Incidence and epidemiology of levofloxacin resistance in Streptococcus pneumoniae: experience from a tertiary referral hospital in England

Abstract

), isolates of S. pneumoniae cultured by the LTHTR microbiology laboratory were examined by Etest to determine MICs of levofloxacin. Isolates from patients in whom there was a shift towards colonization with S. pneumoniae of reduced levofloxacin susceptibility were further characterized by serotyping, multilocus sequence typing (MLST) and sequencing of parC and gyrA genes.Results: Eight hundred and sixty-five isolates were collected; however, 772 isolates from 652 patients were recoverable; 412 (53.4%) came from hospitalized patients, 12 (1.6%) were resistant to levofloxacin according to the BSAC breakpoint (.2 mg/L) and 29 (3.8%) had MICs at the breakpoint (MIC¼ 2 mg/L). Of six patients in whom there was a shift towards isolates with reduced levofloxacin susceptibility, five had acquired new distinct strains. One patient, who had a parC mutation (Ser79Phe) in the original susceptible isolate and an additional second-step mutation in the gyrA gene (Ser81Phe) of the later resistant one, had isolates belonging to the same pneumococcal clone.Conclusions: S. pneumoniae resistance to levofloxacin was uncommon and we managed to identify only one case of probable in vivo resistance development in the 2.5 years of the study. Strain replacement accounted for the majority of incidences where there was an apparent shift towards colonization with isolates of reduced levofloxacin susceptibility.

Serotype distribution and antibiotic resistance of Streptococcus pneumoniae isolates collected at a Chinese hospital from 2011 to 2013

“…Levofloxacin is a broad-spectrum fluoroquinolone with greater antimicrobial activity against S. pneumoniae than older fluoroquinolones. However, increased use of fluoroquinolones has allowed for increasing emergence of levofloxacin-resistant pneumococci [ 41 , 42 ]. Kang et al [ 43 ] recently reported that approximately 4.7 % of pneumococcal isolates collected from individuals affected with community-acquired pneumonia in Asian countries were levofloxacin-nonsusceptible, and that independent risk factors for levofloxacin-nonsusceptible pneumococcal pneumonia were prior treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infections.…”

Global Fluoroquinolone Resistance Epidemiology and Implictions for Clinical Use

“…Thus, the question cannot be answered if resistance may have developed during therapy resulting in clinical failure. This question was recently addressed by Orr et al [205] who investigated in a tertiary referral hospital in England in 865 patients the incidence and epidemiology of levofloxacin-resistant pneumococci. In six patients a shift towards reduced levofloxacin-susceptibility or -resistance was recorded.…”

“…In six patients a shift towards reduced levofloxacin-susceptibility or -resistance was recorded. Five patients had acquired a new distinct strain and one patient only harboured the same clone [205]. This study revealed that levofloxacin pneumococcal resistance still is uncommon and that in vivo fluoroquinolone resistance development is very rare.…”

“…A limitation of this study is that all isolates of S. pneumoniae from any body site were eligible for inclusion in the study, irrespective of whether the patient has been treated with a fluoroquinolone or not. Furthermore, hospital guidelines recommend to treat severe community acquired pneumonia with levofloxacin plus intravenous benzylpenicillin [205]. High-level levofloxacin-resistance (MIC > 8 mg/L) developed under levofloxacin-treatment in eight out of 164 patients with chronic obstructive pulmonary disease whose pretherapy isolates were suceptible [206].…”