Comparison of the EUCAST-AFST broth dilution method with the CLSI reference broth dilution method (M38-A) for susceptibility testing of posaconazole and voriconazole against Aspergillus spp.

The susceptibilities of 40 clinical isolates of Aspergillus spp. (Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus terreus) were determined for posaconazole and voriconazole by the CLSI M38-A and EUCAST-AFST broth dilution methods. Where a discrepancy was observed between the methods, the EUCAST method tended to give higher MIC values. Overall, the level of agreement was 92.5% and the intra-class correlation coefficient was > 0.90.     

Detection of Brucella melitensis by the BacT/Alert automated system and Brucella broth culture

This study was conducted to evaluate the ability of the BacT/Alert automated blood culture system to detect Brucella spp. in comparison with traditional Brucella broth culture. Overall, 100 (50 bone marrow and 50 blood samples) paired cultures were obtained, and 59 were positive by at least one method. The Brucella broth culture method detected all 59 positive cultures (100%), and the BacT/Alert system detected 30 (50.8%) ( P  < 0.05). The mean detection times for B. melitensis were 4.5 days in the BacT/Alert system and 5 days in Brucella broth culture ( P  > 0.05). There is no significant difference between the two methods with respect to growth time of the microorganism, but Brucella broth culture is more sensitive than the BacT/Alert system.     

Molecular characterisation of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella spp. isolates at a tertiary-care centre in Lebanon

The prevalence of bla _CTX-M, bla _TEM and bla _SHV genes among extended-spectrum β-lactamase (ESBL)-producing clinical isolates of Escherichia coli ( n  = 50) and Klebsiella spp. ( n  = 50) from Lebanon was 96%, 57% and 67%, and 40%, 82% and 84%, respectively. Genotyping revealed that the clonal diversity was unrelated to the presence of bla genes. Sequence analysis of 16 selected isolates identified the bla _CTX-M-15, bla _TEM-1, bla _OXA-1 and six bla _SHV genes, as well as the gene encoding the quinolone-modifying enzyme AAC(6')-Ib-cr. The genes encoding CTX-M-15 and AAC(6')-Ib-cr were carried on a 90-kb plasmid of the pC15-1a or pCTX-15 type, which transferred both ESBL production and quinolone resistance from donors to transconjugants.     

Effects of SITS on urate transport by isolated,perfused snake renal tubules

Effects of an inhibitor of membrane anion-exchange transport processes, 4-acetamido-4-isothiocyano-2,2-disulfonic stilbene (SITS), on urate transport by isolated, perfused snake (Thamnophis spp.) proximal renal tubules were studied. SITS (10^–4 mol/l) in the luminal perfusate had absolutely no effect on net urate secretion (J _urate ^net ) or on net fluid absorption (J _v). This observation is compatible with other data that give no support to the concept of a mediated transport step for urate from the cells to the lumen. SITS (10^–4 mol/l) in the bathing medium reversibly inhibitedJ _urate ^net without affectingJ _v. At the time of maximum inhibition ofJ _urate ^net , the concentration of urate in the cell water was increased and the apparent permeability of the luminal membrane to urate was decreased, but the urate efflux across the peritubular membrane and the apparent permeability of the peritubular membrane to urate were unchanged. There was no evidence of significant intracellular binding or trapping of urate. Although an increase in the initial rate of urate transport into the cells across the peritubular membrane could not be demonstrated conclusively in nonperfused tubules, the results still suggest that SITS in the bathing medium may inhibitJ _urate ^net by inhibiting urate movement from the cells to the lumen while actually enhancing transport from the bathing medium into the cells.     

Ribosomal DNA internal transcribed spacer sequences do not support the species status of Ampelomyces quisqualis, a hyperparasite of powdery mildew fungi

Phylogenetic relationships among Ampelomyces isolates, pycnidial hyperparasites and biological control agents of powdery mildews, were inferred from internal transcribed spacer (ITS) sequences of the ribosomal DNA (rDNA). Currently, these hyperparasites are considered to be a single species, A. quisqualis, despite observed morphological and cultural differences. Ten Ampelomyces isolates, representing seven previously defined ITS RFLP groups, were sequenced and analyzed. Sequence-divergence values among isolates belonging to different RFLP groups ranged from 4.3 to 22.4%, suggesting that these isolates may represent different taxa. When Ampelomyces ITS sequences were analyzed by cladistic methods with the sequences of other ascomycetous fungi, they formed two lineages in the Dothideales. Slow-growing Ampelomyces isolates formed a clade with Leptosphaeria microscopica and L. nodorum, whereas fast-growing Ampelomyces isolates formed a clade with Epicoccum nigrum. Sequence-divergence values between these two clades ranged from 17.3 to 22.4%, suggesting that the taxa in the two clades are not closely related and possibly not congeneric. The data presented here indicate that the identification of `A. quisqualis' isolates used in biological control experiments should be re-evaluated. Received: 10 March 1997 / Accepted: 13 February 1998     

Genetic relatedness and antimicrobial resistance determinants among clinical isolates of enterococci from Cuba

This study describes the genetic relationships and antimicrobial resistance determinants found among 99 clinical isolates of enterococci from 15 different hospitals in Cuba. Pulsed-field gel electrophoresis SmaI analysis demonstrated a high degree of genetic diversity. A limited number of multiresistant Enterococcus faecalis clones, showing resistance to three or more families of antimicrobial agents, were detected simultaneously in different institutions, suggesting inter-hospital circulation of selected clones, and/or selection of particular clones following their introduction into the hospital environment. Antimicrobial resistance determinants, including erm(B), aac(6')-aph(2'), aph(3'), ant(6), vanB (E. faecalis) and vanA (Enterococcus faecium) were detected by PCR in various isolates.     

Nosocomial vs. community-acquired infective endocarditis in Greece: changing epidemiological profile and mortality risk

Current epidemiological trends of infective endocarditis (IE) in Greece were investigated via a prospective cohort study of all cases of IE that fulfilled the Duke criteria during 2000-2004 in 14 tertiary and six general hospitals in the metropolitan area of Athens. Demographics, clinical data and outcome were compared for nosocomial IE (NIE) and community-acquired IE (CIE). NIE accounted for 42 (21.5%) and CIE for 153 (78.5%) of 195 cases. Intravenous drug use was associated exclusively with CIE, while co-morbidities (cardiovascular disease, diabetes mellitus, chronic renal failure requiring haemodialysis and malignancies) were more frequent in the NIE group (p <0.05). Prosthetic valve endocarditis (PVE) predominated in the NIE group (p 0.006), and >50% of NIE cases had a history of vascular intervention. Coagulase-negative staphylococci and enterococci were more frequent in cases of NIE than in cases of CIE (26.2% vs. 5.2%, p <0.01, and 30.9% vs. 16.3%, p 0.05, respectively). Enterococci accounted for 19.5% of total IE cases and were the leading cause of NIE. Staphylococcus aureus IE was hospital-acquired in only 11.9% of cases. In-hospital mortality was higher for NIE than for CIE (39.5% vs. 18.6%, p 0.02). Cardiac failure (New York Heart Association grade III-IV; OR 13.3, 95% CI 4.9-36.1, p <0.001) and prosthetic valve endocarditis (OR 3.7, 95% CI 1.3-10.6, p 0.01) were the most important predictors of mortality.     

The significance of blood cultures positive for emerging saprophytic moulds in cancer patients

The significance of blood cultures positive for emerging saprophytic moulds (e.g., Scedosporium apiospermum, Scedosporium prolificans, Paecilomyces spp.) was evaluated in 30 cancer patients (1996-2002). Diagnostic criteria proposed previously for evaluation of aspergillaemia were used. Blood cultures positive for emerging saprophytic moulds represented 1% of all positive fungal cultures. One case of catheter-related fungaemia was excluded. The remaining 29 cases consisted of true (n = 5), probable (n = 1), indeterminate (n = 7) fungaemia, and contamination (n = 16). True fungaemia was seen only in leukaemia patients and allogeneic bone marrow transplant recipients. S. apiospermum and S. prolificans were the commonest causes of true fungaemia.     

中药山豆根的形态组织学研究

对目前国内作山豆根用的9种不同植物来源的生药进行了形态组织学的比较研究,观察并描述了它们的生药性状和组织构造,并列出了生药的分种检索表。     

丹参根腐病及其微生物防治研究

丹参根腐病是由腐皮镰刀菌浸染所致的一种土传病害，近年来在四川的田间发病株率达10%-30%，导致丹参产量下降，品质变劣。对丹参根腐病的防治，一般化学农药难于有效，而且滥用化学农药合造成农药残留污染。利用有益微生物控制病原菌是一种可行的措施，本研究从生长在不同生态环境的丹参根际土样中分离了一批木霉菌株，通过室内拮抗试验和田问防病增产试验，筛选出了对腐皮镰刀菌有较强拮抗作用的哈茨木霉T23、桔绿木霉T56等菌株。田间试验结果，T23、T56对丹参根腐病的防效分别为52．3％和55．7％，与常用化学杀菌剂多菌灵的防效相当，表明木霉防治丹参根病病具有较好的应用前景。