Evaluation of a Rapid Immunochromatographic ODK-0901 Test for Detection of Pneumococcal Antigen in Middle Ear Fluids and Nasopharyngeal Secretions

Since the incidence of penicillin-resistant Streptococcus pneumoniae has been increasing at an astonishing rate throughout the world, the need for accurate and rapid identification of pneumococci has become increasingly important to determine the appropriate antimicrobial treatment. We have evaluated an immunochromatographic test (ODK-0901) that detects pneumococcal antigens using 264 middle ear fluids (MEFs) and 268 nasopharyngeal secretions (NPSs). A sample was defined to contain S. pneumoniae when optochin and bile sensitive alpha hemolytic streptococcal colonies were isolated by culture. The sensitivity and specificity of the ODK-0901 test were 81.4% and 80.5%, respectively, for MEFs from patients with acute otitis media (AOM). In addition, the sensitivity and specificity were 75.2% and 88.8%, respectively, for NPSs from patients with acute rhinosinusitis. The ODK-0901 test may provide a rapid and highly sensitive evaluation of the presence of S. pneumoniae and thus may be a promising method of identifying pneumococci in MEFs and NPSs

PspA family distribution, antimicrobial resistance and serotype of Streptococcus pneumoniae isolated from upper respiratory tract infections in Japan.

The protection against pneumococcal infections provided by currently available pneumococcal polysaccharide conjugate vaccines are restricted to the limited number of the serotypes included in the vaccine. In the present study, we evaluated the distribution of the pneumococcal capsular type and surface protein A (PspA) family of pneumococcal isolates from upper respiratory tract infections in Japan.A total of 251 S. pneumoniae isolates from patients seeking treatment for upper respiratory tract infections were characterized for PspA family, antibiotic resistance and capsular type.Among the 251 pneumococci studied, the majority (49.4%) was identified as belonging to PspA family 2, while most of the remaining isolates (44.6%) belonged to family 1. There were no significant differences between the distributions of PspA1 versus PspA2 isolates based on the age or gender of the patient, source of the isolates or the isolates' susceptibilities to penicillin G. In contrast, the frequency of the mefA gene presence and of serotypes 15B and 19F were statistically more common among PspA2 strains.The vast majority of pneumococci isolated from the middle ear fluids, nasal discharges/sinus aspirates or pharyngeal secretions represented PspA families 1 and 2. Capsular serotypes were generally not exclusively associated with certain PspA families, although some capsular types showed a much higher proportion of either PspA1 or PspA2. A PspA-containing vaccine would potentially provide high coverage against pneumococcal infectious diseases because it would be cross-protective versus invasive disease with the majority of pneumococci infecting children and adults

Distribution of PspA familes based on sex, age and origin of pneumococci.

<p>MEF: middle ear fluid, ND/SA: nasal discharge/sinus aspirate, PS: pharyngeal secretion. Each numbers shows numbers of isolates and percentage shows in parenthesis. There is no significant differences in PspA family distribution based on sex, age and origin of isolates.</p

Distribution of PspA familes based on pneumococcal serotypes.

<p>G23: serogroup 23 strains except serotype 23F. Others: serotypes not included in 23 PPV. Each numbers shows numbers of isolates and percentage shows in parenthesis. *<i>p</i><0.05, **<i>p</i><0.01.</p

Distribution of <i>S. pneumoniae</i> serotypes based on their susceptibilities to PCG.

<p>G23: serogroup 23 strains except serotype 23F. PCG: penicillin G. PSSP: penicillin susceptible <i>S. pneumoniae</i>. PISP: penicillin intermediately resistant <i>S. pneumoniae</i>. PRSP: penicillin resistant <i>S. pneumoniae</i>. DRSP: PRSP+PISP. Others: serotypes not included in 23 PPV.</p>*<p>comparison between ≤2 y.o. vs. ≥3 y.o.</p

Serotype coverage of pneumococcal vaccine formulas among <i>S. pneumoniae</i> isolates from upper respiratory tract infections in Japan.

<p>DRSP: drug resistant <i>S. pneumoniae</i> (PISP+PRSP). MRSP: macrolide resistant <i>S. pneumoniae</i>.</p

Distribution of <i>S. pneumoniae</i> serotypes based on their macroride-resistant traits.

<p>G23: serogroup 23 strains except serotype 23F. PCG: penicillin G. PSSP: penicillin susceptible <i>S. pneumoniae</i>. PISP: penicillin intermediately resistant <i>S. pneumoniae</i>. PRSP: penicillin resistant <i>S. pneumoniae</i>. DRSP: PRSP+PISP. Others: serotypes not included in 23 PPV.</p>*<p>comparison between ≤2 y.o. vs. ≥3 y.o.</p

An Application of Outer Membrane Protein P6-Specific Enzyme-Linked Immunosorbent Assay for Detection of <i>Haemophilus influenzae</i> in Middle Ear Fluids and Nasopharyngeal Secretions

<div><p>An enzyme-linked immunosorbent assay specific to outer membrane protein P6 (P6-ELISA) was applied for detecting <i>Haemophilus influenzae</i> in middle ear fluids (MEFs) from acute otitis media (AOM) patients and in nasopharyngeal secretions (NPSs) from acute rhinosinusitis patients. P6-ELISA had a sensitivity of 83.3% for MEFs and 71.5% for NPSs and a specificity of 85.6% for MEFs and 92.5% for NPSs, respectively. Real-time PCR exhibited significant differences in the number of <i>ompP1</i> gene copies among samples determined by P6-ELISA to be positive and negative for <i>H. influenzae</i>. However, because the P6-ELISA test has the reactivity in <i>Haemophilus</i> species include two commensals <i>H. haemolyticus</i> and <i>H. parainfluenzae</i>, it is thus a weak method in order to detect only NTHi correctly. Consequently, diagnosis using the P6-ELISA should be based on an overall evaluation, including the results of other related examinations and clinical symptoms to prevent misleading conclusions in clinical setting.</p></div

Sensitivity, specificity, positive predicting value, and negative predicting values of P6-ELISA to determine the presence of <i>H. influenzae</i> in MEFs and NPS.

<p>The numbers in a parentheses show the number of samples.</p

Positive and negative predicting values resulting from evaluating NPSs to determine the presence of <i>H. influenzae</i> in MEFs.

<p>Positive and negative predicting values resulting from evaluating NPSs to determine the presence of <i>H. influenzae</i> in MEFs.</p