We investigated whether exposure to sub-lethal concentrations of chlorhexidine digluconate (CHG) changed the response of five Staphylococcus spp. to human beta-Defensin-3 (hBD-3). The change in response for each strain was determined in vitro with time-kill experiments in suspension by comparing the mean log(10) reduction caused by hBD-3 at 1.5 and 3 h in exposed and non-exposed bacteria. The identity of staphylococcal species was verified by DNA sequence homology in the gyrA genes in comparison with reference strains. Baseline sub-lethal concentrations allowing visible bacterial growth were between 0.0625 and 0.25 microg/ml. Sub-lethal CHG concentrations increased within 3 days in two isolates. For S. capitis 19/2, CHG-exposed cells were less susceptible to 0.5 microg/ml hBD-3 (log(10) reduction 0.78 versus 2.06 at 1.5 h; p < 0.001; t-test). For S. aureus, however, CHG-exposed cells were more susceptible to 1 microg/ml hBD-3. The observed changes between CHG-exposed and non-exposed cells did not indicate a general trend in response to hBD-3. Overall, we found no consistent evidence that 3 days of exposure to CHG changed the response of five Staphylococcus spp. to hBD-3. The use of CHG for skin antisepsis is, based on our data, unlikely to change the natural defence activity of hBD-3.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s10096-010-0904-4 | DOI Listing |
Environ Toxicol Chem
January 2025
Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada.
There is growing interest in transcriptomic points of departure (tPOD) values from in vitro experiments as an alternative to animal test method. The study objective was to calculate tPODs in rainbow trout gill cells (RTgill-W1 following OECD 249) exposed to pesticides, and to evaluate how these values compare to fish acute and chronic toxicity data. Cells were exposed to one fungicide (chlorothalonil), ten herbicides (atrazine, glyphosate, imazethapyr, metolachlor, diquat, s-metolachlor, AMPA, dicamba, dimethenamid-P, metribuzin), eight insecticides (chlorpyrifos, diazinon, permethrin, carbaryl, clothianidin, imidacloprid, thiamethoxam, chlorantraniliprole), and OECD 249 positive control 3,4-dichloroaniline.
View Article and Find Full Text PDFMar Biotechnol (NY)
January 2025
College of Earth, Ocean and Environment, School of Marine Science and Policy, University of Delaware, Lewes, DE, 19958, USA.
Application of algicides produced by naturally occurring bacteria is considered an environmentally friendly approach to control harmful algal blooms. However, few studies assess the effects of bacterial algicides on non-target species, either independently or with other stressors. Here, we measured sub-lethal effects of dinoflagellate-specific algicide IRI-160AA on the estuarine fish Fundulus heteroclitus and Menidia menidia in laboratory experiments.
View Article and Find Full Text PDFBMC Microbiol
January 2025
Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, 11562, Egypt.
Background: One of the main issues facing public health with microbial infections is antibiotic resistance. Nanoparticles (NPs) are among the best alternatives to overcome this issue. Silver nanoparticle (AgNPs) preparations are widely applied to treat multidrug-resistant pathogens.
View Article and Find Full Text PDFEnviron Pollut
January 2025
CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
Corrosion significantly affects the maritime industry. To address this issue, corrosion inhibitors are incorporated into polymeric coatings. However, some state-of-the-art inhibitors are toxic, prone to spontaneous leaching, and interact with coating components.
View Article and Find Full Text PDFRes Vet Sci
January 2025
Mammalian and Aquatic Toxicology Department, Central Agricultural Pesticide Lab, Agricultural Research Center, Alexandria, Egypt.
The insecticides Lambda-cyhalothrin (LCT) and imidacloprid (IMD) are extensively utilized in Egyptian agriculture. Embryonic chicken is a readily accessible model organism commonly employed in various studies. Eggs of (Gallus Gallus) chicken were immersed in an aqueous solution of two sub-lethal concentrations (0.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!