Limits...
Prevention of cell-surface attachment and reduction of penicillin-binding protein 2a (PBP2a) level in methicillin-resistant Staphylococcus aureus biofilms by Acalypha wilkesiana.

Santiago C, Lim KH, Loh HS, Ting KN - BMC Complement Altern Med (2015)

Bottom Line: The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics.Fraction 9EA-FC-B and ampicillin exhibited similar inhibitory effect on MRSA's biofilm production at their respective minimum inhibitory concentrations (81.56% vs 84.49%, respectively).PBP2a found in the biofilm matrix is believed to have a role in the development of virulence in MRSA.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor, Malaysia. Carolina.Santiago@nottingham.edu.my.

ABSTRACT

Background: Formation of biofilm is known to enhance the virulence of methicillin-resistance Staphylococcus aureus (MRSA), which is associated with persistent infections in hospital settings. The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics. We have isolated 9EA-FC-B bioactive fraction from Acalypha wilkesiana Müll. Arg. that reverses ampicillin resistant in MRSA through inhibition of the antibiotic resistant protein, penicillin-binding protein 2a (PBP2a). In this study, we aimed to investigate the effects of 9EA-FC-B on MRSA biofilm forming capacity.

Methods: Inhibition of biofilm production and microtiter attachment assays were employed to study the anti-biofilm activity of 9EA-FC-B, while latex agglutination test was performed to investigate the effect on PBP2a in the biofilm matrix. We also attempted to characterise the chemical components of the fraction using high performance liquid chromatography (HPLC) and phytochemical analysis.

Results: Fraction 9EA-FC-B and ampicillin exhibited similar inhibitory effect on MRSA's biofilm production at their respective minimum inhibitory concentrations (81.56% vs 84.49%, respectively). However, the test fraction was more effective in suppressing cell surface attachment (90.85%) compared to ampicillin (37.8%). Interestingly, ampicillin enhanced the level PBP2a and in the contrary 9EA-FC-B attenuated the production of the resistant protein in the bioflim matrix. HPLC and phytochemical analysis revealed that 9EA-FC-B fraction is a complex mixture containing tannins, saponins, sterol/steroids, and glycosides.

Conclusions: Bioactive fraction 9EA-FC-B inhibited the production of MRSA biofilm by preventing the initial cell-surface attachment and reducing the amount PBP2a in the matrix. PBP2a found in the biofilm matrix is believed to have a role in the development of virulence in MRSA.

Show MeSH

Related in: MedlinePlus

Results of PBP2a latex agglutination test on MRSA biofilms. A PBP2a latex agglutination test was performed and interpreted according to the manufacturer’s guidelines. Shown are MRSA biofilm samples from an untreated control MRSA and culture treated with MIC ampicilin (0.05 mg/mL), which had moderate and strong agglutination, respectively. The three disks from right are of biofilms samples from cultures treated with 9EA-FC-B at these concentrations; 0.19 mg/mL, 0.38 mg/mL and 0.75 mg/mL (as indicated) showing a very weak agglutination with turbid background. The middle disk is of biofilm sample from culture treated with MIC 9EA-FC-B (3.00 mg/mL) is showing no agglutination.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4376335&req=5

Fig4: Results of PBP2a latex agglutination test on MRSA biofilms. A PBP2a latex agglutination test was performed and interpreted according to the manufacturer’s guidelines. Shown are MRSA biofilm samples from an untreated control MRSA and culture treated with MIC ampicilin (0.05 mg/mL), which had moderate and strong agglutination, respectively. The three disks from right are of biofilms samples from cultures treated with 9EA-FC-B at these concentrations; 0.19 mg/mL, 0.38 mg/mL and 0.75 mg/mL (as indicated) showing a very weak agglutination with turbid background. The middle disk is of biofilm sample from culture treated with MIC 9EA-FC-B (3.00 mg/mL) is showing no agglutination.

Mentions: PBP2a latex agglutination test was conducted to measure semi-quantitatively the amount of the resistant protein, PBP2a found in the biofilm. A higher intensity of agglutination observed essentially corresponds to a higher level of PBP2a found in the biofilm. MRSA control showed a moderate intensity of agglutination while ampicillin treatment appeared to increase the amount of PBB2a in the biofilm. However, no PBP2a was detected for treatments with 9EA-FC-B at 3.00 mg/mL and 1.50 mg/mL (Table 1 and Figure 4).Table 1


Prevention of cell-surface attachment and reduction of penicillin-binding protein 2a (PBP2a) level in methicillin-resistant Staphylococcus aureus biofilms by Acalypha wilkesiana.

Santiago C, Lim KH, Loh HS, Ting KN - BMC Complement Altern Med (2015)

Results of PBP2a latex agglutination test on MRSA biofilms. A PBP2a latex agglutination test was performed and interpreted according to the manufacturer’s guidelines. Shown are MRSA biofilm samples from an untreated control MRSA and culture treated with MIC ampicilin (0.05 mg/mL), which had moderate and strong agglutination, respectively. The three disks from right are of biofilms samples from cultures treated with 9EA-FC-B at these concentrations; 0.19 mg/mL, 0.38 mg/mL and 0.75 mg/mL (as indicated) showing a very weak agglutination with turbid background. The middle disk is of biofilm sample from culture treated with MIC 9EA-FC-B (3.00 mg/mL) is showing no agglutination.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4376335&req=5

Fig4: Results of PBP2a latex agglutination test on MRSA biofilms. A PBP2a latex agglutination test was performed and interpreted according to the manufacturer’s guidelines. Shown are MRSA biofilm samples from an untreated control MRSA and culture treated with MIC ampicilin (0.05 mg/mL), which had moderate and strong agglutination, respectively. The three disks from right are of biofilms samples from cultures treated with 9EA-FC-B at these concentrations; 0.19 mg/mL, 0.38 mg/mL and 0.75 mg/mL (as indicated) showing a very weak agglutination with turbid background. The middle disk is of biofilm sample from culture treated with MIC 9EA-FC-B (3.00 mg/mL) is showing no agglutination.
Mentions: PBP2a latex agglutination test was conducted to measure semi-quantitatively the amount of the resistant protein, PBP2a found in the biofilm. A higher intensity of agglutination observed essentially corresponds to a higher level of PBP2a found in the biofilm. MRSA control showed a moderate intensity of agglutination while ampicillin treatment appeared to increase the amount of PBB2a in the biofilm. However, no PBP2a was detected for treatments with 9EA-FC-B at 3.00 mg/mL and 1.50 mg/mL (Table 1 and Figure 4).Table 1

Bottom Line: The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics.Fraction 9EA-FC-B and ampicillin exhibited similar inhibitory effect on MRSA's biofilm production at their respective minimum inhibitory concentrations (81.56% vs 84.49%, respectively).PBP2a found in the biofilm matrix is believed to have a role in the development of virulence in MRSA.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor, Malaysia. Carolina.Santiago@nottingham.edu.my.

ABSTRACT

Background: Formation of biofilm is known to enhance the virulence of methicillin-resistance Staphylococcus aureus (MRSA), which is associated with persistent infections in hospital settings. The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics. We have isolated 9EA-FC-B bioactive fraction from Acalypha wilkesiana Müll. Arg. that reverses ampicillin resistant in MRSA through inhibition of the antibiotic resistant protein, penicillin-binding protein 2a (PBP2a). In this study, we aimed to investigate the effects of 9EA-FC-B on MRSA biofilm forming capacity.

Methods: Inhibition of biofilm production and microtiter attachment assays were employed to study the anti-biofilm activity of 9EA-FC-B, while latex agglutination test was performed to investigate the effect on PBP2a in the biofilm matrix. We also attempted to characterise the chemical components of the fraction using high performance liquid chromatography (HPLC) and phytochemical analysis.

Results: Fraction 9EA-FC-B and ampicillin exhibited similar inhibitory effect on MRSA's biofilm production at their respective minimum inhibitory concentrations (81.56% vs 84.49%, respectively). However, the test fraction was more effective in suppressing cell surface attachment (90.85%) compared to ampicillin (37.8%). Interestingly, ampicillin enhanced the level PBP2a and in the contrary 9EA-FC-B attenuated the production of the resistant protein in the bioflim matrix. HPLC and phytochemical analysis revealed that 9EA-FC-B fraction is a complex mixture containing tannins, saponins, sterol/steroids, and glycosides.

Conclusions: Bioactive fraction 9EA-FC-B inhibited the production of MRSA biofilm by preventing the initial cell-surface attachment and reducing the amount PBP2a in the matrix. PBP2a found in the biofilm matrix is believed to have a role in the development of virulence in MRSA.

Show MeSH
Related in: MedlinePlus