We investigated the susceptibility of Streptococcus pneumoniae isolated from 8 hospitals in Chiba prefecture during 2012-2013. We further checked the serotype of S. pneumoniae derived from invasive pneumococ cal disease (IPD). We tested for antimicrobial susceptibility in 256 clinical isolates (137 isolates from children,119 isolates from adults) for 25 drugs. In MIC₅₀ and MIC₉₀, there were very little differences between children and adults, but there were 3 isolates from adults which were resistant to levofloxacin. The most major serotypes were 15A and 3 in IPD. Additionally there was no isolation of the type contained in the 7-valent pneumococcal conjugate vaccine in children, so it seems that the vaccination is very effective for children. Furthermore, in contrast with our preceding report, a decreasing was seen in PCG resistant proportion of S. pneumoniae. The maximum PCG-MIC was 2μg/mL.

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To detect Vibrio parahaemolyticus in seafood, we evaluated efficient combinations of molecular methods with DNA extraction methods using heat extraction and alkaline heat extraction, and PCR, real-time PCR and loop-mediated isothermal amplification (LAMP) assays were performed targeting V. parahaemolyticus species-specific genes (tlh and rpoD) and pathogenic factors genes (tdh and trh). The species-specific genes were detected in all combinations of two strains (a tdh・trh1-positive strain and a trh2-positive strain), two kinds of shellfish (oyster and bloody clams) and molecular methods with tlh-real time PCR or rpoD-LAMP assays with DNA of alkaline heat extraction at 85-145 cfu/test level. tdh was detected in both seafoods with real time PCR assay with DNA of heat extraction at 85 cfu/test level, and detected with the LAMP and real time PCR assays with DNA of alkaline heat extraction at 85 cfu/test level. Detection of both trh1andtrh2 with the PCR assay with DNA of alkaline heat extraction was comparatively high though trh2 was detected with the LAMP assay with DNA of alkaline heat extraction at 145 cfu/test level. It, however, is necessary to investigate more sensitive trh-detection methods. In this study, the results indicated that tlh-real time PCR or rpoD-LAMP, tdh-real time PCR and tdh-LAMP assays with DNA of alkaline heat extraction are relatively sensitive methods to detect V. parahaemolyticus in seafood.

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Purpose : Laser scattering photometry (ESP) is a newly developed plasma endotoxin assay method using horseshoe crab amebocyte lysate (AL) that recognizes small particles produced by polymerization of coagulin under the stirring conditions at　1000　rpm. We elucidated the effect of human serum album (HSA) in the ESP method. Methods : AL was dissolved with 630μL of the specimen and a 200-μL aliquot was used for ESP ; this conventional protocol was regarded as the ESP　630 method. The ESP　210 method was also used, i. e. AL was dissolved with 210μL of the specimen and a 200-μL aliquot was used for ESP. Results : Water induced the agglutination, and HSA prolonged the agglutination time depending on its concentration especially in the ESP630 method. The water-induced agglutination was not inhibited by the addition of anti-factor C monoclonal antibody, and amidinophenyl benzoate hydrochloride, used as a clotting enzyme inhibitor, intensively inhibited the water-induced agglutination. Therefore, the water-induced agglutination was suggested to be a false-positive reaction to non-specific activation of the clotting enzyme. The HSA-induced prolongation of the reaction in the national health insurance-covered turbidimetric kinetic assay was not observed. Conclusion : HSA or plasma protein seemed to affect the result, especially in the ESP630 method, and a non-specific reaction was found to occur in the ESP methods.

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Recently, reports of macrolide-resistant strains of Mycoplasma pneumoniae have been increasing. We examined the antimicrobial susceptibility and clinical significance in patients with M. pneumoniae. Seventy patients in whom M. pneumoniae was detected from 2008 to 2012 were included in the study, and compared with patients between 2003 and 2006. There were no macrolide-resistant strains detected in the 38 strains from 2003 to 2006, but from 2008 to 2012, out of the 70 strains 46 (65.7％) were positive for the macrolide resistant 23SrRNA gene mutant (A2063G), which is consistent with recent trends. Comparison between cases of macrolide resistant strains and those with macrolide sensitive strains did not reveal a significant difference in the hospitalization period. The approximate duration of fever was 7 days ; for both cases : those who received effective antimicrobials as the initial therapy, and for those with macrolide sensitive strains. It seems that the duration of fever depends on susceptibility to the initial antimicrobials regardless of macrolide resistance. There were some patients that improved without use of quinolone or minocycline, though macrolide resistant strains were detected. These patients did not reveal extension of the hospital stay nor aggravation of pneumonia. This suggests that a macrolide drug might be the first choice drug for M. pneumoniae even now, and a change of drug should be considered when fever duration is long.

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Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) has been recently proposed as a clinical-radiological syndrome. Several causes of MERS have been reported including infectious diseases. We present herein on a case of MERS induced by dengue fever in a Japanese traveler. A 48- year-old male returning from Thailand and Cambodia was admitted for an unknown fever. Following admission, the dengue virus was diagnosed with a positive RT-PCR result. On day 5 of the illness, regardless of reduced fever, weakness suddenly developed in both upper limbs. A cerebral MRI showed hyperintensities in the splenium of the corpus callosum on T2-weighted and diffusion-weighted images. The symptoms resolved completely within two days of onset. The patient was diagnosed as having MERS due to the MRI features and the mild clinical course. Although only a few cases of MERS caused by dengue fever have been reported, the condition is possibly underdiagnosed. It is hypothesized that dengue fever can induce MERS as dengue fever can cause increased endothelium permeability and hypo-sodium which have been proposed in the pathogenesis of MERS. However, there is currently limited evidence for this. Further research is recommended to demonstrate a causal association between dengue fever and MERS.

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Nocardia asiatica is a rare causative organism responsible for opportunistic infection, and was first reported by Kageyama et al. in 2004. We report herein on a very rare case of N. asiatica infection in a 76-year old male patient with ANCA-associated vasculitis and a history of pulmonary tuberculosis. The patient developed pulmonary nocardiosis due to N. asiatica while receiving glucocorticoid therapy. Chest computed tomography demonstrated multiple granules and cavity formation mainly in the left lower lobe. From the images, we suspected opportunistic infection, possibly pulmonary tuberculosis or pulmonary damage due to ANCA-associated vasculitis. Nocardia sp. was detected from a bronchoalveolar lavage culture and N. asiatica was identified by 16S ribosomal DNA gene sequencing. Cranial magnetic resonance imaging revealed no abnormality. Administration of Doripenem (1.5g/day) and sulfamethoxazole-trimethoprim (4g/day) was started,and the patientʼs clinical and imaging findings promptly improved. Thereafter, he received sulfamethoxazole-trimethoprim (2g/day) and prednisolone (10mg/day) as maintenance therapy for ANCA associated vasculitis for more than one year, and there has since been no recurrence of the Nocardia infection.

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We report herein on a case of osteomyelitis with a granulomatous lesion caused by Salmonella enterica subsp. enterica serovar Infantis (Salmonella Infantis). A 30-year-old Japanese man presenting with a 3-week history of left ankle pain was suspected to have either a tumor or osteomyelitis, on the basis of imaging study findings. He underwent a surgical resection of the lesion. Histopathological examination revealed a granuloma. However, S. Infantis was cultured from the biopsy sample. Cefazolin was initially administered as empirical therapy. We switched the antibiotic to ampicillin on the basis of the anitibiotic-susceptibility test results. Six weeks after intravenous ampicillin therapy, we switched to oral ciprofloxacin. He has had no recurrence in the 3 years after treatment completion. Salmonella osteomyelitis is rare and this pathogen seldom causes a granulomatous lesion. According to the findings in our case, Salmonella spp. should be considered as one of the differential diagnoses for granulomatous lesions in the bone.

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Bacillus Calmette-Guèrin (BCG) iscommonly used not only as an infant vaccination, but also as a treatment of and prophylaxis to prevent recurrence in the management of non-muscle-invasive bladder cancer. However, the use of “live”BCG is sometimes complicated by associated infection.Wepresentacasestudy of a 77-year-old man who developed bilateral renal masses after intravesical BCG therapy was initiated in November 2013, following transurethral resection of non-muscle-invasive bladder cancer. After four courses of BCG (Japan strain, 80mg per treatment) instillations, a computed tomography examination for febrile episodes showed multiple bilateral renal masses, accompanied by ahistological finding of a granulomatous reaction. An acid fast bacterium was cultured from only urine among blood, urine, and microscopic samples. Using the cultured strain, BCG infection was confirmed by the specific gene deletion pattern based on allelespecificpolymerase chain reaction analysis. Anti-tuberculosis treatment, including isoniazid (300mg/day), rifampicin (600mg/day), and ethambutol (1,000mg/day), was started for the BCG-related renal granuloma in February 2014. After 3 months, antibiotictherapy was discontinued owing to severe appetite loss, though the masses remained solid. No rapid growth has been detected after anti-BCG therapy. Intravesical BCG therapyis recommended worldwide as one of standard treatments for non-muscle-invasive bladder cancer. We should closely observe patients undergoing this approach for emerging BCG complications.

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