In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors, transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting.</p><p><b>METHODS</b>The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35°C. MIC(50), MIC(90) and MIC range were acquired by Whonet 5.4 software.</p><p><b>RESULTS</b>The MIC(90) of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 µg/ml whereas the MIC(90) against A. niger was 0.19 µg/ml. For these four species, the MIC(90) of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC(90) of posaconazole was the lowest. For A. fumigatus and A. flavus, the MIC(90) in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 µg/ml in all 7 strains tested.</p><p><b>CONCLUSIONS</b>The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.</p>

Prevalence of integrons and analysis of resistance genes in integrons among Acinetobacter baumannii isolates from Nanjing region / 中国感染与化疗杂志

Objective To investigate the prevalence of integrons in A.baumannii isolates,analyze the correlation between inte- grons and resistance of A.baumannii,and study the resistance genes in integrons.Methods A total of 106 strains of A.bau- mannii were collected to test the antibiotic susceptibility by disk diffusion method.The classification of integrons was per- formed by analyzing the positive PCR products using restriction fragment length polymorphism (RFLP).The variable region of integrons was amplified by integron PCR.RFLP and DNA sequencing were used to analyze the resistance genes in integrons. Results About 52.8% (56/106) of the isolates showed integron positive.PCR-RFLP analysis revealed that they were all class I integrons.About 94.6%(53/56) of the positive strains with integrons owned the variable region,which was confirmed by integron PCR.The sizes of the amplicons ranged from 0.15 kb to 2.8 kb.All together 7 different cassette arrays were detec- ted,including genes coding resistance to aminoglycosides (aadA1,aadA2,aadA5,aadB,aacA4),sulphonamides (dfrⅫ, dfr17),?-lactam compounds (bla_(ara-10)),chloramphenicol (catB-like,catB8),and two open reading frames (orfF,orfI) with unknown function.A novel cassette array orfI-aadA1 was reported,and its GenBank accession number was DQ092497.Conclu- sions Class I integrons are widespread in A.baumannii isolates in Nanjing.The integrons are closely associated with the resist- ance and multidrug resistance in A.baumannii isolates.