To our knowledge, these patients represent the first reported North American adults with severe community-onset MRSA pneumonia caused by strains carrying the PVL genes.

HPV decontamination reduced environmental contamination and the risk of acquiring MDROs compared with standard cleaning protocols.

We examined the incremental yield of stool culture (with toxin testing on isolates) versus our two-step algorithm for optimal detection of toxigenic Clostridium difficile. Per the two-step algorithm, stools were screened for C. difficile-associated glutamate dehydrogenase (GDH) antigen and, if positive, tested for toxin by a direct (stool) cell culture cytotoxicity neutralization assay (CCNA). In parallel, stools were cultured for C. difficile and tested for toxin by both indirect (isolate) CCNA and conventional PCR if the direct CCNA was negative. The "gold standard" for toxigenic C. difficile was detection of C. difficile by the GDH screen or by culture and toxin production by direct or indirect CCNA. We tested 439 specimens from 439 patients. GDH screening detected all culture-positive specimens. The sensitivity of the two-step algorithm was 77% (95% confidence interval [CI], 70 to 84%), and that of culture was 87% (95% CI, 80 to 92%). PCR results correlated completely with those of CCNA testing on isolates (29/29 positive and 32/32 negative, respectively). We conclude that GDH is an excellent screening test and that culture with isolate CCNA testing detects an additional 23% of toxigenic C. difficile missed by direct CCNA. Since culture is tedious and also detects nontoxigenic C. difficile, we conclude that culture is most useful (i) when the direct CCNA is negative but a high clinical suspicion of toxigenic C. difficile remains, (ii) in the evaluation of new diagnostic tests for toxigenic C. difficile (where the best reference standard is essential), and (iii) in epidemiologic studies (where the availability of an isolate allows for strain typing and antimicrobial susceptibility testing).Since its identification in 1978, Clostridium difficile has emerged as the predominant cause of antibiotic-associated colitis and the leading cause of diarrhea in hospitalized patients (4). Strains of C. difficile can be toxigenic or nontoxigenic; however, only toxigenic strains produce disease. The two main virulence factors are toxin A, a 308-kDa enterotoxin with some cytopathic effects (TcdA), and Toxin B (TcdB), a potent 270-kDa cytotoxin that affects various tissue cell lines in vitro and inhibits bowel motility in vivo (3, 12). The genes encoding both toxins, tcdA and tcdB, have been sequenced, and both are known to disrupt the actin cytoskeleton of intestinal epithelial cells by modifying Rho family proteins. Toxin A has long been considered more important (19,20), but an increasing number of reports of colitis due to TcdA-negative but TcdB-positive strains have now been made (5, 35). Furthermore, other virulence factors have now been identified. Recently, an increase in the frequency and severity of C. difficile-associated colitis, which is associated with a new strain that produces binary toxin (actin-specific ADP-ribosyltransferase) and is resistant to fluoroquinolones in vitro, has refocused attention on early, accurate diagnosis (2,9,23,29,36).Cell culture cytotoxicity neutralization assays (CCNA), which detect ...

Objective To characterize the epidemiology of MRSA transmission and infections in a level IIIC neonatal intensive care unit (NICU) and identify barriers to MRSA control. Setting and Design Retrospective cohort study in a university-affiliated NICU with an MRSA control program including weekly nares cultures of all neonates and admission nares cultures for neonates transferred from other hospitals or admitted from home. Methods Medical records were reviewed to identify neonates with NICU-acquired MRSA colonization or infection between April 2007 and December 2011. Compliance with hand hygiene and a MRSA decolonization protocol were monitored. Relatedness of MRSA strains were assessed using pulsed-field gel electrophoresis (PFGE). Results Of 3,536 neonates, 74 (2.0%) had a culture grow MRSA, including 62 neonates with NICU-acquired MRSA. Nineteen of 74 neonates (26%) had an MRSA infection, including 8 who became infected before they were identified as MRSA colonized, and 11 of 66 colonized neonates (17%) developed a subsequent infection. Of the 37 neonates that underwent decolonization, 6 (16%) developed a subsequent infection, and 7 of 14 (50%) that remained in the NICU for ≥21 days became recolonized with MRSA. Using PFGE, there were 14 different strain types identified with USA300 being the most common (31%). Conclusions Current strategies to prevent infections including active identification and decolonization of MRSA colonized neonates are inadequate as infants develop infections before being identified as colonized or after attempted decolonization. Future prevention efforts would benefit from improving detection of MRSA colonization, optimizing decolonization regimens, and identifying and interrupting reservoirs of transmission.