Stacy G. Beal

Evaluation of the Nanosphere Verigene Gram-Positive Blood Culture Assay with the VersaTREK Blood Culture System and Assessment of Possible Impact on Selected Patients

ABSTRACT The Verigene Gram-positive blood culture (BC-GP) assay (Nanosphere, Northbrook, IL) is a molecular method for the rapid identification of Gram-positive organisms and resistance markers directly from blood culture bottles. A total of 148 VersaTREK REDOX 1 40-ml aerobic bottles demonstrating Gram-positive bacteria were tested. Results were compared with those from conventional biochemical and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) identifications. We obtained isolates of methicillin-resistant Staphylococcus aureus (MRSA) (24), methicillin-susceptible Staphylococcus aureus (MSSA) (14), methicillin-resistant Staphylococcus epidermidis (MRSE) (17), methicillin-susceptible Staphylococcus epidermidis (MSSE) (9), other coagulase-negative staphylococci (19), Streptococcus salivarius (5), Streptococcus parasanguinis (2), Streptococcus sanguinis (1), Streptococcus cristatus (1), the Streptococcus bovis group (5), Streptococcus agalactiae (9), the Streptococcus anginosus group (1), Streptococcus pneumoniae (6), vancomycin-resistant Enterococcus faecium (VRE FCM) (16), vancomycin-susceptible Enterococcus faecalis (3), Aerococcus viridans (2), Bacillus (6), Corynebacterium (8), Lactobacillus (2), Micrococcus (2), Neisseria mucosa (1), Escherichia coli (3), Candida tropicalis (1), Propionibacterium (1), and Rothia (1). Overall agreement with the culture results was 95%. A total of 137 of 138 (99%) monomicrobial cultures were concordant. We tested 9 polymicrobial samples and found 33% agreement. A chart review of 31 patients with MRSA, MSSA, or VRE demonstrated that the Nanosphere BC-GP assay might have led to more appropriate antibiotic selection for these patients an average of 42 h earlier. Additionally, contact isolation could have been initiated an average of 37 h earlier for patients with MRSA or VRE. The BC-GP assay may have a positive impact on patient care, health care costs, and antibiotic stewardship.

Mycobacterium leprae and Mycobacterium haemophilum co-infection in an iatrogenically immunosuppressed patient

We present the case of a native Texan who was diagnosed with tuberculoid leprosy and later developed a cutaneous infection with M. haemophilum following iatrogenic immunosuppression. To our knowledge, there are no such reports of M. haemophilum and M. leprae infection occurring simultaneously in the same host.

Implications of false positive serology of Toxoplasma gondii in a pre-transplant patient.

PATIENT A 21-year-old white male with cystic fibrosis. CHIEF COMPLAINT Pre-transplant workup in preparation for bilateral lung transplant. PAST MEDICAL HISTORY Cystic fibrosis diagnosed at age 3, onset of insulin-dependent diabetes around age 20, and multiple hospitalizations for pulmonary and gastrointestinal complications. FAMILY AND SOCIAL HISTORY: The patient lives with his father and stepmother, has a pet bearded dragon, and has multiple tattoos and piercings. His stepmother has a cat, but he does not clean the litter box. PRINCIPAL LABORATORY FINDINGS The pre-transplant workup included several tests for infectious diseases, tests of organ function, radiology studies, and markers of malignancy. The only significant finding was a positive Toxoplasma gondii (T. gondii) IgM titer (> or = 1:40) (reference values for IgM: negative; < 1:40, positive; > or = 1:40) and IgG (1:2048) (reference values for IgG: negative; < 1:16, equivocal; > or = 1:16 - < 1:256, positive; > or = 1:256). Testing was done by indirect immunofluorescence assay (IFA) in April 2012 in our hospital laboratory. The patient was treated with sulfadiazine, leucovorin, and pyrimethamine. Three months later (July), he returned for follow-up testing. Real-time polymerase chain reaction (PCR) for T. gondii DNA performed by a reference laboratory was negative. One month later (August), Toxoplasma serology was performed by enzyme-linked immunosorbent assay (ELISA) by a different reference laboratory and showed an elevated IgM of 0.95 IU/mL (reference values: negative; < 0.55 IU/mL, equivocal; > or = 0.55- < 0.65 IU/mL, positive; > or = 0.65 IU/mL) and a normal level of IgG (< 4 IU/mL). At this time, PCR was repeated and was negative. An additional month later (September), the patients serology studies were performed at a third reference laboratory and showed an elevated IgM of 1.32 IU/mL (reference values: negative; 0.89, equivocal; 0.90 - 1.09, positive; > 1.10) and a normal IgG.

Relationship between bacteriology report time in the morning and length of stay in hospital after the report

We studied the relationship between the time of day bacteriology reports were available in the electronic medical record (Epic, Verona, WI) and subsequent length of stay (LOS) following the last report before discharge. All patients ≥18years admitted to the UF Health Shands Hospital between 1/1/2014-2/29/2016 were included. We calculated the mean LOS following the report for each half-hour time period between 6AM and 1PM (N=14, 95.6% of all results) and tested the relationship to subsequent LOS. For patients whose total LOS was ≤168hours (N=13,830) there was a highly significant positive linear relationship between the report time and LOS following the last report (r=0.8813, P=0.00001556). For those patients with total LOS>168h, there was no clear relationship between report time in the morning and LOS after the last bacteriology report. The relationship between bacteriology report time in the morning and use of this information by physicians in discharge decision-making is likely to be complex and multi-factorial, but for those patients with a total hospital LOS ≤168h, there is a strong relationship between an earlier report and earlier patient discharge.

Diagnostic Algorithm for the Diagnosis of Pediatric Parasitic Gastroenteritis.

Current practices for ordering stool studies in patients with abdominal and gastrointestinal symptoms are not standardized. We hypothesized that an algorithm involving first‐line use of a Cryptosporidium/Giardia combination antigen test and stricter use of ova and parasite (O&P) examinations would be clinically and cost effective.