Provided are delivery immunostimulatory bacteria that have enhanced colonization of tumors, the tumor microenvironment and/or tumor-resident immune cells, and enhanced anti-tumor activity. The immunostimulatory bacteria are modified by deletion of genes encoding the flagella or modification of the genes so that functional flagella are not produced, and/or are modified by deletion of pagP or modification of pagP to produce inactive PagP product. As a result, the immunostimulatory bacteria are flagellin.sup.− and/or pagP.sup.−. The immunostimulatory bacteria optionally have additional genomic modifications so that the bacteria are adenosine or purine auxotrophs. The bacteria optionally are one or more of asd.sup.−, purI.sup.− and msbB.sup.−. The immunostimulatory bacteria, such as Salmonella species, are modified to encode immunostimulatory proteins that confer anti-tumor activity in the tumor microenvironment, and/or are modified so that the bacteria preferentially infect immune cells in the tumor microenvironment or tumor-resident immune cells and/or induce less cell death in immune cells than in other cells. Also provided are methods of inhibiting the growth or reducing the volume of a solid tumor by administering the immunostimulatory bacteria.

The present invention relates to an inert carrier Salmonella and potential use thereof, which is expected to be developed into a new inert carrier bacteria, and can be applied to the development of an indirect agglutination test method for simple and rapid detection of antigens or infected antibodies. The inert carrier Salmonella has been deposited in CGMCC in Beijing on Mar. 18, 2019 with the accession number of CGMCC No.17340, and is classified as Salmonella sp.with a strain code of S9. The Salmonella has no visible agglutination reaction with various chicken sera derived from different genetic backgrounds, i.e., it has no non-specific agglutination reaction with chicken sera derived from broad range of genetic backgrounds.

Provided are delivery immunostimulatory bacteria that have enhanced colonization of tumors, the tumor microenvironment and/or tumor-resident immune cells, and enhanced anti-tumor activity. The immunostimulatory bacteria are modified by deletion of genes encoding the flagella, or by modification of the genes so that functional flagella are not produced, and/or are modified by deletion of pagP or modification of pagP to produce inactive PagP product. As a result, the immunostimulatory bacteria are flagellin.sup. and/or pagP.sup.. The immunostimulatory bacteria optionally have additional genomic modifications so that the bacteria are adenosine or purine auxotrophs. The bacteria optionally are one or more of asd.sup., purI.sup., and msbB.sup.. The immunostimulatory bacteria, such as Salmonella species, are modified to encode immunostimulatory proteins that confer anti-tumor activity in the tumor microenvironment, and/or are modified so that the bacteria preferentially infect immune cells in the tumor microenvironment, or tumor-resident immune cells, and/or are modified to induce less cell death in immune cells than in other cells. Also provided are methods of inhibiting the growth or reducing the volume of a solid tumor by administering the immunostimulatory bacteria.

Provided are delivery immunostimulatory bacteria that have enhanced colonization of tumors, the tumor microenvironment and/or tumor-resident immune cells, and enhanced anti-tumor activity. The immunostimulatory bacteria are modified by deletion of genes encoding the flagella, or by modification of the genes so that functional flagella are not produced, and/or are modified by deletion of pagP or modification of pagP to produce inactive PagP product. As a result, the immunostimulatory bacteria are flagellin.sup. and/or pagP.sup.. The immunostimulatory bacteria optionally have additional genomic modifications so that the bacteria are adenosine or purine auxotrophs. The bacteria optionally are one or more of asd.sup., purI.sup., and msbB.sup.. The immunostimulatory bacteria, such as Salmonella species, are modified to encode immunostimulatory proteins that confer anti-tumor activity in the tumor microenvironment, and/or are modified so that the bacteria preferentially infect immune cells in the tumor microenvironment, or tumor-resident immune cells, and/or are modified to induce less cell death in immune cells than in other cells. Also provided are methods of inhibiting the growth or reducing the volume of a solid tumor by administering the immunostimulatory bacteria.

Every year, approximately 94 million cases of Salmonella gastroenteritis, with 155000 deaths, are reported each year and 85% of them reported to be food-borne. Investigation of the foods whether they are clean for Salmonella and sensitivity, easy applicability, absence of false positivity and negativity and the speed are the features sought in the analysis method for this investigation. It is not desirable for analysis to detect the presence of dead bacteria in food. Although the final product does not contain microbiologically harmful live bacteria during the food process, the detection of dead bacteria transmitted before the process causes the food product to be unfairly diagnosed as harmful. To prevent this situation, the analysis kits depending on molecular methods, increase their microorganism detection levels up to to 10.sup.4 while reducing their sensitivity. Since the molecular methods cannot discriminate dead and live organisms, a confirmation test is required to prove that the positive result of the analysis belongs to the live bacteria in the food, which results in additional cost and time loss. In the same way, it is necessary to verify whether the colonies that grow in the gold standard culture method, belong to Salmonella bacteria. In the developed system; 10.sup.5 dead bacterial DNA is eliminated in the food to prevent false positive results and the minimum detection limit is 10 bacteria. Also, in developed system, 4 primers specific to 6 regions of DNA are used. Therefore, the specificity of the method is very high (99.9%) and no verification test is needed. Since PCR systems require a device with complex temperature control units, they can make analysis in a laboratory-dependent manner. In the proposed system, DNA is amplified at constant temperature; no temperature cycle is required, therefore no complex instrument and laboratory infrastructure are required. All the procedures can be easily performed outside the laboratory on a portable mini-heater where pre-enrichment, DNA isolation from the sample and PCR steps are performed. For molecular analyses, the device is required to display the result of imaging or analysis. In the developed method, DNAs amplified by the loop-mediated isothermal DNA amplification method, are hybridized and combined with the labeled probe and then can be read by lateral flow method with the naked eye. As the results are visible by eye, no additional device is required. The classical culture method is accepted as the gold standard, but the duration of analysis is 7 days for positive samples, 3 days with verification test, for the molecular methods, and 5.5 hours including pre-enrichment time

Provided are delivery immunostimulatory bacteria that have enhanced colonization of tumors, the tumor microenvironment and/or tumor-resident immune cells, and enhanced anti-tumor activity. The immunostimulatory bacteria are modified by deletion of genes encoding the flagella, or by modification of the genes so that functional flagella are not produced, and/or are modified by deletion of pagP or modification of pagP to produce inactive PagP product. As a result, the immunostimulatory bacteria are flagellin.sup. and/or pagP.sup.. The immunostimulatory bacteria optionally have additional genomic modifications so that the bacteria are adenosine or purine auxotrophs. The bacteria optionally are one or more of asd.sup., purI.sup., and msbB.sup.. The immunostimulatory bacteria, such as Salmonella species, are modified to encode immunostimulatory proteins that confer anti-tumor activity in the tumor microenvironment, and/or are modified so that the bacteria preferentially infect immune cells in the tumor microenvironment, or tumor-resident immune cells, and/or are modified to induce less cell death in immune cells than in other cells. Also provided are methods of inhibiting the growth or reducing the volume of a solid tumor by administering the immunostimulatory bacteria.