Emergency of multi-drug resistance in Pseudomonas aeruginosa isolates after exposure to gentamicin was investigated with reference to their LPS-compositions. Three strains each of P. aeruginosa, different in LPS-compositions (long-and short-LPS strains, and LPS-deficinet strain) were once or repeatedly incubated overnight at 35°Cin Mueller-Hinton broth including different concentrations of gentamicin, a poly-cationic antibiotic. LPS-compositions of the bacteria which survived and were grown after exposure to gentamicin were analyzed and the susceptibility to some of anti-pseudomonal drugs was determined. Of the test 9 strains aftr single exposure, No.4 (long-LPS) and No.41 (short-LPS) formed the LPS-deficient mutants. The resistance to ceftazidime and gentamicin was found in No.4 strain, but not in No.41 stain. Drug resistance in different patterns was also found in Nos. 43, 29, 45 and 52 strains without any change in their LPS-compositions. Contrary to these results, the susceptibility to norflxacin increased in Nos. 21 and 45 strains without any change in their LPS-compositions. After repeated exposures to gentamicin, the LPS-compositions of Nos. 4 and 14 (short-LPS) were altered and formed the LPS-deficinet and the Intermediate-LPS (between short and long compositions) mutants, respectively. The LPS-alteration in both strains were accompanied by the development of resistance to ceftazidime and gentamicin, respectively. The drug resistance in different patterns were also found in Nos. 43, 156, 29, 41, 21, 45 and 52 strains, without any change in the LPS-compositions, whereas the increase in susceptibility to norfloxacin was simultaneously found in No.45 strain. The ionic-binding of [3H]-gentamicin to the cell surfaces of two LPS-deficient mutants of P. aeruginosa decreased markedly, in comparison with that of the respective parents, and these results might lead to the drug resistance in the LPS-deficient mutants. However, the gentamicininduced resistance of some strains of P. aeruginosa (but no change in the LPS-compositions) to the test drugs including gentamicin indicates a possibility that negative charges on the bacterial surface were decreased by the drug exposure. The drug resistance and LPS-compositions in the gentamicin-induced mutants of P. aeruginosa were stable during or after the 15th in vitro serial transfers.
The study was conducted to elucidate the possibility of hospital infection of methicillinresistantStaphylococcus aureus (MRSA) through feces. Fecal cultures of 12 inpatients positive for MRSA in the respiratory tract and 11 inpatients negative for MRSA in the respiratory tract were performed from April to October in 1993. Fecal cultures of inpatients positive for MRSA in the respiratory tract were continued until September in 1996; finally a total of 50 cases were enrolled. MRSA was isolated from feces of 7 patients (58.3%) of the 12 patients positive for MRSA in the respiratory tract, while no MRSA was isolated from feces of 11 patients negative for MRSA in the respiratory tract. Twenty-seven patients (54.0%) of 50 patients positive for MRSA in the respiratory tract yielded MRSA in the feces. Twenty-three patients (85.2%) of the 27 patients positive for MRSA in the fecal flora had received H2-blocker, while 11 patients (47.8%) of the 23 patients negative for MRSA in the fecal flora received H2-blocker; these differences were statistically significant (p<0.01). These findings suggest the possible role of feces in hospital infection with MRSA and the necessity for careful administration of H2-blocker to patients positive for MRSA in the respiratory tract.
The immunologic pathogenesis of conditions characterized by chronic pulmonary infections, such as diffuse panbronchiolitis and those associated with cystic fibrosis, has not been sfully clarified. Organized lymphoid tissue along the airway has been termed bronchus-associated lymphoid tissue (BALT), and hyperplasia of BALT is frequently observed in chronic pulmonary infections in humans. To investigate the role of BALT, we intratracheally inoculated rats with Pseudomonas aeruginosa (PA) enmeshed in agar beads according to the method of Cash et al., thereby establishing a chronic pulmonary infection model. Histopathological examination of tissue from this rat model revealed the accumulation of lymphocytes and foamy cells around bronchioles. This finding corresponds to chronic bronchiolitis in humans. Hyperplasia of BALT was also observed. Immunohistochemical examination demonstrated that Ia+ cells, helper T cells, surface IgM-positive (sIgM+) cells and sIgA+ cells had gradually increased in BALT and the walls of peripheral airways during the period from day 4 to 7. The anti-PA IgA antibody titer in bronchoalveolar lavage fluid (BALF) was also elevated during this period. After day 21, non-helper T cells became predominant in tissue sections, and the numbers of various immunoglobulin-positive cells as well as the anti-PA IgA antibody titer in BALF were reduced. Histological examination revealed that the inflammatory findings had also diminished. The time course of changes in the various immune cells in BALT and the walls of peripheral airways, paralleled the reductions in anti-PA IgA antibody titers in BALF. Our findings suggest that hyperplastic BALT may be one source of the Ig producing cells which play an important role in the local immune response characteristic of chronic pulmonary infections.
In this study, cytomegalovirus (CMV) infection was found in eleven of 21 autopsied cases (52.4%) with adult T-cell leukemia (ATL). Seven cases (63.6%) revealed disseminated infection in more than three organs. The lungs were involved in all eleven cases (100%), adrenal glands in eight cases (72.7%), esophagus in four cases (36.4%), and stomach, small intestine and urinary bladder in three cases (27.3%). Histopathological findings suggested that lung involvement was the cause of death in five of the 11 cases, the small intestine were involved in two of the 3 cases, and the adrenal glands were involved in one of the 8 cases. In summary, CMV infection was found to be the main cause of death in five (45.5%) of the 11 ATL patients.
In the early 1980's methicillin-resistant Staphylococcus aureus(MRSA) was reported as a major pathogenic organism of geriatric hospital infeciton in Japan. At the same time in our geriatric wards, including 190 beds, MRSA infection was prevalent. In the early 1980's in our geriatric wards minocycline was one of the most sensitive antibiotics to MRSA isolated in our wards and used frequently against MRSA pneumonias and bacteremia. In the late 1980's resistant strains of MRSA to minocycline rapidly increased because vancomycin was not allowed to introduce for treatment of MRSA before 1991 in Japan. At the same period the predominant coagulase type changed from type II to type VII. To decrease minocycline-resistant strains to MRSA after 1987, use of minocycline was limited. Moreover since Oct. 1991 to decrease nosocomial infections some active preventive measures against hospital infection, including limited use of 2nd and 3rd cephems, were taken. In this study changing patterns of coagulase type of Staphylococcus aureus were discussed. At least 4 years was needed to find out that the predominant coagulase type changed from type VII to type II again in 1991. In this study about 22 antimicrobial agents MICs of 313 strains of Staphylococus aureusisolated between March 1992 and June 1993 were determined and compared with the data of MICs before introduction of preventive measures. The pattern of susceptibility to MINO was in part improved. Thus the some sensitive strains of S. aureus were observed again in our geriatric wards. Interestingly indeed it took approximately 5 years to find out the emergence of sensitive strains to MINO since limitation of use of MINO in 1987.
The present study investigates the nasopharyngeal flora and defines the carriage rates of Haemophilus influenzae type b of 144 healthy infants who visited the well-baby clinic. 224 nasopharyngeal swabs were obtained (44 swabs from 1-month-old infants, 96 swabs from 4 to 5-month-old infants and 84 swabs from 7 to 8-month-old infants), and 440 organisms were isolated. The most frequently isolated organism was Staphylococcus aureus (45.5%) followed by Corynebacterium (38.6%) from 1-month-old infants, Corynebacterium (55.2%) followed by S. aureus (32.3%) and Streptococcus pneumoniae (25.0%) from 4 to 5-month-old infants, Cor-ynebacterium (59.5%) followed by S. pneumoniae (26.2%) from 7 to 8-month-old infants. Twenty-four strains of H. influenzaewere isolated from 21 infants, being 1 strain from 1-month-old infant, 9 strains from 4 to 5-month-old infants, 14 strains from 7 to 8-month-old infants. Four type b strains were isolated from 3 infants, being 1 strain from 1-month-old infant, none from 4 to 5-month-old infant, 3 strains from 7 to 8-month-old infants. One of the three 7 to 8-month old infants also carried Hib when he was at the age of 1 month old. The nasopharyngeal carriage rates of H. influenzae of infants were 2.3% in 1-month-old infants, 9.4% in 4 to 5-month-old infants, 16.7% in 7 to 8-month-old infants and 10.7% in total. The carriage rates of Hib were 2.3% in 1-month-old infants, 0% in 4 to 5-month-old infant, 3.6% in 7 to 8-month-old infants and 1.8% in total.
The purpose of this study is to evaluate the usefulnes and limitation of Rapizyme CHLAMYDIA ®, enzyme-linked immunosorbent assay (ELISA) for qualitative detection of anti-chlamydial IgG and IgA antibodies, in the serum of 92 PID patients and 73 pregnant women, compared with those of Sero IPALISA CHLAMYDIA ®. The result of Rapizyme analysis was obtained within 10 minutes with no special devices. Overall agreements of Rapizyme and Sero IPALISA were 90.9%(IgG) and 90.3%(IgA) in the total patients, 88.0%(IgG) and 85.9%(IgA) in PID patients, and 94.5%(IgG) and 95.9%(IgA) in pregnent women. The positive rate of Chlamydia in PID was 17.4%(16/92). Positive agreement of Rapizyme in Chlamydia positive PID and pregnant women was 100% in both IgG and IgA, and negative agreement was also 100%. Positive agreement in Chlamydia negative PID was 100% in both IgG and IgA, and negative agreement was 90.0%(IgG) and 83.3%(IgA). The results of Rapizyme were in close agreement with those of Sero IPALISA. COI (cut off index) of Sero IPALISA clearly decreased in 3 of 6 PID patients during a 3 to 6 months period after chemotherapy, but those changes were not observed in Rapizyme. These results suggest that Rapizyme CHLAMYDIA is a useful diagnostic kit for Chlamydial PID of outpatients.
The detection of VT produced by Escherichia coli is very important for the identification of verotoxin-producing Escherichia coli (VTEC). The latex agglutination reagents (Denka Seiken Co. Ltd, Tokyo) which was developed to detect VT was compared with the vero cell bioassay or polymerase chain reaction method. A total 147 VT-positive strains (109 serotype O157: H 7/-and 38 non-O157 serotype) and 31 VT-negative strains which were isolated from human were investigated. In addition, a total of 79 VT-positive strains (14 serotype O157: H7i and 65 non-O157 serotype) and 79 VT-nagative strains which were isolated from animals were also examined The latex agglutination assay for the human isolates showed the 100% sensitivity, specificity and agreement. The assay for the animal isolates showed 94.9% sensitivity, 100% specificity and 97.5% agreement. Although 4 of 8 strains isolated from swine which produce VT2 variant toxin (VT2e) failed in detecting verotoxin by latex agglutination assay, VT2e was not related to human infections. We conclude that this latex agglutination reagent is highly sensitive and specific for detecting and characterizing VT of E. coli. The method is reliable, easy to perform at any laboratories.
We investigated the possible presence of Aspergillus species DNA in serum samples of two patients diagnosed as having non-invasive pulmonary aspergillosis by a nested polymerase chain reaction (PCR) method. The nested PCR results were negative in serum samples of the patients with chronic necrotizing pulmonary aspergillosis and pulmonary aspergilloma. When left pneumothorax happened to the patient with chronic necrotizing pulmonary aspergillosis and bronchial washing was performed to the patient with pulmonary aspergilloma, the nested PCR results turned positive. We consider this method useful for the diagnosis of semi-invasive stage of pulmonary aspergillosis. However, further prospective evaluation with a large clinical sample is required
We report an atypical case of lung abscess occurring in a 73-year-old female who suffered from diabetes for more than 20 years. In 1993 she had a total gasterectomy for gastric cancer. In 1995 she was admitted to our hospital complaining of a mild cough and a small amount of sputa. A CT scan of the chest revealed a huge abscess in the left lung. Streptococcus sanguis was cultured from the intrathoracic fluid. It is possible that the severe lung abscess in spite of the few symptoms occurs in the compromised host, such as this patient who suffered from diabetes for long time. Oral streptococci in close relationship to misswallowing should be taken into consideration as one of the causes of this condition.
Cunninghamella bertholletiae, a rare causative agent of human deep seated mycosis, has been reported with increased frequency in the Western countries, in recent years We experienced a case of Cunninghamella bertholletiae pulmonary infection in a 63-year-old male with pulmonary fibrosis and mild diabetes mellitus. In spite of intensive anti-fungal chemotherapy following clinical diagnosis, he died of exacerbation of the underlying diseases Postmortem examination showed Cunninghamella infection in the cavity of the lung and massive pulmonary fibrosis. There was no fungal invasion, outside the cavity. This is the third report of Cunninghamella human infection in Japan.
A patient in the blastic phase of chronic myelocytic leukemia developed multiple arterial emboli that originated from mitral valve vegetation. The diagnosis of infective endocarditis was not confirmed because blood cultures, serological assays and other examinations detected no pathogens. He died of intracranial hemorrhage after thrombolytic manipulation for embolization of the abdominal aorta and an autopsy was performed. Polymerase chain reaction analysis and Southern blot analysis of tissues from the mitral valve revealed Aspergillus species as the cause of the endocarditis, although none of the tissue specimens were culture-positive. These molecular analyses will be useful in the diagnosis of various types of Aspergillus infections.
Extracellular products of group A streptococci isolated from patients with streptococcal toxic shock syndrome (STSS) examined. The outline of discussion of the 4 products are as follows; Products were streptolysin O (SLO), proteinase, erythrogenic toxin and DNase. SLO showed a large amount of products more than proteinase, erythrogenic toxin and DNase. It should not be concluded that there is a large amount of SLO in the isolated strains from patients with STSS. SLO produced by group A streptococci isolated from the patient with STSS has an isoelectric point (pI) of 6.0 and a molecular weight of 64, 000 and shows a hemolytic activiy in the presence of 2 mercaptoethanol (2-ME). Furthermore, the hemolytic activities of all components were inhibited by γ-globulin and cholesterol. These results indicated that all component with hemolytic activity are SLO. These data suggest that STSS does not make up a single syndrome but, rather, that the multiple STSS clinical criteria probably reflects a different characteristic of individual S. pyogenes isolates.