[Use of multilocus sequence typing and pulsed-field gel electrophoresis for the study of serogroup B Neisseria meningitidis isolates from Casablanca (Morocco)]. / Etude de souches de Neisseria meningitidis sérogroupe B isolées à Casablanca par multilocus sequence typing et électrophorèse en champ pulsé.

A previous study showed that B:4:P1.15 was the most frequent phenotype of Neisseria meningitidis isolated in Casablanca (Morocco). To determine if there was an epidemic clone, MLST and PFGE were used to compare 13 B:4:P1.15 strains isolated from September 1999 to December 2000. MLST showed 4 Sequence Types (ST): ST-33 was the most frequent ST (9/13 strains) and 4 strains belonged to 3 newly described STs. Twelve stains belonged to ST-32 complex, and one strain presenting a new ST (ST-2502) did not belong to any known ST complex. The analysis by PFGE showed that the strains were subdivided into 7 clusters, and that there was no epidemic clone. MLST is useful for long-term epidemiological studies on N. meningitidis strains from varied geographical origins. PFGE seemed to be well adapted to the comparison of a small number of strains isolated during a short period within a defined community.

IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolates from an area of Casablanca, Morocco.

Using IS6110 RFLP, 61 isolates recovered from new cases of pulmonary tuberculosis (TB) were compared from September to December 1999 in Casablanca, Morocco, a city with a high incidence of TB. The majority of the isolates (92%) harboured 6-14 copies of IS6110. The minimal fraction of patients in groups of recently acquired infection is 13.1%. This preliminary study showed that IS6110 RFLP is a suitable method for finger-printing Mycobacterium tuberculosis in Casablanca. The unexpectedly low level of recent transmission of TB found in this study deserves further studies involving higher numbers of isolates recovered during a longer recruitment period.

Molecular biology of extended-spectrum beta-lactamase-producing Enterobacteriaceae responsible for digestive tract colonization.

Twenty-nine extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae strains (14 Klebsiella pneumoniae, 10 Escherichia coli and five Citrobacter diversus) isolated from April to July 1996 from faecal carriers in a surgical intensive care unit at the university hospital of Casablanca (Morocco) were studied. Plasmid content and DNA macrorestriction polymorphism determined by pulsed-field gel electrophoresis (PFGE) were used to compare the strains. Restriction profiles of total genomic DNAs cleaved by XbaI and compared by PFGE revealed nine, four and two clones in K. pneumoniae, E. coli and C. diversus, respectively. Plasmid profile analysis of ESBL-producing strains of K. pneumoniae showed that only seven of 14 isolates had a plasmid; four different plasmid profiles were observed. Three different plasmid profiles were observed in E. coli and two in C. diversus. Plasmids responsible for ESBL production could be transferred by conjugation to E. coli K(12) J53-2 from all E. coli isolates and from four of seven K. pneumoniae. No plasmid transfer could be obtained from C. diversus strains. Restriction enzyme digests of plasmids from transconjugants (four transconjugants of K. pneumoniae and five transconjugants of E. coli) showed different patterns. In the surgical intensive care unit where the survey was conducted, the dissemination of ESBLs was due to a mix of strain spread and strain diversity rather than to plasmid dissemination.

Assessment of the Mycobacteria Growth Indicator Tube for the bacteriological diagnosis of tuberculosis.

Fast, accurate diagnosis is necessary for rapid treatment of patients and to prevent the spread of Mycobacterium tuberculosis strains. The rate of recovery, mean time to detection and contamination rates of the Mycobacteria Growth Indicator Tube (MGIT) were compared with Lowenstein-Jensen (LJ) medium for mycobacterial cultures performed on 405 clinical specimens decontaminated by the trisodium phosphate method without benzalkonium chloride. The recovery rate of M. tuberculosis using MGIT was 45/61 (73.8%) compared with the reference LJ. The mean times to detection of M. tuberculosis in smear-positive specimens were 11.9 days with MGIT and 20 days with LJ. For smear-negative samples, the mean times were respectively 18.6 and 31 days, and the contamination rates were respectively 4% and 1.2%. When the trisodium phosphate decontamination method is used, MGIT cannot be used alone for isolation of mycobacteria, but may be used in combination with LJ.

Serogroups, serotypes, serosubtypes and antimicrobial susceptibility of Neisseria meningitidis isolates in Casablanca, Morocco.

Since antigenic characterization and antibiotic susceptibility testing are useful for generating prophylactic recommendations and treatment guidelines, a total of 163 Neisseria meningitidis isolates obtained between January 1992 and September 2000 at the microbiology laboratory of the IbnRochd University Hospital of Casablanca, Morocco, were serogrouped, serotyped, serosubtyped and tested for their susceptibility to five antibiotics. Serogroup B was detected most frequently (75.5%), followed by serogroup A (13.5%). The phenotype B:4:P1.15 represented 74.8% of all serogroup B isolates. Seven (4.3%) isolates demonstrated decreased susceptibility to penicillin G. All isolates tested were susceptible to cefotaxime, chloramphenicol and rifampin. All isolates were inhibited by spiramycin at a concentration of 0.4 mg/l.

[In vitro evaluation of antileishmania activity of Artemisia herba alba Asso]. / Evaluation in vitro de l'activité antileishmanienne d'Artemisia herba-alba Asso.

Aqueous extract and essential oil of Artemisia herba-alba Asso were tested for their antileshmanial activity again Leishmania tropica and Leishmania major. The strongest leishmanicidal activity was observed with the essential oil at 2 micrograms/ml as versus the other two strains tested. The aqueous extract showed an antileshmanial activity at 4 micrograms/ml.

Molecular techniques open up new vistas for typing of coagulase-negative staphylococci.

Several methods were used to type 64 clinical isolates of coagulase-negative staphylococci (CNS) derived from hospitals in Morocco. The clinical isolates originated principally from blood cultures and wound sources. These isolates provided the opportunity to substantially compare the proficiency of developing molecular techniques with conventional phenotypic tests for use in the identification of clinical staphylococci. The following molecular methods were examined: Utility ribotyping analysis (Ribotyping); PCR analysis performed with 16S-23S ribosomal-DNA intergenic spacer (ITS-PCR); PCR-based random amplified polymorphic DNA (RAPD). The results obtained by the molecular techniques were contrasted to those of conventional phenotypic tests. Conventional phenotypic tests allowed the outright recognition of the majority of isolates (50/64). These 50 isolates were subdivided into 33 novobiocin-susceptible and 17 novobiocin-resistant strains of CNS. However, 2 other novobiocin-susceptible and 12 other novobiocin-resistant isolates remained unclassified by these tests. There was a good agreement between the conventional phenotypic tests and RAPD for the 33 novobiocin-susceptible isolates. But, the RAPD technique permitted the assignment of the two unidentified novobiocin-susceptible isolates to the Staphylococcus hominis species. A complete correlation was obtained between the three molecular tools for recognition of the 12 novobiocin-resistant isolates that were not identified by phenotypic typing; these were in fact identified as 5 Staphylococcus cohnii and 4 Staphylococcus equorum. Three isolates remained unidentified by all three systems of molecular techniques.

Relationship of Staphylococcal isolates in a Moroccan hospital by comparing phenotypical and genotypical tests.

The relationship of Staphylococcus isolates was determined among a collection of 26 clinical strains at the Centre Hospitalier Universitaire de Rabat. These isolates originated principally from blood culture and wounds. In order to affirm the clonal origins of these isolates, six phenotype (biotype, anti-biotype, serotype, phage type), and genotype (random amplified polymorphic DNA, pulsed field gel electrophoresis) methods were used. Biotyping, anti-biotyping, phage and serotyping were generally not sufficient while many isolates remained non-phage typeable. Random amplified polymorphic DNA analysis used in epidemiological typing seemed suitable for S. epidermidis and S. haemolyticus. However, rigorous standardization will be needed to assure reliable results. Pulsed field gel electrophoresis discriminated more efficiently than random amplification polymorphic DNA analysis. This study attests to the suitability of two or more methods in combination for typing Staphylococcus isolates.

Serological, clinical and histopathological changes in naturally infected dogs with Leishmania infantum in the Khemisset province, Morocco.

Canine leishmaniasis (canL) is widespread in the north of Morocco and the Leishmania infantum local strains are highly virulent. An epidemiological survey was carried out in 1993-1995 in the Khemisset province. In this region, the severity of the disease was assessed during regular visits to the identified foci by clinical examination of 323 dogs. Clinical signs were protean and occurred in various combinations. Biopsies were made on available sick dogs; the main histological changes were severe infiltration of the spleen, lymph nodes and bone marrow by mononuclear cells and hyperplasia of macrophage cells with amastigotes in their cytoplasm. The seroprevalence among 323 dog sera tested by ELISA showed a rate of 16.71%. The highest prevalence of the disease was 23.6% in the Sid El Ghandour hamlet. A comparison of the results of this study with those from the year following the first examination on the same site (Sid El Ghandour) of 67 dogs showed that the disease prevalence had not increased significantly (23.6% to 25.33%).

Distribution of Staphylococcus sciuri subspecies among human clinical specimens, and profile of antibiotic resistance.

The distribution of three subspecies comprising Staphylococcus sciuri was determined for a collection of 30 clinical isolates originating from Morocco, the United Kingdom, and France. The sources of these isolates were principally wounds, skin, and soft tissue infections. At the species level, the isolates were identified according to biochemical characteristics and at the subspecies level by the ribotyping technique. PCR analysis performed with the 16S-23S ribosomal DNA intergenic spacer was less powerful for subspecies differentiation. S. sciuri subsp. sciuri was the most frequent subspecies (21 isolates) found in the collection, whereas S. sciuri subsp. rodentium (seven isolates) and S. sciuri subsp. carnaticus (two isolates) were less common. mecA or a mecA-related gene was detected by PCR and Southern blot in all 30 S. sciuri isolates, supporting the suggestion that S. sciuri species are the natural reservoir of the mecA gene. While the linA/linA' gene coding for lincomycin resistance was present in five isolates, an uncharacterized gene for this resistance was suspected in seventeen other isolates.

Methoxybifurcarenone: an antifungal and antibacterial meroditerpenoid from the brown alga Cystoseira tamariscifolia.

A meroditerpenoid metabolite has been isolated from the brown alga Cystoseira tamariscifolia and characterized as methoxybifurcarenone, by spectral analysis. Methoxybifurcarenone possesses antifungal activity against three tomato pathogenic fungi: Botrytis cinerea, Fusarium oxysporum sp. mycopersici and Verticillium alboatrum and antibacterial activity against Agrobacterium tumefaciens and Escherichia coli.

Investigation of bioactivity of extracts from Moroccan solitary tunicate Cynthia savignyi.

Extracts of the tunicate Cynthia savignyi from the Moroccan Atlantic sea have been investigated in five bioassays. The first is an antibacterial test against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Agrobacterium tumefaciens; the second is an antifungal test against three tomato pathogenic fungi, Botrytis cinerea, Fusarium oxysporum and Verticillium albo-atrum; the third is a test based to the ability to reduce DNA peak size in procedures using an HPLC system for detection of antitumour agents; the fourth is a toxicity test using larva of Artemia salina; and the last is an enzymatic inhibitory test against papain and trypsin. For all the bioassays, extracts of C. savignyi were found to be bioactive. This result suggests that this tunicate is able to produce biologically active agents required for an overall defence against their predators.

A simple method for the evaluation of antiseptic and disinfectant virucidal activity.

A simple method for evaluating the virucidal activity of water-soluble antiseptic and disinfectant products using poliovirus type 1 (Sabin strain) is described. Using a commercial concentrator, kinetic studies of four products were carried out. It was shown that 2% glutaraldehyde and 5% povidone iodine are rapidly virucidal. 0.2% glutaraldehyde and 2.5% noxythiolin (37 degrees C) are considerably less effective. 0.05% chlorhexidine digluconate has no virucidal activity.

[In vitro virucidal activity of antiseptics and disinfectants. III. Dilution-ultrafiltration-reconcentration technic]. / Activité virucide in vitro des antiseptiques et désinfectants. III. Technique par dilution-ultrafiltration-reconcentration.

The method for in vitro investigation of virucidal activity of antiseptics (ATS) of disinfectants (DSF) using dilution-ultrafiltration-reconcentration includes two phases following contact of the virus with ATS or DSF: termination of antiviral activity by sudden cold dilution, and one or more filtrations on an immersible molecule separator designed to bring the tested agent's concentration below the cytotoxic level and to reconcentrate the treated viral suspension. Advantages of this technique are the following: precision of time of contact between virus and ATS or DSF, reconcentration of the viral suspension which partly offsets the termination dilution, relative simplicity, and study of true virucidal activity. Drawbacks are: inappropriateness for some agents such as povidone-iodine, and, in some instances, unreliability of immersible separators. Apart for those obtained with povidone-iodine, results are comparable to those yielded by simple dilution or gel filtration, particularly for glutaraldehyde, chlorhexidine and noxythiolin.