Résistance du pneumocoque aux antibiotiques en 1997–1998. Résultats de l'observatoire régional Alsace

Fosfomycin for the treatment of infections caused by Gram-positive cocci with advanced antimicrobial drug resistance: a review of microbiological, animal and clinical studies

BACKGROUND

The advancing antimicrobial drug resistance in Gram-positive cocci complicates the selection of appropriate therapy. The re-evaluation of older antibiotics may prove useful in expanding relevant therapeutic options.

OBJECTIVE

We sought to evaluate fosfomycin for the treatment of infections caused by methicillin-resistant staphylococci, vancomycin-resistant enterococci, and penicillin-non-susceptible pneumococci.

METHODS

We searched in PubMed, Scopus, and the Cochrane Library for studies evaluating the antimicrobial activity of fosfomycin against the above-mentioned pathogens, or the in vivo or clinical effectiveness of fosfomycin for the treatment of infections caused by these pathogens.

RESULTS/CONCLUSIONS

As reported in the identified studies, the susceptibility rate of methicillin-resistant Staphylococcus aureus to fosfomycin was > or = 90% in 12/22, and 50-90% in 7/22 studies; the cumulative susceptibility rate was 87.9% (4240/4892 isolates). The cumulative susceptibility rate of vancomycin-resistant enterococci to fosfomycin was 30.3% (183/604 isolates), and that of penicillin-non-susceptible pneumococci was 87.2% (191/219 isolates). Clinical data show that fosfomycin, primarily in combination regimens, has been associated with clinical success in 28/29 (96.6%) cases of infection (mainly pneumonia, bacteremia, and meningitis) by fosfomycin-susceptible isolates of methicillin-resistant S. aureus. The above data support further research on the role of fosfomycin against infections caused by Gram-positive cocci with advanced antimicrobial drug resistance.

Évolution de la sensibilité de Streptococcus pneumoniae aux antibiotiques: résultats de l'observatoire du pneumocoque Alsace (année 2005)

OBJECTIVES

Between 1st January 2005 and 31st December 2005, 232 strains of Streptococcus pneumoniae were collected in the Alsace county from participating laboratories (one from university hospital, 7 from general hospitals and 12 private laboratories) to assess their susceptibility to penicillin and evaluated serogroups of strains.

METHOD

The coordinating centre performed MICs by the reference agar dilution test, interpreted according to CA-SFM breakpoints. Others antibiotics (erythromycin, cotrimoxazole, tetracycline...) were tested by agar diffusion, ATB-PNEUMO gallery or VITEK gallery (BioMérieux, France) by each participating laboratory. Data were processed, using 4th dimension software.

RESULTS

Strains were collected from 151 blood samples, 38 ear pus, 11 cerebrospinal fluids, 8 pleural liquids and 24 representative pulmonary samples. The prevalence of pneumococci with decreased susceptibility to penicillin G (PDSP) is 35.1% (pulmonary samples excluded). The rate of PNSP decreases for all types of samples compared with other years of surveillance 2003 (44.0%). The rate of blood samples decreases for first time between the creation of Pneumococcal Observatory. The high-level resistance tend to decrease and began low. The PDSP are rather resistant to erythromycin, cotrimoxazole and fosfomycin. Among the PDSP, the most prevalent serotypes were 14, 19, 6 and 9.

CONCLUSION

Among pneumococcal strains, the rate of PDSP tend however to decrease in 2005 compared with 2003. The rate stays inferior to the observed rates in other French counties where the same decreasing is described.

[Streptococcus pneumoniae: lack of emergence of pristinamycin resistance]

Since 1997, a few studies have been published suggesting the emergence of clinical isolates of Streptococcus pneumoniae resistant to pristinamycin. Such results were not confirmed by recent studies from different investigators using reference techniques for the determination of susceptibilities, which is in accordance with the low probability of emergence of resistance to this antibiotic in vitro. Discrepancies are encountered with macrolide-resistant strains and may be due to the type of method used for susceptibility testing (agar-diffusion test), the final inoculum used in this technique, or the recent lowering of breakpoint for susceptibility. On the contrary, correlation between reference techniques and commercial galleries using liquid medium is excellent. Despite 35 years of exerting selective pressure, the in vitro activity of pristinamycin remains constant against clinical isolates of S. pneumoniae.