Antimicrobial Resistance amongStreptococcus pneumoniaein the United States: Have We Begun to Turn the Corner on Resistance to Certain Antimicrobial Classes?

Abstract

It appears that, as fluoroquinolone resistance emerges among S. pneumoniae in the United States, resistance to other antimicrobial classes is becoming less common.

Trends in Antimicrobial Susceptibility of Streptococcus pneumoniae in the Tohoku District of Japan: A Longitudinal Analysis from 1998 to 2007

“…Another US nationwide surveillance study indicated the same trend in PRSP and PISP strains . After 2003, penicillinresistance trends in the US have changed, as indicated in the PROTEKT study and other reports (Doern et al 2005;Jenkins et al 2008;Richter et al 2009). The prevalence of PRSP strains appears to be stable or decreasing, from 21.5% (2000) to 14.6% (2005), while PISP has increased from 12.7% (2000) to 17.9% (2005).…”

Rapid Screening of Topoisomerase Gene Mutations by a Novel Melting Curve Analysis Method for Early Warning of Fluoroquinolone-Resistant Streptococcus pneumoniae Emergence

“…The discrepancies observed in the specificity of the assay were instructive because the conventional phenotypic method failed to pick up strains which have high proportions of a single QRDR mutation. Several reports have noted that a significant number of isolates already have a single mutation but are still considered fully susceptible (7,22). Although our study lacks a collection of moderately FQ-resistant (LVX MIC of 2 g/ml or 4 g/ml) S. pneumoniae strains, Lim et al (16) reported that about 60% of S. pneumoniae isolates with an LVX MIC of 2 g/ml carry preexisting parC mutations.…”

“…The aim of the present study was to develop and validate a rapid single-step PCR-MCA assay for genotyping S. pneumoniae strains, targeting four QRDR positions (Ser79 and Asp83 of the parC gene and also Ser81 and Gly85 of the gyrA gene) that are most frequently associated with FQ resistance (3,7,22).…”

“…Resistance as a result of other mechanisms (such as parE or gyrB mutation and efflux) also cannot be detected. However, these mechanisms provide resistance potential but are not conclusive indicators of high-level resistance to FQs compared with parC and gyrA mutations (7,22).…”

Correlation of the antimicrobial activity of ME1036 with its binding affinities to the penicillin-binding proteins from Streptococcus pneumoniae strains

“…Furthermore, fluoroquinolone-resistant strains with mutations in DNA gyrase are being found. 2 The increase in these S. pneumoniae strains that resist the activities of penicillins, oral cephems, tetracyclines, macrolides and quinolones is a major concern because of decrease of antibiotics effective against these strains. ME1036 ( Figure 1) is a new broad-spectrum parenteral carbapenem that is active against multi-drug resistant Gram-positive and Gramnegative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum b-lactamase-producing Enterobacteriaceae.…”