Beta-lactamase production and susceptibilities to amoxicillin, amoxicillin-clavulanate, ticarcillin, ticarcillin-clavulanate, cefoxitin, imipenem, and metronidazole of 320 non-Bacteroides fragilis Bacteroides isolates and 129 fusobacteria from 28 U.S. centers

Abstract

13-Lactamase production (nitrocefin disk method) and agar dilution susceptibility of amoxicillin, amoxicillin- Among the fusobacteria, Fusobacterium mortferum showed the highest rate of 3-lactamase positivity (76.9%).MICs of amoxicillin (128 ,g/ml) and ticarcillin (64 ,g/ml) for 90% of all ,B-lactamase-positive strains were reduced to 4 and 2 ,ug/ml, respectively, with the addition of clavulanate. MICs of amoxicillin and ticarcillin for 90% of all 1-lactamase-negative strains were 1 and 4 ,ug/ml, respectively, and .98.4% of the strains were susceptible to the P-lactams tested. Of the j-lactamase-producing strains, 45.9% were susceptible to amoxicilHin at c4 pg/ml and 93.4% were susceptible to ticarcillin at c64 ,ug/ml; the addition of clavulanate raised the rates to 90.4 and 100%, respectively. All strains were susceptible to cefoxitin, imipenem, and metronidazole. The activity of amoxicillin against 29 ,B-lactamase-producing strains (10 Bacteroides species and 19 fusobacteria) was not enhanced by the addition of clavulanate; however, 82.7% of these strains were susceptible to amoxicillin, and all were susceptible to ticarcillin. Although P-lactamase positivity is on the increase in non-B. fragilis group Bacteroides species and fusobacteria, amoxicillin-clavulanate, ticarcilHin, cefoxitin, imipenem, and metronidazole should be suitable for the treatment of infections with these strains. The addition of clavulanate does not appreciably improve the efficacy of ticarcillin against these organisms.

Past administration of β-lactam antibiotics and increase in the emergence of β-lactamase–producing bacteria in patients with orofacial odontogenic infections

“…The incidence of ß-lactamase-producing anaerobic gram-negative bacilli has been reported in several studies. [10][11][12]17 ß-lactamase is detected in 26% to 100% of pigmented Prevotella involving P. intermedia, P. melaninogenica, P. loescheii, 10,17 37.5%…”

“…to 77.1% of nonpigmented Prevotella, 10,12 13% to 23.5% of F. nucleatum, 11,12,17 and 33.3% of P. gingivalis. 12 In the present study, 27.3% of pigmented Prevotella, 16.7% of nonpigmented Prevotella, 0% of Fusobacterium, and only one strain of Porphyromonas produced ß-lactamase.…”

Extensive thoracolumbosacral vertebral osteomyelitis after Lemierre syndrome

“…However, this period was insufficient in our patient and an additional 4.5 months of antibiotics was required to treat the recurrent multi-level vertebral osteomyelitis. Since penicillin treatment failures due to b-lactamase production have been described in the past, the initial treatment was already combined with clindamycin and metronidazol which are b-lactamase-resistant antibiotics with anaerobic activity [33,34]. Whether the initial treatment failure was due to further changes in Fusobacterium antibiotic resistance or due to the polymicrobial cause is unknown since the biopsie cultures remained negative.…”

Lemierre Syndrome Following Oropharyngeal Infection: A Case Series

“…8 Fusobacterium spp. have 100% sensitivity to metronidazole, ticarcillin-clavulanate, cefoxitin, and imipenem 15 and are resistant to gentamicin and quinolones. 16 In addition, resistance rates to penicillins and macrolides are as high as 22% and 66%, respectively.…”