The functional characterization of nonsynonymous single nucleotide polymorphisms in human mismatch repair (MMR) genes has been critical to evaluate their pathogenicity for hereditary nonpolyposis colorectal cancer. We previously established an assay for detecting loss-of-function mutations in the MLH1 gene using a dominant mutator effect of human MLH1 expressed in Saccharomyces cerevisiae. The purpose of this study is to extend the functional analyses of nonsynonymous single nucleotide polymorphisms in the MLH1 gene both in quality and in quantity, and integrate the results to evaluate the variants for pathogenic significance. The 101 MLH1 variants, which covered most of the reported MLH1 nonsynonymous single nucleotide polymorphisms and consisted of one 3-bp deletion, 1 nonsense and 99 missense variants, were examined for the dominant mutator effect by three yeast assays and for the ability of the variant to repair a heteroduplex DNA with mismatch bases by in vitro MMR assay. There was diversity in the dominant mutator effects and the in vitro MMR activities among the variants. The majority of functionally inactive variants were located around the putative ATP-binding pocket of the NH 2 -terminal domain or the whole region of the COOH-terminal domain. Integrated functional evaluations contribute to a better prediction of the cancer risk in individuals or families carrying MLH1 variants and provide insights into the function-structure relationships in MLH1. [Cancer Res 2007;67(10):4595-604]

An increasing number of clinical reports are associating Aerococcus urinae with severe infections such as endocarditis, joint infections, and osteomyelitis. A. urinae identification has been hampered for years by morphotype ambiguity with streptococci or coagulase-negative staphylococci as this is a Grampositive α-haemolytic bacteria able to grow in pairs and clusters. In our university hospital, A. urinae was rarely identified before 2009. The identification rate of A. urinae started to increase significantly after the introduction of a matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) system (Bruker Daltonics, Leipzig, Germany) in our diagnostic laboratory in May 2009 ( Fig. 1) [1,2]. It is noteworthy that five of 11 severe infections due to A. urinae that we documented (bloodstream infections, endocarditis, and joint infections) occurred in the setting of negative cultures, and were documented by the use of eubacterial 16S rDNA PCR. The recent literature, our data and the two cases that we describe herein suggest that the prevalence of A. urinae in clinical samples and its pathogenic role might have been underestimated in the pre-molecular diagnostic era.Our first case, a 78-year-old male, presented with persistent fever of 39°C that had lasted for 2 weeks, and that had not responded to 5 days of oral amoxicillin-clavulanate treatment. Cardiac auscultation revealed a systolic heart murmur with axillary irradiations. Intravenous amoxicillin-clavulanate was administered empirically after several blood cultures that remained sterile. Transoesophageal echocardiography revealed a 17-mm mitral valve vegetation and severe valvular insufficiency, which required rapid valvular replacement. The valve showed acute necrotizing inflammation, confirming the diagnosis of endocarditis. As the valve culture remained sterile, we performed a broad-range 16S rRNA gene PCR [3], which revealed the presence of A. urinae, a pathogen that has already been reported in culture-negative endocarditis [4,5]. The Aerococcus strains isolated in our diagnostic laboratory were generally susceptible to beta-lactam antibiotics (of 176 strains, five exhibited intermediate susceptibility to ceftriaxone and two were resistant to cefriaxone). A combination of amoxicillin for 6 weeks and gentamicin for 2 weeks was given, with a favourable clinical evolution.The second patient was a 60-year-old woman who was hospitalized 2 days after a high fever with signs of hip prosthetic joint infection. A one-stage exchange procedure had been performed 4 months earlier because of mechanical failure. She was receiving chronic methotrexate therapy for rheumatoid arthritis, and daily doxycycline for hidradenitis suppurativa. There was no evidence of urinary tract or cardiac infection, and the blood cultures remained sterile. A debridement with retention strategy was chosen. The culture of the sonicated mobile parts of the prosthesis remained sterile, but two of the five perioperative biopsies became positive for Gram-posit...

This 10-year nationwide survey showed that the rate of echinocandin resistance among C. albicans and C. glabrata remains low in Switzerland despite increased echinocandin use. SYO-ECV could discriminate FKS mutants from wild-type isolates tested by SYO in this population.

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