Fluconazole therapy for histoplasmosis. The National Institute of Allergy and Infectious Diseases Mycoses Study Group

We assessed the efficacy of oral fluconazole (200-800 mg daily) in the treatment of non-life-threatening acute pulmonary histoplasmosis, chronic pulmonary histoplasmosis, or disseminated histoplasmosis in patients without human immunodeficiency virus infection. Of 27 evaluable patients, two had progressive acute pulmonary histoplasmosis, 11 had chronic pulmonary histoplasmosis, and 14 had disseminated histoplasmosis. Median durations of treatment in each of the three groups were 6 months, 7 months, and 11 months, respectively. Nineteen patients were treated with 400 mg of fluconazole daily (two of these patients received 800 mg daily for a portion of their treatment courses), seven were treated with 200 mg daily, and one was treated with 800 mg daily. Treatment was successful in 17 (63%) of 27 cases. Both of the patients with acute pulmonary infection responded to therapy, as did five (46%) of 11 patients with chronic pulmonary infection and 10 (71%) of 14 patients with disseminated infection. No substantial toxicity was observed. We conclude that fluconazole therapy for histoplasmosis is only moderately effective and should be reserved for patients who cannot take itraconazole.

Achromobacter xylosoxidans bacteremia: report of four cases and review of the literature

Seventy-seven cases of bacteremia due to Achromobacter xylosoxidans were reviewed, and susceptibility studies were performed on 11 clinical isolates of A. xylosoxidans. Nosocomial bacteremia was noted in 54 of 77 patients (70%), and 28 (36%) had infection associated with an outbreak or acquired from a discrete point source. The most common underlying illnesses were malignancies (30%) and cardiac disease (21%); immunosuppression affected 27%. The most common clinical syndromes were primary and catheter-associated bacteremia (19% each) and pneumonia (16%). The case-fatality rate was 30%; only 3% of patients with primary or catheter-associated bacteremia died, but 65% of patients with meningitis, endocarditis, and pneumonia died. The case-fatality rate in neonates was 80%. Susceptibility studies showed that all strains were resistant to aminoglycosides, most were resistant to quinolones, and all were susceptible to broad-spectrum penicillins, imipenem, ceftazidime, and trimethoprim-sulfamethoxazole. Two-disk approximation and time-kill studies showed synergy or additive effects for the combination of gentamicin and piperacillin against most strains.

Susceptibility of ciprofloxacin-resistant staphylococci and enterococci to trovafloxacin

The susceptibilities of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and enterococci obtained over a 13-year period were tested for trovafloxacin, a new fluoroquinolone, and ciprofloxacin. For MRSA, MIC50 values for trovafloxacin increased from 0.03 microgram/ml to 1 microgram/ml from 1984-1985 to 1995-1996, but were lower than those noted for ciprofloxacin, which increased from 0.25 microgram/ml to > 8 micrograms/ml during the same period. Trovafloxacin also showed lower MIC50 values (0.12-0.25 microgram/ml) than ciprofloxacin (MIC50 of 0.5-1 microgram/ml) for E. faecalis isolates from 1985 through 1991, but against E. faecium and E. faecalis isolated in 1995-1996, the MIC50 values for both trovafloxacin and ciprofloxacin were 2 micrograms/ml and the MIC90 values were > or 8 micrograms/ml. Thus, cross-resistance between fluoroquinolones was shown for both enterococci and MRSA. Whether the greater intrinsic activity of trovafloxacin might allow its use in treating MRSA and enterococcal infections remains to be seen.

Comparative in vitro activity of quinupristin/dalfopristin against multidrug resistant Enterococcus faecium

The in vitro susceptibilities of 82 strains of vancomycin resistant Enterococcus faecium (VREF), (49 vanA and 33 vanB) from over 13 hospitals in Europe and United States were studied. The MIC for several antibiotics showed high levels of resistance to vancomycin, ampicillin, gentamicin, and imipenem. All VREF strains were highly susceptible to quinupristin/dalfopristin with a MIC 90% of 0.5 microgram/ml for both vanA and vanB phenotypes. Time-kill and synergy studies of VREF for quinupristin/dalfopristin alone and quinupristin/dalfopristin in combination with several antibiotics (ampicillin, gentamicin, ciprofloxacin, rifampin and novobiocin) did not show bactericidal activity. In induction experiments using SF6550, (VREF, a vanA strain), quinupristin/dalforpristin showed a delay in the expression of vancomycin resistance by 2.5 hours. The results of this study show quinupristin/dalfopristin to have excellent in vitro activity versus multiple resistant E. faecium.

Role of azoles in antifungal therapy

The addition of itraconazole and fluconazole to the antifungal armamentarium has resulted in less toxic, easily administered therapy for both endemic and opportunistic mycoses. Itraconazole has become the treatment of choice for most patients with mild-to-moderate histoplasmosis, blastomycosis, and sporotrichosis. Coccidioidomycosis is effectively treated with either itraconazole or fluconazole; fluconazole has become the drug of choice for the treatment of coccidioidal meningitis. In several large cooperative trials, fluconazole has been shown to have a useful role in the treatment of patients with candidemia, localized forms of mucocutaneous and visceral candidiasis, and cryptococcal meningitis.

Treatment of lymphocutaneous and visceral sporotrichosis with fluconazole

Thirty patients with documented sporotrichosis were treated with 200-800 mg of fluconazole daily. Fourteen patients had lymphocutaneous infection; only five (36%) of these patients had any underlying illnesses. Sixteen patients had osteoarticular or visceral sporotrichosis; 12 (75%) of these patients had underlying diseases, mostly alcoholism, diabetes mellitus, and chronic obstructive pulmonary disease. Eleven of the 30 patients had relapsed after prior antifungal therapy. Most patients were treated with 400 mg of fluconazole; however, four received 200 mg of fluconazole daily for the entire course, and four received 800 mg of fluconazole daily for a portion of their therapy or for the entire course of therapy. Fluconazole therapy cured 10 (71%) of 14 patients with lymphocutaneous sporotrichosis. However, only five (31%) of 16 patients with osteoarticular or visceral sporotrichosis responded to therapy; the conditions of two of these five patients improved only, and there was no documented cure of their infections. With the exception of alopecia in five patients, toxic effects were minimal. Fluconazole is only modestly effective for treatment of sporotrichosis and should be considered second-line therapy for the occasional patient who is unable to take itraconazole.

Saccharomyces cerevisiae infections and antifungal susceptibility studies by colorimetric and broth macrodilution methods

Saccharomyces cerevisiae was isolated in large numbers from operative specimens from two patients with perforated bowel and peritonitis and from the blood of another patient treated with extracorporeal membrane oxygenation. Susceptibility studies were performed on these three isolates and another 29 isolates that colonized or caused infection in a total of 19 patients seen over the last decade. All isolates had low minimum inhibitory concentration (MIC) values for amphotericin B (MIC90 of < or = 0.02 microgram/ml) and flucytosine (MIC90 of 0.2 microgram/ml), and a broader range of MIC values for itraconazole (MIC90 of 0.8 microgram/ml) and fluconazole (MIC90 of 4 micrograms/ml). A colorimetric method using Alamar blue reagent showed good concordance with the standard broth macrodilution method for amphotericin B, flucytosine, and fluconazole, but less good concordance for itraconazole. Serious infections with S. cerevisiae probably should be treated with amphotericin B, with or without the addition of flucytosine.

Alterations in gastric acidity in patients infected with human immunodeficiency virus

In a randomized crossover trial, gastric acidity and gastric microbial colonization in 19 men infected with human immunodeficiency virus (HIV) (of whom nine had AIDS) were assessed. Gastric acidity was assessed during a baseline period and following pentagastrin or glutamic acid administration. Only two (22.2%) of the nine patients with AIDS and none of the non-AIDS patients were hypochlorhydric, as determined by maximal acid output. However, 60% and 67% of patients in the HIV-infected and AIDS groups, respectively, had persistently elevated gastric pH values during the baseline period. Both pentagastrin and glutamic acid significantly increased gastric acidity. Gastric colonization with Candida albicans and gram-positive mouth flora was common. Overall, this study demonstrates that many HIV-infected patients have elevated gastric pH values that may lead to alteration in drug absorption. The large degree of intrasubject and intersubject variability observed in gastric pH suggests that, unfortunately, one cannot predict which patients will have elevated gastric pH values.

Old and new therapies for sporotrichosis

The old therapies for sporotrichosis--saturated solution of potassium iodide (SSKI) and amphotericin B--have largely been supplanted by itraconazole treatment. Although SSKI is effective for the treatment of lymphocutaneous sporotrichosis, it is difficult to administer and is frequently associated with side effects; response rates of >90% are associated with itraconazole therapy for lymphocutaneous sporotrichosis. Patients with osteoarticular sporotrichosis rarely have systemic symptoms and can be effectively treated with a prolonged course of itraconazole, thus obviating the need for intravenous amphotericin B therapy with its associated toxic effects. Pulmonary sporotrichosis in patients infected with human immunodeficiency virus continue to be difficult therapeutic problems, but itraconazole appears to be at least as effective as amphotericin B as treatment for these forms of sporotrichosis.

Torulopsis glabrata: azole susceptibilities by microdilution colorimetric and macrodilution broth assays

Fluconazole and itraconazole MICs were determined by both the standard macrodilution method of the National Committee for Clinical Laboratory Standards and a colorimetric broth microdilution method for 140 isolates of Torulopsis (Candida) glabrata obtained over a 15-year period. Using the method of the National Committee for Clinical Laboratory Standards the MICs at which 90% of isolates are inhibited (MIC50) for all isolates were 32 and 1.6 micrograms/ml for fluconazole and itraconazole, respectively. For fluconazole, the MIC90 rose from 16 to > 64 micrograms/ml when the MIC90s for isolates collected from July 1980 to June 1991 were compared with those for isolates collected from July 1991 to March 1995. For itraconazole, the MIC90s for isolates from the same time periods were 0.8 and 3.2 micrograms/ml, respectively. Although for isolates from some non-human immunodeficiency virus-infected patients the MICs rose, most of the high MICs were found for isolates from human immunodeficiency virus-infected patients who had been extensively treated with azole drugs for thrush. The colorimetric method yielded endpoints that were more definitive; concordances within 2 dilutions for the two methods were 87% for fluconazole and 86% for itraconazole.

Alopecia associated with fluconazole therapy

OBJECTIVE

To describe the association between fluconazole and reversible alopecia.

DESIGN

A retrospective survey of 1) patients enrolled in NIAID Mycoses Study Group (MSG) protocols involving the long-term use of fluconazole for treatment of endemic mycoses and 2) patients treated with fluconazole outside of a protocol setting but by the MSG investigators who were MSG members.

SETTING

26 MSG sites in the United States.

PATIENTS

33 patients with various deep and superficial mycoses who developed alopecia while receiving fluconazole.

RESULTS

11 of 26 investigators reported a total of 33 patients with substantial alopecia related to fluconazole therapy. Underlying mycoses included blastomycosis, sporotrichosis, histoplasmosis, cryptococcosis, coccidioidomycosis, and mucosal candidiasis. In separate MSG studies, 17 of 136 (12.5%) and 8 of 40 (20%) patients had substantial reversible alopecia associated with fluconazole therapy. Eight patients who were not in the protocol had similar adverse effects. Twenty-nine of 33 patients (88%) received at least 400 mg of fluconazole daily for a mean of 7.1 months. Alopecia developed a median of 3 months after initiation of fluconazole therapy and involved the scalp in all patients. Other sites were involved in about one third of patients. Three patients required wigs because of extensive hair loss. Alopecia resolved within 6 months of discontinuation of fluconazole therapy or reduction of the daily dose by at least 50%.

CONCLUSIONS

Alopecia appears to be a common adverse event associated with higher-dose (400 mg/d) fluconazole given for 2 months or longer. This effect may be severe but is reversed by discontinuing fluconazole therapy or substantially reducing the daily dose.

Mupirocin resistance: clinical and molecular epidemiology

The antistaphylococcal activity of topical mupirocin has made it an attractive agent for the treatment of asymptomatic colonization with Staphylococcus aureus. Increasing use has been associated with the emergence of mupirocin resistance in staphyloccoci, and failure of therapy has been associated with the isolation of strains exhibiting high-level resistance (MIC > 500 micrograms/mL). Fortunately, low-level mupirocin resistance (MIC < 100 micrograms/mL) occurs most commonly. Because a novel gene encoding for mupirocin resistance resides in both low-level and high-level resistant strains, the emergence of low-level mupirocin resistance may not be as epidemiologically insignificant as previously thought.

Using oral antifungal agents for severe fungal infections

The azole antifungal drugs fluconazole and itraconazole have changed our approach to the treatment of serious fungal infections. Increased use of these drugs has generated information of value for clinical practice.

Phialophora verrucosa infection in an AIDS patient

Phialophora verrucosa is one of several pathogenic dematiaceous fungi associated with chromomycosis and occasionally phaeohyphomycosis. Infection appears to be increasing in frequency in both immunocompromised and presumably healthy patients. Medical therapy is often difficult, and a wide variety of antifungal agents have been tried with varying degrees of success. We report a patient with acquired immunodeficiency syndrome (AIDS) and extensive cutaneous fungal infection due to Phialophora verrucosa. The disease failed to respond to ketoconazole, but regression of the lesions was obtained with itraconazole.

Use of a colorimetric system for yeast susceptibility testing

We examined the reliability and accuracy of a colorimetric assay using Alamar Blue reagent in the performance of susceptibility tests for Candida albicans. We compared the broth macrodilution method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) with a macrodilution method modified with the Alamar reagent and a microdilution method modified with the Alamar reagent. The MICs of fluconazole and itraconazole for 97 isolates of C. albicans and 3 control isolates were tested. For fluconazole, the Alamar-modified broth macrodilution method yielded 94% (91 of 97) concordance within 2 dilutions compared with the NCCLS method, while the microdilution method yielded 95% (92 of 97) concordance. With Alamar-modified methods for itraconazole, broth macrodilution yielded 97% (94 of 97) concordance within 2 dilutions. MICs obtained by the microdilution method, although tightly nested, were shifted to a higher value when compared with those obtained by the NCCLS method; there was only 77% (75 of 97) concordance within 2 dilutions but 97% concordance (94 of 97) within 3 dilutions. Tests by all methods with quality control strains showed excellent reproducibilities. For fluconazole, the methods modified with the Alamar reagent yielded clear endpoints and excellent correlation for the broth macrodilution and microdilution methods. For itraconazole, the methods modified with the Alamar reagent yielded clear endpoints and were reproducible, but higher MICs were obtained by the microdilution methods compared with those obtained by the NCCLS methods.

Treatment of blastomycosis with fluconazole: a pilot study. The National Institute of Allergy and Infectious Diseases Mycoses Study Group

There are few clinical data concerning the use of fluconazole, a triazole antifungal agent with in vitro activity against Blastomyces dermatitidis, in the treatment of human blastomycosis. We conducted a multicenter, randomized, open-label pilot trial comparing two daily doses of fluconazole (200 mg and 400 mg) in the treatment of non-life-threatening, non-CNS blastomycosis. Twenty-four patients were enrolled in the study, and 23 patients were evaluable for efficacy analysis. Overall, treatment of 15 (65%) of 23 patients was successful, including eight (62%) of 13 who received 200 mg daily and seven (70%) of 10 who received 400 mg daily. The mean duration of therapy for successfully treated patients was 6.7 months. Of the six patients whose prior antifungal therapy had failed, all six eventually responded to fluconazole treatment. We conclude that fluconazole (200 mg to 400 mg daily) given for at least 6 months is moderately effective treatment for blastomycosis.

Pneumococcal vertebral osteomyelitis

Vertebral osteomyelitis is an unusual complication of pneumococcal infection. This report describes a patient who presented with back pain and lower extremity weakness after bacteremic pneumococcal pneumonia. Magnetic resonance imaging showed destruction of the L-4-L-5 vertebral bodies and thecal sac compression, and Streptococcus pneumoniae was isolated from an aspirate of the disk space. We found only 10 other cases of pneumococcal vertebral osteomyelitis in a review of the literature. In these 11 cases the presentations were usually subacute, and the onset of back pain was insidious. Elevated erythrocyte sedimentation rates were commonly noted. Computed tomography and magnetic resonance imaging were most helpful in delineating the extent of involvement in patients seen in the last decade. Successful treatment included surgery alone in 2 cases that occurred before the antibiotic era, surgery plus 6 weeks of antibiotic therapy in 1, and antibiotics alone for 4 weeks to 7 months in 5. Two patients seen in the preantibiotic era died.

Validity of contour-clamped homogeneous electric field electrophoresis as a typing system for Candida albicans

Instigated by an increase in serious human Candida infections and aided by advances in technology, there has been renewed interest in the study of the epidemiology of fungal infections. Among the newer techniques available, contour-clamped homogeneous electric field (CHEF) electrophoresis has shown great promise as a tool for typing strains of Candida albicans. However, few studies have addressed the reproducibility of the preparatory and electrophoretic methods. Through a series of analyses on clinical isolates of C. albicans, we were able to demonstrate that (a) sample preparation induced no appreciable artifacts in CHEF banding patterns; (b) the electrophoretic patterns were reproducible over time; (c) changes in colony morphology were not associated with changes in the electrophoretic pattern, and (d) the method was more sensitive than restriction enzyme analysis (REA) for demonstrating strain differences. CHEF electrophoresis is a sensitive and reproducible tool for the study of Candida epidemiology. Further use and study of this methodology is warranted.

Susceptibility of ciprofloxacin-resistant staphylococci and enterococci to clinafloxacin

Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis obtained from the Ann Arbor Veterans Affairs Medical Center within the last decade were tested for susceptibility to ciprofloxacin and clinafloxacin. For MRSA isolates, the minimum inhibitory concentrations (MICs) of ciprofloxacin were several fold higher than those noted with clinafloxacin. Prior to the introduction of the fluoroquinolones (1984-1985), all MRSA isolates were susceptible to ciprofloxacin and clinafloxacin. By 1993, virtually all MRSA isolates were resistant to ciprofloxacin and a 50-fold increase in the MIC50 and MIC90 for clinafloxacin was seen. In 1985-1986, most enterococcal isolates were susceptible to ciprofloxacin and clinafloxacin. By 1993, one-third of all enterococci were resistant to both ciprofloxacin and clinafloxacin. Fluoroquinolone resistance developed more quickly in enterococci that demonstrated high-level gentamicin resistance. Thus, cross-resistance between clinafloxacin and ciprofloxacin was seen; however, the lower MICs of clinafloxacin for MRSA may allow the use of this drug for some MRSA infections.

Indolent zygomycosis associated with deferoxamine chelation therapy

This paper describes a 71-year-old man with myelodysplasia who required multiple transfusions and subsequent deferoxamine chelation therapy and who then developed indolent cutaneous and probable pulmonary infection with Rhizopus species. The patient did not have rapidly progressive infection as has been described in almost all previously reported deferoxamine-treated patients with zygomycosis. Amphotericin B therapy was successful in curing the infection.

Colonization and transmission of high-level gentamicin-resistant enterococci in a long-term care facility

OBJECTIVES

To assess the prevalence of high-level gentamicin-resistant enterococcus (HGRE) colonization, transmission patterns, and spectrum of illness among residents of a long-term care facility.

DESIGN

Monthly surveillance for HGRE colonization of wounds, rectum, and perineum over a 1-year period.

SETTING

A Veterans Affairs long-term care facility attached to an acute-care facility.

PATIENTS

All 341 patients in the facility during the observation period.

RESULTS

Over the 1-year period, 120 patients (35.2%) were colonized with HGRE at least once, with an overall monthly colonization rate of 20 +/- 1.5%. HGRE were isolated from rectum (12.8%), wounds (11.7%), and perineum (9.3%). Patients with the poorest functional status had the highest rate of colonization (P < 0.0005). HGRE-colonized patients were more likely to be colonized with methicillin-resistant Staphylococcus aureus (51% versus 25%; P < 0.0005). Seventy-four patients (21.7%) were colonized at admission or at the start of the study. Another 46 patients (13.5%) acquired HGRE during the study, including 36 who acquired HGRE while in the long-term care facility and 10 who were positive when transferred back from the acute-care hospital. Based on plasmid profiles, only two patients appeared to have isolates similar to those of current or previous roommates. Carriage of HGRE was transient in most cases. Only 20 patients were colonized for 4 or more months, and those patients usually carried different strains intermittently. Infections were infrequent, occurring in only 4.1% of total patients.

CONCLUSIONS

In our long-term care facility, HGRE were endemic, and new acquisition of HGRE occurred frequently. However, only two patients had evidence of acquisition from a roommate, suggesting that cross-infection from a roommate was not a major route of spread of HGRE.

Cryptococcal infection of a prosthetic dialysis fistula

Fungal infections of prosthetic dialysis fistulae are rare. We report the first case of infection of a polytetrafluoroethylene dialysis access graft with the yeast Cryptococcus neoformans. Therapy with antifungal agents alone failed to cure the infection and significant improvement was observed only when all prosthetic material was surgically removed. This case emphasizes the potential for fungal infection of prosthetic dialysis fistulae and the importance of removal of intravascular foreign material in conjunction with antifungal therapy for treatment of fungal prosthetic graft infections.

Epidemiology of oral candidiasis in HIV-infected patients: colonization, infection, treatment, and emergence of fluconazole resistance

PURPOSE

To study the epidemiology of oral candidiasis and the effect of treatment of thrush in human immunodeficiency virus (HIV)-infected patients.

PATIENTS AND METHODS

We conducted a prospective observational study of 92 patients over 1 year, including a nonblinded, randomized treatment trial of thrush with clotrimazole troches or oral fluconazole. Oral sites were cultured monthly and when thrush occurred. Candida albicans strains were typed by contour-clamped homogeneous electric field (CHEF) electrophoresis. Changes in strains were evaluated over time and in regard to their associations with particular sites, episodes of thrush, relapse after treatment, and colonization of sexual partners. Susceptibility to fluconazole was tested and CHEF analysis was done on these strains to determine the epidemiology of fluconazole resistance.

RESULTS

Yeasts colonized 84% of patients. C albicans accounted for 81% of all isolates and was separated into 34 distinct strains. Most patients had persistent carriage of 1 or 2 dominant strains of C albicans. Three couples shared strains. Nineteen different C albicans strains caused 82 episodes of thrush in 45 patients. CD4 < 200/microL was associated with development of thrush. Clinical cure rates were similar with fluconazole (96%) and clotrimazole (91%), but mycologic cure was better with fluconazole (49%) than clotrimazole (27%). Following mycologic cure, colonization recurred with the same strain 74% of the time. Colonization with Torulopsis glabrata and Saccharomyces cerevisiae increased after treatment with either drug, but these organisms were never a sole cause of thrush. In a subset of 35 patients followed for over 3 months in whom fluconazole susceptibilities were performed, minimum inhibitory concentrations (MICs) to fluconazole increased only in those on fluconazole prophylaxis. Clinical failure of fluconazole was associated with an MIC > or = 64 micrograms/mL in 3 patients, and with an MIC of 8 micrograms/mL in 1 patient. In 2 of these 4 patients, the prior colonizing strain developed fluconazole resistance. In the other 2, new resistant strains were acquired.

CONCLUSIONS

Many different strains of C albicans colonize and cause thrush in patients infected with HIV. Patients are usually persistently colonized with a single strain, and recurrences following treatment are usually due to the same strain. Transmission of strains may occur between couples. Fluconazole and clotrimazole are equally effective in treating thrush, but mycologic cure occurs more often with fluconazole. Fluconazole resistance in C albicans occurs most often in patients who have low CD4 counts and are taking fluconazole prophylactically for recurrent thrush. Fluconazole resistance may occur through acquisition of a new resistant strain or by development of resistance in a previously susceptible strain.