68  Rhee E, Feng H-P, Xuan F et al Absence of a significant phar

68  Rhee E, Feng H-P, Xuan F et al. Absence of a significant pharmacokinetic interaction Compound Library high throughput between the hepatitis C virus protease inhibitor boceprevir and HIV-1 NNRTI rilpivirine. 20th Conference on Retroviruses and Opportunistic Infections. Atlanta, GA. March 2013 [Abstract 537]. 69  NICE technology appraisal guidance TA253. Boceprevir for the treatment of genotype 1 chronic hepatitis C: April 2012. Available at: http://guidance.nice.org.uk/TA253 (accessed May 2013). 70  NICE technology appraisal guidance TA252. Telaprevir for the treatment of genotype 1 chronic hepatitis C: April 2012. Available at: http://guidance.nice.org.uk/TA252 (accessed May 2013).

71  Sulkowski M, Sherman K, Dieterich D et al. Combination therapy with telaprevir for chronic hepatitis C virus genotype 1 infection in patients with HIV: a randomized trial. Ann Intern Med 2013; epub ahead of print doi: 10.7326/0003-4819-159-2-201307160-00654. 72  ATM/ATR inhibitor Sulkowski M, Pol S, Mallolas J et al. Boceprevir versus placebo with pegylated interferon alfa-2b and ribavirin for treatment of hepatitis C virus genotype 1 in patients with HIV: a randomised, double-blind, controlled phase 2 trial. Lancet Infect Dis 2013; 13: 597–605. 73  Ahmed A, Pepper S, Page E, Anderson M, Nelson M. Clinical Experience of Boceprevir for the Treatment of Chronic Hepatitis C in HIV Coinfection. 3rd International Conference on Viral Hepatitis. New York,

NY. March 2013 [Abstract 24]. 74  Martel-Laferrière V, Brinkley S, Bichoupan K et al. On-Treatment Responses to Telaprevir-Based Hepatitis C Treatment Are Similar in HIV/HCV Coinfected and HCV-Monoinfected Patients. 3rd Inositol oxygenase International Conference on Viral Hepatitis. New York, NY. March 2013 [Abstract 31]. 75  Cotte L, Braun J, Lascoux-Combe C et al. High Early Virological Response with Telaprevir-Pegylated-Interferon-Ribavirin in Treatment-experienced Hepatitis C Virus Genotype 1/HIV Co-infected Patients: ANRS HC26 TelapreVIH Study. 20th Conference

on Retroviruses and Opportunistic Infection. Atlanta, GA. March 2013 [Abstract 36]. 76  Poizot-Martin I, Bellissant E, Piroth L et al. ANRS-HC27 BocepreVIH Interim Analysis: High Early Virologic Response with Boceprevir + Pegylated Interferon + Ribavirin in Hepatitis C Virus/HIV Co-infected Patients with Previous Failure to Pegylated Interferon + Ribavirin. 20th Conference on Retroviruses and Opportunistic Infection. Atlanta, GA. March 2013 [Abstract 37]. 77  Sulkowski MS. Current management of hepatitis C virus infection in patients with HIV co-infection. J Infect Dis 2013: 207(Suppl 1): 26–32. 78  Jacobson I, Dore G, Foster G et al. Simeprevir (TMC435) with peginterferon/ribavirin for chronic HCV genotype-1 infection in treatment-naïve patients: results from QUEST-1, a Phase III trial. 48th Annual Meeting of the European Association for the Study of the Liver. Amsterdam, The Netherlands. April 2013 [Abstract 1425]. 79  Ferenci P, Asselah T, Foster GR et al.

, 1998) Hence, it is believed that P aeruginosa

MVs are

, 1998). Hence, it is believed that P. aeruginosa

MVs are important to survive in microbial communities. Meanwhile, a number of bacteria secrete indole into the extracellular milieu. For other bacteria, it would be that these indole functions as inhibitors of PQS to escape predation by P. aeruginosa. To investigate the effect of indole on antimicrobial activities, we evaluated the ability of P. aeruginosa to inhibit the growth of actively dividing cells of the Gram-positive bacterium Bcl-2 protein family B. subtilis, which is known to be killed by P. aeruginosa (Park et al., 2005). As shown in Fig. 3, while a zone was clear around P. aeruginosa PAO1 on a lawn of B. subtilis cells, ΔpqsH did not kill B. subtilis. This result is consistent with published studies showing that the bactericidal activity is repressed in PQS-defective mutants (Park et al., 2005). The killing activity of PAO1 on the agar including indole was attenuated (Fig. 3), suggesting that indole also repress the killing ability of P. aeruginosa against B. subtilis. To determine whether indole oxidation products also affect MV production,

we tested the effect of oxidole, 4-hydroxyindole (4HI), 5-hydroxyindole (5HI), 6-hydroxyindole (6HI), isatin and indigo (Fig. Selleckchem Ganetespib 1). Oxidole exists in an equilibrium state with 2-hydroxyindole. The growth was not changed significantly with the addition of each molecule (Fig. 4a). 4HI, 5HI, 6HI and isatin inhibited MV production at the same level of indole, oxidole led to a 55% reduction of MVs, and no significant

changes were observed with indigo (Fig. 4b). PQS synthesis was also decreased in the presence of bicyclic compounds, including oxidole, 4HI, 5HI, 6HI and isatin, but not in the presence of indigo (Fig. 4c), suggesting that decreased MV production is caused by inhibition of PQS synthesis. In the same way, the activity of the pqsA promoter was also decreased in the presence of bicyclic compounds (Fig. 4d), indicating that these compounds inhibited PQS-stimulated transcription. Demeclocycline In addition, the results of pyocyanin synthesis showed a similar tendency (data not shown). To investigate whether structure is important for repression of MVs and PQS, we tested the effects of other cyclic compounds, such as catechol, naphthalene, naphthalene derivatives, 8-quinolinole and carbazole (Fig. 5a). In the growth curve assay, exogenous 8-quinolinole resulted in slightly decreased growth curve, whereas significant changes were not observed with other compounds (Fig. 5b). Exogenous catechol and carbazole did not inhibit MV production and PQS synthesis, whereas naphthalene led to a 44% reduction in them, and other naphthalene analogs used in this experiment, including 1-naphthol, 2-naphthol, 2,3-dihydroxynaphthalene and 1-aminonaphthalene and 8-quinolinol, significantly repressed both (Fig. 5c and d).

, 2002; Duan et al, 2003; Peters et al, 2008; Dumitriu et al,

, 2002; Duan et al., 2003; Peters et al., 2008; Dumitriu et al., 2010) and rats (Bloss et al., 2011, 2013). This change in spines represents the most consistent age-related alteration of cellular morphology reported in the frontal cortical literature, and is illustrated in Fig. 3. With respect to the dendritic arbor, IWR-1 order significant regression only occurs at the level of the apical

dendrites in the PFC of aged humans (de Brabander et al., 1998), monkeys (Cupp & Uemura, 1980; Duan et al., 2003; Kabaso et al., 2009) and male rodents (Grill & Riddle, 2002; Markham & Juraska, 2002). The regression of terminal dendrites and synaptic loss that occur during aging probably affects dendritic excitability and plasticity processes in the PFC, thus contributing to the age-related decline in learning and working memory. In support of this, there is

a decline in spine numbers and reduced thin spine volumes in area 46 in monkeys. This reduction was shown to correlate with acquisition and performance on a DNMS task (Peters et al., 1998b; Dumitriu et al., 2010). Additionally, a Selleckchem Idelalisib recent study was able to show that there is a correlation between the age-related overactivation of protein kinase C, the length of basal dendrites and working memory performance in aged rats (Brennan et al., 2009), suggesting that altered protein kinase C activity may be the basis of some of the anatomical and functional deficits found in aged animals. Despite cortical volume and cellular changes reported in the frontal cortex of older adults, many fMRI studies report areas of overactivation, greater bilateralization or recruitment of additional structures in PFC areas of older adults during performance of certain

cognitive tasks (e.g., Spreng et al., 2010; Morcom & Friston, 2012; Spaniol & Grady, 2012). This is a phenomenon thought to reflect compensatory mechanisms and, in support Masitinib (AB1010) this hypothesis, greater activation of frontal areas has been shown to be associated with better performance (Grady et al., 2005). Thus, it is plausible that plastic mechanisms in the PFC compensate for changes occurring in the PFC and other parts of the brain in older adults, thereby contributing to preservation of cognitive function. In support of this idea, under some circumstances accurate retrieval of autobiographical events in older adults also show a similar pattern (as outlined previously). That is, during retrieval the hippocampi of older adults show bilateral activation whereas young adults show hippocampal activation lateralized to the left hemisphere (Maguire & Frith, 2003). In contrast to gray matter volumes that decrease linearly with age, white matter volume change across the lifespan follows a parabolic shape, with the largest volumes in the mid-fifties and an accelerated decline after 65 years of age (Allen et al., 2005; Gunning-Dixon et al., 2009; Bennett et al., 2010; Giorgio et al., 2010; Malykhin et al., 2011).

85, 95% CI 060, 119) Trial participants differed significantly

85, 95% CI 0.60, 1.19). Trial participants differed significantly from non-trial participants by race/ethnicity (P=0.001). Although Black patients comprised the greater proportion (62%) of patients, only 26% of them enrolled in treatment trials. In bivariable analysis, Black patients compared with non-Black patients were significantly less likely to participate

in treatment trials (PR 0.69, 95% CI 0.56, 0.86). After adjustment, Black patients remained slightly selleck screening library less likely to participate in treatment trials than non-Black patients (PR 0.80, 95% CI 0.60, 1.06) (Table 3). The imputed data sets produced adjusted prevalence ratio estimates that were generally similar to the results obtained in the complete case analysis (Table 3). The point estimate for heterosexual www.selleckchem.com/products/MS-275.html men was closer to the null after imputation (PR 0.90, 95% CI 0.70, 1.16), while the point estimate for women was slightly further from the null, although the confidence interval included the null (PR 0.91, 95% CI 0.68, 1.22). The point estimate for Black patients was virtually unchanged (PR 0.78, 95%

CI 0.62, 097). Overall, the confidence interval estimates of the imputed prevalence ratios were narrower than those obtained in the complete case analysis. We observed a high rate of participation in HIV treatment trials in this cohort. In multivariable analysis, compared with MSM, heterosexual men were less likely while women were as likely to participate in HIV treatment trials. Black patients were slightly less likely to participate in these trials compared with non-Black selleck products patients. Almost one-third of treatment-naïve persons received HAART through participating in a treatment trial. Previous studies using the HIV cost and services utilization data and the HIV/AIDS surveillance project data reported lower participation rates of 14 and 17%, respectively [7,12]. Participation in HIV research is reportedly influenced by concern about receiving placebo, lack of information about research, and travel or transport obstacles [27]. In terms of lack of information, we have a dedicated research screener

in the ID clinic whose role is to provide information about clinical trials to patients and a social worker who assists with transportation issues. All the clinical trials included in this analysis involved active antiretrovirals; placebos were only used for the purpose of blinding in combination with active treatments. Our success in recruiting patients into clinical trials may partly be related to the ability of our research site to address these factors and other sites wishing to increase trial participation might consider and address similar factors. In our cohort, women were less likely than MSM to participate in clinical trials. However, after adjusting for other factors we found no difference in participation rates between women and MSM, a finding supported by those of other studies [7,9,12].

After baseline plaque samples were obtained, varnish application

After baseline plaque samples were obtained, varnish application was applied and repeated at an interval of 3 days in each group. Plaque samples were repeated at 48 h, 1 month, and 3 months. The samples were spread over mitis-salivarius-bacitracin

(MSB) culture media, and the colony-forming units per ml (CFU) were measured. In both Groups 1 and 2, Wilcoxon matched-pairs signed-rank test revealed significant differences in log CFU values of MS between baseline and 48 h, baseline and 1 month but no significant difference between baseline and 3 months. An intergroup comparison at different time intervals showed that the difference between three groups was statistically PR-171 manufacturer insignificant. F varnish and CHX/T varnish, with an intensive regimen application have equivocal effect on MS levels in dental plaque. “
“The sedative effect of nitrous oxide–oxygen (N2O/O2) inhalation is relatively well established. Less in known about its analgesic effect. To determine the analgesic effect of N2O/O2 inhalation on pulp sensitivity and jaw muscle pressure pain threshold

in children. A placebo-controlled, double-blind, crossover trial with random allocation to two sequences: atmospheric air at the first session and N2O/O2 at the second; or N2O/O2 at the first session and atmospheric air at the second. Measurements included reaction time, pulp pain sensitivity, jaw muscle pressure pain thresholds and a VAS score of overall discomfort from the pain GDC-0449 order tests. Fifty-six children (12–15 years) completed the study. N2O/O2 inhalation increased second reaction time (P < 0.001). Pulp pain sensitivity

was reduced during N2O/O2 inhalation (P < 0.001), but no effect was found after adjustment for the increased reaction time. Pressure pain threshold on the jaw muscle was also reduced during N2O/O2 inhalation (P < 0.001), also after adjustment for reaction time (P < 0.005). An effect was still found 10 min after the mask had been removed (P = 0.03). No effect on VAS scores of discomfort from the tests could be found. No analgesic effect of N2O/O2 inhalation on pulp pain sensitivity was found, whereas an increased pressure pain threshold of jaw muscles was found. Nitrous oxide–oxygen (N2O/O2) inhalation is commonly used in dental treatment of children. Its effect is generally conceived among dental practitioners as primarily sedative, but an analgesic effect is also assumed. The sedative effect is well established in the paediatric dental clinic, although a Cochrane Review concluded that there is only very weak evidence from placebo-controlled, randomised clinical trials, that N2O/O2 inhalation is in fact an efficient sedative[1].

Aggregation was observed from the Cry8Ea1 toxin after a short per

Aggregation was observed from the Cry8Ea1 toxin after a short period of storage, but no aggregation occurred with the Cry8Ea1 toxin–DNA complex. It may be inferred that (1) the monomer of the Cry8Ea1 toxin is not thermodynamically stable, and aggregation is needed to reach a thermodynamically stable state and that (2) the presence of DNA in association with the toxin can make the protein more stable and prevent the toxin from aggregation to some extent. 5-FU Oligomers have been found in solutions of Cry proteins; however, native Cry toxins do not form oligomers of a defined size (Feng & Becktel, 1994; Walters et al., 1994; Guereca

& Bravo, 1999; Guo et al., 2009b). Oligomers and monomers of Cry1Ac in solution have different abilities to insert into membranes; spontaneous insertion only occurs with the monomers (Convents et al., 1990; Smedley et al., 1997). The fact that the association of DNA with

the Cry8Ea1 toxin can prevent the toxin from nonspecific aggregation in solution may indicate that the DNA is very important for the Cry toxin to retain its subunit state before oligomerization on the midgut epithelial cell BBMV, which is related to the membrane insertion. Using DNA as a protector may be the result of evolution in nature. Our data show that Cry8Ea1 toxin–DNA is more hydrophobic than the toxin alone and has a greater ability to insert into the lipid bilayer in vitro. It may be inferred that in vivo, the Cry8Ea1 toxin–DNA complex may have a greater tendency to move towards phospholipid membranes, which could help the complex to find and interact with its acceptors on the membrane. buy Buparlisib It will be very interesting to compare the ability of the

Cry8Ea1 toxin with and without DNA in membrane insertion in vivo, because partitioning of Cry toxins into monolayers may not be identical to the partitioning Morin Hydrate of Cry toxins into bilayers or in vivo insertion into BBMV or insect midguts, but our further research was restricted by the A. corpulenta larvae supplement because the insect cannot be cultivated in a lab. In conclusion, based on the previous proposals that DNA is essential for crystal formation and probably facilitates the sequestering of the protein during sporulation (Clairmont et al., 1998), we further propose that the role of DNA in binding to the Cry8Ea1 toxin of B. thuringiensis is to stabilize the protein from aggregation and increase the tendency of the toxin to move towards the phospholipid membrane. This work was supported by grants from the Major State Basic Research Development Program of China (973 Program) (No. 2009CB118902 and 2007CB109203). We thank Professor Sengfang Sui of the Department of Biological Science and Biotechnology, Tsinghua University, for providing the NIMA 9000 microbalance and giving helpful suggestions on monolayer studies. We also thank Dr Neil Crickmore for his helpful suggestions on this research.

Baseline assessment of existing diabetes care can inform such des

Baseline assessment of existing diabetes care can inform such design and implementation. The aim of this study was to inventory diabetes health care resources in Qatar. A prospective survey of private and public health care facilities serving outpatients in the country was conducted. A nine-item questionnaire was administered to determine patient access, multidisciplinary services and availability of drug therapy. Thirty-five (67%) of 52 identified health care settings participated. Services devoted to diabetes care were Trametinib mw declared at five hospitals (one private and four public) and 24 clinics (15 private and nine public). The majority were located

in the country’s capital. Few offered services to children and adolescents (20% of hospitals, 55% of clinics). Most were led by general practitioner physicians with limited multidisciplinary contribution (nurses in 73%, dietitians

in 17%). Administration of certain drug therapy may be restricted to specialist prescribers and may be unavailable to non-nationals. Patients with diabetes in Qatar may seek care from an array of private and public health settings. Elements of any comprehensive national plan to address diabetes and its complications must incorporate enhanced training support for primary care physicians, expanded multidisciplinary care and services for children and adolescents. Copyright © 2011 John Wiley & Sons. Diabetes is recognised as a global epidemic affecting some 200 million people worldwide. According to the International Diabetes Federation, this figure is projected to increase to 333 million by 2025.1 Regions Panobinostat research buy with the highest prevalence are currently found in Gulf Corporation Council countries, including the state of Qatar, an Arab emirate occupying a small peninsula in the Persian Gulf.2 This gas- and oil-rich nation has Anacetrapib a population of around 1.9 million predominantly comprised of diverse

expatriate populations, of which as many as 700 000 are from South East Asia and possess inherent predispositions towards diabetes.3,4 Estimates of diagnosed diabetes in Qatar have ranged from 12% (all residents) to 17% (among Qatari only) with another 10% characterised as ‘pre-diabetes’.5,6 The high proportion of people in Qatar with impaired glucose tolerance and other associated modifiable risk factors (central obesity, sedentary behaviour) will only contribute to an increased prevalence of diabetes in the country over the coming years.7 Therapeutic targets are identified for glucose, blood pressure and lipid measurements and other modifiable risk factors. These goals are encompassed in a number of international clinical practice guideline documents outlining standards for diabetes care.8–11 Despite availability of such tools, gaps exist in translating evidence-based care into clinical practice.

Survey teams worked with as many arriving groups as possible, int

Survey teams worked with as many arriving groups as possible, interviewing and swabbing as many pilgrims as possible in each group after they passed through immigration. In each survey, pilgrims were asked for their consent to participate. A nasopharyngeal and throat swab were obtained after the interview. The questionnaire in the arrival

survey included questions about pilgrims’ demographics (age, gender, occupation, and nationality), medical history (chronic disease and smoking), vaccination history (including Carfilzomib separate questions about vaccination against pandemic influenza A(H1N1) and against seasonal influenza), knowledge about H1N1 influenza (symptoms, transmission, and ways to avoid), and compliance with wearing face masks. The questionnaire used in the departure survey included only questions about age, gender, and pandemic influenza A(H1N1) vaccination history. Respiratory specimens were placed in viral transport media (VTM) at the point of collection and transported to Jeddah Regional Laboratory where they were stored at −80°C before testing. Specimens selected for analysis were thawed and subjected to total nucleic acid extraction using Corbett X-tractor Gene (Qiagen, Hilden, Germany) and RNA DNA CorProtocol 25101 (Qiagen). Extracts were then tested using the xTAG Respiratory Viral Panel (RVP) FAST assay (Luminex Molecular Diagnostics Inc.,

Toronto, Canada) per manufacturer’s instructions. The xTAG RVP FAST is a qualitative find more multiplex amplification assay allowing the simultaneous detection of multiple viral nucleic acid targets. In addition to influenza A and B, this test can detect respiratory syncytial virus, parainfluenza virus 1, 2, 3, and 4; rhino-enterovirus, adenovirus, and minor respiratory viruses: coronaviruses, metapneumovirus, and bocavirus. Amplification of specific matrix target was used to detect influenza A and B. Seasonal influenza H1 and H3 subtypes were detected after amplification with hemagglutinin-specific primers and probes. Specimens positive for influenza A but negative for seasonal H1 and H3 were subjected 5-Fluoracil in vivo to additional PCR amplification to detect pandemic H1 and avian H5 (Qiagen

Artus Influenza/H1 RG/LC for H1N1 and TIB MOLBIOL, LightMix kit, Berlin, Germany for H5N1). Demographics, medical history, vaccination history, knowledge of H1N1 influenza, and compliance with infection control practices among arriving pilgrims were analyzed as frequency distributions. Differences in the prevalence of respiratory viruses between the arriving and departing pilgrims were examined using chi-square test or Fisher exact, as appropriate. Differences in the prevalence of respiratory viruses between potential confounding groups such as age groups and getting pandemic influenza A(H1N1) vaccine were examined using chi-square test or Fisher exact, as appropriate. All p values were two-tailed. p Value <0.05 was considered as significant. SPSS (release 17.

, 2008) In our current studies, the HEp-2 cells were cocultured

, 2008). In our current studies, the HEp-2 cells were cocultured with the wild-type or the isogenic scl1-inactivated mutant GAS that were either treated or untreated with cFn or Lm. Following internalization, the numbers of surviving intracellular bacteria were determined. The Scl1-deficient GAS cells were internalized significantly less than BGB324 nmr the wild-type strain in ECM-free medium (Fig. 3). Following preincubation with cFn and Lm, the wild-type strain exhibited about a 4- and 6.5-fold

increase in internalization, respectively, compared with ECM-untreated cells. The scl1-inactivated strain preincubated with cFn and Lm also showed about a 2.2- and a 2.8-fold increase in internalization compared with the ECM-untreated mutant cells; however, the overall levels of mutant internalization were lower compared with the wild-type strain under each corresponding experimental condition, emphasizing the contribution of Scl1 to cell invasion by GAS. It should be noted that the in vivo relevance of GAS internalization by human cells mediated by ECM binding EPZ-6438 in vivo has been debated in recent years. In spite of this, recent investigations using nuclear magnetic resonance spectroscopy, circular dichroism analyses, and experiments with monoclonal antibodies identified structural changes caused by fibronectin upon binding to bacterial

proteins that result in an enhanced Fn recognition by integrins (Bingham et al., 2008; Margarit et al., 2009). It is tempting to speculate that Scl1 binding to cFn and Lm may exert similar biological effects. It was shown previously by our group

that Scl1 from M41-type GAS binds the human collagen integrin receptors, which mediates GAS internalization by host cells (Caswell et al., 2007, 2008a). Integrins bind the GLPGER sequence directly within the Scl1-CL region. Here, we show the V-region of the same Scl1.41 protein binds to cFn and Lm, which also increases GAS internalization by HEp-2 cells. We think it is unlikely that cFn and Lm binding to the globular V domain affects Scl1-CL region binding to α2β1 and α11β1; Tryptophan synthase however, we cannot fully exclude such a possibility. The HEp-2 cells express the α2, α3, α5, and β1 integrin subunits (Caswell et al., 2007), and are thus capable of producing the α2β1, α3β1, and α5β1 heterodimers with the ability to bind collagen, laminin, and fibronectin, respectively (Watt, 2002). The α11β1 integrin expression is restricted to fibroblasts (Popova et al., 2007) and, thus, may not be present on the surface of HEp-2 cells. Therefore, Scl1 may be contributing to internalization of M41-type GAS by HEp-2 cells by two mechanisms: direct binding to the α2β1 integrin and ECM-bridging mechanism via integrins α3β1 and α5β1.

The South African clawed frog epithelial cells (XTC-2) were grown

The South African clawed frog epithelial cells (XTC-2) were grown in Leibovitz L-15 (Gibco) medium supplemented with 10% NBC (Gibco), 0.4% tryptose phosphate broth (Oxoid, UK) and 1% L-glutamine (Gibco) and incubated at 28 °C in 5% CO2. Six 24-well trays (IWAKI, Japan) each containing the four cell culture types were grown to confluency. Each well contained

2 mL of medium. Dilutions 10−6–10−11 (Arandale isolate) or 10−5–10−10 (Henzerling DZNeP nmr strain) were used to infect the cell cultures. Six wells of each cell culture type were inoculated with 100 μL of each dilution of C. burnetii. Cultures were incubated for 6 weeks before the monolayer from each well was harvested by scraping. Cells were pelleted by centrifugation for 5 min at 4500  g and resuspended in 300 μL of phosphate-buffered saline (PBS; find more Oxoid) and analysed by DNA extraction and Com1 PCR. The DNA

was extracted from 200 μL by Qiagen Extraction Kit (Qiagen, Germany), following the manufacturers’ instructions, eluted into 50 μL and analysed by specific PCR targeting a 76-bp sequence of the com1 gene (Lockhart et al., 2011). Extracted DNA (5 μL) was analysed for each reaction. The cycling threshold resulting form the PCR was used to calculate the approximate C. burnetii DNA concentration (μg μL−1) in each reaction. The C. burnetii dose that would infect 50% of cultures (ID50) was calculated using the Spearman–Kärber method (Anellis & Werkowski,

1968). The dilutions of the inoculum were analysed by PCR, and a standard curve was made (data not shown) and used to convert the ID50 calculation from a dilution into a number of bacterial copies required for 50% infection. By determining which wells contained C. burnetii DNA in amounts to suggest growth of the bacteria, the ID50 could be determined for each cell line and C. burnetii isolate. The cell line most susceptible (sensitive) to infection was different for the two C. burnetii isolates (Table 1). Metalloexopeptidase For the Arandale isolate the Vero cell line was the most sensitive with an ID50 of 0.1 copies of C. burnetii, followed by the L929 cell line with an ID50 of 3.2 copies. For the Henzerling strain, the DH82 cell line was the most sensitive with an ID50 of 14.6 copies of C. burnetii followed by the L929 cell line with an ID50 of 22.0 copies. Number of C. burnetii (copy numbers per 100 μL) required for 50% infection of cell line Number of C. burnetii (copy numbers per 100 μL) required for 50% infection of cell line During the growth of C. burnetii the monolayers were routinely observed under light microscopy. Only in Veros could infection with C. burnetii be seen as large vacuoles in the cell cytoplasm.