Charles W. Stratton

Chlamydia pneumoniae infection of the central nervous system in multiple sclerosis.

Our identification of Chlamydia pneumoniae in the cerebrospinal fluid (CSF) of a patient with multiple sclerosis (MS) led us to examine the incidence of this organism in the CSF from 17 patients with relapsing–remitting MS, 20 patients with progressive MS, and 27 patients with other neurological diseases (OND). CSF samples were examined for C pneumoniae by culture, polymerase chain reaction assays, and CSF immunoglobulin (Ig) reactivity with C pneumoniae elementary body antigens. C pneumoniae was isolated from CSF in 64% of MS patients versus 11% of OND controls. Polymerase chain reaction assays demonstrated the presence of C pneumoniae MOMP gene in the CSF of 97% of MS patients versus 18% of OND controls. Finally, 86% of MS patients had increased CSF antibodies to C pneumoniae elementary body antigens as shown by enzyme‐linked immunosorbent assay absorbance values that were 3 SD greater than those seen in OND controls. The specificity of this antibody response was confirmed by western blot assays of the CSF, using elementary body antigens. Moreover, CSF isoelectric focusing followed by western blot assays revealed cationic antibodies against C pneumoniae. Infection of the central nervous system with C pneumoniae is a frequent occurrence in MS patients. Although the organism could represent the pathogenetic agent of MS, it may simply represent a secondary infection of damaged central nervous system tissue. A therapeutic trial directed at eliminating C pneumoniae from the central nervous system may provide additional information on its role in MS. Ann Neurol 1999;46:6–14

Blastomycosis in Patients with the Acquired Immunodeficiency Syndrome

OBJECTIVE To describe the clinical, demographic, radiographic, diagnostic, and therapeutic aspects of blastomycosis in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN A retrospective survey. SETTING Ten university medical centers and community hospitals, six in geographic areas endemic for Blastomyces dermatitidis, and four outside the endemic area. PATIENTS We identified 15 patients with blastomycosis and positive serologic test results for human immunodeficiency virus (HIV). MEASUREMENTS A diagnosis of blastomycosis was based on a positive culture (14 patients) or typical histopathologic features (one patient) for B. dermatitidis in clinical specimens. RESULTS Twelve of 15 patients had a previous or concomitant AIDS-defining illness at the time of diagnosis of blastomycosis, and only one patient had a CD4 lymphocyte count of greater than 200 cells/mm3. Two patterns of disease emerged: localized pulmonary involvement (seven patients), and disseminated or extrapulmonary blastomycosis (eight patients). Central nervous system involvement was common (40%). Six patients died within 21 days of presentation with blastomycosis, including four patients with disseminated and two with fulminant pulmonary disease. Among the nine patients who survived longer than 1 month, all received amphotericin B as initial antifungal therapy, and most received subsequent therapy with ketoconazole. Only two of these nine patients died with evidence of progressive blastomycosis. CONCLUSIONS Blastomycosis is a late and frequently fatal infectious complication in a few patients with AIDS. In these patients, overwhelming disseminated disease including involvement of the central nervous system is common, and it is associated with a high early mortality. Initial therapy with amphotericin B is appropriate in patients with AIDS and presumptive blastomycosis.

Spontaneous bacterial peritonitis: A review of 28 cases with emphasis on improved survival and factors influencing prognosis

During a five year period, 28 episodes of spontaneous bacterial peritonitis were documented. The number of cases recognized annually increased during the study period. Clinical and laboratory features of spontaneous bacterial peritonitis were similar to those previously reported; however, mortality was considerably lower (57 per cent). Factors associated with adverse prognosis were increasing hepatic encephalopathy, more than 85 per cent granulocytes in peripheral blood or ascitic fluid, total bilirubin greater than 8 mg/dl and serum albumin less than 2.5 g/dl. Temperature greater than 38 degrees C was associated with increased survival. Infection by enteric organisms was associated with higher mortality than infection by nonenteric organisms. Unexpectedly, patients with bacteremia fared no worse than those whose blood remained sterile. The data suggest that in patients with leukocyte counts greater than 1,000 cells/mm3 and more than 85 per cent granulocytes in their ascitic fluid, the likelihood of spontaneous bacterial peritonitis is high. Such patients deserve empiric antibiotic therapy pending the results of appropriate cultures.

Multiple sclerosis associated with Chlamydia pneumoniae infection of the CNS

Figure. Changes of serum parameters in two cases of autoimmune hepatitis after thyroid autoimmunity during IFN-a 2a (A) or IFN-Plb (B) treatment for MS. Serum parameters studied are aspartate (AST) and alanine (ALT) aminotransferases, IgM, thyroid-stimulating hormone (TSH), free thyroxine (fT4), anti-human thyroglobulin antibody (HTG Ab), ANA, and anti-smooth muscle antibody (SMA). TSH and HTG A b are expressed in IUIL Medical Research Council serum standard 801558 for TSH or 65/93 for HTG Ab.

Multicenter collaborative evaluation of a standardized serum bactericidal test as a prognostic indicator in infective endocarditis

One hundred twenty-nine patients with bacterial endocarditis were evaluated in a multicenter collaborative study to determine whether a standardized serum bactericidal test could predict the outcome of the infection. All centers used a microdilution test method that defined all known test variables, including inoculum size, culture medium, dilution technique, incubation time, method of subculture, and bactericidal endpoint. Peak serum bactericidal titers of 1:64 or more and trough serum bactericidal titers of 1:32 or more predicted bacteriologic cure in all patients. The traditionally recommended serum bactericidal titer of 1:8 had statistically significant predictive accuracy at trough antibiotic levels only. The serum bactericidal test was a poor predictor of bacteriologic failure and ultimate clinical outcome, which depends on many factors. Wider recognition by physicians and clinical microbiologists that this in vitro test of antimicrobial activity can accurately predict bacteriologic success but cannot accurately predict either bacteriologic failure or clinical outcome could lead to a better consensus about its appropriate use. On the basis of the results of this study, peak serum bactericidal titers of 1:64 or more and trough serum bactericidal titers of 1:32 or more are recommended to provide optimal medical therapy for infective endocarditis.

C. Diff Quik Chek Complete Enzyme Immunoassay Provides a Reliable First-Line Method for Detection of Clostridium difficile in Stool Specimens

ABSTRACT We evaluated a single membrane device assay for simultaneously detecting both Clostridium difficile glutamate dehydrogenase (GDH) and toxin A/B antigens against a standard that combines two PCR assays and cytotoxigenic culture. Results showing dual GDH and toxin A/B antigen positives and negatives can be reported immediately as true positives and negatives, respectively. Specimens with discrepant results for GDH and toxins A/B, which comprised 13.2% of the specimens, need to be retested.

Multicenter Collaborative Evaluation of a Standardized Serum Bactericidal Test as a Predictor of Therapeutic Efficacy in Acute and Chronic Osteomyelitis

Forty-eight episodes of osteomyelitis, 30 acute and 18 chronic, were evaluated in a prospective multicenter collaborative study to determine whether a standardized serum bactericidal test could predict outcome of infection. All centers used a microdilution test method that defined the recognized important test variables, including inoculum size, culture medium, dilution technique, incubation time, method of subculture, and bactericidal endpoint. In patients with acute osteomyelitis, peak serum bactericidal titers had no predictive value; however, trough titers of 1:2 or greater accurately predicted cure, whereas trough titers of less than 1:2 predicted therapeutic failure. In patients with chronic osteomyelitis, peak serum bactericidal titers of 1:16 or greater and trough titers of 1:4 or greater accurately predicted cure, whereas peak titers of less than 1:16 and trough titers of less than 1:2 accurately predicted failure. It is concluded that this standardized serum bactericidal test provides good prognostic information in patients with osteomyelitis, and it is recommended that patients with acute osteomyelitis have serum bactericidal titers of 1:2 or greater at all times and that patients with chronic osteomyelitis have serum bactericidal titers of 1:4 or greater at all times.

Comparison of the Luminex xTAG RVP Fast Assay and the Idaho Technology FilmArray RP Assay for Detection of Respiratory Viruses in Pediatric Patients at a Cancer Hospital

ABSTRACT Respiratory viruses are increasingly recognized as serious causes of morbidity and mortality in immunocompromised patients. The rapid and sensitive detection of respiratory viruses is essential for the early diagnosis and administration of appropriate antiviral therapy, as well as for the effective implementation of infection control measures. We compared the performance of two commercial assays, xTAG RVP Fast (Luminex Diagnostics, Toronto, Canada) and FilmArray RVP (FA RVP; Idaho Technology, Salt Lake City, UT), in pediatric patients at Memorial Sloan-Kettering Cancer Center. These assays detect the following viruses: respiratory syncytial virus; influenza A and B viruses; parainfluenza viruses 1, 2, 3, and 4; human metapneumovirus; adenovirus; enterovirus-rhinovirus; coronaviruses NL63, HKU1, 229E, and OC43; and bocavirus. We tested a total of 358 respiratory specimens from 173 pediatric patients previously tested by direct fluorescence assay (DFA) and viral culture. The overall detection rate (number of positive specimens/total specimens) for viruses tested by all methods was 24% for DFA/culture, 45% for xTAG RVP Fast, and 51% for FA RVP. The agreement between the two multiplex assays was 84.5%, and the difference in detection rate was statistically significant (P < 0.0001). Overall, the FA RVP assay was more sensitive than the xTAG RVP Fast assay and had a turnaround time of approximately 1 h. The sensitivity, simplicity, and random-access platform make FA RVP an excellent choice for laboratory on-demand service with low to medium volume.

Improved Identification of Yeast Species Directly from Positive Blood Culture Media by Combining Sepsityper Specimen Processing and Microflex Analysis with the Matrix-Assisted Laser Desorption Ionization Biotyper System

ABSTRACT Current methods for identification of yeast from blood cultures may take several days after these microorganisms have been observed by Gram stain smears from positive blood cultures. We explored the use of a matrix-assisted laser desorption ionization (MALDI) Biotyper system in combination with Sepsityper specimen processing and Microflex analysis for improved detection and identification of yeast species directly from positive blood culture specimens demonstrating yeast-like organisms by Gram stain. The limit of detection of yeast species in blood culture medium was determined to be 5.9 × 105 CFU, with intra- and interstrain coefficients of variation of 1.8 to 3.6% and 2.9%, respectively. A total of 42 yeast-containing positive blood culture specimens were processed, and the identification results were compared to those obtained by routinely used phenotypic methods. Specimens with discrepant results between the Biotyper and phenotypic methods were identified on the basis of internal transcribed spacer region sequencing. The MALDI Biotyper system correctly identified the 42 specimens to species level, including 28 (66.7%) Candida albicans, 8 (19.0%) Candida parapsilosis, and 5 (11.9%) Candida tropicalis isolates and 1 (2.4%) Cryptococcus neoformans isolate. The entire procedure, from specimen extraction to final result reporting, can be completed within 1 h. Our data indicated that the Sepsityper specimen processing and Microflex analysis by the MALDI Biotyper system provide a rapid and reliable tool for yeast species identification directly from positive blood culture media.

Identification of Staphylococcus aureus and Determination of Methicillin Resistance Directly from Positive Blood Cultures by Isothermal Amplification and a Disposable Detection Device

ABSTRACT A simple, rapid, and user-friendly procedure has been developed to identify Staphylococcus aureus and determine its methicillin resistance directly from gram-positive cocci in cluster-containing blood culture medium. The specimens were diluted and heated prior to amplification of the nuc and mecA genes with isothermal helicase-dependent amplification. Amplicons were detected using a disposable detection device. The analytical sensitivity of the assays was 50 CFU per reaction, and the clinical sensitivity and specificity were both 100% for S. aureus detection and 100% and 98% for methicillin resistance determination, respectively.