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M B Coyle

Publications and source records attributed to M B Coyle.

At least 37 records · Page 2Linked to original sources
PubMed1993

Effects of media, atmosphere, and incubation time on colonial morphology of Arcanobacterium haemolyticum.

Arcanobacterium haemolyticum causes pharyngitis as well as skin and other wound infections. Although it is a beta-hemolytic organism, the hemolysis is less well defined than that of beta-hemolytic streptococci and may be overlooked in cultures with heavy growth of commensal throat flora. To determine whether routine throat culture conditions are sufficient to produce recognizable colonies of A. haemolyticum, the morphology of six distinct strains was studied after various combinations of incubation time, medium, and atmosphere. The agar media, containing 5% sheep blood, were Trypticase soy agar, Columbia agar, and heart infusion agar. Cultures were incubated in ambient air, 6 to 8% CO2, or an anaerobic atmosphere. Cultures were compared after 24, 48, and 72 h of incubation for colony size, clarity and size of hemolytic zone, and macroscopic evidence of agar pitting. A minimum of 48 h was needed for expression of beta-hemolysis and pitting. Trypticase soy agar was the superior medium and CO2 was the superior atmosphere for beta-hemolysis. Agar pitting was not significantly affected by variations in medium or atmosphere. Strains differed in their expression of hemolysis and production of pits at 48 h. After 72 h of incubation, beta-hemolysis and pitting were visible in over 96% of culture observations.

Atmosphere↗
PubMed1993

Evidence of multiple taxa within commercially available reference strains of Corynebacterium xerosis.

Attempts to identify coryneform isolates resembling Corynebacterium xerosis can lead clinical microbiologists to identification schemes with conflicting descriptions which result in confusing C. xerosis with Corynebacterium striatum. For the present study we purchased all available American Type Culture Collection and National Collection of Type Cultures reference cultures of C. xerosis (n = 10) and C. striatum (n = 4) and analyzed them as follows: (i) analysis of biochemical reactions in conventional tests and in the Rapid CORYNE system, (ii) whole-cell fatty acid analysis by using the gas-liquid chromatography research software of Microbial ID, Inc., and (iii) analysis of DNA homology in dot blot hybridizations. Three C. xerosis strains were indistinguishable from the C. striatum strains in whole-cell fatty acid analyses and DNA hybridizations and shared very similar biochemical reactions. The remaining seven strains of C. xerosis clustered into five groups on the basis of fatty acid patterns, DNA hybridizations, and biochemical tests. No reference strain of C. striatum fit the species description in Bergey's Manual of Systematic Bacteriology. The type strains of both C. striatum and C. xerosis fit their respective descriptions by the Centers for Disease Control and Prevention. This study suggests that the 10 commercially available reference strains of C. xerosis represent six different taxa which should be assigned to new species.

Bacterial Typing Techniques↗
PubMed1992

Success of DNA fingerprinting after failure of biotyping, antimicrobial susceptibility testing, and plasmid analysis to reveal clonality of multiple blood and urine isolates from a patient with Escherichia coli urosepsis.

Multiple isolates of Escherichia coli from the blood and urine of a 60-year-old woman with acute pyelonephritis exhibited different biotypes, antimicrobial susceptibility patterns, and plasmid profiles, suggesting the presence of polymicrobial bacteriuria and leaving in question the origin of the bacteremia. Only after bacterial restriction endonuclease analysis of total bacterial DNA was it discovered that all isolates represented the same strain, with plasmid instability possibly accounting for the varied antimicrobial susceptibility patterns observed. We conclude that the biotype, antimicrobial susceptibility profile, and plasmid profile are sometimes inadequate to clarify the relationships between different clinical isolates of E. coli from a single patient and can lead to erroneous epidemiologic conclusions. DNA fingerprinting can resolve dilemmas these less precise techniques leave unresolved.

Anti-Bacterial Agents↗
PubMed1992

Characterization of antibiotic-resistant Corynebacterium striatum strains.

Antibiotic-resistant Corynebacterium strains were isolated from 14 Harborview and one Veterans Administration Hospital patients in Seattle during the period 1987-90. These clindamycin-erythromycin resistant strains were shown to hybridize with the ermCd gene, which was cloned from a Corynebacterium diphtheriae plasmid and encodes for a rRNA methylase. Thirteen of these strains also hybridized with the tetM gene probes, and were tetracycline resistant. The ermCd gene could be transferred, by conjugation, while the tetM gene was not transferable.

Blotting, Southern↗
PubMed1992

Laboratory aspects of "Mycobacterium genavense," a proposed species isolated from AIDS patients.

"Mycobacterium genavense" is a proposed new species recently reported to cause disseminated infections in 18 patients with AIDS in Europe. We have recovered "M. genavense" as slowly growing fastidious mycobacteria in blood cultures of seven patients with AIDS. In the original studies of "M. genavense," the fastidious organism grew only in BACTEC 13A vials. The Seattle, Washington, isolates of "M. genavense" also failed to grow when subcultured from 13A vials to routine solid media, but dysgonic colonies were produced on Middlebrook 7H11 agar supplemented with mycobactin J. The mycolic acid pattern of patients' isolates closely resembled that of the type strain of Mycobacterium simiae when analyzed by one- and two-dimensional thin-layer chromatography and by high-performance liquid chromatography. Whole-cell fatty acid analyses by gas-liquid chromatography distinguished the isolates from M. simiae but misidentified them as Mycobacterium fortuitum. Sequence determinations of the hypervariable regions of the 16S rRNA gene indicate that these organisms belong to the recently proposed new species "M. genavense." Growth from Middlebrook 7H11 agar supplemented with mycobactin J consistently yielded positive tests for catalase (semiquantitative and at 68 degrees C), pyrazinamidase, and urease which enable mycobacteriology laboratories to presumptively identify "M. genavense" without nucleic acid analyses. The failure of "M. genavense" to grow on conventional mycobacterial solid media suggests that mycobacterial blood cultures should include a broth medium incubated for at least 8 weeks.

AIDS-Related Opportunistic Infections↗
PubMed1992

Evaluation of the rapid CORYNE identification system for Corynebacterium species and other coryneforms.

The Rapid CORYNE system for identification of aerobic, nonsporeforming, gram-positive rods was evaluated according to the manufacturer's instructions with 177 organisms. After inoculation with a heavy suspension of growth, strips containing 20 cupules were incubated for 24 h, reagents were added, and the results of 21 biochemical reactions were recorded as numerical profiles. The strains consisted of pathogenic species of the genus Corynebacterium, primarily C. diphtheriae (n = 29), opportunistic species of Corynebacterium including C. jeikeium (n = 75), recognized species of non-corynebacteria such as Gardnerella and Arcanobacterium (n = 51), and Centers for Disease Control (CDC) coryneform groups (n = 22). Results from single tests read after 24 h yielded correct identifications to species level with no additional tests for 26 (89.7%) of the pathogenic species; 64 (85.3%) of the opportunistic organisms; 51 (100%) of the non-corynebacteria, and 8 (36.4%) of the CDC coryneform groups. Supplemental tests produced the correct identification for three additional pathogenic isolates (100% total) and four additional isolates from the opportunistic species (90.6% total). Twelve of the 15 isolates not identified by the system were in the CDC coryneform groups. Four of the six misidentified and one of the unidentified isolates were C. matruchotii, which was not included in the data base. The system is an excellent rapid alternative to conventional biochemical tests.

Actinomycetales↗
PubMed1990

Coryneform bacteria in infectious diseases: clinical and laboratory aspects.

Coryneform isolates from clinical specimens frequently cannot be identified by either reference laboratories or research laboratories. Many of these organisms are skin flora that belong to a large number of taxonomic groups, only 40% of which are in the genus Corynebacterium. This review provides an update on clinical presentations, microbiological features, and pathogenic mechanisms of infections with nondiphtheria Corynebacterium species and other pleomorphic gram-positive rods. The early literature is also reviewed for a few coryneforms, especially those whose roles as pathogens are controversial. Recognition of newly emerging opportunistic coryneforms is dependent on sound identification schemes which cannot be developed until cell wall analyses and nucleic acid studies have defined the taxonomic groups and all of the reference strains within each taxon have been shown by molecular methods to be authentic members. Only then can reliable batteries of biochemical tests be selected for distinguishing each taxon.

Actinomycetales↗
PubMed1989

The molecular epidemiology of three biotypes of Corynebacterium diphtheriae in the Seattle outbreak, 1972-1982.

Between 1972 and 1982 Seattle experienced a diphtheria outbreak involving 1,100 cases, primarily adults with cutaneous lesions. Biotyping revealed three consecutive overlapping outbreaks including 433 toxinogenic intermedius cases. Isolates from each quarter year were examined for DNA restriction fragment patterns and hybridization patterns with three DNA probes. All intermedius outbreak isolates appeared identical in all analyses and most stock cultures had the outbreak DNA fragment pattern, but DNA probes detected six patterns within 11 intermedius stock cultures. The mitis outbreak was heterogeneous, involving at least five restriction fragment patterns. In contrast, DNA restriction fragment analyses indicated that 22 of 25 gravis outbreak isolates belonged to a single strain, whereas there were seven strains within eight gravis stock cultures. DNA probe analyses of gravis outbreak isolates detected seven different patterns, five involving copy numbers of the toxB fragment and attB sites that presumably reflected lysogenic events that occurred during the outbreak.

Bacterial Typing Techniques↗
PubMed1988

Hand infections. Bacteriology and treatment: a prospective study.

In a prospective, double-blind study, 193 patients hospitalized for established hand infections were randomized to receive either cefamandole intravenously followed by cephalexin by mouth or methicillin intravenously followed by dicloxacillin by mouth. Careful aerobic and anaerobic cultures were performed. Multiple organisms grew in cultures from 84% of the patients (over three isolates per infection on average). Human bite wounds contained anaerobes 43% of the time compared with 12% for other wounds. The majority of wounds (72%) required operative treatment. In 128 patients assessable for treatment outcome, results were unsatisfactory in 11 (9%). There was no difference in outcome between cefamandole (6/59, 10%) and methicillin (5/59, 8%). The presence of anaerobes, Eikenella corrodens, human bites, or an increasing number of organisms was associated with an unsatisfactory response. The presence of Staphylococcus aureus and/or beta-hemolytic streptococci was associated with a favorable response. The incidence of antibiotic-resistant isolates did not correlate with outcome.

Adolescent↗
PubMed1987

Rectal swab cultures for Clostridium difficile surveillance studies.

We compared the recovery of Clostridium difficile from hospitalized patients by two collection methods: rectal swabs and stool cultures. Rectal swab cultures were as sensitive as stool cultures and were more easily obtained. Transport of swabs in an anaerobic VACUTAINER system resulted in longer survival times compared with transport in Amies medium.

Clostridium↗
PubMed1987

Whole chromosomal DNA probes for rapid identification of Mycobacterium tuberculosis and Mycobacterium avium complex.

Whole chromosomal DNA probes were used to identify clinical isolates of Mycobacterium tuberculosis, Mycobacterium avium complex, and Mycobacterium gordonae. The probe for M. tuberculosis was prepared from Mycobacterium bovis BCG, which has been shown to be closely related to M. tuberculosis. A probe for the M. avium complex was prepared from three strains representing each of the three DNA homology groups in the M. avium complex. The probes were used in dot blot assays to identify clinical isolates of mycobacteria. The dot blot test correctly identified 57 of the 61 (93%) cultures grown on solid media, and 100% of antibiotic-treated broth-grown cells were correctly identified. Identification by dot blot required a maximum of 48 h. When the probes were tested against 63 positive BACTEC (Johnston Laboratories, Inc., Towson, Md.) cultures of clinical specimens, 59% were correctly identified. However, of the 14 BACTEC cultures that had been treated with antibiotics before being lysed, 13 (93%) were correctly identified.

Chromosomes, Bacterial↗
PubMed1986

Corynebacterium pseudodiphtheriticum pneumonia in an immunologically intact host.

Corynebacterium pseudodiphtheriticum, a gram-positive bacillus commonly found in the human oropharynx, has been reported as a rare cause of infection in compromised hosts. We report herein a case of lower respiratory tract infection with Corynebacterium pseudodiphtheriticum in a previously healthy 29-yr-old trauma victim. The organism was the predominant bacterial isolate from two endotracheal aspirates and a specific humoral response was demonstrated by enzyme-linked immunosorbent assay.

Adult↗
PubMed1986

Comparison of quantitative and semiquantitative culture techniques for burn biopsy.

Accurate evaluation of bacterial colonization as a predictive index for wound sepsis has relied on a quantitative culture technique that provides exact colony counts per gram of tissue by culture of five serial dilutions of biopsy tissue homogenate. The method, while useful to the physician, is both labor intensive and expensive. In this study 78 eschar biopsies were cultured by a semiquantitative technique that involved the use of 0.1- and 0.01-ml samples of inocula and by the serial dilution method. Exact colony counts from the semiquantitative culture method were available only from cultures containing 10(4) to 10(6) CFU/g of tissue. Other colony counts were reported as less than 10(4) or greater than 10(6) CFU/g. Agreement by category of colony counts between the two methods was 96%. For prediction of wound sepsis, the semiquantitative procedure had a positive predictive value of 100% and a negative predictive value of 93.7%. This method also resulted in an approximately 30% reduction of work units (as defined by the College of American Pathologists) and a 60% reduction in the amount of media for specimen processing. Therefore, this semiquantitative culture technique provides accurate information to the physician while saving both time and materials.

Bacteria↗
PubMed1986

Contamination of a multiple-use suction catheter in a closed-circuit system compared to contamination of a disposable, single-use suction catheter.

UNLABELLED: Multiple-use (M-U) closed-system endotracheal suction catheters are effective in preventing arterial oxygen desaturation in patients on positive end-expiratory pressure (PEEP) and may lessen the frequency of bradycardia and hypotension in unstable patients who are prone to these complications of suctioning. However, because M-U catheters remain attached to the ventilator circuit and are reintroduced repeatedly into the patient's airway over 24 hours or longer, they could become heavily contaminated with pathogens. We hypothesized a risk of autocontamination to the patient by re-inoculation of the respiratory tract with organisms that flourished on the M-U catheter while it was isolated from the patient's immune defenses or antibiotic therapy. METHODS: We tested this hypothesis in 30 mechanically ventilated adult patients with positive sputum cultures. We measured and compared the amount of bacteria present on an M-U catheter at the end of a 24-hour use period, the amount of bacteria present in the patient's sputum at that time, and the amount of bacteria present on a single-use (S-U) catheter at that time, after it had made one pass into the patient's airway. Organisms recovered and colony counts were also compared to results of a sputum culture obtained before the study began. RESULTS: Fourteen different pathogens or potential pathogens were recovered, in numbers of 2 x 10(1) to 2 x 10(7)colony-forming units. The greatest number of colonies was most often recovered from the sputum specimen, and statistical analysis showed no differences in rate or magnitude of contamination between M-U and S-U catheters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Microbiologic evaluation of cutaneous cellulitis in adults.

Fifty patients with cellulitis were evaluated prospectively using cultures of aspirates from the advancing edge of cellulitis, skin biopsy specimens, and blood. Potential microbial pathogens were isolated in 13 patients. Biopsy specimen cultures were positive in ten patients, while aspirate and blood cultures were positive in five and two, respectively. Aspirate, biopsy, or blood cultures were more often positive in patients with apparent primary lesions than in patients without such lesions. Apparent primary sites of infection were identified and cultured in 24 patients. beta-Hemolytic streptococci were isolated from 17 primary lesions, and coagulase-positive staphylococci were present in 13. Both organisms were isolated from ten primary lesions. Among patients with positive aspirate, biopsy, and/or blood cultures, the same pathogens were also isolated from primary sites in ten of ten patients. Clinical features, including temperature, white blood cell count, and erythrocyte sedimentation rate, were not predictive of positive aspirate, biopsy, or blood cultures. These cultures provided no microbiologic information that was not obtainable from culture of primary lesions.

Adult↗
PubMed1985

Stratified outcome comparison of clindamycin-gentamicin vs chloramphenicol-gentamicin for treatment of intra-abdominal sepsis.

A randomized, prospective trial was conducted of 93 patients with operatively confirmed intra-abdominal sepsis. The study compared clindamycin-gentamicin and chloramphenicol-gentamicin for treatment of carefully stratified patient groups. Malnutrition, age over 65 years, shock, alcoholism, gastrointestinal tract bleeding, steroid administration, diabetes, obesity, and organ malfunction were present with equal frequencies in each group. The duration of antibiotic treatment averaged 8 1/2 days, and the average length of postoperative hospitalization was 29 days. Study antibiotics were changed for bacteriologic reasons in 11 patients taking clindamycin-gentamicin and 12 patients taking chloramphenicol-gentamicin (25% of the total), and two patients in the clindamycin-gentamicin group had a minor adverse reaction. Initial satisfactory clinical responses were obtained in 59 (63%) patients. Twenty-five patients (27%) subsequently developed unsatisfactory courses, but 48 (52%) patients remained well through the 30-day period. Septic-related mortality occurred in 18 (19%) patients, and two (2%) patients had unrelated deaths. There were no significant differences between the study regimens by the outcome criteria evaluated.

Abdomen↗
PubMed1985

Improved detection times for Mycobacterium avium complex and Mycobacterium tuberculosis with the BACTEC radiometric system.

A total of 2,559 routine clinical specimens were cultured for mycobacteria by using BACTEC Middlebrook 7H12 medium (BACTEC), Lowenstein-Jensen slants (LJ), and Mycobactosel selective Middlebrook 7H11 slants (M7H11). Thirty-three isolates (1.3%) of M. avium complex and 82 isolates (3.2%) of M. tuberculosis were recovered. The BACTEC mean detection time of M. avium complex from 27 smear-negative specimens was earlier than that of conventional media for both decontaminated respiratory specimens (BACTEC, 12 days; LJ, 32 days; and M7H11, 38 days) and untreated tissue and fluid specimens (BACTEC, 8 days; LJ, 30 days; and M7H11, 31 days). The sensitivity for smear-negative M. avium complex with BACTEC (74%) was comparable to that with LJ (74%) and M7H11 (63%). The mean detection times of M. tuberculosis from 56 smear-positive respiratory specimens were 8 days for BACTEC, 16 days for LJ, and 17 days for M7H11, and sensitivities for the detection of positive cultures were 98% for BACTEC, 76% for LJ, and 79% for M7H11. The BACTEC mean detection time of M. tuberculosis in smear-negative specimens was better for tissues and fluids (14 days) than for respiratory specimens (24 days). BACTEC yielded substantially earlier detection of M. avium complex from all specimen types and of M. tuberculosis from smear-positive respiratory specimens. The rapid identification and susceptibility testing of M. tuberculosis in BACTEC agreed completely with conventional tests and provided a 3-week reduction in median time to final reports.

Culture Media↗