We took culture of throat swab from 77 subjects who were negative for infection of HBV, HCV, HIV and syphilis infection before and after endoscopy. Moreover, the existence of bacterium including Helicobacter pyloriat overcoat of endoscopic instrument was investigated right after examination and after disinfection of endoscope. Povidoneiodine, 70% alcohol and 1% benzalkonium chloride was used as a disinfectant for endoscope, and it took less than 10 minutes to wash by hand to disinfection. α-haemolytic streptococci, Staphylococcus epidermids, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Candida, Pseudomonas aeruginosaand MRSA were cultured in throat swab. The rate of adhesion of bacterium especially such asCandida, K.pneumoniaeandS. epidermidsto endoscope was considerably high. 23 of 77 subjects had H. pyloriinfection, and the adhesion ofH. pyloritoendoscope was found to be 65. 2% of the subjects. On the contrast, no bacterium was detected from the endoscopic instrument after carefull disinfection. These findings stress the importance of postoperative disinfection of the endoscope to prevent the chance to acquire bacterial infection.
The cytotoxic effects of electrolyzed strong acid water and acidic hypochlorite solution, as well as these solutions after isotonization, against cultivated L cells were compared along with their microbicidal activities. Isotonization was accompanied by a reduction in the cytotoxic effects of these solutions against L cells. Microbicidal activity was also reduced somewhat but was still retained after isotonization. No difference was observed in these properties between these antiseptic solutions. The results obtained indicate that acidic hypochlorite solution may be useful as well as acidic electrolyzed water.
A study was made of 2202 central venous catheters (CVC), which were inserted for recent 10 years, to know the effect of preventive measures against CVC-related infection. We divided 10 years in 3 periods: 1987-1990 (the first period), 1991-1993 (the second period), and 1994-1996 (the third period). Preventive measures such as thorough antiseptic precaution, shortening of CVC dwelling time, and prohibition of injection from three-way stopcocks were taken after the second period. In the third period, semiclosed infusion system (I-system) was introduced to our division. A febrile catheterized patient (higher than 38°C) was diagnosed as CVC-related infection when the fever droppe immediately (within 72hours) after removal of CVC, or when the tip of the CVC was positive for culture. The rate of CVC-related infection in the second (9.9%) or the third (7.3%) period was significantly lower than that (14.0%) of the first period (p<0.05 and p<0.001, respectively). The mean dwelling time of CVC was 31.5 days for the first period, 27.0 days for the second period, and 24.8 days for the third period. The rate of long-term dwelling catheters (more than 29 days) in the second (34.5%) or the third (28.7%) period was significantly lower than that (40.5%) in the first period (p<0.01 and p<0.001, respectively). The index of CVC-related infection (incidence of infection per 1, 000 days) was 4. 8 for the first period, 3.7 for the second period, and 2. 9 for the third period. The rate of infection of short-term dwelling CVC (less than 28 days) in the second (9.5%) or the third (6.3%) period was significantly lower than that (16.0%) of the first period (p<0.01 and p<0.001, respectively). As to cultures of CVC and/or blood sample, the isolation rate of fungi decreased significantly (p<0.001), and that of gram-negative rods showed a tendency to increase after the second period. It was concluded that shortening of CVC dwelling time and application of semiclosed infusion system were effective to reduce the rate of CVC-related infection.
The rubella vaccination rate remarkably decreased in Japan after a revised vaccination law was passed in 1994, as a result of which individual vaccination replaced mass vaccination at each school. We investigated the rubella antibody of 887 students and the accumulative rubella vaccination rate in an area of Okayama. The vaccination rate in Ibara, where children were inoculated individually, was 22.8%. In contrast, in Yoshii, where the vaccination was done as mass at each school, the rate was 89.8%. After 2003, when the transit period of the law ends, children 12-90 months of age will be the subjects for rubella vaccine. We presume that the vaccination rate in the future will reach 40-50 % through accumulative vaccination. Such a rate of vaccination cannot prevent rubella epidemics and congenital rubella syndrome. In addition, an individual's rubella vaccination is generally done once during lifetime. We doubt whether the immune response induced by a vaccine can be maintained for more than 20 years without boosting. We think that a second vaccination is necessary for at least young girls, and this should be performed as mass at each school.
To investigate the effect of previous influenza vaccination and the difference in antibody induction by single and twice injection of influenza vaccine in the elderly, hemagglutination inhibition (HI) antibody titers of the three types of influenza viruses were measured . Influenza vaccination was done for 217 inpatients. For the patients who had influenza vaccination in the year prior to the study, influenza vaccine was administered once to 77 patients and twice to another 70 patients. Influenza vaccine was injected twice to 70 patients who had not received influenza vaccine in the previous years. The influenza vaccine induced an increase in HI titer in almost all patients . The geometric mean of the HI titer and the frequency of patients with HI titers over 128x were similar after vaccination in the groups of patients who were injected twice, irrespective of whether or not influenza vaccination was given in the year prior to the study. The geometric means of the HI titers for influenzas A/H3N2 and B and the frequency of HI titers over 128x for influenza A/H3N2 after vaccination were lower in the patients who received vaccine once than in the patients vaccinated twice. These results suggest that prior vaccination does not diminish antibody response to influenza vaccine significantly in the elderly when influenza vaccine is injected twice . Although single injection is inferior to twice injection in antibody induction with some vaccine virus strains, induction of HI titers over 128x is found in more than 70% of elderly. Single injection of influenza vaccine may be practically effective and useful for protection of influenza infection in the elderly .
Eleven clinical strains of MRSA which were detected as heterogeneously-resistant to vancomycin (hetero-VRSA) on Mu3-medium (a newly devised hetero-VRSA detecting medium) were subjected to a study to explore the therapeutic possibility of combination therapy. Combination effects of teicoplanin with six different 13-lactam antibiotics (imipenem, panipenem, meropenem, flomoxef, sulbactam/ampicillin, cefoselis), arbekacin, and minocycline were evaluated on the strains of Mu3, Mu50 and the above 11 strains. Combination of teicoplanin with five β-lactam antibiotics individually (except for cefoselis) showed a synergistic effect, while that with cefoselis showed synergistic or additive effect. Neither indifference nor antagonism effect was observed in combination of seicoplanin with β-lactam antibiotics on these MRSA strains. The degree of synergistic effect in combination with teicoplanin was the strongest in imipenem, followed by panipenem>meropenem>flomoxef>sulbactam/ampicillin>cefoselis in this order. The average FTC index of the β-lactam antibiotics against these strains was 0.113, 0.124, 0.163, 0.230, 0.264 and 0.388, respectively. Arbekacin and minocycline showed variable of effects in combination with teicoplanine. In the case of arbekacin, the ratio of synergy, addition, indifference, and antagonism were 30.8, 30.8, 0 and 38.4%, respectively, and in the case of minocycline, they were 15.4, 7.7, 0 and 76.9%, respectively. Vancomycin activity against hetero-VRSA and VRSA is antagonized with β-lactam antibiotics, while teicoplanin activity is synergistic or additive. It is known that MRSA is relatively easy to emerge resistance to teicoplanin. Therefore, teicoplanin is not desirable for a monotherapy. However, in a combination with 13-lactam antibiotics, teicoplanin appeared to be a promising agent for the treatment of MRSA infection.
Though O157 can cause a life-threatening diseases, the therapeutic protocol using antibiotics for the infection is still controversial. Main reasons for hesitating the uses of antibiotics for the infection is their possibility to enhance the release of verotoxins (VT). We have recently established the mouse model of O157 infection using germfree mice. Using this animal model of O157 infection, weexamined therapeutic efficacy of antibiotics. Fosfomycin (FOM) and norfloxacin (NFLX) were selected for in vivo examination, because of their lower MIC under anaerobic condition (MIC: FOM=0.78; NFLX=0.10μg/ml) than those of the other antibiotics including kanamycin, doxycycline, minocycline, choramphenicol, cefaclor and ampicilin. When germfree BALB/c mice were orally infected with 1×105CFU of O157 (clinically-isolated strain, TI001) at day 0, all mice died at 8 to 9 d after the infection. Oral treatment of the mice with FOM (500mg/kg/d, twice a day) or NFLX (50 mg/kg/d, twice a day) everyday for 5 days starting at 3 hr after the infection significantly improved the survival rate from 0% to 83.3%, and 100%, respectively. VT could not be detected in the feces of the mice in either groups, suggesting that neither of these antibiotics enhanced the release of VT . Interestingly, when FOM treatment was started at 3, 6, 12 or 24 hr after the infection, the survival rate was 100%, 100%, 0% and 0%, respectively. Thus, in conclusion, FOM and NFLX are both useful as the therapeutic agents for 0157 infection. However, the treatment should be started in the early phase after the infection.
We investigated the usefulness of a rapid antigen detection kit using optical immunoassay for influenza virus (FLU OIA®, BioStar, USA). Nasal aspirates were taken from 92 influenza suspected outpatients between March to April of 1999. Compared with virus isolation and PCR, the sensitivity of FLU OIA ® was 88.5% and 81.6%, and the specificity was 65.2% and 72.2%. All isolated viruses were influenza type B virus. It was difficult to differentiate the weak-positive and negative cases, leading to the rather low specificity, although the assay procedure was easy and quick. FLU OIA ® may be a useful rapid diagnosis kit for influenza in pediatric outpatient clinics and wards, because it can detect both influenza type A and type B viruses.
The optical immunoassay test (FLU OIA®, BioStar, USA) for rapid detection of influenza A and B viral antigens was compared with viral isolation in cell culture. A total of 103 respiratory specimens were tested on 75 pediatric patients with acute respiratory illnesses. Influenza viruses were recovered in 40 specimens (type A: 5, Type B: 35). FLU OIA®demonstrated 80.0% sensitivity and 68.8% specificity for nasopharyngeal aspirates and 36.7% sensitivity and 83.9% specificity for throat swabs. We also tested FLU OIA®, retrospectively, using 78 supernatant samples from pediatric patients with influenza A virus infection frozen after cell culture. FLU OIA®demonstrated 91.4% sensitivity and 92.3% specificity for nasopharyngeal aspirates and 50.0% sensitivity and 91.7% specificity for throat swabs diluted in viral transport media. Nasopharyngeal aspirates showed higher sensitivity than throat swabs for detection of influenza virus by FLU OIA®. We believe this rapid test kit is useful for the detection of influenza A and B viruses.
A 54-year-old male was admitted to Kawasaki Medical School Hospital with the complaint of fever. His diagnosis of hypoplastic leukemia had been made one year ago. After the admission, cecal mass with pain and high fever were noted. Four days later, he suddenly lost consciousness and died.Aeromonas hydrophilawas isolated from blood cultures and also from the myofascitis specimen . Autopsy specimen of the iliopsoas muscle showed necrotizing myofascitis. The specimen obatined from the cecum showed submucosal hemorrhage with edema and these findings were compatible to ischemic colitis. This pathogen is widely distributed in nature, especially in water fields. Therefore, it would be advised to consider theAeromonas hydrophilaas one of the pathological organisms pathognomonic for the septicemia, when one may see febrile and gastrointestinal symptoms in a patient with hematological malignancies.
A 62-year-old male was admitted with complaints of fever and body weight loss. The patient was diagnosed as acute myeloid leukemia (M1) and chemotherapy was started. About 80 days after admission, the patient developed diarrhea with high fever. AndE. gallinarumwas isolated from the blood culture. We carried out PCR using primers for vanA, vanB and vanC in ourE. gallinarum, and showed the existence of the vanC1. This organism should be considered as one of the possible pathogenes in the infectious complications of the immuno-compromized patient.