1196. Environmental Contamination of Rooms of Patients Harboring Multidrug-Resistant Organisms

Background

Healthcare environmental contamination by patients harboring multidrug-resistant organism (MDROs) is an important source of hospital MDRO transmission. We aimed to determine the MDRO contamination and bioburden of surfaces within hospital rooms of patients with positive MDRO clinical cultures.

Methods

Patients with positive clinical cultures of MDROs (carbapenem resistant Acinetobacter baumannii [CRAB], carbapenem resistant Pseudomonas aeruginosa [CRPA], extended spectrum cephalosporin and carbapenem resistant Enterobacterales [ESCRE, CRE] and vancomycin resistant Enterococcus [VRE]) were identified through daily screening of clinical microbiology results. Patient peri-rectal, inguinal, and wound sampling was performed. E-swab and environmental sampling of room surface composites was performed using environmental sponge wipes. Composite 1 included the TV remote, telephone, call button and bed rails. Composite 2 included the room door handle, IV pole and overbed table. Composite 3 included toileting surfaces. Each composite surface area was no more than 350mm³ each. Sponge wipes were expressed in phosphate-buffered saline containing 0.1% Tween 20 using a stomacher. The eluate was concentrated removed leaving ∼ 5mL, and remaining resuspended by vortex. Undiluted suspension was plated on selective MDRO medias and broth. Microbial burden was calculated by summing composites bioburdens. Samples that were only broth positive were given a value of 1 CFU. Table 1.

Mycobacterium bovis Bacillus Calmette-Guérin Cross-Contamination in the Operating Room: A Case Report

Mycobacterium tuberculosis complex (MTBC) false-positive cultures are commonly attributed to laboratory cross-contamination, but cross-contamination in the operating room (OR) is seldom reported. We report an investigation of cross-contamination in the OR for our case patient, who underwent surgical intervention for a chronic, left-sided breast lesion. Although the case patient had never received Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine or chemotherapy, a subsequent surgical sample culture was identified as MTBC by high-performance liquid chromatography and M. bovis BCG-type by genotyping. A collaborative false-positive investigation was initiated, and we discovered a cross-contamination event in the OR from a source case who received BCG intravesical instillation. Clinicians, public health, and infection control staff should be aware that MTBC cross-contamination in the OR is rare, but possible, and should recognize the importance of conducting thorough false-positive investigations.

1404. The FilmArray Meningitis/Encephalitis (FA ME) May Be of Higher Yield in the Immunocompromised Patient Population

Background

The FilmArray® Meningitis/Encephalitis (FA ME) panel is a PCR-based assay that rapidly detects 14 pathogens directly from CSF specimens. After the introduction of this assay at our institution, there was a steady increase in requests for use; however, the positivity rate remained stable. We sought to understand the characteristics of the patients most likely to have a positive FA ME panel, with particular interest in the immune status of each patient.

Methods

A retrospective chart review was conducted on 124 patients with suspected infectious meningitis/encephalitis at a large academic tertiary referral center who received FA ME testing between October 2016 and November 2018. Patients were considered immunocompromised if they had received chemotherapy, were solid-organ transplant recipients, or were diagnosed with HIV, autoimmune diseases on immunosuppressants, uncontrolled diabetes, cirrhosis, or hematologic malignancy. Clinical CNS infection was determined using chart review based on culture, serologic, or molecular data.

Results

60 (48%) patients were immunocompromised and 64 (52%) patients were immunocompetent. Clinical CNS infection occurred in ~25% of immunocompetent (17, 26%) and immunocompromised (17, 28%) patients. However, only 6 immunocompetent patients were found to have a positive FA ME; this accounts for only 35% of the total number of positive FA ME assays during this study period (P = 0.08). Notably, 4 out of 6 patients with cryptococcal meningitis had false-negative results on the FA ME.

Conclusion

In spite of the relatively small sample size, there was a trend toward significance in the accurate yield of the FA ME panel in the immunocompromised population compared with the immunocompetent. Our immunocompromised patients appear to be more likely to have an infection which is tested for on the panel. The rates of confirmed CNS infections in both populations were very similar, indicating that immunocompromised patients may benefit more from use of this assay. In our study, immunocompetent patients were more likely to have West Nile infection, for example, which is not on the panel. Additionally, had cryptococcal meningitis been accurately diagnosed by the FA ME, an even greater number of immunocompromised patients would have had a positive FA ME.

Disclosures

All authors: No reported disclosures.

Verification of a Novel Multiplex PCR Respiratory Virus Panel in a US Biocontainment Unit

Emerging infectious diseases carry unique logistical, financial, and clinical ramifications. Rapid diagnostic testing methods can alleviate some of these challenges by providing definitive diagnoses earlier in the clinical course, leading to appropriate targeted therapy, cost savings, and improved patient outcomes. The BioFire FilmArray Respiratory Panel 2 plus (RP2plus; bioMérieux, Marcy l’Etoile, France) is a multiplexed nucleic acid test for detection of Middle East respiratory syndrome coronavirus (MERS-CoV) and 14 common viral and 4 bacterial respiratory pathogens in nasopharyngeal swabs obtained from those meeting MERS-CoV epidemiological criteria. The aim of this study was to verify the FilmArray RP2plus for use in our biocontainment unit. Of note, the RP2plus is FDA approved but not currently available for sale in the United States. Eight patient samples were tested with known results (GenMark Respiratory Virus Panel [RVP] or Cepheid Xpert Flu/RSV). We had concordant results between the platforms for samples containing influenza A, respiratory syncytial virus (RSV), parainfluenza virus 2, rhinovirus, and a negative sample. We evaluated two influenza B samples from two different patients. The FilmArray RP2plus did not detect influenza B in one of the patient samples. The sample was exhausted and repeat testing could not be performed. A second rhinovirus sample was not detected by the RP2plus, but Coronavirus 229E was detected in this sample, a virus not detected by the RVP. The sample was repeated and again did not detect rhinovirus. Further investigation into this discrepancy revealed that rhinovirus was originally detected by RVP at a signal of 34.4 nA (repeat of 46.9 nA). The concordant rhinovirus sample had a signal of 226.7 nA by RVP, which was much higher than the discrepant sample. Because of the low signal by RVP in the discrepant sample, perhaps the viral load was below the limit of detection of the RP2plus. All other quality control sample pools passed verification testing, including day-to-day and operator variance. It is not uncommon for a person under investigation (PUI) for a highly communicable disease to be evaluated in our facility. The performance of the RP2plus test on clinical samples showed acceptable concordance with our current means of testing for respiratory pathogens. The RP2plus will eliminate challenges implicated in storing and transporting specimens to an off-site lab, facilitate quicker turnaround time, and streamline the often cumbersome, complex protocols and practices required to work up a serious communicable disease.

Late prosthetic hip joint infection with Actinomyces israelii in an intravenous drug user: case report and literature review

Late infections with Actinomyces israelii have been described for prosthetic hip joints but not in association with intravenous drug use. We present a case of a 43-year-old intravenous drug user who developed A. israelii infection in connection with a hip prosthesis 11 years after implantation, and we review four previously reported cases of Actinomyces prosthetic joint infections.

High levels of hepatitis C virus RNA in native livers correlate with the development of cholestatic hepatitis in liver allografts and a poor outcome

A subset of hepatitis C virus (HCV)-positive liver transplant recipients develop cholestatic hepatitis (CH). We investigated the role of pretransplantation disease activity (estimated by Knodell score and HCV RNA quantitation) in the native liver explant on the development of CH and graft and patient outcome. Eight patients with CH were identified among HCV-positive liver transplants and were compared with 20 consecutive patients with recurrent HCV hepatitis of noncholestatic type in liver transplants. We evaluated all 28 explanted native livers histologically using the Knodell scoring system. HCV viral load was measured in the native explant and 5 allograft explants from the CH group using Amplicor HCV RNA Monitor test. Six of 8 patients with CH had HCV RNA levels of 5,000 copies/microg of DNA or greater in the native liver explant, whereas only 1 of the control group had viral loads greater than this level. Greater HCV RNA levels correlated with worse graft and patient survival (P <.001). The 3-year survival rate in the CH group was 18% compared with 77% in the control group (P <.001). There was no difference in the primary immunosuppressive regimens used in the 2 groups. We conclude that (1) CH has a uniformly poor prognosis, (2) type of immunosuppressive therapy appears to have little influence on the development of CH, (3) high pretransplantation HCV RNA levels in the native explant may predict the development of CH, and (4) patients with high HCV RNA levels in the explanted native liver may be appropriate candidates for antiviral therapy to prevent the development of CH.

The effect of bromocryptine-induced hypoprolactinemia on xenogeneic and allogeneic skin graft survival in a mouse model

Bromocryptine-induced hypoprolactinemia produces immunosuppression capable of extending allograft survival in solid organ transplantation models, but its potential for delaying either xenogeneic or allogeneic skin graft rejection is as yet undefined. In this study the ability of bromocryptine to prolong the survival of either cutaneous human xenografts or murine allografts was compared with cyclosporin A in a mouse model. In xenograft experiments cryopreserved human cadaver skin was grafted to B6D2F1 mice. In allograft experiments skin graft donors (A/J mice) differed genetically from recipients (Balb-C mice) at the major histocompatibility locus. In the untreated control group xenograft survival averaged 7 days and allograft survival 8 days. Xenograft rejection was delayed significantly and nearly equally by both bromocryptine and cyclosporin A (mean 15 and 16 days, respectively). However, allograft rejection was delayed longer by cyclosporin A (mean 24 days; p = 0.0002) than by bromocryptine (mean 15 days; p = 0.066). Administration of porcine prolactin (1 mg) partially reversed the bromocryptine effect (mean xenograft survival, 11 days; mean allograft survival, 10 days). The results of this study suggest that the immunosuppression of prolactin release by bromocryptine may be an effective, benign means of prolonging the survival of biologic dressings (e.g., banked cadaver allograft or porcine xenograft) used for temporary wound coverage in massively burned patients.

Middermal wound healing. A comparison between dermatomal excision and pulsed carbon dioxide laser ablation

BACKGROUND

Continuous-wave carbon dioxide lasers are not widely used for the surgical removal of most skin lesions because it is difficult to control laser ablation and the extensive laser-induced thermal damage slows healing. Pulsed lasers provide means to reduce thermal damage produced during laser ablation and permit precise control of tissue removed during ablation. Using a swine model, we compared on a gross and microscopic level the healing of middermal wounds of similar depth and area created by a dermatome and a focused pulsed CO2 laser.

RESULTS

Pulsed CO2 laser ablation removed skin precisely and bloodlessly with 85 +/- 15 microns (mean +/- SD) of residual thermal damage covering the surface of the wound. Compared with the dermatome, tissue reepithelialization was delayed in the laser wounds at day 3. By day 7, epithelial coverage of the laser-created wounds was not significantly different from the dermatome-created wounds. No significant difference in the appearance of the two wounds was noted at 42 days.

CONCLUSIONS

We conclude that the focused pulsed CO2 laser is capable of precisely and bloodlessly ablating skin with conservation of residual subjacent adnexal elements, minimal early interference with epibolic epithelial outgrowth, and no pathologic effects on the wound healing process. Pulsed CO2 lasers may be a valuable instrument for the conservative ablation of skin and skin lesions.

Fortified antibiotic ointment in bacterial keratitis

We conducted experiments to determine the effectiveness of fortified antibiotic ointment in the treatment of Pseudomonas keratitis in rabbits. We evaluated gentamicin ointment (3, 10, 20, and 40 mg/g), gentamicin solution (3 and 10 mg/ml), and placebo, each given every 30 minutes. We also examined the effectiveness of fortified ointment given in extended treatment intervals. In short-term trials, commercial-strength gentamicin solution (3 mg/ml) was therapeutically superior (P less than .001) to commercial-strength gentamicin ointment (3 mg/g) in reducing corneal bacterial colony counts. No significant difference in antimicrobial effect was noted between fortified gentamicin ointment and fortified gentamicin solution at 30-minute treatment intervals. Fortified gentamicin ointment reduced colony counts even at extended treatment intervals of up to four hours in a severe keratitis model.

The electric kettle flex--a cause for concern

A study of 153 preschool children admitted to a subregional burns unit over a 4-year period revealed 23 who had sustained scalds by pulling on kettle flexes. The dangers of dangling kettle flexes have been noted in the past. However, identifying problems and undertaking education programmes to warn against them has a limited effect on accident prevention. The recent introduction of 'curly' cables makes the prospect of active prevention considerably simpler.