Cost of Unnecessary Amylase and Lipase Testing at Multiple Academic Health Systems.

OBJECTIVES: To determine adherence to Choosing Wisely recommendations for using serum lipase to diagnose acute pancreatitis rather than amylase, avoiding concurrent amylase/lipase testing and avoiding serial measurements after the first elevated test as both are ineffective for tracking disease course. METHODS: Deidentified laboratory data from four large health systems were analyzed to determine concurrent testing rates, serial testing rates, and provider-ordering patterns. RESULTS: While most providers adhered to recommendations with 58,693 lipase-only tests ordered and performed, 86% of amylase tests were performed concurrently with lipase. Ambulatory, inpatient, and emergency department settings revealed concurrent rates of 51%, 41%, and 8%, respectively. Services with order sets containing both amylase and lipase were associated with higher rates of concurrent testing. CONCLUSIONS: Concurrent amylase/lipase testing is an area of opportunity to improve compliance, especially in ambulatory settings. Revision of order sets and provider education could be interventions to reduce unnecessary testing and save costs.

Blastomyces Antigen Detection for Diagnosis and Management of Blastomycosis.

Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection.

Clinical evaluation of a real-time PCR assay for identification of Salmonella, Shigella, Campylobacter (Campylobacter jejuni and C. coli), and shiga toxin-producing Escherichia coli isolates in stool specimens.

Enteric illness affects millions of individuals annually in the United States and results in >50,000 hospitalizations. The rapid and accurate identification of bacterial pathogens associated with gastroenteritis can aid acute patient management decisions, including the use of antibiotic therapy and infection control. This study compared the ProGastro SSCS multiplex real-time PCR assay (Gen-Probe Prodesse, San Diego, CA) to culture for the identification of Campylobacter spp. (Campylobacter jejuni and Campylobacter coli), Salmonella spp., and Shigella spp. and to broth enrichment followed by an FDA-cleared enzyme immunoassay (EIA) for the identification of Shiga toxin-producing Escherichia coli (STEC) isolates in stool specimens. Stool samples submitted in preservatives for routine culture and EIA were prospectively enrolled and tested at four clinical centers. Discrepancies between the ProGastro SSCS assay and culture or EIA were resolved using bidirectional sequencing. The overall prevalence of the pathogens as detected by culture was 5.6% (1.8% Campylobacter, 1.8% Salmonella, 1.3% Shigella, and 0.8% STEC). When results based on the ProGastro SSCS assay and bidirectional sequencing were applied, the overall prevalence increased to 8.3% (2.3% Campylobacter, 2.6% Salmonella, 1.8% Shigella, and 1.6% STEC). Following resolution of the discrepant results, the sensitivity of the ProGastro SSCS assay was 100% for all pathogens, and the specificities ranged from 99.4% to 100%. The sensitivity of culture compared to sequence-confirmed ProGastro SSCS results ranged from 52.9% to 76.9%, with the specificities ranging from 99.9% to 100%. Overall, these results suggest that the ProGastro SSCS assay is highly sensitive and specific in a clinical setting.

Subconjunctival mycetoma caused by Scedosporium apiospermum infection in a horse.

An 11-year-old American Saddlebred gelding was presented for evaluation of a nonpainful subconjunctival mass involving the lateral canthus of the left eye. Other findings included a central corneal scar and a small central cataract of the lens in the left eye. Fine-needle aspiration of the mass was performed and cytologic examination revealed marked pyogranulomatous inflammation with intralesional fungal hyphae, consistent with mycetoma. The fungal structures were elongated and characterized by nonstaining walls; several bulbous yeast-like structures were also observed. The mycetoma was surgically removed and submitted for histopathologic examination and fungal culture. The histopathologic diagnosis was subconjunctival phaeohyphomycosis. Scedosporium apiospermum was identified based on macroscopic and microscopic features of the organism in culture. Scedosporium spp. have been reported as causes of mycetomatous and nonmycetomatous infections in both immunocompromised and immunocompetent people and animals. S. apiospermum and Pseudallescheria boydii, which is its teleomorphic counterpart, have been implicated as potentially emerging human and veterinary pathogens. Timely diagnosis is essential as the organism is often resistant to commonly used antifungal drugs. This report provides a detailed cytologic description of the organism and recent information on the taxonomy of this fungus and the diagnostic peculiarities of this particular infection.

Evidence of multiple virulence subtypes in nosocomial and community-associated MRSA genotypes in companion animals from the upper midwestern and northeastern United States.

OBJECTIVE: Not much is known about the zoonotic transmission of methicillin-resistant Staphylococcus aureus (MRSA) in companion animals in the United States. We report the rate of prevalence of S. aureus and MRSA recovered from clinical samples of animals requiring treatment at veterinary clinics throughout the upper midwestern and northeastern United States. DESIGN: We compared phenotypes, genotypes, and virulence profiles of the MRSA isolates identified in companion animals, such as cats, dogs, horses, and pigs, with typical human nosocomial and community-associated MRSA (CA-MRSA) genotypes to assess implied zoonotic transmission or zooanthroponosis. Five hundred thirty-three coagulase-positive staphylococci (CPS) isolates recovered between 2006 and 2008 from a variety of animal-source samples were screened for S. aureus by S. aureus-specific 16S rDNA primers and were screened for methicillin-resistance. All MRSA isolates were genotyped by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and spa typing. They were also screened for common staphylococcal enterotoxin and adhesion genes by multiplex and singleplex PCR. RESULTS: Among the 533 CPS isolates recovered, 66 (12.4%) were determined to be S. aureus and 24 (4.5%) were MRSA. The percent of animals that were positive for S. aureus were as follows: 6.6% (32 of 487) dogs, 39.6% (19 of 48) cats, 83.3% (10 of 12) horses, and 100% of pigs, rabbits, hamsters and rats. Notably, 36.4% of all S. aureus identified were MRSA. Methicillin-resistant S. aureus was present in clinical samples from 12 of 487 dogs (2.5%), 6 of 48 cats (12.5%), 5 of 12 horses (42%), and 1 of 2 pigs (50%). The 24 MRSA isolates resolved into 4 PFGE clones: USA100 (50%), USA300 (16.7%), USA500 (20.8%) and USA800 (12.5%) and 6 sequence types (ST5, ST8, ST105, ST830, and ST986) or 2 clonal complexes, CC5 and CC8. Five major virulence profiles (clusters A to E) were observed in these MRSA isolates. Genotypic and virulence profiles of cats and dogs were more similar to each other than to those of horses. A Panton-Valentine leukocidin positive isolate with ST8:USA300 background was identified in a pig causing skin and soft infection. CONCLUSION: The presence of human MRSA clones in these animals suggests possible reverse zoonotic transmission. This study reports the first case of a USA300 genotype in a pig. Presence of multiple virulence profiles within a MRSA genotype in these animals suggests the potential of emergence of new MRSA clones by gaining or losing additional virulence genes.

Preparation of corneal donor eyes comparing 1% versus 5% povidone-iodine.

PURPOSE: To compare the effect of 1% versus 5% polyvinylpyrrolidone-iodine (PVP-I) chemical preparation (prep) of the eye on the recovery of organisms from donor globes before in situ recovery of donor corneal tissue. METHODS: One hundred consecutive pairs of donor corneas (200 eyes) were randomized to receive either 1% or 5% PVP-I drops applied to the conjunctival cul-de-sac, which was left in place for 2 minutes. Limbal cultures were obtained before and after prepping of the eye. RESULTS: Twenty-five different species of organisms were recovered. Native flora of the eye included coagulase-negative staphylococci (62%), Corynebacterium species (27%), streptococcal species (9.5%), gram-negative bacilli (14.5%), Staphylococcus aureus (5%), anaerobes (10%), and yeast (2%). After PVP-I instillation of the donor eye, 74 isolates were recovered from the 1% P-I group and 76 isolates from the 5% PVP-I group. Cultures were sterile after PVP-I prep in 49 eyes and 47 eyes in the 1% PVP-I group and 5% PVP-I group, respectively. Microorganism colony forming units were similar among post-prep cultures from both PVP-I groups. The effect of the PVP-I prep on the number of negative cultures and on the reduction in the number of isolates was highly significant for both the 1% PVP-I group and the 5% PVP-I group when compared with the limbal cultures taken before PVP-I instillation. CONCLUSIONS: This study found that 1% and 5% PVP-I solutions are equally effective for chemical prep of the donor eye. Because PVP-I is known to be toxic to the corneal endothelium and corneal fibroblasts, this study suggests that 1% PVP-I should be the preferred disinfectant for the recovery of corneal donors.

Gram-negative bloodstream infections in hematopoietic stem cell transplant patients: the roles of needleless device use, bathing practices, and catheter care.

BACKGROUND: Between August 1 and October 30, 1998 (outbreak period), an increased incidence of central venous catheter (CVC)-associated gram-negative bacterial bloodstream infection (GN-BSI) was detected in hematopoietic stem cell transplantation (HSCT) candidates and recipients in an outpatient HSCT unit. The objectives of the present study were to determine strategies for controlling the outbreak and identify risk factors for GN-BSI. METHODS: Two case-control studies, an assessment of infection control practices, microbiologic studies, and water quality analysis were conducted. A case was defined as any outpatient with a CVC and a primary GN-BSI during the outbreak period. RESULTS: All of the 31 case patients identified had needleless intravenous (IV) access devices. Independent risk factors for CVC-associated GN-BSI were self-administered IV infusion (odds ratio [OR] = 6.2; P = .02), lower frequency of needleless device changes (OR = 15.2; P = .03), and more frequent baths (OR = 1.4; P = .05). Interventions included increased frequency of needleless device change, recommending showers rather than baths, and use of CVC protection during showering/bathing. After these interventions, the CVC-associated GN-BSI rate declined to below the preoutbreak period rate (2.1/1000 vs 0.3/1000 CVC-days; P < .01). CONCLUSIONS: This study demonstrated an increased risk of CVC-associated GN-BSIs related to self-IV infusion, bathing habits, and frequency of needleless device change. Infection control practices associated with the use of needleless devices may expose susceptible patients to increased risk for BSI.

Convenient selective differential broth for isolation of vancomycin-resistant enterococcus from fecal material.

Studies have shown that vancomycin broth enrichment is superior to direct plating for the detection of vancomycin-resistant enterococcus (VRE), but vancomycin selective broth is not generally commercially available. We developed an easy-to-prepare VRE selective differential broth and compared it to direct plating on bile esculin azide (BEA) agar for the isolation of VRE from fecal samples. A total of 528 consecutive rectal swabs and stools were inoculated onto BEA agar and into BEA broth with vancomycin at a concentration of 15 microg/ml (BEA VAN15 microg/ml broth). After 1 to 2 days of incubation, broths were subcultured to BEA VAN6 microg/ml agar. Bile esculin-positive colonies from the direct and broth subculture plates were evaluated for the presence of VRE by standard microbiological techniques. Addition of the broth enrichment step led to the detection of significantly more VRE isolates than did direct plating alone (28 versus 18 VRE isolates, respectively). In all, 30 VRE strains were isolated from 29 cultures, all of which were Enterococcus faecium. MICs of vancomycin ranged from 32 microg/ml (n = 2) to > 256 microg/ml (n = 28). Twenty-two VRE isolates were available for further testing: sixteen exhibited a VanA phenotype and six were of the VanB phenotype. van genotypes were in agreement with phenotypes for all VRE isolates except one, which could not be genotyped. The broth method also resulted in significantly fewer bile esculin-positive, non-VRE isolates requiring further workup. We have thus developed an easily prepared vancomycin selective differential broth that is significantly more sensitive and specific in the detection of VRE than is direct fecal plating to BEA agar.

Genetic diversity among clinical isolates of Acremonium strictum determined during an investigation of a fatal mycosis.

Primarily saprophytic in nature, fungi of the genus Acremonium are a well-documented cause of mycetoma and other focal diseases. More recently, a number of Acremonium spp. have been implicated in invasive infections in the setting of severe immunosuppression. During the course of routine microbiological studies involving a case of fatal mycosis in a nonmyeloablative hematopoietic stem cell transplant patient, we identified a greater-than-expected variation among strains previously identified as Acremonium strictum by clinical microbiologists. Using DNA sequence analysis of the ribosomal DNA intergenic transcribed spacer (ITS) regions and the D1-D2 variable domain of the 28S ribosomal DNA gene (28S), the case isolate and four other clinical isolates phenotypically identified as A. strictum were found to have <99% homology to the A. strictum type strain, CBS 346.70, at the ITS and 28S loci, while a sixth isolate phenotypically identified only as Acremonium sp. had >99% homology to the type strain at both loci. These results suggest that five out of the six clinical isolates belong to species other than A. strictum or that the A. strictum taxon is genetically diverse. Based upon these sequence data, the clinical isolates were placed into three genogroups.

Six rapid tests for direct detection of Clostridium difficile and its toxins in fecal samples compared with the fibroblast cytotoxicity assay.

Clostridium difficile is one of the most frequent causes of nosocomial gastrointestinal disease. Risk factors include prior antibiotic therapy, bowel surgery, and the immunocompromised state. Direct fecal analysis for C. difficile toxin B by tissue culture cytotoxin B assay (CBA), while only 60 to 85% sensitive overall, is a common laboratory method. We have used 1,003 consecutive, nonduplicate fecal samples to compare six commercially available immunoassays (IA) for C. difficile detection with CBA: Prima System Clostridium difficile Tox A and VIDAS Clostridium difficile Tox A II, which detect C. difficile toxin A; Premier Cytoclone A/B and Techlab Clostridium difficile Tox A/B, which detect toxins A and B; and ImmunoCard Clostridium difficile and Triage Micro C. difficile panels, which detect toxin A and a species-specific antigen. For all tests, Triage antigen was most sensitive (89.1%; negative predictive value [NPV] = 98.7%) while ImmunoCard was most specific (99.7%; positive predictive value [PPV] = 95.0%). For toxin tests only, Prima System had the highest sensitivity (82.2%; NPV = 98.0%) while ImmunoCard had the highest specificity (99.7%; PPV = 95.0%). Hematopoietic stem cell transplant (HSCT) patients contributed 44.7% of all samples tested, and no significant differences in sensitivity or specificity were noted between HSCT and non-HSCT patients. IAs, while not as sensitive as direct fecal CBA, produce reasonable predictive values, especially when both antigen and toxin are detected. They also offer significant advantages over CBA in terms of turnaround time and ease of use.