct counting) or 6-carboxyfluorescein diacetate (6CFDA) (for fluorescent vital staining) was used for fluorescent microscopy of bacteria collected on the adhesive face of the sheet. Adhesive sheet sampling showed a higher recovery rate for microbial enumeration than conventional swab method or stamp agar. This method is simple, rapid, inexpensive and reproducible.

[Bacteriological and epidemiological study on Neisseria gonorrhoeae isolated from the pharyngeal specimens of male and female patients with gonorrhea].

Neisseria gonorrhoeae were isolated from pharyngeal specimens of male and female patients and also from urethral and cervical discharges of male and female patients, respectively, suspected of having gonococcal infections in a urologic clinic in Kawasaki City. Microbiological and epidemiological studies were performed in 127 male and 41 female patients. The specimens were streaked onto the modified Thayer-Martin Selective Agar and the plates were incubated at 35 degrees C for 48 h under an atmosphere of 10% CO2. In 127 male patients, N. gonorrhoeae were detected in 117 (92.1%) of the urethral specimens. In these patients, N. gonorrhoeae were detected in pharyngeal specimens from 14 (11.0%) patients, but the pathogen was also detected in urethral specimens from these patients without exception. In 41 female patients. N. gonorrhoeae were detected in 20 (48.8%) of the 41 cervical discharges. When the pharyngeal specimens were tested, N. gonorrhoeae were detected in 14 (34.1%) of the 41 specimens. N. gonorrhoeae was simultaneously detected only in pharyngeal and cervical specimens from 11 of the 41 female patients and the pathogen was detected only in pharyngeal specimens from other 3 patients. There were no marked differences in antimicrobial susceptibilities between N. gonorrhoeae isolates from pharyngeal specimens and those from urethral or cervical discharges in all the patients tested. The PFGE patterns of 50 gonococcal isolates (25 pairs) from 25 patients (14 males and 11 females) in whom N. gonorrhoeae were simultaneously detected from pharyngeal and urethral or cervical specimens were analyzed. In 24 of 25 patients. N. gonorrhoeae isolated from the pharyngeal and urethral or cervical specimens in the same patients showed the same PFGE patterns. However, the 25 pairs showed the different PFGE patterns. From these results it is clarified that N. gonorrhoeae are detected in the pharyngeal specimens from considerable numbers of patients with gonorrhea, and there is a possibility that the pathogens prevailing among the patients differ in genetic sources.

Rapidly spreading CTX-M-type beta-lactamase-producing Proteus mirabilis in Japan.

In recent years, increased isolation of extended-spectrum beta-lactamase (ESBL)-producing Proteus mirabilis has been reported in Japan. We undertook an investigation to determine the prevalence of ESBL-producing P. mirabilis isolated in Japan and to characterise the genotype. Seventy-four P. mirabilis isolates recovered from specimens at 54 hospitals in Japan between March and October 2006 were included in the study. Of the 74 P. mirabilis isolates examined, 28 (37.8%) were ESBL-producers. The bla(CTX-M-2) gene was found in 27 isolates, whilst 1 isolate possessed bla(CTX-M-3). Amongst the 28 ESBL-producers, 25 (89.3%) were non-susceptible to ciprofloxacin, whilst 11 (23.9%) of 46 ESBL-non-producing isolates were non-susceptible to ciprofloxacin. Pulsed-field gel electrophoresis (PFGE) analysis of the 28 ESBL-producing isolates from 19 hospitals revealed 17 clusters. The same PFGE type was observed in two or more hospitals especially in the greater Tokyo area, suggesting possible clonal spread and the need for monitoring to determine whether emergence of a dominant clone occurs. Our results show that in Japan there is a high prevalence of CTX-M-type beta-lactamase-producing P. mirabilis. Moreover, these isolates are characterised by reduced susceptibility to fluoroquinolones.

Antifungal activity of micafungin against Candida and Aspergillus spp. isolated from pediatric patients in Japan.

The in vitro antifungal activities of micafungin in comparison to caspofungin, fluconazole, itraconazole, voriconazole, and amphotericin B were evaluated against 93 Candida and 23 Aspergillus isolates recovered from pediatric patients with fungal infections. MICs were determined by the CLSI M27-A2 and M38-A for Candida and Aspergillus species, respectively. Micafungin showed potent activity against Candida albicans, Candida tropicalis, and Candida glabrata with a MIC range of <= 0.002 to 0.015mug/ml. In contrast, micafungin demonstrated higher MIC levels against Candida parapsilosis with a MIC range of 0.12 to 2 mug/ml. Micafungin showed potent antifungal activity against Aspergillus species tested with a MIC range of 0.004 to 0.015 mug/ml. Overall, micafungin had excellent in vitro antifungal activities against Candida and Aspergillus species recovered from pediatric patients with fungal infections.

Antimicrobial resistance in clinical isolates of Neisseria subflava from the oral cavities of a Japanese population.

A recent study indicated that Neisseria subflava, one of the commensal Neisseria species, may play an important role in the emergence of Neisseria gonorrhoeae strains with chromosomally mediated resistance to penicillin or cephalosporin by the horizontal genetic exchange of penA genes encoding the target site for penicillin or cephalosporin. The present investigation examined the antimicrobial susceptibility of 45 isolates of N. subflava from the oral cavities of Japanese men and women to various agents used for the treatment of gonococcal infections. Of the 45 isolates, 40 (88.9%) and 4 (8.8%) were intermediately resistant and resistant to penicillin, respectively, with the minimal inhibitory concentration (MIC)(50) and MIC(90) of penicillin being 0.5 mg/l and 1 mg/l, respectively. Of the 45 isolates, 13 (28.9%) and 14 (31.1%) were resistant to tetracycline and ciprofloxacin, respectively, and 3 (6.7%) showed reduced susceptibility to cefixime (although the susceptibility category was not determined). These results indicate that several isolates of N. subflava have acquired resistance or intermediate resistance to various antimicrobial agents, including penicillin, cephalosporin, tetracycline, and ciprofloxacin. The present study may thus confirm that N. subflava may be involved in the emergence of N. gonorrhoeae strains with either intermediate or total resistance to penicillin or cephalosporin by the horizontal genetic exchange of the penA gene.

Antibacterial activity of tosufloxacin against major organisms detected from patients with respiratory or otorhinological infections: comparison with the results obtained from organisms isolated about 10 years ago.

The minimum inhibitory concentrations (MICs) of tosufloxacin and other fluoroquinolone antimicrobials for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella (Branhamella) catarrhalis, isolated, between January 2003 and July 2004, from patients suspected of having respiratory or otorhinological infections were determined. The results were compared with those for these organisms isolated in 1994, plus some H. influenzae strains isolated in 1998. Tosufloxacin was the most potent of all the antibiotics tested for antibacterial activity against S. pneumoniae (including penicillin-intermediate S. pneumoniae and penicillin-resistant S. pneumoniae). The MIC50 and MIC90 values did not differ from those obtained for the strains isolated in 1994. Fluoroquinolones exerted the most potent antibacterial activity against M. (B.) catarrhalis; the MICs for most of the strains were < or = 0.06 microg/ml; fluoroquinolones inhibited the growth of all the strains at 0.25 microg/ml or less. Fluoroquinolones showed the most potent antibacterial activity against H. influenzae strains isolated between 2003 and 2004, and in 1994, but, for one H. influenzae strain isolated, between 2003 and 2004, the MICs of fluoroquinolones were high. Some strains of S. pneumoniae and H. influenzae were resistant to fluoroquinolones. Genetic analysis showed that all of these strains had mutations in the quinolone resistance-determining region, but there were no differences according to the years of isolation. These results indicate that tosufloxacin has potent antibacterial activity against major organisms isolated from patients with respiratory or otorhinological infections; further, the results of the present study did not differ from those obtained about 10 years ago.