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Li J, Hu S, Feng P, Xia Y, Pei Z, Tian J, Jiang K, Liu L, Cai X, Wu P. Brucine Sulfate, a Novel Bacteriostatic Agent in 3D Printed Bone Scaffold Systems. Polymers (Basel) 2024; 16:1428. [PMID: 38794621 PMCID: PMC11124991 DOI: 10.3390/polym16101428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/28/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
Bacterial infection is a common complication in bone defect surgery, in which infection by clinically resistant bacteria has been a challenge for the medical community. Given this emerging problem, the discovery of novel natural-type inhibitors of drug-resistant bacteria has become imperative. Brucine, present in the traditional Chinese herb Strychnine semen, is reported to exert analgesic and anti-inflammatory effects. Brucine's clinical application was limited because of its water solubility. We extracted high-purity BS by employing reflux extraction and crystallization, greatly improved its solubility, and evaluated its antimicrobial activity against E. coli and S. aureus. Importantly, we found that BS inhibited the drug-resistant strains significantly better than standard strains and achieved sterilization by disrupting the bacterial cell wall. Considering the safety concerns associated with the narrow therapeutic window of BS, a 3D BS-PLLA/PGA bone scaffold system was constructed with SLS technology and tested for its performance, bacteriostatic behaviors, and biocompatibility. The results have shown that the drug-loaded bone scaffolds had not only long-term, slow-controlled release with good cytocompatibility but also demonstrated significant antimicrobial activity in antimicrobial testing. The above results indicated that BS may be a potential drug candidate for the treatment of antibiotic-resistant bacterial infections and that scaffolds with enhanced antibacterial activity and mechanical properties may have potential applications in bone tissue engineering.
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Affiliation(s)
- Jinying Li
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
| | - Shi Hu
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China; (S.H.); (P.F.)
- Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Pei Feng
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China; (S.H.); (P.F.)
| | - Yang Xia
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
- Changde First Chinese Medicine Hospital, Changde 415000, China
| | - Zihan Pei
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
| | - Jiaxuan Tian
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
| | - Kun Jiang
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
| | - Liang Liu
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
- State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xiong Cai
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
| | - Ping Wu
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (J.L.); (Y.X.); (Z.P.); (J.T.); (K.J.)
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Taponen S, McGuinness D, Hiitiö H, Simojoki H, Zadoks R, Pyörälä S. Bovine milk microbiome: a more complex issue than expected. Vet Res 2019; 50:44. [PMID: 31171032 PMCID: PMC6555717 DOI: 10.1186/s13567-019-0662-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/13/2019] [Indexed: 01/23/2023] Open
Abstract
The aim of this study was to analyze bacterial profiles of bovine mastitic milk samples and samples from healthy quarters using Next Generation Sequencing of amplicons from 16S rRNA genes and to compare results with microbiological results by PCR assays of the same samples. A total of 49 samples were collected from one single dairy herd during the same day. The samples were divided in two sample sets, which were used in this study. The DNA extraction as well as the library preparation and sequencing of these two sets were performed separately, and results of the two datasets were then compared. The vast majority of genera detected appeared with low read numbers and/or in only a few samples. Results of PCR and microbiome analyses of samples infected with major pathogens Staphylococcus aureus or Streptococcus uberis were consistent as these genera also covered the majority of reads detected in the microbiome analysis. Analysis of alpha diversity revealed a much higher species richness in set 1 than in set 2. The dominating bacterial genera with the highest read numbers clearly differed between datasets, especially in PCR negative samples and samples positive for minor pathogens. In addition to this, linear discriminant analysis (LDA) was conducted between the two sets to identify significantly different genera/family level microbes. The genus Methylobacterium was much more common in set 2 compared to set 1, and genus Streptococcus more common in set 1. Our results indicate amplification of contaminating bacteria in excess in samples with no or minor amounts of pathogen DNA in dataset 2. There is a need for critical assessment of results of milk microbiome analyses.
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Affiliation(s)
- Suvi Taponen
- Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
| | - David McGuinness
- Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Heidi Hiitiö
- Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Heli Simojoki
- Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Ruth Zadoks
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Satu Pyörälä
- Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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The impact of dairy consumption on salivary inoculum. Dysphagia 2014; 29:277-82. [PMID: 24385220 DOI: 10.1007/s00455-013-9508-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
Abstract
Quantitative levels of harmful oral microbes present following complex surgical excisions of head and neck cancer are important since wounds are often contaminated through direct connection to the oral cavity and its flora. This possibility is especially important in irradiated patients who have decreased protective salivary function. In addition, high oral microbial levels increase and intensify oral mucositis leading to significant morbidity in patients treated with radiation therapy. One previously untested surgical teaching to decrease the bacterial inoculum present in the oral cavity is to counsel patients against consuming otherwise nutritious dairy products, as they are thought to coat the oral cavity with rate-limiting nutrients vital for bacterial growth. This risk may extend to individuals with chronic laryngeal penetration or aspiration, since salivary bacterial load might represent a lethal threat in the presence of marginal pulmonary reserve. A crossover study using six healthy adult volunteers and six patients who had previously undergone radiation therapy to an oropharyngeal primary site was performed. Saliva samples were quantitatively cultured in both groups with and without the consumption of dairy products at 1-h and 5-h intervals. Analysis of quantitative cultures demonstrated that the consumption of dairy products had no influence on bacterial levels present in previously radiated subjects and nonirradiated controls. Additionally, the consumption of dairy did not affect the composition of microbes present. Due to the lack of changes in both quantity and composition of oral bacteria seen in this study, patients would not benefit from the avoidance of dairy products.
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Detilleux J, Vangroenweghe F, Burvenich C. Mathematical model of the acute inflammatory response to Escherichia coli in intramammary challenge. J Dairy Sci 2008; 89:3455-65. [PMID: 16899679 DOI: 10.3168/jds.s0022-0302(06)72383-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We constructed a mathematical model of the early response to Escherichia coli infection of the mammary gland and explored the roles and interactions between inflammatory cells and bacteria. The model incorporates 3 equations that describe the interactions among bacteria, milk somatic cells, and blood leukocyte densities. These 3 equations were fitted to cell densities observed during acute inflammatory responses in unvaccinated and vaccinated heifers inoculated with 10(4) or 10(6) cfu of E. coli. The rates computed for the cellular transit from the storage sites to the blood and from the blood to the milk were lower in cows receiving 10(4) cfu but increased at approximately 6 x 10(-6) and 30 x 10(-6) microL/cfu per h in nonvaccinated or vaccinated cows inoculated with 10(6) cfu, respectively. The cellular rates of bacterial killing were highest in unvaccinated cows ( approximately 400 x 10(-6) microL/cell per h) when compared with vaccinated cows (200 to 300 x 10(-6) microL/cell per h). A critical density of milk somatic cells at which bacteria density is constant was computed from the model at 2 x 10(6) cells/mL, and a one-way sensitivity analysis revealed that the changes in milk cellular densities were mostly sensitive to variations in the rate of bacterial killing and in the rate of production of inflammatory cells.
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Affiliation(s)
- J Detilleux
- Faculty of Veterinary Medicine, University of Liège, Department of Quantitative Genetics, Liege 4000, Belgium.
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Karimuribo ED, Fitzpatrick JL, Bell CE, Swai ES, Kambarage DM, Ogden NH, Bryant MJ, French NP. Clinical and subclinical mastitis in smallholder dairy farms in Tanzania: Risk, intervention and knowledge transfer. Prev Vet Med 2006; 74:84-98. [PMID: 16488030 DOI: 10.1016/j.prevetmed.2006.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In a cross-sectional study of 400 randomly selected smallholder dairy farms in the Tanga and Iringa regions of Tanzania, 14.2% (95% confidence interval (CI)=11.6-17.3) of cows had developed clinical mastitis during the previous year. The point prevalence of subclinical mastitis, defined as a quarter positive by the California Mastitis Test (CMT) or by bacteriological culture, was 46.2% (95% CI=43.6-48.8) and 24.3% (95% CI=22.2-26.6), respectively. In a longitudinal disease study in Iringa, the incidence of clinical mastitis was 31.7 cases per 100 cow-years. A randomised intervention trial indicated that intramammary antibiotics significantly reduced the proportion of bacteriologically positive quarters in the short-term (14 days post-infusion) but teat dipping had no detectable effect on bacteriological infection and CMT positive quarters. Other risk and protective factors were identified from both the cross-sectional and longitudinal included animals with Boran breeding (odds ratio (OR)=3.40, 95% CI=1.00-11.57, P<0.05 for clinical mastitis, and OR=3.51, 95% CI=1.29-9.55, P<0.01 for a CMT positive quarter), while the practice of residual calf suckling was protective for a bacteriologically positive quarter (OR=0.63, 95% CI=0.48-0.81, P<or=0.001) and for a CMT positive quarter (OR=0.69, 95% CI=0.63-0.75, P<0.001). A mastitis training course for farmers and extension officers was held, and the knowledge gained and use of different methods of dissemination were assessed over time. In a subsequent randomised controlled trial, there were strong associations between knowledge gained and both the individual question asked and the combination of dissemination methods (village meeting, video and handout) used. This study demonstrated that both clinical and subclinical mastitis is common in smallholder dairying in Tanzania, and that some of the risk and protective factors for mastitis can be addressed by practical management of dairy cows following effective knowledge transfer.
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Affiliation(s)
- E D Karimuribo
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, Tanzania.
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Haddadi K, Moussaoui F, Hebia I, Laurent F, Le Roux Y. E. coliproteolytic activity in milk and casein breakdown. ACTA ACUST UNITED AC 2005; 45:485-96. [PMID: 16045896 DOI: 10.1051/rnd:2005033] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Previous studies have focused on both LPS and E. coli experimental mastitis and underlined the respective roles of endogenous proteolysis (including plasmin from the blood stream and other proteases from milk leukocytes), as well as the presence of E. coli in a more intricate system. The aim of this study was to assess the role of E. coli in milk proteolysis and especially that of its proteases in casein breakdown. The first part consisted in the incubation of 104 cfu.mL(-1) of the E. coli strain in raw milk at 37 degrees C for 24 h; the same milk was also incubated with 0.04% sodium azide. Several parameters were evaluated: CFU, plasmin activity, gelatinase activity and pH 4.6 insoluble peptides, including the proportion of gamma-CN. The profile of gelatinase activity was determined by zymography and identified by immunoblotting. In the second part of the study, we examined the profile of CN (alphas-, beta- and kappa-CN) breakdown by E. coli lysate. The results suggest that E. coli proteases have a direct effect on CN, and the increase of gamma-CN in inoculated milk may be generated by both plasmin and the gelatinase. Moreover, the gelatinase activity in the inoculated milk was higher after 24 h of incubation.
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Affiliation(s)
- Kahina Haddadi
- Laboratoire de Sciences Animales, UC INRA 12 340, Ecole Nationale Supérieure d'Agronomie et des Industries Alimentaires (ENSAIA), BP 172, Vandoeuvre-Lès-Nancy, France.
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Abstract
To address the question of whether a minimum concentration of blood neutrophils is necessary to decrease Staphylococcus aureus concentration in mastitic milk, literature was searched for studies in which neutrophils were incubated with Staph. aureus. Different mathematical models that describe the changes in Staph. aureus population as a function of neutrophilic concentrations were applied to the collected data. The best fitted model established (1) that the rate of bacterial killing depended on the ratio of neutrophils to bacteria with neutrophilic attack rate accelerating at first before decelerating as the ratio increases, and (2) that neutrophil concentration should be within a limited range to trigger a decline in the bacterial population. Outcomes of this model are supported by what is known about neutrophilic functions and laboratory findings in bovine and human neutrophils. These results may be of assistance in setting selection goals for a better resilience to Staph. aureus mastitis in dairy cattle. Indeed, an optimal neutrophilic concentration appears to exist for successful clearance of Staph. aureus infection, which is neither the lowest nor the highest one.
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Abstract
Streptococcus uberis is an important environmental pathogen associated with bovine mastitis as well as with high total bacterial numbers in bulk tank milk. This study was conducted to determine whether S. uberis reproduction is likely to contribute to high bacterial numbers in bulk tank milk. Four S. uberis raw milk isolates were individually inoculated into UHT-treated milk and incubated at 4.4 or 7 degrees C for up to 5 d to simulate appropriate cooling; at 10 degrees C for 5 d to simulate marginally inadequate cooling; at 21 or 25 degrees C for 7 h to simulate ambient temperatures; or at 32 degrees C for 7 h to simulate elevated temperature conditions. None of the S. uberis isolates grew at either 4.4 or 7 degrees C. Streptococcus uberis growth at 10 degrees C appeared to be ribotype-specific. Although ribotype 116-520-S-1 isolates did not grow at 10 degrees C, ribotype 116-520-S-2 isolate numbers increased up to 3.5 log10 cfu/mL within 5 d. Generation times were calculated as 2.7 +/- 0.1 h, 2.1 +/- 0.1 h, and 1.0 +/- 0.1 h for 116-520-S-1 isolates and 1.8 +/- 0.4 h, 1.3 +/- 0.3 h, and 0.8 +/- 0.1 h for 116-520-S-2 isolates at 21, 25, and 32 degrees C, respectively. Our results suggest that high numbers of S. uberis in bulk tank milk are more likely to reflect high numbers of S. uberis shed by mastitic cows, rather than multiplication of these organisms under cooling conditions required for production of Grade A milk.
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Affiliation(s)
- B Dogan
- Department of Food Science, Cornell University, Ithaca, New York 14853, USA
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Kornalijnslijper JE, van Werven T, Daemen AJJM, van den Broek J, Niewold TA, Rutten VPMG, Noordhuizen-Stassen EN. In vitro growth of mastitis-inducing Escherichia coli in milk and milk fractions of dairy cows. Vet Microbiol 2003; 91:125-34. [PMID: 12458162 DOI: 10.1016/s0378-1135(02)00266-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The outcome of E. coli mastitis in cows ranges from mild to severe in individual animals. This study explored the hypothesis that milk from individual cows differs in its growth medium properties for E. coli, and whether possible variation could be related to specific milk constituents. To mimic the early phase of intramammary E. coli infection, a low inoculum size and a short incubation period were used. Cell-reduced, cell- and fat-free (skim) and cell- and fat-free and protein-reduced (whey) fractions were prepared from whole milk samples (n=18). Ten ml of whole milk, milk fractions and brain heart infusion broth (BHI) were inoculated with approximately 100cfu E. coli. After 6h of incubation, bacterial counts were assessed by dilution plating in triplicate. Bacterial counts in whole milk differed up to a 100-fold between cows, which was not associated with SCC. Bacterial counts were significantly higher in whey fractions than in whole milk, cell-reduced and skim fractions and variation in whey was smaller, indicating that the acid-precipitable protein fraction contains the milk constituents of major relevance for inhibition of and variation in bacterial growth. The presence of fat and cells added to bacterial growth inhibition to a lesser extent. In conclusion, in vitro growth of E. coli in milk differs substantially between individual cows within an incubation period comparable with the early phase of intramammary infection. This suggests that the growth medium properties of milk could be of importance in the pathogenesis of E. coli mastitis and subsequent outcome of disease.
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Affiliation(s)
- J E Kornalijnslijper
- Department of Farm Animal Health, Ruminant Health Unit, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL, Utrecht, The Netherlands.
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Lammers A, Kruijt E, van de Kuijt C, Nuijten PJM, Smith HE. Identification of Staphylococcus aureus genes expressed during growth in milk: a useful model for selection of genes important in bovine mastitis? MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 4):981-987. [PMID: 10784056 DOI: 10.1099/00221287-146-4-981] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Staphylococcus aureus is a major cause of bovine mastitis. Since gene expression of many bacteria is known to be regulated by the environment, milk may play an important role in the regulation of the early steps in the pathogenesis of bovine mastitis by S. aureus. To get insight into the response of S. aureus to the milk environment, a Tn917-lacZ mutant library was generated and screened for genes specifically expressed during growth in milk. Twenty-eight mutants were identified and analysed. Four groups of genes were found, involved in cell-wall synthesis, nucleotide synthesis, transcriptional regulation and carbohydrate metabolism. A fifth group contained genes with hypothetical or unknown functions. Many of the genes identified belonged to biosynthetic pathways of S. aureus and other bacterial species which have also been shown to play a role in vivo as determined in murine infection models. Therefore, growth on milk may be an attractive model for the identification of genes preferentially expressed during bovine mastitis.
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Affiliation(s)
- Aart Lammers
- Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1
| | - Ellard Kruijt
- Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1
| | - Corine van de Kuijt
- Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1
| | - Piet J M Nuijten
- Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1
| | - Hilde E Smith
- Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1
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