OBJECTIVES To describe a large series of patients with vertebral osteomyelitis (VO), and to compare the clinical, biological, radiological, and prognostic features of pyogenic (PVO), tuberculous (TVO), and brucellar vertebral osteomyelitis (BVO). METHODS A retrospective multicentre study, which included 219 adult patients with VO with confirmed aetiology, who were diagnosed between 1983 and 1995 in two tertiary care centres. Of these patients, 105 (48%) had BVO, 72 (33%) PVO, and 42 (19%) TVO. RESULTS One hundred and forty eight (67.6%) patients were male and 71 (32.4%) female. The mean (SD) age was 50.4 (16.4) years (range 14–84) and the mean (SD) duration of symptoms before the diagnosis was 14 (16.8) weeks. In 127 patients (57.9%) the vertebral level involved was lumbar, in 70 (31.9%) thoracic, and in 16 (7.3%) cervical. One hundred and nineteen patients (54.4%) received only medical treatment and 100 (45.6%) required both medical and surgical treatment. The presence of diabetes mellitus, intravenous drug abuse, underlying chronic debilitating diseases or immunosuppression, previous infections, preceeding bacteraemia, recent vertebral surgery, leucocytosis, neutrophilia, and increased erythrocyte sedimentation rate (ESR) were significantly associated to PVO. A prolonged clinical course, thoracic segment involvement, absence of fever, presence of spinal deformity, neurological deficit, and paravertebral or epidural masses, were significantly more frequent in the group of TVO. The need for surgical treatment and the presence of severe functional sequelae were more frequent in the groups of PVO and TVO. CONCLUSION There are significant clinical, biological, radiological, and prognostic differences between BVO, PVO, and TVO. These differences can point to the causal agent and orient the initial empirical medical treatment while awaiting a final microbiological diagnosis.

We studied 31 cases of postoperative pyogenic spondylodiskitis (POS), comparing them with 72 cases of nonpostoperative pyogenic spondylodiskitis (NPO

We determined the in vitro activities of tigecycline and imipenem against 49 isolates of Acinetobacter baumannii , including those resistant to imipenem. The MIC at which 50% of the isolates were inhibited (MIC ₅₀ ) and the MIC ₉₀ for tigecycline and imipenem were 2 and 2 mg/liter and 32 and 128 mg/liter, respectively, with 92 and 20%, respectively, of the strains being susceptible. Tigecycline did not show bactericidal activity in the time-kill studies ( n = 9 strains). Imipenem showed bactericidal activity against seven out of nine strains. These in vitro results show that tigecycline has good in vitro bacteriostatic activity against A. baumannii , including strains resistant to imipenem.

There are currently no defined optimal therapies available for multidrug-resistant (MDR) Acinetobacter baumannii infections. We evaluated the efficacy of rifampin, imipenem, sulbactam, colistin, and their combinations against MDR A. baumannii in experimental pneumonia and meningitis models. The bactericidal in vitro activities of rifampin, imipenem, sulbactam, colistin, and their combinations were tested using time-kill curves. Murine pneumonia and rabbit meningitis models were evaluated using the A. baummnnii strain Ab1327 (with MICs for rifampin, imipenem, sulbactam, and colistin of 4, 32, 32, and 0.5 mg/liter, respectively). Mice were treated with the four antimicrobials and their combinations. For the meningitis model, the efficacies of colistin, rifampin and its combinations with imipenem, sulbactam, or colistin, and of imipenem plus sulbactam were assayed. In the pneumonia model, compared to the control group, (i) rifampin alone, (ii) rifampin along with imipenem, sulbactam, or colistin, (iii) colistin, or (iv) imipenem plus sulbactam significantly reduced lung bacterial concentrations (10.6 ± 0.27 [controls] versus 3.05 ± 1.91, 2.07 ± 1.82, 2.41 ± 1.37, 3.4 ± 3.07, 6.82 ± 3.4, and 4.22 ± 2.72 log ₁₀ CFU/g, respectively [means ± standard deviations]), increased sterile blood cultures (0% versus 78.6%, 100%, 93.3%, 93.8%, 73.3%, and 50%), and improved survival (0% versus 71.4%, 60%, 46.7%, 43.8%, 40%, and 85.7%). In the meningitis model rifampin alone or rifampin plus colistin reduced cerebrospinal fluid bacterial counts (−2.6 and −4.4 log ₁₀ CFU/ml). Rifampin in monotherapy or with imipenem, sulbactam, or colistin showed efficacy against MDR A. baumannii in experimental models of pneumonia and meningitis. Imipenem or sulbactam may be appropriate for combined treatment when using rifampin.

Two novel IMP-type metallo-β-lactamase variants, IMP-43 and IMP-44, were identified in multidrug-resistant Pseudomonas aeruginosa isolates obtained in medical settings in Japan. Analysis of their predicted amino acid sequences revealed that IMP-43 had an amino acid substitution (Val67Phe) compared with IMP-7 and that IMP-44 had two substitutions (Val67Phe and Phe87Ser) compared with IMP-11. The amino acid residue at position 67 is located at the end of a loop close to the active site, consisting of residues 60 to 66 in IMP-1, and the amino acid residue at position 87 forms a hydrophobic patch close to the active site with other amino acids. An Escherichia coli strain expressing bla_IMP-43 was more resistant to doripenem and meropenem but not to imipenem than one expressing bla_IMP-7. An E. coli strain expressing bla_IMP-44 was more resistant to doripenem, imipenem and meropenem than one expressing bla_IMP-11. IMP-43 had more efficient catalytic activities against all three carbapenems than IMP-7, indicating that the Val67Phe substitution contributed to increased catalytic activities against carbapenems. IMP-44 had more efficient catalytic activities against all carbapenems tested than IMP-11, as well as increased activities compared with IMP-43, indicating that both the Val67Phe and Phe87Ser substitutions contributed to increased catalytic activities against carbapenems.