Frank G. Witebsky

Empiric antibiotic and antifungal therapy for cancer patients with prolonged fever and granulocytopenia

Abstract Since early diagnosis of even a disseminated fungal infection is difficult and treatment often ineffective in a patient with persistent granulocytopenia, we have prospectively evaluated continued antibiotic therapy and early empiric antifungal therapy in patients with prolonged fever and granulocytopenia. Between November 1975 and December 1979, all patients with fever (oral temperature >38 °C three times per 24 hours or >38.5 °C once) plus granulocytopenia (polymorphonuclear leukocytes 3 ), were evaluated and began an empiric antibiotic regimen consisting of Keflin ® , gentamicin and carbenicillin (KGC). Of the 652 episodes of fever and granulocytopenia (in 271 patients), initial evaluation failed to define an infectious etiology in 323 (49.5 percent). In 50 of the patients in whom initial evaluation did not demonstrate an infectious etiology, fever and granulocytopenia continued after seven days of therapy with KGC, without evidence for the etiology of their persistent fever. These patients were randomized to either discontinue receiving KGC (Group 1); continue receiving KGC (Group 2); continue receiving KGC with the addition of empiric amphotericin B (Group 3). The duration of granulocytopenia was comparable in the three groups (median 24 days, range 8 to 51 days). Clinically or microbiologically demonstrable infections occurred in nine of 16 patients who discontinued the KGC regimen (Group 1) (six also experienced shock, p Empiric amphotericin B therapy was also evaluated for its effectiveness in patients whose initial evaluation revealed an infectious etiology with fungal colonization throughout their alimentary tract but in whom fever and granulocytopenia remained despite at least seven days of therapy with appropriate antibiotics. In addition, the postmortem records of all patients dying between 1970 and 1979 were reviewed to ascertain the cause of death and the type of antimicrobial therapy received prior to death. Only one death due to fungal invasion occurred, when therapy with amphotericin B was instituted after one week of broad-spectrum antibiotic therapy. Collectively, these data suggest that continuing antibiotic therapy reduces early bacterial infections in patients with persistent fever and granulocytopenia and that empiric antifungal therapy also appears necessary to prevent fungal superinfections and to control clinically undetected fungal invasion.

Lysis-centrifugation blood cultures in the detection of tissue-proven invasive candidiasis : disseminated versus single-organ infection

Several studies have demonstrated significantly higher frequency and more rapid detection of candidemia with blood culture methods performed by lysis-centrifugation (LC) in comparison with other techniques. Little is known, however, about the ability of LC blood culture methods to detect tissue-proven invasive candidiasis. We therefore investigated the sensitivity of LC blood cultures in the detection of tissue-proven invasive candidiasis. Between 1985 and 1991, invasive candidiasis was detected in 41 (5.1%) of 803 autopsies at the Clinical Center of the National Institutes of Health (Bethesda, MD, USA). Cases were classified as single-organ (SO) candidiasis (n = 20) and as disseminated candidiasis (DI) (n = 21). Patients with DI were more likely than those with SO to have a hematologic malignancy (71% vs 15%, P < 0.001) and to have gastrointestinal mucosal candidiasis (76% vs 25%, P = 0.003). LC detected fungemia in 16 (43%) of all 37 cases with blood cultures. When analyzed by classification, Candida spp. were isolated from blood in 11 (58%) of 19 patients with DI and in five (28%) of 18 patients with SO (P = 0.13). When analyzed by number of organs infected, blood cultures were positive in seven (78%) of nine patients with > 3 organs infected by Candida in comparison to five (28%) of 18 patients with one organ infected (P = 0.024). The mean recovery time for Candida in blood cultures was 2.6 days in DI and 3.2 days in SO (P = 0.017). There was no difference in colonies of organisms per LC tube between patients with DI and those with SO.(ABSTRACT TRUNCATED AT 250 WORDS)

Duration of empiric antibiotic therapy in granulocytopenic patients with cancer

Abstract Early initiation of empiric antibiotic therapy in febrile cancer patients has become established practice, but the appropriate duration of antibiotic therapy when no infectious source can be identified is unknown. The complications of broad-spectrum antibiotics argue for brief treatment, but the risk of an inadequately treated infection in the granulocytopenic patient favors longer therapy. We prospectively studied 306 episodes of fever and granulocytopenia in 143 patients with leukemia or solid tumor (age one to 33 years) with respect to the duration of empiric antibiotic treatment. Eligible patients (fever > 38 °C three times/24 hours or > 38.5 °C once, plus polymorphonuclear leukocytes 3 ) had an extensive diagnostic evaluation, including at least two preantibiotic blood cultures, and therapy was then started with a broad-spectrum antibiotic regimen— Keflin ® , gentamicin and carbenicillin (KGC). Initial evaluation failed to identify an infectious etiology for the fever in 142 of 306 (46 per cent) episodes. Fifty-six of 142 (39 per cent) of these fevers of unknown origin were associated with persistent granulocytopenia for more than seven days; in 33 of these, defervescence occurred while the patients received KGC. After seven days of empiric KGC therapy, the 33 patients with fevers of unknown origin who had become afebrile with empiric antibiotics but whose polymorphonuclear leukocytes remained less than 500/mm 3 were randomized to either continue or discontinue (dc) to receive KGC. The patients who continued to receive KGC until their polymorphonuclear leukocytes were more than 500/mm 3 had no infectious sequelae. However, in seven of 17 (41 per cent) of the patients randomized to dc KGC infectious sequelae developed (p = 0.007) within a median of two days of discontinuing KGC (two with fever which again responded to KGC therapy, and five with a documented infection [two ultimately fatal]). In none of the patients did a resistant microbial flora or superinfection develop. These data suggest that the patient with a fever of unknown origin who becomes afebrile during empiric antibiotic therapy may profit from continued therapy while granulocytopenia persists.

Evaluation of Partial 16S Ribosomal DNA Sequencing for Identification of Nocardia Species by Using the MicroSeq 500 System with an Expanded Database

ABSTRACT Identification of clinically significant nocardiae to the species level is important in patient diagnosis and treatment. A study was performed to evaluate Nocardia species identification obtained by partial 16S ribosomal DNA (rDNA) sequencing by the MicroSeq 500 system with an expanded database. The expanded portion of the database was developed from partial 5′ 16S rDNA sequences derived from 28 reference strains (from the American Type Culture Collection and the Japanese Collection of Microorganisms). The expanded MicroSeq 500 system was compared to (i) conventional identification obtained from a combination of growth characteristics with biochemical and drug susceptibility tests; (ii) molecular techniques involving restriction enzyme analysis (REA) of portions of the 16S rRNA and 65-kDa heat shock protein genes; and (iii) when necessary, sequencing of a 999-bp fragment of the 16S rRNA gene. An unknown isolate was identified as a particular species if the sequence obtained by partial 16S rDNA sequencing by the expanded MicroSeq 500 system was 99.0% similar to that of the reference strain. Ninety-four nocardiae representing 10 separate species were isolated from patient specimens and examined by using the three different methods. Sequencing of partial 16S rDNA by the expanded MicroSeq 500 system resulted in only 72% agreement with conventional methods for species identification and 90% agreement with the alternative molecular methods. Molecular methods for identification of Nocardia species provide more accurate and rapid results than the conventional methods using biochemical and susceptibility testing. With an expanded database, the MicroSeq 500 system for partial 16S rDNA was able to correctly identify the human pathogens N. brasiliensis, N. cyriacigeorgica, N. farcinica, N. nova, N. otitidiscaviarum, and N. veterana.

Fulminant Mulch Pneumonitis: An Emergency Presentation of Chronic Granulomatous Disease

BACKGROUND Chronic granulomatous disease (CGD) is associated with multiple and recurrent infections. In patients with CGD, invasive pulmonary infection with Aspergillus species remains the greatest cause of mortality and is typically insidious in onset. Acute fulminant presentations of fungal pneumonia are catastrophic. METHODS Case records, radiograph findings, and microbiologic examination findings of patients with CGD who had acute presentations of dyspnea and diffuse pulmonary infiltrates caused by invasive fungal infection were reviewed and excerpted onto a standard format. RESULTS From 1991 through 2004, 9 patients who either were known to have CGD or who received a subsequent diagnosis of CGD presented with fever and new onset dyspnea. Eight patients were hypoxic at presentation; bilateral pulmonary infiltrates were noted at presentation in 6 patients and developed within 2 days after initial symptoms in 2 patients. All patients received diagnoses of invasive filamentous fungi; 4 patients had specimens that also grew Streptomyces species on culture. All patients had been exposed to aerosolized mulch or organic material 1-10 days prior to the onset of symptoms. Cases did not occur in the winter. Five patients died. Two patients, 14 years of age and 23 years of age, who had no antecedent history of recognized immunodeficiency, were found to have p47(phox)-deficient CGD. CONCLUSIONS Acute fulminant invasive fungal pneumonia in the absence of exogenous immunosuppression is a medical emergency that is highly associated with CGD. Correct diagnosis has important implications for immediate therapy, genetic counseling, and subsequent prophylaxis.

Sepsis with a New Species of Corynebacterium

Sepsis with a previously undescribed species of Corynebacterium was documented in four patients. All patients had predisposing illness at the time of infection, three patients having leukemia in relapse and one having a porencephalic cyst and a ventriculoatrial shunt. The isolates from blood cultures had a characteristic metallic sheen when grown on blood agar. They were resistant to most antibiotics tested, including the penicillins, but were uniformly sensitive to vancomycin. Common biochemical characteristics, the metallic sheen, and the unusual antibiotic sensitivity pattern suggest that these isolates comprise a new species or group of closely related species of Corynebacterium that is capable of infection in man.

Malignant Lymphoma in Patients with the Wiskott-Aldrich Syndrome

The type and incidence of malignant lymphoma developing in patients with the Wiskott-Aldrich syndrome being followed at the National Cancer Institute (NCI) between the years 1966 and 1982 was evaluated. Histologic material from lymphoid tissue was available for review on 24 of the 50 Wiskott-Aldrich patients followed by the Metabolism Branch of the NCI. In 17 patients, specimens were obtained by biopsy performed for diagnosis of lymphoid mass lesions, and in 16 patients autopsy specimens were reviewed. In 9 of the 24 patients a diagnosis of malignant lymphoma was made. A distinct preponderance of non-Hodgkins lymphoma (NHL) over Hodgkins disease (HD) with a ratio 8:1 was observed, and the overall incidence of malignant lymphoma in all 50 patients was 18%. The most common histologic subtype of NHL was large cell immunoblastic. In all but one patient the diagnosis of lymphoma was made antemortem, most often presenting in extranodal sites or the brain. Involvement of peripheral lymph nodes was conspicuous by its absence. Immunoperoxidase staining for kappa and lambda chain immunoglobulin and lysozyme was negative in the four cases studied, failing to provide supportive evidence for a B-cell or true histiocytic origin for the tumor cells. Histologic subtypes of lymphoma commonly observed in childhood, such as Burkitts lymphoma and lymphoblastic lymphoma, were not observed. Despite treatment with combination chemotherapy in some patients, there were no long-term remissions and median survival was less than one year following the diagnosis of lymphoma.

Nocardia Infection in Chronic Granulomatous Disease

To determine the clinical characteristics and outcome of Nocardia infection in patients with chronic granulomatous disease (CGD), we reviewed data on 28 episodes of Nocardia infection in 23 patients with CGD. All episodes involved pulmonary infection. The frequency of disseminated nocardiosis was 25% for the case series overall, but it was 56% among episodes in patients receiving neither interferon-gamma (IFN-gamma) nor sulfonamide prophylaxis. Patients receiving prophylaxis with IFN-gamma and/or a sulfonamide were significantly less likely to have disseminated nocardiosis than were patients not receiving these medications, and no patient receiving both medications developed disseminated nocardiosis. One-third of the patients had concomitant fungal infections, and 2 patients had concomitant Legionella infections. The majority of patients were successfully treated with a sulfonamide-containing regimen, even though some patients had developed Nocardia infection while receiving sulfonamide prophylaxis. Nocardia infections in patients with CGD are not usually fatal if treated properly, and prophylaxis with IFN-gamma and a sulfonamide may protect against dissemination.

Analysis of secA1 Gene Sequences for Identification of Nocardia Species

ABSTRACT Molecular methodologies, especially 16S rRNA gene sequence analysis, have allowed the recognition of many new species of Nocardia and to date have been the most precise methods for identifying isolates reliably to the species level. We describe here a novel method for identifying Nocardia isolates by using sequence analysis of a portion of the secA1 gene. A region of the secA1 gene of 30 type or reference strains of Nocardia species was amplified using secA1-specific primers. Sequence analysis of 468 bp allowed clear differentiation of all species, with a range of interspecies similarity of 85.0% to 98.7%. Corresponding 16S rRNA gene sequences of a 1,285-bp region for the same isolates showed a range of interspecies similarity of 94.4 to 99.8%. In addition to the type and reference strains, a 468-bp fragment of the secA1 gene was sequenced from 40 clinical isolates of 12 Nocardia species previously identified by 16S rRNA gene sequence analysis. The secA1 gene sequences of most isolates showed >99.0% similarity to the secA1 sequences of the type or reference strain to which their identification corresponded, with a range of 95.3 to 100%. Comparison of the deduced 156 amino acid sequences of the SecA1 proteins of the clinical isolates showed between zero and two amino acid residue differences compared to that of the corresponding type or reference strain. Sequencing of the secA1 gene, and using deduced amino acid sequences of the SecA1 protein, may provide a more discriminative and precise method for the identification of Nocardia isolates than 16S rRNA gene sequencing.

Analysis of Multiple Differing Copies of the 16S rRNA Gene in Five Clinical Isolates and Three Type Strains of Nocardia Species and Implications for Species Assignment

ABSTRACT Five clinical isolates of Nocardia that showed ambiguous bases within the variable region of the 16S rRNA gene sequence were evaluated for the presence of multiple copies of this gene. The type strains of three Nocardia species, Nocardia concava, Nocardia ignorata, and Nocardia yamanashiensis, which also showed ambiguous bases in the variable region, were also examined. Cloning experiments using an amplified region of the 16S rRNA that contains the variable region showed that each isolate possessed 16S rRNA genes with at least two different sequences. In addition, hybridization studies using a 16S rRNA gene-specific probe and extracted genomic DNA of the patient isolates and of the type strain of N. ignorata showed that each isolate possessed at least three copies of the gene. These multiple differing copies of the 16S rRNA gene and the results of DNA-DNA hybridization studies indicate problems of species definition and identification for such isolates. A broader species concept than that currently in vogue may be required to accommodate such organisms.