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Biomedical subjects

K B Waites

Publications and source records attributed to K B Waites.

At least 37 records · Page 2Linked to original sources
PubMed1999

In vitro susceptibilities of Mycoplasma hominis to six fluoroquinolones as determined by E test.

Twenty isolates of Mycoplasma hominis were tested for their susceptibility to six fluoroquinolones by the E test. The MICs at which 90% of the isolates were inhibited (in micrograms per milliliter) were as follows: sparfloxacin, 0.031; clinafloxacin, moxifloxacin, and trovafloxacin, 0.063; levofloxacin, 0.25; and ciprofloxacin, 0.5. Increasing the amount of inoculum or incubation in CO(2) elevated MICs by </=1 dilution. E tests produce fluoroquinolone MICs comparable to those obtained by agar and microbroth dilution for M. hominis.

Anti-Infective Agents↗
PubMed1999

Comparison of direct inoculation and Copan transport systems for isolation of Neisseria gonorrhoeae from endocervical specimens.

Two commercial swab transport systems, Copan Amies gel agar with and without charcoal (Copan Diagnostics, Corona, Calif.), were compared to direct inoculation onto modified Thayer-Martin medium for detection of Neisseria gonorrhoeae in 1,490 endocervical specimens obtained from women attending a sexually transmitted disease clinic. Copan swabs were held in the transport system for 24 h at room temperature prior to inoculation onto modified Thayer-Martin medium. All cultures were incubated at 35 degrees C in 5% CO(2), and bacteria were identified on the basis of Gram stain, oxidase, and biochemical reactions. Copan Amies gel agar transport system without charcoal detected 77 of 81 (95%) direct inoculation culture-positive specimens, and Copan Amies gel agar transport system with charcoal detected 53 of 56 (95%) directly inoculated culture-positive specimens. Copan Amies gel agar without charcoal inoculated after 6 h supported growth of 56 (98%) positive cultures out of only 55 directly inoculated culture-positive specimens. This study demonstrates that Copan swabs represent a reasonable alternative, providing convenience, low cost, and ease of use while still maintaining a satisfactory recovery rate of N. gonorrhoeae from clinical specimens, if specimens can be inoculated onto selective media within a relatively short time period not involving overnight shipment.

Adult↗
PubMed1999

Detection of Chlamydia trachomatis endocervical infections by ligase chain reaction versus ACCESS Chlamydia antigen assay.

Ligase chain reaction (LCR) was compared with ACCESS immunoassay for detection of chlamydial infections in females. Despite efforts to improve ACCESS performance by evaluation of specimens that were in the test performance "grey zone," LCR remained more sensitive and was less expensive to perform. ACCESS had a sensitivity of 83.9%, a specificity of 99.7%, a positive predictive value of 96.3%, and a negative predictive value of 98.5%.

Antigens, Bacterial↗
PubMed1999

No relationship between gastric pH, small bowel bacterial colonisation, and diarrhoea in HIV-1 infected patients.

BACKGROUND/AIMS: Conclusive studies of small bowel bacterial overgrowth in patients with HIV-1 infection are limited. The relation was therefore determined between the quantity and species of bacteria in the proximal small intestine of HIV-1 infected patients and the presence of diarrhoea, gastric acidity, severity of immune deficiency, and clinical outcome. METHODS: Bacteria in the duodenal fluids obtained endoscopically from 32 HIV-1 infected patients, 21 of whom had diarrhoea, and seven control subjects without HIV-1 risk factors were quantified and speciated. Gastric pH was determined at the time of endoscopy. Clinical follow up was performed to assess outcome. RESULTS: Oropharyngeal Gram positive cocci were present in fluids from 28 patients (88%). Gram negative aerobic or facultatively anaerobic bacteria were present in fluids from 12 patients (38%), and strict anaerobes were detected in six patients (19%), but for both groups colony counts infrequently exceeded 10(4) colony forming units/ml. The number and species of bacteria did not correlate with the presence of diarrhoea, gastric pH, or CD4 lymphocyte count. CONCLUSIONS: Small bowel bacterial overgrowth is not common in HIV-1 infected patients, regardless of the presence of diarrhoea, and is not associated with hypochlorhydria

AIDS-Related Opportunistic Infections↗
PubMed1998

The yield of bone marrow biopsy and culture compared with blood culture in the evaluation of HIV-infected patients for mycobacterial and fungal infections.

PURPOSE: To compare the clinical utility of bone marrow biopsy and culture specimens with blood cultures for mycobacterial and fungal infections among human immunodeficiency virus (HIV)-infected patients. PATIENTS AND METHODS: All bone marrow biopsies obtained from HIV-infected patients at the University of Alabama at Birmingham (UAB) Medical Center during 1993 to 1995 were blindly reviewed in a standardized format. Bone marrow culture results and blood culture results obtained within 6 weeks of each bone marrow study were compiled. Medical records were reviewed to determine indications for performing bone marrow biopsies, empiric or prophylactic antimicrobial therapies preceding the biopsy, and CD4 counts. RESULTS: Eighty-two bone marrow studies were obtained from 76 patients. Most were performed during the evaluation of fever, cytopenia, or weight loss. Of 55 bone marrow mycobacterial cultures, 13 yielded Mycobacterium avium complex (MAC) and 2 yielded M tuberculosis (MTB). Of 51 bone marrow fungal cultures performed, 2 yielded Cryptococcus neoformans and 1 Histoplasma capsulatum. All patients with a bone marrow culture positive for MAC had a CD4 count of 20 cells/mm3 or less. The mean CD4 count in this group (+/-95% confidence interval) (8+/-3 cells/mm3) was lower than that of culture-negative cases (41+/-25 cells/mm3); P <0.015). When bone marrow cultures and mycobacterial blood cultures were concurrently obtained, results were usually in agreement between the two sites. The mean time until the report of positive mycobacterial bone marrow cultures (22+/-5 days) was similar to that for blood cultures (24+/-3 days). Most (84%) patients with multiple mycobacterial cultures had completely concordant results (all positive or all negative). When blood or bone marrow culture yielded mycobacteria, only 29% of the corresponding bone marrow examinations revealed stainable acid-fast bacilli (AFB). In contrast, all 3 cases with positive fungal bone marrow cultures also had stainable organisms on histologic examination. CONCLUSIONS: The combined use of bone marrow biopsy and culture as well as blood cultures provide the maximum diagnostic yield when evaluating patients with AIDS for mycobacterial or fungal infections. However, when mycobacterial infections were diagnosed, bone marrow results seldom provided more immediate or specific information than lysis centrifugation blood cultures. A single lysis centrifugation blood culture should be the first step in the routine evaluation of HIV-infected patients when disseminated MAC infection is suspected.

AIDS-Related Opportunistic Infections↗
PubMed1998

Immunogenicity of pneumococcal vaccine in persons with spinal cord injury.

OBJECTIVE: To determine immunogenicity and optimum timing for administering the 23-valent pneumococcal vaccine after spinal cord injury (SCI). DESIGN: Double-blind, randomized, placebo control study. SETTING: SCI unit in a tertiary care medical center and community. PARTICIPANTS: Eighty-seven persons with recent SCI. INTERVENTION: Participants were randomized to receive either placebo or pneumococcal vaccine at 16 to 18 days versus 4 to 6 months postinjury. MAIN OUTCOME MEASURES: Antibody concentrations were measured prior to intervention and 1, 2, and 12 months afterward to evaluate the immune response to five serotypes of Streptococcus pneumoniae. Effects of demographic and injury-related variables on immune response were also evaluated. RESULTS: Timing of vaccination did not influence mean antibody concentrations for any serotype (p > .05). Ninety-five percent of vaccinated persons had twofold or greater increases in antibody concentration for at least one serotype when measured 1 month after vaccination versus 35% of placebo groups (p < .01). After 12 months, 93% of vaccinated persons in both groups maintained antibody concentrations twofold or greater than baseline values. CONCLUSIONS: Most participants developed an immune response to at least one serotype that was maintained for at least 12 months. Immune response varied according to serotype. Given the favorable immune response and no effect of timing, persons with SCI should receive pneumococcal vaccine during initial hospitalization.

Adolescent↗
PubMed1998

Identification of oxacillin-susceptible and oxacillin-resistant Staphylococcus aureus using commercial latex agglutination tests.

Four hundred thirteen Staphylococcus sp. were identified by Staphaurex, Staphaurex Plus, and BACTiStaph kits using tube coagulase as reference. Among 222 coagulase-positive isolates, 56 were oxacillin-resistant Staphylococcus aureus. All tests were accurate in distinguishing between coagulase-positive and -negative staphylococci with sensitivities and specificities > or = 97% and only nine discrepancies.

Agglutination Tests↗
PubMed1998

Direct bacterial identification from positive BacT/Alert blood cultures using MicroScan overnight and rapid panels.

Studies were conducted on a method of direct inoculation of MicroScan overnight and rapid panels from positive BacT/Alert blood culture bottles containing standard aerobic media to determine the correlation with inoculation of the corresponding panels with a standardized bacterial suspension obtained following subculture to agar. For Gram-negative organisms, 122 of 127 (96%) overnight panels and 85 of 118 (72%) rapid panels showed complete agreement with the standard method for species identification. Highest concordance (99%) occurred with Enterobacteriaceae inoculated directly into overnight panels. For Gram-positive organisms, 70 of 85 (82%) overnight panels and 45 of 86 (52%) rapid panels showed complete agreement. These findings suggest that direct inoculation of Gram-negative overnight MicroScan panels yields results most comparable to standard methods when Enterobacteriaceae are detected and allows reporting of results 18 to 24 h sooner. Direct inoculation of Gram-positive overnight or rapid panels and Gram-negative rapid panels from this blood culture medium did not yield acceptable identification results and is not recommended.

Bacteremia↗
PubMed1998

Comparison of two rapid latex agglutination tests for detection of cryptococcal capsular polysaccharide.

The Murex Cryptococcus Test was compared with the Cryptococcal Antigen Latex Agglutination System (CALAS) for detecting cryptococcal polysaccharide in 173 cerebrospinal fluid (CSF) specimens and 117 serum samples with 99% and 97% concordance, respectively. Eighteen CSF samples and 17 serum samples were positive in both assays, and 249 were negative. The sensitivity and specificity of the Murex relative to the CALAS were 90% and 100%, respectively, for CSF, and 81% and 100%, respectively, for serum. Six discrepancies were arbitrated by retesting, using a third analytic method, review of other laboratory and clinical data, or both. The reaction in 1 CSF specimen was considered false positive by the CALAS, and the reactions in 2 serum samples were false negatives by the Murex. For 3 patients with previous cryptococcal meningitis but no active disease, only the CALAS detected antigen, suggesting that the Murex has less analytic sensitivity in this context. Titer differences dictate that direct comparisons between the 2 tests are not feasible. There were no false-positive reactions in limited testing with either method using specimens from patients with concurrent noncryptococcal infections or in rheumatoid factor-positive serum samples. Infections caused by Cryptococcus neoformans serotypes A or AD were detected equally by both assays. Based on our study, we have elected to continue to use the CALAS for routine testing for cryptococcal antigen.

Adult↗
PubMed1998

Comparison of the MB/BacT system with a revised antibiotic supplement kit to the BACTEC 460 system for detection of mycobacteria in clinical specimens.

The MB/BacT system (MB/BacT) with a revised antibiotic supplement kit was compared with the BACTEC 460 system (BACTEC 460) in a test of 488 specimens submitted for mycobacterial culture from 302 patients. Twenty-four Mycobacterium tuberculosis isolates were detected by the BACTEC 460 versus 23 isolates by the MB/BacT. Mean time until detection of M. tuberculosis isolates identified by both systems was 11.9 days for the BACTEC 460 versus 13.7 days for the MB/BacT (P = 0.046). M. avium complex was detected in 12 specimens by the MB/BacT versus 10 specimens by the BACTEC 460. Only 8 of 14 (57%) M. avium isolates were detected by both systems, with a mean time until detection of 10.1 days for the BACTEC 460 and 14.2 days for the MB/BacT (P = 0.009). The BACTEC 460 and the MB/BacT detected M. gordonae in four specimens, but only a single specimen was positive by both systems. One M. fortuitum isolate and one of five M. kansasii isolates were recovered only by the BACTEC 460. The bacterial overgrowth rate was 7.0% for the MB/BacT versus 4.1% for the BACTEC 460. We found the MB/BacT to be comparable to the BACTEC 460 for mycobacterial detection. Even though time until detection with the MB/BacT was slightly longer (1.8 days longer for M. tuberculosis and 4.1 days for M. avium [mean values]) and the bacterial overgrowth rate was somewhat higher, the decreased labor, the availability of a computerized data management system, and the noninvasive, nonradiometric aspects of the MB/BacT offset these relative disadvantages and make it an acceptable alternative for use in the diagnostic laboratory.

Anti-Bacterial Agents↗
PubMed1998

Direct susceptibility testing with positive BacT/Alert blood cultures by using MicroScan overnight and rapid panels.

Studies were conducted on a method of direct inoculation of MicroScan dried overnight and of rapid panels with positive aerobic blood cultures obtained from the BacT/Alert to determine antimicrobial susceptibilities. Inocula were limited to specimens that appeared unimicrobic on Gram stain. Results were compared to those obtained from panels inoculated following subculture. For 133 gram-negative bacilli, there were 94.7 and 93.5% categorical agreements between direct and standard methods for all drugs tested with overnight and rapid panels, respectively. For 104 gram-positive cocci, there were 93.2 and 93.1% categorical agreements for overnight and rapid panels, respectively. The major error (false resistance) rate for gram negatives was 1.4% for overnight versus 0.7% for rapid panels. The very major error (false susceptibility) rate was 2.7% for overnight versus 8.1% for rapid panels. The total error rates were 1.6% for overnight panels and 1.5% for rapid panels. The major error rates for gram-positive direct susceptibility tests were 2.6% for overnight and 2.5% for rapid panels. The very major error rates were 8.8 and 7.2% for overnight and rapid panels, respectively. Total error rates were 3.6% for overnight and rapid gram-positive panels. These findings suggest that susceptibility results obtained from directly inoculated gram-negative overnight panels have the greatest correlation to those obtained by standard methods. When discrepant results occur with direct-susceptibility testing, they are more likely to show false susceptibility than false resistance.

Aerobiosis↗
PubMed1997

Spontaneously colitic C3H/HeJBir mice demonstrate selective antibody reactivity to antigens of the enteric bacterial flora.

The idiopathic inflammatory bowel diseases, ulcerative colitis and Crohn's disease, are chronic disorders that appear to arise from an aberrant interaction of environmental, genetic, and immunologic factors. The aim of this study was to examine the immune reactivity of a spontaneously colitic mouse strain, C3H/HeJBir, to epithelial, food, and enteric bacterial Ags. Serum Ab responses of colitic C3H/HeJBir and noncolitic parental C3H/HeJ mice were measured by enhanced chemiluminescence Western blotting. No reactivity to epithelial or food Ags was detected. However, the sera from C3H/HeJBir mice had a reproducible banding pattern on Western blot to bacterial Ags, whereas sera from C3H/HeJ mice did not. Only a small, highly selected number of enteric bacterial Ags were recognized. There were major differences in the degree of recognition of different bacterial strains, marked by remarkably few Abs to Ags of the major anaerobes of the bacterial flora. The serum Abs detected on immunoblot were primarily IgG2a, suggesting a Th1 response. Comparison of sera reactivity to histopathologic severity showed an inverse relationship: one third of young C3H/HeJBir mice during the peak of colitis produced Abs to bacterial Ags, while later in life, when the colitis had resolved, 96% produced Abs. These data are consistent with an abnormal immune reactivity to enteric bacterial flora in C3H/HeJBir mice, a reactivity that is highly selective considering the abundant bacterial Ags present in the colon lumen. We postulate that this reactivity plays a role in the pathogenesis of colitis in these mice.

Animals↗
PubMed1997

Comparison of long-term renal function after spinal cord injury using different urinary management methods.

OBJECTIVE: To determine the effect of different bladder management methods on long-term renal function in persons with spinal cord injury (SCI). DESIGN: Cohort study. SETTING: Model SCI care system within a large teaching hospital. PATIENTS: Consecutive sample of 1,114 persons with SCI who were injured between 1969 and 1994. MAIN OUTCOME MEASURE: Total and individual kidney effective renal plasma flow (ERPF). RESULTS: ERPF was generally lower in persons with cervical injuries or kidneys that had a renal stone, older persons, and women. Overall, there was very little change in renal function as time postinjury increased, and there were no clinically meaningful differences in the change in renal function over time among persons using different bladder management methods. CONCLUSION: Renal function was adequately preserved in the great majority of persons and did not appear to be influenced to any great extent by method of bladder management.

Adolescent↗
PubMed1997

Genotypic investigation of multidrug-resistant Acinetobacter baumannii infections in a medical intensive care unit.

Multi-resistant Acinetobacter baumannii isolates obtained from 13 hospitalized patients over a six-month period were evaluated. One patient had an isolate susceptible only to imipenem; the next three had isolates susceptible to imipenem and ampicillin/sulbactam; the next six patients had isolates which were susceptible to imipenem, amikacin, and ampicillin/sulbactam; while the final three patients had isolates which were susceptible to imipenem and ampicillin/sulbactam. Ten patients died, five within 10 days of a positive culture. Five of six patients with bacteraemia succumbed to the infection. DNA extracted from all isolates was amplified by polymerase chain reaction using four random primers (RAPD). The resulting band patterns were compared and strains identified. In addition, all isolates were biotyped. RAPD analysis and biotyping showed that there were two distinct strains involved. The first four patients were infected with one strain (genotype ¿A', biotype 9), the subsequent nine patients were infected with a second strain (genotype ¿B', biotype 1). These results suggested that there was patient-to-patient spread of strains. Institution of, and strict adherence to, isolation procedure and other infection control practices controlled the spread of infection. These data emphasize the need for active surveillance for multidrug-resistant organisms in critically ill patients, and the value of molecular typing of strains in a hospital setting to investigate spread of infection.

Acinetobacter↗
PubMed1997

Evaluation of the Etest for detection of tetracycline resistance in Mycoplasma hominis.

The Etest was compared with microbroth dilution for performing in vitro susceptibility tests in 38 isolates of Mycoplasma hominis chosen to represent a wide range of MIC values. MIC50s were 4 micrograms/ml for both methods; whereas, MIC90s were 64 and > 256 micrograms/ml for broth and Etest, respectively. Etest MICs determined on SP 4 agar were usually two or more dilutions greater than microbroth MICs in SP 4 broth, and values were prone to change by one to two dilutions when different inoculum densities were used. Inocula of 10(5) to 10(6) color-changing units/ml gave the most consistently readable MICs, with discrete colony formation surrounding the ellipse. Etest MICs for 5 isolates tested a second time at the same inoculum on SP 4 agar agreed with the original value within 1 dilution. For 12 isolates tested on A 8 agar simultaneously with SP 4 agar, MICs for 10/12 agreed within one dilution; whereas, in the other 2 isolates, MICs varied by two dilutions. These findings suggest that the Etest, when properly controlled, can be used to determine tetracycline MICs for M. hominis.

Microbial Sensitivity Tests↗
PubMed1997

Predicting compliance with annual follow-up evaluations in persons with spinal cord injury.

A prospective study was performed to determine why some persons with spinal cord injury (SCI) fail to return for scheduled evaluations in order to identify predictive factors that could be used to target those at greatest risk for noncompliance and facilitate interventions to improve rates of return. Sixty-one noncompliant subjects and 102 persons compliant with regularly scheduled annual examinations were paid to come to the clinic for evaluation. Each participant completed a psychological questionnaire comprised of theoretical and socioeconomic variables. There was no difference between the two groups according to gender, race, level or completeness of injury, education, etiology of injury, responses to questions from the Health Locus of Control Scale, Health Beliefs Model, inconvenience or discomfort. For noncompliant versus compliant persons, cost (P = 0.0002), distance (P = 0.0047), transportation (P = 0.0330), belief that follow-up was not necessary (P < 0.0001), availability of good local doctor (P = 0.0001) and time (P = 0.0209) were identified as obstacles to returning for follow-up. These data indicate a need to improve the education for newly injured persons as well as those persons residing in the community on the importance of regular urological follow-up, to maintain close contact post-discharge and to assist in identifying community resources to facilitate either compliance with planned evaluations or the development of acceptable alternatives.

Adolescent↗