A study carried out by IDIBELL and the Bellvitge University Hospital has genetically characterised the Haemophilus strains that have been identified in the Hospital’s microbiology service. Two species of this bacterial genus, H. influenzae and H. parainfluenzae, are opportunistic pathogens that colonize the upper respiratory tract and urogenital tract. Although the two species are closely related, H. influenzae predominates in patients with chronic respiratory infections, while H. parainfluenzae is increasingly associated with sexually transmitted diseases and has a high prevalence of multidrug-resistant strains, posing a significant therapeutic challenge. In this study published in the Journal of Antimicrobial Chemotherapy, the differences in H. influenzae and H. parainfluenzae resistance to macrolides, an antibiotic type commonly used as a prophylactic, were analyzed from 3066 samples collected from 2018 to 2021 at the Hospital.
This study found higher levels of resistance in H. parainfluenzae: 10.2% of the samples vs. 2.6% in H. influenzae. Patients colonized by resistant strains had received previous treatment with macrolides, either for chronic respiratory diseases or to treat sexually transmitted diseases. This highlights the importance of monitoring the resistance levels to this antibiotic, which is widely used in such pathologies.
Although the two species belong to the same genus, genomic analysis showed significant differences in the acquisition of antibiotic resistance, with gene acquisition by horizontal transfer – between different species – being more frequent in H. parainfluenzae. Mobile genetic elements were also detected in H. influenzae, for example ICEHpaHUB8, which confers resistance to four families of antibiotics. This data is relevant due to the clinical impact of resistance exchange between bacteria in a given habitat.
In conclusion, this work highlights the importance of monitoring resistance levels and the presence of mobile genetic elements, especially in H. parainfluenzae, a pathogen increasingly recognized as an important reservoir of resistance mechanisms.
The Bellvitge Biomedical Research Institute (IDIBELL) is a biomedical research center created in 2004. It is participated by the Bellvitge University Hospital and the Viladecans Hospital of the Catalan Institute of Health, the Catalan Institute of Oncology, the University of Barcelona and the City Council of L’Hospitalet de Llobregat.
IDIBELL is a member of the Campus of International Excellence of the University of Barcelona HUBc and is part of the CERCA institution of the Generalitat de Catalunya. In 2009 it became one of the first five Spanish research centers accredited as a health research institute by the Carlos III Health Institute. In addition, it is part of the “HR Excellence in Research” program of the European Union and is a member of EATRIS and REGIC. Since 2018, IDIBELL has been an Accredited Center of the AECC Scientific Foundation (FCAECC).