Related Experiment Video
Updated: Aug 30, 2026

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
A common clone of erythromycin-resistant Streptococcus pneumoniae in Greece and the UK
N Fotopoulou1, P T Tassios, D V Beste
1Microbiology Department, Medical School, National and Kapodistrian University of Athens, Mikras Asias 75, GR 115 27 Athens, Greece.
Objective:
To investigate the possible genetic relationship among erythromycin-resistant Streptococcus pneumoniae strains isolated in Greece and the UK.
Methods:
During 1995-97, 140 S. pneumoniae strains were isolated from clinical specimens submitted to the microbiology departments of the two main children's hospital in Athens. All erythromycin-resistant strains were further studied with respect to the presence of genes encoding for the two major mechanisms of macrolide resistance, their serotypes, and pulsed-field gel electrophoresis (PFGE) types, in comparison to a previously characterized UK erythromycin-resistant clone.
Results:
Eleven of the 140 isolates (7.9%) were resistant to erythromycin; nine of these were susceptible to penicillin. Serotyping allocated seven, three and one isolates to serotypes 14, 19F and serogroup 6, respectively. The mefA gene was detected in seven isolates (five serotype 14 and two serotype 19F), ermB in two (one serotype 19F and the serogroup 6 isolate), whilst in the remaining two isolates no resistance gene could be detected by polymerase chain reaction (PCR). Pulsed-field gel electrophoresis of genomic DNA showed that five Greek serotype 14 isolates belonged to the same chromosomal type as the serotype 14 erythromycin-resistant UK clone.
Conclusions:
The present study showed that erythromycin resistance among the S. pneumoniae isolates was mostly owing to the efflux mechanism and suggested a possible clonal spread of serotype 14 erythromycin-resistant S. pneumoniae strains between Greece and the UK.
Related Concept Videos
Mechanism of Antibiotic Resistance in MRSA
Clinical Significance of Antibiotic Resistance
Atypical Pneumonia
Development of Antibiotic Resistance
Antibiotic Selection
Bacterial Phylum Tenericutes
