clinical strains of Streptococcus agalactiae, recovered from female genital specimens and from gastric fluid or ear specimens from infected newborns, were isolated at the Laboratory of Microbiology of Charles Nicolle Hospital of Tunis. They were investigated to determine the prevalence of antibiotic resistance and to characterize the mechanisms of resistance to macrolide and tetracycline. All strains were susceptible to penicillin, ampicillin and quinupristin-dalfopristin. They were resistant to chloramphenicol (3.1 %), rifampicin (19.1 %), erythromycin (40 %) and tetracycline (97.3 %); 3.1 % were highly resistant to streptomycin and 1.3 % to gentamicin. Among the erythromycin-resistant isolates, 78.7 % showed a constitutive macrolide-lincosamide-streptogramin B (MLS B ) phenotype with high-level resistance to macrolides and clindamycin (MIC 50 .256 mg ml ) and low MICs of clindamycin (MIC 50 58 mg ml "1 ) and 2.2 % showed an M phenotype with a low erythromycin-resistance level (MIC range512-32 mg ml "1 ) and low MICs of clindamycin (MIC range: 0.75-1 mg ml). All strains were susceptible to quinupristin-dalfopristin and linezolid (MIC 90 : 0.75 mg ml "1 for each). MLS B phenotypes were genotypically confirmed by the presence of the erm(B) gene and the M phenotype by the mef(A) gene. Resistance to tetracycline was mainly due to the tet(M) gene (93.1 %) encoding a ribosome protection mechanism. This determinant is commonly associated with the conjugative transposon Tn916 (P¡0.0002). tet(O) and tet(T) existed in a minority (2.2 % and 0.4 %, respectively). The efflux mechanism presented by tet(L) was less frequently present (4.5 %). No significant association was found between erm(B) and tet(M) genes.

This study was conducted to investigate the molecular epidemiology of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in community-acquired (urinary tract) infections (CA-UTI) in Tunisia. Between January 2007 and December 2009, 15 E. coli isolates were collected at the laboratory of microbiology of Charles Nicolle Hospital of Tunis. Microbial identification was done with conventional methods. Antibiotic susceptibility was determined by disk diffusion method and ESBL detection was done with double-disk synergy test. ESBL typing was performed by polymerase chain reaction (PCR) and sequencing. Phylogenetic groups, virulence factors, and sequence type (ST)131 were determined by PCR. Genetic relatedness between strains was examined by pulsed-field gel electrophoresis (PFGE) after restriction with XbaI. The prevalence of ESBL-producing E. coli in CA-UTI was 0.046%. The majority of isolates were multidrug resistant. ESBL types were CTX-M-15 (n=13) and SHV-12 (n=2). The most common phylogenetic group was B2 (n=11) and virulence score was greater than or equal to 9 in nine strains. PFGE revealed 12 clusters. The majority of isolates (n=14) belonged to ST131 clone and 11 of them were CTX-M producers. In conclusion, this is the first detailed documentation of CA-ESBLs producing E. coli in Tunisia. Of particular concern is the emergence in our community of the highly diffusing CTX-M-15-B2-ST131 E. coli clone, which requires strengthening surveillance measures to countervail this emergent public health problem.

Eighty-two nonduplicated ampicillin-resistant Enterococcus faecium (AREF) isolates from clinical infections at the Charles Nicolle Hospital of Tunisia were investigated. They were collected from January 2001 to December 2009. Genetic relationship between them was studied using pulsed-field gel electrophoresis. The amino acid sequence difference variations of the C-terminal part of penicillin-binding protein 5 (PBP5) versus levels of expressed mRNA were investigated by polymerase chain reaction (PCR), sequencing, and real-time PCR quantification of (PBP5), respectively. No β-lactamase activity was detected and none of our strains showed resistance to glycopeptides, which retain their therapeutic efficiency against enterococcal infections in our hospital. Pattern analysis of the strains revealed six main clones disseminating in different wards. Sequence data revealed the existence of 19 different plp5 alleles with a difference in 16 amino acid positions spanning from residue 414 to 632. Each allele presented at least five amino acid substitutions (His-470→Gln, Asn-496→Lys, Ala-499→Thr, Glu-525→Asp, and Glu-629→Val). No correlation between amino acid sequence polymorphism of PBP5 and levels of ampicillin resistance was detected. The levels of plp5 mRNA expression varied between strains and did not always correlate with levels of ampicillin resistance in clinical AREF.

SUMMARY Interferon‐gamma (IFN‐γ) titres in 20 patients with active Behçet's disease were examined and compared with those of 20 normal donors. Sera from Behçet's disease patients revealed an IFN‐γ increase but no correlation between IFN level and natural killer (NK) activity. The analysis of lymphocyte subsets by monoclonal antibodies registered an increase of CD8+ T subpopulation and cells co‐expressing CD8+ ‐Leu 7a+ markers. Moreover, a high number of cells expressing CD25+ and HLA‐DR+ phenotype has been noted in patients with active Behçet's disease. Serological analysis showed a high level of IgG antibodies to HSV‐1. The increase of IFN‐γ litre, the high number of activated T cells and the increasing level of IgG antibodies to HSV‐1 are important manifestations during the active stage of Behçet's disease. These findings are discussed in relation to the immunopathogenesis of Behçet's disease.

Introduction: Rhinoviruses (HRV) are among the leading causes of Severe Acute Respiratory Infection (SARI). Their burden and genetic diversity vary from one region to another and little is known in Northern African regions. This study describes epidemiological patterns and genotypic diversity of HRV in SARI cases during a two and half year’s study, in Northern Tunisia. Methodology: A total of 271 SARI cases, admitted into the Pediatric Intensive Care Unit of Bechir Hamza Children's Hospital in Tunis, were collected between September 2015 and December 2017. The investigation concerned 104 samples positive for HRV and/or HEV (Human Enterovirus) obtained among these cases. Specific HRV and HEV detections were assessed by real-time PCRs. The HRV molecular typing was based on the VP4-VP2 genomic region analyses. Results: Among the viral SARI cases, 33.5% and 12.3% were positive for HRV and HEV respectively. Molecular investigations showed high prevalence of HRV-A (63.3%) followed by HRV-C (30.6%) and HRV-B (6.1%) and high genotypic diversity with 27 types. HRV cases were mostly detected in toddlers younger than 6 months. A total of 16 cases (28%) were found with bacterial and/or viral co-infection. HRV-C infection and HRV-A with bacterial co-infection were associated with complicated infection. Some of the detected types showed a continuous circulation or turnover during an extended period. HRV-A101 and HRV-C45 were the most frequently detected types. Conclusions: This study revealed, for the first time, the high HRV diversity in Tunisia, a North-African region. Specific phylogenetic investigations may help to evaluate their diversity and to trace their spread and epidemiological origin.