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Biotechnology Letters Jan 2018To test the inactivation of the antibiotic, virginiamycin, by laccase-induced culture supernatants of Aureobasidium pullulans.
OBJECTIVE
To test the inactivation of the antibiotic, virginiamycin, by laccase-induced culture supernatants of Aureobasidium pullulans.
RESULTS
Fourteen strains of A. pullulans from phylogenetic clade 7 were tested for laccase production. Three laccase-producing strains from this group and three previously identified strains from clade 5 were compared for inactivation of virginiamycin. Laccase-induced culture supernatants from clade 7 strains were more effective at inactivation of virginiamycin, particularly at 50 °C. Clade 7 strain NRRL Y-2567 inactivated 6 µg virginiamycin/ml within 24 h. HPLC analyses indicated that virginiamycin was degraded by A. pullulans.
CONCLUSIONS
A. pullulans has the potential for the bioremediation of virginiamycin-contaminated materials, such as distiller's dry grains with solubles (DDGS) animal feed produced from corn-based fuel ethanol production.
Topics: Anti-Bacterial Agents; Ascomycota; Biotransformation; Chromatography, High Pressure Liquid; Culture Media; Glucans; Hot Temperature; Virginiamycin
PubMed: 29038924
DOI: 10.1007/s10529-017-2454-7 -
Applied Microbiology and Biotechnology Apr 2020L-phenylglycine (L-Phg) is a rare non-proteinogenic amino acid, which only occurs in some natural compounds, such as the streptogramin antibiotics pristinamycin I and...
L-phenylglycine (L-Phg) is a rare non-proteinogenic amino acid, which only occurs in some natural compounds, such as the streptogramin antibiotics pristinamycin I and virginiamycin S or the bicyclic peptide antibiotic dityromycin. Industrially, more interesting than L-Phg is the enantiomeric D-Phg as it plays an important role in the fine chemical industry, where it is used as a precursor for the production of semisynthetic β-lactam antibiotics. Based on the natural L-Phg operon from Streptomyces pristinaespiralis and the stereo-inverting aminotransferase gene hpgAT from Pseudomonas putida, an artificial D-Phg operon was constructed. The natural L-Phg operon, as well as the artificial D-Phg operon, was heterologously expressed in different actinomycetal host strains, which led to the successful production of Phg. By rational genetic engineering of the optimal producer strains S. pristinaespiralis and Streptomyces lividans, Phg production could be improved significantly. Here, we report on the development of a synthetic biology-derived D-Phg pathway and the optimization of fermentative Phg production in actinomycetes by genetic engineering approaches. Our data illustrate a promising alternative for the production of Phgs.
Topics: Anti-Bacterial Agents; Fermentation; Genes, Bacterial; Genetic Engineering; Glycine; Operon; Pseudomonas putida; Stereoisomerism; Streptomyces; Streptomyces lividans; Synthetic Biology
PubMed: 32078019
DOI: 10.1007/s00253-020-10447-9 -
Microorganisms Nov 2020The aim of the present study was to investigate variation in antimicrobial resistance in () isolated from chickens after withdrawal of antimicrobial growth promoters...
The aim of the present study was to investigate variation in antimicrobial resistance in () isolated from chickens after withdrawal of antimicrobial growth promoters (AGPs); and to investigate the correlation between the presence of toxin genes (, , and ) and antimicrobial resistance. Altogether, 162 isolates of were obtained from chickens displaying clinical signs of necrotic enteritis ( = 65) and from healthy chickens ( = 97) in Korea during 2010-2016. Compared to before AGP withdrawal, increased antimicrobial resistance or MIC/MIC value was observed for nine antimicrobials including penicillin, tetracycline, tylosin, erythromycin, florfenicol, enrofloxacin, monensin, salinomycin, and maduramycin. Significantly ( < 0.05) higher resistance to gentamicin, clindamycin, and virginiamycin was found in isolates from chickens with necrotic enteritis compared to those from healthy chickens. gene was not detected in isolates from healthy chickens. A correlation between toxin gene prevalence and antibiotic resistance was found in the isolates. Because the usage of antimicrobials may contribute to the selection of both resistance and toxin genes, these can potentially make it challenging to control antimicrobial resistance in pathogenic colonies. Therefore, a more complete understanding of the interplay between resistance and virulence genes is required.
PubMed: 33228100
DOI: 10.3390/microorganisms8111825 -
Bioprocess and Biosystems Engineering May 2018The production of virginiamycin (VGM) from Streptomyces virginiae was improved by genome shuffling and ribosome engineering companied with a high-throughput screening...
The production of virginiamycin (VGM) from Streptomyces virginiae was improved by genome shuffling and ribosome engineering companied with a high-throughput screening method integrating deep-well cultivation and the cylinder-plate detecting. First, a novel high-throughput method was developed to rapidly screen large numbers of VGM-producing mutants. Then, the starting population of genome shuffling was obtained through ultraviolet (UV) and microwave mutagenesis, and four mutants with higher productivity of VGM were selected for genome shuffling. Next, the parent protoplasts were inactivated by UV and heat when a fusant probability was about 98%. Streptomycin resistance was used as an evolutionary pressure to extend positive effects on VGM synthesis. Finally, after five rounds of genome shuffling, a genetically stable strain G5-103 was obtained and characterized to be able to yield 251 mg/L VGM, which was 3.1- and 11.6-fold higher than that of the mutant strain UV 1150 and the wild-type strain, respectively.
Topics: DNA Shuffling; Genome, Bacterial; Streptomyces; Virginiamycin
PubMed: 29457193
DOI: 10.1007/s00449-018-1906-3 -
Frontiers in Microbiology 2022Antimicrobial growth promoters (AGPs) are commonly used in broiler production. There is a huge societal concern around their use and their contribution to the...
Effects of Dietary Antimicrobial Growth Promoters on Performance Parameters and Abundance and Diversity of Broiler Chicken Gut Microbiome and Selection of Antibiotic Resistance Genes.
Antimicrobial growth promoters (AGPs) are commonly used in broiler production. There is a huge societal concern around their use and their contribution to the proliferation of antimicrobial resistance (AMR) in food-producing animals and dissemination to humans or the environment. However, there is a paucity of comprehensive experimental data on their impact on poultry production and the AMR resistome. Here, we investigated the effect of five antimicrobial growth promoters (virginiamycin, chlortetracycline, bacitracin methyl disalicylate, lincomycin, and tylosin) used in the commercial broiler production in the Indian subcontinent and in the different parts of the world for three consecutive production cycles on performance variables and also the impact on gut bacteria, bacteriophage, and resistome profile using culture-independent approaches. There was no significant effect of AGPs on the cumulative growth or feed efficiency parameters at the end of the production cycles and cumulative mortality rates were also similar across groups. Many antibiotic resistance genes (ARGs) were ubiquitous in the chicken gut irrespective of AGP supplementation. In total, 62 ARGs from 15 antimicrobial classes were detected. Supplementation of AGPs influenced the selection of several classes of ARGs; however, this was not correlated necessarily with genes relevant to the AGP drug class; some AGPs favored the selection of ARGs related to antimicrobials not structurally related to the AGP. AGPs did not impact the gut bacterial community structure, including alpha or beta diversity significantly, with only 16-20 operational taxonomic units (OTUs) of bacteria being altered significantly. However, several AGPs significantly reduced the population density of some of the potential pathogenic genera of bacteria, such as . Chlortetracycline increased the abundance of phage, whereas other AGPs did not influence the abundance of bacteriophage significantly. Considering the evidence that AGPs used in poultry production can select for resistance to more than one class of antimicrobial resistance, and the fact that their effect on performance is not significant, their use needs to be reduced and there is a need to monitor the spread of ARGs in broiler chicken farms.
PubMed: 35783415
DOI: 10.3389/fmicb.2022.905050 -
Scientific Reports May 2023Actinobacteria are well known as a rich source of diversity of bioactive secondary metabolites. Kutzneria, a rare actinobacteria belonging to the family...
Actinobacteria are well known as a rich source of diversity of bioactive secondary metabolites. Kutzneria, a rare actinobacteria belonging to the family Pseudonocardiaceae has abundance of secondary metabolite biosynthetic gene clusters (BGCs) and is one of important source of natural products and worthy of priority investigation. Currently, Kutzneria chonburiensis SMC256 has been the latest type-strain of the genus and its genome sequence has not been reported yet. Therefore, we present the first report of new complete genome sequence of SMC256 (genome size of 10.4 Mbp) with genome annotation and feature comparison between SMC256 and other publicly available Kutzneria species. The results from comparative and functional genomic analyses regarding the phylogenomic and the clusters of orthologous groups of proteins (COGs) analyses indicated that SMC256 is most closely related to Kutzneria sp. 744, Kutzneria kofuensis, Kutzneria sp. CA-103260 and Kutzneria buriramensis. Furthermore, a total of 322 BGCs were also detected and showed diversity among the Kutzneria genomes. Out of which, 38 clusters showing the best hit to the most known BGCs were predicted in the SMC256genome. We observed that six clusters responsible for biosynthesis of antimicrobials/antitumor metabolites were strain-specific in Kutzneria chonburiensis. These putative metabolites include virginiamycin S1, lysolipin I, esmeraldin, rakicidin, aclacinomycin and streptoseomycin. Based on these findings, the genome of Kutzneria chonburiensis contains distinct and unidentified BGCs different from other members of the genus, and the use of integrative genomic-based approach would be a useful alternative effort to target, isolate and identify putative and undiscovered secondary metabolites suspected to have new and/or specific bioactivity in the Kutzneria.
Topics: Actinomycetales; Genomics; Secondary Metabolism; Multigene Family; Phylogeny
PubMed: 37258607
DOI: 10.1038/s41598-023-36039-x -
Journal of AOAC International Sep 2021Antibiotics are used in ethanol production to discourage the growth of bacteria that would lower the yield of the product. Any antibiotic residues remaining in...
BACKGROUND
Antibiotics are used in ethanol production to discourage the growth of bacteria that would lower the yield of the product. Any antibiotic residues remaining in distillers grain (DG) co-product could lead to antimicrobial resistance, which is a public health concern. The U.S. Food and Drug Administration (FDA) Center for Veterinary Medicine (CVM) previously developed an LC-MS/MS analytical method to detect residues of erythromycin A, penicillin G, virginiamycin M1, and virginiamycin S1 in DG to enable regulatory decision making.
OBJECTIVE
The objective of this study was to ensure the method's robustness by carrying out a multi-laboratory validation of the method.
METHOD
Test portions were extracted with a mixture of acetonitrile and buffer. The extract was cleaned by solid phase extraction. The concentrated eluant was reconstituted and analyzed by LC-MS/MS. Eight laboratories participated in the study.
RESULTS
Average accuracies for the combined three matrixes for all four compounds at all fortification levels ranged from 83->109% with repeatability relative standard deviation (RSDr; within laboratory) ≤17% and reproducibility relative standard deviation (RSDR; between laboratory) ≤21%. The Horwitz ration (HorRat) values ranged 0.4-1.0 indicating that method reproducibility is acceptable.
CONCLUSIONS
An interlaboratory study was successfully conducted to evaluate an LC-MS/MS method for the determination of the drugs of interest in DG. The results demonstrate that the method is fit for purpose to determine the drugs in DG and could serve as a regulatory method capable of being used for compliance actions for DG containing these antibiotic contaminants.
HIGHLIGHTS
The method was posted to the FDA/Foods Program Compendium of Analytical Laboratory Methods.
Topics: Anti-Bacterial Agents; Chromatography, Liquid; Penicillin G; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 33774675
DOI: 10.1093/jaoacint/qsab026 -
Poultry Science Sep 2019The effectiveness of some common combination of antibiotic growth promoters (AGP) on growth performance, gut health, and meat quality was evaluated during the medication...
The effectiveness of some common combination of antibiotic growth promoters (AGP) on growth performance, gut health, and meat quality was evaluated during the medication and withdrawal period in broilers. A total of 540 male Arbor Acre broilers at 0 D of age were randomly assigned to 5 treatments, with 6 replicates of 18 chicks. Broilers received diets during the medication period (0 to 42 D) as follows: NC (control diet without AGP), EN (NC + enduracidin 8 ppm + colistin sulfate 8 ppm), BZ (NC + bacitracin zinc 40 ppm + colistin sulfate 8 ppm), CT (NC + chlortetracycline 50 ppm + colistin sulfate 8 ppm), and VG (NC + virginiamycin 20 ppm + colistin sulfate 8 ppm). Broilers were switched to the same finisher diet without AGP during the withdrawal period (43 to 49 D). The feed:gain ratio in EN, BZ, CT, and VG groups were significantly decreased by 0.07, 0.10, 0.06, and 0.05 during 0 to 42 D (P < 0.05), but increased by 0.19 (P > 0.05), 0.33 (P > 0.05), 0.49 (P < 0.05), and 0.69 (P < 0.05) during the withdrawal period, respectively. The jejunum villus height (VH) increased in EN group (P < 0.05) and crypt depth (CD) reduced in BZ, CT, and VG groups (P < 0.05) at 42 D, while jejunum VH increased in EN and BZ groups (P < 0.05) at 49 D compared to NC group (P < 0.05). Meat quality detection at 49 D found all AGP groups with the higher cook loss of the breast muscle, while CT group with the higher cook loss of thigh muscle. Consequently, the overall effects of 4 AGP combinations in the whole period were not significant on growth performance. Their poor growth performance during the withdrawal period should be partly attributed to the falling off a cliff of most digestive enzyme activities from 42 to 49 D. Attention should be paid to the adverse effects of AGP supplementation on meat quality, especially cook loss.
Topics: Animals; Anti-Bacterial Agents; Chickens; Gastrointestinal Tract; Growth Substances; Immune System; Male; Meat; Random Allocation
PubMed: 30690569
DOI: 10.3382/ps/pey598 -
Journal of Biotechnology Jul 2018l-phenylglycine is a rare non-proteinogenic amino acid, which only occurs in a few natural compounds, such as the streptogramin antibiotics pristinamycin I and...
l-phenylglycine is a rare non-proteinogenic amino acid, which only occurs in a few natural compounds, such as the streptogramin antibiotics pristinamycin I and virginiamycin S or the bicyclic peptide antibiotic dityromycin. Here we report on the biochemical characterization of the aminotransferase PglE that catalyzes the transamination from phenylglyoxylate to l-phenylglycine, which represents the final reaction step during phenylglycine biosynthesis. Enzyme assays with the purified PglE enzyme revealed that l-phenylalanine is used as an amino group donor for the transamination reaction, leading to the formation of phenylpyruvate, which may re-enter phenylglycine biosynthesis as a precursor. Based on these results, we postulate a novel l-phenylglycine biosynthetic pathway.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Glycine; Glyoxylates; Mandelic Acids; Metabolic Networks and Pathways; Streptomyces; Transaminases
PubMed: 29738785
DOI: 10.1016/j.jbiotec.2018.05.007 -
Microbiome 2015The emergence and spread of antibiotic resistance in pathogens have led to a restriction on the use of antibiotic growth promoters (AGPs) in animal feed in some...
BACKGROUND
The emergence and spread of antibiotic resistance in pathogens have led to a restriction on the use of antibiotic growth promoters (AGPs) in animal feed in some countries. The potential negative after-effects of a ban on AGPs could be mitigated by improving animal intestinal health with prebiotic dietary fibers such as xylo-oligosaccharides (XOS). However, the mechanism(s) by which an antibiotic or prebiotic contributes to the health and growth of animals are not well understood. Here, we evaluated XOS and virginiamycin (VIRG)-mediated changes in gut microbiota of broiler chickens using pyrosequencing of the 16S rRNA gene.
RESULTS
There was a significant change in the relative abundance of certain bacteria, but the overall microbial diversity was not affected by treatment with either XOS or VIRG. Supplementation of HXOS (2 g XOS/kg diet) increased the proportion of Lactobacillus genus in the cecum, whereas Propionibacterium and Corynebacterium genera were enriched in the ileum of VIRG (16 mg/kg) treated birds. Furthermore, an increase in the cecal concentrations of acetate and propionate was observed in HXOS- and VIRG-fed chickens, respectively. These two groups of birds had better feed conversion efficiencies in comparison with the control group from day 7 to 21. In addition, temporal variations in the gut microbiota were evident in the chickens of different ages.
CONCLUSIONS
Treatments with XOS or VIRG modified the relative abundance but not the presence or absence of specific microbial genus. The increase in both Lactobacillus spp. and acetate production in the cecum of HXOS-treated chickens may promote intestinal health.
PubMed: 25874109
DOI: 10.1186/s40168-015-0079-4