Risk factor analysis of Histoplasma capsulatum fungemia.

The primary objective of the study was to investigate the risk factors for Histoplasma capsulatum fungemia. We conducted a retrospective case-control study among patients with histoplasmosis seen at Mayo Clinic in Rochester from 1 January 1991 through 31 December 2005. Blood cultures were prepared from specimens obtained from 111 patients with a diagnosis of histoplasmosis of which 55 had demonstrated H. capsulatum fungemia whereas the cultures of the remaining 56 patients were negative. The mean age of the patients was 56 years, of which 70% men and 95% were white. In univariate analysis, immunocompromised status (OR 2.9, P=0.008), peripheral leukocyte count (WBC)<3000 cells/mm(3) (OR 7.3, P<0.001), albumin<3.5 g/ dl (OR 3.1, P=0.018), and Charlson score of>4 (OR 2.9, P=0.022) were associated with H. capsulatum fungemia, but age>55 years was not (OR 1.4, P=0.38). In multivariable analysis, immunocompromised status (OR 2.4, P=0.043) and WBC<3000 cells/mm(3) (OR 6.5, P=0.001) remained significant factors associated with H. capsulatum fungemia. Immunocompromised status and WBC<3000 cells/ mm(3) are independent risk factors for the development of H. capsulatum fungemia.

Comparison of abdominal ultrasound and magnetic resonance imaging for detection of abdominal lymphadenopathy in dogs with metastatic apocrine gland adenocarcinoma of the anal sac.

Imaging studies in humans with anal and rectal cancer indicate that magnetic resonance imaging (MRI) is a more sensitive technique than abdominal ultrasound (AUS) for the detection of abdominal lymphadenopathy. The purpose of this retrospective study was to directly compare the efficacy of these two techniques in detecting abdominal lymphadenopathy in dogs with apocrine gland adenocarcinoma of the anal sac (AGAAS). Six dogs with histologically confirmed AGAAS and histopathologic confirmation of metastasis to abdominal lymph nodes (LNs) had AUS and abdominal MRI. AUS identified lymphadenopathy in two of six dogs, whereas MRI identified lymphadenopathy in all the six dogs. Lymphadenopathy was predominantly sacral in location, with involvement of the medial iliac and hypogastric LNs in only two cases. These data suggest that MRI is more sensitive than AUS for detecting sacral abdominal lymphadenopathy in dogs with AGAAS. As such, MRI could be considered in any patient with AGAAS for initial staging of this disease.

Structural fingerprinting of Asn-linked carbohydrates from specific attachment sites in glycoproteins by mass spectrometry: application to tissue plasminogen activator.

A sensitive and specific strategy has been developed for determining the sites of attachment of Asn-linked carbohydrates in glycoproteins, and defining the compositions and molecular heterogeneity of carbohydrates at each specific attachment site. In this carbohydrate 'fingerprinting' strategy, potential glycopeptides are identified by comparing the high pressure liquid chromatography (HPLC) chromatograms of proteolytic digests of a glycoprotein obtained before and after digestion with a glycosidase, usually peptide:N-glycosidase F (PNGase F). The glycopeptide-containing HPLC fractions are analyzed by fast atom bombardment mass spectrometry (FAB MS) prior to and after digestion with PNGase F to identify the former glycosylation site peptide and its sequence location (Carr and Roberts, (1986) Anal. Biochem. 157, 396-406). Carbohydrates are extracted from these fractions as the peracetates which are then permethylated and analyzed by FAB MS. The spectra exhibit molecular weight-related ions for each of the parent oligosaccharides present in the fraction which provide composition in terms of hexose, deoxyhexose, N-acetylhexosamine and sialic acid. The relative ratios of these peaks reflect the relative abundances of the various carbohydrate homologs present in the mixture. The derivatives formed are directly amenable to methylation analysis for determination of linkage. This strategy enables the structural classes of carbohydrates at specific attachment sites to be determined using only a few nmol of glycoprotein. The carbohydrate fingerprinting strategy has been applied to a number of glycoproteins including tissue plasminogen activator, the results for which are described herein.

Trimethoprim/sulfamethoxazole-resistant Nocardia asteroides causing multiple hepatic abscesses. Successful treatment with ampicillin, amikacin, and limited computed tomography-guided needle aspiration.

Hepatic abscesses are rarely encountered in disseminated Nocardia infections. Sulfonamides alone or trimethoprim/sulfamethoxazole is often efficacious in treating infections caused by Nocardia asteroides. In vitro resistance of N. asteroides to trimethoprim/sulfamethoxazole is occasionally present. The patient described in this report had disseminated nocardiosis initially manifesting as multiple subcapsular hepatic abscesses. In vitro susceptibility studies demonstrated resistance to trimethoprim/sulfamethoxazole. Subsequent treatment with ampicillin and amikacin in conjunction with computed tomography-guided needle aspiration of several of the hepatic abscesses, surgical drainage of a right pleural empyema, and eventual discontinuation of use of corticosteroids resulted in cure of the infection.

Laboratory methods for the diagnosis of disseminated histoplasmosis: clinical importance of the lysis-centrifugation blood culture technique.

Disseminated histoplasmosis, an uncommon disease that is usually fatal if not treated, is being recognized with increasing frequency in immunosuppressed patients. We retrospectively reviewed the laboratory methods used to establish the diagnosis of disseminated histoplasmosis in 28 patients examined at our institution. Tissue stains provided the initial diagnosis in 13 of the patients (46%). Serologic tests (complement fixation or immunodiffusion) were positive in 25 patients (89%); the frequencies of positive serologic results were similar in immunocompetent and in immunosuppressed patients. Blood cultures were positive in 20 of the patients (71%) and provided the initial diagnosis in 7 (25%); 5 of these 7 cases (71%) were detected with use of the lysis-centrifugation method. Furthermore, the recovery time for this blood culture method was less than that for a conventional blood culture method (brain-heart infusion biphasic technique). The lysis-centrifugation blood culture technique is an important laboratory method for the diagnosis of disseminated histoplasmosis.

Rhodotorula septicemia: two cases and a review of the literature.

Rhodotorula glutinis var. glutinis was isolated from the blood of two patients who were seriously ill and required long-term intravenous therapy. Although both isolates were sensitive to amphotericin B and 5-fluorocytosine, neither patient received antifungal therapy. One of the two patients died, but Rhodotorula was not recovered at autopsy. Review of the literature shows that Rhodotorula septicemia is often associated with contamination of intravenous infusion equipment, resulting in toxemia and hypotension. Initial therapy for fungemia should consist of removal of infected cannulas and fluid replacement. If fungemia persists, antifungal drug therapy should be considered.

Clinical significance of Pseudallescheria boydii: a review of 10 years' experience.

Pseudallescheria boydii is a recognized cause of mycetoma, a chronic fungal disease that usually affects the extremities. Isolated case reports have also implicated P. boydii in infections of other sites. We report the first large series (83 isolates) of P. boydii in 46 patients, including the second report of P. boydii brain abscess and disseminated infection in a noncompromised host. Between 1974 and 1984 at our institution, P. boydii was cultured from a variety of sites: respiratory tract, 36; soft tissue, 25; bone, 9; gastric aspirate, 4; maxillary sinus, 2; wound, 2; urine, 2; brain abscess, 1; ear, 1; and toenail, 1. Pulmonary colonization proved to be the most common form of pseudallescheriasis of the lung (34 of 36 cultures in this category); 28 of the 32 patients with pulmonary infections had received immunosuppressive therapy or had an underlying disorder. The importance of isolation of P. boydii from bone and soft tissue is supported in this series because all 9 cultures from bone and 21 of 25 cultures from soft tissue were associated with infection. Of 10 cases of infection, 5 were osteomyelitis and 2 were infected wounds; in addition, maxillary sinusitis, disseminated infection, and a lung abscess occurred in 1 patient each.

Should yeasts in respiratory secretions be identified?

Four hundred forty samples of sputa and bronchial washings were examined microscopically for evidence of pulmonary and oropharyngeal secretions. Most (88%) sputa showed definite evidence of oropharyngeal contamination, whereas bronchial washings showed much less frequent (21%) contamination. Culture results of the same specimens showed that yeasts (excluding dimorphic fungi) were recovered from 74% of the sputa and 25% of the bronchial washings. It seems that microscopic evidence of oropharyngeal contamination is a reliable index for predicting the presence of yeasts in respiratory secretions. Their presence in cultures of respiratory secretions probably represents "normal flora" except for Cryptococcus neoformans, and their routine identification is not warranted.

Invasive disease caused by Trichosporon beigelii.

An immunocompromised patient had cellulitis that was unresponsive to conventional antimicrobial therapy. Skin biopsy specimens and fungal blood cultures revealed the offending organism as Trichosporon beigelii. Recognition of this opportunistic pathogen in immunocompromised patients is important.

Quantitative blood cultures in candidemia.

The relationship between quantitative data on peripheral blood cultures and source of infection was studied in 172 episodes of candidemia that occurred in 169 patients. Clinically, the source of candidemia was an intravascular device in 67 episodes, an extravascular source in 73 episodes, and endocarditis in 2 patients; no source was identified for the other 30 episodes. Colony counts were determined in peripheral blood specimens on the first day of candidemia by the lysis-centrifugation system. High-grade and low-grade candidemia were defined as 25 colony-forming units or more per 10 ml and 10 colony-forming units or fewer per 10 ml of blood, respectively. Of 48 episodes of high-grade candidemia, 43 (90%) were associated with an infected intravascular device; therefore, the presence of high-grade candidemia should prompt the removal of intravascular devices. In contrast, 92 of the 112 episodes of low-grade candidemia (82%) had an extravascular or an unidentified source of candidemia. In patients with infections associated with an intravascular device, colony counts declined significantly within 72 hours after removal of the device in the absence of antifungal therapy; failure to decline suggests an alternative source of persistent infection. Quantitative data from peripheral blood cultures may help distinguish intravascular from extravascular sources of candidemia and aid in assessing the response to the removal of infected intravascular devices.

Disseminated Aspergillus terreus infection in immunocompromised hosts.

Aspergillus terreus is ubiquitous in the environment but has rarely been found to be pathogenic. When recovered from clinical specimens, it is commonly considered a saprophyte. We report two cases of fatal disseminated A. terreus infection. The first patient was receiving corticosteroid therapy for immune thrombocytopenia when the condition developed, and the second patient was receiving immunosuppressive therapy after bone marrow transplantation for myelodysplasia. We also describe the frequency of recovery of A. terreus in our laboratory. The serious pathogenic potential of A. terreus in immunocompromised hosts should be recognized.

Massive antigenemia during disseminated cryptococcosis.

Three cases of disseminated cryptococcosis associated with massive levels of cryptococcal antigen in the serum and cerebrospinal fluid are presented. These patients had antigen titers of at least 1:32,768. Titers of this magnitude have not previously been reported.

The diagnosis and incidence of allergic fungal sinusitis.

OBJECTIVE: To reevaluate the current criteria for diagnosing allergic fungal sinusitis (AFS) and determine the incidence of AFS in patients with chronic rhinosinusitis (CRS). METHODS: This prospective study evaluated the incidence of AFS in 210 consecutive patients with CRS with or without polyposis, of whom 101 were treated surgically. Collecting and culturing fungi from nasal mucus require special handling, and novel methods are described. Surgical specimen handling emphasizes histologic examination to visualize fungi and eosinophils in the mucin. The value of allergy testing in the diagnosis of AFS is examined. RESULTS: Fungal cultures of nasal secretions were positive in 202 (96%) of 210 consecutive CRS patients. Allergic mucin was found in 97 (96%) of 101 consecutive surgical cases of CRS. Allergic fungal sinusitis was diagnosed in 94 (93%) of 101 consecutive surgical cases with CRS, based on histopathologic findings and culture results. Immunoglobulin E-mediated hypersensitivity to fungal allergens was not evident in the majority of AFS patients. CONCLUSION: The data presented indicate that the diagnostic criteria for AFS are present in the majority of patients with CRS with or without polyposis. Since the presence of eosinophils in the allergic mucin, and not a type I hypersensitivity, is likely the common denominator in the pathophysiology of AFS, we propose a change in terminology from AFS to eosinophilic fungal rhinosinusitis.

Prospective evaluation of the utility of molecular techniques for diagnosing nosocomial transmission of multidrug-resistant tuberculosis.

OBJECTIVE: To compare molecular techniques with conventional diagnostic methods for evaluating nosocomial transmission of multidrug-resistant tuberculosis (MDR-TB). DESIGN: We conducted a 12-week postexposure inception cohort study of health-care personnel who had been exposed to a patient with MDR-TB. MATERIAL AND METHODS: In addition to baseline and follow-up tuberculin skin tests and chest roentgenography, weekly pulmonary specimens were evaluated by (1) auramine-rhodamine fluorescent staining, (2) culture for mycobacteria, and (3) polymerase chain reaction (PCR) to amplify IS6110, a nucleic acid insertion sequence unique to the Mycobactrium tuberculosis complex. RESULTS: The index patient's isolate of M. tuberculosis showed a mutation in codon 531 of the RNA polymerase beta subunit (rpoB) gene of M. tuberculosis, which is associated with rifampin resistance and considered a marker for this MDR-TB strain. All pulmonary and gastric specimens from study participants had negative auramine stains and cultures for mycobacteria, One person, however, had separate specimens with repeatedly positive PCR results for IS6110 sequences, but the specimens contained a wild-type M. tuberculosis rpoB codon 531 dissimilar from the index patient's strain. CONCLUSION: Although both molecular and conventional testing showed that no exposed person was infected with the MDR-TB strain, molecular test results were available sooner and seemed more sensitive for detecting M. tuberculosis in one exposed person, presumably in a preinfection or "colonized" stage. Molecular methods provided information that helped distinguish this person's M. tuberculosis strain from the index patient's MDR-TB strain. Additional prospective studies should assess the value of these molecular techniques in similar clinical settings.

Laboratory diagnosis of fungal infections.

Most hospitals do not perform mycologic examinations because laboratory personnel still believe in the "old wives' tale" that mycology is too difficult to do and that the fungi are too infectious to handle. This discussion presents methods suitable for use in laboratories of all sizes. It is hoped that laboratories will take the initiative in offering diagnostic mycology services routinely. Medical mycology can be both a challenge and a rewarding experience to those who choose to become involved.

Cryptococcosis, with emphasis on the significance of isolation of Cryptococcus neoformans from the respiratory tract.

Cryptococcus neoformans was isolated from 65 patients: 11 had meningitis, 11 had disseminated cryptococcosis without meningitis, and 43 had C neoformans isolated from the respiratory tract. Predisposing conditions and the diagnostic value of cultures from various sites and of the latex agglutination test on cerebrospinal fluid and serum are analyzed for patients with extrapulmonary disease. Nine patients had pleural effusions; the effusion was cultured in six and yielded C neoformans in four. None of 11 deaths among 43 patients with respiratory tract isolates could be attributed to cryptococosis. The 32 survivors were nor treated with antifungal agents. Twenty-six of 43 patients with respiratory isolates had various bronchopulmonary disorders, with chronic obstructive pulmonary diseases and asthma the most common (28 percent). Seven of 28 patients (25 percent) with roentgenographically detected lung lesions had carcinoma of the lung. Roentgenographic evidence of a lung lesion and C neoformans grown from the respiratory tract warrant a further search for carcinoma of the lung.

Epidemic of pulmonary blastomycosis (Namekagon fever) in Wisconsin canoeists.

Epidemics of pulmonary blastomycosis have rarely been reported. The following epidemic occurred in a Minnesota family and several of their acquaintances after a canoeing trip in northwestern Wisconsin. The common exposure area was most likely a campsite, located along the upper reaches of the Namekagon River. The Namekagon River Valley is a known endemic area of Namekagon fever (blastomycosis) in dogs. Approximately one month after returning home, five of the eight members of the group had positive direct microscopic examinations and cultures of Blastomyces dermatitidis from their sputa, as well as abnormalities on their chest roentgenograms. Among these five patients, four were symptomatic, with fever, cough, and pleuritic chest pain. Of the three others, one had pleuritic chest pain with a transient lung infiltrate, the second was asymptomatic with a transient lung infiltrate, and the third was asymptomatic with a normal chest roentgenogram. Results of acute serologic tests (complement fixation and immunodiffusion) were negative in all five patients evaluated. None of the patients received antifungal therapy. Follow-up five years after the epidemic revealed that all eight were in excellent health, and none had evidence of continuing pulmonary or extrapulmonary disease.

Nocardia otitidiscaviarum (caviae) infection in a heart transplant patient presented as having a thigh abscess (Madura thigh).

The first case of disseminated infection with Nocardia otitidiscaviarum in a heart transplant patient is reported. The clinical spectrum and treatment of infections with N. otitidiscaviarum is discussed, including our patient's apparent response to imipenem/cilastatin.

Replication of fungi in K-Sol corneal preservation medium at 4 degrees C.

We examined the growth of six fungi during 18 days at 4 degrees C in a corneal preservation medium containing 2.5% chondroitin sulfate (K-Sol). The number of viable organisms decreased with time for all six fungi, the average decrease being 65%. The risk of transplanting fungal organisms with a donor cornea stored for up to 18 days at 4 degrees C in preservation media containing chondroitin sulfate is no greater than that with the same cornea stored for only one day.

Fungal sinusitis in healthy and immunocompromised individuals.

Clinical and microbiologic aspects of fungal sinusitis occurring in six patients are presented. Three of the six patients were immunosuppressed. Fatal disseminated fungal disease developed in two of those immunosuppressed. The three patients with normal immune function had fungal infections confined to the nasal sinuses. Aspergillus fumigatus and Aspergillus flavus were recovered from the immunosuppressed patients and Sporothrix schenckii, Alternaria species, and Pseudallescheria boydii were recovered from the immunocompetent patients. Surgical debridement was performed on all patients; however, anti-fungal therapy only was prescribed in patients who were at risk of progressive fungal disease. The microbiology laboratory aids in the diagnosis of fungal sinusitis by examining surgical biopsy material for fungal organisms and by culturing the material for recovery of the fungal pathogen.