Evaluation of a high-speed but low-throughput RT-qPCR system for detection of SARS-CoV-2

With the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), a high-speed and convenient detection technology should be at the forefront of medical care worldwide. This study evaluated the usefulness of GeneSoC, a compact, high-speed reciprocal flow quantitative reverse transcription polymerase chain reaction system, for the detection of SARS-CoV-2. The results support the use of this system for the rapid identification of SARS-CoV-2. This approach can contribute to the strategic selection of initial management strategies for patients with COVID-19.

[Clinical effects of combination therapy with cefozopran and amikacin for infections in patients with hematological disorders]

Cefozopran (CZOP) and amikacin (AMK) were used concomitantly to treat infections complicated by hematological diseases. A total of 103 subjects were evaluated, and the all over efficacy rate was 69.9%. Acute leukemia was found in the largest number of patient, 57, followed by 29 cases of malignant lymphoma and 7 cases of myelodysplastic syndrome. By type of infection, patients having unknown origin were the largest in number, being 66, and the efficacy rate was 71.2%. The efficacy rates for sepsis, pneumonia and upper respiratory infection were 42.9% (7 cases), 71.4% (14 cases) and 90% (10 cases) respectively. The efficacy rates by neutrophil counts before administration of CZOP and AMK and at 1 week after administration were both 53.3% in the group of less than 100/microliter, both 60% in the group of less than 500/microliter. The efficacy rate by neutrophil counts at 1 week after administration was 58.6% in the group of less than 100/microliter. The efficacy rate was 75.4% in the group of granulocyte colony stimulating factor (G-CSF) concomitant usage, and 61.9% in the group of non-concomitant usage group. The efficacy rates by serum albumin levels before administration of CZOP and AMK and at 1 week after administration were both 92.9% in the group of over than 4 g/dl, both 50% in the group of less than 3 g/dl. Concomitant treatment with CZOP and AMK exhibited a high level of safety and efficacy rates in infections complicated by hematological diseases.

[Analysis of patients with middle lobe and lingular syndrome complicated with nontuberculous mycobacterosis, chronic sinusitis, or bronchopulmonary tuberculosis]

The clinical characteristics and chest CT scan findings in 77 cases of middle lobe and lingular syndrome, many of which were complicated with nontuberculous mycobacteriosis (21 cases, 27.3%), chronic sinusitis (16, 20.8%), or bronchopulmonary tuberculosis (11, 14.3%) are reported. Sixteen (76.2%) cases complicated with nontuberculous mycobacteriosis and 14 (87.5%) cases complicated with chronic sinusitis had granular shadows with dilated bronchi of both middle lobe and lingular in their chest CT scans. Granular shadows with a thickening of the bronchial wall or dilated bronchi were common characteristics of the chest CT scans of the patients with nontuberculous mycobacteriosis. However, cicatrization atelectasis of either middle lobe or lingular was the most common finding in patients with bronchopulmonary tuberculosis.

[Study on pulmonary cryptococcosis disclosed by chest radiographic screening in Nagasaki Prefecture]

We conducted a retrospective investigation of 20 cases of pulmonary cryptococcosis discovered by chest radiographic screening in Nagasaki Prefecture among 2,011,577 persons over a period of 9 years, Apr. 1989-Mar. 1998. Eight males and 12 females between 15 and 72 years of age(mean: 46.6 years) were diagnosed as having pulmonary cryptococcosis. The mean detectability of pulmonary cryptococcosis by screening was 0.99 per 10(5) persons: 1.30 for residents, 0.51 for school children and 0.80 for workers. Chest radiography showed shadows of solitary nodules in 9 patients, multiple nodules in 4, infiltration in 4 and others in 3. Cavities were noted in 7. However, it was difficult to distinguish between pulmonary cryptococcosis from pulmonary tuberculosis and pulmonary cancer based on radiographic data alone. Final diagnoses for 11 and 3 patients, respectively, were made using TBLB or BAL, and lung biopsy. Sixteen patients each underwent an Eiken-Latex agglutination test (serum cryptococcus antigen test) and 15 (93.8%) had positive results. The serum antigen level thus appears to be a useful indicator in the supplementary serological diagnosis of pulmonary cryptococcosis.

Intrapulmonary concentrations of inflammatory cytokines in a mouse model of chronic respiratory infection caused by Pseudomonas aeruginosa

We investigated the role of inflammatory cytokines in a mouse model of chronic Pseudomonas aeruginosa infection mimicking diffuse panbronchiolitis (DPB), and determined the effects of clarithromycin therapy on the production of these cytokines. The concentrations of IL-1beta, IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were measured serially in the lungs of mice with experimentally induced chronic respiratory P. aeruginosa infection until 60 days after inoculation. The concentrations of these cytokines during the course of the disease were significantly higher than baseline (before inoculation, P<0.01 for all cytokines). Clarithromycin significantly inhibited the production of IL-1beta and TNF-alpha in the lung (P<0.01). The same treatment also reduced the levels of other cytokines, albeit insignificantly. Treatment with anti-TNF-alpha antibody significantly reduced the number of pulmonary lymphocytes and concentration of IL-1beta in the lung (P<0.01), but did not change the number of viable bacteria. Our findings resemble those detected in bronchoalveolar lavage fluid of patients with DPB and indicate that inflammatory cytokines play an important role in chronic P. aeruginosa lung infection. Our results also show that macrolides modulated the production of these cytokines, ultimately reducing lymphocyte accumulation in the lung. Our data suggest that anti-TNF-alpha antibody might be a useful new strategy for the treatment of chronic respiratory P. aeruginosa infection.

Synergistic effect of ofloxacin and fluconazole against azole-resistant Candida albicans

We investigated the combination effects of ofloxacin and fluconazole against azole-resistant Candida albicans strains in vitro and in vivo. Ofloxacin alone showed no efficacy against the azole-resistant C. albicans strain, C26. The in-vitro combination effects were evaluated by the checkerboard method, calculated as the fractional inhibitory concentration (FIC) index, but there was no synergistic effect of the combination. The activity of the drug efflux pump in the azole-resistant C. albicans strains was measured by intracellular rhodamine 6G concentration. When the cells were incubated with ofloxacin or grepafloxacin, the intracellular rhodamine 6G concentration was significantly increased in the azole-resistant C. albicans strain. In-vivo combination effects were evaluated in murine disseminated candidiasis. The survival of the mice was not prolonged, but counts of the yeast cells in the kidney and spleen were reduced following treatment with the combination of ofloxacin (20 mg/kg) and fluconazole (20 mg/kg). The combination of ofloxacin and fluconazole may represent an effective strategy to treat infections caused by azole-resistant C. albicans.

Attenuation of nephrotoxicity by a novel lipid nanosphere (NS-718) incorporating amphotericin B

NS-718, a lipid nanosphere incorporating amphotericin B, is effective against pathogenic fungi and has low toxicity. We compared the toxicity of NS-718 with that of Fungizone (amphotericin B-sodium deoxycholate; D-AmB) in vitro using renal cell cultures and in vivo by biochemical analysis, histopathological study of the kidney and pharmacokinetic study of amphotericin B following intravenous infusion of the formulation in rats. Incubation with NS-718 resulted in significantly less damage of cultured human renal proximal tubular epithelial cells compared with D-AmB. Serum blood urea and creatinine concentrations increased significantly in rats given an iv infusion of D-AmB 3 mg/kg but not in those given the same dose of NS-718. Histopathological examination of the kidney showed tubular necrosis in D-AmB-treated rats but no change in NS-718-treated rats. Amphotericin B concentrations in the kidney in NS-718-treated rats were higher than those in D-AmB-treated rats. Our in vitro and in vivo results suggest that incorporation of amphotericin B into lipid nanospheres of NS-718 attenuates the nephrotoxicity of amphotericin B.

[An imported case of primary pulmonary coccidioidomycosis]

Coccidioides immitis is a causative agent of coccidioidomycosis, which is one of the most dreadful mycosis because of its infectious and pathogenic nature. The endemic areas are in the southwestern parts of the United States and other semi-arid regions throughout the Western Hemisphere. During the early 1990s, the incidence of coccidioidomycosis in California increased dramatically, resulting in recognition for this mycosis as a reemerging infectious disease in the United States. The patients included a large number of non-informed visitors from non-endemic countries. Our report is on an imported case of primary pulmonary coccidioidomycosis. A 35-year-old Japanese male, after living in the United States for nine months, suffered from a combination of headache and fever. He was given a serological examination, and a chest radiograph in Phoenix, Arizona in the United States and was diagnosed as coccidioidomycosis. A daily dosage of 400 mg of fluconazole was administered and he returned to Japan. His headache and skin rash persisted and he was admitted to our hospital to evaluate the severity of his disease. There were no fungi cultured from neither bronchoalveolar nor cerebrospinal fluid and he was discharged. The patient had been treated with fluconazole and his symptoms, high-resolution CT and serological antibody titer were monitored. After 18 months, his clinical and radiological evolution was favorable and his serological IgM titer was below its sensitivity medication was stopped and there were no relapses.

Combination therapy for chronic Pseudomonas aeruginosa respiratory infection associated with biofilm formation

There had been no reports of investigations into biofilms in chronic respiratory infection in vivo. Recently, we established a new murine model of chronic respiratory infection with Pseudomonas aeruginosa. In the present study, we examined the bacteriological effect of combined clarithromycin and levofloxacin against chronic respiratory infection with P. aeruginosa. Scanning electron micrograph of the surface of the catheter intubated in mouse bronchus for 7 days demonstrated in vivo formation of a biofilm containing blood cells, complex fibrous structures and bacteria. Treatment with either clarithromycin alone or levofloxacin alone had no statistical effect on the number of viable bacteria in lung. The combined use of both drugs resulted in a significant decrease in the number of viable bacteria. The present experiment demonstrates that the newly established murine model was useful to investigate the treatment of biofilm-associated chronic respiratory infection with P. aeruginosa, and combination therapy with clarithromycin and levofloxacin was effective in biofilm-associated chronic respiratory infection.

Efficacy of FK463, a (1,3)-beta-D-glucan synthase inhibitor, in disseminated azole-resistant candida albicans infection in mice

The efficacy of FK463, a new (1,3)-beta-D-glucan synthase inhibitor, against azole-resistant Candida albicans strains has been studied. The MIC of FK463 was lower than those of azoles and amphotericin B against CDR1-expressing C26 and CaMDR-expressing C40 strains. All mice treated with FK463 (1 mg/kg) survived disseminated murine candidiasis. The fungal burden in the kidney after 6 days was markedly reduced after therapy with FK463 and amphotericin B sodium deoxycholate, and plasma (1,3)-beta-D-glucan concentration was found to be lower in FK463-treated mice. In our study, FK463 was found to be a potent antifungal agent against disseminated infection with azole-resistant C. albicans.

Antifungal activity of a new triazole, voriconazole (UK-109496), against clinical isolates of Aspergillus spp

Voriconazole is a new triazole antifungal agent with potent activity against yeast and molds. We investigated the in-vitro activity of voriconazole compared with that of other antifungal agents against 50 clinical isolates of Aspergillus spp., measured by the National Committee for Clinical Laboratory Standards (NCCLS) reference method described in the M27-A document, and by an alamar blue colorimetric method. Voriconazole was the most potent agent against Aspergillus fumigatus (minimum inhibitory concentration [MIC]90, 0.5 mg/l) and Aspergillus niger (MIC90, 1.0 mg/l). Voriconazole was less active (MIC90, 1.0 mg/l) against Aspergillus flavus than itraconazole (MIC90, 0.5 mg/l). Voriconazole was more active than itraconazole against Aspergillus fumigatus and Aspergillus flavus by the alamar blue indicator method for the measurement of MIC. Based on these results, voriconazole has promising activity against commonly encountered isolates of Aspergillus spp., and its clinical usefulness should be established by further studies.

In vitro activity of telithromycin (HMR3647), a new ketolide, against clinical isolates of Mycoplasma pneumoniae in Japan

The in vitro activity of telithromycin (HMR3647), a new ketolide, against Mycoplasma pneumoniae was determined by the broth microdilution test using 41 clinical isolates obtained in Japan, as compared with those of five macrolides (erythromycin, clarithromycin, roxithromycin, azithromycin, and josamycin), minocycline, and levofloxacin. Telithromycin was less potent than azithromycin, but it was more active than four other macrolides, minocycline, and levofloxacin; its MICs at which 50 and 90% of the isolates tested were inhibited were both 0.00097 microg/ml, justifying clinical studies to determine its efficacy for treatment of M. pneumoniae.

Clinical evaluation of 61 patients with pulmonary aspergilloma

OBJECTIVE AND METHODS

We retrospectively evaluated 61 cases with pulmonary aspergilloma representing patients admitted to Nagasaki University Hospital between January 1991 to June 1998.

RESULTS

Fifty-two (85%) were males and 9 (15%) were females, aged between 14 to 80 years (average, 65 years). Forty-four (72%) patients had history of old pulmonary tuberculosis. Chest radiographs showed "fungus ball" in the cavities in 42 (67%) cases while 16 (26%) cases showed thickening of the cavity wall. Aspergillus fumigatus was isolated in 24 (39%) patients. Aspergillus antigen or antibody was positive in 8 (13%) and 43 (70%) patients, respectively. Oral itraconazole was used in 16 (26%) of patients, and surgical excision was performed in 15 (25%) patients. During hospitalization or after discharge, 19 (31 %) patients died.

SUMMARY AND CONCLUSION

Pulmonary aspergilloma usually occurs in elderly patients with old tuberculosis and respiratory failure. Many cases did not respond to antifungal therapy with itraconazole or amphotericin B. Our analysis indicates that more effective and appropriate therapeutic regimens are needed for the treatment of patients with pulmonary aspergilloma.

Effects of macrophage colony-stimulating factor (M-CSF) on anti-fungal activity of mononuclear phagocytes against Trichosporon asahii

Trichosporon asahii is an emerging opportunistic pathogen in immunocompromised patients. Little is known about the mechanisms of host defence against T. asahii. We investigated the fungicidal activity of human peripheral blood monocytes and murine peritoneal macrophages against T. asahii isolates, and the effects of M-CSF on the anti-fungal activity of mononuclear phagocytes. We also established a neutropenic mouse model of disseminated trichosporonosis with T. asahii. M-CSF enhanced the phagocytic fungicidal activity of mononuclear cells, and infected mice treated with human M-CSF at 10 x 106 U/kg showed a significant improvement in survival rate, with fewer fungal colony counts in the lung compared with control mice. Mice treated with human M-CSF showed higher concentrations of tumour necrosis factor-alpha (TNF-alpha) in the lung and plasma compared with control mice. The survival rate was significantly reduced in mice treated with anti-mouse TNF-alpha. Our results showed that M-CSF enhanced the fungicidal activity of mononuclear phagocytes partly by production of TNF-alpha, and suggest that the administration of M-CSF to patients with disseminated trichosporonosis may be a useful adjunct to conventional anti-microbial therapy and prophylaxis.

Aspergillus fumigatus isolated from blood samples of a patient with pulmonary aspergilloma after embolization

Aspergillus DNA was detected by PCR in the serum sample of a 78-year-old man and galactomannan antigen of Aspergillus by sandwich ELISA was found. However, the infiltrative hyphae were not detected by the histopathologic examination of the lung. He developed hemoptysis, which required embolization of bronchial arteries. Aspergillus fumigatus was isolated from blood samples after embolization by the lysis centrifugation method. To our knowledge, this is probably the first case in which Aspergillus spp. has been isolated from the systemic circulatory blood in a patient with pulmonary aspergilloma after embolization.

Evaluation of sandwich ELISA galactomannan test in samples of positive LA test and positive aspergillus antibody

OBJECTIVE

The detection of circulating Aspergillus galactomannan antigen is a useful tool for serodiagnosis of aspergillosis. However, the latex agglutination test for the detection of galactomannan is not completely reliable due to it's low sensitivity. The sandwich ELISA was developed to achieve high sensitivity.

MATERIALS

The sandwich immunocapture ELISA was evaluated by testing 56 sero-positive and 56 sero-negative samples of circulating galactomannan detected by LA test retrospectively.

RESULTS

Sixty of the samples were positive for galactomannan as measured by sandwich ELISA. Fifteen samples out of 56 samples negative by LA test were positive by ELISA and 4 samples out of 56 samples positive by LA test were negative by ELISA. Among 47 serum samples positive for anti-Aspergillus antibody, 14 samples were positive by ELISA.

CONCLUSION

In conclusion, galactomannan may be detected in more samples of by the new sandwich ELISA than by LA test.

In-vitro and in-vivo activities of SCH56592 against Cryptococcus neoformans

The in-vitro and in-vivo activities of SCH56592, a triazole antifungal agent, against Cryptococcus neoformans were studied. MIC(90)s for 16 strains of C. neoformans measured by microdilution method (NCCLS M27-A) were 1 mg/L of SCH56592, 16 mg/L of fluconazole, 32 mg/L of flucytosine, and 0.5 mg/L of amphotericin B. In a murine model of pulmonary cryptococcosis, 10 mg/kg of SCH56592 was more effective than fluconazole. The fungal burden of the lung of animals treated with SCH56592 was significantly reduced (7.40 +/- 0.21 log(10) cfu/g), as compared with fluconazole (7.77 +/- 0.07 log(10) cfu/g) and control (7.79 +/- 0.1 log(10) cfu/g) (P < 0.01). For C. neoformans-infected mice following 7 days treatment with 10 mg/kg of SCH56592 there was a higher concentration in lung (3.36 +/- 0.62 ng/ml) than in plasma (2.16 +/- 0.86 ng/mL), and this was maintained for 12 h after administration.

Elevated levels of beta-chemokines in bronchoalveolar lavage fluid (BALF) of individuals infected with human T lymphotropic virus type-1 (HTLV-1)

Pulmonary complications are known to develop in HTLV-1 carriers, including T lymphocytic alveolitis, and increased IL-2 receptor alpha (CD25)-bearing T cells have been found in BALF. Several chemokines may contribute to accumulation of T lymphocytes in the lungs of HTLV-1 carriers. Here, we compared the distribution of T lymphocyte subsets and beta-chemokines, such as macrophage inflammatory peptide-1alpha (MIP-1alpha), regulated on activation normal T expressed and secreted (RANTES), and macrophage chemoattractant protein-1 (MCP-1), in BALF and peripheral blood between HTLV-1 carriers and non-infected healthy normal subjects. Flow cytometric analysis with MoAbs to cell surface antigens was used to identify T lymphocyte subsets in BALF samples from HTLV-1 carriers (n = 13) and non-infected healthy controls (n = 10). The levels of different beta-chemokines were estimated by ELISA. High percentages of CD3+ cells, CD3 expressing HLA-DR antigen and CD3+CD25+ cells were detected in BALF of HTLV-1 carriers compared with non-infected controls. The concentration of MIP-1alpha in BALF of patients was significantly higher than in non-infected healthy controls and correlated well with the percentage of CD3+CD25+ cells. The level of RANTES in BALF was also significantly high in HTLV-1 carriers, but did not correlate with the percentage of CD3+CD25+ cells. On the other hand, the level of MCP-1 in BALF of HTLV-1 carriers was not different from that of controls. Our results suggest a possible interaction between activated T cells bearing CD25 and beta-chemokines, especially MIP-1alpha, which may contribute to the pulmonary involvement in HTLV-1 carriers.

[Correlations between drug plasma concentration and adverse effects in patients treated with itraconazole for pulmonary aspergilloma]

We measured the plasma concentration of itraconazole (ITCZ) in 18 patients who received ITCZ for the treatment of pulmonary aspergilloma. Abnormal laboratory values were observed in 4 out of 10 patients who received 200 mg/day, 1 out of 3 patients who received 300 mg/day, and 2 out of 5 patients who received 400 mg/day. Four patients discontinued ITCZ therapy because of adverse effects following the administration of 200 mg/day or 400 mg/day. The mean plasma ITCZ concentration was 622 ng/ml in patients treated with less than 4 mg/kg, and 1,352 ng/ml in patients treated with more than 4 mg/kg of ITCZ. The sensitivity of Aspergillus species to ITCZ was measured with the NCCLS microdilution method, using alamar blue indicator. The MIC50 of ITCZ was 0.5 microg/ ml for 25 strains of A. fumigatus, 4 microg/ml for 15 strains of A. niger, and 0.25 microg/ml for 10 strains of A. flavus. In conclusion, this study underscored the necessity of monitoring the plasma concentration of ITCZ for effective treatment of patients with pulmonary aspergilloma.

Invasive pulmonary aspergillosis diagnosed early by polymerase chain reaction assay

We compared the usefulness of a polymerase chain reaction (PCR) assay for the early diagnosis of invasive pulmonary aspergillosis with the serodiagnosis of sufficient concentrations of galactomannan using the same serum samples. A patient was treated with prednisolone for the management of hepatitis. Computed tomography (CT) scan of the chest showed the nodular shadow with a cavity containing a clear fungus ball. DNA of Aspergillus spp. from a serum sample was detected and using the same serum sample, both latex agglutination and sandwich enzyme-linked immunosorbent assay (ELISA) of galactomannan were negative. PCR assay provides an early diagnosis of invasive pulmonary aspergillosis compared with ELISA of galactomannan.

Effect of sequential combination of amphotericin B and azole antifungal agents against Aspergillus fumigatus

Patients with aspergillosis have a poor prognosis because there are no effective antifungal agents except for amphotericin B. However, administration of amphotericin B is limited in immunocompromised patients due to its toxicity, which includes impairment of renal function. We attempted to evaluate the efficacy of a sequential combination of antifungal agents against Aspergillus fumigatus strain. The in vitro effects of sequential combinations of antifungal agents against five strains of Aspergillus fumigatus were determined by assessing changes in the wet weight of mycelial cells. The effect of a sequential combination was examined by pretreating mycelial cells with an antifungal agent, followed by the addition of a second antifungal agent. Pretreatment with amphotericin B (AMPH) followed by miconazole (MCZ) or fluconazole (FLCZ) resulted in better in vitro effects compared with the effect of simultaneous use of the agents. In contrast, pretreatment of mycelial cells with azole antifungal agents, other than MCZ, followed by AMPH, resulted in an increase in the wet weight compared with that recorded after simultaneous incubation with AMPH and azole antifungal agents. Our results showed that combined treatment, of AMPH followed by MCZ or FLCZ, inhibited the growth of A. fumigatus, suggesting that such a regimen may be effective against aspergillosis.

[A rare case of lung adenocarcinoma in cavity wall of pulmonary aspergilloma]

A 67-year-old man was admitted with the complaint of hemosputum. Chest X-ray films resulted in a diagnosis of pulmonary aspergilloma, and treatment with intravenous amphotericin B was initiated. However, therapy was discontinued due to renal insufficiency, an adverse effect of amphotericin B. The size of the fungus ball and cavity increased despite treatment with oral itraconazole (200 mg/day). Cavernostomy was performed and the fungus ball was removed from the upper lobe of the left lung. Computed tomographic scans disclosed thickening of the remaining wall of the cavity, with destruction of the ribs. The patient experienced worsening respiratory distress and died. Necropsy revealed adenocarcinoma of the left lung.

[The future of antifungal agents. Non azole antifungal agents]

We investigated the efficacy of non-azole antifungal agents. Long circulating immunoliposomal amphotericin B was potent in murine invasive pulmonary aspergillosis. The concentration of AMPH-B was still high in the lung after 6 hours of 34A-PEG-liposomal AMPH-B. Lipid nanosphere amphotericin B (NS-718) showed efficacy against pulmonary aspergillosis in rats and pulmonary cryptococcosis in mice. The renal toxicity of NS-718 was estimated to be lower than that of AMPH-B from the results of the toxicity study in the rat infusion model. FK 463, a novel (1,3)-beta-D-glucan synthase inhibitor, showed efficacy against azole-resistant Candida albicans in murine experimental disseminated candidiasis. FK463 could be a promising drug and the therapy of choice for azole resistant C. albicans infection.

[A case of invasive aspergillosis in an amyloidosis patient]

A sixty-four-year-old male patient was admitted on 13 April 1995 with diagnosis of old pulmonary tuberculosis and pulmonary aspergilloma. He developed a tarry stool and frequent loose motion in early November 1995. Histopathological findings of endoscopic biopsy from the duodenum and colon were suggestive of secondary amyloidosis. In spite of antibiotic and steroid pulse, he developed shock, and massive infiltration shadow appeared in chest X-ray. The patient died on 29 December 1995. The postmortem examination in the specimens of the lung, heart, kidney, liver, and spleen revealed hyphae of Aspergillus sp. and in the specimens of the lung, kidney, spleen, esophagus, adrenal gland, and thyroid revealed amyloid. He was finally diagnosed as invasive aspergillosis with secondary amyloidosis.

Rhodamine 6G efflux for the detection of CDR1-overexpressing azole-resistant Candida albicans strains

We investigated the drug efflux mechanism in azole-resistant strains of Candida albicans using rhodamine 6G (R6G). No significant differences in R6G uptake were observed between azole-sensitive B2630 (9.02 +/- 0.02 nmol/10(8) cells) and azole-resistant B67081 (8.86 +/- 0.03 nmol/10(8) cells) strains incubated in glucose-free phosphate buffered saline. A significantly higher R6G efflux (2.0 +/- 0.21 nmol/10(8) cells) was noted in the azole-resistant strain (B67081) when glucose was added, compared with that in the sensitive strain B2630 (0.23 < or = 0.14 nmol/10(8) cells). A fluconazole-resistant strain C40 that expressed the benomyl resistance gene (CaMDR) also showed a low R6G efflux (0.16 +/- 0.06 nmol/10(8) cells) as did the sensitive strains. Accumulation of R6G in growing C. albicans cells was inversely correlated with the level of CDR1 mRNA expression. Our data also suggest that measurement of intracellular accumulation of R6G is a useful method for identification of azole-resistant strains due to CDR1-expressed drug efflux pump.

Genetic analysis of serotype 23F Streptococcus pneumoniae isolates from several countries by penicillin-binding protein gene fingerprinting and pulsed-field gel electrophoresis

We characterized 21 strains of serotype 23F Streptococcus pneumoniae isolated in various countries with various levels of penicillin susceptibility by penicillin-binding protein (PBP) gene fingerprinting and pulsed-field gel electrophoresis (PFGE). Pneumococci isolated in Israel, Hungary, Bulgaria, Slovakia, Rumania, France, the United States, Spain and Japan were included. These strains were classified into 12 and 18 groups by PBP gene fingerprinting and PFGE, respectively. Some of the pneumococci isolated in Spain, the United States and France appeared to be genetically related by PFGE, showed the same PBP gene pattern and had similar antimicrobial susceptibility patterns. One penicillin-susceptible Bulgarian strain, with a similar PFGE pattern but a different fingerprinting pattern, may be an ancestral recipient strain that became transformed into the resistant variants. Rumanian and Israeli strains were also genetically related by PFGE. These results indicate the existence of widely spread but related pneumococci in the world. PBP 2X gene profiles of pneumococci with MICs of 0.25 microg/ml were different from each other and from penicillin-susceptible pneumococci (PSP). PBP 2B gene profiles of these resistant strains were identical. PBP 2B gene profiles of pneumococci (penicillin MICs >/=0.5 microg/ml) were different from PSP. PBP gene profiles may not only be useful for genetic analysis but also for presumed penicillin susceptibility.

[The combination therapy of clarithromycin and sparfloxacin for pulmonary Mycobacterium gordonae infection]

Seventy years old woman had fever and hemosputum at May 1997. She was diagnosed as mycobacteriosis because of the positive acid fast bacilli smear from sputum. Mycobacterium gordonae was isolated from sputum, gastric juice, and bronchial aspirate. The combination therapy of isoniazid, rifampicin, ethambutol, and clarithromycin was administrated; however, M. gordonae was not eradicated from sputum. Sparfloxacin was administered instead of isoniazid based on the result of drug susceptibility test. The smear became negative and M. gordonae was eradicated from sputum one month after the initiation of treatment with the combination of clarithromycin and sparfloxacin.

In vitro and in vivo activities of NS-718, a new lipid nanosphere incorporating amphotericin B, against Aspergillus fumigatus

We evaluated the in vitro and in vivo potencies of a new lipid nanosphere that incorporates amphotericin B (AmB), NS-718, against Aspergillus fumigatus. The in vitro activity of NS-718 (the MIC at which 90% of strains are inhibited [MIC90], 0.25 microgram/ml) against 18 isolates of A. fumigatus was similar to that of deoxycholate AmB (D-AmB; Fungizone; MIC90, 0.25 microgram/ml), but NS-718 was more potent than liposomal AmB (L-AmB; AmBi-some; MIC90, 1.0 microgram/ml). The in vivo efficacy of NS-718 in a rat model of invasive pulmonary aspergillosis was compared with those of D-AmB and L-AmB. A low dose (1 mg/kg of body weight) of L-AmB was ineffective (survival rate, 0%), although equivalent doses of D-AmB and NS-718 were more effective (survival rate, 17%). However, a higher dose of NS-718 (3 mg/kg) was more effective (survival rate, 100%) than equivalent doses of D-AmB and L-AmB (survival rate, 0%). To explain these differences, pharmacokinetic studies showed higher concentrations of AmB in the plasma of rats treated with NS-718 than in the plasma of those treated with D-AmB. Our results suggest that NS-718, a new preparation of AmB, is a promising antifungal agent with activity against pulmonary aspergillosis.

Heat shock protein 70 (hsp70) as a major target of the antibody response in patients with pulmonary cryptococcosis

Cryptococcus neoformans causes infection in individuals with defective T cell function, such as AIDS, as well as without underlying disease. It has been suggested that humoral as well as cellular immunity might play an important role in the immune response to C. neoformans infection. We have recently shown, using immunoblotting, that the 70-kD hsp family of C. neoformans was the major target molecule of the humoral response in murine pulmonary cryptococcosis. In this study we also used immunoblotting to define the antibody responses in the sera of 24 patients with pulmonary cryptococcosis: 21 proven and three suspected diagnoses. Anti-C. neoformans hsp70 antibody was detected in 16 of 24 (66.7%) patients with pulmonary cryptococcosis. Fourteen of 17 (82.3%) patients with high antigen titres (> or = 1:8) and two of seven (28.6%) patients with low titres (< or = 1:4) had detectable levels of anti-hsp70 antibody. Sera from patients positive for anti-hsp70 antibody showed high titres in the Eiken latex agglutination test for the detection of serum cryptococcal antigen. Our results indicate that the 70-kD hsp family from C. neoformans appears to be a major target molecule of the humoral response, not only in murine pulmonary cryptococcosis, but also in human patients with pulmonary cryptococcosis.

[A case of pulmonary cryptococcosis with lung cancer in a pulmonary lobe]

A 63-year old female was admitted because of an abnormal shadow on chest X-ray film. Chest CT showed a nodular shadow in the right S6 and a patchy shadow in the right S10. Right lower lobectomy was performed under a diagnosis of lung cancer made by TBLB in the right S6. Pathological examination of the resected lung revealed papillary adenocarcinoma in the right S6 and numerous cryptococci in the right S10. No cryptococcal infection was found in the resected lymph nodes.

Relationship between genetic alteration of the rpsL gene and streptomycin susceptibility of Mycobacterium tuberculosis in Japan

We have investigated the effect of genetic alterations in the rpsL gene on the MICs of streptomycin for Mycobacterium tuberculosis strains. Direct DNA sequencing showed a point mutation in 23/121 strains; in 18 strains the mutation was associated with an amino acid change. The MICs of streptomycin in 22 out of 23 point-mutated strains were > or = 256 mg/L. Restriction fragment length polymorphism (RFLP) analysis showed mutations at codon 43 in all 18 strains with point mutations in the same codon. Our results suggest that both RFLP and base sequencing analysis of the rpsL gene are useful for the rapid prediction of highly streptomycin-resistant strains of M. tuberculosis.

[Itraconazole-induced hypokalemia in a patient with pulmonary aspergilloma]

An 80-year-old man was admitted to the hospital with a diagnosis of pulmonary aspergilloma. A new azole antifungal agent, D 0870, was administered to the patient for 7 days orally, and itraconazole (400 mg/day) was started on March 5, 1997. After 1 month of chemotherapy, facial and pretibial edema were observed and the patient's serum potassium concentration decreased to 2.5 mEq/l. A chest radiograph disclosed cardiomegaly with cardiac effusion and right pleural effusion on admission. The serum potassium concentration rose after the cessation of itraconazole therapy. The serum ITCZ concentration remained high for 2 weeks after admission. Although reports of hypopotassemia induced by ITCZ are rare, we concluded that blood concentrations should be monitored more carefully when treating pulmonary aspergilloma patients with high-dose regimens of ITCZ.

Comparison between PCR and detection of antigen in sera for diagnosis of pulmonary aspergillosis

We evaluated the usefulness of PCR and antigen detection for the diagnosis of pulmonary aspergillosis. Forty-four serum samples from patients with pulmonary aspergillosis (33 with pulmonary aspergilloma, 4 with allergic bronchopulmonary aspergillosis, 4 with invasive pulmonary aspergillosis, and 3 with aspergillus pyothorax) were used in this study. PCR detection of Aspergillus DNA in serum samples was successful in 39 patients. Galactomannan antigen was detected by sandwich enzyme-linked immunosorbent assay in 25 patients and by latex agglutination test in 13 patients. Detection of Aspergillus DNA in serum samples by nested PCR had the highest sensitivity of the three methods tested for the diagnosis of pulmonary aspergillosis.

Analysis of genetic relationships and antimicrobial susceptibility of verotoxin-producing Escherichia coli strains isolated in Nagasaki Prefecture, Japan in 1996

A total of 19 Escherichia coli O157 isolates were obtained in Nagasaki Prefecture, in the south-western part of Japan, between 1990 and 1996. Pulsed-field gel electrophoresis (PFGE) and computer-assisted analysis were applied to determine genetic relationships among these strains. Fragment patterns of the isolates in Nagasaki, as determined by PFGE, were compared with those of isolates in other areas where large outbreaks and sporadic cases of E. coli O157 infection occurred. Similarity values of all the strains isolated in Nagasaki Prefecture were over 0.65 except for E. coli O26. Some strains were identical to the strains isolated from the areas where large outbreaks occurred. All strains were susceptible to ampicillin, fosfomycin, minocycline, amikacin, ofloxacin and sulfamethoxazole-trimethoprim.

Synergic effects of tactolimus and azole antifungal agents against azole-resistant Candida albican strains

We investigated the effects of combining tacrolimus and azole antifungal agents in azole-resistant strains of Candida albicans by comparing the accumulation of [3H]itraconazole. The CDR1-expressing resistant strain C26 accumulated less itraconazole than the CaMDR-expressing resistant strain C40 or the azole-sensitive strain B2630. A CDR1-expressing Saccharomyces cerevisiae mutant, DSY415, showed a marked reduction in the accumulation of both fluconazole and itraconazole. A CaMDR-expressing S. cerevisiae mutant, DSY416, also showed lower accumulation of fluconazole, but not of itraconazole. The addition of sodium azide, an electron-transport chain inhibitor, increased the intracellular accumulation of itraconazole only in the C26 strain, and not in the C40 or B2630 strains. Addition of tacrolimus, an inhibitor of multidrug resistance proteins, resulted in the highest increase in itraconazole accumulation in the C26 strain. The combination of itraconazole and tacrolimus was synergic in azole-resistant C. albicans strains. In the C26 strain, the MIC of itraconazole decreased from >8 to 0.5 mg/L when combined with tacrolimus. Our results showed that two multidrug resistance phenotypes (encoded by the CDR1 and CaMDR genes) in C. albicans have different substrate specificity for azole antifungal agents and that a combination of tacrolimus and azole antifungal agents is effective against azole-resistant strains of C. albicans.

Relationship between antimycobacterial activities of rifampicin, rifabutin and KRM-1648 and rpoB mutations of Mycobacterium tuberculosis

We compared the in-vitro antimycobacterial activities of rifabutin and KRM-1648, two rifamycin derivatives, with that of rifampicin against 163 strains of Mycobacterium tuberculosis. We also evaluated the correlation between the level of resistance to rifampicin, rifabutin and KRM-1648 and genetic alterations in the rpoB gene. All 82 strains susceptible to rifampicin or resistant to rifampicin with MICs < or = 16 mg/L were susceptible to rifabutin and KRM-1648 with MICs < or = 1 mg/L. Seventy-six of 81 strains resistant to rifampicin with MICs > or = 32 mg/L were resistant to both rifabutin and KRM-1648, but with lower MICs than those of rifampicin. KRM-1648 showed more potent antimycobacterial activity than rifabutin against organisms with low MICs (< or = 1 mg/L), while rifabutin was more active than KRM-1648 against organisms with high MICs (> or = 2 mg/L). A total of 96 genetic alterations around the 69 bp core region of the rpoB gene were detected in 92 strains. Alterations at codons 515, 521 and 533 in the rpoB gene did not influence the susceptibility to rifampicin, rifabutin and KRM-1648. Point mutations at codons 516 and 529, deletion at codon 518 and insertion at codon 514 influenced the susceptibility to rifampicin but not that to rifabutin or KRM-1648. With the exception of one strain, all alterations at codon 513 and 531 correlated with resistance to the three test drugs. The resistant phenotype of strains with an alteration at codon 526 depended on the type of amino acid substitution. Our results suggest that analysis of genetic alterations in the rpoB gene might be useful not only for predicting rifampicin susceptibility, but also for deciding when to use rifabutin for treating tuberculosis. Further studies may be required to determine the usefulness of KRM-1648.

[Pulmonary infection in the emphysematous bulla due to Mycobacterium szulgai diagnosed by percutaneus needle aspiration]

A 73-year-old male was admitted to our hospital because of productive cough and infiltrate on the chest roentogenogram. The underlying diseases was found to be multiple myeloma. He received a physical examination in June, 1996. The chest X-ray and CT scan on admission showed an infiltrative shadow with multiple bulla in the left upper lung field. Internal use of antibiotics and drip infusion of IPM/CS were ineffective. The chest X-ray showed air-fluid level in left upper peripheral bullous lesion and a percutaneus needle aspiration of the lung was performed. The specimen was pus with blood and microscopical examination of smears revealed no acid-fast bacilli, but Mycobacterium szulgai was isolated and identified by DNA-DNA hybridization method. The patient was treated with isoniazid and rifampicin, and improved in a few months. There are a few case reports of pulmonary infection due to M. szulgai associated with emphysematous bulla of the lung in Japan. M. szulgai infection of the lung is similar to M. kansasii infection in respect to clinical features (improvement of chest abnormal shadow, efficacy of drug).

[Severe mycosis-factors with fungus and host]

The deep-seated mycosis occurred in immunocompromized patients. Normally, the deep-seated mycosis became sever infection because of the defects of host defense or the adverse effects of antifungal agents. The major factors of the reason on the severity of the deep-seated mycosis depends on the pathogenesity and the drug resistance for antifungal agents in infected fungi. The clinical factors related with hosts defenses are important to the other reason on the severity. We investigated that the multiple drug resistant (MDR) mechanism may be one of the major roles plays in the azole resistant Candida albicans strains isolated form the patients with oropharyngeal candidiasis infected HIV. We analyzed which clinical factors are related with the prognosis of the patients with pulmonary cryptococcosis and aspergilloma. The titer of cryptococcal capsular antigen was earlier improve in the patient without underline disease than in the patients with underline diseases diagnosed pulmonary cryptococcosis. CRP was higher in the death cases in the patients with pulmonary aspergilloma, compared with alive cases.

Genetic relationship between blood and nonblood isolates from bacteremic patients determined by pulsed-field gel electrophoresis

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram-positive cocci and 42.1% with Pseudomonas aeruginosa bacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia.

[Spontaneous resolution of pulmonary cryptococcosis--report of 2 cases]

We encountered two patients with pulmonary cryptococcosis that resolved spontaneously without antifungal treatment. A 59-year-old man (patient 1) and 37-year-old man (patient 2) were admitted to our hospital for the examination of abnormal shadows on their chest x-ray films. Transbronchial lung biopsies were performed, and cryptococci were detected in both patient's lung tissues. Latex aggultination tests for cryptococcal antigen were positive (1:16 and 1:4, respectively). The size of the shadows reduced spontaneously and the titers of the cryptococcal antigen in sera decreased within three months although no antifungal therapy was performed. Bronchoalveolar lavage fluid (BALF) was obtained from each patient and examined. In patient 1, the lymphocyte to CD 4/8 ratio was high in the BALF obtained on admission and the lymphocyte count was low; however, the CD 4/8 ratio was still high in a BALF sample obtained 3 months after discharge. In patient 2, the findings of the BALF analysis on admission were almost normal. The analysis of BALF may contribute to the immunological conditions to in the patients with pulmonary cryptococcosis.

Escherichia coli O157 interactions with human intestinal Caco-2 cells and the influence of fosfomycin

It is not clear how Escherichia coli O157 invades human enteric epithelium and causes the haemolytic uraemic syndrome (HUS), and nor has the most appropriate treatment of E. coli O157 infection been established. Verotoxins, leucocytes and proinflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-8, are considered essential for the development of HUS. We used the Caco-2 cell monolayer system, well-known as an in-vitro model of human intestinal infection, to determine how E. coli O157 interacts with intestinal epithelial cells and also studied the influence of fosfomycin on the virulence of the bacteria. Results showed that the E. coli O157 used in this study did not penetrate the Caco-2 cell monolayer system, unlike Salmonella typhimurium SL1344, and verotoxin 1 (VT 1), but not VT 2, translocated across the system. In an in-vitro conventional assay, fosfomycin increased the amount of verotoxins but it did not influence penetration of bacteria and translocation of verotoxins in the Caco-2 cell monolayer system. The production of both IL-8 (a potent neutrophil activator) and TNF-alpha in the human monocytic THP-1 cell line was reduced by fosfomycin-treated basolateral medium in this system. These results indicate that fosfomycin may be a potent drug for preventing HUS caused by E. coli O157 infection.

[A study of virulence factors produced by MRSA strains isolated from blood samples]

Toxic shock syndrome toxin-1 (TSST-1) and enterotoxins are important virulence factors produced by Staphylococcus aureus. It is reported that these toxins are associated with septic shock and toxic shock syndrome. We investigated the toxin production and coagulase types of 701 MRSA strains isolated in Sasebo City General Hospital between 1994 and 1996 TSST-1 or/and enterotoxins were detected in 67% of all MRSA strains, and those were detected in 88% of MRSA strains isolated from blood samples. 45% of all MRSA strains produced both TSST-1 and enterotoxin C, and 70% of MRSA strains obtained from blood produced those toxins. Frequency of TSST-1 or/and enterotoxin production by MRSA strains isolated from blood samples was significantly higher than that by MRSA strains isolated from urine and pharynx (p < 0.05), and frequency of both TSST-1 and enterotoxin C production by MRSA isolates from blood was significantly higher than that by MRSA strains isolated from pharyngeal sample (p < 0.05). This study indicated that investigation of virulence factors produced by MRSA might give the useful information on prevention and treatment of MRSA infection.

Rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo-beta-lactamase gene blaIMP

Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, including Pseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of the blaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for the blaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53. 8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carrying blaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis of blaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.

Efficacy of NS-718, a novel lipid nanosphere-encapsulated amphotericin B, against Cryptococcus neoformans

In vitro and in vivo efficacies of NS-718, a lipid nanosphere-encapsulated amphotericin B (AMPH-B), have been studied. Of the tested AMPH-B formulations, NS-718 had the lowest MIC for Cryptococcus neoformans. In a murine model, low-dose therapy (0.8 mg/kg of body weight) with NS-718 showed higher efficacy than that with AmBisome. High-dose therapy (2.0 mg/kg) with NS-718 was much more effective than those with Fungizone and AmBisome. In mice treated with a high dose of NS-718, only a few yeast cells had grown in lung by 7 days after inoculation. A pharmacokinetic study showed higher concentrations of AMPH-B in lung following administration of NS-718 than after administration of AmBisome. Our results indicated that NS-718, a new AMPH-B formulation, is a promising antifungal agent for treatment of pulmonary cryptococcosis and could be the most effective antifungal agent against C. neoformans infections.

Antimicrobial susceptibility testing of Bilophila wadsworthia isolates submitted for routine laboratory examination

MICs of antibiotics against Bilophila wadsworthia isolates were measured by agar and broth microdilution with pyruvic acid and by Etest. The inoculum size influenced greatly agar dilution. Despite discrepancies in MICs depending on the measurement method used, clindamycin consistently showed potent activity. Broth microdilution and Etest appear to be candidates for laboratory susceptibility testing.

Adherence to and penetration of human intestinal Caco-2 epithelial cell monolayers by Pseudomonas aeruginosa

Clinical isolates of Pseudomonas aeruginosa from blood adhered to and penetrated intestinal Caco-2 cell monolayers to a greater degree than did isolates from sputum, with a concomitant drastic decrease in transepithelial electrical resistance. PAO-PR1, an avirulent exotoxin A mutant of PAO1, did not cause a decrease in the resistance. The Caco-2 monolayer system may be useful for the evaluation of certain P. aeruginosa virulence factor activities.

In vitro activities of quinupristin-dalfopristin and the streptogramin RPR 106972 against Mycoplasma pneumoniae

The in vitro activities of quinupristin-dalfopristin and streptogramin RPR 106972 were determined with 44 strains of Mycoplasma pneumoniae and compared to those of macrolides, minocycline, and quinolones. All isolates tested were highly susceptible to macrolides and to quinupristin-dalfopristin (MIC at which 90% of the isolates are inhibited [MIC90], 0.0625 microg/ml), followed by RPR 106972 (MIC90, 0.5 microg/ml), quinolones, and minocycline.