ABSTRACT A total of 395 Haemophilus influenzae strains from 226 Japanese institutions participating in the Nationwide Surveillance Study Group for Bacterial Meningitis were received from 1999 to 2002. All strains were analyzed by PCR to identify the resistance genes, and their susceptibilities to β-lactam agents were determined. Of these strains, 29.1% were β-lactamase nonproducing and ampicillin (AMP) susceptible (BLNAS) and lacked all resistance genes; 15.4% were β-lactamase producing and AMP resistant and had the bla TEM-1 gene; 30.6% were β-lactamase nonproducing and AMP resistant (low-BLNAR) and had a Lys-526 or His-517 amino acid substitution in ftsI encoding PBP 3; 13.9% were β-lactamase nonproducing and AMP resistant (BLNAR) and had an additional substitution of Thr-385 in ftsI ; 9.1% were amoxicillin-clavulanic acid resistant (BLPACR I) and had the bla TEM-1 gene and a Lys-526 or His-517 amino acid substitution in ftsI ; and 1.8% showed resistance similar to that of the BLPACR I group (BLPACR II) but had bla TEM-1 gene and ftsI substitutions, as was the case for the BLNAR strains. All but three strains were serotype b. The prevalence of BLNAR strains has increased rapidly: 0% in 1999, 5.8% in 2000, 14.1% in 2001, and 21.3% in 2002. The MICs at which 90% of BLNAR isolates were inhibited were as follows: AMP, 16 μg/ml; cefotaxime, 1 μg/ml; ceftriaxone, 0.25 μg/ml; and meropenem, 0.5 μg/ml. All of these values were higher than those for the BLNAS counterpart strains. The relatively wide distributions of the β-lactam MICs for BLNAR strains presumably reflect variations in ftsI gene mutations. Pulsed-field gel electrophoresis suggested the rapid spread of specific H. influenzae type b strains throughout Japan. Expedited vaccination, rapid identification, and judicious antibiotic use could slow their spread.
ABSTRACT Among 380 Mycoplasma pneumoniae isolates from 3,678 pediatric patients with community-acquired pneumonia, 50 macrolide-resistant strains had an A2063G transition in domain V of the 23S rRNA, whereas 5 had an A2064G transition. These resistant strains increased rapidly from April 2002 to December 2006.
We compared reactivity between Chlamydia serovar antigens and sera from 18 patients using immunoblotting (IB) and enzyme-linked immunosorbent assay (ELISA). The antigens used were Chlamydia trachomatis serovar L2, D, E, and C organisms for IB and synthetic peptides derived from C, E, G, and L2-VDIV genes for ELISA.Eleven of 12 sera collected from Chlamydia antigen-positive women with cervicitis strongly reacted with C. trachomatis serovar E, as did one serum with serovar C in immunoblotting profiles. ELISA coated individually with peptides E and C strongly reacted with the sera of 6 different natients. The IB result between serovar L2, D, E, and C and sera from the 60ther women patients showed reactivity at E≥D≥L2≥C. ELISA using a synthetic peptide mixture including C, E, G and L2 peptides gave positive results for all 18 sera. These results indicate that IB sensitivity differes with the C. trachomatis serovar antigen used and that certain cases may produce inconsistent results between IB and ELISA. Results of ELISA and IB are thus not always consistent, indicating that different synthetic peptides should be used in ELISA for detecting of low-level C. trachomatis antibodies.
Objective To investigate the novel antiinflammatory mechanism of a disease-modifying antirheumatic drug, bucillamine, on activated T cells, specifically its effect on T cell proliferation, cytokine production, and migration of T cells. Methods T cells were cultured in wells coated with anti-CD3 monoclonal antibodies (mAb) plus anti-CD26 mAb or anti-CD3 plus anti-CD28 mAb, with or without bucillamine. Proliferative responses and the production of interleukin-2 (IL-2), interferon-γ (IFNγ), tumor necrosis factor α (TNFα), IL-6, IL-4, and IL-5 were measured under these costimulatory conditions. Phytohemagglutinin (PHA)–activated T cells were cultured on human umbilical vein endothelial cell–coated transwells in the presence or absence of bucillamine, and T cells migrating through the endothelial cell layer were counted. Immunofluorescence analysis was also performed to analyze the effect of bucillamine on the surface expression of adhesion molecules on T cells. Results Bucillamine (64 μM) significantly inhibited T cell proliferation and the production of IL-2, IFNγ, TNFα, and IL-6, whereas it had no inhibitory effects on the production of IL-4 and IL-5 in the cultures with anti-CD3 plus anti-CD26 mAb. In contrast, bucillamine had no effects on T cell proliferation or any cytokine production in the cultures with anti-CD3 plus anti-CD28 mAb. Furthermore, the same concentration of bucillamine inhibited transendothelial migration of PHA-activated T cells, and reduced the expression level of CD44 on T cells. Conclusion This study demonstrated the novel effects of bucillamine in vitro, showing inhibition of type 1 T helper–type cytokine production and proinflammatory cytokine production induced by certain costimulatory conditions, and inhibition of transendothelial migration of T cells. The inhibition of T cell migration appeared to be mediated partly through the reduced expression of CD44, an adhesion molecule on the T cell surface.
CD26, a 110 kDa cell surface glycoprotein, exhibits dipeptidyl peptidase IV (DPPIV; EC 3.4.14.5) enzyme activity and plays an important role in T cell co-stimulation. In the present study, the function of CD26/DPPIV in transendothelial migration was examined using β-chemokines as chemoattractants. When soluble recombinant CD26 (sCD26/DPPIV+) was added to the transendothelial chemotaxis system, chemotactic migration of T cells toward RANTES was significantly enhanced. Addition of sCD26 to 50 ng/ml of RANTES enhanced the migratory response by a factor of two compared to RANTES alone, whereas mutant soluble CD26 (mCD26), lacking the DPPIV enzyme activity, had no enhancing effect on RANTES-induced T cell migration. In the process of analyzing the mechanisms of the enhancement of T cell migration by sCD26, we showed that RANTES was cleaved by sCD26 under physiologic conditions at the precise site characteristic of its enzyme specificity. However, synthesized RANTES which lacks two N-terminal amino acids showed a chemotactic activity equivalent to full-length RANTES on T cells. Furthermore, addition of sCD26 showed enhancement of T cell migration induced by both forms of RANTES. In contrast to T cells, the truncated RANTES is inactive in chemotaxis of purified monocytes and supplement of sCD26 but not mCD26 reduced the migratory response of monocytes to RANTES. These results suggest that CD26/DPPIV differentially regulate the chemotactic response of T cells and monocytes to RANTES.
