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M T Kelly

Publications and source records attributed to M T Kelly.

At least 55 records · Page 3Linked to original sources
PubMed1990

Clinical comparison of isolator and BACTEC 660 resin media for blood culture.

The 10-ml Isolator system (E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.) was compared with the BACTEC 16A-17A nonradiometric resin system (Johnston Laboratories, Inc., Towson, Md.) for isolation of organisms from 6,839 paired blood cultures. Equal volumes of blood (6 to 10 ml for each Isolator and 3 to 5 ml for each BACTEC bottle) were cultured in parallel in the two systems, and 600 isolates that were judged to be clinically significant by chart review were recovered during the study. The BACTEC resin system detected 510 (85%) and the Isolator system detected 435 (72%) of the clinically significant isolates (P less than 0.001). Of 45 polymicrobial blood cultures, the BACTEC system detected 32 (71%) and the Isolator system detected 21 (47%) (P less than 0.05). Of 253 gram-negative bacilli isolated during the study, 30% were detected only in the BACTEC system and 16% were detected only in the Isolator system (P less than 0.001), and of 56 nonfermentative or fastidious gram-negative bacilli detected, 46% were recovered only in the BACTEC system, while 14% were detected only in the Isolator system (P less than 0.001). Of 86 streptococci isolated during the study, 30% were detected only in the BACTEC system, and 4% were detected only in the Isolator system (P less than 0.001). Recoveries of anaerobic bacteria, staphylococci, and yeasts were equivalent in the two systems. Organisms judged to be contaminants were detected in approximately 1% of the cultures in each system. The results suggest that use of resin media renders the BACTEC nonradiometric system equivalent or superior to the Isolator system for detection of clinically significant organisms in blood cultures.

Blood↗
PubMed1989

Retention characteristics in high-performance liquid chromatography of basic drugs and plasma extracts on an alumina column.

The retention characteristics of 35 drugs on an alumina column using buffered aqueous methanolic mobile phases have been investigated. It has been shown that the effect of pH on retention depends on the pKa of the drug and the type of buffer ion used; that there is an inverse relation between ionic strength and solute retention; and that a decrease in the amount of methanol in the mobile phase causes the drugs to be held longer on the column. The chromatographic system was also coupled to an on-line column-switching assembly to facilitate extraction of the drugs from plasma, and results are presented which indicate that the alumina column lends itself well to this convenient method of plasma clean-up.

Chromatography, High Pressure Liquid↗
PubMed1989

A comparison of silica and alumina columns for high-performance liquid chromatographic separations of basic drugs and plasma constituents following on-line solid-phase extraction with column switching.

A comparison has been made of a silica and an alumina column with respect to retention behaviour in high-performance liquid chromatography of pure drug solutions and plasma profiles following on-line solid-phase extraction. Using methanol-ammonium nitrate buffer (80:20, v/v) as eluent, it was found that these systems lend themselves well to the column switching technique. Increasing the pH of the mobile phase produced similar shifts in retention for basic drugs on both columns, but fewer plasma interferents are retained on the alumina column as compared to the silica column under the same operating conditions.

Aluminum Oxide↗
PubMed1989

Antimicrobial susceptibility of Plesiomonas shigelloides from patients with diarrhea.

Antimicrobial susceptibility testing was performed on 72 fecal isolates of Plesiomonas shigelloides from patients with diarrhea by using a standard agar dilution technique. All isolates were obtained from a single geographic location. Based on the in vitro activities demonstrated in this study, norfloxacin, ciprofloxacin, and trimethoprim may be effective as oral agents in the treatment of P. shigelloides diarrheal disease. For the parenteral treatment of extraintestinal infection, netilmicin and the cephalosporins had the best in vitro activity.

Anti-Bacterial Agents↗
PubMed1989

Urease-positive, Kanagawa-negative Vibrio parahaemolyticus from patients and the environment in the Pacific Northwest.

We previously reported the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. The present studies compare the biochemical characteristics, Kanagawa hemolysin reactions, and plasmid profiles of 13 patient and 221 environmental isolates of the organism. Classical biochemical testing of the isolates revealed similar reactions for the clinical and environmental strains, and analysis in agarose gels revealed that 13 to 15% of the isolates had plasmids. The strains were tested for production of Kanagawa hemolysin on Wagatsuma agar, and 1.4% of environmental isolates and 23% of clinical isolates were positive. Clinical isolates from locally acquired extraintestinal infections were urease negative and Kanagawa hemolysin negative, isolates from locally acquired gastroenteritis cases were urease positive and Kanagawa negative, and isolates from traveler's diarrhea were urease negative and Kanagawa positive. Eight percent of the local environmental isolates were also urease positive and Kanagawa hemolysin negative. These findings suggest that expression of the Kanagawa hemolysin is not essential for the pathogenesis of V. parahaemolyticus infections. In addition, our findings suggest that V. parahaemolyticus gastroenteritis in the Pacific Northwest is associated with a urease-positive, Kanagawa-negative biotype of the organism.

Animals↗
PubMed1989

Clinical features, epidemiology, and treatment of Plesiomonas shigelloides diarrhea.

Recent studies have suggested that Plesiomonas shigelloides is a cause of diarrhea. The present study addresses the clinical features, epidemiology, and response to antimicrobial therapy of P. shigelloides diarrhea. Thirty cases of P. shigelloides infection were defined by isolation of the organism from stool specimens, and 30 age-matched control patients were identified by detection of other enteric pathogens. Clinical and epidemiological information was obtained by interviewing the referring physicians and the patients. Of the P. shigelloides-infected patients, 71% had a history of recent tropical travel, but 29% acquired their infections locally in association with the consumption of seafood or untreated water or both. Seventy-eight percent of the P. shigelloides-infected patients had findings suggestive of colitis, and P. shigelloides-infected patients had a history of tropical travel, acute illness, abdominal pain, and prolonged symptoms significantly more often than did the control patients. Antimicrobial therapy significantly reduced the duration of illness in patients with Plesiomonas diarrhea. These results suggest that P. shigelloides is a significant cause of both locally acquired and traveler's diarrhea that may respond to antimicrobial therapy.

Adolescent↗
PubMed1988

Occurrence of Vibrionaceae in natural and cultivated oyster populations in the Pacific Northwest.

Studies were done to assess the role of oysters from the Pacific Northwest as a potential source of Vibrionaceae. Oysters collected from natural and cultivated populations on the British Columbia Coast were opened using sterile instruments. The gills and oyster meat were each removed, and the meat was cut in half. The gills and the cut surface of the oyster meat were each cultured by inoculating them directly to the surface of agar plating media for the isolation of Vibrionaceae. Overall, 120 oysters were cultured, and 60 yielded Vibrionaceae. Vibrio parahaemolyticus, Vibrio fluvialis, and Vibrio vulnificus were the most commonly isolated organisms. Vibrionaceae were most often recovered from oysters collected under warm-water conditions from natural stocks (83% positive), followed by oysters from the same sites collected under cold-water conditions (35% positive). Only 29% of oysters collected from cultivated commercial stocks under warm water conditions yielded Vibrionaceae, and no Vibrionaceae were isolated from oysters collected from these sites during periods when water temperatures were low. The results suggest that oysters are a significant source of potentially pathogenic Vibrionaceae in the Pacific Northwest. However, the risk of exposure to these bacteria can be reduced by consumption of cultivated oysters harvested under cold-water conditions.

Animals↗
PubMed1988

Comparison of blood agar, ampicillin blood agar, MacConkey-ampicillin-Tween agar, and modified cefsulodin-Irgasan-novobiocin agar for isolation of Aeromonas spp. from stool specimens.

The performance of four media for the isolation of Aeromonas strains from stool specimens, the importance of ampicillin-susceptible Aeromonas strains in the selection of culture media, and the usefulness of beta-hemolysis in screening blood-containing media for Aeromonas strains were evaluated in two phases. In the first phase, 36 of 1,672 stool specimens yielded Aeromonas isolates. Ninety-seven percent of the isolates were detected on blood agar containing 20 micrograms of ampicillin per ml (ABA), and 47% were detected on MacConkey agar containing 100 micrograms of ampicillin per ml and 1% Tween 80. In the second phase of the study, 43 of 1,924 stool specimens yielded Aeromonas isolates. Fifty-one percent of the isolates were detected on blood agar and on modified cefsulodin-Irgasan-novobiocin agar, and 84% were detected on ABA. The combination of ABA and modified cefsulodin-Irgasan-novobiocin agar provided 100% recovery of the Aeromonas isolates encountered. All of the Aeromonas isolates detected on blood agar were also detected on ABA, and 89% of the Aeromonas isolates detected on these media were beta-hemolytic. These results suggest that ABA is superior to the other media evaluated for the isolation of Aeromonas strains from stool specimens, but optimal recovery of the organism may require the use of more than one medium. The results also suggest that the occurrence of ampicillin-susceptible strains is not a limitation on the use of ABA, but at least 10% of Aeromonas isolates will be missed if beta-hemolysis is used to screen ABA plates for these organisms.

Aeromonas↗
PubMed1988

Temporal relationship of Vibrio parahaemolyticus in patients and the environment.

We prospectively compared the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. Inpatient and outpatient stool and wound specimens and water samples from 10 estuarine sites were cultured for V. parahaemolyticus over a period of 3 years. V. parahaemolyticus infections were detected in 13 patients (8 with gastroenteritis; 5 with wound infections), and all of the infections were found in outpatients in physicians' offices. Ten of the infections were locally acquired, and three occurred in patients returning from tropical travel. V. parahaemolyticus was isolated from 11 to 33% of the environmental samples, and each sampling site yielded the organism at some time during the study. V. parahaemolyticus was found in the environment only during the summer months, when water temperatures were greater than or equal to 17 degrees C and salinities were less than or equal to 13% (parts per thousand), and locally acquired infections were detected only when the organism was present in large numbers in the environment. We conclude that V. parahaemolyticus causes locally acquired gastroenteritis and wound infections, as well as traveler's diarrhea, in the Pacific Northwest, that patients with V. parahaemolyticus infections are likely to be seen in physicians' offices rather than hospitals, that locally acquired V. parahaemolyticus infections occur only when the organism is present in the environment, and that the organism is likely to be present during the summer months, when warm, low-salinity water conditions prevail in the coastal marine environment.

Gastroenteritis↗
PubMed1987

Clinical comparison of the Roche Septi-Chek and Dupont Isolator blood culture systems.

A study was conducted to compare the recovery of clinical isolates by the DuPont Isolator and Roche Septi-Chek blood culture systems. A total of 5,262 blood culture specimens were processed by the two systems. Of these, 358 cultures contained significant isolates: 219 were positive in both systems, 68 were recovered only by Isolator, 71 were recovered by Septi-Chek only (not statistically significant). Of the isolates recovered in both systems, 159 were positive the same day, 55 were recovered first by Isolator, and 5 were recovered first by Septi-Chek. In cases where Isolator recovered organisms first, the average difference in time was one to two days. Regarding particular groups of organisms, there was no difference between the systems in recovery of Enterobacteriaceae, anaerobes, yeast, and gram-positive bacteria, except for Streptococcus pneumoniae. Septi-Chek recovered S. pneumoniae significantly more often. These results suggest that these two systems are essentially comparable, except with S. pneumoniae, although the Isolator frequently provided results more rapidly.

Bacteria↗
PubMed1987

Outpatient evaluation of a rapid, direct test for detection of group A streptococci in throat swabs.

A latex agglutination test (Marion Laboratories) was compared with standard culture methods for the detection of Group A streptococci in two studies of 500 throat swabs each. Swabs were first inoculated to sheep blood agar and then tested for Group A streptococcal antigen. The direct test performed with nearly identical sensitivity and specificity in the two phases of the study. Overall, Group A streptococci were isolated from 91 specimens, and 81 (89%) of these were detected by the direct latex test. The predictive value positive for the latex test was 90%, and the accuracy was 98%. The sensitivity of the latex test for detection of specimens having ten or more colonies of Group A streptococci was 95%. Non-Group A beta-hemolytic streptococci were isolated from 65 specimens, and all of these specimens had negative latex tests. The authors' findings suggest that this direct latex agglutination test is a reliable screening method for rapid detection of Group A streptococci in outpatient throat specimens.

Ambulatory Care↗
PubMed1987

Commercial latex agglutination test for detection of Clostridium difficile-associated diarrhea.

A commercially available latex agglutination test for Clostridium difficile was compared with a cell culture cytotoxin assay and bacteriological culture for the laboratory diagnosis of C. difficile-associated diarrhea and colitis (CAD). Stool specimens from 626 patients were tested by the three methods, and specimens from 118 patients (19%) were positive by at least one of the methods. The results of the three tests agreed in 88% of the specimens tested, overall, but they agreed in only 34% of the 118 positive specimens. Ninety-three patients were evaluated to assess the significance of positive and negative results for each assay. Of 40 patients found to have CAD, 70% were positive by the cytotoxin assay, 78% were positive by the latex agglutination test, and 90% were culture positive. Of 53 patients who did not have CAD, 2% were positive by the cytotoxin assay, 8% were positive by the latex test, and 4% were culture positive. The detection of CAD was improved by using the tests in combination, and 97% of specimens positive by two or three methods were from patients who had CAD. Testing of multiple specimens from individual patients also increased the sensitivity of detection of CAD. The results suggest that the latex agglutination test may be useful for rapid diagnosis of CAD, especially in laboratories that lack cell culture facilities. However, the accuracy of CAD detection is improved when the latex test is used in combination with culture or the cytotoxin assay.

Adult↗
PubMed1986

Virulence of Vibrio vulnificus strains from marine environments.

Vibrio vulnificus strains isolated from geographically diverse marine sources were compared with clinical isolates for phenotype and in vitro and in vivo production of virulence factors. There were no differences between environmental and clinical strains on the basis of biochemical characteristics or antimicrobial susceptibility patterns. Cytolysin and cytotoxin titers produced by environmental strains were generally comparable to those of clinical strains. Of 29 environmental isolates tested, 25 were pathogenic for mice. These data show that environmental V. vulnificus strains are phenotypically indistinguishable from clinical isolates and that approximately 90% of the environmental strains tested produced in vitro virulence factors and in vivo pathogenicity for mice comparable to those produced by clinical V. vulnificus isolates.

Animals↗
PubMed1985

Uptake and clearance of Vibrio vulnificus from Gulf coast oysters (Crassostrea virginica).

Oysters collected in late winter, when they were free of Vibrio vulnificus, were exposed in the organism in the laboratory. The oysters effectively concentrated the bacteria from seawater, but when the inoculum was removed, the bacteria were rapidly cleared from the oyster tissues. These results suggest that V. vulnificus may be found in oysters as a result of filtration of the bacteria from seawater rather than active multiplication of the bacteria in the oysters.

Animals↗
PubMed1985

Comparison of the Cathra Repliscan II, the AutoMicrobic system Gram-Negative General Susceptibility-Plus Card, and the Micro-Media System Fox Panel for dilution susceptibility testing of gram-negative bacilli.

A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San Jose, Calif.) in determining MICs of 12 antibiotics for 200 gram-negative bacilli. Of the 200 strains tested, 12 isolates did not grow in one of the three systems. The 188 remaining organisms included 158 members of the family Enterobacteriaceae, 20 Pseudomonas spp., 5 Acinetobacter sp., 3 Aeromonas spp., and 2 Vibrio spp. A total of 2,256 organism-antibiotic combinations were analyzed for each system. An MIC was considered correct if two of the three systems were in agreement. When disagreements occurred, correct MICs were determined by the standard agar dilution method. With this criterion, overall agreements of the Cathra Repliscan II system, AutoMicrobic system, and Micro-Media Fox Panel system were 94.7, 94.9, and 95.5%, respectively. Tetracycline (20%), nitrofurantoin (20%), and ampicillin (16%) accounted for 56% of the discrepancies observed. These results indicate that all three systems perform with a high degree of accuracy for susceptibility testing of gram-negative bacilli.

Gram-Negative Bacteria↗
PubMed1985

Evaluation of a one-hour test for the identification of Neisseria species.

This study presents an evaluation of the RIM-N kit (Austin Biological Laboratories, Inc., Austin, Tex.), a commercial system for rapid identification of Neisseria spp. and Branhamella catarrhalis. The system was compared with the cystine-Trypticase (BBL Microbiology Systems, Cockeysville, Md.) agar method; 218 isolates were tested by each method. There was 96% agreement between the two methods, and only nine discrepancies were encountered. The results suggest that the RIM-N kit may provide a rapid and reliable method for identifying Neisseria spp. and B. catarrhalis.

Bacteriological Techniques↗