Swab Kit Research Articles

GeneMatch: A novel recruitment registry using at-home APOE genotyping to enhance referrals to Alzheimer's prevention studies

IntroductionRecruitment for Alzheimer's disease (AD) prevention research studies is challenging because of lack of awareness among cognitively healthy adults coupled with the high screen fail rate due to participants not having a genetic risk factor or biomarker evidence of the disease. Participant recruitment registries offer one solution for efficiently and effectively identifying, characterizing, and connecting potential eligible volunteers to studies. MethodsIndividuals aged 55-75 years who live in the United States and self-report not having a diagnosis of cognitive impairment such as MCI or dementia are eligible to join GeneMatch. Participants enroll online and are provided a cheek swab kit for DNA extraction and apolipoprotein E (APOE) genotyping. Participants are not told their APOE results, although the results may be used in part to help match participants to AD prevention studies. ResultsAs of August 2018, 75,351 participants had joined GeneMatch. Nearly 30% of participants have one APOE4 allele, and approximately 3% have two APOE4 alleles. The percentages of APOE4 heterozygotes and homozygotes are inversely associated with age (P < .001). DiscussionGeneMatch, the first trial-independent research enrollment program designed to recruit and refer cognitively healthy adults to AD prevention studies based in part on APOE test results, provides a novel mechanism to accelerate prescreening and enrollment for AD prevention trials.

Self-Swabbing for Virological Confirmation of Influenza-Like Illness Among an Internet-Based Cohort in the UK During the 2014-2015 Flu Season: Pilot Study.

BackgroundRoutine influenza surveillance, based on laboratory confirmation of viral infection, often fails to estimate the true burden of influenza-like illness (ILI) in the community because those with ILI often manage their own symptoms without visiting a health professional. Internet-based surveillance can complement this traditional surveillance by measuring symptoms and health behavior of a population with minimal time delay. Flusurvey, the UK’s largest crowd-sourced platform for surveillance of influenza, collects routine data on more than 6000 voluntary participants and offers real-time estimates of ILI circulation. However, one criticism of this method of surveillance is that it is only able to assess ILI, rather than virologically confirmed influenza.ObjectiveWe designed a pilot study to see if it was feasible to ask individuals from the Flusurvey platform to perform a self-swabbing task and to assess whether they were able to collect samples with a suitable viral content to detect an influenza virus in the laboratory.MethodsVirological swabbing kits were sent to pilot study participants, who then monitored their ILI symptoms over the influenza season (2014-2015) through the Flusurvey platform. If they reported ILI, they were asked to undertake self-swabbing and return the swabs to a Public Health England laboratory for multiplex respiratory virus polymerase chain reaction testing.ResultsA total of 700 swab kits were distributed at the start of the study; from these, 66 participants met the definition for ILI and were asked to return samples. In all, 51 samples were received in the laboratory, 18 of which tested positive for a viral cause of ILI (35%).ConclusionsThis demonstrated proof of concept that it is possible to apply self-swabbing for virological laboratory testing to an online cohort study. This pilot does not have significant numbers to validate whether Flusurvey surveillance accurately reflects influenza infection in the community, but highlights that the methodology is feasible. Self-swabbing could be expanded to larger online surveillance activities, such as during the initial stages of a pandemic, to understand community transmission or to better assess interseasonal activity.

Evaluation of a Chlamydia trachomatis-specific, commercial, real-time PCR for use with ocular swabs

BackgroundTrachoma, the leading infectious cause of blindness worldwide, is caused by conjunctival Chlamydia trachomatis infection. Trachoma is diagnosed clinically by observation of conjunctival inflammation and/or scarring; however, there is evidence that monitoring C. trachomatis infection may be required for elimination programmes. There are many commercial and ‘in-house’ nucleic acid amplification tests for the detection of C. trachomatis DNA, but the majority have not been validated for use with ocular swabs. This study evaluated a commercial assay, the Fast-Track Vaginal swab kit, using conjunctival samples from trachoma-endemic areas. An objective, biostatistical-based method for binary classification of continuous PCR data was developed, to limit potential user-bias in diagnostic settings.MethodsThe Fast-Track Vaginal swab assay was run on 210 ocular swab samples from Guinea-Bissau and Tanzania. Fit of individual amplification curves to exponential or sigmoid models, derivative and second derivative of the curves and final fluorescence value were examined for utility in thresholding for determining positivity. The results from the Fast-Track Vaginal swab assay were evaluated against a commercial test (Amplicor CT/NG) and a non-commercial test (in-house droplet digital PCR), both of whose performance has previously been evaluated.ResultsSignificant evidence of exponential amplification (R2 > 0.99) and final fluorescence > 0.15 were combined for thresholding. This objective approach identified a population of positive samples, however there were a subset of samples that amplified towards the end of the cycling protocol (at or later than 35 cycles), which were less clearly defined. The Fast-Track Vaginal swab assay showed good sensitivity against the commercial (95.71) and non-commercial (97.18) tests. Specificity was lower against both (90.00 and 96.55, respectively).ConclusionsThis study defined a simple, automated protocol for binary classification of continuous, real-time qPCR data, for use in an end-point diagnostic test. This method identified a population of positive samples, however, as with manual thresholding, a subset of samples that amplified towards the end of the cycling program were less easily classified. When used with ocular swabs, the Fast-Track Vaginal swab assay had good sensitivity for C. trachomatis detection, but lower specificity than the commercial and non-commercial assays it was evaluated against, possibly leading to false positives.

Enterobius vermicularis infection and its risk factors among pre-school children in Taipei, Taiwan.

The prevalence of pinworm infection is extremely low in Taipei, Taiwan. This population study was designed to determine the current status and the associated risk factors of this infection among pre-school children. Perianal swab specimens were obtained from the parents or guardians using a two-consecutive-day adhesive cellophane perianal swab kit. Information of family background, personal hygiene, and household sanitary conditions were collected by asking the parents or guardians to complete a questionnaire. Of 44,163 children, 0.21% was found to infect with pinworm. The positive rate was highest in Datong (0.59%) and Nangang (0.58%) Districts and lowest in Neihu District (0.02%). There was no significant difference in the rates by gender (boys 0.24% and girls 0.19%) or school (kindergartens 0.25% and nurseries 0.17%). Significantly higher positive rates were found in children having parent with lower educational level and elder brother(s)/sister(s). Children taking bath by themselves and those sleeping in bed with matting had significantly higher positive rates. Five significant independent predictors of pinworm infection were determined by multivariate analysis: having elder brother(s), having elder sister(s), infrequent washing hands after using toilet facilities, bathing without the help of family members, and sleeping on bed with matting. The prevalence of pinworm infection in the pre-school children of Taipei is extremely low and decreasing. Good hand washing habit should be an important preventive measure. Transmission of this infection in pre-school children may occur in the family through their school-age siblings.

The changes in saliva cotinine during Ramadan among a group of Muslim smokers in Malaysia

Background: Smoking is a negative health behaviour that brought in health and social problems into the community. The effects of smoking can be decreased by promoting smoking cessation. One of the approaches in smoking cessation intervention focuses on the supportive environment that can be naturally found during the Ramadan where every Muslim is obligated to fast which included abstaining from smoking.Methods:A total of 61 male, Muslim smokers who currently smoke cigarette on daily basis were recruited. The study was conducted by using the one-group pretest-posttest study design to evaluate the effect of Ramadan environment on saliva cotinine among a group of smokers who work at a local authority in Selangor. The data were collected three times which were one week before Ramadan, 21st of Ramadan and 21 days after Ramadan. The saliva cotinine were measured by using SalivaBio oral swab (SOS) and cotinine biomarker research salivary assay kits and protocols by Salimetrics with the sensitivity of 0.15ng/ml. Data analysis was conducted by using One-way ANOVA with repeated measures and paired t-test.Results: The study showed a significant difference in the saliva cotinine level from before, during and after Ramadan (p = 0.002). From the post-hoc test, there is a significant positive changes in the saliva cotinine level from before Ramadan to during Ramadan (t (60) = 3.66, p = 0.001).Conclusions:The saliva cotinine level of the smokers decreased during Ramadan. This can provide an opportunity for easier initiation of smoking cessation for the smokers.

The Stem Cell Drive: A Canadian Perspective

Patients with a variety of blood cancers and metabolic diseases may require a stem cell transplant as part of their treatment. However, 70% of patients do not have a suitable genetic match in their family. Stem cell donor-databases are used to match potential unrelated donors to patients worldwide. In Canada, individuals aged 17-35 years can register as donors online or at a stem cell drive where they provide consent and a tissue sample (buccal-swab) for Human Leukocyte Antigen (HLA) allele typing. To date, no guidelines have been published to recommend a process for stem cell donor recruitment at drives. Here, I outline a Canadian approach to stem cell drive design, which features evidence-based strategies to identify and recruit the most-needed stem cell donors and to minimize donor ambivalence and withdrawal from the registry. This model of stem cell drive design includes five stations: pre-screening, informed consent, registration, swabbing, and reconciliation. Registrant confidentiality and privacy is maintained at each station, and quality control is emphasized throughout.Registrants are first pre-screened to ensure donor eligibility. Recruiters at the prescreening station target the most-needed stem cell donors according to the literature: young, healthy, and ethnically-diverse males. Non-optimal and ineligible registrants are redirected to help out in other ways. Recruiters then explain the principles of stem cell donation and educate registrants about the stem cell donation process. Next, registrants proceed to the informed consent station, which is designed to meet the requirements of the World Marrow Donor Association's suggested procedures for procurement of informed consent at time of recruitment (2003). Here, recruiters hand registrants an information pamphlet, and explain blood and marrow stem cell collection procedure diagrams. The risks of donation are outlined, and registrants are informed of their right to withdraw at any time and about donor and patient anonymity. Registrants are subsequently guided through registration, where they provide their contact/demographic information, complete a health questionnaire, and sign a consent form to join the registry. Recruiters at this station error check registrants' forms to ensure correct completion, and educate registrants about the data collection, storage, usage, and confidentiality. Following registration, registrants proceed to swabbing, where they swab their cheeks to provide a tissue/DNA sample. Recruiters at this station affix barcode stickers to each swab kit component. While registrants swab their cheeks, volunteers perform an informed consent checkpoint by asking registrants if they understand the donation process, the risks involved, and the right to withdraw at any time. Finally, registrants visit reconciliation, where their paperwork is error checked again, their understanding of the donation process is assessed a final time to verify informed consent, and their kit processed for shipping. In summary, the five-station approach to stem cell drive design outlined in this presentation represents a new model for effective stem cell donor recruitment. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Evaluation of the Impact of Non-Inherited Maternal Antigens on the Outcome of HLA Mismatched Unrelated Donor Hematopoietic Stem Cell Transplantation for Hematological Malignancies on Behalf of the ALWP of the EBMT and the CIBMTR

Allogeneic hematopoietic stem cell transplantation (HSCT) offers a potential cure for a variety of hematological malignancies. Patients without an HLA matched sibling donor can turn to unrelated donor registries to identify a suitably HLA matched donor. In the case where a fully HLA-A, -B, -C, -DRB1 and -DQB1 (10/10) matched donor is unavailable, there are often multiple 9/10 matched donors to select from. However, the prioritization and identification of permissive HLA mismatches in the 9/10 matched setting have proven elusive. Fetal exposure to non-inherited maternal antigens (NIMA) imparts lifelong immune modulating effects leading to tolerance to these antigens. Prior studies have found that matching for non-inherited maternal antigens (NIMA) can lead to lower rates of acute graft versus host disease (aGVHD) and lower treatment-related mortality (TRM) in cord blood HSCT (J.J. van Rood et al., Blood 2002; J. J. van Rood et al., PNAS, 2009; V. Rocha et al., BBMT, 2012). Patients undergoing mismatched HSCT with adult unrelated donors could benefit from NIMA matching by introducing maternal HLA testing during confirmatory typing of the donor and using NIMA matching as a criterion for mismatched donor selection.This joint EBMT-CIBMTR retrospective analysis was designed to evaluate the influence of NIMA matching in HSCT with mismatched adult unrelated donors. Matching criteria were based on HLA-A, -B, -C, -DRB1, -DQB1 at high resolution. Included donor-recipient pairs had 5 loci HLA typing and a minimum of one year follow-up recorded at EBMT or CIBMTR and donors were registered with DKMS German Bone Marrow Donor Center. To obtain maternal HLA typing information, DKMS contacted the respective donors by mail to inform about the study and to provide detailed information, a buccal swab kit and an informed consent form to the donor's mother that the donor could send on. SBT-based HLA typing was performed at the DKMS Life Science Lab, Dresden, Germany once signed informed consent and samples were received. A total of 1735 donors were contacted and maternal samples could be retrieved for 803 cases (46%). A total of 50 NIMA matches (6%) were found reflecting the rate expected from previous studies.Multivariate analyses were performed using Cox proportional hazards models adjusting for significant co-variates for overall survival (OS), disease free survival (DFS), relapse, TRM and acute and chronic GVHD comparing NIMA matched to NIMA mismatched cases.The final analysis population was restricted to 9/10 matched cases (N=452) transplanted for acute myeloid leukemia (N=307) and acute lymphoblastic leukemia (N=145) using myeloablative (N=307) or reduced intensity (N=145) conditioning from 1999-2013. The NIMA matched (N=32) and mismatched (N=420) groups were well balanced for all disease, patient, transplant and donor characteristics. The groups differed by mismatched HLA locus with the NIMA matched group skewed towards more HLA-C mismatches (66% vs. 35%). Univariate analyses did not find any significant differences between the NIMA matched and mismatched groups for any outcomes. TRM rates were similar between the groups at 1 year with 23% (95% CI: 10-40%) and 23% (95% CI: 19-28%) in the NIMA matched and mismatched groups, respectively. No significant associations were observed in multivariate analyses of the NIMA matched versus mismatched groups (Table).In contrast to prior studies of NIMA matched HSCT, no significant associations were found between NIMA matching and any outcomes. However, our findings may be due to the fact that the current study was underpowered to detect the expected difference in TRM observed in prior studies. Investigation on a larger cohort or a prospective trial would be needed.We thank Carlheinz Müller from the German unrelated donor registry ZKRD for providing additional HLA information and the donors and their mothers for their cooperation in this study.Table. Multivariate analysis results of NIMA matched versus mismatched (used as reference) HSCT Table 1OutcomeHR95% CIp-valueOS0.890.54-1.480.653DFS0.880.53-1.430.598TRM0.740.35-1.600.447Relapse0.890.45-1.750.737aGVHD II-IV0.970.53-1.800.935aGVHD III-IV0.590.19-1.910.382cGVHD1.770.99-3.160.053 DisclosuresLee:Bristol-Myers Squibb: Consultancy; Kadmon: Consultancy. Nagler:Biokine LTD: Consultancy.

Paternity analysis based on NGM SElect system in the Medical and Forensic Genetics Laboratory, Department of Forensic Medicine, Medical University of Lodz.

The aim of the study was to evaluate the usefulness of the NGM SElect multiplex kit for paternity testing in the population of central Poland, and compare it with the IDENTIFILER system. The study material consisted of buccal swabs taken from individuals who reported to the Medical and Forensic Genetics Laboratory in Lodz. Samples from 450 trio cases of disputed paternity carried out in 2010-2014 were investigated. Genomic DNA was extracted from buccal swabs collected from 1,350 individuals using the Swab kit (A and A Biotechnology) according to the manufacturer's protocol. DNA amplification was performed using the AmpFℓSTR® NGM SelectTM PCR Amplification Kit (Life Technologies). PCR products were separated by capillary electrophoresis using HID 3500 Genetic Analyzer. In the analyzed cases with paternity confirmation in the NGM SElect system, the maximum value of PI was 3.9 × 1012, which corresponds to the probability of paternity W = 99.9999999999%. It was thus significantly higher than analogical parameters obtained in the IDENTIFILER system (PI = 6.0 × 1010, W = 99.99999999%). The NGM SElect kit was unable to resolve just one case out of 450, which represents only 0.2% of all analyzed disputed paternity cases. The study showed the SE33 (ACTBP2) locus to have the highest evidence value in paternity analysis out of all investigated autosomal STRs.

Noninvasive Buccal Swab Antigen Sample and Molecular Testing Provides Extended Antigen Typing for Patients with Hemoglobinopathies

To demonstrate the feasibility of performing a noninvasive, molecular-based red blood cell (RBC) antigen test on infants and very young children with sickle cell disease as part of a statewide newborn screening follow-up program. A prospective pilot project was conducted using a noninvasive buccal swab and test kit to perform DNA-based, extended RBC phenotyping in 92 children participating in a newborn hemoglobinopathy screening follow-up program. Reported data include the extended panel of antigens detected by molecular analysis compared with unaffected population estimates. Molecular-based RBC antigen testing was successful, with extended RBC typing generated for all subjects. Molecular testing detected several rare negative or rare positive phenotypes, demonstrating the utility of obtaining an extended antigen panel. This study demonstrates the feasibility of performing antigen testing on buccal swab specimens from children with sickle cell disease as part of a newborn screening follow-up program with the aim of allowing specific unit matching to prevent alloimmunization with RBC transfusions. The general applicability of testing may be limited by a lack of uniform insurance coverage for buccal swab testing, however.

Links between DRD4, executive attention, and alphabetic skills in a nonclinical sample

The dopamine D4 receptor gene (DRD4) has been linked to attention deficit hyperactivity disorder (ADHD) and reading disorders. In this study, we examined whether diminished anticipatory dopamine cell firing - typical of the long variant of the DRD4 allele - is related to emergent and advanced alphabetic skills, and whether executive attention is a mediator between this allele and alphabetic skills. We tested alphabetic skills in a normative sample of 159 children in both kindergarten and Grade 1, and executive attention 1 year earlier. Cheek cells were collected and genomic DNA was isolated from the samples using the Chemagic buccal swab kit on a chemagen Module I workstation. Thirty-seven percent of the children were carriers of at least one DRD4 7-repeat allele. Carriers of the long variant scored lower on alphabetic skills, and executive attention appeared to be a mediator of the relation between characteristics of DRD4 and alphabetic skills in kindergarten and first grade. This study shows how a genetic factor which has been shown to relate to variation in attention and regulatory behavior can explain delays in alphabetic skills. A practical implication is that in many cases early interventions should not only target reading skills, but also support children's engagement in tasks.

O1-S07.02 Characteristics of women testing positive for rectal STIs using self-collected mailed specimens

BackgroundThe website http://www.iwantthekit.org/ (IWTK) began offering self-administered rectal swab kits in addition to vaginal swab kits in January 2009 to test for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis.MethodsSwab samples...

P3-S2.04 Clinical evaluation of the BD HSV2 Qx assay for the direct qualitative testing of HSV2 as compared to viral culture and a laboratory-based PCR assay using male and female external anogenital lesions

BackgroundTo compare the performance characteristics of the BD ProbeTecTM HSV2 Qx Assay* on the BD ViperTM System in Extracted Mode to viral culture and a well-characterised molecular assay for the...

P3-S2.03 Clinical evaluation of the BD HSV1 Qx assay for the direct qualitative testing of HSV1 as compared to viral culture and a laboratory-based PCR assay using male and female external anogenital lesions

BackgroundTo compare the performance characteristics of the BD ProbeTecTM HSV1 Qx Assay* on the BD ViperTM System in Extracted Mode to viral culture and a well-characterised molecular assay for the...

O3-S3.06 Rescreening for chlamydial infection using home-based, self-obtained vaginal swabs: a randomised controlled trial in family planning clinic clients

BackgroundFamily planning clinics provide contraceptive and preventive services for millions of low-income individuals. Screening and treatment for Chlamydia trachomatis infection in these clinics is a major part of the chlamydia...

Chromatic (Red/Green) and Luminance Contrast Sensitivity in Monozygotic and Dizygotic Twin Infants

Purpose: To determine the extent to which contrast sensitivity (CS) development is governed by genetic mechanisms vs. environment, we compared CS between pairs of twin infants and pairs of unrelated infants. If genetics have a strong influence on CS, Monozygotic (Mz) twin siblings should be more similar (and more strongly correlated) than Dizygotic (Dz) twin siblings, and both Mz and Dz twins should show greater correlations than unrelated infant pairs. By contrast, if genetics have little influence, correlations should be the same for Dz and Mz twins. In this latter scenario, if both Mz and Dz twins show greater correlations than unrelated infant pairs, this suggests a role of shared environment. The current study measured Luminance (light/dark) and Chromatic (red/green) CS to assess sensitivity of the Magnocellular and Parvocellular pathways, respectively. Methods: Ten and 26 pairs of Mz and Dz twin pairs were tested (mean age = 4.5±1.5 mos). Zygosity was assessed using a questionnaire and cheek swab kits. Luminance and Chromatic CS were obtained for sinusoidal gratings using forced-choice preferential looking (∼200 trials per infant; 0.27 cycles/degree; 4.2 Hz). Results: Multiple regression was conducted on 100 runs of random Twin-1/Twin-2 orderings. Results indicated that the CS of one twin predicted 35-40% of the variance (p <0.0001) in the CS of the other twin, while controlling for postnatal age, gestational length, and gender. Simulations with randomly-matched twins suggest these findings are not due to chance. Discussion: Results suggest shared environment and/or genes influence both Luminance and Chromatic CS. With more subjects, we will address whether Luminance vs. Chromatic CS is more or less affected by shared genes/environment. Once we have enough data to compare Mz vs. Dz twins, we can ask which factor, genes or environment, is more influential using structural equation modeling (Neale et al, 2002).

Chromatic (red/green) and luminance contrast sensitivity in Monozygotic and Dizygotic twin infants

“Purpose: To determine the extent to which contrast sensitivity (CS) development is governed by genetic mechanisms vs. environment, we compared CS between pairs of twin infants and pairs of unrelated infants. If genetics have a strong influence on CS, correlations for Monozygotic (Mz) twin pairs should be greater than those for Dizygotic (Dz) twin pairs, and both Mz and Dz twins should show greater correlations than unrelated infant pairs. By contrast, if genetics have little influence, correlations should be the same for Dz and Mz twins. In this latter scenario, if both Mz and Dz twins show greater correlations than unrelated infant pairs, this suggests a role of shared environment. The current study measured Luminance (light/dark) and Chromatic (red/green) CS to assess sensitivity of the Magnocellular (M) and Parvocellular (P) pathways, respectively. Methods: Nine and 16 pairs of Mz and Dz twin pairs for a total of 50 twin infants were tested (mean age = 5 ±1.5 mos). Zygosity was assessed using a questionnaire and cheek swab kits, when necessary. Luminance and Chromatic CS were obtained using forced-choice preferential looking (˜200 trials per infant; 0.27 cpd; 4.2 Hz; mean luminance = 20 cd/m2). Results: Correlations for both Mz and Dz twins, and for both Luminance and Chromatic CS were significant (all p values 〈 0.002). Monte Carlo simulations on randomly paired unrelated twin infants revealed non-significant correlations (mean r = 0.12 and 0.07 for Luminance and Chromatic), indicating that Mz and Dz twins show greater correlations than unrelated infant pairs, and providing evidence for effects of shared environment. For Luminance CS, the Mz and Dz correlations were nearly identical (rMz = 0.88, rDz = 0.81), suggesting negligible genetic influence. By contrast, for Chromatic CS, the Mz correlation was greater than the Dz correlation (rMz = 0.87; rDz = 0.64), suggestive of a genetic contribution. Multiple regression analyses confirmed that these significant twin effects are not accounted for by small variations in age across infants. Discussion: Results suggest shared environment influences on both Luminance and Chromatic CS, as evidenced by Mz and Dz twins showing greater correlations than unrelated infant pairs. Although more Mz and Dz twins need to be tested, preliminary data suggest less genetic influence on Luminance CS (mediated by the M pathway) than on Chromatic CS (mediated by the P pathway). Future analysis, with more subjects, will employ maximum-likelihood based structural equation modeling (Neale, et al, 2002)”

Novel insight in the association between salmonellosis or campylobacteriosis and chronic illness, and the role of host genetics in susceptibility to these diseases

We studied the role of host genetics in the susceptibility to severe Salmonella and Campylobacter infections and chronic sequelae of these infections. Participants of a previous case-control study were sent a buccal swab kit and a questionnaire about occurrence of chronic sequelae. Single nucleotide polymorphisms (SNPs) in the TLR4 (rs4986790), IFNG (rs2430561 and rs1861493), STAT1 (rs1914408), IL1B (rs16944), NRAMP (SLC11A1 rs2276631), JUN (rs11688) and VDR (rs10735810) genes were determined. In total, 687 controls, 457 Campylobacter cases and 193 Salmonella cases participated. None of the SNPs were associated with Campylobacter or Salmonella infections. None of the participants developed Guillain-Barré, Miller-Fisher or Reiter's syndrome. Reactive arthritis occurred in 5% and 2% of cases and controls, respectively. Campylobacter cases more frequently experienced gastroenteritis episodes than controls. Campylobacter or Salmonella infection in women, use of proton pump inhibitors and an SNP in the IFNG gene were independent risk factors for reactive arthritis. Another SNP in the IFNG gene and use of proton pump inhibitors were risk factors for recurrent episodes of gastroenteritis. In conclusion, reactive arthritis and recurrent gastroenteritis episodes are common after infection and host genetic factors play a role in susceptibility to these long-term health effects.

Use of Buccal Swabs for Sampling DNA from Nestling and Adult Birds

We evaluated the feasibility and efficiency of using swabs to collect buccal epithelial cells from small (2- to 13-g) birds as a source of DNA for genetic studies. We used commercially available buccal swab kits to collect samples from 42 adult and 39 nestling (4- to 8-day-old) black-capped chickadees (Poecile atricapillus) and from 6 4-day-old nestling boreal chickadees (P. hudsonica). We compared DNA from buccal epithelial samples to that from blood samples from the same individuals. We extracted sufficient quantities of DNA for analysis from all buccal samples, and samples remained viable even after being stored in original plastic sampling tubes at room temperature for up to 18 months. Yields were equivalent whether extracted using the proprietary quick-extraction solution provided with buccal swab kits or using a salt-extraction process with inexpensive reagents. Yields of DNA from buccal samples were consistently lower than those from blood samples, but quantities were sufficient for all analyses. Assignment of sex, based on DNA extracted from paired buccal and blood samples, was identical for all 87 birds. We found no difference in the genotypes obtained from buccal and blood samples for 12 individuals tested using 5 microsatellite loci and found perfect concordance in sequencing of an 823-base-pair segment within the control region of mitochondrial DNA for 7 individuals tested. Use of buccal swabs is highly recommended as a rapid, noninvasive technique for sampling avian genomic DNA, especially for extremely young altricial nestlings or small-bodied adults, or for any birds for which blood sampling may be impossible or stressful.

Fast and simple DNA extraction from saliva or sperm cells obtained from the skin or isolated from swabs

The forensic scientist often has to cope with problematic samples from the crime scene due to their size and thus the amount of extractable DNA. The retrieval of DNA from swabs taken from the surface of the skin, for example in cases of strangulation, can be especially difficult. We systematically investigated swabs taken from the skin (to obtain a genetic profile from the victim and also from a possible offender) and from sperm cells containing swabs using two extraction kits: the Invisorb Forensic and the Spin Swab kit (both Invitek, Germany). DNA quality and quantity were tested on ethidium bromide containing agarose gels and in a highly sensitive Duplex-PCR which amplifies fragments specific for mitochondrial and nuclear DNA. Absolute quantification was done using real time PCR. Samples which were positive in the Duplex-PCR were also employed to genetic fingerprinting using the Powerplex ES and the AmpFlSTRIdentifiler™ kit. Our study shows that the easy-to-use Spin Swab kit is very suitable for DNA isolation from swabs taken from the skin and also from sperm cells. Retrieval of cells from the skin with swabs modified in extraction buffer, not in distilled water, led to a significant higher DNA yield.

Enzyrim: A new additive to increase the DNA yield from different materials such as teeth, blood or saliva

Enzyrim (Arte Copia, Zürich, Switzerland) is an enzyme mixture normally used for bone maceration. It is cheap, easy to handle, non-toxic and disposal is simple. When extracting DNA from Enzyrim treated teeth we discovered that the amount of extracted DNA was unexpectedly high. We then systematically investigated different biological materials using three extraction kits, the Invisorb Forensic kit, the PSP Spin Swab kit (both Invitek, Berlin, Germany) and the NucleoSpin Blood Quick pure kit (Macherey Nagel, Düren, Germany). DNA was extracted from buccal swabs, dried blood spots on filter paper, whole blood and toothpowder. All DNA extractions were performed according to the manufacturer's recommendations as well as after addition of Enzyrim to the lysis step of each kit. DNA quality and quantity were tested on ethidium bromide stained agarose gels. Absolute quantification was done using real time PCR. The DNA samples were also employed to genetic fingerprinting using the Powerplex ES and the AmpFlSTRIdentifiler kits. The application of Enzyrim greatly improves the DNA yield from forensically important materials and does not hamper DNA amplification. Thus Enzyrim apparently is a very useful additive for the optimisation of DNA extraction in the forensic routine.