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PubMed2006

Identification and susceptibility testing of Staphylococcus aureus by direct inoculation from positive BACTEC blood culture bottles.

This study explored the possibility of combining direct inoculation of tube coagulase and DNase tests, and the VITEK2 system, from BACTEC blood culture bottles in order to achieve rapid identification and susceptibility testing of Staphylococcus aureus. All isolates were identified correctly as S. aureus or coagulase-negative staphylococci (CNS). Antimicrobial susceptibility testing with the VITEK2 system gave 99.6% correct category agreement, with 0.1% very major errors and 0.3% minor errors among S. aureus isolates, and 97.4% correct category agreement, with 0.9% very major errors and 1.7% minor errors among CNS isolates. The results suggested that direct identification and susceptibility testing is sufficiently accurate for immediate reporting.

Anti-Bacterial Agents↗
PubMed1981

Comparison of silver sulfadiazine, povidone-iodine and physiologic saline in the treatment of chronic pressure ulcers.

The presence of bacteria and local infection is an important factor in the local management of chronic pressure ulcers. For successful closure of the ulcer, the bacterial count should be 10(5) or less per gram of tissue in the granulating wound. In a prospective randomized study of 45 (eventually 40) hospitalized patients, silver sulfadiazine (Silvadene) cream and povidone-iodine (Betadine) solution were compared to physiologic saline for effectiveness in preparing pressure ulcers for closure. Quantitative bacteriologic techniques on tissue biopsy specimens were used for objective evaluation. In 100 percent of the ulcers treated with silver sulfadiazine cream (15 patients) the bacterial counts were reduced to 10(5) or less per gram of tissue within the three-week test period, compared to 78.6 percent in those treated with saline (14 patients) and 63.6 percent in those treated with povidone-iodine solution (11 patients). Moreover, the ulcers treated with silver sulfadiazine cream responded more rapidly, with one-third showing bacterial levels of less than 10(5) within three days, and half within a week.

Adolescent↗
PubMed2006

Differences in the API 20E biochemical patterns of clinical and environmental Vibrio parahaemolyticus isolates.

Genetic differences in clinical and environmental strains of Vibrio parahaemolyticus have been widely used as criteria in identifying pathogenic isolates. However, few studies have been carried out to assess the differences in biochemical characteristics of V. parahaemolyticus isolates from human and environmental sources. We compared the biochemical profiles obtained by the characterization of V. parahaemolyticus isolates from human infections and the marine environment using the API 20E system. Environmental and clinical isolates showed significant differences in the gelatin and arabinose tests. Additionally, clinical isolates were correctly identified according to the API 20E profile using 0.85% NaCl diluent, but they presented nonspecific profiles with 2% NaCl diluent. In contrast, use of 2% NaCl diluent facilitated correct identification of the environmental isolates. Clinical isolates showed significant differences in up to five biochemical tests with respect to the API 20E database. The API 20E system is widely used in routine identification of bacteria in clinical laboratories, and this discrepancy in an important number of biochemical tests may lead to misidentification of V. parahaemolyticus infection.

Animals↗
PubMed2000

Ribosomal RNA-targeted nucleic acid probes for studies in microbial ecology.

With readily applicable hybridization assays, mainly based on rRNA-targeted nucleic acid probes, and direct, cultivation-independent sequence retrieval, microbiologists can for the first time determine the true composition of microbial communities. Phylogenetic identification and exact spatiotemporal quantification of microorganisms will in the future become prerequisites for high quality studies in microbial ecology just as good taxonomy and solid quantification have always been for macroecology. This review is intended to give a short history of the development of rRNA-targeted nucleic acid probes and probe technologies, as well as of their application in microbial ecology. The current state of the art is described, and we will try to look into the future. Over the last decade, rRNA-targeted probes have become a handy tool for microbial ecologists. In order to speed up the transformation of microbial ecology from a mostly descriptive to a hypothesis-driven, experimental science more intense use must be made of the taxonomic precision and quantitativeness of rRNA-targeted probes.

Bacteria↗
PubMedDate not supplied

Molecular genetic methods in diagnosis and direct characterization of acute bacterial central nervous system infections.

Acute bacterial infection of the central nervous system requires rapid and adequate management. Etiological diagnosis is hence crucial. Moreover, the epidemic threat of certain bacteria necessitates a reliable characterization of the involved bacterial strains to follow the spread of epidemic strains. Conventional identification and characterization of etiological agents are basically based on culture and identification of bacterial markers most frequently by serological assays. Molecular identification and characterization of bacteria have been employed. They provide more reliable analysis of bacterial isolates. Molecular methods for non-culture diagnosis of bacterial infections have recently been developed. In many cases, the molecular assays have decreased the identification time of positive cultures and rescued detection of pathogens in culture-negative clinical samples.

Acute Disease↗
PubMed1986

Short-term failure of IUD removal to alter bacterial flora in a patient with chronic anaerobic endometritis.

A patient with cytological and clinical evidence of IUD-associated anaerobic endometritis was studied with quantitative and qualitative bacteriological techniques. With the exception of elimination of Actinomyces israelii from the deep endocervical/endometrial culture, IUD removal induced minimal qualitative changes in the bacterial flora of the endocervical/endometrial sample during the 35 days the patient was monitored. The interposition of menstruation did not significantly alter either the quantitative or qualitative interrelationship of the bacteria present.

Adult↗
PubMed1979

Staphylococcal septic arthritis in three horses.

Three horses were diagnosed as having monarticular septic arthritis due to Staphylococcus aureus on the basis of culture of articular cartilage, synovial membrane and/or synovial fluid. The organisms were all well recognised human phage types and in two cases demonstrated beta-lactamase (penicillinase) activity. Details of case histories are presented and the bacteriological techniques and antibiotic management with cloxacillin, methicillin and penicillin discussed. Following treatment, sterile cultures of synovial fluid were achieved in all cases, but in two horses the infections resulted in degenerative articular changes. This necessitated arthrodesis of the fetlock joint in one case.

Animals↗
PubMed1985

Use of a species-specific DNA hybridization probe for enumerating Bacteroides vulgatus in human feces.

pBV-1, a recombinant plasmid that contains a chromosomal DNA fragment from Bacteroides vulgatus, hybridized to DNA from B. vulgatus but not to DNA from other colonic Bacteroides species. This plasmid was used as a DNA probe to detect and enumerate B. vulgatus in pure culture, in mixed cultures, and in a bacterial fraction from human feces. Bacteria in a pure or mixed culture were lysed by heating the culture in NaOH. The DNA in the disrupted cell suspension was then trapped on nitrocellulose paper by vacuum filtration. If fecal samples were used instead of pure or mixed cultures, it was first necessary to partially purify the DNA by low-speed centrifugation (2,000 X g) and phenol-chloroform extraction before filtering. When 32P-labeled pBV-1 was incubated with filters containg B. vulgatus DNA, the amount of radioactivity that bound to the filters was proportional to the number of B. vulgatus filtered as long as the filtering capacity of the nitrocellulose was not exceeded. Using this procedure, we obtained a value for the concentration of B. vulgatus in human feces (2 X 10(10) to 3 X 10(10) per g of dry weight) that is similar to values obtained by other investigators using conventional bacteriological techniques (3 X 10(10) to 6 X 10(10) per g of dry weight). The advantage of the DNA hybridization method over conventional techniques is that it is not necessary to isolate pure cultures of bacteria from complex specimens such as feces. Furthermore, our method bypasses the cumbersome set of biochemical tests normally used to identify anaerobic bacteria. The major limitation of our method is its sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteroides↗
PubMed1996

Hemolytic activity reevaluation of putative nonpathogenic Listeria monocytogenes strains.

Identification of 12 strains originally characterized as nonpathogenic Listeria monocytogenes was reassured following the evaluation of their hemolytic capability with a newly developed horse blood agar plate. Seven of the strains were observed consistently to be hemolytic and confirmed as L. monocytogenes with the use of two commercial systems: the Gene-Trak L. monocytogenes-specific colorimetric DNA hybridization assay and the API Listeria system. Except for one strain that formed typical smooth colonies, these hemolytic strains formed rough colonies on a selective medium, lithium chloride-ceftazidime agar. The rest of the strains were nonhemolytic and did not hybridize with the DNA probe; they were identified as Listeria innocua on the basis of their API Listeria system biochemical profile. All but one of these nonhemolytic strains formed smooth colonies on lithium chloride-ceftazidime agar.

Agar↗
PubMed2005

Effect of culture conditions on microorganism identification by matrix-assisted laser desorption ionization mass spectrometry.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used to identify bacteria based upon protein signatures. This research shows that while some different proteins are produced by vegetative bacteria when they are cultured in different growth media, positive identification with MALDI-TOF MS is still possible with the protocol established at the Pacific Northwest National Laboratory (K. H. Jarman, S. T. Cebula, A. J. Saenz, C. E. Petersen, N. B. Valentine, M. T. Kingsley, and K. L. Wahl, Anal. Chem. 72:1217-1223, 2000). A core set of small proteins remain constant under at least four different culture media conditions and blood agar plates, including minimal medium M9, rich media, tryptic soy broth (TSB) or Luria-Bertani (LB) broth, and blood agar plates, such that analysis of the intact cells by matrix-assisted laser desorption/ionization mass spectrometry allows for consistent identification.

Algorithms↗
PubMed1962

Experiences with the Coulter counter in bacteriology.

Viable and killed suspensions of Staphylococcus aureus SM, Escherichia coli, and Serratia marcescens, as well as polystyrene spheres, 0.81 and 2.85 mu in diameter, were counted electronically with a model A Coulter Counter. Simultaneous counts by standard bacteriological methods and microscopy were done for purposes of control and comparison with the data from the Coulter Counter. Results indicated: (i) electrical characteristics of different bacterial populations are different; (ii) electronic counts were consistent for species used; (iii) live S. aureus exhibits a denser pattern of thick bright pulses on the cathode-ray tube than does live E. coli; (iv) killed bacteria resemble inert particles in pulse pattern; and (v) some viable bacteria do not react independently of current flow, as do inert particles and killed bacteria.

Bacteria↗
PubMed1964

BACTERIOLOGY OF SPOILAGE OF FISH MUSCLE. II. INCIDENCE OF SPOILERS DURING SPOILAGE.

A test medium consisting of a sterile raw press juice from fish muscle was used to determine the incidence of spoilage bacteria on stored fillets of English sole (Parophrys vetulus). The initial load of spoilers was shown to be consistently below 10%. This percentage rose but slightly toward the middle of the spoilage runs, and actually declined when spoilage was most apparent both organoleptically and chemically. Further evidence implicating the Pseudomonas and Achromobacter groups in the spoilage of fresh fish is presented.

Achromobacter↗
PubMed1969

Effect of shaking speed and type of closure on shake flask cultures.

Growth of microorganisms and biosynthesis of microbial products in shake flasks may be limited by operating conditions which provide inadequate supplies of oxygen. Methods are described for meeting the oxygen requirements of test organisms by using standard baffled flasks with pad-type closures and shaking at relatively high speeds. Growth of Escherichia coli B in a rich medium and production of candidin by Streptomyces viridoflavus were the test systems used. Flasks shaken at 230 to 385 rev/min gave sulfite oxidation rates of 1 to 8 mmoles of oxygen per liter per min over a useful working volume range (40 to 150 ml in 300-ml flasks). These rates are as high as those obtained in agitated fermentors under usual operating conditions.

Anti-Bacterial Agents↗
PubMed2005

Manual and automated instrumentation for identification of Enterobacteriaceae and other aerobic gram-negative bacilli.

Identification of gram-negative bacilli, both enteric and nonenteric, by conventional methods is not realistic for clinical microbiology laboratories performing routine cultures in today's world. The use of commercial kits, either manual or automated, to identify these organisms is a common practice. The advent of rapid or "spot" testing has eliminated the need for some commonly isolated organisms to be identified with the systems approach. Commercially available systems provide more in-depth identification to the species level as well as detect new and unusual strains. The answers obtained from these systems may not always be correct and must be interpreted with caution. The patient demographics, laboratory workload and work flow, and technologist's skill levels should dictate the system of choice. Cost considerations introduce another variable into the equation affecting choice. Each system has its own strengths and weaknesses, and each laboratory must decide on the level of sophistication that fulfills its particular needs.

Automation↗