[2] As recently reported by the Global TravEpiNet, up to 59% of s

[2] As recently reported by the Global TravEpiNet, up to 59% of selected travelers have an underlying medical condition and many immunocompromised patients are traveling to developing countries.[3] Previous studies have documented that 20% to 64% of international travelers will develop some health problem while abroad.[4] We set out to perform a retrospective, observational analysis of 3 years of post-travel survey data to determine associations between travel-related illness and unique features of the travel itinerary, along with other specific demographic variables. We hypothesized that we selleck would be better able

to define high-risk travel destinations, determine predictors, and develop a more meaningful survey tool to monitor the quality of itinerary-specific care delivered in the clinic. Our travel medicine clinic is best described as a medium-size practice CYC202 manufacturer incorporated into a large Infectious Diseases practice. We are located in the third largest catchment in Pennsylvania.

For 14 years, we have been collecting post-travel survey data for purposes of quality control and process improvement. Each year, we see more than 500 individuals, including those traveling in large group trips, for pre-travel medical care and counseling. The number of visits has been increasing by about 10% per year for the past 3 years. The travel medicine database and survey tool used in the study were approved by our network’s institutional review board. We mailed one-page surveys (Appendix 1) to all previously counseled travelers within 1 month of their planned departure date, with instructions to complete and mail back the surveys upon their return. No repeat mailings or other reminders were sent. Travelers were queried if they became ill, what symptoms they experienced, and if they sought medical help (arbitrarily defined as a serious illness). We also obtained information D-malate dehydrogenase about their diagnoses and the medications prescribed. If travelers developed diarrhea, they were asked to record the type of medication that they used

for treatment. Data gathered from all surveys returned over a 14-year period were entered into a de-identified database, from which we identified a retrospective cohort of 525 individuals who were seen in the travel clinic from May 2007 through December 2010. From this cohort, simple percentages were calculated for rates of illness by category (gastrointestinal, respiratory, etc.) and also rates of illness based on the destination continent. We then compared the travel-specific itinerary and demographics, including age of traveler, lag time from pre-travel visit to travel, the destination (by continent), and duration of travel related to the likelihood of illness, travel-related gastrointestinal illness (usually diarrhea), and the likelihood of seeing a medical care provider.

, 2005) This number corresponds to a small minority of the S ce

, 2005). This number corresponds to a small minority of the S. cerevisiae genome (< 1%); however, these genes have contributed to important functional innovations, including the ability to synthesize biotin, the ability to grow under anaerobic conditions and the ability to utilize Lumacaftor research buy sulphate from several organic sources (Hall et al., 2005). Similarly, a recent sequencing project of the commercial wine yeast strain EC118 uncovered three genomic regions that have been transferred horizontally from other

fungal sources (Novo et al., 2009). The three regions encode 34 genes, which are important in wine fermentation including nitrogen and carbon metabolism, cellular transport and stress responses, that aid yeast wine strains adapt to high sugar, low nitrogen and high ethanol concentrations (Novo et al., 2009). Other HGT events that have contributed to niche specification include the acquisition of glycosyl hydrolases (GHs) by rumen fungi from prokaryotes (Garcia-Vallve et al., 2000). GHs have permitted rumen fungi to establish a niche in the rumen of herbivorous mammals where cellulose and plant hemicellulose are

the main carbon sources (Garcia-Vallve et al., 2000). Similarly, the entomopathogenic fungus Metarhizium anisopliae has acquired a phosphoketolase (Mpk1) from an unspecified Epigenetics inhibitor bacterial source. It has been demonstrated that Mpk1 is necessary for insect virulence and is highly expressed in trehalose-rich insect haemolymph, thus playing an important role in niche adaptation for this fungus in the insect haemocoel. Slot & Hibbett (2007) have also uncovered an ancient transfer of a nitrate assimilation cluster from the Oomycota to an ancestral Dikarya species and propose that the acquisition of high-affinity nitrate assimilation contributed to the success of Dikarya on land by allowing exploitation Erastin nmr of nitrate in aerobic soils. Furthermore, the subsequent transfer of a complete Basidiomycete nitrate assimilation cluster into the ascomycetous mould Trichoderma reesei improved fitness and corresponds to a change in nutritional mode (wood decayer), providing

further evidence that horizontal transfer can facilitate niche shift in fungi (Slot & Hibbett, 2007). Incidences of HGT have also been linked to virulence in fungi, and the recent acquisition of a toxin gene (ToxA) by Pyrenophora tritici-repentis from Stagonospora nodorum has resulted in serious Pyrenophora infestations of wheat (Friesen et al., 2006). ToxA exerts its toxic effect via internalization into sensitive wheat mesophyll cells where it localizes to chloroplasts (Manning & Ciuffetti, 2005); however, the mechanisms involved in ToxA-mediated cell death remain to be elucidated. Interfungal HGT of a pea pathogenicity gene (PEP) cluster from Fusarium oxysporum to Nectria haematococca has also been linked to disease. The PEP cluster increases pathogenicity by converting a pea phytoalexin (pisatin) into a less toxic compound (Matthews & Van Etten, 1983).

The tree is on the endangered species list in Florida due to erad

The tree is on the endangered species list in Florida due to eradication efforts; however, it continues to be valued in see more coastal regions for the excellent shade it provides and root system which helps prevent beach erosion.1,2 We report four cases of Manchineel dermatitis and ophthalmitis that occurred when four students (100% attack rate) took shelter under a Manchineel tree during a rain storm. A 22-year-old Caucasian male had direct exposure with the bark and leaves of the Manchineel tree

as well as leaf runoff from the rain while taking refuge. He was wearing bathing trunks, sun glasses, and a brimmed cap. His exposure lasted 1 hour and his onset of symptoms was approximately 12 hours. The symptoms included “burning” of the skin, erythema, Selleckchem Sirolimus swelling of the affected areas, and some blistering at areas of direct contact (face, abdomen, arms, and legs). There was no conjunctival irritation noted. He applied “Benadryl” cream shortly after the “rash” appeared and had resolution of all symptoms and lesions in 5 days with no scarring. A 23-year-old Caucasian female had direct contact with the bark and leaves of the Manchineel while repairing from the rain, leaning against the tree trunk, and touching the leaves. She was wearing a bikini and strapless dress during her exposure of 1 hour. She did

not have a brimmed cap during that time. Twelve hours after her exposure she noted the onset of severe pain, Liothyronine Sodium erythema, and swelling of her eyelids and face. This extended rapidly to all of her exposed skin including chest, arms, and legs with accompanying burning and irritation. The lesions progressed

with conjunctivitis and blisters including the eyelids (Figure 1) and several of her body surfaces. Healing occurred in about 5 days with mild scarring of the left upper eyelid. She was treated with oral corticosteroid and bathing of the skin to remove remaining toxin. A 23-year-old Caucasian male stood under the Manchineel tree for approximately 40 minutes. He made no direct contact with the tree or its leaves. His onset of symptoms was about 30 minutes after the exposure. His initial symptoms included facial burning, erythema, and itching followed by swelling of his lips and ears. The lesions progressed to his anterior neck and chest. He noticed itching of his eyes, but no erythema. The symptoms subsided after approximately 2 hours. He applied vinegar at the recommendation of a local restaurateur with rapid resolution of his “rash” and symptoms. A 25-year-old Caucasian male took refuge under the same tree as subjects 1, 2, and 3 during a heavy rain storm. He was wearing bathing trunks and brimmed cap. The duration of exposure was approximately 40 minutes and he denied direct contact with the tree. Onset of mild burning of his face, nose, and forehead accompanied by mild erythema occurred about 30 minutes after the exposure. He did not develop itching or erythema of his conjunctiva.

, 2007a, b) and compared to a larger

, 2007a, b) and compared to a larger this website published database of P. aeruginosa isolates from nonocular sources (Stewart et al., 2011). Various markers in the set of P. aeruginosa isolates associated with keratitis were discordant with the wider P. aeruginosa population. These included previously reported associations, such as carriage of exoU. It was also demonstrated that 17 of 63 (27%) keratitis isolates from 2003 to 2004 carried a distinctive allele of pilA, the gene that encodes the pilin of type IV pili. Thus, the keratitis isolates were associated

with specific characteristics, suggesting that a subpopulation of P. aeruginosa may be adapted to causing corneal infections (Stewart et al., 2011). However, we could not be sure whether these genetic features of keratitis-associated isolates would be consistent temporally or represented a feature of the particular time Cisplatin period chosen

for sampling. To address this question, in this study, we report the analysis of a set of keratitis-associated P. aeruginosa isolates, collected by the MOG from patients in the UK, during a different time period, 5 years later. Sixty isolates (listed in Table 1) from corneal scrape samples were collected from patients with bacterial keratitis (2009–2010) from the six hospitals comprising the MOG. DNA was purified using the Wizard Genomic DNA purification kit (Promega, UK), as per the manufacturer’s instructions. A further 18 isolates of P. aeruginosa from bloodstream infections (collected and stored in Liverpool 2010–2011) Fludarabine were also used. All isolates tested positive for the oprL gene using a P. aeruginosa-specific PCR assay (De Vos et al., 1997). Genotyping of P. aeruginosa was conducted using the AT genotyping system (Wiehlmann et al., 2007a, b; Alere Technologies, Jena, Germany), as per the manufacturer’s instructions. Analysis of 13 single nucleotide polymorphisms (SNPs) based on the conserved genome, and three variable markers (flagellin types a or b and the mutually exclusive type III secretion exotoxin genes exoU or exoS),

was used to generate a four character hexadecimal code as described previously (Wiehlmann et al., 2007a, b; Stewart et al., 2011). This hexadecimal code was used to assign specific clone types. The genotypic relationships between keratitis isolates of P. aeruginosa and nonocular isolates were assessed by analysing each strain for 14 binary markers as described previously (Stewart et al., 2011). Presence or absence of exoS or exoU was not included in this analysis. The wider population was represented by a database of 322 nonkeratitis P. aeruginosa isolates, representing 128 clones, taken from various sources (Wiehlmann et al.,2007a, b; Mainz et al., 2009; Rakhimova et al., 2009). The analysis was undertaken using the eBURST(v3) algorithm (Feil et al., 2004; Spratt et al., 2004).

, 2009) In our study, tet(40) was located in tandem with tet(O)

, 2009). In our study, tet(40) was located in tandem with tet(O). Sequence homology search showed that the ARGs we identified in this study

were of diverse bacterial origin, including nonpathogenic species such as Bifidobacterium longum, as well as opportunistic pathogens such as Streptococcus suis and Staphylococcus pseudintermedius. Because the potential for gene transfer in the human gut is very high due to the dense microbial population (Kazimierczak & Scott, 2007), it is worth addressing in the future to what extent these bacteria serve as donors, disseminating the ARGs to other bacteria, especially the incoming pathogenic bacteria. The www.selleckchem.com/products/sch772984.html fosmid-based method has some potential disadvantages in ARG screening. Genes on smaller plasmids (< 30 kb) might not be represented in the metagenomic library. Moreover, only ARGs that are properly expressed in E. coli with their own promoters will be identified. However, the fosmid-based

method also has advantages. The larger insert size increases the likelihood Avasimibe in vitro of cloning complete ARGs. In fact, nearly one-third of resistant fosmid clones could not be subcloned, even after several trials. This could be because different vectors were used for cloning (pCC2FOS) and subcloning (pUC118 or pHSG298) or because some resistant determinants are out of the range of length chosen for subcloning (1–5 kb). Our further work will focus on whole-length sequencing to elucidate the resistance mechanisms conferred by the clones that failed to be subcloned.

It is worth noting that although the human subjects we used in this study were not exposed to antibiotic treatment for at least Amylase 6 months prior to sampling, we cannot exclude their antibiotic consumption history. As antibiotic-resistant strains can persist in the human host environment in the absence of selective pressure for a long time (Jernberg et al., 2010), the ARGs we identified cannot be considered intrinsic; they are probably the results of selective pressure conferred by antibiotics that the gut microbes previously encountered and somehow managed to maintain in the gut. In summary, we constructed a metagenomic library from four human gut microbiota and screened for ARGs, uncovering diverse new genes, including a new kanamycin resistance gene fusion. This work helps us to further understand the ARG reservoir of the human gut microbiota, and we believe that other new ARGs will be mined from human gut in the near future. However, to what degree these ARGs in our gut are linked to the potential emergence and dissemination of antimicrobial resistance genes in human pathogens is unclear. This work was supported in part by the National Basic Research Program of China (973 Program grants 2007CB513002 and 2009CB522605). Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors.


“Reverse complementary DNA sequences – sequences that are


“Reverse complementary DNA sequences – sequences that are inadvertently given backwards with all purines and pyrimidines transposed – can affect sequence analysis detrimentally unless taken into account. We present an open-source, high-throughput software tool –v-revcomp (http://www.cmde.science.ubc.ca/mohn/software.html) – to detect and reorient reverse complementary entries of the small-subunit rRNA (16S) gene from sequencing datasets, particularly from environmental sources. The software supports sequence lengths ranging from full length down to the short reads that are characteristic of next-generation sequencing technologies. We evaluated the reliability of selleck v-revcomp by screening all 406 781 16S sequences deposited

in release 102 of the curated SILVA database and demonstrated that the tool has a detection accuracy of virtually 100%. We subsequently used v-revcomp to analyse 1 171 646 16S sequences deposited in the International GSK-3 activity Nucleotide Sequence Databases and found that about 1% of these user-submitted sequences were reverse complementary. In addition, a nontrivial proportion of the entries were otherwise anomalous, including reverse complementary chimeras, sequences associated with wrong taxa, nonribosomal genes, sequences of poor quality or otherwise erroneous sequences without a reasonable match to any other entry in the database. Thus, v-revcomp is highly efficient in detecting and reorienting reverse

complementary 16S sequences of almost any length and can be used to detect various sequence anomalies. The bacterial and archaeal small-subunit rRNA (SSU rRNA, 16S) gene has emerged as the gold standard genetic marker for determining

the diversity and structure of prokaryotic communities in the environment and for the assessment of phylogenetic relationships within the microbial tree of life (reviewed in Tringe & Hugenholtz, 2008; Pace, 2009). Numerous international efforts to characterize microbial communities have led to an unparalleled accumulation of 16S sequences in the International Nucleotide Sequence Databases (INSDs, Sayers et al., 2010) and warranted the establishment of curated 16S reference databases such as SILVA MTMR9 (Pruesse et al., 2007), RDP (Cole et al., 2007) and Greengenes (DeSantis et al., 2006). As per October 2010 release of SILVA version 104, close to 3 million 16S sequences are currently deposited in the INSDs, not counting the enormous number of short reads currently generated by massively parallel sequencing technologies (Margulies et al., 2005) and typically deposited as raw data in the Sequence Read Archive (Leinonen et al., 2011). The contribution of these data repositories to scientific progress is indisputable. However, as the number of public 16S sequences increases, so does the number of sequences exhibiting poor read quality, chimaerism and incomplete or incorrect taxonomic annotation (Bridge et al., 2003; Hugenholtz & Huber, 2003; Ashelford et al., 2005; Bidartondo et al.

23) programmes (Altschul et al, 1990) ORFs were identified usi

2.3) programmes (Altschul et al., 1990). ORFs were identified using the National Centre for Biotechnology Information (NCBI) ORF finder tool. In order to clone FE hydrolase gene into pET29a(+) with NdeI and XhoI, overlapping PCR was carried out

to eliminate the XhoI site at 386 bp of the deduced ORF. The forward primer F1: 5′-CATATGGCGAACATCGAAGGCGTA-3′ learn more overlapped an NdeI site (underlined) at the initiation site for esterase gene, the reverse primer R1: 5′-CTCGAGTCAACTCAAAGCGTCGTAGGC-3′ overlapped an XhoI site (underlined) after the termination codon. They were used to amplify the complete sequence of FE hydrolase gene. The forward primer F2: 5′-GTTCACCCTGGAGAACATTTG-3′ and the reverse primer R2: 5′-CAAATGTTCTGGAGGGTGAAC-3′ were a pair of overlapping complementary primers, which were synthesized to obtain the structural genes without XhoI. And they would bind to the structural gene of the FE hydrolase gene at the 377–398 bp. The complete amplified fragment of the FE hydrolase gene was about 1.14 kb length. It was purified by PCR GSK1120212 cell line purification kit, digested with NdeI and XhoI, ligated with NdeI–XhoI-digested pET-29a(+), and then transformed into E. coli BL21(DE3) competent cells. The recombinant

plasmid was designated pET-29a-feh. E. coli BL21(DE3) harbouring pET-29a-feh was grown to OD600 nm = 0.5–0.6 in LB medium containing 50 mg L−1 kanamycin at 37 °C and the feh gene expression was induced by adding 0.2 mmol L−1 IPTG (isopropyl-β-D-thiogalacto-pyranoside)

for 24 h at 18 °C. The crude enzyme extract of E. coli BL21(DE3) was prepared by ultrasonic disruption. Zymogram analysis of the crude enzyme extract was carried out according to the procedure described previously. The activity of the crude enzyme extract was determined according to the enzyme assay of CFE of strain T1. The molecular mass of FE hydrolase was determined by SDS-PAGE. FE and its metabolites in the cultures were extracted with an equal volume of dichloromethane after the whole culture had been acidified to pH 2.0 by the addition of 10% HCl. Extracts were then dried over anhydrous Na2SO4. The treated extracts were examined at 200–350 nm with an ultraviolet spectrophotometer (UV-2450, Shimadzu). Next, 1 mL of extract Resminostat was evaporated at room temperature. Residual material was re-dissolved in an equal volume of methanol. All samples were immediately analysed by HPLC (RID-10A, Shimadzu). The mobile phase was 100% methanol, and the flow rate was 1.0 mL min−1. The separation column (Inertsil ODS-SP, 4.6 × 250 mm) was filled with Kromasil 100-5C18 and the injection volume was 20 μL. The metabolites of FE were analysed by HPLC/MS (Agilent Technologies, LC/MSD VL). The metabolites were ionised by negative polarity electro-spray. The nucleotide sequences of the Rhodococcus sp.

, 2007) There is a pressing need for the identification of novel

, 2007). There is a pressing need for the identification of novel drug targets, virulence factors and development of vaccines to expand our understanding of the prevention and treatment of leishmaniasis. The enzymes of the sterol biosynthesis pathway are attractive targets for the specific treatment of leishmaniasis as the aetiological agents of the disease require endogenous ergosterol and other alkylated sterols for growth and survival (Urbina et al., 2002). The formation of squalene is the first committed step in sterol biosynthesis and a blockade at this level of the pathway Pexidartinib supplier does not affect the production of other essential isoprenoids and the accumulated isoprenoid intermediates (farnesyl pyrophosphate

and precursors) can be readily metabolized and excreted (Gonzalez-Pacanowska et al., 1988). For

these reasons, SSN is currently under intense study as a possible target for cholesterol-lowering agents in humans (Bergstrom et al., 1995; Watson & Procopiou, 1996). Significant advances have been made in the understanding of the reaction mechanism of the vertebrate SSN (Mookhtiar et al., 1994) and recently, the crystal structure of a soluble, fully active form of the human enzyme was reported (Pandit et al., 2000). Overexpression or selection studies in Leishmania major (Cotrim et al., 1999) have shown that the expression of SSN is strongly activated in these cells in the presence Erastin datasheet of sterol biosynthesis inhibitors. Quinuclidines inhibit the leishmanial SSN, disrupt endogenous sterol biosynthesis and cause the inhibition of the growth of the leishmanial parasite (Lorente et al., 2005; Rodrigues et al., 2005; Cammerer et al., 2007). E5700, an inhibitor of SSN, has been tested in a murine model of chagas disease and is able to provide complete protection against death and completely suppress parasitimia (Urbina et al., 2004; Rodrigues et al., 2008). Studies related to structure–function relationship may lead to a better understanding of this potential drug target. We have cloned, overexpressed the Leishmania donovani SSN gene in pET-28(a) transformed in Escherichia coli and designated

as LdSSN. This recombinant L. donovani SSN enzyme was purified and biochemically characterized. Here, we describe, for the first time, Carbohydrate partial purification of full-length LdSSN through anion exchange chromatography followed by hydrophobic interaction chromatography and finally validated by Western blot. Biochemical properties such as pH optimum, thermal stability and the effect of denaturants on LdSSN are reported here. Farnesyl pyrophosphate (FPP) unlabelled, squalene unlabelled, 2-mercaptoethanol, NADPH, phenylmethylsulfonyl fluoride (PMSF) and Zaragozic acid A (microbial origin) were obtained from Sigma-Aldrich. Restriction enzymes used for cloning were obtained from MBI, Fermentas. Monoclonal His-antibody and Ni-NTA superflow were obtained from Qiagen. pGEM-T Easy cloning vector was purchased from Promega.

, 2007) There is a pressing need for the identification of novel

, 2007). There is a pressing need for the identification of novel drug targets, virulence factors and development of vaccines to expand our understanding of the prevention and treatment of leishmaniasis. The enzymes of the sterol biosynthesis pathway are attractive targets for the specific treatment of leishmaniasis as the aetiological agents of the disease require endogenous ergosterol and other alkylated sterols for growth and survival (Urbina et al., 2002). The formation of squalene is the first committed step in sterol biosynthesis and a blockade at this level of the pathway Sorafenib research buy does not affect the production of other essential isoprenoids and the accumulated isoprenoid intermediates (farnesyl pyrophosphate

and precursors) can be readily metabolized and excreted (Gonzalez-Pacanowska et al., 1988). For

these reasons, SSN is currently under intense study as a possible target for cholesterol-lowering agents in humans (Bergstrom et al., 1995; Watson & Procopiou, 1996). Significant advances have been made in the understanding of the reaction mechanism of the vertebrate SSN (Mookhtiar et al., 1994) and recently, the crystal structure of a soluble, fully active form of the human enzyme was reported (Pandit et al., 2000). Overexpression or selection studies in Leishmania major (Cotrim et al., 1999) have shown that the expression of SSN is strongly activated in these cells in the presence Dabrafenib of sterol biosynthesis inhibitors. Quinuclidines inhibit the leishmanial SSN, disrupt endogenous sterol biosynthesis and cause the inhibition of the growth of the leishmanial parasite (Lorente et al., 2005; Rodrigues et al., 2005; Cammerer et al., 2007). E5700, an inhibitor of SSN, has been tested in a murine model of chagas disease and is able to provide complete protection against death and completely suppress parasitimia (Urbina et al., 2004; Rodrigues et al., 2008). Studies related to structure–function relationship may lead to a better understanding of this potential drug target. We have cloned, overexpressed the Leishmania donovani SSN gene in pET-28(a) transformed in Escherichia coli and designated

as LdSSN. This recombinant L. donovani SSN enzyme was purified and biochemically characterized. Here, we describe, for the first time, Alanine-glyoxylate transaminase partial purification of full-length LdSSN through anion exchange chromatography followed by hydrophobic interaction chromatography and finally validated by Western blot. Biochemical properties such as pH optimum, thermal stability and the effect of denaturants on LdSSN are reported here. Farnesyl pyrophosphate (FPP) unlabelled, squalene unlabelled, 2-mercaptoethanol, NADPH, phenylmethylsulfonyl fluoride (PMSF) and Zaragozic acid A (microbial origin) were obtained from Sigma-Aldrich. Restriction enzymes used for cloning were obtained from MBI, Fermentas. Monoclonal His-antibody and Ni-NTA superflow were obtained from Qiagen. pGEM-T Easy cloning vector was purchased from Promega.

Practical steps for shared decision-making include outlining the

Practical steps for shared decision-making include outlining the range of options, providing information in their FDA approved Drug Library manufacturer preferred format, checking understanding and exploring

ideas to arrive at an agreed decision [7]. Such parameters have been incorporated into standardized measures of concordance [11]. Multiple benefits of a concordance-based approach have been demonstrated in various settings, including improved adherence, increased patient satisfaction with care, and reductions in the number of medications prescribed and in medication-related problems [12,13]. Doctor–patient concordance has been associated with improved mental health, social function and vitality [14,15]. Patient-centred communicative behaviours that stress a collaborative selleck chemicals approach between doctor and patient have been shown to be associated with stronger coping mechanisms, improved quality of life, quicker recovery, and enhanced functional status [13,16,17]. Despite these benefits, the extent to which concordance is routinely incorporated in clinical consultations is unclear [7,12]. Third-party observers of general practice (GP) consultations have shown low levels of concordance activity [11]. Identified barriers include patient reticence and doctors’ lack of skills to facilitate the process [12]. HIV treatment involves complex decisions about starting, switching and stopping treatment, yet no published

studies exist on concordance in this area. Decisions about whether, when, and how to change antiretroviral regimens can be particularly complicated, involving consideration of factors such as virological and immunological parameters, drug resistance, Thiamet G drug-related toxicity and tolerability

and regimen complexity [18–22]. This study aimed to retrospectively assess patients’ perceptions of concordance during the making of decisions on HAART switching and stopping. In particular, the aims were (1) to explore levels of concordance and (2) to examine the relationship between concordance and physical and psychological symptoms, quality of life, adherence, satisfaction, HIV sexual risk behaviour, and laboratory markers [CD4 cell count and viral load (VL)] at baseline and 6–12 months after patients completed the questionnaire. This quantitative, self-completion questionnaire study was conducted during a 3-month period in 2005/2006 in five NHS out-patient HIV clinics, of which four were in London and one in Brighton. Clinics were selected to reflect the demographics of the HIV epidemic in this part of the United Kingdom and had large HIV-infected patient cohorts. All consecutive patients aged 18 years or over with sufficient English to complete a questionnaire who attended the clinics during the study period were invited to participate by a researcher or research nurse. The questionnaire collected the following information. Demographics.