From 1982 to 1985, single lumen catheters or double lumen catheters were inserted for blood access in 134 at Niigata University Hosoital. In 17 and 13 out of 134 cases, microorganisms were isolated from blood and from catheter tip, respectively. We investigated these cases, and the results obtained are as follows; 1. Microorganisms isolated from blood culture were Staphylococcus aureus in 6 cases, Pseudomonas aeruginosa in 3, Pseudomonas cepacia in 2, Achromobacter xylosoxidans in 1, Acinetobacter calcoaceticus in 1, Escherichia coli in 1, Morganella morganii in 1, Enterobacter cloacae in 1, yeast like fungi in 3. 2. In 9 cases, same kinds of microorganisms were isolated from blood and catheter tips. These findings suggest a focus of bacteremia was catheter tip. 3. Five strains of S. aureus isolated from blood were methicillin resistant S. aureus (MRSA). These type of all strains were coagulase II type. 4. In four cases, microorganisms were isolated from catheter tips but were not isolated from blood culture. These isolated microorganisms were 4 strains of Staphylococcus epidermidis, one of Enterococcus faecalis, one of Staphylococcus aureus, one of yeast like fungi. 5. Prior to bacteremia, interval of placement was 19.59±13.80 days, and was 10.69±9.93 days in cases without bacteremia. The differens was significantly (p<0.01). A coagulation is easily to grow in a catheter. But it is difficult to find. So, bacteremia occur frequently in cases placed catheters for hemodialysis.
Two hundred and forty sera obtained from patients of enterotoxigenic Escherichia coli food poisoning infection were analyzed for rises in titer of antibody to somatic O, heat-labile enterotoxin (LT) and colonization-factor antigen (CFA). The geometric mean antibody titers to somatic O and LT after infection increased gradually, and reached the peak after 21-30 days, and decreased afterward. The daily pattern of the antibody titer to somatic O was similar to that of the antibody titer to LT, except the titer to somatic O increased greater than the titer to LT. 60% of the patients after 31-40 days infection had a response to CFA, in spite of very few patients after 1-5 days infection had the antibody titer to CFA. Although response to the somatic O correlated significantly with response to the LT, rises of antibody titer to somatic O and LT had not so many relation to that of CFA.
In 1983, 3 outbreaks of food poisoning caused by enterotoxigenic Escherichia coli (ETEC) occurred in Osaka. The causative agent of all the outbreaks was ETEC O6: H16 that produced both LT and ST. In 1 of the outbreaks, ETEC was isolated from the water (well water) in caterer where incriminated food was made. The outbreak may be occurred because ETEC in water transmitted the food. ELISA was utilized to detect LT directly in stool specimens obtained from patients. LT was detected 18 of the 22 (81.8%), 7 of the 27 (25.9%), 2 of the 16 (12.5%) stool specimens obtained from patients within 4 days, 5 to 9 days, 11 and 12 days after infection, respectively. The detection rate of LT in stool specimens was high in early stage of disease. The highest amount of LT was 40 ng/g in stool specimens obtained from 2 patients within 4 days after infection. These results suggest that ELISA can be used to detect LT in stool without or before bacterial isolation, and it is a useful method to diagnose the infection caused by LT-producing ETEC rapidly.
Experimental pneumonia infected with Escherichia coli, Klebshiella aerogenes, Serratia marcescens, Pseudomonas aeruginosa and Acinetobacter calcoaceticus was induced in mice to study the back ground factor of opportunistic infection. Ddy mice, 20 g weight, was infected by aerosol of bacteria (108 CFU/ml) and the number of bacteria in the lung was examined. In normal mice, 104-105 CFU/ml of bacteria in the lung at inoculation were cleared at 48-72 hours after inoculation. In cyclophosphamide treated mice, the clearance rate was diminished. Cyclophosphamice treated mice was administerd with ABPC, GM, CFS or CEZ and left in ordinary room of University hospital to observe the occurrence of pneumonia. In normal mice, only one mouse showed pneumonia, but one treated by CFS, twotreated by CEZ and four treated by ABPC showed pneumonia. To evaluate this phenomenon that mice treated by antibiotics showed higher incidence of pneumonia rather than normal mice, the experimental pneumonia with Pseudomonas and Serratia was treated with these antibiotics. The change ofnumber of bacteria in the lung was observed and showed the increase of that according with the pathological changes. Those results showed that infection by opportunistic pathogen is closely related to the immunological state of host, the kind of pathogen and the use of antibiotics.
The virulence of methicillin-resistant Staphylococcus aureus (MRSA) was compared with that of methicillin-susceptible S. aureus (MSSA). Although growth rate of MRSA was lower than that of MSSA, no remarkable difference was seen in the biological characteristics, between MRSA and MSSA. The virulence of MRSA and MSSA in normal mice was very low. In intraperitoneal infection of mice pretreated with cyclophosphamide, the virulence of MRSA was distinctly lower than that of MSSA. Thus, the lower virulence of MRSA in mice than that of MSSA might be due to its poor growth rate.
We examined the in vitro activities of various antibiotics against Chlamydia trachomatis (three laboratory strains and seven clinical strains) by growth of Chlamydia in cycloheximide-treated HeLa 229 cells. Chlamydia infected monolayer cells prepared in 24 wells plates were exposed to the various concentrations of antibiotics for 72 hrs to determine the minimal inhibitory concentrations (MICs), and for 48 hrs followed by incubation for an additional 48 hrs after withdrawal of antibiotics to determine the minimal lethal concentrations (MLCs), and were exposed to the antibiotics whichwere the mixtures of various concentrations of two antibiotics: doxycycline (DOXY)-erythromycin (EM), EMchloramphenicol (CP), CP-DOXY, DOXY-ampicillin (ABPC), EM-ABPC and CP-ABPC, for 72 hrs to examine possible snergy or antagonism. Inclusions were visualized by indirect immuno peroxidase (IP) method, and the effect of the antibiotic was determined by inclusion formation or by the inclusion forming units generated in the monolayers. The MICs of antibiotics were (per milliter): minocycline, 0.025μg; DOXY, 0.0125 to 0.025 μg; oxytetracycline, 0.02 to 0.04 μg; EM, 0.0125 to 0.025 μg; CP, 6.25 to 25pg; and lincomycin, 7.5μg. Penicillin and ABPC failed to completely inhibit inclusion formation at a concentration of 10, 000 units/ml and 200μg/ml, respectively. No inhibitory activity was demonstrated in vancomycin, kanamycin, streptomycin, gentamicin and amphotericin B treatment. These results were obtained in all strains tested. It was found that these results were essentially the same as the results obtained by other investigators using Giemsa and iodine. The MLCs were about 4 to 8 times higher than the MICs. On the other hand, about 50 times or higher concentrations of MLC and treatment for over 52 hrs were required to cure already infected (48 hrs after infection) cultures, when the cells were treated with DOXY. No detectable synergy and antagonism were observed among antibiotic combinations: DOXY-EM, EM-CP and CP-DOXY. ABPC and DOXY (or EM, CP) showed independent activity. This finding suggests that antibiotic combinations may be effective for regimen of the patients with simultaneous infection of Neisseria gonorrhoeae and Chlamydia trachomatis. Our experiments wereperformed easily in demonstration of Chlamydial inclusions. We believe that IP method with 24 wells plates is useful for determination of the in vitro activities of various antibiotics against Chlamydia trachomatis.
We experienced two cases definitely diagnosed to be TSS (toxic shock syndrome) failed to DIC and septic shock due to the infection of methicillin cefem resistant staphylococcus aureus (MRSA) after the gastrectomy. There was another case of which the on set of TSS was prevented though the infection of MRSA occured. This is the report of some discussion from literatures about these cases and the result of investigations performed on MRSA isolated from them.
We reported a case of pneumonia associated with increased antibody titers to simultaneous Mycoplasma pneumoniae and Chlamydia psittaci. A 17-year-old man was admitted because of fever, cough, sputum, sore throat and headache. His chest X-ray showed consolidation with air bronchogram at lingula. He was treated with minocycline intravenously, and his symptoms and shadow improved. However, in the course of this, he showed transient liver disfunction, splenomegaly, skin eruption and eosinophilia. The result of lymphocyte stimulation test was negative to minocycline. Cold agglutinin titer rose to 1: 256. Complement-fixing antibody titers for Mycoplasma pneumoniae and Chlamydia psittaci rose to 1: 1024 and 1: 128, respectively. Therefore, we supposed that he had two separate infections simultaneously, because of no evidence of serologic cross reaction between Mycoplasma pneumoniae and Chlamydia psittaci. In literatures, the cases of pneumonia associated with increased antibody titers to simultaneous Mycoplasma pneumoniae and Chlamydia psittaci had sometimes been reported in children but rarely reported in adults.
A case of acute myelogenous leukemia complicated with multiple liver abscesses by Candida albicans was reported. The patient was a 46-year-old Japanese woman, who was referred to Kyushu University Hospital because of severe anemia. Before admission, she was transfused more than 1, 000 ml of packed red blood cells in total. On admission, the number of bone marrow nucleated cells was 38 × 104/mm3, and 91% of them were peroxidase positive myeloblasts. During the course of remission inductiontherapy with BH-AC, daunorubicin, 6-mercaptopurine and prednisolone, she developed high fever which was unresponsive to various kinds of antibiotics. Twenty days after the onset of high fever, ultrasound tomography revealed multiple “bull's eye” lesions in the liver. Multiple liver abscesses were demonstrated by abdominal CT. Culture of the aspirate demonstrated Candida albicans in the lesion. Treatment with Amphotericin B of a total dose of 3800 mg for more than six monthsand drainage of some abscesses were ineffective. Eight months after her admission, acute myelogenous leukemia relapsed.