42 research outputs found
XENOFOOD—An Autoclaved Feed Supplement Containing Autoclavable Antimicrobial Peptides—Exerts Anticoccidial GI Activity, and Causes Bursa Enlargement, but Has No Detectable Harmful Effects in Broiler Cockerels despite In Vitro Detectable Cytotoxicity on LHM Cells
No full textAbstract: Entomopathogenic bacteria are obligate symbionts of entomopathogenic nematode (EPN) species.
These bacteria biosynthesize and release non-ribosomal-templated hybrid peptides (NR-AMPs),with strong,
and large-spectral antimicrobial potential, capable of inactivating pathogens belonging to different prokaryote,
and eukaryote taxa. The cell-free conditioned culture media (CFCM) of Xenorhabdus budapestensis and
X. szentirmaii efficiently inactivate poultry pathogens like Clostridium, Histomonas, and Eimeria. To learn
whether a bio-preparation containing antimicrobial peptides of Xenorhabdus origin with accompanying
(in vitro detectable) cytotoxic effects could be considered a safely applicable preventive feed supplement,
we conducted a 42-day feeding experiment on freshly hatched broiler cockerels. XENOFOOD (containing
autoclaved X. budapestensis, and X. szentirmaii cultures developed on chicken food)were consumed by the
birds. The XENOFOOD exerted detectable gastrointestinal (GI) activity (reducing the numbers of the colonyforming
Clostridium perfringens units in the lower jejunum. No animalwas lost in the experiment. Neither the
bodyweight, growth rate, feed-conversion ratio, nor organ-weight data differed between the control (C) and
treated (T) groups, indicating that the XENOFOOD diet did not result in any detectable adverse effects. We
suppose that the parameters indicating amoderate enlargement of bursas of Fabricius (averageweight, size,
and individual bursa/spleenweight-ratios) in the XENOFOOD-fed groupmust be an indirect indication that
the bursa-controlled humoral immune systemneutralized the cytotoxic ingredients of the XENOFOOD in the
blood, not allowing to reach their critical cytotoxic concentration in the sensitive tissues.Entomopathogenic bacteria are obligate symbionts of entomopathogenic nematode (EPN) species. These bacteria biosynthesize and release non-ribosomal-templated hybrid peptides (NR-AMPs), with strong, and large-spectral antimicrobial potential, capable of inactivating pathogens belonging to different prokaryote, and eukaryote taxa. The cell-free conditioned culture media (CFCM) of Xenorhabdus budapestensis and X. szentirmaii efficiently inactivate poultry pathogens like Clostridium, Histomonas, and Eimeria. To learn whether a bio-preparation containing antimicrobial peptides of Xenorhabdus origin with accompanying (in vitro detectable) cytotoxic effects could be considered a safely applicable preventive feed supplement, we conducted a 42-day feeding experiment on freshly hatched broiler cockerels. XENOFOOD (containing autoclaved X. budapestensis, and X. szentirmaii cultures developed on chicken food) were consumed by the birds. The XENOFOOD exerted detectable gastrointestinal (GI) activity (reducing the numbers of the colony-forming Clostridium perfringens units in the lower jejunum. No animal was lost in the experiment. Neither the body weight, growth rate, feed-conversion ratio, nor organ-weight data differed between the control (C) and treated (T) groups, indicating that the XENOFOOD diet did not result in any detectable adverse effects. We suppose that the parameters indicating a moderate enlargement of bursas of Fabricius (average weight, size, and individual bursa/spleen weight-ratios) in the XENOFOOD-fed group must be an indirect indication that the bursa-controlled humoral immune system neutralized the cytotoxic ingredients of the XENOFOOD in the blood, not allowing to reach their critical cytotoxic concentration in the sensitive tissues
Internally controlled real-time PCR method for quantitative species-specific detection and vapA genotyping of Rhodococcus equi
No full textWe developed a novel quantitative real-time PCR (Q-PCR) method for the soil actinomycete Rhodococcus equi, an important horse pathogen and emerging human pathogen. Species-specific quantification was achieved by targeting the chromosomal monocopy gene choE, universally conserved in R. equi. The choE Q-PCR included an internal amplification control (IAC) for identification of false negatives. A second Q-PCR targeted the virulence plasmid gene vapA, carried by most horse isolates but infrequently found in isolates from other sources. The choE-IAC and vapA assays were 100% sensitive and specific as determined using 178 R. equi isolates, 77 nontarget bacteria, and a panel of 60 R. equi isolates with known vapA+ and vapA-negative (including vapB+) plasmid genotypes. The vapA+ frequency among isolate types was as follows: horse, 85%; human, 20%; bovine and pig, 0%; others, 27%. The choE-IAC Q-PCR could detect up to one genome equivalent using R. equi DNA or 100 bacteria/ml using DNA extracted from artificially contaminated horse bronchoalveolar lavage (BAL) fluid. Quantification was linear over a 6-log dynamic range down to approximately 10 target molecules (or 1,000 CFU/ml BAL fluid) with PCR efficiency E of >0.94. The vapA assay had similar performance but appeared unsuitable for accurate (vapA+) R. equi quantification due to variability in target gene or plasmid copy number (1 to 9). The dual-reaction Q-PCR system here reported offers a useful tool to both medical and veterinary diagnostic laboratories for the quantitative detection of R. equi and (optional) vapA+ "horse-pathogenic" genotype determination
Antimicrobial Peptides (AMP) in the Cell-Free Culture Media of Xenorhabdus budapestensis and X. szentirmaii Exert Anti-Protist Activity against Eukaryotic Vertebrate Pathogens including Histomonas meleagridis and Leishmania donovani Species
No full textAnti-microbial peptides provide a powerful toolkit for combating multidrug resistance. Combating eukaryotic pathogens is complicated because the intracellular drug targets in the eukaryotic pathogen are frequently homologs of cellular structures of vital importance in the host organism. The entomopathogenic bacteria (EPB), symbionts of entomopathogenic–nematode species, release a series of non-ribosomal templated anti-microbial peptides. Some may be potential drug candidates. The ability of an entomopathogenic–nematode/entomopathogenic bacterium symbiotic complex to survive in a given polyxenic milieu is a coevolutionary product. This explains that those gene complexes that are responsible for the biosynthesis of different non-ribosomal templated anti-microbial protective peptides (including those that are potently capable of inactivating the protist mammalian pathogen Leishmania donovanii and the gallinaceous bird pathogen Histomonas meleagridis) are co-regulated. Our approach is based on comparative anti-microbial bioassays of the culture media of the wild-type and regulatory mutant strains. We concluded that Xenorhabdus budapestensis and X. szentirmaii are excellent sources of non-ribosomal templated anti-microbial peptides that are efficient antagonists of the mentioned pathogens. Data on selective cytotoxicity of different cell-free culture media encourage us to forecast that the recently discovered “easy-PACId” research strategy is suitable for constructing entomopathogenic-bacterium (EPB) strains producing and releasing single, harmless, non-ribosomal templated anti-microbial peptides with considerable drug, (probiotic)-candidate potential
Molecular Diversity and Genetic Relatedness of Candida albicans Isolates from Birds in Hungary
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Characterisation of some Ornithobacterium rhinotracheale strains and examination of their transmission via eggs
No full textThe biochemical characteristics and antibiotic susceptibility of 12 Ornithobacterium rhinotracheale strains isolated from chickens and turkeys suffering from respiratory clinical signs and the survival of some isolates on egg-shell and within chicken eggs during hatching were examined. All O. rhinotracheale strains showed typical biochemical characteristics. Among the 16 drugs examined, penicillin G, ampicillin (MICs ranging from ≤ 0.06 μg/ml to 1 μg/ml), ceftazidim (with MICs from ≤ 0.06 μg/ml to 0.12 μg/ml), erythromycin, tylosin, tilmicosin (with some exceptions MICs ranged from ≤ 0.06 μg/ml to 1 μg/ml) and tiamulin (MICs varied from ≤ 0.06 μg/ml to 2 μg/ml) were the most effective. Lincomycin, oxytetracycline and enrofloxacin also gave good inhibitions, but with most strains in a higher concentration (MICs ranged in most cases from 2 μg/ml to 8 μg/ml). The other antibiotics inhibited the growth of O. rhinotracheale only in very high concentrations (colistin) or not at all (apramycin, spectinomycin, polymyxin B). At 37 °C, O. rhinotracheale did not survive on egg-shell for more than 24 hours, while upon inoculation into embryonated chicken eggs it killed embryos by the ninth day, and from the 14th day post-inoculation no O. rhinotracheale could be cultured from the eggs at all. These results suggest that O. rhinotracheale is not transmitted via eggs during hatching
The Photosynthetic Performance of Oak (Quercus robur L.) Populations Exposed to Automobile Exhaust as an Air Pollutant
No full textAn investigation of the aetiological role of bovine herpesvirus 4 in bovine endometritis
No full textUteri from 31 infertile cattle were examined for the presence of bovine herpesvirus 4 (BoHV-4) by nested polymerase chain reaction (PCR). Samples were also tested for bacteria, including chlamydiae and Mycoplasma bovis. BoHV-4 was detected by PCR in 27/31 (87.1%) samples, but the presence and amount of viral DNA was not correlated with histological and bacteriological findings. A pyogenes, Histophilus somni and Pasteurella multocida were isolated from five cows with endometritis. Chlamydiae were detected in four cases (12.9%), but only two of these had endometritis. The study does not support a role for BoHV-4 as primary agent in bovine endometritis. (C) 2007 Elsevier Ltd. All rights reserve
Antimicrobial susceptibility of Francisella tularensis subsp. holarctica strains from Hungary, Central Europe
No full textObjectives: Determining the in vitro susceptibility to 11 antibiotics of Francisella tularensis subsp. holarctica
strains belonging to the phylogenetic group B.13, from different areas of Hungary.
Methods: Twenty-nine F. tularensis strains isolated between 2003 and 2010 from free-ranging European brown
hares (Lepus europaeus) and a captive patas monkey (Erythrocebus patas) were collected from different parts of
Hungary and examined for antibiotic susceptibility with commercially available MIC test strips on modified
Francis agar plates; values were interpreted according to CLSI breakpoints.
Results: The strains were susceptible to aminoglycosides (MIC90 values: gentamicin, 0.75 mg/L; and streptomycin,
6.0 mg/L), tetracyclines (MIC90 values: tetracycline, 0.5 mg/L; and doxycycline, 1.0 mg/L), quinolones (MIC90
values: ciprofloxacin, 0.047 mg/L; and levofloxacin, 0.023 mg/L) and chloramphenicol (MIC90 value: 1.5 mg/L),
i.e. antibiotics commonly used in therapy. Tigecycline (MIC90 value: 0.19 mg/L) and rifampicin (MIC90 value:
1.0 mg/L) were also active against F. tularensis strains, while resistance to erythromycin (MIC90 value:
.256 mg/L) and linezolid (MIC90 value: 32 mg/L) was observed in all strains.
Conclusions: Based on the results, quinolones are recommended as first choice therapy for F. tularensis infection.
The in vitro susceptibility of the strains to tigecycline may encourage the application of this antibiotic as
well. The similar antibiotic susceptibilities of the Hungarian strains belonging to different subclades of phylogenetic
group B.13 indicates that strains from other Central and Eastern European countries belonging to this group
might also have the same susceptibility profile
