Home About us Contact
|
Home About us Contact | ||
|
|
||
Test Kit (test + kit)
Selected AbstractsComparison of Presumptive Blood Test Kits Including Hexagon OBTIJOURNAL OF FORENSIC SCIENCES, Issue 3 2008Emma Johnston M.Sc. Abstract:, Four presumptive blood tests, Hexagon OBTI, Hemastix®, Leucomalachite green (LMG), and Kastle-Meyer (KM) were compared for their sensitivity in the identification of dried bloodstains. Stains of varying blood dilutions were subjected to each presumptive test and the results compared. The Hexagon OBTI buffer volume was also reduced to ascertain whether this increased the sensitivity of the kit. The study found that Hemastix® was the most sensitive test for trace blood detection. Only with the reduced buffer volume was the Hexagon OBTI kit as sensitive as the LMG and KM tests. However, the Hexagon OBTI kit has the advantage of being a primate specific blood detection kit. This study also investigated whether the OBTI buffer within the kit could be utilized for DNA profiling after presumptive testing. The results show that DNA profiles can be obtained from the Hexagon OBTI kit buffer directly. [source] Engineering a chemical implementation device and an imaging device for detecting chemiluminescence with a PolaroidÔ high-speed detector film: application to influenza diagnostics with the ZstatFlu®-II testLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2003Komandoor E. Achyuthan Abstract We describe the engineering and product development of the chemiluminescent ZstatFlu®-II Test kit for influenza diagnostics. The reaction vessel is a chemical implementation device with a polystyrene bottom chamber and a polypropylene top chamber that screw together. The patient's specimen is dispersed in a proprietary diluent and mixed inside the bottom chamber with the influenza viral neuraminidase-specific substrate, 1,2-dioxetane-4,7-dimethoxy-Neu5Ac. Neuraminidase catalysis releases the dioxetane. The top chamber contains 40% NaOH and is sealed at the top with an ABS plastic plug-crush pin assembly. The top chamber floor is 85% thinner at the centre, forming a frangible flap. An automated imaging device serves as an incubator for the chemical implementation devices and also facilitates the piercing of the flap by the crush pin. This action results in NaOH flushing into the bottom chamber, initiating chemiluminescence. The imaging device also exposes the PolaroidÔ high-speed detector film to chemiluminescence. At the end of exposure, the film is automatically processed and ejected. Chemiluminescence from an influenza virus-positive specimen produces a ,+'-shaped white image, archiving the diagnostic outcome. The modular ZstatFlu®-II test kit components are easily adaptable for the chemiluminescent detection of a wide range of analytes. Copyright © 2003 John Wiley & Sons, Ltd. [source] Prevalence of yeasts in saliva and root canals of teeth associated with apical periodontitisINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2002M. W. Egan Abstract Egan MW, Spratt DA, Ng Y-L, Lam JM, Moles DR, Gulabivala K. Prevalence of yeasts in saliva and root canals of teeth associated with apical periodontitis. International Endodontic Journal, 35, 321,329, 2002. Aims To determine: (i) the relative prevalence and diversity of yeasts in salivary and root canal samples from the same patients; and (ii) the clinical factors associated with their presence in saliva and root canals. Methodology Sixty root canal samples from teeth associated apical periodontitis and the corresponding whole unstimulated saliva samples were obtained from 55 patients. The medical history including antibiotic therapy and clinical/radiographic data on the teeth were recorded. The samples were serially diluted and cultured on yeast & fungi-selective sabouraud dextrose agar. Isolates were characterized and speciated by the germ tube formation test, hyphal morphology and a commercial biochemical test kit (Rapid ID32C® system). Results Twenty-three yeast isolates were recovered from 19 saliva samples and eight isolates from six root canal samples. Candida albicans (17/23 & 3/8) and Rodotorula mucilaginosa (2/23 & 4/8) were the most prevalent isolates from saliva and root canal samples. It was significantly (13.8 times) more probable that yeasts would be recovered from root canals when they were also present in the saliva (P = 0.021). The effect of coronal restoration leakage (P = 0.08) and previous root canal treatment (P = 0.123) were equivocal. The history of antibiotic therapy had no association with the presence of yeasts in saliva (OR = 1.1). Conclusions Yeasts occurred relatively infrequently (10%) in root canals. Their presence in root canals was significantly associated with their presence in saliva. The role of yeasts in the initiation and perpetuation of periapical disease remains to be determined. [source] PPL and MDM skin test: New test kit is helpful in detecting immediate-type allergy to beta-lactamsJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2007Regina Treudler Summary Background: The diagnosis of PPL (major determinant) and MDM (minor determinant) sensitization as relevant allergens in beta-lactam allergy has been recently hampered by withdrawal from the market of formerly available test kits. We investigated a new PPL/MDM test kit in the work-up of beta-lactam allergy. Patients and Methods: 15 patients with history of beta-lactam allergy were investigated for specific IgE and received patch, skin prick (SPT) and intracutaneous tests (ICT; immediate and late readings) using the relevant beta-lactams. In addition the new test kit was used for parallel SPT and ICT. Results: 14 women and 1 man (16,73 years) with immediate (n = 7), delayed (n = 7) or unclear (n = 1) reactions to beta-lactams 8,300 months previously (penicillin G/V n = 3, aminopenicillins n = 7, cephalosporins n = 4, unknown n = 2) were tested. In patients with immediate type reactions, n = 2 had specific IgE, n = 4 reacted to the new test kit (n = 3 MDM, all of whom reacted exclusively to this test, n = 1 PPL). Two patients with non-immediate reactions reacted to other beta-lactams. Conclusions: Our data show that the new test kit may be helpful in detecting patients with immediate type allergy to beta-lactams. Without this test, in those three patients reacting exclusively to MDM, and oral provocation test would have been necessary to clarify their allergy. Data from larger groups of patients are needed to determine the sensitivity and specificity of this test kit. [source] INCIDENCE AND CHARACTERIZATION OF BACILLUS CEREUS IN MEAT AND MEAT PRODUCTS CONSUMED IN TURKEYJOURNAL OF FOOD SAFETY, Issue 1 2006KIYMET GÜVEN ABSTRACT A total of 100 retail samples of meat and meat products were examined for Bacillus cereus using mannitol egg yolk polymyxin (MYP) agar as a selective isolation medium. Only 22.4% of the samples contained detectable levels of B. cereus, with counts ranging from log10 0.69 to 4.80 cfu/g, but a large number of other organisms up to log10 9.06 cfu/g were sometimes observed on the plates and may have masked the presence of B. cereus or inhibited growth. Two samples of soudjouck contained significant levels of B. cereus, sufficient enough to create a public health hazard. Selected isolates were tested for diarrheal enterotoxin production by a reversed passive latex agglutination (RPLA) test kit. Results showed no difference in the toxin production of B. cereus between beef, ground meat, soudjouck and pastrami samples. Plasmid-profile analysis and susceptibility to the six commonly used antimicrobial agents were done on selected B. cereus isolates. About 96.4% of the isolates contained plasmids. Plasmid sizes ranged between 2.5 and 3.5 kb. The isolates showed a high rate of resistance to oxacillin (OXA) and amoxicillin (AMC) and a low frequency of resistance to the other antimicrobial agents, with all of them being susceptible to vancomycin (VAN). Approximately 54% of the isolates showed multiple resistance. There was no apparent relationship between drug resistance and carriage of plasmids. [source] Photothermal antimicrobial nanotherapy and nanodiagnostics with self-assembling carbon nanotube clustersLASERS IN SURGERY AND MEDICINE, Issue 7 2007Jin-Woo Kim PhD Abstract Background and Objectives Unique properties of carbon nanotubes (CNTs) would open new avenues for addressing challenges to realize rapid and sensitive antimicrobial diagnostics and therapy for human pathogens. In this study, new CNTs' capabilities for photothermal (PT) antimicrobial nanotherapy were explored in vitro using Escherichia coli as a model bacterium. Study Design/Materials and Methods Single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) were incubated with E. coli K12 strain. CNTs' locations in bacteria and laser-induced thermal and accompanied effects around CNTs were estimated with TEM and PT microscopy, respectively. Multi-pulse lasers at 532 and 1064 nm with 12-ns pulse duration were used for irradiating sample mixtures at different laser fluences. Cell viability was evaluated using a bacterial viability test kit and epi-fluorescence microscopy. Results This study revealed CNTs' high binding affinity to bacteria, their capability to self-assemble as clusters at bacteria surfaces, and their inherent near-infrared (NIR) laser responsiveness. Cell viability was affected neither by CNTs alone nor by NIR irradiations alone. Notable changes in bacteria viability, caused by local thermal and accompanied bubble-formation phenomena, were observed starting at laser fluences of 0.1,0.5 J/cm2 with complete bacteria disintegration at 2,3 J/cm2 at both wavelengths. Furthermore, ethanol in reaction mixtures significantly (more than one order) enhanced bubble formation phenomena. Conclusion This first application of laser-activated CNTs as PT contrast antimicrobial agents demonstrated its great potential to cause irreparable damages to disease-causing pathogens as well as to detect the pathogens at single bacterium level. This unique integration of laser and nanotechnology may also be used for drinking water treatment, food processing, disinfection of medical instrumentation, and purification of grafts and implants. Furthermore, the significant ethanol-induced enhancement of bubble formation provides another unique possibility to improve the efficiency of selective nanophotothermolysis for treating cancers, wounds, and vascular legions. Lesers Surg. Med. 39:622,634, 2007. © 2007 Wiley-Liss, Inc. [source] Evaluation of a rapid diagnostic field test kit for identification of Phytophthora species, including P. ramorum and P. kernoviae at the point of inspectionPLANT PATHOLOGY, Issue 5 2007C. R. Lane Plant health regulations to prevent the introduction and spread of Phytophthora ramorum and P. kernoviae require rapid, cost effective diagnostic methods for screening large numbers of plant samples at the time of inspection. Current on-site techniques require expensive equipment, considerable expertise and are not suited for plant health inspectors. Therefore, an extensive evaluation of a commercially available lateral flow device (LFD) for Phytophthora species was performed involving four separate trials and 634 samples. The assay proved simple to use, provided results in a few minutes and on every occasion a control line reacted positively confirming the validity of the test. LFD results were compared with those from testing a parallel sample, using laboratory methods (isolation and real-time PCR). The diagnostic sensitivity of the LFD (87·6%) compared favourably with the standard laboratory methods although the diagnostic specificity was not as stringent (82·9%). There were a small number (n = 28) of false negatives, but for statutory purposes where all positive samples must be identified to species level by laboratory testing, overall efficiency was 95·6% as compared with visual assessment of symptoms of between 20-30% for P. ramorum and P. kernoviae. This work demonstrates the value of the LFD for diagnosing Phytophthora species at the time of inspection and as a useful primary screen for selecting samples for laboratory testing to determine the species identification. [source] Retronasal and Orthonasal Olfactory Function in Relation to Olfactory Bulb Volume in Patients With Posttraumatic Loss of SmellTHE LARYNGOSCOPE, Issue 6 2006Philippe Rombaux MD Abstract Objective: The aims of this study were to evaluate olfactory function with orthonasal and retronasal testing in patients with posttraumatic olfactory loss and to investigate the relation between residual olfactory function and olfactory bulb (OB) volume. Method: A retrospective study of 25 patients with posttraumatic olfactory loss was performed. Orthonasal olfactory function was assessed with the Sniffin' Sticks test kit; retronasal olfactory function was assessed with intraorally applied odors. Magnetic resonance imaging was used to determine OB volume and cortical damage in the frontal and temporal areas. Results: The main outcomes of the present study were the demonstration of a correlation between olfactory function and OB volume, which was more pronounced for retronasal than for orthonasal olfactory function; retronasal olfactory function was most affected in the patients with the most extensive cerebral damage and was least compromised in patients without such damage; OB volumes were smaller in patients with parosmia compared with those without; and the presence of parosmia was clearly associated with the presence of cerebral damage. Conclusion: The data confirm that OB volume is an indicator of olfactory function but, interestingly, in this study, it is largely determined by retronasal olfactory sensitivity. In addition, these results emphasize the role of higher cortical centers in olfactory function, and especially in parosmia, which may, at least in some cases, be related to lesions in the fronto-orbital and anterior temporal cortices. It would be of interest to investigate OB volume further in relation to the prognosis of the disorder. [source] Assessment of Five Interleukins in Human Synovial Fluid as Possible Markers for Aseptic Loosening of Hip ArthroplastyARTIFICIAL ORGANS, Issue 7 2009Alina Beraudi Abstract One of the most important factors that seems to be involved in total hip replacement is periprosthetic osteolysis. As it is well documented that several interleukins (ILs) are triggered in periprosthetic osteolysis, this article investigates the role of five ILs in primary and replacement total hip arthroplasty, understanding if one of them can also predict hip implant loosening, secondary surgery, and prosthesis breakage. The levels of IL-1,, 1,, 6, 8, and 10 in synovial fluid were examined, using a high sensitivity enzyme-linked immunosorbent assay (ELISA) test kit (Pierce Biotechnology, Inc., Rockford, IL, USA) to determine whether these cytokines could be used as markers of enhanced periprosthetic osteolysis, leading to aseptic loosening of total/partial hip arthroplasty or revision surgery. Synovial fluid was harvested from 23 patients undergoing primary total hip arthroplasty and 35 patients undergoing total/partial hip revision due to aseptic loosening. In the revision group, four cases had suffered a prosthesis fracture and five were second revisions. ILs 6 and 8 were significantly higher in the revisions (305 and 817 pg/mL) compared with the primary arthroplasties (151 and 151 pg/mL), including cases with prosthesis fracture and those requiring a second revision. IL-10 levels were lower (not significantly) in second revision samples compared with those of revision samples. IL-1, levels were significantly higher in prosthesis fracture samples compared with those of all the other revision samples. No statistically significant differences in IL levels were found between osteoarthritis samples and those of other diseases. These results are a step forward to elucidating the complex network of events that are involved in loosening of hip implants. [source] Analysis of HER2 expression in primary urinary bladder carcinoma and corresponding metastasesBJU INTERNATIONAL, Issue 7 2005Truls Gårdmark OBJECTIVE To evaluate the expression of HER2 receptors (previously reported to be over-expressed in malignant urothelium) in both primary tumours and metastases of transitional cell cancer, using two different staining methods and two different scoring techniques, considering the potential use of these receptors as targets for planned systemic anti-HER2 nuclide-based treatment. MATERIALS AND METHODS HER2 expression was evaluated with two different immunohistochemical methods in 90 patients with primary urinary bladder cancer tumours and corresponding metastases. Sections were first stained with the commercially available breast cancer test kit (HercepTest®, Dako, Glostrup, Denmark). Parallel sections were then stained with a modified HercepTest procedure. Two different evaluation criteria were compared; the HercepTest score that requires ,,10% stained tumour cells (as for breast cancer) and a proposed ,Target score' that requires >67% stained tumour cells. The latter score is assumed to be preferable for HER2-targeted radionuclide therapy. RESULTS Using the HercepTest kit, the Target score gave lower fractions of positive primary tumours and metastases than the HercepTest score. The modified HercepTest staining procedure and Target score gave high HER2 values in 80% of primary tumours and 62% of metastases, which is considerably more than that obtained with the HercepTest staining and score. There was a significant decrease in HER2 positivity with increasing distance from the primary tumour. In nine sentinel-node metastases assessed, all but one were HER2-positive. Considering all regional metastases, 74% were positive, and of distant metastases, 47%; 72% of the patients with positive primary tumours also expressed HER2 in their metastases. CONCLUSIONS When combining the modified HercepTest with customised evaluation criteria, more HER2-positive tumours were diagnosed. The degree of HER2 down-regulation was significantly higher in distant than in regional metastases. HER2-targeted therapy may be an alternative or complementary to other methods in the future treatment of metastatic urinary bladder carcinoma. [source] Black teeth: beauty or caries prevention?COMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 2 2006Practice, beliefs of the Kammu people Abstract , Background:, To be beautiful and caries-free, Kammu women in Laos and Vietnam habitually paint their teeth black. Although this practice existed for many generations, it is now known only among the elderly. Objectives:, To describe how the tooth-blackening procedure is performed and to test the black stain for possible antimicrobial effects in laboratory experiments. Methods:, Information on how to blacken teeth was obtained by interviewing groups of elderly Kammu people living in different villages in Laos and Vietnam. Water extracts of the stain were placed in wells in agar plates and the plates incubated with Streptococcus mutans or S. sobrinus. The stain was also let such that it covered half of the strip test-side of the Dentocult SM® Strip Mutans test kit and incubated with saliva from five persons known to carry mutans streptococci in their saliva. Results:, Interviews revealed that three plants were commonly used: Dracontomelon dao nuts (DD nuts), Cratoxylum formosum (CF) wood or Croton cascarilloides (CC) wood. The parts (nut, wood) were burned and soot collected on metal plates. The fresh soot, which had a viscous consistency, was applied to teeth with the index finger. Extracts of soot of the DD nuts had no effect on the streptococci on agar plates but inhibited the growth of salivary mutans streptococci on strips. Controls using soot from birch tree (Betula pendula) had no effect. Conclusions:, The procedure was simple and resulted in black, beautiful (?) teeth. The soot of DD nuts effectively inhibited growth of salivary mutans streptococci in in vitro experiments. [source] Pollen beetle in the UK; the start of a resistance problem?EPPO BULLETIN, Issue 1 2008D. M. Richardson In 2003, the first report of poor control of pollen beetle Meligethes aeneus at a site in South East England in the UK was investigated but resistance to pyrethroid insecticides was not confirmed in subsequent laboratory testing. Bioassays of 26 UK samples of M. aeneus collected in 2004 with the pyrethroid lambda-cyhalothrin showed little or no divergence from the response expected of a fully susceptible strain. In 2006 samples of pollen beetle from the UK were sent to Germany, and again these were shown to be fully susceptible. In 2007 using test kits supplied by Udo Heimbach, BBA, 19 samples of pollen beetle were tested, again from across the UK. Results indicated that a small number of individuals were fully resistant, surviving the highest dose of lambda-cyhalothrin tested (0.375 microg/L) after 5-h exposure at 4 sites, and after 24-h exposure at 2 of these sites. [source] Influence of factor VIII:C and factor IX activity in plasmas of haemophilic dogs on the activated partial thromboplastin time measured with two commercial reagentsHAEMOPHILIA, Issue 3 2000R. Mischke The present study is based on 145 plasma samples with a reduced activity of factor VIII:C (range: 0.009,0.62 IU mL,1) and 28 samples with a reduced factor IX activity (range: 0.035,0.55 IU mL,1). The samples were collected from dogs with haemophilia A (n=22) or haemophilia B (n=3), some of these during substitution therapy. For all samples the activated partial thromboplastin time (APTT) was measured with two commercial reagents containing kaolin as a contact activator. In each case, the deficiency of factor VIII:C or IX was reflected in abnormal results of the APTT. This was true for both reagents. A significant correlation (P < 0.001) was found between factor VIII:C activity and APTT (reagent 1, Pathromtin®; Spearman's rank correlation coefficient, rS=,0.731, reagent 2, PTT-Reagenz; rS=,0.875) as well as between factor IX activity and APTT (reagent 1, rS=,0.819; reagent 2, rS=,0.955]. In each case, the relationship between coagulation factor activity and APTT could be proven most precisely by geometric regression. The results of this study illustrate the applicability of commercial APTT test kits as a sensitive screening test of factor VIII:C and IX deficiencies in canine plasma. [source] PPL and MDM skin test: New test kit is helpful in detecting immediate-type allergy to beta-lactamsJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2007Regina Treudler Summary Background: The diagnosis of PPL (major determinant) and MDM (minor determinant) sensitization as relevant allergens in beta-lactam allergy has been recently hampered by withdrawal from the market of formerly available test kits. We investigated a new PPL/MDM test kit in the work-up of beta-lactam allergy. Patients and Methods: 15 patients with history of beta-lactam allergy were investigated for specific IgE and received patch, skin prick (SPT) and intracutaneous tests (ICT; immediate and late readings) using the relevant beta-lactams. In addition the new test kit was used for parallel SPT and ICT. Results: 14 women and 1 man (16,73 years) with immediate (n = 7), delayed (n = 7) or unclear (n = 1) reactions to beta-lactams 8,300 months previously (penicillin G/V n = 3, aminopenicillins n = 7, cephalosporins n = 4, unknown n = 2) were tested. In patients with immediate type reactions, n = 2 had specific IgE, n = 4 reacted to the new test kit (n = 3 MDM, all of whom reacted exclusively to this test, n = 1 PPL). Two patients with non-immediate reactions reacted to other beta-lactams. Conclusions: Our data show that the new test kit may be helpful in detecting patients with immediate type allergy to beta-lactams. Without this test, in those three patients reacting exclusively to MDM, and oral provocation test would have been necessary to clarify their allergy. Data from larger groups of patients are needed to determine the sensitivity and specificity of this test kit. [source] Failure to confirm HIV infection in two end-stage HIV/AIDS patients using a popular commercial line immunoassayJOURNAL OF MEDICAL VIROLOGY, Issue 9 2008Julian W. Tang Abstract Immunoassays using either viral lysate (Western blot) or recombinant/synthetic antigen (immunoblot) for anti-HIV capture are still the preferred method to confirm HIV infection. Two cases of HIV-1-infected patients presented with acquired immunodeficiency syndrome (AIDS)-defining illnesses. Laboratory tests were performed using multiple commercial HIV test kits on multiple sera from both patients over several weeks. Both patients were strongly positive on the anti-HIV/p24 antigen combined screening assay. Yet, HIV-1 infection could not be confirmed using a popular commercial immunoassay. Eventually, HIV infection was confirmed using an alternative commercial Western blot assay as well as an HIV quantitative PCR test. In laboratories without nucleic acid testing (NAT) for HIV, indeterminate results may delay confirmation of HIV infection, if commercial line immunoassays alone are available. Some end-stage HIV/AIDS patients may not produce antibodies to specific HIV antigens and may therefore give indeterminant or negative results on some immunoassays, depending on the type of antigen used. This report highlights the utility of having NAT available when diagnosing difficult cases of HIV infection, especially in light of the recent Centers for Disease Control and Prevention move towards more universal, routine, HIV testing. J. Med. Virol. 80:1515,1522, 2008. © 2008 Wiley-Liss, Inc. [source] Estimation of the day-specific probabilities of conception: current state of the knowledge and the relevance for epidemiological researchPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2006Courtney D. Lynch Summary Conception, as defined by the fertilisation of an ovum by a sperm, marks the beginning of human development. Currently, a biomarker of conception is not available; as conception occurs shortly after ovulation, the latter can be used as a proxy for the time of conception. In the absence of serial ultrasound examinations, ovulation cannot be readily visualised leaving researchers to rely on proxy measures of ovulation that are subject to error. The most commonly used proxy measures include: charting basal body temperature, monitoring cervical mucus, and measuring urinary metabolites of oestradiol and luteinising hormone. Establishing the timing of the ovulation and the fertile window has practical utility in that it will assist couples in appropriately timing intercourse to achieve or avoid pregnancy. Identifying the likely day of conception is clinically relevant because it has the potential to facilitate more accurate pregnancy dating, thereby reducing the iatrogenic risks associated with uncertain gestation. Using data from prospective studies of couples attempting to conceive, several researchers have developed models for estimating the day-specific probabilities of conception. Elucidating these will allow researchers to more accurately estimate the day of conception, thus spawning research initiatives that will expand our current limited knowledge about the effect of exposures at critical periconceptional windows. While basal body temperature charting and cervical mucus monitoring have been used with success in field-based studies for many years, recent advances in science and technology have made it possible for women to get instant feedback regarding their daily fertility status by monitoring urinary metabolites of reproductive hormones in the privacy of their own homes. Not only are innovations such as luteinising hormone test kits and digital fertility monitors likely to increase study compliance and participation rates, they provide valuable prospective data that can be used in epidemiological research. Although we have made great strides in estimating the timing and length of the fertile window, more work is needed to elucidate the day-specific probabilities of conception using proxy measures of ovulation that are inherently subject to error. Modelling approaches that incorporate the use of multiple markers of ovulation offer great promise to fill these important data gaps. [source] Clonal dissemination of a toxin-A-negative/toxin-B-positive Clostridium difficile strain from patients with antibiotic-associated diarrhea in PolandCLINICAL MICROBIOLOGY AND INFECTION, Issue 8 2001H. Pituch Objective To determine the incidence of toxin-A-negative/toxin-B-positive Clostridium difficile strains and their genetic relatedness in the feces of patients suffering from antibiotic-associated diarrhea (AAD) in Polish hospitals. MethodsC. difficile strains were cultured from patients' stool samples. The present study characterises these strains with respect to their cytopathogenicity on McCoy cells and the absence of toxin A despite a functional toxin B as determined with commercial test kits (Culturette Brand Toxin CD-TCD toxin A test and C. difficile Tox A/B test). In addition, PCR using different primer pairs aiming at non-repeating or repeating regions of the toxin A and B genes were used to confirm the findings. All toxin A,B+ strains were genetically characterised by random amplification of polymorphic DNA (RAPD) analysis, PCR ribotyping and, in part, pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Results We here present the presence of 17 toxin A,B+ strains among 159 C. difficile strains (11%) isolated from fecal samples from 413 patients with antibiotic-associated diarrhea. All 17 strains possessed the toxin B gene, demonstrated a cytopathogenic effect on the McCoy cells, and were positive in the Tox A/B test. Molecular typing of these 17 C. difficile strains revealed that 7 of 17 (41%) toxin A,/B+C. difficile strains could not be discriminated. It appeared that these strains had a genotype that could not be distinguished from that of a Japanese control strain. Conclusion Our observations imply that a particular genotype of toxin A,B+C. difficile has spread extensively, not only in Poland but possibly even worldwide. [source] | ||||||||||||||||