In vitro susceptibility of 96 Capnocytophaga strains, including a beta-lactamase producer, to new beta-lactam antibiotics and six quinolones

Capnocytophaga species have been associated with a wide variety of infections in both immunocompetent and immunocompromised patients. On the basis of data from antimicrobial susceptibility studies, beta-lactam antibiotics have been considered efficacious therapy. Six of 19 isolates from primarily clinical sources across Canada demonstrated ,-lactamase production, and agar dilution susceptibility testing showed broad resistance to beta-lactam antibiotics. For the P-lactamase producing isolates, clavulanate reduced the MIC of amoxicillin for 90% of the strains tested by 64-fold. Isolates were highly susceptible to clindamycin, imipenem, and ciprofloxacin. Characterization of the 13-lactamases produced by two of these isolates (Vanl and Van2) was performed. Isoelectric focusing revealed an identical isoelectric point of 5.6 for both enzymes, but they had markedly different relative hydrolysis efficiencies, and different conditions were required to extract the enzymes. This study demonstrates the production of different types of 13-lactamases by Capnocytophaga spp. and suggests the need to screen all clinical isolates of Capnocytophaga spp. for the presence of 13-lactamases.

mentioning

confidence: 95%

Antimicrobial susceptibilities and beta-lactamase characterization of Capnocytophaga species

Roscoe

Zemcov

Thornber

et al. 1992

“…In general, many antibiotics, including penicillins, clindamycin, macrolides, and quinolones, are effective in treating Capnocytophaga infections (6,10,11,21). However, strains that produce beta-lactamases and that cause septicemia have recently been described (1,7,9,19). These beta-lactamase-producing strains increase the risk of infection in neutropenic patients, especially during chemotherapy.…”

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confidence: 99%

In Vitro Susceptibilities of Capnocytophaga Isolates to β-Lactam Antibiotics and β-Lactamase Inhibitors

Jolivet‐Gougeon¹,

Buffet²,

Dupuy³

et al. 2000

The susceptibilities of 43 pharyngeal isolates of Capnocytophaga to beta-lactam antibiotics, alone or in combination with beta-lactamase inhibitors, were tested by an agar dilution method. The 34 beta-lactamasepositive strains were highly resistant to beta-lactams, but the intrinsic activities of clavulanate, tazobactam, and sulbactam against Capnocytophaga, even beta-lactamase producers, indicates that these beta-lactamase inhibitors could be used for empirical treatment of neutropenic patients with oral sources of infection.The genus Capnocytophaga is composed of a group of capnophilic, gram-negative fusiform bacteria that are part of the normal oral flora in humans and animals. Capnocytophaga species have been identified as the cause of a variety of infections in immunocompetent hosts (18). In immunocompromised and neutropenic patients, Capnocytophaga spp. have been isolated more frequently from patients with bloodstream infections, including bacteremia (2, 5, 9), and patients with endocarditis (4) with severe chemotherapy-induced ulcerations (8). Variations in the prevalence, number, and proportion of Capnocytophaga spp. have been shown to occur in the dental plaque of pediatric cancer patients undergoing a course of immunosuppressive chemotherapy (22). In general, many antibiotics, including penicillins, clindamycin, macrolides, and quinolones, are effective in treating Capnocytophaga infections (6,10,11,21). However, strains that produce beta-lactamases and that cause septicemia have recently been described (1,7,9,19). These beta-lactamase-producing strains increase the risk of infection in neutropenic patients, especially during chemotherapy. The aim of this study was to determine the susceptibilities of 43 Capnocytophaga strains isolated from neutropenic pediatric patients to beta-lactams and beta-lactamase inhibitors.Forty-three Capnocytophaga strains were isolated by swabbing the throats of pediatric cancer patients undergoing a course of chemotherapy in the Department of Pediatric Oncology at Centre Hospitalier Universitaire Sud (Rennes, France). Two reference strains (Escherichia coli CIP 7624 and Staphylococcus aureus CIP 7625) were also included in the study. Throat samples were collected with sterile swabs, which were immediately taken to the Department of Microbiology, dispersed in sterile distilled water, and inoculated onto TBBP agar (4% Trypticase soy agar supplemented with 5% sheep blood, 0.1% yeast extract [AES Laboratory, Combourg, France], 100 g of polymyxin per ml, 50 g of bacitracin [Sigma] per ml) (15). The agar plates were incubated in a 10% CO 2 atmosphere for 5 days at 37°C. The isolates were identified on the basis of colony morphology, Gram staining, negative catalase and oxidase reactions, and API ZYM profiles (BioMérieux, Marcy l'Etoile, France) (13, 23).All isolates were tested for beta-lactamase production by a chromogenic cephalosporin nitrocefin method (Cefinase; BBL Microbiology Systems, Cockeysville, Md.) by the recommended procedure (Becton Dickinson). The test results we...

“…Antibiotic treatment was originally based on its susceptibility to penicillins, including benzylpenicillin (7). The organism was later shown to be susceptible to extended-spectrum cephalosporins, making it possible to prescribe these drugs (2). Enzymatic resistance to ␤-lactams, including extended-spectrum cephalosporins, was reported as early as 1986 in clinical isolates of C. ochracea (3,8,18,19).…”

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confidence: 99%

Capnocytophaga ochracea : Characterization of a Plasmid-Encoded Extended-Spectrum TEM-17 β-Lactamase in the Phylum Flavobacter-Bacteroides

Rosenau¹,

Cattier²,

Gousset³

et al. 2000