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Frontiers in Bioengineering and... 2021Lithium (Li) reportedly has anti-bacterial properties. Thus, it is an ideal option to modify barrier membranes used for guided bone regeneration to inhibit the bacterial...
Lithium (Li) reportedly has anti-bacterial properties. Thus, it is an ideal option to modify barrier membranes used for guided bone regeneration to inhibit the bacterial adhesion. The aims of this study were to fabricate and characterize nanofibrous poly(L-lactic acid) (PLLA) membranes containing Li, and investigate their antibacterial effects on and . Li (5%Li, 10%Li, and 15%Li)-loaded nanofibrous PLLA membranes were fabricated using an electrospinning technique, and characterized via scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, a contact angle measuring device, and a universal testing machine. Sustained release of Li ions was measured over a 14-day period and biocompatibility of the Li-PLLA membranes was investigated. Evaluation of bacterial adhesion and antibacterial activity were conducted by bacterial colony counting, LIVE/DEAD staining and inhibition zone method using and . Of the three Li-loaded membranes assessed, the 10%Li-PLLA membrane had the best mechanical properties and biocompatibility. Adhesion of both and on Li-PLLA membranes was significantly lower than adhesion on pure PLLA membranes, particularly with regard to the 10%Li and 15%Li membranes. Significant antibacterial activity of Li-PLLA were also observed against according to the inhibition zone test. Given their better mechanical properties, biocompatibility, and antibacterial activity, PLLAs with 10%Li are a better choice for future clinical utilization. The pronounced antibacterial effects of Li-loaded PLLA membranes sets the stage for further application in guided bone regeneration.
PubMed: 33996786
DOI: 10.3389/fbioe.2021.676874 -
MBio May 2018Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this...
Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this report, we describe a new family of polymerases that combine glycosyltransferase and hexose- and polyol-phosphate transferase activity to generate complex poly(oligosaccharide phosphate) and poly(glycosylpolyol phosphate) polymers, the latter of which display similarity to wall teichoic acid (WTA), a cell wall component of Gram-positive bacteria. Using modeling and multiple-sequence alignment, we showed homology between the predicted polymerase domains and WTA type I biosynthesis enzymes, creating a link between Gram-negative and Gram-positive cell wall biosynthesis processes. The polymerases of the new family are highly abundant and found in a variety of capsule-expressing pathogens such as , , , , and with both human and animal hosts. Five representative candidates were purified, their activities were confirmed using nuclear magnetic resonance (NMR) spectroscopy, and their predicted folds were validated by site-directed mutagenesis. Bacterial capsules play an important role in the interaction between a pathogen and the immune system of its host. During the last decade, capsule polymerases have become attractive tools for the production of capsule polymers applied as antigens in glycoconjugate vaccine formulations. Conventional production of glycoconjugate vaccines requires the cultivation of the pathogen and thus the highest biosafety standards, leading to tremendous costs. With regard to animal husbandry, where vaccines could avoid the extensive use of antibiotics, conventional production is not sufficiently cost-effective. In contrast, enzymatic synthesis of capsule polymers is pathogen-free and fast, offers high stereo- and regioselectivity, and works with high efficacy. The new capsule polymerase family described here vastly increases the toolbox of enzymes available for biotechnology purposes. Representatives are abundantly found in human pathogens but also in animal pathogens, paving the way for the exploitation of polymerases for the development of a new generation of vaccines for animal husbandry.
Topics: Bacterial Capsules; Bacterial Proteins; Glycosyltransferases; Gram-Negative Bacteria; Multigene Family; Phosphotransferases; Polymers; Teichoic Acids
PubMed: 29844111
DOI: 10.1128/mBio.00641-18 -
Journal of Veterinary Diagnostic... Jul 2022We assessed the bacterial agents found in 8-12-wk-old post-weaning pigs with arthritis. The bodies of 178 post-weaning pigs from 90 farms (average of 2 pigs/farm) with...
We assessed the bacterial agents found in 8-12-wk-old post-weaning pigs with arthritis. The bodies of 178 post-weaning pigs from 90 farms (average of 2 pigs/farm) with recurrent problems of lameness and swollen joints in a high-density breeding area were submitted for autopsy and sampled for further bacterial investigation. The most common articular gross lesions and histopathologic findings were serofibrinous (95 of 178; 53%) or serous (65 of 178; 37%) arthritis; suppurative lesions were less frequent (18 of 178; 10%). In 133 of 178 (74.7%) cases, a bacterial agent was detected in joints. was the most common bacterium detected (82 of 133; 61.6%). and spp. were observed in 27 of 133 (20.3%) and 24 of 133 (18.0%) cases, respectively. Other bacteria in the 113 cases, considered less important, in order of their low frequency, were spp. (13; 9.8%), (11; 8.2%), (4; 3.0%), spp. (3; 2.2%), (2; 1.5%), and spp. (2; 1.5%). Our results highlight the primary role of compared to other microorganisms involved in young pigs with arthritis.
Topics: Animals; Arthritis; Mycoplasma Infections; Mycoplasma hyosynoviae; Swine; Swine Diseases; Weaning
PubMed: 35593676
DOI: 10.1177/10406387221090903 -
Medicine Jan 2016Actinobacillus actinomycetemcomitans infection is a rare and easily misdiagnosed ocular disease. In this article, the authors report a chronic, purulent, and... (Review)
Review
Actinobacillus actinomycetemcomitans infection is a rare and easily misdiagnosed ocular disease. In this article, the authors report a chronic, purulent, and difficult-to-treat case of A actinomycetemcomitans keratitis following a glaucoma infiltration surgery.A 56-year-old man with a long-standing history of open-angle glaucoma in both eyes presented with a 12-week history of ocular pain, redness, and blurred vision in his right eye. He underwent a glaucoma infiltration surgery in his right eye 6 months ago. Three months postoperatively, he developed peripheral corneal stromal opacities associated with a white, thin, cystic bleb, and conjunctival injection. These opacities grew despite topical treatment with topical tobramycin, levofloxacin, natamycin, amikacin, and metronidazole eye drops.Multiple corneal scrapings revealed no organisms, and no organisms grew on aerobic, anaerobic, fungal, or mycobacterial cultures. The patient's right eye developed a severe purulent corneal ulcer with a dense hypopyon and required a corneal transplantation. Histopathologic analysis and 16S ribosomalribonucleic acid polymerase chain reaction sequencing revealed A actinomycetemcomitans as the causative organism. Postoperatively, treatment was initiated with topical levofloxacin and cyclosporine, as well as oral levofloxacin and cyclosporine. Graft and host corneal transparency were maintained at the checkup 1 month after surgery.Although it is a rare cause of corneal disease, A actinomycetemcomitans should be suspected in patients with keratitis refractory to topical antibiotic therapy. Delay in diagnosis and appropriate treatment can result in vision loss.
Topics: Aggregatibacter actinomycetemcomitans; Glaucoma Drainage Implants; Glaucoma, Open-Angle; Humans; Keratitis; Male; Middle Aged; Pasteurellaceae Infections
PubMed: 26817919
DOI: 10.1097/MD.0000000000002608 -
Frontiers in Microbiology 2019Potential synergism between florfenicol (FF) and thiamphenicol (TAP) was investigated for efficacy against and/or as well as efficacy in swine. Among isolates of (...
Potential synergism between florfenicol (FF) and thiamphenicol (TAP) was investigated for efficacy against and/or as well as efficacy in swine. Among isolates of ( = 58) and ( = 79) from pigs in Taiwan that were tested, high percentages showed resistance to FF (52 and 53%, respectively) and TAP (57 and 53%, respectively). Checkerboard microdilution assay indicated that synergism [fractional inhibitory concentration index (FICI) ≤ 0.5] was detected in 17% of (all serovar 1) and 24% of isolates. After reconfirming the strains showing FICI ≤ 0.625 with time kill assay, the synergism increased to around 32% against both bacteria and the number could further increase to 40% against resistant and 65% against susceptible isolates. A challenge-treatment trial in pigs with showed that the FF + TAP dosage at ratios correspondent to their MIC deduction was equally effective to the recommended dosages. Further on the combination, the resistant mutation frequency is very low when is grown with FF + TAP and similar to the exposure to sub-inhibitory concentration of FF or TAP alone. The degree of minimum inhibitory concentration (MIC) reduction in FF could reach 75% (1/4 MIC) or more (up to 1/8 MIC for , 1/16 for ) when combined with 1/4 MIC of TAP (or 1/8 for ). The synergism or FICI ≤ 0.625 of FF with oxytetracycline (47%), doxycycline (69%), and erythromycin (56%) was also evident, and worth further investigation for FF as a central modulator facilitating synergistic effects with these antimicrobials. Taken together, synergistic FF + TAP combination was effective against swine pulmonary isolates of and both and Thus, this study may offer a potential alternative for the treatment of and infections and has the potential to greatly reduce drug residues and withdrawal time.
PubMed: 31749775
DOI: 10.3389/fmicb.2019.02430 -
PloS One 2017Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules for florfenicol for two pig pneumonia pathogens, Actinobacillus...
Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules for florfenicol for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Pharmacokinetic data were pooled for two bioequivalent products, pioneer and generic formulations, administered intramuscularly to pigs at a dose rate of 15 mg/kg. Antibacterial potency was determined in vitro as minimum inhibitory concentration (MIC) and Mutant Prevention Concentration in broth and pig serum, for six isolates of each organism. For both organisms and for both serum and broth MICs, average concentration:MIC ratios over 48 h were similar and exceeded 2.5:1 and times greater than MIC exceeded 35 h. From in vitro time-kill curves, PK/PD modelling established serum breakpoint values for the index AUC24h/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4log10 reductions in bacterial count; means were 25.7, 40.2 and 47.0 h, respectively, for P. multocida and 24.6, 43.8 and 58.6 h for A. pleuropneumoniae. Using these PK and PD data, together with literature MIC distributions, doses for each pathogen were predicted for: (1) bacteriostatic and bactericidal levels of kill; (2) for 50 and 90% target attainment rates (TAR); and (3) for single dosing and daily dosing at steady state. Monte Carlo simulations for 90% TAR predicted single doses to achieve bacteriostatic and bactericidal actions over 48 h of 14.4 and 22.2 mg/kg (P. multocida) and 44.7 and 86.6 mg/kg (A. pleuropneumoniae). For daily doses at steady state, and 90% TAR bacteriostatic and bactericidal actions, dosages of 6.2 and 9.6 mg/kg (P. multocida) and 18.2 and 35.2 mg/kg (A. pleuropneumoniae) were required. PK/PD integration and modelling approaches to dose determination indicate the possibility of tailoring dose to a range of end-points.
Topics: Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Area Under Curve; Microbial Sensitivity Tests; Monte Carlo Method; Pasteurella multocida; Swine; Thiamphenicol
PubMed: 28552968
DOI: 10.1371/journal.pone.0177568 -
Porcine Health Management Oct 2023Antimicrobial resistance is one of the most important health challenges in humans and animals. Antibiotic susceptibility determination is used to select the most...
BACKGROUND
Antimicrobial resistance is one of the most important health challenges in humans and animals. Antibiotic susceptibility determination is used to select the most suitable drug to treat animals according to its success probability following the European legislation in force for these drugs. We have studied the antibiotic susceptibility pattern (ASP) of Actinobacillus pleuropneumoniae (APP) and Pasteurella multocida (PM) isolates, collected during the period 2019-2022 in Spain. ASP was measured by determining minimum inhibitory concentration using standardized laboratory methods and its temporal trend was determined by logistic regression analysis of non-susceptible/susceptible isolates using clinical breakpoints.
RESULTS
It was not observed any significant temporal trends for susceptibility of Actinobacillus pleuropneumoniae to ceftiofur, florfenicol, sulfamethoxazole/trimethoprim, tulathromycin and tildipirosin during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for quinolones (enrofloxacin and marbofloxacin), tetracyclines (doxycycline and oxyteracycline), amoxicillin, tiamulin and tilmicosin. On the other hand, it was not observed any significant temporal trends for susceptibility of Pasteurella multocida to quinolones (enrofloxacin and marbofloxacin), amoxicillin, ceftiofur, florfenicol and macrolides (tildipirosin, tulathromycin and tilmicosin) during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for tetracyclines (oxyteracycline), tiamulin and sulfamethoxazole/trimethoprim.
CONCLUSIONS
In general terms, pig pathogens (APP and PM) involved in respiratory diseases analysed herein appeared to remain susceptible or tended to increase susceptibility to antimicrobials over the study period (2019-2022), but our data clearly showed a different pattern in the evolution of antimicrobial susceptibility for each combination of drug and microorganism. Our results highlight that the evolution of antimicrobial susceptibility must be studied in a case-by-case situation where generalization for drug families and bacteria is not possible even for bacteria located in the same ecological niche.
PubMed: 37858281
DOI: 10.1186/s40813-023-00341-x -
AMB Express Dec 2021Porcine infectious pleuropneumonia is characterized by a high-rate of carriage and mixed infection with other pathogens. The host immune response induced by...
Porcine infectious pleuropneumonia is characterized by a high-rate of carriage and mixed infection with other pathogens. The host immune response induced by Actinobacillus pleuropneumoniae (APP) is the basis for elucidating pathogenesis and controlling disease. However, there is currently no comprehensive and dynamic data characterising the host immune response. In this study, piglets were infected with APP and differentially expressed proteins of bronchoalveolar lavage fluid (BALF) and peripheral serum were identified by iTRAQ-LC-MS/MS, and differentially expressed genes of peripheral blood mononuclear cells (PBMC) by RNA-seq. The results of the integrated analysis of serum, BALF and PBMC showed significant metabolism and local immune responses in BALF, the general immune response in PBMC mainly involves cytokines, while that in serum mainly involves biosynthesis, phagosome, and complement and coagulation cascades. Furthermore, immune responses in PBMCs and serum were rapid and maintained compared to the lung where metabolism and cell adhesion activities were enriched. Some innate immunity pathways of the cellular response to ROS, neutrophil mediated immunity, granulocyte activation and leukocyte cell-cell adhesion were identified as central points, connecting multiple signaling pathways to form an integrated large network. At 24 h post-infection, 14 molecules were up regulated in BALF, 10 of which were shared with PBMC, but at 120 h, 20 down-regulated molecules were identified in BALF, 11 of them still up- regulated in PBMC. We conclude that, the immune response in the lung is different from that in blood, but there is a similarity in response in PBMC and serum.
PubMed: 34952961
DOI: 10.1186/s13568-021-01336-z -
Frontiers in Veterinary Science 2022Actinobacillus pleuropneumoniae causes porcine pleuropneumonia. The function of the outer membrane protein W gene () of has not been evaluated. Thus a deletion mutant...
Actinobacillus pleuropneumoniae causes porcine pleuropneumonia. The function of the outer membrane protein W gene () of has not been evaluated. Thus a deletion mutant of , Δ, was constructed to explore the effect of gene deletion on bacterial growth, biofilm formation, bacterial morphology, oxidative tolerance, susceptibility to antibiotics, and the expression of ribosome synthesis and ABC transporter related genes. Results showed that the gene deletion did not affect biofilm formation and the growth of but did affect bacterial morphology during steady growth, oxidative tolerance, and bacterial susceptibility to polymyxin B, kanamycin, and penicillin. The gene deletion also affected the expression of ribosome synthesis and ABC transporter related genes. These results suggested that may regulate the biological phenotype of .
PubMed: 35664844
DOI: 10.3389/fvets.2022.846322 -
Medicine Mar 2021Oral microbiota has been implicated in pathogenesis of recurrent aphthous stomatitis (RAS), which is a common mucosal disorder with unclear etiology. This study has... (Observational Study)
Observational Study
Oral microbiota has been implicated in pathogenesis of recurrent aphthous stomatitis (RAS), which is a common mucosal disorder with unclear etiology. This study has explored the association between oral microbiota disorder and RAS in high-risk young female population.Forty-five young females were enrolled, including 24 RAS patients and 21 healthy individuals. Oral microbiome was analyzed by Illumina Miseq sequencing.Oral microbiota associated with RAS was characterized by the lower alpha-diversity indices (Chao1 and ACE). Several infectious pathogens increased in RAS, such as genera Actinobacillus, Haemophilus, Prevotella and Vibrio. The PICRUSt analysis indicated that the oral microbiota might be related with the up-regulation of genes involving infectious and neurodegenerative diseases, environmental adaptation, the down-regulation of genes involving basal metabolism, such as carbohydrate, energy, and amino acid metabolism.This study indicated that oral microbiota may play a significant role in RAS development.
Topics: Female; High-Throughput Nucleotide Sequencing; Humans; Microbiota; Mouth Mucosa; Recurrence; Saliva; Stomatitis, Aphthous; Young Adult
PubMed: 33725829
DOI: 10.1097/MD.0000000000024742