Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Shibl, Atef M.; Gemmell, C. G.

doi:10.1099/00222615-16-3-341

Cited by 18 publications

(7 citation statements)

References 21 publications

(11 reference statements)

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“…The clindamycin effect has been observed for extracellular proteins in a variety of organisms, including streptolysin S and M protein production by Streptococcus pyogenes (9,37) and extracellular lipase production by Propionibacterium acnes and P. granulosum (39). Similar effects have been observed for tetracycline and aminoglycosides, which down-regulate protease production by Pseudomonas aeruginosa (36) and hemolysin production by Escherichia coli (38). In some cases, disparate results have been reported by different investigators, which may well represent interstrain differences.…”

Section: Discussionsupporting

confidence: 52%

Subinhibitory Clindamycin Differentially Inhibits Transcription of Exoprotein Genes in Staphylococcus aureus

2001

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It has long been known that certain antibiotics, at subinhibitory concentrations, differentially inhibit the synthesis of ␣-hemolysin and other staphylococcal virulence factors. In this report, we show that subinhibitory clindamycin (SBCL) eliminates production of nearly all exoproteins by Staphylococcus aureus but has virtually no effect on cytoplasmic proteins. The effect was abolished by a gene conferring resistance to macrolides-lincosamides-streptogramin B, showing that differential inhibition of protein synthesis is responsible; remarkably, however, subinhibitory clindamycin blocked production of several of the individual exoprotein genes, including spa (encoding protein A), hla (encoding ␣-hemolysin), and spr (encoding serine protease), at the level of transcription, suggesting that the primary effect must be differential inhibition of the synthesis of one or more regulatory proteins. In contrast to earlier reports, however, we found that subinhibitory clindamycin stimulates synthesis of coagulase and fibronectin binding protein B, also at the level of transcription. agr and sar expression was minimally affected by subinhibitory clindamycin. These effects varied from strain to strain and do not seem to be responsible for the effects of subinhibitory clindamycin on the overall exoprotein pattern.

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Section: Discussionsupporting

confidence: 52%

Subinhibitory Clindamycin Differentially Inhibits Transcription of Exoprotein Genes in Staphylococcus aureus

2001

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“…In general, the MIC is reported as the lowest concentration of the antimicrobial agent that prevents growth or hemolysis. However, reading end points by means of hemolysis can be subjective because subinhibitory concentrations of some antimicrobial agents may prevent hemolysis in certain bacterial species (24,25). With regard to Brachyspira spp., this situation is a problem because growth on agar after inoculation with 10 5 CFU/spot is difficult to detect for many isolates and the absence of hemolysis is the only means of observing growth inhibition.…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial Susceptibility Testing of Porcine Brachyspira ( Serpulina ) Species Isolates

Karlsson¹,

Fellström

Gunnarsson

et al. 2003

J Clin Microbiol

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No standardized method for susceptibility testing of Brachyspira spp. is currently available. A broth dilution procedure was evaluated and used to test the activities of six antimicrobial agents for 108 isolates of Swedish porcine Brachyspira spp. representing biochemical groups I, II, and III. Group I corresponds to Brachyspira hyodysenteriae, group II corresponds to B. intermedia, and group III corresponds to B. murdochii and B. innocens. A panel was designed with the antimicrobial agents dried in tissue culture trays with wells that allowed a liquid volume of 0.5 ml in each and agitation of the broth when incubated on a shaker. The MICs were determined by using brain heart infusion broth with 10% fetal calf serum. For 10 isolates, the results obtained in broth were compared to the MICs obtained on two different types of agar. Different inoculum densities and incubation times were also compared. The concentrations at which 90% of the B. hyodysenteriae isolates (n ‫؍‬ 72) were inhibited in the broth dilution test by tiamulin (0.25 g/ml), tylosin (>256 g/ml), erythromycin (>256 g/ml), clindamycin (>4 g/ml), virginiamycin (4 g/ml), and carbadox (0.06 g/ml) were determined. The MICs tended to be lower in broth than on agar. Differences in inoculum densities and incubation times had little influence on the MICs. The evaluated broth dilution test was simple to perform, the end points were easily read, and the results were reproducible and reliable. No isolates with decreased susceptibility to tiamulin were found among the Swedish isolates tested.

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“…The biosynthesis of toxins may be stimulated or inhibited when the producer organism is grown in media containing sub-MIC levels of antibiotics. For example, streptomycin inhibited the production of haemolysin by Escherichia coli (Shibl and Gemmell 1983). Coagulase and haemolysin production by Staphylococcus aureus was inhibited by lincomycin and clindamycin (Gemmell and Shibl 1976).…”

Section: Introductionmentioning

confidence: 99%

Effect of sub‐inhibitory concentrations of antibiotics on the virulence of Staphylococcus aureus

Doss

Tillotson

Amyes

1993

Journal of Applied Bacteriology

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The production of virulence factors by various bacteria can be influenced by sub-inhibitory concentrations of antibiotics. The effect of six antibiotics on the production of representative extracellular enzymes and toxins produced by Staphylococcus aureus was investigated. The production of the virulence determinants coagulase, protein A, alpha and delta haemolysin was monitored in the presence of ciprofloxacin, enoxacin, chloramphenicol, gentamicin, tetracycline and methicillin. The protein synthesis inhibitors reduced the production of coagulase and protein A, and almost completely inhibited the production of the haemolysins. Haemolysin production was also reduced by ciprofloxacin and enoxacin, but these antibiotics had little effect on the production of coagulase and protein A. Methicillin stimulated the production of alpha and delta haemolysins but had no effect on the production of coagulase and protein A.

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Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli

Cited by 18 publications

References 21 publications

Subinhibitory Clindamycin Differentially Inhibits Transcription of Exoprotein Genes in Staphylococcus aureus

Subinhibitory Clindamycin Differentially Inhibits Transcription of Exoprotein Genes in Staphylococcus aureus

Antimicrobial Susceptibility Testing of Porcine Brachyspira ( Serpulina ) Species Isolates

Effect of sub‐inhibitory concentrations of antibiotics on the virulence of Staphylococcus aureus

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