Citations

A 35-year-old male greenhouse worker presented with myalgia, fatigue, and fever. Initially, he was thought to have an unspecified viral infection and was treated with conservative therapy. However, the patient’s symptoms persisted, and he reported additional symptoms of mild abdominal pain and headaches. Laboratory evaluation was significant for elevated liver enzymes. Due to concern for acute hepatitis and persistent fever the patient was hospitalized. During his hospital course, no infectious etiology was found to explain his symptoms. After discharge from the hospital, additional testing showed positive serology for Q fever IgG phase II antibody (1:8192) and phase II antibody IgM (> 1:2048). He was treated with doxycycline and had a good clinical response. Upon follow-up, he had worsening Phase I IgG serologies. Transesophageal echo demonstrated vegetations consistent with endocarditis.

Diagnosis of persistent infection at the time of reimplantation for staged revision of infected arthroplasties is challenging. Implant sonication culture for the diagnosis of prosthetic joint infection (PJI) has improved sensitivity compared to standard periprosthetic tissue culture.

ABSTRACT Streptococcus suis is an emerging swine-associated zoonotic agent that can cause meningitis and septicemia in humans. We present, to our knowledge, the first case of S. suis arthroplasty infection and streptococcal toxic shock-like syndrome due to an nonencapsulated serotype 5 strain in North America.

ABSTRACT We previously showed that culture of samples obtained by prosthesis vortexing and sonication was more sensitive than tissue culture for prosthetic joint infection (PJI) diagnosis. Despite improved sensitivity, culture-negative cases remained; furthermore, culture has a long turnaround time. We designed a genus-/group-specific rapid PCR assay panel targeting PJI bacteria and applied it to samples obtained by vortexing and sonicating explanted hip and knee prostheses, and we compared the results to those with sonicate fluid and periprosthetic tissue culture obtained at revision or resection arthroplasty. We studied 434 subjects with knee ( n = 272) or hip ( n = 162) prostheses; using a standardized definition, 144 had PJI. Sensitivities of tissue culture, of sonicate fluid culture, and of PCR were 70.1, 72.9, and 77.1%, respectively. Specificities were 97.9, 98.3, and 97.9%, respectively. Sonicate fluid PCR was more sensitive than tissue culture ( P = 0.04). PCR of prosthesis sonication samples is more sensitive than tissue culture for the microbiologic diagnosis of prosthetic hip and knee infection and provides same-day PJI diagnosis with definition of microbiology. The high assay specificity suggests that typical PJI bacteria may not cause aseptic implant failure.

ABSTRACT Periprosthetic tissue and/or synovial fluid PCR has been previously studied for prosthetic joint infection (PJI) diagnosis; however, few studies have assessed the utility of PCR on biofilms dislodged from the surface of explanted arthroplasties using vortexing and sonication (i.e., sonicate fluid PCR). We compared sonicate fluid 16S rRNA gene real-time PCR and sequencing to culture of synovial fluid, tissue, and sonicate fluid for the microbiologic diagnosis of PJI. PCR sequences generating mixed chromatograms were decatenated using RipSeq Mixed. We studied sonicate fluids from 135 and 231 subjects with PJI and aseptic failure, respectively. Synovial fluid, tissue, and sonicate fluid culture and sonicate fluid PCR had similar sensitivities (64.7, 70.4, 72.6, and 70.4%, respectively; P > 0.05) and specificities (96.9, 98.7, 98.3, and 97.8%, respectively; P > 0.05). Combining sonicate fluid culture and PCR, the sensitivity was higher (78.5%, P < 0.05) than those of individual tests, with similar specificity (97.0%). Thirteen subjects had positive sonicate fluid culture but negative PCR, and 11 had negative sonicate fluid culture but positive PCR (among which 7 had prior use of antimicrobials). Broad-range PCR and culture of sonicate fluid have equivalent performance for PJI diagnosis.

ABSTRACTActinobaculumspecies are anaerobic Gram-positive rods that have previously been associated with urinary tract infection (UTI) in the elderly. We report 12 patients withActinobaculumbacteremia. Only 40% of blood cultures were clinically considered significant by the treating physicians, but most patients were treated for UTI, suggesting a possible urinary source of bacteremia. Clinicians should be aware of the pathogenic potential ofActinobaculumspp.

ABSTRACT Robinsoniella peoriensis is a recently described anaerobic, spore-forming, Gram-positive bacillus originally recovered from swine manure. We report four human cases in which R. peoriensis was isolated from clinical samples.

ABSTRACT The laboratory diagnosis of syphilis is based primarily upon serologic findings. Historically, serologic testing for syphilis has relied on assays such as rapid plasma reagin, fluorescent treponemal antibody absorption, Treponema pallidum particle agglutination (TP-PA), and more recently, enzyme immunoassay (EIA). In this study, we evaluated the performance of a novel multiplex flow immunoassay (BioPlex 2200 Syphilis; Bio-Rad Laboratories, Hercules, CA) for the detection of antitreponemal IgG- and IgM-class antibodies. Serum specimens ( n = 1,008) submitted for routine treponema-specific antibody testing by syphilis IgM and IgG EIA (Trep-Chek; Phoenix-Biotech, Mississauga, Ontario, Canada) were also analyzed by the BioPlex Syphilis multiplex assay. Specimens showing discordant results were repeat tested, with further discrepancies being arbitrated by TP-PA. Compared directly to the results of EIA, the BioPlex IgG assay demonstrated 98.7% (77/78) sensitivity and 99.4% (916/930) specificity. Compared to the Trep-Chek IgM EIA, the BioPlex IgM assay showed 80% (4/5) sensitivity and 97.9% (652/666) specificity. These results indicate that the BioPlex Syphilis multiplex assay shows similar serological agreement with EIA while allowing for a fully automated random-access platform that provides faster (1.7 h for 100 samples versus 4.5 h by EIA) and higher-throughput (800 samples per 9 h versus 200 samples by EIA) analysis of the syphilis serologic response.