To assess the humoral response to the influenza vaccine in patients undergoing R-CHOP therapy (rituximab combined with cyclophosphamide, doxorubicin, vincristine, and predonisolone) for non-Hodgkin lymphoma (NHL), the anti-hemagglutinin (HA) titer in 7 NHL patients undergoing therapy was compared with those in 10 control group subjects in the 2005/2006 season. Four weeks after vaccination, the HA titers against the influenza type A H1N1 and type B antigens, the same antigens that had been used in the previous seasons, were elevated in all patients treated with R-CHOP. In contrast, there was no increase in the geometric mean titer for type A H3N2 antigen, which was newly included in 2005/2006 season, in the patients treated with R-CHOP, while there was a significant increase in the 10 control subjects (p = 0.014). This study showed that vaccination against influenza virus generated an appreciable humoral response to recall antigens in NHL patients treated with R-CHOP therapy, but not to the primary antigen. [J Clin Exp Hematopathol 49(1) : 9-13, 2009]

Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA). MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF) and low-biofilm formers (L-BF). These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections.

The role of a dprA ortholog (Cj0634) in Campylobacter jejuni transformation was phenotypically assessed using two strains. C. jejuni strain 11168 was naturally competent for transformation by chromosomal DNA, while efficiency decreased 100-fold in a Cj0634::aphA mutant, whereas C. jejuni strain 480 was not naturally competent. C. jejuni strain 480 but not 11168 could be electro-transformed by shuttle plasmid pRY111, an effect completely abolished by Cj0634 interruption. Complementation of the Cj0634 mutation in C. jejuni strain 480 in trans with vectors containing the dprA homologs from C. jejuni, Helicobacter pylori, or Haemophilus influenzae, completely (for Cj0634) or partially (H. pylori>H. influenzae) restored electro-transformation. Thus, C. jejuni expresses a DprA ortholog that functionally most closely resembles that of H. pylori and is involved in DNA transformation.

The objective of this study was to evaluate the effects of earlier intervention by an antimicrobial stewardship team (AST) on antimicrobial use, antimicrobial resistance rates, and the clinical outcomes, without changing the weekly intervention schedule. A retrospective study was conducted at Fukuoka University Hospital between April 2013 and March 2016. The effects were compared among three study periods (SP): SP1 (patients receiving anti-methicillin-resistant Staphylococcus aureus agents and carbapenems for ≥14 days), SP2 (patients receiving specific antimicrobials for ≥14 days), and SP3 (patients receiving specific antimicrobials regardless of the duration of treatment). The timing of AST intervention was shortened from an average of 15.5days after administration in SP1 to 4.2 days in SP3. The antimicrobial use density (AUD) of carbapenems and piperacillin-tazobactam decreased significantly (SP2 vs. SP3, p<0.05), and the costs of specific antimicrobials decreased (SP1, US$ 1080000; SP2, US$ 944000; SP3, US$ 763000). The rates of carbapenem resistance among Pseudomonas aeruginosa isolates showed a significant reduction from 16.2% in SP2 to 8.7% in SP3 (p<0.05). The mortality rate and length of stay did not change during the study period. Earlier intervention by an AST could contribute to the proper use of antimicrobials without adversely affecting patient outcomes.

To determine relationships between Helicobacter pylori geographical origin and type II methylase activity, we examined 122 strains from various locations around the world for methylase expression. Most geographic regions possessed at least one strain resistant to digestion by each of 14 restriction endonucleases studied. Across all of the strains studied, the average number of active methylases was 8.2 ± 1.9 with no significant variation between the major geographic regions. Although seven pairs of isolates showed the same susceptibility patterns, their cagA/vacA status differed, and the remaining 108 strains each possessed unique patterns of susceptibility. From a single clonal group, 15 of 18 strains showed identical patterns of resistance, but diverged with respect to M.MboII activity. All of the methylases studied were present in all major human population groupings, suggesting that their horizontal acquisition pre-dated the separation of these populations. For the hpyV and hpyAIV restriction-modification systems, an in-depth analysis of genotype, indicating extensive diversity of cassette size and chromosomal locations regardless of the susceptibility phenotype, points toward substantial strain-specific selection involving these loci.