1
|
Zhao Q, Bertolli S, Park YJ, Tan Y, Cutler KJ, Srinivas P, Asfahl KL, Fonesca-García C, Gallagher LA, Li Y, Wang Y, Coleman-Derr D, DiMaio F, Zhang D, Peterson SB, Veesler D, Mougous JD. Streptomyces umbrella toxin particles block hyphal growth of competing species. Nature 2024; 629:165-173. [PMID: 38632398 PMCID: PMC11062931 DOI: 10.1038/s41586-024-07298-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 03/11/2024] [Indexed: 04/19/2024]
Abstract
Streptomyces are a genus of ubiquitous soil bacteria from which the majority of clinically utilized antibiotics derive1. The production of these antibacterial molecules reflects the relentless competition Streptomyces engage in with other bacteria, including other Streptomyces species1,2. Here we show that in addition to small-molecule antibiotics, Streptomyces produce and secrete antibacterial protein complexes that feature a large, degenerate repeat-containing polymorphic toxin protein. A cryo-electron microscopy structure of these particles reveals an extended stalk topped by a ringed crown comprising the toxin repeats scaffolding five lectin-tipped spokes, which led us to name them umbrella particles. Streptomyces coelicolor encodes three umbrella particles with distinct toxin and lectin composition. Notably, supernatant containing these toxins specifically and potently inhibits the growth of select Streptomyces species from among a diverse collection of bacteria screened. For one target, Streptomyces griseus, inhibition relies on a single toxin and that intoxication manifests as rapid cessation of vegetative hyphal growth. Our data show that Streptomyces umbrella particles mediate competition among vegetative mycelia of related species, a function distinct from small-molecule antibiotics, which are produced at the onset of reproductive growth and act broadly3,4. Sequence analyses suggest that this role of umbrella particles extends beyond Streptomyces, as we identified umbrella loci in nearly 1,000 species across Actinobacteria.
Collapse
Affiliation(s)
- Qinqin Zhao
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Savannah Bertolli
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Young-Jun Park
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Yongjun Tan
- Department of Biology, St Louis University, St Louis, MO, USA
| | - Kevin J Cutler
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Pooja Srinivas
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Kyle L Asfahl
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA, USA
| | - Citlali Fonesca-García
- Plant Gene Expression Center, USDA-ARS, Albany, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Larry A Gallagher
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Yaqiao Li
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Yaxi Wang
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Devin Coleman-Derr
- Plant Gene Expression Center, USDA-ARS, Albany, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Dapeng Zhang
- Department of Biology, St Louis University, St Louis, MO, USA
- Program of Bioinformatic and Computational Biology, St Louis University, St Louis, MO, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - David Veesler
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA, USA.
| |
Collapse
|
2
|
Wu M, Yu G, Chen W, Dong S, Wang Y, Liu C, Li B. A pulp foam with highly improved physical strength, fire-resistance and antibiosis by incorporation of chitosan and CPAM. Carbohydr Polym 2022; 278:118963. [PMID: 34973778 DOI: 10.1016/j.carbpol.2021.118963] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/18/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022]
Abstract
Bio-inspired borate cross-linked pulp foam (PF) with high porosity and low density can be widely used in many fields. However, PF is flammable, and lack of mechanical strength and antibacterial activity. To solve these issues, an ultra-strong PF was prepared by incorporation of chitosan and cationic polyacrylamide (CPAM). Results showed that the obtained PF exhibited highly improved mechanical properties (the compressive strength (485 kPa at a strain of 50%) was over 6 times higher compared with the borate cross-linked PF without chitosan and CPAM, and it was even higher than most of the reported cellulose-based porous materials). Also, the prepared PF has good performance on fire-retardance (hard to light), thermal insulation, antibiosis and sound absorption, due to the synergistic actions of borate, chitosan and CPAM. Additionally, spent liquor in preparing PF could be fully recycled, and thus this sustainable approach has potential for large-scale production of high-performance PF.
Collapse
Affiliation(s)
- Meiyan Wu
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, PR China
| | - Guang Yu
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Wei Chen
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Sheng Dong
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Yiran Wang
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Chao Liu
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, PR China.
| | - Bin Li
- CAS Key Laboratory of Biofuels, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
| |
Collapse
|
3
|
Li X, Zhang J, Lin S, Xing Y, Zhang X, Ye M, Chang Y, Guo H, Sun X. (+)-Catechin, epicatechin and epigallocatechin gallate are important inducible defensive compounds against Ectropis grisescens in tea plants. Plant Cell Environ 2022; 45:496-511. [PMID: 34719788 DOI: 10.1111/pce.14216] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
The tea plant, Camellia sinensis (L.) O. Kuntze, is an economically important, perennial woody plant rich in catechins. Although catechins have been reported to play an important role in plant defences against microbes, their roles in the defence of tea plants against herbivores remain unknown. In this study, we allowed the larvae of Ectropis grisescens, a leaf-feeding pest, to feed on the plants, and alternatively, we wounded the plants and then treated them with E. grisescens oral secretions (WOS). Both approaches triggered jasmonic acid-, ethylene- and auxin-mediated signalling pathways; as a result, plants accumulated three catechin compounds: (+)-catechin, epicatechin and epigallocatechin. Not only was the mass of E. grisescens larvae fed on plants previously infested with E. grisescens or treated with WOS significantly lower than that of larvae fed on controls, but also artificial diet supplemented with epicatechin, (+)-catechin or epigallocatechin gallate reduced larval growth rates. In addition, the exogenous application of jasmonic acid, ethylene or auxin induced the biosynthesis of the three catechins, which, in turn, enhanced the resistance of tea plants to E. grisescens, leading to the coordination of the three signalling pathways. Our results suggest that the three catechins play an important role in the defences of tea plants against E. grisescens.
Collapse
Affiliation(s)
- Xiwang Li
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Jin Zhang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Songbo Lin
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Yuxian Xing
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Xin Zhang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Meng Ye
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Yali Chang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Huawei Guo
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| | - Xiaoling Sun
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China
| |
Collapse
|
4
|
Li A, Okada BK, Rosen PC, Seyedsayamdost MR. Piperacillin triggers virulence factor biosynthesis via the oxidative stress response in Burkholderia thailandensis. Proc Natl Acad Sci U S A 2021; 118:e2021483118. [PMID: 34172579 PMCID: PMC8256049 DOI: 10.1073/pnas.2021483118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Natural products have been an important source of therapeutic agents and chemical tools. The recent realization that many natural product biosynthetic genes are silent or sparingly expressed during standard laboratory growth has prompted efforts to investigate their regulation and develop methods to induce their expression. Because it is difficult to intuit signals that induce a given biosynthetic locus, we recently implemented a forward chemical-genetic approach to identify such inducers. In the current work, we applied this approach to nine silent biosynthetic loci in the model bacterium Burkholderia thailandensis to systematically screen for elicitors from a library of Food and Drug Administration-approved drugs. We find that β-lactams, fluoroquinolones, antifungals, and, surprisingly, calcimimetics, phenothiazine antipsychotics, and polyaromatic antidepressants are the most effective global inducers of biosynthetic genes. Investigations into the mechanism of stimulation of the silent virulence factor malleicyprol by the β-lactam piperacillin allowed us to elucidate the underlying regulatory circuits. Low-dose piperacillin causes oxidative stress, thereby inducing redox-sensing transcriptional regulators, which activate malR, a pathway-specific positive regulator of the malleicyprol gene cluster. Malleicyprol is thus part of the OxyR and SoxR regulons in B. thailandensis, allowing the bacterium to initiate virulence in response to oxidative stress. Our work catalogs a diverse array of elicitors and a previously unknown regulatory input for secondary metabolism in B. thailandensis.
Collapse
Affiliation(s)
- Anran Li
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Bethany K Okada
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| | - Paul C Rosen
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| | - Mohammad R Seyedsayamdost
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544;
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| |
Collapse
|
5
|
Noskov YA, Kabilov MR, Polenogova OV, Yurchenko YA, Belevich OE, Yaroslavtseva ON, Alikina TY, Byvaltsev AM, Rotskaya UN, Morozova VV, Glupov VV, Kryukov VY. A Neurotoxic Insecticide Promotes Fungal Infection in Aedes aegypti Larvae by Altering the Bacterial Community. Microb Ecol 2021; 81:493-505. [PMID: 32839879 DOI: 10.1007/s00248-020-01567-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Symbiotic bacteria have a significant impact on the formation of defensive mechanisms against fungal pathogens and insecticides. The microbiome of the mosquito Aedes aegypti has been well studied; however, there are no data on the influence of insecticides and pathogenic fungi on its structure. The fungus Metarhizium robertsii and a neurotoxic insecticide (avermectin complex) interact synergistically, and the colonization of larvae with hyphal bodies is observed after fungal and combined (conidia + avermectins) treatments. The changes in the bacterial communities (16S rRNA) of Ae. aegypti larvae under the influence of fungal infection, avermectin toxicosis, and their combination were studied. In addition, we studied the interactions between the fungus and the predominant cultivable bacteria in vitro and in vivo after the coinfection of the larvae. Avermectins increased the total bacterial load and diversity. The fungus decreased the diversity and insignificantly increased the bacterial load. Importantly, avermectins reduced the relative abundance of Microbacterium (Actinobacteria), which exhibited a strong antagonistic effect towards the fungus in in vitro and in vivo assays. The avermectin treatment led to an increased abundance of Chryseobacterium (Flavobacteria), which exerted a neutral effect on mycosis development. In addition, avermectin treatment led to an elevation of some subdominant bacteria (Pseudomonas) that interacted synergistically with the fungus. We suggest that avermectins change the bacterial community to favor the development of fungal infection.
Collapse
Affiliation(s)
- Y A Noskov
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091.
- National Research Tomsk State University, Tomsk, Russia, 634050.
| | - M R Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630090
| | - O V Polenogova
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - Y A Yurchenko
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - O E Belevich
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - O N Yaroslavtseva
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - T Y Alikina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630090
| | - A M Byvaltsev
- Novosibirsk State University, Novosibirsk, Russia, 630090
| | - U N Rotskaya
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - V V Morozova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630090
| | - V V Glupov
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| | - V Y Kryukov
- Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, 630091
| |
Collapse
|
6
|
Dwidar M, Jang H, Sangwan N, Mun W, Im H, Yoon S, Choi S, Nam D, Mitchell RJ. Diffusible Signaling Factor, a Quorum-Sensing Molecule, Interferes with and Is Toxic Towards Bdellovibrio bacteriovorus 109J. Microb Ecol 2021; 81:347-356. [PMID: 32892232 DOI: 10.1007/s00248-020-01585-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Bdellovibrio bacteriovorus 109J is a predatory bacterium which lives by predating on other Gram-negative bacteria to obtain the nutrients it needs for replication and survival. Here, we evaluated the effects two classes of bacterial signaling molecules (acyl homoserine lactones (AHLs) and diffusible signaling factor (DSF)) have on B. bacteriovorus 109J behavior and viability. While AHLs had a non-significant impact on predation rates, DSF considerably delayed predation and bdelloplast lysis. Subsequent experiments showed that 50 μM DSF also reduced the motility of attack-phase B. bacteriovorus 109J cells by 50% (38.2 ± 14.9 vs. 17 ± 8.9 μm/s). Transcriptomic analyses found that DSF caused genome-wide changes in B. bacteriovorus 109J gene expression patterns during both the attack and intraperiplasmic phases, including the significant downregulation of the flagellum assembly genes and numerous serine protease genes. While the former accounts for the reduced speeds observed, the latter was confirmed experimentally with 50 μM DSF completely blocking protease secretion from attack-phase cells. Additional experiments found that 30% of the total cellular ATP was released into the supernatant when B. bacteriovorus 109J was exposed to 200 μM DSF, implying that this QS molecule negatively impacts membrane integrity.
Collapse
Affiliation(s)
- Mohammed Dwidar
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, 44195, USA.
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
| | - Hyochan Jang
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea
| | - Naseer Sangwan
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, 44195, USA
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Wonsik Mun
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea
| | - Hansol Im
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea
| | - Sora Yoon
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea
| | - Sooin Choi
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea
| | - Dougu Nam
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea.
| | - Robert J Mitchell
- School of Life Sciences, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, 44919, Republic of Korea.
| |
Collapse
|
7
|
Zhang J, Zhang X, Ye M, Li XW, Lin SB, Sun XL. The Jasmonic Acid Pathway Positively Regulates the Polyphenol Oxidase-Based Defense against Tea Geometrid Caterpillars in the Tea Plant (Camellia sinensis). J Chem Ecol 2020; 46:308-316. [PMID: 32016775 DOI: 10.1007/s10886-020-01158-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/18/2020] [Accepted: 01/27/2020] [Indexed: 01/25/2023]
Abstract
Polyphenol oxidases (PPOs) as inducible defense proteins, contribute to tea (Camellia sinensis) resistance against tea geometrid larvae (Ectropis grisescens), and this resistance has been associated with the jasmonic acid (JA) signaling by testing geometrid performance in our previous work. However, the regulation of PPO-based defense by JA and other hormone signaling underlying these defense responses is poorly understood. Here, we investigated the role of phytohormones in regulating the PPO response to tea geometrids. We profiled levels of defense hormones, PPO activity and CsPPO genes in leaves infested with tea geometrids. Then, hormone levels were manipulated by exogenous application of methyl jasmonate (MeJA), gibberellin acid (GA3), abscisic acid (ABA), JA biosynthesis inhibitors (sodium diethyldithiocarbamate trihydrate, DIECA and salicylhydroxamic acid, SHAM) and GA inhibitor (uniconazole, UNI). Upon geometrid attack, JA levels significantly increased, whereas GA levels notably decreased and ABA level was slightly decreased. And the PPO activity significantly increased in line with the transcript levels of CsPPO2 and CsPPO4 but not CsPPO1. There were an obvious antagonistic cross-talk between JA and GA signals and an association among JA signals, PPO response and herbivore resistance in tea plants. Pretreatment with MeJA increased PPO activity by activating the transcripts of CsPPO2 and CsPPO4, whereas application of JA inhibitor DIECA suppressed PPO activity. GA3 strongly enhanced PPO activity, but ABA did not alter PPO activity. These findings strongly suggest that JA is a central player in PPO-mediated tea resistance against tea geometrids in a manner that prioritizes defense over growth.
Collapse
Affiliation(s)
- Jin Zhang
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
| | - Xin Zhang
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
| | - Meng Ye
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
| | - Xi-Wang Li
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
| | - Song-Bo Lin
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China
| | - Xiao-Ling Sun
- Tea Research Institute, Chinese Academy of Agricultural Sciences, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, No. 9 South Meiling Road, Hangzhou, 310008, Zhejiang, China.
| |
Collapse
|
8
|
Mohd Taha MD, Mohd Jaini MF, Saidi NB, Abdul Rahim R, Md Shah UK, Mohd Hashim A. Biological control of Erwinia mallotivora, the causal agent of papaya dieback disease by indigenous seed-borne endophytic lactic acid bacteria consortium. PLoS One 2019; 14:e0224431. [PMID: 31841519 PMCID: PMC6913974 DOI: 10.1371/journal.pone.0224431] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/15/2019] [Indexed: 11/18/2022] Open
Abstract
Dieback disease caused by Erwinia mallotivora is a major threat to papaya plantation in Malaysia. The current study was conducted to evaluate the potential of endophytic lactic acid bacteria (LAB) isolated from papaya seeds for disease suppression of papaya dieback. Two hundred and thirty isolates were screened against E. mallotivora BT-MARDI, and the inhibitory activity of the isolates against the pathogen was ranging from 11.7–23.7 mm inhibition zones. The synergistic experiments revealed that combination of W. cibaria PPKSD19 and Lactococcus lactis subsp. lactis PPSSD39 increased antibacterial activity against the pathogen. The antibacterial activity was partially due to the production of bacteriocin-like inhibitory substances (BLIS). The nursery experiment confirmed that the application of bacterial consortium W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 significantly reduced disease severity to 19% and increased biocontrol efficacy to 69% of infected papaya plants after 18 days of treatment. This study showed that W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 are potential candidate as biocontrol agents against papaya dieback disease.
Collapse
Affiliation(s)
- Mariam Dayana Mohd Taha
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Mohammad Fahrulazri Mohd Jaini
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Noor Baity Saidi
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Raha Abdul Rahim
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Umi Kalsom Md Shah
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Amalia Mohd Hashim
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- * E-mail:
| |
Collapse
|
9
|
Kim JA, Bayo J, Cha J, Choi YJ, Jung MY, Kim DH, Kim Y. Investigating the probiotic characteristics of four microbial strains with potential application in feed industry. PLoS One 2019; 14:e0218922. [PMID: 31242260 PMCID: PMC6594638 DOI: 10.1371/journal.pone.0218922] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 06/13/2019] [Indexed: 12/21/2022] Open
Abstract
The present study aimed to evaluate the probiotic characteristics of certain microbial strains for potential use as feed additives. Three bacterial strains and a yeast previously isolated from different environments were investigated. The strains were subjected to molecular identification and established as Lactobacillus paracasei CP133, Lactobacillus plantarum CP134, Bacillus subtilis CP350 and Saccharomyces cerevisiae CP605. Lactobacillus sp. CP133 and CP134 exhibited antibiosis, antibiotic activity, and relative odor reduction ability. Bacillus subtilis CP350 was thermotolerant, reduced hydrogen sulfide gas and showed significant proteolytic activity, whereas Saccharomyces cerevisiae CP605 exhibited high acid and bile salt tolerance. In general, the isolates in this study demonstrated improved functional characteristics, particularly acid and bile tolerance and relative cell adhesion to HT-29 monolayer cell line. Results in this work provides multifunctional probiotic characteristics of the strains for potential development of probiotics and cleaning of the environment.
Collapse
Affiliation(s)
- Jung-Ae Kim
- Center for Industrialization of Agricultural and Livestock Microorganisms, Jeongeup-si, Korea
| | - Joel Bayo
- Department of Agricultural Convergence Technology, Chonbuk National University, Jeonju-si, Korea
| | | | - Yeon Jae Choi
- International Agricultural Development and Cooperation Center, Chonbuk National University, Jeonju-si, Korea
| | - Min Young Jung
- Center for Industrialization of Agricultural and Livestock Microorganisms, Jeongeup-si, Korea
| | - Dae-Hyuk Kim
- Center for Industrialization of Agricultural and Livestock Microorganisms, Jeongeup-si, Korea
- Department of Molecular Biology, Chonbuk National University, Jeonju-si, Korea
| | - Yangseon Kim
- Center for Industrialization of Agricultural and Livestock Microorganisms, Jeongeup-si, Korea
- * E-mail:
| |
Collapse
|
10
|
Méndez-Bravo A, Cortazar-Murillo EM, Guevara-Avendaño E, Ceballos-Luna O, Rodríguez-Haas B, Kiel-Martínez AL, Hernández-Cristóbal O, Guerrero-Analco JA, Reverchon F. Plant growth-promoting rhizobacteria associated with avocado display antagonistic activity against Phytophthora cinnamomi through volatile emissions. PLoS One 2018; 13:e0194665. [PMID: 29558512 PMCID: PMC5860777 DOI: 10.1371/journal.pone.0194665] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 03/07/2018] [Indexed: 12/16/2022] Open
Abstract
Rhizobacteria associated with crops constitute an important source of potentially beneficial microorganisms with plant growth promoting activity or antagonistic effects against phytopathogens. In this study, we evaluated the plant growth promoting activity of 11 bacterial isolates that were obtained from the rhizosphere of healthy avocado trees and from that of avocado trees having survived root rot infestations. Seven bacterial isolates, belonging to the genera Bacillus, Pseudomonas and Arthrobacter, promoted in vitro growth of Arabidopsis thaliana. These isolates were then tested for antagonistic activity against Phytophthora cinnamomi, in direct dual culture assays. Two of those rhizobacterial isolates, obtained from symptomatic-declining trees, displayed antagonistic activity. Isolate A8a, which is closely related to Bacillus acidiceler, was also able to inhibit P. cinnamomi growth in vitro by 76% through the production of volatile compounds. Solid phase microextraction (SPME) and analysis by gas chromatography coupled with mass spectrometry (GC-MS) allowed to tentatively identify the main volatiles emitted by isolate A8a as 2,3,5-trimethylpyrazine, 6,10-dimethyl-5,9-undecadien-2-one and 3-amino-1,3-oxazolidin-2-one. These volatile compounds have been reported to show antifungal activity when produced by other bacterial isolates. These results confirm the significance of rhizobacteria and suggest that these bacteria could be used for biocontrol of soil borne oomycetes through their volatiles emissions.
Collapse
Affiliation(s)
- Alfonso Méndez-Bravo
- CONACYT—Escuela Nacional de Estudios Superiores, Laboratorio Nacional de Análisis y Síntesis Ecológica, Universidad Nacional Autónoma de México; Morelia, Michoacán, México
- * E-mail: (AMB); (FR)
| | - Elvis Marian Cortazar-Murillo
- Facultad de Ingenierías y Ciencias Químicas, Química Farmacéutica Biológica, Universidad Veracruzana; Xalapa, Veracruz, México
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
| | - Edgar Guevara-Avendaño
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
| | - Oscar Ceballos-Luna
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
- Facultad de Biología, Universidad Veracruzana; Xalapa, Veracruz, México
| | - Benjamín Rodríguez-Haas
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
| | - Ana L. Kiel-Martínez
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
| | - Orlando Hernández-Cristóbal
- Escuela Nacional de Estudios Superiores, Laboratorio de Microscopía, Universidad Nacional Autónoma de México; Morelia, Michoacán, México
| | - José A. Guerrero-Analco
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
| | - Frédérique Reverchon
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A.C.; Xalapa, Veracruz, México
- * E-mail: (AMB); (FR)
| |
Collapse
|
11
|
Abstract
Carious lesions develop in tooth surfaces where there is an imbalance of the processes of acid and alkali production by supragingival biofilms. Since low pH is the main driving factor in the development of carious lesions, most efforts to identify an effective anticaries therapy have focused on targeting the acid-producing bacteria and their mechanisms of acid production. An expanding area of oral microbiology has now been devoted to explore microbial metabolic activities that help to neutralize biofilm pH and thus inhibit the caries process. Arginine metabolism via the arginine deiminase pathway (ADS) produces alkali in the form of ammonia that counteracts the effects of biofilm acidification from bacterial glycolysis. ADS also functions as an adaptive strategy used by certain bacteria to thrive in oral biofilms. Substantial evidence accumulated from laboratory and clinical observations supports the hypotheses that measurements of arginine metabolism via ADS may serve as an important caries risk assessment criterion and that providing arginine regularly to supragingival biofilms can be an effective therapy for caries intervention. This article reviews the potential of arginine-based therapies such as the use of arginine as prebiotic, ADS+ strains as probiotics, and oral care formulations containing arginine for prevention and management of dental caries.
Collapse
Affiliation(s)
- M M Nascimento
- 1 Department of Restorative Dental Sciences, Division of Operative Dentistry, College of Dentistry, University of Florida, Gainesville, FL, USA
| |
Collapse
|
12
|
Baker M, Negus D, Raghunathan D, Radford P, Moore C, Clark G, Diggle M, Tyson J, Twycross J, Sockett RE. Measuring and modelling the response of Klebsiella pneumoniae KPC prey to Bdellovibrio bacteriovorus predation, in human serum and defined buffer. Sci Rep 2017; 7:8329. [PMID: 28827526 PMCID: PMC5567095 DOI: 10.1038/s41598-017-08060-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/04/2017] [Indexed: 01/26/2023] Open
Abstract
In worldwide conditions of increasingly antibiotic-resistant hospital infections, it is important to research alternative therapies. Bdellovibrio bacteriovorus bacteria naturally prey on Gram-negative pathogens, including antibiotic-resistant strains and so B. bacteriovorus have been proposed as "living antibiotics" to combat antimicrobially-resistant pathogens. Predator-prey interactions are complex and can be altered by environmental components. To be effective B. bacteriovorus predation needs to work in human body fluids such as serum where predation dynamics may differ to that studied in laboratory media. Here we combine mathematical modelling and lab experimentation to investigate the predation of an important carbapenem-resistant human pathogen, Klebsiella pneumoniae, by B. bacteriovorus in human serum versus buffer. We show experimentally that B. bacteriovorus is able to reduce prey numbers in each environment, on different timescales. Our mathematical model captures the underlying dynamics of the experimentation, including an initial predation-delay at the predator-prey-serum interface. Our research shows differences between predation in buffer and serum and highlights both the potential and limitations of B. bacteriovorus acting therapeutically against K. pneumoniae in serum, informing future research into the medicinal behaviours and dosing of this living antibacterial.
Collapse
Affiliation(s)
- Michelle Baker
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
- School of Computer Science, Jubilee Campus, University of Nottingham, Wollaton Road, Nottingham, NG8 1BB, UK
| | - David Negus
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Dhaarini Raghunathan
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Paul Radford
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Chris Moore
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Gemma Clark
- Empath Pathology Services Reception Floor A, West Block, Queens Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, NG7 2UH, UK
| | - Mathew Diggle
- Empath Pathology Services Reception Floor A, West Block, Queens Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, NG7 2UH, UK
| | - Jess Tyson
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Jamie Twycross
- School of Computer Science, Jubilee Campus, University of Nottingham, Wollaton Road, Nottingham, NG8 1BB, UK
| | - R Elizabeth Sockett
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| |
Collapse
|
13
|
Miliordos DE, Galetto L, Ferrari E, Pegoraro M, Marzachì C, Bosco D. Acibenzolar-S-methyl may prevent vector-mediated flavescence dorée phytoplasma transmission, but is ineffective in inducing recovery of infected grapevines. Pest Manag Sci 2017; 73:534-540. [PMID: 27116913 DOI: 10.1002/ps.4303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/01/2016] [Accepted: 04/24/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Acibenzolar-S-methyl (BTH), a functional analogue of salicylic acid (SA), is known to elicit a systemic resistance across a broad range of plant-pathogen interactions, but so far it has not been tested against flavescence dorée (FDP), one of the most devastating grapevine diseases. The aim of this work was to evaluate the activity of BTH in preventing FDP transmission by the insect vector and in inducing recovery of infected grapevines. RESULTS Repeated 2 mM applications of BTH to test grapevine cuttings (cv. Barbera) exposed to adults of the infectious vector Scaphoideus titanus Ball reduced the rate of infected plants. The effect was not recorded following similar BTH applications to highly susceptible young in vitro propagated vines. A high natural recovery rate (more than 70%) was observed over a 3 year period in field-infected grapevines of the same cultivar. Under these conditions, BTH repeated applications over the whole period clearly failed to increase recovery of field-infected grapevines. CONCLUSION Following a 3 year experiment, it can be concluded that, although high doses and repeated applications of BTH reduced vector transmission of FDP, BTH was ineffective in inducing recovery of FDP-infected grapevines cv. Barbera under field conditions. © 2016 Society of Chemical Industry.
Collapse
Affiliation(s)
| | - Luciana Galetto
- CNR - Istituto di Protezione Sostenibile delle Piante, Turin, Italy
| | - Ester Ferrari
- DISAFA - Entomologia, Università degli Studi di Torino, Grugliasco, Turin, Italy
| | - Mattia Pegoraro
- DISAFA - Entomologia, Università degli Studi di Torino, Grugliasco, Turin, Italy
| | | | - Domenico Bosco
- DISAFA - Entomologia, Università degli Studi di Torino, Grugliasco, Turin, Italy
- CNR - Istituto di Protezione Sostenibile delle Piante, Turin, Italy
| |
Collapse
|
14
|
Jung JE, Cai JN, Cho SD, Song KY, Jeon JG. Influence of fluoride on the bacterial composition of a dual-species biofilm composed of Streptococcus mutans and Streptococcus oralis. Biofouling 2016; 32:1079-1087. [PMID: 27643392 DOI: 10.1080/08927014.2016.1230607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 08/23/2016] [Indexed: 06/06/2023]
Abstract
Despite the widespread use of fluoride for the prevention of dental caries, few studies have demonstrated the effects of fluoride on the bacterial composition of dental biofilms. This study investigated whether fluoride affects the proportion of Streptococcus mutans and S. oralis in mono- and dual-species biofilm models, via microbiological, biochemical, and confocal fluorescence microscope studies. Fluoride did not affect the bacterial count and bio-volume of S. mutans and S. oralis in mono-species biofilms, except for the 24-h-old S. mutans biofilms. However, fluoride reduced the proportion and bio-volume of S. mutans but did not decrease those of S. oralis during both S. oralis and S. mutans dual-species biofilm formation, which may be related to the decrease in extracellular polysaccharide formation by fluoride. These results suggest that fluoride may prevent the shift in the microbial proportion to cariogenic bacteria in dental biofilms, subsequently inhibiting the cariogenic bacteria dominant biofilm formation.
Collapse
Affiliation(s)
- Ji-Eun Jung
- a Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea
| | - Jian-Na Cai
- a Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea
| | - Sung-Dae Cho
- b Department of Oral Pathology, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea
| | - Kwang-Yeob Song
- c Department of Prosthodontics, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea
| | - Jae-Gyu Jeon
- a Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea
| |
Collapse
|
15
|
Simonetti E, Viso NP, Montecchia M, Zilli C, Balestrasse K, Carmona M. Evaluation of native bacteria and manganese phosphite for alternative control of charcoal root rot of soybean. Microbiol Res 2015; 180:40-8. [PMID: 26505310 DOI: 10.1016/j.micres.2015.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 07/18/2015] [Accepted: 07/18/2015] [Indexed: 11/15/2022]
Abstract
Plant growth promoting rhizobacteria (PGPR) are potential agents to control plant pathogens and their combined use with biopesticides such as phosphites may constitute a novel strategy to incorporate in disease management programs. In the present study, 11 bacterial isolates were selected on the basis of their antagonistic activity against Macrophomina phaseolina in dual-culture tests, and their plant growth promoting traits. Selected isolates were characterised on the basis of auxin and siderophore production, phosphate solubilisation and rep-PCR genomic fingerprinting. Two of these isolates, identified as Pseudomonas fluorescens 9 and Bacillus subtilis 54, were further evaluated for their inhibitory capacity against M. phaseolina using in vitro (on soybean seeds) and in vivo (greenhouse assay) tests. Both bacteria were applied individually as well as in combined treatment with manganese phosphite as seed treatments. Damage severity on soybean seeds was significantly reduced, compared with the untreated control, by both bacterial strains; however, the individual application of phosphite showed to be least effective in controlling M. phaseolina. Interestingly, the phosphite treatment improved its performance under greenhouse conditions compared to the results from the in vitro assays. In the greenhouse trials, the greatest reductions in disease severity were achieved when strain P. fluorescens 9 was applied singly or when strain B. subtilis 54 was combined with manganese phosphite, achieving 82% of control in both cases. This work is the first to report the control of M. phaseolina using combined treatment with PGPR and phosphite under greenhouse conditions.
Collapse
Affiliation(s)
- Ester Simonetti
- Cátedra de Microbiología Agrícola, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET/UBA), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Natalia Pin Viso
- Cátedra de Fitopatología, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcela Montecchia
- Cátedra de Microbiología Agrícola, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET/UBA), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina
| | - Carla Zilli
- Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET/UBA), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina
| | - Karina Balestrasse
- Cátedra de Bioquímica, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET/UBA), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Carmona
- Cátedra de Fitopatología, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina
| |
Collapse
|
16
|
Krüger M, Shehata AA, Schrödl W, Rodloff A. Glyphosate suppresses the antagonistic effect of Enterococcus spp. on Clostridium botulinum. Anaerobe 2013; 20:74-8. [PMID: 23396248 DOI: 10.1016/j.anaerobe.2013.01.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 01/15/2013] [Accepted: 01/29/2013] [Indexed: 01/06/2023]
Abstract
During the last 10-15 years, an increase of Clostridium botulinum associated diseases in cattle has been observed in Germany. The reason for this development is currently unknown. The normal intestinal microflora is a critical factor in preventing intestinal colonisation by C. botulinum as shown in the mouse model of infant botulism. Numerous bacteria in the gastro-intestinal tract (GIT) produce bacteriocines directed against C. botulinum and other pathogens: Lactic acid producing bacteria (LAB) such as lactobacilli, lactococci and enterococci, generate bacteriocines that are effective against Clostridium spp. A reduction of LAB in the GIT microbiota by ingestion of strong biocides like glyphosate could be an explanation for the observed increase in levels of C. botulinum associated diseases. In the present paper, we report on the toxicity of glyphosate to the most prevalent Enterococcus spp. in the GIT. Ingestion of this herbicide could be a significant predisposing factor that is associated with the increase in C. botulinum mediated diseases in cattle.
Collapse
Affiliation(s)
- Monika Krüger
- Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 29, D-04103 Leipzig, Germany
| | | | | | | |
Collapse
|
17
|
Rampelli S, Candela M, Severgnini M, Biagi E, Turroni S, Roselli M, Carnevali P, Donini L, Brigidi P. A probiotics-containing biscuit modulates the intestinal microbiota in the elderly. J Nutr Health Aging 2013; 17:166-72. [PMID: 23364497 DOI: 10.1007/s12603-012-0372-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVES Evaluation of the impact of a biscuit containing the probiotics Bifidobacterium longum Bar33 and Lactobacillus helveticus Bar13 on the intestinal microbiota in the elderly. DESIGN Randomized double-blind placebo-controlled trial. PARTICIPANTS Thirty-two elderly volunteers living in Italy. The group was composed of 19 women and 13 men aged between 71 and 88 years (mean 76). INTERVENTION Subjects were randomized in two groups consuming one dose of the probiotics-containing biscuit or placebo once a day for 30 days. MEASUREMENTS For each subject the intestinal microbiota was characterized using the phylogenetic microarray platform HTF-Microbi.Array before and after intervention. RESULTS Our data demonstrated that one-month consumption of a probiotics-containing biscuit was effective in redressing some of the age-related dysbioses of the intestinal microbiota. In particular, the probiotic treatment reverted the age-related increase of the opportunistic pathogens Clostridium cluster XI, Clostridium difficile, Clostridium perfringens, Enterococcus faecium and the enteropathogenic genus Campylobacter. CONCLUSION The present study opens the way to the development of elderly-tailored probiotic-based functional foods to counteract the age-related dysbioses of the intestinal microbiota.
Collapse
Affiliation(s)
- S Rampelli
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Otto-Hanson LK, Grabau Z, Rosen C, Salomon CE, Kinkel LL. Pathogen variation and urea influence selection and success of Streptomyces mixtures in biological control. Phytopathology 2013; 103:34-42. [PMID: 23035630 DOI: 10.1094/phyto-06-12-0129-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Success in biological control of plant diseases remains inconsistent in the field. A collection of well-characterized Streptomyces antagonists (n = 19 isolates) was tested for their capacities to inhibit pathogenic Streptomyces scabies (n = 15 isolates). There was significant variation among antagonists in ability to inhibit pathogen isolates and among pathogens in their susceptibility to inhibition. Only one antagonist could inhibit all pathogens, and antagonist-pathogen interactions were highly specific, highlighting the limitations of single-strain inoculum in biological control. However, the collection of pathogens could be inhibited by several combinations of antagonists, suggesting the potential for successful antagonist mixtures. Urea generally increased effectiveness of antagonists at inhibiting pathogens in vitro (increased mean inhibition zones) but its specific effects varied among antagonist-pathogen combinations. In greenhouse trials, urea enhanced the effectiveness of antagonist mixtures relative to individual antagonists in controlling potato scab. Although antagonist mixtures were frequently antagonistic in the absence of urea, all n= 2 and n = 3 antagonist-isolate combinations were synergistic in the presence of urea. This work provides insights into the efficacy of single- versus multiple-strain inocula in biological control and on the potential for nutrients to influence mixture success.
Collapse
Affiliation(s)
- L K Otto-Hanson
- Department of Plant Pathology, University of Minnesota, St. Paul 55108, USA.
| | | | | | | | | |
Collapse
|
19
|
Horokhovs'kyĭ II, Ieshchenko IV, Bovt VD, Ieshchenko VA, Iurchuk II. [Functional state of the ileum, cationic peptids and zinc content in the Paneth cells of the rats following lincomycin, indomethacin and methotrexate andministration]. Fiziol Zh (1994) 2013; 59:78-88. [PMID: 23957168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the paper the relation between the changes of a functional condition of ileum, composition of its microflora and secretory activity of Paneth cells has been investigated. Administration of lincomycin led to a reduction of total of symbiotic bacteria and appearance of opportunistic microflora. Statistically insignificant changes of speed of transit of intestinal contents and damage of barrier function of an intestinal epithelium were noted. The intestinal epithelium was characterized by signs of inflammation. Administration of indomethacin and methotrexate led to significant changes of a functional state of a small intestine of rats. The speed of transit of intestinal contents following indomethacin administration increased by 30%, and, on the contrary, decreased by 90% following administration of methotrexate. The ability of epithelium of ileum to adsorb vital dye in both cases increased (by 32 and 51%, respectively) indicating the damage of barrier function. Thus there were significant changes in structure of microflora of ileum: reduction of quantity symbiotic and emergence of opportunistic microflora, a translocation of bacteria to a mucous wall. It was concluded that animal of all three experimental groups had a reduction of the contents of cationic proteins and zinc in the secretory granules of Paneth cells. These results can testify that balance changes between simbiotic and opportunistic microflora are a factor which has an impact on intestine damage and also causes activation of secretory function of Paneth cells.
Collapse
|
20
|
Emerstorfer F, Hein W, Resch R, Poetsch EM, Zitz U, Kneifel W. Application of plant-based antimicrobials for the growth inhibition of clostridia in pressed beet pulp silage. J Sci Food Agric 2011; 91:2038-2044. [PMID: 21495041 DOI: 10.1002/jsfa.4416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 02/24/2011] [Accepted: 03/07/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND In this study the inhibition of hop beta acids on the growth of clostridia in soil-contaminated pressed sugar beet pulp silages was investigated. Hop beta acids are natural substances which display their effect at low concentrations. Fresh pressed beet pulp material was mixed with soil to artificially contaminate it with clostridia. Laboratory silos were filled with the substrate, stored at 25 °C and opened for sampling at 0, 2, 8, 15, 30, 60, and 90 days. The impact on clostridial growth during silage fermentation was monitored by determination of the pH value and dry matter content, as well as chemical analysis of the fermentation products. Throughout the experiments, the effect of a commercial silage inoculant based on lactic acid bacteria (LAB) and hop-resistant LAB were examined with and without the combination of plant-based antimicrobials. RESULTS Results indicate that in contaminated silage samples without any additives high butyric acid contents occurred due to clostridial growth. This spoilage could not be suppressed by the application of LAB, whereas the combined application of LAB and hop beta acids significantly improved silage quality, which was reflected by favourable organic acid composition (P < 0.05). CONCLUSION The experimental data indicate that the application of hop beta acids improves the preservation effect of LAB in suppressing clostridial growth in silages and thus demonstrates some potential for the combined use of plant-based antimicrobials and LAB.
Collapse
|
21
|
Louis J, Leung Q, Pegadaraju V, Reese J, Shah J. PAD4-dependent antibiosis contributes to the ssi2-conferred hyper-resistance to the green peach aphid. Mol Plant Microbe Interact 2010; 23:618-627. [PMID: 20367470 DOI: 10.1094/mpmi-23-5-0618] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Myzus persicae, commonly known as green peach aphid (GPA), is a sap-sucking insect with a broad host range. Arabidopsis thaliana responds to GPA infestation with elevated expression of the PHYTOALEXIN DEFICIENT4 (PAD4) gene. Previously, we had demonstrated that the loss of PAD4 gene function compromises Arabidopsis resistance to GPA. In contrast, a mutation in the Arabidopsis SUPPRESSOR OF SALICYLIC ACID INSENSITIVITY2 (SSI2) gene, which encodes a desaturase involved in lipid metabolism, resulted in hyper-resistance to GPA. We demonstrate here that PAD4 is required for the ssi2-dependent heightened resistance to GPA. Based on electrical monitoring of insect behavior and bioassays in which the insect was given a choice between the wild type and the ssi2 mutant, it is concluded that the ssi2-conferred resistance is not due to deterrence of insect settling or feeding from the phloem of the mutant. Instead, hyper-resistance in the ssi2 mutant results from heightened antibiosis that curtails insect reproduction. Petiole exudates collected from uninfested ssi2 plants contain elevated levels of an activity that interferes with aphid reproduction in synthetic diets. PAD4 was required for the accumulation of this antibiotic activity in petiole exudates, supporting the role of PAD4 in phloem-based resistance. Because PAD4 expression is not elevated in the ssi2 mutant, we suggest that basal PAD4 expression contributes to this antibiosis.
Collapse
Affiliation(s)
- Joe Louis
- Department of Biological Sciences, University of North Texas, Denton, USA
| | | | | | | | | |
Collapse
|
22
|
Mikhaĭlova NA, Grin'ko OM. [Bacillus genus bacteria are producers of biologically active compounds with antimicrobial effect]. Zh Mikrobiol Epidemiol Immunobiol 2010:85-89. [PMID: 20737685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Biologically active compounds of spore-forming bacteria of Bacillus genus, which have antagonistic effect on opportunistic and pathogenic microorganisms, are characterized in the review. Information about known to date antibiotics and bacteriocins produced by Bacillus species is presented.
Collapse
|
23
|
Grin'ko OM, Zverev VV, Mikhaĭlova NA. [Effect of growth medium content on antagonistic characteristics of Bacillus pumilus]. Zh Mikrobiol Epidemiol Immunobiol 2010:72-76. [PMID: 20218349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
AIM To study the effect of growth medium content on antagonistic characteristics of "Pashkov" strain of B. pumilus. MATERIALS AND METHODS The following strains were used in the study: B. subtitlis 3H, B. subtitlis 534, B. subtitlis 1719, B. pumilus "Pashkov". Test strains from collection of Tarasevich State Institute for Standardization and Control of Medical Biological Preparations were used for determination of antagonistic activity. Growing of B. pumilus cultures on medium (No. 9, No. 5, VK-2, Spizeisen, and L-broth) was performed by periodic cultivation during 72 h in conditions of continuous aeration at 37 degrees C. Inhibiting effect of obtained samples was assessed on growth kinetics of test strains using microbiological analyzer with plan-table photometer "BIOSCREEN/iEMS--reader MF" (LabMetod, Finland). RESULTS Expressed antagonistic characteristics were revealed during cultivation on media No. 9 and No. 5 with maximal expression on day 3. Addition of lactose to medium No. 9 resulted in increase of bacteriostatic effect (BSE) against both individual strains and all test strains--up to 16% in average. Selection of optimal concentrations of different components allowed to develop a new growth medium which provides maximal antagonistic activity in studied strain of B. pumilus. CONCLUSION Effect of growth medium content on antagonistic characteristics against pathogenic and opportunistic bacteria was confirmed on the example of cultivation of spore-forming strain "Pashkov" of B. pumilus. Optimization of carbohydrate, salt and other components of growth medium allowed to increase up to 100% the BSE of "Pashkov" strain of B. pumilus against both individual and all test strains. This study opens perspectives for generation of compounds with directional probiotic effect.
Collapse
|
24
|
Wu MN, Zhang HW, Li XY, Zhang Y, Su ZC, Zhang CG. [Relationship between soil fungistasis and bacterial community structure]. Ying Yong Sheng Tai Xue Bao 2008; 19:1574-1578. [PMID: 18839921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
As a natural attribute of clean and healthy soil, fungistasis is an important indicator of soil quality, and has positive ecological significance to the inhibition of plant disease eruption caused by soil-borne fungal pathogens. In this study, soil samples (0-15 cm) were collected from the abandoned land at Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, to which pesticides and fertilizers have never been applied for nearly 10 years. A series of soil samples with gradient fungistasis was obtained by heating (CK, 100 degrees C, 110 degrees C, and 121 degrees C for 4 min, respectively), and bacterial community structure was analyzed by Polymerase Chain Reaction coupled with Denaturing Gradient Gel Electrophoresis method (PCR-GGGE). The results showed that there was a significant correlation between soil fungistasis and bacterial community composition. Treatment CK showed the strongest capacity to control the growth of target soil-borne pathogenic fungi. The further the bacterial community structure of treated soil deviated from that of CK, the lower the soil fungistasis was. Sequencing and the following phylogenetic analysis of special bands in DGGE indicated that Sphingomonas asaccharolytica, Nitrospira sp., Hyphomicrobiaceae sp., Bacillus megaterium, and Micrococcus sp. could be involved in soil fungistasis.
Collapse
Affiliation(s)
- Min-Na Wu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
| | | | | | | | | | | |
Collapse
|
25
|
Saikia R, Varghese S, Singh BP, Arora DK. Influence of mineral amendment on disease suppressive activity of Pseudomonas fluorescens to Fusarium wilt of chickpea. Microbiol Res 2007; 164:365-73. [PMID: 17604612 DOI: 10.1016/j.micres.2007.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 05/09/2007] [Accepted: 05/10/2007] [Indexed: 11/29/2022]
Abstract
Fusarium wilt caused by Fusarium oxysporum f. sp. ciceri causes considerable yield loss of chickpea. Pseudomonas fluorescens4-92 (Pf4-92) strain can suppress the disease. Amendment of zinc EDTA and copper EDTA could not suppress the disease significantly when used alone; however, they significantly suppressed the disease in presence of Pf4-92. In vitro observation showed that at 40, 30 and 20microgml(-1) concentrations of these minerals, i.e. Zn, Cu and Zn plus Cu, respectively, completely repressed the production of the phytotoxin, fusaric acid (FA). FA concentration (0.5microgml(-1)) has been shown to suppress the production of 2,4-diacetylphloroglucinol (DAPG) by Pf4-92, and DAPG, salicylic acid, pyochelin and pyoluteorin production was enhanced by these mineral amendments. In rockwool bioassays, Zn, Cu and Zn plus Cu amendments reduced FA production and enhanced DAPG production. This study demonstrates that Zn and Cu enhance biocontrol activity by reducing FA produced by the pathogen, F. oxysporum f. sp. ciceri.
Collapse
Affiliation(s)
- Ratul Saikia
- National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Mau 275 101, Uttar Pradesh, India.
| | | | | | | |
Collapse
|
26
|
Regev-Yochay G, Trzcinski K, Thompson CM, Malley R, Lipsitch M. Interference between Streptococcus pneumoniae and Staphylococcus aureus: In vitro hydrogen peroxide-mediated killing by Streptococcus pneumoniae. J Bacteriol 2006; 188:4996-5001. [PMID: 16788209 PMCID: PMC1482988 DOI: 10.1128/jb.00317-06] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bactericidal activity of Streptococcus pneumoniae toward Staphylococcus aureus is mediated by hydrogen peroxide. Catalase eliminated this activity. Pneumococci grown anaerobically or genetically lacking pyruvate oxidase (SpxB) were not bactericidal, nor were nonpneumococcal streptococci. These results provide a possible mechanistic explanation for the interspecies interference observed in epidemiologic studies.
Collapse
Affiliation(s)
- Gili Regev-Yochay
- Department of Epidemiology, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115, USA.
| | | | | | | | | |
Collapse
|
27
|
Abstract
Bacterial interactions that include antagonism (interference) and synergism help maintain balance between the members of the normal endogenous flora. Alpha-streptococci that predominate in the normal respiratory tract flora attracted most attention in studies of bacterial interference. Other organisms that possess interfering characteristics in upper respiratory tract infections (URTIs) are nonhemolytic streptococci, and Prevotella and Peptostreptococcus spp. The production of bacteriocins by some microorganisms is one of the important mechanisms of interference. The role of bacterial interference in the development of URTI and its effect on the eradication of these infections is discussed. These infections include pharyngo-tonsillitis, otitis media, and sinusitis. Treatment with various antimicrobial agents can affect the balance between members of the oro-pharyngeal bacterial flora and interfering organisms. Implantation into the indigenous microflora of low virulence bacterial strains that are potentially capable of interfering with colonization and infection with other more virulent organisms has been used in preliminary studies as a means of coping with the failure of antimicrobials in the treatment of several URTI.
Collapse
Affiliation(s)
- Itzhak Brook
- Department of Pediatrics, Georgetown University, USA.
| |
Collapse
|
28
|
Brook I, Foote PA. Effect of antimicrobial therapy with amoxicillin and cefprozil on bacterial interference and beta-lactamase production in the adenoids. Ann Otol Rhinol Laryngol 2004; 113:902-5. [PMID: 15562900 DOI: 10.1177/000348940411301109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To compare the effects on the bacterial flora of the adenoids of antimicrobial therapy with amoxicillin or cefprozil, we enrolled in a prospective randomized study 60 children scheduled for elective adenoidectomy because of recurrent otitis media. They were randomized before surgery into 3 groups of 20 patients each: a no-therapy group, and groups with 10 days of either amoxicillin or cefprozil therapy. Core adenoid materials were quantitatively cultured for aerobic and facultative bacteria. The in vitro ability of alpha-hemolytic streptococci (AHS) to inhibit the growth of non-type B Haemophilus influenzae and Streptococcus pneumoniae was determined. The number of organisms in adenoids obtained from patients treated with either antibiotic was reduced as compared to that in adenoids from controls. However, in patients treated with amoxicillin, a significant decline in the number of AHS, and an increase (in Staphylococcus aureus) or no change in the number of other beta-lactamase-producing bacteria (BLPB) was noted. In contrast, in those treated with cefprozil, no change was noted in the frequency of recovery of AHS, and the number of BLPB decreased. Interfering AHS were more often recovered in patients treated with cefprozil. We conclude that the adenoids contain more interfering AHS after therapy with a second-generation oral cephalosporin (cefprozil) than after amoxicillin therapy. This study suggests a potential beneficial effect of using an antimicrobial that selectively spares interfering AHS while inhibiting BLPB.
Collapse
Affiliation(s)
- Itzhak Brook
- Department of Pediatrics, Georgetown University, Washington, DC, USA.
| | | |
Collapse
|
29
|
Zhuo C, Qian YS, Xiao GX. [Investigation on the antibiotic resistance and risky factors of nosocomial infections caused by Stenotrophomonas maltophilia]. Zhonghua Shao Shang Za Zhi 2004; 20:10-3. [PMID: 15059439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE To investigate the antibiotic resistance and risky factors of nosocomial infections caused by Stenotrophomonas maltophilia, so as to help elucidate the difference of drug resistance between metallic beta-lactamase (MBL) producing and non-MBL producing strains. METHODS Standard agar dilution method of NCCLS was employed in the isolation of 36 strains of Stenotrophomonas maltophilia from patients with nosocomial infection with respect to their in vitro antibiotic resistance to 18 kinds of antibiotics. MBL strains were identified by MBL-E test method. RESULTS Stenotrophomonas maltophilia in our hospital was mainly identified in the lower respiratory tract (88.9%), in which 88.2% (30/34) of the patients had serious original diseases, 50% of whom had received Imipenem/cilastatin sodium treatment. Thirty-six strains of Stenotrophomonas maltophilia were susceptible to new types of fluoquinolone antibiotics, i.e. Sparfloxacin, levofloxacin, gatifloxacin and doxycycline, with inhibitory rate ranging 97.2%, 94.4%, 91.7% to 83.3%, respectively. They could also be inhibited by SMZ/TMP and Ticarcillin/Lavulanic acid with inhibitory rate of 63.9% and 58.3%, respectively. There were 16 strains out of 36 of MBL bacteria with complete resistance to Imipenem/cilastatin sodium, but with higher susceptibility to aztreonam than those non-MBL producing strains. CONCLUSION The nosocomial infection in our hospital caused by Stenotrophomonas maltophilia seemed to be related with severe primary disease and the use of Imipenem/cilastatin sodium. The newly developed fluoroquinolones possessed powerful antibacterial potency on Stenotrophomonas maltophilia found in nosocomial infection.
Collapse
Affiliation(s)
- Chao Zhuo
- Department of Infectious Diseases, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, P.R. China
| | | | | |
Collapse
|
30
|
Boĭtsov AG, Lastovka ON. [Isolation of quasi-lethally injured Salmonella strains from water surface in water basins]. Gig Sanit 2003:76-7. [PMID: 12852053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
|
31
|
Abstract
The adhesion of Lactobacillus rhamnosus GG to human enterocyte-like Caco-2 cells was not inhibited by eight carbohydrates tested, namely N-acetyl-glucosamine, galactose, glucose, fructose, fucose, mannose, methyl-alpha-D-mannopyranoside and sucrose. The degree of hydrophobicity predicted the adhesion of L. rhamnosus GG to Caco-2 cells. L. rhamnosus GG, however, was able to compete with Escherichia coli and Salmonella spp. of low hydrophobicity and high adhesin-receptor interaction for adhesion to Caco-2 cells. The interference of adhesion of these gastrointestinal (GI) bacteria by L. rhamnosus GG was probably through steric hindrance, and the degree of inhibition was related to the distribution of the adhesin receptors and hydrophobins on the Caco-2 surface. A Carbohydrate Index for Adhesion (CIA) was used to depict the binding property of adhesins on bacteria surfaces. CIA was defined as the sum of the fraction of adhesion in the presence of carbohydrates, with reference to the adhesion measured in the absence of any carbohydrate. The degree of competition for receptor sites between Lactobacillus casei Shirota and GI bacteria is a function of their CIA distance. There were at least two types of adhesins on the surface of L. casei Shirota. The study provides a scientific basis for the screening and selection of probiotics that compete with selective groups of pathogens for adhesion to intestinal surfaces. It also provides a model for the characterisation of adhesins and adhesin-receptor interactions.
Collapse
Affiliation(s)
- Y-K Lee
- Department of Microbiology, Faculty of Medicine, National University of Singapore, 5 Science Drive 2, 117597.
| | | |
Collapse
|
32
|
Pal KK, Tilak KV, Saxena AK, Dey R, Singh CS. Suppression of maize root diseases caused by Macrophomina phaseolina, Fusarium moniliforme and Fusarium graminearum by plant growth promoting rhizobacteria. Microbiol Res 2002; 156:209-23. [PMID: 11716210 DOI: 10.1078/0944-5013-00103] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A plant growth-promoting isolate of a fluorescent Pseudomonas sp. EM85 and two bacilli isolates MR-11(2) and MRF, isolated from maize rhizosphere, were found strongly antagonistic to Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina, causal agents of foot rots and wilting, collar rots/stalk rots and root rots and wilting, and charcoal rots of maize, respectively. Pseudomonas sp. EM85 produced antifungal antibiotics (Afa+), siderophore (Sid+), HCN (HCN+) and fluorescent pigments (Flu+) besides exhibiting plant growth promoting traits like nitrogen fixation, phosphate solubilization, and production of organic acids and IAA. While MR-11(2) produced siderophore (Sid+), antibiotics (Afa+) and antifungal volatiles (Afv+), MRF exhibited the production of antifungal antibiotics (Afa+) and siderophores (Sid+). Bacillus spp. MRF was also found to produce organic acids and IAA, solubilized tri-calcium phosphate and fixed nitrogen from the atmosphere. All three isolates suppressed the diseases caused by Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina in vitro. A Tn5:: lacZ induced isogenic mutant of the fluorescent Pseudomonas EM85, M23, along with the two bacilli were evaluated for in situ disease suppression of maize. Results indicated that combined application of the two bacilli significantly (P = 0.05) reduced the Macrophomina-induced charcoal rots of maize by 56.04%. Treatments with the MRF isolate of Bacillus spp. and Tn5:: lacZ mutant (M23) of fluorescent Pseudomonas sp. EM85 significantly reduced collar rots, root and foot rots, and wilting of maize caused by Fusarium moniliforme and F. graminearum (P = 0.05) compared to all other treatments. All these isolates were found very efficient in colonizing the rhizotic zones of maize after inoculation. Evaluation of the population dynamics of the fluorescent Pseudomonas sp. EM85 using the Tn5:: lacZ marker and of the Bacillus spp. MRF and MR-11(2) using an antibiotic resistance marker revealed that all the three isolates could proliferate successfully in the rhizosphere, rhizoplane and endorhizosphere of maize, both at 30 and 60 days after seeding. Four antifungal compounds from fluorescent Pseudomonas sp. EM85, one from Bacillus sp. MR-11(2) and three from Bacillus sp. MRF were isolated, purified and tested in vitro and in thin layer chromatography bioassays. All these compounds inhibited R. solani, M. phaseolina, F. moniliforme, F. graminearum and F. solani strongly. Results indicated that antifungal antibiotics and/or fluorescent pigment of fluorescent Pseudomonas sp. EM85, and antifungal antibiotics of the bacilli along with the successful colonization of all the isolates might be involved in the biological suppression of the maize root diseases.
Collapse
Affiliation(s)
- K K Pal
- Division of Microbiology, Indian Agricultural Research Institute, New Delhi.
| | | | | | | | | |
Collapse
|
33
|
Artamonov VE, Masharova AA, Gorodetskiĭ VV, Vertkin AL. [Tolerance and safety of anti-Helicobacter drugs in the treatment of ulcer disease]. Klin Med (Mosk) 2001; 79:53-7. [PMID: 11419089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
132 patients (mean age 46.9 +/- 1.4 years) with exacerbation of gastroduodenal ulcer (GDU) positive by Helicobacter pylori (HP) were examined clinically and using laboratory tests. All the patients received treatment with anti-HP drugs. Side effects were registered in 81(61.4%) patients. Negative trend in colon biocenosis occurred in all the patients. The treatment was poorly tolerated by women, aged patients and those with ulcer in the stomach. Biocenosis aggravation is indication for administration of eubiotics.
Collapse
|
34
|
Joki-Erkkilä VP, Pukander J. alpha Streptococci and recurrences of otitis media. Right choice of antibiotic can decrease risk of recurrence. BMJ 2001; 322:1543; author reply 1543-4. [PMID: 11439992 PMCID: PMC1120582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
|
35
|
Cantekin EI. alpha Streptococci and recurrences of otitis media. Tampering with microbial ecology is risky. BMJ 2001; 322:1543; author reply 1543-4. [PMID: 11439993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
|
36
|
Pichkhadze GM, Rusanov VP, Novoselov VE. [The antagonistic activity of the eubiotic Maxilin towards wound infection and its effect on the antibiotic resistance of microorganisms]. Stomatologiia (Mosk) 2001; 79:22-7. [PMID: 10961107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Antagonistic activity of lactic acid bacteria of strain N 2585 of "Maxilin" probiotic in respect to the strains S. aureus, P. aeruginosa, E. coli, Candida albicans and their effect on the level of sustainability of the antibiotic resistant strains S. aureus, E. coli, P. aeruginosa, which are extracted from the patients with open fractures of the mandible under various course of wound process, have been studied. The studies showed that lactic acid bacteria have suppressed growth of strains Candida most actively, followed by P. aeruginosa, S. aureus and E. coli. The use of "Maxilin" probiotic allowed reducing the epidemiological significance of pathogenetic strains already in 3 to 4 days. The sensibility studies showed high activity of the lactic acid bacteria in reducing antibiotic resistance of the strains investigated. It was revealed that "Maxilin" probiotic affects Ps. aeruginosa effectively, somewhat less St. aureus and E. coli. The extracted strains demonstrated sensibility to all investigated antibiotics already in 3 to 4 days.
Collapse
|
37
|
Abstract
Antibacterial activity of 17 strains of lactobacilli was tested against 10 strains of H. pylori. The inhibition observed was related to the acid production and the low pH attained. No relationship between CagA phenotype of H. pylori strains and tolerance to lactic acid was observed. In mixed cultures, L. acidophilus CRL 639 showed an autolytic behavior after 24 h of culture. At this moment, H. pylori CCUG17874 showed a decrease of 2 log-cycle, and no viable count was detected after 48 h. The bactericidal effect of L. acidophilus CRL 639 in mixed cultures is related to a proteinaceous compound released after cell lysis.
Collapse
Affiliation(s)
- G L Lorca
- Centro de Referencia para Lactobacilos (CERELA), Chacabuco 145, 4000 Tucumán, Argentina
| | | | | | | |
Collapse
|
38
|
Kigel' NF. [AF, a new bacterial preparation based on lactobacilli and its biological properties]. Mikrobiol Z 2000; 62:49-55. [PMID: 10932543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
A highly efficient bacterial composition "AF" which includes representatives of two genera of microorganisms Enterococcus faecium and Lactobacillus acidophilus has been created as a result of analysis of biological properties of a number of strains of lactic-acid bacteria. Their biological properties--antagonistic activity in respect to pathogenic and conditionally pathogenic microorganisms, ability to adhesion and function in the intestine, sensitivity to antibiotics, etc., have been studied in the laboratory conditions. Prospects of the use of the given composition in production of milk products of functional effects have been shown.
Collapse
Affiliation(s)
- N F Kigel'
- Meat and Milk Technological Institute, Ukrainian Academy of Agrarian Sciences, Kyiv, Ukraine
| |
Collapse
|
39
|
Furzikova TM, Sergeĭchuk MG, Sorokulova IB, Smirnov VV. [The effect of the cultivation conditions on the properties of bacilli comprising the basis of probiotics]. Mikrobiol Z 1999; 61:19-27. [PMID: 10643273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Such biological factors as bile, gastric juice, blood serum, amino acids and pH of the medium have been studied for their effect on the growth intensity and antagonistic activity of bacilli being the basis of biosporin and subalin. It has been established that pH of the medium within 7.0-9.0 as well as certain concentrations of the gastric juice, bile, blood serum and most of amino acids did not affect the growth of Bacillus subtilis 3 and Bacillus subtilis 2335/105. A regular decrease of growth intensity in bacilli under the increase of the gastric juice concentration or decrease of pH of the medium to 5.0-2.0 is registered. The mentioned biological factors affect differently the antagonistic properties of the studied cultures.
Collapse
|
40
|
Sorokulova IB. [A comparative study of the biological properties of Biosporin and other commercial Bacillus-based preparations]. Mikrobiol Z 1997; 59:43-9. [PMID: 9511375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new probiotic Biosporin and other commercial biopreparations based on aerobic sporulating bacteria of the Bacillus genus have been comparatively studied for their specific activity and safety. It has been established that only Biosporin is characterized by expressed antagonistic activity in respect to a wide range of pathogenic and conditionally pathogenic microorganisms including those with multiple resistance to antibiotics. Biosporin is also characterized by the absence of any negative action on the organism of animals even in the doses considerably exceeding those recommended for use.
Collapse
Affiliation(s)
- I B Sorokulova
- Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Kyiv
| |
Collapse
|
41
|
Affiliation(s)
- N M Bolder
- ID-DLO branch Spelderholt Centre for Poultry Research and Information Services, Beekbergen, The Netherlands
| | | |
Collapse
|
42
|
Ogino J, Yamada T, Kikushima K, Fujimori I, Goto R, Kozeni T, Hisamatsu K, Murakami Y. [Effect of 14-member lactone ring macrolides on anti staphylococcal activity and swarming ability of Pseudomonas aeruginosa]. Kansenshogaku Zasshi 1994; 68:191-5. [PMID: 8151144 DOI: 10.11150/kansenshogakuzasshi1970.68.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The purpose of this report is to examine the effect of Macrolides (Erythromycin and Roxythromycin) on swarming ability and antistaphylococcal activity of Pseudomonas aeruginosa. The standard strain (ATCC27854) and clinically isolated P. aeruginosa were used as test strains. The influence of Macrolides on antistaphylococcal activity and swarming ability were determined by the agar plate dilution method. The antistaphylococcal activity of P. aeruginosa was not affected at the concentration of 1.56 micrograms/ml of both Erythromycin and Roxythromycin. But the antistaphylococcal activity was not observed at the concentration over 100 micrograms/ml. The swarming ability was not affected at the concentration up to 12.5 micrograms/ml. It has been proved that Macrolides reveal inhibition of virulent factors of P. aeruginosa such as protease, elastase, piocianin and so on. Furthermore our data revealed that Macrolides inhibited swarming ability of P. aeruginosa, and did not affect the antistaphylococcal activity of P. aeruginosa under 1.56 micrograms/ml concentration. Consequently, these results suggest that Macrolides have exhibited a previously unknown pharmacological effect, and may be of interest in that there may be bacterial interaction between MRSA and P. aeruginosa.
Collapse
Affiliation(s)
- J Ogino
- Department of Otorhinolayngology, Yamanashi Medical College
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
The antibacterial effects of 209 Pseudomonas strains isolated from spoiled iced fish and newly caught fish were assessed by screening target organisms in agar diffusion assays. One-third (67 strains) inhibited the growth of one or several of six target organisms (Escherichia coli, Shewanella putrefaciens, Aeromonas sobria, Pseudomonas fluorescens, Listeria monocytogenes, and Staphylococcus aureus), of which S. aureus and A. sobria were the most sensitive. The inhibitory action was most pronounced among the strains producing siderophores, and the presence of iron eliminated the antibacterial effect of two-thirds of the inhibitory strains. Siderophore-mediated competition for iron may explain the inhibitory activity of these strains. All but nine of the inhibiting strains were found to inhibit the growth of 38 psychrotrophic S. putrefaciens strains isolated from spoiling fish and fish products. Siderophore-containing Pseudomonas culture supernatants inhibited growth of S. putrefaciens, as did the addition of iron chelators (ethylenediamine dihydroxyphenylacetic acid [EDDHA]). In particular, Pseudomonas strains isolated from newly caught and spoiled Nile perch (Lates niloticus) inhibited S. putrefaciens. This suggests that microbial interaction (e.g., competition or antagonism) may influence the selection of a microflora for some chilled food products.
Collapse
Affiliation(s)
- L Gram
- Technological Laboratory, Danish Ministry of Fisheries, Technical University, Lyngby
| |
Collapse
|
44
|
Tiuren MV, Shenderov BA. [The effect of chemical preparations on the biological properties of the intestinal lactobacilli in experimental animals]. Zh Mikrobiol Epidemiol Immunobiol 1991:6-9. [PMID: 1887714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The oral administration of the therapeutic doses of tetracycline, pefloxacin, ampicillin, cephalexin, rifampicin, sisomicin to Wistar rats for 5 days was accompanied by a decrease in the total number of lactobacilli in feces and by changes of the species spectre of these microorganisms. In those rats species, never found in intact animals, could be revealed rather frequently. All antimicrobial preparations administered in this investigation induced a decrease in the proportion of antibiotic-sensitive cultures and led to the selection of strains having multiresistance and increased antagonistic activity with respect to Pseudomonas indicator strain. The possible relationship between the markers antibiotic resistance and antagonistic activity in lactobacilli is discussed.
Collapse
|
45
|
Tzannetis SE, Bigis A, Konidaris N, Ioannidis H, Genimatas V, Papavassiliou J. In-vitro bacteriocin-mediated antagonism by oral streptococci against human carrier strains of staphylococci. J Appl Bacteriol 1991; 70:294-301. [PMID: 2055791 DOI: 10.1111/j.1365-2672.1991.tb02939.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
All strains of oral streptococci tested and specially those of Streptococcus mutans, Strep. sanguis and Strep. mitior produced more than one distinct bacteriocin-like substance with variable inhibitory activity on 20 indicator staphylococci. Inhibitory activity was comparatively higher on nasal strains of Staph. aureus and Staph. epidermidis than on strains of both species isolated from the mouth. Nineteen of 20 staphylococcal indicators were inhibited by 1-12 of the 12 effector streptococci. Sensitivity of nasal staphylococci to bacteriocins (frequency of positive inhibitory tests and total inhibition zone diameters) was significantly higher (P less than 0.001, chi 2 test and P less than 0.05, t test respectively) than that of oral ones. The sensitivity of nasal over oral Staph. aureus (P less than 0.001 and P less than 0.01) and of oral Staph. epidermidis over oral Staph. aureus (P less than 0.01 and P less than 0.05) was also significantly higher. The evaluation of variability of inhibitory patterns of bacteriocins produced by streptococci (p-typing), of sensitivity patterns of staphylococci to bacteriocins (s-typing) and of the significantly higher sensitivity of nasal over oral staphylococci to bacteriocins from the epidemiological and ecological viewpoints are discussed.
Collapse
Affiliation(s)
- S E Tzannetis
- Department of Microbiology, School of Medicine, University of Athens, Greece
| | | | | | | | | | | |
Collapse
|
46
|
Josaki K, Contrino J, Kristie J, Krause P, Kreutzer DL. Pentoxifylline-induced modulation of human leukocyte function in vitro. Am J Pathol 1990; 136:623-30. [PMID: 2316627 PMCID: PMC1877473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We previously demonstrated that pentoxifylline stimulated leukocyte migration in vitro and leukocyte accumulation in vivo and protects neonatal mice from experimentally induced Staphylococcus aureus infections. In the present studies we have investigated pentoxifylline's effect on human leukocyte function in vitro. In these studies we demonstrate that pentoxifylline at low concentrations (ie, 0.01 and 0.1 mg/ml) stimulates both leukocyte migration and microbicidal activity in vitro. Alternatively, low concentrations (0.001 to 0.1 mg/ml) of pentoxifylline had no significant effect on the binding uptake of S. aureus by leukocytes, nor did it enhance phagocytic degranulation. At extremely low concentrations (0.001 mg/ml), pentoxifylline enhanced oxygen metabolism by human leukocytes, as reflected by increased H2O2 production and chemiluminescence (CL). At higher concentrations (ie, 0.1 to 1 mg/ml), pentoxifylline consistently suppressed these leukocyte functions in vitro. Thus, this study supports the following hypothesis: 1) the in vivo effects of pentoxifylline may involve a direct effect on both leukocyte mobilization and microbicidal activity, and 2) the enhanced microbicidal activity induced by pentoxifylline may be a result of enhanced leukocyte oxygen metabolism. In summary, pentoxifylline appears to be an interesting immunomodulator (ie, immunoenhancement and immunosuppression) of leukocyte function in vitro, but additional studies will be required before the efficacy of pentoxifylline in man can be determined.
Collapse
Affiliation(s)
- K Josaki
- Department of Pediatrics, Keio University Medical School, Tokyo, Japan
| | | | | | | | | |
Collapse
|
47
|
Gorskaia EM. [Gnotobiotic studies to determine the colonization resistance of the intestines]. Antibiot Khimioter 1989; 34:601-6. [PMID: 2589900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The literature data and the results of the author studies on determination of intestine colonization resistance are presented. The mechanisms of the colonization resistance defined by the macroorganism factors and representatives of indigenic microflora are discussed. The results of the experiments with animal gnotobiotes aimed at elucidating new aspects of the colonization resistance mechanism: antagonistic interrelations between pathogenic and nonpathogenic bacteria and the role of transitory microflora, factors lowering the colonization resistance are presented. The up-to-date methods for testing the colonization resistance and the ways for its increasing are indicated.
Collapse
|
48
|
Flesch IE, Kaufmann SH. Attempts to characterize the mechanisms involved in mycobacterial growth inhibition by gamma-interferon-activated bone marrow macrophages. Infect Immun 1988; 56:1464-9. [PMID: 2453466 PMCID: PMC259422 DOI: 10.1128/iai.56.6.1464-1469.1988] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Bone marrow-derived murine macrophages are able to inhibit the growth of Mycobacterium bovis and of some strains of M. tuberculosis after stimulation with either recombinant gamma interferon (rIFN-gamma) or lymphokines from antigen-specific T-cell clones. To elucidate the mechanism(s) involved in antimycobacterial activity, macrophages were infected with M. bovis in the presence of agents thought to influence the antimicrobial effects of phagocytes. Scavengers of toxic oxygen metabolites failed to influence the capacity of IFN-gamma-activated bone marrow macrophages to inhibit the growth of M. bovis. Suramin slightly affected mycobacterial growth in IFN-gamma-activated macrophages, and chloroquine markedly induced growth inhibition of M. bovis in unstimulated macrophages. We conclude that growth inhibition of M. bovis by IFN-gamma-activated macrophages is an oxygen-independent process.
Collapse
Affiliation(s)
- I E Flesch
- Max-Planck-Institut für Immunbiologie, Freiburg, Federal Republic of Germany
| | | |
Collapse
|
49
|
Abstract
To characterize the antimicrobial activities of Kupffer cells, I harvested macrophages from livers with a technique involving perfusion with collagenase and DNase. Ninety-nine percent of glass-adherent cells had typical macrophage morphology, 99% were esterase positive, and 60% phagocytosed opsonized zymosan when challenged with four particles per macrophage. Toxoplasma gondii multiplied within Kupffer cells from unmanipulated mice, but multiplication was intermediate between that observed in highly permissive peritoneal macrophages and highly activated macrophages. Intravenous injection of heat-killed Propionibacterium acnes, a stimulus known to activate macrophages in other compartments, resulted in a uniform, highly activated population of liver macrophages. Kupffer cells from P. acnes-injected mice were capable of generating reactive oxygen intermediates as shown by reduction of Nitro Blue Tetrazolium during phagocytosis of T. gondii or opsonized zymosan. In contrast, intravenous P. acnes injection did not activate spleen macrophages. Intravenous injection of P. acnes into athymic mice activated Kupffer cells, which suggested that T cells were not essential for this response. Kupffer cells were not activated in mice with latent Toxoplasma infection or during acute Giardia muris infection. Ordinarily, Kupffer cells became highly permissive for T. gondii during 48 h in culture, but inclusion of recombinant murine gamma interferon maintained their moderate inhibitory activity.
Collapse
Affiliation(s)
- G A Filice
- Infectious Disease Section, Veterans Administration Medical Center, Minneapolis, Minnesota 55417
| |
Collapse
|
50
|
Altavilla D, Berlinghieri MC, Focà A, Cook JA. Effect of bacterial endotoxin on lipoxygenase and cyclo-oxygenase metabolites by rat neutrophils and correlation with cellular functional parameters. Res Exp Med (Berl) 1988; 188:9-17. [PMID: 2832910 DOI: 10.1007/bf01852089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effect of Salmonella enteritidis endotoxin on in vitro rat neutrophil cyclo-oxygenase and lipoxygenase metabolism, phagocytic activity, superoxide (O2-) generation, and microbicidal activity was investigated. Incubation of polymorphonuclear leukocytes (PMN) with 5, 25, and 50 micrograms of endotoxin significantly enhanced synthesis of immunoreactive (i) leukotriene (LT)C4/D4 and thromboxane (Tx)B2 (P less than 0.001) as compared to control cells. Endotoxin 5 micrograms/ml produced optimal stimulation of the arachidonic acid metabolites. Calcium ionophore, A23187, significantly enhanced iLTC4/D4 and iTxB2 synthesis more than that elicited with endotoxin. Although phagocytic function was not significantly altered by endotoxin, intracellular killing of C. albicans demonstrated enhanced microbicidal activity at 5 micrograms/ml of endotoxin. Superoxide generation was significantly enhanced in neutrophils stimulated with phorbol myristate acetate (PMA). Endotoxin (5 micrograms/ml) further potentiated superoxide generation by these cells when stimulated by PMA. These findings demonstrate that endotoxin directly enhances neutrophil iLTC4/D4 and iTxB2 synthesis. The enhanced arachidonic acid metabolism elicited by endotoxin in these cells parallels increased microbicidal activity and superoxide generation.
Collapse
Affiliation(s)
- D Altavilla
- Institute of Medical Microbiology, University of Messina, Italy
| | | | | | | |
Collapse
|