Leila Fozouni, Maryam Yaghoobpour, Ania Ahani Azari,
Volume 7, Issue 2 (7-2019)
Abstract
Background and objectives: Acinetobacter is a genus of opportunistic pathogens that are commonly found in the environment. Given the unique ability of these bacteria to survive in the hospital, they are considered as one of the main causes of hospital-acquired infections. The emergence of multidrug-resistant Acinetobacter spp., particularly Acinetobacter baumannii has become a major health threat worldwide. In this study, we investigate antibacterial effects of probiotic isolates from goat milk on clinical isolates of A. baumannii.
Methods: In this study, 100 clinical specimens were taken from patients hospitalized in six hospitals in the Golestan Province, north of Iran. Following isolation and identification of A. baumannii strains, antibiotic resistance patterns of the isolates were investigated using the Kirby-Bauer method according to the Clinical and Laboratory Standards Institute (CLSI-2015) guidelines. Probiotic bacteria in goat milk were isolated and identified by culture in MRS and M17 media and carbohydrate fermentation tests. Antibacterial effects of the probiotic bacteria against resistant A. baumannii isolates were evaluated using the agar well diffusion method.
Results: Overall, 55% of the isolates were identified as A. baumannii. The highest resistance rates were observed against tobramycin (76.3%), mezlocillin (74.5%) and cefotaxime (74.5%). Resistance to levofloxacin, tetracycline, imipenem and minocycline was detected in 72.7%, 72.7%, 70.9% and 29.1% of the isolates, respectively. The most common probiotic isolates were Lactobacillus plantarum and Lactococcus piscium (30% each). The highest and lowest effects were exerted by Lactococcus lactis (34.54%) and Lactobacillus bulgaricus (3.63%), respectively.
Conclusion: Our results demonstrate that the prevalence of drug-resistant A. baumannii strains is high in the hospitals. Given the promising antimicrobial effects of the isolated probiotic bacteria, goat milk can be recommended as an adjuvant therapy or an alternative to common antibiotics for improving treatment outcome of infections caused by drug-resistant A. baumannii.
Vahideh Faghani Zadeh, Nazila Arbab Soleimani, Ayyoob Khosravi, Mohammad Mahdi Forghanifard,
Volume 10, Issue 4 (12-2022)
Abstract
Background and Objectives: Oral cancer relates to oral and intestinal microbiota composition. Lactobacillus species are considered probiotic bacteria due to their ability to modulate human immune responses and therapeutic effects. This study aimed to investigate the effects of Lactobacillus plantarum (L. plantarum) on TLR4 gene expression and its downstream pathways in a mouse model of oral cancer.
Material and Methods: This experimental study was conducted in the Stem Cell Research Center, Faculty of Modern Technologies, Golestan University of Medical Sciences, Gorgan, Iran, in 2021. L. plantarum strain ATCC 8014 was used in this study. Twenty-eight male Wistar rats were divided into four groups (n = 7). 4-Nitroquinoline 1-oxide (4NQO) was used to establish oral cancer in rats. A pathological examination was adopted to confirm cancer establishment. Rats were treated with probiotic L. plantarum before and after cancer development. After extracting RNA from blood and synthesizing cDNA, the ability of lactobacilli to modulate the expression of TLR4 genes was investigated by Real-Time PCR Methods (RT-PCR).
Results: In the present study, it was observed that after causing cancer and treating the animal with L. plantarum, the expression of the TLR4 gene decreased significantly (P-value < 0.05), which might, in turn, affect the downstream pathways, which included the decrease in the expression of BCL-2 and NF-ĸB genes. Accordingly, the expression of the NF-ĸB gene was significantly reduced in rats received L. plantarumgavaged for two weeks after cancer induction.
Conclusion: According to the obtained results, probiotic L. plantarum significantly affects the gene expression of NF-ĸB and TLR4 in cancerous rats. It was also shown that L. plantarum was more efficient in reducing TLR-4 and NF-ĸB genes expression when it was gavaged for 14 days after tumor induction.
