Phenotypic and genotypic identification of Staphylococcus aureus resistant to clindamycin in Mansoura University Children Hospital, Egypt

Background: Clindamycin has been a good alternative drug to penicillins in the treatment of infections caused by Staphylococcus aureus but resistance to this agent has led to therapeutic failure. Inducible clindamycin resistance in staphylococci carrying erm genes may not be detectable by routine disk diffusion test. The objective of this study is to phenotypically detect clindamycin resistance in clinical S. aureus isolates and determine the prevalence of ermA, ermB and ermC carriage among these isolates. Methodology: A total of 230 non-duplicate S. aureus were isolated from children admitted to Mansoura University Children Hospital during the period January 2016 and June 2017 by conventional microbiology method. Invitro antibiotic susceptibility to selected antibiotics including erythromycin was performed by the disk diffusion technique. The „D-zone‟ test was used to phenotypically detect inducible clindamycin resistance. The presence of ermA, ermB and ermC genes was confirmed by multiplex polymerase chain reaction (m-PCR) assay. Results: One hundred and seven (46.6%) isolates were phenotypically resistant to erythromycin while 109 (47.3%) were methicillin (cefoxitin) resistant S. aureus (MRSA). The macrolidelincosamin-streptograminB (MLSB) phenotypes among the erythromycin resistant isolates were 47 (44%) inducible MLSB and 46 (43%) constitutive MLSB, while 14 (13.0%) were MS phenotype. Although, the MLSB phenotype was more predominant in MRSA (n=60, 56.1%) than MSSA (n=33, 30.7%) while the MS phenotype was more predominant in MSSA (n=9, 8.4%) than MRSA (n=5, 4.6%) isolates, the difference was not statistically significant (p=0.0777). The ermA (29.0%, n=31) and ermC (18.7%, n=20) were the most prevalent genes carried by the isolates while ermB was carried by a few (4.7%, n=5). Forty six (43%) isolates did not carry any detectable erm gene. Conclusion: In this study, both inducible and constitutive clindamycin resistance phenotypes were common among S. aureus isolates. Although the genetic basis for this may be attributed to carriage of ermA, ermB and ermC genes, a number of the resistant isolates did not carry any of these genes.Keywords: phenotypic, genotypic, macrolide-lincosamide-streptogramin B, S. aureus, children

Methanol extract of smokeless tobacco alters inflammation and nociception process in animal models

Purpose: To investigate the inflammatory and nociceptive alterations due to the use of Nicotiana tabacum or smokeless tobacco (MEST) owing to the fact that it is used by some people to relieve dental pain.Methods: Hepatic biochemical indicators and thiobarbituric acid reactive substances assay were used to assess MEST toxicity and pharmacological doses selection. The effects on inflammation of different pharmacological doses (100, 200 and 500 mg/kg i.p.) of MEST were evaluated using xylene-induced ear edema and cotton pellet granuloma tests. Indomethacin (10 mg/kg, i.p.) was used as positive standard drug, whereas the vehicle 0.5 % CMC treated group was considered as negative control. Acetic acid-induced abdominal contraction test and formalin-induced hind paw licking model were utilized to assess the role of MEST in nociception. Indomethacin (10 mg/kg i.p.) and diclofenac sodium (10 mg/kg i.p.) were used as positives standard drugs. The vehicle used was 0.5% CMC which served as the negative control.Results: MEST (50 %, 200 mg/kg) and indomethacin (47.5 %) both elicited a significant (p < 0.001) anti-edematogenic effect on xylene-induced ear edema. MEST also showed a significant (p < 0.001) inhibitory effect on granuloma formation at all administered doses as compared to the untreated groups which was comparable to standard drug indomethacin. The number of acetic acid induced writhings was observed to be significantly increased (p < 0.001) by MEST at all doses, unlike diclofenac that led to significant reduction (p < 0.001) in the number of writhings, when compared to the untreated group. MEST also showed a significant (p < 0.05) dose-dependent reduction of the hind paw licking caused by formalin when compared to the vehicle control.Conclusion: These results signify that administration of MEST induces inflammatory and nociceptive alterations. However, the extract is not recommended for dental pain due to its other toxic effects that have previously been reported.Keywords: Nicotiana tabacum, Smokeless tobacco, Inflammation, Nociceptio

Antidepressant effect of methanol extract of smokeless tobacco and identification of its bioactive components

Purpose: To investigate the antidepressant effect of methanol extract of smokeless tobacco and identify its bioactive compounds. Methods: Adult Wistar rats were randomly assigned to five groups of five rats each: normal control group, standard (reference) control group as well as 100, 200 and 500 mg/kg extract group. The extract, standard drug (imipramine) and normal saline were administered via the intraperitoneal (i.p.) route. The rats were subjected to forced swim test (FST) and tail suspension test (TST) to assess the antidepressant effect of methanol extract of smokeless tobacco. Gas chromatography–mass spectrometry (GC-MS) was used to identify the bioactive compounds of the extract. Results: The oral LD50 of the extract was > 2000 mg/kg. Significant decrease in immobility time was observed after single administration of imipramine (p < 0.05). The extract significantly and dosedependently decreased the immobility time, but increased climbing and swimming times, when compared with normal control group (p < 0.05). The immobility time of stressed rats regardless of sex was significantly and dose-dependently lowered, relative to normal control group (p < 0.05). Four major compounds were identified in the extract: nicotine (45.88 %); 1,5-dimethyl-2-pyrrolidinone (23.00 %), nhexadecanoic acid (11.31 %) and vitamin A aldehyde (9.38 %). Conclusion: These results demonstrate that the methanol extract of smokeless tobacco possesses antidepressant and mood-elevating effects in rats. However, its use should be discouraged since it contains a number of hazardous and carcinogenic components such as N-nitroso compounds and benzo(a)pyrene which are categorized as Class-I carcinogens

A single tube system for the detection of Mycobacterium tuberculosis DNA using gold nanoparticles based FRET assay

The global combat against MTB is limited by challenges in accurate affordable detection. In this study, a rapid, affordable, single tube system for detection of unamplified MTB16s rDNA was developed. Utilizing a AuNP based FRET system, this assay achieved a sensitivity and specificity of 98.6% and 90% respectively.This report was made possible by a NPRP award [NPRP 4-1215-3-317] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors

EFFECT OF DIFFERENT PERIODS OF IRRIGATION AND ASCORBIC ACID ON GROWTH, YIELD AND QUALITY OF ESSENTIAL OIL OF MENTHA PIPERITA L. PLANTS

The present study was carried out during two growing seasons (2019 and 2020) at the Nursery of Department of Floriculture, Ornamental Horticulture, Faculty of Agriculture, Alexandria University, Egypt to study the effect of irrigation intervals (4 days as control stress, 8 days as moderate stress and 12 days as severe stress) and ascorbic acid (AsA) at 0, 100, 150, 200, 250 mg l-1 on the growth, quantity and quality of the essential oil of Mentha piperita L. plants. The main results of this study indicated that most of the vegetative growth characteristics were increased when AsA was applied at 150 or 200 mg l-1 to the plants grown under control stress (irrigation interval at 4 days). AsA at 200 mg l-1 was more effective on leaves fresh weight than 150 mg l-1 which affects mostly the number of branches of the plants grown under moderate stress (irrigation interval at 8 days). Increasing irrigation interval to 12 days (severe stress) in addition to AsA at 200 mg l-1 decreased the harmful effects in most peppermint plants and leads to obtain high oil percentage and yield. Peppermint oil was analyzed according to GC analysis of fresh leaves grown under water stress and sprayed with ascorbic acid with different concentrations identified 9 components, the major component was menthol with an average of 34.55-52.67% during the three cuts. In general, there was a direct relationship between increasing irrigation intervals and oil components percentage (menthol, menthone and limonene). These results suggest that normal water deficit (4 days irrigation interval) in peppermint will be appropriate to enhance better growth and productivity. In addition, ascorbic acid treatment reduced the damaging action of water stress, especially at concentrations of 150 and 200 mg l-1, so we can conclude that these concentrations are sufficient enough to support peppermint growth, leaves fresh weight and consequently maximum oil yield

Pathogenicity of three genetically distinct and highly pathogenic Egyptian H5N8 avian influenza viruses in chickens

In late 2016, Egypt encountered multiple cases of the highly pathogenic avian influenza (HPAI) virus of the H5N8 subtype. In a previous study, three distinct genotypes, including A/common-coot/Egypt/CA285/2016 (H5N8) (CA285), A/duck/Egypt/SS19/2017 (H5N8) (SS19), and A/duck/Egypt/F446/2017 (H5N8) (F446), were isolated from wild birds, a backyard, and a commercial farm, respectively, during the first wave of infection. In this current study, we investigated the differences in the pathogenicity, replication and transmissibility of the three genotypes and A/chicken/Egypt/15S75/2015 (H5N1) (S75) was used as the control. The intravenous pathogenicity index was between 2.68 and 2.9. The chicken lethal dose 50 values of F446, SS19 and CA285 were 103.7, 103.7, an 104 with a natural route of infection, respectively. These strains took longer than S75 to cause death when infection was carried out through the natural route (HPAI H5N1). After inoculation with the original concentration of 105 and 106 egg infective dose 50 (EID50), F446 had a higher mortality rate with short mean death times of 4, and 7 days, respectively compared with the other H5N8 viruses. Chickens inoculated with F446 and contacted exposed chickens infected with F446 showed the highest viral titer with remarkable differences in all H5N8 tested swabs at 2-4 days postinfection (dpi) compared to S75 at 2 dpi. This indicates that F446 had a more efficient transmission and spread from contact exposed birds to other birds. All H5N8 viruses were able to replicate systematically in all organs (trachea, brain, lung, and spleen) of the chicken with high viral titer with significantly different and more pathological changes observed in F446 than in other H5N8 viruses at 2 and 4 dpi. Compared with H5N1, we recorded a significantly high viral titer in the samples obtained from the lung, brain and both cloacal and tracheal swabs at 2 and 4 dpi, respectively and in the samples obtained from the spleen at 2 and 4 dpi among the experimental chicken. The comparative pathogenesis study revealed that in comparison with the other HPAI H5N8 viruses, the genotype F446 was more pathogenic, and showed more efficient viral replication and transmissibility in chickens in Egypt. The genotype F446 also showed a high viral titer than HPAI H5N1 and short mean death time at the third day after inoculation with 106 and 105 EID50, which revealed a conservation of certain H5N8 genotypes and a decrease in the incidence of H5N1

Brane Induced Gravity, its Ghost and the Cosmological Constant Problem

"Brane Induced Gravity" is regarded as a promising framework for addressing the cosmological constant problem, but it also suffers from a ghost instability for parameter values that make it phenomenologically viable. We carry out a detailed analysis of codimension > 2 models employing gauge invariant variables in a flat background approximation. It is argued that using instead a curved background sourced by the brane would not resolve the ghost issue, unless a very specific condition is satisfied (if satisfiable at all). As for other properties of the model, from an explicit analysis of the 4-dimensional graviton propagator we extract a mass, a decay width and a momentum dependent modification of the gravitational coupling for the spin 2 mode. In the flat space approximation, the mass of the problematic spin 0 ghost is instrumental in filtering out a brane cosmological constant. The mass replaces a background curvature that would have had the same function. The optical theorem is used to demonstrate the suppression of graviton leakage into the uncompactified bulk. Then, we derive the 4-dimensional effective action for gravity and show that general covariance is spontaneously broken by the bulk-brane setup. This provides a natural realization of the gravitational Higgs mechanism. We also show that the addition of extrinsic curvature dependent terms has no bearing on linearized brane gravity.Comment: v2: LaTeX, JHEP style, 41 pages, 3 eps figures. Partly rewritten to improve presentation, results unchanged, published versio

The relationship among avian influenza, gut microbiota and chicken immunity: An updated overview

The alimentary tract in chickens plays a crucial role in immune cell formation and immune challenges, which regulate intestinal flora and sustain extra-intestinal immunity. The interaction between pathogenic microorganisms and the host commensal microbiota as well as the variety and integrity of gut microbiota play a vital role in health and disease conditions. Thus, several studies have highlighted the importance of gut microbiota in developing immunity against viral infections in chickens. The gut microbiota (such as different species of Lactobacillus, Blautia Bifidobacterium, Faecalibacterium, Clostridium XlVa, and members of firmicutes) encounters different pathogens through different mechanisms. The digestive tract is a highly reactive environment, and infectious microorganisms can disturb its homeostasis, resulting in dysbiosis and mucosal infections. Avian influenza viruses (AIV) are highly infectious zoonotic viruses that lead to severe economic losses and pose a threat to the poultry industry worldwide. AIV is a challenging virus that affects gut integrity, disrupts microbial homeostasis and induces inflammatory damage in the intestinal mucosa. H9N2 AIV infection elevates the expression of proinflammatory cytokines, such as interferon (IFN-γ and IFNα) and interleukins (IL-17A and IL-22), and increases the proliferation of members of proteobacteria, particularly Escherichia coli. On the contrary, it decreases the proliferation of certain beneficial bacteria, such as Enterococcus, Lactobacillus and other probiotic microorganisms. In addition, H9N2 AIV decreases the expression of primary gel-forming mucin, endogenous trefoil factor family peptides and tight junction proteins (ZO-1, claudin 3, and occludin), resulting in severe intestinal damage. This review highlights the relationship among AIV, gut microbiota and immunity in chicken

Is Prolonged Sitting a Risk Factor in Developing Hemorrhoids and Anal Fissures?

Background: Anal fissures and hemorrhoids are common anal conditions. They cause significant morbidity, social embarrassment, and work absenteeism. In addition, they form a significant workload on the healthcare system. Nevertheless, the etiology of these conditions is still contentious. It has been observed that hemorrhoids and anal fissures are associated with prolonged sitting. This study aims to investigate this observation.Methods: This is a case–control study. We compared 81 patients with symptomatic and endoscopically proven hemorrhoids and/or anal fissures with 162 controls with no symptoms or endoscopic evidence of perianal disease. The study was conducted at Khartoum North Teaching Hospital (KNTH) endoscopy unit between January and December 2019. Demographic data, sitting hours per day, and endoscopic findings of patients and controls were recorded in a proforma. The cases and controls were matched for age, sex, and bowel habits. Data were analyzed and compared using the SPSS version 23.Results: The mean sitting hours for cases was 5.99 (SD 3.4) whereas that for controls was 4.0 (SD 3.0) with a highly significant difference (P < 0.001). Sitting for 5 hr or more per day (exposure) was associated with an increased risk of developing hemorrhoids and/or anal fissures [odds ratio 3.68, 95% CI: 2.1–6.47].Conclusion: The study showed that sitting down for 5 hr or more per day might increase the risk of developing hemorrhoids and/or anal fissures. This finding could help in the prevention and treatment of these diseases and the reduction of recurrences