Recovery of Bordetella holmesii from Patients with Pertussis-Like Symptoms: Use of Pulsed-Field Gel Electrophoresis To Characterize Circulating Strains

Abstract

A 4-year retrospective study showing that we isolated Bordetella holmesii, but not Bordetella pertussis, from patients with pertussis-like symptoms was performed. From 1995 through 1998, we isolated B. holmesii from 32 nasopharyngeal specimens that had been submitted from patients suspected of having pertussis. Previously, B. holmesii had been associated mainly with septicemia and was not thought to be associated with respiratory illness. A study was undertaken to describe the characteristics of the B. holmesii isolates recovered and why we were successful in detecting the organism in nasopharyngeal specimens. B. holmesii isolates were characterized for drug sensitivities and for genetic relatedness by pulsed-field gel electrophoresis (PFGE). These isolates, an additional strain of B. holmesii isolated from a blood culture and previously confirmed by the Centers for Disease Control and Prevention, Atlanta, Ga., and 14 other clinical isolates of Bordetella spp., including 4 of B. bronchiseptica, 5 of B. parapertussis, and 5 of B. pertussis, were studied. They were all separately inoculated on three Bordet Gengou (BG) selective media containing either 0.625 g of oxacillin per ml, 40 g of cephalexin per ml, or 2.5 g of methicillin per ml, on BG agar with no antibiotic (control), and on charcoal agar (CA) with and without 40 g of cephalexin per ml. We found that cephalexin, the antibiotic commonly incorporated in both CA and BG agar for the recovery of Bordetella spp., is inhibitory to the growth of B. holmesii. In addition, the genotypic analysis of the 32 B. holmesii isolates by PFGE following restriction with XbaI and SpeI identified the dominant strains circulating during the study period.

The Role of Mucosal Immunity in Pertussis

“…The main causative agent of whooping cough is Bordetella pertussis (2), a gram negative coccobacillus which is able to colonize the human upper respiratory tract by attaching to the ciliated cells. Other Bordetella species, such as Bordetella parapertussis (3) and Bordetella holmesii (4), can cause diseases similar to pertussis, albeit usually with much less severe symptoms than typical whooping cough caused by B. pertussis .…”

Identification and regulation of expression of a gene encoding a filamentous hemagglutinin-related protein in Bordetella holmesii

“…Moreover, B. holmesii is known to contain several copies of the insertion elements IS481 and IS1001, otherwise found only in B. pertussis and B. parapertussis , respectively [ 20 , 21 ]. In addition to its isolation from immunocompromised patients [ 22 - 24 ], B. holmesii was found to be able to cause whooping-cough like symptoms in otherwise healthy persons [ 25 , 26 ]. Very little was known about the virulence properties of this bacterium and attempts to identify virulence factors related to those of B. pertussis failed.…”

Bordetella petriiClinical Isolate

“…B. hinzii is a commensal of the respiratory tract of fowl but has some pathogenic potential in immunocompromised humans ( 10 ) and was implicated as the causative agent in a fatal case of septicemia ( 11 ). B. holmesii has been isolated from blood of young adults, and nasopharyngeal specimens ( 9 , 12 , 13 ). B. trematum has been isolated from human ear infections and wounds, but its pathogenicity remains unknown ( 7 ).…”