In insects, external chemical defences, such as reflex bleeding, have been proved to be an efficient strategy against various predators. At the same time, significant costs of reflex bleeding can be expected because bled haemolymph is lost and all valuable components included have to be renewed. Interestingly, this issue has rarely been investigated for adult insects. In this study, we examined the immune and fitness costs of repeated reflex bleeding in adults of the invasive ladybird Harmonia axyridis, investigating several haemolymph parameters. Reflex bleeding induced twice a week for three weeks resulted in a significant reduction in haemocyte concentration, total protein content, and antimicrobial activity against Micrococcus luteus, and a marginally non-significant decrease in antimicrobial activity against Escherichia coli. Repeated reflex bleeding did not result in significant body mass reduction. Interestingly, resource limitation in the form of complete food absence did not significantly interact with reflex bleeding, even though starvation itself had a strong negative effect on all haemolymph parameters investigated and individual body mass. Daily reflex bleeding did not result in decreased fecundity of young ladybirds during the first 30 days of their adult life, but the start of ladybird reproduction was delayed by about two days. Moreover, ladybirds bleeding larger amounts of haemolymph started their reproduction significantly later. Overall, our results indicate that repeated reflex bleeding weakens a ladybird's immune system and can increase their susceptibility to pathogens, but a ladybird's reproductive potential remains almost unaffected, even by very intensive reflex bleeding.
- MeSH
- Coleoptera immunology physiology MeSH
- Escherichia coli pathogenicity MeSH
- Hemolymph MeSH
- Immune System * MeSH
- Micrococcus luteus pathogenicity MeSH
- Reproduction MeSH
- Body Weight MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Avian eggs contend with omnipresent microorganisms entering the egg interior, where they affect embryo viability and hatchling phenotype. The incubation behaviour and deposition of egg white antimicrobial proteins (AMPs) vary highly across the avian altricial-precocial spectrum. Experimental evidence of how these alterations in avian reproductive strategies affect the antimicrobial properties of the precocial and altricial egg interior is lacking, however. Here, we tested the egg white antimicrobial activity in eggs of two representative model species, from each end of the avian altricial-precocial spectrum, against potentially pathogenic and beneficial probiotic microorganisms. Eggs were experimentally treated to mimic un-incubated eggs in the nest, partial incubation during the egg-laying period, the onset of full incubation and the increased deposition of two main egg white AMPs, lysozyme and ovotransferrin. We moreover assessed to what extent egg antimicrobial components, egg white pH and AMP concentrations varied as a result of different incubation patterns. Fully incubated precocial and altricial eggs decreased their antimicrobial activity against a potentially pathogenic microorganism, whereas partial incubation significantly enhanced the persistence of a beneficial probiotic microorganism in precocial eggs. These effects were most probably conditioned by temperature-dependent alterations in egg white pH and AMP concentrations. While lysozyme concentration and pH decreased in fully incubated precocial but not altricial eggs, egg white ovotransferrin increased along with the intensity of incubation in both precocial and altricial eggs. This study is the first to experimentally demonstrate that different incubation patterns may have selective antimicrobial potential mediated by species-specific effects on antimicrobial components in the egg white.
- MeSH
- Anti-Infective Agents pharmacology MeSH
- Bacillus subtilis drug effects MeSH
- Columbidae physiology MeSH
- Coturnix physiology MeSH
- Micrococcus luteus drug effects MeSH
- Muramidase pharmacology MeSH
- Conalbumin pharmacology MeSH
- Ovum enzymology physiology MeSH
- Avian Proteins pharmacology MeSH
- Reproduction * MeSH
- Egg White chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of Cannabis sativa L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span). The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring), hydrophilic lipophilic balance (HLB), type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm) comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against Micrococcus luteus and Staphylococcus aureus subsp. aureus. The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.
- MeSH
- Anti-Bacterial Agents chemistry isolation & purification pharmacology MeSH
- Cannabis chemistry MeSH
- Emulsions MeSH
- Hydrophobic and Hydrophilic Interactions MeSH
- Micrococcus luteus drug effects MeSH
- Microbial Sensitivity Tests MeSH
- Plant Oils chemistry isolation & purification pharmacology MeSH
- Plant Extracts chemistry isolation & purification pharmacology MeSH
- Seeds chemistry MeSH
- Staphylococcus aureus drug effects MeSH
- Particle Size MeSH
- Publication type
- Journal Article MeSH
Myxobacteria, a group of antimicrobial producing bacteria, have been successfully cultured and characterized from ten soil samples collected from different parts of Slovakia. A total of 79 myxobacteria belonging to four genera (Myxococcus, Corallococcus, Sorangium, and Polyangium) were isolated based on aspects of their life cycle. Twenty-five of them were purified, fermented, and screened for antimicrobial activities against 11 test microorganisms. Results indicated that crude extracts showed more significant activities against Gram-positive than against Gram-negative bacteria or fungi. Based on a higher degree and broader range of antimicrobial production, the two most potential extracts (K9-5, V3-1) were selected for HPLC fractionation against Micrococcus luteus and Staphylococcus aureus and LC/MS analysis of potential antibiotic metabolites. The analysis resulted in the identification of polyketide-peptide antibiotics, namely corallopyronin A and B (K9-5) and myxalamid B and C (V3-1), which were responsible for important Gram-positive activity in the observed strains. A sequence similarity search through BLAST revealed that these strains showed the highest sequence similarity to Corallococcus coralloides (K9-5, NCBI accession number KX256198) and Myxococcus xanthus (V3-1, NCBI accession number KX256197). Although screening of myxobacteria is laborious, due to difficulties in isolating cultures, this research represented the first report covering the isolation and cultivation of this challenging bacterial group from Slovakian soils as well as the screening of their antimicrobial activity, cultural identification, and secondary metabolite identification.
- MeSH
- Anti-Bacterial Agents chemistry metabolism pharmacology MeSH
- Phylogeny MeSH
- Micrococcus luteus drug effects MeSH
- Myxococcales chemistry genetics isolation & purification metabolism MeSH
- Polyketides chemistry metabolism pharmacology MeSH
- Soil Microbiology * MeSH
- Staphylococcus aureus drug effects MeSH
- Publication type
- Journal Article MeSH
Pre-separation and pre-concentration of bacteria is an important step especially when they are uncultured and bacterial concentration in the matrix is low. This study describes a preparative method based on isoelectric focusing of colored microorganisms in a cellulose-based separation medium from a high conductivity matrix. The isoelectric points found for the examined cells were 1.8 for Micrococcus luteus, 3.5 for Dietzia sp., and 4.7 for Rhodotorula mucilaginosa using capillary isoelectric focusing. The final positions of the zones of colored microbial cells in the cellulose-bed are indicated by colored pI markers. Segments of the separation medium with cells were harvested by a spatula, simply purified using centrifugation and analyzed by capillary isoelectric focusing and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The determined recovery ranged from 78% to 93%. The viability of the harvested cells was verified by their cultivation.
Limulus Clotting Factor C is a multi-domain serine protease that triggers horseshoe crab hemolymph clotting in the presence of trace amounts of bacterial lipopolysaccharides. Here we describe and functionally characterize an homologous molecule, designated as IrFC, from the hard tick Ixodes ricinus. Tick Factor C consists of an N-terminal cysteine-rich domain, four complement control protein (sushi) modules, an LCCL domain, a truncated C-lectin domain and a C-terminal trypsin-type domain. Developmental expression profiling by quantitative real-time PCR revealed that the irfc mRNA is expressed in all stages including eggs. In tissues dissected from adult I. ricinus females, the irfc mRNA is present mainly in tick hemocytes and accordingly, indirect immunofluorescence microscopy localized IrFC intracellularly, in tick hemocytes. Irfc mRNA levels were markedly increased upon injection of sterile saline, or different microbes, demonstrating that the irfc gene transcription occurs in response to injury. This indicates a possible role of IrFC in hemolymph clotting and/or wound healing, although these defense mechanisms have not been yet definitely demonstrated in ticks. RNAi silencing of irfc expression resulted in a significant reduction in phagocytic activity of tick hemocytes against the Gram-negative bacteria Chryseobacterium indologenes and Escherichia coli, but not against the yeast, Candida albicans. This result suggests that IrFC plays a role in the tick primordial complement system and as such possibly mediates transmission of tick-borne pathogens.
- MeSH
- Borrelia immunology MeSH
- Candida albicans immunology MeSH
- Escherichia coli immunology MeSH
- Gene Expression MeSH
- Phagocytosis MeSH
- Ixodes enzymology genetics immunology microbiology MeSH
- Complement System Proteins physiology MeSH
- RNA, Messenger biosynthesis genetics MeSH
- Micrococcus luteus immunology MeSH
- Molecular Sequence Data MeSH
- Enzyme Precursors biosynthesis genetics MeSH
- Immunity, Innate MeSH
- Arthropod Proteins biosynthesis genetics MeSH
- Serine Endopeptidases biosynthesis genetics MeSH
- Up-Regulation immunology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
A novel antimicrobial peptide, designated macropin (MAC-1) with sequence Gly-Phe-Gly-Met-Ala-Leu-Lys-Leu-Leu-Lys-Lys-Val-Leu-NH2 , was isolated from the venom of the solitary bee Macropis fulvipes. MAC-1 exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria, antifungal activity, and moderate hemolytic activity against human red blood cells. A series of macropin analogs were prepared to further evaluate the effect of structural alterations on antimicrobial and hemolytic activities and stability in human serum. The antimicrobial activities of several analogs against pathogenic Pseudomonas aeruginosa were significantly increased while their toxicity against human red blood cells was decreased. The activity enhancement is related to the introduction of either l- or d-lysine in selected positions. Furthermore, all-d analog and analogs with d-amino acid residues introduced at the N-terminal part of the peptide chain exhibited better serum stability than did natural macropin. Data obtained by CD spectroscopy suggest a propensity of the peptide to adopt an amphipathic α-helical secondary structure in the presence of trifluoroethanol or membrane-mimicking sodium dodecyl sulfate. In addition, the study elucidates the structure-activity relationship for the effect of d-amino acid substitutions in MAC-1 using NMR spectroscopy.
- MeSH
- Anti-Bacterial Agents chemical synthesis chemistry pharmacology MeSH
- Antifungal Agents chemical synthesis chemistry pharmacology MeSH
- Bacillus subtilis drug effects MeSH
- Erythrocytes drug effects MeSH
- Escherichia coli drug effects MeSH
- Antimicrobial Cationic Peptides chemistry isolation & purification pharmacology MeSH
- Micrococcus luteus drug effects MeSH
- Microbial Sensitivity Tests MeSH
- Models, Molecular MeSH
- Pseudomonas aeruginosa drug effects MeSH
- Staphylococcus aureus drug effects MeSH
- Bee Venoms chemistry isolation & purification pharmacology MeSH
- Bees chemistry MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Tributyltin (TBT) contamination remains a major problem worldwide. Many laboratories are committed to the development of remediation methodologies that could help reduce the negative impact of this compound in the environment. Furthermore, it is important to have at hand simple methodologies for evaluating TBT toxicity in the laboratory, besides the use of complex and costly analytical instrumentation. With that purpose, a method was adapted that is based on the inhibition of growth of an indicator strain, Micrococcus luteus ATCC 9341, under TBT. Different types of matrices, of TBT concentrations and sample treatments were tested. The results herein reported show that the bioassay method can be applied for both aqueous and soil samples and also for a high range of TBT concentrations (at least up to 500 μmol/L). Besides being cheap and easy to perform, it can be performed in any laboratory. Additionally, one possible application of the method to monitor TBT degradation is presented as an example.
Plagiodera versicolora (Laicharting, 1781) (Coleoptera: Chrysomelidae) is an important forest pest which damages many trees such as willow, poplar, and hazelnut. In order to find new microbes that can be utilized as a possible microbial control agent against this pest, we investigated the culturable bacterial flora of it and tested the isolated bacteria against P. versicolora larvae and adults. We were able to isolate nine bacteria from larvae and adults. The isolates were characterized using a combination of morphological, biochemical, and physiological methods. Additionally, we sequenced the partial sequence of the 16S rRNA gene to verify conventional identification results. Based on characterization studies, the isolates were identified as Staphylococcus sp. Pv1, Rahnella sp. Pv2, Rahnella sp. Pv3, Rahnella sp. Pv4, Rahnella sp. Pv5, Pantoea agglomerans Pv6, Staphylococcus sp. Pv7, Micrococcus luteus Pv8, and Rahnella sp. Pv9. The highest insecticidal activity against larvae and adults was obtained from M. luteus Pv8 with 50 and 40 % mortalities within 10 days after treatment, respectively. Extracellular enzyme activity of the bacterial isolates such as amylase, proteinase, lipase, cellulose, and chitinase was also determined. Consequently, our results show that M. luteus Pv8 might be a good candidate as a possible microbial control agent against P. versicolora and were discussed with respect to biocontrol potential of the bacterial isolates.
- MeSH
- Amylases metabolism MeSH
- Biological Control Agents MeSH
- Coleoptera microbiology MeSH
- Cellulose metabolism MeSH
- Chitinases metabolism MeSH
- Phenotype MeSH
- Larva microbiology MeSH
- Lipase metabolism MeSH
- Micrococcus luteus enzymology isolation & purification pathogenicity MeSH
- Microbial Sensitivity Tests MeSH
- Microbiota * MeSH
- Pantoea enzymology isolation & purification pathogenicity MeSH
- Peptide Hydrolases metabolism MeSH
- Rahnella enzymology isolation & purification pathogenicity MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Staphylococcus enzymology isolation & purification pathogenicity MeSH
- Virulence MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Po dobu jednoho roku (červenec 2010 až srpen 2011) bylo prováděno 1krát měsíčně monitorování mikrobiální kontaminace vnitřního vzduchu v prostorech transplantační jednotky – oddělení 5C, Hemato-onkologické kliniky FN Olomouc. Cílem studie bylo zjištění bakteriální kontaminace ve vnitřním vzduchu. Bylo vytipováno 20 odběrových míst a celkem bylo provedeno 240 odběrů vnitřního vzduchu. Jednalo se o aktivní nasávání 100 litrů vnitřního vzduchu aeroskopem MAS-100. Naměřené hodnoty teploty vnitřního vzduchu byly stabilní. Hodnoty relativní vlhkosti se pohybovaly v rozmezí od minimální hodnoty cca 17 % po maximální hodnotu cca 68 %. Nejvyšší průměrná hodnota mikrobiální kontaminace vnitřního vzduchu byla zjištěna v místnosti „vstupní filtr personálu“ (1170 CFU/m3). Nejnižší mikrobiální kontaminace vnitřního vzduchu (150–250 CFU/m3) byla naměřena na izolačních boxech pacientů. Nejčastěji izolovanými bakteriálními kmeny byly koaguláza-negativní stafylokoky, které tvořili 94,3 % všech zachycených bakteriálních kmenů. Druhým nejčastěji izolovaným kmenem byl Micrococcus spp., který tvořil 67 % všech izolovaných kmenů a Bacillus subtilis (11 %). Je možné předpokládat, že zdrojem izolovaných bakteriálních kmenů ve vnitřním ovzduší jsou pacienti a personál. Jedná se o bakteriální kmeny řazené mezi podmíněně patogenní, přesto se mohou u hemato-onkologických pacientů stát původci nemocničních infekcí.
For one year (August 2010 to July 2011), microbial contamination of the indoor air in the Transplant Unit of the Haemato-Oncology Clinic, Olomouc University Hospital was monitored monthly. Twenty sampling sites were singled out and a total of 240 indoor air samples were collected. An MAS-100 air sampler (Merck, GER) was used, air flow rate of 100 liters per minute, 1 minute. The measured values of indoor air temperature were stable. The relative air humidity ranged from 17% to 68%. The highest average value of microbial air contamination was found in the "staff entry room" (1170 CFU/m3). The lowest microbial air contamination (150–250 CFU/m3) was measured in the patient isolation units. The most frequently isolated bacterial strains were coagulase-negative staphylococci (94.3%), followed by Micrococcus spp. (67%) and Bacillus subtilis (11%). It can be assumed that the source of these airborne bacterial strains are both patients and medical staff. They are classified as opportunistic pathogens and as such can cause hospital infections among haemato-oncology patients.
- Keywords
- nemocniční prostředí, riziko infekce, koaguláza-negativní stafylokoky, hemato-onkologičtí pacienti, čisté prostory,
- MeSH
- Bacillus subtilis isolation & purification MeSH
- Epidemiological Monitoring MeSH
- Cross Infection prevention & control MeSH
- Patient Isolation MeSH
- Intensive Care Units MeSH
- Micrococcus isolation & purification MeSH
- Air Microbiology * MeSH
- Environment, Controlled * MeSH
- Staphylococcus isolation & purification MeSH
- Temperature MeSH
- Transplantation * MeSH
- Humidity MeSH
- Air Pollution, Indoor statistics & numerical data MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
