Chronic hepatitis C virus (HCV) infection is the leading cause for the development of liver cirrhosis and hepatocellular carcinoma, however, it also causes metabolic disorders. Insulin resistance is representative of these metabolic disorders, and not only leads to the development of diabetes but also affects the outcome of antiviral treatment with interferon. Historically, the standard of care for chronic HCV infection was pegylated interferon and ribavirin, but only 40-50％of HCV genotype 1 patients achieve a sustained virological response (SVR). We successfully established a pretreatment prediction model for the treatment outcome using a homeostasis model assessment of insulin resistance (HOMA-IR) and the interleukin 28B genotype (rs 8099917). In recent years, antiviral agents targeting viral proteins critical for HCV replication have become available. Of these, telaprevir, an HCV NS3/4A serine protease inhibitor, has been available in Japan since 2011. As a result, about 80％of patients with HCV genotype 1 can achieve SVR. Nonetheless, insulin resistance is associated with treatment failure, especially for difficult-to-treat patients. In the near future, almost all patients with chronic HCV infection will achieve virological clearance with combined direct antiviral agents,however, insulin resistance will remain a risk for hepatocellular carcinoma. Therefore, the prevention of obesity and avoidance of excessive alcohol intake are very important after achieving SVR.
Gram-negative cocci with a rod-like shape were isolated from a blood sample of a patient with acute myelogenous leukemia (AML). The 16S rRNA sequence of the isolate was similar to that of Neisseria elongata. Because previous reports about N. elongata as a pathogen have been extremely rare, more reliable identification seemed to be needed. We thus additionally performed a Multilocus Sequencing Analysis (MLSA) based on another four regions (argF, rho, recA, glnA), and confirmed the identification of N. elongata. The results from the MLSA identified the species ; however, we could not identify the isolates into subspecies from the sequences. Three subspecies of N. elongata (N. elongata subsp. elongata, N. elongata subsp. glycolytica and N. elongata subsp. nitroreducens) were classified based on three definitive characteristics (catalase possession, nitrite reducibility, and acid from glucose). The results of the tests of three characteristics supported the identification of the isolate as N. elongata subsp. elongata. Therefore we determined the isolate from the AML patient to be N. elongata subsp. elongata.
To clarify the epidemiologic features of Mycoplasma pneumoniae, we examined 358 M. pneumoniae strains isolated between 2004 and 2013 in Yamagata, Japan. Analysis of macrolide-resistance-associated 23S ribosomal RNA (rRNA) domain V mutations revealed 6 kinds of mutants (81 A2063G, 43 A2063T, 1 A2063C, 1 A2064C, 4 C2617G and 1 C2617 mutation). There were only two mutants before 2009, but mutants A2063T and A2063G increased in 2009 and from 2010, respectively. The annual ratio of mutants varied from 20.4％to 76.4％between 2009 and 2013. Typing of the p1 gene revealed 4 types ; 278 type 1, and 3 kinds of type 2 variant strains (10 type 2a, 5 type 2b and 65 type 2c). Type 1 strains accounted for between 85.2％and 100％of isolates from 2004 to 2011, whereas type 2 variant strains increased by 26.5％and 66.1％in 2012 and 2013, respectively. These results indicate that type 1 strains may have been replaced by type 2 variant strains in 2013. Furthermore,the ratio of type 1 strains with a 23S rRNA mutation was 65.1％in 2012 and 95.2％in 2013, but none of the type 2 variant strains had this mutation. In conclusion, type 1 strains with macrolide-resistant mutations appeared in 2006 and increased from 2009. In contrast, type 2 variant strains, which increased in 2012 and became predominant in 2013, showed no mutations.
Object：It is important to know the precise number of varicella patients infected for evaluation of routine immunization and anti-bioterrorism attack using smallpox. Prescription Surveillance (PS) has been providing the estimated number of varicella patients up to the present. However, the estimated number of varicella patients cannot be validated because to date there has been no other comparable precise method of estimation. Recently, all electronic medical claims nationwide (NDB) have been disclosed. In this paper, we compare the number of varicella patients estimated by PS with NDB data, and adjust the number estimated with PS, if necessary. Method：For both NDB and PS, we used the monthly data from April, 2010 to March, 2013. The estimation of the number of varicella patients from the PS data was adjusted by the proportion of estimated number based on PS to the one based on NDB in the entire study period. Moreover, we adjusted it month by month, if the former method may not be enough to compensate for the discrepancy between the two data sets. Results：The average discrepancy between NDB and PS was 48.00％in three years. By the adjustment using NDB in the three years, the discrepancy was improved to 11.49％. However, seasonal patterns of overestimation or underestimation were found. Conversely, by the adjustment using NDB month by month, the discrepancy was greatly reduced to 4.33％. Moreover, the seasonal patterns of overestimation or underestimation disappeared. Conclusion：The number of patients based on NDB would appear the most precise number, however,there may be a delay of about one year before it becomes available. On the other hand, PS data are updated every day and provide us with the up-to-date situation. This paper found that combining the timeliness of the PS data and preciseness of the NDB data will provide substantial benefit for public health.
Yokohama city started a regular, free vaccine program for Haemophilus influenzae type b (Hib) from February of 2011. This study was completed to verify the effectiveness of the vaccine on the nasopharyngeal Hib carriage among healthy children attending daycare centers in the Isogo area. The research was conducted during the late spring (Jun～Jul) and fall (Oct～Nov) of 2012. There was a significant decrease in the Hib carriage rate (spring 8.8％, fall 1.6％). During this period there was no increase in the Hib vaccine coverage. The Hib carriage rate of each daycare center was 0～18.4％in spring and 0～4.9％in fall. There was no significant relationship between the rate of non immunized children and that of Hib carriage. This improvement in nasopharyngeal Hib carriage shows the impact of community immunity.
Thirty isolates of enteropathogenic Escherichia coli (EPEC) and 32 isolates of enteroaggregative E. coli (EAggEC) were isolated from 1,029 stool samples collected from Spring 2012 to December 2013 in Kawasaki city with the polymerase chain reaction (PCR) method targeting eae and aggR genes. Among the 30 EPEC and 32 EAggEC isolates, only 9 strains of EPEC and 8 strains of EAggEC were typed with the commercial O-antisera, whereas the majority of strains were untypable. However, several Ountypable EPEC and EAggEC strains were suggested to harbor the same O-antigen because of the detection of several examples of the same H-antigen. Analysis of the HEp-2 cell adherence test showed positive for only 2 strains (6.6％) of 30 EPEC isolates,meanwhile it showed positive for 16 strains (50.0％) of 32 EAggEC isolates. From these data, we concluded that EAggEC might be more virulent than EPEC, although both EAggEC and EPEC were isolated with almost similar rates from collected stool specimens.
Department of Microbiology, Tokyo Metropolitan Institute of Public Health A total of 477 Salmonella strains isolated from retail domestic chicken meat during 1992-2012 in Tokyo,were examined regarding their serovars and drug-resistance. These strains were detected in 469 (29.8％) of 1,576 samples. The detection rate in every two years was 10.1％to 46.3％of the range. Serological typing results showed that 477 strains were classified into 22 serovars excepting 2 untypable strains. Among them, S. Infantis (312 strains) was the most prevalent, followed by II O4 : b : [e, n, x] (S.II Sofia) (71 strains), S. Hadar (20 strains), S. Typhimurium (20 strains), S. Manhattan (12 strains), S. Schwarzengrund (9 strains), S. Agona (7 strains), and other 15 serovars (24 strains). Results of the antibacterial drug susceptibility test for 477 strains revealed that 89.9％was resistant to some of the 12 drugs tested, and multidrug-resistant strains accounted for 90.2％among them. The frequencies of resistance to each drug were 81.8％, 77.8％, 45.5％, 33.3％, 11.3％, 9.6％, 2.9％, 0.6％, 0.6％and 0.2％, in order with high frequency, for SM, TC, KM, ST, NA, ABPC, CP, FOM, CTX and CAZ, respectively. None of the strains was resistant to NFLX or IPM. Three CTX-resistant strains were CTX-M type extended-spectrum β-lactamase (ESBL) producers, and the group of CTX-M type ESBL genes were CTX-M-2 group (2 strains) and CTX-M-9 group (1 strain). CAZresistant 1 strain was an ESBL producer, but the ESBL gene was not determined.
We report herein on a case of community-acquired necrotizing soft tissue infection caused by Serratia marcescens. The patient had been treated with prednisolone, tocilizumab and tacrolimus for rheumatoid arthritis. Since Gram staining of the tissue revealed Gram negative rod bacteria, ceftriaxone and clindamycin were administered as empiric therapy. Tissue culture revealed S. marcescens. Ceftriaxone was continued according to the antibiotic sensitivity. She underwent debridement of necrotic tissue and continued ceftriaxone for 17days. She recovered and was discharged after skin grafting.
Pseudomonas aeruginosa is a significant causative bacterium in hospital-acquired pneumonia and nursing and healthcare-associated pneumonia, but it seems to be rare in community-acquired pneumonia (CAP). We report two cases of severe CAP due to P. aeruginosa. Case 1 : A 52-year-old man was referred to our hospital for chest and back pain. He was being treated for diabetes mellitus and had a long history of smoking. Chest images showed consolidation in the right upper lobe. Soon after hospitalization, he developed sepsis shock and died seven hours later. Case 2 : A 73-year-old man with a history of heavy smoking was referred to our hospital for right chest pain. Chest images showed right upper lobe pneumonia. Although wide-spectrum antimicrobial agents were administrated, he died ten hours after admission. In both cases, there was a rapid progression to death, despite administration of a broad spectrum of antibiotics and treatment for sepsis. In cases of CAP involving the right upper lobe, the possibility of bacteremia and rapid progress should be considered.