Clostridium difficile infection (CDI) is changing as evidenced by increasing virulence, rising incidence, unresponsiveness to metronidazole therapy, and worse outcomes. Thus, it is critical that CDI diagnosis be accurate so ongoing epidemiology, disease prevention, and treatment remain satisfactory. We tested 10 diagnostic assays, including 1 commercial real-time polymerase chain reaction (qPCR) test for the laboratory detection of toxigenic C difficile on 1,000 stool samples. Sensitive culture for toxigenic C difficile using 2 types of media with broth enrichment defined the reference standard. For the study, 1,000 tests were performed on samples from 919 patients. Of the samples, 146 contained evidence for toxigenic C difficile and represented the true-positive results. Only the US Food and Drug Administration-cleared qPCR assay (Becton Dickinson, Franklin Lakes, NJ) and 1 glutamate dehydrogenase test (TechLab, Blacksburg, VA) were not statistically inferior to culture in sensitivity. The common enzyme immunoassay tests all had sensitivity values less than 50%. Clinical laboratory professionals need to seriously consider their diagnostic testing and use the assays that perform best for the detection of CDI.

The rate of methicillin-resistant Staphylococcus aureus (MRSA) infection continues to rise in many health care settings. Rapid detection of MRSA colonization followed by appropriate isolation can reduce transmission and infection. We compared the performance of the new Roche LightCycler MRSA advanced test to that of the BD GeneOhm MRSA test and culture. Double-headed swabs were used to collect anterior nasal specimens from each subject.

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On-site MRSA surveillance with targeted decolonization resulted in a significant decrease in clinical MRSA infection among LTCF residents.

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic has resulted in significant shortages of RT-PCR testing supplies including RNA extraction kits. The goal of our study was to determine if a simplified heat-RNA release method would provide comparable detection of SARS-CoV-2 without the need for nucleic acid extraction. RT-PCR results using the ChromaCode HDPCR™ SARS-CoV-2 were compared using the heat-RNA release method and an automated RNA extraction system (EMAG). The heat-RNA release method correctly identified 94 % (81/86 nasopharyngeal samples) that were positive for SARS-CoV-2. Five samples that were missed by heat-RNA release method had a mean Ct value: 35 using the automated extraction instrument, indicating a very low viral load. Our findings show that a simple heat-RNA release method is a reasonable alternative for the majority of COVID-19 positive patients and can help overcome the cost and availability issues of RNA extraction reagents.

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We evaluated the BD GeneOhm MRSA achromopeptidase (ACP) assay, which incorporates a new specimen preparation approach. A total of 1,216 leftover nasal samples were tested; using culture as the gold standard, the sensitivity and specificity were 92% and 94.6%, respectively. The new lysis method provides good sensitivity and simplifies specimen preparation.Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of health care-associated infections and is responsible for increased hospital stays with high financial cost (7,19,24). In fact, by 2005 MRSA had a higher mortality rate than tuberculosis, salmonella infection, influenza, and HIV-AIDS combined within the United States (5). Moreover, Delorme and colleagues recently reported an increase of MRSA infections and disease rate in long-term care facility (LTCF) residents between 2006 and 2007 (6). There has been some success reported in the reduction of invasive infection since 2005, but most of the improvement was related to bloodstream infection and may be related to improved central venous catheter management in acute care hospitals (11). Another recent study has shown that a reduction in the rate of MRSA invasive infection must involve more than a general improvement in basic infection control practice, such as improved hand hygiene, since improved hand hygiene did not lower hospitalacquired MRSA colonization (14).MRSA detection is often followed by either decolonization or isolation to reduce MRSA prevalence within hospitals and in the community (4,8,10). In an elegant crossover study of the impact rapid testing has on MRSA transmission, Hardy and colleagues demonstrated significantly reduced transmission when surveillance testing was done using a real-time PCR assay, as opposed to no significant impact when routine, culture-based testing was utilized by the laboratory (9). Thus, rapid and reliable screening tests for MRSA detection are very important. Real-time PCR assays are fast, reliable, and accurate, which has been useful to reduce the incidence of MRSA disease (19,20).Paule and colleagues developed an achromopeptidase (ACP) lysis procedure for high-volume testing and compared its performance with the original BD GeneOhm MRSA lysis kit method (IDI-MRSA assay). The study results demonstrated that the assay performed equally well using both procedures (18). BD Diagnostics subsequently developed an ACP lysis method for use with the BD GeneOhm MRSA kit. The purpose of this current study was to assess the BD GeneOhm MRSA ACP assay for direct detection of MRSA in nasal specimens as part of an application to the U.S. FDA for clearance as an in vitro diagnostic device.Nasal swabs were collected using double-headed BBL culture swabs with liquid Stuart (Becton Dickinson, Sparks, MD) or liquid Amies (Becton Dickinson) transport medium; singleheaded Amies gel swabs without charcoal (Becton Dickinson) were also included. Excess, deidentified nasal specimens were used for testing after routine laboratory procedures were completed. The subjects enrolled ...

Our results suggest that the performance of the three commercial assays is similar. When assessing economic cost benefit of methicillin-resistant Staphylococcus aureus screening, the two measures with the most impact are the cost of the test and the specificity of the assay results.