Activity of the renin-angiotensin-aldosterone system in euglycemic type I diabetic patients on intensive insulin treatment without diabetic neuropathy

The yeast Candida albicans coaggregates with a variety of streptococcal species, an interaction that may promote oral colonization by yeast cells. C. albicans and Candida tropicalis are the yeasts most frequently isolated from the human oral cavity and our data demonstrate that both these species bind to Streptococcus gordonii NCTC 7869 while two other Candida species (Candida krusei and Candida kefyr) do not. Adherence of C. albicans was greatest when the yeast had been grown at 30 degrees C to mid-exponential growth phase. For 21 strains of C. albicans there was a positive correlation between the ability to adhere to S. gordonii and adherence to experimental salivary pellicle. Whole saliva either stimulated or slightly inhibited adherence of C. albicans to S. gordonii depending on the streptococcal growth conditions. The results suggest that the major salivary adhesins and coaggregation adhesins of C. albicans are co-expressed.     

Utility of Fluoroplate Candida for the rapid identification of Candida albicans

BACKGROUND: Candida albicans infections are frequent in immunocompromised patients and a prompt diagnosis could favor an early and proper antifungal treatment. The rapid identification of clinical yeast isolates facilitate this diagnosis. METHODS: The utility of Fluoroplate Candida ready-to-use plates for Candida albicans rapid identification was evaluated with 653 clinical isolates from 23 yeast species, including 307 C. albicans plated onto Fluoroplate Candida agar (Merck, Germany). Rapid identification of C. albicans was based on the hydrolysis of 4-methylumbelliferyl-N-acetyl-beta-D-galactosaminide by the galactosaminidase activity of C. albicans producing white fluorescent colonies under ultraviolet light. Identification on Fluoroplate Candida was confirmed by germ tube, chlamydoconidia formation and API-ATB ID 32C assays. RESULTS: Three hundred and five of 306 isolates showing fluorescent colonies were C. albicans and one was Candida glabrata (false positive). The rest of the isolates showed colonies without fluorescence and with the exception of two false negatives, these isolates were identified as non-C. albicans by other methods. CONCLUSIONS: Fluoroplate Candida allows a rapid and excellent identification of C. albicans showing a sensitivity and specificity of 99.3 and 99.7%, respectively.     

Antitumor effect of electrochemotherapy on colorectal carcinoma in an orthotopic mouse model

Although Candida albicans remains the fungal species most frequently isolated as an opportunistic oral pathogen, other yeast species are often identified in human immunodeficiency virus (HIV)-seropositive patients. Candida dubliniensis phenotypically resembles C. albicans in many respects, yet it can be identified and differentiated as a unique Candida species by its phenotypic and genetic profiles. The purpose of the present study was to prospectively test for the presence of C. dubliniensis among clinical isolates and to determine the clinical and demographic characteristics of patients harboring C. dubliniensis. Over a 90-day period, isolates from 724 patients that were presumptively identified as C. albicans were screened for C. dubliniensis by use of tests for germ tube and chlamydospore production, by detection of an inability to grow at 45 degrees C, by colony color on CHROMagar Candida medium, and by the results of a sugar assimilation test with the API 20C AUX yeast identification system. Among 699 isolates retrieved from those specimens evaluated, 5 from 25 HIV-seropositive patients and 1 isolate from a patient whose HIV status was unknown were shown to be consistent by phenotyping and by electrophoretic karyotyping with the European reference strain of C. dubliniensis. One of the C. dubliniensis isolates had dose-dependent susceptibility to fluconazole (MIC, 16 microg/ml). These results confirm the presence of this interesting species in the United States and support the need for further investigations into the prevalence and pathogenesis of C. dubliniensis.     

Increased prevalence of oral Candida albicans serotype B in homosexual men: a comparative and longitudinal study in HIV-infected and HIV-negative patients

Several investigators have shown a comparatively high prevalence of Candida albicans serotype B among HIV-infected individuals. We serotyped oral C. albicans strains from 50 HIV-infected homosexual men, 39 HIV-seronegative homosexual men and 40 clinical oral isolates of a control group. The prevalence of serotype B was significantly higher in homosexual men, regardless of HIV serostatus, than in the control subjects. We suggest that the reported high prevalence of serotype B among AIDS patients in Europe and the USA simply reflects the high proportion of homosexual men among HIV-infected patients. In 22 subjects, oral C. albicans isolates were obtained at two or more time points, up to 8 years apart. No change in serotype was observed over time. The serotype prevalences in HIV-infected patients with oral thrush or AIDS-defining illness were similar to the group of homosexual men as a whole, indicating that there is no serotype-related variation in pathogenicity.     

Detection of Candida dubliniensis in oropharyngeal samples from human immunodeficiency virus-infected patients in North America by primary CHROMagar candida screening and susceptibility testing of isolates

Candida dubliniensis has been associated with oropharyngeal candidiasis in patients infected with human immunodeficiency virus (HIV). C. dubliniensis isolates may have been improperly characterized as atypical Candida albicans due to the phenotypic similarity between the two species. Prospective screening of oral rinses from 63 HIV-infected patients detected atypical dark green isolates on CHROMagar Candida compared to typical C. albicans isolates, which are light green. Forty-eight atypical isolates and three control strains were characterized by germ tube formation, differential growth at 37, 42, and 45 degreesC, identification by API 20C, fluorescence, chlamydoconidium production, and fingerprinting by Ca3 probe DNA hybridization patterns. All isolates were germ tube positive. Very poor or no growth occurred at 42 degreesC with 22 of 51 isolates. All 22 poorly growing isolates at 42 degreesC and one isolate with growth at 42 degreesC showed weak hybridization of the Ca3 probe with genomic DNA, consistent with C. dubliniensis identification. No C. dubliniensis isolate but only 18 of 28 C. albicans isolates grew at 45 degreesC. Other phenotypic or morphologic tests were less reliable in differentiating C. dubliniensis from C. albicans. Antifungal susceptibility testing showed fluconazole MICs ranging from 相似文献   

In vitro susceptibility of clinical yeast isolates to fluconazole and terconazole

OBJECTIVE: Fifty clinical yeast isolates, representing equally Candida albicans, Candida krusei, Candida parapsilosis, Candida tropicalis, and Torulopsis glabrata, were tested in vitro for their susceptibility to terconazole and fluconazole. STUDY DESIGN: The minimal inhibitory concentrations of terconazole and fluconazole were determined by use of a proposed standardized broth macrodilution assay. Also, the response of selected yeast isolates to 25 micrograms of either drug was measured by agarose disk diffusion experiments. RESULTS: For all species the minimum inhibitory concentrations for terconazole were significantly lower than those for fluconazole (p < 0.05). In fact, for each individual isolate the minimum inhibitory concentration of terconazole was consistently lower than that of fluconazole. Differences in the geometric mean of terconazole and fluconazole minimum inhibitory concentrations were largest among C. krusei and T. glabrata, followed by C. parapsilosis, C. tropicalis, and C. albicans, in order of decreasing difference. Disk diffusion experiments suggested that terconazole is a more effective fungistatic agent than fluconazole is. CONCLUSION: Terconazole may be more effective than fluconazole against yeast species other than C. albicans.     

Prevalence of Candida dubliniensis isolates in a yeast stock collection

To establish the historical prevalence of the novel yeast species Candida dubliniensis, a survey of 2,589 yeasts originally identified as Candida albicans and maintained in a stock collection dating back to the early 1970s was undertaken. A total of 590 yeasts, including 93 (18.5%) beta-glucosidase-negative isolates among 502 isolates that showed abnormal colony colors on a differential chromogenic agar and 497 other isolates, were subjected to DNA fingerprinting with the moderately repetitive sequence Ca3. On this basis, 53 yeasts were reidentified as C. dubliniensis (including the C. dubliniensis type strain, included as a blind control in the panel of yeasts). The 52 newly found isolates came from 36 different persons, and a further 3 C. dubliniensis isolates were detected by DNA fingerprinting of previously untested isolates from one of these individuals. The prevalence of C. dubliniensis among yeasts in oral and fecal samples was significantly higher than that among yeasts from other anatomical sites and was significantly higher among human immunodeficiency virus (HIV)-infected individuals than among known or presumed HIV-negative individuals. However, a single vaginal isolate and two oral isolates from healthy volunteers confirmed that the species is restricted neither to gastrointestinal sites nor to patients with overt disease. The oldest examples of C. dubliniensis were from oral samples of three patients in the United Kingdom in 1973 and 1975. In comparison with age-matched control isolates of C. albicans, the C. dubliniensis isolates showed slightly higher levels of susceptibility in vitro to amphotericin B and flucytosine and slightly lower levels of susceptibility to three azole antifungal agents.     

Oral contraceptive use and vaginal candida colonization

Fungal vaginal infections/colonisations can be divided into a symptomatic vaginal candidiasis and an asymptomatic vaginal Candida-carriage. The latter seems to be a predisposing factor for the development of a symptomatic vaginal candidiasis. The fungal organism isolated most frequently is Candida albicans, followed by Candida glabrata, which was previously also known as Torulopsis glabrata. To a lower extend, other Candida species such as Candida tropicalis and Candida krusei can be prevalent in the vulvovaginal region. Predisposing factors for vaginal candidiasis are gravidity, diabetes mellitus or a therapy with immunosuppressive agents. Also gestagenes showed to be a pre-disposing factor for vaginal candidiasis. Divergent results concerning the predisposition to vaginal candidiasis or colonisation due to oral contraception have so far been reported. Therefore we performed a study with two healthy collectives of female volunteers (n = 2 x 60) which were different concerning the taking of oral contraceptives. Overall, in 17% of the subjects (20/120) yeast could be cultured out of the vaginal secretions. There was no evidence for a higher rate of Candida-colonisation in subjects taking oral contraceptives. Further, there was no evidence for a relationship between the length of the taking of oral contraceptives and the rate of vaginal yeast-carriage. Also the type of oral contraceptive (combination or sequential contraceptive) had no influence on the frequency of Candida-carriage. Candida albicans was the most prevalent yeast (16/20), followed by Candida glabrata (4/20).     

The antifungal effect of lactoferrin and lysozyme on Candida krusei and Candida albicans

Lactoferrin and lysozyme (muramidase) are non-immune defence factors present in various exocrine secretions, including saliva. Previous studies have shown that both proteins, either singly or in combination, are bactericidal in nature and their combined activity is synergistic. As little is known of their interactions with Candida species, 20 oral isolates of C. krusei and 5 isolates of C. albicans were studied for their susceptibility to human apo-lactoferrin and lysozyme, either singly or in combination, using an in vitro assay system. The two species exhibited significant interspecies differences in susceptibility to lactoferrin (p < 0.05), but not for lysozyme; C. krusei being more sensitive to lactoferrin (c 1.4 times) than C. albicans. Both species revealed significant intraspecies differences in their susceptibility to lysozyme (p < 0.05), but not for lactoferrin. No synergistic antifungal activity of the two proteins on either Candida species was noted. The results imply that the variable expression of the fungicidal activity of lactoferrin and lysozyme on Candida species may modulate the oral carriage of yeasts in a complex manner.     

Molecular and phenotypic characterization of genotypic Candida albicans subgroups and comparison with Candida dubliniensis and Candida stellatoidea

There have been increased reports of the isolation of unusual genotypic groups of Candida albicans (groups C and D) based on a well-defined genotypic method; this method uses cellular DNA digested with the EcoRI enzyme and the restriction fragment length polymorphisms (RFLPs) generated by agarose gel electrophoresis. The aim of the present study was to use additional molecular tools to characterize these unusual strains and to compare them with authentic strains of C. dubliniensis, a recently delineated species, and type I C. stellatoidea. The RFLPs of PCR products generated from the intergenic transcribed spacer (ITS) region did not differentiate among C. albicans genotypes A, B, and C and type I C. stellatoidea. However, this method did differentiate the C. albicans genotype D strains, which were identical to C. dubliniensis. The RFLPs generated by HaeIII digestion of the PCR products of the V3 region of the 25S rRNA gene (rDNA) could differentiate the same groups as RFLP analysis of the PCR amplicon of the ITS region. C. albicans genotype B isolates have been shown to have a transposable intron in the 25S rDNA, whereas genotype A isolates do not; C. dubliniensis strains also have an intron that is larger than that in genotype B C. albicans strains but that is in the same location. PCR designed to span this region resulted in a single product for C. albicans genotype A (450 bp), B (840 bp), type 1 C. stellatoidea (840 bp), and C. dubliniensis (1,080 bp), whereas the C. albicans genotype C isolates had two major products (450 and 840 bp). All C. albicans genotype D isolates gave a PCR product identical to that given by C. dubliniensis. These results indicate that those strains previously designated C. albicans genotype D are in fact C. dubliniensis, that no differences were found between type 1 C. stellatoidea and C. albicans genotype B strains, and that the C. albicans genotype C strains appear to have the transposable intron incompletely inserted throughout the ribosomal repeats in their genomes. The results of the antifungal susceptibility testing of 105 of these strains showed that, for fluconazole, strains of C. dubliniensis were significantly more susceptible than strains of each of the C. albicans genotypes (genotypes A, B, and C). The flucytosine susceptibility results indicated that strains of C. albicans genotype A were significantly less susceptible than either C. albicans genotype B or C. albicans genotype C strains. These results indicate that there is a correlation between the Candida groups and antifungal susceptibility.     

Comparison of the rapid yeast plus panel with the API20C yeast system for identification of clinically significant isolates of Candida species

The RapID Yeast Plus system (Innovative Diagnostic Systems, Norcross, Ga.) is a qualitative micromethod employing conventional tests and single-substrate chromogenic tests and having a 4-h incubation period. This system was compared with the API20C (bioMerieux Vitek, Hazelwood, Mo.) system, a 24- to 72-h carbohydrate assimilation method. One hundred thirty-three clinical yeast isolates, including 57 of Candida albicans, 26 of Candida tropicalis, 23 of Candida glabrata, and 27 of other yeasts, were tested by both methods. When discrepancies occurred, isolates were further tested by the Automated Yeast Biochemical Card (bioMerieux Vitek). Germ tube production and microscopic morphology were used as needed to definitively identify yeast isolates. The RapID Yeast Plus system correctly identified 125 yeast isolates, with an overall accuracy of 94% (125 of 133). Excellent correlation was found in the recognition of the three yeasts most commonly isolated from human sources. The test was 99% (105 of 106 isolates) accurate with C. albicans, C. tropicalis, and C. glabrata. The RapID Yeast Plus system compares favorably with the API20C system and provides a simple, accurate alternative to conventional assimilation methods for the rapid identification of the most commonly encountered isolates of Candida species.     

International surveillance of bloodstream infections due to Candida species: frequency of occurrence and antifungal susceptibilities of isolates collected in 1997 in the United States, Canada, and South America for the SENTRY Program. The SENTRY Participant Group

An international program of surveillance of bloodstream infections (BSIs) in the United States, Canada, and South America between January and December 1997 detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in South America). Eighty percent of the BSIs were nosocomial and 50% occurred in patients hospitalized in an intensive care unit. Overall, 53.3% of the BSIs were due to Candida albicans, 15.7% were due to C. parapsilosis, 15.0% were due to C. glabrata, 7.8% were due to C. tropicalis, 2.0% were due to C. krusei, 0.7% were due to C. guilliermondii, and 5.8% were due to Candida spp. However, the distribution of species varied markedly by country. In the United States, 43.8% of BSIs were due to non-C. albicans species. C. glabrata was the most common non-C. albicans species in the United States. The proportion of non-C. albicans BSIs was slightly higher in Canada (47.5%), where C. parapsilosis, not C. glabrata, was the most common non-C. albicans species. C. albicans accounted for 40.5% of all BSIs in South America, followed by C. parapsilosis (38.1%) and C. tropicalis (11.9%). Only one BSI due to C. glabrata was observed in South American hospitals. Among the different species of Candida, resistance to fluconazole (MIC, > or = 64 microg/ml) and itraconazole (MIC, > or = 1.0 microg/ml) was observed with C. glabrata and C. krusei and was observed more rarely among other species. Isolates of C. albicans, C. parapsilosis, C. tropicalis, and C. guilliermondii were all highly susceptible to both fluconazole (99.4 to 100% susceptibility) and itraconazole (95.8 to 100% susceptibility). In contrast, 8.7% of C. glabrata isolates (MIC at which 90% of isolates are inhibited [MIC90], 32 microg/ml) and 100% of C. krusei isolates were resistant to fluconazole, and 36.9% of C. glabrata isolates (MIC90, 2.0 microg/ml) and 66.6% of C. krusei isolates were resistant to itraconazole. Within each species there were no geographic differences in susceptibility to fluconazole or itraconazole.     

In vitro antifungal activity of CAN-296: a naturally occurring complex carbohydrate

The in vitro activity of a naturally occurring complex carbohydrate, CAN-296, was evaluated by testing 132 clinical and ATCC isolates of yeast and Aspergillus fumigatus, many of which were azole-resistant. The in vitro susceptibility tests were performed by standardized broth micro- and macrodilution methods and results were compared with those obtained for amphotericin B, fluconazole, ketoconazole, flucytosine and the pneumocandin L-733,560. All tested Candida species showed highly uniform susceptibility to CAN-296 at concentrations of 0.078 to 0.312 microgram/ml; non-albicans Candida were as susceptible to CAN-296 as the Candida albicans strains. Multi-azole-resistant Candida species were highly sensitive to CAN-296. Minimum inhibitory concentration measurements did not differ from minimum lethal concentrations by more than two-fold for all tested Candida species. Aspergillus fumigatus, on the other hand, showed only moderate susceptibility to CAN-296. The kinetics of the anti-Candida activity of CAN-296 was investigated by kill-curve experiments using C. albicans and C. glabrata and the results were compared with those obtain for amphotericin B. CAN-296 was found to be rapidly fungicidal in concentrations ranging from 4-16 fold the mean MIC value. The broad spectrum of anti-Candida activity together with the rapid fungicidal effect make this complex carbohydrate a promising agent for clinical use.     

Role of the multifunctional Trio protein in the control of the Rac1 and RhoA gtpase signaling pathways

Two rapid spectroscopic approaches for whole-organism fingerprinting of pyrolysis-mass spectrometry (PyMS) and Fourier transform-infrared spectroscopy (FT-IR) were used to analyze a group of 29 clinical and reference Candida isolates. These strains had been identified by conventional means as belonging to one of the three species Candida albicans, C. dubliniensis (previously reported as atypical C. albicans), and C. stellatoidea (which is also closely related to C. albicans). To observe the relationships of the 29 isolates as judged by PyMS and FT-IR, the spectral data were clustered by discriminant analysis. On visual inspection of the cluster analyses from both methods, three distinct clusters, which were discrete for each of the Candida species, could be seen. Moreover, these phenetic classifications were found to be very similar to those obtained by genotypic studies which examined the HinfI restriction enzyme digestion patterns of genomic DNA and by use of the 27A C. albicans-specific probe. Both spectroscopic techniques are rapid (typically, 2 min for PyMS and 10 s for FT-IR) and were shown to be capable of successfully discriminating between closely related isolates of C. albicans, C. dubliniensis, and C. stellatoidea. We believe that these whole-organism fingerprinting methods could provide opportunities for automation in clinical microbial laboratories, improving turnaround times and the use of resources.     

Constant low rate of fungemia in norway, 1991 to 1996. The Norwegian Yeast Study Group

Since 1991 information on yeast isolates from blood cultures has been recorded prospectively from all microbiological laboratories (5 university and 16 county or local hospital laboratories) in Norway (population, 4.3 million). From 1991 to 1996 a total of 571 episodes of fungemia in 552 patients occurred (1991, 109 episodes; 1992, 81 episodes; 1993, 93 episodes; 1994, 89 episodes; 1995, 98 episodes; and 1996, 101 episodes). The fungemia rates per 10,000 patient days were 0.29 in 1991 and 0.27 in 1996. The average rates for the years 1991 to 1996 were 0.37 for the university laboratories and 0.20 for the other laboratories. These rates are low compared to the rate (0. 76) in five Dutch university hospitals in 1995 and the rate (2.0) in Iowa in 1991. The four most frequently isolated species were Candida albicans (66%), Candida glabrata (12.5%), Candida parapsilosis (7.6%), and Candida tropicalis (6.4%). The incidences of both C. albicans (range, 63 to 73%) and C. glabrata (range, 8.4 to 15.7%) varied somewhat throughout this period, but no significant increase or decrease was noted. MICs of amphotericin B, flucytosine, and fluconazole were determined for 89% of the isolates. All were susceptible to amphotericin B, and only 29 (5.6%) strains had decreased susceptibility to flucytosine. All C. albicans isolates were susceptible to fluconazole. The percentage of yeast isolates with decreased susceptibility to fluconazole (MICs, >/=16 microgram/ml) did increase, from 9.6% in 1991 and 1992 to 12.2% in 1994, 16.1% in 1995, and 18.6% in 1996. This was largely due to increases in the percentages of resistant C. glabrata and Candida krusei strains in the last 2 years. Compared to the incidence in other countries, it is remarkable that Norway has such a low and constant incidence of fungemia. A possible reason for this difference might be a restricted antibiotic use policy in Norway.     

Chronic urinary tract infection due to Candida utilis

An elderly male was seen at an outpatient urology clinic over a period of 3 years with repeat urine specimens containing 10(4) to 10(5) CFU of a "Candida species, not C. albicans." The urine specimens were described as infected due to the presence of pyuria, but no antifungal therapy was administered. On two occasions, the patient presented to the emergency room and urine specimens were sent to the clinical microbiology laboratory. On both occasions, a yeast was isolated at concentrations of >10(5) CFU/ml. The organism was identified as the anamorphic yeast Candida utilis (teleomorph: Pichia jadinii) by conventional methods. Molecular methods, including karyotyping and restriction enzyme analysis, confirmed that the isolates were identical and were C. utilis. The patient developed benign prostatic hypertrophy and chronic obstructive pulmonary disease during the 3-year course. This report is the first demonstration of the isolation of the industrially important yeast C. utilis from a urinary tract infection. In the present case, the organism was associated with chronic, symptomatic disease. The significance of this unusual, low-virulence isolate from a case of urinary tract infection is discussed.     

Mucocutaneous fungal colonization in HIV-infected children

The prevalence of symptomatic mucocutaneous candidiasis in HIV-infected children is well documented. Information, however, of the carriage rate of potential fungal pathogens is lacking. In this study we determined the fungal colonization rate of multiple mucocutaneous sites from 13 HIV-infected and 12 control children. The rate of yeast and mould colonization and the species of fungal isolates were essentially the same for both groups of patients. However, several HIV-infected children asymptomatic for thrush proved to be colonized by Candida albicans, and disseminated colonization with Trichosporon beigelii occurred in one HIV-infected child. All cultures for dermatophytes were negative. While the carriage rate with fungi other than C. albicans was not increased in the HIV-infected group, the isolates recovered are known pathogens in the immunocompromised host and the colonization of these organisms may be a potential source of infection.     

Stable phenotypic resistance of Candida species to amphotericin B conferred by preexposure to subinhibitory levels of azoles

The fungicidal activity of amphotericin B (AmB) was quantitated for several Candida species. Candida albicans and C. tropicalis were consistently susceptible to AmB, with less than 1% survivors after 6 h of exposure to AmB. C. parapsilosis and variants of C. lusitaniae and C. guilliermondii were the most resistant, demonstrating 50 to 90% survivors in this time period and as high as 1% survival after a 24-h exposure time. All Candida species were killed (<1% survivors) after 24 h of exposure to AmB. In contrast, overnight exposure to either fluconazole or itraconazole resulted in pronounced increases in resistance to subsequent exposures to AmB. Most dramatically, C. albicans was able to grow in AmB cultures after azole preexposure. Several other Candida species did not grow in AmB but showed little or no reduction in viability after up to 24 h in AmB. Depending on the growth conditions, Candida cells preexposed to azoles may retain AmB resistance for days after the azoles have been removed. If this in vitro antagonism applies to the clinical setting, treatment of patients with certain antifungal combinations may not be beneficial. The ability of some Candida isolates to survive transient exposures to AmB was not reflected in the in vitro susceptibility changes as measured by standard MIC assays. This finding should be considered in studies attempting to correlate patient outcome with in vitro susceptibilities of clinical fungal isolates. Patients who fail to respond to AmB may be infected with isolates that are classified as susceptible by standard in vitro assays but that may be resistant to transient antifungal exposures which may be more relevant in the clinical setting.     

Use of CHROMagar Candida for genital specimens in the diagnostic laboratory

OBJECTIVE: To evaluate CHROMagar Candida (CA), a new yeast differential medium, for yeast isolation in a clinical laboratory for the routine examination of high vaginal swabs. METHODS: Results of high vaginal swab cultures processed in a standard manner on plates containing equal halves of Sabouraud dextrose agar (SDA) and CA were compared. Non-Candida albicans yeast isolates were further speciated with API 20C AUX or API 32C. To assess the ease of use of CA, laboratory staff lacking in experience of the medium were asked to identify 23 unlabelled yeast cultures on CA by referring to six labelled reference plates. RESULTS: Of the 1784 swab cultures processed, yeasts were isolated from 373 SDA and 368 CA. Of the 78 non-albicans isolates further speciated, CA identified correctly all cultures of C krusei and C tropicalis, and 82% of C glabrata. All the 38 inexperienced laboratory staff achieved 100% accuracy for C albicans and over 90% for C krusei and C tropicalis. CONCLUSIONS: CA is a satisfactory isolation medium for genital specimens, allowing immediate and correct identification of the commonly encountered yeasts and easy recognition of mixed cultures.     

A novel technique for assessment of adherence of Candida albicans to solid surfaces

A novel approach for the assessment of adherence of Candida albicans to translucent acrylic material is described. The method uses the inverted microscope to visualise yeast adhering to acrylic surfaces while the test material remains immersed in buffer. Adherent cells were not subjected to surface tension forces that can occur during drying processes, so that an even distribution of yeast with no aggregation occurred. The process of counting attached yeast was subsequently performed without difficulty. From the 11 C albicans isolates examined, two groups were evident with respect to acrylic adherence: one group of four isolates with an adherence level of 400 yeast/mm2 acrylic, and one group of seven isolates with adherence levels of 1000 yeast/mm2 acrylic.