Polyvalent Bacterial Lysate with Potential Use to Treatment and Control of Recurrent Urinary Tract Infections.

Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of infectious diseases. This is the case with urinary tract infections (UTIs), which represent a substantial percentage of worldwide public health problems, thus the need to look for alternatives for their control and treatment. Previous studies have shown the usefulness of autologous bacterial lysates as an alternative for the treatment and control of UTIs. However, a limitation is the high cost of producing individual immunogens. At the same time, an important aspect of vaccines is their immunogenic amplitude, which is the reason why they must be constituted of diverse antigenic components. In the case of UTIs, the etiology of the disease is associated with different bacteria, and even Escherichia coli, the main causal agent of the disease, is made up of several antigenic variants. In this work, we present results on the study of a bacterial lysate composed of 10 serotypes of Escherichia coli and by Klebsiella pneumoniae, Klebsiella aerogenes, Enterococcus faecalis, Proteus mirabilis, Citrobacter freundii, and Staphylococcus haemolyticus. The safety of the compound was tested on cells in culture and in an animal model, and its immunogenic capacity by analysing in vitro human and murine macrophages (cell line J774 A1). The results show that the polyvalent lysate did not cause damage to the cells in culture or alterations in the animal model used. The immunostimulatory activity assay showed that it activates the secretion of TNF-α and IL-6 in human macrophages and TNF-α in murine cells. The obtained results suggest that the polyvalent lysate evaluated can be an alternative for the treatment and control of chronic urinary tract infections, which will reduce the use of antimicrobials.

UNAM-HIMFG Bacterial Lysate Activates the Immune Response and Inhibits Colonization of Bladder of Balb/c Mice Infected with the Uropathogenic CFT073 Escherichia coli Strain.

Urinary tract infections (UTIs) represent a clinical and epidemiological problem of worldwide impact that affects the economy and the emotional state of the patient. Control of the condition is complicated due to multidrug resistance of pathogens associated with the disease. Considering the difficulty in carrying out effective treatment with antimicrobials, it is necessary to propose alternatives that improve the clinical status of the patients. With this purpose, in a previous study, the safety and immunostimulant capacity of a polyvalent lysate designated UNAM-HIMFG prepared with different bacteria isolated during a prospective study of chronic urinary tract infection (CUTI) was evaluated. In this work, using an animal model, results are presented on the immunostimulant and protective activity of the polyvalent UNAM-HIMFG lysate to define its potential use in the control and treatment of CUTI. Female Balb/c mice were infected through the urethra with Escherichia coli CFT073 (UPEC O6:K2:H1) strain; urine samples were collected before the infection and every week for up to 60 days. Once the animals were colonized, sublingual doses of UNAM-HIMFG lysate were administrated. The colonization of the bladder and kidneys was evaluated by culture, and their alterations were assessed using histopathological analysis. On the other hand, the immunostimulant activity of the compound was analyzed by qPCR of spleen mRNA. Uninfected animals receiving UNAM-HIMFG lysate and infected animals administered with the physiological saline solution were used as controls. During this study, the clinical status and evolution of the animals were evaluated. At ninety-six hours after infection, the presence of CFT073 was identified in the urine of infected animals, and then, sublingual administration of UNAM-HIMFG lysate was started every week for 60 days. The urine culture of mice treated with UNAM-HIMFG lysate showed the presence of bacteria for three weeks post-treatment; in contrast, in the untreated animals, positive cultures were observed until the 60th day of this study. The histological analysis of bladder samples from untreated animals showed the presence of chronic inflammation and bacteria in the submucosa, while tissues from mice treated with UNAM-HIMFG lysate did not show alterations. The same analysis of kidney samples of the two groups (treated and untreated) did not present alterations. Immunostimulant activity assays of UNAM-HIMFG lysate showed overexpression of TNF-α and IL-10. Results suggest that the lysate activates the expression of cytokines that inhibit the growth of inoculated bacteria and control the inflammation responsible for tissue damage. In conclusion, UNAM-HIMFG lysate is effective for the treatment and control of CUTIs without the use of antimicrobials.

Bactofection of sequences encoding a Bax protein peptide chemosensitizes prostate cancer tumor cells.

BACKGROUND: Tumor cell resistance to chemotherapy agents is one of the main problems in the eradication of different neoplasias. One of the mechanisms of this process is the overexpression of anti-apoptotic proteins such as Bcl-2 and Bcl-XL; blocking the activity of these proteins may contribute to the sensitization of tumor cells and allow the adequate effects of chemotherapeutic drugs. METHODS AND RESULTS: This study adressed the transfection of prostate cancer cells (PC3) with a plasmid encoding a recombinant protein with an antagonist peptide from the BH3 region of the Bax protein fused to the GFP reporter protein (BaxGFP). This protein induced apoptosis of these tumor cells; further, selective transport of this plasmid to the tumor cell with Salmonella enterica serovar Typhimurium (strain SL3261), a live-attenuated bacterial vector, can induce sensitization of the tumor cell to the action of drugs such as cisplatin, through a process known as bactofection. CONCLUSIONS: These results suggest that Salmonella enterica can be used as a carrier vector of nucleotide sequences encoding heterologous molecules used in antitumor therapy.

Bactofection of sequences encoding a Bax protein peptide chemosensitizes prostate cancer tumor cells / Bactofección de secuencias que codifican para un péptido de la proteína Bax quimiosensibiliza a células tumorales de cáncer de próstata

Abstract: Background: Tumor cell resistance to chemotherapy agents is one of the main problems in the eradication of different neoplasias. One of the mechanisms of this process is the overexpression of anti-apoptotic proteins such as Bcl-2 and Bcl-XL; blocking the activity of these proteins may contribute to the sensitization of tumor cells and allow the adequate effects of chemotherapeutic drugs. Methods and results: This study adressed the transfection of prostate cancer cells (PC3) with a plasmid encoding a recombinant protein with an antagonist peptide from the BH3 region of the Bax protein fused to the GFP reporter protein (BaxGFP). This protein induced apoptosis of these tumor cells; further, selective transport of this plasmid to the tumor cell with Salmonella enterica serovar Typhimurium (strain SL3261), a live-attenuated bacterial vector, can induce sensitization of the tumor cell to the action of drugs such as cisplatin, through a process known as bactofection. Conclusions: These results suggest that Salmonella enterica can be used as a carrier vector of nucleotide sequences encoding heterologous molecules used in antitumor therapy.

Resumen: Introducción: La resistencia a los agentes quimioterapéuticos por parte de las células tumorales es uno de los principales problemas para la erradicación de distintas neoplasias. Uno de los mecanismos involucrados en este proceso es la sobreexpresión de proteínas antiapoptóticas como Bcl-2 y Bcl-XL. El bloquear la actividad de estas proteínas puede contribuir a la sensibilización de las células tumorales, permitiendo que los fármacos quimioterapeúticos funcionen de forma adecuada. Métodos y resultados: En este trabajo se llevó a cabo la transfección de células de cáncer de próstata (PC3) por un plásmido que codifica para una proteína recombinante que contiene un péptido antagónico perteneciente a la región BH3 de la proteína Bax fusionada a la proteína reportera GFP (BaxGFP). Esta proteína fue capaz de inducir apoptosis en las células PC3. El transporte selectivo de este plásmido hacia la célula tumoral empleando Salmonella enterica serovar Typhimurium cepa SL3261, un vector bacteriano vivo atenuado, permitió la sensibilización de la célula tumoral a la acción de fármacos como el cisplatino mediante un proceso denominado bactofección. Conclusiones: Estos resultados sugieren que Salmonella enterica puede emplearse como un vector acarreador de secuencias nucleotídicas que codifican para moléculas heterólogas empleadas en la terapia antitumoral.