In vitro assessment of activity of graphene silver composite sheets against multidrug-resistant bacteria and Tomato Bushy Stunt Virus

Purpose: To synthesize graphene-based silver nanocomposites and evaluate their antimicrobial and anti-Tomato Bushy Stunt Virus (TBSV) activities.Methods: A graphene-based silver composite was prepared by adsorbing silver nanoparticles AgNPs to the surfaces of graphene oxide (GO) sheets. Scanning electron microscopy was used to analyze the morphology of the synthesized graphene-based silver nanocomposite. This compound was investigated for its antimicrobial activity against several multidrug-resistant human pathogens using the agar well diffusion technique. Moreover, the biocompatibility and antiviral activity of the graphene-based nanocomposite against TBSV was studied in lettuce.Results: The graphene-based silver composite exhibited remarkable antimicrobial effects against pathogenic bacteria including Shigella sonnei and Pseudomonas aeruginosa with zones of inhibition of 32 ± 0.11 and 29 ± 0.05 mm, respectively. They inhibited TBSV better than graphene and GO.Conclusion: The synthesized graphene-based silver composite exhibits potent activity against TBSV and multidrug resistant bacteria, indicating that they are good candidates for future therapeutic applications.Keywords: Graphene oxide, Graphene-based nanocomposite, Antiviral, Antimicrobial, Multidrugresistant (MDR) human pathogen

BACTEC MGIT 960 TM system for screening of Mycobacterium tuberculosis complex among cattle

Bovine tuberculosis remains a disease of economic and public health importance in developing countries. The largest number of new cases of tuberculosis usually occurs in South-East Asia region and Africa. This study was aimed to evaluate the recent technique (BACTEC MGIT 960 TM system) for screening of Mycobacterium tuberculosis complex among cattle in Egypt. From the 1180 cattle examined in three different Governorates (El-Sharkia, El-Gharbia and El-Monefeia) by single intradermal tuberculin test, 29 animals (2.46%) were positive reactors. The post mortem examination of the positive reactors showed that 22 animals (75.9%) had visible lesions [respiratory form (31.0%), digestive form (13.8%), mixed form (20.7%) and generalized form (10.3%)], while seven (24.1%) did not show visible lesions. The results of isolation and identification using conventional culture method (Lowenstein- Jensen medium) were 22 mycobacterial isolates (75.9%), 20 (68.97%) Mycobacterium bovis and 2 (6.9%) unidentified slow growth. The BACTEC MGIT 960 TM system was used for recovery of Mycobacteria and compared with conventional culture method (Lowenstein-Jensen medium). The recovery rate of BACTEC MGIT 960 TM system was 82.8%, while that of Lowenstein-Jensen medium was 75.9%. The mean time for detection of Mycobacteria was 17.8 ± 0.9 days and 46.5 ± 0.4 days for BACTEC MGIT 960 TM system and Lowenstein-Jensen medium, respectively while the contamination rate with BACTEC MGIT 960 TM system was 6.9% and 10.3% in Lowenstein-Jensen medium.Key words: Bovine tuberculosis, tuberculin test, Lowenstein-Jensen medium, BACTEC system

Multiplex polymerase chain reaction for detection and characterization of shiga toxigenic Escherichia coli (STEC)

Escherichia coli is ubiquitous in the cow's environment that is contaminated by feces, and it is also a frequent cause of bovine mastitis. Thus, the present study was targeted at the rapid detection and characterization of shiga toxigenic E. coli (STEC) in bovine fecal and milk samples. Twenty two strains of E. coli (39.29%) were isolated from 56 diarrheic calves, while only 5 strains (20.83%) were isolated from apparently normal contact calves. Moreover, 20 strains of E. coli (25%) were isolated from milk samples collected from 80 animals suffering from mastitis and subclinical mastitis. E. coli serovars yielded from bacteriological examination of milk samples were similar to that of fecal samples. Serogroup-specific multiplex polymerase chain reaction (PCR) assay could detect all the bacteriologically positive samples as well as 4 strains (7.98%), O157:H7 and 3 strains (5.36%), O111 from diarrheic calves and 2 strains (8.33%), O111 from normal calves. Such samples were proved to be negative by bacteriological examination. Multiplex PCR for detection of genes encoding accessorySTEC virulence factors, such as shiga toxin type-2 (stx2) and intimin gene (eaeA) revealed the specificity of such gene to O157:H7 serovars and small number of other sero-groups

Oral HPV infection and MHC class II deficiency (A study of two cases with atypical outcome)

<p>Abstract</p> <p>Background</p> <p>Major histocompatibility complex class II deficiency, also referred to as bare lymphocyte syndrome is a rare primary Immunodeficiency disorder characterized by a profondly deficient human leukocyte antigen class II expression and a lack of cellular and humoral immune responses to foreign antigens. Clinical manifestations include extreme susceptibility to viral, bacterial, and fungal infections. The infections begin in the first year of life and involve usually the respiratory system and the gastrointestinal tract. Severe malabsorption with failure to thrive ensues, often leading to death in early childhood. Bone marrow transplantation is the curative treatment.</p> <p>Case reports</p> <p>Here we report two cases with a late outcome MHC class II deficiency. They had a long term history of recurrent bronchopulmonary and gastrointestinal infections. Bone marrow transplantation could not be performed because no compatible donor had been identified. At the age of 12 years, they developed oral papillomatous lesions related to HPV (human papillomavirus). The diagnosis of HPV infection was done by histological examination. HPV typing performed on the tissue obtained at biopsy showed HPV type 6. The lesions were partially removed after two months of laser treatment.</p> <p>Conclusions</p> <p>Viral infections are common in patients with MHC class II and remain the main cause of death. Besides warts caused by HPV infection do not exhibit a propensity for malignant transformation; they can cause great psychosocial morbidity.</p

Increased circulating ANG II and TNF-α represents important risk factors in obese Saudi adults with hypertension irrespective of diabetic status and BMI

Central adiposity is a significant determinant of obesity-related hypertension risk, which may arise due to the pathogenic inflammatory nature of the abdominal fat depot. However, the influence of pro-inflammatory adipokines on blood pressure in the obese hypertensive phenotype has not been well established in Saudi subjects. As such, our study investigated whether inflammatory factors may represent useful biomarkers to delineate hypertension risk in a Saudi cohort with and without hypertension and/or diabetes mellitus type 2 (DMT2). Subjects were subdivided into four groups: healthy lean controls (age: 47.9±5.1 yr; BMI: 22.9±2.1 Kg/m2), non-hypertensive obese (age: 46.1±5.0 yr; BMI: 33.7±4.2 Kg/m2), hypertensive obese (age: 48.6±6.1 yr; BMI: 36.5±7.7 Kg/m2) and hypertensive obese with DMT2 (age: 50.8±6.0 yr; BMI: 35.3±6.7 Kg/m2). Anthropometric data were collected from all subjects and fasting blood samples were utilized for biochemical analysis. Serum angiotensin II (ANG II) levels were elevated in hypertensive obese (p<0.05) and hypertensive obese with DMT2 (p<0.001) compared with normotensive controls. Systolic blood pressure was positively associated with BMI (p<0.001), glucose (p<0.001), insulin (p<0.05), HOMA-IR (p<0.001), leptin (p<0.01), TNF-α (p<0.001) and ANG II (p<0.05). Associations between ANG II and TNF-α with systolic blood pressure remained significant after controlling for BMI. Additionally CRP (p<0.05), leptin (p<0.001) and leptin/adiponectin ratio (p<0.001) were also significantly associated with the hypertension phenotype. In conclusion our data suggests that circulating pro-inflammatory adipokines, particularly ANG II and, TNF-α, represent important factors associated with a hypertension phenotype and may directly contribute to predicting and exacerbating hypertension risk

The role of clathrin in post-golgi trafficking in toxoplasma gondii

Apicomplexan parasites are single eukaryotic cells with a highly polarised secretory system that contains unique secretory organelles (micronemes and rhoptries) that are required for host cell invasion. In contrast, the role of the endosomal system is poorly understood in these parasites. With many typical endocytic factors missing, we speculated that endocytosis depends exclusively on a clathrin-mediated mechanism. Intriguingly, in Toxoplasma gondii we were only able to observe the endogenous clathrin heavy chain 1 (CHC1) at the Golgi, but not at the parasite surface. For the functional characterisation of Toxoplasma gondii CHC1 we generated parasite mutants conditionally expressing the dominant negative clathrin Hub fragment and demonstrate that CHC1 is essential for vesicle formation at the trans-Golgi network. Consequently, the functional ablation of CHC1 results in Golgi aberrations, a block in the biogenesis of the unique secretory microneme and rhoptry organelles, and of the pellicle. However, we found no morphological evidence for clathrin mediating endocytosis in these parasites and speculate that they remodelled their vesicular trafficking system to adapt to an intracellular lifestyle

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Fasciola hepatica calcium-binding protein FhCaBP2: structure of the dynein light chain-like domain

The common liver fluke Fasciola hepatica causes an increasing burden on human and animal health, partly because of the spread of drug-resistant isolates. As a consequence, there is considerable interest in developing new drugs to combat liver fluke infections. A group of potential targets is a family of calcium-binding proteins which combine an N-terminal domain with two EF-hand motifs and a C-terminal domain with predicted similarity to dynein light chains (DLC-like domain)