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C J Shanholtzer

Publications and source records attributed to C J Shanholtzer.

At least 19 recordsLinked to original sources
PubMed1998

Ambiguity in the identification of Streptococcus pneumoniae. Optochin, bile solubility, quellung, and the AccuProbe DNA probe tests.

We prospectively evaluated 639 sequential clinical isolates of alpha-hemolytic gram-positive cocci as possible Streptococcus pneumoniae. On the basis of results of tests for optochin susceptibility, tube bile solubility, and the quellung reaction, 74 strains (11.6%) were categorized as unequivocal pneumococci (optochin positive, tube bile solubility positive, quellung reaction positive). Among 450 optochin- and tube bile solubility-negative organisms, a subset of 56 strains was tested for quellung reaction (all negative); these isolates were categorized as unequivocal nonpneumococci. A final 115 organisms with an inconsistent or discordant combination of susceptibility to optochin, tube bile solubility, and quellung reaction were categorized as equivocal strains. With the unequivocal isolates, a commercial molecular probe for S pneumoniae (AccuProbe; Gen-Probe, San Diego, Calif) showed 100% sensitivity (74/74) and 100% specificity (56/56). Among the 115 equivocal strains, however, 33 (28.7%) reacted with the AccuProbe, whereas only 3 (2.6%) showed a capsule that reacted in the quellung test. A subset of the equivocal strains identified in this group of primarily respiratory isolates may have been S pneumoniae that only partially expressed their classic phenotype of optochin susceptibility and bile solubility and only rarely expressed capsular antigens. A practical, cost-sparing algorithm is proposed to facilitate the routine clinical identification of S pneumoniae.

Bacteriological Techniques↗
PubMed1995

Laboratory detection of Clostridium difficile. A comparison of media and incubation systems.

Parallel testing for culture recovery of Clostridium difficile was performed using three selective media in each of four anaerobic incubation environmental systems. Testing was completed on 67 stool samples from 60 hospitalized patients in whom C difficile-associated diarrhea was suspected. Three different media were evaluated: CCFA (modified cycloserine-cefoxitin-fructose agar), CCFA-PRAS (CCFA, prereduced-anaerobically-sterilized) and CMBA (modified cycloserine-mannitol-blood agar). The incubation systems compared were an anaerobic chamber (Model 800 Anaerobic Environmental System, Anaerobe Systems, San Jose, CA), the anaerobic jar (BBL, Cockeysville, MD), the anaerobic Bio-Bag (BBL), and the anaerobic pouch (BBL). C difficile was found in 16 samples collected from 15 patients. Comparing recovery on the various types of media in all four anaerobic atmospheres, C difficile was recovered on all (64) CCFA plates, 56 of 64 CCFA-PRAS plates, and 43 of 64 CMBA plates (P < .03 comparing CCFA and CMBA). Of the 48 plates in each incubation system that were inoculated with specimens positive for C difficile, the organism was recovered from 43 plates in the anaerobe chamber, 41 incubated in an anaerobe jar, 40 in the Bio-Bag, and 39 incubated in the GasPak pouch, all providing similar recovery of C difficile (P = .08). The CCFA-PRAS and CMBA media demonstrated less inhibition of normal stool flora compared to the CCFA. Overall CCFA that was anaerobically reduced at least 4 hours before use, and contained the original concentration of antimicrobial agents described by George and colleagues, was superior to CMBA for recovery of C. difficile.

Clinical Laboratory Techniques↗
PubMed1995

User interface reengineering. Innovative applications of bar coding in a clinical microbiology laboratory.

Some clinical laboratory departments (such as microbiology) provide extensive reporting of text and other data not generated by instruments that can be interfaced to a laboratory information system. These data are usually entered into the laboratory information system manually by keyboard data entry, which can be cumbersome and time consuming. Bar codes, which are already used in laboratories to facilitate rapid entry of sample-identifying information, have the potential to be used much more broadly as a generalizable data entry technique. We developed a comprehensive system that takes advantage of several applications of bar coding to facilitate the work of our Clinical Microbiology Laboratory. Central to our system is the use of bar code "scripts" to meet many of our complex data entry requirements. Use of these scripts is transparent to the laboratory information system (ie, no special "drivers" are needed) because data are received as if they had been generated by typing the characters on the keyboard. The scripts consist of bar codes that encode the series of keystrokes needed to give the appropriate response at the series of prompts offered by the laboratory information system. Both alphanumeric and other keys, including carriage returns and special characters, can be converted into bar codes and incorporated into scripts. By creating and printing these scripts in the laboratory using standard wordprocessing software and bar code fonts for personal computers, laboratorians without specialized computer training have the tools to substantially improve the data entry efficiency of existing data entry terminals for a variety of laboratory information systems.

Clinical Laboratory Information Systems↗
PubMed1994

Bactericidal action of gentamicin against enterococci that are sensitive, or exhibit low- or high-level resistance to gentamicin.

Treatment of serious enterococcal infection involves the use of penicillin-aminoglycoside combination therapy if the aminoglycoside minimum inhibitory concentration (MIC) is < or = 2000 micrograms/ml, and the organism is susceptible to penicillin or ampicillin. We evaluated killing of 15 enterococci that differ in their susceptibility to gentamicin using time-kill studies at different gentamicin concentrations. Sensitive strains had a uniform population killed by gentamicin concentrations equal to or above the MIC. Low-level resistant strains (MIC > or = 8 but < or = 2000 micrograms/ml of gentamicin) had a diverse population with large numbers of cells killed at one-half the MIC, while the highly resistant strains (MIC > 2000 micrograms/ml) showed no killing by any concentration of gentamicin.

Drug Resistance, Microbial↗
PubMed1994

Ten years of prospective Clostridium difficile-associated disease surveillance and treatment at the Minneapolis VA Medical Center, 1982-1991.

OBJECTIVES: To understand the epidemiology, risks, and management of Clostridium difficile-associated disease (CDAD) and to establish and evaluate reliable methods of surveillance. DESIGN: Case finding was done by daily ward and laboratory rounds. The criteria for CDAD diagnosis were: at least four unformed stools per day for 2 days and a positive culture or cytotoxin for C difficile, or positive endoscopy or autopsy for pseudomembranes. SETTING: The surveillance covered all patients from 1982 through 1991 in the 820-bed Minneapolis Veterans Affairs Medical Center. PARTICIPANTS: The criteria were met by 908 patients. Medical service patients numbered 488; surgical patients, 420. Frequencies ranged from a high of 149 cases in 1982 to a low of 50 cases in 1989. RESULTS: Stool specimens were obtained on 898 (99%) of the 908 CDAD patients. Stools were culture-positive in 864 (96%) of 898, cytotoxin-positive in 569 (63%) of 898. Endoscopy was performed on 196 (22%) of the 908 patients, and 80 (41%) of 196 patients had pseudomembranes. Ten (1%) of the 908 patients were diagnosed by endoscopy without a stool specimen, or at autopsy. No treatment was needed for 135 (15%) of the 908 CDAD patients, and 19 (2%) of the 908 died before treatment was started. Oral metronidazole was the treatment for 632 (70%) of 908 patients (1% intolerance, 2% failure, 7% relapse) and oral vancomycin was given to 122 (13%) of 908 patients (1% intolerance, 1% failure, 10% relapse). Twelve patients had pseudomembranous colitis at autopsy, and it was the primary cause of death in 5 (0.6%) of 908. CONCLUSIONS: CDAD usually responds to oral metronidazole or vancomycin but is nonetheless responsible for a high morbidity and occasional mortality in patients even when the diagnosis and treatment are pursued aggressively.

Administration, Oral↗
PubMed1993

Utility of slide centrifuge gram's stain versus quantitative culture for diagnosis of urinary tract infection.

The slide centrifuge (cytospin) Gram's-stain technique has been shown in previous studies to be a sensitive technique for detecting bacteriuria when compared to culture. The method concentrates urine sediment in a small defined area on a glass slide for Gram's staining. A positive test provides morphologic information about suspected pathogens. This study evaluated the cytospin technique using 788 urine specimens, on which routine culture was simultaneously performed, and compared both with clinical evidence for urinary tract infection. One hundred twelve of these specimens, which were cytospin positive and had a culture growing more than 100,000 CFU/mL, were assumed, by definition, to represent true urinary tract infection. Five hundred twenty-six specimens had negative cytospin and negative culture results (less than 1,000 CFU/mL) and were assumed, by definition, to rule out the diagnosis of urinary tract infection. Clinical data were evaluated for 56 cytospin-positive specimens in which culture results were less than 100,000 CFU/mL. Of these specimens, 37 were false positive (no clinical evidence of urinary tract infection), 9 had clinical evidence of urinary tract infection, and for the remaining 10, data regarding clinical status could not be interpreted. Seventy-one specimens were cytospin negative, with cultures growing more than 1,000 CFU/mL. Of these, only one patient had clinical evidence of a urinary tract infection, and his culture result was less than 10,000 CFU/mL. The predictive value of a negative cytospin test was 99.8% compared to clinical information, whereas the predictive value of a negative culture (less than 100,000 CFU/mL) was 98.4%.

Cells, Cultured↗
PubMed1992

Tests for bactericidal effects of antimicrobial agents: technical performance and clinical relevance.

Bactericidal testing has been used for several decades as a guide for antimicrobial therapy of serious infections. Such testing is most frequently performed when bactericidal antimicrobial agent therapy is considered necessary (such as when treating infectious endocarditis or infection in an immunocompromised host). It has also been used to ensure that the infecting organism is killed by (not tolerant to) usually bactericidal compounds. However, few data are available to support the role of such tests in direct patient care. Several important variables affect the reproducibility of the test results; however, proposed reference methods are now available for performing the MBC test. With minor modifications, these can provide a standardized approach for laboratories that need to perform them. Currently, little evidence is available to support the routine use of such testing for the care of individual patients. However, testing of new (investigational) antimicrobial agents can be beneficial in determining their potential to provide bactericidal antimicrobial activity during clinical use. New methods to assess bactericidal activity are being developed, but as yet none have been rigorously tested in patient care settings; further, for most of these methods, little information is available as to which technical parameters affect their results. In clinical laboratories, all bactericidal tests must be performed with rigorously standardized techniques and adequate controls, bearing in mind the limitations of the currently available test procedures.

Animals↗
PubMed1992

Comparison of the VIDAS Clostridium difficile toxin A immunoassay with C. difficile culture and cytotoxin and latex tests.

The VIDAS Clostridium difficile toxin A immunoassay (CDA) is a new, automated, enzyme-linked fluorescent-antibody assay for detection of C. difficile toxin A antigen in stool specimens. Simultaneous, parallel testing was performed by using the VIDAS CDA, the Culturette brand CDT latex test for C. difficile antigens, and conventional laboratory cell culture tests for C. difficile, cytotoxicity and C. difficile culture. One hundred ninety-four consecutive fresh soft or liquid stool samples submitted for C. difficile testing between July and September 1990 were evaluated. Of the 194 samples tested, 19 (10%) were from 16 patients who met our case definition for C. difficile-associated disease. The in vitro tests were evaluated in relation to two forms of a clinical case definition. In one form, a positive culture for toxin-producing C. difficile or a positive cytotoxin result obtained directly from the stool specimen was required as laboratory evidence of C. difficile. In the other, a positive result of any of the four laboratory tests was accepted for the laboratory portion of the case definition. No significant difference between the sensitivity of the VIDAS CDA and that of the Culturette brand CDT latex test was found (48 to 58% sensitivity for the CDT latex test and 52 to 63% sensitivity for the VIDAS CDA compared with 93 to 100% sensitivity for culture and 70 to 100% sensitivity for cytotoxin testing). The performance of the VIDAS CDA, however, was hampered by a high percentage of tests (19%) which gave an uninterpretable result.

Bacterial Toxins↗
PubMed1991

An evaluation of three commercial fecal transport systems for the recovery of enteric pathogens.

Twenty-five isolates, including six strains of Shigella species, six strains of Salmonella species, five strains of Yersinia enterocolitica, six strains of Campylobacter jejuni, and two strains of Vibrio parahaemolyticus, were inoculated at a concentration of 1.5 x 10(4) colony-forming units/mL into the following transport systems: Fekal Enteric Plus (Trend Scientific, Inc., St. Paul, MN), Cary Blair Transport Medium (Remel, Inc., Lenexa, KS), and Para-Pak C & S (Meridian Diagnostics, Inc., Cincinnati, OH). The Fekal Enteric Plus system showed a greater than or equal to 50% recovery of the original bacterial inoculum after 96 hours for all Salmonella, Shigella, and Yersinia strains tested and after as long as 72 hours for Vibrio strains. The Cary Blair Transport System showed greater than or equal to 50% recovery of the initial inoculum at 96 hours for five of six Salmonella strains, four of six Shigella strains, all Yersinia strains, and one of two Vibrio strains. With the use of the Para-Pak C & S, greater than or equal to 50% recovery of the original inoculum after 96 h was demonstrated for five of six Salmonella strains, four of six Shigella strains, all Yersinia strains, and one of two Vibrio strains. All three systems did not demonstrate even 10% recovery of the initial C. jejuni inoculum at 24 hours when held at room temperature.

Bacteriological Techniques↗
PubMed1991

The slide centrifuge gram stain as a urine screening method.

A slide centrifuge Gram stain procedure was performed to screen for bacteriuria 4161 urine specimens submitted in urine preservative tubes for routine culture. For slide centrifuge Gram staining, each urine sample was mixed well. Thereafter, 0.2 mL of each sample was placed, using a pipette, into a slide centrifuge chamber and centrifuged at 2,000 rpm for 5 minutes. The slides were heat fixed, Gram stained, and read by laboratory personnel who scanned 12 consecutive oil-immersion fields using a set pattern. The presence of the same organism in six or more fields was defined as a positive urine screen. Urine samples were cultured using a 0.001-mL loop and a comparison of culture growth with slide centrifuge screening was made. When growth of 100,000 or more colony-forming units per milliliter (CFU/mL) was the reference for comparison, the screen had a sensitivity rate of 98%, a specificity rate of 90%, a negative predictive value of 99%, and a positive predictive value of 65%. When a lower colony count of 10,000 or more CFU/mL was the reference for comparison, the screen had a sensitivity rate of 88%, a specificity rate of 95%, a negative predictive value of 96%, and a positive predictive value of 84%. The slide centrifuge Gram stain is a very sensitive screening method to detect bacteriuria in an adult male population.

Adult↗
PubMed1991

Comparison of traditional gas chromatography (GC), headspace GC, and the microbial identification library GC system for the identification of Clostridium difficile.

Three gas chromatography (GC) methods were compared for the identification of 52 clinical Clostridium difficile isolates, as well as 17 non-C. difficile Clostridium isolates. Headspace GC and Microbial Identification System (MIS) GC, an automated system which utilizes a software library developed at the Virginia Polytechnic Institute to identify organisms based on the fatty acids extracted from the bacterial cell wall, were compared against the reference method of traditional GC. Headspace GC and MIS were of approximately equivalent accuracy in identifying the 52 C. difficile isolates (52 of 52 versus 51 of 52, respectively). However, 7 of 52 organisms required repeated sample preparation before an identification was achieved by the MIS method. Both systems effectively differentiated C. difficile from non-C. difficile clostridia, although the MIS method correctly identified only 9 of 17. We conclude that the headspace GC system is an accurate method of C. difficile identification, which requires only one-fifth of the sample preparation time of MIS GC and one-half of the sample preparation time of traditional GC.

Bacteriological Techniques↗
PubMed1988

Results of a prospective, 18-month clinical evaluation of culture, cytotoxin testing, and culturette brand (CDT) latex testing in the diagnosis of Clostridium difficile-associated diarrhea.

An 18-mo evaluation of culture, cytotoxin, and latex testing for Clostridium difficile was performed between July 1, 1985, and December 31, 1986, on 1,536 specimens from 1,406 patients during evaluation of diarrhea. All cases with at least one test positive were investigated for clinical status. There were 144 Clostridium difficile-associated diarrhea (CAD) patients; 139 (97%) were positive by culture, 96 (67%) by cytotoxin, and 98 (68%) by latex testing. In the 1,262 non-CAD patients with diarrheal stool, 89 (7.1%) were positive by culture, 18 (1.4%) by cytotoxin, and 68 (5.4%) by the latex test. No CAD patient was positive by cytotoxin testing only, and two were positive by latex testing only. The culture and cytotoxin positivity were similar to our previous reports of 90-97% and 70-73%, respectively. Latex sensitivity (68%) was comparable to that of cytotoxin testing in this large group of patients (p greater than 0.5). Overall, in the 1,262 patients without clinical evidence of Clostridium difficile disease, positive tests by latex testing (5.4%) were intermediate between those of culture (7.1%, p less than 0.1) and cytotoxin (1.4%, p less than 0.001).

Bacteriological Techniques↗
PubMed1988

Using the microbiology laboratory in the diagnosis of pneumonia.

Pneumonia/influenza is one of the top ten leading causes of mortality in the United States each year. The identification of the etiologic agent responsible for lower respiratory tract infection plays an important role in the proper management of this clinical problem. The specimens submitted for evaluation are obtained in diverse ways and include expectorated sputum, material from transtracheal and bronchoscopic procedures, pleural fluid and lung aspirates, and biopsy of actual lung tissue. Processing of material can include stained smears, aerobic and anaerobic cultures, and special processing techniques for fungal, viral, Pneumocystis carinii, Legionella, mycobacterial, and mycoplasma identification. Modifications of smear preparation techniques and application of the new DNA probe technology are providing the opportunity for rapid microbiologic testing of clinical specimens with increased sensitivity and specificity, often obviating the need for invasive diagnostic procedures. Laboratory methodology is continually undergoing technological change, and optimal care of the patient with pneumonia requires close cooperation between the attending physician and the clinical laboratory.

Bacteriological Techniques↗
PubMed1987

Pseudomonas infection of the biliary system resulting from use of a contaminated endoscope.

Pseudomonas aeruginosa was present in bile cultures from 10 patients who had undergone previous endoscopic retrograde cholangiopancreatography in 1984. After environmental cultures and review of instrument disinfection, we traced the infections to a single endoscope contaminated with P. aeruginosa, serotype 10. Although the instrument had been cleaned repeatedly with an automatic endoscope cleaning machine, P. aeruginosa survived on residual moisture left in the channels of the endoscope. Contamination ended only after we began to manually suction alcohol through the endoscope before air drying. In 5 of 10 patients, P. aeruginosa caused clinical infections including gangrenous cholecystitis, abscesses, and death. We could identify no factor that distinguished symptomatic from asymptomatic patients. In asymptomatic patients, P. aeruginosa was recovered from gallbladder bile up to 2 mo after endoscopic retrograde cholangiopancreatography. As this P. aeruginosa epidemic was discovered retrospectively because we monitor bile cultures, we advocate this practice as part of endoscopic retrograde cholangiopancreatography procedures.

Bile↗
PubMed1987

In vitro activity of efrotomycin, ciprofloxacin, and six other antimicrobials against Clostridium difficile.

The susceptibility of 69 clinical isolates of Clostridium difficile from the Minneapolis Veterans Administration Medical Center and 29 C. difficile strains from other hospitals to efrotomycin, ciprofloxacin, and six other antimicrobials was tested in vitro by agar dilution. Ciprofloxin (MIC50 and MIC90 = 8 mcg/ml) was only moderately active whereas efrotomycin (MIC50 = 0.125, MIC90 = 0.25 mcg/ml) was highly active against C. difficile.

Anti-Bacterial Agents↗
PubMed1987

Occurrence and reproducibility of the "skip" phenomenon in bactericidal testing of Staphylococcus aureus.

A "skip" phenomenon, in which subcultures to determine bactericidal endpoints show discordant results, can make bactericidal testing of Staphylococcus aureus difficult to interpret. Either a single or several consecutive concentrations may be skipped, with insignificant growth from these concentrations, but heavy growth from higher antimicrobic concentrations. Replicate macrodilution minimum bactericidal concentration testing of cephalothin against S. aureus was investigated to determine the frequency and reproducibility of the skip phenomenon in this test. In preliminary testing, the skip phenomenon occurred at 24 hr in 11 of the 30 tests performed on ten S. aureus strains. Incubation of tubes for 48 hr before subculture markedly reduced the number of tests containing a skip tube (four of 30). The skip phenomenon was not reproducible either within concurrent replicate testing or on repeat testing of the same isolate on subsequent days. The ten strains were retested in replicative trials using the macrodilution test comparing Mueller-Hinton broth (MHB) and MHB supplemented with Tween 80. The number of skips occurring in the supplemented broth test was the same (two of 22) at 24 hr as nonsupplemented broth. For reproducible results, macrodilution minimum bactericidal testing requires performance of the test in duplicate, with repeat subculture at 48 hr if the skip phenomenon occurs in both trials at the 24-hr subculture. Killing curves performed on these isolates did not appear to demonstrate any relationship between the skip phenomenon and the paradoxical effect described by Eagle.

Cephalothin↗
PubMed1987

Selenomonas bacteraemia--case report and review of the literature.

Selenomonas species are crescent shaped Gram-negative bacilli with a characteristic tuft of flagella located on the concave surface. They are normally found in human gingiva or the rumen of herbivores. The first case of Selenomonas bacteraemia to be reported in a patient immunocompromised by malignant disease is described and the two previously reported cases of Selenomonas bacteraemia as reviewed. The importance of careful anaerobic culturing to recover the organism and special diagnostic techniques to classify the bacteria as Selenomonas species are emphasised. These organisms may cause serious human disease including bacteraemia.

Aged↗