Use of Selective Media in Bacteriological Investigation of Patients With Chronic Suppurative Respiratory Infection

Roberts, D E; Cole, Peter

doi:10.1016/s0140-6736(80)91295-7

Cited by 50 publications

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“…1 2 By contrast, patients with bronchiectasis and chronic obstructive pulmonary disease (COPD) are often colonised with potentially pathogenic microorganisms (PPMs). 3 Scientific evidence suggests that colonisation of distal airways by PPMs may be harmful to patients with bronchiectasis. These microorganisms represent a potential risk for lung infections and may secrete several inflammatory mediators that cause progressive tissue damage and airway obstruction.…”

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Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

Angrill

2002

Thorax

300

205

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Background: A study was undertaken to investigate the incidence, diagnostic yield of non-invasive and bronchoscopic techniques, and risk factors of airway colonisation in patients with bronchiectasis in a stable clinical situation. Methods: A 2 year prospective study of 77 patients with bronchiectasis in a stable clinical condition was performed in an 800 bed tertiary university hospital. The interventions used were pharyngeal swabs, sputum cultures and quantitative protected specimen brush (PSB) bacterial cultures (cut off point >10 2 cfu/ml) and bronchoalveolar lavage (BAL) (cut off point >10 3 cfu/ml). Results: The incidence of bronchial colonisation with potential pathogenic microorganisms (PPMs) was 64%. The most frequent PPMs isolated were Haemophilus influenzae (55%) and Pseudomonas spp (26%). Resistance to antibiotics was found in 30% of the isolated pathogens. When the sample was appropriate, the operative characteristics of the sputum cultures were similar to those obtained with the PSB taken as a gold standard. Risk factors associated with bronchial colonisation by PPMs in the multivariate analysis were: (1) diagnosis of bronchiectasis before the age of 14 years (odds ratio (OR)=3.92, 95% CI 1.29 to 11.95), (2) forced expiratory volume in 1 second (FEV 1 ) <80% predicted (OR=3.91, 95% CI 1.30 to 11.78), and (3) presence of varicose or cystic bronchiectasis (OR=4.80, 95% CI 1.11 to 21.46). Conclusions: Clinically stable patients with bronchiectasis have a high prevalence of bronchial colonisation by PPMs. Sputum culture is a good alternative to bronchoscopic procedures for evaluation of this colonisation. Early diagnosis of bronchiectasis, presence of varicose-cystic bronchiectasis, and FEV 1 <80% predicted appear to be risk factors for bronchial colonisation with PPMs.

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Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

Angrill

2002

Thorax

300

205

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“…The patients are relatively young (mean age approximately 40 years), non-smokers mainly (80%), wheezy (80%), they are colonised by rela tively avirulent organisms (eg. unencapsu lated Haemophilus influenzae) which can be isolated from the sputum, particularly using selective bacteriological media [4]; and in response to this respiratory coloni sation they mount normal or exuberant immunological responses (80% having in creased immunoglobulins in one or more of the major classes). The upper respira tory tract (nose and paranasal sinuses) is affected in 80% of patients who have lower respiratory chronic infection -a third having chronic purulent sinusitis.…”

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Host-Microbe Relationships in Chronic Respiratory Infection

Cole

1989

Respiration

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Infection of the upper and lower respiratory tracts accounts for 85% of the respiratory disease seen by primary-care physicians. Acute infection is usually attributable to microbial virulence but may occur on a background of immune deficiency. Recurrent acute bronchial and pneumonic infection is associated with considerable immunological abnormality (up to 75%) for which a high index of suspicion must be maintained. Chronic bronchial sepsis, on the other hand, has a paradoxically low prevalence of immune deficiency ( < 10%) and the pathogenesis depends on initially compromised mucociliary clearance (by exogenous agents or underlying genetic disease) allowing certain microbes to be selected for airway colonisation according to their ability to release cilio-inhibitory factors and factors damaging ciliated epithelium. Once microbial colonisation is established, the host responds exuberantly with non-specific and immune inflammatory responses which fail to clear the microbial flora but damage the ‘innocent bystander’ lung. This further compromises bronchial clearance mechanisms in a ‘vicious circle’ of events whose end result is progressive lung damage and cardio-respiratory failure.

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“…In contrast, protein synthesis in 2-DAM-resistant clinical isolates and transformants was inhibited by 1 ,ug of tobramycin per ml, and inhibition increased with higher drug concentrations. Since the stimulating effect of low concentrations of tobramycin in susceptible H. influenzae strains is probably due to misreading, these findings suggest that 2-DAM-resistant strains of H. influenzae have reduced sensitivity to misreading, indicating that altered ribosomes are responsible for the resistance.Although its pathogenic role has not been defined with certainty, nontypable Haemophilus influenzae can be cultured in high densities from the bronchial secretions of patients with cystic fibrosis (CF) or chronic bronchitis (21,26,33,38). With the use of selective culture media, this organism frequently can be recovered in the presence of other pathogenic organisms, such as members of the Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Staphylococcus aureus (33,45).…”

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“…With the use of selective culture media, this organism frequently can be recovered in the presence of other pathogenic organisms, such as members of the Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Staphylococcus aureus (33,45). When patients with CF harbor P. aeruginosa and H. influenzae in similar densities in their bronchial secretions, the former organism is generally considered the main pathogen, and antimicrobial therapy that is effective against P. aeruginosa (i.e., an antipseudomonal penicillin and a 2-deoxystreptamine aminoglycoside [2-DAM]) is administered.…”

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confidence: 99%

“…Although its pathogenic role has not been defined with certainty, nontypable Haemophilus influenzae can be cultured in high densities from the bronchial secretions of patients with cystic fibrosis (CF) or chronic bronchitis (21,26,33,38). With the use of selective culture media, this organism frequently can be recovered in the presence of other pathogenic organisms, such as members of the Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Staphylococcus aureus (33,45).…”

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confidence: 99%

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Effect of tobramycin on protein synthesis in 2-deoxystreptamine aminoglycoside-resistant clinical isolates of Haemophilus influenzae

Levy¹,

Burns²,

Mendelman³

et al. 1986

Antimicrob Agents Chemother

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Clinical isolates of Haemophilus influenzae resistant to a broad range of 2-deoxystreptamine aminoglycosides (2-DAM) were studied. The gene responsible for resistance could be mobilized by transformation into a 2-DAM susceptible laboratory strain of H. influenzae, enabling isogenic comparisons. The transformants had the same resistance phenotype as the parental strains. There was close linkage between 2-DAM resistance and streptomycin resistance, a chromosomal marker, but weak linkage between 2-DAM and erythromycin resistance. Resistant transformants exhibited a decreased accumulation of gentamicin due to the absence of the rapid, energy-dependent phase of uptake. Resistance was not through metabolic inactivation of the antibiotic; no aminoglycoside-acetylating, -adenylylating, or -phosphorylating activity was detected in the wild-type strains or in the 2-DAM-resistant transformants. Protein synthesis in 2-DAM-susceptible H. influenzae strains increased in the presence of low (1 ,ug/ml) and moderate (50 ,ug/ml) concentrations of tobramycin. With higher concentrations (100 and 500 ,ug/ml), protein synthesis was progressively inhibited. In contrast, protein synthesis in 2-DAM-resistant clinical isolates and transformants was inhibited by 1 ,ug of tobramycin per ml, and inhibition increased with higher drug concentrations. Since the stimulating effect of low concentrations of tobramycin in susceptible H. influenzae strains is probably due to misreading, these findings suggest that 2-DAM-resistant strains of H. influenzae have reduced sensitivity to misreading, indicating that altered ribosomes are responsible for the resistance.Although its pathogenic role has not been defined with certainty, nontypable Haemophilus influenzae can be cultured in high densities from the bronchial secretions of patients with cystic fibrosis (CF) or chronic bronchitis (21,26,33,38). With the use of selective culture media, this organism frequently can be recovered in the presence of other pathogenic organisms, such as members of the Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Staphylococcus aureus (33,45). When patients with CF harbor P. aeruginosa and H. influenzae in similar densities in their bronchial secretions, the former organism is generally considered the main pathogen, and antimicrobial therapy that is effective against P. aeruginosa (i.e., an antipseudomonal penicillin and a 2-deoxystreptamine aminoglycoside [2-DAM]) is administered. The diffusion of these antibiotics into the bronchial secretions is poor, and their bioactivity in this environment is reduced; antipseudomonal penicillins are inactivated by P-lactamases (15), and aminoglycosides are bound to DNA from lysed cells (24,40) and antagonized by the low pH (3) and the ionic content of purulent bronchial secretions (24). Thus, high densities of H. influenzae in the bronchial secretions may be exposed for prolonged periods to subinhibitory concentrations of 2-DAM.We hypothesized that this situation could favor the emergence of resistance. ...

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Use of Selective Media in Bacteriological Investigation of Patients With Chronic Suppurative Respiratory Infection

Cited by 50 publications

References 0 publications

Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

Host-Microbe Relationships in Chronic Respiratory Infection

Effect of tobramycin on protein synthesis in 2-deoxystreptamine aminoglycoside-resistant clinical isolates of Haemophilus influenzae

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