Relation between beta-lactamase producing bacteria and patient characteristics in chronic obstructive pulmonary disease (COPD).

BACKGROUND: In addition to bronchodilator and anti-inflammatory therapy, exacerbations in patients with chronic obstructive pulmonary disease (COPD) are often treated with antibiotics. Haemophilus influenzae and Moraxella (Branhamella) catarrhalis, two important respiratory pathogens, may produce beta-lactamase which makes them resistant to ampicillin. Surveillance studies conducted in various countries have shown an increasing incidence of these beta-lactamase producing bacteria. Although this may simply be a consequence of the increasing use of antibiotics, it is possible that other factors are important. A study was undertaken to investigate whether clinical factors are related to the presence of beta-lactamase forming bacteria in the sputum of patients with COPD. METHODS: One hundred patients with COPD aged over 40 years were sequentially selected from an outpatient clinic on the basis of sputum culture results. Fifty had beta-lactamase positive (beta L+) and 50 had beta-lactamase negative (beta L-) bacteria in their sputum. Patients were included only if sputum culture results yielded one pathogen. The files of these patients were investigated for possible causative factors present during the two preceding years. RESULTS: Both groups were almost identical in terms of lung function, maintenance medication, and smoking history. The total number of antibiotic courses in the beta L+ group was higher, as were individual courses of cephalosporins, tetracyclines, and macrolides. The number of patients admitted to hospital was higher in the beta L+ group, but admissions were of equal duration in both groups. Patients admitted to hospital had poorer lung function. Risk factors for beta-lactamase producing bacteria were identified by logistic regression analysis which revealed an odds ratio for one course of antibiotics of 1.15 (95% CI 1.04 to 1.28). CONCLUSIONS: An increased number of antibiotic courses is related to a higher incidence of beta-lactamase producing bacteria and more patients had hospital admissions in the beta L+ group. beta-lactamase stable antibiotics were used more frequently in the beta L+ group, probably because prescribing was adapted to the presence of beta-lactamase producing bacteria. No other differences were found between the beta L+ and beta L- groups.

Antigen detection in oropharyngeal secretions for rapid diagnosis of pneumococcal pneumonia.

To determine the value of detection of antigen in the oropharynx in the diagnosis of pneumococcal pneumonia, oropharyngeal secretions were cultured for the presence of Streptococcus pneumoniae and tested for the presence of pneumococcal antigen. Sputum (if available) collected on the same day was also investigated for the presence of antigen. Detection of pneumococcal antigen was found to be directly related to the severity of pneumococcal carriership or infection (p < 0.0001) and was not related to culture results. Patients with pneumococcal pneumonia had the highest antigen detection rate (38%), followed by patients with pneumonia of unknown etiology (32%) and patients with an acute lower respiratory tract infection due to Streptococcus pneumoniae (20%). Pneumococcal carriers had a detection rate of only 9%. Antigen could be detected in only one patient of the control groups. Although antigen detection in sputum was superior to that in oropharyngeal secretions, concordant results were obtained in 8 (40%) and 6 (36%) patients with pneumococcal pneumonia and pneumonia of unknown etiology respectively. The results strongly suggest that pneumococcal carriage seldom leads to a detectable level of antigen, and that antigen detection in the oropharynx appears to be of additive value in the diagnosis of pneumococcal pneumonia.

Rapid detection of pneumococcal antigen in pleural fluid of patients with community acquired pneumonia.

BACKGROUND: Detection of pneumococcal antigen may help to increase the rate of diagnosis of pneumococcal pneumonia. This study was designed to determine the value of rapid detection of pneumococcal antigen in pleural fluid from patients with community acquired pneumonia. METHODS: Thoracentesis was performed in patients suspected of having empyema and in patients with pneumonia of unknown aetiology. Pneumococcal capsular antigen was detected by latex agglutination and this method was compared with Gram staining and culture, specimens of pleural fluid being examined in parallel by the three methods. RESULTS: Pleural fluid was radiographically identified in 63 of 135 patients with community acquired pneumonia. In nine of 45 patients with pneumococcal pneumonia and pleural fluid pneumococci were identified by Gram stain in two and by culture in one specimen of pleural fluid, whereas antigen was detected in eight of these specimens. In 12 of 33 patients with pneumonia of other known aetiology only one pleural fluid specimen was antigen positive, providing a specificity of 92% for this test. Pleural fluid obtained from 12 of 58 patients with pneumonia of unknown aetiology yielded detectable antigen in seven cases. CONCLUSIONS: Detection of pneumococcal antigen by latex agglutination in pleural fluid may yield important and rapid information in patients with community acquired pneumonia.

The role of antigen detection in pneumococcal carriers: a comparison between cultures and capsular antigen detection in upper respiratory tract secretions.

During the winter season upper respiratory tract secretions from 166 patients with stable chronic obstructive pulmonary disease (COPD) or asthma were simultaneously cultured for Streptococcus pneumoniae and tested for pneumococcal capsular antigen. Latex agglutination was employed to investigate the effect of pneumococcal carriership on pneumococcal capsular antigen detection in upper respiratory tract secretions. All specimens originating from the oropharynx, nasopharynx and saliva were both cultured and investigated in parallel for the presence of antigen. The recovery of pneumococci from the different areas was unequally distributed (oropharynx 29%, nasopharynx 8%, and saliva 16%), with the highest isolation rate from the oropharynx alone. Only 4 (3%) of the oropharyngeal swabs, 1 (1%) of the nasopharyngeal swabs and 14 (9%) of the saliva specimens yielded both pneumococcal antigen and a positive culture for S. pneumoniae. A further 9 (6%) of the oropharyngeal swabs, 5 (3%) of the nasopharyngeal swabs, and 50 (33%) of the saliva specimens were antigen positive only, with no pneumococci isolated on culture. It is speculated that these reactions were due to cross-reacting microorganisms (especially alpha-haemolytic streptococci) present in saliva and contaminating the oropharynx and the nasopharynx. Quantitative cultures of 9 oropharyngeal swabs yielded S. pneumoniae in concentrations too low to be detectable by latex agglutination. The study indicates that there is a poor relation between pneumococcal colonization and antigen detection in the oropharynx and nasopharynx. Antigen present in these secretions is probably not an important disrupting factor by contamination when detecting pneumococcal antigen in washed sputum. The false positive antigen results in saliva are probably due to cross-reactions with alpha-haemolytic streptococci.

Pneumococcal antigen persistence in sputum from patients with community-acquired pneumonia.

The purpose of this study was to establish the diagnostic value of pneumococcal capsular antigen by comparing this with the results of Gram stain and culture in representative and nonrepresentative sputa during follow-up in patients with community-acquired pneumonia. Antigen was detected by a latex particle agglutination test. At the time of hospital admission, antigen was detected in 17 representative sputum specimens from 30 patients with pneumococcal pneumonia, which was comparable to the results of Gram stain and culture. In five additional patients, antigen was demonstrated in nonrepresentative specimens. During follow-up under antibiotic treatment, this number increased by six: three patients with representative and three patients with nonrepresentative sputum, respectively. Two of the 22 patients with pneumonia of other known cause had an antigen-positive sputum on admission and in another two patients, sputum antigen was detected during follow-up. Ten of 34 patients with pneumonia of unknown cause had detectable antigen in representative or nonrepresentative sputum on admission. During follow-up, antigen was detected in sputa of an additional seven patients. There was no difference in duration of antigen persistence between patients with pneumococcal pneumonia and pneumonia of unknown cause. It was observed that the first antigen-positive sputum specimen was always detected within the first five days of the hospital stay. We conclude that antigen detection in both representative and nonrepresentative sputum specimens at the time of hospital admission and during follow-up is of additional value for the diagnosis of pneumococcal pneumonia. It markedly increases the number of patients with pneumococcal pneumonia detected, who would otherwise be considered to have pneumonia of unknown cause. However, antigen-positive results should be interpreted carefully, especially in those pneumonia patients with chronic bronchitis, because detectable antigen may be caused by pneumococcal carriership of the lower respiratory tract.

Pneumococcal capsular antigen detection and pneumococcal serology in patients with community acquired pneumonia.

BACKGROUND: Methods to determine the microbial cause of community acquired pneumonia include detection of pneumococcal antigen and measurement of pneumococcal capsular antibody response. Their usefulness compared with conventional microbiological techniques was investigated in patients with pneumonia, some of whom had been treated with antibiotics. METHODS: Pneumococcal capsular antigen was detected by latex agglutination in sputum and the results compared prospectively with results of conventional microbiological techniques in 90 patients with community acquired pneumonia. Serum, urine, and pleural fluid samples were also tested for antigen. Serum pneumococcal capsular antibody titres were measured. RESULTS: A diagnosis was established by conventional microbiological techniques in 53 patients, 30 of whom had pneumococcal pneumonia. The sensitivity of antigen detection in first day sputum specimens (n = 18) in those with pneumococcal pneumonia was 94%; antigen was present in 23 of the 27 patients who produced representative sputum on admission and during follow up. The specificity of antigen detection in sputum in patients with non-pneumococcal pneumonia and lung infarction was 87%. Antigen was present in 12 of 25 patients with pneumonia of unknown aetiology who produced representative sputum. Antigen was rarely detected in serum and urine, but was present in pleural fluid in three of four patients with pneumococcal pneumonia and in all four patients with pneumonia of unknown aetiology. Pneumococcal antigen remained detectable in patients treated with antibiotics. Pneumococcal capsular antibody detection was as specific (85%) as antigen detection, but had a lower sensitivity (50%). CONCLUSION: Pneumococcal antigen detection in sputum or pleural fluid is of value in making a rapid diagnosis and provides an additional diagnostic result in patients with pneumococcal pneumonia, especially those receiving antibiotic treatment.

Pneumococcal antibody levels in patients with acute lung infiltrates.

We assessed the diagnostic value of serial serum antibody titers (IgG, IgM) to a polyvalent pneumococcal antigen preparation containing capsular polysaccharides from 14 different serotypes in the differential diagnosis between infectious lung infiltrates and lung infarction. A two-fold or higher change in antibody level, measured by means of an enzyme-linked immunosorbent assay (ELISA) was considered significant. Of 30 patients with pneumococcal pneumonia, 13 were infected with a Streptococcus pneumoniae serotype included in the vaccine (group A), five with a non-vaccine type (group B), and in 12 patients the S. pneumoniae serotype was not identified (group C). The sensitivity was 62% (group A). A heterotypic antibody rise was observed in one patient (group B). There was no difference in antibody rises between groups A and C. In 13 patients the pulmonary infiltrates were associated with different etiological factors (group D). The specificity determined in this group was 85%. The positive predictive value of an antibody rise was 89% (SD = 0.07) in pneumococcal pneumonia and a negative result signified in only 46% of the patients (SD = 0.10) that the pulmonary infiltrates were not associated with pneumococcal infection. Four patients suffering from pulmonary infarction had no antibody rise. Preliminary data of a current similar study, using a 23-valent antigen of pneumococcal capsular polysaccharides supported the aforementioned results. It is noteworthy that ten additional patients with lung infarction showed no seroconversion. The results suggest that serum antibody changes to a polyvalent pneumococcal vaccine may be of value in the differential diagnosis between infectious lung infiltrates and lung infarction.

Bronchial hyperreactivity and bronchial obstruction in respiratory viral infection. An attempt to evaluate the relationship.

The aim of this study was to investigate the relation of viral respiratory infection with bronchial hyperreactivity and bronchial obstruction. A viral infection using a live attenuated influenza virus was induced successfully in 10 of 30 patients with chronic obstructive pulmonary disease (COPD) and in 3 subjects without COPD (non-COPD). No significant change in bronchial reactivity and lung function could be found in comparison with the baseline values.

Legionella pneumophila pneumonia associated with reactivation of cytomegalovirus infection.

Two patients with Legionella pneumophila infection (serogroup 1) associated with a reactivated cytomegalovirus infection are described. Predisposing underlying factors were not evident.

Oropharyngeal flora as a source of bacteria colonizing the lower airways in patients on artificial ventilation.

During 1 year 27 patients admitted to the respiratory intensive care unit were monitored bacteriologically for a minimum of 10 days (mean: 26.7 days). Oropharyngeal swabs and tracheal aspirates were qualitatively and semi-quantitatively cultured twice weekly. A correlation between oropharyngeal and tracheal flora was found: once a bacterial species colonized the oropharyngeal cavity in high numbers, the identical microorganism was frequently isolated (greater than 50%) from the lower respiratory tract. Six of the 27 patients acquired an infection of the lower airways in the respiratory intensive care unit. The bacteria involved belonged to the patients oropharyngeal flora: S. aureus, Enterobacteriaceae and Pseudomonadaceae. As a result of this study showing the oropharynx to be the source of lower airway colonization/infection, a policy for infection prevention has been outlined. This policy is based on the concept of source elimination by means of oropharyngeal decontamination.

Viral, mycoplasma and bacterial infections in nurses with symptoms of respiratory diseases.

A consecutive series of 282 nurses of the University Hospital, Groningen, with complaints of the nose and/or throat associated with coughing and/or hoarseness were examined between April 1965 and February 1968. The intent was to obtain information on the incidence of viral, mycoplasma and bacterial infections, and on the relationship of these infections in nurses with chronic nonspecific lung disease (CNSLD). The following results were obtained: 1. Virus infections caused by influenza virus (A, B, and C), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus and/or Mycoplasma pneumoniae were confirmed in 30% of the nurses examined; if influenza was excluded, this figure was 20%. 2. Rhinovirus infections were found more often than all the other virus infections together (if influenza was excluded). 3. Approximately 25% of the nurses had signs of CNSLD. 4. In the course of the virus infections, nine out of 14 nurses with a history of chronic obstructive lung disease showed symptoms of exacerbation or recurrence of a generalized bronchial obstruction. 5. There was no difference in the incidence of virus infections in the group of nurses with and without CNSLD. 6. There were more bacterial infections (without a confirmed virus infection) in the subjects with CNSLD than in those without CNSLD. 7. There were more combined viral/bacterial infections in the patients with CNSLD than in those without CNSLD. 8. Patients with influenza did not have more bacterial infections than patients with other virus infections. This is also true for patients with CNSLD and influenza when regarded separately. The patients without CNSLD tended to have more bacterial infections with influenza than with other viral infections, but the difference was not statistically significant.