Molecular mechanisms and clonal lineages of colistin-resistant bacteria across the African continent: a scoping review.

Colistin (also known as polymyxin E), a polymyxin antibiotic discovered in the late 1940s, has recently reemerged as a last-line treatment option for multidrug-resistant infections. However, in recent years, colistin-resistant pathogenic bacteria have been increasingly reported worldwide. Accordingly, the presented review was undertaken to identify, integrate and synthesize current information regarding the detection and transmission of colistin-resistant bacteria across the African continent, in addition to elucidating their molecular mechanisms of resistance. PubMed, Google Scholar and Science Direct were employed for study identification, screening and extraction. Overall, based on the developed literature review protocol and associated inclusion/exclusion criteria, 80 studies published between 2000 and 2021 were included comprising varying bacterial species and hosts. Numerous mechanisms of colistin resistance were reported, including chromosomal mutation(s) and transferable plasmid-mediated colistin resistance (encoded by mcr genes). Perhaps unexpectedly, mcr-variants have exhibited rapid emergence and spread across most African regions. The genetic variant mcr-1 is predominant in humans, animals and the natural environment, and is primarily carried by IncHI2- type plasmid. The highest number of studies reporting the dissemination of colistin-resistant Gram-negative bacteria were conducted in the North African region.

High occurrence of enterotoxigenic isolates and low antibiotic resistance rates of Staphylococcus aureus isolated from raw milk from cows and ewes.

This study aimed to analyse the frequency of genes encoding virulence factors and to characterize resistance profiles of Staphylococcus aureus isolated from raw milk. In total, 47 and 9 S. aureus isolates were recovered from 150 and 100 raw bovine and ovine milk samples, respectively, in Tunisia. The majority of isolates was resistant to penicillin, and no methicillin-resistant S. aureus was detected. Eighteen and two isolates harboured etd and eta genes respectively. Sixteen enterotoxin-encoding genes were detected (n, %): sed (25, 44·6%), sec (16, 28·6%), sei (16, 28·6%), seh (13, 23·2%), seln (13, 23·2%), sell (10, 17·8%), seg (9, 16%), selu (8, 14·3%), selq (7, 12·5%), selo (7, 12·5%), selm (7, 12·5%), seb (7, 12·5%), sea (6, 10·7%), selk (3, 5·4%), ser (1, 1·8%) and selp (1, 1·8%). Ten isolates carried the tsst1 gene. All isolates carried the haemolysin toxin (hla, hld and hlg). The immune evasion cluster system-type B was predominant (20 isolates) followed by C (3 isolates), A and E (1 isolate each). The occurrence of enterotoxigenic S. aureus in raw milk constitutes a potential risk for human health. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper describes the characteristics of Staphylococcus aureus isolated from raw milk samples from healthy cows and ewes collected from small family farms in Tunisia. Fifty-six strains were analysed by determining their antibiotic susceptibility and genes encoding antibiotic resistance and virulence factors. Methicillin-resistant strains were not detected, and overall low level of antimicrobial resistance was reported. However, our strains harboured several genes encoding virulence factors and 87·5% of them carried at least one gene encoding for enterotoxins showing a high risk of spread of food-borne diseases.

Gender differences in the association of ELMO1 genetic variants with type 2 diabetes in Tunisian Arabs.

PURPOSE: Polymorphisms of the engulfment and cell motility 1 (ELMO1) gene were recently associated with type 2 diabetes (T2DM) and its complications. We investigated the association of rs10255208, rs7782979, and rs2041801 ELMO1 gene variants with T2DM in Tunisian Arabs. METHODS: Subjects comprised 900 T2DM patients and 600 normoglycemic controls. ELMO1 genotyping was done by PCR-RFLP; the contribution of ELMO1 variants to T2DM was analyzed by Haploview and regression analysis. RESULTS: Minor allele frequencies of rs7782979 and rs10255208 ELMO1 variants were significantly higher among unselected T2DM cases than controls, and significant differences in the distribution of rs7782979 genotypes were seen between T2DM cases and control subjects, which was seen in male but not female subjects. Three-locus ELMO1 haplotype analysis identified haplotype GAA to be positively associated, and haplotypes GCA, AAA, and GCG to be negatively associated with T2DM. The distribution of these haplotypes was gender-dependent for some (GCA, GCG, AAG), and gender-independent for others (GAA, AAA). This translated into altered risk of T2DM in male or female subjects, which persisted after adjusting for BMI, systolic and diastolic blood pressure, and serum lipid profile. CONCLUSION: These results confirm role for ELMO1 as T2DM susceptibility locus, which appears to be gender-dependent.

Phenotypic abnormalities of peripheral blood mononuclear cells in patients with Behçet's disease and association with HLA-B51 expression.

The aim of this study was to investigate the subclasses and the immunophenotypic profile of peripheral mononuclear cells in patients with Behçet's disease (BD) and to assess associations between the expression of HLA-B51 antigen and that of other cell markers. Thirty healthy volunteer blood donors and forty patients with BD were enrolled into this study. Phenotyping was performed using two color flow cytometry. HLA-B51 typing was performed using the complement dependent microlymphocytotoxicity assay. Unlike controls, patients with BD presented a modified immunophenotypic profile of lymphocytes. Compared to those in the remission phase, patients with active BD showed an increased mean of MFI ratio of CD56 on CD16+CD56+ cells (32.47 ± 14.26 versus 23.87 ± 10.3; p = 0.032), increased absolute numbers of CD4(-)CD8(bright) and CD4(+)CD8(+) cells (657.1 ± 463.6 cells/µL versus 319.24 ± 116.4 cells/µL; p = 0.017 and 40.77 ± 36.41 cells/µL versus 10.77 ± 9.78 cells/µL; p < 0.0001, respectively) and an elevated mean of MFI ratio of CD19 on B cells (252.3 ± 56.7 versus 205.67 ± 32.3; p = 0.021). However, expression of HLA-B51 was not associated with any specific immunophenotypic profile. In conclusion, abnormal immunophenotypic profile of peripheral lymphocytes was found in patients with BD, especially in active phase, reflecting an immune dysregulation. Moreover, HLA-B51 expression was not found to be related to the expression of other cell markers.

ANALYSIS OF BIOTIC AND ABIOTIC FACTORS INFLUENCING THE OCCURRENCE OF WEST NILE VIRUS INFECTION IN TUNISIA.

Eco-climatic conditions are often associated with the occurrence of West Nile Disease (WND) cases. Among the complex set of biotic and abiotic factors influencing the emergence and spread of this vector-borne disease, two main variables have been considered to have a great influence on the probability of West Nile Virus (WNV) introduction and circulation in Tunisia: the presence of susceptible bird populations and the existence of geographical areas where the environmental and climatic conditions are more favourable to mosquito multiplications. The aim of this study was to identify and classify the climatic and environmental variables possibly associated with the occurrence of WNVhuman cases in Tunisia. The following environmental and climatic variables have been considered: wetlands and humid areas, Normalised Difference Vegetation Index (NDVI), temperatures and elevation. A preliminary analysis for the characterization of main variables associated with areas with a history of WNV human cases in Tunisia between 1997 and 2011 has been made. This preliminary analysis clearly indicates the closeness to marshes ecosystem, where migratory bird populations are located, as an important risk factor for WNV infection. On the contrary the temperature absolute seems to be not a significant factor in Tunisian epidemiological situation. In relation to NDVI values, more complex considerations should be made.

Developmental competence and embryo quality of small oocytes from pre-pubertal goats cultured in IVM medium supplemented with low level of hormones, insulin-transferrin-selenium and ascorbic acid.

The aim of this study was to test the effect of insulin-transferrin-selenium (ITS) and L-ascorbic acid (AA) supplementation and the hormonal level during in vitro maturation (IVM) of small oocytes from pre-pubertal goat on the blastocyst yield and quality. Concretely, we used four maturation media: conventional IVM medium (CM), growth medium (GM: CM+ITS+AA and low level of hormones), modified CM (mCM: CM with low level of hormones) and modified GM (mGM: CM+ITS+AA and normal level of hormones). Cumulus-oocyte complexes (COCs) were classified into two categories according to oocyte diameter: <125 µm and ≥ 125 µm. Large oocytes were matured 24 h in CM (Treatment A). Small oocytes were matured randomly in six experimental groups: Treatment B: 24 h in CM; Treatment C: 12 h in GM and 12 h in CM; Treatment D: 24 h in mGM; Treatment E: 12 h in mGM and 12 h in CM; Treatment F: 12 h in mCM and 12 h in CM; and Treatment G: 12 h in GM and 12 h in mGM. After IVM, oocytes were fertilized and cultured for 8 days. The blastocyst quality was assessed by the survival following vitrification/warming and the mean cell number. When different maturation media were combined, the blastocyst rate did not improve. The large oocytes produced the highest blastocysts yield. However, the culture of small oocytes in GM (53.3%) enhanced the post-warming survival of blastocysts compared to large oocytes matured in CM (35.7%). In conclusion, IVM of pre-pubertal goat small oocytes in GM would be useful to improve the quality of in vitro-produced blastocysts.

Molecular analysis and antimicrobial resistance of Salmonella isolates recovered from raw meat marketed in the area of "Grand Tunis", Tunisia.

A total of 315 samples of chicken (60), beef (144), minced meat (56), lamb meat (33), merguez (10) and fish (12) were collected from various local outlet stores in the area of "Grand Tunis", Tunisia between 2006 and 2008. Salmonella was recovered from 80 samples with the highest occurrence in chicken (48.3%) followed by beef (29.8%), minced meat (10.7%) and lamb (6.0%). No Salmonella were isolated from 12 fish and 10 merguez samples (typical Tunisian sausages). Nine serovars were identified among the isolates with the predominance of Salmonella Typhimurium (n=25) followed by Salmonella Kentucky (n=14), Salmonella Suberu (n=12) and Salmonella Zanzibar (n=11). Isolated Salmonella were characterized by serotyping, pulsed-field gel electrophoresis (PFGE) analysis, plasmid content and antimicrobial resistance profiling. Sixteen (20.0%) Salmonella isolates displayed resistance to ampicillin (13 isolates), streptomycin (five isolates), cefoperazone (two isolates), furazolodine (two isolates), with seven of these isolates displaying multiple resistance to at least two of these antimicriobal agents. PFGE analysis showed homogenous restriction patterns in each serovar. Compiled serotyping, PFGE analysis, plasmid profiling and antimicrobial resistance data provided additional discrimination.

Polymorphism of the N-acetyltransferase 2 gene as a susceptibility risk factor for antituberculosis drug-induced hepatotoxicity in Tunisian patients with tuberculosis.

SETTING: Antituberculosis drug-induced hepatitis attributed to isoniazide (INH) is one of the most prevalent drug-induced liver injuries. INH is metabolized by hepatic N-acetyltransferase 2 (NAT2) to form hepatotoxins. AIM: To evaluate whether polymorphism of the NAT2 gene was associated with antituberculosis drug-induced hepatotoxicity in Tunisian patients. METHODS: A total of 66 patients with tuberculosis (TB) who received anti-TB treatment were followed prospectively. Their NAT2 genotype was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We identified three single nucleotide polymorphisms (SNPs); 481C to T (NAT2*5B), 590G to A (NAT2*6A) and 857G to A (NAT2*7B). Univariate analysis and logistic regression analysis were used to evaluate the risk factors of isoniazid-induced hepatitis. RESULTS: Fourteen patients (21.2%) were diagnosed with anti-TB drug-induced hepatitis. None of the rapid acetylators-type patients have expressed serum aminotransferase elevation. Among patients with hepatotoxicity, slow acetylators-type patients had a higher risk of hepatotoxicity than intermediate acetylators (21.4% vs. 78.6%, P=0.01). Statistical analysis revealed that the frequency of a variant diplotypes, NAT2*5B/5B and NAT2*6A/6A, were significantly increased in TB patients with hepatotoxicity, compared with those without hepatotoxicity (P=0.01, odds ratio [OR]=7.6 and P=0.029, OR=15, respectively). By contrast, the frequency of the rapid acetylation NAT2*4 allele was significantly lower in TB patients with hepatotoxicity than those without hepatotoxicity (P=0.02, OR=0.18). Moreover, 590G/G genotype was associated with decreased hepatotoxicity (P=0.01); by contrast, homozygous point mutation at position 481 and 590 were associated with a higher risk of hepatotoxicity (P=0.01). CONCLUSION: Our results suggest that the slow-acetylator status of NAT2 is risk factor for INH-induced hepatotoxicity. Moreover, diplotypes, NAT2*5B/5B, NAT2*6A/6A, 481T/T and 590A/A, are useful new biomarkers for predicting anti-TB drug-induced hepatotoxicity.

[Screening for depression in an elderly population living at home. Interest of the Mini-Geriatric Depression Scale]. / Dépistage de la dépression chez une population âgée vivant à domicile. Intérêt de la « Mini-Geriatric Depression Scale ¼

BACKGROUND: Depression is the most usual mental disorder in the elderly, but underdiagnosed and undertreated. Its prevalence is variable. Symptoms of depression present in the elderly can be masked and difficult to recognize. The purpose of this study was to examine prevalence and risk factors for depression in elderly living in their home. METHODS: A cross-sectional study of randomly selected homes in randomly selected geographical islets was carried out Monastir City (Tunisia). Questionnaire-based interviews were conducted among the elderly aged more than 65 years living in their home. Depression symptoms were assessed using a Mini-Geriatric Depression Scale. The relationship between the risk of depression and sociodemographic and health-related variables was studied using logistic regression. RESULTS: Out of 598 (female 66 %, mean (SD) age 72.3 (7.4) years) elderly persons interviewed, 136 (22.7 %) were screened to have a Mini-Geriatric Depression Scale more than or equal to 1. Multiple logistic regression analysis revealed that the following were significant (P<0.01) independent predictors of risk of depression: female sex (OR=2.36 [95 % CI=1.43-3.94]), having a low level of education (OR=4.02 [95 % CI=1.38-11.65]), disability (OR=3.50 [95 % CI=1.94-6.46]), a history of stroke (OR=2.90 [95 % CI=1.20-7.72]) and the use of hypnotic medications (OR=2.47 [95 % CI=1.38-4.42]). CONCLUSION: This study suggests that the risk of depression is a common psychiatric disorder in elderly living in their home, and underlines the usefulness of the Mini-Geriatric Depression Scale to detect the risk of depression in the elderly. This clinical approach should be encouraged in all medical practices to improve the prognosis of depression in the elderly.

Absence of viral hemorrhagic septicemia virus (VHSV) and infectious hemorrhagic necrosis virus (INHV) in a Tunisian fish farm: a case study.

Beyond the obvious problems related to the sustainable management of wild stocks, current fish farming practices in the Mediterranean area entail important environmental risks and potential outbreaks of fish diseases linked to massive translocations across regional boundaries. Viral haemorrhagic septicaemia (VHS) and infectious hematopoietic necrosis (IHN) are well-known fish diseases caused by the VHSV and IHNV viruses, and positive cases are subject to obligatory reporting to the World Organisation for Animal Health (OIE). In August 2004, the OIE published the first record of a VHS outbreak in a sea bass (Dicentrarchus labrax) aquaculture facility on the coast of the Mediterranean Sea. However, D. labrax is not considered as a susceptible host species for viral hemorrhagic septicaemia according to OIE's International Aquatic Animal Health Code (2009) and VHSV was not previously reported in the Mediterranean. In this sense and given the high risk of disease translocation associated with farmed fish in marine aquaculture, the present study was aimed at investigating the presence of VHSV and IHNV in stocks of sea bass and sea bream (Sparus aurata) reared inside a Tunisian coastal fish farm. Cell culture, IFAT and RT-PCR were applied to screen for both VHSV and IHNV in 69 pooled samples of sea bass and 24 pooled samples of sea bream. All three techniques showed the absence of both viruses within fish at the selected site.

The efficiency of in vitro ovine embryo production using an undefined or a defined maturation medium is determined by the source of the oocyte.

In vitro oocyte maturation can be influenced by oocyte source and maturation media composition. The aim of the present study was to compare the efficiency of a defined in vitro maturation medium (TCM199 supplemented with cysteamine and epidermal growth factor; Cys + EGF) with an undefined medium (TCM199 supplemented with follicle-stimulating hormone and follicular fluid; FSH + FF) for in vitro production (IVP) of ovine embryos, using oocytes obtained by laparoscopic ovum pick-up from FSH-stimulated [n=11; 158 cumulus-oocyte complexes (COCs)] and non-stimulated (n=16; 120 COCs) live ewes, as well as abattoir-derived oocytes (170 COCs). The produced blastocysts were vitrified and some of them were transferred to synchronized recipients. The best and the worst final yields of embryo IVP observed in this study were obtained using oocytes from FSH-stimulated ewes matured in FSH + FF (41.3%; 33/80) and in Cys + EGF (19.2%; 15/78) medium, respectively (p<0.01). No significant differences between both media were attained in the blastocyst development rate or in the final yield of embryo IVP using oocytes from non-stimulated ewes or abattoir-derived oocytes. The overall in vivo survival rate of the transferred vitrified blastocysts was 13.1% (8/61), without significant differences between oocyte sources or maturation media. In conclusion, under the experimental conditions of the present study, TCM199 supplemented with cysteamine and EGF is a convenient defined maturation medium for IVP of embryos from oocytes of live non-stimulated ewes or from oocytes of abattoir-derived ovaries. However, the best final yield of embryo IVP observed in this study was attained when oocytes came from FSH-stimulated donors and TCM199 was supplemented with FSH and follicular fluid.

[Relationship between plasma concentrations of valproic acid and hepatotoxicity in patients receiving high doses]. / Relation entre les concentrations plasmatiques d'acide valproïque et la survenue d'une hépatotoxicité.

INTRODUCTION: Valproic acid (VPA) is an anticonvulsivant drug widely prescribed in the treatment of many forms of generalized epilepsy. In literature, the incidence of liver damage induced by AVP is 0.01%. It is potentialized by the combination therapy (phenobarbital, carbamazepine). Severe hepatotoxicity is rare and appears to be independent of dose and to cause a high mortality. METHODS: The aim of our study was to evaluate the relationship between plasma concentrations of AVP and the occurrence of side effects especially hepatotoxicity in patients receiving high doses of AVP. RESULTS: In this period, 425 plasmatic AVP monitoring were carried out in our laboratory. From 128 patients treated by high doses of AVP, only 73 were included in this study. Our work showed that adverse effects in epileptics under high doses of AVP was related to the association of the AVP with other antiepileptic in particular carbamazépine, phenobarbital and benzodiazepines rather than supra-therapeutic plasmatic concentrations of AVP. The association of AVP to major antiepileptics (carbamazépine and or phenobarbital) does not seem to generate an increase in the plasmatic concentration of AVP, which was not associated with a greater risque of adverse effects. CONCLUSION: Consequently, clinical signs of liver toxicity may be present in AVP concentrations generally considered in the therapeutic range especially when used in high doses and or combined with antiepileptic drugs like phenobarbital or carbamazepine.

[Detection of circulation of West Nile virus in equine in the north-west of Tunisia]. / Détection de la circulation de virus West Nile chez les Équidés dans le nord-ouest de la Tunisie.

Two outbreaks of West Nile Fever (FWN) were observed in the Sahel of Tunisia in 1997 and 2003. Several cases of meningitis and meningoencephalitis have been described in humans during these two outbreaks. However, no animal or clinical findings or seroconversion have been detected despite a high seroprevalence in human beings found around the affected areas. Few data are available regarding the spreading of this virus in other parts of the country. The purpose of this study was to detect a possible WNV spread in horses in some areas of Tunisia considered to be at risk for WNV but which had not been affected by previous outbreaks. A total of 133 equine blood samples were collected in six delegations from three governorates in the north-west of Tunisia. A second blood sampling was taken from animals that were tested negative after the first sampling for IgG to identify possible seroconversion. Detection of IgG was done using competitive ELISA. A significant viral spread was detected in the study area. Out of 133 samples tested for IgG during the first sampling, 36 samples were tested positive (27.1%). Two seroconversions were detected between September and October 2008 out of 84 samples tested. Statistical analysis showed a significant association between the presence of a wetland within 10 km and seroconversion. The presence of cattle seems to be a protective factor.

Rabies in Tunisia: A spatio-temporal analysis in the region of CapBon-Nabeul.

Human rabies is a significant public health concern in Tunisia. However, the spatiotemporal spread pattern of rabies in dogs, the major reservoir and vector, and its determinants are poorly understood. We collected geographic locations and timeline of reported animal rabies cases in the region of CapBon (study area), for the years 2015-2019 and integrated them in Geographical Information System (GIS) approach to explore the spatio-temporal pattern of dog rabies. The results show that roads and irrigated areas can act as ecological corridors to viral spread. Our study showed that there was a significant seasonal variation in the number of cases of rabies recorded, with a strong peak in spring and lower peak in winter and summer. These findings may play a role in updating and directing public health policy, as well as providing opportunities for authorities to explore control options in time and space. A better knowledge of the ecology and dog population dynamics is still necessary and important to achieve an effective rabies control.

Attenuation of 7-ketocholesterol- and 7ß-hydroxycholesterol-induced oxiapoptophagy by nutrients, synthetic molecules and oils: Potential for the prevention of age-related diseases.

Age-related diseases for which there are no effective treatments include cardiovascular diseases; neurodegenerative diseases such as Alzheimer's disease; eye disorders such as cataract and age-related macular degeneration; and, more recently, Severe Acute Respiratory Syndrome (SARS-CoV-2). These diseases are associated with plasma and/or tissue increases in cholesterol derivatives mainly formed by auto-oxidation: 7-ketocholesterol, also known as 7-oxo-cholesterol, and 7ß-hydroxycholesterol. The formation of these oxysterols can be considered as a consequence of mitochondrial and peroxisomal dysfunction, leading to increased in oxidative stress, which is accentuated with age. 7-ketocholesterol and 7ß-hydroxycholesterol cause a specific form of cytotoxic activity defined as oxiapoptophagy, including oxidative stress and induction of death by apoptosis associated with autophagic criteria. Oxiaptophagy is associated with organelle dysfunction and in particular with mitochondrial and peroxisomal alterations involved in the induction of cell death and in the rupture of redox balance. As the criteria characterizing 7-ketocholesterol- and 7ß-hydroxycholesterol-induced cytotoxicity are often simultaneously observed in major age-related diseases (cardiovascular diseases, age-related macular degeneration, Alzheimer's disease) the involvement of these oxysterols in the pathophysiology of the latter seems increasingly likely. It is therefore important to better understand the signalling pathways associated with the toxicity of 7-ketocholesterol and 7ß-hydroxycholesterol in order to identify pharmacological targets, nutrients and synthetic molecules attenuating or inhibiting the cytotoxic activities of these oxysterols. Numerous natural cytoprotective compounds have been identified: vitamins, fatty acids, polyphenols, terpenes, vegetal pigments, antioxidants, mixtures of compounds (oils, plant extracts) and bacterial enzymes. However, few synthetic molecules are able to prevent 7-ketocholesterol- and/or 7ß-hydroxycholesterol-induced cytotoxicity: dimethyl fumarate, monomethyl fumarate, the tyrosine kinase inhibitor AG126, memantine, simvastatine, Trolox, dimethylsufoxide, mangafodipir and mitochondrial permeability transition pore (MPTP) inhibitors. The effectiveness of these compounds, several of which are already in use in humans, makes it possible to consider using them for the treatment of certain age-related diseases associated with increased plasma and/or tissue levels of 7-ketocholesterol and/or 7ß-hydroxycholesterol.

A combined RT-PCR and dot-blot hybridization method reveals the coexistence of SJNNV and RGNNV betanodavirus genotypes in wild meagre (Argyrosomus regius).

AIMS: To detect the possible coexistence of striped jack nervous necrosis virus (SJNNV) and red-spotted grouper nervous necrosis virus (RGNNV) genotypes in a single fish, a methodology based on the combination of PCR amplification and blot hybridization has been developed and applied in this study. METHODS AND RESULTS: The degenerate primers designed for the PCR procedure target the T4 region within the capsid gene, resulting in the amplification of both genotypes. The subsequent hybridization of these amplification products with two different specific digoxigenin-labelled probes resulted in the identification of both genotypes separately. The application of the RT-PCR protocol to analyse blood samples from asymptomatic wild meagre (Argyrosomus regius) specimens has shown a 46.87% of viral nervous necrosis virus carriers. The combination of RT-PCR and blot hybridization increases the detection rate up to 90.62%, and, in addition, it has shown the coexistence of both genotypes in 18 out of the 32 specimens analysed (56.25%). CONCLUSIONS: This study reports the coexistence of betanodaviruses belonging to two different genotypes (SJNNV and RGNNV) in wild fish specimens. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report demonstrating the presence of SJNNV and RGNNV genotypes in the same specimen. This study also demonstrates a carrier state in this fish species for the first time.

Complete sequencing of Tunisian redspotted grouper nervous necrosis virus betanodavirus capsid gene and RNA-dependent RNA polymerase gene.

Finfish nodaviruses (betanodaviruses) can cause highly destructive infections in numerous species of farmed marine fish larvae and juveniles worldwide. The betanodavirus genome consists of two single-stranded positive-sense RNA molecules (RNA1 and RNA2). The virus can be classified into four genotypes based on the partial sequences of the coat protein (CP) gene (T2 and T4 regions). Currently, genomic sequence information for RNA1 regions of RNA2 outside of T2 and T4 is less well documented. This study reports on the characterization of the full RNA2 sequence of a Tunisian betanodavirus with a length of 1433 nt, containing a 339 amino acid open-reading frame encoding the CP, and typing to the redspotted grouper nervous necrosis virus Ia genotype following phylogenetic analysis. The homology of the capsid protein to other betanodaviruses or alphanodaviruses was compared. In addition, a full length RNA1 sequence of 3104 nt encoding a 982 amino acid RNA-dependent RNA polymerase was obtained.

[Ciclosporin-associated cerebral tumor-like location of Behçet's disease]. / Forme pseudotumorale cérébrale de la maladie de Behçet sous ciclosporine.

INTRODUCTION: Cerebral tumor-like location is uncommon in the course of Behçet's disease. We report herein a patient with tumor-like lesions associated with ciclosporin therapy. CASE REPORT: A 45-year-old male treated for 17 years with colchicine and ciclosporin for Behçet's disease with cutaneomucosal, ocular and joint involvement was admitted for sudden onset of meningo-encephalitis with lymphocytic meningitis. CT-scan showed a nodular lesion of the brainstem enhanced by iodine. Ciclosporin was discontinued; prednisone and IV cyclophosphamide were started. After three months of favorable outcome, a relapse occurred when ciclosporin was started again. MRI showed two additional capsulothalamic lesions. Prednisone and cyclophosphamide were started again with a favorable response and minimal sequelae. CONCLUSION: The main challenge in cerebral tumor-like location of Behçet's disease is to rule out other inflammatory or tumor processes. Neuronal toxicity of ciclosporin limits indications for this therapy in Behçet's disease.

Mechanisms of carbapenem resistance in non-metallo-beta-lactamase-producing clinical isolates of Pseudomonas aeruginosa from a Tunisian hospital.

AIM OF THE STUDY: An increasing rate of imipenem-resistant Pseudomonas aeruginosa infections has become an important clinical problem in our hospital. The aim of this study is to determine the mechanisms involved in carbapenem resistance. MATERIALS AND METHODS: Ten strains have been randomly selected among 144 clinical isolates of carbapenem-resistant non-metallo-beta-lactamase (MBL)-producing P. aeruginosa. A phenotypic and genotypic study was performed using serotyping, antimicrobial susceptibility, detection of MBL and clonality. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for the expression of the genes oprD, mexA and mexE and by western blot for the expression of OprM. Sequencing of oprD gene was performed. RESULTS: Five genotypes have been determined by arbitrary primer polymerase chain reaction and seven strains were selected to study the mechanisms involved. The predominant serotype was O12. All isolates exhibited high minimum inhibitory concentration (MICs) to both imipenem and meropenem (MIC ranged from 16 to more than 32 microg/ml) and did not harbor genes encoding MBL as confirmed by PCR. RT-PCR showed a decline in oprD expression with increased expression of mexA compared to PAO1 wild type strain. None of the isolates overexpressed mexE. Western blot analysis of outer membrane showed overproduction of OprM in all isolates. CONCLUSION: Resistance to both imipenem and meropenem of clinical isolates of P. aeruginosa was due to two combined mechanisms: decreased transcription of oprD gene and overproduction of the MexAB-OprM efflux system.

Co-occurrence pulmonary haemosiderosis with coeliac disease in child.

Idiopathic pulmonary haemosiderosis (IPH) is a rare and serious disorder in children of unknown aetiolopathogeny. Association of IPH and coeliac disease (CD) is even rarer. Immunological origin of IPH is now well accepted. We report the case of an 11-year-old female admitted for evaluation of recurrent streaky haemoptysis that had been evolving over the previous 9 months. Physical examination revealed weight loss with normal weight, but there was cutaneous and mucosal pallor due to severe anaemia (haemoglobin 4.6g/dl). The chest X-rays showed unilateral alveolo-intertitial infiltrate. Broncho-alveolar lavage revealed 70% haemosiderin-laden macrophages. The diagnosis of IPH was made. Since severe anaemia is disproportionate to radiologic findings, searching associated CD was performed and then confirmed by biological and histological examinations. A gluten-free diet was initiated. Evolution was favourable. Looking for especially CD in IPH should be systematic, even in the absence of gastrointestinal symptoms.