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S Ben Redjeb

Publications and source records attributed to S Ben Redjeb.

67 records · Page 4Linked to original sources
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Epidemiology of extended spectrum beta-lactamases.

Beta-lactamases play a major part in resistance, as recently redemonstrated by the emergence of extended spectrum beta-lactamases. Since its discovery in FR Germany, SHV-2 has been reported from four continents and CTX-1 (TEM-3) was established in at least 26 French hospitals. More than 12 other enzymes have been individualized. The newest aspect of resistance was probably underestimated because most strains of enterobacteria (mainly Klebsiella pneumoniae) appeared susceptible to oxyimino-beta-lactams as suggested by MICs or diameters of inhibition zone sizes. The double-disk synergy test between amoxicillin/clavulanic acid and oxyimino-beta-lactams was useful to easily detect two susceptibility patterns (CTX, CAZ). Extended spectrum beta-lactamases isolated among nosocomial isolates of enterobacteria (urines, blood, wound, sputum cultures) mostly from intensive care units have spread through hospitals. If outbreaks were described, numerous serotypes were identified in Klebsiella pneumoniae. In France the distribution of extended spectrum beta-lactamases showed that CTX-1 (TEM-3) was well distributed among ten species unlike SHV-type enzymes (SHV-2, SHV-3, SHV-4) preferentially detected in Klebsiella pneumoniae. A majority of strains produced CAZ-type enzymes in Escherichia coli. Some isolates produced two extended spectrum beta-lactamases. In Tunisia extended spectrum beta-lactamase producing strains were mainly identified among pediatric isolates of Klebsiella pneumoniae, Salmonella and Escherichia coli; SHV-2 was predominant but recently CTX-1 and two other types with an isoelectric point of 6.35 and 5.4 (phenotype CTX) were individualized. Because plasmid-encoded, this mechanism was spreading in France among enterobacteria with other resistance markers (e.g. netilmicin, amikacin) for CTX-1 unlike SHV-2.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMedDate not supplied

[Pseudomonas aeruginosa and beta-lactam resistance phenotypes (Tunisia 1989-1990)].

366 strains of P. aeruginosa were studied. More than half of samples were issued from urology (40%) and general surgery (21%) and samples are mostly urine specimens (46%). The phenotypes of resistance to 3 beta-lactams (respectively ticarcillin, cefotaxime and ceftazidime) showed that 73% of the strains were wild phenotype (SSS-SIS-SRS). The MIC of ticarcillin +/- clavulanic acid, azlocillin, cefoperazone, cefsulodin, cefotaxime and ceftazidime against 93 strains chosen among different phenotypes of resistance showed that ceftazidime is the most active beta-lactam, 93% of strains being inhibited by 16 micrograms/ml. These MIC and iodometric test performed on 33 strains with ticarcillin MIC > 128 mg/l showed that acquired resistance was non enzymatic in 21% of cases and was related to beta-lactamase production in 79% of cases.

Cefotaxime↗
PubMedDate not supplied

[Non-groupable streptococci: identification, sensitivity to antibiotics (Charles Nicolle Hospital in Tunis)].

50 strains of viridans streptococci isolated from human material are identified by biochemical tests (bile esculin, Cl Na 6,5%, acid production from lactose, mannitol, sorbitol, inulin, arginine, esculin and starch hydrolysis; production of levan and dextran in sucrose media) Streptococcus salivarius and Streptococcus mitis are predominant species. Susceptibility to antibiotics was studied: 70% of viridans streptococci were susceptible to all antibiotics tested, high level resistance to aminoglycoside was not present. The only resistance observed were to tetracycline, macrolides and related drugs.

Aminoglycosides↗
PubMedDate not supplied

[Group D streptococci and enterococci: identification, sensitivity to antibiotics and a study of the high level resistance to aminosides (Charles Nicolle Hospital in Tunis)].

197 strains of enterococcus and group D Streptococcus were isolated from human material at Charles Nicolle Hospital (Tunis) and identified by biochemical tests: 174, Enterococcus faecalis, 6 Enterococcus faecium, 2 Enterococcus durans and 15 Streptococcus bovis. The sensitivity to antibiotics was studied: all Enterococcus faecium were resistant at least to one antibiotic, 15% of Enterococcus faecalis were sensitive for all antibiotics tested the other species were frequently sensitive. High level resistance to aminoglycosides were frequent in Enterococcus faecalis 40%: among these strains high level resistance to gentamicin accounts for 12% and 18 frequently associated with resistance to kanamycin and streptomycin, this situation present therapeutic problems in case of severe infection.

Aminoglycosides↗
PubMedDate not supplied

[Study of antibiotic sensitivity of Streptococcus pyogenes isolated in the hospital milieu (Charles Nicolle hospital of Tunis)].

The purpose of the present work was to investigate the susceptibility of S. pyogenes to antimicrobial agents. The strains have been taken from the bacteriological Service of Charles Nicolle's hospital at Tunis, and that during the period from January 1988- to December 1990. The antibiogram results as well as the minimal inhibitrice concentration determined by the agar diffusion technique, reveal that S. pyogenes continues to be very susceptible to the beta-lactamins (M.I.C. of penicillin G is "0.15 for 50% of strains tested. Resistance are noted for chloramphenicol; tetracycline and novobiocine (13%, 93%, 80%) not considered as good antibiotics anti-streptococcies. The macrolids are effective against S. pyogenes (100% of susceptibility) that's they are considered as the best alternating antimicrobiologents to the beta-lactamins (M.I.C. of erythromycin is 0.015.

Anti-Bacterial Agents↗