PubMed Health⌕ Search

Biomedical subjects

M Krajden

Publications and source records attributed to M Krajden.

At least 37 records · Page 2Linked to original sources

Oral prostaglandin (PGE2) therapy for chronic viral hepatitis B and C.

The cytoprotective effects of prostaglandins have been utilized in the prevention of hepatitis B virus reactivation after liver transplantation. This pilot study evaluated the effects of oral prostaglandin E2 (PGE2) in chronic viral hepatitis B and C. Twenty patients with chronic hepatitis B and 20 patients with chronic hepatitis C received 4mg day-1 PGE2 for 6 months. The lymphocyte antiviral enzyme 2',5'-oligoadenylate synthetase (2',5'-OAS) and peripheral blood monocyte procoagulant activity (PCA) were measured before, during and after the treatment. Three of 20 hepatitis B and five of 20 hepatitis C patients withdrew from the study. Eight of 17 hepatitis B patients responded: in seven of these eight patients, serum alanine aminotransferase (ALT) levels normalized; loss of viral replication was sustained in all eight patients; and seroconversion from hepatitis Be antigen (HBeAg) to hepatitis Be antibody (HBeAb) positivity occurred in seven patients over the 48-week duration of this study. In 14 of the 15 hepatitis C patients, hepatitis C virus (HCV) RNA remained detectable and the serum ALT levels remained elevated. 2',5'-OAS levels and PCA values did not correlate with other markers of response to PGE2 therapy in either chronic hepatitis B or C. In summary, PGE2 was associated with sustained loss of viral replication in 47% of chronic hepatitis B patients; no beneficial effects were apparent in chronic hepatitis C.

2',5'-Oligoadenylate Synthetase↗

Effect of multiple freeze-thaw cycles on hepatitis B virus DNA and hepatitis C virus RNA quantification as measured with branched-DNA technology.

Quantification of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA often is performed in specimens that have been frozen and thawed more than once. To ensure optimal therapeutic and prognostic value, it is important to establish whether viral load measurements are affected by repeated freeze-thaw (FT) cycles. We therefore evaluated the effect of multiple FT cycles on HBV DNA and HCV RNA quantification by testing serum specimens subjected to one (baseline), two, four, and eight FT cycles with the appropriate Chiron Quantiplex assay. Linear regression analysis showed minor increases of 1.7% per FT cycle for both HBV DNA and HCV RNA. The rise in HCV RNA levels was more pronounced among low-concentration samples, since further analysis revealed an increase of 3.2% per FT cycle among samples with 0.2 to 3.86 Meq of HCV RNA per ml. Given that the coefficient of variation for the Quantiplex assays is generally 10 to 15%, the minor increases in HBV DNA and HCV RNA levels with progressive FT cycles for the specimens tested were recognized only because analysis of variance revealed a statistically significant trend (P < 0.05). Due to the minor statistical trend, the clinical impact for individual patient specimens is likely to be limited, but it may deserve further study. In conclusion, the concentration of HBV DNA and HCV RNA in serum specimens subjected to up to eight short-term FT cycles was stable.

DNA, Viral↗

Polymerase chain reaction based assessment of leukoreduction efficacy using a cytomegalovirus DNA transfected human T-cell line.

BACKGROUND AND OBJECTIVES: Detection of CMV DNA by PCR in seropositive blood donors is affected by nucleic acid extraction, amplification conditions and PCR product detection sensitivity. Clinical studies have shown that leukoreduced blood products are as effective as CMV-seronegative blood products in minimizing transfusion-associated CMV infection. We developed a PCR-based test model to assess the efficacy of leukoreduction on the removal of CMV DNA from blood donations. MATERIALS AND METHODS: Whole blood units were spiked with a human Jurkat T-lymphocyte cell line which had been stably transfected with a CMV DNA immediate early sequence. All blood units were either CMV seronegative or shown to be CMV PCR negative. The amount of CMV DNA by PCR before, during and after filtration of blood units with third-generation leukocyte reduction filters were determined using a semi-quantitative adaptation of the Digene SHARP Signal System Assay (DSSSA). RESULTS: Whole blood units spiked with 1-2 x 10(6) CMV transfected Jurkat cells contained no detectable CMV DNA after leukoreduction. With a higher inoculum of 2.9 x 10(8) transfected Jurkat cells per unit, CMV DNA was detected after leukoreduction; however, there was an approximate 3 log decrease in the amount of CMV DNA detected. CONCLUSION: This CMV DNA transfected human Jurkat cell line in conjunction with semi-quantitative CMV PCR may be used to model leukoreduction efficacy and provides evidence that leukoreduction of blood products can decrease the amount of cellular CMV DNA by approximately 3 logs.

Cytomegalovirus↗

Multi-measurement method comparison of three commercial hepatitis B virus DNA quantification assays.

Serum specimens (327) from patients with chronic hepatitis B were evaluated for hepatitis B virus (HBV) DNA using three commercial assays--Chiron Quantiplex (CA), Digene Hybrid Capture (DA) and Abbott HBV DNA assay (AA). The HBV DNA values obtained following evaluation were used to compare the linearity, responsiveness and precision of each assay and to determine the conversion between the three different assay values. The comparison was accomplished using a new statistical approach termed the multi-measurement method (MMM). MMM is a minimal bias, non-linear regression technique that allows simultaneous multiassay performance evaluation as well as assay value interconversion. MMM analysis demonstrated that the CA was more sensitive and responsive than either the DA or the AA. Both the CA and DA were more precise than the AA. Validation of the MMM results was performed using two additional data sets of 551 and 100 specimens, respectively. MMM is a novel statistical tool that has a broad application for the generation of statistically normalized laboratory data and for interassay standardization.

DNA, Viral↗

Durability of serological remission in chronic hepatitis C treated with interferon-alpha-2B.

OBJECTIVE: We assessed the long-term effect of a course of interferon therapy on the biochemical and virological markers of Canadian patients with chronic hepatitis C. METHODS: Thirty-six patients with chronic hepatitis C were treated with a median total dose of interferon-alpha-2B of 181.0 million U (range 109.0-384.0 million U) and were followed for a median of 37.2 months (range 12.0-94.2 months) after completing treatment. All patients received an initial 16 wk of interferon at a dose of 3 million U three times weekly; this was followed by either no further interferon or by 8 wk more at doses ranging from 1.5 to 10.0 million U three times weekly. Serum alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA levels were measured before interferon therapy, 6 months after treatment, and at the end of follow-up for each patient. HCV RNA was analyzed by branched DNA 1.0 assay and, if undetectable, by polymerase chain reaction. HCV genotyping was performed on serum samples. RESULTS: Five (13.6%) of the 36 patients had a sustained treatment response, defined as normal ALT and undetectable viremia 6 months after treatment. All five patients remained in serological remission to the end of their follow-up, a median of 48.2 months (range 23.0-66.2 months) after interferon therapy. Responders were similar to nonresponders in age, gender, initial ALT and serum HCV RNA levels, pretreatment histology, and total dose of interferon received. CONCLUSIONS: In patients with chronic hepatitis C, 13.6% had normal ALT and undetectable serum HCV RNA 6 months after finishing interferon therapy. These patients remained in serological remission to the end of their follow-up, 48.2 months after interferon therapy.

Adult↗

Long-term predictive value of a single cytomegalovirus (CMV) DNA PCR assay for CMV disease in human immunodeficiency virus-infected patients.

Universal prophylaxis with oral ganciclovir is not cost-effective for the prevention of cytomegalovirus (CMV) disease in human immunodeficiency virus infection. For a preemptive strategy to be considered, patients at highest risk for CMV disease need to be easily and accurately identified. In this study, the sensitivity, specificity, positive predictive value, and negative predictive value of a single CMV DNA PCR assay for the subsequent development of CMV disease were 0.75, 0.89, 0.75, and 0.89, respectively.

AIDS-Related Opportunistic Infections↗

Assessment of hepatitis B virus DNA stability in serum by the Chiron Quantiplex branched-DNA assay.

Quantification of hepatitis B virus (HBV) DNA in serum is used to establish eligibility for treatment and to monitor therapeutic response. With the trend toward centralized testing, defining the conditions that preserve sample integrity is of paramount importance. We therefore evaluated the stability of HBV DNA in 26 previously frozen (PF) and 5 fresh, never previously frozen serum specimens. PF specimens, covering a 3-log10 HBV DNA dynamic range, were thawed and stored at -70, 4, 23, 37, and 45 degrees C (+/-1.5 degrees C) for 0, 24, 72, and 120 h (+/-2 h) and were refrozen at -70 degrees C prior to testing. Five fresh specimens were split into two groups. Both group FG1 and group FG2 specimens were handled as described above; however, group FG1 specimens were subsequently maintained at 4 degrees C and were never frozen prior to testing. Linear regression analysis of PF specimens demonstrated no significant HBV DNA degradation at < or =4 degrees C over 5 days; however, HBV DNA levels decreased by 1.8, 3.4, and 20% per day at 23, 37, and 45 degrees C, respectively. Three independent statistical methods confirmed that the probability of specimen failure, defined as a loss of 20% or more of HBV DNA and/or coagulation of serum, was lowest at < or =4 degrees C and increased with temperature. Because only 10 to 20% of individual patient specimens demonstrated losses of HBV DNA of > or =20% at 23 or 37 degrees C, sufficient numbers of serum specimens must be evaluated to determine overall statistical trends. In conclusion, HBV DNA integrity in separated serum specimens is preserved for at least 5 days when the specimens are stored at -70 or 4 degrees C.

DNA, Viral↗

Cytomegalovirus viremia in lung transplant recipients receiving ganciclovir and immune globulin.

BACKGROUND: Cytomegalovirus (CMV) disease is an important cause of organ transplant-related morbidity and mortality. During the last 5 years at our institution, prophylactic ganciclovir and hyperimmune globulin have been routinely administered to lung transplant recipients whenever the donor or the recipient was CMV antibody-positive. We sought to assess the efficacy of prophylaxis on viremia, CMV disease, and bronchiolitis obliterans syndrome (BOS). METHODS: A retrospective chart review of 61 consecutive lung transplants performed between recipients between January 1993 and August 1995 was performed. Fifty-six patients who survived at least 1 month were analyzed. Patients were considered at risk for CMV disease whenever pretransplant donor or recipient serology was positive. RESULTS: Fourteen of the 39 patients at risk (36%) had viremia while on prophylaxis. The rate of CMV disease was 13% during the first 6 months following transplantation. A donor whose CMV serology was positive appeared to increase the risk of BOS in a Cox regression model (relative risk=2.4; 95% confidence interval=0.86-6.74; p=0.0957). Neither age, CMV infection (viremia or a positive specimen from BAL), recipient's serology at the time of transplantation, or CMV disease was associated with BOS. None of these variables was associated with mortality on Cox regression analysis or univariate analysis. CONCLUSIONS: Administration of combination ganciclovir and hyperimmune globulin prophylactic therapy to lung transplant recipients at risk for CMV infection and disease is associated with a relatively low incidence of disease, which appears only after prophylaxis treatment with ganciclovir is completed. Ganciclovir prophylaxis does not prevent CMV viremia; however, viremia while on prophylaxis is not predictive of disease.

Adult↗

Clinical practice guidelines: prevention of cytomegalovirus disease after renal transplantation.

OBJECTIVE: To develop a set of comprehensive, standardized, evidence-based guidelines for the use of antiviral therapy to prevent cytomegalovirus disease in adult patients having undergone renal transplantation. OPTIONS: The use of medication, at the time of induction therapy or at the earliest sign of viremia. Treatments were evaluated by patient and donor serologic groups and the induction regimen used. OUTCOMES: The control of symptoms and features of cytomegalovirus disease over the first 6 mo to 1 yr after transplantation. EVIDENCE: Articles, compiled using a MEDLINE search from 1976 to July 1997, were reviewed by representatives of nephrology, microbiology, pharmacy, and epidemiology. Additional information was obtained from recent review articles and conference abstracts, and from experts in the field. VALUES: The evidence-based methods and values of the Canadian Task Force on the Periodic Health Examinations were used. High value was placed on studies with a randomized controlled design and blinded outcome observers. Study quality was classified as poor when cointervention was present (especially with regard to immunosuppressive regimens), when more than 20% of patients were lost to follow-up, and when intention to treat analysis was not performed. Recommendations were made with a graded system (grades A and B: Use of the intervention advised, based on high or fair quality evidence, respectively; grades D and E: Use of the intervention not advised, based on high or fair quality evidence, respectively: grade C: No recommendation made because of insufficient or conflicting evidence). RECOMMENDATIONS: (1) Seropositive recipient; donor seropositive or seronegative; immunosuppression with antilymphocyte products. Prophylaxis with antiviral therapy recommended (grade A recommendation). (2) Seronegative recipient; seropositive donor; immunosuppression with antilymphocyte products. Prophylaxis with antiviral therapy recommended (grade A recommendation) (3) Seronegative recipient; seropositive donor; conventional immunosuppression. Prophylaxis with antiviral therapy recommended (grade B recommendation). (4) Seronegative recipient; seronegative donor; any immunosuppressive regimen. No prophylaxis with antiviral therapy required (grade D/E recommendation). (5) Seropositive recipient: donor seropositive or seronegative; conventional immunosuppression. Prophylaxis left to the discrimination of the physician in charge (grade C recommendation).

Acyclovir↗

Efficient adenovirus-mediated gene expression in malignant human plasma cells: relative lymphoid cell resistance.

Although adenoviruses offer several potential advantages as gene transfer vectors, some hematopoietic cells, particularly lymphoid cells, are considered relatively resistant to adenovirus-mediated gene transfer. To examine the role of adenovirus-mediated gene transfer in the lymphoid malignancy multiple myeloma (MM), we used E1- and E3-deleted adenoviral vectors to infect myeloma and lymphoma cell lines and subsequently primary bone marrow plasma cells and lymphocytes from patients with MM. Adenoviral vectors expressing LacZ or luciferase (AdCA18) reporter genes were used initially. Subsequently, we studied adenoviral vectors expressing genes of potential value in therapeutic immunomodulation, i.e., CD80 (AdB7-1) and interleukin-2 (AdIL-2). A human plasma cell line (OCI-My5) infected with LacZ or AdB7-1 vectors expressed the corresponding gene product in 95% and 85% of exposed cells, respectively. Time course experiments indicated that maximum expression of adenoviral transgenes in plasma cells was reached 3 days after infection. IL-2 was detected in the supernatant of AdIL-2-infected plasma cells, was functional, and could be detected for at least 30 days after infection. In contrast, three lymphoma cell lines (OCI-Ly2, OCI-Ly13.2, and OCI-Ly17) were significantly less sensitive to adenovirus infection, with relatively low efficiencies of gene transfer even using high adenoviral titers: Surface CD80 expression (13-25% of infected cells) and positive LacZ staining (0-5% of infected cells). Indeed, expression of luciferase was 96-168 times higher in AdCA18-infected OCI-My5 cells than in the OCI-Ly2 lymphoma cell line. Similar patterns were observed in primary plasma cells and lymphocytes from 19 MM patient bone marrow samples. After infection with AdB7-1, increased levels of CD80 expression on CD38 bright bone marrow plasma cells were observed in 84% of patients, with a 33% average increase in the number of plasma cells expressing CD80. In contrast, although increased CD80 expression was also detected on AdB7-1-infected CD19+ B lymphocytes from 63% of the MM patients, an average of only 14% of the infected lymphocytes demonstrated increased expression of CD80. Circulating T lymphocytes could not be transduced with AdB7-1. The relative resistance of B and T lymphocytes to adenovirus-mediated gene transfer warrants further investigation. Adenoviral vectors can efficiently infect malignant plasma cells and may be useful vehicles for therapeutic gene transfer.

Adenoviridae↗

A pilot study of ribavirin therapy for recurrent hepatitis C virus infection after liver transplantation.

Ribavirin is a guanosine analogue that normalizes serum liver enzymes in most nontransplant patients with chronic hepatitis C virus (HCV) infection. We conducted an uncontrolled pilot study of ribavirin in 9 liver transplantation recipients that had persistently elevated liver enzymes, active hepatitis by liver biopsy, and HCV RNA in serum by polymerase chain reaction. Ribavirin was given orally at dosages of 800-1200 mg per day for 3 mo. All 9 patients promptly responded to ribavirin: mean (+/- SD) ALT decreased from 392 +/- 377 IU/L immediately before treatment to 199 +/- 185 and 68 +/- 37 IU/L after 1 and 12 weeks of treatment, respectively, complete normalization of enzymes occurred in 4 patients. None of the patients cleared the virus from their serum during therapy, and biochemical relapse occurred in all patients 4 +/- 4.2 weeks after cessation of therapy. The hepatitis activity index of liver biopsy specimens obtained before and at the cessation of therapy was similar. Ribavirin treatment was resumed in 4 patients because of increasing fatigue (2 patients), rising bilirubin (3), or increasing necroinflammation on liver biopsy (2); the biochemical response to the second course of therapy was similar to the first course in all 4 patients. Ribavirin caused reversible hemolysis in all patients, including symptomatic anemia in 3 patients that resolved after reduction of drug dosage. These results suggest that ribavirin may be of benefit in the treatment of HCV infection after liver transplantation. Further studies are needed to determine the optimal dosage and duration of therapy.

Adult↗

Investigation of a multiyear multiple critical care unit outbreak due to relatively drug-sensitive Acinetobacter baumannii: risk factors and attributable mortality.

From 1990 to 1993, an outbreak of respiratory Acinetobacter baumannii infection occurred in five intensive care units (ICUs) of a tertiary care center. A. baumannii was subsequently isolated from disinfected temperature probes and ventilator circuits. Pulsed-field gel electrophoresis suggested that a single strain accounted for 93% of patient isolates and 88% of environmental isolates. Univariate risk factors for A. baumannii acquisition were tracheostomy (P < .01), ventilation >3 days (P < .01), dialysis (P = .03), Stenotrophomonas maltophilia respiratory colonization (P = .02), parenteral nutrition (P = .05), and enteric feeding (P < .01). Logistic regression analysis showed duration of ventilation and enteric feeding to be independent risk factors. The outbreak strain was relatively antibiotic-susceptible, but the mortality attributable to respiratory A. baumannii acquisition was 23%. Only the APACHE II score was independently associated with increased mortality. Multifaceted control measures, including gas sterilization of temperature probes, terminated the outbreak.

Acinetobacter Infections↗

Evaluation of Roche Amplicor PCR assay for Mycobacterium tuberculosis.

The Roche Amplicor Mycobacterium tuberculosis PCR test (RMtb-PCR) was compared with mycobacterial culture, with the BACTEC 460 system and inoculation on Lowenstein-Jensen media. Results were interpreted with an adjusted "gold standard" incorporating clinical diagnosis. A total of 1,480 clinical specimens from 1,155 patients, including tissues and fluids, as well as 141 specimens which demonstrated a positive growth index on the BACTEC 460 system were assessed. The sensitivity, specificity, and positive and negative predictive values of RMtb-PCR compared with the adjusted gold standard for clinical specimens were 79, 99, 93, and 98%, respectively. In smear-positive specimens, the sensitivity of RMtb-PCR was 98% versus 53% for smear-negative specimens. When RMtb-PCR was performed two times per week, PCR results were available an average of 21 days before the culture results. For specimens demonstrating a positive growth index on the BACTEC 460 system, RMtb-PCR had a sensitivity and specificity of 98 and 100%, respectively. This study demonstrates the value of a commercial nucleic acid amplification kit for rapid diagnosis of M. tuberculosis, particularly in smear-positive specimens or BACTEC culture-positive specimens.

Bacteriological Techniques↗

Detection of cytomegalovirus in blood donors by PCR using the digene SHARP signal system assay: effects of sample preparation and detection methodology.

Cytomegalovirus (CMV) is an important cause of transfusion-associated morbidity and mortality; however, only 0.4 to 12% of the blood products obtained from seropositive blood donors transmit infection. The effects of three commercially available whole-blood sample preparation kits on the detection of CMV PCR products by a semiquantitative adaptation of the Digene SHARP Signal System Assay (DSSSA) in samples from volunteer blood donors was assessed. Of 101 samples from seropositive blood donors, CMV was detected in 0 (0%) of the samples extracted with a QIAamp blood kit (QIAGEN), 1 (1%) of the samples extracted with an Amplicor whole-blood specimen preparation kit (Roche), and 8 (8%) of the samples extracted with an Isoquick nucleic acid extraction kit (modified by the addition of carrier tRNA) (Microprobe). CMV DNA was not detected in samples from seronegative blood donors (n = 13). Nested PCR of selected samples confirmed the detection of CMV in the sane eight samples extracted with the modified Isoquick nucleic acid extraction kit and detected an additional nine CMV-positive samples (n = 50). Samples from volunteer blood donors contain low copy numbers of CMV DNA. PCR amplification of such specimens can result in analytical sampling errors, giving results similar to the variations in titers recognized during determinations of the 50% tissue culture infective dose. The detection of CMV in blood samples from volunteer blood donors by PCR is a function of sample preparation, amplification conditions, and detection methodology. Accurate assessments of the clinical utility of CMV DNA detection by nucleic acid amplification for blood product screening and patients will require highly standardized and quantitative methodology.

Blood Donors↗

Detection of hepatitis C virus by PCR in second-generation enzyme immunoassay-seropositive blood donors by using matched pairs of fresh frozen plasma and pilot tube sera.

Between April 1993 and March 1995, 429 of 334,454 (0.13%) blood donations at the Toronto Centre of the Canadian Red Cross were reactive for hepatitis C virus (HCV) by second-generation enzyme immunoassay (EIA-2). Of the 429 EIA-2-positive donations, 189 (44%), 138 (32%), and 102 (24%) were positive, indeterminate, and negative by Second-Generation Recombinant Immunoblot Assay (RIBA-2). To assess HCV viremia and minimize the risk that specimen handling affected PCR-based detection, the qualitative AMPLICOR HCV test was performed on both pilot tube sera (PTS) and the corresponding fresh frozen plasma (FFP) from 294 EIA-2-reactive donations. AMPLICOR PCR results for PTS and FFP were 100% concordant and were confirmed by nested HCV PCR for 27 of 294 donations. The AMPLICOR HCV test was positive for 127 of 140 (91%) of RIBA-2-positive donations (81, 91, and 96% of donations with two, three, and four reactive bands, respectively), 5 of 88 (5.7%) indeterminate donations, and 0 of 66 (0%) RIBA-2-negative donations. The Third-Generation Recombinant Immunoblot Assay (RIBA-3) was performed on RIBA-2-negative, -indeterminate, and -positive, PCR-negative donations. RIBA-3 demonstrated enhanced specificity and resolved 18 of 88 (20%) of RIBA-2-indeterminate samples as HCV antibody positive. The study demonstrates that PTS are as suitable as FFP for PCR-based detection of HCV and can be used to determine if EIA-2-reactive blood donors are viremic at the time of donation.

Blood Donors↗

Multi-organ donor transmission of hepatitis C virus to five solid organ transplant recipients and lack of transmission to corneal transplant recipients.

BACKGROUND: A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection. OBJECTIVES: To demonstrate the discordance between serological and PCR-based HCV detection in solid organ transplant recipients and the lack of transmission of HCV to the two corneal transplant recipients. STUDY DESIGN: All 5 solid organ recipients were retrospectively shown to be HCV PCR-negative and -seronegative pre-transplant and HCV PCR-positive post-transplant. Serial serum samples on 3 recipients were evaluated by 2nd generation EIA, a prototypic structural and non-structural dual bead assay (EIA-SA, Abbott), the Chiron Recombinant Immunoblot Assay, 2nd generation (RIBA-2), and the Chiron RIBA HCV Test System Strip Immunoblot Assay 3.0 (RIBA-3, Chiron). RESULTS: The dual bead EIA-SA and RIBA-3 were able to detect HCV seroconversion approximately 6 months earlier than the 2nd generation EIA in 2 recipients, and in 1 recipient only PCR detected infection within the first 10 months. There was no evidence of HCV transmission to the corneal recipients. CONCLUSIONS: Although third generation assays such as the RIBA-3 and EIA-SA narrowed the window of HCV seronegativity in transplant recipients compared with the 2nd generation EIA, PCR was the most sensitive method of detecting acute HCV infection. Despite transmission of HCV to all of the solid organ recipients HCV was not transmitted to the corneal transplant recipients.

Journal Article↗

Molecular typing of Stenotrophomonas (Xanthomonas) maltophilia by DNA macrorestriction analysis and random amplified polymorphic DNA analysis.

Stenotrophomonas (Xanthomonas) maltophilia is a multidrug-resistant, nosocomial pathogen for which optimal typing methods in epidemiologic investigations of nosocomial outbreaks have not been defined. We compared DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) with random amplified polymorphic DNA (RAPD) analysis by arbitrarily primed PCR for molecular typing of 109 multidrug-resistant strains of S. maltophilia from multiple outbreaks at our institution over a 10-month period in 1993. PFGE after digestion with restriction endonuclease DraI revealed 62 unique DNA restriction profiles among the 109 strains, with 23, 11, 6, 6, and 3 strains having concordant profiles in each of five types. There were four concordant profiles among 8 strains (2 strains with each profile), while unique profiles were present in each of the remaining 52 strains. Further RAPD analysis with a decanucleotide primer showed the same number of distinct strain types as PFGE but more subtype diversity within each clonal type. We concluded that DNA macrorestriction analysis and RAPD analysis are sufficiently discriminatory and useful for differentiation of S. maltophilia strains in epidemiologic investigations of nosocomial outbreaks. However, RAPD analysis by arbitrarily primed PCR is faster and less laborious method of molecular typing.

Bacterial Typing Techniques↗