Changes in Outer Membrane Proteins of Nontypable Haemophilus influenzae in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Five individual colonies of Haemophilus influenzae were isolated from each of one to three cultures of sputum collected from 18 patients with chronic obstructive pulmonary disease (COPD). The isolates were studied to investigate whether the major outer membrane proteins (MOMPs) changed during persistence. The relationship between isolates was analyzed by fingerprinting their chromosomal DNA. The fingerprints of eight strains (isolated from eight patients) with various MOMP compositions were different, whereas fingerprints of isolates with identical MOMP compositions were indistinguishable. In 12 patients, two or more strains with different MOMP compositions were found; one strain was isolated from the sputum samples of each of the six remaining patients. In seven of the 12 patients, strains with different MOMPs but with indistinguishable fingerprints were found. The differences were found in proteins b,c (five patients) and d (five patients). In patients with COPD, the MOMPs of H. influenzae are subject to changes that may enable this bacterium to escape immunological defense mechanisms.

Secondary Structure and Molecular Analysis of Interstrain Variability in the P5 Outer-Membrane Protein of Non-Typable Haemophilus Influenzae Isolated from Diverse Anatomical Sites

“…Chromosome fingerprint analysis of NTHi isolates from patients with COPD demonstrated genetic diversity [4]. However, analysis of genetic types by multi-locus enzyme electrophoresis suggested that isolates from persistent carriage or chronic infections are more diverse than isolates from acute infections [5].…”

“…However, analysis of genetic types by multi-locus enzyme electrophoresis suggested that isolates from persistent carriage or chronic infections are more diverse than isolates from acute infections [5]. The major outer-membrane protein (OMP) profile of chronic bronchitic isolates varies in the electrophoretic mobility of proteins P2 (protein b, c) and P5 (protein d) [4]. Furthermore, sequence analysis of the heatmodifiable protein, P5, from five isolates and their variants from chronic bronchitics, has identified four hypervariable regions that are proposed to be surfaceexposed and subject to the immune pressure of the host [6].…”

Identification of two iron-repressed periplasmic proteins in Haemophilus influenzae

“…It was observed that a major protein of 37 to electrophoretic mobility due to minor differences in its amino acid composition (14,32). That the major 37-to 40-kDa protein band was P2 was confirmed by immunoblotting using a guinea pig anti-P2 antiserum.…”

Epitope-specific immune recognition of the nontypeableHaemophilus influenzaeouter membrane protein 26

“…To remove any potential E. coli antibodies that may have cross-reacted with NTHi, sera were pre-absorbed with E. coli prior to flow cytometry as previously described. 40 NTHi-289 was grown as previously described, 16 harvested and washed twice with sterile PBS by centrifugation (400 g, 10 min at room temperature). The bacterial cell pellets were subsequently incubated for 1 h at 37°C with 200 μl of pre-adsorbed sera from the immunized rats, which had been diluted 1:50 in PBS.…”