Biochemical characterization of a cefotaximehydrolysing &#946-lactamase encoded by a conjugative plasmid

During the nosocomials infections occurring in the intensive care unit of the military hospital of Tunis in 2005, the Enterobacter cloacae BW 1150 strain was isolated from a stool culture. This strain was found to have a high level resistance to broad-spectrum -lactams. Resistance profile against thevarious families of antibiotics was determined using the disc diffusion test. The minimal inhibitory concentrations values showed that this strain was resistant to the -lactams such as ampicillin and the extended spectrum cephalosporins (cefotaxime, ceftriaxon and cefpirome). Analysis of this strain by the disk diffusion test revealed synergies between amoxicillin-clavulanate (AMX-CA) and ceftriaxon, ceftazidime and cefotaxime. Cell sonicate of this isolate is very active against cefotaxime and showed aspecific activity (AS) of 7.54 U/mg for the same antibiotic. This activity was inhibited by the sulbactam and the clavulanic acid. Isoelectrofocusing methods revealed that the crude extract of the E. cloacae BW 1150 strain showed 1 - lactamase activity with an isoelectric piont (pI) of about 8. This activity was transferred by conjugation and was highly expressed in the transconjugant

Estabilización de aceite de oliva virgen extra ecológico con antioxidantes naturales de hojas de Artemisia absinthium obtenidos por maceración y extracción asistida por ultrasonido

Olive oil is the most popular product derived from Olea europaea L. due to its organoleptic characteristics and its beneficial effects on human health. Nowadays, there is a growing interest in olive oil enrichment with medicinal plants. In this regard, Artemisia absinthium L. is an edible source of antioxidants. The aim of the present study was to improve the oxidative stability and the nutritional value of Organic Tunisian Chetoui Olive oil by its enrichment with the phenolic compounds in Artemisia absinthium. The enrichment carried out by maceration and ultrasound-assisted extraction did not affect the organic criteria of olive oil. The comparative study, performed during one year of storage, showed that ultrasound-assisted extraction led to the lowest final peroxide and extinction coefficient values. At the end of storage, this method increased oleic acid content and biophenol contents. Furthermore, the anti-radical activities of enriched samples were higher than the control.El aceite de oliva es el producto derivado de Olea europaea L. muy popular debido a sus características organolépticas y sus efectos beneficiosos para la salud humana. En la actualidad existe un interés creciente por enriquecer el aceite de oliva con plantas medicinales. En este sentido, Artemisia absinthium L. es una fuente comestible de antioxidantes. El objetivo del presente estudio fue la mejora de la estabilidad oxidativa y el valor nutricional del aceite de oliva Chetoui tunecino orgánico mediante su enriquecimiento con compuestos fenólicos de Artemisia absinthium. El enriquecimiento realizado por maceración y extracción asistida por ultrasonidos no afectó a los criterios ecológicos del aceite de oliva. El estudio comparativo, realizado durante un año de almacenamiento, mostró que la extracción asistida por ultrasonidos condujo a los valores finales de peróxido y coeficientes de extinción más bajos. Al final del almacenamiento, este método aumentó el contenido de ácido oleico y de biofenoles. Además, las actividades antirradicales de las muestras enriquecidas fueron mayores que las del control

High-level cefotaxime-resistant Proteus mirabilis strain isolated from a Tunisian intensive care unit ward: CTX-M-8 extended-spectrum β-lactamase coproduced with a plasmid mediated AmpC lactamase

The aimed of this study was to determine the implication of the biochemical and the molecular mechanism and to describe the properties of an extended-spectrum β-lactamase (ESBL) CTX-M-8 which was reported for the first time in Africa. A clinical isolate of Proteus mirabilis FS6449 was isolated from a patient hospitalized at an intensive care unit of the Military Hospital in Tunisia in 2009. Antimicrobial susceptibility was determined with the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines and revealed that this strain was resistant to expanded-spectrum β-lactams. Analysis of P. mirabilis FS6449 by double-disk synergy test yielded a positive result suggesting the production of ESBLs. Sonicate of the isolate hydrolysed cefotaxime and benzylpenicillin. Isoelectric focusing exhibited four β-lactamase bands of isoelectric points (pIs) 5.6, 6, 6.5 and over 7.6. Polymerase chain reaction (PCR) and sequencing experiments revealed the presence of four β-lactamase genes encoding TEM-2, CTX-M-8, TEM-24, and an AmpC enzyme. Among them, the genes encoding TEM-24 and an AmpC enzyme were transferred to the recipient by conjugation experiments.Keywords: Resistance, β-lactamase, Proteus mirabilisAfrican Journal of Biotechnology Vol. 12(21), pp. 3278-328

Effects of Chia Seed Levels on Quality and Bio-Functional Profile of Stirred Yoghurt

Yoghurt is considered as a healthy food. Thus, it could convey functional and bioactive ingredients. Chia seeds are of great interest due to their ability to improve consumer health. In this study, chia seeds were added to stirred yoghurt at diff erent doses (1.5, 3, 4.5, or 6%). The effects of chia seeds on physicochemical, microbiological, and sensory qualities were assessed during 28 days of refrigerated storage. The results showed that chia seeds slightly decreased post-acidification, the lowest value was obtained in yogurt with 3% chia seeds (24°D), but syneresis rose significantly (P<0.05) when 6% of chia seeds was added. Furthermore, chia seeds promote viability of yoghurt bacteria, and antioxidant activity reached 62.20±0.02% in yoghurt added with 1.5% chia seeds. However, proteolysis is not affected. The effects of chia seeds were not dose dependent as 4.5% and 6% did not follow trend. These findings were affirmed by sensory characteristics. Thus, stirred yoghurt containing 1.5 or 3% of chia seeds proved to be the most adequate choices

Development of Aloe vera (Aloe barbadensis Miller) Probiotic Lassi Using Lactobacillus fermentum Bacteria

The aim of this research was to investigate the effect of Aloe vera gel on the quality of probiotic lassi. Probiotic lassi was prepared by adding 15% of Aloe vera gel and inoculating with probiotic Lactobacillus fermentum strain. Results showed that physicochemical properties of fortified probiotic lassi were not affected by these modifications during the storage period (P>0.05), however, antioxidant activities, texture and aroma sensory parameters differed significantly (P0.05) after 21 days of storage. Aloe vera probiotic lassi has a beneficial effect on human health

Nonadiabatic geometric phase induced by a counterpart of the Stark shift

We analyse the geometric phase due to the Stark shift in a system composed of a bosonic field, driven by time-dependent linear amplification, interacting dispersively with a two-level (fermionic) system. We show that a geometric phase factor in the joint state of the system, which depends on the fermionic state (resulting form the Stark shift), is introduced by the amplification process. A clear geometrical interpretation of this phenomenon is provided. We also show how to measure this effect in an interferometric experiment and to generate geometric "Schrodinger cat"-like states. Finally, considering the currently available technology, we discuss a feasible scheme to control and measure such geometric phases in the context of cavity quantum electrodynamics

Development and characterisation of functional cultured buttermilk fortified with flaxseed

Abstract Cultured buttermilk is a dairy beverage with a high nutritive value. In the current study, functional cultured buttermilk was formulated using probiotic Lactobacillus plantarum and flaxseed fortification to improve the potential health benefits. The cultured buttermilk samples were analysed for pH, lactic acidity, colour, phase separation, viscosity, microbiology and sensory properties. The results showed non-significant changes in acidity and pH. However, flaxseed fortification decreased phase separation and increased viscosity of buttermilks. In addition, a significant difference in colour attributes was revealed between samples. Sensory characteristics of cultured buttermilks were acceptable to produce a functional food

Acute myocardial infarction in a patient with hypofibrinogenemia: a case report

<p>Abstract</p> <p>Introduction</p> <p>Congenital fibrinogen deficiency is a rare coagulation disorder usually responsible for hemorrhagic diathesis. However, it can be associated with thrombosis and there have been limited reports of arterial thrombotic complications in these patients.</p> <p>Case presentation</p> <p>A 42-year-old Tunisian man with congenital hypofibrinogenemia and no cardiovascular risk factors presented with new onset prolonged angina pectoris. An electrocardiogram showed features of inferior acute myocardial infarction. His troponin levels had reached 17 ng/L. Laboratory findings confirmed hypofibrinogenemia and ruled out thrombophilia. Echocardiography was not useful in providing diagnostic elements but did show preserved left ventricular function. Coronary angiography was not performed and our patient did not receive any anticoagulant treatment due to the major risk of bleeding. Magnetic resonance imaging confirmed myocardial necrosis. Our patient was managed with aspirin, a beta-blocker, an angiotensin-converting enzyme inhibitor and statin medication. The treatment was well tolerated and no ischemic recurrence was detected.</p> <p>Conclusion</p> <p>Although coronary thrombosis is a rare event in patients with fibrinogen deficiency, this condition is of major interest in view of the difficulties observed in managing these patients.</p

Twenty-three unsolved problems in hydrology (UPH) – a community perspective

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focussed on process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery