Inhibitory effects of lactobionic acid on Vibrio parahaemolyticus planktonic cells and biofilms

An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both strains were less susceptible to the selected antibiotics than their planktonic counterparts. In addition, certain antibiotics were more effective against biofilm cells, while others performed better on the planktonic cells. Against P. aeruginosa, ciprofloxacin was the most potent on both planktonic and biofilm cells, whereas ofloxacin was the least potent on both biofilm and planktonic cells. Moxifloxacin and gatifloxacin were the most potent against both planktonic and biofilm MRSA bacteria, however, not in the same order of activity. Norfloxacin was the least active when tested against both planktonic and biofilm cells. The results of this work are expected to provide insight into the efficacy of various fluoroquinolones against MRSA and Pseudomonas aeruginosa biofilms. This study could form the basis for future clinical studies that could recommend special guidelines for the management of infections that are likely to involve bacteria in their biofilm state.

Download Full-text

Inhibitory effects of Bacillus licheniformis (DAB1) and Pseudomonas aeruginosa (DAP1) against Vibrio parahaemolyticus isolated from Fenneropenaeus indicus

Aquaculture International ◽

10.1007/s10499-012-9617-2 ◽

2013 ◽

Vol 21 (5) ◽

pp. 1121-1135 ◽

Cited By ~ 10

Author(s):

Gopalakrishnan Vinoj ◽

Baskaralingam Vaseeharan ◽

Baranabas DavidJayaseelan ◽

Perumal Rajakumaran ◽

Cyril Ravi

Keyword(s):

Pseudomonas Aeruginosa ◽

Bacillus Licheniformis ◽

Vibrio Parahaemolyticus ◽

Inhibitory Effects ◽

Fenneropenaeus Indicus

Download Full-text

The Antibacterial and Antibiofilm Activity of Telithromycin Against Enterococcus spp. Isolated From Patients in China

Frontiers in Microbiology ◽

10.3389/fmicb.2020.616797 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yanpeng Xiong ◽

Junwen Chen ◽

Xiang Sun ◽

Guangjian Xu ◽

Peiyu Li ◽

...

Keyword(s):

Biofilm Formation ◽

Housekeeping Genes ◽

Antibiofilm Activity ◽

Potential Candidate ◽

Inhibitory Effects ◽

Planktonic Cells ◽

Gram Positive Bacteria ◽

Enterococcus Spp ◽

Sequence Types

Telithromycin has been reported to possess robust in vitro antibacterial activity against many species of gram-positive bacteria, and telithromycin is also effective against Staphylococcus aureus biofilms. However, the in vitro antimicrobial susceptibility of telithromycin against clinical enterococci isolates in China is rarely reported and the impacts of telithromycin on the biofilm formation and eradication of enterococci remain elusive. Therefore, this study aimed to explore the inhibitory effects of telithromycin on planktonic cells and biofilms of Enterococcus strains. A total of 280 Enterococcus faecalis and 122 Enterococcus faecium isolates were collected from individual inpatients in China. The 50% minimum inhibitory concentration (MIC50) values of telithromycin against the E. faecalis and E. faecium strains carrying erythromycin-resistant methylase (erm) genes such as the ermA, ermB, or ermC, were 2 and 4 μg/mL, respectively. In addition, these isolates were typed using multilocus sequence typing (MLST) based on housekeeping genes. The predominant sequence types (STs) of E. faecalis were ST16, ST30, and ST179, and the main STs of E. faecium isolates were ST18, ST78, and ST80. Among these major STs, 87.1% (135/158) of E. faecalis and 80.4% (41/51) of E. faecium carried erm genes. Furthermore, at the subinhibitory concentrations (1/4 and 1/8 × MIC) of telithromycin, the biofilm formation of 16 E. faecalis isolates were inhibited by approximately 35%. Moreover, treatment with 8 × MIC of telithromycin or ampicillin led to an almost 40% reduction in the established biofilms of E. faecalis isolates, whereas vancomycin or linezolid with 8 × MIC had minimal effects. The combination of telithromycin and ampicillin resulted in an almost 70% reduction in the established biofilms of E. faecalis. In conclusion, these results revealed that telithromycin significantly decreased the planktonic cells of both E. faecalis and E. faecium. In addition, the data further demonstrated that telithromycin has the robust ability to inhibit E. faecalis biofilms and the combination of telithromycin and ampicillin improved antibiofilm activity. These in vitro antibacterial and antibiofilm activities suggest that telithromycin could be a potential candidate for the treatment of enterococcal infections.

Download Full-text

Antibacterial activity of three wild wood-decaying fungi in southern Vietnam toward Vibrio parahaemolyticus bacterium in aquaculture wastewater

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/14/4/12304 ◽

2018 ◽

Vol 14 (4) ◽

pp. 705-712

Author(s):

Ngo Nguyen Vu ◽

Pham Van Kim Ngoc ◽

Pham Thi Hoa

Keyword(s):

Antibacterial Activity ◽

Vibrio Parahaemolyticus ◽

Schizophyllum Commune ◽

Culture Broth ◽

Fungal Mycelium ◽

Inhibitory Effects ◽

Southern Vietnam ◽

Application Potential ◽

Fungal Adaptation ◽

Aquaculture Wastewater

This research demonstrated antibacterial activity of wood-decaying fungi to treat the aquaculture pathogenic bacterium, Vibrio parahaemolyticus (V. parahaemolyticus). Three wild wood-decaying fungi (WDF) collected in Southern Vietnam including Flavodon flavus (F. flavus), Physisporinus vitreis (P. vitreis), and Schizophyllum commune (S. commune) were tested to treat V. parahaemolyticus presented in aquaculture wastewater. Fungal adaptation to different salt concentrations at 0, 10, 15, 20, and 30‰ was tested for the assessment of application potential of these fungi in the aquaculture farming. Fungal mycelium could adapt differently to saline conditions. All three strains grew well at low salt concentration (0-10‰), but only F. flavus survived up to 20‰ NaCl. For the antibacterial ability toward V. parahaemolyticus, two experiments using mycelium culture broth and mycofiltration were performed. Results revealed that all the three species of WDF effectively inhibited V. parahaemolyticus. Thus, mycelium culture broth of P. vitreis, S. commune, and F. flavus could inhibit 98.7, 96.5 and 97.8% V. parahaemolyticus, respectively after 8 hours. Even higher inhibitory effects were observed in the mycofiltration experiment, the efficiency reached 100% for P. vitreis, and 98% for F. flavus and S. commune after 8 hours. The obtained results showed very good application potential of myco-remediation technique using WDF in the treatment of V. parahaemolyticus in aquaculture farming. Mycofilter can be used as a new approach for controlling aquaculture disease, specifically Vibrio sp. treatment based on the antibiotic capability of these WDF. The reduction in pH of the mycelium broth can illustrated for the acidification during the mycelium development and could link with the bactericide capacity of these WDF.

Download Full-text