China
Africa
Explore chapters and articles related to this topic
Antimicrobial Resistance, Climate Change, and Public Health
Published in Suhaib A. Bandh, Javid A. Parray, Nowsheen Shameem, Climate Change and Microbial Diversity, 2023
Right from the beginning of antibiotic usage, naturally antibiotic resistance evolved because it is a natural adaptation due to the evolution and mutation of resistance genes in a pathogen against which the chemicals are aimed to either kill or arrest the microbial growth and development. In fact, a particular antibiotic chooses itself a specific population or genotype of microbes to depict resistance against it. The microbes have evolved a variety of mechanisms and methods to develop antimicrobial resistance which subsequently results in the generation of superbugs or rogue bacteria that dominate the microbial world. Resistance to drugs or antibiotics is mediated by a variety of microbial enzymes coded majorly by plasmid genes which become active due to antimicrobial chemotherapy.
Precision or Personalized Medicine for Cancer Chemotherapy: Is There a Role for Herbal Medicine?
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2020
Zhijun Wang, Xuefeng Liu, Rebecca Lucinda Ka Yan Ho, Christopher Wai Kei Lam, Moses Sing Sum Chow
CS is the ability of the herbal extract or compound to selectively inhibit the growth or kill the resistant cells more than the non-resistant parent cells. The mechanism is believed to be related to inhibition of anti-oxidant effect [61, 62]. Certain flavonoids, verapamil, tiopronin and related compounds as well as extracts of Tripterygium wilfordii have been reported to significantly exert such effect in different resistant prostate cancer cell lines, as well as conditional reprogrammed cells from patients with breast, prostate and renal cell carcinoma [61, 62]. In our preliminary test of collateral sensitivity of herbal products, the extracts of several commercially available Tripterygium wilfordii tablets (obtained from a Chinese medicine store in Shenzhen, China) were found more toxic in the prostate cancer cells resistant to TRAIL (PC3-TR) than its parent cell line (PC3) (see Fig. 29.1 for one such product). In addition, a Tripterygium wilfordii extract also showed significant collateral sensitivity in prostate cancer cells resistant to docetaxel (PC3-TxR) than its parent cell line (PC3) (see Fig. 29.2). This could be an exciting area of herbal research. The combined CE and CS effects by herbal medicines could be an exciting potential to retard the development of chemoresistance, as based on clinical experience in antimicrobial chemotherapy and treatment of HIV infections [63, 64]. Such activities may pave the way for further investigations to achieve enhanced benefit of herbal medicine in resistant cancer, which is a major problem at present.
Precision or Personalized Medicine for Cancer Chemotherapy: Is There a Role for Herbal Medicine?
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2019
Zhijun Wang, Xuefeng Liu, Rebecca Lucinda Ka Yan Ho, Christopher Wai Kei Lam, Moses Sing Sum Chow
CS is the ability of the herbal extract or compound to selectively inhibit the growth or kill the resistant cells more than the non-resistant parent cells. The mechanism is believed to be related to inhibition of anti-oxidant effect [61, 62]. Certain flavonoids, verapamil, tiopronin and related compounds as well as extracts of Tripterygium wilfordii have been reported to significantly exert such effect in different resistant prostate cancer cell lines, as well as conditional reprogrammed cells from patients with breast, prostate and renal cell carcinoma [61, 62]. In our preliminary test of collateral sensitivity of herbal products, the extracts of several commercially available Tripterygium wilfordii tablets (obtained from a Chinese medicine store in Shenzhen, China) were found more toxic in the prostate cancer cells resistant to TRAIL (PC3-TR) than its parent cell line (PC3) (see Fig. 29.1 for one such product). In addition, a Tripterygium wilfordii extract also showed significant collateral sensitivity in prostate cancer cells resistant to docetaxel (PC3-TxR) than its parent cell line (PC3) (see Fig. 29.2). This could be an exciting area of herbal research. The combined CE and CS effects by herbal medicines could be an exciting potential to retard the development of chemoresistance, as based on clinical experience in antimicrobial chemotherapy and treatment of HIV infections [63, 64]. Such activities may pave the way for further investigations to achieve enhanced benefit of herbal medicine in resistant cancer, which is a major problem at present.
Characterization of Burkholderia cepacia complex from environment influenced by human waste
Published in International Journal of Environmental Health Research, 2022
Jasna Hrenovic, Martina Seruga Music, Martina Drmic, Lucija Pesorda, Branka Bedenic
The BCC isolates possess a wide range of intrinsic resistance to antimicrobial agents (CLSI 2019; EUCAST 2021), leaving few antibiotics for the treatment of infected patients such as ceftazidime, meropenem, minocycline, sulfamethoxazole, chloramphenicol. The occurrence of acquired resistance traits make the antimicrobial chemotherapy very challenging for clinicians (Isles et al. 1984; Martina et al. 2020). Therefore, the mechanisms responsible for antibiotic resistance in BCC are extensively studied. The putative β-lactamases of the class A (Pen-like), class C (AmpC) and class D (OXA-like) play a role in antibiotic resistance (Becka et al. 2018; Degrossi et al. 2019). The acquired extended-spectrum β-lactamases (ESBLs) of TEM family with good activity against penicillins and cephalosporins were also reported in some BCC isolates (Maravic et al. 2012). Except the production of specific enzymes, the expression of efflux pumps could be responsible for the resistance to clinically significant antibiotics (Maravic et al. 2012; Podnecky et al. 2015). In addition to numerous antibiotic resistance mechanisms, BCC expresses many virulence traits, such as biofilm production, cell invasion and intracellular survival, responsible for severe infections and poor clinical outcome (Fazli et al. 2015).
Asymmetrical zinc(II) phthalocyanines conjugated to metal tungstate nanoparticles for photoinactivation of Staphylococcus aureus
Published in Journal of Coordination Chemistry, 2022
Sithi Mgidlana, Muthumuni Managa, Tebello Nyokong
Photodynamic antimicrobial chemotherapy (PACT) has become a promising therapeutic option against bacteria. PACT uses photosensitizers (PS) and light irradiation to induce microbial cell death [1, 2]. Upon exposure to light of appropriate wavelength, the PS can transfer energy to surrounding oxygen molecules and produce cytotoxic reactive oxygen species (ROS), including singlet oxygen, which efficiently eliminate highly proliferating cells by irreversible damage to their organelle [3–5]. PACT offers various advantages over antibiotics such as minimal possibility of developing resistance, since in PACT multiple and alternative sites in the bacteria cell are targeted [1, 2]. The PS that have been used in PACT include porphyrins [6, 7], boron-dipyrromethene dyes [8], and metallophthalocyanines (MPcs) [1, 9, 10]. Due to their high stability and ability to generate high singlet oxygen quantum yields, MPcs are preferred, hence employed in this work. In addition, phthalocyanines strongly absorb in the visible region and can be structurally modified. We report on the PACT activities of a series of asymmetric Zn phthalocyanines containing a COOH group for linking to metal tungstate (MWOx) nanoparticles. The dominant substituents on the Pc ring contain trimethoxy and acetophenone, which are employed since complexes containing these groups show antimicrobial activity [11, 12]. In addition, asymmetrically substituted phthalocyanines are employed since MPcs with reduced symmetry are reported to demonstrate enhanced triplet state properties [13].
Syntheses and biological activity of platinum(II) and palladium(II) complexes with phenyl-oxadiazole-ethylenediamine ligands
Published in Journal of Coordination Chemistry, 2021
Caroline de Souza Pereira, Karine Braga Enes, Angelina Maria de Almeida, Camille Carvalho de Mendonça, Vânia Lúcia da Silva, Cláudio Gallupo Diniz, Mara Rubia Costa Couri, Heveline Silva
Pseudomonas aeruginosa remains an important putative pathogen specially in nosocomial infections related to high mortality rates in immunocompromised individual of about 30% [1]. According to the World Health Organization these Gram-negative bacteria along the Gram-positive Staphylococcus aureus belong to a catalogue of twelve concerned families of bacteria considered the greatest threat to human health [2]. Besides that, as antimicrobial chemotherapy is often necessary to overcome bacterial infections, the emergence of antibiotic-resistant bacteria was considered a significant health challenge worldwide [3]. Thus, these facts may provide a clear picture of the magnitude of the antimicrobial resistance phenomenon and the necessity of new compounds that can act against bacterial infection and overcome resistance.