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[
Front Pharmacol,
2021]
<i>Staphylococcus aureus</i> and <i>Candida</i> spp. are commonly linked with topical biofilm-associated infections such as those found on chronic wounds. These biofilms are notoriously difficult to treat, highlighting the grave need to discover and study new broad-spectrum agents to combat associated infections. Here we report that the kinase inhibitor Bay 11-7085 exhibited bactericidal activity against multidrug-resistant <i>S. aureus</i> with a minimum inhibitory concentration (MIC) of 4g/ml. In addition, <i>S. aureus</i> strain MW2 did not acquire resistance to antibiotic pressure. Furthermore, Bay 11-7085 exhibited potency against <i>Candida albicans</i> and the emerging pathogen <i>Candida auris</i> with a MIC of 0.5-1g/ml. Bay 11-7085 partially inhibited and eradicated biofilm formation of various pathogens, such as VRSA (vancomycin-resistant <i>S. aureus</i>), as well as antifungal-resistant <i>Candida</i> spp. isolates. Notably, Bay 11-7085 partially inhibited initial cell attachment and formation of a VRSA-<i>C. albicans</i> polymicrobial biofilm <i>in vitro</i>. In contrast to <i>C. albicans</i>, inhibition of VRSA biofilm was linked to initial cell attachment independent of its bactericidal activity. Finally, Bay 11-7085 was effective <i>in vivo</i> at increasing the lifespan of <i>C. elegans</i> during an <i>S. aureus</i> and a <i>C. albicans</i> infection. Our work proposes kinase inhibitor Bay 11-7085 as a potential compound capable of combating biofilms associated with primary multidrug-resistant bacteria and yeast pathogens associated with wound infections.
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[
Acta Trop,
2001]
Bay 44-4400 was used as a spot on formulation and administered in single doses of 25 and 100 mg/kg to Acanthocheilonema viteae, Brugia malayi, and Litomosoides sigmodontis infected Mastomys coucha on various dates during prepatency, aiming to affect third stage larvae, fourth stage larvae or preadult worms. Microfilaraemia levels were controlled in comparison to untreated controls until necropsies were performed 100 days p.i. (A. viteae, L. sigmodontis) and 150 days p.i. (B. malayi) to determine the numbers of surviving worms and the condition of intrauterine developing stages. A significant proportion (86-100%) of larval and preadult stages of A. viteae were killed by Bay 44-4400 at a dose of 100 mg/kg. A dose of 25 mg/kg had only insignificant effects on the developing parasites, however, it strongly reduced microfilaraemia levels caused by surviving worms in the early phase of patency. Larval and preadult B. malayi and L. sigmodontis were not killed by Bay 44-4400 to a significant degree. Microfilaraemia developing by surviving parasites was generally and significantly reduced throughout the observation period when treatment was performed to affect the preadult parasites. In the other cases variable results were obtained. Intrauterine early embryonic stages were found to be pathologically altered in worms which had been treated at a preadult stage.
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[
Eur J Pharmacol,
1985]
The paralyzing effects of the anthelmintic drugs amidantel (BAY d 8815) and its deacylated derivative (BAY d 9216) on whole and cut C. elegans were investigated. The minimum effective concentrations with whole worms were 350 and 180 microM, respectively, compared to only 4 microM for another anthelmintic drug, levamisole. After rendering the worms permeable by cutting them at their approximate midsections, the minimum effective concentrations were: amidantel 0.30 microM, deacylated amidantel 0.07 microM and levamisole 0.15 microM. Comparison of the effects produced by amidantel and deacylated amidantel with those produced by levamisole, a known cholinergic agonist, suggested a common mode of action for all three drugs. The drugs were moderately potent inhibitors of both E. electricus and C. elegans acetylcholinesterase but at concentrations too high to account for their abilities to contract cut worms. Their primary mode of action appears to be as agonists at the level of the acetylcholine receptor, a view supported by the observation that their effects may be blocked by the nicotinic antagonists d-tubocurarine and gallamine.
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[
Parasitol Res,
2001]
The present investigations deal with the activity of the cyclic depsipeptide emodepside (BAY 44-4400) against larval and adult stages of three rodent nematodes. While emodepside acts strongly against the adult stages of the rat nematodes Nippostrongylus brasiliensis and Strongyloides ratti, as well as against the mouse nematode Heligmosomoides polygyrus, its actions against the larval stages of these nematodes vary according to the species. Thus, emodepside is highly effective against the lung and intestine larval stages of N. brasiliensis and S. ratti. By contrast. the larval stages of H. polygyrus in the intestine are only partly affected by higher emodepside dosages.
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[
Int J Parasitol,
2001]
PF 1022A, a novel anthelmintically active cyclodepsipeptide, and Bay 44-4400, a semisynthetic derivative of PF 1022A were tested for filaricidal efficacy in Mastomys coucha infected with Litomosoides sigmodontis, Acanthocheilonema viteae and Brugia malayi. The parent compound PF 1022A showed limited anti-filarial efficacy in L. sigmodontis and B. malayi infected animals. Oral doses of 5 x 100 mg/kg on consecutive days caused only a temporary decrease of microfilariaemia levels. By contrast, Bay 44-4400 was highly effective against microfilariae of all three species in single oral, subcutaneous and cutaneously applied (spot on) doses. Minimum effective doses (MED, reducing parasitaemia density by > or =95%) determined 3 and 7 days after treatment were 3.125-6.25 and 6.25-12.5mg/kg, respectively. Using the spot on formulation, doses of 6.25mg/kg (L. sigmodontis), 12.5mg/kg (A. viteae) and 25mg/kg (B. malayi) were required to cause reductions of microfilaraemia levels by > or =95% until day 56. Adulticidal effects, determined as minimum curative doses (MCD, eliminating adult parasites within 56 days by >95%) after single dose treatment were limited to A. viteae (MCD, 100mg/kg independent of the route of administration). Repeated oral treatment (100mg/kg on 5 consecutive days) killed all adult L. sigmodontis but did not affect B. malayi. However, single doses of 6.25 and 25mg/kg resulted in severe pathological alterations of intrauterine stages of L. sigmodontis and B. malayi, respectively. These alterations may be responsible for long-lasting reductions of microfilaraemia even when curative effects could not be achieved.
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[
Canadian Journal of Zoology,
1986]
The anthelmintic drugs amidantel (BAY d 8815) and its deacylated derivative (BAY d 9216) inhibited the growth of wild-type (N2) Caenorhabditis elegans but had little effect on development or reproductive capacity. Inhibition of growth correlated well with drug-induced paralysis, both becoming maximal at around 1.0 mM concentration of either drug. Egg laying was delayed by about 24 h and the rate of laying was only about 60-70% of the controls. However, the period during which eggs were laid was extended by a similar amount and the total number of eggs laid was the same for the controls and the drug-treated worms. Five drug-resistant mutants ( T(1)14, T(2)2, T(2)6, T(2)16, and T(2)26 ) were isolated following ethylmethanesulphonate mutagenesis. All were shorter than N2 at 96 h on drug-free medium; their growth was not further impaired by either of the anthelmintic drugs. All except T(1)14 exhibited a normal pattern of sexual maturation. Cultures of T(1)14 at 96 h contained many immature worms. This mutant also exhibited the most impaired motility, being severely uncoordinated in liquid suspension. The other mutants could swim normally but were noticeably slower than N2. Genetic analysis indicated that each mutant was the result of a single genetic lesion, that the mutants were recessive, and that there were two genes for amidantel resistance (
adt1 and
adt2). In vitro studies on representatives of each class ( T(1)14 aand T(2)2 ) indicated a defect in the acetylcholine receptor. T(2)2 mutants showed a moderate decrease in sensitivity towards typical cholinergic agonists as well as the anthelmintic drugs, while T(1)14 mutants were apparently devoid of functional pharmacological acetylcholine receptors.
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[
Mar Pollut Bull,
2019]
The Caribbean Coast of Colombia has a flourishing plastic industry with weak and insufficient waste management policies and practices, leading to plastic pollution along its touristic beaches. In this work, primary and secondary microplastics (MPs) were surveyed at four different locations along the Colombian Caribbean Coast. Primary microplastics, specifically white new plastic pellets, represented the largest amount of MPs found, with densities decreasing in the order Cartagena>Covenas>Puerto Colombia>Riohacha. This distribution was connected to the vicinity of MPs sources, marine currents and wind direction. The presence of secondary MPs was associated with urban centers and proximity to river mouths. The FTIR characterization showed polyethylene as the predominant resin type, with different degrees of surface oxidation. Aqueous extracts from sampled MPs were tested on Caenorhabditis elegans. Secondary MPs elicited greater toxicological responses than pellets, especially those from Cartagena Bay, suggesting MPs act as carriers for biologically-active pollutants.
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Blackmore C, Chen A, Hasan NA, Colwell RR, Tall BD, Grim CJ, Haley BJ, Choi SY, Kothary MH, Taviani E, Hutchinson R, Onifade TJ, Baker R, Carter L, Cebula TA, Sahu SN, Cinar HN, Huq A, Abdullah AH
[
PLoS One,
2014]
Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.
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[
Sci Rep,
2016]
Enterohemorrhagic Escherichia coli O157:H7 (EHEC) has caused foodborne outbreaks worldwide and the bacterium forms antimicrobial-tolerant biofilms. We investigated the abilities of various plant essential oils and their components to inhibit biofilm formation by EHEC. Bay, clove, pimento berry oils and their major common constituent eugenol at 0.005% (v/v) were found to markedly inhibit EHEC biofilm formation without affecting planktonic cell growth. In addition, three other eugenol derivatives isoeugenol, 2-methoxy-4-propylphenol, and 4-ethylguaiacol had antibiofilm activity, indicating that the C-1 hydroxyl unit, the C-2 methoxy unit, and C-4 alkyl or alkane chain on the benzene ring of eugenol play important roles in antibiofilm activity. Interestingly, these essential oils and eugenol did not inhibit biofilm formation by three laboratory E. coli K-12 strains that reduced curli fimbriae production. Transcriptional analysis showed that eugenol down-regulated 17 of 28 genes analysed, including curli genes (csgABDFG), type I fimbriae genes (fimCDH) and ler-controlled toxin genes (espD, escJ, escR, and tir), which are required for biofilm formation and the attachment and effacement phenotype. In addition, biocompatible poly(lactic-co-glycolic acid) coatings containing clove oil or eugenol exhibited efficient biofilm inhibition on solid surfaces. In a Caenorhabditis elegans nematode model, clove oil and eugenol attenuated the virulence of EHEC.
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[
Virulence,
2018]
The innate immune response of the nematode Caenorhabditis elegans has been extensively studied and a variety of Toll-independent immune response pathways have been identified. Surprisingly little, however, is known about how pathogens activate the C. elegans immune response. Enterococcus faecalis and Enterococcus faecium are closely related enterococcal species that exhibit significantly different levels of virulence in C. elegans infection models. Previous work has shown that activation of the C. elegans immune response by Pseudomonas aeruginosa involves P. aeruginosa-mediated host damage. Through ultrastructural imaging, we report that infection with either E. faecalis or E. faecium causes the worm intestine to become distended with proliferating bacteria in the absence of extensive morphological changes and apparent physical damage. Genetic analysis, whole-genome transcriptional profiling, and multiplexed gene expression analysis demonstrate that both enterococcal species, whether live or dead, induce a rapid and similar transcriptional defense response dependent upon previously described immune signaling pathways. The host response to E. faecium shows a stricter dependence upon stress response signaling pathways than the response to E. faecalis. Unexpectedly, we find that E. faecium is a C. elegans pathogen and that an active wild-type host defense response is required to keep an E. faecium infection at bay. These results provide new insights into the mechanisms underlying the C. elegans immune response to pathogen infection.