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Entomopathogenic nematodes (EPNs) are obligate insect parasites symbiotically associated with entomopathogenic bacteria. They can be used as a natural infection model combining bacterial infection with infection by multicellular parasite and as such, can be used in biological control and also offer a powerful tool to study insect immunity. Both mix of non-pathogenic bacteria and even nectar alkaloids were previously hypothesized to positively modulate honey bee health. We used EPNs for evaluating the overall immune resistance of honey bee larvae treated with potentially immuno-modulating substances - a plant alkaloid sanguinarine (extracted from Macleaya cordata) and non-pathogenic strains of Lactobacillus apis, Lactobacillus melliventris and Gilliamella apicola, native to honey bee gut isolates. Honey bee 5th instar larvae (L5) and white pupae were infected with Heterorhabditis bacteriophora or Steinernema feltiae, both carrying their symbiotic bacteria. In comparison to untreated honey bee larvae we observed an increase in survival of 13.5 ± 6.43 or 11.25 ± 5.77% in case of sanguinarine and S. feltiae or H. bacteriophora, respectively. Similarly, mix of above mentioned bacteria inoculated at the same time increased survivorship to 23.25 ± 1.53 or 11.0 ± 6.0% for S. feltiae or H. bacteriophora. This is the first record of use of nematobacterial infection for evaluating the immune status of a beneficial insect. Addition of low doses of both sanguinarine and non-pathogenic strains of selected bacteria had a positive impact on the resistance of honey bee to pathogen. This method can serve as a valuable tool for immunological tests in honey bees. [ABSTRACT FROM AUTHOR]

A 6-carboxycellulose (in medicine known as 'oxidized cellulose' or 'oxycellulose') is one of the cellulose derivatives popular in the field of surgery. Health products based on oxidized cellulose are great local hemostatics with unique bactericidal and fully bioabsorbable effects. Traditional process of native cellulose oxidation is described as a complex radical reaction in strong acidic liquid medium doped by toxic nitrous radicals (NO*). Our plasma-chemical reaction demonstrates a new synthesis method of oxidized cellulose with unique bactericidal effect. This plasma-chemical treatment is based on atmospheric plasma discharge in liquid medium leading to the oxidation of polysaccharide molecules resulting in oxycellulose. Final oxycellulose properties were evaluated by infrared spectroscopy and carboxyl content determination. The biological impact showed a strong germicidal effect. [ABSTRACT FROM AUTHOR]

ABSTRACT Photorhabdus luminescens luxCDABE genes were integrated into E. coli K-12 using a high copy number plasmid containing modified luxABCDE genes under the control of the powerful Lac promoter. This strain emitted 10 times higher bioluminescence (BL) than P. luminescens. BL production under different growth conditions was studied. In both bacterial strains, the increase in BL signal correlated with the increase in optical density (OD) in a rich growth medium. However, at the logarithmic growth phase, the BL signal was roughly constant. By contrast, in minimal growth media, there was no substantial growth and the BL/cell was approximately five times higher than in the rich medium. The dynamic measurement range of BL was 102-107 colony-forming units (CFU) in E. coli and 103-107 CFU in P. luminescens. Because the decrease in the BL signal correlated with the decrease in CFU and OD, i.e. the number of bacterial cells killed, it proved to be very suitable for assessing the antibacterial effects of different antimicrobial agents. Unlike with plate counting, the kinetics of killing can be monitored on a real-time basis using BL measurements. Complement activities in different samples can be estimated using only one serum dilution. The transformed E. coli strain appeared to be superior to P. luminescens in these applications because E. coli was complement sensitive, the detection limit of E. coli was one order lower and the BL-producing system of P. luminescens appeared to be quite unstable. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of a long-term sodium chloride bath on rainbow trout Oncorhynchus mykiss naturally infected by Tetracapsuloides bryosalmonae. A total of 106 infected fish were divided into 2 groups. One group was left untreated and the other was treated with sodium chloride in increasing doses up a concentration of 0.8%. After 14 d, treatment was stopped and for a further 7 d the fish response to the sodium chloride bath was observed. Cumulative mortality was significantly lower in the treated group (19.2%) compared to the untreated group (31.5%) after 21 d. This corresponded to the lower but non-significant parasite intensity in kidney and spleen in the treated group after 14 d of treatment. However, lower prevalence of parasites in both tissues was recorded in the untreated group after 21 d of treatment, but a significant difference was observed only in spleen tissue. Furthermore, significant increases in leukocytes, hemoglobin, haematocrit, ferric reducing ability of plasma, and ceruloplasmin, and significant decreases in alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities were noticed in the treated group compared to the untreated group. In contrast, significant decreases in lysozyme concentration in the mucus and phagocyte oxidative burst in the blood were observed in the treated group. Histopathological examination revealed proliferative and reparative changes in parenchymatous tissues in the treated group. The 14- and 21-d salt bath used in rainbow trout with proliferative kidney disease was associated with a reduction in mortality and enhanced the reparative phase in the treated group.

Photorhabdus luminescens luxCDABE genes were integrated into E. coli K-12 using a high copy number plasmid containing modified luxABCDE genes under the control of the powerful Lac promoter. This strain emitted 10 times higher bioluminescence (BL) than P. luminescens. BL production under different growth conditions was studied. In both bacterial strains, the increase in BL signal correlated with the increase in optical density (OD) in a rich growth medium. However, at the logarithmic growth phase, the BL signal was roughly constant. By contrast, in minimal growth media, there was no substantial growth and the BL/cell was approximately five times higher than in the rich medium. The dynamic measurement range of BL was 10(2) -10(7) colony-forming units (CFU) in E. coli and 10(3) -10(7)  CFU in P. luminescens. Because the decrease in the BL signal correlated with the decrease in CFU and OD, i.e. the number of bacterial cells killed, it proved to be very suitable for assessing the antibacterial effects of different antimicrobial agents. Unlike with plate counting, the kinetics of killing can be monitored on a real-time basis using BL measurements. Complement activities in different samples can be estimated using only one serum dilution. The transformed E. coli strain appeared to be superior to P. luminescens in these applications because E. coli was complement sensitive, the detection limit of E. coli was one order lower and the BL-producing system of P. luminescens appeared to be quite unstable., (Copyright © 2012 John Wiley & Sons, Ltd.)