Acupuncture and Related Therapies for Endometriosis: A Network Meta-Analysis of Randomized Controlled Trials.

Background: Acupuncture and related therapies are effective and safe ways to relieve the pain, and improve the health and quality of life in women with endometriosis-related pain. However, it is still unclear which treatment is the most effective. Our study aims to summarize the evidence and determine the most effective and safe method to treat the endometriosis. Methods: We searched PubMed, EMBASE, Cochrane Library, and Web of science, China Biology Medicine, China National Knowledge Infrastructure, Wan fang Data, Chinese Scientific Journal Database and conducted manual searches of relevant papers, summarized randomized clinical trials of acupuncture-related therapies for endometriosis from database inception to 21 April 2024. After independent literature screening and data extraction that pain VAS was selected as the primary outcome measure. The quality evaluation was conducted by Review Manager 5.4. Perform network meta-analysis (NMA) used Stata 15.0 software. Results: Forty-two eligible trials involving six acupuncture-related interventions and 3,635 participants were included in this NMA. Pairwise meta-analyses show that combination therapy was more efficacious than western medicine and Chinese herb medicine for pain VAS scores, serum CA125 level and response rate results. The NMA estimates indicated that: for pain VAS scores, acupuncture (SMD: -2.33; 95% CI: -4.37, -0.29) and combination therapy (SMD: 1.79 95% CI: 1.21, 2.41) were superior to western medicine. For serum CA125 level, acupoint application (SMD: -11.33 95% CI: -20.28, -2.97) and combination therapy (SMD: 6.20; 95% CI: 1.60, 10.75) were associated with better efficacy when considered alongside western medicine. For response rate, combination therapy (SMD: 0.20; 95% CI: 0.14, 0.29) and auricular therapy (SMD: 8.01; 95% CI: 2.08, 45.37) were more efficacious than western medicine. The comprehensive ranking results show that acupoint catgut embedding was the best performing at lowering pain VAS scores, acupoint application was identified as the most effective in reducing serum CA125 level, and auricular therapy was ranked first in improving the response rate. Conclusion: Acupoint catgut embedding, auricular therapy, acupoint application and combination therapy may be the best solutions for the treatment of endometriosis. Additional trials are needed to develop higher-quality evidence and optimal regimens.

Comparative study of different dosages of grain-sized moxibustion on uterine artery blood flow in patients with cold and dampness primary dysmenorrhea. / ä¸åŒå‰‚é‡éº¦ç²’ç¸å¯¹å¯’æ¹¿å‡æ»žåž‹åŽŸå‘æ€§ç—›ç»æ‚£è€ å­å®«åŠ¨è„‰è¡€æµå½±å“çš„æ¯”è¾ƒç ”ç©¶.

OBJECTIVES: To observe the differences in the effects of different dosages of grain-sized moxibustion on uterine artery blood flow in patients with cold and dampness primary dysmenorrhea (PD). METHODS: A total of 60 patients with PD were randomly divided into 3 groups with 20 cases in each group. Acupoints Sanyinjiao (SP6), Diji (SP8) and Xuehai (SP10) were selected in all the 3 groups, and different dosages of grain-sized moxibustion were used (3 moxa cones, 6 moxa cones, 9 moxa cones) respectively. Treatment started 7 days before menstruation for 3 times, lasting for a total of 3 menstrual cycles. The values of uterine artery blood flow parameters including pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio (S/D) were recorded before and after treatment. The visual analog scale (VAS) score and cox menstrual symptom scale (CMSS) score (including severity ［CMSS-S］ and time of duration ［CMSS-T］) were evaluated before treatment, at the end of each menstrual cycle, and one menstrual cycle after treatment. RESULTS: The values of uterine artery blood flow parameters (PI, RI, S/D) after treatment in the 9 moxa cones group were lower than those before treatment, as well as lower than those in the 3 and 6 moxa cones groups after treatment (P<0.05). The VAS scores of the 3 moxa cones group were lower than those before treatment in the first and second cycle (P<0.05). The VAS scores of the 6 and 9 moxa cones groups were lower than those before treatment at each observation point (P<0.05), and were lower than those of the 3 moxa cones group in the third cycle of treatment and follow-up period (P<0.05). And the VAS score of the 9 moxa cones group was lower than that of the 6 moxa cones group during the follow-up period (P<0.05). Compared with the scores before treatment, the CMSS-T scores at each observation point after treatment were lower in the 9 moxa cones group (P<0.05)；the CMSS-T scores in the second and third cycle after treatment, and follow-up period were lower in the 6 moxa cones group (P<0.05), with the CMSS-S scores in the second and third cycle after treatment, and follow-up period lower in the 6 and 9 moxa cones groups (P<0.05). The CMSS-T and CMSS-S scores of the 6 and 9 moxa cones groups were lower than those of the 3 moxa cones group in the third cycle and follow-up period (P<0.05). The CMSS-T and CMSS-S scores of the 9 moxa cones group were lower than those of the 6 moxa cones group during the follow-up period (P<0.05). CONCLUSIONS: Grain-Sized moxibustion has dose-effect relationship in the treatment of PD. Compared with 3 and 6 moxa cones groups, 9 moxa cones group has advantages in improving uterine artery blood flow parameters and alleviating dysmenorrhea symptoms in PD patients.

Transcriptomics integrated with metabolomics reveal the competitive relationship between co-cultured Trichoderma asperellum HG1 and Bacillus subtilis Tpb55.

Microbial co-culture has proven to be an effective way to improve the ability of microorganisms to biocontrol. However, the interactive mechanisms of co-cultural microbes, especially between fungi and bacteria, have rarely been studied. By comparative analysis of morphology, transcriptomics and metabolomics, the interactive mechanisms of a sequential co-culture system of Trichoderma asperellum HG1 and Bacillus subtilis Tpb55 was explored in this study. The results revealed that co- culture has no significant effect on the growth and cell morphology of the two strains, but lead to mycelium wrinkling of HG1. RNA-seq analysis showed that co-culture significantly upregulated the HG1 genes concerning amino acid degradation and metabolism, proteolysis, resisting environmental stress, cell homeostasis, glycolysis, the glyoxylate cycle, and the citric acid (TCA) cycle, while Tpb55 genes related to cell homeostasis, spore formation and membrane fluidization were significantly upregulated, but genes associating to TCA, glycolytic cycles and fatty acid ß-oxidation were significantly downregulated. Metabolomic results revealed that some amino acids related to energy metabolism were significantly altered in HG1, whereas palmitic acid, which is related to cell membrane functions, was upregulated in Tpb55. These results indicated that HG1 could interfere with carbon metabolism and cell membrane fluidity, but accelerate spore formation of Tpb55. Biophysical assays further convinced that co-culture could decrease ATP content and inhibit ATPase activity in HG1, and could promote spore formation and reduce the cell membrane fluidity of Tpb55. In addition, co-culture also accelerated the production of intracellular anti-oomycete compound octhilinone. The above results indicate that HG1 and Tpb55 are mainly in a competitive relationship in the co culture system. These findings provide new insights for understanding the interaction mechanism between co cultured microbes.

Knowledge mapping of acupoint sensitization and acupoint specificity: a bibliometric analysis.

Objective: The relationship between acupoint sensitization and acupoint specificity is a topic of significant interest in acupuncture research. Numerous clinical studies have demonstrated that needling pain sensitive acupoints yields superior therapeutic outcomes compared to traditional acupoints, particularly in the context of pain disorders. However, there is a lack of bibliometric analysis in acupuncture area. Therefore, the objective of this study is to offer a comprehensive overview of the knowledge structure and research hotspots pertaining to acupoint sensitization and acupoint specificity. Methods: The search for publications pertaining to acupoint sensitization and acupoint specificity was conducted in the Web of Science Core Collection (WoSCC) database from its inception until August 11, 2023. Subsequently, bibliometric analyses were carried out using VOSviewer, CiteSpace, R software (Bibliometrix package), and GraphPad Prism software. Results: This study includes 4,940 articles from 72 countries, with China and the United States being the leading countries. The number of publications related to acupoint sensitization and specificity has been increasing annually. Major research institutions involved in this field include the Shanghai University of Traditional Chinese Medicine, Kyung Hee University, Beijing University of Chinese Medicine, Chinese Academy of Chinese Medical Sciences, and China Medical University, among others. "Evidence-based Complementary and Alternative Medicine" is the most popular journal in acupuncture field, and "PAIN" is the most co-cited journal. Publications are contributed by 20,325 authors from all over the world, with Wu Huangan, Fang Jianqiao, Lin Yi-Wen, Liu Huirong, and Chen Rixin having published the most articles. Han Ji-Sheng is the most cited author in this research area. The main directions include the study of temperature specificity of acupoints, the diagnosis of acupoint sensitization diseases, and the study of the mechanism of acupoint sensitization. The most listed keywords in recent years are "TRPV1," "signaling pathway," and "diagnosis." Conclusion: This is the first bibliometric study to comprehensively summarize research trends and advances in acupoint sensitization and acupoint specificity, and the information highlights recent research preliminary and main directions that serve as a reference for acupoint sensitization and acupoint specificity research.

[The skin surface microcirculation of conception vessel, governor vessel and thoroughfare vessel in patients with primary dysmenorrhea].

OBJECTIVE: To observe the skin surface microcirculation of acupoints of conception vessel, governor vessel and thoroughfare vessel in patients with primary dysmenorrhea using laser speckle contrast imaging (LSCI), and provide acupoint selection basis of acupuncture-moxibustion for primary dysmenorrhea. METHODS: Ninety-nine healthy female college students with regular menstrual cycles (normal group) and 94 female college students with primary dysmenorrhea (dysmenorrhea group) were recruited. Before menstrual period, on the first day of menstruation, and on the third day after menstruation, LSCI was used to observe the surface microcirculation at the abdominal acupoints of conception vessel, i. e. Yinjiao (CV 7), Qihai (CV 6), Shimen (CV 5), Guanyuan (CV 4), Zhongji (CV 3) and Qugou (CV 2), acupoints of thoroughfare vessel, i. e. Huangshu (KI 16), Zhongzhu (KI 15), Siman (KI 14), Qixue (KI 13), Dahe (KI 12), Henggu (KI 11) and acupoints of lumbosacral region of governor vessel, i. e. Xuanshu (GV 5), Mingmen (GV 4), Yaoyangguan (GV 3), Yaoshu (GV 2) as well as two non-acupoints. RESULTS: Before menstrual period, there was no significant difference in the surface blood perfusion of the acupoints between the dysmenorrhea group and the normal group (P>0.05). On the first day of menstruation, the surface blood perfusion of Xuanshu (GV 5), Mingmen (GV 4), Yaoyangguan (GV 3) and right Huangshu (KI 16) in the dysmenorrhea group was higher than that in the normal group (P<0.05, P<0.01). On the third day after menstruation, the surface blood perfusion of the right Henggu (KI 11) in the dysmenorrhea group was lower than that in the normal group (P<0.05). CONCLUSION: In patients with primary dysmenorrhea, on the first day of menstruation, the surface blood perfusion of Xuanshu (GV 5), Mingmen (GV 4), Yaoyangguan (GV 3) of governor vessel, and the right Huangshu (KI 16) of thoroughfare vessel is increased, while on the third day after menstruation, the surface blood perfusion of the right Henggu (KI 11) of thoroughfare vessel is decreased. These findings might provide a basis for acupoint selection in the acupuncture-moxibustion treatment of primary dysmenorrhea.

Metabolomic and regular analysis reveal phytotoxic mechanisms of sterigmatocystin in Amaranthus retroflexus L.

Sterigmatocystin (STE) is a common hepatotoxic and nephrotoxic contaminant in cereals, however, its phytotoxicity and mechanisms are poorly understood. Here, the phytotoxic mechanisms of STE were investigated via the metabolomics of Amaranthus retroflexus L. A total of 140 and 113 differential metabolites were detected in the leaves and stems, respectively, among which amino acids, lipids, and phenolic compounds were significantly perturbed. Valine, leucine, isoleucine, and lysine biosynthesis were affected by STE. These metabolic responses revealed that STE might be toxic to plants by altering the plasma membrane and inducing oxidative damage, which was verified by measuring the relative electrical conductivity and quantification of reactive oxygen species. The elevated amino acids, as well as the decreased of D-sedoheptuiose-7-phosphate indicated increased proteolysis and carbohydrate metabolism restriction. Furthermore, the IAA level also decreased. This study provides a better understanding of the impacts of STE on the public health, environment and food security.

Role of the Global Fitness Regulator Genes on the Osmotic Tolerance Ability and Salinity Hazard Alleviation of Trichoderma asperellum GDFS 1009 for Sustainable Agriculture.

Velvet family proteins are global regulators of fungal growth and development. Here, we reported the role of Vel1 and Lae1 from T. asperellum in osmotic tolerance. Deletion of the Vel1 and Lae1 genes led to the retardation of vegetative mycelial growth under saline conditions. The strain carrying the overexpression locus of the Vel1 and Lae1 genes was highly resistant to oxidative stress by upregulating the enzymes and genes involved in antioxidant activity. Major physiological changes in the cell wall and vacuoles occurred under high saline conditions. The Vel1 and Lae1 overexpression strains increased cell wall thickness and the number of vacuoles, which seems to lead to an increase of the osmolyte content of glycerol and proline. The absorption of Na+ content in the vacuole of the Vel1 and Lae1 overexpression strains was increased, while the absorption of Na+ was impaired in the Vel1 and Lae1 knock out strains, in which the Na+ was localized in the cell wall membrane. This result supported the significant correlation of the expression of genes with the ionic transportation in T. asperellum. Maize root colonization by the Vel1 and Lae1 gene overexpression strain was increased, which would mitigate the stress caused by the absorption of Na+ in the maize roots and increased the plant growth. Our results highlighted the importance of Vel1 and Lae1 proteins to the salinity stress tolerance of T. asperellum and the mitigation of Na+ stress to plants for sustainable agriculture.

2E,4E-Decadienoic Acid, a Novel Anti-Oomycete Agent from Coculture of Bacillus subtilis and Trichoderma asperellum.

Phytophthora nicotianae is an oomycete pathogen of global significance threatening many important crops. It is mainly controlled by chemosynthetic fungicides, which endangers ecosystem and human health; thus, there is an urgent need to explore alternatives for these fungicides. In this study, a new anti-oomycete aliphatic compound, 2E,4E-decadienoic acid (DDA), was obtained through coculture of Bacillus subtilis Tpb55 and Trichoderma asperellum HG1. Both in vitro and in vivo tests showed that DDA had a strong inhibitory effect against P. nicotianae. In addition, rhizosphere microbiome analysis showed that DDA reduced the relative abundance of Oomycota in rhizosphere soil. Transcriptome sequencing (RNA-Seq) analysis revealed that treatment of P. nicotianae with DDA resulted in significant downregulation of antioxidant activity and energy metabolism, including antioxidant enzymes and ATP generation, and upregulation of membrane-destabilizing activity, such as phospholipid synthesis and degradation. The metabolomic analysis results implied that the pathways influenced by DDA were mainly related to carbohydrate metabolism, energy metabolism, and the cell membrane. The biophysical tests further indicated that DDA produced oxidative stress on P. nicotianae, inhibited antioxidant enzyme and ATPase activity, and increased cell membrane permeability. Overall, DDA exerts inhibitory activity by acting on multiple targets in P. nicotianae, especially on the cell membrane and mitochondria, and can therefore serve as a novel environment-friendly agent for controlling crop oomycete disease. IMPORTANCE P. nicotianae is an oomycete pathogen that is destructive to crops. Although some oomycete inhibitors have been used during crop production, most are harmful to the ecology and lead to pathogen resistance. Alternatively, medium-chain fatty acids have been reported to exhibit antimicrobial activity in the medical field in previous studies; however, their potential as biocontrol agents has rarely been evaluated. Our in vivo and in vitro analyses revealed that the medium-chain fatty acid 2E,4E-decadienoic acid (DDA) displayed specific inhibitory activity against oomycetes. Further analysis indicated that DDA may acted on multiple targets in P. nicotianae, especially on the cell membrane and mitochondria. Our findings highlight the potential of DDA in controlling oomycete diseases. In conclusion, these results provide insights regarding the future use of green and environment-friendly anti-oomycete natural products for the prevention and control of crop oomycete diseases.

Antifungal Nafuredin and Epithiodiketopiperazine Derivatives From the Mangrove-Derived Fungus Trichoderma harzianum D13.

A new polyketide derivative, nafuredin C (1), a novel heterocyclic dipeptide, trichodermamide G (3), together with four known biogenetically related compounds nafuredin A (2), trichodermamide A (4), aspergillazin A (5), and peniisocoumarin H (6), were isolated from the mangrove-derived fungus Trichoderma harzianum D13. Their structures, including their absolute configurations, were determined by spectroscopic analysis and time-dependent density functional theory-electronic circular dichroism (ECD) calculations. Trichodermamide G was found to be a novel epithiodiketopiperazine derivative with an unprecedented cyclic system containing a sulfur bridge, and nafuredin C represented the third nafuredin derivative of these homologous compounds. The new compound nafuredin C exhibited obvious antifungal activity against Magnaporthe oryzae with a minimum inhibitory concentration (MIC) of 8.63 µM, which is on the same order of magnitude as the positive control carbendazim (MIC = 3.27 µM).

Cell-free DNA as a biomarker for colorectal cancer: a retrospective analysis in patients before and after surgery.

This study was aimed at investigating the potential of cell-free DNA (cfDNA) as a biomarker for colorectal cancer prognosis. Sixty patients with colorectal cancer who had not undergone surgery were enrolled as study group. Their peripheral blood samples were collected, and peripheral blood of 30 healthy volunteers (control) was collected. The cfDNA concentration and integrity were determined using q-PCR so as to ascertain if cfDNA was associated with clinical presentations of the disease. Then, the specificities and sensitivities of cfDNA, CFA and CA199 were determined with ROC curve. The level and integrity of cfDNA in patients with colorectal cancer before surgery were significantly higher than those in patients with colorectal cancer after surgery, and cfDNA concentration of colorectal cancer patients after surgery was also significantly higher than that in healthy control group. However, the integrity was not significantly different from that of control group. There was a significant correlation between cfDNA concentration and TNM stage, differentiation degree and CEA expression, while cfDNA integrity was significantly correlated with TNM stage and degree of differentiation. Moreover, specificity and sensitivity of cfDNA concentration and integrity were higher than those of CEA and CA199. The TNM stage and cfDNA concentration were independent risk factors for progression-free survival (PFS) in colorectal cancer patients. In conclusion, cfDNA concentration and integrity were more sensitive and specific than traditional tumor markers (CA199, CEA). Thus, changes in cfDNA changes can be effectively used to determine the prognosis of postoperative colorectal cancer patients.

The global regulator Crc plays a multifaceted role in modulation of type III secretion system in Pseudomonas aeruginosa.

The opportunistic pathogen Pseudomonas aeruginosa utilizes type III secretion system (T3SS) to translocate effector proteins into eukaryotic host cells that subvert normal host cell functions to the benefit of the pathogen, and results in serious infections. T3SS in P. aeruginosa is controlled by a complex system of regulatory mechanisms and signaling pathways. In this study, we described that Crc, an RNA-binding protein, exerts a positive impact on T3SS in P. aeruginosa, as evidenced by promoter activity assays of several key T3SS genes, transcriptomics, RT-PCR, and immunoblotting in crc mutant. We further demonstrated that the regulatory function of Crc on the T3SS was mediated through the T3SS master regulator ExsA and linked to the Cbr/Crc signaling system. Expression profiling of the crc mutant revealed a downregulation of flagship T3SS genes as well as 16 other genes known to regulate T3SS gene expression in P. aeruginosa. On the basis of these data, we proposed that Crc may exert multifaceted control on the T3SS through various pathways, which may serve to fine-tune this virulence mechanism in response to environmental changes and nutrient sources.

A novel two-component system BqsS-BqsR modulates quorum sensing-dependent biofilm decay in Pseudomonas aeruginosa.

Pseudomonas aeruginosa can grow either as planktonic- or biofilm-form in response to environmental changes. Recent studies show that switching from biofilm to planktonic lifestyle requires rhamnolipids. Here we report the identification of a novel twocomponent system BqsS-BqsR that regulates biofilm decay in P. aeruginosa. BqsS is a multidomain sensor kinase and BqsR is an OmpR-like response regulator. Deletion of either bqsS or bqsR in P. aeruginosa mPAO1 resulted in a significant increase in biofilm formation. Time course analysis showed that the bqsS-bqsR mutants were defective in biofilm dispersal and in rhamnolipid production. Mutation of the BqsS-BqsR two-component system did not affect the biosynthesis of long chain quorum sensing (QS) signal N-3-oxo-dodecanoyl-homoserine lactone (3OC12HSL) but resulted in reduced production of the short chain QS signal N-butyryl-L-homoserine lactone (C4HSL) and the Pseudomonas quinolone signal (PQS). Exogenous addition of C4HSL, PQS or rhamnolipids to the bqsS mutant reduced the biofilm formation to the wild-type level. Evidence suggests that the BqsS-BqsR two-component system might promote conversion of anthranilate to PQS. Taken together, these results establish BqsS-BqsR as a novel two-component system that regulates biofilm decay in P. aeruginosa by modulating biosynthesis of QS signals and rhamnolipids.

VqsM, a novel AraC-type global regulator of quorum-sensing signalling and virulence in Pseudomonas aeruginosa.

Human pathogen Pseudomonas aeruginosa uses quorum-sensing (QS) signalling systems to synchronize the production of virulence factors. There are two interrelated QS systems, las and rhl, in P. aeruginosa. In addition to this complexity, a number of transcriptional regulators were shown to have complicated interplays with las and rhl central QS components. Here, we describe a novel virulence and QS modulator (VqsM) that positively regulates the QS systems in P. aeruginosa. Mutation in vqsM resulted in much reduced production of N-acylhomoserine lactones (AHLs) and extracellular enzymes. Sequence analysis revealed that vqsM encodes a transcriptional regulator with an AraC-type helix-turn-helix DNA binding domain at the C-terminal of the peptide. Global gene expression profile analysis showed at least a total of 302 genes to be influenced, directly or indirectly, by VqsM. Among the 203 VqsM-promoted genes, 52.2% were known to be QS upregulated. Several genes encoding the key regulators implicated in QS, such as rhlR, rsaL, vqsR, mvfR, pprB and rpoS, and two AHL synthesis genes, lasI and rhlI, were suppressed in the vqsM mutant. Similar to the 'AHL-blind' phenotype of vqsR and pprB mutants, vqsM mutant did not respond to external addition of N-3-oxo-dodecanoyl-homoserine lactone signals. Moreover, overexpression of vqsR in vqsM mutant more or less restored the production of both AHL and virulence factors. The results demonstrate that VqsM, largely through modulation of vqsR expression, plays a vital role in regulation of QS signalling in P. aeruginosa.

The two-component response regulator PprB modulates quorum-sensing signal production and global gene expression in Pseudomonas aeruginosa.

The response regulator PprB and its cognate sensor PprA were recently reported as a two-component regulatory system that controls membrane permeability and antibiotic sensitivity of Pseudomonas aeruginosa. We found that a Tn5 insertion mutation in pprB caused a drastic reduction in virulence factor production and cell motility. A transcriptome analysis revealed that 175 genes were regulated by PprB. Among the 113 PprB-activated genes, 85.5% are known to be activated by N-3-oxo-dodecanoyl-homoserine lactone (OdDHL) and N-butanoyl-homoserine lactone (BHL). In particular, the expression of lasI, rhlI and rhlR, which encode key components of the las and rhl quorum-sensing (QS) systems, were significantly decreased in the pprB mutant. These data suggest that PprB might regulate QS signal production. Measurement of OdDHL and BHL in cultures of the mutant sustained this hypothesis. By using various OdDHL- or BHL-responsive QS reporter systems, including lasB-lacZ, lasI-lacZ and rsaL-lacZ, we found that the mutation in pprB resulted in a large decrease in the sensitivity of P. aeruginosa to exogenous OdDHL. However, there was no difference in sensitivity to BHL. Further analysis showed that the OdDHL influx was significantly reduced in the pprB mutant. We conclude that PprB is a novel QS modulator that positively regulates N-acylhomoserine lactone production probably by affecting the OdDHL signal influx and thereby influences global expression of the QS-dependent genes.

Insecticidal Bacillus thuringiensis silences Erwinia carotovora virulence by a new form of microbial antagonism, signal interference.

It is commonly known that bacteria may produce antibiotics to interfere with the normal biological functions of their competitors in order to gain competitive advantages. Here we report that Bacillus thuringiensis suppressed the quorum-sensing-dependent virulence of plant pathogen Erwinia carotovora through a new form of microbial antagonism, signal interference. E. carotovora produces and responds to acyl-homoserine lactone (AHL) quorum-sensing signals to regulate antibiotic production and expression of virulence genes, whereas B. thuringiensis strains possess AHL-lactonase, which is a potent AHL-degrading enzyme. B. thuringiensis did not seem to interfere with the normal growth of E. carotovora; rather, it abolished the accumulation of AHL signal when they were cocultured. In planta, B. thuringiensis significantly decreased the incidence of E. carotovora infection and symptom development of potato soft rot caused by the pathogen. The biocontrol efficiency is correlated with the ability of bacterial strains to produce AHL-lactonase. While all the seven AHL-lactonase-producing B. thuringiensis strains provided significant protection against E. carotovora infection, Bacillus fusiformis and Escherichia coli strains that do not process AHL-degradation enzyme showed little effect in biocontrol. Mutation of aiiA, the gene encoding AHL-lactonase in B. thuringiensis, resulted in a substantial decrease in biocontrol efficacy. These results suggest that signal interference mechanisms existing in natural ecosystems could be explored as a new version of antagonism for prevention of bacterial infections.