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B Joly

Publications and source records attributed to B Joly.

At least 73 records · Page 4Linked to original sources
PubMed1987

Multiplicity of serogroups and adhesins in enteropathogenic and enterotoxigenic Escherichia coli isolated from acute diarrhea in Senegal.

Escherichia coli strains were isolated from 228 children with diarrhea in Senegal from 1982 to 1984. Among these E. coli involved in cases of diarrhea, we found that 20.3% were enteropathogenic E. coli. Only 3.9% of the strains adhered to the brush borders of human intestinal enterocytes, and they belonged to different serotypes. All these adhesion-positive strains possessed genes encoding for the heat-stable enterotoxin, but their adhesive factors were different regarding serology with anti-colonization factor sera, hemagglutination patterns, electron microscopy structures, or major surface protein subunits.

Acute Disease↗
PubMed1986

[In vitro comparative study of piperacillin-aminoglycosides combinations against Enterococci and Enterobacteriaceae].

The hundred and ninety-two combinations were tested against 17 strains chosen from the results of MIC determination (disc method): 5 enterococci exhibiting low level resistance (r) or high level resistance (R) to streptomycin (S) and gentamicin (G): 2 strains Sr Gr, 2 strains SR Gr and 1 strain Sr GR; 12 enterobacteria chosen for their resistance phenotypes to beta-lactams and aminoglycosides and because they are the most frequent clinical isolates: 2 strains Amos Tics Ctns (group 1), 4 strains AmoR Tics CtnR (gr. II), 4 strains AmoR TicR Ctns (gr. III) and 2 strains AmoR TicR CtnR (gr. IV). MIC and MBC were assessed for the 17 strains (Mueller Hinton broth). Combinations were carried out by a checkerboard micromethod. FBC index was calculated for each combination. Against enterococci the 50 combinations were: piperacillin versus ampicillin + aminoglycosides (streptomycin, tobramycin, amikacin, gentamicin, netilmicin). Against enterobacteria piperacillin was combined with different aminoglycosides depending on their resistance phenotypes. These combinations were compared with ticarcillin or mezlocillin or cefotaxime + aminoglycosides (total number 142). The species studied produced different results: with the enterococci Gr synergistic effects (FBC = 0.62-0.75) were rare; additive and indifferent effects were predominant. With the GR strain some antagonistic effects were observed. With the enterobacteria, in groups I and II synergistic effects were frequent and almost equivalent regardless of the beta-lactam chosen. In groups III and IV (TicR) piperacillin MICs were greater than or equal to 128 mg/l and mezlocillin MICs greater than 512 mg/l; the synergistic effects were significant (FBC from 0.25 to 0.62). beta-lactam + amikacin or netilmicin, and especially piperacillin + amikacin, were found to have the most frequent synergistic effects upon the strains tested. Mezlocillin combinations cannot be used clinically; the use of piperacillin combinations requires further discussion. On the other hand, cefotaxime + aminoglycosides combinations are active against those TicR strains.

Aminoglycosides↗
PubMed1986

A comparison of agar dilution, identification of beta-lactamases and disc diffusion methods for assessing the sensitivity to ticarcillin-clavulanic acid.

The in-vitro antibacterial activity of Timentin has been evaluated with a view to proposing valid criteria for sensitivity and resistance. Minimal inhibitory concentrations (MIC) were determined for 284 strains including Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp., staphylococci and enterococci. The same strains were also used for the determination of inhibition zones around discs containing 75 micrograms ticarcillin and 10 micrograms clavulanic acid, and a straight regression line was drawn correlating MIC with inhibition zones. The bacterial population was subsequently grouped according to the diameters of inhibition zones of the antibiogram for 2427 strains of Enterobacteriaceae classified by phenotypes. The comparison of MICs of Timentin and ticarcillin for these strains shows that for penicillinase-producing strains, the Timentin MIC is lower than for ticarcillin whereas cephalosporinase-producing strains have equal MICs for the two. Finally strains that produce many different beta-lactamases are not affected by the presence of clavulanic acid. These results should make it possible to propose provisional zone diameters for determining sensitivity and resistance to Timentin.

Agar↗
PubMed1986

Identification of a nonfimbrial adhesive factor of an enterotoxigenic Escherichia coli strain.

An enterotoxigenic Escherichia coli strain (strain 2230), isolated from a patient with acute infantile diarrhea, was found to adhere only to the brush border of human intestinal epithelial cells. This strain does not hemagglutinate human, bovine, chicken, or guinea pig erythrocytes. The adhesion of E. coli 2230 appears to be mediated by a nonfimbrial bacterial surface protein of 16,000 daltons which can be extracted by heating the bacteria at 60 degrees C for 20 min. This surface protein is implicated as an adhesive factor because pretreatment of enterocytes with this protein extract completely inhibits the adhesion of E. coli 2230. This adhesive factor is serologically distinct from other adhesive factors found in enterotoxigenic E. coli strains. A plasmid DNA of 66 megadaltons is involved in the synthesis of this nonfimbrial adhesive factor.

Adhesiveness↗
PubMed1986

Resistance to beta-lactams in Enterobacteriaceae: distribution of phenotypes related to beta-lactamase production.

Phenotypes of susceptibility to amoxycillin (Amo), ticarcillin (Tic), cephalothin (Ctn) were determined in 1366 isolates of Enterobacteriaceae by disk method and beta-lactamases were identified in 243 strains belonging to different phenotypes of amoxycillin-resistant strains. AmoR TicR CtnS strains (25%) were penicillinase producers and all of them were susceptible to the combination amoxycillin/clavulanic acid (Amo/CA) and ticarcillin/clavulanic acid (Tic/CA). Amo1/R TicS CtnR strains (12%) were cephalosporinase producers and resistance to Amo/CA was observed, except for Proteus vulgaris. AmoR TicR CtnR strains (18%) often produced two beta-lactamases (penicillinase and cephalosporinase) and they were resistant to Amo/CA; in this group, susceptibility to Tic/CA depends on the nature and the amount of the beta-lactamase produced, except for Serratia marcescens for which antibiotic resistance is probably due to other mechanisms. Tic/CA resistance was mainly found in Serratia marcescens (41%) and Enterobacter cloacae (36%).

Amoxicillin↗
PubMed1986

[In-vitro activity of cefonicid on hospital bacteria. Regression line and proposal for critical values].

Antimicrobial activity of cefonicid, a new second generation cephalosporin, against 315 hospital isolates (4th trimester 1984) was investigated. E. coli and Proteus mirabilis were the most susceptible species. All E. coli strains except one were inhibited at 8 mg/l (modal MIC: 0.5); MICs of all indole + Proteus were 8 mg/l (modal MIC: 0.06). Another group was moderately susceptible: MICs of Klebsiella and Citrobacter ranged from 0.12 to 128 mg/l, but MICs of 50% of these strains were less than or equal to 4 mg/l; MIC was less than or equal to 8 mg/l for 75% of indole + Proteus and Providencia strains; tested Proteus vulgaris were especially resistant (MICs greater than 128 mg/l). Most Enterobacter and Serratia strains showed little susceptibility (modal MIC for both species greater than or equal to 128 mg/l). MICs of all tested Pseudomonas aeruginosa strains were greater than 128 mg/l. 20 of the 24 tested Acinetobacter strains had a MIC of greater than or equal to 128 mg/l. For Staphylococcus aureus, 88% of methicillin-sensitive strains were inhibited by concentrations of 2 to 4 mg/l whereas methicillin-resistant strains were resistant to cefonicid (75%: MIC greater than 64 mg/l). Enterococci were resistant to cefonicid. A correlation curve was established (Enterobacteria and Staphylococci). On the basis of cefonicid's pharmacokinetic characteristics, critical concentrations are proposed.

Bacteria↗
PubMed1986

[Proposal for a method of studying the activity of soap or antiseptic against the microbial flora of the hands after a single surgical scrub].

The authors, all members of the Antiseptics group of the Societé Française de Microbiologie, propose a standardised method for the evaluation of the activity of antiseptics on the microbial flora of the hands in the context of surgical scrubbing. This paper defines the aims of the method, its field of application and describes the media and materials required. The various phases of the preliminary study and the definitive trial also described.

Anti-Infective Agents, Local↗
PubMed1985

[Carbenicillin resistance of gram-negative bacteria: incidence, biochemical and genetic determinism].

Of nine hundred ampicillin resistant (Amp-R) enterobacteria strains, isolated in hospital between July and December 1981, 73,7% are also carbenicillin-resistant (Carb-R). This particular double resistance varies depending upon the species considered: indole positive Proteus (23%), Enterobacter cloacae (64%), Citrobacter freundii (67%), Acinetobacter calcoaceticus (73%), Proteus mirabilis (75%), Serratia marcescens (90%), Escherichia coli (91%), Providencia stuartii (96%) and Klebsiella pneumoniae (100%). The biochemical and genetic basis of resistance to beta-lactamines was studied in 27 strains belonging to these 9 species. A constitutive beta-lactamase was found in all the strains. These enzymes were identified by determination of the isoelectric point on crude sonic extracts, the enzymic activity profile, the inhibition by clavulanic acid and cloxacillin of enzyme activity. Two types of enzymes were predominant: TEM-1 (20 strains) and TEM-2 (7 strains); two strains of Klebsiella pneumoniae produced both SHV-1 and TEM-1. The transfer by conjugation to E. coli K12 of ampicillin and carbenicillin resistance was obtained with 14 strains: (E. coli: 9, C. freundii: 1, K. pneumoniae: 1, E. cloacae: 2, P. stuartii: 1). In all strains but one E. coli we noted the co-transfer of other antibiotic resistance markers.

Ampicillin↗
PubMed1984

Effects of antibiotics on adhesion of enterotoxigenic Escherichia coli strains.

Subinhibitory concentrations of 28 antibiotics were tested for their effects on MRHA patterns of four enterotoxigenic Escherichia coli strains possessing colonization factor antigens CFA/I, CFA/II or CFA/III. Only penicillin G, oleandomycin, doxycycline and minocycline inhibited the haemagglutination pattern of three Escherichia coli strains with CFA/I and CFA/II when added to the medium culture at concentrations ranging from 1/2 to 1/50 of the MIC. At the same concentrations they also decreased the adhesion index of the four strains to human intestinal cells. However, neither the specific agglutination of bacterial cells with CFA antisera nor the production of CFAs was affected.

Adhesiveness↗
PubMed1984

[Qualitative and quantitative analysis of the residual hand flora after hygienic-type washing with a soap and a foaming antiseptic solution].

Activity of a liquid soap and of a 4% povidone iodine detergent solution on hand skin flora after application for one minute ("hygienic type" handwashing) was studied. Samples were taken using a "bag" washing method. Total aerobic flora was determined quantitatively. Transient flora (Gram negative bacilli and mannitol positive Staphylococci) was determined both quantitatively and qualitatively. 54 determinations were performed (29 with liquid soap and 25 with povidone iodine) on 17 volunteers of the staff of the hospital bacteriology laboratory. After application of liquid soap, total flora, i.e. 10(6) bacteria per hand, was not reduced and the number of mannitol positive Staphylococci was increased. With povidone iodine, the reduction in total flora was 0.2-0.3 log 10 and the number of mannitol positive Staphylococci was decreased. With both products, Gram negative bacilli were eliminated in 60% of cases and greatly reduced in the remainder.

Hand↗
PubMed1984

[Comparative activity of sulfamethoxazole-trimethoprim (SMZ-TMP) on bacteria responsible for ORL infections].

The bacteriostatic activity in vitro of co-trimoxazole (SMZ-TMP); ampicillin, tetracycline and oleandomycin was evaluated against 225 bacterial strains. All the strains (49 Pneumococci, 49 Haemophilus, 41 Streptococci and 86 Staphylococcus aureus) were isolated from sinusitis (63 strains) and otitis (162 strains) in monomicrobial samples. The minimal inhibitory concentrations (MICs) of the 4 antibiotics were determined by the agar diffusion method on all strains. Moreover MICs of SMZ-TMP were determined by the broth dilution method on Haemophilus strains. Seventy seven p. cent of the strains were found sensitive to SMZ-TMP, 70.7% to ampicillin, 85.4% to tetracycline and 73% to oleandomycin. SMZ-TMP was the most effective on Staphylococcus aureus (80% of the isolates were sensitive), whereas ampicillin was effective on all Streptococcus, and Pneumococcus strains and tetracycline was the most active on Haemophilus strains (88% of the isolates were sensitive).

Ampicillin↗
PubMed1983

[In vitro activity of combinations of cefotaxime and moxalactam with aminoglycosides on beta-lactamase-producing Enterobacteriaceae].

The in vitro synergistic activities of cefotaxime (Ctx) or moxalactam (Mox) in combination with gentamicin, amikacin, dibekacin or netilmicin were compared against 15 beta-lactamases non-producing or producing isolates of Enterobacteriaceae. The strains were classified according to their resistance to ampicillin (Am), carbenicillin (Cb) and cephalotin (Ce), but all were sensitive to the antibiotics tested in combination. In vitro checkerboard studies were performed using a microtiter technique for the selected strains. The FIC index was less than or equal to 0.62 for AmR CbR CeR strains (E. coli, E. cloacae, Serratia), for AmR CbS CeR strains (E. cloacae, Serratia, P. vulgaris) and for AmS CbS CeR strains (Serratia, P. morganii). These combinations were frequently additive (FIC = 0.75 - 1.0) against the AmS CbS CeS or AmR CbR CeS strains. Thus, the synergistic activities of Ctx and Mox in combination with an aminoglycoside seem to be correlated with beta-lactamase type produced by the Enterobacteriaceae.

Aminoglycosides↗
PubMed1983

[In vitro study of the bacteriostatic and bactericidal activity of temocillin (BRL 17421)].

Temocillin is a carboxypenicillin; a methoxy group in the 6-alpha position should confer to the molecule greater stability to beta-lactamases. 236 strains isolated from clinical specimens were tested. MICs were determined by agar dilution method. Enterobacteriaceae were very susceptible, MICs being generally less than or equal to 8 micrograms/ml and always less than 32 micrograms/ml. The activity of the drug was equal against the beta-lactamases producing strains. On the other hand temocillin was not active against aerobes (Pseudomonas aeruginosa and 90% of Acinetobacter), and against Gram positive bacteria. The bactericidal effect was strong: (formula; see text) A regression-line was proposed for Enterobacteriaceae and "break-points" were discussed.

Bacteria↗
PubMed1983

[Effect of trimethoprim at a subinhibitory concentration on the appearance of mutants resistant to rifampicin].

Experiments have been performed to establish the effect of trimethoprim (Tmp) on the emergence of Staphylococcus aureus (S. aureus) mutants to rifampicin (Ramp). Four S. aureus strains were used: two strains with low MIC of Ramp (0,01 microgram/ml), two strains with enhanced MIC of Ramp (2 micrograms/ml). For each of them the frequency of mutants and the mutation rates to Ramp were determined when various concentrations of Tmp were added. Results showed that subinhibitory concentrations of Tmp reduced 10 to 100 folds the frequency of mutants and the rates of mutation to Ramp alone. The more the Tmp concentrations were near the MIC, the more this effect was important.

Drug Resistance, Microbial↗