Traitement chirurgical du Mal de Pott et de ses séquelles au Centre Hospitalier de l'Ordre de Malte Dakar / Surgical treatm ent of Pott's diseaseand its sequelae at the Hospital of the Order of Malta/Daka

Introduction. Evaluer les résultats du traitement chirurgical du Mal de Pott et de ses séquelles au Centre hospitalier de l'ordre de Malte de Dakar. Patients et méthodes. Nous présentons les résultats préliminaires d'une série consécutive de 23 patients (13 hommes et 10 femmes) d'âge moyen de 32,35 ans [6 ­70 ans] présentant des Maux de Pott ou de leurs séquelles nécessitant un traitement chirurgical. L'échelle d'incapacité d'Oswestry, l'échelle visuelle analogique et le score ASIA ont été utilisés pour l'évaluation clinique. Les radiographies pré opératoires, post opératoires et au recul ont été utilisés pour les résultats anatomiques. Tous ces patients ont été opérés selon trois stratégies opératoires sur une période de 67 mois (Avril 2014- Novembre 2019). Nous avons réalisé une laminectomie arthrodèse postérieure dans 52,2% ; une laminectomie plus OTP et arthrodèse postérieure dans 43,5% ; une discectomie et hémicorporectomie avec arthrodèse antérieure par plaque vissée de Roy Camille à l'étage cervical dans 4,3%. Résultats. La symptomatologie était dominée par la douleur rachidienne, la cyphose et les troubles neurologiques. La cyphose post opératoire était significativement améliorée (la moyenne passe de 48,52° en pré opératoire à 17,09° en post opératoire). On a obtenu 100% de fusion vertébrale. On note une nette amélioration de la douleur rachidienne (avec une baisse au recul de 55,44 points pour l'OID et de 5,66 pour l'EVA) ; 78,3% des patients étaient très satisfaits, 17,4% satisfaits et 4,3% mécontents. Conclusion. Le traitement chirurgical du Mal de Pott et de ses séquelles a fortement amélioré les rachis au Centre hospitalier de l'Ordre de Malte.

Introduction. To evaluate the results of the surgical treatment of Pott's disease and its sequelae at the Hospital Center of the Order of Malta in Dakar. Patients and methods. We present the preliminary results of a consecutive series of 23 patients (13 men and 10 women) with an average age of 32.35 years [6-70 years] presenting with Pott's disease or its sequelae requiring treatment. surgical treatment. Oswestry Disability Scale, Visual Analogue Scale and ASIA score were used for clinical assessment. Preoperative, postoperative and followup radiographs were used for anatomical results. All these patients were operated according to three operating strategies over a period of 67 months (April 2014- November 2019). We performed posterior laminectomy-arthrodesis in 52.2%; laminectomy plus OTP and posterior arthrodesis in 43.5%; discectomy and hemicorpectomy with anterior arthrodesis by Roy Camille screwed plate at the cervical level in 4.3%. Results. The symptomatology was dominated by spinal pain, kyphosis and neurological disorders. Postoperative kyphosis was significantly improved (the average goes from 48.52° preoperatively to 17.09° postoperatively). We got 100% spinal fusion. There is a clear improvement in spinal pain (with a drop at follow-up of 55.44 points for the OID and 5.66 for the EVA); 78.3% of patients were very satisfied, 17.4% satisfied and 4.3% dissatisfied. Conclusion. The surgical treatment of Pott's disease and its sequelae greatly improved the spines at the Hospital Center of the Order of Malta.

Irreducible posterolateral elbow dislocation: A case report.

Elbow dislocations are very common, particularly in the posterolateral variety. Closed reduction is usually easy. However, an irreducible elbow dislocation without associated fracture is rare. We report the case of a 21-year-old patient who presented with an isolated posterolateral irreducible elbow dislocation. Open reduction revealed the buttonhole radial head in the capsule and the complex ligaments. A significant protrusion of the radial head associated with a closed reduction failure is highly suspicious of an irreducible dislocation.

[Performance of magnetic resonance imaging ang genourob laximetry in anterior cruciate ligament rupture in 30 cases]. / Performance de l'imagerie par resonance magnetique et de la laximetrie a genourob dans les ruptures du ligament croise anterieur a propos de 30 cas.

INTRODUCTION: The aim of this work was to evaluate the diagnostic contribution of magnetic resonance imaging and genourob compared to intraoperative arthroscopy. The objective was to implement a protocol based on magnetic resonance imaging and / or genourob. MATERIALS AND METHODS: We did a cross-sectional study from July 18, 2016 to July 19, 2017 at the Maltese hospital comparing the results of MRI and GNRB from 30 patients compared to intraoperative arthroscopy data. RESULTS: Complete break.- In MRI, we obtained a sensitivity (Se) of 95.7%, a specificity (Sp) of 85.7%.- At the GNRB, we found a Se of 87%, a Sp of 42.9%.Partially broken.- In MRI we obtained a Se of 85.7%, a Sp of 95.7%.- At the GNRB, we found a Se of 42.9%, a Sp of 87%. CONCLUSION: MRI is better than GNRB. The GNRB does not improve the results of the MRI. It has no diagnostic contribution in the rupture of the ACL knee. It is a device used by the orthopedists to evaluate knee laxity that does not depend on the ACL alone.

INTRODUCTION: Le but de ce travail était d'évaluer l'apport diagnostique de l'imagerie par résonance magnétique (IRM) et du genourob (GNRB) par rapport à l'arthroscopie per opératoire. L'objectif était de mettre en place un protocole basé sur l'IRM et / ou le GNRB. MATÉRIELS ET MÉTHODES: Nous avons fait une étude transversale allant du 18 Juillet 2016 au 19 juillet 2017au centre hospitalier de l'ordre de malte en comparant les résultats d'IRM et du GNRB de 30 patients par rapport aux données de l'arthroscopie per opératoire. RÉSULTATS: ✓ Rupture complète.- En IRM, nous avons obtenu une sensibilité (Se) de 95,7 %, une spécificité(Sp) de 85,7%.- Au GNRB, nous avons trouvé une Se de 87 %, une Sp de 42,9%.✓ Rupture partielle.- En IRM, nous avons obtenu une Se de 85,7 %, une Spde 95,7%.- Au GNRB, nous avons trouvé uneSe de 42,9 %, une Sp de 87%. CONCLUSION: L'IRM est plus performante que le GNRB. Le GNRB ne permet pas d'améliorer les résultats de l'IRM. Il n'a pas d'apport diagnostique dans la rupture du LCA du genou. C'est un dispositif utilisé par les orthopédistes pour évaluer une laxité du genou qui ne dépend pas du LCA à lui seul.

Performance de l'imagerie par resonance magnetique et de la Laximetrie a Genourob dans les ruptures du ligament croise anterieur a Propos de 30 cas

Introduction:Le but de ce travail était d'évaluer l'apport diagnostique de l'imagerie par resonance magnétique (IRM) et du genourob (GNRB) parrapport à l'arthroscopie per opératoire.L'objectif était de mettre en place un protocole basé sur l'IRMet / ou le GNRB.Matériels et méthodes:Nous avons fait une étude transversale allant du 18 Juillet 2016 au 19 juillet 2017au centre hospitalier de l'ordre de malte en comparant les résultats d'IRM et du GNRB de 30 patients par rapport aux données del'arthroscopie per opératoire. Résultats Rupture complète:En IRM, nous avons obtenu une sensibilité (Se) de 95,7 %, une spécificité(Sp) de 85,7%;Au GNRB, nous avons trouvé une Se de 87 %, une Sp de 42,9%.Rupture partielle:En IRM,nous avons obtenu une Se de 85,7 %,une Spde 95,7%;Au GNRB, nous avons trouvé une Se de 42,9 %, une Sp de 87%.Conclusion:L'IRM est plus performante que le GNRB Le GNRB ne permet pas d'améliorer les résultats de l'IRM. Il n'a pas d'apport diagnostique dans la rupture du LCA du genou. C'est un dispositif utilisé par les orthopédistes pour évaluer une laxité du genou qui ne dépend pas du LCA à lui seul

[Pulmonary Metastase of a Knee Mycetoma in Senegal]. / Métastase pulmonaire d'un mycétome du genou au Sénégal.

Mycetoma is transmitted by thorns infected. The commonest site for mycetoma is the foot. The primary pulmonary are rare and usually secondary to other primary site. We report a case of pulmonary fungal mycetoma secondary to primary site in the knee. We do a review of the literature and we discuss the way of dissemination.

Le mycétome se transmet principalement par piqures d'épines d'arbustes infectés. Les localisations primitives au niveau du pied sont les plus fréquentes. Les localisations pulmonaires sont exceptionnelles et secondaires à des localisations périphériques primitives. Nous rapportons un cas de localisation pulmonaire d'un mycétome fongique secondaire à une localisation au niveau du genou, puis nous faisons une revue de la littérature et nous discutons de la voie de dissémination.

[Recidives of Mycetoma after Amputation in Dakar (Senegal)]. / Récidives de mycétome après amputation à Dakar (Sénégal).

The treatment of fungal mycetoma is essentially surgical. This carcinological-like surgery consists of amputation in case of bone involvement. The recurrences after amputation are rare and address the problem of the operative indication. We report 5 cases of recurrence of fungal black-grain mycetoma after amputation of leg or thigh. Case 1: a 52-year-old patient with a mycetoma of the knee evolving for 8 years. There is no history of surgery. A thigh amputation with ganglion dissection is performed. One year after the surgical procedure, the patient presents a recurrence on the amputation stump and on the lymph node dissection site. An indication of hip disarticulation is made and performed 17 months after amputation. Case 2: a 25-year-old patient who has a black-grain mycetoma of the foot with osteitis evolving since 10 years. A leg amputation was performed. The patient had a recurrence at the popliteal level at 15 months postoperatively. An indication of amputation of the thigh is posed and refused by the patient. Case 3: a30-year-old woman with black-grain mycetoma of the knee with bone involvement for more than 10 years. A thigh amputation was performed and at nine months postoperativeshe presented a recurrence in the amputation stump. She was lost of sight despite the decision of surgical revision. Case 4: a 43-year-old patient operated on his foot and leg mycetoma at least 5 timesbefore amputation in 2000. The recurrence occurred one year after amputation. 18 years after amputation, a new surgical procedure was difficult due to extension of the lesions in the pelvis. Case 5: a 50-year-old female patient operated in Mauritania in 2012 (thigh amputation for mycetoma of the knee). She presented a recurrence on the amputation stump in 2018. An indication of disarticulation of the hip was posed and refused by the patient. These recurrences were testified by to the persistence of grains on the preserved segment. They pose the problem of the level of amputation and therefore of preoperative planning. Good preoperative planning allows optimization of the surgical procedure and avoids certain recurrences.

La chirurgie constitue le temps essentiel du traitement des mycétomes fongiques. Elle consiste en une amputation en cas d'atteinte osseuse. Nous avons observé 5 cas de récidives après amputation pour mycétome. Il s'agit dans tous les cas de patients présentant des mycétomes à grain noir avec atteintes osseuses. Les récidives sont survenues à moins de 18 mois de l'amputation faisant parler de reprise évolutive et posant le problème du niveau de l'amputation.

Surgical Treatment of Angular Pott's Kyphosis with Posterior Approach, Pedicular Wedge Osteotomy and Canal Widening.

BACKGROUND: It has been observed that the correction of severe posttuberculous angular kyphosis is still a challenge, mainly because of the neurologic risk. METHODS: Nine patients were reviewed after surgery (mean follow-up 18 months). There were 2 thoracic, 4 thoraco-lumbar and 3 lumbar kyphosis. The mean age at surgery was 23. Clinical results were evaluated by the Oswestry Disability Index (ODI) and by the neurologic evaluation. Preoperative, postoperative and final follow-up X-rays were assessed. The surgery included a posterior approach with cord release and correction by transpedicular wedge osteotomy and widening of the spinal canal. RESULTS: Average kyphotic angulation was 72° before surgery, 10° after surgery and 12° at follow-up. Three out of four patients with neural deficit showed improvement. Neurologic complications included a transitory quadriceps paralysis, likely by foraminal compression of the root. CONCLUSION: A posterior transpedicular wedge osteotomy allows a substantial correction of the kyphosis, more by deflexion than by elongation, with limited neurologic risks. However it is mandatory to widely enlarge the spinal canal on the levels adjacent to the osteotomy, in order to allow the dura to expand backwards.

Modified Dunn osteotomy using an anterior approach used to treat 26 cases of SCFE.

INTRODUCTION: Osteotomy performed below the femoral neck plays a leading role in the treatment of slipped capital femoral epiphysis (SCFE). It results in anatomical reduction. Several modifications have been made to Dunn's original osteotomy technique. We have developed another modification to this technique that uses an anterior surgical approach on a traction table with fluoroscopy control. HYPOTHESES: Will this technique help to reduce the number of complications? Will its results be superior to those achieved with the standard Dunn osteotomy procedure? MATERIAL AND METHODS: This was a retrospective single-center study of 26 cases in 24 patients (2 bilateral cases). Patients were positioned supine on a traction table with fluoroscopy control. An anterior surgical approach was used. A trapezoid-shaped osteotomy was performed below the femoral head. The head's reduction was checked on the fluoroscope and the fixation confirmed. The Postel Merle d'Aubigné (PMA) score was used for the clinical assessment. The radiographic assessment was based on Southwick's angle. RESULTS: The mean slip angle of the femoral head was 57°. A mean correction of 47° was achieved. Based on the PMA score, good and excellent results were achieved in 20 cases (77%) and poor results occurred in 6 cases (23%). The surgical treatment had a significant effect on the PMA score (P=0.0008). In terms of complications, there were five cases of chondrolysis and one case of necrosis associated with chondrolysis. DISCUSSION: The anterior approach provides direct access to the femoral neck, and thereby a cautious osteotomy at the site of the slip itself. Use of a traction table makes the external manipulations, reduction and fixation procedures easier to carry out. The results of this study were comparable to published results. LEVEL OF PROOF: IV, retrospective treatment study.

Traitement par la méthode d'Ilizarov des pseudarthroses des os longs

Introduction: Plusieurs techniques permettent de traiter les pseudarthroses des os longs. L'objectif de ce travail était d'évaluer les résultats préliminaires du traitement de ces lésions avec la méthode d'Ilizarov. Matériels et méthodes: Dans cette étude prospective réalisée entre janvier 2007 et juin 2013, 11 patients avec un âge moyen de26ansontétéopérésselon laméthoded'Ilizarov. Ils'agissaitdeneuf pseudarthroses post-traumatiques et deux pseudarthroses congénitales. La pseudarthrose siégeait au tibia (n=9), à l'humérus (n=1), et au fémur (n=1). Les modalités thérapeutiques étaient une compression pure sans abord du foyer (n=8), une compression après abord du foyer pour ablation de matériel d'ostéosynthèse et débridement (n=2) et une compression-distraction bifocale ou technique de « l'ascenseur »( n=1). Les résultats ont été analysés avec un recul moyen de 2,5 ans selon les critères anatomiques et fonctionnels de l'ASAMI. Résultats: La consolidation osseuse était obtenue chez 10 patients qui ont tous repris leur activité. Les résultats anatomiques étaient excellents (n=5), bons (n=4), moyen (n=1), et mauvais (échec) (n=1). Les résultats fonctionnels étaient excellents (n=3),bons(n=5), moyens(n=2) et mauvais (n=1). Conclusion: Dans cette étude préliminaire portant sur 11 cas de pseudarthroses des os longs traitées par la méthode d'Ilizarov la consolidation osseuse a été obtenue chez 10 patients qui ont tous repris leur activité. Cette technique est contraignante pour le chirurgien et le malade, mais constitue une alternative fiable pour le traitement des pseudarthroses

Résultats de l'ostéotomie tibiale d'ouverture médiale fixée par plaque verrouillée type SURFIX® dans les gonarthroses sévères

Introduction: L'ostéotomie tibiale de valgisation par ouverture médiale est indiquée dans les gonarthrose fémorotibiales varisantes modérées. Ses indications pourraient être étendues aux arthroses avancées dans les pays en développement du fait de l'accessibilité limitée des prothèses. L'objectif de cette étude était d'évaluer les résultats de l'ostéotomie tibiale de valgisation par ouverture médiale dans les gonarthroses évoluées. Matériel et méthodes: Une étude rétrospective monocentrique de 3 ans a été réalisée. Quatorze patients totalisant 16 gonarthroses avec un âge moyen 48 ans ont été opérés selon cette technique. L'ostéotomie a été fixée par une plaque verrouillée type SURFIX® Treize genoux étaient classés au stade III et trois au stade IV de la classification de Ahlbäck. L'angle tibial interne préopératoire moyen était de 82°. l'IKS genou était en moyenne de 58,33 et l'IKS fonction de 52,08. Résultats: Les patients ont été évalués avec un recul moyen de 30 mois. La correction angulaire moyenne était de 7,81°. L'IKS genou était en moyenne 87,08 et l'IKS fonction 89,16. L'angle tibial interne était de 89°. La comparaison des variations de l'IKS avant et après l'opération était significative. Onze patients étaient satisfaits du résultat de l'intervention. Conclusion: Les résultats de l'ostéotomie tibiale de valgisation par ouverture médiale instrumentée par une plaque verrouillée sont satisfaisants. Ils nous encouragent à élargir les indications dans les gonarthroses avancées dans un contexte où l'indication d'arthroplastie du genou dans le traitement des gonarthroses sévères se heurte à des difficultés économiques des patients

Clinical characteristics of the smooth tubercle bacilli 'Mycobacterium canettii' infection suggest the existence of an environmental reservoir.

Over a 3-year follow-up, 30 out of the 318 unique Mycobacterium tuberculosis complex isolates recovered in the Republic of Djibouti had a smooth-type morphology and were Niacine-negative, the characteristics of 'Mycobacterium canettii' strains. Unlike M. tuberculosis, 'M. canettii' grew on nutrient-poor media at 30°C, and possessed characteristic lipids. They were isolated from respiratory and extra-respiratory sites from patients with typical forms of tuberculosis. Most cases resolved with antibiotic therapy but in two human immunodeficiency virus-positive patients 'M. canettii' infection led to septicaemia and death. No cases of human-to-human transmission were observed. The proportion of tuberculosis cases caused by 'M. canettii' was higher among French patients than among Djiboutian patients. Patients with 'M. canettii' were significantly younger than those with tuberculosis caused by other M. tuberculosis complex strains. Smooth tubercle bacilli could be misidentified as non-tuberculous mycobacteria and appear to be limited to the Horn of Africa. Their characteristics are consistent with the existence of non-human sources of infection.

Hypervirulence of a rough variant of the Mycobacterium abscessus type strain.

We isolated a rough variant of Mycobacterium abscessus CIP 104536T during experimental infection of mice. We show that this variant has lost the ability to produce glycopeptidolipids, is hyperlethal for C57BL/6 mice infected intravenously, and induces a strong tumor necrosis factor-alpha response by murine monocyte-derived macrophages.

Characterization of an unusual Mycobacterium: a possible missing link between Mycobacterium marinum and Mycobacterium ulcerans.

In an attempt to characterize an unusual mycobacterial isolate from a 44-year-old patient living in France, we applied phenotypic characterizations and various previously described molecular methods for the taxonomic classification of mycobacteria. The results of the investigations were compared to those obtained in a previous study with a set of temporally and geographically diverse Mycobacterium ulcerans (n = 29) and Mycobacterium marinum (n = 29) isolates (K. Chemlal, G. Huys, P.-A. Fonteyne, V. Vincent, A. G. Lopez, L. Rigouts, J. Swings, W. M. Meyers, and F. Portaels, J. Clin. Microbiol. 39:3272-3278, 2001). The isolate, designated ITM 00-1026 (IPP 2000-372), is closely related to M. marinum according to its phenotypic properties, lipid pattern, and partial 16S rRNA sequence. Moreover, fingerprinting by amplified fragment length polymorphism (AFLP) analysis unequivocally classified this strain as a member of the species M. marinum, although it lacked two species-specific AFLP marker bands. However, PCR and restriction fragment length polymorphism analysis based on M. ulcerans-specific insertion sequence IS2404 showed the presence of this element in a low copy number in isolate ITM 00-1026. In conclusion, the designation of this isolate as a transitional species further supports the recent claim by Stinear et al. (T. Stinear, G. Jenkin, P. D. Johnson, and J. K. Davies, J. Bacteriol. 182:6322-6330, 2000) that M. ulcerans represents a relatively recent phylogenetic derivative of M. marinum resulting from the systematic acquisition of foreign DNA fragments.

Identification of the first eubacterial endonuclease coded by an intein allele in the pps1 gene of mycobacteria.

A survey of a vast range of mycobacterial strains led us to discover a new Pps1 intein allele in Mycobacterium gastri which differs from those of Mycobacterium tuberculosis and Mycobacterium leprae in both its sequence and insertion site. While little is known about Pps1, except that it belongs to the YC24 family of ABC transporters, we show that, unlike the other inteins described so far from Eubacteria, the MgaPps1 intein possesses a specific endonuclease activity. The intein is the first eubacterial intein to be characterised as an endonuclease. Like other intein endonucleases, its minimal sequence for recognition and cleavage is quite large, with 22 bp spanning the Pps1-c site. The fact that an active endonuclease is found among the mycobacterial inteins supports the concept of a cyclical model of invasion by horizontal transfer of these genes, followed by degeneration and loss until a new invasion event, thus explaining their long-term persistence in closely related eubacterial species.

Distribution of GyrA intein in non-tuberculous mycobacteria and genomic heterogeneity of Mycobacterium gastri.

To gain further insights into the understanding of the intein invasion process in mycobacteria, intein sequences in the gyrA gene of 42 mycobacterial strains were searched and a new gyrA intein was found in Mycobacterium gastri (Mga). This 1260 bp intein, named MgaGyrA, inserted at the GyrA-a site, is highly homologous to the members of the Mycobacterium leprae GyrA allelic family. As the recA intein, MgaGyrA was detected in only one out of six Mga strains examined, while the pps1 intein was a constant character of Mga. This data supports the genomic heterogeneity of Mga towards intein invasion, a finding that may have phylogenetic implications.

Accurate molecular mass determination of mycolic acids by MALDI-TOF mass spectrometry.

Mycolic acids, major and specific long-chain fatty (C70-C90) acid components of the mycobacterial cell envelope, were analyzed for the first time using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry operating in a reflectron mode. The various types of purified mycolates from representative mycobacterial species were analyzed using 2,5-DHB as matrix, because less than 10 pmol of mycolates was sufficient to obtain well-resolved mass spectra composed exclusively of pseudomolecular [M + Na]+ ions consistent with the structures deduced from the chemical analytical techniques applied to these molecules. Examination of the MALDI mass spectra demonstrated that the chain lengths of the various mycolates correlated with the growth rate of mycobacterial strains. Although slow growers, such as Mycobacterium tuberculosis and Mycobacterium ulcerans, produced a series of odd carbon numbers (C74-C82) of alpha-mycolic acids, rapid growers synthesized both odd and even carbon numbers. In addition, the main chain of oxygenated mycolic acids from slow growers were four to six carbon atoms longer than the corresponding alpha-mycolic acids, whereas rapid growers elaborated oxygenated homologues possessing the same chain lengths as their alpha-mycolic acids. Furthermore, a comparative analysis of the crude fatty acid mixtures from a wild-type strain of M. tuberculosis and its isogenic mutant effected in the synthesis of oxygenated mycolates by MALDI mass spectrometry revealed structural differences between the alpha-mycolates from the two strains. Thus, this technique appeared to be a rapid and highly sensitive technique for the analysis of mycolic acids, not only by providing accurate molecular masses and new structural information, but also by both reducing sample consumption and saving time.

Analysis of the phthiocerol dimycocerosate locus of Mycobacterium tuberculosis. Evidence that this lipid is involved in the cell wall permeability barrier.

Among the few characterized genes that have products involved in the pathogenicity of Mycobacterium tuberculosis, the etiological agent of tuberculosis, are those of the phthiocerol dimycocerosate (DIM) locus. Genes involved in biosynthesis of these compounds are grouped on a 50-kilobase fragment of the chromosome containing 13 genes. Analysis of mRNA produced from this 50-kilobase fragment in the wild type strain showed that this region is subdivided into three transcriptional units. Biochemical characterization of five mutants with transposon insertions in this region demonstrated that (i) the complete DIM molecules are synthesized in the cytoplasm of M. tuberculosis before being translocated into the cell wall; (ii) the genes fadD26 and fadD28 are directly involved in their biosynthesis; and (iii) both the drrC and mmpL7 genes are necessary for the proper localization of DIMs. Insertional mutants unable to synthesize or translocate DIMs exhibit higher cell wall permeability and are more sensitive to detergent than the wild type strain, indicating for the first time that, in addition to being important virulence factors, extractable lipids of M. tuberculosis play a role in the cell envelope architecture and permeability. This function may represent one of the molecular mechanisms by which DIMs are involved in the virulence of M. tuberculosis.

Mycobacterium smegmatis laminin-binding glycoprotein shares epitopes with Mycobacterium tuberculosis heparin-binding haemagglutinin.

Mycobacterium tuberculosis, the causative agent of tuberculosis, produces a heparin-binding haemagglutinin adhesin (HBHA), which is involved in its epithelial adherence. To ascertain whether HBHA is also present in fast-growing mycobacteria, Mycobacterium smegmatis was studied using anti-HBHA monoclonal antibodies (mAbs). A cross-reactive protein was detected by immunoblotting of M. smegmatis whole-cell lysates. However, the M. tuberculosis HBHA-encoding gene failed to hybridize with M. smegmatis chromosomal DNA in Southern blot analyses. The M. smegmatis protein recognized by the anti-HBHA mAbs was purified by heparin-Sepharose chromatography, and its amino-terminal sequence was found to be identical to that of the previously described histone-like protein, indicating that M. smegmatis does not produce HBHA. Biochemical analysis of the M. smegmatis histone-like protein shows that it is glycosylated like HBHA. Immunoelectron microscopy demonstrated that the M. smegmatis protein is present on the mycobacterial surface, a cellular localization inconsistent with a histone-like function, but compatible with an adhesin activity. In vitro protein interaction assays showed that this glycoprotein binds to laminin, a major component of basement membranes. Therefore, the protein was called M. smegmatis laminin-binding protein (MS-LBP). MS-LBP does not appear to be involved in adherence in the absence of laminin but is responsible for the laminin-mediated mycobacterial adherence to human pneumocytes and macrophages. Homologous laminin-binding adhesins are also produced by virulent mycobacteria such as M. tuberculosis and Mycobacterium leprae, suggesting that this adherence mechanism may contribute to the pathogenesis of mycobacterial diseases.

Analysis of the Capsule of Mycobacterium tuberculosis.

Mycobacterium tuberculosis and the other pathogenic mycobacteria examined so far by electron microscopy are seen to be surrounded within host cells by an electron-transparent zone (ETZ). For Mycobacterium lepraemurium, this space between the phagosomal membrane of the infected cellthe wall of the enclosed bacteria was called a "capsular space" (1). Using light microscopic techniques (2-4), Hanks demonstrated the presence of an unstainable "halo" around some pathogenic mycobacteria and pointed out (5) that what appeared to be a capsule could be seen in several published images of pathogenic mycobacteria.

Inteins invading mycobacterial RecA proteins.

Five new inteins were discovered in a survey of 39 mycobacterial strains that was undertaken to clarify the role of RecA inteins in mycobacteria. They are all inserted at the RecA-b site of the recA gene of Mycobacterium chitae, 4. fallax, M. gastri, M. shimodei and M. thermoresistibile and belong to the MleRecA allelic family. Sequence analysis showed that although only M. tuberculosis harbours an intein at the RecA-a site the sequence of the RecA-b site is well conserved between species. Furthermore, the presence of inteins does not correlate with specific characteristics of the species such as pathogenicity or growth rate.