Detection of Pneumococcus from whole blood, buffy coat and serum samples by PCR during bacteremia in mice

Whole blood, purified leukocyte fraction and serum were investigated as specimens for the detection of pneumococcal bacteremia by polymerase chain reaction (PCR) in mice. The PCR findings were compared to the blood culture results. Samples were taken from animals 3 and 12 h after intraperitoneal bacterial challenge. The pneumococcal culture was positive in 27% and 77% of blood samples at 3 and 12 h after challenge, respectively. All whole blood samples were positive by PCR at both time points. Of the buffy coat samples, two of the three pools were PCR-positive at 3 h and all pools at 12 h after bacterial challenge. In the serum sample group, only 40% of the sera were PCR-positive at 3 h, while at 12 h 90% of the samples were PCR-positive. According to these results, whole blood seems to be the best specimen for the detection of pneumococcal DNA by PCR in bacteremic mice.

Bacteraemia in febrile children presenting to a pae3iatric emergency department

OBJECTIVE

To determine the prevalence of bacteraemia in young febrile children presenting to a paediatric emergency department.

DESIGN

Prospective observational case study.

SETTING

Emergency Department of the Royal Children's Hospital, Melbourne, between May 1996 and May 1997.

PARTICIPANTS

Patients aged 3-36 months presenting to the Emergency Department with temperature > or = 39 degrees C and without specific viral illnesses (varicella, croup or herpes gingivostomatitis).

OUTCOME MEASURES

Bacteraemia (defined as presence of pathogenic bacteria in a blood culture), white blood cell count (WCC), McCarthy score, and final diagnosis based on clinical features and investigations.

RESULTS

Bacteraemia was identified in 18 of 534 patients (3.4%). Pathogens isolated were Streptococcus pneumoniae (15), Neisseria meningitidis (2) and Klebsiella pneumoniae (1). Increased WCC counts (P < 0.001) and brief duration of fever (P < 0.001) were associated with bacteraemia. Nevertheless, clinical features, including McCarthy scores, and high WCC counts (> or = 20 x 10(9)/L) had < 10% predictive accuracy for bacteraemia. Overall, final diagnoses in the 534 febrile children included non-specific viral infections (25%), upper respiratory tract infections (24%), otitis media (10%), gastroenteritis (9%), pneumonia (7%), and urinary tract infection (5%).

CONCLUSIONS

Most urban Australian children aged 3-36 months presenting to a paediatric emergency department with temperature > or = 39 degrees C without a clinical focus have a viral infection. However, 3%-4% have occult bacteraemia. Neither clinical features nor high WCC counts reliably identify these patients. As empiric antibiotics may contribute to increasing antibiotic resistance and have not been shown to prevent the rare complication of meningitis, we believe that close contact and regular review of these patients is preferable to empiric antibiotic therapy.

The origin and function of soluble CD14 in experimental bacterial meningitis

Murine experimental meningitis models induced by either Escherichia coli LPS, live Streptococcus pneumoniae, or Listeria monocytogenes were used to study the origin and potential function of soluble CD14 (sCD14) in the brain during bacterial meningitis. Whereas intracerebral infection caused only a minor and/or transient increase of sCD14 levels in the serum, dramatically elevated concentrations of sCD14 were detected in the cerebrospinal fluid. Reverse-transcriptase PCR and FACS analysis of the leukocytes invading the subarachnoid compartment revealed an active amplification of CD14 transcription and concomitant surface expression. These findings were confirmed by in situ hybridization and immunohistochemical analysis. In contrast, parenchymal astrocytes and microglial cells were shown not to significantly contribute to the elevated levels of sCD14. Simultaneous intracerebral inoculation of rsCD14 and S. pneumoniae resulted in a markedly increased local cytokine response. Taken together, these data provide the first evidence that sCD14 can act as an inflammatory co-ligand in vivo. Thus, during bacterial meningitis, sCD14 is massively released by intrathecal leukocytes, and the sCD14 found in the cerebrospinal fluid can play an important role in the pathogenesis of this disease.

Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae strains causing childhood infections in Bangladesh, 1993 to 1997

Three hundred sixty-two Streptococcus pneumoniae strains were isolated from children under 5 years of age at Dhaka Shishu (Children) Hospital from 1993 to 1997. The strains were isolated from blood (n = 105), CSF (n = 164), ear swab (n = 61), eye swab (n = 20), and pus (n = 12). Of the 362 isolates, 42 (11.6%) showed intermediate resistance (MIC, <0.1 microgram/ml) and only 4 (1.1%) showed complete resistance (MIC, >2.0 microgram/ml) to penicillin. Penicillin resistance exhibited a strong relationship with serotype 14; 47.8% of the penicillin-resistant strains belonged to this type. A remarkably high (64.1%) resistance to co-trimoxazole was observed, along with a significant increase during the time period studied; there was no relationship to capsular type. By way of contrast, penicillin resistance did not show any significant change during the study period. Resistance to chloramphenicol (2.2%) and erythromycin (1.1%) was rare. The high resistance to co-trimoxazole and its increasing trend demand elucidation of the clinical impact of pneumonia treatment by this antimicrobial and reconsideration of the World Health Organization recommendation for co-trimoxazole administration to children with community-acquired pneumonia at the health care worker level in Bangladesh.

Pneumolysin PCR-based diagnosis of invasive pneumococcal infection in children

Blood-based pneumolysin PCR was compared to blood culture and detection of pneumolysin immune complexes, as well as to detection of antibodies to pneumolysin and to C polysaccharide, in the diagnosis of pneumococcal infection in 75 febrile children. Invasive pneumococcal infection was suspected on clinical grounds in 67 of the febrile children, and viral infection was suspected on clinical grounds in 8 of the febrile children. In addition, 15 healthy persons were examined to test the specificity of the PCR assay. Plasma, serum, and leukocyte fractions were analyzed by PCR. The combination of all test results led to the diagnosis of pneumococcal infection in 25 patients. Pneumolysin PCR was positive in 44% of these children, an increase occurred in the pneumolysin antibodies in 39% and in the C polysaccharide antibodies in 30% of the patients; pneumolysin immune complexes were found in convalescent serum in 30%, pneumolysin immune complexes occurred in acute-phase serum samples in 16%, and a positive blood culture was found in 20% of the patients. None of the healthy controls had positive results by PCR. The results suggest that the diagnosis of Streptococcus pneumoniae infection from blood samples necessitates the use of several different assays. Pneumolysin PCR was the most sensitive assay, but its clinical value is reduced by the fact that three blood fractions are needed.

Efficacy of high-dose amoxicillin-clavulanate against experimental respiratory tract infections caused by strains of Streptococcus pneumoniae

The purpose of the present investigation was to determine if the efficacy of amoxicillin-clavulanate against penicillin-resistant Streptococcus pneumoniae could be improved by increasing the pediatric amoxicillin unit dose (90 versus 45 mg/kg of body weight/day) while maintaining the clavulanate unit dose at 6.4 mg/kg/day. A rat pneumonia model was used. In that model approximately 6 log10 CFU of one of four strains of S. pneumoniae (amoxicillin MICs, 2 microg/ml [one strain], 4 microg/ml [two strains], and 8 microg/ml [one strain]) were instilled into the bronchi of rats. Amoxicillin-clavulanate was given by computer-controlled intravenous infusion to approximate the concentrations achieved in the plasma of children following the administration of oral doses of 45/6.4 mg/kg/day or 90/6.4 mg/kg/g/day divided every 12 h or saline as a control for a total of 3 days. Infusions continued for 3 days, and 2 h after the cessation of infusion, bacterial numbers in the lungs were significantly reduced by the 90/6.4-mg/kg/day equivalent dosage for strains for which amoxicillin MICs were 2 or 4 microg/ml. The 45/6.4-mg/kg/day equivalent dosage was fully effective only against the strain for which the amoxicillin MIC was 2 microg/ml and had marginal efficacy against one of the two strains for which amoxicillin MICs were 4 microg/ml. The bacterial load for the strain for which the amoxicillin MIC was 8 microg/ml was not reduced with either dosage. These data demonstrate that regimens which achieved concentrations in plasma above the MIC for at least 34% of a 24-h dosing period resulted in significant reductions in the number of viable bacteria, indicating that the efficacy of amoxicillin-clavulanate can be extended to include efficacy against less susceptible strains of S. pneumoniae by increasing the amoxicillin dose.

Two pharmacodynamic models for assessing the efficacy of amoxicillin-clavulanate against experimental respiratory tract infections caused by strains of Streptococcus pneumoniae

Two models of respiratory tract infection were used to investigate the pharmacodynamics of amoxicillin-clavulanate against Streptococcus pneumoniae. Eight strains of S. pneumoniae were used in a mouse model in which the animals were infected intranasally and were then treated with a range of doses and dose intervals. The time that the plasma amoxicillin concentration remained above the MIC (T>MIC) correlated well with bacterial killing, such that if T>MIC was below 20% there was no effect on bacterial numbers in the lungs. As T>MIC increased, the response, in terms of decreased bacterial load, improved and at T>MICs of greater than 35 to 40% of the dosing interval, bacteriological cure was maximal. On the basis of equivalent T>MICs, these data would suggest that in humans a dosage of 500 mg three times daily (t.i.d.) should have efficacy equal to that of a dosage of 875 mg twice daily (b.i.d.). This hypothesis was evaluated in a rat model in which amoxicillin-clavulanate was given by computer-controlled intravenous infusion to achieve concentrations that approximate the concentrations achieved in the plasma of humans following oral administration of 500/125 mg t.i.d. or 875/125 mg b.i.d. Infusions continued for 3 days and bacterial numbers in the lungs 2 h after the cessation of the infusion were significantly reduced (P < 0.01) by both treatments in strains of S. pneumoniae for which amoxicillin MICs were below 2 microg/ml. When tested against a strain of S. pneumoniae for which the amoxicillin MIC was 4 microg/ml, the simulated 500/125-mg dose was ineffective but the 875/125-mg dose demonstrated a small but significant (P < 0. 01) reduction in bacterial numbers. These data confirm the findings in the mouse and indicate that amoxicillin-clavulanate administered at 875/125 mg b.i.d. would be as effective clinically as amoxicillin-clavulanate administered at 500/125 mg t.i.d.

Prediction of clinical severity and outcome of ventilator-associated pneumonia. Comparison of simplified acute physiology score with systemic inflammatory mediators

Systemic kinetics of three inflammatory mediators (bactericidal/permeability-increasing protein [BPI], soluble intercellular adhesion molecule [sICAM], and soluble E-selectin [sE-selectin]) were studied during the development of ventilator-associated pneumonia (VAP) (n = 42), diagnosed on quantitative cultures of bronchoscopic samples. From a pool of collected samples, nested samples were used to measure mediators on Days -4, -2, 0, and +2, relative to diagnosis. Correlations between systemic levels of mediators and clinical severity of infection (VAP with or without severe sepsis or septic shock) and patient outcome (mortality at Day 10 after diagnosis) were studied. Predictive values of inflammatory mediators were compared with daily Simplified Acute Physiology Score II (SAPS II) values and the logarithmic number of bacteria in bronchoscopic samples. During the development of VAP, increasing SAPS II scores and rising systemic mediator levels were only found in patients in whom VAP was accompanied with severe sepsis or septic shock. Values of SAPS II and plasma levels of BPI and sE-selectin, but not sICAM, increased from the day of diagnosis on in patients who died within 10 d of diagnosis. Systemic levels of inflammatory mediators did not better predict clinical severity or patient outcome than daily SAPS II scores. The logarithmic number of bacteria in bronchoscopic samples poorly correlated with circulating levels of inflammatory mediators, severity of infection, and patient outcome. Our findings show that a clinical scoring system (SAPS II score) is at least as good as a predictor for the clinical severity of infection and patient outcome, and provide new information on the kinetics of inflammatory mediators during the development of VAP.

Invasive pneumococcal infection in South and West England

Variation in the incidence of invasive pneumococcal disease across South and West England, in 1995, was measured through a survey of microbiology laboratories. A 100% response rate was achieved. The incidence by laboratory varied between 5.2 and 20.4 per 100,000 catchment population (P < 0.001). Adjusting for pneumococcal vaccine uptake rate in over 65 year olds, hospital admission rates, blood culture system used and for the age and sex structure of the population, did not account for this variation. When blood culture sampling rates were included in a logistic regression model, the variation between laboratories was much less and of lower statistical significance (P = 0.019). Higher rates of blood culture sampling were associated with a higher incidence of invasive pneumococcal disease. Consistently high sampling should be encouraged because a higher diagnostic rate should result in more selective prescribing of antibiotics, and secondly because improved ascertainment of severe pneumococcal infections is a prerequisite for the evaluation of new pneumococcal conjugate vaccines.

Streptococcus pneumoniae bacteremia in a community hospital

We reviewed 71 consecutive patients with Streptococcus pneumoniae bacteremia. The patients were analyzed by age, sex, ethnic background, and clinical presentation. Laboratory data reviewed included a CBC count, electrolyte levels, liver function studies, chest radiograph, HIV status, a sputum culture and Gram's stain, and sensitivities for the S pneumoniae isolated. Modalities of therapy, response to treatment, and ultimate outcome were examined. Many of the patients with pneumococcal bacteremia did not have cough, fever, or chills. HIV positivity was a risk factor for pneumococcal infection although it was not associated with increased mortality. Mortality correlated with elderly status, leukopenia, and lack of fever. Many patients had symptoms suggestive of atypical pneumonia including myalgia and mental status change. Hyponatremia and hyperbilirubinemia were commonly noted.

In vitro and in vivo antibacterial activities of S-4661, a new carbapenem

The in vitro and in vivo antibacterial activities of S-4661, a new 1beta-methylcarbapenem, were compared with those of imipenem, meropenem, biapenem, cefpirome, and ceftazidime. The activity of S-4661 against methicillin-susceptible staphylococci and streptococci was comparable to that of imipenem, with an MIC at which 90% of the strains tested were inhibited (MIC90) equal to 0.5 microg/ml or less. S-4661 was highly active against members of the family Enterobacteriaceae, Haemophilus influenzae, and Moraxella catarrhalis, with MIC90s ranging from 0.032 to 0.5 microg/ml. Against imipenem-resistant Pseudomonas aeruginosa, S-4661 was the most active among test agents (MIC90, 8 microg/ml). Furthermore, S-4661 displayed a high degree of activity against many ceftazidime-, ciprofloxacin-, and gentamicin-resistant isolates of P. aeruginosa. The in vivo efficacy of S-4661 against experimentally induced infections in mice caused by gram-positive and gram-negative bacteria, including penicillin-resistant Streptococcus pneumoniae and drug-resistant P. aeruginosa, reflected its potent in vitro activity and high levels in plasma in mice. We conclude that S-4661 is a promising new carbapenem for the treatment of infections caused by gram-positive and -negative bacteria, including penicillin-resistant S. pneumoniae and drug-resistant P. aeruginosa.

Pleiotropic mutations alter the kinetics of calcium transport, competence regulation, autolysis and experimental virulence in Streptococcus pneumoniae

Streptococcus pneumoniae is a pathogen in which the extracellular calcium concentration plays a major physiological role, in growth as well as in the induction of competence for genetic transformation and activation of autolysis. Both responses are under the control of a protein activator exported in the medium. We have checked the impact of mutations which alter the regulation of competence and autolysis on experimental virulence. Isogenic encapsulated derivatives carrying the relevant mutations were serotype 3 smooth clones, obtained by transformation of the relevant rough strains with DNA from a serotype 3 smooth isolate. Survival kinetics and bacterial clearance from the blood were followed after intraperitoneal infection of Swiss mice with the different bacterial cultures. In this model, mutants showing an attenuation of virulence relative to the wild type fell into two classes. In the first, represented by the lytA::ery mutant V1095 defective for calcium-induced autolysis, attenuated virulence could be correlated with rapid bacterial clearance from the blood. In the second, represented by the dmb mutants V2200 and V3300, attenuation was associated with delayed bacterial clearance from the blood, and correlated with altered kinetics of calcium transport and of regulation of competence and autolysis. It appeared unlikely that attenuation of virulence for strains V2200 and V3300 was a direct consequence of their competence phenotype, since the com::ery mutants V1008 and V1019, defective for the production of the competence activator, were as virulent as the wild-type strain. Autolysis involving an N-acetyl-muramyl-alanine amidase encoded by lytA was also regulated by calcium. The inserted allele lytA0::ery further reduced virulence in the dmb1 background (V2200). This additive effect of lytA- to dmb1 points to different routes of virulence regulation by LYT and DMB1 and suggests that the kinetics of calcium traffic controls several pathways involved in the virulence of pneumococcus.

Differences in N-acetylmuramyl-L-alanine amidase and lysozyme in serum and cerebrospinal fluid of patients with bacterial meningitis

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.

Serum inhibitory titers and serum bactericidal titers for human subjects receiving multiple doses of the antibacterial oxazolidinones eperezolid and linezolid

In Phase I trials subjects received multiple doses of eperezolid (PNU-100592; formerly U-100592) and linezolid (PNU-100766; formerly U-100766), and steady-state samples were drawn at the projected peak and trough timepoints. Serum inhibitory titer and serum bactericidal titer values were determined using single strains of Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pneumoniae. Serum inhibitory titer values generally correlated with drug concentration in serum and inherent organism susceptibility. Against S. aureus and E. faecalis sera from patients dosed with either drug were generally inhibitory at the peak timepoint, but at trough only linezolid exhibited a persistent effect. No bactericidal activity was seen for either drug against S. aureus or E. faecalis. The sera from patients dosed with either drug exhibited inhibition of S. pneumoniae at peak and trough. Bactericidal activity was seen against S. pneumoniae for both drugs at peak time and at trough for many of the sera for patients on the higher dose regimens. The results demonstrated that the sera from most human subjects dosed with eperezolid or linezolid were inhibitory to S. aureus and E. faecalis and S. pneumoniae and that many of the samples exhibited bactericidal activity for S. pneumoniae.

Use of polymerase chain reaction to identify pneumococcal infection associated with hemorrhage and shock in two previously healthy young children

A PCR assay was developed for detection of Streptococcus pneumoniae in clinical specimens including blood and paraffinized tissues. We were able to detect one organism of purified DNA or 4.5 colony-forming units in blood. The primers did not cross-react with other upper respiratory tract streptococci or with pathogens commonly found in clinical specimens. This assay was used in an investigation of an outbreak of severe illness characterized by septic shock and hemorrhage in previously healthy children. PCR detected S. pneumoniae in cerebrospinal fluid and autopsy tissues of the two infants who died. The findings from this assay indicated that PCR offers increased specificity and sensitivity over latex agglutination and counterimmunoelectrophoresis and should prove useful in the identification of additional cases of severe illness caused by S. pneumoniae.

A pilot study of the predictive value of plasma tumor necrosis factor alpha and interleukin 1 beta for Streptococcus pneumoniae bacteremia in febrile children

OBJECTIVE

To determine the value of tumor necrosis factor alpha (TNF) and interleukin 1 beta (IL1) levels in predicting Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children who do not have a bacterial source for their fever on physical examination.

METHODS

A prospective, nested case-control study was conducted in a children's hospital ED. All febrile children < 3 years old who were believed to be immunocompetent and not in shock, had no obvious bacterial source for their fever on physical examination, and had a blood culture obtained were eligible. Plasma obtained at the time of the blood culture was available for analysis by enzyme-linked immunosorbent assays for TNF and IL1. Children who had positive blood cultures for Streptococcus pneumoniae were the cases. The controls were selected from children who had negative blood cultures.

RESULTS

During a 1-year period, 12 cases and 65 controls were identified. There was no significant difference in age, height or duration of fever, or illness acuity between the groups. The following were used as threshold values for positive test: white blood cell (WBC) count > 15.0 x 10(9) cells/L, TNF > 21.5 ng/mL, and IL1 > 9.0 ng/mL. Using an estimated prior probability of bacteremia of 4%, the positive predictive value (PPV) and the negative predictive value (NPV) for bacteremia were 11.7% and 98.6% using the WBC count, 11.1% and 98.6% using the IL1 level, and 9.0% and 98.9% using the TNF level. The combination of WBC count with either TNF or IL1 gave an NPV of 100%, with PPVs of 8.5% for TNF and 9.9% for IL1.

CONCLUSIONS

Like the WBC count, TNF and IL1 are good negative but poor positive predictors of Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children. At present, the addition of plasma TNF or IL1 levels would add little to emergency physicians' ability to predict Streptococcus pneumoniae bacteremia. However, as the quantification of these cytokines becomes more rapid, available, and standardized, and more knowledge of TNF and IL1 levels during various illnesses is gained, their utility in the clinical setting for ruling out bacteremia should be further assessed.

Resistance patterns of Streptococcus pneumoniae and Haemophilus influenzae isolates recovered in Egypt from children with pneumonia. The Antimicrobial Resistance Surveillance Study Group

Treatment of childhood pneumonia in developing countries requires knowledge of susceptibility patterns for Streptococcus pneumoniae and Haemophilus influenzae. Between October 1991 and April 1993, a surveillance survey of antimicrobial resistance was performed at two fever hospitals in Egypt; nasopharyngeal swab and blood specimens obtained from 1,635 children with pneumonia were cultured for these organisms. Susceptibility testing of these organisms was performed. At least one of these organisms was isolated from nasopharyngeal swab specimens from 73% of the children; 3.7% of blood cultures were positive. For S. pneumoniae strains, 70.9% of nasopharyngeal isolates were calculated to be susceptible to penicillin vs. 77.6% of blood isolates; the percentages of isolates susceptible to co-trimoxazole were 73.0% and 75.0%, respectively. For H. influenzae strains, 93.0% of nasopharyngeal isolates were calculated to be susceptible to ampicillin vs. 100% of blood isolates; the percentages of isolates susceptible to co-trimoxazole were 84.9% and 100%, respectively. Although most S. pneumoniae and H. influenzae strains associated with childhood pneumonia in Cairo were susceptible to penicillins and co-trimoxazole, antimicrobial resistance did not occur.

Detection of Haemophilus influenzae and Streptococcus pneumoniae DNA in blood culture by a single PCR assay

A multiplex PCR assay was developed to screen blood cultures from children in The Gambia with suspected pneumonia for the simultaneous detection of Haemophilus influenzae type b and Streptococcus pneumoniae isolates. Analysis of 295 blood cultures showed that PCR detected the organisms in all samples positive by culture in two samples infected with H. influenzae type b and four samples infected with S. pneumoniae that were culture negative, indicating that this method is sensitive for detecting these organisms in blood cultures.

Preimmunization and postimmunization pneumococcal antibody titers in children with recurrent infections

BACKGROUND

Patients with recurrent infections and normal IgG levels may have an abnormal response to pneumococcal polysaccharides. The ability to develop antibodies against different pneumococcal polysaccharides develops gradually in the first years of life, but the sequence of development and the influence of preexisting antibody titers has not been defined.

METHODS

Preimmunization and postimmunization IgG antibody titers against pneumococcal serotypes 3, 7F, 9N, and 14 were evaluated in a population of 100 1- to 18-year-old children referred to a pediatric allergy-immunology clinic because of recurrent respiratory infections. None of the patients had a known immunodeficiency syndrome; all had normal total IgG levels. Postimmunization antibody levels were obtained 4 to 6 weeks after immunization. Patients less than/=5 years of age who failed to develop antibody levels above 200 ng Ab N/mL against any serotype and older patients who failed to develop these levels against a second serotype in addition to serotype 3 were considered for IgG replacement therapy.

RESULTS

Prior to immunization, 50% of 51 patients did not have protective antibody levels against any of the serotypes tested. Immunization induced a high response to serotype 3 in all age groups, but responses to serotypes 7F and 14 increased with age. Five of 78 patients (6.4%) failed to develop protective antibody levels against any serotype tested. Three of these patients had clinical criteria that justified the use of IgG replacement therapy; all improved. Three patients were re-immunized 1 to 2 years after the first immunization and all developed protective levels of antibodies against serotype 3 after the second immunization.

CONCLUSION

We conclude that, although measurement of antibody levels against pneumococcal serotype 3 allows a good differentiation of patients who are able to develop anti-polysaccharide antibodies from those who are not, further studies of the development of specific antibodies against other vaccine serotypes in normal populations of different ages are needed to define a normal response to pneumococcal polysaccharides.

Comparison of serum antibodies to pneumolysin with those to pneumococcal capsular polysaccharides in children with acute otitis media

BACKGROUND

Streptococcus pneumoniae is a major bacterial pathogens in acute otitis media. Pneumolysin is a species-specific protein toxin produced intracellularly by all clinically relevant pneumococcal strains, and antibodies to pneumolysin should therefore represent pneumococcal involvement in the disease, regardless of the serotype.

METHODS

Antibodies to pneumococcal pneumolysin and capsular polysaccharides were measured by enzyme immunoassay in acute and convalescent sera of 121 children with acute otitis media. A pneumococcal otitis episode was defined by a positive middle ear fluid culture and/or pneumolysin PCR.

RESULTS

Median age of the 10 children who developed a seroconversion response to pneumolysin was 1 year 8 months, and of the 21 children responding to polysaccharides it was 2 years 9 months. Eight of the 10 seroconversion responses to pneumolysin were of IgA class alone, whereas 17 of the 21 polysaccharide responses were of IgG class alone or IgG together with IgM and/or IgA. Of the 41 children with a pneumococcal otitis episode, 13 (39%) showed a seroconversion response, 3 (7%) to pneumolysin and 11 (27%) to capsular polysaccharides. The children with a pneumococcal otitis episode had lower titers of acute phase IgG to the capsular polysaccharide pool of S. pneumoniae (containing types 6B, 14, 19F and 23F), as compared with the titers in children with otitis caused by other pathogens and pneumococci only in the nasopharynx or not found at all (P = 0.04).

CONCLUSIONS

Serum antibodies to pneumolysin can be detected at an earlier age than those to the capsular polysaccharides. However, a seroconversion is rare and therefore of no diagnostic value. The presence of serum IgG to the pneumococcal capsular polysaccharides seems beneficial in the prevention of pneumococcal otitis.

Basophil-bound IgE and serum IgE directed against Haemophilus influenzae and Streptococcus pneumoniae in patients with chronic bronchitis during acute exacerbations

The investigation includes 12 patients hospitalized with acute exacerbations of chronic bronchitis (CB) and infected in the lower respiratory tract with Haemophilus influenzae (HI) or Streptococcus pneumoniae (SP). Eight patients were infected the HI, three with SP, and one patient with both species. Basophil-bound IgE and serum IgE directed against these species were examined using the patients' own bacterial isolates. All patients showed IgE-mediated histamine release when their peripheral leukocytes were incubated in vitro with the infecting species, indicating basophil-bound IgE directed against their own bacterium. No IgE-mediated response was obtained in the control group of 12 healthy individuals. Bacteria-specific IgE in serum was demonstrated by immunofluorescence assay and further verified by passive sensitization. There was a positive serum titre in seven of nine patients housing HI and in all SP-infected patients but not in the control group. No synchronism was found between a positive response in the histamine release test and the immunofluorescence assay by parallel testing during the test period. This may be due to a time delay between production of serum IgE and its fixation to the cell surface. The results indicate a potential for a bacteria-specific IgE-mediated immune response in CB. Thus, by triggering mediator release, bacteria may be involved in the pathogenesis of exacerbations in CB.

Human C-reactive protein is protective against fatal Streptococcus pneumoniae infection in transgenic mice

C-reactive protein (CRP) is an acute phase protein with a well known association with infection and other inflammatory conditions. Studies with use of purified CRP in in vitro assays provided early evidence that CRP has antibacterial activity. Subsequently it was shown that passively administered human CRP can protect mice from lethal infection with Streptococcus pneumoniae. In this study, we extend these observations to an in vivo model of host resistance by using human CRP transgenic mice. CRP transgenic mice experimentally infected with S. pneumoniae lived longer and had significantly lower mortality than their nontransgenic littermates. This increased resistance to infection was associated with q 10- to 400-fold reduction of bacteremia. Furthermore, male transgenics exhibited longer survival time than females, and this difference could be attributed to increased expression of CRP by males, which was mediated by testosterone. This study provides the first unequivocal evidence that CRP plays an important role in vivo in host defense against pneumococcal infections, and shows that sex hormones can affect expression of the human CRP transgene in mice.

Plasma levels of cytokines in primary septic shock in humans: correlation with disease severity

Thirteen patients (median age, 20 years) with life-threatening primary septic shock (10 meningococcal, 3 pneumococcal infections) were studied prospectively. All had a short history of sepsis (< or = 24 h) and no severe underlying disease. Two (15%) died. The logarithm of the initial plasma levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-1 receptor antagonist (ra), and plasminogen activator inhibitor (PAI)-1 correlated significantly with APACHE II scores (r2 = .67, .57, .68, .81, and .68, respectively). The plasma levels of endotoxin, TNF-alpha, IL-1 beta, and PAI-1 decreased toward normal levels within the first 24 h of treatment, but IL-6 and IL-1ra levels remained high until clinical recovery. On admission, the molar excess of IL-1ra to IL-1 beta was > 2000-fold in 11 of the 13 patients. Acute plasmapheresis in 11 of the 13 patients significantly increased the plasma clearance of TNF-alpha (P = .02).

Analysis of immunoglobulin isotype levels in acute pneumococcal bacteremia and in convalescence

In 48 patients with a history of a pneumococcal bacteremia, serum taken during the acute phase of the infection was analyzed for IgG and IgG subclasses. Once the patients were free of infection, a serum sample was analyzed for IgG, IgG subclasses, IgA and IgM. In an additional 20 patients, it was only possible to analyze serum from the infection-free phase. Seventeen of 48 (35%) patients had reduced levels of total IgG or of one or more of the IgG subclasses during acute disease. Of the 48 patients in whom both acute phase and infection-free phase serum were analyzed, values of IgG (p < 0.001), IgG1 (p < 0.001), IgG2 (p < 0.001), IgG3 (p < 0.01) and IgG4 (p < 0.01) were decreased during the acute infection. During the infection-free phase, 12 of 68 (18%) patients had a recognizable immunodeficiency, including two patients with common variable immunodeficiency. Routine screening for immunoglobulins during the infection-free period could result in the discovery of previously unrecognized immunoglobulin deficiencies in patients with a history of bacteremic pneumococcal infection.

Upper airway carriage by Haemophilus influenzae and Streptococcus pneumoniae in Australian aboriginal children hospitalised with acute lower respiratory infection

When nasopharyngeal secretions from 171 Australian Aboriginal children hospitalized with acute lower respiratory tract infections (ALRI) were cultured selectively for Streptococcus pneumoniae and Haemophilus influenzae, 136 (79.5%) and 151 (88.3%) children yielded 166 and 254 isolates of S. pneumoniae and H. influenzae, respectively. In colonized subjects multiple populations of S. pneumoniae (20% of carriage-positive patients) and H. influenzae (55%) were common. Pneumococci belonging to 27 types or groups were identified. H. influenzae serotype b colonized 16.4% of all children studied. More than one half of 152 children tested were excreting antibiotics at the time of admission to hospital. Significantly fewer children with serum antibiotic residues were colonized with S. pneumoniae than were antibiotic free children. Antibiotic usage had no measurable impact on the isolation rate of H. influenzae.

Bacteremic necrotizing pneumococcal pneumonia in children

Necrotizing pneumonia, massive necrosis of lung tissue, is a serious, often fatal, complication of lobar pneumonia. Four children 1.3 to 7.5 yr of age were hospitalized with bacteremic pneumococcal pneumonia. All of them were acutely ill on presentation with arterial desaturation, and they developed anemia and thrombocytosis. Two patients had pleural effusion requiring drainage. A chest CT scan revealed segmental or lobar pulmonary liquification, which led to the diagnosis of necrotizing pneumonia. This finding could be demonstrated early in the course of the disease. Subsequently, all of the patients developed cavitating lesions. With adequate antipneumococcal therapy and/or chest tube drainage, all of the patients recovered completely; however, clinical improvement was prolonged: fever lasted 9 to 20 days, and length of hospitalization was 12 to 26 days. Contrary to that in adults, complete recovery is anticipated in children with bacteremic necrotizing pneumococcal pneumonia, and no invasive investigations are required.

Effect of increased dosages of amoxicillin in treatment of experimental middle ear otitis due to penicillin-resistant Streptococcus pneumoniae

A gerbil model of acute middle ear otitis was used to evaluate the efficacy of increased dosages of amoxicillin in eradicating infection induced by penicillin-resistant Streptococcus pneumoniae. Three different strains were used: (i) a serotype 23 penicillin-susceptible strain; (ii) a serotype 23 penicillin-resistant strain (MIC of penicillin, 2 micrograms/ml); and (iii) a serotype 19 highly penicillin-resistant strain (MIC of penicillin, 4 to 8 micrograms/ml). Animals were inoculated bilaterally with 10(7) CFU per ear by transbulla challenge and treated 2 to 4 h postinfection by amoxicillin administrated subcutaneously. The course of the disease was monitored bacteriologically on days 2, 4, and 8 postinfection. The three strains had a similar pathogenicity in untreated animals in terms of the duration of the disease, bacterial counts in middle ear (ME) fluid, and systemic complications. Infection due to the penicillin-susceptible strain was cured after two injections of 2.5 mg/kg of body weight. No bacteria were recovered at day 2 after two injections at 10 and 25 mg/kg with the penicillin-resistant and highly penicillin-resistant strains, respectively. Under these experimental conditions, increased does of amoxicillin consistent with MICs were able to clear ME infection. Pharmacokinetic parameters of amoxicillin in serum and ME fluid were within the clinical range at the doses used in the study.

Pneumococcal bacteraemia in south Auckland: a five year review with emphasis on prescribing practices

AIMS

to determine incidence, predisposing factors, management and outcome of pneumococcal bacteraemia in south Auckland.

METHODS

medical records were reviewed retrospectively of patients identified as having pneumococcal bacteraemia at Middlemore Hospital during five years 1986-90.

RESULTS

records were available for 143 of 149 episodes. The incidence of pneumococcal bacteraemia was 12.1/10,000 admissions. The male to female ratio was 1.2:1, 61.5% were over the age of 50 years, 76% had underlying medical conditions, and the mortality was 16.1%. Twenty of the 23 who died were over the age of 60 years. Just over half attended hospital within 48 hours of becoming unwell, while 10.5% had had symptoms for more than one week. Pneumonia was seen in 85% and meningitis in 7%. Initial treatment was with a single antibiotic in 94%. Following microbiological diagnosis, 54% were treated with penicillin G, but in over one-third, an unnecessarily broad spectrum antibiotic was continued as definitive treatment.

CONCLUSIONS

the incidence, age distribution, predisposing factors and mortality of pneumococcal bacteraemia in south Auckland is similar to those reported elsewhere. Inappropriately broad spectrum antibiotics are used too often in definitive treatment.

Neonatal septicemia caused by pneumococci

Pneumococci (Streptococcus pneumoniae) infrequently cause neonatal septicemia. An increased number of cases have been reported in recent years, but no increase in the relative incidence among neonatal infections has been noted. On the basis of two cases of our own and a review of 40 recently published case reports, the clinical characteristics of pneumococcal septicemia are described and the pathogenesis is discussed. The presenting clinical picture in early-onset pneumococcal septicemia is dominated by respiratory distress, frequently accompanied by leukopenia, and is indistinguishable from that seen in septicemia caused by Group B Streptococci (GBS). The onset is preceded by prelabor rupture of the fetal membranes in almost half of the instances. The mortality is 50%, twice the figure given in recent GBS reports.

Metabolic responses to swimming exercise in Streptococcus pneumoniae infected rats

The present study was performed to determine whether alterations in fuel reserves or energy substrate utilization might explain the performance decrements that occur in bacterial infections. Male Fisher-Dunning rats were studied at 24, 48, and 72 h after inoculation with Streptococcus pneumoniae. Rats were either sedentary or subjected to a 2-h swimming session at these three time points (N = 10 in each group). A more than 60% reduction (P less than 0.01) in performance capacity was observed on day 3 of infection compared with that in noninfected controls. This infection in the rat is characterized by fever (P less than 0.01), depression of plasma zinc (P less than 0.01) and free fatty acid (FFA) levels (P less than 0.01), inhibition of the two- to threefold increase in fasting ketonemia, and a decreased (NS) insulin:glucagon ratio, indicating a catabolic state. Glycogen stores were reduced in the heart (47%), liver (43%), and skeletal muscles (39%) but not in the carcass. Superimposed exercise resulted in a further reduction but not depletion of liver, muscle, and carcass glycogen stores, a less pronounced lactic acid accumulation, and a lower oxygen debt. However, plasma FFA and ketone body levels were still maintained or even elevated, suggesting that fat is supplied as fuel during swimming exercise in this infection. Thus, results indicate that unavailability of energy substrates or lactacidosis is not limiting for performance capacity during this severe infection.

Interleukin 6 activity in infants and children with bacterial meningitis. The Collaborative Study on Meningitis

Concentrations of interleukin 6 (IL-6) in cerebrospinal fluid (CSF) and serum of infants and children with bacterial meningitis were determined and correlations were sought with other indices of inflammation and with outcome. Forty-two patients ages 1 month to 15 years (mean, 2.5 years) were studied. IL-6 activity was detectable (greater than 50 units/ml) in 30 of 36 CSF samples collected at admission from patients with meningitis and in 1 of 23 controls with fever and normal CSF findings. Mean values were 36,000 units/ml (range, 151-156,000). IL-6 activity in CSF persisted during the first 5 days of illness. IL-6 concentrations at admission were not associated with clinical findings, CSF leukocyte, protein and glucose concentrations, serum C-reactive protein concentration and neurologic complications or sequelae. IL-6 was also detected in the serum of 3 of 14 patients with meningitis and in 0 of 7 controls with no infectious disease. The presence of IL-6 was not associated with bacteremia or with duration of fever before admission. The presence of IL-6 in the CSF of pediatric patients with bacterial meningitis is in accordance with available data on other cytokines and suggests their role as mediators of meningeal inflammation.

Deficiencies in opsonic defense to pneumococci in the human newborn despite adequate levels of complement and specific IgG antibodies

We studied the major determinants of opsonophagocytosis against Streptococcus pneumoniae serotypes 14 and 19 in paired cord/maternal sera from 27 healthy term and 24 preterm infants in an attempt to gain more insight in the susceptibility of newborns to pneumococcal infection. For both pneumococcal serotypes studied, opsonic activity in neonatal sera varied greatly, but was moderately to profoundly deficient when compared to paired maternal sera, both in preterm (34.5 and 34.9% of the activity in maternal serum, for serotypes 14 and 19, respectively, p less than 0.001 for both) and in term serum (43.5 and 52.7% of the activity in maternal serum, for serotypes 14 and 19, respectively, p less than 0.001 for both). The opsonic deficiency in preterm sera could be ascribed to a diminished level of the major opsonins for pneumococci, i.e. complement factor C3 deposited on the bacterial surface (69.5 and 66.2% of C3 deposition in maternal serum on serotypes 14 and 19, respectively, p less than 0.01 for both) and specific anticapsular IgG antibodies (48.5 and 14.1% of maternal levels for serotypes 14 and 19, respectively, p less than 0.001 for both). However, the opsonic defect in serum from term infants could not be explained in a similar way, because C3 deposition and specific anticapsular IgG levels were equal to the values found in the paired maternal sera. Therefore, we conclude that the opsonic defect in newborn serum for pneumococci cannot be solely explained by a deficiency in the major opsonins for these bacteria. A dysfunction in these opsonins seems to be a more likely explanation for the observed opsonic defect in the neonate.

[The metal content of the blood in patients with bacterial meningoencephalitis]

A study is presented of the quantitative content of blood metals in 60 patients depending on the duration and severity of bacterial meningoencephalitis. It was established that examination of the concentration of macro- and microelements in their dynamics reflects the state of mineral blood homeostasis and can be used as supplementary criterion in the diagnosis of bacterial meningoencephalitis.

The pathobiology of red cell cryptantigen exposure

This article has defined in part the circumstances in which red cell cryptantigen exposure occurs and its significance in children. Bacteria-induced cryptantigens (T and Tk) are the most commonly encountered and, when present, suggest a guarded prognosis, a complicated clinical course, and a need for care in transfusion management with particular attention to the avoidance of plasma-containing products. Nonbacterial-induced cryptantigens (Th and Tn) are much less commonly seen and are encountered as a complicating feature of a serious hematologic condition and may be a potential source of confusion in the neonate.

Changes in anti-endotoxin-IgG antibody and endotoxaemia in three cases of gram-negative septic shock

Circulating endotoxin levels and IgG antibodies to a range of Gram-negative bacterial lipopolysaccharides (LPS) (endotoxins) of different sizes and structures were measured daily in three cases of septic shock. There was an inverse relationship between endotoxin levels and cross-reactive antibodies to the core glycolipid (CGL) region of lipopolysaccharide. This suggests that antibody to LPS-CGL was initially consumed by a superabundance of endotoxin, and that a resurgence of intrinsic anti-LPS-CGL antibody levels may be associated with a reduction of circulating endotoxin. The implications of these findings for passive antibody therapy of septic shock are discussed.

Multiple forms of IFN-beta 2/IL-6 in serum and body fluids during acute bacterial infection

Many of the major alterations in plasma proteins characteristic of the hepatic acute phase response are regulated by IFN-beta 2/IL-6. Using a specific bioassay for IFN-beta 2/IL-6, which relies on the induction of the hepatic acute phase plasma protein alpha 1-antichymotrypsin in the human hepatoma cell line Hep3B clone 2 and its inhibition by anti-rIFN-beta 2/IL-6 antiserum, we have detected high levels of IFN-beta 2/IL-6 in the body fluids of patients with acute bacterial infections. Cerebrospinal fluid from four patients with acute bacterial meningitis (Streptococcus pneumoniae, Staphylococcus aureus, two cases of Listeria monocytogenes) all had high levels of IFN-beta 2/IL-6 (up to 500 ng/ml). Two of these patients with concomitant bacteremia had lower concentrations of IFN-beta 2/IL-6 in the serum (5 to 70 ng/ml). Three additional patients with Escherichia coli, Pseudomonas aeruginosa, and Neisseria meningitidis bacteremia had high levels of serum IFN-beta 2/IL-6, as did the ankle fluid of a patient with Streptococcus canis arthritis. Normal cerebrospinal fluid and serum had little detectable IFN-beta 2/IL-6. A combination of immunoaffinity chromatography and immunoblotting procedures were used to characterize the IFN-beta 2/IL-6 species present in a representative sampling of serum and cerebrospinal fluids. Multiple immunoreactive species of IFN-beta 2/IL-6 in the size range 23 to 30 kDa as well as immunoreactive complexes in the range 60 to 70 kDa were detected in human body fluids. This is the first demonstration that previous descriptions of heterogeneity in human IFN-beta 2/IL-6 species produced in cell culture correspond to observations in the infected host.

Occult bacteremia in children with simple febrile seizures

The controversy surrounding the diagnostic workup for simple febrile seizures has centered around the lumbar puncture. This focus has obscured the potential importance of other tests. A retrospective study was performed to determine the frequency of occult bacteremia in simple febrile seizures. In a pediatric emergency department, we identified 115 cases of simple febrile seizures in children treated as outpatients. Blood cultures were performed in 93 (81%) of 115 patients; five (5.4%) were positive. Children were less likely to have blood cultures performed if they were older than 24 months or had a medical history of simple febrile seizures. However, neither age nor history of febrile seizures affected the risk of bacteremia. These data suggest that patients with simple febrile seizures are at approximately the same risk for bacteremia as children with fever alone. Patients with simple febrile seizures should be treated in the same manner as other patients of the same age with regard to the performance of blood cultures.

[Role of ceruloplasmin, transferrin and lipid peroxidation in bacterial infections of the CNS]

Ceruloplasmin and transferrin blood serum levels were measured during bacterial infection of the CNS. A decrease in ceruloplasmin level and a gradual increase in transferrin level were observed on the 5th day of the disease. The minimum ceruloplasmin level was observed simultaneously with the maximum MDA and GOT levels. There was a close correlation between the time course of ceruloplasmin, transferrin, MDA and GOT changes and the clinical condition of the patient.

Effect of splenectomy and hemisplenectomy on pneumococcal infection and bacteria clearance in the rat

Median survival times 1 month after intraperitoneal inoculation of Streptococcus pneumoniae Felton UC 41 show that the difference between hemisplenectomized and control rats is not at all significant (chi 2 = 0.04). On the other hand, comparing splenectomized rats with hemisplenectomized and control rats taken together, there is a significant difference: 10% level (chi 2 = 2.84; 1 degree of freedom; p less than 0.10). The blood concentrations of pneumococci at different time intervals after inoculation do not differ between control and hemisplenectomized rats (F = 0.02; 1 and 135 degrees of freedom), but they differ very significantly when the splenectomized rats are compared with the hemisplenectomized rats and controls taken together (F = 10.00; 1 and 135 degrees of freedom; p less than 0.01).

Similarity in white blood cell counts between white and black children with bacteremia

The charts of 104 white and 52 black children with bacteremia caused by Streptococcus pneumoniae or Haemophilus influenzae type b were reviewed to determine each patient's white blood cell (WBC) and absolute polymorphonuclear cell (PMN) counts at the time of presentation to the emergency room. Mean WBC and PMN counts were virtually identical for the racial groups, 18,300 vs. 18,700/microliter and 12,900 vs. 13,000/microliter, respectively. Examination of subgroups of white and black children with or without meningitis or other focal infection also revealed no significant differences between races, although significantly lower mean WBC and PMN counts were found in children with, compared to those without, meningitis regardless of race. As an aid to the identification of children at high risk for S. pneumoniae or H. influenzae type b bacteremia, it appears that WBC and PMN counts may be interpreted without regard to race.

Serotype distribution of Streptococcus pneumoniae strains isolated from blood and cerebrospinal fluid in Sweden

215 strains of Streptococcus pneumoniae isolated from blood or cerebrospinal fluid at 3 different laboratories in Sweden were serotyped by coagglutination and subtyped by the capsular reaction test. 78% of the strains belonged to serotypes which are included in or completely cross-immunogenic with serotypes included in the 14-valent vaccine while serotypes included in the 23-valent vaccine covered 89% of the isolates. Types 7F, 14 and 33F, which cannot be detected by counterimmunoelectrophoresis constituted 19% of all strains.

Methods of splenic preservation and their effect on clearance of pneumococcal bacteremia

The intravascular clearance of type 3 Streptococcus pneumoniae was studied in Sprague-Dawley rats. Sham celiotomy was performed on 20 animals while another 20 rats underwent splenectomy. Four weeks later, bacteremia was induced by intraperitoneal (IP) injection of S. pneumoniae. Serial cultures of peripheral blood were obtained. Splenectomy produced significant impairment of intravascular clearance of bacteria compared to that noted among control animals (p less than 0.01). Eighty animals were divided into four equal groups: I--splenectomy, II--50% splenectomy with the upper half left in situ connected to the short gastric vessels, III--50% splenectomy with the lower half left in situ connected to the hilar vessels, and IV--splenectomy with implantation of splenic fragments. Pneumococcus was administered IP 16 weeks later. Rats were killed 6 hours after bacterial challenge. Residual splenic tissue was weighed. There was significantly less splenic tissue in Groups II-IV than noted in sham animals after 16 weeks (p less than 0.01). The type of partial splenectomy did not significantly affect the weight of residual splenic tissue 16 weeks later. Implantation did yield viable splenic tissue, though the amount proved significantly less than that resulting from either type of partial splenectomy (p less than 0.01). Mean bacterial counts with time for short gastric (Group II) and hilar (Group III) remnant animals were significantly different from those for the asplenic (Group I) rats (p less than 0.02 and p less than 0.001, respectively). Animals with splenic implants (Group IV) were not significantly different from asplenic rats (Group I). Animals with hilar splenic remnants proved significantly different from those with short gastric splenic remnants (p less than 0.01). Partial splenectomy offers protection against pneumococcal bacteremia, though preservation of the hilar blood supply affords the most benefit. The utility of splenic implantation remains unproven.

Plasma fibronectin concentrations in healthy and septic infants

The concentration of plasma fibronectin was determined by Laurell's electroimmunoassay in 75 preterm or term newborns within the first 2 days of life, in 97 healthy infants aged from 3 days to 12 months, in 40 septic infants and in 38 healthy adult subjects. The mean fibronectin concentration in citrated plasma of normal adults was 318 +/- 84 ml/l. Healthy eutrophic term newborns 1-2 days old had approximately one-third of the fibronectin concentration of adults. There was no significant difference in the values between healthy term and eutrophic preterm newborns or between eutrophic and hypotrophic newborns. The plasma fibronectin increased strongly over the 1st month of life. No significant difference was observed between fibronectin levels in infant boys and girls. The values in septic newborns and septic older infants were significantly lower when compared with those of age-matched healthy controls. It is speculated that this deficiency, because of linkage to fibrin in disseminated intravascular coagulation or due to increased utilisation as a nonspecific opsonin and sequestration at sites of tissue injury, may contribute to organ failure in septicaemia.

Distribution of pneumococcus-induced augmentation of tissue leukostasis in rabbits: specificity for the pulmonary vascular bed

We studied whether pneumococcal (PNC) sonicate-induced leukostasis is specific for the lung or whether it occurs in extrapulmonary foci as well. Indium 111-radiolabeled rabbit granulocytes were infused into rabbits that were then challenged with nonviable PNC or normal saline solution. Animals were killed at either 3 or 24 hours after infusion and washed tissue sections from lung, liver, spleen, brain, heart, and kidney were weighed. Tissue 111In radioactivities from each PNC sonicate-challenged animal were compared with those from a control simultaneously injected with saline solution. At both 3 and 24 hours after injection, 111In radioactivity was significantly (p less than 0.01) increased in the lungs of animals challenged with PNC compared with controls injected with saline solution. There were no significant differences between experimental and control animals in liver, spleen, heart, kidney, or brain radioactivities. Animals in another group were injected with PNC through catheters placed in either the right atrium or left ventricle. Significantly (p less than 0.03) increased 111In radioactivity was found after either route of administration only in the lung.