We have reported in this journal in vitro susceptibilities of clinical isolates to
antibiotics every year since 1992. In this paper, we report the results of an analysis of in vitro susceptibilities of 12,919 clinical isolates from 72 centers in Japan to
selected antibiotics in 2007 compared with the results from previous years. The common
respiratory pathogens,
Streptococcus pyogenes,
Streptococcus pneumoniae,
Moraxella catarrhalis and
Haemophilus influenzae maintained a high susceptibility to
fluoroquinolones (FQs). The resistance of
S. pyogenes to
macrolides has been increasing every year and this was especially clear this year. Most strains of
Enterobacteriaceae except for
Escherichia coli showed a high susceptibility to FQs. Almost 30% of
E. coli strains were resistant to FQs and the resistance increased further this year. FQs resistance of
methicillin-resistant Staphylococcus aureus (
MRSA) was approximately 95% with the
exception of 45% for
sitafloxacin (STFX). FQs resistance of methicillin-susceptible
S. aureus (
MSSA) was low at about 10%. FQs resistance of methicillin-resistant
coagulase negative Staphylococci (MRCNS) was higher than that of methicillin-susceptible
coagulase negative Staphylococci (MSCNS), but it was lower than that of
MRSA. However, FQs resistance of MSCNS was higher than that of
MSSA. FQs resistance of
Enterococcus faecalis was 22.5% to 29.6%, while that of Enterococcusfaecium was more than 85% except for STFX (58.3%). In clinical isolates of
Pseudomonas aeruginosa derived from
urinary tract infections, FQs resistance was 21-27%, which was higher than that of
P. aeruginosa from
respiratory tract infections at 13-21%, which was the same trend as in past years.
Multidrug resistant strains accounted for 5.6% in the
urinary tract and 1.8% in the
respiratory tract.
Acinetobacter spp. showed high susceptibility to FQs. The
carbapenem resistant strains, which present a problem at present, accounted for 2.7%.
Neisseria gonorrhoeae showed high resistance of 86-88% to FQs. The results of the present survey indicated that although methicillin-resistant
Staphylococci,
Enterococci,
E. coli,
P. aeruginosa, and
N. gonorrhoeae showed resistance tendencies, and other species maintained high susceptibility rates more than 90% against FQs, which have been used clinically for over 15 years.
