Epidemiological study of Enterobacteriaceae resistance to colistin in Sfax (Tunisia).

OBJECTIVES: The authors had for aim to monitor Enterobacteriaceae resistance to colistin, during 6 years (2005-2010), and to study the epidemiology of Enterobacteriaceae resistant strains isolated in the Sfax region (Tunisia). DESIGN: This retrospective study was carried out in the microbiology laboratory, at the Habib Bourguiba teaching hospital in Sfax. All strains of colistin resistant Enterobacteriaceae isolated from patients were studied. RESULTS: One hundred and twenty one strains of colistin resistant Enterobacteriaceae were isolated from 93 patients. Klebsiella pneumoniae was the most frequent species (60.2%), followed by Enterobacter cloacae (26.9%), and Escherichia coli (12.9%). Thirteen strains (E. cloacae) were heteroresistant to colistin. Eighty one isolates (87.1%) were resistant to third generation cephalosporins. The rate of resistance to colistin ranged from 0.09% for E. coli to 1.2% for K. pneumoniae, and 1.5% for E. cloacae. A progressively increasing colistin resistance was observed for K. pneumoniae. Most resistant strains were isolated from urine in the urology department. Previous exposure to colistin was reported in 59.2% of patients. Pulsed field gel electrophoresis typing revealed different clones. CONCLUSIONS: Colistin resistance in Enterobacteriaceae is a worrying phenomenon in Sfax. It is related to polyclonal diffusion. Continuous epidemiological monitoring and a rational use of colistin are necessary to limit the spreading of these colistin resistant strains and to maintain this antibiotic's effectiveness.

Comparison of disc diffusion, Etest and agar dilution for susceptibility testing of colistin against Enterobacteriaceae.

AIMS: In this study, we compared different methods of colistin susceptibility testing, disc diffusion, agar dilution and Etest using a set of Enterobacteriaceae isolates that included colistin-resistant strains. METHODS AND RESULTS: Susceptibility of 200 clinical isolates of Enterobacteriaceae to colistin was tested to compare agar dilution (reference method), disc diffusion (50 and 10 µg) and Etest. MICs (minimum inhibitory concentrations) were interpreted using the criteria established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Colistin exhibited excellent activity against Escherichia coli and E. cloacae (MIC90 = 0·5 mg l(-1)). In contrast, colistin was less active against Klebsiella pneumoniae (MIC90 = 16 mg l(-1)). Resistance rates varied from 0% in E. coli to 1·8% in E. cloacae and 13% in K. pneumoniae. High rates of very major errors were observed in the disc diffusion test using either the criteria of the Comité de l'antibiogramme de la Société Française de Microbiologie (CA-SFM) or the criteria of the Clinical and Laboratory Standards Institute (CLSI), respectively, 3·5 and 2·5%. When the criteria of Gales et al. were applied, the number of very major errors was reduced to one (0·5%). The Etest showed good concordance with agar dilution method. CONCLUSION: Disc susceptibility testing methods are unreliable on detecting colistin resistance. MIC should be determined to confirm the susceptibility results by disc diffusion. SIGNIFICANCE AND IMPACT OF THE STUDY: We recommend the determination of MIC by Etest for all multidrug-resistant Enterobacteriaceae when colistin is required for the treatment.

[Breast cancer in young women in the south of Tunisia]. / Le cancer du sein de la femme jeune dans le sud tunisien.

OBJECTIVE: The objective of this retrospective study was to discuss the epidemioclinical criteria, the therapeutic results and the prognostic factors of breast cancer in young women throughout a comparative study of 72 young patients aged less than 35 years and a second group of older premenopausal patients aged between 36 and 50 years. PATIENTS AND METHODS: We reviewed the epidemioclinical records of all the patients. Non-metastatic and operable patients were treated with surgery (conservative or radical) followed by an adjuvant treatment (chemotherapy, radiotherapy, endocrine therapy) indicated according to the prognostic factors. Locally advanced or metastatic tumors were treated with chemotherapy. Overall survival was calculated according to the Kaplan-Meier method. The comparison of survival curves was performed according to log-rank test. The multivariate analysis was performed according to the Cox model. RESULTS: The mean age was of 31.5 years. T2N1, node positive (N+), high grade (SBRII and III) and endocrine non-responsive tumors were the most frequent. There was no difference with the second group of older patients regarding the risk factors and the clinical criteria but mammography was more sensitive in the second group. The 5 years overall survival of young patients was of 57% and pejorative prognostic factors in univariate analysis were: tumor size, N+ and endocrine non-responsiveness. There were not any significant prognostic factors at the multivariate analysis. Young age less than 35 years was not a prognostic factor influencing overall survival in the totality of patients or in the different sub-groups according to the other prognostic factors. CONCLUSION: Clinical presentation and outcome of breast cancer in our young patients aged under 35 years seems not to be different from that in older patients. The conclusions of the different authors are controversial but the majority has reported more advanced tumors with worse prognostic than those of older patients.

Novel mutations in LAMA2 gene responsible for a severe phenotype of congenital muscular dystrophy in two Tunisian families.

Congenital muscular dystrophies are a group of common genetically determined disorders often transmitted with a recessive mode of inheritance. In recent years, several deficiencies of proteins from the muscle membrane, extra cellular matrix, sarcomere, muscle cytosol and the nucleus have been described to cause CMD. The occidental type of CMD (MDC1A) in which the primary defect is a deficiency in laminin alpha2 chain (merosin) encoded by LAMA2 gene, accounts for 30-40% of cases. The clinical course of CMD with complete laminin alpha2 chain deficiency may be variable but most often; severe forms characterized by hypotonia at birth, profound muscle weakness, marked delay in motor milestones are observed. Since the identification of the first LAMA2 gene mutations leading to merosin deficiency in 1995, several mutations have subsequently been reported in many exons of this gene without any "hotspot" region. In this work, we report two novel homozygous mutations c.8005delT and c.8244+1G>A in the LAMA2 gene in four Tunisian patients with a severe MDC1A phenotype belonging to two unrelated consanguineous families.

[Clinical, biological and genetic study of 24 patients with ataxia telangiectasia from southern Tunisia]. / L'ataxie-télangiectasie. Etude clinique, biologique et génétique de 24 cas du sud Tunisien.

Ataxia telangiectasia is a multisystem disease with an autosomal recessive inheritance. It is characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia, humoral and cellular immunodeficiencies and high incidence of neoplasia and radiosensitivity. A 5 year retrospective survey included 24 patients belonging to 17 families. Cerebellar ataxia was the first clinical symptom and was usually noticed when the child began to walk. Mean age of onset was 2.9+/-1.8 years. Oculocutaneous telangiectasia was present in 17 cases and appeared between 2 and 8 years and then spread in a characteristic symmetrical pattern. When ocular telangiectasia was absent (6 cases), the diagnostic of ataxia telangiectasia was retained on oculomotor apraxia (2 cases), recurrent sinopulmonary infections (3 cases) and/or a sib with typical ataxia telangiectasia (1 case). Recurrent sinopulmonary infections, absence or low serum level of IgA (78 p.100) and lymphopenia revealed immunodeficiency. Among 12 patients, chromosomal instability was observed in 5. Balanced rearrangements involving chromosomes 2, 7, 14, 22, 1, 3 and 11. The responsible gene, ATM, encodes a large protein kinase with a phosphatidylinositol 3-kinase-like domain. Ataxia telangiectasia patients have a 100 fold higher risk of cancer than the general population. We reported, in the same family two patients who developed neoplasia, (lymphoma and leukemia). During follow-up, a progressive worsening was observed in all cases. Three patients have died.

[Contralateral axillary lymph node metastasis of cancer of the breast]. / Les métastases ganglionnaires axillaires controlatérales du cancer du sein.

Contralateral axillary metastases (CAM) of breast cancer are uncommon, they state some diagnostics and therapeutics problems. From February 1993 until June 1996, 6 cases of CAM were detected in 123 women having a breast's cancer (4.9%). The diagnostic of CAM, was retained after a normal clinical and mammographic examination of ipsilateral breast, and a anatomopathological proof confirming the carcinomatous infiltration of axillary ganglions. These metastases were synchronous for 3 patients and metachronous for the 3 others with an appearance's mean delay of 12 months. The 6 patients were treated for a breast's cancer locally advanced and a tumour with internal or central seat in 5 cases. The CAM were associated to others metastatic areas in 2 patients. Five patients have had a locoregional treatment of CAM (curage and/or axillary radiotherapy), associated to chemotherapy. The 6th patient, is multimetastatic, had refused the treatment. Only 1 patient has developed a tumor of ipsilateral breast after a mean delay of 7 months, others metastatic localizations are appeared in 2 patients after a mean delay of 8 months. The CAM are considered a scare entity with physiopathological mechanism not yet well elucidated. They are perhaps, the prerogative of advanced tumors and the often before metastatic spreading. A problem remains to be raised: is it a question of a real CAM, or an expression of a ipsilateral breast's occult carcinomatous?

[Sarcoma of the spine in Paget's disease of bone. Apropos of 8 cases]. / Sarcomes pagétiques rachidiens. A propos de huit observations.

Eight cases of spinal sarcoma complicating Paget's disease seen in different centers were reviewed. Clinical and radiological features of this condition were determined on the basis of these 8 cases and of 51 previously published cases. In the current series as well as in previous reports, most cases involved the lumbar and sacral spine and manifested as low back pain with sciatica and early development of neurological deficits. Roentgenographic diagnosis proved difficult because of the anatomic complexity of the spine and architectural changes characteristic of the pagetic bone. The most common radiological features was a mixed pattern with both sclerosis and central osteolysis. Computed tomography performed in one patient of current series disclosed osteolysis of the sacrum (not visible on plain roentgenograms) with tumor spread to adjacent soft tissues. Features shared by spinal and nonspinal sarcomas complicating Paget's disease include advanced mean age of patients, predominance of osteogenic sarcomas among histologic forms, increased risk of sarcoma in polyostotic Paget's disease, and a very grim prognosis. Development of a neurological deficit in a patient with Paget's disease is an unusual occurrence which should suggest sarcomatous transformation. Roentgenographic changes are difficult to identify on plain films of the spine and consequently CT scan studies are warranted whenever a sarcoma is suspected.

[Perineo-transpubic approach in the treatment of traumatic rupture of the posterior urethra. Apropos of 14 cases]. / La voie périnéo-trans-symphysaire dans le traitement des ruptures traumatiques de l'urètre postérieur. A propos de 14 observations.

Traumatic lesions of posterior urethra pose a problem in management because of the difficult access behind the pubic position. Twelve successful results among fourteen patients are treated by perineum transpubic surgery. The direct attack upon the lesion constitute the superiority of this approach.