Saccharomyces cerevisiae is widely used as a probiotic compound. Clinical data suggest that this agent is safe and effective. We report two cases of fungemia caused by S. cerevisiae occurring in immunosuppressed patients treated orally with S. boulardii Molecular typing confirmed clonality in isolate strains from patients and the capsule. Physicians caring for immunosuppressed patients must be aware of this potential serious complication of probiotic use.

During 2005, 66 carbapenem-resistant isolates of Acinetobacter baumannii were collected from seven tertiarycare hospitals participating in a nationwide surveillance network in Colombia. The isolates were multidrug resistant and produced the carbapenemases OXA-23 and OXA-51. Forty-five belonged to four clones while 21 were unique pulsotypes. One clone was present in two hospitals within one city, while another had spread between two hospitals in different cities. Blood, secretions, and abdominal fluids were the most frequent sites of isolation. This is the first description of widespread dissemination of OXA-23 in South America.Acinetobacter baumannii is an important nosocomial pathogen which appears to be increasing in frequency (8). Carbapenems have been the drugs of choice for treatment of severe Acinetobacter infections, but their efficacy is increasingly compromised by resistance (19).According to the SENTRY reports, resistance rates for nosocomial gram-negative pathogens, including A. baumannii, are higher in Latin American countries than in the United States or Europe. The prevalence of carbapenem resistance in A. baumannii isolates across Latin America in the SENTRY database in 2001 was estimated at 25% (13,24). During 2005, carbapenem resistance rates for A. baumannii were around 40% in 12 Colombian tertiary-care hospitals (18).Carbapenem-hydrolyzing OXA enzymes are the most important cause of carbapenem resistance in A. baumannii worldwide (23). These began to be described over a decade ago, in 1993, with the description of ARI-1, later renamed OXA-23, in an imipenem-resistant A. baumannii strain from a patient in the Edinburgh Royal Infirmary (22). The strain was isolated in 1985, before the use of imipenem in the hospital. Imipenem resistance was subsequently demonstrated to be transferable (25). Since then, carbapenem-resistant isolates of A. baumannii carrying oxacillinases have been reported worldwide (4,14,29). It has been recognized that most A. baumannii strains have a chromosomal carbapenemase gene (a bla OXA-51 -like gene) (10), though this is expressed at a high level only if an insertion sequence, such as ISAba1, is inserted upstream (30). In addition, a minority of A. baumannii strains have further OXA carbapenemase genes that are not part of the normal genomic repertoire of the species; these include the bla OXA-23 -like gene, the bla OXA-24 -like gene, and bla . Although they are lessefficient hydrolyzers of carbapenems in vitro than are the metallo-␤-lactamases (M␤Ls), these oxacillinases can inactivate carbapenems and their presence or activation by ISAba1 is demonstrably correlated with resistance (4, 30).Based on the high rates of resistance to carbapenems in A. baumannii strains from 10 tertiary-care hospitals in the Colombian network, an investigation into the underlying mechanisms and strain structure was undertaken.(This report was presented in part at the 46th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy, San Francisco, CA, 2006 [13a].) MATERIALS AND M...

Each entire hypervariable region of the mitochondrial DNA control region was screened for mutations from paired normal and tumor DNA corresponding to a group of 21 patients (13 colorectal and 8 gastric adenocarcinomas) using both heteroduplex analysis and single-strand conformation analysis. These two mutation scanning strategies allowed the identification of sequence alterations in 3/13 (23%) colorectal tumors and in 3/8 (37%) gastric tumors. Heteroduplex analysis showed the heteroplasmic state of the majority of these tumor mutations. Sequence analysis revealed two A:T/G:C transitions (nucleotide positions: 16241 and 16166) in hypervariable region 1 (HV1) and two C:G/T:A transitions (nucleotide positions: 76 and 312), one A:T/G:C transition (nucleotide position: 93), a 1-basepair C:G deletion (nucleotide position: 309), and a 2-base-pair CC:GG insertion (nucleotide position: 309) in the HV 2 region. A considerable proportion of these mutations was found in homopolymeric regions which are highly polymorphic among humans. Different mechanisms (clonal expansion, increased oxidative damage, and nuclear mutator mutations) were suggested to explain the increased mitochondrial DNA mutation rate observed in cancer.

The technique RT-qPCR for viral RNA detection is the current worldwide strategy used for early detection of the novel coronavirus SARS-CoV-2. RNA extraction is a key pre-analytical step in RT-qPCR, often achieved using commercial kits. However, the magnitude of the COVID-19 pandemic is causing disruptions to the global supply chains used by many diagnostic laboratories to procure the commercial kits required for RNA extraction. Shortage in these essential reagents is even more acute in developing countries with no means to produce kits locally. We sought to find an alternative procedure to replace commercial kits using common reagents found in molecular biology laboratories. Here we report a method for RNA extraction that takes about 40 min to complete ten samples, and is not more laborious than current commercial RNA extraction kits. We demonstrate that this method can be used to process nasopharyngeal swab samples and yields RT-qPCR results comparable to those obtained with commercial kits. Most importantly, this procedure can be easily implemented in any molecular diagnostic laboratory. Frequent testing is crucial for individual patient management as well as for public health decision making in this pandemic. Implementation of this method could maintain crucial testing going despite commercial kit shortages.

Coagulase-negative staphylococci (CNS) are frequently isolated from blood cultures, where they may be only a contaminant or the cause of bacteraemia. Determining whether an isolate of CNS represents a true CNS bacteraemia is difficult, and there is no single criterion with sufficient specificity. The aim of this study was to assess those clinical, microbiological, pathogenic and genotypic features that characterize true CNS bacteraemia. Twenty patients having two or more blood cultures positive for CNS and 20 patients with only one positive blood culture were studied. Significant bacteraemia was defined according to clinical and laboratory criteria. Incubation time for blood cultures to become positive, macroscopic appearance of colonies, species determination, biotype, susceptibility to antimicrobials, PFGE pattern and adherence capacity were all studied. Clinical bacteraemia was present in 16/20 patients with two or more positive blood cultures and in 2/ 20 patients with only one positive blood culture. A significant difference was seen in the median time to positivity between the 18 clinical bacteraemias and 22 contaminations (23 . 6 versus 29 . 2 h; P ¼ 0 . 04, Wilcoxon). There was also a significant difference between the two groups in the median absorbance of the slime test (1 . 36 versus 0 . 58; P ¼ 0 . 005). All significant bacteraemias with two or more positive blood cultures had the same species identified, the same antimicrobial susceptibility pattern and the same PFGE pattern. In two patients with true bacteraemia with only one positive blood culture, the incubation time for the culture to turn positive was ,24 h and the slime production absorbance was .2 . 5. The most useful parameters for the diagnosis of true CNS bacteraemia for patients with two positive blood cultures were incubation time until positive, species identification, antimicrobial susceptibility pattern, slime production and PFGE pattern. For patients with only one blood culture positive for CNS, the useful parameters for prediction of true bacteraemia were incubation time until positive and slime production, both of which are simple, low-cost tests.