Biomedical subjects

M T Pezzlo

Publications and source records attributed to M T Pezzlo.

11 recordsLinked to original sources

PubMed1995

Value of terminal subcultures for blood cultures monitored by BACTEC 9240.

Blood cultures collected in BACTEC Plus Aerobic/F bottles and BACTEC Plus Anaerobic/F bottles were monitored for 5 days by BACTEC 9240 and subsequent terminal subcultures. Of the 13,471 bottles subcultured, 11.0% (1,477 of 13,471) were culture positive. Of these, 94.0% (1,388 of 1,477) were detected by BACTEC 9240; the additional 6.0% (89 of 1,477) were considered to be false negatives by BACTEC 9240 since they were detected by terminal subculture only. The false-negative bottles consisted of 17 BACTEC Plus Aerobic/F and 72 BACTEC Plus Anaerobic/F bottles, accounting for 2.2 (17 of 786) and 10.4% (72 of 691) of the total positive aerobic and anaerobic bottles, respectively. The positive blood culture bottles most frequently not detected by BACTEC 9240 grew Pseudomonas spp. (24), Staphylococcus spp. (21), and yeasts (24). Of the 86 blood cultures represented by the 89 false-negative bottles, 41 would not have been identified as positive since the other bottle in the blood culture set was either a false negative or a true negative. In general, terminal subcultures of false-negative BACTEC bottles had heavy growth, indicating that BACTEC Plus media were able to support the growth of microorganisms, but the BACTEC 9240 instrument was unable to detect this growth.

Adult↗

PubMed1992

Detection of bacteriuria and pyuria by URISCREEN a rapid enzymatic screening test.

A multicenter study was performed to evaluate the ability of the URISCREEN (Analytab Products, Plainview, N.Y.), a 2-min catalase tube test, to detect bacteriuria and pyuria. This test was compared with the Chemstrip LN (BioDynamics, Division of Boehringer Mannheim Diagnostics, Indianapolis, Ind.), a 2-min enzyme dipstick test; a semiquantitative plate culture method was used as the reference test for bacteriuria, and the Gram stain or a quantitative chamber count method was used as the reference test for pyuria. Each test was evaluated for its ability to detect probable pathogens at greater than or equal to 10(2) CFU/ml and/or greater than or equal to 1 leukocyte per oil immersion field, as determined by the Gram stain method, or greater than 10 leukocytes per microliter, as determined by the quantitative count method. A total of 1,500 urine specimens were included in this evaluation. There were 298 specimens with greater than or equal 10(2) CFU/ml and 451 specimens with pyuria. Of the 298 specimens with probable pathogens isolated at various colony counts, 219 specimens had colony counts of greater than or equal to 10(5) CFU/ml, 51 specimens had between 10(4) and 10(5) CFU/ml, and 28 specimens had between 10(2) and less than 10(4) CFU/ml. Both the URISCREEN and the Chemstrip LN detected 93% (204 of 219) of the specimens with probable pathogens at greater than or equal to 10(5) CFU/ml. For the specimens with probable pathogens at greater than or equal to 10(2) CFU/ml, the sensitivities of the URISCREEN and the Chemstrip LN were 86% (256 of 298) and 81% (241 of 298), respectively. Of the 451 specimens with pyuria, the URISCREEN detected 88% (398 of 451) and Chemstrip LN detected 78% (350 if 451). There were 204 specimens with both greater than or equal to 10(2) CFU/ml and pyuria; the sensitivities of both methods were 95% (193 of 204) for these specimens. Overall, there were 545 specimens with probable pathogens at greater than or equal to 10(2) CFU/ml and/or pyuria. The URISCREEN detected 85% (461 of 545), and the Chemstrip LN detected 73% (398 of 545). A majority (76%) of the false-negative results obtained with either method were for specimens without leukocytes in the urine. There were 955 specimens with no probable pathogens or leukocytes. Of these, 28% (270 of 955) were found positive by the URISCREEN and 13% (122 of 955) were found positive by the Chemstrip LN. A majority of the false-positive results were probably due, in part, to the detection of enzymes present in both bacterial and somatic cells by each of the test systems. Overall, the URISCREEN is rapid, manual, easy-to-perform enzymatic test that yields findings similar to those yielded by the Chemstrip LN for specimens with both greater than or equal to 10(2) CFU/ml and pyuria or for specimens with greater than or equal to 10(5) CFU/ml and with or without pyuria. However, when the data were analyzed for either probable pathogens at less 10(5) CFU/ml or pyuria, the sensitivity of the URISCREEN was higher (P less than 0.05).

Bacteriological Techniques↗

PubMed1989

Rapid bioluminescence method for bacteriuria screening.

A study was performed to evaluate the UTIscreen (Los Alamos Diagnostics, Los Alamos, N. Mex.), a rapid bioluminescence bacteriuria screen. The UTIscreen was compared with three other rapid bacteriuria screens: the Bac-T-Screen (Vitek Systems, Hazelwood, Mo.), an automated filtration device; the Chemstrip LN (Boehringer Mannheim Diagnostics, BioDynamics, Indianapolis, Ind.), an enzyme dipstick; and the Gram stain. A semiquantitative plate culture was used as the reference method. Of the 1,000 specimens tested, 276 had colony counts of greater than 10(5) CFU/ml by the culture method. Of these, the UTIscreen detected 96% (265 of 276) using greater than or equal to 5% of the integrated light output of the standard reading as a positive interpretive breakpoint, the Bac-T-Screen detected 96% (266 of 276), the Chemstrip LN detected 90% (249 of 276), and the Gram stain detected 96% (264 of 276). Of the 214 probable pathogens isolated at greater than 10(5) CFU/ml, the UTIscreen detected 95% (204 of 214), the Bac-T-Screen detected 98% (210 of 214), the Chemstrip LN detected 92% (198 of 214), and the Gram stain detected 98% (209 of 214). The predictive values of negative test results at greater than 10(5) CFU/ml for the UTIscreen, the Bac-T-Screen, the Chemstrip LN, and the Gram stain were 98, 97, 93, and 98%, respectively. The overall specificities at greater than 10(5) CFU/ml for the UTIscreen, the Bac-T-Screen, the Chemstrip LN, and the Gram stain were 70, 48, 51, and 69%, respectively. There were 532 specimens with colony counts of >10(3) CFU/ml, and of these, the UTIscreen, the Bac-T-Screen, the Chemstrip LN, and the Gram stain detected 72, 81, 76, and 73%, respectively. Of the 249 probable pathogens isolated at >10(3) CFU/ml, the UTIscreen, the Bac-T-Screen, the Chemstrip LN, and the Gram stain detected 91, 95, 89, and 93%, respectively. The overall specificities at > 10(3) CFU/ml for these methods were 79, 55, 57, and 78%, respectively. The cost per test for detection was approximately $0.50 for the Chemstrip LN. Overall, the UTIscreen is rapid and easy to perform; its sensitivity compared favorably with those of the other screening methods; it had higher specificity than the Bac-T-Screen and Chemstrip LN; and it allowed for bathing of specimen.

Bacteria↗

PubMed1987

Rapid identification of pathogenic Neisseria species and Branhamella catarrhalis.

Two systems, the Identicult-Neisseria (IDN; Scott Laboratories, Inc., Fiskeville, R.I.) strip and the Neisseria/Haemophilus Identification Test Kit (NHI; Vitek Systems, Inc., Hazelwood, Mo.) card, were compared with the 4-h Minitek system (BBL Microbiology Systems, Cockeysville, Md.) for their ability to rapidly identify 157 pathogenic Neisseria and Branhamella catarrhalis isolates. IDN, limited in its identification to four species, when incubated at 35 degrees C for 10 min identified 99% of the isolates. However, when IDN was incubated at 22 degrees C for 20 min, it identified only 92% of the isolates. The NHI card, a rapid semiautomated system with the ability to identify 25 organisms to the species level, correctly identified all of the isolates. A test for beta-lactamase production included in the NHI card identified the 12 Neisseria gonorrhoeae and 10 B. catarrhalis beta-lactamase-positive isolates included in the study. The IDN strip (35 degrees C) and the NHI card compared favorably with the Minitek system.

Moraxella catarrhalis↗

PubMed1986

Evaluation of four anti-microbic susceptibility testing systems for gram-negative bacilli.

A total of 200 clinical isolates were assayed by five anti-microbic susceptibility testing systems. Two frozen minimal inhibitory concentration (MIC) systems (MicroScan and Pasco), an automated MIC system (AMS, Vitek Systems), and the standard disk diffusion were compared with a reference broth dilution method. Organisms tested included 100 resistant clinical stock strains and 100 fresh random clinical isolates. Overall, there were 1,600 anti-microbic-organism combinations analyzed. The Pasco and MicroScan systems had no major discrepancies, the AMS system had seven, and the disk diffusion two. The number of very major discrepancies were as follows: AMS, 11; disk diffusion, 9; MicroScan, 5; Pasco, 2. Of the total 36 major or very major discrepancies in the study, 33% (12 of 36) were with an aminoglycoside and 44% (16 of 36) occurred with a second-generation cephalosporin, of which 10 of 16 were with cefamandole. Overall, there was a greater than 98.8% essential agreement with all systems compared with the reference method.

Drug Resistance, Microbial↗

PubMed1985

Detection of bacteriuria and pyuria within two minutes.

A study was performed to evaluate two rapid urine screening methods, Bac-T-Screen (Marion Laboratories, Inc., Kansas City, Mo.) and Chemstrip LN (Boehringer Mannheim Diagnostics, BioDynamics, Indianapolis, Ind.), for their ability to screen for bacteriuria and pyuria within 2 min. A total of 1,000 urine specimens were tested with the Bac-T-Screen and the Chemstrip LN and compared with a semiquantitative plate culture method. Of the 1,000 specimens tested, 249 had colony counts of greater than or equal to 10(5) CFU/ml by the culture method. Of these, the Bac-T-Screen detected 94.8% (236 of 249) and the Chemstrip LN detected 84.7% (210 of 249). There were 120 pure cultures of probable pathogens of which the Bac-T-Screen detected 97.5% (117 of 120) and the Chemstrip LN detected 91.7% (110 of 120). Leukocyte counts were performed on all specimens, and both methods have the ability to detect greater than 10 leukocytes per mm3 in a majority (greater than 93%) of the specimens. The cost per test for a negative screen is approximately $1.30 for the Bac-T-Screen and $0.40 for the Chemstrip LN. Overall there is a similar negative predictive value with both methods for bacteriuria and pyuria.

Bacteriological Techniques↗

PubMed1984

Effect of the B-D Urine Culture Kit on an automated bacteriuria screen.

The effect of urine collected in the B-D Urine Culture Kit (BDT; Becton, Dickinson & Co., Rutherford, N.J.) on the Autobac urine screen (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.) was investigated. Upon collection, 1,000 clean-voided urine specimens were divided into sterile urine tubes and BDTs. Within 24 h of collection, urine from each tube was cultured by a semiquantitative plate method and screened by the Autobac system. Overall, when screened by the Autobac system, urine collected in the BDT gave fewer false-positive results: 14.4 compared with 22.7% from the sterile urine tubes. However, in comparison with the sterile urine tubes, the BDT false-negative rate was 10.5 versus 4.7%, the detection time was longer, and the cost was increased.

Bacteria↗

PubMed1983

Automated methods for detection of bacteriuria.

Urine specimens represent a large portion of cultures received by the clinical microbiology laboratory. Much time and effort are spent screening these specimens and approximately 80 percent show no growth. The methods employed for detection of bacteriuria include microscopic, chemical, culture, and automated. The most widely used procedure has been an agar plate culture method. However, this method requires overnight incubation and therefore results are delayed. Within the last decade many automated methods have been introduced for detecting bacteriuria, and results are available more rapidly than with the agar plate culture method. In addition to decreased detection time, these systems are accurate and cost-effective. The purpose of this report is to review these automated bacteriuria screening systems, which include bioluminescence, colorimetry, electrochemical screening, electrical impedance, microcalorimetry, photometry, and radiometry. Accuracy, detection time, and cost are also discussed in this review.

Adenosine Triphosphate↗

PubMed1983

Evaluation of a two-minute test for urine screening.

A study was conducted to evaluate the ability of a urine filtration system (Bac-T-Screen, Marion Laboratories, Inc., Kansas City, Mo.) to detect negative urine cultures within 2 min. A total of 1,000 urine specimens were tested with the Bac-T-Screen and compared with a standard semiquantitative culture plate method and the Autobac system (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.). Of the 1,000 clean voided urine specimens tested, 246 specimens had colony counts greater than or equal to 10(5) CFU/ml by the culture plate method. Of these, the Bac-T-Screen detected 65.4% (161 of 246), and the Autobac detected 63.0% (155 of 246). When pure cultures of diphtheroids, lactobacilli, and viridans streptococci other than group D and cultures containing multiple organisms were considered to be contaminants and, therefore, were excluded, there were 106 pure cultures of probable pathogens of which the Bac-T-Screen detected 76.4% (81 of 106) and the Autobac detected 90.6% (96 of 106). Some 133 specimens were uninterpretable with the Bac-T-Screen because 36 clogged the filter and 97 left a residual pigment on the filter. A majority of those clogging the filter (69.4%) had positive plate counts, whereas the majority of the pigmented urines had negative plate counts. Of those urine specimens tested. 754 were negative by the culture plate method. The false-positive rates for Bac-T-Screen and Autobac were 16.2 and 5.8%, respectively. As a urine screen, the Bac-T-Screen has a negative predictive value comparable to the Autobac system and has the advantage of being a 2-min test.

Bacteriological Techniques↗

PubMed1982

Screening of urine cultures by three automated systems.

A study was conducted to compare three automated systems and the Gram stain for their ability to detect significant bacteriuria. A total of 1,000 urine specimens were evaluated by Autobac MTS (General Diagnostics), Auto Microbic system (AMS; Vitek Systems, Inc.), and MS-2 (Abbott Laboratories) and compared with a semiquantitative culture plate method. Two hundred thirty-nine (23.9%) specimens had colony counts of >10(5) colony-forming units (CFU)/ml by the culture plate method (group I). Of these, 204 (85.3%) were positive by Autobac, 198 (82.8%) were positive by AMS, and 179 (74.9%) were positive by MS-2. When pure cultures of diphtheroids, lactobacilli, and viridans streptococci not group D were considered contaminants and therefore excluded, there were 118 specimens containing pure cultures of probable pathogens. The percentage of significant isolates detected was 97.4% (115 of 118) by the Gram stain, 96.6% (114 of 118) by Autobac, and 95.8% (113 of 118) by AMS and MS-2. The average detection time for all organisms was 2.2 h by Autobac, 6.1 h by AMS, and 1.8 h by MS-2; therefore, all three methods were more rapid than the 18- to 24-h standard plate culture method. One hundred sixty-one (16.1%) specimens had colony counts of 10(4) to 10(5) CFU/ml (group II). The probable pathogens not detected in this group were two (1.2%) by Autobac and MS-2 and three by AMS (1.9%). The average detection time for group II was 4.2 h by Autobac, 8.9 h by AMS, and 3.8 h by MS-2. Six hundred specimens had colony counts of <10(4) CFU/ml. Of these, 188 had colony counts equal to 10(3) and <10(4) CFU/ml (group III), and 412 cultures were below detectable limits by the standard plate method (group IV). Less than 37 and 15% of groups III and IV, respectively, were detected by instrumentation. Average detection times for groups III and IV were 4.6 and 4.8 h by Autobac, 10 and 11 h by AMS, and 4.2 and 4.4 h by MS-2. The cost of supplies and technical time with Gram stain, Autobac, and MS-2, when used as screening methods, were comparable and considerably less expensive than for the reference method. The AMS was the least expensive system when the cost for identifying probable pathogens was included.

Bacteria↗

PubMed1979

Improved laboratory efficiency and diagnostic accuracy with new double-lumen-protected swab for for endometrial specimens.

Intrauterine specimens were obtained from 22 patients with endometritis and 24 control patients following cesarean section by using both a new protected swab and a standard anaerobic swab. The protected swab improved the value of the direct smear and Gram stain, resulted in fewer false-positive cultures, better defined endometrial flora in patients with endometritis, and permitted major savings in laboratory personnel time and materials.

Bacteria↗