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Background: Increases in penicillin-resistant Streptococcus pneumoniae have been documented worldwide. Methods: During 1999 and 2000, 5,015 S. pneumoniae isolates were collected from 13 countries on five continents and tested for antimicrobial susceptibility. Results: Penicillin resistance rates were as follows: South Korea, 70.1%; Hong Kong, 50.3%; Thailand, 39.3%; France, 28.7%; Spain, 24.8%; Mexico, 18.1%; Ireland, 11.8%; South Africa, 11.1%; Italy, 9.4%; United Kingdom, 3.1%; Brazil, 2.9%; China, 2.3%, and Germany, 0.7%. Resistance to azithromycin, clarithromycin and trimethoprim-sulfamethoxazole was commonly associated with penicillin resistance. Levofloxacin-resistant isolates were detected in 8 of 13 countries: Germany (0.2%), France (0.4%), Thailand (0.5%), South Korea (0.9%), Mexico (1.5%), Spain (1.6%), China (3.3%) and Hong Kong (8.0%). Multidrug resistance (resistance to ≧3 antimicrobial classes) occurred in 626/5,015 isolates (12.5%). Levofloxacin was active against 96.0% (601/626) of the multidrug-resistant (MDR) isolates and 99.7% (4,374/4,389) of the non-MDR isolates. Conclusion: Although relatively high levels of levofloxacin resistance were detected in China and Hong Kong, overall, levofloxacin remained active against >99% of clinical isolates of S. pneumoniae despite their resistance to other agents. Continued surveillance of S. pneumoniae will track any changes in levofloxacin activity, should they occur.

beta-Galactosidase [EC 3.2.1.23] was isolated from a partially purified preparation obtained from cultured cells of a special strain of Aspergillus oryzae, RT 102 (FERM-P1680). The enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis and was free from alpha-galactosidase, alpha- and beta-mannosidase, alpha- and beta-N-acetylhexosaminidase, and protease activities. The beta-galactosidase was capable of acting on aryl beta-galactosides, lactose, and lactosides. It also hydrolyzed beta-galactosyl linkages in urinary glycoasparagines and asialo alpha1-acid glycoprotein. The enzyme was rather stable in aqueous solution, retaining full activity at 4 degrees for at least several months. At pH 4.5, the optimum pH for the enzyme activity, and 37 degrees, full activity was maintained for several days.

The IgE-potentiating and IgE-suppressive factors share a common structural gene and therefore a common polypeptide chain, and their biologic activities are decided by a post-translational glycosylation process. Under physiological conditions, this process is controlled by two T cell factors, i.e., the glycosylation-enhancing factor (GEF) and glycosylation-inhibiting factor (GIF). GIF is a fragment of phosphorylated lipocortin and has immunosuppressive effects. Repeated injections of this lymphokine into antigen-primed mice switched their T cells from the formation of IgE-potentiating factor to the formation of IgE-suppressive factor and facilitated the generation of antigen-specific suppressor T cells, which form antigen-specific GIF upon antigenic stimulation. The antigen-specific GIF suppressed the antibody response in a carrier-specific manner and has properties similar to antigen-specific suppressor T cell factors.

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The effects of N2-(N-acetyl-muramyl-L-alanyl-D-isoglutamyl)-N6-stearoyl-L-lysine (MDP-Lys(L18], a muramyl dipeptide (MDP) analog, on the immune responses in mice were studied. MDP-Lys(L18) augmented the mitogenic responses of splenic lymphocytes to phytohemagglutinin (PHA) and lipopolysaccharide (LPS) at 0.1-10 micrograms/ml, and antibody formation to sheep red blood cell (SRBC) in normal and immunosuppressed mice, and to dinitrophenyl (DNP)-Ficoll. In addition, MDP-Lys(L18) potentiated polyclonal B cell activation both in vivo and in vitro. It was also found that MDP-Lys(L18) augmented the cellular immune responses, such as mixed lymphocyte reaction (MLR) and delayed type hypersensitivity (DTH). These effects of MDP-Lys(L18) were more potent than those of MDP. These findings may be attributed to the interleukin 1 (IL-1)-inducing activity of MDP-Lys(L18).

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