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INTRODUCTION: Campylobacter(C) fetus meningoencephalitis is rare and occurs mainly in elderly and immunocompromised patients. We report an observation of C. fetus meningoencephalitis in a woman with a favorable evolution. CASE REPORT: A 54-year-old woman with systemic lupus erythematosus was treated with mycophenolate mofetil (MMF) and corticosteroids. The patient presented at the emergency department of Sahloul University Hospital with a fever and headache for 24 hours. She had regular contact with sheep and cattle. She reported a penicillin allergy. On admission, she had a temperature of 39°C and she was confused. Brain CT scan was normal. Lumbar puncture showed a clear cerebrospinal fluid (CSF) with 1300 leukocytes/mm3 (65% lymphocytes) and low glucose levels. CSF microscopic examination was negative. She was treated with vancomycin, cotrimoxazole, and gentamicin with an improvement of the neurological symptoms and apyrexia. The next day, she had a neurological deterioration. Brain angio-magnetic resonance imaging was normal. The culture of the CSF became positive for C. fetus. Our patient was treated with imipenem combined with ciprofloxacin and obtained clinical and biological improvements. CONCLUSIONS: C. fetus is a rare cause of bacterial meningoencephalitis. The underlying immunodepression should always be considered.

Cosmetics have been extremely popular throughout history and continue to be so today. Cosmetic and personal care products, including toothpaste, shampoo, lotions, and makeup, are typically made with petroleum-based surfactants. Currently, there is an increasing demand to enhance the sustainability of surface-active compounds in dermal formulations. Biosurfactants, derived from living cells, are considered more environmentally friendly than synthetic surfactants. Thus, the use of biosurfactants is a promising strategy for formulating more environmentally friendly and sustainable dermal products. Biosurfactants have the potential to replace chemical surface-active agents in the cosmetic sector due to their multifunctional qualities, such as foaming, emulsifying, and skin-moisturizing activities.In this study, two glycolipopeptide biosurfactants derived from Lactiplantibacillus plantarum OL5 were used as stabilizing factors in oil-in-water emulsions in the presence of coconut oils. Both biosurfactants increased emulsion stability, particularly in the 1:3 ratio, dispersion, and droplet size. Moreover, the cytotoxicity of the two Lactiplantibacillus plantarum biosurfactants was assessed on B lymphocytes and MCF-7 cells. Overall, the results gathered herein are very promising for the development of new green cosmetic formulations., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in around 1 million COVID-19 infection cases and over 29,000 deaths in Tunisia thus far. There is great variability in the prevalence of asthma among patients with COVID-19, but the impact of asthma on patients with COVID-19 is not clear. We sought to describe the clinical features of Tunisian patients with COVID-19 and to compare asthmatic and non-asthmatic patients., Methodology: This retrospective study included 675 Tunisian patients who were hospitalized with COVID-19. Clinical characteristics were collected from medical records. Bivariate analyses and multivariate regression models were used to assess the associations between asthma and the risk of severe symptoms, including death/recovery., Results: The prevalence of asthma in the sample was 14.5%. The results show that asthmatic patients with COVID-19 have significantly less severe symptoms and better outcomes than non-asthmatic patients., Conclusions: Asthma was not found to be associated with higher severity or worse prognosis among patients with COVID-19 in Tunisia., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2023 Imen Ben Rebeh, Marwa Gargouri, Marwa Ghariani, Nesrine Kallel, Sana Rouis, Wafa Marrakchi, Dhekra Chebil, Riadh Ben Marzoug, Hela Gargouri, Latifa Merzougui, Houda Ghorbel, Mohamed Chakroun, Hassen Hadj Kacem, Ahmed Rebai.)

This study was conducted to assess the effectiveness of a health education program on mothers' knowledge and practices related to amebiasis. Pre- and post-I and II-tests were used, along with a two-group quasi-experimental design. The study included a convenience sample of 120 mothers, including 60 from the study and 60 from the control group. Out of the entire number of PHCs in Wasit Governorate, seven were used for the study. A three-part structured questionnaire tests mothers' knowledge of the illness and attitudes about it. The results of this study indicated that there is statistically significant difference between the study and control groups during the post-test I and post-test II periods (t=14.968, P=.000 and t=13.731, P=.000, respectively). Data from the study group during the pre-test period of 31.17(9.14) revealed that (70%) of mothers had bad practices connected to Entameba Histolytica among children. According to the post-test I results, 47.4 (9.48) respondents, or 70%, identified good practices. The main finding showed that, after the educational program was implemented, mothers' knowledge and practice of amebiasis dramatically increased, with pre-post implementation differences that are statistically significant., (Copyright © 2023, the Author(s).)

Bacillus thuringiensis -based products are key in the biopesticides market. Bacillus thuringiensis kurstaki strains Lip and BLB1 were isolated from Lebanese and Tunisian soils, respectively. These strains are highly toxic against lepidopteran larvae, Ephestia kuehniella . Here, we report Lip and BLB1 complete genomes, including their plasmid and toxin contents., Competing Interests: The authors declare no conflict of interest.

Background: The outbreak of the coronavirus disease 2019 (COVID-19) has become an evolving worldwide health crisis. With the rising prevalence of diabetes mellitus has come an increasing awareness of their impacts on infectious diseases, and the risk for postinfection complications and mortality from critical infections., Objective: The objective of this study was to evaluate the prevalence and impact of diabetes mellitus on the severity and mortality of COVID-19., Methods: Data of laboratory-confirmed hospitalized patients at the COVID-19 unit between September 2020 and August 2021 were analyzed, in a cross-sectional study. The population was classified into two groups: COVID-19 patients with and without diabetes. Primary outcomes were the overall length of hospital stay, the admission to the ICU, and death. The association between diabetes and death was assessed in a Cox proportional hazards model., Results: A total of 866 patients were included. There were 270 (31.2%) patients with diabetes. Diabetic patients were more likely to have hypertension (58.1 vs. 33.4%), cardiovascular disease (18.5 vs. 10.4%), and dyslipidaemia (17.8 vs. 7.2). Overall, 263 patients died, among them only 86 in the diabetic group ( P =0.523). Patients with diabetes had a higher risk of developing complications ( P <0.001). Multivariate Cox regression analysis showed that diabetes was not significantly associated with death [HR (95% CI): 1.253 (0.963-1.631)]., Conclusion: Diabetes was associated with a greater risk of complications in patients with COVID-19. Special attention to diabetic patients during treatment must be given to avoid these complications., Competing Interests: The authors declare that they have no financial conflicts of interest with regard to the content of this report.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The COVID-19 pandemic has presented various challenges, one of which is the discovery that after the acute episode, around 30% of patients experience persistent symptoms or develop new ones, now known as long COVID. This new disease has significant social and financial impacts. The objective is to determine the prevalence of long COVID in the Tunisian population and identify its predictive factors., Methods: This was a cross-sectional study conducted among Tunisians who were infected with COVID-19 between March 2020 and February 2022. An online self-administered questionnaire was distributed through social media, radio, and television channels over the course of one month (February 2022). Long COVID was defined as the persistence of existing symptoms or the development of new symptoms within three months after onset, lasting for at least two months, and with no differential diagnosis. We performed univariate and multivariate analyses using binary stepwise logistic regression with a significance level set at 5%., Results: A total of 1911 patients participated in our study, and the prevalence of long COVID was 46.5%. The two most frequent categories were general and neurological post-COVID syndrome, with a prevalence of 36.7% each. The most commonly observed symptoms were fatigue (63.7%) and memory problems (49.1%). In the multivariate analysis, the predictive factors for long COVID were female gender and age of 60 years or older, while complete anti-COVID vaccination was found to be a protective factor., Conclusions: Our study found that complete vaccination was a protective factor against long COVID, while female gender and age of 60 years or older were identified as the main risk factors. These findings are consistent with studies conducted on other ethnic groups. However, many aspects of long COVID remain unclear, including its underlying mechanisms, the identification of which could guide the development of potential effective treatments., (© 2023. The Author(s).)

Background: Association between antibiotic use and antimicrobial resistance has been demonstrated in several studies; hence the importance of antibiotic stewardship programs (ASPs) to reduce the burden of this resistance., Aim: To describe the antibiotic stewardship team (AST) interventions in a Tunisian university hospital., Methods: a cross-sectional study was conducted in the infectious diseases department in Sousse-Tunisia between 2016 and 2020. Hospital and private practice doctors have been informed of the existence of an antibiotic stewardship team. Interventions consisted of some helps to antibiotic therapy (i.e.; prescription, change or discontinuation) and/or diagnosis (i.e.; further investigations)., Results: Two thousand five hundred and fourteen interventions were made including 2288 (91%) in hospitalized patients, 2152 (86%) in university hospitals and 1684 (67%) in medical wards. The most common intervention consisted of help to antibiotic therapy (80%). The main sites of infections were skin and soft tissues (28%) and urinary tract (14%). Infections were microbiologically documented in 36% of cases. The most frequently isolated microorganisms were Enterobactriaceae (41%). Antibiotic use restriction was made in 44% of cases including further investigations (16%), antibiotic de-escalation (11%), no antibiotic prescription (9%) and antibiotic discontinuation (8%). In cases where antibiotics have been changed (N=475), the intervention was associated with an overall decrease in the prescription of broad-spectrum antibiotics from 61% to 50% with a decrease in the prescription of third generation cephalosporins from 22% to 15%., Conclusions: The majority of antibiotic stewardship team's interventions were made in hospitalized patients, university hospitals and medical wards. These interventions resulted in an overall and broad-spectrum antibiotic use reduction.

Introduction: Motivation is an important component of learning. It remains a complex phenomenon to explore, largely influenced by multiple external and internal factors. It is important to measure the strength of student motivation in a long training course such as medical studies and its influencing factors., Aim: to measure strength of motivation among medical students the Faculty of Medicine of Sousse (FMS)., Methods: It was a cross-sectional study conducted among medical students enrolled at the FMS during the 2021/2022 academic year for 3 months using a questionnaire based on a validated scale: Strength of Motivation for Medical School-Revised (SMMS-R)., Results: A total of 185 students participated in the study. The mean age was 20.97 ± 1.8 years. The sex ratio was 0.34. The SMMS-R score was 55[47-63]. This score was higher international students (p=0.029), students who chose medical studies before passing the baccalaureate (p<10-3) and students satisfied with their choice of medical studies (p<10-3)., Conclusion: Our results revealed a strong association between students' satisfaction and motivation. Thus, the learning environment, governed mainly by institutional rules, educational activities and evaluative practices, greatly influences satisfaction and therefore motivation of medical students.

Introduction: Cerebral malaria which occurs during the active infection is the most common neurological complication of malaria. Other complications including post-malaria neurological syndrome (PMNS) can rarely occur following complete recovery from the disease. We report a case of post-malaria neurological syndrome in a Tunisian patient., Case Presentation: A 26-year-old Tunisian man with no past medical history was admitted in 2016 for a muscle weakness of the 4 limbs, seizures, tetraparesis and myoclonus which appeared after he returned from Côte d'Ivoire where he had been treated three weeks ago for Plasmodium falciparum malaria with favorable outcome. Blood smears for malaria were negative. Brain MRI showed multiple hypersignal cerebral lesions. Investigations didn't show any infectious, metabolic, toxic, vascular or tumoral etiology. Thus, the diagnosis of PMNS was considered. The patient was treated with methylprednisolone with favorable outcome. Two years later, he was completely asymptomatic., Conclusion: PMNS should be considered in patients with neurological symptoms occurring within two months of cured acute disease in which blood smears for malaria are negative and other etiologies have been ruled out. In most cases, the disease is self-limited while in severe cases corticosteroid therapy should be prescribed with favorable outcome., (© 2021 Bellazreg F et al.)

Background: Human herpesviruses (HHVs) remain latent after primary infection and can be reactivated in response to immunosuppression and chemotherapy. Little is known about their incidence, potential relationships, risk factors and clinical impact in non-transplant leukemia patients. This study investigated prospectively incidence, risk factors, clinical impact and possible association of HHVs-(1-7) infections in patients with newly diagnosed acute leukemia., Methods: Study design involved longitudinal sampling before chemotherapy and in different phases of chemotherapy: post-induction, post-remission, and post-salvage during 2016-2018. A total of 734 plasma samples from 95 patients were analyzed by a qualitative, multiplex PCR for HHVs detection and a quantitative real-time PCR was used for cytomegalovirus (CMV) quantification. HHVs-(1-6) IgG and IgM antibodies were tested using immunoassays. Risk factors were analyzed by binary logistic regression and relationships between viruses were analyzed using the Chi-square or Fisher's exact test as appropriate., Results: The overall seroprevalences of HHV-(1-6) IgG were high (> 80%). At least one herpes viral agent was detected in 60 patients (63.3%). CMV was the most commonly detected virus in the different phases of chemotherapy (19.4%), followed by HHV-6 (9.7%), HHV-7 (5.2%) and EBV (2.7%). HSV-1/2 and VZV DNA were not detected. Twenty-seven patients (28.4%) had more than one virus detected in the follow-up, with 23 who were co-infected. CMV/HHV-6 was the most frequent co-infection (69.5%, 16/23). HHV-6 infection (p = 0.008) was identified as a risk factor for CMV infection while salvage treatment (p = 0.04) and CMV infection (p = 0.007) were found to be independent risk factors for HHV-6 infection. CMV co-infection was associated with severe lymphopenia with an absolute lymphocyte count (ALC) (< 500/μL) (p = 0.009), rash (p = 0.011), pneumonia (p = 0.016) and opportunistic infections [bacteremia, p < 0.001 and invasive fungal infection, (p = 0.024)] more frequently than CMV mono-viral infections., Conclusions: Our data suggest that co-infection with HHVs, especially CMV and HHV-6, may contribute to the development of serious clinical manifestations with profound lymphopenia, pneumonia rash and increased risk for bacterial and fungal co-infections. These findings may suggest the synergistic effect of HHVs associated infection.

Objective: To describe the bibliometric profile of Tunisian "case report" publications in general surgery over the last thirty years (1989-2018)., Methods: This is a descriptive bibliometric study on "case reports", general surgery, Tunisian affiliation, indexed in the Medline database, between January 1, 1989 and December 31, 2018. The themes of Search articles were defined by referring to their major keywords used for their indexing., Results: During 30 years of study, Medline indexed 188 papers in "General Surgery" type "case reports", signed by 80 authors in first position and 71 authors in last position, belonging to ten academic specialties and 19 professional affiliations. These papers were published by 60 journals, including the Ugandan magazine "Pan African Medical Journal", which published 23% of these "case reports" alone. The number of major indexing keywords was 299 words, mainly "Echinococcosis", "Pancreatic Cancers" and "Echinococcosis of the liver", together accounting for 18.1% of articles., Conclusion: The plethora of "case reports" in Tunisian general surgery publications over the last three decades was accompanied by a preferential edition in the journal "Pan Afr Med J" and a thematic focus on hydatid cysts and cancers pancreatic. Hence the importance of strengthening the capacity of Tunisian surgeons in research methodology and scientific medical writing.

Aim: To describe the bibliometric characteristics of Tunisian publications on respiratory tract diseases, during the quinquennium 2010-2014., Methods: This is a descriptive bibliometric study of respiratory medicine publications, indexed in "Medline", based on their MSDSs. All included articles were written by Tunisian researchers regardless of their position in the list of co-authors. The topics of the publications were explored through their "major" and "generic" keywords., Results: A total of 340 publications was captured in Medline. These articles were co- authored by 218 authors in first position and 163 in last position. They were signed by pulmonologists, in first and last position respectively in 21.5% and 22.4% of articles. The A. Mami Hospital was the major affiliation of the first authors in 19.7% of the publications. These articles were published by 138 journals including "La Tunisie Medicale" in 11.8% of cases. They were "case reports" and written in English respectively in 44.4% and 54.1% of cases. Among 639 major keywords indexing, three were dominant: «Lung Neoplasms» (Tumeurs du poumon), «Chronic Obstructive Pulmonary Disease» (Broncho-pneumopathie chronique obstructive) and «Tuberculosis, Pulmonary» (Tuberculose pulmonaire), in 13.5%, 10.3% and 7.4% of articles respectively., Conclusion: Tunisian research on respiratory tract diseases has been thematically concordant with the public health needs. However, it has often been of low-level evidence and published in low-impact factor journals.

Aim: To describe the essential bibliometric characteristics of Tunisian publications in "infectiology", during the five-year period 2010-2014., Methods: This is a descriptive bibliometric study, on the papers of "infectiology", indexed in "«Medline»", based on their data sheets. Were included all the articles written by Tunisian researchers regardless of their position in the list of co-signers. The themes of the publications were explored through the key words "major" and "generic" in the three chapters of the descriptors: "Bacterial Infections and Mycoses", "Parasitic Diseases", and "Viral Diseases"., Results: A total of 846 publications in "Infectiology" were analyzed, of which 66% were written in English and 31% were "case reports". They were signed by 536 authors in first position belonging mainly to microbiology (20.7%), parasitology (20.1%) and virology (7.1%). The 391 co-signatories in last position belonged to 44 specialties, of which pediatrics, internal medicine and infectious diseases respectively occupy the 4th, the 9th and the 10th positions. These publications were edited in 258 journals, mainly "Tunisie Medicale" (9%) and "Pan African Medical Journal" (3.8%). The greatest interest of the Tunisian researchers in infectious diseases have been staphylococcal / tuberculosis infections, chronic viral hepatitis C / human influenza, and echinococcosis / leishmaniasis., Conclusion: In Tunisia, infectious diseases research has been relatively prolific and concordant with the population's health needs. Infectious diseases physicians should build their network of care, research and education with biologists, while focusing their research on multicenter and high-level studies.

Objective: Measure the prevalence of smoking among students of health sciences Faculties in Monastir (Tunisia) and identify factors associated with smoking behavior., Methods: A cross-sectional study based on a self-administered questionnaire conducted among students registered in their second, fourth and sixth year at the Faculties of Medicine and Pharmacy in Monastir, in 2013. Smoker was the subject who, at the time of the survey, smoked at least one cigarette per day. Academic difficulties were used to denote any of the following incidents that a student may experience: passing exams at the retake session, revalidating an internship or repeating a school year. A logistic regression analysis was used to identify factors associated with smoking., Results: The number of participants was 634 (285 Medical students and 349 Pharmacy students); they were 170 males and 464 females. The prevalence of smoking was 15%; 95% IC [12.1-17.7]. It was nearly five times higher among male compared to female students (35.3%; 95% IC [28.1-42.5]) vs 7.5%; 95% IC [5.1-9.9]); It was also higher among Pharmacy students than among Medical students (18.9%; 95% IC [14.8-23.0]) vs 10.2%; 95% IC [6.7-13.7]). In the multivariate analysis, the Faculty of Pharmacy (ORa=3.081; 95% IC=[1.7-5.7]), the male sex (ORa=6.929; 95% IC [3.9-12.0]) and the academic difficulties (ORa=1.854; 95% IC [1.02-3.38]) were found to be significantly associated with smoking., Conclusion: The level of tobacco use found among Medical and Pharmacy students is alarming. This serious problem has a negative impact on their behavior and can hinder their role model as future health professionals. Greater efforts are needed to develop anti-smoking programs, to educate students and to offer psychological support to deal with school difficulties.

Background: Despite the wealth of knowledge on hospital performance, the majority of health facilities in the Maghreb don't have yet a Balanced Scorecard for its measurement., Objective: Elaborate, through a systematic review of the biomedical literature, a Balanced Scorecard for hospital performance, consisting of indicators of quality of care, highly recommended and suitable for the professional and managerial contexts of Greater Maghreb health systems., Materials and Methods:   This is a "systematic review" study on the topic of indicators to measure hospital performance. A documentary query combining the "Mesh Major Topic" for the two following descriptors "hospitals" and "health quality indicators", has been applied to the "Medline" database over a period of ten years (2004-2013). A focus group composed of clinicians, managers and representatives of civil society, was formed for the selection of a Balanced Scorecard of health facilities in Maghreb, composed of 20 systemic indicators., Results: An in-depth reading of 166 articles included in the study identified 926 quality of care assessment indicators. It is in one of three cases "systemic" indicators applicable to multi-purpose health facilities, and in one case of two, it is"process"indicators focused on a health care activity. Following the work of the focus group, a Balanced Scorecard for hospital performance was developed in a consensual manner. Among these indicators, 18 explored the "care" dimension (average length of stay, bed occupancy rates, turnover beds rates, occupational blood exposure rates, unplanned admission rates, discharge rates, prolonged admissions rates, antibiotic prescription rates, mortality rates, health care-associated infection rates, readmission rates, pressure ulcer rates, patient / staff ratio, staff turnover rates, maintenance of medical records, time sending of the report of hospitalization, staff burnout rates, patients' satisfaction rates), and two indicators were related to training functions and research (number of hours of staff training, publication rates)., Conclusion: The use, by health care facilities, of this Balanced Scorecard, based on the current data from the literature and adapted to the specific professional context of Greater Maghreb, would be a preliminary condition for the start-up of a strategy to measure and improve hospital performance in the Maghreb countries.

The economically important crop pest Ephestia kuehniella was tested at two stages of larval development for susceptibility to Bacillus thuringiensis Cry1Aa toxin. Bioassays showed that toxicity decreased during the development of larvae stage. In fact, Cry1Aa toxins from BNS3-Cry - (pHT-cry1Aa) showed low toxicity against the first-instar larvae (L1) with a LC 50 value of about 421.02μg/g of diet and was not toxic against the fifth-instar (L5), comparing to the BLB1 toxins used as positive control which represent a LC 50 value of about 56.96 and 84.21μg/g of diet against L1 and L5 instars larvae, respectively. Effects of Cry1Aa toxins were reflected in histopathological observations by the weak destruction of midgut epithelium, slight hypertrophy of epithelial cells, and minor alteration of brush border membrane (BBM) detected mainly in L1 larvae stage comparing to the more extensive damage caused by BLB1 toxins. Interestingly, in vitro proteolysis of Cry1Aa toxins was found to correlate with the difference of toxicity during larval stage development. In fact, the weak proteinase activity detected inside the L1 midgut has led to the persistence of the Cry1Aa active forms (65 and 58kDa) during prolonged incubations, causing the alterations described previously. Three subfamilies of aminopeptidase (APN) receptors were detected in both larvae instars with different intensities and molecular weights (150kDa and 55kDa for APN1, and 90kDa for APN2 and APN4). Remarkably, binding assay using Cry1Aa toxin seems to have no direct correlation with larval stages toxicity differences, since same putative receptors were detected. Understanding the reasons for the clear differences in the effectiveness of Cry1Aa toxins during larval development stages of E. kuehniella is very important for the design of future improvement insecticidal approaches and for the accomplishment of resistance prevention strategies., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The basis of the different susceptibility of Ephestia kuehniella to the Cry1Aa and Cry1Ac δ-endotoxins from Bacillus thuringiensis kurstaki BNS3 was studied. Both toxins bound specifically to the BBMV of E. kuehniella. The result of the ligand blot showed that Cry1Ac bound to three putative receptors of about 100, 65 and 80 kDa and Cry1Aa interacted only with a 100 kDa protein. Pronase digestion of the BBMV-bound toxins was used to analyze the toxin insertion. Both toxins inserted into the BBMV as monomers however, a 14 kDa peptide of α4-α5 which correspond to the oligomeric form of this peptide was detected in case of Cry1Ac only. Analysis of the in vitro oligomerisation of these toxins in the presence of the BBMV of E. kuehniella showed reduced oligomer formation in case of Cry1Aa in comparison with Cry1Ac. Taken together, these results strongly suggest that the difference of toxicity between Cry1Aa and Cry1Ac to E. kuehniella is due to a deficient oligomerisation of Cry1Aa., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Cry2 proteins play an essential role in current Bacillus thuringiensis (Bt) applications and in the prevention of insect resistance to Cry1A toxins. This paper reports on the screening and characterisation of novel Bt strains harbouring effective cry2A-type genes and higher insecticidal activity to Ephestia kuehniella., Results: A total of 29 native Bt strains were screened to search for the potent strain against E. kuehniella. The plasmid pattern of the selected strains showed interesting variability. PCR-RFLP analysis of two amplified regions showed high sequence identity within the selected cry2A-type genes. SDS-PAGE and western blot analysis revealed the presence of Cry2Aa toxin only in the MEB4 and BLB240 strains. The activation of Cry2Aa protoxins by larval midgut juice, trypsin or chymotrypsin enzymes revealed significant differences in terms of proteolysis profiles. Interestingly, a 49 kDa band was detected in the proteolysis pattern of BLB240, suggesting the presence of a chymotrypsin cleavage site that might have affected its insecticidal activity. Further, bioassays demonstrated that MEB4 (103.08 ± 36 µg g(-1)) was more active than BLB240 (153.77 ± 45.65 µg g(-1)) against E. kuehniella., Conclusion: Based on its potent insecticidal activity, the MEB4 strain could be considered to be an effective alternative agent for the control of E. kuehniella., (© 2015 Society of Chemical Industry.)

In the great expansion of the social networking activity, young people are the main users whose choices have vast influence. This study uses the flow theory to gauge the impact of Facebook usage on Tunisian students' achievements, with the presumption that the high usage level might reduce students' scholar achievements. The research design suggests that this impact would vary among students with different interests for the university and multitasking capabilities. Facebook usage would develop students' satisfaction with friends and family, which could enhance their academic performance. Analyses from 161 Tunisian students show that Facebook usage does not affect significantly students' academic performance and their satisfaction with the family, whereas it decreases their actual satisfaction with friends. Yet, a high level of satisfaction of the student with his family continues to enhance his academic performance. Overall, though, Facebook usage appears to do not have a significant effect on undergraduate students' academic performance. However, this interdependency is significantly moderated by the student's interest for the university and his multitasking capabilities. Students with multitasking skills and students with initial interest for the university might experience a positive effect of Facebook usage on their studies, as they keep control over their activity and make it a beneficial leisure activity. However, students who do not have these characteristics tend to not have any significant effect. Results help to understand the psychological attitude and consequent behavior of the youths on this platform. Implications, limitations, and further research directions are offered.

BUPM95 is a Bacillus thuringiensis subsp. kurstaki strain producing the Vip3Aa16 toxin with an interesting insecticidal activity against the Lepidopteran larvae Ephestia kuehniella. Study of different steps in the mode of action of this Vegetative Insecticidal Protein on the Mediterranean flour moth (E. kuehniella) was carried out in the aim to investigate the origin of the higher susceptibility of this insect to Vip3Aa16 toxin compared to that of the Egyptian cotton leaf worm Spodoptera littoralis. Using E. kuehniella gut juice, protoxin proteolysis generated a major band corresponding to the active toxin and another band of about 22kDa, whereas the activation of Vip3Aa16 by S. littoralis gut juice proteases generated less amount of the 62kDa active form and three other proteolysis products. As demonstrated by zymogram analysis, the difference in proteolysis products was due to the variability of proteases in the two gut juices larvae. The study of the interaction of E. kuehniella BBMV with biotinylated Vip3Aa16 showed that this toxin bound to a putative receptor of 65kDa compared to the 55 and 100kDa receptors recognized in S. littoralis BBMV. The histopathological observations demonstrated similar damage caused by the toxin in the two larvae midguts. These results demonstrate that the step of activation, mainly, is at the origin of the difference of susceptibility of these two larvae towards B. thuringiensis Vip3Aa16 toxin., (Copyright © 2011 Elsevier Inc. All rights reserved.)

LGMD (limb-girdle muscular dystrophy) and CMD (congenital muscular dystrophy) are two common forms of neuromuscular disorders which are distinguishable by their age of onset but with probably a similar underlying pathway. In the present study, we report immunohistochemical, Western-blot and genetic analyses in a large consanguineous Tunisian family with two branches, including seven patients sharing similar LGMD2 phenotype in one branch and one CMD patient in the other branch. Linkage analyses were compatible with the LGMD2A locus in one branch and the MDC1A (muscular dystrophy congenital type 1A) locus in the other branch. This result was supported by deficiency in merosin and calpain3 in the CMD patient and LGMD patients respectively. Mutation analysis revealed two distinct mutations: a c.8005delT frameshift deletion in exon 56 of the LAMA2 (laminin-α2) gene (MDC1A) was found in the CMD patient and a new homozygous mutation c.1536+1G>T in the donor splice site of intron 12 of the CAPN3 (calpain3) gene (LGMD2A) was found in the LGMD patients. RT-PCR (reverse transcription-PCR) performed on total RNA from a LGMD2A patient's muscle biopsy showed complete retention of intron 12 in CAPN3 cDNA, generating a PTC (premature termination codon) that potentially elicits degradation of the nonsense mRNA by NMD (nonsense-mediated mRNA decay). Our results indicate that mRNA analysis is necessary to clarify the primary effect of genomic mutations on splicing efficiency that alters mRNA processing and expression level.

Chitinases have been successfully used in combination with Bacillus thuringiensis delta-endotoxins forming crystals in order to enhance their insecticidal activities. In this context, we opted for promoting the chitinase integration into these crystals. Thus, we engineered, for the first time, a fusion protein (CDF) consisting of the chitinase Chi255 and the carboxy-terminal half of Cry1Ac, both from B. thuringiensis subsp. kurstaki. The constructed transcriptional fusion (chi255Δsp-CTcry1Ac) was cloned into a shuttle vector (Escherichia coli/B. thuringiensis) downstream the sporulation-dependent promoters BtI-BtII and upstream the cry1Ac transcription terminator. The resulting plasmid, named pF, was transferred by electroporation to crystalliferous B. thuringiensis strain BNS3 and acrystalliferous strain BNS3Cry-. The functionality of the chimerical chitinase was demonstrated by an improvement of the relative chitinolytic activity of the recombinant strain BNS3/pF by 2.5 folds. Western blot analyses showed that, despite of the instability of CDF when expressed in the acrystalliferous strain, the C-terminal half of Cry1Ac succeeded to allow the integration of the chimerical chitinase into the crystal of BNS3. The recombinant strain BNS3/pF (LC(50) = 144.06 μg g(-1)) was 1.5 times more active against Ephestia kuehniella larvae than the wild strain (LC(50) = 212.10 μg g(-1)).

The study of 257 crystal-producing Bacillus thuringiensis isolates from bioinsecticide free soil samples collected from different sites in Tunisia, was performed by PCR amplification, using six primer pairs specific for cry1, cry2, cry3, cry4, and vip3A genes, by the investigation of strain plasmid pattern, crystal morphology and delta-endotoxin content and by the assessment of insecticidal activities against the lepidopteran insect Ephestia kuehniella. Based on plasmid pattern study, 11 representative strains of the different classes were subjected to morphological and molecular analyses. The comparison of the PFGE fingerprints confirmed the heterogeneity of these strains. B. thuringiensis kurstaki strains, harbouring at the same time the genes cry1A, cry2, cry1Ia, and vip3A, were the most abundant (65.4%). 33.34% of the new isolates showed particular delta-endotoxin profiles but no PCR products with the used primer sets. B. thuringiensis israelensis was shown to be also very rare among the Tunisian B. thuringiensis isolates diversity. These findings could have considerable impacts for the set up of new pest control biological agents.

Cry1Ia and Cry1Aa proteins exhibited toxicities against Prays oleae with LC(50) of 189 and 116 ng/cm(2), respectively. The ability to process Cry1Ia11 protoxin by trypsin, chymotrypsin and P. oleae larvae proteases was studied and compared to that of Cry1Aa11. After solubilization under high alkaline condition (50mM NaOH), Cry1Aa11 was converted into a major fragment of 65 kDa, whereas Cry1Ia11 protoxin was completely degraded by P. oleae larvae proteases and trypsin and converted into a major fragment of 70 kDa by chymotrypsin. Using less proteases of P. oleae juice, the degradation of Cry1Ia11 was attenuated. When the solubilization (in 50mM Na(2)CO(3) pH 10.5 buffer) and activation were combined, Cry1Ia11 was converted into a proteolytic product of 70 kDa after 3h of incubation with trypsin, chymotrypsin and P. oleae juice. These results suggest that the in vivo solubilization of Cry1Ia11 was assured by larval proteases after a swelling of the corresponding inclusion due to the alkalinity of the larval midgut., ((c) 2010 Elsevier Inc. All rights reserved.)

Vegetative insecticidal protein (Vip) is a class of insecticidal proteins produced by many Bacillus thuringiensis strains during their vegetative growth stage. The vip3LB gene of B. thuringiensis strain BUPM95, which encodes a protein active against the Lepidoptera olive tree pathogenic insect Prays oleae, was cloned into pET-14b vector and overexpressed in Escherichia coli. The expressed Vip3LB protein, found in the E. coli cytoplasmic fraction, was purified and used to produce anti-Vip3LB antibodies. Using the midgut extract of P. oleae, the purified Vip3LB bound to a 65-kDa protein, whereas Cry1Ac toxin bound to a 210-kDa midgut putative receptor. This result justifies the importance of the biological pest control agent Vip3LB that could be used as another alternative particularly in case of resistance to Cry toxins.

The expression of recombinant antibodies in transgenic plants has been proved to be an efficient approach for large-scale production. However, the stability of these molecules and their accumulation level depend on their molecular properties and cellular targeting. The expression of single-domain antibody fragment (VH) can be advantageous since it offers small length, high expression, solubility and stability. It can therefore be preferred to other antibody derivatives avoiding the expression difficulties related to immunoglobulin domain folding via the formation of disulfide bridge. This report describes the production of transgenic potato plants expressing a VH antibody directed against the NIa protease of potato virus Y. The antibody was driven by the constitutive CaMV 35S RNA promoter. The expression cassette was transferred into potato plants via Agrobacterium tumefaciens mediated transformation. All transgenic lines showed detectable levels of VH protein confirming the efficient translation and stability of this protein. The cellular localisation of the VH antibody was investigated. Transgenic and control plants were transferred in the greenhouse and mechanically inoculated by PVY(o) suspension. Some of the transgenic lines showed delayed symptoms at the first period post inoculation and then displayed a recovery phenomenon while the virions were still detected in the leaves., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

BLB1 is a new Bacillus thuringiensis kurstaki strain, isolated from a Tunisian soil sample. Assay of toxicity of BLB1 crystal proteins resulted in an LC50 of 70.32 ng of toxin per mg of flour against third instar Ephestia kuehniella with confidence limits of (31.6-109.04 ng). This LC50 is less than that of the commercial strains HD1 used as a reference. The characterization of this strain by scanning transmission electron microscopy, analysis of its cry genes content by PCR-sequencing, and analysis of its delta-endotoxin patterns demonstrate that it belongs to the same subgroup than HD1, but ruled out the involvement of cry gene content or protoxin activation in the hypertoxicity of this strain. Taking into account the delta-endotoxin/spore ratio for each strain, and by allowing the estimation of the production level per spore, it might be concluded that BLB1 production is the highest, when compared with that of HD1. On the basis of its toxicity, BLB1 could be considered as a strain of great interest and would allow the production of quantities of bioinsecticides at low cost.

A comparative study of different steps in the mode of action of the individual Bacillus thuringiensis kurstaki BNS3 Cry1Aa and Cry1Ac delta-endotoxins on E. kuehniella larvae was performed in order to investigate the origin of the difference in the response of this larvae to each of the latter. Proteolytic activation was shown to be one of the main steps impaired in E. kuehniella tolerance to Cry1Aa. The absence of two proteinase activities as well as an altered activity level observed in the case of Cry1Aa would be the consequence of proteinase-mediated tolerance of E. kuehniella to this toxin. In situ binding and histopathological effect analyses allowed concluding that the binding of the toxin to BBMV receptors is the key step in E. kuehniella tolerance to Cry1Aa toxin. The latter was slightly bound to apical membranes of epithelial cells that remained intact, whereas Cry1Ac was tightly bound to completely damaged cells basal membranes.

Bacillus thuringiensis subsp. kurstaki BUPM255 secretes a chitobiosidase Chi255 having an expected molecular weight of 70.665 kDa. When the corresponding gene, chi255, was expressed in E. coli, the active form, extracted from the periplasmic fraction of E. coli/pBADchi255, was of about 54 kDa, which suggested that Chi255 was excessively degraded by the action of E. coli proteases. Therefore, in vitro progressive C-terminal Chi255 deleted derivatives were constructed in order to study their stability and their activity in E. coli. Interestingly, when the chitin binding domain (CBD) was deleted from Chi255, an active form (Chi2555Delta5) of expected size of about 60 kDa was extracted from the E. coli periplasmic fraction, without the observation of any proteolytic degradation. Compared to Chi255, Chi255Delta5 exhibited a higher chitinase activity on colloidal chitin. Both of the enzymes exhibit activities at broad pH and temperature ranges with maximal enzyme activities at pH 5 and pH 6 and at temperatures 50 degrees C and 40 degrees C, respectively for Chi255 and Chi255Delta5. Thus, it was concluded that the C-terminal deletion of Chi255 CBD might be a nice tool for avoiding the excessive chitinase degradation, observed in the native chitinase, and for improving its activity.

Unlike classical digestive lipases, the scorpion digestive lipase (SDL) has a strong basic character. The SDL activity's optimal pH, when using tributyrin or olive oil as substrate, was 9.0. Added to that, the estimated isoelectric point of the native SDL using the electrofocusing technique, was found to be higher than 9.6. To our knowledge, this is the first report of an animal digestive lipase having such a basic character. When olive oil was used as substrate, SDL was shown to be insensitive to the presence of amphiphilic proteins such as bovine serum albumin (BSA). Furthermore, the hydrolysis was found to be specifically dependent on the presence of Ca(2+) ions, since no significant SDL activity was detected in the presence of ions chelator such as EDTA. Nevertheless, the SDL does not require Ca(2+) to trigger the hydrolysis of tributyrin emulsion. Interestingly Zn(2+) and Cu(2+) ions act as strong inhibitors of SDL activity when using tributyrin as substrate. An internal chymotryptic cleavage of SDL generated two fragments of 28 and 25 kDa having the same N-terminal sequence. This sequence of 19 residues does not share any homology with known animal and microbial lipases. Polyclonal antibodies directed against SDL (pAbs anti-SDL) failed to recognise ostrich pancreatic and dog gastric lipases (OPL and rDGL). Moreover, both pAbs anti-OPL and anti-rDGL failed to immunoreact with SDL. These immunological as well as distinct biochemical properties strengthen the idea that SDL appears to belong to a new invertebrate's lipase group.

Considering the fact that Prays oleae is one of the most pathogenic insects to the olive tree in the Mediterranean basin, particularly in Tunisia, the mode of action of Cry insecticidal toxins of Bacillus thuringiensis kurstaki in Prays oleae midgut was investigated. The proteolysis of Bacillus thuringiensis delta-endotoxins in the midgut was a key step in determining their potency against Prays oleae. The latter's proteases activated the delta-endotoxins early, yielding stable toxins. The in vitro and in vivo binding of these toxins to Prays oleae larvae midgut was studied immunohistochemically, evidencing a midgut columnar cell vacuolization, microvilli damage, and then a pass of epithelium cell content into the larvae midgut. Moreover, Bacillus thuringiensis toxins were shown to bind to the apical microvilli of the midgut epithelial cells. The in vitro study of the interaction of Prays oleae midgut proteins with biotinylated Bacillus thuringiensis toxins allowed the prediction of four suitable receptor proteins in Prays oleae.

gyrB DNA fragments of seven Bacillus thuringiensis local collection family representatives were amplified by PCR and sequenced. Several differences in their corresponding sequences were evidenced. Both in silico and in vitro restriction maps of gyrB sequences and fragments respectively confirmed that EcoRI and Sau3AI could be used to differentiate between B. thuringiensis strains. However, the phylogeny analysis showed that only the gyrB PCR-Sau3AI allows a strains classification that correlates very well with that obtained on the basis of the sequences analysis. Thus, these finds show that gyrB PCR- Sau3AI digestion could be considered as an efficient, rapid, and easy method to make a distinction, not only between strains belonging to the Bacillus cereus group, but also between those belonging to B. thuringiensis.

Three single-chain variable fragment (scFv) antibodies recognizing the nuclear inclusion a (NIa) and capsid proteins of potato virus Y were obtained from two mouse derived hybridoma clones secreting, respectively, an anti-NIa (22-1) and an anti-coat protein (136-13) monoclonal antibodies. The first monoclonal antibody was able to inhibit in vitro the PVY polyprotein cleavage by blocking the NIa protease activity. The amplified scFv cDNAs were first inserted into the TOPO vector and then sequenced. Several recombinant E. coli clones carrying the accurate scFv sequences were selected and the corresponding cDNAs were subcloned in pHEN phagemid and transferred in E. coli strain. The expressed scFv fragments showed an antibody activity that recognized the viral target proteins in infected tissues. Their activity was comparable to the parental monoclonal antibodies.

The scorpion hepatopancreas consists of digestive diverticula and interstitial tissue. A digestive diverticulum is composed of two differentiated cell types: the secretory zymogene-like cells and the digestive cells which are the most abundant. The scorpion digestive lipase (SDL) has been previously purified from scorpion hepatopancreas, but its cellular localization has not yet been established. Polyclonal antibodies specific to SDL were prepared and used in immunofluorescence and immunogold techniques to determine the cellular location of SDL. Our results clearly established that SDL was detected intracellularly in specific vesicles tentatively named (SDL+) granules of the digestive cells. No immunolabelling was observed in secretory zymogene-like cells. This immunocytolocalization indicates that lipid digestion might occur in specific granules inside the digestive cells, as suggested by previous studies on the scorpion digestive process.

A synthetic gene encoding a single chain Fv fragment of an antibody directed against the nuclear inclusion a (NIa) protein of potato virus Y (PVY) was used to transform two commercial potato cultivars (Claustar and BF15). The NIa protease forms the nuclear inclusion body A and acts as the major protease in the cleavage of the viral polyprotein into functional proteins. Immunoblot analysis showed that most of the resulting transgenic plants accumulate high levels of the transgenic protein. Furthermore, a majority of the selected transgenic lines showed an efficient and complete protection against the challenge virus after mechanical inoculation with PVYO strain. Two transgenic lines showed an incomplete resistance with delayed appearance of symptoms accompanied by low virus titers, whereas one line developed symptoms during the first days after inoculation but recovered rapidly, leading to a low virus accumulation rate. These results confirm that expression of scFv antibody is able to inhibit a crucial step in the virus multiplication, such as polyprotein cleavage is a powerful strategy for engineered virus resistance. It can lead to a complete resistance that was not obtained previously by expression of scFv directed against the viral coat protein.

Objective: To minimize the uncertainty in clinical diagnosis and improve the classification of 14 Tunisian patients belonging to 12 families and affected with congenital muscular dystrophy (CMD)., Methods: Fourteen patients belonging to 12 unrelated families originating from the south of Tunisia and affected with CMD were clinically examined between 1990 and 2001 in the neurology service of Chu Habib Bourguiba, Sfax, Tunisia. Immunohistochemical and western blot analyses were used to explore protein expression in muscular biopsies and homozygosity mapping using microsatellite markers for the genetic study. These analyses were performed in the human molecular genetics laboratory., Results: Among the patients tested with anti-merosin antibodies, 3 showed total laminin-a2 deficiency and the remaining patients showed partial laminin-a2 deficiency. All patients expressed normally a-sarcoglycan, b-dystroglycan and dystrophin except 2 showing reduction of expression in a-sarcoglycan and b-dystroglycan. Linkage analysis, performed for 8 families, was compatible with linkage to the LAMA2 gene for only 2., Conclusion: Our results showed that clinical and immunohistochemical analyses have allowed classification of only 3 patients, immunohistochemical and genotyping studies have contributed to the classification of 7 patients. In the remaining cases, there is no evident classification due to the lack of the genetic exploration. Our results also confirmed the broad spectrum of phenotypes associated with a defect in laminin-a2.

Aims: To characterize hypochlorous acid (HOCl) stress resistance of Staphylococcus aureus and to assess physiological state and changes in cell morphology., Methods and Results: Clinical wild-type strain of S. aureus was used in the stress with HOCl at concentrations ranging from 0 to 4 mg l(-1). Concentrations below 1.5 mg l(-1) caused no significant drop in viability. During 2 h of HOCl stress at 2 mg l(-1), there was appearance of minicells capable of passing through the 0.45 microm pores of filtration membranes. Intracellular proteins increased gradually to reach a level of 51% of dry weight and an enhanced synthesis of at least two proteins of 23 and 220 kDa was concluded., Conclusions, Significance and Impact of the Study: Staphylococcus aureus can undergo morphological and physiological changes during 2 h of exposure to 2 mg l(-1) of HOCl, which represents an adaptative response towards the hypochlorous acid stress. This evolution limits the use of 0.45 microm pores size membrane filters for research on S. aureus in waters and the clinical environment.