Epidemiological characteristics of Salmonella enterica serovar typhimurium from healthy pigs in Japan.

We characterized 53 Salmonella enterica ser. Typhimurium strains recovered from healthy pigs during 1998-1999 (n=12) and 2004-2005 (n=41) as to their carriage of DT104 spacer region, class 1 and 2 integrons, virulence genes (spvC, rck, and pefA), and XbaI- and BlnI-Pulsed-Field Gel Electrophoresis (PFGE) profiles. No DT104 strain was detected in 1998-1999, whereas 65.9% (27/41) of the strains in 2004-2005 were DT104 showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, and cephaloridine (R-type ACSSuT+). Class 1 intergron-associated genes, aadA2 (1.0-kbp amplicon) and pse1 (1.2-kbp amplicon), were found in all the DT104 strains (27/27). One strain showing resistance to streptomycin, sulfonamides, tetracyclin, and trimethoprim (R-type SsuTTm) harbored another class 1 integron-associated gene (dhfrXII-orfF- aadA2) on 1.9-kbp amplicon. Virulence gene spvC was found in 92.5% (49/53) and rck and pefA were found in 88.7% (47/53) of the strains, whereas spvC, rck, and pefA were found in all the DT104 strains. Ser. Typhimurium strains were categorized into four clusters (X1, X2, X3, and X4a/X4b) by XbaI-PFGE, or into nine clusters (B1, B2, B3a/B3b, B4, B5, B6, B7, B8, B9a/B9b) by BlnI-PFGE analyses. DT104 strains were restricted into X2, or into B2, B3a/B3b, and B6 clusters, indicating that our multidrug-resistant DT104 strains from healthy pigs might have derived from at least three independent clones, with the most widespread clone being the cluster B6 strains isolated in Kanto, Tokai, Chugoku, and Kyushu regions.

Association between Chlamydophila pneumoniae infection and risk of coronary heart disease for Japanese: the JPHC study.

BACKGROUND: Chlamydophila pneumoniae infection is considered a risk factor for atherosclerosis and coronary heart disease in western countries. However, evidence of it being a risk for Japanese is very limited because of a lower risk of coronary heart disease than for western people. The aim of this study was to examine further the association between C. pneumoniae infection and risk of coronary heart disease in Japanese. METHODS: We conducted a nested case-control study of 49,011 Japanese men and women who participated in The Japan Public Health Center (JPHC) study. By the end of 2004, 196 cases of coronary heart disease and 155 cases of myocardial infarction had been documented among the participants. Two controls were selected for each case. For these subjects, we examined the association between serum anti C. pneumoniae IgA and IgG on the one hand and risk of coronary heart disease on the other. RESULTS: Concentration of C. pneumoniae IgA antibody was positively associated with risk of coronary heart disease and more specifically myocardial infarction. Subjects with the highest quartile of IgA antibody showed 2.29 (95%CI, 1.21-4.33) times higher risk of coronary heart disease and 2.58 (95%CI, 1.29-5.19) times higher risk of myocardial infarction than those with lowest quartile. However, no such association was detected for IgG antibody. CONCLUSION: C. pneumoniae infection was found to be positively associated with risk of coronary heart disease.

Chlamydia pneumoniae infection was associated with risk of mortality from coronary heart disease in Japanese women but not men: the JACC Study.

AIM: To investigate the association between Chlamydia pneumoniae infection and mortality from coronary heart disease, a nested case-control study was conducted for 39,242 Japanese who participated in the JACC Study. METHODS: Immunoglobulin A and G titers of C. pneumoniae were measured in stored serum samples collected from 209 patients (113 men and 96 women) who subsequently died of coronary heart disease after 13-year follow-up; and 209 controls matched for gender, age (+/-5 years) and area of residence. RESULTS: After adjustment for high-sensitive CRP and other cardiovascular risk factors, the multivariate odds ratio (OR) of coronary heart disease for highest vs. lowest tertiles of IgA titers was 2.69 (95%CI, 1.00-7.20), p=0.049 for women and 0.58 (0.23-1.46), p=0.25 for men (p for interaction=0.03). A similar association was observed by high (++) vs. low (-/+/-) titers of IgA: multivariate OR was 4.09 (0.86-19.4), p=0.07 for women. CONCLUSIONS: Since high IgA titers indicate persistent and repeated infection, such a state is associated with an increased risk of coronary heart disease mortality for women.

Identification of first exfoliative toxin in Staphylococcus pseudintermedius.

Staphylococcus aureus, Staphylococcus hyicus, and Staphylococcus chromogenes are known to cause skin infections in human or animals by producing exfoliative toxins (ETs). Staphylococcus pseudintermedius can also cause canine pyoderma, but no exfoliative toxins or similar toxins have been reported. PCR with degenerate primers targeted to the conserved regions in ETA, ETB, and ETD from S. aureus and SHETB from S. hyicus, and subsequent chromosome walking identified a novel gene, designated as exi (exfoliative toxin of pseudintermedius) in S. pseudintermedius. EXI had significant homologies with the exfoliative toxins (43-68% identity), particularly with ETB (67.1%), ETD (67.9%), and SHETB (65.1%). Phylogenetic analysis showed close relation between EXI and ETB with a bootstrap value of 80%. Neonatal mice injected with the crude proteins from the culture supernatant or recombinant EXI showed gross blisters and/or characteristic skin exfoliation. The prevalence of exi assessed by dot-blot hybridization was 23.3% (10/43) in S. pseudintermedius isolates from canine pyoderma. The EXI reported herein is the first exfoliative toxin identified in S. pseudintermedius.

Risk of transmission of imipenem-resistantPseudomonas aeruginosa through use of mobile bathing service.

OBJECTIVES: The demand for mobile bathing service (MBS) is increasing in the Japanese society. Therefore, we assessed the risk of MBS-associated infection in MBS clients and their caregivers by examining the bacterial colonization of MBS equipment and utensils. METHODS: Bacterial isolates collected by the stamp agar culture method were examined by disk diffusion assay for their susceptibility to the following drugs: imipenem, ciprofloxacin, amikacin, azutreonam, ceftazidim, meropenem, piperacillin, tobramycin, ofloxacin and cefoperazone. Furthermore, these isolates were subtyped bySpeI-pulsed field gel electrophoresis (SpeI-PFGE). RESULTS: Fifty-fourP. aeruginosa isolates were recovered from different sampling sites, and of these, 26 (47.3%) were isolated from pillows. Eighteen isolates (33.3%) were imipenem (IPM) resistant. The minimum inhibitory concentrations (MICs) of 17 isolates were between 16 and 32 µg/ml, and the MIC of one isolate was greater than 32 µg/ml. TheSpeI-PFGE typing of IPM-resistant isolates revealed that 13 of the 18 isolates were closely related (F=1.0-0.87). CONCLUSION: Our findings suggest that MBS equipment and utensils, particularly pillows, are the primary sources of bacterial contamination and transmission and that there is a risk of MBS-mediated infection among MBS clients and their caregivers.