ABSTRACT
BACKGROUND: Patients with cystic fibrosis (CF) are at an increased risk of pulmonary colonisation by opportunistic micro-organisms. Using specialised methods, the black yeast Exophiala dermatitidis could consistently be cultured from CF patients. Isolation rates from sputum samples ranged between 1.8 and 15.7%. Occasionally, infection could be recognised. OBJECTIVES: This study aimed at investigating the isolation rates of E. dermatitidis in samples taken from CF patients at the University of Bonn, Germany. METHODS: Altogether, 439 respiratory specimens taken from 81 CF patients were screened for the occurrence of E. dermatitidis over a period of 18 months. For the selective isolation of this fungus erythritol-chloramphenicol agar (ECA) produced in house was applied. RESULTS: The isolation rate of E. dermatitidis was 1.1% from all specimens, 1.6% from all sputum samples and 6.2% in all patients examined. CONCLUSIONS: Prior to the introduction of ECA, E. dermatitidis had never been isolated in our laboratory, either from CF, or from any other patient. During this study, E. dermatitidis was found to colonise the respiratory tract of some CF patients. The use of additional selective culture media is necessary for the recognition of uncommon fungi, e.g. E. dermatitidis, in CF patients.
Subject(s)
Cystic Fibrosis/microbiology , Exophiala/isolation & purification , Respiratory System/microbiology , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Prospective Studies , Sputum/microbiologyABSTRACT
The protein B of group B streptococci can bind in a nonimmune reaction to Ig of the IgG and IgM classes of various mammalian species (i.e., human, mouse, rabbit, and bovine). Protein B binding involves the Fc parts of both IgG and IgM molecules. Monoclonal or polyclonal IgG or IgM and the IgM-FC5 mu fragment of human myeloma protein combined with the protein B thereby inhibiting protein B-induced hemolysis in the CAMP reaction. The protein B/Ig complex can be dissociated with 1% Triton or guanidine-HCl (6 M). Mice infected intraperitoneally with sublethal doses of group B streptococci (GBS) and that received seven repeated intravenous injections of highly purified protein B during the first 9 h of infection developed fatal septicemia within 24 h with colony counts of up to 10(8) CFU/ml in the blood. Animals treated in the same way with either PBS or trypsinized protein B recovered. The protein B itself was not pathogenic when injected into healthy mice. Tissue sections of liver or spleen from mice infected with a lethal dose of GBS revealed the presence of protein B together with large numbers of cocci when stained by the peroxidase method using specific antibodies raised against purified protein B in the rabbit.
Subject(s)
Bacterial Proteins/immunology , Immunoglobulin G/metabolism , Immunoglobulin M/metabolism , Sepsis/immunology , Streptococcal Infections/immunology , Animals , Antibodies, Monoclonal/immunology , Bacterial Proteins/analysis , Binding Sites, Antibody , Hemolysin Proteins , Histocytochemistry , Immunoenzyme Techniques , Immunoglobulin Fc Fragments/metabolism , Liver/analysis , Liver/microbiology , Male , Mice , Sepsis/microbiology , Spleen/analysis , Spleen/microbiology , Streptococcal Infections/microbiology , Streptococcus agalactiae/isolation & purificationABSTRACT
The reaction components and conditions affecting CAMP factor (Streptococcus agalactiae) induced lysis of target cells have been investigated. Both the amount of sphingomyelinase used and the time of preincubation with sphingomyelinase directly affected the rate of haemolysis by CAMP factor. The CAMP factor induced lysis was temperature dependent between 15 and 30 degrees C and was proportional to the amount of CAMP factor added.
