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J. Maxwell Dow Lynn M. Naughton Birte Hollmann Shi-Qi An Robert P. Ryan 《Israel journal of chemistry》2016,56(5):321-329
Bacterial cell-to-cell signals of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids that differ in their chain length and branching patterns. Signaling involving DSF family members occurs in diverse bacteria to include plant and human pathogens. In the majority of these organisms, the perception of DSF is linked to turnover of the second messenger cyclic di-GMP by one of two “core” pathways. Additional “accessory” signal transduction pathways can also be found, but are not widely conserved. DSF signaling acts to regulate diverse functions to include biofilm formation and architecture, antibiotic resistance, and the production of virulence factors in pathogens. DSF family signals can also participate in interspecies signaling with other bacteria and interkingdom signaling with the yeast Candida albicans. Such interactions may have importance in modifying microbial behavior during polymicrobial infections. 相似文献
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Ingudam Shakuntala Samir Das Sandeep Ghatak Rajkumari Sanjukta Kekungu-U Puro 《Food Biotechnology》2019,33(3):237-250
Listeria monocytogenes is a pathogenic microorganism infects man mostly through food. A total of 1615 samples of foods of animal origin and water were collected from retail meat shops of North-Eastern India and processed. Sixty-three (3.9%) samples were positive for L. monocytogenes. Animal origin foods showing the highest prevalence was chevon (9.8%) followed by beef (8.9%), chicken (8.5%), pork (2.8%) and milk (1.8%). The prevalence rate in water from retail meat shops was 10%. Recovered L. monocytogenes were distributed into 3 serogroups, of which 74.6% fit in to 1/2a, 3a serogroup, 17.5% to 1/2b, 3b and 7.9 % to 4b, 4d, 4e serogroups. Thirty-five isolates out of 63 possessed all the tested four virulence genes. RAPD- and ERIC -PCR based analyses jointly revealed a discriminative genetic profile for the L. monocytogenes. On the whole, the occurrence of L. monocytogenes in foods of animal origin of North Eastern India displays public health hazard. 相似文献
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Sabina Kdzierska-Mieszkowska Michal Zolkiewski 《International journal of molecular sciences》2021,22(10)
This review focuses on the molecular chaperone ClpB that belongs to the Hsp100/Clp subfamily of the AAA+ ATPases and its biological function in selected bacterial pathogens, causing a variety of human infectious diseases, including zoonoses. It has been established that ClpB disaggregates and reactivates aggregated cellular proteins. It has been postulated that ClpB’s protein disaggregation activity supports the survival of pathogenic bacteria under host-induced stresses (e.g., high temperature and oxidative stress), which allows them to rapidly adapt to the human host and establish infection. Interestingly, ClpB may also perform other functions in pathogenic bacteria, which are required for their virulence. Since ClpB is not found in human cells, this chaperone emerges as an attractive target for novel antimicrobial therapies in combating bacterial infections. 相似文献
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Jacky Lu Kathryn P. Haley Jamisha D. Francis Miriam A. Guevara Ryan S. Doster Kelly M. Craft Rebecca E. Moore Schuyler A. Chambers Alberto G. Delgado Maria Blanca Piazuelo Steven M. Damo Dr. Steven D. Townsend Dr. Jennifer A. Gaddy 《Chembiochem : a European journal of chemical biology》2021,22(18):2783-2790
Chronic infection with Helicobacter pylori increases risk of gastric diseases including gastric cancer. Despite development of a robust immune response, H. pylori persists in the gastric niche. Progression of gastric inflammation to serious disease outcomes is associated with infection with H. pylori strains which encode the cag Type IV Secretion System (cag T4SS). The cag T4SS is responsible for translocating the oncogenic protein CagA into host cells and inducing pro-inflammatory and carcinogenic signaling cascades. Our previous work demonstrated that nutrient iron modulates the activity of the T4SS and biogenesis of T4SS pili. In response to H. pylori infection, the host produces a variety of antimicrobial molecules, including the iron-binding glycoprotein, lactoferrin. Our work shows that apo-lactoferrin exerts antimicrobial activity against H. pylori under iron-limited conditions, while holo-lactoferrin enhances bacterial growth. Culturing H. pylori in the presence of holo-lactoferrin prior to co-culture with gastric epithelial cells, results in repression of the cag T4SS activity. Concomitantly, a decrease in biogenesis of cag T4SS pili at the host-pathogen interface was observed under these culture conditions by high-resolution electron microscopy analyses. Taken together, these results indicate that acquisition of alternate sources of nutrient iron plays a role in regulating the pro-inflammatory activity of a bacterial secretion system and present novel therapeutic targets for the treatment of H. pylori-related disease. 相似文献
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从罹病的玉米螟(Ostrinia furnacalis G)中分离纯化获得一株新菌株,命名为Bb-1。通过对该菌株的培养性状、形态特征观察,以及ITS基因序列分析,鉴定出Bb-1菌株为白僵菌属的球孢白僵菌(Beauveria bassiana)。用该菌株的5种浓度孢子液对黄胸散白蚁进行毒力试验。结果表明:用浓度为5×10~7孢子/mL的孢子液处理8d,黄胸散白蚁的校正死亡率达95.00%。5~8d的LC_(50)值为2.05×10~4~9.05×10~6孢子/mL。在5×10~3~5×10~7孢子/mL浓度下,菌株的LT_(50)值为4.28~8.59d。 相似文献
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Jon R Saunders Heather Allison Chloe E James Alan J McCarthy Richard Sharp 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(7):662-666
Bacteriophages as accessory genetic elements play a crucial role in the dissemination of genes and the promotion of genetic diversity within bacterial populations. Such horizontal transfer of DNA is critical in the emergence of new pathogenic organisms, through the dissemination of genes encoding virulence factors such as toxins, adhesins and agressins. Phages can transfer genes that are not necessary for bacteriophage persistence and are generally recognised by their ability to convert their host bacteria to new phenotypes. This phenomenon is known as phage conversion. If such converting genes encode for virulence factors, the consequences of phage infection may include increased virulence of the host bacteria, and the conversion of a non‐pathogenic strain to a potentially dangerous pathogen. A number of virulence factors in bacteria causing diseases in plants, animals and humans are encoded by converting phages, the vast majority of which are temperate as opposed to lytic in nature. © 2001 Society of Chemical Industry 相似文献
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《Journal of dairy science》2022,105(7):5685-5699
More than 30 types of artisanal cheeses are known in Brazil; however, microorganisms, such as Staphylococcus spp., can contaminate raw milk cheeses through different sources, from milking to processing. Staphylococcal food poisoning results from the consumption of food in which coagulase-positive staphylococci, mostly Staphylococcus aureus, have developed and produced enterotoxins. In addition, an emerging public health concern is the increasing antimicrobial resistance of some Staphylococcus strains. Furthermore, the ability of Staphylococcus spp. in sharing antibiotic resistance-related genes with other bacteria increases this problem. In light of these observations, this review aims to discuss the presence of, enterotoxins of, and antibiotic-resistant of Staphylococcus spp. in Brazilian artisanal cheese produced with raw milk. 相似文献
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目的研究北疆部分地区食源性大肠杆菌的优势血清型、毒力基因和耐药基因的相关性。方法采用玻片凝集法测定了大肠杆菌血清型分布,PCR方法调查11种耐药基因和9种毒力基因。结果血清试验,定型菌株26株,分别属于17种血清型,其中O1、O115为优势血清型;PCR结果表明,不含有所检测耐药基因的分离株占12.50%,至少含有2种以及以上的分离株占50.00%,分离株对blaOXA基因携带率高达57.14%;检出率较高的毒力基因为fimC(64.29%)和fimA(25.00%)。结论 O1、O115为主要的血清型,2种血清型菌株拥有的耐药基因谱和毒力基因谱不相同。 相似文献