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Recent Discoveries of Natural Products as Antimicrobial Alternatives for Bovine Mastitis Treatment
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Pâmella B. A. Domingues, João Paulo L. Morgado, Maria Aparecida S. Moreira, Valdir F. Veiga-Júnior, Fábio A. Pieri
Most studies that investigate natural products as antimicrobial agents use plants from a specific geographic region. Despite satisfactory results, according to Pașca et al. (2017 and 2020), studies with acclimated plants are necessary to enable greater access. Thus, the authors tested extracts from 11 indigenous species or acclimated plants against 10 species of microorganisms, including Staphylococcus spp. and E. coli. The best MIC results were obtained for the following species: Evernia prunastri, Artemisia absinthium and Lavandula angustifolia, between 0.9 µg/mL and 6.25 µg/mL, similar to the antimicrobial activity of the known antimicrobials, florfenicol and enrofloxacin.
New Strategies to Discover Non-Ribosomal Peptides as a Source of Antibiotics Molecules
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Mario Alberto Martínez-Núñez, Zuemy Rodríguez-Escamilla, Víctor López y López
The second antibiotic resistance mechanism are structural modifications of antibiotic targets, such as the PBPs and ribosomes, avoiding that antibiotics bind specifically to them with high affinity conferring resistance to antibiotics (Blair et al., 2015). The ribosome is one of the main targets of antibiotic in the cell, since a wide variety of natural, semisynthetic or synthetic antibiotics inhibit the proliferation of pathogenic bacteria by binding to their ribosomes and interfering with translation (Tenson and Mankin, 2006). An example of this type of mechanism is the resistance to oxazolidinones, which are heterocyclic organic compounds that function as protein synthesis inhibitors. It have been described three classes of resistance to oxazolidinone: mutations in the 23S rRNA central loop domain V (peptidyl transferase center) which lead to small conformational changes of the linezolid binding pocket affecting drug binding; the second is a less common mechanism that involves mutations in the genes rplC and rplD that encode 50S ribosomal proteins L3 and L4, respectively; and the last is the acquisition of the ribosomal methyltransferase gene cfr (chloramphenicol-florfenicol resistance) (Chellat et al., 2016). The Cfr protein, through C8 methylation of the residue A2503Ec in the 23S rRNA, reduces susceptibility to antibiotics such amphenicols, lincosamides, pleuromutilins, streptogramin A, 16-membered macrolides, and linezolid (Smith and Mankin, 2008; Chellat et al., 2016). In Gram-positive organisms, structural modifications of the cell wall or cytosolic components such as ribosomes are the main mechanism of resistance and not those due to the enzymatic mechanisms.
Coptisine modulates the pharmacokinetics of florfenicol by targeting CYP1A2, CYP2C11 and CYP3A1 in the liver and P-gp in the jejunum of rats: a pilot study
Published in Xenobiotica, 2023
Si-cong Li, Min Zhang, Bin Wang, Xu-ting Li, Ge Liang
Florfenicol is a broad-spectrum antibiotic that is extensively employed in veterinary clinics for the treatment of bacterial infections (Wang et al. 2013, Sidhu et al. 2014, Pérez et al. 2015). Compared to chloramphenicol, florfenicol has been found to exhibit superior antibacterial activity while being less toxic (Cannon et al. 1990; Paape et al. 1990; Ho et al. 2000). The pharmacokinetics of florfenicol have been investigated in various animal species, including equidaes, epinephelus coioides, sheep, rats, rabbits, and chickens (McKellar and Varma 1996; Shen et al. 2003; Abd El-Aty et al. 2004; Liu 2011; Wang et al. 2013; Feng et al. 2016; Balcomb et al. 2018). Studies have also elucidated potential metabolic pathways and mechanisms of florfenicol in vivo. The metabolism of florfenicol by cytochrome P450 (P450) enzymes appears to be mediated by different isoforms in different species, likely due to genetic and evolutionary differences. For instance, in rats, CYP1A has been identified as the primary enzyme responsible for the metabolism of florfenicol (Liu, 2011), while P-glycoprotein (P-gp) and/or CYP3A may play a crucial role in the disposition of the drug in rabbits (Liu et al. 2012). In chickens, CYP3A is likely involved in the pharmacokinetics of florfenicol (Wang et al. 2013). These findings suggest that the metabolism of florfenicol varies between species and that different enzymes may be responsible for its metabolism and disposition.
Improving intestinal absorption and antibacterial effect of florfenicol via nanocrystallisation technology
Published in Journal of Microencapsulation, 2022
Yanling Liu, Yuqi Fang, Yuan Chen, Weibin Chen, Ziyu Cheng, Jun Yi, Xiaofang Li, Chongkai Gao, Fang Wu, Bohong Guo
Florfenicol (FF) is a broad-spectrum antibiotic, which belongs to the bisphenol class and has antibacterial potency similar to that of chloramphenicol. It has stronger antibacterial activity against a variety of Gram-positive, Gram-negative bacteria, and mycoplasma than thiamphenicol in vitro, such as Escherichia coli (E. coli) (Cannon et al.1990, Marshall et al.1996), Klebsiella pneumoniae, Proteus vulgaris, Salmonella Typhimurium (Booker et al.1997), Staphylococcus aureus (S. aureus), Pasteurella species (Kim and Aoki 1996), Actinobacillus species (Ueda et al.1995), and Mycoplasma mycoides (Ayling et al.2000). This type of antibiotics can inhibit the protein synthesis of bacteria through binding to the 50S ribosomal subunit (Schwarz et al.2004). They are commonly used to prevent and treat bacteria-caused respiratory or digestive infectious diseases in veterinary and aquaculture owing to their higher antibacterial activity and less toxicity (Yun et al.2020). However, FF is limited by very low water solubility and oral bioavailability (Xiao et al.2015). Therefore, clinical use for curing diseases often requires large doses, resulting in waste of raw materials and increased risk of drug resistance.
Nanoparticles obtained by confined impinging jet mixer: poly(lactide-co-glycolide) vs. Poly-ε-caprolactone
Published in Drug Development and Industrial Pharmacy, 2018
Ludmila N. Turino, Barbara Stella, Franco Dosio, Julio A. Luna, Antonello A. Barresi
Florfenicol (2,2-dichloro-N-[(1 R,2 S)-3-fluoro-1-hydroxy-1–(4-methanesulfonylphenyl)propan-2-yl]acetamide) (Figure 1) is a broad-spectrum antibiotic, active (bacteriostatic) against many gram-negative and gram-positive organisms. Florfenicol molecule has a fluorine atom in its structure making it more resistant to deactivation by bacteria than chloramphenicol. Florfenicol commercial formulations are indicated in the treatment of respiratory infections and pododermatitis in cattle [30]. Few studies are available on the synthesis of nanocarriers containing this drug: Song et al. [31] obtained silica nanoparticles with adsorbed florfenicol; Kou et al. [32] studied its adsorption on molecularly imprinted nanospheres obtained by premix membrane emulsification method; Pinto et al. [33] prepared florfenicol-PLGA nanoparticles using an emulsion/diffusion/evaporation method; while Wang et al. [34] prepared florfenicol-loaded solid lipid nanoparticles by hot homogenization and ultrasonic technique. To our knowledge, florfenicol encapsulation within PCL or PLGA nanoparticles using nanoprecipitation in CIJM has not been reported yet. The feature of being slightly soluble (and not insoluble) in water makes its loading into hydrophobic polymeric matrices challenging.