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Both the emergence of multidrug-resistant and extensively drug-resistant tuberculosis (TB) are currently the majorchallenges in the treatment of TB. Only delamanid and bedaquiline have been recently approved as anti-TB drugs inthe past 40 years. In an attempt to search for active anti-TB compounds against the sensitive strain of Mycobacteriumtuberculosis, H37Rv—a series of synthetic ethyl 7-acetyl-2-substituted-3-(4-substituted benzoyl)indolizine-1-carboxylates (2a–r)—have been screened for in vitro qualitative anti-TB activity using an agar dilution method. Itwas found that compounds 2a, 2b, 2c, 2f, 2g, 2i, 2j, 2l, 2o, 2p, and 2r, which have various functional groups on theindolizine nucleus, were active against the H37Rv strain.
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Objective To observe the effects of 19 kinds of traditional Chinese medicine (TCM) aqueous extracts in vitro on the standard and clinical strains of propionibacterium acnes.Methods We collected lesion contents of acne vulgaris patients and conducted anaerobic cultivation of propionibacterium acnes at 35 ℃ for forty-eight hours.After tested by oxygen resistance experiment,Gram staining microscopy,catalytic test,nitrate test and sugar fermentation experiment,ANI anaerobic identification card,and VITEK fully-automatic microbe instrument,the strains were identified as propionibacterium acnes.We used AGAR dilution method to test the MIC values of various TCM aqueous extracts.Results The MIC values of Cortex phellodendri,Scutellaria baicalensis,and Rhiubarb were 25 mg/ml,respectively;the MIC values of Sophora flavescens and Honeysuckle were 50 mg/ml;the MIC values of Forsythia was 100 mg/ml.13 kinds of TCM aqueous extract did not produce bacteriostasis at the highest concentration of 200 mg/ml including Belvedere fruit,Chinese bulbul,Hedyotis diffusa,Houttuynia cordata,Purslane,Yerbadetajo herb,Radix isatidis,Lithospermum erythrorhizon,Folium isatidis,Taraxacum,Semen plantaginis,Angelica dahurica,and Fructus cnidii.Conclusions Aqueous extracts of Cortex phellodendri,Scutellaria baicalensis,Rhubarb,Sophora flavescens,Honeysuckle and Forsythia have good inhibitory effects in vitro on Propionibacterium acnes.
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Objective To observe the antimicrobial effect of a kind of Chinese medicine Qingre compound preparation on the common pathogenic bacteria of upper respiratory tract infection (URTI). Methods A total of 163 common pathogen?ic bacteria of URTI was selected in this study, including 74 non extended-spectrum β- lactamases (ESBLs)-producing Gram-negative bacteria (33 Escherichia coli, 24 Klebsiella pneumonia and 17 Pseudomonas aeruginosa), 10 ESBLs-produc?ing Gram-negative bacteria (6 Escherichia coli and 4 Klebsiella pneumoniae) and 79 Gram-positive bacteria [11 methicil?lin-resistant Staphylococcus aureus (MRSA), 46 methicillin-sensitive Staphylococcus aureus and 22 Streptococcus pneu?moniae]. Agar dilution method was adopted to perform the quantitative drug sensibility test. Agar plates that contained differ?ent concentrations of Qingre compound preparation were prepared. The bacterial suspension was planted on the plates. Then we observed the plates after incubation, and recorded the minimum inhibitory concentration (MIC). Results The antimicro?bial rates of Qingre compound preparation were 88, 176 and 22 g/L for MIC90 of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The antimicrobial effects of Qingre compound preparation were coincident on the MIC 90 of ES?BLs-producing strains and non ESBLs-producing strains. The accumulated antibacterial rates of different concentrations of medicine to Pseudomonas aeruginosa were the highest. The MIC90 values of Qingre compound preparation were 11, 11 and 22 g/L for MSSA, MRSA and Streptococcus pneumoniae. The MIC90 of MRSA was coincident with MSSA, but MIC50 of MRSA was slightly higher than that of MSSA. The accumulated antibacterial rates of different concentrations of medi cine to MSSA and MRSA were all higher than those of Streptococcus pneumonia. The accumulated antibacterial rate of MSSA was similar with that of MRSA. Conclusion The Chinese medicine Qingre compound preparation could restrain common patho?genic bacteria of URTI except Klebsiella pneumoniae. The antibacterial effect of Qingre compound preparation is significant?ly better in Ggram-positive bacteria than that of Gram-negative bacteria.
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Objective To compare broth microdilution and agar dilution methods for in vitro testing of activities of fluconazole,ketoconazole and itraconazole against clinical Malassezia isolates.Methods Broth microdilution and agar dilution methods were used to determine the minimal inhibitory concentration(MIC)of fluconazole,ketoconazole and itraconazole for 27 clinical strains(5 species)of Malassezia.Results The minimal inhibitory concentration(MIC)ranges of fluconazole,ketoconazole and itraconazole were 0.25-≥64 mg/L,≤0.03-0.5 mg/L and ≤0.03-0.125 mg/L respectively as shown by broth microdilution method,2-≥64 mg/L,≤0.03-0.5 mg/L and ≤0.03-0.25 mg/L respectively as revealed by agar dilution method.Both methods demonstrated that itraconazole possessed the strongest activity against Malassezia species,followed by ketoconazole and fluconazole.The agreement rate in MICs between the two methods was 78.8％,85.2％ and 88.9％,respectively for fluconazole,ketoconazole and itraconazole,with the intraclass correlation coefficients (ICCs)being 0.88,0.80 and 0.76 respectively.Conclusions Fluconazole,ketoconazole and itraconazole are highly active against Malassezia species in vitro,and itraconazole is the most active.Broth microdilution and agar dilution method coincide well in,and are applicable for,the antifungal susceptibility testing of Malassezia species in vitro.
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Objective To observe antibacterial efficiency of Prunus mume Sieb et Zucc against clinical isolates. Method Antibacterial activity of Prunus mume Sieb et Zucc against 308 strains of clinical isolates were determined by agar dilution method. Results MIC50 of Prunus mume Sieb et Zucc against staphylococcus aureus (112 strains), S.epidermidis (112 strains), and Enterococci (28 strains) were 0.72, 1.44, 0.72 mg/mL, and MIC90 were 1.44, 1.44, 0.72 mg/mL respectively. The MIC90 of Prunus mume Sieb et Zucc to Klebsiella pneumoniae and E. coli were 2.88, 1.44 mg/mL respectively. Conclusion Prunus mume Sieb et Zucc has good antibacterial activity against Gram positive cocci and some Gram negative bacilli.
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BACKGROUND: The rising incidence of fungal infections and the increasingly frequent use of antifungal agents have intensified the need for practical and reliable antifungal susceptibility test methods. In the present study, the minimal inhibitory concentration(MIC) distribution of Candida species was investigated and the agar dilution method was compared with the National Committee for Clinical Laboratory Standards(NCCLS) "reference" broth microdilution method for antifungal susceptibility testing. METHODS: A total of 116 clinical isolates of Candida species from patients at Hanyang University Kuri Hospital were studied from October 1997 to July 1999, and the MICs of Candida species were evaluated against amphotericin B and fluconazole by the NCCLS method and the agar dilution method. RESULTS: There were no differences in the MIC50 and MIC90 of Candida albicans and Candida tropicalis against amphotericin B between the two methods, but the MIC50 of C. albicans against fluconazole was higher in the agar dilution method than in the broth microdilution method. The resistant rate of C. albicans against fluconazole was 20.8% in the broth microdilution method and 33.8% in the agar dilution method. For C. tropicalis, 31.3% were resistant to fluconazole in the broth microdilution method and 25.0% in the agar dilution method. The agreement of C. albicans and C. tropicalis between the agar dulution method and the broth microdilution method within one doubling dilution of the microdilution reference were 88.8% for amphotericin B and 34.4% for fluconazole. CONCLUSIONS: The MICs of amphotericin B showed good agreement between the agar dilution and the broth microdilution method. Therefore, resistant strains could easily be detected by screening with agar of 2 g/mL concentrations. However, in the case of fluconazole, the agreement between the two methods was low and the trailing effect could not be ruled out in agar dilution method with some strains, indicating the need for further studies in this area.
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Humans , Agar , Amphotericin B , Antifungal Agents , Candida albicans , Candida tropicalis , Candida , Fluconazole , Incidence , Mass ScreeningABSTRACT
BACKGROUND: Enterococci are a leading cause of nosocomial infection and the emergence of resistant strain to various antibiotics including vancomycin is increasingly serious problems among enterococci. And the risk of spread of glycopeptide genes to other Gram-positive cocci makes the problems more serious. To evaluate the presence of vancomycin-resistant enterococci (VRE) in Ewha Womans University Hospital (EWUH), we screened hospitalized patients for fecal colonization and clinical isolates. METHODS: We screened VRE in 574 stool specimens requested for routine cultures and 91 perirectal swabs or stool specimens from patients who reside in intensive care unit and hemato-oncologic ward in Mookdong and Tongdaemoon EWUH from December 1996 through April 1997. And 295 enterococcal species isolated from various clinical specimens were also included. To detect VRE, specimens were cultured in BHI agar medium including 6 g/mL of vancomycin and to determine the antibiotic susceptibility pattern, broth microdilution test using VITEK GPS-IZ, disk diffusion test and standard agar dilution test were performed. Multiplex PCR was done to determine the genotypes of VRE. RESULTS: Nine enterococci (0.9%) were interpreted as VRE in standard agar dilution method. Two (0.3%) out of 665 were from stool speciemens for surveillence cuture and 7 (2.3%) out of 295 were from various clinical specimens for ordinary cultures including 5 E. casseliflavus, 2 E. gallinarum, 1 E. flavescens and 1 Enterococcus species. All isolates showed low-level resistance against vancomycin (8-16 g/mL) by standard agar dilution. But both disk diffusion method and VITEK system demonstrated difficulties in detecting low-level resistance. The genotypes of VRE were classified as van C-1 in 2 isolates and as van C-2 in 6 isolates except 1 isolates, which was unclassifiable in our study. CONCLUSIONS: Even though VRE with high- or medium-level resistance against glycopeptide was not detected in EWUH from this period of investigation, the possibility of presence of VRE is impanding because several teaching hospitals already reported the presence of VRE in clinical isolates and fecal colonization. So continuous surveillence and strict infection control measures must be implemented to detect and prevent transmission of VRE infection.