Microbiological and clinical aspects of respiratory infections associated with Bordetella bronchiseptica

Bordetella bronchiseptica is a well-known veterinary pathogen, but its implication in human disease is probably not fully recognized. The purpose of this study was to determine the clinical significance of 36 B. bronchiseptica isolates from respiratory samples of 22 patients. Therefore, we describe microbiological characteristics, including phenotypic and genotypic identification as well as antimicrobial susceptibilities of the isolates. Clonal relatedness was evaluated using pulsed-field gel electrophoresis (PFGE). Most of the patients had some underlying immunosuppressive condition. Eighteen out of 22 (82%) patients had respiratory symptoms, and the death of 2 patients was associated with respiratory infection.All strains were correctly identified at species level by the simultaneous use of phenotypic methods and were confirmed by specific amplification of the upstream region of the fla gene. Tigecycline, minocycline, doxycycline, colistin, and meropenem were the most active agents tested. PFGE analysis revealed that repeated infections involving each patient had been caused by the same strain.

Comparison of different culture media and growth conditions for recognition of Arcanobacterium haemolyticum

Detection of Arcanobacterium haemolyticum is based upon typical beta-hemolysis and colony morphology, but it may go undetected if only conventional sheep blood agar media for detection of beta-hemolytic streptococci are used. The influence of different culture media, atmospheres, and times of incubation for the recognition of colonies of 47 isolates of A. haemolyticum was studied. After 48 h of incubation, trypticase soy agar with 5% horse blood in 5% CO(2) was the best medium.

Post-operative mediastinitis, pleuritis and pericarditis due to Mycoplasma hominis and Ureaplasma urealyticum with a fatal outcome

Post-sternotomy mediastinitis, although infrequent, is a potentially life-threatening complication of cardiac surgery. We report an unusual case of Mycoplasma hominis and Ureaplasma urealyticum post-surgical mediastinitis with persistent pleural and pericardial effusion. Clinical manifestations and response to therapy are described, and the difficulties of establishing the diagnosis are discussed.

Geographical and ecological analysis of resistance, coresistance, and coupled resistance to antimicrobials in respiratory pathogenic bacteria in Spain

A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLS(B) (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events.