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Opposite effects of cefoperazone and ceftazidime on S‑ribosylhomocysteine lyase/autoinducer-2 quorum sensing and biofilm formation by an Escherichia coli clinical isolate.

Shi HQ, Sun FJ, Chen JH, Yong XL, Ou QY, Feng W, Xia PY - Mol Med Rep (2014)

Bottom Line: CAZ at 1/4 MIC reduced luxS mRNA levels and the production of AI‑2, whereas CFP at 1/4 MIC had the opposite effect.AS‑ODNs targeting luxS significantly decreased the aforementioned inhibitory effects of CAZ and the induction effects of CFP on E. coli biofilm formation.Therefore, biofilm formation by the E. coli clinical isolate E42 was evoked by CFP but attenuated by CAZ at sub‑MICs, via a luxS/AI‑2‑based quorum sensing system.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.

ABSTRACT
To investigate the effects of subminimum inhibitory concentrations of cephalosporins on bacterial biofilm formation, the biofilm production of 52 Escherichia (E.) coli strains was examined following treatment with cephalosporin compounds at 1/4 minimum inhibitory concentrations (MICs). Ceftazidime (CAZ) inhibited biofilm formation in seven isolates, while cefoperazone (CFP) enhanced biofilm formation in 18 isolates. Biofilm formation of E. coli E42 was inhibited by CAZ and induced by CFP. Therefore, using reverse transcription‑polymerase chain reaction, the expression of the biofilm‑modulating genes of this isolate was investigated. To monitor the production of the autoinducer of quorum sensing in E. coli, autoinducer‑2 (AI‑2) production was detected by measuring the bioluminescence response of Vibrio harveyi BB170. Antisense oligonucleotides (AS‑ODNs) targeting S‑ribosylhomocysteine lyase (luxS) inhibited the expression of the luxS gene in E. coli. CAZ at 1/4 MIC reduced luxS mRNA levels and the production of AI‑2, whereas CFP at 1/4 MIC had the opposite effect. AS‑ODNs targeting luxS significantly decreased the aforementioned inhibitory effects of CAZ and the induction effects of CFP on E. coli biofilm formation. Therefore, biofilm formation by the E. coli clinical isolate E42 was evoked by CFP but attenuated by CAZ at sub‑MICs, via a luxS/AI‑2‑based quorum sensing system.

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Expression of pfs, luxS, hha, tomB, ariR and tnaA in the cultures grown for 3 h in the presence of 1/4 MIC of CAZ or CFP. A 16S rRNA was used as an internal standard. For all experiments, n=3. *P<0.05, compared with C. CAZ, ceftazidime; CFP, cefoperazone; MICs, minimum inhibitory concentrations; C, control; luxS, S-ribosylhomocysteine lyase.
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f2-mmr-10-05-2334: Expression of pfs, luxS, hha, tomB, ariR and tnaA in the cultures grown for 3 h in the presence of 1/4 MIC of CAZ or CFP. A 16S rRNA was used as an internal standard. For all experiments, n=3. *P<0.05, compared with C. CAZ, ceftazidime; CFP, cefoperazone; MICs, minimum inhibitory concentrations; C, control; luxS, S-ribosylhomocysteine lyase.

Mentions: To determine which regulator gene is involved in the effects of CAZ and CFP on E42 biofilm formation, the changes in the mRNA levels of important regulator genes (pfs, luxS, ariR, tnaA, hha and tomb) in the bacterial cultures 3 h following inoculation were examined. Among these six genes, the levels of luxS mRNA were associated with CAZ or CFP treatment, whereas mRNA levels of the five other genes were not changed (Fig. 2). The present data suggested that luxS/AI-2 QS may be involved in the inhibitory effects of CAZ and the inductive functions of CFP on E. coli biofilm formation. Therefore, the subsequent experiments focused on luxS/AI-2 QS.


Opposite effects of cefoperazone and ceftazidime on S‑ribosylhomocysteine lyase/autoinducer-2 quorum sensing and biofilm formation by an Escherichia coli clinical isolate.

Shi HQ, Sun FJ, Chen JH, Yong XL, Ou QY, Feng W, Xia PY - Mol Med Rep (2014)

Expression of pfs, luxS, hha, tomB, ariR and tnaA in the cultures grown for 3 h in the presence of 1/4 MIC of CAZ or CFP. A 16S rRNA was used as an internal standard. For all experiments, n=3. *P<0.05, compared with C. CAZ, ceftazidime; CFP, cefoperazone; MICs, minimum inhibitory concentrations; C, control; luxS, S-ribosylhomocysteine lyase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4214345&req=5

f2-mmr-10-05-2334: Expression of pfs, luxS, hha, tomB, ariR and tnaA in the cultures grown for 3 h in the presence of 1/4 MIC of CAZ or CFP. A 16S rRNA was used as an internal standard. For all experiments, n=3. *P<0.05, compared with C. CAZ, ceftazidime; CFP, cefoperazone; MICs, minimum inhibitory concentrations; C, control; luxS, S-ribosylhomocysteine lyase.
Mentions: To determine which regulator gene is involved in the effects of CAZ and CFP on E42 biofilm formation, the changes in the mRNA levels of important regulator genes (pfs, luxS, ariR, tnaA, hha and tomb) in the bacterial cultures 3 h following inoculation were examined. Among these six genes, the levels of luxS mRNA were associated with CAZ or CFP treatment, whereas mRNA levels of the five other genes were not changed (Fig. 2). The present data suggested that luxS/AI-2 QS may be involved in the inhibitory effects of CAZ and the inductive functions of CFP on E. coli biofilm formation. Therefore, the subsequent experiments focused on luxS/AI-2 QS.

Bottom Line: CAZ at 1/4 MIC reduced luxS mRNA levels and the production of AI‑2, whereas CFP at 1/4 MIC had the opposite effect.AS‑ODNs targeting luxS significantly decreased the aforementioned inhibitory effects of CAZ and the induction effects of CFP on E. coli biofilm formation.Therefore, biofilm formation by the E. coli clinical isolate E42 was evoked by CFP but attenuated by CAZ at sub‑MICs, via a luxS/AI‑2‑based quorum sensing system.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.

ABSTRACT
To investigate the effects of subminimum inhibitory concentrations of cephalosporins on bacterial biofilm formation, the biofilm production of 52 Escherichia (E.) coli strains was examined following treatment with cephalosporin compounds at 1/4 minimum inhibitory concentrations (MICs). Ceftazidime (CAZ) inhibited biofilm formation in seven isolates, while cefoperazone (CFP) enhanced biofilm formation in 18 isolates. Biofilm formation of E. coli E42 was inhibited by CAZ and induced by CFP. Therefore, using reverse transcription‑polymerase chain reaction, the expression of the biofilm‑modulating genes of this isolate was investigated. To monitor the production of the autoinducer of quorum sensing in E. coli, autoinducer‑2 (AI‑2) production was detected by measuring the bioluminescence response of Vibrio harveyi BB170. Antisense oligonucleotides (AS‑ODNs) targeting S‑ribosylhomocysteine lyase (luxS) inhibited the expression of the luxS gene in E. coli. CAZ at 1/4 MIC reduced luxS mRNA levels and the production of AI‑2, whereas CFP at 1/4 MIC had the opposite effect. AS‑ODNs targeting luxS significantly decreased the aforementioned inhibitory effects of CAZ and the induction effects of CFP on E. coli biofilm formation. Therefore, biofilm formation by the E. coli clinical isolate E42 was evoked by CFP but attenuated by CAZ at sub‑MICs, via a luxS/AI‑2‑based quorum sensing system.

Show MeSH
Related in: MedlinePlus