Standardized molecular typing of Candida albicans strains

Summary. A method is presented for the standardization of Candida albicans DNA fingerprinting, which is based on Southern hybridization of Eco RI-digested chromosomal DNA with the moderately repetitive DNA element CARE-2 and the subsequent rehybridization of the blots with a molecular size marker also included in each DNA sample. This method resulted in extremely precise alignment of all strain-specific CARE-2 hybridization patterns, even when analysed on different gels, and will enhance the accuracy of genetic relationship determinations in epidemiological studies including large numbers of strains.
Zusammenfassung. Zur Standardisierung des DNA-Fingerprinting von Candida albicans wurde eine Methode entwickelt, die auf der Southern Hybridisierung Eco RI-gespaltener chromosomaler DNA mit dem mittelrepetitiven DNA-Element CARE-2 und der darauffolgenden Rehybridisierung der Blots mit einem auch in den Proben enthaltenen molekularen Größenmarker beruht. Dies resultierte in einer äußerst präzisen Größen-bestimmung der hybridisierenden Fragmente, so daß alle stammspezifischen CARE-2-Hybridisierungsmuster exakt verglichen werden konnten, auch wenn die Isolate auf verschiedenen Gelen analysiert wurden. Die Methode erhöht die Genauigkeit der Bestimmung genetischer Verwandtschaftsbeziehungen in epidemiologischen Untersuchungen, in denen eine große Anzahl von Stämmen analysiert wird.     

Synovial fluid levels of fluconazole in a patient with Candida parapsilosis prosthetic joint infection who had an excellent clinical response

A 73-year-old woman presenting with persistent swelling of the right knee 30 months after total joint arthroplasty was found to have a Candida parapsilosis infection. Treatment with fluconazole resulted in full recovery.     

抗白色念珠菌鸡卵黄抗体(IgY)的研制

目的：观察鸡蛋黄中抗体的产量、纯度、来源及稳定性。方法：应用白色念珠菌作为抗原免疫25周龄Leghorn鸡，通过改良水溶法（WD）提取蛋黄中抗体IgY，双紫外光测定抗体含量，SDS-APGE电泳检测抗体纯度，Western blot免疫印迹法测定该抗体来源，ELISA检测热处理后的抗体活性。结果：抗体含量13mg/ml蛋黄液，抗体纯度达到95%，Western blot免疫印迹证明该抗体与鸡血清中的IgG具有相同的分子量和抗原性。ELISA检测热处理后的抗体活性，其具有良好的热稳定性。结论：鸡蛋黄内含有丰富的抗体，通过WD水溶提取法可得到高产量，高纯度的特异性抗体IgY，证明其来源于鸡血清中的IgG，对热具有高度稳定性。     

白色念珠菌感染的分子生物学诊断研究进展

综述了白色念珠菌感染的分子生物学诊断研究进展，包括核型分析，限制性片段长度多态性分析，特异的ＤＮＡ探针及ＰＣＲ等方法。     

Virulence of Candida albicans mutants

Mutant strains of the fungal pathogen Candida albicans blocked in pyrimidine transport and salvage metabolism were tested for virulence in various animal models. The growth rate, germination and proteolytic enzyme production did not correlate with the virulence of the strains. However, a defect in the uridine transport system significantly decreased virulence in murine candidosis, although it had no effect in vaginal candidosis or in a Candida cyst model. It remains unclear whether this is due to the differing host defence mechanisms involved in systemic and superficial mycoses, or to the different requirements of the fungal systems for adherence and tissue invasion in the two types of infection.     

Contrasting mutation rates in mitochondrial and nuclear genes of yeasts versus mammals

Summary Base substitutions have been compared in two mitochondrial and two nuclear genes from three yeasts and three mammals. In yeasts, the two mitochondrial genes, cytochrome oxidase subunit 2 (COX2) and apocytochrome b (CYB), have fewer changes on a percentage basis than the nuclear-encoded cytochrome c (CYC) gene. By contrast, in mammals, the same mitochondrial genes have more mutations than CYC on a percentage basis. Sequence comparisons of the nuclear small-subunit ribosomal RNA (nSSU) gene shows that there are more substitutions per unit length in the three yeasts than in the three mammals. This result suggests that although the yeasts are more distantly related than the mammals, their mitochondrial genes have accumulated fewer changes.     

Potential risk factors for infection with Candida spp. in critically ill patients

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.     

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.     

Candida albicans osteomyelitis of the spine: progressive clinical and radiological features and surgical management in three cases

Candida albicans vertebral osteomyelitis is rare. Three cases are presented. Without antifungal treatment, they developed spinal collapse and neurological deterioration within 3–6 months from the onset of symptoms. There was a delay of 4.5 and 7.5 months between the onset of symptoms and surgery. All patients were managed with surgical debridement and reconstruction and 12-week fluconazole treatment. The neurological deficits resolved completely. The infection has not recurred clinically or radiologically at 5–6 years follow-up. Although rare, Candida should be suspected as a causative pathogen in cases of spinal osteomyelitis. Without treatment the disease is progressive. As soon as osteomyelitis is suspected, investigations with MRI and percutaneous biopsy should be performed followed by medical therapy. This may prevent the need for surgery. However, if vertebral collapse and spinal cord compression occurs, surgical debridement, fusion and stabilisation combined with antifungal medications can successfully eradicate the infection and resolve the neurological deficits.     

Prosthetic valve endocarditis due to candida albicans treated successfully with medical treatment alone

Prosthetic valve endocarditis (PVE) caused by Candida species is associated with high morbidity and mortality. A combination of surgical resection and antifungal drug therapy is the golden standard for treatment, yet surgical intervention is not possible in all cases of Candida PVE. We report a case of PVE due to Candida albicans cured by medical treatment alone. This case suggests that, in some instances, Candida PVE can be managed medically with antifungal therapy. Such a conservative approach should be applied with caution and necessitates very close follow-up on a long-term basis.