A synovial fluid cell count of >3000 white blood cells/mL was the most predictive perioperative testing modality in our study for determining the presence of periprosthetic infection when combined with an elevated preoperative erythrocyte sedimentation rate and C-reactive protein level in patients undergoing revision total hip arthroplasty.

The Mycobacterium fortuitum third biovariant complex (sorbitol-negative and sorbitol-positive) contains unnamed taxa first characterized in 1991. These organisms can cause respiratory infections, a spectrum of soft tissue and skeletal infections, bacteraemia and disseminated disease. To evaluate this group of organisms, clinical reference isolates and the type strains of M. fortuitum third biovariant complex sorbitol-negative (n=21), M. fortuitum third biovariant complex sorbitol-positive (n=3), M. fortuitum (n=3), Mycobacterium peregrinum (pipemidic acid-susceptible) (n=1), Mycobacterium porcinum (n=1), Mycobacterium senegalense (n=2) and Mycobacterium septicum (n=1) were characterized by using conventional phenotypic (morphological, physiological and antimicrobial susceptibilities), chemotaxonomic (HPLC and cellular fatty acids) and genotypic [RFLP of the rRNA gene (ribotyping), PCR-RFLP of a 439 bp segment of the 65 kDa hsp gene (PCR restriction analysis) and 16S rRNA gene sequence] analysis, DNA G+C content and DNA–DNA relatedness analyses. The results of these studies indicated that the strains comprised M. porcinum (n=13), M. septicum (n=1) and four novel closely related genetic groups within the M. fortuitum third biovariant complex: Mycobacterium boenickei sp. nov. (n=6), Mycobacterium houstonense sp. nov. (n=2), Mycobacterium neworleansense sp. nov. (n=1) and Mycobacterium brisbanense sp. nov. (n=1), with type strains ATCC 49935T (=W5998T=DSM 44677T), ATCC 49403T (=W5198T=DSM 44676T) ATCC 49404T (=W6705T=DSM 44679T) and ATCC 49938T (=W6743T=DSM 44680T), respectively.

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Opsonophagocytosis is a correlate of protection that measures the functional activity of vaccine-induced antibodies. A standardized opsonophagocytosis assay (OPA) should be used as part of the evaluation of current and future pneumococcal (Pnc) polysaccharide (Ps)-based vaccines. We enrolled five laboratories to evaluate a previously standardized viability OPA. Each laboratory was provided with a detailed OPA protocol, seven target Pnc strains (serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F), two quality control sera and 12 paired sera (blinded) from adult donors who received one dose of the 23-valent Pnc Ps vaccine. Laboratories sent their results to the Centers for Disease Control and Prevention for analysis. Sera were tested in duplicate (single run), and the results were averaged to yield a single OPA titer (>50% killing) for each serum sample. The percentage of sera within one or two dilutions of the calculated median OPA titer was determined for each laboratory and for each serotype. In general, laboratories were capable of detecting OPA titers within one or two dilutions of the median for at least 75 and 88%, respectively, of the sera tested. The level of agreement with the median OPA titers varied depending on the participating laboratory (overall agreement ‫؍‬ 0.8 [99% confidence interval ‫؍‬ 0.75 to 0.85]). All OPA median titers reported for quality control sera were within one dilution of the expected titer. We conclude that this OPA can be done in multiple laboratories with a high degree of interlaboratory reproducibility.Vaccine-induced protection to Streptococcus pneumoniae (pneumococcus) has been determined through vaccine efficacy trials for both polysaccharide (Ps) vaccines (1, 4, 22) and Psprotein conjugate vaccines (2,5,8). Trials of these pneumococcal (Pnc) vaccine formulations have shown various efficacies for protection depending on the end point being measured and the population being studied. These trials are costly and difficult to perform given the large sample size. In addition, pneumococcus has 90 different capsular serotypes, with the majority of disease being caused by about 30 of these 90 serotypes. Distribution of these serotypes also varies with the geographical region, making the estimation of the burden of disease and the impact of vaccination rather difficult (3, 9, 10).Efforts have been made for the identification and standardization of laboratory correlates of protection that can aid vaccine efficacy trials in the estimation of vaccine-induced protection. Currently, a highly standardized enzyme-linked immunosorbent assay (ELISA) is available (www.vaccine.uab.edu) for the evaluation of infant sera. Several modifications to the protocol described by Quartaert et al. (20) allowed for the measurement of Ps-specific antibodies in children and adults (6,19,18). Adults can have cross-reactive antibodies, which confound the measurements of immunoglobulin G (IgG) antibodies by ELISA, especially if absorption with a nonrelevant serotype is not performed prior to testing (6,7,26). These c...

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The rapidly growing mycobacterial species Mycobacterium porcinum was described in 1983 by Tsukamura et al. as a causative agent of submandibular lymphadenitis in swine (23). Tsukamura et al. characterized these strains as being similar to M. fortuitum but differing from this species by being D-mannitol and i-myo-inositol positive, nitrate negative, and succinamidase positive and utilizing benzoate as a sole source of carbon in the presence of ammoniacal nitrogen. Until recently, no isolation of this species had been reported since that report.Bönicke studied isolates previously identified as M. fortuitum and placed them into three subgroups (1). Subgroup A was negative for D-mannitol and i-myo-inositol and now is recognized as M. fortuitum. Subgroup B was positive for D-mannitol but negative for i-myo-inositol and is now recognized as M. peregrinum. Subgroup C was positive for mannitol and inositol, and its taxonomic status has taken much longer to establish and is still evolving. A study by Wallace et al. in 1991 showed this subgroup to consist of two major groups. One group was D-sorbitol positive, had low semiquantitative catalase, and was pipemidic acid resistant, and MICs of cefoxitin (27) and clarithromycin (4) were high for members of the group. ␤-Lactamase patterns on polyacrylamide gels following isoelectric focusing (IEF) had previously showed these isolates to have primarily a single enzyme pattern (28). These isolates were named the M. fortuitum third biovariant complex D-sorbitol-positive group, and ATCC 49403 was chosen as the reference strain (27).Subsequent 16S rRNA gene sequencing showed these isolates to have a unique hypervariable A region (11,19) and an 880-bp sequence of ATCC 49403 to differ by 6 to 15 bp from previously recognized species within the M. fortuitum group (11). To date, three species are recognized within this D-sorbitol-positive group based on 16S rDNA complete sequencing and DNA-DNA homology studies: M. mageritense (7,26), M. houstonense (of which ATCC 49403 is the proposed type strain), and M. brisbanense (16).

Postvaccination immunoglobulin G serum antibody concentrations were not significantly different from normal control subjects regardless of the time of vaccination (1, 7, or 14 days). Although concentrations approach normal, functional antibody activity was significantly lower. Better functional antibody responses against the serogroup and serotypes studied seemed to occur with delayed (14-day) vaccination.

Highly cross-linked polyethylene has been associated with low in vitro wear, but also has decreased in vitro ultimate yield strength. We therefore asked whether highly cross-linked polyethylene would result in lower outcome scores, wear, or early failure in a young patient population. Seventy THAs in 64 patients were performed using a highly cross-linked (electron beam-irradiated to 9 Mrads) acetabular liner and a cobalt-chrome femoral head. The average age of the patients at surgery was 41 years (range, 19-50 years). The minimum followup was 2.4 years (average, 4 years; range, 2.4-6.5 years). We recorded demographic and clinical data, including Harris hip score. Polyethylene wear measurements were analyzed with a validated, computer-assisted, edge detection method. The average Harris hip score improved from 53 to 92 at last followup. There was no evidence of acetabular or femoral loss of fixation, subsidence, or loosening. Linear wear was undetectable at this followup interval. No patient experienced catastrophic failure or underwent revision surgery. These data show low polyethylene wear rates and no catastrophic failures at early followup in a young patient cohort.