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[Infectious resistance to antibiotics in Haemophilus influenzae (author's transl)]
Abstract:
Ampicillin-resistant Haemophilus influenzae does occur now in the FRG. In one isolate a plasmid with resistance genes (R-factor) could be demonstrated as cause of the ampicillin resistance. This R-factor influences production of a beta-lactamase of the TEM type which destroys ampicillin. The infectious nature of the ampicillin resistance was proven by the fact that it was transferable to other bacterial species through cocultivation. Parallel to ampicillin resistance tetracycline resistant Haemophilus influenzae has occurred in the FRG. Here the resistance was equally bound to plasmids. These R-factors are infectious as well. Molecular analysis of the 3 isolated resistance factors in Haemophilus influenzae showed that they carry the same resistance genes which are known from R-factors of Enterobacteriaceae. In the therapy of purulent infections due to Haemophilus influenzae such as childhood meningitis one can no longer rely on general ampicillin sensitivity of the offender. Apart from ampicillin and tetracycline resistant Haemophilus influenzae chloramphenicol resistance has been observed in a few cases.
Insights
Ampicillin resistance in Haemophilus influenzae is emerging in the FRG, often due to transferable R-factors encoding beta-lactamase. This impacts treatment of serious infections like childhood meningitis.
Area of Science:
- Microbiology
- Molecular Biology
- Infectious Diseases
Background:
- Haemophilus influenzae is a significant human pathogen.
- Antibiotic resistance in bacteria poses a growing global health threat.
- Previous understanding assumed general ampicillin sensitivity in Haemophilus influenzae.
Purpose of the Study:
- To investigate the emergence and mechanisms of antibiotic resistance in Haemophilus influenzae in the FRG.
- To characterize the genetic basis and transferability of ampicillin and tetracycline resistance.
- To assess the implications for treating Haemophilus influenzae infections.
Main Methods:
- Isolation and characterization of antibiotic-resistant Haemophilus influenzae strains.
- Plasmid analysis to identify resistance genes (R-factors).
- Detection of beta-lactamase production.
- Bacterial conjugation experiments to assess resistance transferability.
- Molecular analysis of resistance factors.
Main Results:
- Ampicillin-resistant Haemophilus influenzae strains were identified in the FRG.
- Amplicillin resistance was linked to R-factors encoding TEM-type beta-lactamase, which inactivates ampicillin.
- Resistance was transferable to other bacterial species via conjugation.
- Tetracycline-resistant Haemophilus influenzae strains, also plasmid-bound and infectious, were found.
- Molecular analysis revealed that these R-factors share resistance genes common in Enterobacteriaceae.
- Chloramphenicol resistance was observed in a few cases.
Conclusions:
- The emergence of ampicillin-resistant Haemophilus influenzae in the FRG is confirmed, driven by transferable R-factors.
- Treatment strategies for Haemophilus influenzae infections, particularly childhood meningitis, must account for increasing antibiotic resistance.
- The genetic basis of resistance in Haemophilus influenzae mirrors that found in other bacterial pathogens, highlighting potential cross-species transfer.