Iranian Journal of Microbiology最新文献

Background and objectives: The growing resistance of Helicobacter pylori to antibiotics poses significant challenges in managing gastric ulcers. The application of IgY antibodies against H. pylori is a promising strategy. The current study evaluated the preventive and synergistic effects of IgY antibodies in conjunction with pantoprazole for treating H. pylori infection.

Materials and methods: This investigation specifically focused on the inhibitory effects of IgY in the AGS cell line infected with H. pylori. In addition, the synergistic activity of IgY with pantoprazole and its preventive and therapeutic effects were assessed in male C57BL/6 mice.

Results: The findings indicated that IgY antibodies possess a substantial inhibitory effect on the adhesion of H. pylori to the AGS cell line. Furthermore, IgY antibodies resulted in a significant reduction (P<0.05) in the population of H. pylori and the severity of gastritis in infected C57BL/6 mice in both treatment and prevention groups. Notably, the optimal outcome was observed when IgY was administered alongside pantoprazole.

Conclusion: The use of IgY has the potential to repair damaged cells and prevent infection by decreasing bacterial adherence to gastric epithelial cells. Given its synergistic effect with pantoprazole, IgY can be recommended as a suitable complementary treatment in conjunction with pantoprazole.

Background and objectives: This study investigates the impact of Helicobacter pylori (H. pylori)-derived outer membrane vesicles (OMVs) on the regulation of Snail/β-Catenin cascade and the production of metastasis-related proteins, such as E-cadherin and Vimentin, in the 4T1 cell line.

Materials and methods: OMVs were purified from H. pylori (ATCC 700392) cultures and applied to 4T1 cells at concentrations of 1, 5, and 10 μg/mL, with untreated cells serving as controls. The MTT assay was employed to quantify cell viability. Expression profiles of +vimentin, Snail, α-SMA, and β-catenin genes were evaluated by qRT-PCR, while protein expression of E-cadherin and Vimentin was analyzed via immunohistochemistry. Data were analyzed using appropriate statistical methods with SPSS and GraphPad Prism software.

Results: The MTT assay showed that 1 μg/mL OMVs were safe for normal cells. At this concentration, the expression of vimentin, Snail, α-SMA, and β-catenin genes significantly increased in the treatment group (P≤0.05). Additionally, Vimentin protein decreased, and E-cadherin protein increased (P≤0.05).

Conclusion: H. pylori-derived OMVs activate the Snail/β-Catenin cascade, influencing inflammatory responses and metastasis-related proteins, ultimately reducing migration in advanced cancer stages by modulating Vimentin and E-cadherin expression.

Background and objectives: A unique characteristic of probiotics is obesity and fatty liver control. In this study, the effect of lactic-acid-bacteria (LABs) isolated from dairy products was investigated on weight changes, blood biochemical indexes and liver tissue in mice fed a high-fat diet.

Materials and methods: A total of 49 rats were assigned to 7 groups. The LAB-treated groups received the high-cholesterol diet supplemented with Lactobacillus reuteri, Lactobacillus plantarum, and Bifidobacterium animalis isolated from yogurt. At the end of 4 weeks, body weight changes, lipid factors and liver enzymes as well as liver lipid deposition and adipocyte size were measured.

Results: Serum low-density lipoprotein, total cholesterol, triglyceride levels and hepatic lipid deposition were significantly decreased in rats treated with LABs. The maximum and minimum weights were observed in the first and fourth weeks after treating with Lactobacillus and Bifidobacterium isolates, respectively. Liver enzymes were significantly decreased by LABs, especially in the group receiving concomitant administration of Lactobacillus and Bifidobacterium. Fatty liver process was reduced in the fat-fed group treated with L. reuteri.

Conclusion: LABs caused decreases in body weight gain, liver function, and adipocyte size. Therefore, coadministration of Lactobacillus and Bifidobacterium in dairy products can significantly decrease lipid profile.

Background and objectives: Probiotic yogurts enriched with Lactobacillus paracasei (L. paracasei), protein hydrolysates derived from Sargassum angustifolium macroalgae (SAPH), and encapsulated SAPH were formulated to inhibit Streptococcus mutans (S. mutans), the primary bacterium responsible for dental caries.

Materials and methods: The yogurt samples were evaluated for physicochemical, microbiological, and sensory characteristics.

Results: On day 21, the yogurt supplemented with L. paracasei demonstrated the greatest titratable acidity (97.35°D), the lowest pH value (4.24), reduced syneresis, and enhanced antioxidant, antihypertensive, and rheological properties. In terms of antibacterial activity, the lowest S. mutans count was detected in formulations containing free SAPH, either alone or in combination with L. paracasei. Conversely, yogurts formulated with encapsulated SAPH exhibited higher survival rates of both L. paracasei and S. mutans compared to those containing the free form of SAPH.

Conclusion: The findings indicated that although the probiotic yogurt containing free SAPH was more effective in reducing S. mutans levels within the yogurt matrix, the encapsulated form achieved an acceptable level of antibacterial activity while contributing to improved sensory acceptance.

Background and objectives: This research aimed to explore the genetic diversity and phylogenetic relationships of Mycobacterium tuberculosis (Mtb) strains, as well as to assess their drug susceptibility, specifically in strains isolated from immigrant patients attending the Referral Tuberculosis Laboratory in Mashhad.

Materials and methods: A total of 52 sputum samples isolated from patients were examined utilizing the Mycobacterial Interspersed Repetitive-Unit Variable Number of Tandem Repeats (MIRU-VNTR). Drug-susceptibility testing against rifampin (RIF) and isoniazid (INH) was measured utilizing the proportional strategy. Thereafter, for more examination, Xpert MTB/RIF and multiplex allele-specific PCR (MAS-PCR) was performed to determine RIF and INH-resistance within the Mtb strains.

Results: Among 52 Mtb isolates, 2 (3.8%) were resistant to rifampin and one isolate was resistant to both INH and RIF and considered as multidrug-resistance (MDR) isolate. According to MIRU-VNTR, the most prominent genetic-variation patterns of these samples, were related to NEW-1 (n=18, 34.6%), followed by CAS/Delhi (n=17, 32.7%), Haarlem (n=12, 23%), Uganda I (n=2, 3.8%), S (n=1, 1.9%), Beijing (n=1, 1.9%), and unknown (n=1, 1.9%) genotypes. The statistical analysis showed that the estimated percentage of the recent TB-transmission in this study was 0.21%.

Conclusion: The result of this study indicated a great diversity of MTBC circulating among Afghan-immigrants which might be one of the reasons for the infection to become active. The relatively high percentage of resistant isolates in the studied population shows the importance of screening the immigrants especially at the entry borders and treatment and follow up of patients, to control TB-incidence in country.

Background and objectives: Viral membrane glycoproteins are essential for host cell recognition, membrane fusion and immune evasion, making them critical targets for antiviral therapies and vaccine development. However, their isolation in native conformation is challenging due to structural complexity and limitations of conventional purification methods. The aim of current study was to develop a cost-effective, reproducible method for the isolation and purification of glycoprotein B (gB) from Herpes Simplex Virus type 1 (HSV-1) while maintaining its native conformation for functional and interaction studies.

Materials and methods: HSV-1 particles were concentrated via ultracentrifugation and membrane proteins were extracted using a modified protocol of the Mem-PER™ Plus Membrane Protein Extraction Kit. Native PAGE with a 4-8% gradient gel was employed to isolate multimeric gB (~300 kDa), followed by electroelution to extract the protein from the gel. The purity and integrity of gB were validated using SDS-PAGE and Western blot analysis.

Results: The method successfully isolated glycoprotein B in its native multimeric form with high purity and adequate concentration (0.157 mg/mL). The pH of the native gel (8.3) and the high molecular weight of gB facilitated separation from other viral surface proteins. SDS-PAGE and Western blot confirmed the specificity and structural integrity of the purified protein.

Conclusion: This study introduces a cost-effective and reliable method for isolating viral glycoproteins in their native conformation. The approach offers significant advantages over traditional chromatography-based techniques, making it ideal for research-scale applications, including functional and interaction studies.

Background and objectives: Crystalluria refers to the occurrence of crystals in urine resulting from urinary supersaturation, which disrupts the balance between factors that promote and those that inhibit crystal formation in urine. This study aimed to assess the prevalence of crystalluria, identify crystal types, determine associated comorbidities, and assess links with bacterial urinary tract infections in outpatients at Hassan II Hospital in Settat.

Materials and methods: A retrospective study was conducted from January 2022 to May 2023 at Hassan II Hospital. Urine samples from patients suspected of urinary tract infections, who underwent cytobacteriological urine examinations, were analyzed.

Results: Among 1,025 urine samples, 22.04% showed crystalluria. The mean age of patients was 51.3 with a standard deviation of 18.1 years. The most common crystal types were calcium oxalate (46.4%), uric acid (23.5%), urates (15.1%) and struvite (9.3%). Comorbidities including, diabetes, kidney failure, prostatitis, and nephrotic syndrome was associated with urinary crystal formation. The prevalence of urinary tract infections in patients with urinary crystals was 10.6%. Struvite crystals were specifically associated with bacterial infections, especially with Proteus mirabilis, Escherichia coli, Citrobacter freundii, Citrobacter koseri, and Enterobacter cloacae.

Conclusion: Monitoring urinary crystals is essential for preventing the formation of kidney calculi and crystal-associated infections, especially in high-risk individuals.

Background and objectives: Dyspepsia is a disorder characterized by difficulty in digestion and represents a major health concern. Therefore, it is crucial to identify functional dyspepsia linked to Helicobacter pylori (H. pylori). This research aimed to determine the prevalence of H. pylori among patients with dyspepsia and to examine the potential risk factors associated with the infection.

Materials and methods: From August 14^th to September 21^st, 2024, a total of 105 patients with dyspepsia, who attended the Central Laboratory of Baghdad Medical City Complex (Iraq), were enrolled in this study. Data on nonsteroidal anti-inflammatory drugs (NSAIDs), smoking, family history, fasting habits and frequent fast food consumption were collected through participant interviews.

Results: Based on the urea breath test results, dyspeptic patients were categorized into infected (63.8%) and non-infected (36.2%) groups. Factors that influenced these patients included the intake of NSAIDs (48.6%), smoking (21.9%), family history (29.5%), fasting habits (36.2%) and regular consumption of fast food (57.1%).

Conclusion: Dyspeptic patients exhibit a high prevalence of H. pylori infection, indicating the significant impact of H. pylori on this population. However, the intake of NSAIDs, smoking, family history, fasting habits and regular fast food consumption have no significant effects on the presence of H. pylori.

Background and objectives: Staphylococcus aureus (S. aureus) is a pathogenic bacterium whose virulence is attributed to its extracellular compounds and biofilm-forming ability. This study aimed to evaluate the inhibitory effects of the methanolic extract (AGME) and the essential oil (AGEO) of Anvillea garcinii on the growth and the biofilm formation of S. aureus.

Materials and methods: The antibacterial and antibiofilm activities of AGME and AGEO against S. aureus ATCC 6538 were assessed using the microbroth dilution method and the Crystal Violet Staining Assay, respectively. The expression levels of sarA, spa, and icaA, genes involved in biofilm formation, were analyzed using real-time PCR.

Results: AGME and AGEO inhibited S. aureus growth at minimum inhibitory concentrations (MIC) of 1 mg/ml and 0.6 mg/ml, respectively. AGME exhibited a 72% inhibition of biofilm formation at ¼ MIC, whereas AGEO showed no significant antibiofilm activity. AGME downregulated the expression of sarA, a key regulator of biofilm formation, as well as spa, and icaA genes.

Conclusion: This study demonstrated that A. garcinii essential oil (AGEO) exhibits significant antimicrobial activity, while its methanolic extract (AGME) effectively inhibits biofilm formation in S. aureus. These findings suggest the potential application of AGEO and AGME as antimicrobial and antibiofilm agents. Further investigations on their efficacy against other bacterial pathogens are recommended.

Background and objectives: Bacteriocins are interested as antibacterial and anticancer agents due to their high specificity and low side effects. This study aimed to isolate bacteria which produce bacteriocins of the lacticin family from whey and to investigate their antibacterial and anticancer effects.

Materials and methods: Lactic acid bacteria were isolated from different whey samples. The presence of the lacticin gene in the isolates was checked using PCR and then the inhibitory effects of their bacteriocin was investigated on Staphylococcus aureus utilizing well plate method. The protein content was separated by dialysis. The presence of lacticin was checked with the help of SDS-PAGE. The lacticin producing bacterium was identified through the sequencing of the 16S rRNA gene. Finally, the cytotoxicity of the obtained protein was studied on the MCF-7 breast cancer cells using MTT and scratching tests.

Results: The isolated lacticin-producing Lactococcus lactis was able to grow in acidic conditions (pH = 2.5 for 3 h) and in bile salts (0.3% for 24 h). The bacterium produced 4.2 μg/μl bacteriocin with a molecular weight of 3.1 KD. The lacticin showed antibacterial effect against S. aureus. The cancerous cells treated with lacticin had slower growth than the control in Scratch test. Based on the MTT results, more than 80% of cancerous cells were inhibited at a concentration of 7 μg/ml lacticin with IC = 5.2 μg/ml.

Conclusion: The bacteriocin produced in this study is a promising antibacterial and anticancer agent.