Serotype and drug susceptibility of Bordetella pertussis isolated in Japan from 1975 to 1984

Pharmacotherapy for Bordetella pertussis infection. I. A synthesis of laboratory sciences

There is considerable history and practice experience both with laboratory susceptibility testing for Bordetella pertussis and clinical treatment. This two-part narrative review provides a synthesis of the laboratory and clinical sciences as they apply to this bacterium and the clinical consequences of treating infection. It is generally held that antibiotic susceptibility testing for B. pertussis is not sufficiently standardised, but there has not been an urgent need to consolidate the same given the lack global experience with major resistance profiles. Experience in China, however, has provided concern for high-level macrolide resistance. The nature of and frequency of such resistance has raised the bar for reconsideration of susceptibility testing given that first-line treatment may be regionally compromised. Disk diffusion and Etest susceptibility testing can be recommended for screening resistance among individual isolates of B. pertussis and on an ad hoc manner. Disk diffusion, Etest and/or critical agar dilution testing can be recommended for large-scale studies. Standards for inoculum, growth atmosphere, timing of interpretation, preferred testing media and controls can be extrapolated from the publications to date. Such methods should be able to detect high-level resistance to several antibiotics, but especially macrolides. Concern for intermediate-susceptible categories requires consideration as well as the correlation with bacteriological and clinical outcomes. Provisional standards can be applied at this time, and modification or fine-tuning of any such standards are open to future investigation.

Genetic analysis of clinical and vaccine strains of Bordetella pertussis by Pulsed-Field Gel Electrophoresis (PFGE), Multi Locus Sequence Typing (MLST) and serotyping

In spite of high vaccination coverage in the Expanded Program of Immunization (EPI), pertussis has not been eradicated yet and the re-emergence of the disease is still reported worldwide. The genetic divergence study of circulating clinical strains of Bordetella pertussis among the population with high vaccination coverage is a useful tool to have an insight in the understanding of genetic patterns of this bacterium and deviation of them from vaccine strains. Different methods are accessible for studying of Bordetella pertussis that can perform appropriate assessment between populations. Strains used in this study were a collection of two pertussis vaccine strains used to create killed pertussis vaccine over years at Razi Vaccine and Serum Research Institute, 10 clinical and 2 reference strains (ATCC9797 and Tohama I) in Multilocus Sequence Typing (MLST), Pulsed-Field Gel Electrophoresis (PFGE), and serotyping. The genetic profiles of vaccine working and master seeds showed no important change(s) in frequencies of fingerprint types investigated in the vaccine strains and had homogeneity in PFGE method where the clinical isolates showed diversity in genetic profile. Serotyping method showed that all of 10 clinical strains expressing Fim 3. In MLST study, seven housekeeping genes including adk, pgm, fum C, tyr B, gly A, pep A and icd were analyzed which showed no changes in the sequence of clinical and vaccine strains with 100% homology. The genes that cause pathogenicity like ptxC, tcfA and fhaB were also evaluated and the results illustrated heterogeneity in the vaccine and circulating strains.

Use of monoclonal antibodies to serotype Bordetella pertussis isolates: comparison of results obtained by indirect whole-cell enzyme-linked immunosorbent assay and bacterial microagglutination methods

Sixty-one Bordetella pertussis isolates were tested blindly in two laboratories to determine their serotype nature by monoclonal antibodies using two independent methods: the standard bacterial microagglutination assay and an indirect whole-cell enzyme-linked immunosorbent assay. Both methods gave concordant results in 60 of the 61 isolates.

Simple, speedy, sensitive, and specific serodiagnosis of pertussis by using a particle agglutination test

We developed a particle agglutination test (KPA) with poly(gamma-methyl L-glutamate) as the solid particle for measurement of pertussis toxin (PT) antibody. In this study, KPA was assessed as a means of serodiagnosing pertussis, and the results were compared with those of indirect enzyme-linked immunosorbent assay (indirect ELISA) and the microagglutination test. First, four serum samples were collected from each of 21 healthy children: before and 4 weeks after receiving three primary doses of acellular pertussis vaccines and before and 4 weeks after receiving a booster dose. In all 21 vaccinees, a significant rise in PT antibody titers was observed by KPA after each vaccination, and among all 84 serum samples collected, an excellent correlation was demonstrated between the values obtained by indirect ELISA and those obtained by KPA (r = 0.92). Second, paired serum samples were collected at intervals of approximately 2 weeks from 51 patients with culture-confirmed pertussis. A significant increase in titer (fourfold or more) was observed in 39 (76%) patients by KPA, 34 (67%) patients by indirect ELISA, and 23 (45%) patients by the microagglutination test. In acute- and convalescent-phase sera collected from 20 nonpertussis patients, there were no changes in titers by KPA. The KPA procedure was as simple as that of the microagglutination test, and the reaction time was only 2 h (or overnight). In this study, KPA was demonstrated to be a simple, speedy, sensitive, and specific serodiagnostic method for pertussis.

Efficacy of short-term treatment of pertussis with clarithromycin and azithromycin

The recommended treatment for pertussis is erythromycin, 40 to 50 mg/kg per day for 2 weeks. The newly developed macrolides, clarithromycin and azithromycin, have been demonstrated to be superior to erythromycin because of improved absorption and a longer half-life. As a result, we conducted two separate comparison studies to evaluate the efficacies of clarithromycin, 10 mg/kg per day, twice a day for 7 days, and azithromycin, 10 mg/kg per day, once a day for 5 days, compared with the standard erythromycin regimen. A total of 17 patients, including 10 infants 1 year of age or less, for whom pertussis had been confirmed by culture, were allocated to receive either clarithromycin or azithromycin treatment, and each patient was matched (age, sex, and immunization status) with historical control subjects who had been treated with erythromycin. Eradication rates examined at 1 week after treatment were as follows: 9 of 9 with clarithromycin versus 16 of 18 with erythromycin (psi M-H = 1.13), and 8 of 8 with azithromycin versus 13 of 16 with erythromycin (psi M-H = 1.23). No bacterial relapse after treatment was detected in either group. All isolated strains of Bordetella pertussis were susceptible to clarithromycin, azithromycin, and erythromycin, and no change in drug susceptibility has been confirmed for the past 20 years in Japan. Because of the very low incidence of pertussis resulting from widespread use of acellular pertussis vaccination, this study did not enroll a large number of patients; however we conclude that short-term treatment with clarithromycin or azithromycin is expected to be equal or superior to the standard long-term erythromycin regimen for pertussis.

Respiratory failure caused by dual infection with Bordetella pertussis and respiratory syncytial virus

Two infants with pneumonia caused by both Bordetella pertussis and respiratory syncytial virus (RS virus) suffered respiratory failure preceded by convulsion. Detection of respiratory pathogens with polymerase chain reaction and enzyme-linked immunosorbent assay was crucial in the management of dually infected infants.

Comparison of media for agar dilution susceptibility testing of Bordetella pertussis and Bordetella parapertussis

Antimicrobial susceptibility testing of the fastidious species Bordetella pertussis and Bordetella parapertussis is not standardized. In an attempt to find the optimal medium for agar dilution testing, the activity of erythromycin against Bordetella pertussis and Bordetella parapertussis (34 isolates each) was assessed using homologous broth/agar combinations of Bordet-Gengou, charcoal, Iso-Sensitest (Oxoid) and Mueller-Hinton media. Each medium was supplemented with 5% and 20% whole defibrinated horse blood. Mueller-Hinton medium supplemented with 5% horse blood performed best overall.

In vitro susceptibility of Bordetella parapertussis to various antimicrobial agents

The in vitro activity of 18 antimicrobial agents against 32 strains of Bordetella parapertussis isolated from whooping cough patients was studied. The most active antimicrobial agents were piperacillin and minocycline, followed (in descending order of activity) by moxalactam, erythromycin, cefoperazone, tetracycline, ampicillin, cefotaxime, chloramphenicol, josamycin, sulfamethoxazole, and nalidixic acid. Isolates were resistant to benzylpenicillin, cephalothin, cefatrizine, cefaclor, streptomycin, and cephalexin.