Infection with aerosolized
or
can lead to lethal disease in humans if treatment is not initiated promptly. Finafloxacin is a novel fluoroquinolone which has demonstrated broad-spectrum activity ...against a range of bacterial species
, and in humans, activity which is superior in acidic, infection-relevant conditions. Human-equivalent doses of finafloxacin or ciprofloxacin were delivered at 24 h (representing prophylaxis) or at 72 or 38 h (representing treatment) postchallenge with
or
, respectively, in BALB/c mouse models. In addition, a short course of therapy (3 days) was compared to a longer course (7 days). Both therapies provided a high level of protection against both infections when administered at 24 h postchallenge, irrespective of the length of the dosing regimen; however, differences were observed when therapy was delayed. A benefit was demonstrated with finafloxacin compared to ciprofloxacin in both models when therapy was delivered later in the infection. These studies suggest that finafloxacin is an effective alternative therapeutic for the prophylaxis and treatment of inhalational infections with
or
.
We evaluated antibiotic activity against the intracellular bacterium Coxiella burnetii using an activated THP-1 cell model of infection. At clinically relevant concentrations, the intracellular ...bacterial load was reduced 300-fold by levofloxacin and finafloxacin, 40-fold by doxycycline, and 4-fold by ciprofloxacin and was unaffected by azithromycin. Acidification of the culture medium reduced antibiotic activity, with the exceptions of doxycycline (no change) and finafloxacin (slight improvement). This model may be used to select antibiotics to be evaluated
.
Burkholderia pseudomallei is a soil-dwelling organism present throughout the tropics. It is the causative agent of melioidosis, a disease that is believed to kill 89,000 people per year. It is ...naturally resistant to many antibiotics, requiring at least two weeks of intravenous treatment with ceftazidime, imipenem or meropenem followed by 6 months of orally delivered co-trimoxazole. This places a large treatment burden on the predominantly middle-income nations where the majority of disease occurs. We have established a high-throughput assay for compounds that could be used as a co-therapy to potentiate the effect of ceftazidime, using the related non-pathogenic bacterium Burkholderia thailandensis as a surrogate. Optimization of the assay gave a Z' factor of 0.68. We screened a library of 61,250 compounds and identified 29 compounds with a pIC50 (-log10(IC50)) greater than five. Detailed investigation allowed us to down select to six "best in class" compounds, which included the licensed drug chloroxine. Co-treatment of B. thailandensis with ceftazidime and chloroxine reduced culturable cell numbers by two orders of magnitude over 48 hours, compared to treatment with ceftazidime alone. Hit expansion around chloroxine was performed using commercially available compounds. Minor modifications to the structure abolished activity, suggesting that chloroxine likely acts against a specific target. Finally, an initial study demonstrates the utility of chloroxine to act as a co-therapy to potentiate the effect of ceftazidime against B. pseudomallei. This approach successfully identified potential co-therapies for a recalcitrant Gram-negative bacterial species. Our assay could be used more widely to aid in chemotherapy to treat infections caused by these bacteria.
BACKGROUND: Low levels of physical activity and high time spent in sedentary activities have been associated with unfavourable health outcomes in adolescents. During adolescence, physical activity ...declines and sedentary time increases, however little is known about whether the magnitude of these changes differs within or between school-time, after-school time, or at weekends. METHODS: Adolescents (n = 363) participating in the PEACH (Personal and Environmental Associations with Children’s Health) project provided accelerometer data at 12 and 15 years of age. Data were collected in 2008/2009 and 2012/2013. Time spent sedentary (<100 cpm), in light physical activity (LPA (100-2295 cpm) and in moderate to vigorous physical activity (MVPA: ≥ 2296 cpm) were generated for school-time, after-school time and for weekends using school-specific start and finish times. All data were analysed in 2014. RESULTS: The proportion of time spent sedentary significantly increased during school (+8.23%, 95% CI = 7.35 to 9.13), after-school (+6.99%, 95% CI = 5.91 to 8.07) and at weekends (+6.86%, 95% CI = 5.10 to 8.62). A parallel decrease was found in the proportion of time spent in LPA during school (-7.62%, 95% CI = -8.26 to -6.98), after-school (-7.01%, 95% CI = -7.74 to -6.28) and at weekends (-6.72%, 95% CI = -7.80 to -5.65). The proportion of time spent in MVPA remained relatively stable during school (-0.64, 95% CI = -1.11 to -0.18), after-school (0.04%, 95% CI = -0.58 to 0.67) and at weekends (-0.14%, 95% CI = -1.18 to 0.90). CONCLUSIONS: Objectively measured sedentary time increased between 12 and 15 years of age during-school, after-school, and at weekends, suggesting that interventions aiming to reduce the age-associated changes in sedentary time are needed in all three time contexts. Future work should identify which sedentary activities change more than others to inform interventions which aim to minimise the increase in time spent sedentary during adolescence.
The Burkholderia pseudomallei K96243 genome encodes six type VI secretion systems (T6SSs), but little is known about the role of these systems in the biology of B. pseudomallei. In this study, we ...purified recombinant Hcp proteins from each T6SS and tested them as vaccine candidates in the BALB/c mouse model of melioidosis. Recombinant Hcp2 protected 80% of mice against a lethal challenge with K96243, while recombinant Hcp1, Hcp3, and Hcp6 protected 50% of mice against challenge. Hcp6 was the only Hcp constitutively produced by B. pseudomallei in vitro; however, it was not exported to the extracellular milieu. Hcp1, on the other hand, was produced and exported in vitro when the VirAG two-component regulatory system was overexpressed in trans. We also constructed six hcp deletion mutants (Δhcp1 through Δhcp6) and tested them for virulence in the Syrian hamster model of infection. The 50% lethal doses (LD₅₀s) for the Δhcp2 through Δhcp6 mutants were indistinguishable from K96243 (<10 bacteria), but the LD₅₀ for the Δhcp1 mutant was >10³ bacteria. The hcp1 deletion mutant also exhibited a growth defect in RAW 264.7 macrophages and was unable to form multinucleated giant cells in this cell line. Unlike K96243, the Δhcp1 mutant was only weakly cytotoxic to RAW 264.7 macrophages 18 h after infection. The results suggest that the cluster 1 T6SS is essential for virulence and plays an important role in the intracellular lifestyle of B. pseudomallei.
Previous work indicated that the incidence of travellers' diarrhoea (TD) is higher in soldiers of British origin, when compared to soldiers of Nepalese descent (Gurkhas). We hypothesise that the ...composition of the gut microbiota may be a contributing factor in the risk of developing TD in soldiers of British origin. This study aimed to characterise the gut microbial composition of Gurkha and non-Gurkha soldiers of the British Army. Recruitment of 38 soldiers (n = 22 Gurkhas, n = 16 non-Gurkhas) and subsequent stool collection, enabled shotgun metagenomic sequencing-based analysis of the gut microbiota. The microbiota of Gurkhas had significantly (P < 0.05) lower diversity, for both Shannon and Simpson diversity indices, using species level markers than the gut microbiota of non-Gurkha soldiers. Non-metric Multidimensional Scaling (NMDS) of the Bray-Curtis distance matrix revealed a significant difference in the composition of the gut microbiota between Gurkhas and non-Gurkha soldiers, at both the species level (P = 0.0178) and the genus level (P = 0.0483). We found three genera and eight species that were significantly enriched in the non-Gurkha group and one genus (Haemophilus) and one species (Haemophilus parainfluenzae) which were enriched in the Gurkha group. The difference in the microbiota composition between Gurkha soldiers and soldiers of British origin may contribute to higher colonization resistance against diarrhoeal pathogens in the former group. Our findings may enable further studies into interventions that modulate the gut microbiota of soldiers to prevent TD during deployment.
Raynaud's phenomenon is a vasospastic disease characterized by digital pallor, cyanosis, and extremity pain. Primary Raynaud's phenomenon is not associated with underlying disease, but secondary ...Raynaud's phenomenon is associated with connective tissue disorders such as systemic sclerosis, systemic lupus erythematosus, and mixed connective tissue disease. Calcium channel blockers promote vasodilation and are commonly used when drug treatment for Raynaud's phenomenon is required.
To assess the benefits and harms of calcium channel blockers (CCBs) versus placebo for treatment of individuals with Raynaud's phenomenon with respect to Raynaud's type (primary vs secondary) and type and dose of CCBs.
We searched the Cochrane Central Register of Controlled Trials (May 19, 2017), MEDLINE (1946 to May 19, 2017), Embase (1947 to May 19, 2017), clinicaltrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Portal. We applied no language restrictions. We also searched bibliographies of retrieved articles and contacted key experts for additional and unpublished data.
All randomized controlled trials (RCTs) comparing calcium channel blockers versus placebo.
Two review authors independently assessed search results and risk of bias and extracted trial data. We used the GRADE approach to assess the quality of evidence.
This review contains 38 RCTs (33 cross-over RCTs) with an average duration of 7.4 weeks and 982 participants; however, not all trials reported all outcomes of interest. Nine of the identified trials studied patients with primary Raynaud's phenomenon (N = 365), five studied patients with secondary Raynaud's phenomenon (N = 63), and the rest examined a mixture of patients with primary and secondary Raynaud's phenomenon (N = 554). The most frequently encountered risk of bias types were incomplete outcome data and poor reporting of randomization and allocation methods.When researchers considered both primary and secondary Raynaud's phenomenon, evidence of moderate quality (downgraded for inconsistency) from 23 trials with 528 participants indicates that calcium channel blockers (CCBs) were superior to placebo in reducing the frequency of attacks. CCBs reduced the average number of attacks per week by six ( weighted mean difference (WMD) -6.13, 95% confidence interval (CI) -6.60 to - 5.67; I² = 98%) compared with 13.7 attacks per week with placebo. When review authors excluded Kahan 1985C, a trial showing a very large reduction in the frequency of attacks, data showed that CCBs reduced attack frequency by 2.93 per week (95% CI -3.44 to -2.43; I² = 77%).Low-quality evidence (downgraded for imprecision and inconsistency) from six trials with 69 participants suggests that the average duration of attacks did not differ in a statistically significant or clinically meaningful way between CCBs and placebo (WMD -1.67 minutes, 95% CI -3.29 to 0); this is equivalent to a -9% difference (95% CI -18% to 0%).Moderate-quality evidence (downgraded for inconsistency) based on 16 trials and 415 participants showed that CCBs reduced attack severity by 0.62 cm (95% CI -0.72 to - 0.51) on a 10-cm visual analogue scale (lower scores indicate less severity); this was equivalent to absolute and relative percent reductions of 6% (95% CI -11% to -8%) and 9% (95% CI -11% to -8%), respectively, which may not be clinically meaningful.Improvement in Raynaud's pain (low-quality evidence; downgraded for imprecision and inconsistency) and in disability as measured by a patient global assessment (moderate-quality evidence; downgraded for imprecision) favored CCBs (pain: WMD -1.47 cm, 95% CI -2.21 to -0.74; patient global: WMD -0.37 cm, 95% CI -0.73 to 0, when assessed on a 0 to 10 cm visual analogue scale, with lower scores indicating less pain and less disability). However, these effect estimates were likely underpowered, as they were based on limited numbers of participants, respectively, 62 and 92. For pain assessment, absolute and relative percent improvements were 15% (95% -22% to -7%) and 47% (95% CI -71% to -24%), respectively. For patient global assessment, absolute and relative percent improvements were 4% (95% CI -7% to 0%) and 9% (95% CI -19% to 0%), respectively.Subgroup analyses by Raynaud's type, CCB class, and CCB dose suggest that dihydropyridine CCBs in higher doses may be more effective for primary Raynaud's than for secondary Raynaud's, and CCBs likely have a greater effect in primary than in secondary Raynaud's. However, differences were small and were not found for all outcomes. Dihydropyridine CCBs were studied as they are the subgroup of CCBs that are not cardioselective and are traditionally used in RP treatment whereas other CCBs such as verapamil are not routinely used and diltiazem is not used as first line subtype of CCBs. Most trial data pertained to nifedipine.Withdrawals from studies due to adverse effects were inconclusive owing to a wide CI (risk ratio RR 1.30, 95% CI 0.51 to 3.33) from two parallel studies with 63 participants (low-quality evidence downgraded owing to imprecision and a high attrition rate); absolute and relative percent differences in withdrawals were 6% (95% CI -14% to 26%) and 30% (95% CI -49% to 233%), respectively. In cross-over trials, although a meta-analysis was not performed, withdrawals were more common with CCBs than with placebo. The most common side effects were headache, dizziness, nausea, palpitations, and ankle edema. However, in all trials, no serious adverse events (death or hospitalization) were reported.
Randomized controlled trials with evidence of low to moderate quality showed that CCBs (especially the dihydropyridine class) may be useful in reducing the frequency, duration, severity of attacks, pain and disability associated with Raynaud's phenomenon. Higher doses may be more effective than lower doses and these CCBs may be more effective in primary RP. Although there were more withdrawals due to adverse events in the treatment groups, no serious adverse events were reported.
is the causative agent of the tropical disease, melioidosis. It is intrinsically resistant to many antimicrobials and treatment requires an onerous regimen of intravenous and orally administered ...drugs. Relapse of disease and high rates of mortality following treatment are common, demonstrating the need for new anti-
agents. The cationic bola-amphiphile, 12,12'-(dodecane-1,12-diyl) bis (9-amino-1,2,3,4-tetrahydroacridinium), referred to as 12-bis-THA, is a molecule with the potential to treat
infections. 12-bis-THA spontaneously forms cationic nanoparticles that bind anionic phospholipids in the prokaryotic membrane and are readily internalized. In this study, we examine the antimicrobial activity of 12-bis-THA against strains of
. As
produces a polysaccharide capsule we first examined if this extra barrier influenced the activity of 12-bis-THA which is known to act on the bacterial envelope. Therefore two strains of
were selected for further testing, strain E264 which does not produce a capsule and strain E555 which does produce a capsule that is chemically similar to that found in
. In this study no difference in the minimum inhibitory concentration (MIC) was observed when capsulated (E555) and unencapsulated (E264) strains of
were compared, however time-kill analysis showed that the unencapsulated strain was more susceptible to 12-bis-THA. The presence of the capsule did not affect the membrane permeation of 12-bis-THA at MIC concentrations. Proteomic and metabolomic analyses showed that 12-bis-THA causes a shift in central metabolism away from glycolysis and glyoxylate cycle, and suppressed the production of the F
domain of ATP synthase. In summary, we provide insight into the molecular mechanisms underpinning the activity of 12-bis-THA against
and discuss its potential for further development.
Raynaud's phenomenon is a vasodilatory phenomenon characterised by digital pallor, cyanosis, and pain of the extremities. Primary Raynaud's phenomenon has no underlying disease associated with it, ...while secondary Raynaud's phenomenon is associated with connective tissue disorders such as systemic sclerosis. Systemic sclerosis causes fibrosis and commonly affects the skin and internal organs such as the gastrointestinal tract, lungs, kidney, and heart. Phosphodiesterase 5 inhibitors (PDE5i) are a class of drugs that increases blood flow to the extremities and may be beneficial in the treatment of Raynaud's phenomenon.
To assess the benefits and harms of PDE5i compared to placebo for the treatment of Raynaud's phenomenon.
We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and clinical trial registries up to June 2022. We did not apply any language restrictions. We searched the bibliographies of retrieved articles and contacted key experts in the field for additional and unpublished data.
Randomised controlled trials (RCTs) comparing PDE5i to placebo in people with primary and secondary Raynaud's phenomenon.
We used standard methodological procedures expected by Cochrane.
This review included nine RCTs which ranged in duration from four to eight weeks and included a total of 411 participants. The majority had Raynaud's phenomenon secondary to systemic sclerosis. Tadalafil was assessed in four studies, sildenafil in three studies, vardenafil in one study, and a new PDE5 inhibitor known as "PF-00489791" in one study. Three studies were parallel design and six studies were cross-over. The frequency of attacks per week was 24 with placebo and PDE5i reduced the frequency of attacks by an average of three attacks per week (mean difference (MD) -3.07, 95% confidence interval (CI) -5.15 to -1.00; 8 studies; low-certainty evidence). The duration of attacks per day was 55 minutes with placebo and PDE5i reduced the duration of attacks by an average of five minutes (MD -5.31, 95% CI -8.90 to -1.71; 8 studies; low-certainty evidence). Very low-certainty evidence from one study with eight participants showed severity of Raynaud's attacks (assessed on a 10 cm visual analogue scale with lower scores indicating less severity) was 20% lower with a PDE5i (3.7 with placebo compared to 1.6 with treatment; MD -2.1, 95% CI -2.7 to 1.4; very low-certainty evidence). Pain and patient global assessment were assessed on a 10 cm visual analogue scale with lower scores indicating improvement. Low-certainty evidence showed that the use of PDE5i may result in little to no difference compared to placebo in reducing the average pain of Raynaud's attacks (3 to 2.9; MD -0.10, 95% CI -0.78 to 0.57; 4 studies). Global scores were 36% lower with the use of a PDE5i compared to placebo (9.2 to 5.6; MD -3.59, 95% CI -4.45 to -2.73; 1 study, 24 participants; low-certainty evidence). The rate of withdrawals during treatment with PDE5i ranged from 4% to 20% compared with 2% in the placebo group in five studies. Four studies reported no withdrawals due to adverse events. Seven studies reported no serious adverse events. The rate of serious adverse events reported in two studies ranged from 2% during treatment to 4% with placebo. The majority of the studies were judged as low or unclear risk of bias for selection, performance, and detection bias. Almost half were judged at high risk of attrition bias and unclear risk for selective reporting bias. We downgraded frequency of attacks, duration of attacks, pain intensity, and patient global assessment for small sample sizes and concerns about inconsistency and graded each as low certainty of evidence. We downgraded severity of attacks to very low certainty due to serious concerns about imprecision and publication bias. We downgraded withdrawals due to adverse events and serious adverse events to moderate certainty of evidence due to a low number of reported events.
Based on low-certainty evidence, PDE5i may reduce the frequency of attacks of Raynaud's phenomenon by a small amount per week, result in a small reduction in the duration of attack, improve patients' global assessment of their disease, and result in little to no difference in pain. PDE5i probably result in little or no difference in serious adverse events but slightly increase the likelihood of withdrawing from treatment due to an adverse event.
The efficacy of finafloxacin as a component of a layered defense treatment regimen was determined
in vitro
and
in vivo
against an infection with
Burkholderia pseudomallei
. Doxycycline was ...down-selected from a panel of antibiotics evaluated
in vitro
and used in combination with finafloxacin in a Balb/c mouse model of inhalational melioidosis. When treatment was initiated at 24 h post-infection with
B. pseudomallei
, there were no differences in the level of protection offered by finafloxacin or doxycycline (as monotherapies) when compared to the combination therapy. There was evidence for improved bacterial control in the groups treated with finafloxacin (as monotherapies or in combination with doxycycline) when compared to mice treated with doxycycline. Survival comparisons of finafloxacin and doxycycline (as monotherapies) or in combination initiated at 36 h post-infection indicated that finafloxacin was superior to doxycycline. Doxycycline was also unable to control the levels of bacteria within tissues to the extent that doxycycline and finafloxacin used in combination or finafloxacin (as a sole therapy) could. In summary, finafloxacin is a promising therapy for use in the event of exposure to
B. pseudomallei.
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