JoAnn P. Fenn

Comparison of the Murex, Candida albicans CA50 test with germ tube production for identification of C. albicans

A total of 502 yeast isolates were tested with the 30-min MUREX Candida albicans CA50 (Norcross, GA) test for presumptive identification of C. albicans. The results were compared with the standard 2-h germ tube test, which was the reference standard. Of the 502 isolates, 316 were C. albicans and 186 were non-C. albicans. Identifications were based on germ tube reactions; the API20C and chlamydospore agars were used when discrepant results persisted between the germ tube and MUREX test after repeat testing of the MUREX method. A total of 16 C. albicans gave negative results on initial testing with the MUREX test but were interpreted as positive when repeated. Three germ tube negative yeasts initially tested positive with the MUREX but were negative when repeated. Two additional yeast isolates gave incorrect results with the MUREX, even with repeat testing: C. albicans and C. lusitaniae. The initial sensitivity and specificity for the MUREX C. albicans CA50 test were 94.6% and 97.8%, respectively. As an addition to the study, two fetal bovine sera were compared for production of germ tubes; fetal bovine serum and Fetal Clone II. The testing found them to be in 100% agreement.

Update of Medically Important Yeasts and a Practical Approach to Their Identification

While Candida albicans remains the major yeast pathogen, several other Candida species and other genera of yeasts are now considered medically important. Significant fungal infections caused by yeasts are seen in septicemia, the urinary tract, organ transplantation, meningitis, pneumonia, endocarditis, and hematologic malignancies. Because more patients are at risk for fungal infections, and because the rate of yeast isolation is increasing, hospital and reference laboratories face an important challenge: to select an approach for isolation and identification of yeasts that is not only accurate and cost effective but also provides results in a reasonable time period. Rapid, traditional, and commercial methodologies can be blended to accomplish this.

Use of and cost savings with morphologic criteria and the spot indole test as a routine means of identification of Escherichia coli

The use of primary isolation plate colonial morphologic criteria (CMC) of a flat, nonmucoid, lactose-fermenting, gram-negative rod on MacConkey agar and the spot indole (SI) test from the sheep blood agar plate was evaluated as a means for identification of Escherichia coli in comparison to kit (Micro-ID, API-20E) and conventional biochemical testing. In this preliminary phase of comparison of accuracy, 427 isolates of E. coli (69.8%) from a total of 612 isolates of lactose-fermenting gram-negative rods were evaluated. Of these E. coli isolates, 357 (83.6%) fit the CMC and were SI positive; 3 (less than 1% error rate) were not E. coli. In the second phase of the evaluation, using CMC and SI alone as a means for identification of E. coli, 472 (57.6%) E. coli isolates from a total of 820 Enterobacteriaceae isolates were assessed. Of these E. coli isolates, 326 could be identified using only CMC and SI (69.1% of the E. coli isolates and 39.8% of all Enterobacteriaceae isolates); 146 (30.9%) required additional biochemical testing because of atypical colonial morphology, because of the investigators inability to differentiate colony types on both media or lack of isolated colonies on either of the two required media, or because as isolates from sterile body sites they were processed directly to Micro-ID kits. A minimum of 40% savings on Enterobacteriaceae identification schemes without compromising accuracy was calculated. As of November 1983, a direct (labor and materials) cost savings of approximately +200.80 per 100 Enterobacteriaceae identifications was projected.

Impact of time lapse on ASCP board of certification medical laboratory scientist (MLS) and medical laboratory technician (MLT) examination scores

BACKGROUND Research in several professional fields has demonstrated that delays (time lapse) in taking certification examinations may result in poorer performance by examinees. Thirteen states and/or territories require licensure for laboratory personnel. A core component of licensure is passing a certification exam. Also, many facilities in states that do not require licensure require certification for employment or preferentially hire certified individuals. OBJECTIVE To analyze examinee performance on the American Society for Clinical Pathology (ASCP) Board of Certification (BOC) Medical Laboratory Scientist (MLS) and Medical Laboratory Technician (MLT) certification examinations to determine whether delays in taking the examination from the time of program completion are associated with poorer performance. METHODS We obtained examination data from April 2013 through December 2014 to look for changes in mean (SD) exam scaled scores and overall pass/fail rates. First-time examinees (MLS: n = 6037; MLT, n = 3920) were divided into 3-month categories based on the interval of time between date of program completion and taking the certification exam. RESULTS We observed significant decreases in mean (SD) scaled scores and pass rates after the first quarter in MLS and MLT examinations for applicants who delayed taking their examination until the second, third, and fourth quarter after completing their training programs. CONCLUSIONS Those who take the ASCP BOC MLS and MLT examinations are encouraged to do so shortly after completion of their educational training programs. Delays in taking an exam are generally not beneficial to the examinee and result in poorer performance on the exam.

Microbiology Education in Nursing Practice

Nurses must have sufficient education and training in microbiology to perform many roles within clinical nursing practice (e.g., administering antibiotics, collecting specimens, preparing specimens for transport and delivery, educating patients and families, communicating results to the healthcare team, and developing care plans based on results of microbiology studies and patient immunological status). It is unclear whether the current microbiology courses required of nursing students in the United States focus on the topics that are most relevant to nursing practice. To gauge the relevance of current microbiology education to nursing practice, we created a confidential, web-based survey that asked nurses about their past microbiology education, the types of microbiology specimens they collect, their duties that require knowledge of microbiology, and how frequently they encounter infectious diseases in practice. We used the survey responses to develop data-driven recommendations for educators who teach microbiology to pre-nursing and nursing students. Two hundred ninety-six Registered Nurses (RNs) completed the survey. The topics they deemed most relevant to current practice were infection control, hospital-acquired infections, disease transmission, and collection and handling of patient specimens. Topics deemed least relevant were the Gram stain procedure and microscope use. In addition, RNs expressed little interest in molecular testing methods. This may reflect a gap in their understanding of the uses of these tests, which could be bridged in a microbiology course. We now have data in support of anecdotal evidence that nurses are most engaged when learning about microbiology topics that have the greatest impact on patient care. Information from this survey will be used to shift the focus of microbiology courses at our university to topics more relevant to nursing practice. Further, these findings may also support an effort to evolve national recommendations for microbiology education in pre-nursing and nursing curricula.