Erysipelothrix rhusiopathiae Prosthetic Joint Infection in an Immunocompromised Patient: A Case Report.

CASE: We report the case of an immunosuppressed 65-year-old man with prosthetic joint infection (PJI) 23 years postoperatively because of Erysipelothrix rhusiopathiae, through hematogenous seeding of cutaneous erysipeloid. Immunotherapy was discontinued, washout was performed, and antimicrobial therapy was guided by laboratory sensitivities. The patient was discharged on suppressive oral ciprofloxacin monotherapy. First-stage revision was performed at 5 months after presentation-subsequent aspiration at 1 year postoperatively demonstrated no organisms and no leucocytes. At 18-month follow-up, the patient continues to do well and has elected not to proceed with second-stage surgery. CONCLUSION: E. rhusiopathiae is a rarely seen pathogen in PJI-it should be considered with immunosuppression and relevant exposure risks. The patient achieved good clinical outcome and has experienced no sequelae to date.

Antimicrobial stewardship failure: time for a new model.

There are now 10 years of national antimicrobial consumption data in Ireland. Despite the creation of an 'antimicrobial stewardship and infection control industrial complex' over this period, the data demonstrate a 16% increase in consumption nationally. Given the ongoing challenges with carbapenemase-producing Enterobacterales and Clostridioides difficile within the acute hospital system, the data point to the ineffectiveness of the national antimicrobial stewardship programme/model. A different model of antimicrobial stewardship is therefore needed. This new model is one based around the collection and dissemination of physician-specific consumption, together with greater education of clinicians in the management of infections. By shining a light on individual clinician antibiotic prescribing, outlier identification, along with peer to peer (or clinician to clinician) pressure, can be brought to bear on the problem and shift the emphasis from the current 'policing' oversight, to self-regulation instead.

Development and validation of a quantitative real-time PCR assay using fluorescence resonance energy transfer technology for detection of Aspergillus fumigatus in experimental invasive pulmonary aspergillosis.

Invasive pulmonary aspergillosis (IPA) is a frequently fatal infection in immunocompromised patients that is difficult to diagnose. Present methods for detection of Aspergillus spp. in bronchoalveolar lavage (BAL) fluid and in tissue vary in sensitivity and specificity. We therefore developed an A. fumigatus-specific quantitative real-time PCR-based assay utilizing fluorescent resonance energy transfer (FRET) technology. We compared the assay to quantitative culture of BAL fluid and lung tissue in a rabbit model of experimental IPA. Using an enzymatic and high-speed mechanical cell wall disruption protocol, DNA was extracted from samples of BAL fluid and lung tissues from noninfected and A. fumigatus-infected rabbits. A unique primer set amplified internal transcribed spacer regions (ITS) 1 and 2 of the rRNA operon. Amplicon was detected using FRET probes targeting a unique region of ITS1. Quantitation of A. fumigatus DNA was achieved by use of external standards. The presence of PCR inhibitors was determined by use of a unique control plasmid. The analytical sensitivity of the assay was

Clinical spectrum and laboratory characteristics associated with detection of herpes simplex virus DNA in cerebrospinal fluid.

OBJECTIVE: To determine the clinical, neurologic, and laboratory characteristics of patients with herpes simplex virus (HSV) type 1 (HSV-1) or HSV type 2 (HSV-2) DNA detected in cerebrospinal fluid (CSF) with use of polymerase chain reaction. PATIENTS AND METHODS: Clinical, laboratory, and demographic data were determined from 249 CSF specimens (collected from 247 patients >10 years of age) that tested positive for HSV-1 or HSV-2 DNA at the Mayo Clinic from January 1999 to August 2000. RESULTS: The median age of the 200 patients whose age was available was 70 years vs 40 years for those with HSV-1 or HSV-2 DNA in CSF, respectively. Detailed data were available for 39 and 78 patients with positive polymerase chain reaction results for HSV-1 and HSV-2, respectively. Of those with HSV-1 DNA detected in CSF, 89% had encephalitis, whereas most patients with HSV-2 DNA detected in CSF had findings compatible with meningitis. Only 5 (7%) of 69 patients in whom HSV-2 was detected in CSF had genital lesions at presentation, and none of the assessable patients with HSV-2 who had recurrent meningitis had active genital lesions at presentation. CONCLUSION: The vast majority (82%) of patients with HSV-2 detected in CSF had no history of genital herpes and no lesions at the time of presentation. Polymerase chain reaction assays designed to detect HSV in CSF should detect HSV-1 and HSV-2 and differentiate between HSV-1 and HSV-2.

Epstein-Barr virus and human immunodeficiency virus serological responses and viral burdens in HIV-infected patients treated with HAART.

Epstein-Barr virus (EBV) associated non-Hodgkin lymphoma is recognized as a complication of human immunodeficiency virus (HIV) infection. Little is known regarding the influence of highly active antiretroviral therapy (HAART) on the biology of EBV in this population. To characterize the EBV- and HIV-specific serological responses together with EBV DNA levels in a cohort of HIV-infected adults treated with HAART, a study was conducted to compare EBV and HIV serologies and EBV DNA copy number (DNAemia) over a 12-month period after the commencement of HAART. All patients were seropositive for EBV at baseline. Approximately 50% of patients had detectable EBV DNA at baseline, and 27/30 had detectable EBV DNA at some point over the follow-up period of 1 year. Changes in EBV DNA copy number over time for any individual were unpredictable. Significant increases in the levels of Epstein-Barr nuclear antigen (EBNA) and Epstein-Barr early antigen (EA) antibodies were demonstrated in the 17 patients who had a good response to HAART. Of 29 patients with paired samples tested, four-fold or greater increases in titers were detected for EA in 12/29 (41%), for EBNA in 7/29 (24%), for VCA-IgG in 4/29 (14%); four-fold decreases in titers were detected in 2/29 (7%) for EA and 12/29 (41%) for EBNA. A significant decline in the titer of anti-HIV antibodies was also demonstrated. It was concluded that patients with advanced HIV infection who respond to HAART have an increase in their EBV specific antibodies and a decrease in their HIV-specific antibodies. For the cohort overall, there was a transient increase in EBV DNA levels that had declined by 12 months.

Evaluation of Gen-Probe amplified mycobacterium tuberculosis direct test by using respiratory and nonrespiratory specimens in a tertiary care center laboratory.

The performance of the Amplified Mycobacterium Tuberculosis Direct (AMTD) test (Gen-Probe Inc., San Diego, Calif.) was assessed in a large tertiary care mycobacteriology laboratory. Both acid-fast smear-positive and smear-negative respiratory and nonrespiratory clinical specimens were analyzed. From February 1998 to 4 October 2001, AMTD assays were performed on 391 respiratory specimens and 164 nonrespiratory specimens. The AMTD assay was compared to the "gold standard" of combined culture and clinical diagnosis. The overall sensitivity for all specimens, including those for which no smear result was available, was 91.2%. The overall sensitivities of the assay, including acid-fast smear-positive and -negative specimens, were 97.8 and 77.3% for respiratory and nonrespiratory specimens, respectively. The corresponding specificities for respiratory and nonrespiratory specimens were 99.1 and 98.5%, respectively. The overall specificity for all specimens was 98.9%. Positive and negative predictive values were 93.9 and 99.7% and 91.7 and 96.4% for respiratory and nonrespiratory specimens, respectively. The time saved by using the AMTD test for making a diagnosis of tuberculosis instead of using culture was 8.99 days. Inhibitors to the AMTD assay were found in 3.1% of respiratory specimens and 3.1% of nonrespiratory specimens. The assay, used in a general mycobacteriology laboratory setting, represents an important advance in improving the speed and accuracy of diagnosis in the management of patients with tuberculosis.