scholarly journals Potential Inhibitory Effect of Apis mellifera’s Venom and of Its Two Main Components—Melittin and PLA2—on Escherichia coli F1F0-ATPase

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 824
Author(s):  
Hala Nehme ◽  
Helena Ayde ◽  
Dany El Obeid ◽  
Jean Marc Sabatier ◽  
Ziad Fajloun

Bacterial resistance has become a worrying problem for human health, especially since certain bacterial strains of Escherichia coli (E. coli) can cause very serious infections. Thus, the search for novel natural inhibitors with new bacterial targets would be crucial to overcome resistance to antibiotics. Here, we evaluate the inhibitory effects of Apis mellifera bee venom (BV-Am) and of its two main components -melittin and phospholipase A2 (PLA2)- on E. coli F1F0-ATPase enzyme, a crucial molecular target for the survival of these bacteria. Thus, we optimized a spectrophotometric method to evaluate the enzymatic activity by quantifying the released phosphate from ATP hydrolysis catalyzed by E. coli F1F0-ATPase. The protocol developed for inhibition assays of this enzyme was validated by two reference inhibitors, thymoquinone (IC50 = 57.5 μM) and quercetin (IC50 = 30 μM). Results showed that BV-Am has a dose-dependent inhibitory effect on E. coli F1F0-ATPase with 50% inhibition at 18.43 ± 0.92 μg/mL. Melittin inhibits this enzyme with IC50 = 9.03 ± 0.27 µM, emphasizing a more inhibitory effect than the two previous reference inhibitors adopted. Likewise, PLA2 inhibits E. coli F1F0-ATPase with a dose-dependent effect (50% inhibition at 2.11 ± 0.11 μg/mL) and its combination with melittin enhanced the inhibition extent of this enzyme. Crude venom and mainly melittin and PLA2, inhibit E. coli F1F0-ATPase and could be considered as important candidates for combating resistant bacteria.

Author(s):  
Dominique Tertigas ◽  
Gemma Barber

Antibiotic resistance is a pressing issue in the medical field today. It is important to understand the development of bacterial resistance to implement effective preventative measures against antibiotic resistant bacteria. This study investigated the rate at which Escherichia coli (E. coli), a common pathogen, developed resistance to streptomycin and doxycycline, as Oz et al. (2014) showed differing levels of resistance in E. coli to these two antibiotics. The development of antibiotic resistance was measured by adding E. coli to 96-well plates in the presence of increasing doses of doxycycline, streptomycin, or a combination treatment. Successive generations were added to the same treatments to see whether they would grow at higher concentrations of antibiotic. The change in minimum inhibitory concentration for streptomycin and doxycycline was determined as the bacteria became increasingly resistant to each antibiotic. The fastest rate of antibiotic resistance was observed for streptomycin, with doxycycline resistance exhibiting a slower rate of development. The rate of resistance development for the combination treatment was the slowest, potentially due to small differences in target domains. Some cross-resistance was also observed. This study provides a small-scale methodological basis and preliminary insight on antibiotic resistance trends for two antibiotic classes and a combination treatment.


2017 ◽  
Vol 38 (4) ◽  
pp. 1887
Author(s):  
Laura Gonçalves da Silva Chagas ◽  
Poliana De Castro Melo ◽  
Silvia Cassimiro Brasão ◽  
Gabriela Bim Ramos Silvestre ◽  
Ednaldo Carvalho Guimarães ◽  
...  

The presence of biofilm-forming bacteria from the mammary gland of dairy cows adhered to equipment in the milking environment represents one of the major causes of bacterial resistance during mastitis treatment. The aim of this study was to identify strains of Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli in milk samples from cows with mastitis, as well as in the expansion tank and milking set liners. We aimed to quantify the extracellular proteins and polysaccharides in the biofilm produced by each strain. A total of 294 samples were collected from a dairy farm in the municipality of Uberlândia, Minas Gerais. To identify the S. aureus, S. epidermidis and E. coli isolates responsible for biofilm production, we tested the phenotype using the Congo red agar (CRA) and microplate adhesion tests. Protein quantification was performed with a Bicinchoninic Acid Protein Assay Kit (BCA kit), and polysaccharides were quantified by the phenol sulfuric acid method. We identified eight strains of S. aureus, one strain of S. epidermidis and 11 strains of E. coli responsible for biofilm production, all of which showed a higher concentration of polysaccharides than proteins in the matrix. Escherichia coli was considered the most prevalent bacterium among the samples, and S. aureus was determined to be the largest biofilm producer. The results of the CRA and microplate adhesion tests were similar in regard to identification of the biofilm-producing strains according to their phenotype and matrix composition. The classification of S. aureus strains as major biofilm producers is of great concern for producers, as such bacteria are considered one of the predominant contagious etiological agents that cause bovine mastitis. In addition, our observation that E. coli and S. epidermidis can produce biofilms highlights the need to reassess prophylactic measures to avoid the adhesion of biofilm-producing bacteria.


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 605
Author(s):  
Janne Rojas ◽  
Gautier Mark-Arthur Ndong Ntoutoume ◽  
Patrick Martin ◽  
Marielba Morillo

Essential oils obtained by hydrodistillation of Montanoa quadrangularis leaves, flowers, and stems were analyzed by GC and GC/MS techniques revealing myrcene, limonene, β-phellandrene, and sabinene among the main components. The aim of the present study was to evaluate the MDR modulator activity on human MDR1 gene transfected mouse lymphoma cell line and the antimicrobial activity on the essential oils obtained from different parts of the species under investigation. The results revealed that MQL caused a similar increase in the fluorescence activity of the cells at 0.02 μL/mL comparing to the Verapamil® value. The antimicrobial assay was carried out according to the disc diffusion method. Five different bacterial strains (Staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli AG 100, and Escherichia coli AG100A) were treated with the essential oils and the zones of inhibition were determined on TSA plates and TSA agar plates supplemented with Tween 20. MQF and MQL showed activity against B. subtilis, S. epidermidis, and E. coli AG 100A while MQS was only active against E. coli AG 100A on TSA agar plates experiment. In case of TSA agar plates supplemented with 0.1 v/v% Tween 20 detergent, MQF showed inhibition on B. subtilis, S. epidermidis, and E. coli AG 100A; MQL was active against B. subtilis, E. coli AG 100, and E. coli AG 100A while MQS was only active against E. coli AG 100A.


Author(s):  
Andry Maharo Andrianarivelo ◽  
Christian Emmanuel Mahavy ◽  
Marson Raherimandimby ◽  
Tsiry Rasamiravaka

Enterobacteriaceae, in particular Escherichia coli, are habitual residents of the gastrointestinal tract, capable of causing a large number of infections. The MIC varies according to the bacterial strains and the antibiotics used, hence the need to carry out antibiotic sensitivity tests. The objective of this study is to evaluate the behavior of Escherichia coli after repeated exposure to the same antibiotic to demonstrate a possible correlation between excessive intake of antibiotics and bacterial resistance. A prospective and descriptive study was carried out in the Laboratory of Microbiology of Fundamental and Applied Biochemistry (Faculty of Sciences Antananarivo) during the month of November 2019. The strains studied were the reference strain Escherichia coli ATCC 25922 provided by the Laboratory and two clinical strains from the Microbiology Laboratory of the Joseph Ravoahangy Andrianavalona University Hospital Center (CHU JRA) Antananarivo. Repeated exposure to Tobramycin and Ofloxacin of these strains were performed. The results of our study showed that most E. coli is exposed to the antibiotic, the more it develops resistance. The evolution of E. coli's sensitivity is different in the presence of Tobramycin with MICs up to 4 times the starting value while in the presence of Ofloxacin, the MIC increases to 125 times the initial value. This difference may be due to the different target of the antibiotic which causes the bacteria to develop variable mechanisms to escape it. Key words: E. coli - MIC - antibiotics - repeated exposure


2018 ◽  
Vol 6 (4) ◽  
pp. 125 ◽  
Author(s):  
Ana Lopes ◽  
Carla Pereira ◽  
Adelaide Almeida

The emergence of antibiotic resistance in bacteria is a global concern. The use of bacteriophages (or phages) alone or combined with antibiotics is consolidating itself as an alternative approach to inactivate antibiotic-resistant bacteria. However, phage-resistant mutants have been considered as a major threat when phage treatment is employed. Escherichia coli is one of the main responsible pathogens for moderate and serious infections in hospital and community environments, being involved in the rapid evolution of fluoroquinolones and third-generation cephalosporin resistance. The aim of this study was to evaluate the effect of combined treatments of phages and antibiotics in the inactivation of E. coli. For this, ciprofloxacin at lethal and sublethal concentrations was added at different times (0, 6, 12 and 18 h) and was tested in combination with the phage ELY-1 to inactivate E. coli. The efficacy of the combined treatment varied with the antibiotic concentration and with the time of antibiotic addition. The combined treatment prevented bacterial regrowth when the antibiotic was used at minimum inhibitory concentration (MIC) and added after 6 h of phage addition, causing less bacterial resistance than phage and antibiotic applied alone (4.0 × 10-7 for the combined treatment, 3.9 × 10-6 and 3.4 × 10-5 for the antibiotics and the phages alone, respectively). Combined treatment with phage and antibiotic can be effective in reducing the bacterial density and it can also prevent the emergence of resistant variants. However, the antibiotic concentration and the time of antibiotic application are essential factors that need to be considered in the combined treatment.


Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1469
Author(s):  
Haseena ◽  
Adnan Khan ◽  
Iqra Ghaffar ◽  
Roua S. Baty ◽  
Mohamed M. Abdel-Daim ◽  
...  

The rise in bacterial resistance to currently used antibiotics is the main focus of medical researchers. Bacterial multidrug resistance (MDR) is a major threat to humans, as it is linked to greater rates of chronic disease and mortality. Hence, there is an urgent need for developing effective strategies to overcome the bacterial MDR. Metal–organic frameworks (MOFs) are a new class of porous crystalline materials made up of metal ions and organic ligands that can vary their pore size and structure to better encapsulate drug candidates. This study reports the synthesis of ribose-coated Cu-MOFs for enhanced bactericidal activity of chloramphenicol (CHL) against Escherichia coli (resistant and sensitive) and MDR Pseudomonas aeruginosa. The synthesized Cu-MOFs were characterized with DLS, FT-IR, powder X-ray diffraction, scanning electron microscope, and atomic force microscope. They were further investigated for their efficacy against selected bacterial strains. The synthesized ribose-coated Cu-MOFs were observed as spherical shape structure with the particle size of 562.84 ± 13.42 nm. CHL caused the increased inhibition of E. coli and MDR P. aeruginosa with significantly reduced MIC and MBIC values after being encapsulated in ribose-coated Cu-MOFs. The morphological analysis of the bacterial strains treated with ribose-coated CHL-Cu-MOFs showed the complete morphological distortion of both E. coli and MDR P. aeruginosa. Based on the results of the study, it can be suggested that ribose-coated Cu-MOFs may be an effective alternate candidate to overcome the MDR and provide new perspective for the treatment of MDR bacterial infections.


2000 ◽  
Vol 182 (21) ◽  
pp. 6154-6160 ◽  
Author(s):  
Kenji Atarashi ◽  
Akira Kaji

ABSTRACT Ribosome recycling factor (RRF) of Thermotoga maritimawas expressed in Escherichia coli from the cloned T. maritima RRF gene and purified. Expression of T. maritima RRF inhibited growth of the E. coli host in a dose-dependent manner, an effect counteracted by the overexpression of E. coli RRF. T. maritima RRF also inhibited the E. coli RRF reaction in vitro. Genes encoding RRFs fromStreptococcus pneumoniae and Helicobacter pylori have been cloned, and they also impair growth of E. coli, although the inhibitory effect of these RRFs was less pronounced than that of T. maritima RRF. The amino acid sequence at positions 57 to 62, 74 to 78, 118 to 122, 154 to 160, and 172 to 176 in T. maritima RRF differed totally from that ofE. coli RRF. This suggests that these regions are important for the inhibitory effect of heterologous RRF. We further suggest that bending and stretching of the RRF molecule at the hinge between two domains may be critical for RRF activity and therefore responsible forT. maritima RRF inhibition of the E. coli RRF reaction.


2001 ◽  
Vol 64 (11) ◽  
pp. 1667-1673 ◽  
Author(s):  
SO HYUN KIM ◽  
SOO JIN YANG ◽  
HYE CHEONG KOO ◽  
WON KI BAE ◽  
JI YEON KIM ◽  
...  

Vero cytotoxin (VT)-producing Escherichia coli (VTEC), such as E. coli O157:H7, are emerging foodborne pathogens worldwide. VTs are associated with hemorrhagic colitis and hemolytic uremic syndrome in humans. Attachment of the B subunit of VTs to its receptor, globotriaosylceramide (Gb3), at gut epithelium is the primary step and, consequently, the A subunit of VTs inhibits protein synthesis in the target cell. Proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, up-regulate Gb3 expression, increase sensitivity to VTs, and enhance VT action in developing disease. Currently, there is a growing interest in probiotics, given the increasing occurrence of antibiotic-resistant bacteria. In particular, much work on bifidobacteria among probiotics, regarded as microorganisms targeted for technological and therapeutic applications, has been performed. In Korea, the neutralizing effect of the culture supernatant of Bifidobacterium longum HY8001, Korean isolate, against the VTs from E. coli O157:H7 was found. Therefore, this study focused on the raveling of the inhibitory effect of B. longum HY8001 against VTs, through the interference B subunit of VTs and Gb3 interaction. Mice were inoculated intragastrically with B. longum HY8001 culture supernatant before and after challenge with E. coli O157:H7. Control mice were inoculated intragastrically only with E. coli O157:H7. Cytokine, TNF-α, and IL-1β levels in sera and expression of their mRNA were decreased, and expression of Gb3 in renal tubular epithelial cells was reduced in mice treated with B. longum HY8001 culture supernatant. In competitive enzyme-linked immunosorbent assays (ELISAs), the culture supernatant of B. longum HY8001 primarily binds VTs to interfere the VTs with Gb3 interaction. These results suggest that soluble substance(s) in B. longum HY8001 culture supernatant may have inhibitory activity on the expression of Gb3, VT-Gb3 interaction, or both. Further study should be done to elucidate the property of soluble substances in B. longum HY8001 culture supernatant.


Author(s):  
Harvinder Kaur Sneha Mohan ◽  
Tarana Sarwat Dalip K. Kakru

The increasingly frequent application of carbapenemases induces a selective pressure on bacteria to acquire resistance against carbapenems. A large variety of carbapenemases have been identified in Enterobacteriaceae. The emergence of carbapenemases in E. coli and Klebsiella species possess a serious therapeutic problem in hospitals because carbapenems are often antibiotics of last resort for the treatment of serious infections caused by multidrug-resistant bacteria. The main aim of this study to determine the carbapenem-resistant strains of Escherichia coli and Klebsiella species. Detection of carbapenemase enzyme in the carbapenem-resistant Escherichia coli and Klebsiella species. This is a cross-sectional study, performed in the bacteriological laboratory. A total of 204 strains of Escherichia coli and 122 strains of Klebsiella species were isolated from patients admitted & attending the OPD at Sharda Hospital during the study period. The identification of the clinical isolates was based on morphological and biochemicals characterization. Result: Among the total number of bacterial growth received during the study period, the E. coli (204) was more in number as compared to other bacterial strains followed by Klebsiella species (122), Pseudomonas species (117), Staphylococcus aureus (100) and Enterococcus species (80). Among the following specimen i.e, urine (58.8%), was highly received during the study period followed by pus (15.3%) and sputum (7.5%). Colistin (100%) and Polymyxin B (100%) is found to be the most sensitive drug. Gentamicin (19.6%) and Cefuroxime (12.2%) are the least sensitive drugs. In the present study, we found that the Klebsiella species (75%) and Escherichia coli (64%) was the major reason of carbapenemase production but the organisms incidentally were susceptible to colistin and polymyxins (100%) followed by other antibiotics. This is a welcome finding in times of increasing carbapenem resistance & is reason enough to suggest the use of Polymyxins in the health care settings where the carbapenems to be used for the treatment of infections caused by Enterobacteriaceae.


2017 ◽  
Vol 45 ◽  
pp. 5
Author(s):  
Carla Faria Orlandini ◽  
André Giarola Boscarato ◽  
Rodrigo Assunção Moura ◽  
Patrícia Sapateiro ◽  
Zilda Cristiani Gazim ◽  
...  

Background: Due to the bacterial resistance to conventional antibiotics, studies on natural products with antibacterial or bactericidal activity are becoming more and more frequent. Among multi-resistant bacteria, Escherichia coli is a producer of extended-spectrum beta-lactamase (ESBL). Papain, coming from papaya latex (Carica papaya), stands out for its capacity to degrade the devitalized tissue that delays the healing process. Parsley (Petroselinum crispum) has been studied, mainly for its diuretic, antioxidant and antimicrobial properties. The aim of this work was to report the use of these two phytotherapic agents in an equine presenting abscess infected by multi-resistant ESBL producing E. coli.Case: A four and a half year old male neutered equine weighing 400 kg of undefined race (SRD) was admitted to the Veterinary Hospital of the Paranaense University (UNIPAR), presenting an increased volume on the left side of the middle third of the neck, one year ago, probably due to an intramuscular injection in the splenius muscle performed by the animal’s owner, who did not remember which drug had been applied. Physical examination revealed a characteristic abscess lesion that involved the subcutaneous and muscular tissue of approximately 10 cm in diameter, and presented a fistulous trajectory with purulent content drainage and pain upon palpation. The animal was initially submitted to surgical drainage of the abscess and to systemic treatment with ceftiofur. In view of the failure of the therapy proposed, the lesion was treated with 2% papain cream and, subsequently, in association with lyophilized parsley extract (Petroselinum crispum) after the identification of the presence of multi-resistant ESBL producing E. coli, isolated from the lesion and identified through standard laboratory tests. The use of 2% papain cream reduced the inflammatory process and fibrous tissue. Lyophilized parsley root extract was effective against infection by multi-resistant bacteria.Discussion: The reduction of purulent secretion and the size of the inflammatory process are due to the proteolytic activity of papain, which decreases bacterial adhesion, and the degree of wound contamination, promoting healing. Several studies have indicated the bacteriostatic and bactericidal activity of papain, but in some trials, this effect was only found in a concentration of 10% for Pseudomonas aeruginosa and Staphylococcus aureus, and no effect for E. coli bacteria. In vitro studies have shown that the essential oil of Petroselinum crispum leaves and stems is more effective than the essential oil of seeds against this bacterium. Reports of isolation and bacterial identification of wounds and abscesses of horses present a large amount of microorganisms, but the presence of multi-resistant E. coli is uncommon. In other countries, the presence of this bacterium in wounds and other regions has been described in this species. In the Netherlands and Germany, the presence of ESBL producing E. coli in horses was detected in clinical samples of pus, stomach, uterus, feces and synovial fluid, presenting a real risk of human contamination by these resistant bacteria. In this sense, the study of antimicrobial agents has great scope, being a crucial point in several sectors of the pharmaceutical field. The phytotherapeutic association, used in this case, represents a possible promising, low-cost alternative for the treatment of contaminated wounds, emphasizing the importance of studies involving alternative treatments for bacterial resistance.


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