Diagnostic algorithm using a sensitive broth culture method for detection of Clostridium difficile toxin from stool samples.

Background: The two-step glutamate dehydrogenase antigencytotoxicity neutralization assay algorithm has been found to be reliable for the diagnosis of toxigenic Clostridium difficile. However, the high sensitivity of the screening method is compromised by the relative low sensitivity of the second step, the direct cytotoxin neutralization assay (DCNA) using a fecal filtrate. The objective of the present study was to compare the DCNA with an indirect cytotoxin neutralization assay (ICNA).

Waterborne pathogen detection by use of oligonucleotide-based microarrays.

A small-oligonucleotide microarray prototype was designed with probes specific for the universal 16S rRNA and cpn60 genes of several pathogens that are usually encountered in wastewaters. In addition to these two targets, wecE-specific oligonucleotide probes were included in the microarray to enhance its discriminating power within the Enterobacteriaceae family. Universal PCR primers were used to amplify variable regions of 16S rRNA, cpn60, and wecE genes directly in Escherichia coli and Salmonella enterica serovar Typhimurium genomic DNA mixtures (binary); E.

Optimization of microbial DNA extraction and purification from raw wastewater samples for downstream pathogen detection by microarrays.

Numerous waterborne pathogens are difficult to detect and enumerate with accuracy due to methodological limitations and high costs of direct culturing. The purity of DNA extracted from wastewater samples is an important issue in the sensitivity and the usefulness of molecular methods such as polymerase chain reaction (PCR) and hybridizations on DNA microarrays. Ten different DNA extraction procedures, including physical and chemical extraction and purification steps, were examined to ascertain their relative effectiveness for extracting bacterial DNA from wastewater samples.

Development of oligonucleotide primers for the specific PCR-based detection of the most frequent Enterobacteriaceae species DNA using wec gene templates.

Oligonucleotide primers were designed for the PCR-based detection of the wec gene cluster involved in the biosynthetic pathway leading to the production of enterobacterial common antigen (ECA). Escherichia coli DNA was detected using wec A, wec E, and wec F gene primers. The wec A primers were specific for E.

Sacroiliitis and septicemia caused by Campylobacter rectus and Actinomyces odontolyticus.

Campylobacter rectus, formerly known as Wolinella recta, is an anaerobic Gram-negative bacillus, generally recognized as an agent responsible for severe periodontitis; only two cases of extra-oral infections have been reported. The first case of septicemia with C rectus and Actinomyces odontolyticus is described in a 37-year-old farmer who suffered from severe sacroiliitis. Also presented are a review of C rectus in human pathology, and a brief review of pyogenic sacroiliitis, a rather rare disease.

Capnocytophaga ochracea and group F beta-hemolytic streptococcus suppurative thyroiditis.

The route of infection in acute suppurative thyroiditis is unknown in most cases; when demonstrated, pyriform sinus fistula appears to be the most frequent one. We report the clinical and laboratory findings of a child in whom culture of the thyroid pus yielded two bacteria which are part of the normal oropharyngeal flora: capnocytophaga ochracea and group F Beta-hemolytic streptococcus. The preliminary results of the culture, which showed a mixed flora, prompted us to search and to find a pyriform sinus fistula.

Rapid screening for bacteriuria with a laser nephelometer.

Detection of significant bacteriuria with a laser nephelometer was evaluated in this study and compared with the results obtained by the quantitative loop method. We screened 1002 urine specimens and 220 (21.95%) were found to be positive at greater than or equal to 10(5) colony-forming units (CFU)/mL of urine by the standard method.

Rapid detection of bacteriuria by laser nephelometry.

A total of 1,002 urine specimens were evaluated by laser nephelometry. This technique was compared with both colony counts, done with a calibrated loop, and serial dilutions. For urine specimens containing between 10(4) and 10(5) bacteria per ml, laser nephelometry detected 75.

Macular coccidioidomycosis.

A 26-year-old woman had an enlarging dense macular lesion in the right eye. The funduscopic and angiographic findings were distinctly different from those in macular histoplasmosis. She was found to have a coccidioidomycotic granuloma in the left lung and was treated with amphotericin B.

Rapid detection of bacteremia caused by Enterobacteriaceae with subculture in broth and laser nephelometry.

The early detection of Gram-negative rod bacteremia favors the prompt institution of appropriate antimicrobial therapy. During a 6-week period, blood cultures were subcultured in broth during the first 18 h of incubation. The turbidity of these subcultures was studied by laser nephelometry.