ABSTRACT
Prevention and management of Clostridium difficile infection (CDI) can be improved by rapid and reliable diagnostics. The Vidas C. difficile glutamate dehydrogenase assay had performance comparable to that of the Quik Chek-60 assay (overall agreement, 95%) and a sensitivity of >93%; thus, it is suitable as the first test in two-stage algorithms for a CDI diagnosis.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Bacterial Proteins/genetics , Bacterial Typing Techniques/methods , Clostridioides difficile/isolation & purification , Enzyme-Linked Immunosorbent Assay/methods , Feces/microbiology , Polymerase Chain Reaction/methods , Adolescent , Adult , Child , Child, Preschool , Clostridioides difficile/genetics , Culture Media , Enterocolitis, Pseudomembranous/diagnosis , Enterocolitis, Pseudomembranous/microbiology , Humans , Infant , Infant, Newborn , Male , Middle Aged , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
Sepsis caused by Staphylococcus aureus is a major health problem worldwide. Better outcomes are achieved when rapid diagnosis and determination of methicillin susceptibility enable early optimization of antimicrobial therapy. Eight large clinical laboratories, seven from the United States and one from Scotland, evaluated the combination of the Staphylococcus QuickFISH BC and the new mecA XpressFISH assay (both AdvanDx, Woburn, MA, USA) for the detection of methicillin-resistant S. aureus in positive blood cultures. Blood cultures flagged as positive by automated blood culture instruments and demonstrating only Gram-positive cocci in clusters on Gram stain were tested by QuickFISH, a 20-min assay. If only S. aureus was detected, mecA XpressFISH testing followed. The recovered S. aureus isolates were tested by cefoxitin disk diffusion as the reference method. The QuickFISH assay results were concordant with the routine phenotypic testing methods of the testing laboratories in 1,211/1,221 (99.1%) samples and detected 488/491 S. aureus organisms (sensitivity, 99.4%; specificity, 99.6%). Approximately 60% of the samples (730) contained coagulase-negative staphylococci or nonstaphylococci as assessed by the QuickFISH assay and were not tested further. The 458 compliant samples positive exclusively for S. aureus by the QuickFISH assay were tested by the mecA XpressFISH assay, which detected 209 of 211 methicillin-resistant S. aureus organisms (sensitivity, 99.1%; specificity, 99.6%). The mecA XpressFISH assay also showed high reproducibility, with 534/540 tests performed by 6 operators over 5 days achieving reproducible results (98.9% agreement). The combination of the Staphylococcus QuickFISH BC and mecA XpressFISH assays is sensitive, specific, and reproducible for the detection of methicillin-resistant S. aureus and yields complete results in 2 h after the blood culture turns positive.
Subject(s)
Blood/microbiology , In Situ Hybridization, Fluorescence/methods , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Molecular Diagnostic Techniques/methods , Sepsis/diagnosis , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Bacteriological Techniques/methods , Humans , Methicillin-Resistant Staphylococcus aureus/genetics , Reproducibility of Results , Scotland , Sensitivity and Specificity , Sepsis/microbiology , United StatesABSTRACT
The combustion of western U.S. coals releases significant amounts of strontium, which is relatively enriched in the fine particles of fly ash. Fly ash-derived strontium is readily absorbed by agronomic and native plant species when incorporated in soil. The strontium-87 to strontium-86 ratios of fly ash and soils were significantly different, but similar ratios were found in fly ash and plants treated with fly ash. A technique for measuring and monitoring deposition from coal-fired power plants is inferred from the enhanced plant uptake of fly ash strontium and the similarity in the isotopic ratios of fly ash and treated plants.
ABSTRACT
Ovarian and adrenal function were studied in premenopausal breast cancer patients before and at intervals during adjuvant therapy with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF), CMF plus prednisone (CMFP), or CMFP plus tamoxifen (CMFPT). Amenorrhea developed within 10 months of starting therapy in 13 of 15 patients given CMF, 8 of 10 receiving CMFP, and all of 13 CMFPT-treated patients. The amenorrheic patients receiving CMF showed a reduction in their plasma total estrogens and an increase in plasma luteinizing and follicle-stimulating hormones, indicating that these cytotoxic drugs directly suppressed ovarian function. Plasma androstenedione levels, which are derived equally from the ovaries and adrenals before the menopause, were also reduced. Plasma dehydroepiandrosterone sulfate, a steroid predominantly of adrenal origin, was unaffected. CMFP-induced amenorrhea was associated with similar changes in the plasma estrogens and gonadotropins, but patients receiving this combination showed significantly greater reductions in plasma androstenedione and also decreased levels of plasma dehydroepiandrosterone sulfate. Suppression of androstenedione secretion from both the ovaries and adrenals did not affect the total plasma estrogen concentrations. Initially, CMFPT-treated patients showed significant elevations in plasma total estrogens, without a change in the gonadotropin levels. Although the plasma sex hormone-binding capacity was increased during CMFPT therapy, there was only a small reduction in the percentage of free plasma estradiol, with the result that the level of circulating unbound estrogen was increased. The plasma estrogens declined, with a corresponding increase in gonadotropins, after the onset of CMFPT-inducted amenorrhea.
Subject(s)
Adrenal Cortex/physiopathology , Antineoplastic Agents/administration & dosage , Breast Neoplasms/drug therapy , Ovary/physiopathology , Prednisone/administration & dosage , Tamoxifen/administration & dosage , Androstenedione/blood , Breast Neoplasms/physiopathology , Dehydroepiandrosterone/blood , Drug Therapy, Combination , Estradiol/blood , Estrone/blood , Female , Follicle Stimulating Hormone/blood , Humans , Luteinizing Hormone/blood , Menstruation/drug effects , Sex Hormone-Binding Globulin/metabolismABSTRACT
After review of the published clinical experience with systemic hypothermia, we concluded that a simple system which controls radiant heat balance to supplement metabolic heat might provide several advantages, including: (a) decreased morbidity; (b) elimination of the requirement for general anesthesia; (c) improved patient comfort; (d) favorable cost-benefit considerations. We have tested a prototype radiant heat device for whole-body hyperthermia (WBH) in patients with disseminated cancer. From preclinical evaluation of this device, the lightly anesthetized pig was found to be an ideal model for WBH. This species has physiological characteristics closely resembling those of humans. The pig's core, pulmonary artery, liver, rectal, and esophageal temperatures were raised to 41.8 degrees in 80 to 90 min. The air temperatures near the chamber wall never exceeded 65 degrees while the air temperature adjacent to the animal was 46 degrees. Skin temperatures were approximately 42.5 degrees at a core temperature of 41.8 degrees. Once the core temperature is raised to 41.8 degrees, this temperature is maintainable for approximately 3.5 hr without additional external heating if evaporative losses are controlled. Prolonged WBH was accomplished with light sedation and without the requirement for endotracheal intubation. No significant acute toxicity was encountered in a series of 6 pigs undergoing 9 separate exposures to WBH. From these results, we conclude that our radiant heat apparatus is feasible for clinical trials. Additionally, the use of the pig as an appropriate animal model for further physiological and pharmacological WBH studies is strongly recommended.
Subject(s)
Body Temperature , Equipment and Supplies , Hot Temperature/therapeutic use , Neoplasms/therapy , Animals , Blood Pressure , Cardiac Output , Evaluation Studies as Topic , Female , Humidity , Swine , Time FactorsABSTRACT
The activity of an isoenzyme of alkaline phosphatase (FHAP) was measured in serum samples obtained from 1692 individual subjects. The median FHAP concentration in patients with untreated or recurrent cancer (2.73 IU/liter) was two-fold higher than in hospitalized control patients with illnesses other than cancer (1.17 IU/liter) and three-fold higher than in healthy control subjects (0.93 IU/liter). Among patients with either breast or colorectal cancer who were clinically disease free following their initial therapy, the median FHAP concentration (1.54 IU/liter) was intermediate between the median FHAP concentration in patients with untreated or recurrent cancer and that of healthy control subjects. In order to illustrate the potential clinical application of FHAP as a diagnostic cancer marker, we have selected a serum FHAP concentration of 2.22 IU/liter as a reference value above which only 3% of healthy control subjects would have a "positive" test. Utilizing this reference value, 58% of the patients in the present study with untreated or recurrent cancer would have a positive FHAP test, whereas only 11%, of hospitalized patients with illnesses other than cancer would have a positive test. These data suggest that FHAP may be equivalent to the carcinoembryonic antigen as a diagnostic cancer marker.
Subject(s)
Alkaline Phosphatase/isolation & purification , Isoenzymes/isolation & purification , Neoplasms/enzymology , Adult , Alkaline Phosphatase/antagonists & inhibitors , Breast Neoplasms/enzymology , Colonic Neoplasms/enzymology , Female , Homoarginine/pharmacology , Humans , Male , Middle Aged , PregnancyABSTRACT
A Phase I study of whole-body hyperthermia (WBH) (52 treatments/12 patients) was completed with no significant clinical toxicity. The study incorporated a thermal dose escalation scheme from 39.5 degrees-41.8 degrees C for up to 151 min. A radiant-heat device was utilized for producing WBH. During WBH, patients were sedated; endotracheal intubation was not required. No changes in cardiovascular, respiratory, hematological, or biochemical indices requiring clinical intervention occurred during the study. We conclude the radiant-heat device coupled with a defined pharmacological approach to WBH with appropriate patient screening yields a system for 41.8 degrees C WBH which is safe and efficient, is not labor intensive, and does not require general anesthesia and endotracheal intubation. This system is appropriate for a multimodality approach to various systemic cancers.
Subject(s)
Hyperthermia, Induced/instrumentation , Neoplasms/therapy , Adolescent , Adult , Alkaline Phosphatase/analysis , Aspartate Aminotransferases/blood , Blood Cell Count , Blood Glucose/analysis , Creatine Kinase/blood , Evaluation Studies as Topic , Female , Heart/physiopathology , Humans , Hyperthermia, Induced/adverse effects , L-Lactate Dehydrogenase/blood , Lung/physiopathology , Male , Middle Aged , Neoplasms/blood , Neoplasms/physiopathologyABSTRACT
The diagnostic value of a recently described cancer marker, fast homoarginine-sensitive alkaline phosphatase ( FHAP ), was compared with the established marker, carcinoembryonic antigen (CEA), in the diagnosis of colon cancer. Comparisons were made with respect to sensitivity, specificity, predictive value of a positive result, and efficiency. An upper limit of normal of 2.1 units/L was assumed for FHAP , based on earlier studies. Two values for the upper limit of normal for CEA were tested: 2.5 ng/mL and 5.0 ng/mL. When 2.5 ng/mL was used as the upper limit of normal for CEA, FHAP was less sensitive, more specific, and had a higher predictive value. The diagnostic efficiency was not significantly different. When the upper limit of normal for CEA was set at 5.0 ng/mL, the two tests were roughly equal in sensitivity, specificity, predictive value, and diagnostic efficiency.
Subject(s)
Alkaline Phosphatase/blood , Carcinoembryonic Antigen/analysis , Colonic Neoplasms/enzymology , Isoenzymes/blood , Colonic Neoplasms/immunology , Humans , Reference ValuesABSTRACT
One hundred twenty-eight patients with purely nodular lymphocytic poorly differentiated lymphoma (NLPDL) without any prior therapy, entered on Eastern Cooperative Oncology Group protocol EST 2474, were analyzed for response, progression-free and overall survival. The restaged complete response rates with cyclophosphamide-prednisone (CP) (moderate regimen) of 54% compared favorably with those of the more intensive regimens; cyclophosphamide, vincristine, procarbazine and prednisone (COPP) (56%) and BCNU, cyclophosphamide, vincristine, and prednisone (BCVP) (53%). The toxicity of the regimens decreased from BCVP to COPP to CP. The median survival rate for the entire group was 7.8 years. Estimated progression-free survival at five years by regimen was COPP, 57%; BCVP, 26%; CP, 22% (P = .02). No other prognostic parameter significantly affected progression-free survival. In spite of the better progression-free survival of COPP-treated patients, the overall survival rates with the different induction regimens were similar. Maintenance therapy for patients in complete response at the end of induction therapy with periodic BCVP reinduction did not significantly affect the disease-free or overall survival. Cyclophosphamide-prednisone is a minimally toxic regimen effective in the treatment of NLPDL, but COPP, in view of its acceptable toxicity in this patient population and apparent superiority in providing a longer disease-free state, deserves further testing.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lymphoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carmustine/administration & dosage , Cyclophosphamide/administration & dosage , Female , Follow-Up Studies , Humans , Leukopenia/chemically induced , Lymphoma/pathology , Male , Middle Aged , Neoplasm Staging , Prednisone/administration & dosage , Procarbazine/administration & dosage , Prognosis , Random Allocation , Risk , Vincristine/administration & dosageABSTRACT
Ninety-seven eligible and evaluable women with metastatic breast cancer were placed on a prospective clinical protocol to evaluate the use of continuous cyclic therapy with dibromodulcitol, doxorubicin, vincristine, tamoxifen, and fluoxymesterone (DAVTH) v DAVTH alternating with cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone (CMFP); and the use of pretreatment and serial carcinoembryonic antigen (CEA) levels in these patients. Continuous DAVTH and DAVTH/CMFP were equivalent therapies with respect to response rates, time to treatment failure (TTF), and survival. Pretreatment CEA levels were elevated (greater than 5 ng/mL) in 42/97 patients and less than 5 ng/mL in the remaining patients. Patients with elevated pretreatment CEA levels were more likely to be estrogen receptor (ER) positive (P = .006), to have prolonged disease-free intervals (P = .017), to have hepatic (P = .004) and/or osseous (P = .01) metastases, and to have multiple sites of metastatic disease (P = .004). Pretreatment CEA levels did not significantly predict for overall response rates, TTF, or survival; nonetheless, those patients with low pretreatment CEA levels had more complete responses (CRs) (16/55 v 4/42; P = .02). Serial CEA levels during therapy revealed a number of interesting patterns. During the first 4 months of treatment, serial CEA levels in responding patients either (1) progressively declined (15/29 women with elevated pretreatment CEA levels), or (2) initially rose significantly (mean, 243% of pretreatment value) and then declined (14/29 women with elevated pretreatment CEA levels). Peak CEA levels in the latter patients were seen 27 to 135 days following initiation of cytotoxic therapy. In some patients the initial increase in the CEA level was incorrectly interpreted as evidence of impending disease progression. CEA levels frequently increased around the time of clinical disease progression. However, rising CEA levels rarely provided a clinically meaningful lead time before the appearance of other clinical evidence of disease progression. These data suggest that routine pretreatment and monthly serial CEA levels in metastatic breast cancer patients have minimal use in clinical practice. Two further noteworthy findings were observed in this prospective study. First, patients with an unknown ER status had a prolonged median survival when compared with patients with ER positive or negative tumors; this appeared to be related to prolonged disease-free intervals in ER unknown patients. Second, two case of secondary acute leukemia were seen in patients treated with continuous DAVTH therapy.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Breast Neoplasms/drug therapy , Carcinoembryonic Antigen/analysis , Clinical Laboratory Techniques , Clinical Trials as Topic , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Drug Administration Schedule , Female , Fluorouracil/administration & dosage , Fluoxymesterone/administration & dosage , Follow-Up Studies , Humans , Methotrexate/administration & dosage , Mitolactol/administration & dosage , Neoplasm Metastasis , Prednisone/administration & dosage , Prognosis , Prospective Studies , Random Allocation , Tamoxifen/administration & dosage , Vincristine/administration & dosageABSTRACT
PURPOSE: This study analyzes the long-term results and causes of death in elderly women with node-positive breast cancer who participated in a double-blind adjuvant trial that compared tamoxifen with placebo to determine the benefit of 2 years of treatment. PATIENTS AND METHODS: One hundred eighty-one women 65 to 84 years old were given 20 mg of tamoxifen or placebo daily for 2 years after stratification by estrogen receptor status, tumor size, and degree of lymph node involvement. Approximately 30% of patients were older than 70 years and 20% were older than 75 years. Eighty-five percent were estrogen receptor-positive. Median follow-up was 10 years. RESULTS: Among the 168 eligible patients, there have been 98 recurrences (59 placebo v 39 tamoxifen), with reduced distant and bone-only first sites in patients treated with tamoxifen. Median time to failure was 4.4 years for placebo versus 7.4 years for tamoxifen (log-rank P = .001). A similar number of new nonbreast cancers occurred in each arm (seven placebo v six tamoxifen), but a reduced number of opposite-breast cancers (five placebo v one tamoxifen) was noted. Overall, there were 102 deaths (57 placebo v 45 tamoxifen). Median survivals were 8.0 years with placebo and 8.5 years with tamoxifen (log-rank P = .063); 50% of the tamoxifen patients and 33% of the placebo patients are still alive. Sixty-one percent of the deaths were reported to have been caused by breast cancer recurrence, 4% by other cancers, and 22% by the sequelae of non-cancer-related illness, with equal distributions for cardiovascular and cerebrovascular disease. There was no increase in the number of endometrial or other types of cancer, or thrombotic or orthopedic complications in this older group. CONCLUSION: Tamoxifen currently is the treatment of choice for elderly women with breast cancer. It extends the time to treatment failure by 3 years and reduces the number of recurrences, deaths, distant and bone-only first recurrences, and second breast cancers.
Subject(s)
Breast Neoplasms/drug therapy , Tamoxifen/therapeutic use , Aged , Aged, 80 and over , Breast Neoplasms/pathology , Cause of Death , Chemotherapy, Adjuvant , Female , Humans , Lymphatic Metastasis , Prospective Studies , Receptors, Estrogen/physiology , Survival Analysis , Treatment OutcomeABSTRACT
Plasma triiodothyronine (T3), reverse T3 (rT3), thyroxine (T4), total thyroid hormone-binding globulin (TBG) capacity, and serum albumin were assayed in patients with early and advanced breast and colonic cancer and in healthy women. Plasma T3 levels were reduced in both breast cancer group, but were reduced only in colonic cancer patients with systemic metastases. Plasma rT3 was normal in early cancer, but increased in nine of 38 (24%) with advanced breast cancer and four of 17 (24%) with metastatic colonic cancer; in consequence their rT3/T3 ratios were elevated. Plasma T4 concentrations were normal in all patient groups. Plasma TBG capacity was reduced in breast cancer patients with systemic metastases and a similar tendency occurred in metastatic colonic cancer. Levels of TBG were positively correlated with the serum albumin values. These changes were associated particularly with liver metastases.
Subject(s)
Breast Neoplasms/blood , Carcinoma/blood , Colonic Neoplasms/blood , Thyronines/blood , Adult , Female , Humans , Liver Neoplasms/secondary , Middle Aged , Thyroxine/blood , Thyroxine-Binding Proteins/analysis , Triiodothyronine/bloodABSTRACT
Malignancy-associated hypercalcemia is a common and recalcitrant problem. Current modes of therapy are often ineffective or prohibitively toxic. Clodronate disodium is a diphosphonate capable of inhibiting bone resorption resulting in a hypocalcemic effect. In this randomized, placebo-controlled study, we investigated the effect of hydration only (Rx-1) vs the effect of hydration plus either intravenously administered clodronate disodium, 4 mg/kg of body weight per day for three days (Rx-2) or intravenously administered clodronate disodium, 12 mg/kg of body weight given once only (Rx-3). By the third day of observation, Rx-2 produced a significant 2.8 mg/dL (0.70 mmol/L) reduction in serum calcium levels, whereas Rx-1 and Rx-3 did not produce a significant hypocalcemic effect when compared with baseline values. There were no toxicities observed. Intravenously administered clodronate appears to be an excellent agent for the acute treatment of malignancy-associated hypercalcemia.
Subject(s)
Clodronic Acid/therapeutic use , Diphosphonates/therapeutic use , Hypercalcemia/drug therapy , Neoplasms/complications , Adult , Aged , Clinical Trials as Topic , Double-Blind Method , Female , Humans , Hypercalcemia/etiology , Male , Middle Aged , Random Allocation , Saline Solution, Hypertonic/therapeutic useABSTRACT
Breast cancer is the most common malignancy of women in the United States, affecting one out of every 13 women at some time in their lives. Although only 10% of patients have demonstrable distant metastases at the time of diagnosis, a majority will eventually die of disseminated disease. Chemotherapy was formerly considered to be the treatment of last resort in patients with breast cancer, reserved for those who had failed surgery, radiotherapy and hormonal manipulation. However, combination chemotherapy has now been shown to be highly effective. The most active drug combinations produce objective tumour regression in about 60% of patients with advanced disease. Parallel to the development of effective chemotherapy, there has been a renewal of interest in hormonal therapy. The ability to predict whether or not a patient will respond to hormonal therapy has been improved significantly by the clinical application of the oestrogen receptor assay. The selection of a specific treatment for the patients with advanced breast cancer must be individualised. It should take into account a number of prognostic variables, including: sites of metastatic involvement; total extent of disease; disease free interval; menopausal status; and the presence or absence of oestrogen receptor in tumour tissue. The final decision regarding treatment should then be based not only on the probability of response, but also on the anticipated degree of toxicity. Current efforts to improve the management of advanced breast cancer include the development of more effective drug regimens and the combination of chemotherapy with hormonal manipulation. For instance, it would appear that in premenopausal patients, the combination of chemotherapy with oophorectomy may yield results that are superior to those achieved with either treatment alone. The most promising development in the management of early breast cancer has been the use of chemotherapy as an adjuvant treatment in patients with operable disease.
Subject(s)
Breast Neoplasms/drug therapy , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Drug Therapy, Combination , Humans , PrognosisABSTRACT
The role of endocervical curettage was studied in women with cervical dysplasia who underwent satisfactory colposcopic evaluation. Among 1130 women seen in the colposcopy clinic of a large city hospital during a 2-year period, 96 with satisfactory colposcopy and positive endocervical curettage constituted the study group. In these patients, the extent of dysplasia in the endocervical canal in cone biopsy specimens was measured using an ocular micrometer. When true-positive endocervical curettage was defined as dysplasia extending 5 mm or more inside the transformation zone, the false-positive rate for endocervical curettage was 81.8%. No patient with mild or moderate dysplasia on endocervical curettage had dysplasia that was more than moderate in degree or that extended more than 4.5 mm inside the transformation zone on histopathologic examination of the cone biopsy specimen. Because of the high rate of false-positive endocervical curettage, patients with mild and moderate dysplasia and selected women with severe dysplasia in endocervical curettings could be treated by local cervical ablation, with follow-up by endocervical curettage.
Subject(s)
Colposcopy , Curettage , Uterine Cervical Dysplasia/diagnosis , Adult , Biopsy , Carcinoma in Situ/diagnosis , Carcinoma in Situ/pathology , Cervix Uteri/pathology , Curettage/methods , Cytodiagnosis , False Positive Reactions , Female , Humans , Middle Aged , Uterine Cervical Dysplasia/pathology , Uterine Cervical Dysplasia/surgery , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Neoplasms/pathologyABSTRACT
The case of a 33-year-old white female with an endodermal sinus tumor of the ovary who manifested remission of her disease as a result of the intermittent administration of chlorambucil is described. This remission following chemotherapy with a single alkylating agent is unusual.
Subject(s)
Chlorambucil/therapeutic use , Ovarian Neoplasms/drug therapy , Adult , Female , Humans , Ovarian Neoplasms/pathology , Ovarian Neoplasms/surgery , Remission, SpontaneousABSTRACT
We compared the BACTEC 9240 continuous-read instrument using Peds Plus/F, Lytic/F, Aerobic/F, and Anaerobic/F media (Becton Dickinson Diagnostic Instrument Systems, Sparks, MD) with and without fastidious organism supplement to conventional centrifugation preparation and plating for the recovery and speed of detection of microorganisms. A total of 908 sterile body fluid specimens were collected and processed, yielding 116 (13%) positive cultures. Of the 80 isolates considered clinically significant, 48 (60%) were recovered by both the BACTEC system and conventional culture, whereas 32 (40%) were recovered by BACTEC only. No clinically significant isolates were recovered only by conventional culture methods. The time to detection for isolates recovered from both sets was faster for BACTEC. It was found that BACTEC, with or without the addition of fastidious organisms supplement, exhibited improved sensitivity for the recovery of microorganisms.
Subject(s)
Body Fluids/microbiology , Enterobacteriaceae/isolation & purification , Gram-Negative Bacteria/isolation & purification , Staphylococcus/isolation & purification , Streptococcus/isolation & purification , Bacteria, Anaerobic/isolation & purification , Body Fluids/chemistry , Culture Media/economics , Humans , Microbiological Techniques , Yeasts/isolation & purificationABSTRACT
To develop safe and rapid methods for identification of Staphylococcus aureus and Streptococcus pneumoniae directly from positive blood culture bottles (BCB) (BACTEC, Johnston Laboratories), several commercial biochemical and immunological tests as well as modified conventional tests were evaluated. Preliminary studies demonstrated that both S. aureus and St. pneumoniae could be identified directly using only a small aliquot (100 microliters) of the blood culture broth obtained via vent without need for centrifugation or other separation steps. A simple tube coagulase exhibited 98% sensitivity and 100% specificity for 32 S. aureus isolates and 157 blood cultures positive for coagulase-negative staphylococci when read at 2 hr. All systems employed for direct identification of St. pneumoniae exhibited excellent sensitivity and specificity using aliquots from blood culture broths, but Pneumoslide (BBL Microbiology Systems, Cockeysville, MD) was easiest to perform and interpret. The results of this study show that S. aureus and St. pneumoniae can be identified directly from blood culture broth aliquots using rapid methods that eliminate the need for centrifugation or use of needles and syringes.
Subject(s)
Bacteriological Techniques , Blood/microbiology , Staphylococcus aureus/isolation & purification , Streptococcus pneumoniae/isolation & purification , Humans , Sensitivity and Specificity , Staphylococcus aureus/growth & development , Streptococcus pneumoniae/growth & developmentABSTRACT
Chemiluminescent DNA probes (AccuProbe, species specific; and FlashTrack, bacterial generic) were used to determine oxacillin resistance in Staphylococcus aureus. Ribosomal RNA was measured at designated intervals in the presence and absence of antibiotic. A total of 48 (AccuProbe assay) and 24 (FlashTrack) S. aureus isolates with known oxacillin susceptibility patterns were inoculated into Bactec 6A bottles both with and without 4 micrograms/ml oxacillin and incubated at 35 degrees C for 4 h. Aliquots were removed at 0 and 4 h, and pellets of bacteria were obtained via selective centrifugation. Probe assay counts (relative light units, RLUs) were performed. Of 21 oxacillin-resistant S. aureus (ORSA) strains, 20 showed a > 5-fold RLU increase during the incubation period (Accu-Probe assay): 25 of 27 oxacillin-susceptible strains demonstrated a < or = 4-fold increase. AccuProbe test sensitivity and specificity were 95% and 92%, respectively. With the generic FlashTrack probe assay, all nine ORSA isolates showed a > or = 4- to 10-fold increase in RLUs, and all 15 oxacillin-susceptible strains showed a < or = 4-fold increase in RLUs during the 4-h incubation. The FlashTrack test sensitivity and specificity were both 100%. Probe assays were completed within 5 h. This study suggests that rapid and reliable determination of oxacillin resistance in S. aureus clinical isolates can be accomplished using commercially available DNA probes.
Subject(s)
DNA Probes , Oxacillin/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Bacteriological Techniques , Evaluation Studies as Topic , Humans , Luminescent Measurements , Microbial Sensitivity Tests , Molecular Probe Techniques , Penicillin Resistance/genetics , Staphylococcal Infections/drug therapy , Staphylococcus aureus/isolation & purificationABSTRACT
Eight Neisseria gonorrhoeae isolates, negative by direct fluorescent antibody (DFA) but positive by a DNA probe, were characterized by pulsed field gel electrophoresis and compared to eight DFA-positive, probe-positive isolates. Results indicate that DFA-negative, probe-positive Neisseria gonorrhoeae isolates may be clonal.