Cephalosporin resistant bacterial strains isolated from respiratory infections

Objectives: The objective of the study is the evaluation of the actual resistance to second, third, and fourth generation cephalosporins over bacterial strains isolated from respiratory infections. The main causes for cephalosporin resistance of pathogenic and conditioned pathogen bacteria are: widespread usage, and impair immune response.

Materials and methods: The analyzed specimens were throat swabs and sputum, from adult patients. The tests were performed using disk diffusion technique. We tested the following cephalosporin: From second generation: cefuroxime axetil; from third generation: cefotaxime, ceftazidime, cefpodoxime; Combinations of cephalosporins and beta-lactamase inhibitors: cefotaxime + clavulanic acid; ceftazidim + clavulanic acid; From fourth generation: cefepime; and association cefepime and clavulanic acid.

Results: The following bacterial strains were isolated: Staphylococcus aureus, Streptococcus pneumoniae, Group C β-hemolytic Streptococcus, E. coli, Klebsiella pneumoniae and Proteus sp. The Group A. β-hemolytic Streptococcus isolated strains were not tested. For Staphylococcus aureus, E. coli, K. pneumoniae and Proteus, we found a high frequency resistance tocefuroxim, approximately 47%. Highest resistance to third generation cephalosporin was identified to E.coli and Klebsiella pneumoniae, especially resistant to cefotaxime, cefotaxime + clavulanic acid and ceftazidime.

Conclusions: Cefpodoxime can be considered as a first election antibiotic in treating upper and lower respiratory tract infections, due to the lowest level of bacterial strain resistance, approximately 10% of the third generation cephalosporines tested. Also, cefepime may be proper in treating severe respiratory tract infections, with resistant broad-spectrum antibiotics bacterial strains. In our trial, resistance to cefepime was to a minimum low, approximately 4%, represented by the E.coli strains.