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Biomedical subjects

S Ben Redjeb

Publications and source records attributed to S Ben Redjeb.

At least 55 records · Page 3Linked to original sources
PubMed1991

Species incidence and antimicrobial-agent resistance patterns of Enterobacteriaceae in Charles Nicolle Hospital, Tunis, from 1983 to 1987.

Between July 1983 and December 1987, 13,108 strains of enterobacteriaceae were isolated at Charles Nicolle Hospital in Tunis. This study reports the prevalence of different species isolated, their resistance and the evolution of bacterial resistance during that period. There appeared to be a great stability in the distribution of bacterial groups. Among the commonly sensitive species, Proteus mirabilis showed a high proportion of strains resistant to ampicillin (79.3%), carbenicillin (75.9%), cefalotin (73.8%) and gentamicin (46%). The proportions of resistant strains in P. mirabilis were much the same for each successive year from 1983 to 1987, and the percentages of resistant strains in the majority of the bacterial species were similarly stable. Amikacin and cefotaxime remained the most active antibiotics against enterobacteriaceae.

Drug Resistance, Microbial↗
PubMed1991

[Beta-lactam and aminoglycoside resistant phenotypes in enterobacteria isolated in pediatrics].

Beta-lactams and aminoglycosides are widely used in the therapy of serious Gram negative infections in pediatrics. In order to survey acquired resistance, the phenotype of resistance to beta-lactams and aminoglycosides were characterized for 260 strains of enterobacteriaceae among the mainly isolated species in pediatrics. These phenotypes were established according to the results of the disk susceptibility tests for beta-lactams respectively ampicillin, ticarcillin, cefaloridin and cefotaxim, and aminoglycosides, streptomycin (S), gentamicin (G), tobryamycin (T), amikacin (A), and netilmicin (N). 49% of E. coli and 73% of P. mirabilis strains were resistant to 3 beta-lactams (RRRS). 72% of Salmonella spp. strains were resistant to 4 beta-lactams (RRRR). For the majority of strains, the mainly observed resistance phenotype to aminoglycosides was streptomycin resistance excepted for Salmonella spp., which was S + KGTNA. The high level of acquired resistance to beta-lactams and aminoglycosides among Enterobacteriaceae with the selection of multiresistant strains would be explained by the wild use of cefotaxim and amikacin in pediatrics.

Aminoglycosides↗
PubMed1990

Two novel transferable extended-spectrum beta-lactamases from Klebsiella pneumoniae in Tunisia.

Two novel beta-lactamases conferring multiresistance to antibiotics including oxyimino beta-lactams have been identified in two nosocomial K. pneumoniae strains isolated in Tunis in 1986 and 1988. Both enzymes were encoded by ca. 150-kilobase plasmids. Donor and transconjugant strains producing these enzymes exhibited highly similar pattern of resistance (CTX phenotype) to beta-lactams including penicillins and oxyimino beta-lactams e.g. cefotaxime, ceftriaxone, ceftazidime, and aztreonam. High and variable synergy (16 to 1066-fold) was obtained when combined to 0.1 microgram/ml of clavulanate (beta-lactamase inhibitor). The isoelectric points of these two enzymes were 5.4 and 6.4. These beta-lactamases differed from TEM types by hydrolysis for cefotaxime or ceftriaxone but were inhibited by clavulanate and cloxacillin. DNA hybridization studies suggested that that the genes of these enzymes may be derived from genes encoding TEM-type enzymes.

DNA, Bacterial↗
PubMed1990

[Enzymatic resistance to cefotaxime in 56 strains of Klebsiella spp., Escherichia coli and Salmonella spp. at a Tunisian hospital (1984-1988)].

The enzymatic and plasmid-encoded resistance towards oxyimino-beta-lactams has been recently reported as related to the production of an extended-spectrum beta-lactamase (e.g. SHV-2, CTX-1 or TEM-3), in particular in our hospital since 1984. The prevalence of that resistance has been examined from January 1984 to December 1988 in function of specimen, unit and type of enzyme among 8,421 isolates of Klebsiella spp., E. coli, Salmonella spp. Each isolate showing a diameter of inhibition zone size inferior or equal to 25 mm for cefotaxime, the double disk synergy test was performed between a disk of amoxicillin and a clavulanic acid disk of cefotaxime, ceftriaxone, ceftazidime and aztreonam. In case of synergy, sonicated extracts have been prepared and examined by isoelectrofocusing with the detection of beta-lactamase activity by ceftriaxone and nitrocefin. 56 isolates (K. pneumoniae, K. oxytoca, E. coli, S. wien, S. typhimurium scored positive including 27 in pediatrics, 18 in surgery, and 8 in medicine. 41% of isolates have been obtained from blood cultures and 26.8% from urines. A majority of isolates (49/56) produced the SHV-2 type, but other types mediating the resistance phenotype CTX have been individualized initially by their isoelectric points e.g. 5.4 (TEM-20 in K. pneumoniae in July 1986), 6.4 (TEM-21 in E. coli, 1 K. pneumoniae in July 1988). The prevalence of resistance to cefotaxime from 1984 to 1988 has increased (from 0.3 to 1.4%), the highest rate being observed in pediatrics (5.6% in 1984 and 22.1% in 1988).

Cefotaxime↗