ABSTRACT
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. The quality of the differentially extracted DNAs was subsequently assessed by PCR amplification and microarray hybridization. Our results showed that great differences existed among the ten procedures and only a few of the methods gave satisfactory results when applied to bacterial pathogens. This observation suggested that the extraction method needed to be carefully selected to produce significant and confident results in the detection of pathogens from environmental samples.
Subject(s)
Bacteria/isolation & purification , DNA, Bacterial/isolation & purification , Oligonucleotide Array Sequence Analysis/methods , Polymerase Chain Reaction/methods , Waste Disposal, Fluid/methods , Water Microbiology , Bacteria/genetics , Bacteria/pathogenicity , Bacteriological Techniques , DNA, Bacterial/analysis , DNA, Bacterial/geneticsABSTRACT
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.
ABSTRACT
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. Apart from the onset in infancy, the left lobe involvement and the frequent recurrence, the recovery from the thyroid pus of bacteria from normal oropharyngeal flora should be included in the characteristic features of thyroiditis resulting from an infection through the pyriform sinus fistula.
Subject(s)
Bacterial Infections , Streptococcal Infections , Thyroiditis/etiology , Adolescent , Capnocytophaga , Female , Fistula/complications , Fistula/diagnostic imaging , Humans , Laryngeal Diseases/complications , Laryngeal Diseases/diagnostic imaging , Radiography , Thyroiditis/pathologyABSTRACT
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. Of the 220 positive specimens, 210 (95.4%) were detected in 6 h or less and 177 (80.4%) were detected within 3 h. The false-positive rate was 2.3% at 3 h and 19.7% at 6 h. These findings suggest that a 6-h procedure is necessary to detect 95% or more of significant bacteriuria. Laser nephelometer is versatile and can be used for rapid screening of bacteriuria.
Subject(s)
Bacteriuria/diagnosis , Bacteria/isolation & purification , Bacteriological Techniques , Diagnostic Errors , Evaluation Studies as Topic , Humans , Lasers , Nephelometry and Turbidimetry/methodsSubject(s)
Brain Abscess/diagnosis , Adolescent , Adult , Aged , Brain Abscess/etiology , Brain Abscess/therapy , Humans , Middle Aged , Prognosis , RiskABSTRACT
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 75.4% of those detected by colony count and 65.6% of those detected by serial dilution. For specimens where the concentration of bacteria was greater than 10(5) per ml, laser nephelometry detected 95.8 and 92.4% of those detected by colony count and serial dilution, respectively. The mean detection time for bacteriuria varied from 1.57 h for more than 10(5) bacteria per ml to 4.47 h for more than 10(4) bacteria per ml. To determine the number of bacteria according to the voltage growth curve, the passage time at 3 V was used as an index. The mean passage time at 3 V decreased from 5.18 h for fewer than 10(4) bacteria per ml to 1.42 h for more than 10(6) bacteria per ml. The mean passage time at 3 V differed significantly for different concentrations of bacteria. Thus, this index allowed us to predict the number of bacteria in the urine specimens. Laser nephelometry has been used for many years for the immunological determination of proteins; it can now also be considered a tool for rapid screening in bacteriology.
Subject(s)
Bacteriological Techniques , Bacteriuria/diagnosis , Lasers , Humans , Nephelometry and TurbidimetrySubject(s)
Actinomycosis/diagnosis , Hepatitis/diagnosis , Liver Neoplasms/diagnosis , Diagnosis, Differential , Female , Humans , Middle AgedSubject(s)
Liver Abscess/diagnosis , Adolescent , Adult , Aged , Female , Humans , Liver Abscess/etiology , Liver Abscess/therapy , Male , Middle Aged , PrognosisABSTRACT
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. Within a month the macular lesion was cicatricial. This appears to be the first reported case of presumed ocular coccidioidomycosis in Canada.
Subject(s)
Coccidioidomycosis/diagnosis , Lung Diseases, Fungal/diagnosis , Macula Lutea , Retinal Diseases/diagnosis , Adult , Amphotericin B/therapeutic use , Canada , Coccidioidomycosis/drug therapy , Coccidioidomycosis/surgery , Female , Fluorescein Angiography , Humans , Lung Diseases, Fungal/surgeryABSTRACT
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. Fifty-five percent of the blood cultures positive for Enterobacteriaceae were reported on the same day the sample was taken from the patient; this constitutes a marked acceleration in comparison with the results obtained by a conventional method. The identification and results of the antimicrobial susceptibility tests were available 2 days after the specimen was taken. Early subculture in broth combined with laser nephelometry studies of broth turbidity is readily applied to the study of bacteremia due to Enterobacteriaceae and may favorably influence the outcome of such disease by providing specific results more rapidly.
