Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2010: General view of the pathogens' antibacterial susceptibility.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and -resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be ß-lactamase-non-producing ABPC-resistant and 11.0% to be ß-lactamase-producing ABPC-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

Nationwide surveillance of bacterial respiratory pathogens conducted by the Surveillance Committee of Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Clinical Microbiology in 2009: general view of the pathogens' antibacterial susceptibility.

For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis, 78 Klebsiella pneumoniae, and 103 Pseudomonas aeruginosa). A maximum of 45 antibacterial agents including 26 ß-lactams (four penicillins, three penicillins in combination with ß-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), four aminoglycosides, four macrolides (including ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). Incidence of methicillin-resistant S. aureus (MRSA) was as high as 58.5 %, and that of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) was 6.3 % and 0.0 %, respectively. Among H. influenzae, 21.1 % of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 18.7 % to be ß-lactamase-non-producing ABPC-resistant (BLNAR), and 5.7 % to be ß-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5 %) of ß-lactamase-producing strains has been suspected in Moraxella catarrhalis isolates. Four (3.2 %) extended-spectrum ß-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5 %) of P. aeruginosa were found to be metallo-ß-lactamase-producing strains, including three (1.9 %) suspected multi-drug resistant strains showing resistance against imipenem, amikacin, and ciprofloxacin. Continuous national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

[Methicillin-resistant Staphylococcus aureus-induced pyomyositis that emerged during recovery from drug-induced pancytopenia].

Pyomyositis is a purulent infection of skeletal muscle characterized by fever, localized muscle pain and stiffness, swelling and tenderness. Hematological disorder is one of the predisposing conditions for the development of pyomyositis. A 54-year-old man developed methicillin-resistant Staphylococcus aureus pyomyositis during drug-induced pancytopenia. Debridement of the infection foci combined with antimicrobial agents proved effective even in the advanced stage of the disease. In patients with hematological disorders, pyomyositis should be considered when evaluating local myalgia and high fever because this disease can be very difficult to identify and can become rapidly progressive under a myelosuppressive condition.

[In vitro activity of methylrosaniline chloride (gentian violet) as disinfectant against Candida spp. and Trichosporon spp. isolated from blood samples].

OBJECTIVE: Methylrosaniline Chloride (MRC) is recognized as a disinfectant, but recently is rarely used in the clinic, because of its cytotoxicity when used continuously with conventional concentrations (1% MRC). We have reported the antibacterial activity of MRC with lower concentration against Methicillin-resistant Staphylococcus aureus (MRSA). In this study, we evaluated the antifungal activity of MRC with lower concentrations. MATERIAL AND METHODS: Antifungal activities of MRC against Candida spp. and Trichosporon spp. were tested. All strains tested were isolated from 106 blood or intravenous catheter samples at Juntendo University Hospital from 1995 to 2004. Minimum inhibitory concentrations against fungi were assayed by agar dilution, under both aerobic and anaerobic conditions. RESULTS: A 0.01% or less concentration of MRC solutions showed marked antifungal activity against Candida spp. and Trichosporon spp. under aerobic or anaerobic conditions. CONCLUSION: A 0.01% or less concentration of MRC should be reevaluated for the control of fungal infection and MRSA infection control.

[Bacterial interaction and indirect pathogenesis of Pseudomonas aeruginosa at the growth of MRSA].

Bacterial interactions such as methicillin-resistant Staphylococcus aureus (MRSA) growth inhibition or inactivation of anti-MRSA antibiotics by Pseudomonas aeruginosa as an indirect pathogen were tested by in vitro assay. Paired strains, P. aeruginosa and MRSA, used in this experiment were isolated from 63 respiratory samples at Juntendo University Hospital from 2002 to 2003. Growth inhibitory activities against MRSA by P. aeruginosa were tested with reversed agar plate method. Inactivation of anti-MRSA antibiotics by P. aeruginosa were assayed with disk diffusion method using agar over lay technique. Fifty-six (88.9%) out of 63 samples showed the significant MRSA growth inhibitory activity by co-existed P. aeruginosa. Anti-MRSA antibiotics such as trimetoprim-sulfamethoxazole combination (ST), arbekacin (ABK) and minocycline (MINO) except Vancomycin (VCM) and Teicoplanin (TEIC) were inactivated by the co-existed P. aeruginosa. Our data suggests that P. aeruginosa may play not only as a chronic respiratory pathogen but also as an indirect pathogen. Further, the most P. aeruginosa with anti-MRSA activity isolated respiratory sample may play as a modulator of MRSA infection.

[In vitro indirect pathogenesis of Pseudomonas aeruginosa against anti MRSA chemotherapy].

In the patient with a chronic respiratory disease, both Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) are frequently detected from expectoration. Vancomycin (VCM) and arbekacin (ABK) are both recommended for the chemotherapy of MRSA infection in Japan. Minocycline (MINO) is also selected for the treatment of MRSA infection. While rifampicin (RFP) and a trimetoprim-sulfamethoxazole combination (ST) are also recommended in Europe and USA but not recommended in Japan for the chemotherapy of MRSA infection. It is pointed out that coexistence bacteria affect chemotherapy as an indirect pathogen. Not only an antibacterial action but the immunological action or the metabolic effect against chronic P. aeruginosa infection such as DPB is known by the administration of 14-membered ring macrolides including erythromycin (EM). We considered the influence of P. aeruginosa isolated with MRSA on the activity against anti-MRSA agents by the disk diffusion method with bilayer flat agar in vitro. Moreover, we also examined the influence of EM against the activity of the anti-MRSA agents when P. aeruginosa was coexistence. One strain of MRSA as an indicator strain and 100 strains of P. aeruginosa as test strains, which were obtained from clinical materials, were used for the following experiment. P. aeruginosa was streaked on to the Mueller-Hinton agar culture medium (MHA), and they incubated at 35 degrees C for 24 hours. Then, the blood agar plate was piled up, MRSA was streaked on the blood agar surface, the susceptibility test disks (VCM, ABK, MINO, RFP, ST) were put on it, and incubated at 35 degrees C for a further 24 hours. The diameter of the zone of inhibition around the susceptibility disks against MRSA was measured and compared with P. aeruginosa free experiments. The anti-MRSA activity of MINO, ST and ABK was reduced by coexistence of P. aeruginosa. In RFP and VCM, the anti-MRSA activity was reinforced by coexistence of P. aeruginosa. Although the anti-MRSA activity of ST and ABK has improved by EM addition in the MHA plates, the anti-MRSA activity has not improved in MINO. These results are suggesting that in a MRSA infection, the chemotherapy by anti-MRSA agents were affected by coexistence of P. aeruginosa as an indirect pathogen. The macrolides such as EM may be useful as a modulator for chemotherapy by ST or ABK when MRSA and P. aeruginosa are isolated at the same time from the patient.

[Evaluation of rapid identification method for Mycobacterium tuberculosis complex using the immunochromatographic slide test kit].

Capilia TB, a lateral flow immunochromatographic slide test kit for directly identifying Mycobacterium tuberculosis complex (MTC), was evaluated by using culture-positive specimens from Mycobacteria Growth Indicator Tubes (MGIT). Sputum specimens from patients suspected of having tuberculosis were treated with NALC-NaOH and cultivated in MGIT960. Liquid specimens were collected from the positive tubes and directly inoculated with Capilia TB. Liquid specimens were also directly tested with AccuProbe. Of the organisms isolated from the 100 MGIT positive tubes, M. tuberculosis complex was identified in 49 (49%) tubes with Capilia TB and not identified in 51 (51%) with Capilia TB. Mycobacterium avium-intracellulare complex (MAC) was identified in 46 (46%) with AccuProbe MAC and other acid-fast bacteria were identified in 5 (5%) by DNA-DNA hybridization method. There were one tube in which M. tuberculosis complex was detected with Capilia TB and M. tuberculosis complex was not detected with AccuProbe MTC, but no tubes in which M. tuberculosis complex was detected with AccuProbe MTC and M. tuberculosis complex was not detected with Capilia TB. Capilia TB is excellent in sensitivity and specificity and very suitable for rapid diagnosis of tuberculosis and is considered to contribute to public health intervention measures taken for the tuberculosis control in Japan.

Methylenetetrahydrofolate reductase genotype, vitamin B12, and folate influence plasma homocysteine in hemodialysis patients.

Hyperhomocysteinemia, a well-recognized cardiovascular risk factor, is frequent in hemodialysis (HD) patients. A common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, C-->T substitution at nucleotide 677, is associated with homocysteine (Hcy) level elevation. We examined whether three factors involved in the methionine cycle could influence plasma Hcy concentrations in HD patients: MTHFR polymorphism; vitamin B12, an essential cofactor; and folate, the substrate. In a cross-sectional study, serum vitamin B12, folate, and plasma Hcy were measured and MTHFR genotyping was performed in 534 HD patients. Effects of MTHFR genotypes, vitamin B12, and folate on plasma Hcy levels were examined in 450 HD patients not administered vitamin B12 or folate. To examine the effect of vitamin B12 on plasma Hcy concentrations, we compared plasma Hcy concentrations in HD patients with and without vitamin B12 supplementation. To examine whether functional vitamin B12 deficiency exists even in HD patients with normal vitamin B12 concentrations, 15 HD patients (serum vitamin B12 concentrations, 250 to 2,100 pg/mL) were treated with vitamin B12 (mecobalamin, 1.5 mg/d) for 8 weeks. Serum concentrations of methylmalonic acid (MMA) and vitamin B12 were measured. Hcy levels were higher and folate levels were lower in patients with the TT and CT genotypes compared with patients with the CC genotype. Analysis of covariance to determine independent predictors of high Hcy levels identified low serum vitamin B12 and folate levels and high albumin (Alb) levels in CC-genotype patients, low folate levels and high Alb levels in CT-genotype patients, and low folate levels in TT-genotype patients. Plasma Hcy levels were lower in CC- and CT-genotype patients with vitamin B12 supplementation than in those without supplementation. Vitamin B12 supplementation for 8 weeks significantly reduced MMA concentrations in HD patients with normal serum vitamin B12 concentrations. These results indicate that MTHFR genotype influences the correlation of Hcy level with vitamin B12 and folate levels in HD patients. Functional vitamin B12 deficiency may exist, even in HD patients with normal vitamin B12 concentrations. The efficacy of vitamin B12 and folate supplementation on plasma Hcy levels may depend on MTHFR genotype.