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B Toye

Publications and source records attributed to B Toye.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the IDI-MRSA assay for detection of methicillin-resistant staphylococcus aureus from nasal and rectal specimens pooled in a selective broth.

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) by PCR can be performed directly from nasal specimens with the IDI-MRSA assay. To improve the efficiency of screening, we evaluated the performance of the IDI-MRSA assay for the detection of MRSA from pooled and unpooled specimens cultured in a selective broth. Of the 287 specimens evaluated, 71 were culture and PCR positive, 203 were culture and PCR negative, 3 were culture positive and PCR negative, 8 were culture negative and PCR positive, and 2 remained inhibited. A methicillin-susceptible Staphylococcus aureus isolate was recovered from five of the eight specimens with false-positive PCR results. Compared to the results of culture, the sensitivity, specificity, and positive and negative [corrected] predictive values of the IDI-MRSA assay for detection of MRSA from broth were 96%, 96%, 90%, and 98%, respectively. Following implementation of the IDI-MRSA assay, PCR-positive broths were subcultured for evaluation of assay performance. Of the 298 IDI-MRSA assay-positive broths, the results for 103 could not be confirmed by culture. A methicillin-susceptible S. aureus (MSSA) isolate was recovered from 77 of these 103 broths. Repeat testing by the IDI-MRSA assay directly with the MSSA isolates confirmed the original positive PCR result. The positive predictive value of the IDI-MRSA assay fell from 90% during the evaluation phase to 65% postimplementation. The IDI-MRSA assay performed well for the detection of MRSA from a selective broth compared to the performance of the detection of MRSA from culture. However, because of the burden associated with implementation of infection control precautions, cultures remain essential in confirming positive IDI-MRSA results.

Bacterial Typing Techniques↗
PubMed2005

Delays in the administration of antibiotics are associated with mortality from adult acute bacterial meningitis.

BACKGROUND: Bacterial meningitis continues to cause high mortality. Few studies address the possible association between this mortality and antibiotic administration delays. AIM: To determine whether delays in antibiotic administration are associated with mortality from bacterial meningitis, and to identify inappropriate diagnostic-treatment sequences leading to such delays. DESIGN: Retrospective case record study. METHODS: We reviewed 123 cases of adult acute bacterial meningitis in 119 patients aged >/=16 years admitted to hospital from January 1990 to March 2002, using multivariate regression analysis to assess the association between meningitis mortality and door-to-antibiotic time (the time elapsed between emergency room presentation and antibiotics administration). RESULTS: The case fatality rate was 13% (16/123). Adjusted odds ratios (OR) for mortality were: 8.4 (95%CI 1.7-40.9) for door-to-antibiotic time >6 h; 39.4 (95%CI 4.3-358.1) for afebrility at presentation; and 12.6 (95%CI 2.2-72.0) for severely impaired mental status at presentation. Factors associated with a door-to-antibiotic time of >6 h were: (i) failure to administer antibiotics prior to transfer from another institution (OR 21.8); (ii) the diagnostic-treatment sequence: head CT then lumbar puncture, then antibiotics (OR 5.6); and (iii) the absence of the classic meningitis triad (OR 4.9). DISCUSSION: There is an independent incremental association between delays in administrating antibiotics and mortality from adult acute bacterial meningitis. Inappropriate diagnostic-treatment sequences were significant predictors of such treatment delays.

Acute Disease↗
PubMed2004

The use of a bacteria detection system to evaluate bacterial contamination in PLT concentrates.

BACKGROUND: Random-donor PLTs (RDPs) are functional at 7 days. Nevertheless, since the mid-1980s, concern for bacterial contamination has caused the storage period to be reduced to 5 days. The ability of a bacteria detection system (BDS, Pall) to determine bacterial contamination and permit extension of the PLT shelf life to 7 days was assessed. STUDY DESIGN AND METHODS: Blood was collected into CP2D and leukoreduced RDPs were prepared. Upon arrival at the hospital, a 2- to 3-mL aliquot was removed from each RDP and introduced into the Pall BDS pouch with a sterile docking device. The pouch was incubated at 37 degrees C for 24 hours and then the oxygen content was measured to determine bacterial contamination. Additionally, the RDPs were pooled and an aliquot was removed for culture with standard manual techniques. CCIs were calculated 1 hour after infusion. RESULTS: A total of 12,062 individual RDPs were tested. The Pall BDS detected bacteria in 5 units. All of these were positive on repeat sampling. Propionibacterium acnes, coagulase-negative Staphylococcus, and Bacillus species were confirmed by manual technique in 3 units, one could not be identified, and one was negative. Aliquots from PLT pools were positive in 80 of 2201 pools when tested by manual methods. Of these, 79 were false-positives and 1 unit contained coagulase-negative Staphylococcus. The Pall BDS was easy to use and required less than 5 minutes for all manipulations. After 7 days of storage, the PLTs gave an average CCI of 16 x 10(11)+/- 3.39 x 10(11) 1 hour after transfusion (n = 9). CONCLUSIONS: The Pall BDS permits evaluation of RDPs for bacterial contamination. Culture-negative PLTs were successfully transfused in our institution up to and including 7 days after storage with good CCIs.

Bacillus↗
PubMed2004

Prevalence and mechanisms of erythromycin resistance in group A and group B Streptococcus: implications for reporting susceptibility results.

Increased rates of erythromycin resistance among group B Streptococcus (GBS) and group A Streptococcus (GAS) have been reported. Cross-resistance to clindamycin may be present, depending on the mechanism of resistance. We determined the prevalence of macrolide-resistant determinants in GBS and GAS isolates to guide the laboratory reporting of erythromycin and clindamycin susceptibility. Susceptibilities were determined by the disk diffusion and broth microdilution methods. Inducible and constitutive resistance to clindamycin was determined by the double-disk diffusion method. The presence of the ermTR, ermB, and mefA genes was confirmed by PCR. Of the 338 GBS isolates, 55 (17%) were resistant to erythromycin, whereas 26 (8%) were resistant to clindamycin. The erm methylase gene was identified in 48 isolates, 22 of which had inducible resistance to clindamycin and 26 of which had constitutive resistance to clindamycin. The remaining seven resistant isolates had mefA. Of the 593 GAS isolates, 49 (8%) and 6 (1%) isolates were resistant to erythromycin and clindamycin, respectively. Erythromycin resistance was due to mefA in 33 isolates, whereas 14 isolates had erm-mediated resistance (9 isolates had inducible resistance and 5 isolates had constitutive resistance). In our population, erythromycin resistance in GAS was predominantly mediated by mefA and erythromycin resistance in GBS was predominantly mediated by erm. Regional differences in mechanisms of resistance need to be taken into consideration when deciding whether to report clindamycin susceptibility results on the basis of in vitro test results. Testing by the double-disk diffusion method would be an approach that could be used to address this issue, especially for GAS.

Adolescent↗
PubMed2001

Oxacillin susceptibility testing of Staphylococcus saprophyticus using disk diffusion, agar dilution, broth microdilution, and the Vitek GPS-105 card.

Eighty-three mecA negative isolates of S. saprophyticus had oxacillin zone diameters <or= 15 mm or MICs ranging from <or= 0.25-1.0 microg/ml when tested by either agar dilution, broth microdilution, or the Vitek GPS-105 card. Greater than 90% of these isolates would be considered resistant using NCCLS M7-A5, M100-S10 criteria. These results suggest that the current NCCLS MIC and zone diameter breakpoints for oxacillin resistance in coagulase-negative Staphylococci are not appropriate for S. saprophyticus as they do not correlate with the presence of the mecA gene.

Bacterial Proteins↗
PubMed2001

Direct detection of mecA, nuc and 16S rRNA genes in BacT/Alert blood culture bottles.

A benzyl alcohol-guanidine hydrochloride extraction method was used to remove sodium polyanetholesulfonate present in BacT/Alert blood culture bottles. Multiplex PCR using touchdown annealing was used to detect the mecA, nuc, and 16S rRNA genes in bottles growing staphylococci. This direct PCR assay demonstrated excellent sensitivity, specificity and improved accuracy compared to routine phenotypic methods for determination of methicillin resistance in coagulase negative staphylococci (CoNS). However, with this PCR assay, bottles that contained both methicillin-resistant CoNS and methicillin-susceptible Staphylococcus aureus would be misidentified as containing methicillin-resistant S. aureus.

Bacterial Proteins↗
PubMed2000

Comparison of phenotypic methods to identify enterococci intrinsically resistant to vancomycin (VanC VRE).

Clinical laboratories must be able to differentiate between enterococci possessing acquired resistance to vancomycin (vanA and vanB genotypes) from those that are inherently resistant (vanC1 and vanC2/C3 genotypes). We compared several routine phenotypic tests to determine the species identity of clinical isolates of enterococci and a PCR assay for the van ligase genes was used to confirm identification of VanC VRE. The Vitek Gram Positive Identification card identified 53/60 (88%) Enterococcus faecalis and E. faecium isolates and 81/141 (57%) VanC VRE without additional testing. Another 32 of the VanC VRE required additional testing (e.g., motility and pigmentation) for correct identification. However, 7 of these 32 VanC VRE were nonmotile. The rapid ID 32 STREP strips identified 50/60 (83%) E. faecalis and E. faecium isolates and 102/141 (72%) VanC VRE. All E. faecalis and E. faecium isolates were nonmotile and did not acidify 1% methyl-alpha-D-glucopyranoside (MGP). Only 93/115 (81%) E. gallinarum and 21/26 (81%) E. casseliflavus/E. flavescens were motile but all 141 VanC VRE acidified MGP. MGP acidification can accurately differentiate VanC VRE from E. faecalis and E. faecium. Because some VanC VRE isolates are nonmotile, MGP acidification is preferred as a simple and less costly test for identification of these isolates.

Bacterial Proteins↗
PubMed2000

Polymicrobial tenosynovitis with Pasteurella multocida and other gram negative bacilli after a Siberian tiger bite.

Mammalian bites present a considerable clinical problem because they are often associated with bacterial infections. Pasteurella multocida is a microorganism that commonly infects both canine and small feline bites. Zoonotic infections developing after large feline bites have been recognised, although their reports are limited. We describe a 35 year old man who was bitten by a Siberian tiger and who developed infectious tenosynovitis secondary to P multocida, Bergeyella (Weeksella) zoohelcum, and Gram negative bacteria most like CDC group EF-4b and comamonas species. The latter three bacteria have not been isolated previously from large feline bite wounds.

Adult↗
PubMed1998

Detection of methicillin resistance in coagulase-negative staphylococci initially reported as methicillin susceptible using automated methods.

Reliable detection of methicillin resistance in coagulase-negative staphylococci (CNS) is required for appropriate therapy of serious infections from these pathogens. To determine the most accurate method of measuring methicillin resistance in CNS initially reported as methicillin susceptible by automated methods, we compared mecA detection by polymerase chain reaction (PCR) with phenotypic methods. One hundred eighty-eight blood culture isolates of CNS that were initially reported as susceptible to methicillin using commercial methods (Vitek or MicroScan) were tested by agar dilution, disk diffusion, oxacillin salt agar screen plate, and a multiplex PCR assay using primer sets for mecA and 16S rRNA. Sixteen isolates (8.5%) previously reported as methicillin susceptible by automated methods contained the mecA gene. MICs of these isolates ranged from 0.5 microgram/mL to > or = 128 micrograms/mL. Ten of these isolates had MICs equal to or below the NCCLS breakpoint of 2 micrograms/mL. Six of the 10 isolates (4 with MICs of 0.5 microgram/mL and 2 with MICs of 2 micrograms/mL) did not grow on any of the oxacillin screen plates after 48 h of incubation at 30 degrees C or 35 degrees C. All six isolates were induced to grow in the presence of oxacillin at 128 micrograms/mL by serial passaging on plates containing increasing concentrations of antibiotic. Retesting with MicroScan and Vitek detected methicillin resistance in 7 and 10 isolates, respectively. Disk diffusion testing with incubation for 48 h proved to be the next best method after PCR for detection of methicillin resistance (15 of 16 isolates). Commercial automated methods and some methods recommended by National Committee for Clinical Laboratory Standards may not detect methicillin resistance in CNS that carry the mecA gene and have MICs just below breakpoint.

Bacterial Proteins↗
PubMed1998

Epidemiology of methicillin-resistant Staphylococcus aureus in three Canadian tertiary-care centers.

OBJECTIVE: To describe the epidemiology and spread of methicillin-resistant Staphylococcus aureus (MRSA) in three tertiary-care centers in Ottawa, Ontario, Canada, where MRSA is encountered infrequently. DESIGN: Retrospective review over a 6-year period, from January 1, 1990, through December 31, 1995. SETTING: Three tertiary-care teaching hospitals in Ottawa. PARTICIPANTS: Patients and healthcare workers (HCWs) with MRSA isolated from any body site. METHODS: Patients and HCWs were identified retrospectively through hospital microbiology and infection control records. Patient charts were reviewed for clinical and epidemiological data, including age, gender, previous hospital admissions (where noted), and current and recent antibiotic use. MRSA isolates that were available were typed using pulsed-field gel electrophoresis (PFGE). Methicillin resistance was confirmed by standard methods and by polymerase chain reaction using mecA-specific primers. RESULTS: MRSA was identified in 53 patients and 2 HCWs. Three patients were excluded from further analysis because medical records were incomplete. Epidemiological data were collected on the remaining 52 individuals. Thirty-nine isolates from 31 patients and 2 HCWs were available for PFGE typing. Five epidemiologically linked nosocomial clusters involving 10 patients and 2 HCWs were identified and were confirmed by PFGE. MRSA isolates from a sixth cluster were not available for PFGE. In each cluster, nosocomial spread was minimized by standard infection control practices, including strict isolation of patients and screening of contacts. There was no evidence of secondary spread of MRSA involving the remaining 36 patients. Recent antibiotic use, surgery, admission to an intensive-care unit, and previous hospitalization were common among patients. There was no evidence of spread of MRSA among the three hospitals, and no endemic strains were apparent in any of these centers. CONCLUSIONS: MRSA remains an infrequent isolate in our centers, with no apparent interhospital spread. In institutions with little or no endemic MRSA, rigorous application of standard infection control practices is effective in limiting nosocomial transmission of this organism.

Hospitals, Teaching↗
PubMed1998

Can serology diagnose upper genital tract Chlamydia trachomatis infections? Studies on women with pelvic pain, with or without chlamydial plasmid DNA in endometrial biopsy tissue.

BACKGROUND: Upper genital tract chlamydial infections in women are on the increase, and serology might be a convenient tool for diagnosis. Evaluations of this approach are needed in women with or without microbiologic evidence of organisms in the upper genital tract. GOALS: To compare the results of antibody assays with cervical culture and upper genital tract histopathology in women with pelvic pain and chlamydial plasmid DNA in endometrial biopsies. STUDY DESIGN: Chlamydia trachomatis plasmid DNA was detected by polymerase chain reaction (PCR) on extracted deparaffinized endometrial biopsy tissue. Five antichlamydial antibody assays were performed measuring total antibodies or immunoglobulin G (IgG), IgM, and IgA classes on sera from 14 women with plasmid DNA as well as 31 without plasmid DNA. RESULTS: Accepting the presence of plasmid DNA as the gold standard, no single test had total diagnostic accuracy. The best sensitivity and specificity occurred with the following assays: whole inclusion fluorescence (WIF) (100% and 80.6%); microimmunofluorescence IgM (MIF IgM) (78.6% and 93.6%); and heatshock protein-60 enzyme immunoassay (42.9% and 100%). Although recombinant anti-lipopolysaccharide enzyme-linked immunosorbent assays measured anti-chlamydial antibodies in a large proportion of these women, specificity was low. The sensitivity and specificity of cervical culture was 28.6% and 100% and of endometrial histopathology was 71.4% and 48.4%. Analysis of patient serological profiles suggested that and 6 women without plasmid DNA may have been cases that were missed by PCR. CONCLUSIONS: Evaluations of assays to diagnosis Chlamydia trachomatis upper genital tract infections could use the presence of organisms or their markers in the upper genital tract as a standard of comparison. Some of these serological assays, such as WIF or MIF IgM, may be helpful in diagnosis, but more studies are needed.

Antibodies, Bacterial↗
PubMed1998

Inhibition of PCR in genital and urine specimens submitted for Chlamydia trachomatis testing.

We determined the frequency of PCR inhibition in genital and urine specimens submitted for Chlamydia trachomatis testing using the internal control DNA provided with the COBAS AMPLICOR C. trachomatis test and assessed methods to remove it. Inhibition occurred in 65 of 906 (7%) cervical swabs, 23 of 51 (45%) urethral swabs, and 2 of 175 (1.1%) urine samples. Overall, inhibition was eliminated in processed specimens after storage at 4 degrees C in 77 of 90 specimens (86%), freezing at -70 degrees C in 59 of 82 specimens (72%), storage at 4 degrees C followed by either 1:100 dilution in 37 of 43 specimens (86%) or 1:10 dilution in 42 of 47 specimens (89%), and phenol-chloroform extraction in 79 of 80 specimens (99%). No positive specimens were missed due to inhibition. We conclude that PCR inhibition is rare with urine specimens and infrequent with endocervical swabs but occurs frequently with urethral swabs. The frequency of PCR inhibition may be significantly reduced by methods which can be easily incorporated into the processing of specimens.

Automation↗
PubMed1998

Pooling of urine specimens for PCR testing: a cost saving strategy for Chlamydia trachomatis control programmes.

OBJECTIVES: To evaluate pooling of first catch urine (FCU) specimens as a cost effective strategy for chlamydia testing. METHODS: Mock specimens were pooled with and without dilution to determine optimal pool size and ease of work flow. The performance of the Amplicor Chlamydia trachomatis PCR assay on pooled specimens was compared with individual testing using 370 FCU specimens from asymptomatic men presenting to an STD clinic. Cost savings associated with pooling were estimated. RESULTS: Using mock specimens, the sensitivity and specificity of the Amplicor PCR assay were not affected by pool sizes of two and five, but at a pool size of 10 decreased sensitivity due to inhibition was observed in one of five mock pools when the pooling method which involved no dilution was used. Archived FCU specimens from a study of 370 asymptomatic men were combined consecutively into 74 pools of five and tested by PCR. Of the 18 pools that contained positive specimens, 17 were PCR positive. Compared with testing FCU specimens individually, pooling resulted in a sensitivity of 95%, specificity of 100%, and a cost savings of 57% based on reduced number of tests required. CONCLUSION: Depending on the prevalence of infection, pooling of FCU specimens for PCR testing may result in cost savings compared with testing specimens individually. Further evaluations to validate this strategy using fresh FCU specimens are needed.

Bacteriological Techniques↗
PubMed1997

The presence of serum antibody to the chlamydial heat shock protein (CHSP60) as a diagnostic test for tubal factor infertility.

OBJECTIVE: To study the utility of testing for heat shock protein 60 (CHSP60) antibodies in the diagnosis of tubal factor infertility. DESIGN: Prospective case control. SETTING: Canadian university hospital infertility clinic. PATIENT(S): Women presenting for infertility investigation. INTERVENTION(S): Sera were collected from 77 patients. MAIN OUTCOME MEASURE(S): The relationship between tubal factor infertility and the presence of antibodies to Chlamydia trachomatis and CHSP60 was assessed. RESULT(S): There were no significant differences between antibodies to C. trachomatis in women with tubal factor infertility (63%) and other causes of infertility (46%). However, more women with tubal factor infertility (44%) had anti-CHSP60 antibodies compared with other causes of infertility (8%). Antibody testing for C. trachomatis has only a 63% sensitivity and a 54% specificity for detecting tubal factor infertility. In contrast, the CHSP60 antibody test has a 44% sensitivity and a 92% specificity for detecting tubal factor infertility. There is a good positive likelihood ratio of 5.5 for CHSP60 antibody testing detecting the presence of tubal factor infertility. Combining CHSP60 antibody with antibody testing for C. trachomatis has an excellent positive likelihood ratio of 10 for the detection of C. trachomatis-associated tubal factor infertility. CONCLUSION(S): CHSP60 antibody testing is a more accurate test than antibody testing for C. trachomatis for predicting chlamydia-associated tubal factor infertility. These tests, when used in combination at initial infertility evaluation, would provide a rapid noninterventive means of diagnosing tubal factor infertility.

Adult↗
PubMed1997

Clinical and epidemiological significance of enterococci intrinsically resistant to vancomycin (possessing the vanC genotype)

Constitutive low-level vancomycin resistance is found intrinsically in certain enterococcal species and is encoded by vanC ligase genes. These intrinsically vancomycin-resistant enterococci (VRE) will be referred to as VANC VRE. A prospective study to determine the clinical and epidemiologic significance of VANC VRE was conducted. VANC VRE were recovered from the stools of 34 of 601 (5.7%) patients, a rate similar to that obtained for the stools of 100 outpatients in the community (5%). VANC VRE were also isolated from the nonstool specimens of 9 of 538 patients (1.7%), including two patients with bacteremia. No VRE of the vanA or vanB genotypes were detected in nonstool specimens. Eighty-two hospital contacts of the first 23 patients found to be colonized or infected with VANC VRE were screened, and 6 contacts were found to be gastrointestinal carriers of VANC VRE. However, typing of isolates from these 6 contacts by pulsed-field gel electrophoresis with SmaI showed the isolates to be unique and different from those recovered from the index patients. In fact, all VANC VRE isolates from different patients in this study were unique. A case-control study with patients who were negative when screened for VANC VRE as controls failed to identify any risk factor associated with colonization or infection with this organism. VANC VRE were infrequently recovered from clinical specimens but were occasionally found as part of the normal stool flora. Since no transmission between patients was documented, additional isolation procedures may not be necessary for patients colonized or infected with VANC VRE.

Adult↗
PubMed1996

Does serologic evidence of remote Chlamydia trachomatis infection and its heat shock protein (CHSP 60) affect in vitro fertilization-embryo transfer outcome?

OBJECTIVE: To examine IVF-ET outcome in patients with and without serologic evidence of Chlamydia trachomatis infection and chlamydia heat shock protein 60 (CHSP 60) antibodies. DESIGN: Retrospective case control. SETTING: University-affiliated IVF-ET program. MAIN OUTCOME MEASURES: A total of 195 IVF-ET patients with tubal factor infertility underwent oocyte pick-up, 166 of these women had ET resulting in a total of 37 pregnancies. Serum antibody testing for evidence of remote C. trachomatis and CHSP 60, as well as pregnancy outcome, were determined for all patients. RESULTS: There were no differences in pregnancy rates or outcomes between C. trachomatis seropositive versus seronegative groups: 27/118 (23%) C. trachomatis seropositive versus 10/77 (13%) C. trachomatis seronegative patients achieved pregnancy per oocyte pick-up. Pregnancy rates per ET were 27/105 (26%) in C. trachomatis seropositive versus 10/61 (16%) C. trachomatis seronegative patients. In the C. trachomatis positive subgroup, significantly higher pregnancy rates were found in the CHSP 60 antibody positive patients: 24/67 (36%) CHSP 60 positive versus 3/51 (6.0%) CHSP 60 negative patients were pregnant after oocyte pick-up (OR = 8.9, 95% CI = 2.3 to 27.5). Pregnancy rates per ET were 24/57 (42%) in CHSP 60 positive versus 3/48 (7%) CHSP 60 negative patients (OR = 10.9, 95% CI = 2.8 to 33.6). There were no significant differences in any group when examining the following pregnancy outcomes: spontaneous abortion, ectopic pregnancy, preterm and multiple pregnancy rates. CONCLUSIONS: [1] There are no differences in pregnancy rates or outcomes in patients with and without serologic evidence of previous C. trachomatis infections. [2] In women seropositive for C. trachomatis, significantly higher pregnancy rates are found in women who are CHSP 60 antibody positive versus negative. [3] Pregnancy outcomes do not appear to be different between these groups.

Antibodies, Bacterial↗