Anticancer Potential of Postbiotic Derived from Lactobacillus brevis and Lactobacillus casei: In vitro Analysis of Breast Cancer Cell Line

Breast cancer has emerged as the most widespread and dangerous type of malignancy among women worldwide. Postbiotics have recently emerged as a promising novel adjunct in breast cancer therapy, due to their immunomodulatory effects and the potential to mitigate the adverse effects of conventional treatments. This study aims to investigate the therapeutic effects of postbiotics derived from Lactobacillus brevis (CSF2) and Lactobacillus casei (CFS5), specifically examining their ability to inhibit cell proliferation and induce apoptosis in MCF-7 breast cancer cells. In the current study, the anticancer activity of the cell-free supernatant of L. brevis and L. casei was investigated against MCF-7 cells using MTT assay, flow cytometry, and qRT-PCR technique. Both bacteria showed a high potential for the induction of cell death in MCF-7 cells. However, CFS2 cytotoxicity was significantly higher than CFS5. Flow cytometry results showed significant induction of early apoptosis in cells treated with both CFS2 and CFS5 within 48 h. The induction was notably higher in cells treated with CFS2 compared to CFS5. Overall, CFS2 therapy resulted in a greater increase in BAX and CASP9 gene expression, as well as an elevated BAX/BCL2 ratio within 48 h. These findings indicate that the CFS2 treatment showed a higher level of apoptotic activity than the CFS5 treatment. High biocompatibility was demonstrated following treatment with CFS2 and CFS5. These CFSs may serve as adjunctive medications for suppressing the proliferation of cancer cells. The results of the current study highlight the potential of postbiotics in cancer treatment and suggest that supernatants may serve as effective agents for suppressing cancer cell growth and viability.

Design of a chimeric protein composed of FimH, FyuA and CNF-1 virulence factors from uropathogenic Escherichia coli and evaluation its biological activity and immunogenicity in vitro and in vivo

Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC) are among the most prevalent bacterial infections in humans. Antibiotic resistance among UPEC isolates is increasing, and designing an effective vaccine can prevent or reduce these infections. FimH adhesin, iron scavenger receptor FyuA, and cytotoxic necrotizing factor -1 (CNF-1) are among the most important virulence factors of UPEC strains. Thus, a novel multi-epitope protein composed of FimH, FyuA, and CNF-1 was designed to evaluate its biological activity and immunogenicity in vitro and in vivo, respectively. The final vaccine design had seven domains, including the N-terminal domain of FimH, four domains of FyuA, and two domains of CNF-1, as determined by immunoinformatics analysis. The results of tertiary structure prediction showed that the chimeric protein had a C-score of -0.25 and Z-score of -1.94. Molecular docking indicated that thirty six ligand residues of the chimeric protein interacted with 53 receptor residues of TLR-4 by hydrogen bonds and hydrophobic interactions. Analysis of protein expression by SDS-PAGE showed an approximately 44 kDa band with different concentrations of IPTG which were confirmed by Western blot. According to ELISA results, the level of IL-8 produced by stimulated Ht29 cells with the chimeric protein was significantly higher than the stimulated Ht29 cells with CNF-1 alone and un-stimulated Ht29 cells. Rabbits subcutaneously immunized with the chimeric protein admixed with Freund adjuvant induced higher level of serum IgG on day 14 after the first vaccination than control rabbits. Furthermore, the booster dose of the chimeric protein significantly enhanced the IgG levels as compared to day 14 and also controls. As, the chimeric protein has suitable B-cell epitopes and MHC-I and MHC-II binding epitopes to stimulate humoral and cellular immunity, it could be a promising vaccine candidate against UTIs caused by UPEC. Evaluating the multi-epitope protein in inducing humoral and cellular immune responses, as well as protection, is ongoing in the mice models.

Antibacterial Activity and Toxicity of Zinc Oxide Nanoparticles Combined with Supernatants of Lactobacillus spp. Against ESKAPE Bacteria: A Novel Mixture

Background

The emergence of multidrug resistance among nosocomial pathogens has prompted researchers to look for new antibacterial sources. Metal nanoparticles and probiotic products have attracted the attention of researchers. However, combination therapy is an attractive alternative in this field.

Objectives

This study evaluated the antibacterial activity and toxicity of Zinc Oxide nanoparticles (ZnO-NPs) combined with cell-free supernatant (CFS) of Lactobacillus plantarum and Lactobacillus acidophilus alone and in a novel mixture.

Methods

Antibacterial effects and cytotoxic properties of ZnO-NPs, CFS of L. plantarum (SLP), and CFS of L. acidophilus (SLA) were determined alone and in a mixture against ESKAPE strains. In addition, the viability percentage of the cells was evaluated after exposure to these agents.

Results

Antibacterial mixtures (ZnO-NPs with SLP or ZnO-NPs with SLA) demonstrated synergistic and additive effects against Pseudomonas aeruginosa (FIC≤0.75), Acinetobacter baumannii (FIC = 1), and Escherichia coli (FIC≤0.75). The viability percentage of the cells after 24 h of exposure to a mixture of ZnO-NPs and SLA (about 50%) was more than when the cells were exposed to ZnO-NPs alone (about 30%) at the same concentration.

Conclusions

A mixture of ZnO-NPs and CFS of probiotics can be an alternative to antibiotics, with more effectiveness and fewer side effects.

Clinical Effects of Chlorhexidine 0.2% and Cetylpyridinium 0.05% Combination in Comparison with Chlorhexidine, Cetylpyridinium and Persica in Reducing Oral Bacteria in Healthy Individuals

Background:  Preparation of a new product with the goal of reducing chlorhexidine’s side effects without decreasing (and even increasing) its effectiveness is a desirable goal for researchers in the field of oral hygiene. The aim of this study was to evaluate the efficacy of Chlorhexidine 0.2% and Cetylpyridinium 0.05% combination in reducing oral bacteria in comparison with Chlorhexidine 0.2%, Cetylpyridinium 0.05% and Persica mouthwashes. Methods: 100 healthy volunteers aged between 18 and 30 years were randomly assigned to 5 groups. The first group received Chlorhexidine 0.2%, the second group received Cetylpyridinium 0.05%, the third received Persica, the fourth received Chlorhexidine 0.2% plus Cetylpyridinium 0.05%, and the fifth group received Chlorhexidine 0.05% plus Cetylpyridinium 0.05%. Samples were obtained at baseline and thirty minutes after oral rinsing with the mouthwashes. The number of colony-forming units (CFU/mL) before and after mouthwash administration was compared for each sample.                                                                                                                          Results: The preparation with the most bacterial count reduction was found to be Chlorhexidine 0.2% and Cetylpyridinium 0.05% combination. However, the difference between efficacy of Chlorhexidine 0.2% plus Cetylpyridinium 0.05% and Chlorhexidine 0.05% plus Cetylpyridinium 0.05% was found not to be statistically significant.                                                              Conclusions: A new mouthwash preparation including chlorhexidine 0.05% and cetylpyridinium 0.05 % combination is the most desirable due to the increased efficacy and fewer side effects.

Multilocus sequence typing analysis of Leishmania clinical isolates from cutaneous leishmaniasis patients of Iran

Cutaneous leishmaniasis (CL) is mainly caused by L. major and L. tropica in Old World and might be represented as typical skin lesion(s) or sometimes as a spectrum of atypical manifestations. We applied multilocus sequence typing (MLST) to explore genetic variations of Leishmania strains isolated from atypical vs. typical CL patients from Iran. A PCR-sequencing was performed for seven housekeeping genes (g6pd, mpi, asat, icd, 6pgd, fh, and trys) and genetic diversity indices and phylogenetic relationships were analyzed. A total of 41 isolates of L. major (28/41) and L. tropica (13/41) from 21 (51.2%) atypical CL and 20 (48.8%) typical CL cases were included. A set of additional sequences of 41 strains of 17 species of Leishmania were retrieved from databases. Different SNP variations were detected and the highest rate of heterozygous sites was found in g6pd and 6pgd genes (6 sites) for L. tropica and in asat and 6pgd genes (7 sites) for L. major strains. All strains were clustered into 58 unique sequence types (STs) including 17 STs related to 41 strains of Leishmania of this study. Concatenated tree clustered all strains in 6 main clades (A to F) including L. major (clade D) and L. tropica (clade B) strains. Two strains of L. major (codes 28 and 42) with highest nucleotide variations were more close to L. tropica and were grouped in Clade B. All of the STs were related in clonal complexes by using eBURST with the prediction of founder genotypes. A high rate of genetic variations and heterozygocity was evident in L. tropica and L. major strains; nevertheless, there was no significant difference in the diversity of Leishmania strains between typical CL and atypical CL groups. This study represents the first successful application of MLST approach to L. tropica and L. major strains in Iran.

Evaluating the clinical significance of nontuberculous mycobacteria isolated from respiratory samples in Iran: an often overlooked disease

Purpose

Nontuberculous mycobacteria (NTM) infection is an increasing problem worldwide whose clinical significance is still largely unknown. The aim of this study was to investigate the epidemiology of NTM infection from respiratory samples and to determine their clinical significance.

Patients and methods

This cross-sectional study was performed on 7,825 clinical samples from December 2015 to December 2017. Detection was conducted using phenotypic and genotypic (hsp65 PCR-RFLP, rpoB, and 16S rRNA genes sequencing) methods. All clinical information including symptoms and radiological findings was extracted from patients’ records.

Results

A total of 478 were confirmed to have respiratory samples which were culture positive for mycobacteria, with the prevalence of NTM infection obtained as 53 (11.1%). Overall, Mycobacterium (M.) fortuitum was the most frequent NTM isolate, followed by M. simiae, M. kansasii, M. gordonae, and M. conceptionense. There was a relationship between NTM isolates and gender (P=0.039), symptoms (P=0.048), and radiographic findings (P=0.013). Bronchiectasis, infiltration, and cavitary lesion were the most frequent radiological findings in M. fortuitum, M. simiae, and M. kansasii, respectively, with cough being the most frequent symptom.

Conclusion

We reported five different NTM isolates in respiratory samples with a high frequency of M. fortuitum. NTM infections may play an important role in causing pulmonary disease and in tuberculosis management in endemic settings. Nevertheless, more studies are required to further examine the clinical significance of NTM isolates.

Simultaneous detection and differentiates of Brucella abortus and Brucella melitensis by combinatorial PCR

OBJECTIVE

To evaluate simultaneous detection and differentiates of Brucella abortus (B. abortus) and Brucella melitensis (B. melitensis) through the combinatorial PCR method.

METHODS

This study was designed using three primers that could simultaneously identify and differentiate two major species of pathogenic Brucella in humans and animals. Identification and differentiation of each species using the size of the PCR product were determined. To determine the specificity of the method, bacteria close to the genus Brucella were used. Finally, to confirm PCR products, In addition to the products sequence, RFLP was performed on PCR products using restriction enzymes.

RESULTS

The method of optimized combinatorial PCR in this study could simultaneously detect and differentiate B. abortus and B. melitensis with high specificity and sensitivity in clinical samples. Differentiation of species is based on the resulting bands; therefore, the band 494 bp for B. abortus and 733 bp for B. melitensis were obtained. RFLP and sequencing results confirmed PCR results.

CONCLUSIONS

The results of this study shows that without routine diagnostic methods such as culture and serology tests, using the molecular method of combinatorial PCR, important species of Brucella can be simultaneously identified and differentiated in clinical samples.