Candidemia in immunocompromised patients

Antifungal susceptibility of Aspergillus species isolated from invasive oral infection in neutropenic patients with hematologic malignancies

OBJECTIVE

The aim of this study was to evaluate the relevance of in vitro antifungal susceptibility to clinical response in neutropenic patients with invasive oral aspergillosis.

STUDY DESIGN

Nine isolates of Aspergillus species were obtained from invasive oral infections in 9 patients with hematologic malignancies and tested for their in vitro susceptibility to amphotericin B, fluconazole, miconazole, 5-fluorocytosine, and itraconazole. Minimal inhibitory concentration values of the 5 drugs were obtained for each fungus through use of a microdilution broth method. The patients were treated with intravenous amphotericin B (30-50 mg/day) in combination with oral 5-fluorocytosine (3000-6000 mg/day) and/or oral itraconazole (200 mg/day).

RESULTS

Amphotericin B and itraconazole were found to be very active, with minimal inhibitory concentration values of 0.861 and 0.194 microg/mL, respectively. Miconazole and 5-fluorocytosine showed minimal inhibitory concentration values of 1.72 and 3.56 microg/mL, respectively. On the other hand, fluconazole FCZ showed low activity, with a minimal inhibitory concentration value in excess of 64.0 microg/mL. During neutropenia, combined antifungal chemotherapy stabilized oral aspergillosis and prevented the spread of oral lesions in 8 patients in whom neutrophil counts eventually recovered.

CONCLUSIONS

The results imply that in vitro susceptibility testing may serve as an informative parameter with respect to the efficacy of these antifungals in the treatment of invasive oral aspergillosis, inducing fungal stasis until the neutrophils recover.

Nosocomial bloodstream infections in HIV-infected patients: attributable mortality and extension of hospital stay

A 3-year prospective matched case-control study was performed to investigate the potential risk factors, prognostic indicators, extension of hospital stay, and attributable mortality of nosocomial bloodstream infections in HIV-infected patients. Matching variables were: age, gender, number of circulating CD4+ T lymphocytes, cause of hospital admission, hospitalization in the same ward within the 6 weeks of diagnosis of the case, and length of stay before the day of infection in the case. Eighty-four cases and 168 matched controls were studied. Nosocomial bloodstream infections complicated about 3 of 1000 hospital days per patient in the study period. With step-wise logistic regression analysis, the most important predictors for developing nosocomial bloodstream infections were: increasing value of Acute Physiology and Chronic Health Evaluation (APACHE II) score (p = .001) and use of central venous catheter (CVC) (p = .002). The excess of hospital stay attributable to nosocomial bloodstream infections was 17 days. The crude mortality rate was 43%. The attributable mortality rate was estimated to be 27% (95% confidence interval [CI] = 13%-48%). The estimated risk ratio for death was 3.91 (95% CI = 2.06-7.44). Multivariate analysis identified two prognostic indicators that were significantly associated with unfavorable outcome of bloodstream infections: number of circulating CD4+ T cells <100/mm3 (p = .002) and APACHE II score >15 (p = .01). Nosocomial bloodstream infections are more common in patients with advanced HIV disease. Important cofactors are high APACHE II score and use of CVC. These infections can cause an excess mortality and significantly prolong the hospital stay of HIV-infected patients.

Evaluation of the new API Candida system for identification of the most clinically important yeast species

The API Candida system (bioMérieux) a new yeast identification system, was evaluated for its reliability in identifying 198 clinical yeast isolates in comparison with the API 20C system (bioMérieux) that was used as reference standard. The API Candida system correctly identified 91.4% and 71.7% of the isolates, with and without additional tests, respectively. The API Candida system identified 96.3% of common isolates studied, and 66.6% of uncommon isolates. We think that API Candida system is an easy and good yeast identification system and it could be used in a routine clinical microbiology laboratory.

Liposomal amphotericin B compared with amphotericin B deoxycholate in the treatment of documented and suspected neutropenia-associated invasive fungal infections

It has been suggested that a better outcome of neutropenia-associated invasive fungal infections can be achieved when high doses of lipid formulations of amphotericin B are used. We now report a randomized multicentre study comparing liposomal amphotericin B (AmBisome, 5 mg/kg/d) to amphotericin B deoxycholate (AmB, 1 mg/kg/d) in the treatment of these infections. Of 106 possible patients, 66 were enrolled and analysed for efficacy: nine had documented fungaemia, 17 had other invasive mould infections and 40 had suspected pulmonary aspergillosis. After completion of the course medication, in the AmBisome group (n = 32) 14 patients had achieved complete response, seven a partial response and 11 were failures as compared to 6, 13 and 15 patients (n = 34) treated with AmB (P=0.09); P=0.03 for complete responders. A favourable trend for AmBisome was found at day 14, in patients with documented infections and in patients with pulmonary aspergillosis (P=0.05 and P=0.096 respectively). Mortality rates were lower in patients treated with AmBisome (adjusted for malignancy status, P=0.03). More patients on AmB had a >100% increase of their baseline serum creatinine (P<0.001). The results indicate that, in neutropenic patients with documented or suspected invasive fungal infections AmBisome 5 mg/kg/d was superior to AmB 1 mg/kg/d with respect to efficacy and safety.

Epidemiology of infectious complications in cancer patients

Patients with underlying malignancies are at risk for a wide array of infectious diseases that cause significant morbidity and mortality. To develop a clear etiologic understanding of the infectious agents involved first requires a knowledge of the factors that predispose to infection. Neutropenia is clearly the single most important risk factor for infection in the cancer patient. However, a variety of both host and treatment-associated factors act together to predispose these patients to opportunistic infections. Approaching the individual malignancies with a knowledge of the underlying risk factors helps logically guide diagnosis and therapy. The astute clinician must also be aware of new and emerging infections in this patient population. As new pathogens are discovered and established pathogens become increasingly drug resistant, they will continue to present challenges for physicians caring for these patients in the years ahead.

A nosocomial cluster of Candida inconspicua infections in patients with hematological malignancies

Candida inconspicua was recovered from three patients with hematological malignancies. Two patients had intravenous-catheter-associated fungemia, whereas the third had fungal hepatitis. The three cases of infection occurred over a period of 1 month in patients staying in adjacent single rooms. In vitro susceptibility testing of fungal strains showed all isolates to be resistant to fluconazole, with MICs greater than 32 microg/ml. All of the strains had identical DNA restriction profiles and randomly amplified polymorphic DNA fingerprints. These data suggest a nosocomially acquired infection emanating from a common source within the hospital environment.

Construction and use of PCR primers from a 70 kDa heat shock protein gene for identification of Candida albicans

Methods for detection of Candida albicans in culture or biological samples were developed by the use of polymerase chain reaction (PCR) with oligonucleotide primers from C. albicans 70 kDa heat shock protein gene (Cahsp70). The PCR amplifies a 335-base pair fragment which is then hybridized with a non-radioactive probe, leading to the specific identification of C. albicans and its differentiation from all other human pathogenic Candida and/or yeast species. Candida albicans could be rapidly detected in human urine and blood, with a sensitivity of 10 and 50 fungal cells per sample, respectively.

The cytokine stew and innate resistance to L. monocytogenes

The Listeria monocytogenes (L. monocytogenes) infection model has been a useful system to evaluate the cellular interactions leading to host immunity. The initiation of the innate immune response in naive animals and subsequent progression to acquired immunity represent an integrated system with numerous layers of complexity. Coincident with experimental infection is the induction of cytokines. Cytokines, which are soluble mediators of cell growth, maintenance and function, from a network of pleiotropic stimuli that serve as one of the main driving forces for the progressive development of cellular responses. A variety of in vivo approaches, such as injection of the recombinant cytokines themselves or antibodies to neutralize their activity, have been used to define these stimuli. Perhaps one of the most useful tools is that of germline-manipulated animals. One of the many cytokines implicated in resistance to L. monocytogenes infection is interleukin (IL)-6, a molecule associated with diverse infectious and pathophysiological disease states. This review concentrates on various cytokines (IL-1, TNF alpha, IFN-gamma, IL-12, IL-10 and the colony-stimulating factors (CSF)) thought to play a role during the innate host response to L. monocytogenes infection, with a special emphasis on studies using IL-6-deficient mice. Additionally, we show unpublished data obtained when the concepts learned from L. monocytogenes infection in IL-6-deficient mice were applied to other infection models.

Hospital-acquired candidaemia: experience from a developing country

Thirty-seven episodes of hospital-acquired candidaemia, which occurred over a two-year period, were reviewed. The predominant risk factors were previous antibiotic therapy (100%), indwelling central venous catheter (94.6%), parenteral hyperalimentation (78.3%) and preceding surgery (51.4%). Eighty-nine percent of the patients had three or more risk factors. Candida albicans (56.8%), and Candida tropicalis (13.5%) were the most common isolates. Mortality was 48.6%. No significant difference was observed between patients treated with amphotericin B and those treated with fluconazole. The age of the patient, species of Candida, number of positive blood cultures for Candida, concomitant bacteraemia, and antifungal therapy did not have any significant effect on outcome. Our results were similar, in many aspects, to those reported from developed countries.

Comparison of the new API Candida system to the ID 32C system for identification of clinically important yeast species

API Candida was evaluated in comparison with the ID 32C system for the identification of 619 yeast isolates. The sensitivity of API Candida for the identification of the 15 species it claims to identify with and without additional tests was 97.4% (593 of 609) and 75.2% (458 of 609), respectively. The API Candida system is easy to use and rapid (result in 18 to 24 h).

Is there a therapeutic or pharmacokinetic rationale for amphotericin B dosing in systemic Candida infections?

OBJECTIVE

To review the literature regarding the dosage of amphotericin B in Candida infections. The correlation or rationale of current dosing practices is assessed in light of the literature.

DATA SOURCES

A MEDLINE search encompassing the years 1968-1995 was used to identify pertinent literature. Additional references were obtained from the articles retrieved from MEDLINE.

STUDY SELECTION

Studies that directly assessed amphotericin B dosage and/or duration, pharmacokinetic literature dealing with plasma concentrations and amphotericin B disposition, and literature dealing with dose and/or concentration as well as clinical outcome were selected for inclusion. Additional relevant citations were used in the introductory material and discussion.

DATA EXTRACTION

Although there was a large number of articles related to amphotericin B, surprisingly few large studies were designed to address the issues in question. The description of the methods and results of these heterogeneous articles are the basis of this review. Although additional controlled studies with more subjects need to be performed, the results to date provide a foundation from which to make some inferences regarding optimal use of this therapeutic modality until more definitive data become available.

DATA SYNTHESIS

Despite numerous articles addressing the pharmacokinetics of amphotericin B, little is known about its tissue distribution, the rate of transfer of the drug from vascular to peripheral sites, or its terminal disposition. Less information is available regarding the relevance of pharmacokinetic parameters or serum concentrations to clinical outcome. Most of the articles mentioning dosing provide little or no justification for the doses employed. The variety of the dosages used and the heterogeneity of the populations studied make determination of dose-outcome relationships difficult.

CONCLUSIONS

From the available clinical data, it appears that early initiation of amphotericin B therapy is crucial to a favorable outcome. Daily dosing initially followed by every-other-day administration of twice the daily dose is better tolerated by the patient than daily dosing and produces a similar therapeutic outcome. The drug should be continued until therapeutic endpoints have been achieved, rather than until a specific total dosage has been administered. The nephrotoxicity that occurs with amphotericin B administration is apparently reversible and should not be used as an endpoint for therapy if total dosages do not exceed 4 g. Additional well-designed, controlled trials evaluating standardized dosing methods of amphotericin B with predetermined dosing regimens and/or definitive therapeutic endpoints are needed to determine the optimal dosing approach for this agent.

Catheter-related complications of cancer therapy

Although the management of CVC-related infection appears complex and at times the literature seems to be contradictory, simple guidelines can direct the clinician in a stepwise fashion. Knowledge of the pathogenesis of each organism and the immune status of the host is crucial to decide whether catheter removal or retention is indicated. For example, in general, GNB bacteremia does not immediately prompt catheter removal in a neutropenic patient but does in a nonneutropenic host because of the gastrointestinal source of the former and a primary catheter source in the latter. In summary, as more CVCs are inserted in patients undergoing chemotherapeutic, antimicrobial, transfusional, and nutritional supportive care, novel approaches to prevention and treatment of the associated infectious complications inherent with such devices are needed. A multifaceted approach from impregnated catheters to local catheter-site antisepsis was reviewed. We may find, however, that as simple handwashing between patients is crucial to infection control, so too is a trained catheter-care team using total barrier precautions and ensuring proper local catheter maintenance critical to preventing CVC-related infections.

Re-expression by Candida albicans germ tubes of antigens lost during subculture of blastospores

The effect of germ tube induction on the antigenic variability in C.albicans was studied in strains from blood cultures (Group I) and superficial candidiasis (Group II). When compared by immunoblotting with a rabbit antiserum, antigenic extracts from Group I strains grown as blastospores showed a higher reactivity than that of Group II strains. Major bands in Group I strains (45-47, 33, 30 kDa) were continuously expressed through the subcultures in vitro but, with the exception of the 45 kDa band, the reactivity of all of them decreased or disappeared after the tenth subculture in Group II strains. The induction of the germ tubes produced the re-expression of the antigens lost during subculture in the yeast form, the effect being very clear in Group II strains. The re-expression by C. albicans germ tubes of antigens lost during subculture of blastospores in vitro and the higher reactivity shown by Group I strains grown in mycelial phase should be taken into consideration when a test to detect anti-C. albicans antibodies is to be developed.

Factors associated with the development of candidemia and candidemia-related death among liver transplant recipients

OBJECTIVE

The authors' objective was to identify factors associated with candidemia and candidemia-related death among adult liver transplant recipients.

SUMMARY BACKGROUND DATA

Invasive candidiasis is the most common severe fungal infection occurring after liver transplantation and is associated with high morbidity and mortality rates. Although candidemia is not always found during invasive candidiasis, it has been considered as an indicator of invasive candidiasis in immunocompromised patients.

METHODS

A time-matched case-control study of 26 patients with candidemia, which was defined as the isolation of Candida from at least one blood culture, and 52 control patients without candidemia was reported. Two control patients were matched with each case patient regarding time of transplantation and duration of follow-up.

RESULTS

Between December 1985 and December 1992, candidemia developed in 1.4% of adult liver transplant recipients a median of 25 days after transplantation (range, 2-1690 days). The overall mortality rate among patients with candidemia was 81%, and 71% of these deaths were related to candidemia. Conditional logistic regression analysis was used to identify factors associated with candidemia, which were 1) hyperglycemia treated with insulin up to 2 weeks before candidemia (odds ratio [OR], 16.15; p = 0.002), and 2) exposure to more than three different intravenous antibiotics before development of candidemia (OR, 11.15; p = 0.005). The variables predictive of death related to candidemia were abdominal surgery performed up to 1 week before candidemia (relative risk [RR], 7.25; p = 0.02), high white blood cell count (RR, 1.10; p = 0.01), lower platelet count (RR, 0.99; p = 0.02), and elevated AST with candidemia (RR, 1.001; p = 0.01).

CONCLUSIONS

Hyperglycemia that requires insulin and exposure to more than three antibiotics are the factors associated with the development of candidemia in liver transplant recipients. When candidemia develops shortly after abdominal surgery and in patients with elevated AST, high white blood cell count, or low platelet count, it is associated with a high mortality rate.

Comparison of the Murex Candida albicans CA50 test with germ tube production for identification of C. albicans

A total of 502 yeast isolates were tested with the 30-min MUREX Candida albicans CA50 (Norcross, GA) test for presumptive identification of C. albicans. The results were compared with the standard 2-h germ tube test, which was the reference standard. Of the 502 isolates, 316 were C. albicans and 186 were non-C. albicans. Identifications were based on germ tube reactions; the API20C and chlamydospore agars were used when discrepant results persisted between the germ tube and MUREX test after repeat testing of the MUREX method. A total of 16 C. albicans gave negative results on initial testing with the MUREX test but were interpreted as positive when repeated. Three germ tube negative yeasts initially tested positive with the MUREX but were negative when repeated. Two additional yeast isolates gave incorrect results with the MUREX, even with repeat testing: C. albicans and C. lusitaniae. The initial sensitivity and specificity for the MUREX C. albicans CA50 test were 94.6% and 97.8%, respectively. As an addition to the study, two fetal bovine sera were compared for production of germ tubes; fetal bovine serum and Fetal Clone II. The testing found them to be in 100% agreement.

Targeting fungi: a challenge

Invasive fungal infections are more commonly identified in various categories of patients, mainly in cancer patients but also in those undergoing organ transplantation, patients in intensive care units, and those with AIDS. There is a great need to increase the awareness of practitioners who are still underestimating the morbidity and mortality relating to invasive fungal infections, and to stress the economic burden for the society and healthcare systems of invasive fungal infections. The list of fungal pathogens causing life-threatening complications has also increased recently, with the emergence of unusual fungi being more frequently identified in such settings. Early diagnosis of invasive fungal infections is still a major challenge for the clinician at the bedside. Identification of state-of-the-art management is also a difficult task for the clinical scientist involved in the assessment of optimal strategies to prevent and to treat those invasive fungal infections, although major progress has occurred in the last 5 years with the development of new, safe, and effective antifungal agents. Empiric therapy remains a very controversial issue that should be further investigated in high-quality clinical trials. Overall, clinical research in this difficult field requires independent and objective analysis; only large multicenter clinical trials can address these critical issues and rapidly provide convincing results leading to a better prognosis of patients with invasive fungal infections. These complications still represent too often an obstacle to successful control of severe underlying diseases. Clinical research on the appropriate ways to target fungi will not only define state-of-the-art management but also identify ineffective or redundant treatments. Such an approach will make a substantial contribution to the care of the high-risk patients within the next decade and will preserve our capacity for medical excellence.

Contribution of molecular typing methods and antifungal susceptibility testing to the study of a candidemia cluster in a burn care unit

We investigated a cluster of cases of Candida septicemia diagnosed in four burn patients. Twenty clinical isolates of Candida albicans and two of Candida parapsilosis, plus eight isolates of C. albicans recovered from nurses' clothes, were analyzed by antifungal susceptibility testing and three genotyping methods (restriction fragment length polymorphism analysis with EcoRI and HinfI, arbitrarily primed PCR, and karyotyping). The high MICs of the azoles for all of the C. albicans isolates tested suggest either a natural resistance of the endogenous flora or the transmission of isolates with acquired resistance. The genotyping methods demonstrated the involvement of four different strains, cross-infections with one C. albicans strain and one C. parapsilosis strain, and identity between some of the strains from the patients and nurses. The origins of the strains remain unclear. Our results show that the use of a combination of at least two different methods such as those used in the present study is recommended for C. albicans typing.

Postoperative infections in immunocompromised patients after oncological surgery

Immunodeficiency secondary to cancer chemotherapy (chemotherapy for less than 3 months, or intensive chemotherapy with bone marrow transplant) may be responsible for postoperative infections. To estimate the value of this hypothesis, a prospective study was done over a period of 18 months in patients who had undergone pulmonary surgery. Antibiotic prophylaxis was by pefloxacin, one tablet (400 mg) 1 h before surgery then 11 h after. Clinical examination, a chest X-ray and blood cell count were carried out every day for 10 days and on the 15th day. All the drain-tips were cultured. In a case of infection, samples were obtained and cultured. One group comprised 22 immunodeficient patients (group A), and 33 patients (group B) had received no prior chemotherapy (bone-marrow transplantation = 36.7%). There were differences between the two groups in age (A:33.5 +/- 12.3 years; B:50.8 +/- 18.4 years), and type of tumour (A: metastasis = 95.5%; B: lung cancer = 51.5%). Surgical operation was bilateral for 36.4% of the patients in group A. There was more anatomical resection (pneumonectomy and lobectomy) in group B. Lung function did not differ between the two groups (abnormalities: A = 54.6%; B = 63.6%). In group A, there were 3 pulmonary infections (13.7%), but in group B 10 infections (30.3%) with 9 pulmonary infections (4 with bacteraemia) and 1 wound infection. The bacteriological finding showed two pathogens in 7 cases and no bacteriological isolates in 2 cases. With broad-spectrum antibiotherapy all the patients were cured except 1. There was one postoperative death in group B. This patient died of respiratory distress after pneumonectomy complicated by pneumonia and septicaemia (Streptococcus pneumoniae) in the remaining lung. Surgical procedures are performed with increasing frequency on patients with immunocompromised status. Classically the risk of infection is more important for these patients. In this study prior cancer chemotherapy or bone marrow transplantation did not seem to be an aggravating factor of the risk of infection. But further methodological analysis would not allow us to distinguish between a real impact of chemotherapy and the influence of group heterogeneity.

New and emerging yeast pathogens

The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed.

Antifungal Prophylaxis in Severely Neutropenic Patients: How Much Fluconazole is Necessary?

OBJECTIVES: To evaluate the efficacy of low dose fluconazole treatment for the prevention of yeast colonization and infection in severely neutropenic patients. METHODS: An open randomized trial, comparing fluconazole (100 mg per day) with nystatin (800,000 IU per day), in a University Hospital setting. RESULTS: Antifungal prophylaxis was given during the period of neutropenia, defined as less than 500 polymorphonuclear cells (PMN)/mm3). Thirty-six patients were randomly assigned to fluconazole and 33 to nystatin treatment groups. New oropharyngeal colonizations were significantly reduced by fluconazole (P=0.005), and oropharyngeal infections occurred less frequently in the fluconazole group (3% versus 16%, P=0.07). Stool colonization was identical between both groups. Systemic fungal infections were rare; one fluconazole patient had pulmonary aspergillosis and one nystatin patient developped Candida pseudotropicalis fungemia. Empiric amphotericin B was given with the same frequency in both groups. No side effects were associated with fluconazole. However, the administration of nystatin became impossible for three patients because of vomiting and lack of compliance. CONCLUSIONS: Fluconazole (100 mg per day) is more effective than nystatin for the prevention of oropharyngeal yeast colonization. Comparison with results in the literature suggests that a 100-mg dose of fluconazole has similar effects to 200 or 400 mg per day.

Antibody response that protects against disseminated candidiasis

We previously showed that surface mannans of Candida albicans function as adhesins during yeast cell attachment to mouse splenic marginal zone macrophages. The mannan adhesin fraction was encapsulated into liposomes and used to vaccinate mice over a 5- to 6-week period. Circulating agglutinins specific for the fraction correlated with increased resistance to disseminated candidiasis. Antiserum from vaccinated animals protected naive BALB/cByJ mice against C. albicans serotype A and B strains and Candida tropicalis. Antiserum also protected SCID mice against disseminated disease. The serum protective ability was stable at 56 degrees C, but this ability was adsorbed by C. albicans cells. The antiserum was divided into three fractions after separation by high-performance liquid chromatography. One fraction contained all of the agglutinin activity and transferred resistance to naive mice. A second fraction also transferred resistance. Two monoclonal antibodies (MAbs) specific for candidal surface determinants were obtained. MAb B6.1 is specific for a mannan epitope in the adhesin fraction, and MAb B6 is specific for a different epitope in the fraction. Both MAbs are immunoglobulin M, and both strongly agglutinate candidal cells, but only MAb B6.1 protected both normal and SCID mice against disseminated candidiasis. In one experiment, 10 normal mice were given MAb B6.1 and challenged with yeast cells. Six mice survived the 67-day observation period; 4 of the survivors were cured as evidenced by the lack of CFU in the kidney and spleen. Our studies show that antibodies against certain cell surface antigens of C. albicans help the host resist disseminated candidiasis.

Prophylactic use of fluconazole in neutropenic cancer patients

This study was carried out on 70 patients with haematological or solid malignancies who were receiving chemotherapy and/or radiotherapy. Forty-one patients were randomly assigned to receive fluconazole, 400 mg/day, while they were neutropenic. Systemic fungal infection developed in four of the 41 patients (9%) receiving prophylaxis in comparison to nine of 29 patients (31%) not receiving prophylaxis. The incidence of systemic fungal infection was significantly different between the groups receiving prophylaxis and those not receiving it (p < 0.05). Fluconazole was found to be effective for preventing systemic fungal infections in neutropenic patients with cancer.

Comparison of fluconazole with oral polyenes in the prevention of fungal infections in neutropenic patients. A prospective, randomized, single-center study

The goal of this prospective randomized single-center study was the comparison of safety and efficacy of high-dose oral/intravenous fluconazole (400 mg daily) (group A) with oral nystatin plus miconazole inhalations (group B) in the prevention of fungal infections on a hemato-oncological isolation Ward. Of 157 patients admitted to the isolation ward during the study period only 90 (57%) were eligible for randomization; 22 (14%) had a fungal infection at admission. Of the 90 randomized patients, 89 were evaluable, 43 in group A and 46 in group B. The age, sex, diagnosis, planned therapy and risk factors for fungal infections at admission as well as the duration of neutropenia were in the same proportions in both groups. Oral thrush and mucocutaneous candidiasis were prevented in all patients of both groups, and 29 patients (32%: 17 in group A, 12 in group B) were discharged after successful prophylaxis (NS). Empiric amphotericin B was given according to predetermined criteria to 45 patients (51%: 23 group A, 22 group B; NS). Fluconazole significantly delayed the time before the start of intravenous amphotericin B. It was begun after a median of 10 days (0-45 days, range) of neutropenia below 0.5 x 10(9) granulocytes/l in group A and 7.5 days (0-26, range) in group B (P < 0.05). The duration of successful prophylaxis was significantly longer in group A (26 days median) than in group B (21 days, median) (P < 0.05). Systematic fungal infection was documented in 3 patients (1 group A, 2 group B; NS).

SCH 51048, a new antifungal triazole active against hematogenous Candida krusei infections in neutropenic mice

Candida krusei is increasingly recognized as an opportunistic pathogen in immunocompromised patients and is inherently resistant to fluconazole. We tested the in vivo efficacy of SCH 51048, an investigational antifungal triazole, in experimental hematogenous murine infection caused by two C. krusei isolates and compared its activity with those of amphotericin B and fluconazole. CF1 mice were immunosuppressed with cyclophosphamide and cortisone acetate and were challenged intravenously with infecting inocula of each C. krusei isolate. Treatment with SCH 51048 (50 or 100 mg/kg of body weight per day orally) or amphotericin B (2 mg/kg/day intraperitoneally) significantly prolonged the survival of infected mice and significantly reduced fungal titers in the kidneys (P < or = 0.05). Treatment with fluconazole (100 mg/kg/day orally) had no effect. Both dosages of SCH 51048 were as effective as amphotericin B in improving survival, but the higher dosage was significantly (P < or = 0.05) better in reducing the fungal burden in the kidneys of infected animals. A dose-dependent response was observed with SCH 51048 treatment, especially in organ clearance. Our results indicate that SCH 51048 is the first triazole that has in vivo activity against experimental infection with C. krusei and deserves further evaluation.

Fungemia: An increasing problem in a Danish university hospital 1989 to 1994

OBJECTIVE: To present data on episodes of fungemia in a Danish tertiary-care university hospital admitting all types of patients and to compare the data with previous findings from the same hospital. METHODS: Retrospective identification of episodes of fungemia from 1989 to 1994 and collection of data from computerized files at the Clinical Microbiology Department at Rigshospitalet and the Mycology Reference Laboratory at Statens Seruminstitut. RESULTS: The incidence of fungemia increased gradually from 19 episodes in 1989 to 57 episodes in 1994. An earlier report from the same hospital showed 20 to 25 episodes of fungemia per year between 1984 and 1988. Candida albicans was the dominating species during both periods, accounting for 73% of isolates during 1984 to 1988 and 67% during 1989 to 1994. However, in the hematology department where fluconazole has been used extensively, C. albicans constituted 47% of isolates with Candida krusei and Candida glabrata comprising 25%. CONCLUSIONS: The incidence of fungemia in our tertiary-care hospital has increased threefold from 1989 to 1994. Candida albicans was the dominating cause of fungemia but, in the hematology department, this yeast accounted for less than half of the isolates during the same time period.

An open study on the safety and efficacy of fluconazole in the treatment of disseminated Candida infections in patients treated for hematological malignancy

Disseminated candidiasis is a serious infectious complication with a mortality as high as 50%. Standard therapy consists of parenteral amphotericin B which is associated with major side effects and prolonged hospitalization. The aim of the study was to assess the efficacy and safety of fluconazole in an open, noncomparative study. Fluconazole, as a single agent, was given intravenously for the first 3 days at a dose of 200 mg twice daily, followed by 200 mg twice daily orally until resolution of signs and symptoms or evident treatment failure. The study group comprised 24 consecutive patients of whom nine had acute and 15 chronic disseminated candidiasis. A clinical response was achieved in 67% of cases of acute disseminated candidiasis and in 86% of cases of chronic disseminated candidiasis. The median duration of therapy was 15 days and 6 months, respectively. Superinfections with Aspergillus fumigatus developed in five patients who were persistently neutropenic. No drug-related toxicity was registered.

Evaluation of the ATB 32 C system for identification of clinical yeast isolates

OBJECTIVE: To compare the ATB 32 C system for routine identification of clinical yeast isolates in a clinical microbiology laboratory with identification carried out by conventional methods in a mycology reference laboratory. METHODS: A total of 113 strains initially isolated at our hospital and identified in the reference laboratory were returned in duplicate, under separate code numbers, to the microbiology laboratory where the ATB 32 C system was used for identification by: 1) visual assessment of turbidity at 72 h with use of identification table; 2) visual assessment at 72 h with use of ATB 32 C analytical profile index; and 3) automatic readings with the ATB reader at 48 h and 72 h with results of growth assessments transmitted to a computer and interpreted by the ATB 32 C software. RESULTS: Visual assessment plus identification table and visual assessment plus profile index provided correct identification in 98% and 91% of strains, respectively. Visual assessment was, however, sometimes difficult and required more experience than is usually available in a routine clinical microbiology laboratory. Automatic readings with computer identification plus supplementary tests correctly identified 87% and 86% after 48 h and 72 h, respectively. CONCLUSIONS: The ATB 32 C system with automatic readings and computer identification is a satisfactory system for identification of clinical yeast isolates in a routine clinical microbiology laboratory.

In vitro susceptibility of Candida species isolated from patients with haematological malignancies

Candida spp. (83 isolates including C. (Torulopsis) glabrata) were tested in vitro for their susceptibility to 5-fluorocytosine, amphotericin B, ketoconazole, itraconazole, fluconazole, and miconazole. The yeasts were isolated from clinical specimens, mostly from the lower respiratory tract, of 30 oncologic patients, 27/30 with haematological malignancies, during a 6-month period (December 1991-May 1992). Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values of the 6 drugs were obtained for each yeast using a microdilution broth method developed in our laboratory. Amphotericin B, and 5-fluorocytosine were active against the majority of the yeasts with MIC90/MFC90 values within achievable serum concentrations (3.12/6.25 micrograms ml(-1) and 0.625/0.625 micrograms ml(-1) respectively). Azole derivatives showed a species-specific activity. MFC values were two to four times higher than those of the MICs, confirming the fungistatic rather than fungicidal activity of azole derivatives. An interesting correlation was found when the in vitro susceptibility values of the isolates were compared with data of patients with or without antifungal prophylaxis or therapy during that period. In general, with respect to fluconazole, C. albicans strains isolated from patients who received no treatment showed MIC and MFC values lower than those obtained from patients who were under prophylaxis or treatment with this drug. Fluconazole administration appears to influence in vitro susceptibility testing.

Misidentification of clinical yeast isolates by using the updated Vitek Yeast Biochemical Card

The Vitek Yeast Biochemical Card (YBC) is widely used as a rapid identification (RI) (within 48 h) system for clinical yeast isolates. We compared the RI results obtained by the YBC technique with matched results obtained with the API 20C system. The RI of germ tube-negative yeasts isolated from 222 clinical specimens was performed with the YBC system, and the results were compared with those of standard identifications obtained by using the API 20C system and morphology, with additional biochemical reactions performed as required. Commonly isolated yeasts (Candida albicans [n = 29], Candida tropicalis [n = 40], Torulopsis [Candida] glabrata [n = 28], Candida parapsilosis [n = 12], and Cryptococcus neoformans [n = 14]) were generally well identified (115 of 123 [93%] identified correctly, with only C. albicans, C. tropicalis, and C. neoformans mis- or unidentified more than once). The RI of less commonly isolated yeasts included in the YBC database, however, was less successful (54 of 99 [55%] correct). The YBC card failed to identify 42% (10 of 24) of Candida krusei isolates, 80% (4 of 5) of Candida lambica isolates, 88% (7 of 8) of Trichosporon beigelii isolates, and 83% (10 of 12) of Cryptococcus isolates (non-C. neoformans species). For most identification failures (79%; 42 of 53) there was no identification by the end of 48 h; the other identification failures (21%; 11 of 53) gave definite but incorrect identifications. Of eight rare clinical yeast isolates not included in the Vitek database, six were correctly, not identified, while two (25%) were falsely assigned a definite RI (one Hansenula fabianii isolate was identified as Rhodotorula glutinis, and one Hansenula isolate [non-Hansenula anomala] was identified as Hansenula anomala). While the Vitek YBC rapidly and adequately identifies common yeast isolates, it fails in the RI of more unusual organisms.

Antibiotic strategy in orofacial/head and neck infections in severe neutropenia

A strategy for empiric antibiotic therapy for orofacial/head and neck bacterial infections that appear as clinical swellings in patients with severe neutropenia is assessed. Daily examinations were made in the hospital. Only those with peripheral blood neutrophil counts < 100/mm3 that persisted for at least 5 days after the commencement of resolution of the swelling were included in this article. The strategy consisted of sequential additions of a beta-lactam/aminoglycoside combination, metronidazole to intensify anaerobe cover and a beta-lactamase stable agent (such as vancomycin and floxacillin) as dictated by clinical signs. Progressive and complete resolution of infection occurred in 26 of 27 patients treated.

Candida carriage in the alimentary tract of liver transplant candidates

Thirty randomly selected patients with advanced chronic liver disease, which had been evaluated for possible liver transplantation, were sampled endoscopically at 7 alimentary tract locations to assess the frequency and amount of Candida carriage. Eighty-one percent (127/156) of the samples obtained contained Candida and 53% (82/156) yielded high counts (> 300 CFU/ml). The most predominant Candida species isolated at each site was Candida albicans, which accounted for 103 (64%) of the 160 fungal isolates. The other Candida species isolated included C tropicalis 30 (19%), C krusei 16 (10%), and C glabrata 11 (7%). Although the number of sites at which yeast was present and the quantities of yeast at each site varied widely among the patients studied, 100% of the patients had Candida in at least one site of the gastrointestinal tract. Eighty-six percent (24/28) of the duodenal aspirates contained Candida and 50% (14/28) of the duodenal samples contained greater than 300 CFU/ml. A positive culture from the stomach was a reliable predictor of the presence of Candida in the duodenum (P = 0.0001), but a positive culture at no other site readily predicted the presence of Candida at yet another site. Importantly, there was no correlation between the presence or absence of Candida in either oral or rectal swabs and colonization at other anatomic sites within the gastrointestinal tract. These findings are important in liver transplantation, particularly in those cases in which the bowel has been opened to create a choledochojejunostomy anastomosis. The operative attempts to reduce gastrointestinal fungal carriage using oral antifungal agents may be justified before liver transplantation in an effort to lower the risk of posttransplantation fungal infections, particularly in those patients expected to have a Roux-en-Y choledochojejunostomy biliary reconstruction.

Candidemia: current epidemiologic characteristics and a long-term follow-up of the survivors

All consecutive patients with positive blood culture for Candida species over a 6-year period were evaluated to define recent epidemiologic characteristics of candidemia, and to assess the prevalence of late complications. We encountered 106 cases; medical records were available for 99 of them. The rate of candidemia was increasing until 1990, after which it declined. C. albicans was the most common species, but in the last 2 years, C. tropicalis and C. parapsilosis were emerging. Overall mortality rate was 54.5% without significant variation during the study period. Antifungal therapy was withheld in 24/99 cases (24.2%). Decision to withhold treatment was taken in 19/59 cases (32.2%) before the availability of fluconazole in 1990, compared with 5/40 cases (12.5%) afterward (p < 0.05). Follow-up was possible in 35 instances for an average period of 17.1 months (range: 1-48 months); 7 of these individuals, all with transient candidemia, were untreated. None of the survivors developed late complications. These findings demonstrate that candidemia appears to be declining since 1990, with a noticeable decrease in the prevalence of C. albicans but an increase in that of C. tropicalis and C. parapsilosis, that fewer patients are left untreated since fluconazole became available, and that the risk of late complications among the survivors is low.

Nonculture methods for diagnosis of disseminated candidiasis

Two of the nonculture approaches to the diagnosis of DC, enzymatic-fluorometric determination of serum D-arabinitol and detection of marker antigens in antigenemia (enolase and CWMP), have been commercialized and have shown promise in limited clinical trials. These approaches are not new but are the culmination of efforts made over 10 or more years. Clearly, further fine-tuning of both metabolite and antigen detection is needed to simplify the methods and to improve their sensitivity and specificity so that they will be valuable in guiding clinical treatment decisions. An alternative approach, detection of DC by DNA amplification methods such as PCR, is a special case of a compelling technology and one that is capable of standardization across microbial genera. The availability of simplified PCR diagnostic methods for DC remains a tantalizing prospect. Nevertheless, the development of methods to release DNA from very small numbers of Candida organisms in the blood in a form that is sufficiently free of inhibitors of PCR will require further intensive effort. The maturation of these converging laboratory approaches to nonculture diagnosis of DC leads to more optimism about the eventual use of these methods in clinical laboratories.

Fungemia in patients with leukemia

A nine-year retrospective study on fungemia in patients with leukemia was conducted. A total of 79 episodes of fungemia in 77 patients with leukemia were documented. Candida parapsilosis fungemia was associated more frequently with the presence of a central venous line and to the use of parenteral nutrition than the other fungal species (p = 0.00026 and p = 0.01, respectively). The same fungus was isolated from both blood and surveillance cultures in 95% of Candida albicans and in 89% of Candida tropicalis fungemia (p < 0.01 and p = 0.02, respectively). The neutropenia and fungus colonization that resulted was associated significantly with the presence of invasive disease (p = 0.0024 and p = 0.0028, respectively). Conversely, central venous catheterization and parenteral nutrition appeared to be associated with episodes without deep tissue invasion (p = 0.000037 and p = 0.001, respectively). Invasive mycosis due to the fungus isolated from blood was documented in 51 patients with a mortality rate of 69%, whereas in 20 patients without invasive mycosis, mortality rate was 21% (p = 0.000059). In patients with fungemia, related or unrelated to the presence of a central venous catheter, mortality was 24% and 64%, respectively (p = 0.00042). Mortality was highest with C. tropicalis (p = 0.0017) and lowest with C. parapsilosis (p = 0.057). Severe neutropenia (polymorphonuclears < 100/mmc) appeared associated with a higher mortality rate (p = 0.012), whereas the recovery of neutropenia was related adversely to a fatal outcome (p < 0.01). With antifungal therapy, there was no statistically significant difference whether antifungal therapy was given or not.(ABSTRACT TRUNCATED AT 250 WORDS)