Detection and Isolation of Clostridium difficile Asymptomatic Carriers During Clostridium difficile Infection Outbreaks: An Exploratory Study.

During 4 Clostridium difficile infection outbreaks, unit-wide screening of 114 patients led to detection and isolation of 15 (13%) C. difficile asymptomatic carriers. Carriage prevalence varied between outbreaks, from 0% to 29% (P = .

Assay for estimating total bacterial load: relative qPCR normalisation of bacterial load with associated clinical implications.

Relative microorganism abundance is a parameter describing biodiversity, referring to how common a bacterial species is within the total bacterial flora. Anal, rectal, skin, mucal, and respiratory swabs are typical clinical samples where knowledge of relative bacterial abundance might make distinction between asymptomatic carriers and symptomatic cases. Assays trying to measure total bacterial load are usually based on the amplification of universal segments of 16S rRNA genes.

Predictors of asymptomatic Clostridium difficile colonization on hospital admission.

Background: Clostridium difficile (CD) is the leading cause of health care-associated diarrhea and can result in asymptomatic carriage. Rates of asymptomatic CD colonization on hospital admission range from 1.4%-21%.

Significantly improved performance of a multitarget assay over a commercial SCCmec-based assay for methicillin-resistant Staphylococcus aureus screening: applicability for clinical laboratories.

Detection of the SCCmec gene is a common strategy for methicillin-resistant Staphylococcus aureus (MRSA) screening assays. However, if SCCmec is used alone, it may not be specific for detecting MRSA. Herein, we describe an in-house MSRA PCR-based screening assay involving detection of three targets (nuc, coa, and mecA).

Host and pathogen factors for Clostridium difficile infection and colonization.

Background: Clostridium difficile infection is the leading cause of health care-associated diarrhea, and the bacterium can also be carried asymptomatically. The objective of this study was to identify host and bacterial factors associated with health care-associated acquisition of C. difficile infection and colonization.

Community-acquired Clostridium difficile-associated diarrhea, Montréal, 2005-2006: frequency estimates and their validity.

A retrospective search for community-acquired Clostridium difficile-associated diarrhea in 15 hospitals revealed important discrepancies with numbers for the same period reported in real time to the surveillance system. Several of the observed problems could be solved by implementing case-by-case notification with subsequent investigation by local public health, as for other reportable diseases.

Fourteen-genome comparison identifies DNA markers for severe-disease-associated strains of Clostridium difficile.

Clostridium difficile is a common cause of infectious diarrhea in hospitalized patients. A severe and increased incidence of C. difficile infection (CDI) is associated predominantly with the NAP1 strain; however, the existence of other severe-disease-associated (SDA) strains and the extensive genetic diversity across C.

Evidence of viremia in 2 cases of severe pandemic influenza A H1N1/09.

The recent pandemic of the 2009 pandemic influenza A (H1N1) infrequently caused severe disease. We describe 2 cases of 2009 H1N1 influenza with rapid progression resulting in respiratory failure and need for prolonged intensive care support. Real-time polymerase chain reaction amplification for influenza A (using a Centers for Disease Control and Prevention protocol) and the 2009 H1N1 influenza (using an in-house protocol) was performed on serial respiratory and serum specimens from both patients collected over 3 weeks.

Impact of strain type on detection of toxigenic Clostridium difficile: comparison of molecular diagnostic and enzyme immunoassay approaches.

A multicenter clinical trial assessed the performance of the Cepheid Xpert C. difficile assay on stool specimens collected from patients suspected of having Clostridium difficile infection (CDI). A total of 2,296 unformed stool specimens, collected from seven study sites, were tested by Xpert C.

Patterns of antibiotic use and risk of hospital admission because of Clostridium difficile infection.

Background: Previous observations have indicated that infection with Clostridium difficile occurs almost exclusively after exposure to antibiotics, but more recent observations have suggested that prior antibiotic exposure may be less frequent among cases of community-acquired disease.

Methods: We used 2 linked health databases to perform a matched, nested case-control study of elderly patients admitted to hospital with community-acquired C. difficile infection.

Highly diversified multiply drug-resistant HIV-1 quasispecies in PBMCs: a case report.

Background: Although drug resistance is a major challenge in HIV therapy, the effect of drug resistance mutations on HIV evolution in vivo is not well understood. We have now investigated genetic heterogeneity in HIV-1 by performing drug resistance genotyping of the PR-RT regions of viruses derived from plasma and peripheral blood mononuclear cells (PBMCs) of a single patient who had failed multiple regimens of anti-retroviral therapy.

Results: Patterns of drug resistance mutations showed that the viral populations in PBMCs were more heterogeneous than in plasma.

Antimicrobial drugs and community-acquired methicillin-resistant Staphylococcus aureus, United Kingdom.

We report results of a case-control study of the association between receipt of antimicrobial agents and diagnosis of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in the United Kingdom. Eligible adults, selected from the General Practice Research Database, had no previous diagnosis of MRSA, no hospitalization in the past 2 years, and > or = 2 years of follow-up recorded in the database. For 2000-2004, we identified 1,981 MRSA case-patients and 19,779 matched control-patients.

A protocol for the in vitro selection of specific oligonucleotide probes for high-resolution DNA typing.

The confident discrimination of nucleic acids that share a high degree of sequence identity is the major obstacle for the widespread applicability of multiplex DNA-based techniques. This diagnostic uncertainty originates in the insufficient specificity of hybridization, allowing cross-hybridization between unwanted probe-target combinations. Starting from a random mixture of oligonucleotides, we describe a protocol to selectively amplify the probes that bind to the target but not to the similar, unintended targets.

A portrait of the geographic dissemination of the Clostridium difficile North American pulsed-field type 1 strain and the epidemiology of C. difficile-associated disease in Québec.

Background: An increase in the incidence and severity of Clostridium difficile-associated disease in Québec and the United States has been associated with a hypervirulent strain referred to as North American pulsed-field type 1 (NAP1)/027.

Methods: In 2005, a prospective study was conducted in 88 Québec hospitals, and 478 consecutive nosocomial isolates of C. difficile were obtained.

A predominantly clonal multi-institutional outbreak of Clostridium difficile-associated diarrhea with high morbidity and mortality.

Background: In March 2003, several hospitals in Quebec, Canada, noted a marked increase in the incidence of Clostridium difficile-associated diarrhea.

Methods: In 2004 we conducted a prospective study at 12 Quebec hospitals to determine the incidence of nosocomial C. difficile-associated diarrhea and its complications and a case-control study to identify risk factors for the disease.