muramidase and Meningitis--Bacterial

Human and bovine Streptococcus bovis strains had the same 16S ribosomal DNA restriction fragment length polymorphism and often had the same patterns of starch, mannitol, lactose, and raffinose utilization. PCRs of BOX sequences differed, but numerical analyses indicated that some human strains clustered with bovine strains. However, human and bovine strains had distinctly different sensitivities to lysozyme and 2-deoxyglucose.

Topics: Animals; Cattle; Cattle Diseases; Deoxyglucose; DNA, Ribosomal; Humans; Meningitis, Bacterial; Muramidase; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 16S; Streptococcal Infections; Streptococcus bovis; Substrate Specificity

N-acetylmuramyl-L-alanine amidase (NAMLAA) specifically degrades peptidoglycan, a major component of bacterial cell walls. Lysozyme degrades peptidoglycan differently by hydrolyzing the aminosugar backbone of peptidoglycan. In another study, it was shown that the two enzymes act synergistically to inactivate the inflammatory properties of peptidoglycan. The presence of lysozyme and NAMLAA was determined in serum and cerebrospinal fluid (CSF) of patients with bacterial meningitis. High concentrations of lysozyme were found in CSF while, surprisingly, NAMLAA was not present. To explain this phenomenon, the degranulation pattern of neutrophils in CSF was compared with that of neutrophils from blood. Specific granules contain lysozyme and the azurophil granules contain both lysozyme and NAMLAA. CD66b expression on the cell surface, indicative for fusion of the specific granules with the cell membrane, was higher in CSF than in blood, while the marker for the azurophil granules was lower.

Topics: Adolescent; Adult; Aged; Antigens, CD; Antigens, Neoplasm; Cell Adhesion Molecules; Cell Degranulation; Cell Membrane; Child; Child, Preschool; Female; Flow Cytometry; GPI-Linked Proteins; Haemophilus Infections; Humans; Infant; Male; Membrane Glycoproteins; Meningitis, Bacterial; Meningitis, Meningococcal; Middle Aged; Muramidase; N-Acetylmuramoyl-L-alanine Amidase; Neutrophil Activation; Neutrophils; Pneumococcal Infections

The authors have modified the technique of the lysozyme test by adding polimixin M sulfate into the gel bacterial medium. Rapid diagnosis with the use of this test is based on different time of the appearance of the lysis areas: in bacterial meningitides the CSF lysozyme activity is detectable within 15-120 min, whereas in viral meningitides it manifests 40-50 min later or does not manifest at all. The results were found to depend on the time of the CSF collection: the earlier the CSF samples were obtained, the higher was the share of positive results.

Topics: Clinical Enzyme Tests; Diagnosis, Differential; Gels; Humans; Meningitis, Bacterial; Meningitis, Viral; Muramidase; Polymyxins; Time Factors

Lysozyme (LZM), immunoglobulin M (IgM) and C-reactive protein (CRP) levels were determined in cerebrospinal fluid (CSF) from patients classified on the basis of clinical and laboratory findings into three groups: bacterial meningitis (n = 33), lymphocytic meningitis (n = 21) and controls (n = 54). IgM and CRP levels were determined by enzyme-linked immunosorbent assay (ELISA) and LZM by the lysoplate method. Discriminant analysis demonstrated that 93.94% (31/33) and 96.97% (32/33) of patients with bacterial meningitis were correctly classified on the basis of CSF determinations of IgM and LZM, respectively. However, the measurement of CRP levels in CSF correctly classified 100% of these patients (33/33), thus representing a useful additional marker for the screening of bacterial meningitis. Moreover, no more than 4% (3/75) of patients were incorrectly classified as belonging to the bacterial group on the basis of the CRP test. Thus, CRP titres less than or equal to 80 identify cases belonging to one of the non-bacterial groups, whereas titres greater than or equal to 640 classify the bacterial group, with a very low chance of misclassification. The authors recommend that CSF IgM or LZM levels be also measured for patients with CSF CRP titres of 160 and 320, for a more accurate diagnosis. The probability of these cases being of bacterial aetiology, as calculated from the combined results of these measurements, is presented.

Topics: Adolescent; Adult; Aged; C-Reactive Protein; Child; Child, Preschool; Diagnosis, Differential; Discriminant Analysis; Humans; Immunoglobulin M; Infant; Meningitis; Meningitis, Bacterial; Middle Aged; Muramidase