Role of CRISPR-cas system on virulence traits and carbapenem resistance in clinical Klebsiella pneumoniae isolates.

Background And Objectives: The bacterial adaptive immune system known as CRISPR-Cas (clustered regularly interspersed short palindromic repeats-CRISPR-associated protein) is engaged in defense against various mobile genetic elements (MGEs) such as plasmids and bacteriophages. The purpose of this study was to characterize the CRISPR-Cas systems in carbapenem-resistant Klebsiella pneumoniae isolates and assess any possible correlation between these systems with antibiotic susceptibility, biofilm formation, and bacterial virulence.

Materials And Methods: A total of 156 CRKP isolates were collected from different specimens of the inpatients.

Role of CRISPR-Cas systems and anti-CRISPR proteins in bacterial antibiotic resistance.

The emergence and development of antibiotic resistance in bacteria is a serious threat to global public health. Antibiotic resistance genes (ARGs) are often located on mobile genetic elements (MGEs). They can be transferred among bacteria by horizontal gene transfer (HGT), leading to the spread of drug-resistant strains and antibiotic treatment failure.

Prevalence of the CRISPR-cas system and its association with antibiotic resistance in clinical Klebsiella pneumoniae isolates.

Background And Objective(s): CRISPR-Cas is a prokaryotic adaptive immune system that protects bacteria and archaea against mobile genetic elements (MGEs) such as bacteriophages plasmids, and transposons. In this study, we aimed to assess the prevalence of the CRISPR-Cas systems and their association with antibiotic resistance in one of the most challenging bacterial pathogens, Klebsiella pneumoniae.

Materials And Methods: A total of 105 K.

CRISPR-like sequences association with antibiotic resistance and biofilm formation in clinical isolates.

Role of clustered regularly interspaced short palindromic repeats (CRISPR)-like sequences in antibiotic resistance and biofilm formation isn't clear. This study investigated association of CRISPR-like sequences with antibiotic resistance and biofilm formation in isolates. Thirty-six of isolates were studied for existence of CRISPR-like sequences using PCR method and their correlation with biofilm formation and antibiotic resistance.

Comparing proteome changes involved in biofilm formation by Streptococcus mutans after exposure to sucrose and starch.

Streptococcus mutans is a main organism of tooth infections including tooth decay and periodontitis. The aim of this study was to assess the influence of sucrose and starch on biofilm formation and proteome profile of S. mutans ATCC 35668 strain.

Dysregulation of lncRNA in -Infected Gastric Cancer Cells.

() infection is the most common cause of gastric cancer (GC). This microorganism is genetically diverse; GC is caused by several genetic deregulations in addition to environmental factors and bacterial virulence factors. lncRNAs (long noncoding RNAs) are significant biological macromolecules in GC, have specific functions in diseases, and could be therapeutic targets.

Role of CRISPR-Cas system on antibiotic resistance patterns of Enterococcus faecalis.

Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems are one of the factors which can contribute to limiting the development and evolution of antibiotic resistance in bacteria. There are three genomic loci of CRISPR-Cas in Enterococcus faecalis. In this study, we aimed to assess correlation of the CRISPR-Cas system distribution with the acquisition of antibiotic resistance among E.

Induction of proteome changes involved in biofilm formation of Enterococcus faecalis in response to gentamicin.

Background: Enterococcus faecalis is a significant cause of nosocomial infections and other diseases, including endocarditis, bacteremia, and urinary tract infections. This microorganism forms biofilms to overcome difficult environmental conditions, such as lack of oxygen, lack of water, and the presence of antimicrobials. These biofilms make diseases difficult by changing their proteome contents, protecting the bacterium, and increasing their pathogenicity.

CRISPR- system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of .

is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of .

Serotyping of and Its Relation with Capsule-Associated Virulence Genes, Antimicrobial Resistance Pattern, and Clinical Infections: A Descriptive Study in Medical Practice.

Objective: , one of the clinical superbugs, causes diverse infections because of its variable capsular antigens. This study focused on and aimed to assess any correlation between capsular serotype, capsule-associated virulence genes, and evaluate its resistance to conventional antibiotics in order to gain insight into any regional differences.

Materials And Methods: A total of 61 collected from various clinical specimens were confirmed genotypically.

Virulence characterization of and its relation with ESBL and AmpC beta-lactamase associated resistance.

Background And Objectives: Trend analysis reveals that has witnessed a steep enhancement in the antibiotic resistance and virulence over the last few decades. The present investigation aimed at a comprehensive approach investigating antibiotic susceptibility including, extended spectrum beta-lactamase (ESBL) and AmpC β-lactamase (AmpC) resistance and the prevalence of virulence genes among the isolates.

Materials And Methods: Sixty-one isolates were obtained from various clinical infections.

Clostridium difficile in patients with nosocomial diarrhea, Northwest of Iran.

Clostridium difficile is known as a prevalent pathogen leading to infections ranging from mild diarrhea to severe disease and death. The aim of the present study was to evaluate the incidence of C. difficile from inpatients with nosocomial diarrhea hospitalized in different wards in the northwest region of Iran.

The Effect of Photodynamic Therapy and Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) on the Remineralization Rate of Non-Cavitated Root: an In-vitro Study.

Using laser treatments and calcium and phosphate compounds to enhance remineralization has been investigated in this study. Seventy two premolar teeth were divided into four groups of 18: 1) control group; 2) laser therapy group; 3) CPP-ACP paste group; and 4) laser therapy and CPP-ACP group. Mineralization and remineralization of samples were investigated by Diagnodent.

Peptide nucleic acid-mediated re-sensitization of colistin resistance Escherichia coli KP81 harboring mcr-1 plasmid.

Escherichia coli is a gram-negative bacterium and it causes a variety of diseases in humans. It causes a wide range of clinical infections in humans; urinary tract infections is the most prevalent infection caused by uropathogenic Escherichia coli. In recent years, the observation of antibiotic-resistant genes such as resistance to colistin, makes the Escherichia coli resistant to antibiotics like colistin (polymyxin E), because of that the use of new therapies like peptide nucleic acid (PNA) has attracted the consideration of scientists.

Comparison of the disinfectant effects of Nanosil D2 and Korsolex extra solutions on thermoset acrylic resin contaminated with and .

This study was conducted to compare the disinfectant effects of Nanosil D2 and Korsolex extra on thermoset acrylic resin contaminated with and . In this experimental study, 90 acrylic samples were made and sterilized. Two samples were cultured as a sterilization control in brain-heart infusion (BHI) and the rest of samples were divided into two groups.

nim gene-independent metronidazole-resistant Bacteroides fragilis in surgical site infections.

is the most common anaerobic pathogen isolated from surgical site infections (SSIs). Metronidazole resistance is increasing and the mechanisms of resistance are not clear in some isolates. The aim of the present study was to investigate the metronidazole susceptibility prevalence, and detect genes in isolates from SSIs.

Disinfection effect of microwave radiation on Bacillus subtilis as indicator organism on contaminated dental stone casts under dry and wet conditions.

The disinfection of dental stone casts using microwave radiation has been shown, but doubts remain regarding its efficacy under various conditions. The aim of the present study was to evaluate the efficacy of microwave disinfection on wet and dry dental stone casts contaminated by a resistant microorganism. In this in vitro study, 34 stone half-casts were prepared, contaminated with and divided into two groups.

Role of Enterotoxigenic Bacteroides fragilis in Children Less Than 5 Years of Age With Diarrhea in Tabriz, Iran.

Background: Diarrhea is the most frequent health problem among children in developing countries. Defining the etiology of acute diarrhea is critical to disease therapy and prevention. Some anaerobic bacteria such as Enterotoxigenic Bacteroides fragilis (ETBF) strains cause diarrheal disease by production of enterotoxin in children less than 5 years old.

Detection, Virulence Gene Assessment and Antibiotic Resistance Pattern of O157 Enterohemorrhagic Escherichia coli in Tabriz, Iran.

Background: Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen and infection with this organism causes illnesses such as bloody diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome.

Objectives: Considering the lack of any information about the prevalence rate and the antibiotic resistance pattern of O157:H7 serotype in Tabriz, finding answers to the above mentioned subjects was among the goals of this study.

Materials And Methods: Two hundred E.

Antibiotic Sensitivity of Clostridium perfringens Isolated From Faeces in Tabriz, Iran.

Background: Clostridium perfringens, a Gram-positive, anaerobic bacterium that produces at least 16 virulence factors including 12 toxins (α-ν), enterotoxin, hemolysin and neuraminidase, can create variable pathogenic condition, ranging from a food poisoning to life-threatening myonecrosis. Among C. perfringens strains, resistance to the drug choices such as penicillin as well as to alternatives of penicillin like metronidazole and clindamycin has also been observed.

Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients.

Background: Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity.

Objectives: This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates.

Bacterial etiology and antibiotic susceptibility pattern of diabetic foot infections in Tabriz, Iran.

Aim: The aim of this study was to investigate anaerobic and aerobic bacteria profile and determination of antibiotic susceptibility pattern in aerobic bacteria.

Method: Specimens were cultured using optimal aerobic and anaerobic microbiological techniques. Identification of bacterial isolates was performed by standard microbiological methods and antibiotic susceptibility testing was performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI).

Comparison of in vitro activities of meropenem productions on Klebsiella pneumoniae isolated from hospitalized patients.

Purpose: Antimicrobial activities of meropenem products on Klebsiella pneumoniae isolates were determined.

Methods: 212 non-duplicated Klebsiella pneumoniae isolates were examined for in vitro meropenem susceptibility test by using the following disks, which were made from Meronem (AstraZeneca, UK), Exipenem (Exir, Iran) and Meroxan (DAANA, Iran) powders. MIC50 and MIC90 for meropenem antibiotics were determined.

Role of efflux pumps: MexAB-OprM and MexXY(-OprA), AmpC cephalosporinase and OprD porin in non-metallo-β-lactamase producing Pseudomonas aeruginosa isolated from cystic fibrosis and burn patients.

Purpose Of The Research: In order to gain a better understanding of the role of several mechanisms in antibiotic resistance in Pseudomonas aeruginosa clinical isolates obtained from CF and burn patients, we evaluated gene expression of efflux pumps MexAB-OprM and MexXY(-OprA), the natural β-lactamase AmpC and outer membrane porin protein OprD. Also, the presence of genes encoding Ambler classes A, B β-lactamases and aminoglycoside modifying enzymes (AMEs) was examined.

Principal Results: Piperacillin-tazobactam and amikacin retained the highest in vitro activities among 21 CF and 27 burn P.