Isolation of Bordetella Pertussis and Bordetella Parapertussis from Clinical Specimens at Different Provinces

Background and Bordetella pertussis is a gram negative and obligate aerobic bacteria that is cause of Whooping cough. It is exclusively human pathogen. In the last decade increasing rate of pertussis was observed especially in those under 6 months old and also over 10 years. Despite importance of pertussis as a contagious disease, we have not enough information about it our country. In this research pertussis suspicious specimens collected from different provinces of Iran in 2009-2010 were studied. Totally 1084 samples from nasopharyngeal secretion or nasal of patients with coughing more than 2 weeks were collected from different provinces of Iran and sent to pertussis reference laboratory in Pasteur institute of Iran. In this research the specimens were studied by culture. On receipt, all swab specimens were inoculated on pertussis charcoal agar and Bordet Jengou plates containing (40 µg/ml) cephalexin and without cephalexin. The plates were incubated at 36 0c. Colonies were identified as B. pertussis, B. parapertussis by gram staining and complementary tests. B. pertussis and B. parapertussis was found in 11 and 1 patients, respectively. Three cases of culture positive specimens was from the patients with the age of under 2 years of old and 6 was from the patients with the age of 2 month-2 years, 2 was from the patients with the age of 2-10 years, and 1 isolate was from a patient over 10 years. Eight patients of culture positive specimens were vaccinated and 7 cases were from patients after initiation of antibiotic therapy. Results of this study indicated that this illness is associated with the age group of 2 month-2 years of old in Iran. Culture is highly specific method but its sensitivity is low. According to clinical and paraclinical problems of this illness in Iran, for diagnosis of infection with B. pertussis other molecular methods such as Real-Time PCR should be done.