Membrane biofouling control using polyvinylidene fluoride membrane blended with quaternary ammonium compound assembled on carbon material

2017 ◽  
Vol 539 ◽  
pp. 229-237 ◽  
Author(s):  
Xingran Zhang ◽  
Zhiwei Wang ◽  
Mei Chen ◽  
Jinxing Ma ◽  
Shipei Chen ◽  
...  
2018 ◽  
Vol 9 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Yue Wen ◽  
Xingran Zhang ◽  
Mei Chen ◽  
Zhichao Wu ◽  
Zhiwei Wang

Abstract In this study, we systematically evaluated the antibiofouling behavior of quaternary ammonium compound (QAC) blended polyvinylidene fluoride (PVDF) membrane using quartz crystal microbalance with dissipation monitoring (QCM-D) combined with flow cytometry (FCM) and confocal laser scanning microscopy (CLSM) measurements. QCM-D tests showed that the introduction of QAC reduced bacterial attachment due to the biocidal functions of QAC. FCM indicated that cell integrity of the bacteria in the suspension flowing along QAC-modified membrane surfaces during the QCM-D test was severely affected. CLSM confirmed the significantly lower attachment of bacteria and higher dead/live cell ratio onto the surface of modified membranes after the washing step in QCM-D tests. Both FCM and CLSM results validated the antibacterial behavior of QAC-modified membranes by a contact-killing mechanism, which is in agreement with that of QCM-D tests. In addition, the bacterial cells accumulated on modified membrane surface exhibited higher reversibility compared to the control membrane, indicating ease of membrane cleaning. The results highlight that the combined use of QCM-D, FCM, and CLSM can comprehensively characterize the antibiofouling behavior of membranes.


Author(s):  
Solange Gahongayire ◽  
Adamu Almustapha Aliero ◽  
Charles Drago Kato ◽  
Alice Namatovu

Bacterial infections are on a rise with causal-resistant strains increasing the economic burden to both patients and healthcare providers. Salons are recently reported as one of the sources for transmission of such resistant bacterial strains. The current study aimed at the identification of the prevalent bacteria and characterization of quaternary ammonium compound (qac) genes from disinfectant-resistant S. aureus isolated from salon tools in Ishaka town, Bushenyi District of Uganda. A total of 125 swabs were collected from different salon tools (combs, brushes, scissors, clippers, and shaving machines), and prevalent bacteria were isolated using standard microbiological methods. Identification of isolated bacteria was done using standard phenotypic methods including analytical profile index (API). Susceptibility patterns of the isolated bacteria to disinfectant were determined using the agar well diffusion method. Quaternary ammonium compound (qac) genes (qacA/B and qacC) associated with disinfectant resistances were detected from disinfectant-resistant S. aureus using multiplex polymerase chain reaction (PCR) and Sanger sequencing methods. Of the 125 swab samples collected from salons, 78 (62.4%) were contaminated with different bacteria species. Among the salon tools, clippers had the highest contamination of 20 (80.0%), while shaving machines had the lowest contamination of 11 (44.0%). The most prevalent bacteria identified were Staphylococcus epidermidis (28.1%) followed by S. aureus (26.5%). Of all the disinfectants tested, the highest resistance was shown with sodium hypochlorite 1%. Out of the eight (8) disinfectant-resistant S. aureus analysed for qac genes, 2 (25%) isolates (STP6 and STP9) were found to be qacA/B positive, while 2 (25%) isolates (STP8 and STP9) were found to be qacC gene positive. This study has shown that bacterial contamination of salon tools is common, coupled with resistance to disinfectants with sodium hypochlorite resistance being more common. Furthermore, observed resistance was attributed to the presence of qac genes among S. aureus isolates. A search for qac genes for disinfectant resistance from other bacteria species is recommended.


ChemMedChem ◽  
2016 ◽  
Vol 11 (13) ◽  
pp. 1401-1405 ◽  
Author(s):  
Megan E. Forman ◽  
Megan C. Jennings ◽  
William M. Wuest ◽  
Kevin P. C. Minbiole

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