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[Distribution and changes of antibiotic susceptibility of genus Haemophilus (author's transl)]
Abstract:
We studied on the distribution and changes of antibiotic susceptibility of H. influenzae, H. parainfluenzae and H. parahaemolyticus isolated from clinical materials, mainly from sputum and pharyngeal swabs. In this study we used 132 strains of H. influenzae, 89 strains of H. parainfluenzae and 43 strains of H. parahaemolyticus isolated during January and June of 1975, and estimated the susceptibility for the following eighteen antibiotics by the agar plate dilution method: ampicillin, amoxicillin, ciclacillin, sulbenicillin, carbenicillin, cephalothin, cefazolin, ceftezole, cephalexin, streptomycin, kanamycin, gentamicin, dibekacin, tetracycline, doxycycline, chloramphenicol, thiamphenicol and colistin. We compared these with previously reported results and observed the changes of antibiotic susceptibility. Ampicillin has the strongest antibiotic activity on three species of Haemophilus and the activity of four cephalosporins was weakest. Among three species H. parahaemolyticus was most susceptible and H. influenzae least susceptible to cephalosporins. Antibiotic activity of cyclacillin was rather weak. Other twelve antibiotics have good activity on Haemophilus. We could not find any ampicillin-resistant strain, but found five (3.8%) streptomycin-resistant, one (0.8%) kanamycin-resistant, eleven (8.3%) tetracycline-resistant, and seven (5.3%) chloramphenicol-resistant strains of H. influenzae. Six years ago we found five (9.6%) streptomycin-resistant and one (1.9%) tetracycline-resistant strains, but no resistant strain to other antibiotics. Tetracycline- and chloramphenicol-resistant strains are supposed to have a tendency to increase. There were very few strains which were resistant to more than two antibiotics among H. influenzae. We found a few strains resistant to tetracycline or chloramphenicol among H. parainfluenzae and H. parahaemolyticus, and one strain of H. parainfluenzae was less susceptible to ampicillin.
Insights
Antibiotic resistance in Haemophilus species is increasing, particularly for tetracycline and chloramphenicol. Ampicillin remains highly effective, while cephalosporins show the weakest activity against these bacteria.
Area of Science:
- Microbiology
- Antimicrobial Resistance
Context:
- Investigating antibiotic susceptibility patterns of Haemophilus species.
- Clinical isolates primarily from sputum and pharyngeal swabs.
Purpose:
- To determine the distribution and changes in antibiotic susceptibility of Haemophilus influenzae, H. parainfluenzae, and H. parahaemolyticus.
- To compare current susceptibility data with historical findings.
Summary:
- Tested 132 H. influenzae, 89 H. parainfluenzae, and 43 H. parahaemolyticus strains against 18 antibiotics.
- Ampicillin showed the strongest activity; cephalosporins were weakest. H. parahaemolyticus was most susceptible, H. influenzae least susceptible to cephalosporins.
- Observed increases in streptomycin, kanamycin, tetracycline, and chloramphenicol resistance in H. influenzae compared to six years prior.
Impact:
- Highlights the emerging resistance to tetracycline and chloramphenicol in Haemophilus species.
- Identifies ampicillin as a consistently effective antibiotic.
- Provides crucial data for guiding antimicrobial therapy and surveillance of respiratory tract infections.