Synergistic phage-antibiotic combinations for the control of Escherichia coli biofilms in vitro.

The potential application of phage therapy for the control of bacterial biofilms has received increasing attention as resistance to conventional antibiotic agents continues to increase. The present study identifies antimicrobial synergy between bacteriophage T4 and a conventional antibiotic, cefotaxime, via standard plaque assay and, importantly, in the in vitro eradication of biofilms of the T4 host strain Escherichia coli 11303. Phage-antibiotic synergy (PAS) is defined as the phenomenon whereby sub-lethal concentrations of certain antibiotics can substantially stimulate the host bacteria's production of virulent phage. Increasing sub-lethal concentrations of cefotaxime resulted in an observed increase in T4 plaque size and T4 concentration. The application of PAS to the T4 one-step growth curve also resulted in an increased burst size and reduced latent period. Combinations of T4 bacteriophage and cefotaxime significantly enhanced the eradication of bacterial biofilms when compared to treatment with cefotaxime alone. The addition of medium (10(4) PFU mL(-1) ) and high (10(7) PFU mL(-1) ) phage titres reduced the minimum biofilm eradication concentration value of cefotaxime against E. coli ATCC 11303 biofilms from 256 to 128 and 32 µg mL(-1) , respectively. Although further investigation is needed to confirm PAS, this study demonstrates, for the first time, that synergy between bacteriophage and conventional antibiotics can significantly improve biofilm control in vitro.

Inactivation of macrophage Rab7 by Burkholderia cenocepacia

Strains of the Burkholderia cepacia complex can survive within macrophages by arresting the maturation of phagocytic vacuoles. The bacteria preclude fusion of the phagosome with lysosomes by a process that is poorly understood. Using murine macrophages, we investigated the stage at which maturation is arrested and analyzed the underlying mechanism. Vacuoles containing B. cenocepacia strain J2315, an isolate of the transmissible ET12 clone, recruited Rab5 and synthesized phosphatidylinositol-3-phosphate, indicating progression to the early phagosomal stage. Despite the fact that the B. cenocepacia-containing vacuoles rarely fused with lysosomes, they could nevertheless acquire the late phagosomal markers CD63 and Rab7. Fluorescence recovery after photobleaching and use of a probe that detects Rab7-guanosine triphosphate indicated that activation of Rab7 was impaired by B. cenocepacia, accounting at least in part for the inability of the vacuole to merge with lysosomes. The Rab7 defect was not due to excessive cholesterol accumulation and was confined to the infected vacuoles. Jointly, these experiments indicate that B. cenocepacia express virulence factors capable of interfering with Rab7 function and thereby with membrane traffic.

Tobramycin Inhalation Powder™:a novel drug delivery system for treating chronic Pseudomonas aeruginosa infection in cystic fibrosis

Lung disease in cystic fibrosis (CF) is typified by the development of chronic airways infection culminating in bronchiectasis and progression to end-stage respiratory disease. Pseudomonas aeruginosa, a ubiquitous gram-negative bacteria, is the archetypical CF pathogen and is associated with an accelerated clinical decline. The development and widespread use of chronic suppressive aerosolized antibacterial therapies, in particular Tobramycin Inhalation Solution (TIS), in CF has contributed to reduced lung function decline and improved survival. However, the requirement for the aerosolization of these agents through nebulizers has been associated with increased treatment burden, reduced quality of life and remain a barrier to broader uptake. Tobramycin Inhalation Powder (TIP™) has been developed by Novartis with the express purpose of delivering the same benefits as TIS in a time-effective manner. Administered via the T-326™ (Novartis) Inhaler in four individual 28-mg capsules, TIP can be administered in a quarter of the time of traditional nebulizers and is inherently portable. In clinical studies, TIP has been shown to be safe, result in equivalent or superior reductions in P. aeruginosa sputum density and produce similar improvements in pulmonary function. TIP offers significant advantages in time saving, portability and convenience over traditional nebulized TIS with comparable clinical outcomes for individuals with CF.

Defects in acute responses to TLR4 in Btk-deficient mice result in impaired dendritic cell-induced IFN-γ production by natural killer cells

This study defines a critical role for Btk in regulating TLR4-induced crosstalk between antigen presenting cells (APCs) and natural killer (NK) cells. Reduced levels of IL-12, IL-18 and IFN-? were observed in Btk-deficient mice and ex vivo generated macrophages and dendritic cells (DCs) following acute LPS administration, whilst enhanced IL-10 production was observed. In addition, upregulation of activation markers and antigen presentation molecules on APCs was also impaired in the absence of Btk. APCs, by virtue of their ability to produce IL-12 and IL-18, are strong inducers of NK-derived IFN-?. Co-culture experiments demonstrate that Btk-deficient DCs were unable to drive wild-type or Btk-deficient NK cells to induce IFN-? production, whereas these responses could be restored by exogenous administration of IL-12 and IL-18. Thus Btk is a critical regulator of APC-induced NK cell activation by virtue of its ability to regulate IL-12 and IL-18 production in response to acute LPS administration.

Insights into Langerhans cell function from Langerhans cell ablation models

Langerhans cells (LC) are the principal dendritic cell (DC) population in the epidermis of the skin. Owing to their prominent position at the environmental barrier, LC have long been considered to be prototypic sentinel DC. More recently, the precise role of LC in the initiation and control of cutaneous immune responses has become debatable. To elucidate their contribution to immune regulation in the skin, our laboratories have generated genetically modified mice in which LC can be followed in situ by expression of enhanced green fluorescent protein and can be either inducibly or constitutively depleted in vivo. This review highlights the similarities and differences between these mouse models, discusses the discovery and functional significance of Langerin(+) dermal DC, and examines some recent data that help to shed light on LC function.

Steroid injection for inferior heel pain: a randomised controlled trial

BACKGROUND:

Plantar fasciitis is a common cause of heel pain. The aim of this study was twofold: to compare steroid injection with placebo injection and to compare ultrasound guided with unguided steroid injection in the management of this condition.

METHODS:

65 patients with inferior heel pain were recruited between November 2008 and June 2011. Heel pain was measured using a visual analogue scale (VAS) at baseline and follow-up 6 and 12 weeks after injection.

RESULTS:

22 patients were randomised to ultrasound guided steroid injection, 21 patients to palpation guided steroid injection and 22 to ultrasound guided placebo injection. There was a significant difference in VAS scores between the groups at 6 and 12 weeks (p=0.018 and p=0.004, respectively). There was a 19.7 (95% CI 2.5 to 37.0) difference in mean VAS scores at 6 weeks between the ultrasound guided steroid group and the placebo group and a 24.0 (95% CI 6.6 to 41.3) difference between the unguided steroid group and the placebo group at 6 weeks. At 12 weeks, the mean difference was 25.1 (95% CI 6.5 to 43.6) and 28.4 (95% CI 11.1 to 45.7) respectively between both steroid injection groups and the placebo group. There was no difference in VAS scores following steroid injection between the ultrasound guided and the unguided groups at either time point. Plantar fascia thickness was significantly reduced after injection in both active treatment groups (p=0.00).

CONCLUSIONS:

In this study, steroid injection showed a clear benefit over placebo at 6 weeks and this difference was maintained at 12 weeks.Trial Registration No ISRCTN79628180 (www.controlled-trials.com).

Ciprofloxacin-induced phototoxicity in an adult cystic fibrosis population

The incidence of phototoxicity as a side effect of ciprofloxacin appears to be increased in patients with cystic fibrosis compared to the general population (approximately 2.4%). We used an interview-based questionnaire to determine the incidence of such phototoxic skin reactions in cystic fibrosis patients. Results from 105 respondents revealed the incidence of ciprofloxacin-induced phototoxicity in the adult cystic fibrosis population in Northern Ireland to be 48.4% with only 66% of the patients recalling being given sun care information beforehand. We concluded that the incidence of phototoxicity is increased in patients with cystic fibrosis and that it is important for all to receive good sun care information prior to taking ciprofloxacin given the high risk of developing phototoxic rash.

Clinico-epidemiological features of infections caused by CTX-M type extended spectrum beta lactamase-producing Escherichia coli in hospitalised patients

A review of medical records of 45 of 53 hospitalised patients with positive cultures for CTX-M type ESBL-producing Escherichia coli between 01 January and 31 May 2004 was conducted. The mean age of the population studied was 73.1 (+/-14.6) years and the majority (55.6%) had been under the care of the internal medicine or elderly care service. In the majority (77.8%) of instances the isolate was attributed to a clinical infection rather than colonisation and the commonest clinical specimen to yield the organism was urine, which was positive in 57.8% of patients. Acquisition of the organism was categorised as nosocomial in 68.9% of patients; in this subgroup, the median duration of inpatient stay prior to recovery of the organism was 24 (range 3-240) days. Haemodialysis-dependence was the most common of the comorbidities evaluated. The mean number of antibiotics prescribed per patient in the 30 days prior to first isolation of the organism was 1.7 (range 0-4). Furthermore, the mean number of antibiotic-days exposure per patient during this period was 13.9 (range 0-48). The most frequently received class of antibiotic was beta-lactam/beta-lactamase inhibitor combinations. Of 35 infections, 26 (74.2%) were successfully treated. Overall 12 patients with infection died (34.3%); attributable mortality was presumed in seven (20%).

The epidemiology of peritonsillar abscess disease in Northern Ireland

1. To describe the epidemiology of peritonsillar abscess disease in Northern Ireland. 2. To describe the impact of the nature of microbiological sampling on culture results.

Mycobacterium triplex pulmonary infection in an immunocompetent patient

We present the case of a 47-year-old immunocompetent patient with clinical evidence of pulmonary mycobacterial disease which was found to be due to Mycobacterium triplex. This novel organism is an uncommon, emerging, pathogen for which few reports of clinical infection exist in the medical literature. © 2002 The British Infection Society.

Increased expression of bronchial epithelial transient receptor potential vanilloid 1 channels in severe asthma

BACKGROUND: The airway epithelium is exposed to a range of physical and chemical irritants in the environment that are known to trigger asthma. Transient receptor potential (TRP) cation channels play a central role in sensory responses to noxious physical and chemical stimuli. Recent genetic evidence suggests an involvement of transient receptor potential vanilloid 1 (TRPV1), one member of the vanilloid subfamily of TRP channels, in the pathophysiology of asthma. The functional expression of TRPV1 on airway epithelium has yet to be elucidated.

OBJECTIVE: In this study we examined the molecular, functional, and immunohistochemical expression of TRPV1 in asthmatic and healthy airways.

METHODS: Bronchial biopsy specimens and bronchial brushings were obtained from healthy volunteers (n = 18), patients with mild-to-moderate asthma (n = 24), and patients with refractory asthma (n = 22). Cultured primary bronchial epithelial cells from patients with mild asthma (n = 4), nonasthmatic coughers (n = 4), and healthy subjects (n = 4) were studied to investigate the functional role of TRPV1.

RESULTS: Quantitative immunohistochemistry revealed significantly more TRPV1 expression in asthmatic patients compared with healthy subjects, with the greatest expression in patients with refractory asthma (P = .001). PCR and Western blotting analysis confirmed gene and protein expression of TRPV1 in cultured primary bronchial epithelial cells. Patch-clamp electrophysiology directly confirmed functional TRPV1 expression in all 3 groups. In functional assays the TRPV1 agonist capsaicin induced dose-dependent IL-8 release, which could be blocked by the antagonist capsazepine. Reduction of external pH from 7.4 to 6.4 activated a capsazepine-sensitive outwardly rectifying membrane current.

CONCLUSIONS: Functional TRPV1 channels are present in the human airway epithelium and overexpressed in the airways of patients with refractory asthma. These channels might represent a novel therapeutic target for the treatment of uncontrolled asthma.

Estudo da prevalência de fungos em travesseiros de crianças com rinite e, ou, asma

Pós-graduação em Biologia Geral e Aplicada - IBB

Modulação da imunidade adaptativa por produtos solúveis de células de carcinoma espinoceular de cabeça e pescoço (HNSCC): um papel da galanina derivada do tumor?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modulação da imunidade adaptativa por produtos solúveis de células de carcinoma espinoceular de cabeça e pescoço (HNSCC): um papel da galanina derivada do tumor?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)