Quantitation of bacteria in cerebrospinal fluid and blood of children with meningitis and its diagnostic significance

Abstract

Cerebrospinal fluid (CSF) specimens from pediatric patients with meningitis were examined for their concentration of microbes and the relationship of this count to the bacteremia levels, microscopy results, and polymorphonuclear leukocyte concentration. A total of 2,031 consecutive CSF specimens were analyzed, of which 63 (3.1%) were positive by culture from the same number of patients. We observed that 85% of the total CSF specimens positive for Haemophilus influenza type b, Streptococcus agalactiae, Streptococcus pneumoniae, and Neisseria meningitidis had counts in excess of 103 CFU/mI, with 56% of the specimens exceeding 105 CFU/ml. A correlation existed between the number of organisms present in the CSF and blood. For example, from a total of 22 patients who had counts of H. influenza >î03 CFU/ml in the CSF, 16 or 73% had levels of bacteremia >103 CFU/ml. It was also noted that the bacterial concentration had a profound effect on the sensitivity of microscopy. The percentage of positive results increased from 25% with sO03 CFU/ml to 60% in the range of >103 to 105 CFU/ml and to 97% at concentrations of >105 CFU/ml. Furthermore, a significant correlation (P < 0.01) was noted between the concentration of bacteria in the CSF and the number of polymorphonuclear leukocytes observed on microscopy.

Detection of bacterial contamination in prestorage culture‐negative apheresis platelets on day of issue with the Pan Genera Detection test

“…Previous studies of apheresis PLTs retested by culture at outdate provide limited insight into when contaminated units grew to high titers and what ultimate titer was attained. In this study, in seven of the nine cases detected by PGD, contaminating bacteria were shown to be at concentrations that were at least 10 5 CFU/mL based on detection by Gram stain 8,30 . These findings suggest that PLT doses had been held for sufficient lengths of time to allow low levels of contaminating bacteria to grow to dangerous titers, occurring in four units that were 3 days old and two that were 4 days old.…”

Large scale genomic analysis shows no evidence for repeated pathogen adaptation during the invasive phase of bacterial meningitis in humans

“…Initially the population size is small, so selection is inefficient and the population-wide mutation rate is low. However, the eventual carrying capacity of the blood and CSF are large enough (>1.5×10 5 ) [34, 35] for beneficial mutations to fix rapidly. Due to the short generation time of around an hour [36], this carrying capacity is reached early in the course of the disease (after 1-2 days) [37].…”

Use of PCR with Universal Primers and Restriction Endonuclease Digestions for Detection and Identification of Common Bacterial Pathogens in Cerebrospinal Fluid

“…Our universal PCR was determined to have a sensitivity of 10 gram-negative bacteria (e.g., E. coli) and 250 gram-positive bacteria (e.g., S. aureus). Therefore, it would be adequate for detection of bacteria in CSF specimens, since 85% of CSF samples with bacterial infection contained more than 10 3 CFU of bacteria/ml (8). Although detection of bacterial pathogens in serum or whole blood by PCR has been reported (5,12,16), the universal PCR developed in this study may not have sufficient sensitivity for blood specimens, because the number of organisms in the blood is usually quite low.…”