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The aims of this study were to regain new epidemiology information about frequency, drug resistance rates, and typing of Campylobacter jejuni (C. jejuni) isolates, obtained from some poultry and cattle farms, slaughterhouses, and people with diarrhea. In this regard, Minimal Inhibitory Concentration (MIC) of several antibiotics and the associated antibiotic resistance genes, including tetO, tetA, cmeB, and blaOXA-61 were evaluated. The isolates were also typed, using the Fla-RFLP method. Generally, between 233 food animal samples, 80 (34.33%) C. jejuni were isolated. Moreover, 20 out of 74 (27%) human specimens suspected to infectious diarrhea were C. jejuni positive. High frequencies of resistance to tetracycline (100%), ciprofloxacin (95%), and nalidixic acid (86%), and low frequencies of resistance to florfenicol (0%), erythromycin (5%), and gentamicin (8%) were observed. Furthermore, in the tetracycline-resistant isolates, the existences of tetO, tetA, and cmeB were 86%, 23%, and 48%, respectively. There was a significant correlation between the cluster types obtained from Fla-RFLP method and antibiotic resistance pattern. The results suggested that the genomic link between Campylobacter spp. should be always evaluated in each country to provide an insight about the Campylobacter spp., spread in the region, in order to implement the health-controlling programs efficiently.

Background and Aims: Colorectal cancer is considered to be an important cause of morbidity and mortality worldwide. Anti-cancer properties of probiotic lactic acid bacteria are considerable for treatment of cancers such as colorectal cancer. The aim of this study was to investigate the molecular characterization of probiotic bacterial isolates from collected stool specimens in west of Mazandaran province, in order to confirm the probiotic effect of isolated strains, so to compare their effect on cancer cell lineages, in future studies. Materials and Methods: In this study, out of 60 stool samples collected from healthy children and adult people, 50 bacterial strains were isolated. Antibiotic susceptibility was performed by 15 antibiotics for 7 strains. Then, pH and bile salts tolerance were measured in the strains. Molecular analysis of these strains was carried out by PCR-sequencing and their results were used to draw a phylogenetic tree. Results: Of the 50 isolates, 7 isolates were lactic acid bacteria and two strains were completely probiotic. These strains were resistance to low pH and 0.3% bile salt. Molecular analysis showed that two strains SE and SG were probiotics related to Lactobacillus fermentum (86% homology) and Lactobacillus rhamnosus (61% homology) family, respectively, which were known as new strains. Conclusion: The results suggested that there are 7 strains with good tolerance in the gastrointestinal tract that have probiotic properties and this is the basis of future studies to evaluate their anti-tumor properties and ultimately oral administration.

Staphylococcus. aureus is often considered as a potential pathogen and resistant to a wide range of antibiotics. The pathogenicity of this bacterium is due to the presence of multiple virulence factors and ability to form biofilm. SCCmec types I, II and III are mainly attributed to HA-MRSA, while SCCmec types IV and V have usually been reported in CA-MRSA infections. In this study, we performed a cross-sectional study in order to determine the antimicrobial resistance, adhesion and virulence factors, biofilm formation and SCCmec typing of clinical S. aureus isolates in Iran. S. aureus isolate was identified using microbiological standard methods and antibiotic susceptibility test was performed as described by the Clinical and Laboratory Standards Institute (CLSI) guidelines. Inducible resistance phenotype and biofilm formation were determined using D-test and tissue culture plate methods, respectively. Multiplex-PCRs were performed to detect adhesion and virulence factors, antibiotic resistance genes, biofilm formation and SCCmec typing by specific primers. Among 143 clinical samples, 67.8% were identified as MRSA. All isolates were susceptible to vancomycin. The prevalence of cMLSB, iMLSB and MS phenotypes were 61.1%, 22.2% and 14.8%, respectively. The TCP method revealed that 71.3% of isolates were able to form biofilm. The predominant virulence and inducible resistance genes in both MRSA and MSSA isolates were related to sea and ermC respectively. SCCmec type III was the predominant type. Data show the high prevalence rates of virulence elements among S. aureus isolates, especially MRSA strains. This result might be attributed to antibiotic pressure, facilitating clonal selection.

Background and Objectives: Staphylococcus aureus is a common cause of nosocomial infections. The ability of S. aureus to form biofilm and acquire antimicrobial resistance has made this organism a major health problem. In this study, we investigate the biofilm-forming ability of S. aureus isolates from clinical samples. Methods: Sixty S. aureus isolates from clinical specimens were collected from the 5th Azar Hospital of Gorgan (Iran) in 2018. The isolates were identified using conventional methods including Gram staining and biochemical tests (catalase and coagulase). Biofilm formation by S. aureus isolates was evaluated using a microplate-based method. Results: Of 60 S. aureus isolates, 47 (78.3%) strains were identified as biofilm-forming and 13 (21.7%) strains were non-biofilm-forming. Conclusion: The high prevalence of biofilm-producing S. aureus isolates in the 5th Azar hospital of Gorgan could pose a major health challenge with serious consequences for hospitalized patients. Therefore, it is crucial to disinfect and sterilize hospital surfaces and equipment effectively to minimize the risk of contamination and spread of bacteria in the hospital settings. Keywords: Biofilms, Staphylococcus aureus, sample.

Background: Staphylococcus aureus is a frequent cause of hospital and community-associated infections on a global scale. This pathogen is responsible for causing an extensive range of diseases and sometimes create biofilms for their survival. Biofilm formation, leads to difficulty in treatment with antibiotics and antibiotic resistance which is another rising concern in health centers. Some S. aureus virulence factors encode on the core genome, such as alpha-toxin and phenol-soluble modulins (PSMs), which are produced by nearly all strains. Objectives: There is no information about the expression of PSM A gene in clinical isolates of biofilm-producing S. aureus in Iran. This study was performed on clinical samples to determine the prevalence and expression of PSM A gene in biofilm-producing S. aureus clinical isolates. Methods: The clinical samples were collected and examined for S. aureus by microbiological and biochemical tests. Then, the biofilm formation in S. aureus isolates was detected by microtiter plate. Finally, the expression of PSM A was determined using SYBR Green real-time PCR. Results: From a total of 60 isolates of S. aureus, 47 strains (78.3%) had ability of biofilm formation and the others were negative for biofilm formation. Real-time PCR testing showed that 100% of the strains were positive for biofilms and PSM A genes. The results of phenotypic and genotypic tests of biofilm were closely related to each other and the expression of PSM A gene was 80%. It was found that 100% of strains were biofilm producing and PSM A gene was present in 78.3% (47 strains) of them. Conclusions: The prevalence of biofilm production in S. aureus strains isolated from clinical samples was high, so it is highly important to monitor the prevalence of these organisms in hospitals and community as well as their antimicrobial resistance.

Acinetobacter baumannii is commonly distributed as a significant opportunistic pathogen, particularly in burn cases, all over the world. The purpose of this research was the molecular identification of imipenem-resistant A. baumannii isolated from burns patients in a Motahari hospital in Tehran, Iran. In a 9-month period, 173 A. baumannii isolates were obtained from burns cases subjected to the Motahari Burn Center, Tehran, Iran. The resistance pattern of several antibiotics was evaluated. Metallo-β-lactamase (MBL)-producing isolates were detected by double-disk synergy and an MBL E-test. Polymerase chain reaction (PCR) was conducted to detection following β-lactamase genes: blaIMP, blaVIM, blaSIM, blaGIM, blaSPM, blaAIM, blaNDM, blaDIM, blaKPC, blaOXA-23/24/51, and blaOXA-58. The integron classes (I, II and III) were recognized using PCR. Out of the 173 tested isolates, 79.7% and 22.5% of the strains were multi drug-resistant (MDR) and extensively drug-resistant (XDR), respectively. The rate of resistance to imipenem was 87.3%. Based on double disk synergy and E-test, 87.4% and 62.3% of the isolates, were MBL-producing isolates respectively. The frequency of blaOXA-23 and blaOXA-24 were 74.2% and 32.5%, respectively. Our results showed 58.9%, 43%, and 1.3% of the strains were positive for blaVIM, blaIMP and blaNDM genes, respectively. Furthermore, 32.5%, 66%, and 1.5% of strains harbored intI, intII, and intIII genes, respectively. The increasing frequency of carbapenem-resistant A. baumannii in burns patients emphasizes the essential of infection management measures, including antibiotic susceptibility patterns and prompt detection of beta-lactamase-producing strains.