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Abstract: Colorectal cancer (CRC) is the third most prevalent malignant neoplasm in the world. CRC is influenced by both environmental and genetic factors. Through toxin-mediated DNA damage and the promotion of persistent dysregulated inflammation, the gut microbiota plays a crucial role in the development of CRC. In this review, we discussed the correlation between the bacterial microbiota and CRC carcinogenesis as well as the mechanism by which Streptococcus bovis/gallolyticus, Fusobacterium nucleatum, Bacteroides fragilis, and Escherichia coli can cause CRC.

This study evaluated the antimicrobial efficacy of grape seed extract medicament combined with Nd:YAG laser, against Enterococcus faecalis, Staphylococcus aureus and Candida albicans biofilms. Root canals infected with 4-week-old biofilms were divided into five groups (n = 11): calcium hydroxide, 6.5% GSE, Nd:YAG laser (1064 nm, 1.5 w, 15 Hz and 100 mj) and 6.5% GSE followed by Nd:YAG laser and normal saline (control). Dentin chips were collected using Gates-Glidden and cultured to obtain colony-forming units. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U test. GSE showed higher antibacterial activity against all species investigated compared to Ca(OH)

Background: Self-curing acrylic resins, mainly composed of Polymethyl Methacrylate (PMMA), are widely used to manufacture removable orthodontic appliances. Self-curing acrylic resins have higher porosity than heat-curing acrylic resins leading to a susceptible place for microbial plaque colonization. Due to some of these microorganisms' activities, a very unpleasant odor is emitted from orthodontic base plates, which has adverse effects on patients' cooperation. This study aimed to investigate the antimicrobial properties of cold-curing PMMA acrylic resin containing ZnO nanoparticles supported in 4A zeolite and evaluating its mechanical properties. Methods: The synthesized nanocomposite ZnO/4A zeolite was added to SR Triplex® Cold orthodontic self-curing acrylic resin powder with 2wt% and 4wt% concentrations. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), energy dispersive X-ray (EDX), MAP analysis, and Dynamic light scattering (DLS) were performed to investigate the sample's characteristics. Direct test method was used to assess the antibacterial properties of the fabricated acrylic samples against three bacterial strains Streptococcus mutans, Klebsiella Pnemoniae, and Esherichia coli. Flexural strength was evaluated by a three-point bending test, and One-way ANOVA and Tukey's post hoc test were used for statistical evaluation of data. The p-value of less than 0.05 was considered significant. Results: The addition of ZnO/4A in 2wt% and 4 wt% concentrations lead to more than 99% destruction of colonies in all three types of microorganisms. The mean flexural strength of acrylic specimens containing 2wt% and 4wt% of ZnO/4A significantly lower than the control group. Despite the considerable reduction, all mean values are greater than 50 MPa. Conclusion: The ZnO/4A zeolite nanocomposite due to its potent antibacterial properties and minimal toxicity can reduce the unfavorable odor of orthodontic base plates consequently increases patient cooperation and reaching the desired result. Method: The synthesized nanocomposite ZnO/4A zeolite was added to SR Triplex® Cold orthodontic self-curing acrylic resin powder with 2wt% and 4wt% concentrations. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy(FE-SEM), energy dispersive X-ray (EDX), MAP analysis, and Dynamic light scattering (DLS) were performed to investigate the sample's characteristics. Direct test method was used to assess the antibacterial properties of the fabricated acrylic samples against three bacterial strains Streptococcus mutans, Klebsiella Pnemoniae, and Esherichia coli. Flexural strength was evaluated by a three-point bending test, and One-way ANOVA and Tukey's post hoc test were used for statistical evaluation of data. The p-value of less than 0.05 was considered significant. Results: The addition of ZnO/4A in 2wt% and 4 wt% concentrations lead to more than 99% destruction of colonies in all three types of microorganisms. The mean flexural strength of acrylic specimens containing 2wt% and 4wt% of ZnO/4A significantly lower than the control group. Despite the considerable reduction, all mean values are greater than 50 MPa. Conclusion: The addition of ZnO/4A zeolite nanocomposite due to its potent antibacterial properties and minimal toxicity can reduce the unfavorable odor of orthodontic base plates consequently increases patient cooperation and reaching the desired result.

Background Carbapenem-resistant Enterobacteriaceae (CRE) is a major concern leading to morbidity and mortality in the world. CRE often is becoming a cause of therapeutic failure in both hospital and community-acquired infections. Aim This study aimed to investigate the resistance mechanisms of CRE by phenotypic and molecular methods. Materials and methods Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Antimicrobial susceptibility testing was carried out using phenotypic methods. The carbapenem resistance mechanisms including efflux pump hyperexpression, AmpC overproduction, carbapenemase genes, and deficiency in OmpK35 and OmpK36 were determined by phenotypic and molecular methods, respectively. Results Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Amikacin was found to be the most effective drug against CRE isolates. All isolates were resistant to imipenem and meropenem by the micro-broth dilution. AmpC overproduction was observed in all Enterobacter spp. and three K. pneumoniae isolates. No efflux pump activity was found. Carba NP test and Modified Hodge Test could find carbapenemase in 59 (98%) isolates and 57 (95%) isolates, respectively. The most common carbapenemase gene was bla OXA-48-like (72.8%) followed by bla NDM (50.8%), bla IMP (18.6%), bla VIM (11.8%), and bla KPC (6.7%). The ompK35 and ompK36 genes were not detected in 10 and 7 K. pneumoniae isolates, respectively. Conclusion The amikacin is considered as a very efficient antibiotic for the treatment of CRE isolates in our region. Carbapenemase production and overproduction of AmpC are the main carbapenem resistance mechanisms in CRE isolates. Finally, Carba NP test is a rapid and reliable test for early detection of carbapenemase-producing isolates.

Klebsiella pneumoniae complex (KPC) accounts for approximately one-third of all Gram-negative infections. Moreover, it is highly resistant and can taxonomically be distributed into KpI, KpII, and KpIII phylogroups. This study aimed to investigate the distribution of phylogenetic groups and the relationship between them and antibiotic resistance patterns. For this purpose, we collected KPC isolates from Tabriz, Iran, between 2018 and 2020. Antimicrobial susceptibility testing was performed by disk diffusion agar, and phylogenetic groups were then examined using gyrA restriction fragment length polymorphism (RFLP) and parC PCR methods. A total of 100 KPC isolates were obtained from the clinical specimens (urine, respiratory secretion, blood, wounds, and trachea). The enrolled patients included 47 men and 53 women aged from 1 to 91 years old. The highest sensitivity was found related to fosfomycin as 85%, followed by amikacin as 66%. The three phylogenetically groups by the RFLP-PCR method were found in KPC, 96% (96 isolates) as KpI, 3% (3 isolates) as KpII, and 1% (1isolate) as KpIII. The highest antibiotic resistance was observed in KpI. It was shown that a valid identification of three phylogenetic groups of KPC can be done by combining both gyrA PCR-RFLP and parC PCR. Of note, the KpI group was also observed as the dominant phylogenetic group with the highest resistance to antibiotics.

BackgroundNowadays, a shift in age distribution and the increasing incidence of pertussis among adolescents and adults have been reported in the world. The aim of this study was to evaluate the prevalence, clinical characteristics, and seasonality of pertussis in Azerbaijan, Iran.MethodsA total of 3

Acinetobacter baumannii is known as the main pathogenic organisms, especially for the nosocomial infections. Multi-drug resistance and the presence of different virulence factors are recognized as causes of the organism's survival and the infection's risk. In this study, 70 Acinetobacter baumannii isolates were collected from three hospitals located in the Northwest of Iran. Antimicrobial susceptibility of these isolates was determined by agar dilution and disk diffusion methods. Production of gelatinase, proteolytic, and hemolytic activities of the isolates was also assessed. The frequencies of epsA, pld, ptk, luxR, luxI, and blaPER-1 genes were investigated by polymerase chain reaction (PCR). Furthermore, molecular typing of the isolates was performed using random amplified polymorphic DNA (RAPD-PCR). All the obtained isolates were multi drug resistant and 58.5% of them were extensively drug resistance. Six of the 70 study isolates were found to be resistant to all the tested antibiotics. Nine (12.8%) of the isolates were found to be resistant to colistin (MIC = 4 μg/mL). 38.5%, 45.7%, and 15.5% of the isolates were positive for gelatinase production, protease, and hemolysis, respectively. The frequency of the genes was as follows: pld 100%, epsA 91.9%, luxI 85.7%, ptk 80%, luxR 75.7% and blaPER-1 64.2%. Based on the RAPD patterns obtained, the 70 isolates in this study clustered into twelve major genotypes. In this study, the prevalence of blaPER-1 was worryingly high. On the other hand, a significant relationship was found between the presence of this gene and the production of some virulence factors in the strains.

Introduction: High-level aminoglycoside resistance due to methylase genes has been reported in several countries. The purpose of this study was to investigate the diversity of the genes encoding 16...

Introduction: Lactulose is a prebiotic with bifidogenic and urea reduction effects. It can improve Bifidobacteria and Lactobacilli counts in healthy humans and it may possibly have similar effects in chronic kidney disease (CKD) patients. Objectives: To investigate the effect of lactulose on fecal microflora of patients with CKD. Patients and Methods: Thirty-two patients with stages 3 and 4 of CKD (43.8% male with mean age of 58.09±12.75 years) were randomly assigned to intervention (n=16) and control (n=16) groups. Patients in intervention group received 30 mm lactulose syrup three times a day for an 8-week period. Control group received placebo 30 mm three times a day. A fecal sample was obtained from all patients at the beginning and at the end of the study and Bifidobacteria and Lactobacilli was counted. Results: Creatinine (Cr) significantly decreased in intervention group (3.90±1.43 to 3.60±1.44, P=0.003) and increased in control group (3.87±2.08 to 4.11±1.99, P=0.03). Although Bifidobacterial and Lactobacilli counts were similar before intervention, they were significantly higher at the end of the study in lactulose group (P=0.01 and P=0.04, respectively). Lactulose led to significant increase in fecal Bifidobacterial counts (3.61±0.54 to 4.90±0.96, P

The aims of this study were to investigate the antibiotics susceptibility, multidrug- resistant (MDR) frequency and the association of integrons with MDR among phylogenic groups of uropathogenic E. coli (UPEC). In total, 176 non-duplicated UPEC isolates were collected from urinary tract infections (UTIs) specimens. The disk diffusion method was performed for determination of antibiotic susceptibility patterns. Phylogenetic grouping and the presence of integron-associated genes (int) were detected by the PCR technique. A high frequency of resistance was observed to cotrimoxazole (96.9%), ampicillin (85%), trimethoprim (80.1%) and cefazolin (79.6%); and 140 isolates (79.5%) were MDR. Carbapenems and fosfomycin were the most effective antibiotics. The majority of isolates (60.8%) belonged to the phylogenic group B2. Integrons were detected in 135 (76.7%) of isolates and, class I was the most common (63.6%) class. MDR isolates were found to be significantly associated with class І integrons. These isolates were found to be closely associated with the phylogenic group D (82%), however, the presence of class І integrons was higher among MDR isolates of the phylogroup B1. This pattern is believed to be due to other mechanisms such as the overexpression of the efflux pumps. Our findings show a significant correlation between MDR and the presence of class І integron. We conclude that class 1 integron plays an important role in the development of MDR UPEC, especially among the phylogroup B1.

Enzymatic inactivation is one of the most important mechanisms of resistance to aminoglycosides. The aim of this study was to investigate the prevalence of armA and diversity of the genes encoding aminoglycoside-modifying enzymes (AMEs) and their associations with resistance phenotypes in Enterobacteriaceae isolates.Three hundred and seven Enterobacteriaceae isolates were collected from five hospitals in northwest Iran. The disk diffusion method for amikacin, gentamicin, tobramycin, kanamycin, and streptomycin, as well as the minimum inhibitory concentration for amikacin, gentamicin, tobramycin, and kanamycin were done for susceptibility testing. Thirteen AME genes and armA methylase were screened using the PCR and sequencing assays.Two hundred and twenty (71.7%) of isolates were resistant to aminoglycosides and 155 (70.5%) of them were positive for aminoglycoside resistance genes. The most prevalent AME genes were ant(3″)-Ia and aph(3″)-Ib with the frequency 35.9% and 30.5%, respectively. Also, 21 (9.5%) of resistant isolates were positive for armA methylase gene.The prevalence of resistance to aminoglycoside is high and AME genes frequently are disseminated in Enterobacteriaceae isolates. There is an association between phenotypic resistance and the presence of some aminoglycoside genes.

Due to the increasing prevalence of infections caused by resistant bacteria and especially multiple drug resistance Enterobacteriaceae, availability of alternative effective antibiotics is restricted. The goal of this study was to investigate the susceptibility profile of multiple drug resistance and extensively drug resistance Enterobacteriaceae isolated from various clinical samples to fosfomycin. A total of 303 non-duplicate Enterobacteriaceae isolates were collected. Identification and susceptibility testing were done according to standard microbiological procedures and the Kirby-Bauer test, respectively. Of all isolates, 272 (89.8%) and 26 (8.6%) were detected as multiple drug resistance and extensively drug resistance strains, respectively. The most effective antibiotic (98%) was fosfomycin, when compared with other antibiotics against multiple drug resistance and extensively drug resistance Enterobacteriaceae isolates. In this study, we find high levels of resistance to commonly used antibiotics. However, fosfomycin can be a good option for treating multiple drug resistance Enterobacteriaceae.

Acute bacterial meningitis (ABM) is one of the most severe infectious diseases, causing neurologic sequel, and a case fatality rate of 20-30%. The aim of this paper was to summarize the main causes of ABM in Iran. We searched the data for relevant articles using meningitis, etiology, and Iran as search terms. We found 23 papers for inclusion in the review that focused specifically on the ABM, addressing etiology and acute meningitis. Finally, during the 23 years, a total of 18163 cases were recorded, and 1074 cases of which met the criteria for bacterial meningitis. The most common agent associated with bacterial meningitis was S. pneumoniae, followed by H. influenzae, Enterobacter spp., N. meningitidis, and group B streptococcus. The total incidence of ABM during 1991 to 2002 was higher than during 2003-2013. S. pneumoniae still remains a main cause of bacterial meningitis. For improved outcomes, studies are needed to further clarify the etiology of meningitis in Iran, explore simple, accurate, and practical diagnostic tools as PCR, and investigate the most appropriate specific and supportive interventions to manage and prevent meningitis as vaccination.