Importance of New Edible Oil Extracted from Seeds of Seven Cereals Species

Cereals constitute a major source of human and animal nutrition. In spite of the extensive production of numerous cereal species, some information is unavailable in terms of lipid composition. Due to the oil increasing demand by the overgrowth of the world population, oleaginous species have encountered problems in recent years. In order to find new sources of edible oil, the aim of this study was to describe the importance of seventeen varieties oil of seven cereal species. Oils were extracted by the Soxhlet method, and fatty acids were measured by gas chromatography. The present study demonstrated that the lipid content of cereal seeds ranged from 1.42% to 5.97%. In average, oat, millet, and maize had significantly higher lipid content, respectively, 5.97%, 5.06%, and 4.71%. The main fatty acid recorded in the studied cereal species, except oat, was linoleic acid C18 : 2 (ω6). Regarding the essential fatty acids linoleic acid C18 : 2 and linolenic acid C18 : 3 (ω3), the oil of all studied species, except oat, was rich in ω6 fatty acids (47.50 to 60.13%) and poor in ω3 (0.45% to 5.33%). The content of unsaturated fatty acids in all studied species ranged from 77.22 to 81.89%. Cereal oil was considered as highly unsaturated oil with the presence of the essential fatty acids necessary for human health. Therefore, cereal oils could be commercialized in small quantities in pharmacies or parapharmacies.

Breast Cancer burden in Tunisia: situation in 2017 and projections by 2030

Introduction

Despite advances in diagnostic and treatment of cancer, burden of this disease is increasing worldwide. Breast Cancer is one of the leading cancers and major causes of death among female worldwide. The aim of this study was to describe the breast cancer burden in Tunisia in terms of disability adjusted life years (DALY) in 2017 and to perform projections by 2030.

Methods

DALYs for cancer are the sum of years of potential life lost due to premature mortality (Years Life Lost (YLL) and the years lived with disability (YLD). We used epidemiological data (incidence rate, death rate, DALY, YLL and YLD) estimated by the Institute for Health Metrics and Evaluation (IHME). Demographic data were provided by the National institute of statistics. The projection of DALYs for breast cancer through 2030 was performed by a Poisson Regression analysis with Age -Period -Cohort (APC) using SPSS software while using IHME estimated data for the period 1990-2017.

Results

In 2017, breast cancer incidence and mortality rate among females in Tunisia were 50.17/100000 persons years and 14.04/100000 persons years respectively. Breast cancer DALY values were 25145 (438 /100000 persons years). The percentage of YLL in DALYS was 92.4%. Without effective interventions, the number of DALYs due to breast cancer would reach 40071 in 2030 with a standardized rate of 507/100000 persons years (IC 95% = [501/100000 to 514/100000]. The number of YLL predicted will attain 36457 with a standardized rate of 461/100000 persons years.

Conclusions

The burden of breast cancer among Tunisian women in 2017 is relatively high mainly due to the lack of screening program. There is an urgent need of a strong plan of early detection and appropriate care.

Key messages

Burden of breast cancer among women in 2017 is high and will rise in 2030. Renforcing screening program is urgent.

Cancer incidence trend in northern tunisia: 1994-2009

Background

Cancer is a major public health problem in Tunisia. The objectives of this study were to describe the epidemiological pattern of cancer for all and main cancer sites in Northern Tunisia during the period 2007-2009 and to analyze it’s incidence trend between 1994 and 2009.

Methods

Cancer registry of Northern Tunisia was the source of data for the identification of patients for this study. This registry notify, since 1994, all cases of malignant tumor in people living in the District of Tunis, Nabeul, Zaghouan, Bizerte (North East) Beja, Jendouba, Kef and Siliana (North West). Cases were codified using the third version of International Classification of Diseases for Oncology. Demographic data were provided by the National Statistical Institute. Incidence trend analysis was achieved by using JoinPoint Software.

Results

During the period 2007-2009, the age-standardised incidence rate of all sites combined was 149.2/100 000 person-years and 112.3/100 000 person-years respectively among males and females. The sex ratio was 1.26. The mean age at diagnosis was 58.28±16.77 years. The most common sites for males were: lung, bladder, prostate and colorectal; while for females, they were breast, colorectal, thyroid and cervix uteri. Local stage at diagnosis was observed in 37.7% of cases. The highest incidence rates were observed in the District of Tunis and in the governorates of North East. The trend incidence cancer of all sites combined during the period from 1994 to 2009 was significantly risen except for stomach cancer among males and cervix uteri among females with annual percent changes of -2.5% and of -4.1% respectively.

Conclusions

Despite the existence of a national cancer strategy in Tunisia, many barriers affect the implementation of interventions; while the trend cancer incidence continues to rise particularly in males. Strengthening prevention strategy of this scourge is strongly recommended.

Key messages

Cancer is a major public health in world and in Tunisia. Prevention must be applied to reduce the incidence of cancer.

Current and future burden of prostate cancer in Tunisia projections to 2030

Introduction

Prostate Cancer is the second most common cancer among men worldwide. Current and future estimates on the burden of cancer are needed. The aim of this study was to assess prostate cancer burden in Tunisia in terms of disability adjusted life years (DALY) in 2017 and to perform projections by 2030.

Methods

DALYs for cancer are the sum of years of potential life lost due to premature mortality (Years Life Lost YLL) and the years lived with disability (YLD). Estimated data related to Burden of disease (Incidence rate, death rate, DALY, YLL and YLD)are obtained by the Institute for Health Metrics and Evaluation (IHME). Demographic data were provided by the National institute of statistics. The projection of DALYs for prostate cancer through 2030 was performed by a Poisson Regression analysis with Age -Period -Cohort (APC) using SPSS software, while using IHME estimated data for the period 1990-2017.

Results

In 2017, prostate cancer incidence rate and mortality rates among males in Tunisia were 24.17/100000 persons years and 7.08/100000 persons years respectively. Prostate cancer DALY values were 6548 (114 /100000). The number of YLLs was 5712 with a higher contribution of YLL in DALYS (87.2%). Without effective interventions, the number of DALYs due to prostate cancer would reach 10105 in 2030 with a standardized rate of 113/100000 persons years (IC 95% = [110/100000 to 116/100000].

Conclusions

The burden of prostate cancer in Tunisia in 2017 is relatively high and will still rising until 2030. This highlights the urgent need to focus resources on disease prevention and in the improvement of treatment.

Key messages

The burden of prostate cancer is high in Tunisia in 2017. Need to focus ressources on disease prevention and in the improvement of treatment.

Biodegradation ability of two selected microbial autochthonous consortia from a chronically polluted marine coastal area (Priolo Gargallo, Italy)

The aims of this study were: (i) the characterization of the structure of the indigenous microbial community associated with the sediments under study; (ii) the isolation and characterization of microbial consortia able to degrade the aged hydrocarbons contaminating the sediments, and (iii) the assessment of related biodegradation capability of selected consortia. Samples of surface sediments were collected in Priolo Gargallo harbour (Sicily, Italy). The samples were analysed for physical, chemical (GC-FID analysis) and microbiological characteristics (qualitative (16S rDNA clone library) and quantitative (DAPI, CFU and MPN count) analysis). The sediment samples were used for the selection of two microbial consortia (indicated as PSO and PSM) with high biodegradation capacity for crude oil (∼95%) and PAHs (∼63%) respectively. Genetic analysis showed that Alcanivorax and Cycloclasticus were the dominant genera in both the PSO and PSM consortia. Oil-polluted environments naturally develop an elevated biorecovery potential. The presence of a highly specialized microbial flora (adapted to support the contamination) and their stimulation through favourable induced conditions provides a promising recovery strategy. The chance to identify and select indigenous bacteria and/or consortia with a high biodegradation capacity is fundamental for the development and optimization of bioaugmentation strategies especially for those concerning in situ applications.

Composition and characterization by GC-MS of the essential oil extracted from

Fresh leaves of N. glauca were collected from the northern region of Tunisia. The leaves were submitted to water distillation for 4 h, using a Clevenger-type apparatus. The obtained essential oils were dried over anhydrous sodium sulphate and after filtration, stored at 4 °C until use. The chemical composition of the isolated essential oil was analyzed by gas chromatography–mass spectrometry (GC–MS). Eighteen compounds were identified: eugenol, the major compound in the essential oil, was present at a high level (58.49%), followed by nonadecane, eugenyl acetate and tridecane, 3-methyl at 6.38; 5.57 and 5.19%, respectively. The percentage of compounds dodecane, 2, 6, 11 trimethyl, tetradecane, docosane, tricosane and 1, 2-benzene dicarboxilic, dibutyl ester varied between 1 and 2%; whereas the other compounds (including limonene, and saturated hydrocarbons) remained at low percentages, not exceeding 1%. This study could be very useful for the characterization, pharmaceutical and therapeutic applications of the essential oil from N. glauca.

Radiation Therapy for Primary Eyelid Cancers in Tunisia

Management of eyelid cancers is based on surgery and/or radiotherapy (RT). The treatment objective is to control tumors with acceptable functional and esthetic outcomes. The aim of this study was to evaluate the results of radiation therapy in management of epithelial eyelid cancers, reviewing retrospectively the clinical records of patients treated in our institution from January 1989 to December 2013. We focused on clinical and histological features, treatment characteristics, tolerance and disease control. One hundred and eight patients (62 men and 46 women) were enrolled, with a mean age of 61 years [ranges 1587]. The most frequent tumor location was the inner canthus (42.6%). Median tumor size was 21 mm [ranges 470]. Histological type was basal cell carcinoma in 88 cases (81.5%), squamous cell carcinoma in 16 (14.8%) and sebaceous carcinoma in 4 (3.7%). Radiation therapy was exclusive in 67 cases (62%) and postoperative for positive or close margins in the remaining cases. Kilovoltage external beam radiotherapy (KVRT) was used in 63 patients (58.3%) and lowdoserate interstitial brachytherapy in 37 (34.3%). Eight (7.4%) were treated with cobalt or with a combination of KVRTcobalt, KVRTelectron beams, KVRTbrachytherapy or cobaltelectron beams. The total delivered radiation doses were 70 Gy (2 Gy/fraction) in 62 patients (57.4%), 66 Gy (2 Gy/fraction) in 37 (34.3%) and 61.2 Gy (3.4Gy/fraction) in 9 (8.3%). After a median followup of 64 months, we noted 10 cases of local recurrences(9.2%): 7 after exclusive and 3 after postoperative RT. No local recurrence occurred in patients treated with brachytherapy. Actuarial 5year local recurrencefree rate, diseasefree survival and overall survival were respectively 90%, 90% and 97%. Tstage was found to be a significant factor for recurrence (p=0.047). All acute radiationrelated reactions were scored grade I or II. Delayed effects were eye watering in 24 cases (22.2%), eye dryness in 19 (17.6%), unilateral cataract in 7 (6.4%) and ectropion in 4 (3.7%). Radiation therapy and especially brachytherapy is an efficient treatment of eyelid cancers, allowing eye conservation and functional preservation with good local control rates and acceptable toxicity.

[Evaluation of administration errors of injectable drugs in neonatology]

OBJECTIVE

Use of injectable drugs in newborns represents more than 90% of prescriptions and requires special precautions in order to ensure more safety and efficiency. The aim of this study is to gather errors relating to the administration of injectable drugs and to suggest corrective actions.

METHODS

This descriptive and transversal study has evaluated 300 injectable drug administrations in a neonatology unit. Two hundred and sixty-one administrations have contained an error. Data are collected by direct observations of administrative act.

RESULTS

Errors observed are: an inappropriate mixture (2.6% of cases); an incorrect delivery rate (33.7% of cases); incorrect dilutions (26.7% of cases); error in calculation of the dose to be injected (16.7% of cases); error while sampling small volumes (6.3% of cases); error or omission of administration schedule (1% of cases).

CONCLUSION

These data have enabled us to evaluate administration of injectable drugs in neonatology. Different types of errors observed could be a source of therapeutic inefficiency, extended lengths of stay or iatrogenic drug. Following these observations, corrective actions have been undertaken by pharmacists and consist of: organizing training sessions for nursing; developing an explanatory guide for dilution and administration of injectable medicines, which was made available to the clinical service. Collaborative strategies doctor-nurse-pharmacist can help to reduce errors in the medication process especially during his administration. It permits improvement of injectable drugs use, offering more security and better efficiency and contribute to guarantee ideal therapy for patients.

Allochthonous bioaugmentation in ex situ treatment of crude oil-polluted sediments in the presence of an effective degrading indigenous microbiome

Oil-polluted sediment bioremediation depends on both physicochemical and biological parameters, but the effect of the latter cannot be evaluated without the optimization of the former. We aimed in optimizing the physicochemical parameters related to biodegradation by applying an ex-situ landfarming set-up combined with biostimulation to oil-polluted sediment, in order to determine the added effect of bioaugmentation by four allochthonous oil-degrading bacterial consortia in relation to the degradation efficiency of the indigenous community. We monitored hydrocarbon degradation, sediment ecotoxicity and hydrolytic activity, bacterial population sizes and bacterial community dynamics, characterizing the dominant taxa through time and at each treatment. We observed no significant differences in total degradation, but increased ecotoxicity between the different treatments receiving both biostimulation and bioaugmentation and the biostimulated-only control. Moreover, the added allochthonous bacteria quickly perished and were rarely detected, their addition inducing minimal shifts in community structure although it altered the distribution of the residual hydrocarbons in two treatments. Therefore, we concluded that biodegradation was mostly performed by the autochthonous populations while bioaugmentation, in contrast to biostimulation, did not enhance the remediation process. Our results indicate that when environmental conditions are optimized, the indigenous microbiome at a polluted site will likely outperform any allochthonous consortium.

Evaluation of a new supraglottic airway device in ambulatory surgery: the I-gel

BACKGROUND

The I-gel® is a new single-use supraglottic airway device with a non-inflatable cuff. It is composed of a thermoplastic elastomer and a soft gel-like cuff that adapts to the hypopharyngeal anatomy. Its tube is profiled to facilitate and stabilize its insertion. aim : The aim of our study is to state the efficiency and the place of I-gel® in airway management in adult anaesthetic practice. methods: One hundred patients, ASA I-II, scheduled for shortduration elective surgery under general anaesthesia were included in this prospective study. Patients with neck pathology, previous or anticipated airway problems, increased risk of regurgitation or aspiration, ASA III and above and undergoing emergency surgery were not included in the study. We collected the following data: adequacy of the size recommended to the patient, ease in inserting the I-gel®, leak fraction, gastric leak, complications during insertion and removal, ease in inserting the gastric tube, haemodynamic and ventilatory parameters, stability during patient movement and satisfaction of the anaesthetists. results: The success rate of insertion and the use of the I-gel was respectively 99% and 96%. The device was inserted at the first attempt in 92% of cases. The introduction of the I-gel® was rated easy in 99% of cases taking a median of 13 seconds. Complications of insertion were restricted to coughing in 5 patients and hiccups in 7 patients. There were no significant increase in heart rate and mean arterial blood pressure compared to pre-insertion values. An audible leak was recorded in 14.6% of cases. The need for additional manoeuvres was less than or equal to 2 in 96.9 % of patients. The mean of the recorded peak airway pressure values was 18 cmH2O. After a fibreoptic exam via the airway tube, the glottis was completely seen in 74% of cases and partially seen in 14.6%. Two cases of gastric inflation were recorded. There was no case of regurgitation or hypoxemic episode during this trial. Post-operatively sore-throat was reported by one patient in recovery. After I-gel withdrawal, trace of blood was observed in 5 devices. One case of dental trauma was noted. 95% of the anaesthetists were satisfied with the use of the I-gel in their pratice.

CONCLUSION

This study showed that I-gel® can be used safely and effectively in patients undergoing short-duration elective surgery because the I-gel® has a very good insertion success rate and few complications. The fibreoptic position of the device was correct and the ventilation was highly effective. These elements must be corroborated in larger series.

[Predictive factors of esophagojejunal fistula after total gastrectomy in gastric cancer patients]

BACKGROUND

The main complication observed after total gastrectomy is the oesophagojejunal anastomosic fistla. Its incidence varies between 7.4% and 11.5%. The mortality after anastomic leafage is high at around 20%, representing 30% and 54% of global mortality after total gastrectomy.

AIM

This study aimed to evaluate mortality and morbidity after total gastrectomy and to determine their predictive factor

METHODS

this is retrospective study about 80 cases of total gastrectomy for gastric cancer, collected in the departmentof General Surgery of the University Hospital Habib Thameur Tunis during the period 1 January 1995 to 31 December 2010. Reconstruction of the alimentary tract was achieved by Roux-en-Y-jejunal-loop.

RESULTS

Esophagojejunal anastomotic leeakage developed in 14 patients (17%). In 8 patients treatment of anastomotic leakage consisted of re-operation with surgical drainage and confection of jejunostomy. in one patient treatment required resutre of the anastomosis and drainage of an abscess. In one patient treatment required resuture of the anastomosis and drainage of an abscess. in 5 of the 14 patients with a proven leak of oesophagojejunal anastomosis, conservative treatment with parental alimentation, placement of an irrigation-aspiration system and systemic antibiotics was performed. This treatment was successful in all cases. The presence of anastomic fistula extends the median lenght of post operative stay in the hospital of 20 days compared for the payents withiut fistula.Global mortalilty was 8/80 (10%). After esophagojejunal anastomotic leakage, the mortality was 3/8 (21%).

CONCLUSION

Leakage of the oesophago-intestinal anastomosis may occur after total gastrectomy for gastric cancer. it's serious complication contributes to mortality after total gastrectomy. Knowledge of the predective factors of esophagojejunal fistula after total gastrectomy in gastric cancer can decrease its incidence .

[Preeclampsia increases the risk of hyaline membrane disease in premature infant: a retrospective controlled study]

OBJECTIVES

Relation between preeclampsia (PE) and hyaline membrane disease (HMD) is still controversial. We found interesting to contribute to the study of this relation by comparing a HMD group to a control group with the aim to know if the risk to develop HMD was more important in case of PE.

MATERIAL AND METHODS

Two groups of premature infants (HMD group and control group) weighing less than 2000g and hospitalized between 1st January 2004 and 31st December 2005, were compared for data concerning mother (age, parity, diabetes, corticotherapy), PE (severity, complications, type and treatment), delivery (mode, infectious context, perinatal asphyxia) and neonatal stay (gestational age, birth, weight, sex). A multivariate analysis by logistic regression was used to control the effect of potential confounding variables that were considered risk factors for HMD.

RESULTS

Ninety-seven neonates were retained and were compared to 97 control. PE was present in 71 cases in HMD group and in 51 cases of control group. This difference was statistically very significant (p=0.003). When we controlled for confounding variables, there was a significant increase in risk to develop HMD (odds ratio, 1.3; 95% confidence interval, 0.7-1.8).

CONCLUSION

The risk to develop HMD, in premature infant weighing less than 2000g, is increased in case of PE. These finding support that fetal lung maturity is not accelerated in PE, in the opposite, it is delayed.

Heteroduplex structures in 16S-23S rRNA intergenic transcribed spacer PCR products reveal ribosomal interoperonic polymorphisms within single Frankia strains

AIMS

Detection of polymorphisms in intergenic transcribed spacer (ITS) 16S-23S rRNA within single Frankia strains.

METHODS AND RESULTS

Polymorphisms in the 16S-23S rRNA ITS were investigated in single-colony subcultures of seven Frankia isolates. Multiple ITS-polymerase chain reaction (PCR) bands were detected solely in isolates BMG5.5 and BMG5.11. The slow-migrating bands in the ITS-PCR agarose gel electrophoresis profiles of the isolates were revealed to be heteroduplexes on the basis of their migration shift in different electrophoretic matrices, southern hybridization and the single-strand DNA mung bean endonuclease digestion. Laser-scanned capillary electrophoresis detected two ITS-PCR fragments differing in length by three and six nucleotide insertions/deletions in strains BMG5.5 and BMG5.11, respectively. Sequence analysis of the cloned ITS showed that in strain BMG5.5 the two ITS differed by the presence of three to four copies of the 3-bp tandem repeat 5'-TGG-3'. In strain BMG5.11, the two ITS differed by the presence of two to three copies of the 6-bp tandem repeat 5'-CTTGGG-3'.

CONCLUSIONS

We demonstrate the occurrence of ITS 16S-23S rRNa polymorphisms within single Frankia strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

We reported the occurrence of ITS 16S-23S rRNA polymorphisms within single Frankia strains from Elaeagnus host group recognized as the more flexible strains within Frankia genus. Furthermore, we underscored the applied interest of strains BMG5.11 and BMG5.5 in future ecological studies using ITS 16S-23S rRNA as molecular marker.

[Vein of Galen aneurysmal malformation: a neonatal case with unusual evolution]

We report on a neonatal patient case with a cerebral vascular dilation consistent with a vein of Galen malformation diagnosed on an antenatal doppler ultrasound examination. Antenatal diagnosis was confirmed by fetal MRI scan. After delivery, cerebral MRI scan found the same dilatation and showed no cerebral parenchymal damage. The infant's condition was stable and particularly there was no congestive cardiac failure. Before discharge at ten days of age, clinical examination and particularly cardiac examination was normal. At 14 days of age, symptoms in relation to a congestive cardiac failure appeared. Echocardiography showed a high output cardiac failure with no cardiac malformation. Infectious laboratory tests were normal. Evolution was initially favourable after digitalo-diuretic treatment. Unfortunately, death occurred at 36 days of age due to intractable cardiac failure. This case highlights that, unusually, heart failure can occur long after the first days of life in cases of Galen vein aneurysmal malformation. The optimal time for vascular embolization in neonatal cases of Galen vein aneurysmal malformation is discussed.

Épidémie d'infection respiratoire à Pseudomonas aeruginosa O:12 résistante à l'imipénème dans une unité de réanimation néonatale à Tunis

OBJECTIVE

Investigation of an outbreak caused by an imipenem-resistant Pseudomonas aeruginosa strain and research of its hospital reservoir.

PATIENTS AND METHODS

Nine strains isolated from protected tracheal specimens during 14 weeks (October 2004 to January 2005) from 8 infants, and one strain from vacuum interrupter were studied. Epidemiological study was investigated by determination of antibiotics susceptibility, serotyping and Pulsed-field gel electrophoresis (PFGE).

RESULTS

Strains were of O:12 serotype, they have the same antibiotype characterised by imipenem resistance. Strains were indistinguishable or closely related as determined by PFGE. The common source of P. aeruginosa O:12 strains was not determined, however eradication of the epidemic strain was obtained by amelioration of hygiene conditions and the change of disinfectors.

CONCLUSION

Outbreak of respiratory infections due to an imipenem-resistant P. aeruginosa O:12. The common source of the epidemic strain was not determined.

The autolytic phenotype of the Bacillus cereus group

AIM

To determine the autolytic phenotype of five species in the Bacillus cereus group.

METHODS AND RESULTS

The autolytic rate of 96 strains belonging to five species in the B. cereus group was examined under starvation conditions at pH 6, 6.5 and 8.5 in different buffers. The autolytic rate was strain-dependent with a wide variability at pH 6, but higher and more uniform at pH 6.5. At pH 8.5, and respect to the extent of autolysis at pH 6.5, it was relatively low for most of the strains with the lowest values between 13 and 52% in Bacillus mycoides and Bacillus pseudomycoides. Peptidoglycan hydrolase patterns evaluated by renaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis using cells of Bacillus thuringiensis ssp. tolworthi HD125 as an indicator, revealed complex profiles with lytic bands of about 90, 63, 46, 41, 38, 32, 28 and 25 kDa in B. cereus, B. thuringiensis and Bacillus weihenstephanensis. Bacillus mycoides and B. pseudomycoides had simpler profiles with lytic bands of 63, 46 and 38 kDa. Changes in the autolytic pattern were observed for cells harvested at the stationary phase of growth (72 h) showing an increase in the intensity of the 25 kDa band in the case of B. cereus, B. thuringiensis and B. weihenstephanensis, while no changes were observed for B. mycoides. Using Micrococcus lysodeicticus and Listeria monocytogenes as indicators lytic activity was retained by proteins of 63, 46, 38, 32 and 25 kDa and a new one of about 20 kDa in B. mycoides. Growth in the different media did not affect the autolytic pattern. NaCl abolished the activity of all the peptidoglycan hydrolases except for those of B. mycoides and B. weihenstephanensis. Lytic activity was retained in the presence of MgCl(2), MnCl(2) and EDTA and increased at basic pH.

CONCLUSIONS

Bacillus cereus/B. thuringiensis/B. weihenstephanensis showed a high extent of autolysis around neutral pH, even though they presented relatively complex autolysin profiles at alkaline pH. Bacillus mycoides/B. pseudomycoides had a higher extent of autolysis at acidic pH and a simpler autolysin pattern.

SIGNIFICANCE AND IMPACT OF THE STUDY

Information on the autolytic phenotype expand the phenotypic characterization of the different species in the B. cereus group.

The autolytic phenotype of Bacillus thuringiensis

AIMS

To evaluate the autolytic phenotype of Bacillus thuringiensis.

METHODS AND RESULTS

The autolytic rate of 87 strains belonging to different subsp. of B. thuringiensis was examined at pH 6, 6.5 and 8.5 in different buffers under starvation conditions. At pH 6 the extent of autolysis (average in the strain collection 38.3 +/- 21.1) was strain-dependent with wide variability, while at pH 6.5 and 8.5 (averages 72.0 +/- 9.0 and 63.1 +/- 8.2, respectively) it was much more uniform with only a few strains showing low autolytic rates. Forty-one per cent of the strains showed high resistance (>/=80%) to mutanolysin, a commercial muramidase from Streptomyces. The peptidoglycan hydrolase pattern was evaluated by renaturing SDS-PAGE using cells of B. thuringiensis subsp. tolworthi HD125 as indicator. The strain collection showed seven major lytic bands of about 90, 63, 46, 38, 32, 28 and 25 kDa, and in the stationary growth phase (72 h) there was a more intense 25 kDa band in the autolytic pattern. Using Micrococcus lysodeicticus and Listeria monocytogenes as the indicators lytic activity was retained, as seen by the bands of 63, 46, 38, 32 and 25 kDa. Growth in the different media did not affect the autolytic pattern. NaCl abolished the activity of all the peptidoglycan hydrolases in the gel, but in the presence of KCl, MgCl(2), MnCl(2) and EDTA some activity was retained. At basic pH the lytic activity increased.

CONCLUSIONS

The autolytic phenotype of B. thuringiensis was found to be strain-dependent, and different proteins exibited peptidoglycan hydrolase activity, particularly at alkaline pH. Several of these proteins retained lytic activity against other bacterial species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The characterisation of the autolytic phenotype of B. thuringiensis should expand the prospects of using this species in bacterial bio-control and field applications.

Identification of glycerophospholipids in rapeseed, olive, almond, and sunflower oils by LC–MS and LC–MS–MS

HPLC employing a thermostatted Lichrospher 100 diol column was used to separate mixtures of glycerophospholipids of rapeseed, olive, almond, and sunflower oils. Elution was performed with a binary gradient of two mixed solvents A: hexane – isopropanol – acetic acid – triethylamine (82:17:1.0:0.08 v/v/v/v) and B: isopropanol – water – acetic acid – triethylamine (85:14:1.0:0.08 v/v/v/v). The LC effluent was directly introduced into the mass spectrometer through an electrospray capillary. Information about the fatty acid composition of each glycerophos pho lipid class was given by tandem mass spectrometry (MS–MS). These techniques permitted a rapid separation and identification of complex mixtures of glycerophospholipids. The relative abundance of each lipid class in each oil was also determined. The resulting glycerophospholipid signature may provide an efficient means of identifying oil origin and possible adulteration.Key words: glycerophospholipids, vegetable oils, tandem mass spectrometry, LC–MS.

Detection and characterization of the novel bacteriocin entomocin 9, and safety evaluation of its producer, Bacillus thuringiensis ssp. entomocidus HD9

AIMS

To identify and characterize new bacteriocins from a collection of 41 strains belonging to 27 subspecies of Bacillus thuringiensis, and to evaluate the safety of the producers.

METHODS AND RESULTS

Bacillus thuringiensis ssp. entomocidus HD9 produced in the culture supernatant an antimicrobial activity against Gram-positive bacteria including Listeria monocytogenes, one of four pathogenic Pseudomonas aeruginosa and several fungi. Production of the antibacterial activity, named entomocin 9, started during mid-logarithmic growth reaching its maximum at the early stationary phase. Entomocin 9 retained more than 72% of activity after incubation for 20 min at 121 degrees C. Activity was lost after proteinase K treatment, it was stable in a pH range between 3 and 9, and resistant to lyophilization. After partial purification with ammonium sulphate precipitation followed by gel-filtration and anion-exchange chromatography, an active protein of ca 12.4 kDa was isolated. The mode of action of entomocin 9 was bactericidal and caused cell lysis of growing cells. Despite the presence of a range of virulence related genes, including haemolysin BL, nonhaemolytic enterotoxin, cytotoxin K and several hydrolytic activities, B. thuringiensis HD9 was not toxic against Vero cells.

CONCLUSIONS

Entomocin 9 is a novel heat-stable, bacteriocin produced by B. thuringiensis HD9. The absence of toxicity against Vero cells suggests the suitability of strain HD9 for a safe application in antimicrobial treatments.

SIGNIFICANCE AND IMPACT OF THE STUDY

New finding on entomocin 9 would make B. thuringiensis attractive in biotechnological applications as an antimicrobial agent in agriculture and food industry.

[Diastematomyelia: antenatal diagnosis with successful outcome, two cases]

To discuss, through a review of the literature, clinical signification and antenatal and postnatal management of diastematomyelia. We present two cases highlighting the clinical presentation and discuss management options. The first case was diagnosed in a 32-year-old primagravida female physician. The conssanguinous couple had a history of primary hypofertility. Antenatal magnetic resonance imaging revealed the presence of a sagittal spinal spur separating two asymmetrical hemi cords. Pregnancy was not interrupted due to the lack of factors of poor prognosis. The infant was delivered at term and outcome has been favorable at 18 months follow-up. Ultrasonography performed at 22 weeks gestation provided the diagnosis in the second case. The mother was a 30-year-old primagravida anesthesist who had been addressed for suspected spina bifida. The consanguinous couple had a history of male hypoferility. The ultrasound scan revealed an echogenic spinal spur and integrity of the skin. Pregnancy was not interrupted due to the lack of factors of poor prognosis. The infant was delivered at term and outcome has been favorable at 18 months follow-up. Diastematomyelia is a rare malformation which can be diagnosed antenatally. Careful ultrasonography can distinguish diastematomyelia from myelomeningocele. Antenatal assessment is essential to identify forms with good prognosis because the neonatal outcome of isolated diastematomyelia is generally good, even if surgical repair is required.

Genetic relationship in the 'Bacillus cereus group' by rep-PCR fingerprinting and sequencing of a Bacillus anthracis-specific rep-PCR fragment

AIMS

To evaluate the genetic relationship in the Bacillus cereus group by rep-PCR fingerprinting.

METHODS AND RESULTS

A collection of 112 strains of the six species of the B. cereus group was analysed by rep-PCR fingerprinting using the BOX-A1R primer. A relative genetic distinctness was found among the species. Cluster analysis of the rep-PCR patterns showed clusters of B. thuringiensis strains quite separate from those of B. cereus strains. The B. anthracis strains represented an independent lineage in a B. cereus cluster. The B. mycoides, B. pseudomycoides and B. weihenstephanensis strains were clustered into three groups at some distance from the other species. Comparison of sequences of AC-390, a typical B. anthracis rep-PCR fragment, from 27 strains of B. anthracis, B. cereus, B. thuringiensis and B. weihenstephanensis, representative of different clusters identified by rep-PCR fingerprinting, confirmed that B. anthracis diverges from its related species.

CONCLUSIONS

The genetic relationship deduced from the rep-PCR patterns indicates a relatively clear separation of the six species, suggesting that they can indeed be considered as separate units.

SIGNIFICANCE AND IMPACT OF THE STUDY

rep-PCR fingerprinting can make a contribution in the clarification of the genetic relationships between the species of the B. cereus group.

[Pharmacologic study of monohydrated caffeine in the treatment of apnoea of premature infant]

Monohydrated caffeine was the only respiratory xanthine available in our country to treat apnea of premature infant. The aim of this study was to evaluate plasma levels of this molecule at dosages of 20 mg/kg (equal to 18 mg/kg of caffeine base) as a loading dose and 5 mg(-1) kg(-1) (equal to 4.5 mg(-1) kg(-1) of caffeine base) as a maintenance dose.

PATIENTS AND METHODS

The study was prospective including premature infants less than 34 weeks of gestational age born between the 1st of july 2001 and 15th december 2001 and receiving monohydrated caffeine to prevent apnea. Each premature infant has received orally a loading dose of 20 mg/kg in the first hours of life followed, 24 h after, by a maintenance dose orally once a day of 5 mg/kg until 35 weeks of post-conceptional age. Caffeinemia plasma levels were measured by high performance liquid chromatography immediately before the second dose to determine the loading residual rate and immediately before the sixth dose to determine the maintenance residual rate.

RESULTS

Twenty-one premature infants were included. Their medium term was 31.4 weeks (27.4-33.3 weeks), birth weight was 1684 g (1000-2800 g) and sex-ratio M/F was 1.3. Fifteen infants (71.4%) have presented apnea with an average of 4.1 episodes per infant and per day. Tolerance of the medicament was good in all cases. The medium loading residual rate was 3.26 microg/ml (1.75-7.80) and the medium maintenance residual rate was 4.26 microg/ml (2.13-7.64).

CONCLUSION

Prescribed at a dosage close to twice the recommendations of the literature, monohydrated caffeine does not provide efficient plasma rates. This is probably due to a difference in its oral bio-availability compared with caffeine citrate and further study with greater dosages is needed to appreciate its efficacy.

Characterization of a repetitive element polymorphism-polymerase chain reaction chromosomal marker that discriminates Bacillus anthracis from related species

AIMS

To identify a chromosomal marker with signature nucleotides specific for Bacillus anthracis.

METHODS AND RESULTS

Repetitive element polymorphism-polymerase chain reaction with BOX-A1R primer was used to discriminate 52 strains of all six species of the 'B. cereus group'. A B. anthracis signature fragment, named AC-390, was cloned and sequenced. The deduced amino acid sequence was homologous to that of YwfK of B. subtilis. Using two internal primers, the AC-390 fragment was sequenced from two other B. anthracis strains as well as from strains of B. cereus and B.thuringiensis which have an AC-390 fragment homologous to that of B. anthracis as shown by Southern hybridization experiments.

CONCLUSIONS

Two new signature sequences specific for B. anthracis were identified on a chromosomal fragment homologous to YwfK, a transcriptional regulator of B. subtilis.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results show a new chromosomal DNA trait useful for distinguishing B. anthracis from the related species of the B. cereus group, regardless of the presence of the virulence plasmids pXO1 and pXO2.

Autolytic phenotype of Lactococcus lactis strains isolated from traditional Tunisian dairy products

AIMS

To evaluate the autolytic properties of Lactococcus lactis strains isolated from artisan Tunisian dairy products, their peptidoglycan hydrolase content and their activity spectrum.

METHODS AND RESULTS

The autolytic phenotype of Lactococcus strains was evaluated under starvation conditions in potassium phosphate buffer. The results obtained highlighted a high degree of diversity among the strains analysed, allowing the identification of high and low autolytic Lactococcus lactis strains. Peptidoglycan hydrolase content was evaluated by renaturing SDS-PAGE using cells of Micrococcus lysodeikticus as a target for the enzymatic activity. A major activity band migrating at about 45 kDa was observed. The lytic activity, evaluated in the presence of different chemicals, was retained in 8% NaCl, 15 mmol l(-1) CaCl2, and in a pH range between 5 and 9.5. The substrate specificity of peptidoglycan hydrolase from Lactococcus strains was evaluated in renaturing SDS-PAGE incorporating cells of different bacterial species. The major autolysin of Lactococcus lactis was active against cells of Lactococcus lactis subsp. lactis, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus helveticus and Listeria monocytogenes.

CONCLUSIONS

Autolytic activity is widely distributed in Lactococcus lactis and the rate of autolysis is strain-dependent. The major peptidoglycan hydrolase showed a wide spectrum of activity against several lactic acid bacteria and bacterial species involved in food-related infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

The autolytic phenotype of Lactococcus lactis strains isolated from Tunisian artisan dairy products has been determined, and the data obtained should allow the selection of strains of technological interest in the cheese-ripening process.