Efficacy of common antiseptics against multidrug-resistant Mycobacterium tuberculosis.

OBJECTIVES: The incidence of infections caused by multidrug-resistant strains of Mycobacterium tuberculosis (MDR-TB) has been increasing. Antiseptics are frequently used to prevent mycobacterial infection. The aim of this study was to determine those antiseptics that are useful against MDR-TB. DESIGN: We evaluated bactericidal activity against clinical isolates of MDR-TB in vitro. METHOD: Thirteen strains of MDR-TB were tested against povidone-iodine (PVP-I), cresol, akyldiaminoethyl glycine hydrocloride (AEG), and glutaraldehyde. After bacilli were exposed to the antiseptic solution with 2% human serum, the disinfectant was inactivated by addition of neutraliser. RESULTS: PVP-1 at a final concentration of 0.2% killed all of the strains within 120 seconds, and PVP-I at 0.1% killed 99.9% or more bacilli within 60 seconds. Most strains were killed after exposure to 0.5% cresol at 300 seconds and to 1.0% cresol at 60 seconds; 3.0% cresol killed all bacilli within 120 seconds, while 0.1%, 0.2%, and 0.5% AEG all required 60 minutes to kill 99.9% or more of the bacilli; 2.0% glutaraldehyde required 10 minutes to kill all bacilli. CONCLUSION: The bactericidal activities of antiseptics for MDR-TB were similar to those for drug-sensitive M. tuberculosis strains. PVP-I would be a useful antiseptic against MDR-TB. The bactericidal activities of glutaraldehyde are effective against MDR-TB as an antiseptic for medical equipment.

Antibacterial activity of calozeyloxanthone isolated from Calophyllum species against vancomycin-resistant Enterococci (VRE) and synergism with antibiotics.

Calozeyloxanthone ( 1) was re-isolated from the root bark of Calophyllum moonii, an endemic species of Sri Lanka, and found to be active against vancomycin-resistant Enterococci (VRE) and vancomycin-sensitive Enterococci (VSE) with MIC values of 6.25 microg/ml and 12.5 microg/ml, respectively. Further, a marked synergism between 1 and vancomycin hydrochloride (VCM) against VRE was also observed. These findings suggest that 1 in combination with VCM against VRE may be useful in controlling VRE infections.

Bactericidal activities of commonly used antiseptics against multidrug-resistant mycobacterium tuberculosis.

Seventeen clinical isolates of Mycobacterium tuberculosis were selected in order to study the bactericidal activities against drug-resistant M. tuberculosis. The effects of different antiseptics against multidrug-resistant M. tuberculosis (MDR-TB) were examined. Each of the test strains was cultured on the surface of an agar slant containing Löwenstein-Jensen medium. 0.05 ml of the bacillary suspension was poured into a test tube, and 0.45 ml of various antiseptics was added. After the bacilli had been exposed to the antiseptic solution with 2% human serum for various periods of incubation time, the antiseptic was inactivated by addition of 0.45 ml neutralizer, a mixture containing 10% Tween 80, 3% soybean lecithin and 0.5% sodium thiosulfate. As the results, povidone-iodine (PVP-I) at a concentration of 0.2% killed 99.9% or more of all strains tested within 30 s. All of the strains tested with PVP-I were killed almost completely within 60 s. There was no difference in bactericidal activities of PVP-I between standard strain H37Rv and MDR-TB. 99.9% or more of all strains tested were killed after exposure to 1.0% cresol for 60 s. In the case of cresol however, the exposure time of 30 s was not enough to get satisfactory effects. 2.0% glutaraldehyde needed 5 min to kill 99.99% or more of the bacilli tested, and 0.2% alkyldiaminoethylglycine hydrochloride required 60 min to do so. The results of bactericidal activities of common antiseptics against MDR-TB were similar to those against H37Rv. We conclude that the commercially available PVP-I product is a useful antiseptic against MDR-TB similar to other M. tuberculosis.

Bactericidal activities of disinfectants against vancomycin-resistant enterococci.

The bactericidal activities of 35 commercially available disinfectants against vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) were investigated under both clean and dirty (albumin added) conditions using a microtitration plate method. No differences in bactericidal time were observed with any of the test disinfectants when comparing activity against VRE or VSE. Isopropyl alcohol (70 v/v%), alcohol-containing preparations such as Welpas, Wellup and Maskin W . ethanol solution, 0.2% of cation surfactant disinfectants such as Osvan solution 'daigo', Germitol 'Maruishi' 10% and Hyamine solution, and 0.5% of amphoteric compound disinfectants such as TEGO-51, Hygieel and Hypal No.3, were the most effective compounds when compared with other disinfectants. These results suggest that the use of a disinfectant with activity against VRE may be one appropriate method for preventing infections caused by this micro-organism.

[Changes in the antibacterial activity of chemotherapeutic agents (especially carbapenems) for 10 species of clinical isolates between 1994 and 1996. Surveillance group of the sensitivities of clinical isolates to antibacterial agents].

During October and December of each year of from 1994 to 1996, 3,849 strains of 10 species of bacteria were isolated from clinical materials in 21 institutions nationwide. The minimum inhibitory concentrations (MICs) for these bacteria of four carbapenems (imipenem [IPM], panipenem [PAPM], meropenem [MEPM], and biapenem [BIPM]) and other representative antibacterial agents were measured to investigate annual changes in antibacterial activity. Carbapenems showed potent activity against methicillin-sensitive S. aureus (MSSA), S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, and the B. fragilis group, with the activity being stable. However, these drugs showed weak activity against methicillin-resistant S. aureus (MRSA) and P. aeruginosa. The antibacterial activity (MIC90) against the tested organisms generally remained stable. Particularly, there was annual improvement of the MIC90 values of IPM and BIPM for S. pneumoniae, as well as the values of IPM and PAPM for H. influenzae, and those of IPM, PAPM, and BIPM for S. marcescens. On the other hand, the activity of carbapenems (including IPM) against MRSA was not necessarily strong, but there was annual improvement of MIC90 values.

Electron-microscopic study of the bactericidal effect of OPB-2045, a new disinfectant produced from biguanide group compounds, against methicillin-resistant Staphylococcus aureus.

The bactericidal effect of OPB-2045, a new disinfectant produced from biguanide group compounds, against methicillin-resistant Staphylococcus aureus (MRSA), MRSA IID 1677, was investigated by transmission electron microscopy. OPB-2045 showed strong bactericidal activity against MRSA. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of OPB-2045 against the test strain were 0.78 and 1.56 microg mL(-1), respectively. The test bacteria were incubated in the presence of OPB-2045 at 1/2 MIC (0.39 microg mL(-1)), 1 MIC (0.78 microg mL(-1)), 2 MIC (1 MBC, 1.56 microg mL(-1)), 4 MIC (2 MBC, 3.13 microg mL(-1)) or 10 MIC (5 MBC, 7.8 microg mL(-1)) at 37 degrees C for 30 s, 3 min, 30 min or 6h. The morphology of the cells was examined by transmission electron microscopy. The cell damage observed after 30-min or 6-h incubation in the presence of OPB-2045 at 1/2 or 1 MIC was the same as that at 2, 4 or 10 MIC. The numbers of damaged MRSA cells increased according to the increase in concentration of added disinfectant, and the image of bacteriolysis was observed, too. After treatment at 1/2 or 1 MIC, a few leaking cells were recognized, but no destroyed cells were found. No morphological changes were observed after treatment at 1 or 2 MIC for 30 s, 3 min or 30 min. When the incubation time was extended to 6 h, morphological changes in the MRSA cells treated at 1 or 2 MIC were observed. When examining the relationship between the numbers of surviving bacteria and the MIC (MBC) values in soybean casein digest broth, no decrease in MRSA cell numbers was recognized in the untreated control or at 1/2 MIC, but a marked decrease in MRSA cell numbers was recognized as the OPB-2045 concentration was increased. The new disinfectant OPB-2045 would make a useful contribution to the medical field for the prevention of infections caused by pathogenic bacteria such as MRSA.

Electron-microscopic study of the bactericidal effect of OPB-2045, a new mono-biguanide disinfectant produced from biguanide group compounds, against Pseudomonas aeruginosa.

The bactericidal activity of OPB-2045 (1-(3,4-dichlorobenzyl)-5-octylbiguanide monohydrochloride hemihydrate) at several concentrations against Pseudomonas aeruginosa IFO 13275 was investigated morphologically by transmission and scanning electron microscopy. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of OPB-2045 against P. aeruginosa were the same, at 12.5 microg mL(-1), suggesting that it may be a suitable disinfectant for use in the medical field. Test bacteria were treated at concentrations of one half the MIC value (6.25 microg mL(-1)), the MIC value (12.5 microg mL(-1)), twice the MIC value (25 microg mL(-1)) or ten times the MIC value (125 microg mL(-1)) at 37 degrees C for 30 min or 6 h and the cells were then examined by transmission and scanning electron microscopy. The cell damage evident after 6h incubation was greater than observed after 30 min incubation. Especially, at one half the MIC, no cell damage was evident after 30 min incubation, but damaged cells were observed after 6 h incubation. The proportion of empty cells of P. aeruginosa increased as the concentration of added disinfectant was increased, and the release of intracellular components was also recognized. These results suggest that OPB-2045 acts on the cell membrane and cell wall of P. aeruginosa, and destroys their integrity at the level of the MIC (MBC). With the increase in OPB-2045 concentration and the increase in reaction time, the bactericidal effect increased markedly. Agglutination of the cells was observed at high concentrations of OPB-2045. This indicates that the bactericidal effect at high concentrations of OPB-2045 differs from that at low concentrations. A clear cell-damaging effect against the test strain was recognized which was dependent on the OPB-2045 concentration and the incubation time. From experiments concerning the relationship between the number of surviving bacteria and MIC values in soybean casein digest broth, the decrease in bacterial numbers was found to be dependent on the OPB-2045 concentration. We conclude that it would be a useful contribution to the medical field to supply a new disinfectant to be employed in preventive countermeasures against infection caused by pathogenic bacteria.

Involvement of gicerin, a cell adhesion molecule, in development and regeneration of oviduct and metastasis of oviductal adenocarcinomas of the chicken.

Gicerin is a novel cell adhesion molecule in the immunoglobulin superfamily and has both homophilic adhesion and heterophilic adhesive activity to neurite outgrowth factor (NOF), an extracellular matrix protein in the laminin family. We investigated the possible involvement of gicerin in oviductal development, regeneration, and metastasis of oviductal adenocarcinomas of the chicken. In the oviductal epithelium, gicerin was expressed strongly during development, disappeared after maturation, and reappeared during regeneration. NOF was constitutively expressed in the basement membrane of the epithelium. These molecules were expressed strongly in oviductal adenocarcinomas in both primary and metastatic lesions in the mesentery. An anti-gicerin antibody inhibited the attachment of adenocarcinoma cells to the mesentery in vitro. Many cells migrated from adenocarcinoma tissues on NOF, which were inhibited by an anti-gicerin antibody. These results suggest that gicerin might play a role in oviductal development and regeneration and also in the metastasis of adenocarcinomas.

Inhibitory effect of creosote and its main components on production of verotoxin of enterohaemorrhagic Escherichia coli O157:H7.

The inhibitory effects of creosote and its main components, alpha-methoxyphenol and o-ethylphenol, on production of verotoxin by enterohaemorrhagic Escherichia coli O157 (VTEC E. coli) were investigated. The production of verotoxin by VTEC E. coli was inhibited by the administration of 0.001-0.1% of creosote or o-ethylphenol (final concentration). On the other hand, weak inhibition of production of verotoxin was observed with 0.1% alpha-methoxyphenol administration. As the inhibitory effects were obtained below Minimal Inhibitory Concentration (MIC) values, these test compounds exerted their effects at the active site of VTEC E. coli cells prior to their production of verotoxin. These findings suggest that pre-administration of creosote and its main components might prevent human intestinal food poisoning by VTEC E. coli and contribute to maintenance of public health.

[Resistance against oral antibiotics to Streptococcus pneumoniae isolated from adult respiratory tract infections].

The resistance against oral antibiotics to Streptococcus pneumoniae (S. pneumoniae) isolated from adult patients with respiratory tract infections in the Kurume area in 1998 was studied. The frequency of resistant strains, which were isolated penicillin-intermediate S. pneumoniae and resistant S. pneumoniae (PISP, PRSP) were both 41.2%. We examined the minimal inhibitory concentrations (MIC) of oral antibiotics and the susceptibility ratio of the strains for the drugs based on the breakpoint MIC. The breakpoint MIC of pneumonia against oral beta-lactam antibiotics to PISP, PRSP, which were determined by Japan Society of Chemotherapy, were high in the order of FRPM > CDTR, CFPN > CFTM > CFDN, CPDX. In the case of the new oral quinolones, DU6859a > SPFX > LVFX > CPFX showed good results, in this order, DU6859a showed the most significant inhibitory effect to PISP, PRSP (MIC90 0.06 microgram/ml). By serotyping the percentage of 19, 6, 23 was 42.9%, 21.4% and 14.3%.

[Inhibitory effects of natural medicines on the enzymes related to the skin].

In this paper, we investigated the inhibitory effects of water extracts from sixty-six natural medicines on the enzymes related to the skin, which were tyrosinase, hyaluronidase and collagenase. To clarify the inhibitory components in water extracts, tannin quantity and the inhibitory activity of the water extracts after removal of phenolic compounds using polyclar AT, were measured. Twelve kinds of natural medicines were found to have tyrosinase inhibitory activity. Six of them showed that tannin, which contains sufficient amounts in extracts, might be major inhibitory compounds due to a significant decrease of inhibition by these samples after removal of phenolic compounds. The inhibitory compound of Aurantii fructus immaturus was thought phenolic compounds except tannin. The inhibitory compounds may include Armeniacae semen, Perillae folium and Persicae semen besides a phenolic compound. Twenty-seven species among the natural medicines studied showed inhibitory activity on hyaluronidase. Phenolic compounds in these extracts except Artemisiae argyi folium, could not be candidates for hyaluronidase inhibitors. Seven kinds of the natural medicines have inhibitory activity on collagenase. It was estimated that these inhibitory compounds were phenolic compounds. These results are to be expected for finding novel compounds for skin disease or skin-care cosmetics.

Anti-MRSA activity of sophoraflavanone G and synergism with other antibacterial agents.

Anti-MRSA activity of sophoraflavanone G (SFG) and synergism between SFG and antibacterial agents against MRSA (methicillin-resistant Staphylococcus aureus) were evaluated by means of Minimal Inhibitory Concentrations (MIC). The MICs of SFG against 27 strains of MRSA ranged from 3.13 to 6.25 micrograms ml-1. Synergism between SFG and vancomycin hydrochloride (VCM) or fosfomycin (FOM) was observed (the fraction inhibitory concentration (FIC) indices were 0.16 and 0.48), while partial synergism was admitted between SFG and other antibacterial agents such as methicillin (DMPPC), cefzonam (CZON), gentamicin (GM), minocycline (MINO) and levofloxacin (LVFX) (the FIC indices were 0.71, 0.73, 0.69, 0.65 and 0.58, respectively). These findings suggest that SFG in combination with VCM or FOM may be useful in controlling MRSA infections.

Effects of preparations of Chinese medicinal prescriptions on digestive enzymes in vitro and in vivo.

The effects of preparations of Chinese medicinal prescriptions on the activities of digestive enzymes were investigated. The starch dextrinizing activity of pancreatin was inhibited by Keishi-bukuryo-gan, Sho-seiryu-to, Hachimi-jio-gan, Unsei-in and Keishi-ka-shakuyaku-to to below 40% of the control activity. Hachimi-jio-gan and Sho-seiryu-to, in particular, lowered the activity to 4% and 24% of the control activity, respectively. The protein digestive activity of pancreatin was lowered by Keishi-bukuryo-gan, Oren-gedoku-to, Ryutan-shakan-to, Tokaku-joki-to, Yokuinin-to and Hange-shashin-to, to 56 to 70% of the control activity. To investigate the effects of the preparations of Chinese medicinal prescriptions on digestive enzymes in vivo, 600 mg (185 kBq) of 125I-egg white albumin were administered orally to rats 30 min before the administration of 100 mg of Tokaku-joki-to or Oren-gedoku-to. The radioactivity which transferred to the blood was less in the animals pre-fed these prescriptions than in the control animals, indicating that the digestion of egg white albumin was delayed in the presence of the prescriptions.

Polysaccharide of Astragali radix enhances IgM antibody production in aged mice.

The effect of Astragali Radix (AR) on IgM antibody production in mice of various ages (10 weeks, 36 weeks and 60 weeks) was examined. The antibody production levels in the 36- and 60-week-old mice were significantly decreased to about 70 and 60% of that in the 10-week-old mice. The enhancement effect of a crude polysaccharide AR fraction on the antibody production was nil in the 10-week-old mice, but significant enhancement effects were observed in the 36- and 60-week-old mice, compared to the age-matched control. Two polysaccharides active in the enhancement of the IgM antibody production in the aged mice were isolated from the high molecular weight fraction of AR by cetavlon precipitation, ion-exchange and gel permeation chromatography. The molecular masses of these polysaccharides were calculated by HPLC in salt solution. Only one major peak was observed for each, and their molecular masses were estimated to be 1.2 x 10(4) and 2.2 x 10(4). The major components of these polysaccharides were neutral carbohydrates (89.3 and 95.5%), followed by uronic acid and protein; glucose was the predominant sugar component.

Gicerin, a cell adhesion molecule, participates in the histogenesis of retina.

Gicerin is a novel cell adhesion molecule that belongs to the immunoglobulin superfamily. Gicerin protein adheres to neurite outgrowth factor (NOF), an extracellular matrix protein in the laminin family, and also exhibits homophilic adhesion. Heterophilic adhesion of gicerin to NOF is thought to play an active role in neurite outgrowth of developing retinal cells in vitro. In this study, we examined the adhesion activity of gicerin during the retinal development of Japanese quail using an antibody directed against gicerin, to elucidate the biological importance of gicerin in retinal histogenesis. Immunohistochemical and Western blot analysis showed that gicerin was highly expressed in the developing retina but suppressed in the mature retina. The aggregation of neural retinal cells from 5-day embryonic quail retina was significantly inhibited when incubated with a polyclonal antibody to gicerin, suggesting that gicerin protein participates in the adhesion of neural retinal cells of the developing retina. Furthermore, histogenesis of retina both in the organ cultures and in ovo embryos was severely disrupted by incubation with a gicerin antibody. These findings provide evidence that gicerin plays an important role in retinal histogenesis.

Renal disease in young Japanese black cattle.

This paper reports the occurrence of renal disease in six young Japanese Black cattle. Their kidneys were atrophic and of granular appearance. Histologically, they exhibited interstitial fibrosis with inflammatory cell infiltration, clusters of atrophic and cystic tubules, and thickening of tubular and Bowman's basement membranes. Glomeruli were markedly reduced in numbers and were hypercellular due to mesangial proliferation. The affected cattle had a common male ancestor, suggesting a familial basis for this disease.

Protective effect of astragali radix by oral administration against Japanese encephalitis virus infection in mice.

We investigated the protective effect of Astragali Radix (AR) by oral administration against Japanese encephalitis virus (JEV) infection in mice, the pharmacological effects of AR extracts (AE) in different origin, and the chemical composition of the AEs. A protective effect was demonstrated in all four AEs used, however, the effective grade for each one was different. In the control group, an increase of hemagglutination inhibition (HI) antibody titer was observed in all mice surviving 25 d after JEV inoculation. However, the increase of HI antibody titer was not observed in some animals administered an AE. In the control group, the rate of HI antibody positive mice was 90% 3 d after JEV inoculation, while the four groups which received the AE had a 30-60% positive rate. In mice which received the AE, the peritoneal exudate cell (PEC) numbers increased significantly compared to the control group. The predominant cell population of PECs in mice receiving the AE was macrophages, and in the PEC, the active oxygen (AO) production was high. From these results, we propose that the protective effect of AE by oral administration is based on a non-specific mechanism during the early stage of infection, before shifting to antibody production, and that macrophages play an important role in this resistance to JEV infection, e.g., by inducing the production of AO. In the chemical composition of each AE, carbohydrate was the major component.