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G L Woods

Publications and source records attributed to G L Woods.

At least 19 recordsLinked to original sources
PubMed2001

Effect of homologous preovulatory follicular fluid on in vitro maturation of equine cumulus-oocyte complexes.

The objective of this study was to test the hypothesis that incubating equine cumulus-oocyte complexes (COCs) in medium containing 50% or 100% homologous preovulatory follicular fluid would improve cumulus expansion and nuclear maturation. Oocytes were incubated in one of three media: 1) supplemented TCM-199 (control), 2) 50% (v/v) follicular fluid in control medium or 3) 100% follicular fluid. Cumulus expansion was evaluated subjectively, and nuclear maturation was evaluated by staining oocytes with Hoechst 33258. The hypothesis that incubating COCs in medium containing follicular fluid would improve cumulus expansion was supported. More (P < 0.05) compact COCs incubated in 50% or 100% follicular fluid developed a moderately to completely expanded cumulus after 24 and 36 h of incubation and more (P < 0.05) expanded COCs incubated in 100% follicular fluid developed a moderately to completely expanded cumulus after 36 h of incubation compared to control medium. The hypothesis that incubating COCs in medium containing follicular fluid would improve nuclear maturation was not supported. Although more (P < 0.05) compact COCs incubated in 50% follicular fluid reached polar body-stage compared to those in control medium, the nuclear maturation rate in the control medium was lower than it was when the same medium was used in a preliminary experiment (described in main text); therefore, the apparent superiority of 50% follicular fluid must be interpreted cautiously. Based on these results, future studies are warranted to further address the value of adding preovulatory follicular fluid to equine IVM culture systems.

Animals↗
PubMed2001

Confocal microscopy of germinal vesicle-stage equine oocytes.

The objectives were to compare cumulus type with nucleus form in equine cumulus oocyte complexes (COCs), to define the percentage of germinal vesicle (GV)-stage oocytes within a population of mares, and to further define GV nucleus shapes of equine oocytes. Cumulus types were as follows: 1) compact (56/208, 26.9%), 2) slightly expanded (37/208, 17.8%), 3) moderately expanded (27/208, 13.0%), 4) greatly expanded (15/208, 7.2%), or 5) denuded (73/208, 35.1%). One hundred thirty of 208 COCs (62.5%) were GV-stage, 21/208 (10.1%) were condensed chromatin-stage, 8/208 (3.8%) were polar body-stage, 40/208 (19.2%) were negative (nonstaining), and 9/208 (4.3%) were fragmented. Cumulus types were associated with nucleus forms because higher proportions (P < 0.05) of GV-stage oocytes occurred in compact (42/56, 75.0%), slightly expanded (30/37, 81.1%), moderately expanded (16/27, 59.3%), or denuded (40/73, 54.8%) COCs than in greatly expanded (2/15, 13.3%) COCs. In contrast, lower proportions (P<0.05) of condensed chromatin-stage oocytes occurred in compact (3/56, 5.4%), slightly expanded (0/37, 0.0%), moderately expanded (3/27, 11.1%) or denuded (9/73, 12.3%) COCs than in greatly expanded (6/15, 40.0%) COCs, and lower proportions (P < 0.05) of polar body-stage oocytes occurred in compact (0/56, 0.0%) or denuded (2/73, 2.7%) COCs than in greatly expanded (3/15, 20.0%) COCs. Germinal vesicle-stage equine oocytes had 4 distinct shapes, with higher proportions (P<0.05) having large-regular (54/130, 41.5%) than scattered (10/130, 7.7%), small-round (29/130, 22.3%), or large-irregular (37/130, 28.5%) shapes. Lower proportions (P<0.05) of large-regular GVs occurred in compact (11/42, 26.2%) COCs than in slightly expanded (15/30, 50.0%), or moderately expanded (12/16, 75.0%) COCs. Therefore oocytes with the large-regular GV shape are probably more advanced in development.

Animals↗
PubMed2001

Increasing culture time from 48 to 96 or 144 hours increases the proportions of equine cumulus oocyte complexes with negative or fragmented nucleus morphology.

The objective was to test the hypothesis that increasing equine oocyte culture time from 48 to 96 or 144 h increases nucleus maturation of equine oocytes. The hypothesis was not supported because condensed chromatin-stage oocytes decreased (P<0.01) from 33/126 (26.2%) at 48 h or 34/95 (35.8%) at 96 h to 11/117 (9.4%) at 144 h, and polar body-stage oocytes decreased (P<0.01) from 65/126 (51.6%) at 48 h to 25/95 (26.3%) at 96 h and (P<0.01) to 1/117 (0.9%) at 144 h. Negative (non-staining) oocytes increased (P<0.01) from 16/126 (12.7%) at 48 h or 15/95 (15.8%) at 96 h to 39/117 (33.3%) at 144 h. Fragmented oocytes (with and without fluorescent areas) increased (P<0.01) from 4/126 (3.2%) at 48 h to 20/95 (21.1%) at 96 h and increased again to 60/117 (51.3%) at 144 h. When fragmented oocytes having 1 fluorescent area were defined as condensed chromatin-stage and fragmented oocytes having 2 fluorescent areas were defined as polar body-stage, condensed chromatin-stage oocytes increased (P < 0.05) from 34/126 (27.0%) at 48 h to 38/95 (40.0%) at 96 h, but decreased (P<0.05) to 19/117 (16.2%) at 144 h. Polar body-stage oocytes decreased (P<0.01) from 66/126 (52.4%) at 48 h to 27/95 (28.4%) at 96 h and decreased again to 7/117 (6.0%) at 144 h. Fragmented oocytes without any fluorescent areas increased (P<0.01) from 2/126 (1.6%) at 48 h to 14/95 (14.7%) at 96 h and increased again to 46/117 (39.3%) at 144 h. Under the conditions of this experiment, the hypothesis that increasing the culture time of equine oocytes from 48 to 96 or 144 h would increase oocyte maturation was not supported. We propose that the culture system needs to be improved before this hypothesis can be adequately tested, because prolonged culture significantly increased the proportions of negative and fragmented equine oocytes.

Animals↗
PubMed2001

Clinical Evaluation of the Gen-Probe amplified mycobacterium tuberculosis direct test for rapid detection of Mycobacterium tuberculosis in select nonrespiratory specimens.

The performance of the Amplified Mycobacterium Tuberculosis Direct Test (MTD; Gen-Probe, Inc., San Diego, Calif.) for rapid diagnosis of extrapulmonary tuberculosis was evaluated by testing 178 nonrespiratory specimens from 158 patients. Criteria for specimen inclusion were (i) a positive smear for acid-fast bacilli (n = 54) and (ii) the source if the smear was negative (tissue biopsies and aspirates and abscess material were tested; n = 124). Results were compared to those of mycobacterial culture; clinical history was reviewed when MTD and culture results disagreed. Forty-eight specimens (27.0%) were positive for mycobacteria, including 23 Mycobacterium tuberculosis complex specimens; of which 21 were smear positive. Twenty-five specimens were MTD positive; 20 of these grew M. tuberculosis complex. All of the five MTD-positive, M. tuberculosis complex culture-negative specimens were considered truly positive, based on review of the medical record. Of the three MTD-negative, M. tuberculosis complex culture-positive specimens, two contained inhibitory substances; one of the two was smear positive. Excluding the latter specimen from analysis, after chart review, the sensitivity, specificity, and positive and negative predictive values of the MTD were 92.6, 100, 100, and 98.7%, respectively, by specimen and 89.5, 100, 100, and 98.6% by patient. Given the few smear-negative samples from patients with extrapulmonary tuberculosis in our study, additional similar studies that include more smear-negative, M. tuberculosis complex culture-positive specimens to confirm our data are desirable.

Abscess↗
PubMed2001

Clinical and pathologic features of Mycobacterium fortuitum infections. An emerging pathogen in patients with AIDS.

The clinical and pathologic features of Mycobacterium fortuitum infection in 11 patients with AIDS were characterized. Nine patients had cervical lymphadenitis; 2 had disseminated infection. The infection occurred late in the course of AIDS, and the only laboratory abnormality seen in more than half of patients (7/11) was relative monocytosis. Absolute monocytosis also was seen in 4 of 11 patients. In both cytologic and histologic preparations, the inflammatory pattern was suppurative with necrosis or a mixed suppurative-granulomatous reaction. M fortuitum, a thin, branching bacillus, stained inconsistently in direct smear and histologic preparations. Staining was variable with Gram, auramine, Brown-Hopps, Gram-Weigert, Kinyoun, Ziehl-Neelsen, modified Kinyoun, and Fite stains. Organisms, when present, were always seen in areas of suppurative inflammation. Incorrect presumptive diagnosis, based on misinterpretation of clinical signs and symptoms or on erroneous identification of M fortuitum bacilli as Nocardia species, led to a delay in proper therapy for 7 of 11 patients. Definitive therapy after culture identification resulted in complete resolution of infection in all patients except 1.

AIDS-Related Opportunistic Infections↗
PubMed2001

Molecular techniques in mycobacterial detection.

OBJECTIVE: To assess the clinical utility of the commercial nucleic acid amplification (NAA) tests (ie, Amplified Mycobacterium Tuberculosis Direct Test, Gen-Probe, Inc and AMPLICOR Mycobacterium tuberculosis Test, Roche Molecular Systems, Inc) for direct detection of Mycobacterium tuberculosis complex. DATA SOURCES: Review of the English-language literature. CONCLUSIONS: The performance of both NAA tests is excellent (sensitivity, > or = 95%; specificity, 100%) when testing respiratory specimens that are smear-positive for acid-fast bacilli (AFB). Only the Gen-Probe assay is approved for testing respiratory specimens regardless of the AFB smear result. Data from 3 studies showed that the sensitivity of the Mycobacterium Tuberculosis Direct Test in smear-negative patients ranged from 83% to 85%, and that the specificity was 99%. Both NAA tests have been used to test nonrespiratory specimens; in some studies, the performance was comparable to the performance obtained for respiratory specimens, whereas in others, it was lower. The NAA tests also appear to be reliable tools for rapid detection of M tuberculosis complex in positive broth cultures of all specimen types (except blood). The impact of the NAA tests on patient outcome varies based on the result of the AFB smear. In smear-positive patients, public health and hospital infection-control resources are predominantly affected. The potential for influencing patient outcome is much greater when the AFB smear is negative. In smear-negative patients, the NAA test could provide more rapid diagnosis of tuberculosis and subsequent initiation of therapy; eliminate the need for invasive diagnostic procedures, which are both costly and pose an added risk to the patient; and allow earlier discharge of hospitalized patients. Prospective studies concerning the cost-effectiveness of the NAA tests are needed.

Bacteriological Techniques↗
PubMed2000

Susceptibility testing for mycobacteria.

Mycobacterial susceptibility testing is important for the management of patients with tuberculosis and those with disease caused by certain nontuberculous mycobacteria. To help standardize methods used in the clinical microbiology laboratory for testing susceptibility of mycobacteria, the National Committee for Clinical Laboratory Standards (NCCLS) recently updated NCCLS document M24-T (published in 1995), which is the tentative standard for antimycobacterial susceptibility testing of Mycobacterium tuberculosis. The second edition of the NCCLS tentative standard (document M24-T2) differs considerably from the initial document. It contains revised guidelines for the testing of M. tuberculosis complex and newly proposed guidelines for the testing of some nontuberculous mycobacteria, including the rapidly growing mycobacteria (Mycobacterium fortuitum group, Mycobacterium chelonae, and Mycobacterium abscessus), Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium marinum, as well as Nocardia species and other aerobic actinomycetes. The recommendations for mycobacterial susceptibility testing that are outlined in NCCLS document M24-T2 are reviewed.

Anti-Bacterial Agents↗
PubMed2000

Evaluation of the Bio-Rad syphilis IgG test performed on the CODA system for serologic diagnosis of syphilis.

The performance of the Bio-Rad Syphilis IgG EIA test as a "screen for syphilis" [testing first by EIA and then by the rapid plasma reagin (RPR) assay if the EIA was positive or equivocal] and as a confirmatory test was evaluated by comparing results to those obtained by CAPTIA Syphilis-G. Discrepancies were resolved by repeating both EIAs and/or the SeroDia TP-PA (a particle agglutination assay that replaced the microhemagglutination Treponema pallidum test). Both EIAs were totally automated, the Bio-Rad test using the AutoPrep instrument for pipetting and the CODA system to perform all of the steps required to complete the EIA and interpret results, and the CAPTIA test using the LabOTech(R) to accomplish both functions. Of 449 unselected sera submitted to "screen for syphilis," both EIAs agreed for 432 (96.2%) specimens: 395 negative, 36 positive, and one equivocal. Fifty-four specimens were positive or equivocal by one or both EIAs; 41 of these were RPR reactive. Three of these 41 were incorrectly called negative by Bio-Rad (sensitivity 92.7%), and there was 1 false-negative result by CAPTIA (sensitivity, 97.6%) (P, not significant). To further evaluate the Bio-Rad assay as a confirmatory test, 144 known RPR-reactive specimens were tested by both EIAs. Results agreed for 134 (93.1%): 123 positive, 11 negative. After resolving discrepancies, there were 3 false-negative and no false-positive results by Bio-Rad (sensitivity 97.8%, specificity 100%), and with CAPTIA there were no false-negative results and 1 false-positive (sensitivity 100%, specificity 91.7%) (P, not significant). The sensitivity of the Bio-Rad assay could be improved, without altering specificity, by lowering the cut-off value for equivocal results. In summary, the Bio-Rad Syphilis IgG EIA performed using the AutoPrep instrument and CODA system is a reliable, efficient method of syphilis testing.

Evaluation Studies as Topic↗
PubMed2000

Comparison of four methods for identifying Streptococcus pneumoniae.

Four methods (bile solubility, optochin, latex agglutination, and DNA probe) were compared for identification of clinical isolates of Streptococcus pneumoniae. Of 209 isolates tested, 151 (Group I) were selected based on typical colony morphology of S. pneumoniae, while 58 (Group II) were selected on the basis of alpha-hemolysis alone. Using the DNA probe as a reference method, 141 isolates from Group I and 10 from Group II were identified as S. pneumoniae. The optochin disk test and the latex agglutination test both exhibited a 100% sensitivity and specificity for Group I isolates; bile solubility identified all but 1 isolate in this group. For Group II isolates, the sensitivity and specificity of optochin testing was 100%, 80 and 94% for latex and 80 and 100% for bile. The results of this study indicate that all methods tested give reliable results for isolates with typical colony morphology of S. pneumoniae. Bile solubility and latex may not be as reliable when testing alpha-hemolytic colonies without colony morphology typical S. pneumoniae.

Bacterial Typing Techniques↗
PubMed2000

Evaluation of a latex agglutination assay for rapid detection of oxacillin resistant Staphylococcus aureus.

Oxacillin resistance in Staphylococcus aureus is mediated by the mecA gene, resulting in production of penicillin-binding protein 2a (PBP2a), which is not present in the oxacillin susceptible strains. We evaluated the ability of a 30-min latex agglutination (LA) test (Seiken, Tokyo, Japan) to detect production of PBP2a in 315 clinical isolates of S. aureus. The LA results were compared with results of susceptibility testing using the Vitek GPS-SV test card. The latex test was positive for all 206 isolates determined to be methicillin resistant by Vitek (sensitivity 100%), the latex test was negative for 108 of 109 isolates determined to be oxacillin susceptible by Vitek, and the latex test was positive for 1 isolate determined to be susceptible by Vitek (specificity 99.1%). The discrepant isolate was negative for the mecA gene by polymerase chain reaction (PCR). The LA test is a rapid and reliable method for detecting oxacillin resistant S. aureus.

Evaluation Studies as Topic↗
PubMed2000

Comparison of gen-probe AccuProbe group B streptococcus culture identification test with conventional culture for the detection of group B streptococci in broth cultures of vaginal-anorectal specimens from pregnant women.

The performance of the AccuProbe Group B Streptococcus Culture Identification Test (Gen-Probe Incorporated, San Diego, CA, USA) for the detection of group B streptococci (GBS) directly from LIM broth cultures of vaginal-anorectal swab specimens from pregnant women (two swabs per patient in most cases) was evaluated by comparing results to those of conventional GBS culture. Of 411 specimens analyzed, 82 were positive and 312 were negative for GBS by both methods. After initial testing, the percent agreement was 95.9%. The initial sensitivity, specificity, and positive and negative predictive values for the AccuProbe test were 90.1%, 97.5%, 91.1%, and 97.2%, respectively. Results were discrepant for 17 specimens: eight were GBS positive by probe and negative by culture; nine were negative by probe and positive by culture. To resolve discrepancies, culture plates were re-examined for GBS colonies, AccuProbe testing was repeated on the initial LIM broth cultures, and the second swab (if received) was inoculated to LIM broth for AccuProbe testing after overnight incubation. After discrepant resolution testing, the percent agreement between the two test methods was 97.8%. The final sensitivity, specificity, and positive and negative predictive values for the AccuProbe test were 95.6%, 98.4%, 94.6%, and 98.7%, respectively. These data suggest that the AccuProbe test is a reliable method for detecting GBS in vaginal-anorectal specimens, providing results more rapidly than conventional culture. However, strict adherence to the manufacturer's test protocol is necessary to limit technical errors.

Anal Canal↗
PubMed2000

Comparison of the BACTEC MGIT 960 and ESP culture system II for growth and detection of mycobacteria.

The performances of two continuously monitoring mycobacterial culture systems-ESP Culture System II (ESP II; Trek Diagnostics, Inc. , Westlake, Ohio) and BACTEC MGIT 960 (BD Biosciences, Sparks, Md. )-were compared. In addition to both liquid media, all specimens were plated onto Middlebrook 7H11/7H11 selective agar. A total of 3, 151 specimens of all types (56.3% were respiratory specimens) were cultured; 231 (7.3%) yielded mycobacteria. The most common species recovered were Mycobacterium avium complex (69 isolates) and Mycobacterium tuberculosis complex (MTBC; 65 isolates). The recovery rates for ESP II, BACTEC MGIT 960, and Middlebrook agar, respectively, were 71.2, 63.9, and 61.8% for all mycobacteria; 70.2, 72.6, and 66.3% for all mycobacteria except Mycobacterium gordonae; and 73.8, 84.6, and 87.7% for MTBC. For liquid plus solid medium combinations, recovery rates for all mycobacteria and for MTBC, respectively, were 84.1 and 92.3% for ESP II plus Middlebrook agar and 81.5 and 98.5% for BACTEC MGIT 960 plus Middlebrook agar. The differences in recovery of all mycobacteria by ESP II and by BACTEC MGIT 960 were not significant; for the individual species, the only significant difference was recovery of more isolates of M. gordonae by ESP II. For those isolates recovered in both automated systems, mean times to detection of all mycobacteria and MTBC, respectively, were 15.8 and 17.4 days for ESP II and 12.5 and 11.9 days for BACTEC MGIT 960 (P < 0.05). False-positive signals occurred with 23 (0.7%) BACTEC MGIT 960 cultures and 84 (2.7%) ESP II cultures (P < 0.01). Overall contamination rates were 17.1% for BACTEC MGIT 960, 18.9% for ESP II, and 11.0% for Middlebrook agar. In summary, the ESP II and BACTEC MGIT 960 systems performed comparably with regard to growth and detection of mycobacteria, and the contamination rates were similar. However, with ESP II, times to detection of all mycobacteria and of MTBC were significantly longer, the recovery rate of M. gordonae was significantly higher, and the number of false-positive signals was greater than with BACTEC MGIT 960.

Bacteriological Techniques↗
PubMed2000

Multisite reproducibility of Etest for susceptibility testing of Mycobacterium abscessus, Mycobacterium chelonae, and Mycobacterium fortuitum.

A multicenter study was conducted to assess the inter- and intralaboratory reproducibility of the Etest for susceptibility testing of the rapidly growing mycobacteria. The accuracy also was evaluated by comparing Etest results to those obtained by broth microdilution. Ten isolates (four of the Mycobacterium fortuitum group, three of Mycobacterium abscessus, and three of Mycobacterium chelonae) were tested against amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, and trimethoprim-sulfamethoxazole in each of four laboratories. At each site, isolates were tested three times on each of three separate days (nine testing events per isolate) using common lots of media and Etest strips. Interlaboratory agreement among MICs (i.e., mode +/- 1 twofold dilution) varied for the different drug-isolate combinations and overall was best for trimethoprim-sulfamethoxazole (75% for one isolate and 100% for all others), followed by doxycycline and ciprofloxacin. Interlaboratory agreement based on interpretive category also varied and overall was best for doxycycline (100% for all isolates), followed by trimethoprim-sulfamethoxazole and ciprofloxacin. Interlaboratory reproducibility among MICs was most variable for imipenem, and agreement by interpretive category was lowest for imipenem and amikacin. Modal Etest MICs agreed with those by broth microdilution only for doxycycline and the sulfonamides. For all other drugs, the modal MICs by the two methods differed by more than +/- 1 twofold dilution for one or more isolates. In all cases, the Etest MIC was higher and would have caused reports of false resistance. In summary, the Etest in this evaluation did not perform as well as broth microdilution for susceptibility testing of the rapidly growing mycobacteria. It was problematic for most species and drugs, primarily because of a trailing endpoint and/or high MICs compared to broth. Its use will necessitate further investigation, including determination of the optimal medium and incubation conditions and clarification of endpoint interpretation.

Anti-Bacterial Agents↗
PubMed2000

Clinical evaluation of the BDProbeTec ET system for rapid detection of Mycobacterium tuberculosis.

The performance of the BDProbeTec ET system (BD Biosciences, Sparks, Md.) for direct detection of Mycobacterium tuberculosis complex (MTBC) in respiratory specimens was evaluated by comparing results to those of conventional mycobacterial culture performed with the BACTEC 460 TB system and Middlebrook 7H11 biplates. Patients known to have been on antituberculous therapy were excluded from the analysis. Of 600 evaluable specimens (4 specimens were excluded from the analysis due to failure of the internal amplification control [IAC]) from 332 patients, 57 grew mycobacteria; 16 were MTBC (from 12 patients), and 41 were nontuberculous mycobacteria. Of the 16 MTBC culture-positive specimens, 12 were smear positive and 4 were smear negative. BDProbeTec ET detected 14 of the 16 MTBC culture-positive specimens, resulting in initial overall sensitivity, specificity, and positive and negative predictive values of 87.5, 99.0, 70.0, and 99.7%, respectively. After resolution of discrepancies by review of medical records and retesting of samples yielding discordant MTBC culture and BDProbeTec ET results, the revised overall sensitivity, specificity, and positive and negative predictive values of the BDProbeTec ET were respectively 93.8, 99.8, 93.8, and 99.8% by specimen and 91.7, 99.7, 91.7, and 99.7% by patient. The BDProbeTec ET System offers the distinct advantage of including an IAC in the specimen well. These data suggest that the test performance is very good, especially for smear-positive samples. However, the number of patients with tuberculosis in our study, especially those with smear-negative disease, was small; therefore, additional studies are needed.

Bacteriological Techniques↗
PubMed2000

Evaluation of the BBL MGIT (Mycobacterial growth indicator tube) AST SIRE system for antimycobacterial susceptibility testing of Mycobacterium tuberculosis to 4 primary antituberculous drugs.

OBJECTIVE: To evaluate the performance of the BBL MGIT (Mycobacterial Growth Indicator Tube) AST SIRE system for the antimycobacterial susceptibility testing of Mycobacterium tuberculosis to isoniazid (at a concentration equivalent to the lower concentration used for testing by the method of proportion), rifampin, ethambutol, and streptomycin. DESIGN: Thirty-one clinical isolates and 30 challenge strains provided by the Centers for Disease Control and Prevention (CDC) were tested by MGIT AST SIRE using 2 methods of inoculum preparation, and results were compared with those of the method of proportion, which was considered the reference method. Clinical isolates for which the results of the 2 methods were discordant also were tested at 2 reference laboratories. RESULTS: Based on data from our site and the reference laboratories, agreement rates between initial MGIT AST SIRE results and the method of proportion for the clinical isolates with the inoculum prepared from a McFarland equivalent and from a positive MGIT tube, respectively, were 100% and 96.8% for isoniazid, 100% and 100% for rifampin, 96.8% and 100% for ethambutol, and 100% and 100% for streptomycin, excluding the isolate for which the discordant streptomycin result could not be resolved. For the 30 challenge isolates, agreement rates between MGIT AST SIRE and expected results and between method of proportion and expected results, respectively, were 96.7% and 93.3% for isoniazid, 93.3% and 100% for rifampin, 83. 3% and 100% for ethambutol, and 93.3% and 100% for streptomycin. For the clinical isolates, the mean time to an MGIT AST SIRE result of susceptible was 6.15 +/- 0.13 days (range, 5-8 days). For a result of resistant, the mean time overall was 5.00 +/- 0.24 days (range, 3-8 days). CONCLUSION: These data suggest that the MGIT AST SIRE system, using either method of inoculum preparation, is an acceptable alternative to the BACTEC 460 TB method of susceptibility testing of clinical isolates of M tuberculosis to isoniazid, rifampin, ethambutol, and streptomycin. Reasons for the lower agreement with the CDC challenge isolates should be investigated. Further evaluation of the MGIT AST SIRE system using a concentration of isoniazid equivalent to the higher concentration tested by the method of proportion would be useful, because the decision concerning use of this agent generally is based on the susceptibility test result at the higher concentration.

Antitubercular Agents↗
PubMed2000

Generalized tuberculosis in the acquired immune deficiency syndrome.

OBJECTIVE: Generalized, or hematogenously disseminated, tuberculosis (TB) in patients with the acquired immune deficiency syndrome (AIDS) has been associated with a high incidence of cases remaining undiagnosed until postmortem. To better characterize generalized TB in the setting of AIDS, this report describes the clinical, laboratory, radiologic, and pathologic features of 20 fatal cases. DESIGN: The medical records, autopsy protocols, and histologic material from patients with AIDS and concomitant TB were reviewed. All patients were autopsied at a tertiary care medical center during the years 1985-1997. RESULTS: In 50% of our 20 cases, diagnosis was not made until postmortem. Signs and symptoms were few, including the absence of fever (temperature > or = 38 degrees C) in 55% of patients. Consistent laboratory abnormalities of a nonspecific nature were limited to hyponatremia (sodium <135 mmol/L) in 60%. Both peripheral and deep (thoracic and abdominal) lymphadenopathy, unusual in adults with TB, occurred in 45% and 95% of cases, respectively. In contrast to previous reports, all of the 6 cases of tuberculous meningitis presented as acute meningitis with a predominance of neutrophils in cerebrospinal fluid. Necrotizing encephalitis with extension of the acute inflammation into the superficial cortex was seen in all cases and tuberculous brain abscesses occurred in 50% of cases, a higher frequency than previously reported. Despite lung involvement in 90% of the cases, 33% of chest radiographs were interpreted as normal and disseminated mycobacterial disease was not suggested in the radiograph report in any of the other cases. Soft tissue abscesses in uncharacteristic locations such as the neck, mediastinum, and perirectal area occurred in these patients. Histologically, 95% of organs sampled showed inflammatory foci characterized by extensive necrosis with numerous neutrophils and/or karyorrhectic debris, numerous acid-fast bacilli, few or no epithelioid histiocytes, and no Langhans giant cells. CONCLUSION: Clinically and pathologically, generalized TB in the setting of AIDS is characterized by either unusual features or a lack of the typical features described for generalized TB in patients who do not have AIDS. This absence of classic features contributes to the high incidence of cases that remain undiagnosed until postmortem examination.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Enhanced mycobacterium tuberculosis direct test for detection of M. tuberculosis complex in positive ESP II broth cultures of nonrespiratory specimens.

The reliability of the Gen-Probe enhanced Mycobacterium Tuberculosis Direct Test (E-MTD) for identification of M. tuberculosis complex (MTBC) in ESP II broth cultures of nonrespiratory specimens was evaluated by testing aliquots from 262 signal-positive bottles. Cultures of blood were excluded from analysis because of the high rate (13/18 [72.2%]) of equivocal results for aliquots from cultures that were negative for MTBC. E-MTD results were compared to those obtained by usual laboratory protocol, whereby MTBC was identified by DNA probe (Gen-Probe, Inc.), testing colonies on a solid medium. For the first 112 cultures, from which 34 mycobacteria (including 8 MTBC) were recovered, both fresh and frozen aliquots were tested. E-MTD results on both fresh and frozen aliquots agreed with identification by usual protocol in all cases; so for the remaining 150 cultures, only frozen aliquots were tested. Of the total 262 ESP II cultures (158 patients) evaluated, 60 (22.9%) grew mycobacteria, including 17 MTBC. Of these 17 aliquots, 16 were E-MTD positive, as was one culture that was negative for mycobacteria. The latter culture was from a patient who had a specimen collected the following day from which MTBC was isolated; therefore, the E-MTD result was considered a true positive. Sensitivity, specificity, and positive and negative predictive values of E-MTD were 94.1, 100, 100, and 99.6%, respectively. The mean times (+/- SEM) from specimen receipt to identification of MTBC were 17 (+/- 2) days (range, 5-30 days) for ESP II plus E-MTD and 19 (+/- 1) days (range, 6-28 days) for the usual protocol (Student's t test, P, not significant). These data indicate that the performance of E-MTD for identification of MTBC in fresh or frozen aliquots of broth from positive ESP II cultures of nonrespiratory specimens, excluding blood, is excellent. However, because the E-MTD did not significantly reduce time to identification of MTBC in these cultures, limiting testing to those types of specimens most likely to yield MTBC is reasonable.

Culture Media↗