Antimicrobial Susceptibilities of Multidrug-Resistant Campylobacter jejuni and C. coli Strains: In Vitro Activities of 20 Antimicrobial Agents

Abstract

There is a paucity of information regarding antimicrobial agents that are suitable to treat severe infections caused by multidrug-resistant Campylobacter spp. Our aim was to identify agents that are potentially effective against multiresistant Campylobacter strains. The in vitro activities of 20 antimicrobial agents against 238 Campylobacter strains were analyzed by determining MICs by the agar plate dilution method or the Etest. These strains were selected from 1,808 Campylobacter isolates collected from Finnish patients between 2003 and 2005 and screened for macrolide susceptibility by using the disk diffusion test. The 238 strains consisted of 183 strains with erythromycin inhibition zone diameters of <23 mm and 55 strains with inhibition zone diameters of >23 mm. Of the 238 Campylobacter strains, 19 were resistant to erythromycin by MIC determinations (MIC > 16 g/ml). Given that the resistant strains were identified among the collection of 1,808 isolates, the frequency of erythromycin resistance was 1.1%. All erythromycin-resistant strains were multidrug resistant, with 18 (94.7%) of them being resistant to ciprofloxacin (MIC > 4 g/ml). The percentages of resistance to tetracycline and amoxicillin-clavulanic acid (coamoxiclav) were 73.7% and 31.6%, respectively. All macrolide-resistant strains were susceptible to imipenem, meropenem, and tigecycline. Ten (52.6%) multiresistant strains were identified as being Campylobacter jejuni strains, and 9 (47.4%) were identified as being C. coli strains. These data demonstrate that the incidence of macrolide resistance was low but that the macrolide-resistant Campylobacter strains were uniformly multidrug resistant. In addition to the carbapenems, tigecycline was also highly effective against these multidrug-resistant Campylobacter strains in vitro. Its efficacy for the treatment of human campylobacteriosis should be evaluated in clinical trials.Campylobacteriosis is usually a mild and self-limiting disease requiring no antimicrobial treatment (3, 5). Only rarely is it associated with extraintestinal manifestations, e.g., septicemia, skin and soft tissue infection, infective endocarditis, or meningitis (3). These infections usually require treatment with intravenous antimicrobial agents (3). Infections of immunocompromised patients and pregnant women as well as very young and very old patients or those with persisting symptoms (Ͼ1 week) also require antimicrobial treatment (3). Guillain-Barré syndrome and reactive arthritis are major postinfectious complications of campylobacteriosis (3,24,26).For many years, macrolides and fluoroquinolones have been the first-and second-choice alternatives for the antimicrobial treatment of campylobacter enteritis. Since the late 1980s, however, the emergence of resistance to these antimicrobial groups has complicated the treatment of this disease (1). For example, in Thailand, the rate of resistance to the fluoroquinolones has been up to 80% (8, 14). In Finland, the rate of fluoroquinolone resistance increased between 1995 and 2000 f...

Potential Use of Fosfomycin-Tromethamine for Treatment of Recurrent Campylobacter Species Enteritis

“…The prevalence of macrolide resistance is higher in C. coli human isolates than in C. jejuni isolates, reaching 18% to 23% in recent surveys (4). It has also been noted that macrolide-resistant strains are often resistant to fluoroquinolones and other antimicrobial groups (13). These infections are a therapeutic challenge, and there is some evidence that drug-resistant strains may be associated with more severe and prolonged illness (14).…”

Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp

“…Of these strains, 23 were collected locally in the area of the Turku University Hospital. The rest of the strains were collected from 10 different hospital districts around Finland; their susceptibilities have been reported in our earlier paper (14). The cultivation of the stool samples and the preliminary identification of the samples were carried out by standard microbiological methods.…”

“…The antimicrobial agents evaluated were clindamycin, erythromycin, nalidixic acid, and tetracycline (Sigma, Steinheim, Germany) and azithromycin and ciprofloxacin (Fluka, Buchs, Switzerland). The MICs of the isolates to tigecycline were determined by the Etest (Biodisk AB, Solna, Sweden) as described previously (14).…”

First Case Report of Campylobacter volucris Bacteremia in an Immunocompromised Patient

“…Our isolates showed "susceptible" results for both agents; however, clinicians made the decision to use meropenem to cover the pathogen of the concomitant urinary tract infection, K. pneumoniae, which was found to be producing extended-spectrum ␤-lactamases. Campylobacter is also known to be susceptible to carbapenem agents (21) as patients were cured with meropenem and discharged with an improved general condition.…”

“…However, strains that are resistant to macrolide or quinolone agents have emerged and are currently becoming more widespread (21,22). Therefore, precautions against promoting resistance are needed, especially when the condition of the patient is worsening despite the use of these agents.…”