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.

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.

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.

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.

Increased incidence of beta-lactamase-plasmid negative, high level methicillin-resistant Staphylococcus aureus (MRSA).

Recently isolated strains of methicillin-resistant Staphylococcus aureus (MRSA) have high levels of resistance to the agent and produce beta-lactamase less frequently than methicillin-susceptible strains (MSSA). This phenomenon has been observed in Japan. The majority of MSSA strains (26 of 30) isolated in 1992 produced beta-lactamase while only 18 of 31 and 25 of 67 MRSA strains, isolated in 1991 and in 1992 respectively, produced the enzyme. We analyzed the beta-lactamase gene (blaZ) in 30 strains each of MRSA and MSSA isolated from our hospital using the polymerase chain reaction. We found that 28 MSSA strains but only 14 MRSA strains possessed the gene. In addition, the present study indicates that many recently isolated MRSA strains, which lacked blaZ gene and were negative for beta-lactamase, consistently produced coagulase of type II (coagulase typing is a marker of epidemiology for Staphylococcus aureus). These beta-lactamase negative, type II coagulase producing and highly methicillin-resistant MRSA strains are considered to have an increased ability to successfully colonize individuals and an increased epidemic potential, probably because of the saving of the energy otherwise expended in beta-lactamase production and of the loss of beta-lactamase plasmid coding the mecA gene repressor, resulting in constitutive PBP2' production. These factors may contribute to the wide spread of these strains of MRSA in a nosocomial environment.

[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%.

[Antibiotics susceptibilities and other biological properties of methicillin-resistant Staphylococcus aureus: observation in the last 2 years in our university hospital].

We examined biological properties of strains of methicillin-resistant Staphylococcus aureus (MRSA) which were isolated in our ward in 1991 and 1992. A total of 47 MRSA strains were isolated in 1991 and 64 in 1992. The majority of these strains of MRSA were highly resistant to DMPPC, CEZ and IPM, and were intermediately resistant to MINO. All these strains were, however, sensitive to VCM. The number of coagulase type II strains increased from 22 (46.8%) to 51 (79.7%), and that of enterotoxin type A strains from 27 (57.4%) in 1991 to 47 (73.4%) in 1992. The number of strains which produce Toxic Shock Syndrome Toxin-1 (TSST-1) also increased from 19 (40.4%) to 45 (70.3%), and those strains that produce beta-lactamase decreased from 24 (51.1%) to 21 (32.8%). From the above results, we confirmed the recent change in types of the epidemic strains of MRSA. Namely, there was a marked increase in number of strains which produce type II coagulase type A enterotoxin and TSST-1. For the prevention of a patient to patient-, room to room- and ward to ward-spread, strict isolation was indicated both the infection patients, immunocompromised patients who were at high risk for the infection and the proved carriers. Treatment with VCM was started immediately if MRSA infection was thought plausible. These countermeasures seemed to succeed in reducing the incidence of the infection in our ward.

[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.

[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.

[Rapid detection of mycobacteria in sputa using media supplemented with culture filtrate of Gemella haemolysans].

The effect of the culture filtrate Gemella haemolysans in enhancing mycobacterial growth has been previously demonstrated. In the present studies, an attempt was made to confirm whether the addition of the filtrate into the medium would be an effective method to promote the rapid detection of mycobacteria in sputum specimens of patients. One-hundred and one sputum specimens pretreated with NaOH were inoculated with various media (Dubos, Dubos-agar, 1% Ogawa, Kudo PD, and Middlebrook 7H9) supplemented with the culture filtrate of Gemella haemolysans grown in blood-BHI or blood-HEM at the dilutions of 1/32 or 1/64. Addition of the filtrate reduced the amount of time required to detect mycobacterial growth (Mycobacterium tuberculosis, M. avium complex, and M. kansassi) by an average of 60-70%. The media containing the filtrate formed significantly larger numbers of colonies compared with the control media, and those colonies inoculated developed more rapidly in size. The findings clearly indicated that the culture filtrate promotes the effective growth of mycobacteria which cannot or only slowly grows in ordinary media. Also indicated was that the addition of the culture filtrate of Gemella haemolysans into media provides as a useful tool to allow the rapid diagnosis of mycobacterial diseases.

[A case of sacral neuroblastoma in an adult successfully treated with combination chemotherapy].

A 35-year-old woman was admitted with complaints of severe posterior femoral pain and was diagnosed as having sacral neuroblastoma by tumor open biopsy. After admission, combination chemotherapy consisting of CDDP, etoposide, CPA, and THP was started intra-arterially and intravenously. After 2 courses of chemotherapy, her symptoms markedly improved and the tumor size was reduced. Now, after completion of 16 courses of chemotherapy, she is in a state of partial remission. Hereafter, we intend to reconsider the treatment strategy including surgical therapy.

[Evaluation of the number of clones and the degree of nucleotide diversity of the HCV genome by FSSA (fluorescence single strand conformation polymorphism and sequence analysis) in patients with chronic active hepatitis C receiving interferon therapy].

We evaluated the number of clones and the degree of nucleotide diversity in the HVR of the HCV genome in patients with chronic active hepatitis C who were treated with IFN (interferon). We could not obtain the nucleotide sequence per se of the HCV genome but were able to evaluate the degree of diversity in the nucleotide sequence of the HCV genome using FSSA. Nonresponders to IFN therapy showed significant diversity in the nucleotide sequence, even if their number of HCV clones are small. Responders showed little diversity in the nucleotide sequence, which suggests that their viral clones were composed of populations with less variability in the HVR. IFN therapy had more impact on diversity in the nucleotide sequence than on the number of HCV clones.

[Effect of vasopressin on rabbit hepatic energy metabolism evaluated using in vivo P-31 magnetic resonance spectroscopy].

Changes in metabolic state of rabbit livers after administration of vasopressin (10 mU/kg/min d.i.v.) were evaluated using in vivo P-31 magnetic resonance (MR) spectroscopy. Targets were nine normal control rabbits and eight with chronically carbon tetrachloride-damaged livers. A 2.0 Tesla whole-body MR imager was used for measurement. After administration of vasopressin, liver spectroscopy showed a mild ischemic pattern. The inorganic phosphate peak increased statistically significantly (p less than 0.05) both in the normal control group and in the damaged-liver group (20% and 16% above base line value respectively). In the normal control group, there was a statistically significant decrease (p less than 0.05) in the ATP peak to 18% below the base line value while the PME (phosphomonoester) peak increased slightly (about 10%); there was little change in the damaged-liver group. It was thought that the difference between the two groups was due to differences in blood flow mechanism and liver metabolism. Magnetic resonance spectroscopy was considered to be useful in studying the detailed changes in metabolic state of rabbit liver after administration of vasopressin.

[Hepatocellular carcinoma--a comparative study of MR imaging and angiography].

We used magnetic resonance imaging (MRI) at 0.2 T and angiography to evaluate hepatocellular carcinoma (HCC) in 43 patients who had not received therapy. Tumor detection rate by MRI was 84%, T2-weighted spin echo imaging being the best detection method, though one case could only be detected by T1-weighted imaging (Inversion Recovery method). The signal intensity of the tumor relative to the surrounding liver parenchyma was studied using MRI, and tumor staining using angiography. Where there was a high signal intensity in the T2-weighted spin echo images there was a corresponding tendency for tumor staining to be marked. MRI demonstrated the inner structure--which resembles random high-intensity threads on a lower-intensity background--of hypervascular tumors. Tumors with capsules appeared with the capsule clearly delineated irrespective of the signal intensity of the tumor itself.

[Changes in portal blood flow by intravenous administration of glucagon--the relationship between those changes and the total serum bile acid values in UDCA.GLUCAGON tolerance test].

G30TBA is the total serum bile acid concentration obtained thirty minutes after injection of glucagon in the UDCA.GLUCAGON tolerance test. We have previously reported the usefulness of G30TBA in evaluating liver function. In this paper, changes in the portal blood flow in response to glucagon administration are measured and the relationship between those changes and G30TBA studied. We used an ultrasonic duplex system composed of a B-mode scanner and doppler flow meter of measure portal blood flow after injection of glucagon in thirty seven patients with chronic liver diseases. The results are as follows: The increase in portal blood flow by exogenous glucagon in liver cirrhosis is statistically significantly lower than that in chronic hepatitis. G30TBA in the good-response-to-glucagon group is statistically significantly lower than that in the poor-response group. These results suggest that the effect of glucagon on portal blood flow significantly influences the serum bile acid concentration in the UDCA.GLUCAGON tolerance test.

[Measurement of portal blood flow with magnetic resonance imaging].

A new method for measuring portal blood flow using magnetic resonance imaging has been developed. Flow velocities are calculated from distances that are directly visualized using a new pulse sequence. In a phantom study, the measured flow rates showed a close correlation (r = 0.9996) with actual flow rates in the range 4.7 cm/sec to 22.8 cm/sec. In a study using volunteers, portal blood flow was quickly measured (about 18 seconds) using electrocardiographic gating. These measurements were compared with those obtained by Doppler ultrasound, with which they showed a close correlation in flow velocity (r = 0.968) and flow volume (r = 0.936). This method allows reasonably accurate quantitative analysis of portal blood flow in patients in whom the Doppler method can not be used because of obesity or intestinal gas.

[Evaluation of the relationship between esophageal varices and azygos vein using percutaneous transhepatic cine-portography].

To evaluate the relationship between esophageal varices and the azygos vein--which is generally considered to drain the major part of the esophageal variceal blood--we examined 36 patients with portal hypertension using percutaneous transhepatic cine-portography. The patients were classified into three groups (azygos, cervical and combined) according to the amount of blood to be considered drained by the azygos vein. Eighteen patients (50%) fell into the azygos type group, five (14%) into the cervical, and 13 (36%) into the combined. Highly developed esophageal varices were recognized endoscopically in all patients in the combined and cervical type groups while some of the patients in the azygos type group had less well developed varices. In the azygos type group, there was a tendency for the varices to be increasingly severe the higher the part of the azygos vein they drained into. Because it helps us to fully comprehend the significance of the azygos venous blood flow and the occasionally uncertain effect of endoscopic injection sclerotherapy for esophageal varices, it is important to evaluate the drainage route of esophageal varices in vivo and in detail. Percutaneous transhepatic cine-portography is the useful method for this purpose as it enables us to visualize even the most minute blood stream.

[1H-NMR studies of plasma from patients with liver diseases].

We examined the 1H-NMR spectra of the lipid region of human plasma according to the method of Fossel et al. as the specific blood test for cancer. The study group included 20 patients with hepatocellular carcinoma (HCC), 10 patients with liver cirrhosis (LC) and 10 normal controls (NC). We measured the linewidths of methyl and methylene resonances of lipoprotein lipids at a proton resonance frequency of 400 MHz using a JNM GX400 FT NMR spectrometer. The mean linewidth values and the standard deviation of methyl were as follows: 41.3 +/- 7.2 Hz (NC), 34.8 +/- 6.9 Hz (LC), 29.6 +/- 5.7 Hz (HCC). There was thus a significant difference between NC and HCC. On the other hand, there was no significant difference between the three groups in the case of methylene. Although the spectrum in the HCC and LC groups had a blunt head but narrow body, that of the NC group had a pointed head but wide body, and the linewidth values thus showed wide dispersion. This difference in spectral patterns between the two groups was characteristic. Linewidth values, however, did not correlate well with the laboratory data.

[Portal hemodynamic changes from partial hepatectomy--quantitative analysis of portal flow before, during and after hepatectomy, using an Doppler ultrasound system].

We investigated portal hemodynamic changes in 86 patients with hepatic tumors who underwent partial hepatectomy. Portal blood flow was measured using a sector type Doppler ultrasound system before, during and after operation. In the intraoperative studies, the portal flow in patients who underwent massive liver resection decreased significantly. On the other hand, the portal flow in patients with minor liver resection tended to increase, but not significantly. Overall, portal flow per unit of cardiac out put decreased significantly; it also decreased significantly in patients who underwent massive or major liver resection, in patients with liver cirrhosis, and in patients whose post operative clinical course was satisfactory. In the post-operative studies (10-12 days after surgery), the portal blood flow decreased significantly in patients who manifested a severe post-operative clinical course; it showed no significant change in other patients. It is thus essential to monitor the portal hemodynamics of partial-hepatectomy patients. This is most readily realized using Doppler ultrasound.