Prevalence of Vibrio spp. in raw shrimps (Parapenaeus longirostris) and performance of a chromogenic medium for the isolation of Vibrio strains.

UNLABELLED: Vibrios are natural inhabitants of estuarine ecosystems and some species may pose public health problem as agents of sporadic or collective food-borne infections associated with the consumption of fish or shellfish. Samples of raw shrimp (n = 299), fished in coastal areas of the city of Agadir, Morocco, and collected from its fish marketplace, were examined for the presence of pathogenic vibrios. Microbiological analysis was carried out according to a protocol using thiosulphate citrate bile sucrose (TCBS) agar and CHROMagar Vibrio (CV) as selective media. Presumptive-positive colonies were identified by biochemical and species-specific PCR systems, and further tested by PCR for the presence of pathogenicity factors. The overall prevalence of Vibrio spp. in shrimps was 55·8%. Vibrio parahaemolyticus was recovered from 25 of 299 samples (8·4%), Vibrio cholerae from six samples (2%) and Vibrio alginolyticus from 161 samples (53·8%). No virulence genes were found among V. parahaemolyticus and V. cholerae isolates. The CHROMagar Vibrio plating medium was found to be more efficient than the Thiosulphate Citrate Bile salt Sucrose (TCBS) Agar in the isolation of Vibrio organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: A significant proportion of shrimps marketed and consumed in Morocco are caught in the coastal region of the city of Agadir. This study provides interesting data of prevalence of Vibrio spp. in raw shrimps as well as better understanding of their potential virulence. It is apparent from this study that genes and primers used in multiplex PCR for identification and detection of virulence factors, can be used to monitor shrimps for the presence of potentially pathogenic strains of Vibrio cholerae and Vibrio parahaemolyticus. The results highlight the added value of using a chromogenic medium for research and isolation of pathogenic Vibrio in seafood, more specific and accurate than TCBS.

[Progression of diabetic retinopathy after cataract surgery by phacoemulsification]. / Évolution de la rétinopathie diabétique après chirurgie de la cataracte par phacoémulsification.

PURPOSE: To study the effect of cataract surgery by phacoemulsification and intraocular lens implantation on the progression of diabetic retinopathy (DR) using the nonoperated fellow eye as a control, by a retrospective comparative study. PATIENTS AND METHODS: We studied 46 diabetic patients who underwent monocular cataract surgery by phacoemulsification with implantation of an intraocular lens within the capsular bag, with the nonoperated fellow eye used as a control. In all cases, the fellow eye exhibited only a very mild cataract, allowing for visualization of the fundus. Preoperative and 1, 3, 6 and 12 months postoperative ophthalmic examination and fundus photographs, supplemented if necessary by retinal fluorescein angiography, were performed to assess DR using the Alfediam classification. Patients were followed for at least 1 year. RESULTS: Among the 46 patients, preoperative DR was absent in 40 patients, and six patients had bilateral, symmetric non-proliferate diabetic retinopathy (NPDR): mild in four patients, moderate in one patient and moderately severe in another patient. Thirty-five eyes (76%) had postoperative best corrected visual acuity of 8/10 or better. Progression of DR occurred at about 23.9% (11/46) in the operated eyes and 19.6% (9/46) in the nonoperated eyes. As compared by the MacNémar test, there was no significant difference between operated and nonoperated eyes (P=0.68). CONCLUSION: This study demonstrates that cataract surgery by phacoemulsification does not represent an apparent risk factor for progression of DR.

[Amyloid goiter: first sign of systemic amyloidosis]. / Goitre amyloïde : première manifestation d'une amylose systémique.

Although amyloid infiltration of the thyroid gland is an uncommon but well-known phenomenon, the appearance of a goiter secondary to amyloid deposits is rare. The goiter enlarges rapidly and progressively, often becoming compressive like thyroid cancer. The diagnosis is rarely suggested clinically even in the presence of known amyloidosis. We describe the case of a 45-year-old patient who presented an amyloid goiter as the first manifestation of systemic amyloidosis, probably secondary to bronchiectasis.

[Beta interferon and thyroid]. / Interféron bêta et thyroïde.

We report the case of a thyroiditis in a 44-year-old woman with relapsing-remitting multiple sclerosis treated with interferon beta. Before treatment, thyroid function tests were normal and anti-thyroid (anti-thyroglobulin and anti-thyroid peroxidase) antibodies were negative. After 18 months of treatment, the patient presented clinical features of thyroiditis. We noted a rise in TSH values and anti-thyroid antibodies were found positive. Treatment was not discontinued and further surveillance showed an improvement in clinical and biological features. We conclude that thyroid function should be monitored during INF beta treatment. Laboratory tests must be carried out before therapy. Clinical follow-up is indicated before undertaking biological tests.

[Pure gonadal dysgenesis XX and XY: observations in fifteen patients]. / Dysgénésies gonadiques pures XX et XY: à propos de 15 cas.

BACKGROUND: Pure gondal dysgenesis is characterized by impuberism with a female phenotype without genital ambiguity. The aim of the study is to describe the diagnostic and therapeutic patterns as well as the clinical features. PATIENTS AND METHODS: A retrospective study of 15 patients with pure gonadal dysgenesis (15 patients, 46 XX and two 46 XY). Clinical parameters, familial cases, serum gonadotropin levels, pelvic ultrasonography, endoscopic data, karyotype, analysis of SRY (sex determining Y chromosome) and therapeutic control and clinical course were recorded. RESULTS: Average age at diagnosis was 21+/-2.83 years. Primary amenorrhea was the most frequent reason for consultation. A familial case was found in five patients. The association of sensorineural deafness was noted in one patient, suggesting Perrault's syndrome. Serum gonadotropin levels were elevated. Celioscopic evaluation carried out for six patients confirmed the diagnosis. There was one case of uterine and vaginal aplasia association (Mayer-Rokytansky-Küster-Hauser syndrome). In one XY patient, SRY analysis was normal. Prophylactic gonadectomy was performed in both XY patients. Substitution therapy was initiated in 11 patients. Follow-up in 6 patients revealed development of secondary sexual characters. DISCUSSION: The clinical, biological and histological features of our patients presenting pure gonadal dysgenesis XX were in agreement with earlier reports in the literature. Familial cases suggest possible autosomal transmission. The lack of a mutation in XY patients suggests a post-transcription anomaly. Complete or parital dysgenesis can be identified by histological analysis of the gondads. CONCLUSION: Study of sex determining genes should provide new perspectives for earlier diagnosis and treatment of pure gondadal dysgenesis.

Performance of a new chromogenic plating medium for the isolation of Listeria monocytogenes from marine environments.

AIMS: This study investigated the performance of a new chromogenic plating medium for the detection of Listeria monocytogenes from naturally contaminated samples obtained from marine environments in Morocco in comparison with the conventional plating media PALCAM and Oxford. METHODS: A total of 479 marine samples (sea water, sediment and mussels) were collected from 16 littoral sites in the region of Agadir (western centre of Morocco). They were examined for the presence of L. monocytogenes using a slight modification of the standardized French method (AFNOR V 08-055) for the detection of L. monocytogenes from food and three different isolation media: PALCAM, Oxford and a new chromogenic plating medium. RESULTS AND SIGNIFICANCE OF THE STUDY: The Oxford and the new chromogenic plating media were found relatively more efficient than the PALCAM medium for the isolation of L. monocytogenes (chi-square test, P < 0.05) from marine samples. However, the new chromogenic plating medium was significantly more selective for L. monocytogenes (P < 0.005) than the two other isolation media as 87.5% of the suspect colonies on this medium were indeed confirmed through identification of the isolates vs 12.7% for Oxford and only 3.8% for the PALCAM medium.

[Gonadal dysgenesis associated with Mayer-Rokitansky-Küster-Hauser syndrome: a case report]. / Association dysgénésie gonadique et syndrome de Rokitansky Kuster Hauser: à propos d'un cas.

Gonadal dysgenesis with female phenotype is defined as the absence or insufficient development of the ovaries. Hypogonadism or impuberism are variable, depending on the degree of gonadal development. Mayer-Rokitansky-Küster-Hauser syndrome is a rare malformative anomaly (1/5000 women) associating uterine and vaginal aplasia with normal ovaries. We report the case of a 19-year-old woman who presented primary amenorrhea and impuberism. Hormone assay revealed hypergonadotrophic hypogonadism. The karyotype was normal, 46XX. Internal genitalia could not be identified on the pelvic ultrasound. Laparoscopy was undertaken and revealed concomitant ovarian dysgenesis and Mayer-Rokitansky-Küster-Hauser syndrome. There were no other morphological malformations. An association between these two conditions is very exceptional and appears to be coincidental, independent of chromosomal anomalies. Hormone substitution therapy remains the only therapeutic option. Hormone substitution is aimed at triggering the development of secondary sexual characters and prevent osteoporosis. There remains the unsolved problem of infertility.

Noise-free holographic storage in iron-doped lithium niobate crystals.

We show that fanning noise in lithium niobate crystals can have a deleterious effect on holographic storage in configurations in which the c axis and the grating wave vector coincide, for both ordinary and extraordinary light polarizations. We then demonstrate that this noise is drastically reduced when the c axis is perpendicular to the grating wave vector. Images have been fixed and read out for many hours at high intensity levels, demonstrating long-term storage and good-quality image recall.

Occurrence of Listeria monocytogenes in Milk and Dairy Products Produced or Imported Into Morocco.

Examination of 227 samples of milk and dairy products for Listeria monocytogenes showed that raw milk and some Moroccan traditionally made dairy products such as Iben and raib (fermented milks) and jben (fresh cheese) were contaminated with this pathogen. L. monocytogenes was the only Listeria species isolated except in one case in which it was associated with Listeria innocua . Pasteurized milk, fresh cream, and fresh and ripened cheeses (industrially made) were free from L. monocytogenes .

Occurrence of Yersinia enterocolitica in milk and dairy products in Morocco.

A total of 227 samples of milk and dairy products were examined for the presence of Yersinia enterocolitica. Yersinia spp. were recovered from 11 of 30 raw milks (36.6%), one of 20 pasteurized milks (5%), 15 of 63 traditional fermented milks (23.8%), seven of 94 cheeses and one of 20 cream samples (5%). The overall incidence of Y. enterocolitica in milk and dairy products was 6.6%. The other Yersinia species were Y. intermedia, Y. kristensenii, Y. frederiksenii and Y. pseudotuberculosis. Y. enterocolitica was detected only in raw milk (30% of the samples), in traditional fermented milks (6.3%) and in raw milk-made cheese (4%). The majority of the Y. enterocolitica isolates were of biotype 1 (environmental strains). The Celfulodin-Irgasan-Novobiocin (CIN) Agar was found to be more efficient than the Mac Conkey Agar in the isolation of Yersinia organisms.

Photorefractive particle image velocimetry: performance enhancement with bismuth silicon oxide crystals.

The polarization properties of diffraction from bismuth silicon oxide crystals are used to enhance the signal-to-noise ratio of a photorefractive particle image velocimeter. We explain these diffraction characteristics by using a simple picture of the processing steps and the beam-propagation method, accounting for the multiplicity of the recorded gratings. Experimental measurements are also presented.

Programmable coherent source arrays generated by spatial light modulators.

Programmable coherent source arrays are generated by using addressable liquid-crystal spatial light modulators and two-dimensional arrays of Fresnel lenses. The modulators used are an optically addressed liquid-crystal light valve, a matrix-addressed pixelated display, and two devices that have individually addressable elements with specially designed patterned electrodes. One such device has a transparent electrode patterned as a Fresnel zone plate array; the other is a gate array used in a hybrid implementation with a Fresnel lens array etched on a glass substrate. The operation of devices that use binary-amplitude and binary-phase Fresnel lenses is described, identifying programmable features, resolution limits, and applications.

A bacteriological survey of an oyster-growing area: The Oualidia Lagoon, Morocco.

A 3-year bacteriological survey of an oyster-growing area in Morocco, where the Japanese oyster (Crassostrea gigas) is grown, showed that the contamination of this lagunar ecosystem was not continuous but intermittent and that animal manure and human recreational activities were important sources of pollution. The major source of contamination was of animal origin, except during the summer, when human contamination prevailed.

Fan-in issues in a holographic grating interconnect system.

Coherent holographic grating interconnect systems exhibit deleterious interference effects when multiple optical beams are fanned into a single beam with the use of multiplexed gratings. Elimination of such effects is possible with the use of arrays of incoherent sources for readout, temporal sequencing, random phase modulation of the readout beams, or allocated volume configurations. The merits and drawbacks of each alternative are analyzed.

Generation of programmable coherent source arrays using spatial light modulators.

We demonstrate and characterize arrays of coherent focused spots generated by writing multiple Fresnel zone plates on optically and electrically addressed modulators. The programmable parameters of the array are its size (number of generated spots) and the transmissivity and focal length of each lens. As expected, phase modulators have a better conversion efficiency than amplitude modulators do.

Binary phase Fresnel lenses for generation of two-dimensional beam arrays.

Two-dimensional arrays of mutually coherent optical beams are needed in holographic interconnections for both recording and reading gratings. We analyze the use and limitations of binary phase Fresnel lenses to generate beams for these applications. Two known techniques of ion beam milling and thin film deposition are compared to fabricate such lens arrays in SiO(2) and Si(3)N(4). Each lens in the 8 x 8 arrays has a 1.2-mm square aperture with a focal length of 20 mm. Diffraction of a single argon-ion beam into an 8 x 8 array of highly uniform coherent focused beams (with 12-microm spot size) was achieved by the lenses with an efficiency of approximately 30% (41% theoretical limit).

Optoelectronic chip implementation of a quadratic associative memory.

High-order associative memories are of interest because of their potentially large storage capacity. We describe an optoelectronic implementation of a second-order, or quadratic, associative memory. The two-layer network is based on an inner-product representation, which allows for a compact implementation using an optical chip design. Experimental results obtained from our system are discussed.

Sensory, Chemical, and Microbiological Assessments of Moroccan Sardines ( Sardina pilchardus ) Stored in Ice.

Sensory, chemical, and microbiological analyses were carried out on sardines during 18 d of storage in ice. Sensory results indicate that the sardines used in this experiment had a shelf life of 9 d. The pH and dimethylamine (DMA) were found to be useless in determining the degree of sardine deterioration, while trimethylamine (TMA) and total volatile bases (TVB) were accurate in predicting the spoilage process. Histamine production was slowed by refrigeration in ice (2-4°C). The amounts of histamine in flesh at the time of rejection (12th day of storage) were 11.7 and 16.2 mg/100 g of flesh, respectively, with the colorimetric method and the fluorimetric method. At the end of the experiment (highly spoiled sardines), the critical value of histamine (20 mg/100 g) was not reached. However, at the 12th d of storage, the count of all microflora studied was above the limit of 106 CFU/g of flesh.