Limited genetic diversity among genotypes of Enterocytozoon bieneusi strains isolated from HIV-infected patients from Sydney, Australia

Microsporidia are intracellular parasites, with over 1200 species belonging to 143 genera described to date. They are opportunistic pathogens in humans and can cause chronic diarrhoea in immunosuppressed patients. Both Enterocytozoon bieneusi and Encephalitozoon intestinalis cause intestinal disease, with Enterocytozoon bieneusi more commonly identified in patients with human immunodeficiency virus (HIV) infection. In this study, intestinal microsporidial clinical isolates from patients in Sydney, Australia, were genotyped. All specimens were from HIV-infected men with low CD4(+) T-cell counts (<100 cells mm(-3)). Genotyping of the internal transcribed spacer regions of the rRNA gene showed the presence of only one genotype, the anthroponotic Enterocytozoon bieneusi genotype B strain. This study thus highlighted the limited genetic diversity among Australian Enterocytozoon bieneusi isolates, and it is hypothesized that, due to the reduced incidence of microsporidia and the subsequent reduction in the human reservoir of the anthroponotic genotype B, locally acquired intestinal microsporidiosis will rarely be seen in HIV-infected persons undergoing highly active antiretroviral therapy in the future in Australia.

Achromobacter xylosoxidans subsp. xylosoxidans prosthetic aortic valve infective endocarditis and aortic root abscesses

We report a case of prosthetic valve infective endocarditis and aortic root abscesses caused by Achromobacter xylosoxidans subsp. xylosoxidans. The patient was an intravenous drug user and had injected amphetamines using 'duck pond water' as a diluent. After surgical intervention and 6 weeks of intravenous meropenem therapy, the patient made an uneventful recovery.

Comparison of stool antigen detection kits to PCR for diagnosis of amebiasis

The present study was conducted to compare two stool antigen detection kits with PCR for the diagnosis of Entamoeba histolytica infections by using fecal specimens submitted to the Department of Microbiology at St. Vincent's Hospital, Sydney, and the Institute of Medical and Veterinary Science, Adelaide, Australia. A total of 279 stool samples containing the E complex (E. histolytica, Entamoeba dispar, and Entamoeba moshkovskii) were included in this study. The stool specimens were tested by using two commercially produced enzyme immunoassays (the Entamoeba CELISA PATH and TechLab E. histolytica II kits) to detect antigens of E. histolytica. DNA was extracted from all of the samples with a Qiagen DNA stool mini kit (Qiagen, Hilden, Germany), and a PCR targeting the small-subunit ribosomal DNA was performed on all of the samples. When PCR was used as a reference standard, the CELISA PATH kit showed 28% sensitivity and 100% specificity. The TechLab ELISA (enzyme-linked immunosorbent assay) kit did not prove to be useful in detecting E. histolytica, as it failed to identify any of the E. histolytica samples which were positive by PCR. With the TechLab kit, cross-reactivity was observed for three specimens, one of which was positive for both E. dispar and E. moshkovskii while the other two samples contained E. moshkovskii. Quantitative assessment of the PCR and ELISA results obtained showed that the ELISA kits were 1,000 to 10,000 times less sensitive, and our results show that the CELISA PATH kit and the TechLab ELISA are not useful for the detection of E. histolytica in stool samples from patients in geographical regions where this parasite is not endemic.

[An improved model of a catheterised human bladder for screening bactericidal agents]

PURPOSE

Catheter encrustation and associated blockage by a crystalline Proteus mirabilis biofilm constitute a continuous problem in long-term catheterised patients. The objective of the present work was to verify a new, physiological bladder model possessing the ability to show that triclosan-blocking solutions exert bactericidal and bacteriostatic activities.

MATERIAL AND METHODS

Catheterised sterile infusion bags served as human bladder models. Artificial urine inoculated with Proteus mirabilis was administered by a further aperture. Samples for measurement of pH value and microbial count were collected at intervals of 24 h. Upon completion of testing catheter encrustation was assessed and visualised by scanning electron microscopy.

RESULTS

In contrast to the application of placebo solution, in models filled with triclosan-blocking solution the catheters drained freely for the experimental period. Similar results were obtained for pH values and microbial count. The pH of the artificial urine did not exceed a critical value of pH 7 and the numbers of organisms correspond approximately to the initially inoculated number of organisms.

CONCLUSION

In the model developed here, triclosan inhibits the growth of Proteus mirabilis over the test period by diffusing into the artificial urine through the catheter balloon. Thus, triclosan acts against the pH increase as well as the formation of a crystalline biofilm. Taken together, the adaptability of this new, physiological model of the human bladder could be shown.

Topotecan, pegylated liposomal doxorubicin hydrochloride and paclitaxel for second-line or subsequent treatment of advanced ovarian cancer: a systematic review and economic evaluation

OBJECTIVES

To examine the clinical effectiveness and cost-effectiveness of intravenous formulations of topotecan monotherapy, pegylated liposomal doxorubicin hydorocholoride (PLDH) monotherapy and paclitaxel used alone or in combination with a platinum-based compound for the second-line or subsequent treatment of advanced ovarian cancer.

DATA SOURCES

Electronic databases covering publication years 2000-4. Company submissions.

REVIEW METHODS

Seventeen databases were searched for randomised controlled trials (RCTs) and systematic reviews for the clinical effectiveness of PLDH, topotecan and paclitaxel and economic evaluations of the cost-effectiveness of PLDH, topotecan and paclitaxel. Selected studies were quality assessed and data extracted, as were the three company submissions. A new model was developed to assess the costs of the alternative treatments, the differential mean survival duration and the impact of health-related quality of life. Monte-Carlo simulation was used to reflect uncertainty in the cost-effectiveness results.

RESULTS

Nine RCTs were identified. In five of these trials, both the comparators were used within their licensed indications. Of these five, three included participants with both platinum-resistant and platinum-sensitive advanced ovarian cancer, and a further two only included participants with platinum-sensitive disease. The comparators that were assessed in the three trials that included both subtypes of participants were PLDH versus topotecan, topotecan versus paclitaxel and PLDH versus paclitaxel. In the further two trials that included participants with the subtype of platinum-sensitive disease, the comparators that were assessed were single-agent paclitaxel versus a combination of cyclophosphamide, doxorubicin and cisplatin (CAP) and paclitaxel plus platinum-based chemotherapy versus conventional platinum-based therapy alone. A further four trials were identified and included in the review in which one of the comparators in the trial was used outside its licensed indication. The comparators assessed in these trials were oxaliplatin versus paclitaxel, paclitaxel given weekly versus every 3 weeks, paclitaxel at two different dose levels and oral versus intravenous topotecan. Four studies met the inclusion criteria for the cost-effectiveness review. The review of the economic evidence from the literature and industry submissions identified a number of significant limitations in existing studies assessing the cost-effectiveness of PLDH, topotecan and paclitaxel. Analysis 1 assessed the cost-effectiveness of PLDH, topotecan and paclitaxel administered as monotherapies. Sensitivity analysis was undertaken to explore the impact of patient heterogeneity (e.g. platinum-sensitive and platinum-resistant/refractory patients), the inclusion of additional trial data and alternative assumptions regarding treatment and monitoring costs. In the base-case results for Analysis 1, paclitaxel monotherapy emerged as the cheapest treatment. When the incremental cost-effectiveness ratios (ICERs) were estimated, topotecan was dominated by PLDH. Hence the options considered in the estimation of the ICERs were paclitaxel and PLDH. The ICER for PLDH compared with paclitaxel was pound 7033 per quality-adjusted life-year (QALY) in the overall patient population (comprising platinum-sensitive, -refractory and -resistant patients). The ICER was more favourable in the platinum-sensitive group ( pound 5777 per QALY) and less favourable in the platinum-refractory/resistant group ( pound 9555 per QALY). The cost-effectiveness results for the base-case analysis were sensitive to the inclusion of additional trial data. Incorporating the results of the additional trial data resulted in less favourable estimates for the ICER for PLDH versus paclitaxel compared with the base-case results. The ICER of PLDH compared with paclitaxel was pound 20,620 per QALY in the overall patient population, pound 16,183 per QALY in the platinum-sensitive population and pound 26,867 per QALY in the platinum-resistant and -refractory population. The results from Analysis 2 explored the cost-effectiveness of the full range of treatment comparators for platinum-sensitive patients. The treatment options considered in this model comprised PLDH, topotecan, paclitaxel-monotherapy, CAP, paclitaxel/platinum combination therapy and platinum monotherapy. Owing to the less robust approaches that were employed to synthesise the available evidence and the heterogeneity between the different trials, the reliability of these results should be interpreted with some caution. Topotecan, paclitaxel monotherapy and PLDH were all dominated by platinum monotherapy (i.e. higher costs and lower QALYs). After excluding these alternatives, the treatments that remained under consideration were platinum monotherapy, CAP and paclitaxel-platinum combination therapy. Of these three alternatives, platinum monotherapy was the least costly and least effective. The ICER for CAP compared with platinum monotherapy was pound 16,421 per QALY. The ICER for paclitaxel-platinum combination therapy compared with CAP was pound 20,950 per QALY.

CONCLUSIONS

For participants with platinum-resistant disease there was a low probability of response to treatment with PLDH, topotecan or paclitaxel. Furthermore, there was little difference between the three comparators in relation to overall survival. The comparators did, however, differ considerably in their toxicity profiles. Given the low survival times and response rates, it appears that the maintenance of quality of life and the control of symptoms and toxicity are paramount in this patient group. As the three comparators differed significantly in terms of their toxicity profiles, patient and physician choice is also an important element that should be addressed when decisions are made regarding second-line therapy. It can also be suggested that this group of patients may benefit from being included in further clinical trials of new drugs. For participants with platinum-sensitive disease there was a considerable range of median survival times observed across the trials. The most favourable survival times and response rates were observed for paclitaxel and platinum combination therapy. This suggests that treatment with combination therapy may be more beneficial than treatment with a single-agent chemotherapeutic regimen. In terms of single-agent compounds, the evidence suggests that PLDH is more effective than topotecan. Evidence from a further trial that compared PLDH and paclitaxel suggests that there is no significant difference between these two comparators in this trial. The three comparators did, however, differ significantly in terms of their toxicity profiles across the trials. Although treatment with PLDH may therefore be more beneficial than that with topotecan, patient and physician choice as to the potential toxicities associated with each of the comparators and the patient's ability and willingness to tolerate these are of importance. Assuming the NHS is willing to pay up to pound 20,000-40,000 per additional QALY, PLDH appears to be cost-effective compared with topotecan and paclitaxel monotherapy, in terms of the overall patient population and the main subgroups considered. The cost-effectiveness results for the base-case analysis were sensitive to the inclusion of additional trial data. Incorporating the results of additional trial data gave less favourable estimates for the ICER for PLDH versus paclitaxel monotherapy, compared with the base-case results. Although the ICER of PLDH compared with paclitaxel monotherapy was less favourable, PLDH was still cost-effective compared with topotecan and paclitaxel monotherapy. For platinum-sensitive patients, the combination of paclitaxel and platinum appears to be cost-effective. On the strength of the evidence reviewed here, it can be suggested that participants with platinum-resistant disease may benefit from being included in further clinical trials of new drugs. To assess the effectiveness of combination therapy against a single-agent non-platinum-based compound, it can be suggested that a trial that compared paclitaxel in combination with a platinum-based therapy versus single-agent PLDH would be a reasonable option.

Methicillin-resistant Staphylococcus aureus (MRSA) detection: comparison of two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) with three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA) for use with infection-control swabs

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem. Rapid detection of MRSA-colonized patients has the potential to limit spread of the organism. We evaluated the sensitivities and specificities of MRSA detection by two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) and three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA), using 205 (101 nasal, 52 groin, and 52 axillary samples) samples from consecutive known MRSA-infected and/or -colonized patients. All detection methods had higher MRSA detection rates for nasal swabs than for axillary and groin swabs. Detection of MRSA by IDI-MRSA was the most sensitive method, independent of the site (94% for nasal samples, 80% for nonnasal samples, and 90% overall). The sensitivities of the GenoType MRSA Direct assay and the MRSA ID, MRSASelect, and CHROMagar MRSA agars with nasal swabs were 70%, 72%, 68%, and 75%, respectively. All detection methods had high specificities (95 to 99%), independent of the swab site. Extended incubation for a further 24 h with selective MRSA agars increased the detection of MRSA, with a corresponding decline in specificity secondary to a significant increase in false-positive results. There was a noticeable difference in test performance of the GenoType MRSA Direct assay in detection of MRSA (28/38 samples [74%]) compared with detection of nonmultiresistant MRSA (17/31 samples [55%]) (susceptible to two or more non-beta-lactam antibiotics). This was not observed with selective MRSA agar plates or IDI-MRSA. Although it is more expensive, in addition to rapid turnaround times of 2 to 4 h, IDI-MRSA offers greater detection of MRSA colonization, independent of the swab site, than do conventional selective agars and GenoType MRSA Direct.

Declining incidence of intestinal microsporidiosis and reduction in AIDS-related mortality following introduction of HAART in Sydney, Australia

Limited data exist regarding the incidence of intestinal microsporidiosis following the introduction of highly active antiretroviral therapy (HAART) in Australia. At St Vincent's Hospital, Sydney, all faecal samples submitted for diarrhoea from HIV-infected patients between 1995 and 2006 underwent screening for microsporidiosis. A total of 3564 patients (7366 faecal specimens) was examined, resulting in 159 patients identified with microsporidiosis. The incidence of microsporidiosis declined from 11% in 1995 to 0% from 2004 onwards. At presentation the majority of patients were severely immunocompromised (median CD4 105 cells/mm(3)), with only 16% of patients on effective HAART. Twenty-four patients (24/76, 32%) died within a median of 22 months following microsporidiosis diagnosis. Significant predictors of AIDS-related mortality at presentation included the level of immunodeficiency and receiving no or ineffective HAART (P<0.05). Patients presenting after 1998 had a significant reduction in the risk of AIDS-related mortality compared with patients presenting before 1998 (hazard ratio 0.27, 95% CI 0.79-0.92). All 52 (68%) surviving patients were on effective HAART, with a median CD4 count 382 cells/mm(3) and HIV RNA of < 50 copies/ml at follow-up (median 4 years). The dramatic decline of intestinal microsporidiosis in our study reconfirms the importance of effective HAART in preventing advanced immunodeficiency, opportunistic infections and associated AIDS-related deaths.

Laboratory diagnostic techniques for Entamoeba species

The genus Entamoeba contains many species, six of which (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba polecki, Entamoeba coli, and Entamoeba hartmanni) reside in the human intestinal lumen. Entamoeba histolytica is the causative agent of amebiasis and is considered a leading parasitic cause of death worldwide in humans. Although recent studies highlight the recovery of E. dispar and E. moshkovskii from patients with gastrointestinal symptoms, there is still no convincing evidence of a causal link between the presence of these two species and the symptoms of the host. New approaches to the identification of E. histolytica are based on detection of E. histolytica-specific antigen and DNA in stool and other clinical samples. Several molecular diagnostic tests, including conventional and real-time PCR, have been developed for the detection and differentiation of E. histolytica, E. dispar, and E. moshkovskii in clinical samples. The purpose of this review is to discuss different methods that exist for the identification of E. histolytica, E. dispar, and E. moshkovskii which are available to the clinical diagnostic laboratory. To address the need for a specific diagnostic test for amebiasis, a substantial amount of work has been carried out over the last decade in different parts of the world. The molecular diagnostic tests are increasingly being used for both clinical and research purposes. In order to minimize undue treatment of individuals infected with other species of Entamoeba such as E. dispar and E. moshkovskii, efforts have been made for specific diagnosis of E. histolytica infection and not to treat based simply on the microscopic examination of Entamoeba species in the stool. The incorporation of many new technologies into the diagnostic laboratory will lead to a better understanding of the public health problem and measures to control the disease.

Rhizopus microsporus var. rhizopodiformis sinus-orbital zygomycosis in an immunosuppressed patient: successful treatment with posaconazole after a complicated clinical course

A case of sinus-orbital Rhizopus microsporus var. rhizopodiformis infection in a patient with graft versus host disease following allogeneic blood stem cell transplantation is reported. Commercially available pea straw compost used for gardening was suspected to be the source of the infection. After an initial relapse, treatment with surgical debridement, liposomal amphotericin B and posaconazole was successful.

Bordetella petrii from a clinical sample in Australia: isolation and molecular identification

The first isolation of Bordetella petrii from a patient with chronic suppurative mastoiditis is reported. Molecular characterization of the isolate was performed by sequencing the small-subunit rRNA gene, the Bordetella outer-membrane protein A gene (ompA) and the RisA response regulator gene (risA). This is the first reported case of B. petrii causing suppurative mastoiditis and only the second documented case of a clinically significant B. petrii isolate.

Lymphogranuloma venereum in Australia: anorectal Chlamydia trachomatis serovar L2b in men who have sex with men

Lymphogranuloma venereum (LGV) is a sexually transmitted infection that is causing an ongoing epidemic in men who have sex with men (MSM) in Europe, the United Kingdom, and North America. Twenty-nine rectal swabs positive for Chlamydia trachomatis were analyzed by real-time PCR for the presence of LGV serovars. Genotyping revealed an identical L2b serovar from four specimens. All patients were MSM and human immunodeficiency virus infected. Three of the four presented with severe ulcerative proctitis. We report a cluster of rectal LGV serovar L2b infections in Sydney, Australia.

PCR detection of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii in stool samples from Sydney, Australia

This study investigated the presence of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii in stool samples from a patient population in Sydney, Australia. Stool samples were tested by microscopy and PCR. Five patients were found with E. histolytica infections, while E. dispar and E. moshkovskii were observed in 63 (70.8%) and 55 (61.8%) patients, respectively, by PCR. This is the first study in Australia using molecular techniques to determine the presence of E. histolytica, E. dispar, and E. moshkovskii.

The initial development of an item bank to assess and screen for psychological distress in cancer patients

Psychological distress is a common problem among cancer patients. Despite the large number of instruments that have been developed to assess distress, their utility remains disappointing. This study aimed to use Rasch models to develop an item-bank which would provide the basis for better means of assessing psychological distress in cancer patients.An item bank was developed from eight psychological distress questionnaires using Rasch analysis to link common items. Items from the questionnaires were added iteratively with common items as anchor points and misfitting items (infit mean square >1.3) removed, and unidimensionality assessed.A total of 4914 patients completed the questionnaires providing an initial pool of 83 items. Twenty items were removed resulting in a final pool of 63 items. Good fit was demonstrated and no additional factor structure was evident from the residuals. However, there was little overlap between item locations and person measures, since items mainly targeted higher levels of distress. The Rasch analysis allowed items to be pooled and generated a unidimensional instrument for measuring psychological distress in cancer patients. Additional items are required to more accurately assess patients across the whole continuum of psychological distress.

Veillonella parvula discitis and secondary bacteremia: a rare infection complicating endoscopy and colonoscopy?

We report a case of Veillonella parvula lumbar discitis and secondary bacteremia confirmed by molecular characterization of the 16S rRNA genes. Identification of the organism was essential for an appropriate choice of antimicrobial therapy following the failure of empirical flucloxacillin. Veillonella spp. are normal flora of the gastrointestinal tract, raising the possibility that an endoscopy and colonoscopy performed 8 weeks prior to presentation, during which small intestinal and rectal biopsies were obtained, was the portal of entry. This case highlights the importance of obtaining a microbiologic diagnosis, particularly in patients who previously have had procedures involving instrumentation.

Conservative management of pelvic organ prolapse in women

BACKGROUND

Pelvic organ prolapse is common, and some degree of prolapse is seen in 50% of parous women. Women with prolapse can experience a variety of pelvic floor symptoms. Treatments include surgery, mechanical devices and conservative management. Conservative management approaches, such as giving lifestyle advice and delivering pelvic floor muscle training, are often used in cases of mild to moderate prolapse.

OBJECTIVES

To determine the effects of conservative management (physical interventions and lifestyle interventions) for women with pelvic organ prolapse in comparison with no treatment or other treatment options (such as mechanical devices or surgery).

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Trials Register (searched on 19 September 2005), MEDLINE (January 1966 to August 2005), MEDLINE In Process & Other Citations (15 September 2005), EMBASE (January 1996 to Week 43 2005), CINAHL (January 1982 to October 2005), PEDro (September 2005), the UK National Research Register (Issue 3, 2005), the US National Institute of Health clinical trial register (5 October 2005), Current Controlled Trials register (5 October 2005), Controlled Clinical Trials (September 2005) and ZETOC (September 2005). We searched the reference lists of relevant articles.

SELECTION CRITERIA

Randomised and quasi-randomised trials in women with pelvic organ prolapse that included a physical or lifestyle intervention in at least one arm of the trial.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed all trials for inclusion/exclusion and methodological quality. Data were extracted by the lead reviewer onto a standard form and cross checked by another. Disagreements were resolved by discussion. Data were processed as described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Three trials of relevance to this review were identified. The largest of these, of pelvic floor muscle training in preventing anterior prolapse from worsening, had significant limitations which affect the generalisability and rigor of the findings. A small feasibility study (which is to be followed up with a larger trial) randomised 47 women to pelvic floor muscle training or control and found suggestions of better outcomes (better self-reported improvement, decreased severity) in the intervention group. The third trial evaluated peri-operative physiotherapy for women undergoing surgery for prolapse and/or incontinence. The authors report that urinary symptoms, pelvic floor muscle function and quality of life were improved more in the treatment group than the control group, but data were not provided to allow this to be assessed. The trial was small and no prolapse-specific outcome measures were used. It was not possible to combine data from the three trials.

AUTHORS' CONCLUSIONS

Despite there now being reports of three eligible trials in this update, the evidence available is not significant to guide practice. There is some encouragement from a feasibility study that pelvic floor muscle training, delivered by a physiotherapist to symptomatic women in an outpatient setting, may reduce severity of prolapse. Further evidence from larger, better quality randomised control trials is however still necessary.

Irritable bowel syndrome: a review on the role of intestinal protozoa and the importance of their detection and diagnosis

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder in which abdominal pain is associated with a defect or a change in bowel habits. Gut inflammation is one of the proposed mechanisms of pathogenesis. Recent studies have described a possible role for protozoan parasites, such as Blastocystis hominis and Dientamoeba fragilis, in the etiology of IBS. Dientamoeba fragilis is known to cause IBS-like symptoms and has a propensity to cause chronic infections but its diagnosis relies on microscopy of stained smears, which many laboratories do not perform, thereby leading to the misdiagnosis of dientamoebiasis as IBS. The role of B. hominis as an etiological agent of IBS is inconclusive, due to contradictory reports and the controversial nature of B. hominis as a human pathogen. Although Entamoeba histolytica infections occur predominately in developing regions of the world, clinical diagnosis of amebiasis is often difficult because symptoms of patients with IBS may closely mimic those patients with non-dysenteric amoebic colitis. Clinical manifestations of Giardia intestinalis infection also vary from asymptomatic carriage to acute and chronic diarrhoea with abdominal pain. These IBS-like symptoms can be continuous, intermittent, sporadic or recurrent, sometimes lasting years without correct diagnosis. It is essential that all patients with IBS undergo routine parasitological investigations in order to rule out the presence of protozoan parasites as the causative agents of the clinical signs.

Post-kala-azar dermal leishmaniasis due to Leishmania infantum in a human immunodeficiency virus type 1-infected patient

We report the first case of post-kala-azar dermal leishmaniasis due to Leishmania infantum in a human immunodeficiency virus type 1-infected patient in Australia. Molecular characterization of the isolate was performed using PCR restriction fragment length polymorphism targeting both repetitive sequences from Leishmania nuclear DNA and repetitive kinetoplast DNA minicircles for species differentiation.

Evaluation of three diagnostic methods, including real-time PCR, for detection of Dientamoeba fragilis in stool specimens

Dientamoeba fragilis is a protozoan parasite of humans that infects the mucosa of the large intestine and is associated with gastrointestinal disease. We developed a 5' nuclease (TaqMan)-based real-time PCR assay, targeting the small subunit rRNA gene, for the detection of D. fragilis in human stool specimens and compared its sensitivity and specificity to conventional PCR and microscopic examination by a traditional modified iron-hematoxylin staining procedure. Real-time PCR exhibited 100% sensitivity and specificity.

Prospective study of the prevalence, genotyping, and clinical relevance of Dientamoeba fragilis infections in an Australian population

A prospective study was conducted over a 30-month period, in which fecal specimens from 6,750 patients were submitted to the Department of Microbiology at St. Vincent's Hospital, Sydney, Australia. Trophozoites of Dientamoeba fragilis were detected in 60 (0.9%) patients by permanent staining, and confirmation was performed by PCR. Gastrointestinal symptoms were present in all patients, with diarrhea and abdominal pain the most common symptoms. Thirty-two percent of patients presented with chronic symptoms. The average age of infected patients was 39.8 years. No correlation was found between D. fragilis and Enterobius vermicularis, a proposed vector of transmission for D. fragilis. The genetic diversity of 50 D. fragilis isolates was examined by PCR, and the PCR products were analyzed for the presence of restriction fragment length polymorphisms. These results showed no variation in the small-subunit rRNA gene and demonstrated a single genotype for all Australian isolates. This study shows the potential pathogenic properties of D. fragilis and the need for all laboratories to routinely test for this organism.

Detection of Dientamoeba fragilis in fresh stool specimens using PCR

Dientamoeba fragilis is a trichomonad parasite that causes human gastrointestinal disease. Currently microscopy is considered to be the gold standard for diagnosis of D. fragilis infection. However, this method is time-consuming and relatively insensitive. A PCR assay based on the small-subunit ribosomal RNA gene of D. fragilis for the specific detection of D. fragilis DNA in fresh unpreserved stool samples was developed. The D. fragilis PCR was positive in 29/31 samples with positive microscopy and did not cross-react with other protozoan parasites. The PCR protocol showed a specificity of 100% and a sensitivity of 93.5% and the entire procedure can be performed in one day.