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Background: In this study, the effects of pure AH Plus sealer and its combination with triple antibiotic paste at different concentrations on Enterococcus faecalis bacteria have been investigated. Materials and Methods: This in vitro study was accomplished by the means of a triple antibiotic paste combination (minocycline, metronidazole, and ciprofloxacin) at different concentrations (0%, 1%,5%, 10%, and 25%) with AH Plus sealer on E. faecalis bacteria. Sealers were set in an incubator for 1 h, 1 day, 3 days, and 7 days, and then 10 µL of bacteria solution was placed on all samples except the negative control group. After drying for 1 h, 250 µL brain-heart infusion broth culture medium was added, and it was cultured in solid media. Direct contact test technique was performed, and the obtained data were analyzed by 1-way ANOVA, 2-way ANOVA, 3-way ANOVA, and post hoc test least significant difference. It should be noted that the data were evaluated at the significance level of P < 0.05. Results: The average of colony-forming unit (CFU)/mL illustrated that there were no significant differences between fresh antibiotic-sealer combination, 1-day set, and 3-day set (P = 0.525), while in sealer with 7-day set, the average of CFU/mL was notably lower than other sets (P < 0.001). The outcomes revealed a considerable variation by passing time and the number of CFU/mL was remarkably reduced (P < 0.05).The data suggested that, by increasing the concentration, the average of CFU/mL was decreased, whereas the average of CFU/mL did not have significant differences in all concentrations of the antibiotic-sealer combination compared to pure sealer (P < 0.05). Conclusion: The concentration of 1% triple antibiotic in combination with root canal sealer may become a crucial factor for inhibiting the growth of remaining bacteria. [ABSTRACT FROM AUTHOR]

Background & Aim: Enterococcus faecalis, play a significant role in plaque formation and tooth decay. Mouthwashes are one of the tools used to reduce decay..the aim of study was comparision of fluorine total with chlorhexidine on Enterococcus faecalis. Material and Methods: In this in-vitro study a total of 24 samples (18 samples in each groups and 6 control samples) were examined, the diameter of the growth inhibition zone of Enterococcus faecalis was compared between two mouthwashes of fluorine total and chlorhexidine 0.2% Enterococcus faecalis was first cultured on a blood agar plate and incubated for 24 hours at 37 °C. The bacteria were then cultured on 18 plates of blood agar (9 plates for chlorhexidine mouthwash and 9 plates for fluorine total mouthwash). To evaluate the absence of bacterial inside the mouthwashes, 2 plates containing fluorine total and chlorhexidine mouthwash were cultured separately. The plates were prepared by well method, then the growth inhibition zone in the two study groups was measured and analyzed by Repeated Measure ANOVA test of 25th version of SPSS software. Results: The growth inhibition zone in the chlorhexidine and fluorine total group was 15/94±0.8 mm and 18/61±1.4 mm, respectively, which was in the chlorhexidine group, which is statistically significant (P<0/0001). Conclusion: Fluorine total mouthwash is more effective than chlorhexidine mouthwash on enterococcus faecalis. [ABSTRACT FROM AUTHOR]

Enterococcus faecalis (E. faecalis) and E. faecium (E. faecium) are commensals of the gastrointestinal biota of humans and animals and are considered opportunistic pathogens. This study aimed to improve the knowledge about E. faecalis and E. faecium isolated from meat. To this end, 104 meat samples were collected from sheep, goats, cattle, and calves from Shahrekord local markets in Iran. Presumptive colonies of E. faecalis and E. faecium were isolated from the samples and subjected to identification tests. Antimicrobial susceptibility was determined using the Kirby-Bauer disc diffusion method, and polymerase chain reaction (PCR) was performed to detect some virulence genes. Furthermore, randomly amplified polymorphic DNA typing and repetitive element sequencebased PCR fingerprinting were used to show the clonal relatedness of the isolates. The results revealed that enterococci were present in 90 out of 104 samples. Specifically, E. faecalis and E. faecium were the commonly isolated species, with the predominance of E. faecalis, which exhibited high resistance to streptomycin (95%) but was susceptible to vancomycin (85.6%). Virulence genes detection showed that ccf and cpd genes were the most prevalent genes in both species. In addition, the molecular typing method indicated that the isolates belonged to separate subgroups. This study shows the contamination of meat products by potential pathogens and resistant enterococci. There is a need to implement regular surveillance to monitor the emergence of antimicrobial-resistant E. faecalis and E. faecium in food, particularly in meat production. [ABSTRACT FROM AUTHOR]

BACKGROUND: Enterococci are naturally found in the gastrointestinal (GI) tract of animals and humans, as well as animal-derived foods and vegetables. We here aimed to determine the prevalence, antibiotic resistance, and virulence determinants of E. faecium and E. faecalis in traditional cheese in the North-west of Iran. MATERIALS AND METHODS: Fifty specimens of popular traditional cheese from dairy stores of Urmia and Tabriz, Iran, were collected. Identification of the genus and species of enterococci was done using molecular and phenotypic techniques. RESULTS: Forty-eight (96 %) of 50 traditional cheese samples were harboring Enterococcus spp, including Enterococcus faecalis (n= 40; 83.33 %) and E. faecium (n= 8; 16.67 %). The prevalence of enterococci ranged from 1.1×105 to 9.7×104 CFU/g, and 1.1×103 to 9.8×103 CFU/g in Urmia and Tabriz samples, respectively. Rifampicin resistance (n= 38; 79.2 %) was the most common pattern observed in the susceptibility test, which was followed by quinupristin/dalfopristin (n= 33; 68.75 %). Among E. faecalis isolates, cpd (100 %), ace (92.5 %) and gelE (87.5 %), and among E. faecium isolates, gelE (100 %) and asa1 (75 %) were found to have the most common virulence genes. CONCLUSION: E. faecalis was the predominant species, displaying more virulence determinants. It also had high antibiotic resistance, as compared to E. faecium. The enterococci identified here commonly expressed virulence and antibiotic resistance determinants. So, it is required to improve the maintenance and production quality of traditional cheese to avoid enterococci contamination. [ABSTRACT FROM AUTHOR]

Background: The association between specific bacteria and colorectal cancer (CRC) has been proposed. Only a few studies have, however, investigated this relationship directly in colorectal tissue with conflicting results. So, we aimed to quantitate Streptococcus gallolyticus, Fusobacterium spp, Enterococcus faecalis and enterotoxigenic Bacteroides fragilis (ETBF) in formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples of Iranian CRC patients and healthy controls.Methods: A total of 80 FFPE colorectal tissue samples of CRC patients (n = 40) and healthy controls (n = 40) were investigated for the presence and copy number of above bacterial species using quantitative PCR. Relative quantification was determined using ΔΔCT method and expressed as relative fold difference compared to reference gene.Results: Relative abundance and copy number of E. faecalis and ETBF were significantly higher in CRC samples compared to control group. E. faecalis was more prevalent than ETBF in tumor samples. Frequency of ETBF and E. faecalis in late stages (III/IV) of cancer was significantly higher than early stages (I/II). We did not detect a significant difference in abundance of S. gallolyticus and Fusobacterium spp between two groups.Conclusion: Our study revealed the higher concentration of E. faecalis and ETBF in FFPE samples of CRC patients than controls. However, additional investigations on fecal and fresh colorectal cancer tissue samples are required to substantiate this correlation. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to investigate the distribution pattern of genes responsible for erythromycin and tetracycline resistance and their association with resistance phenotypes in enterococcus isolates.Materials and Methods: Eighty-six Enterococcus faecalis and 26 E. faecium isolates were collected from 2 hospitals in Kerman, Iran. Minimum inhibitory concentration of erythromycin and tetra-cycline was determined and then genes encoding resistance to erythromycin - erm (A-C), mef, and msr - and tetracycline - tet (M), tet (O), tet (S), tet (K), and tet (L) - were investigated.Results: In all resistant isolates (n = 72, 64%), high-level resistance to both tested antibiotics was found. The most prevalent erm gene was erm (B) (77.7%), followed by erm (A) (15.2%) and erm (C) (8.3%). Genes mediating erythromycin efflux were detected in 70.8% (mef) and 9.7% (msr) of resistant isolates. Regarding tetracycline, tet (M) was detected at the highest rate (50%), followed by tet (O) (31%) and tet (S) (11%). Export of tetracycline was found in 31% (tet (K)) and 12% (tet (L)) of isolates.Conclusion: A high prevalence of high-level resistance to both erythromycin and tetracycline was documented. Alterations at the ribosomal level was more frequently detected in erythromycin and tetracycline resistance than efflux systems. Concurrent resistance mechanisms were more involved in resistance to erythromycin than tetracycline. [ABSTRACT FROM AUTHOR]

Background: This study aims to specify the antimicrobial resistance pattern and virulence genes of Enterococcus faecalis isolated from urinary tract infections in Shahrekord, Iran. Methods: Urine samples of 1000 people suspected of having urinary tract infections referred to Shahrekord medical diagnostic laboratories were examined. Biofilm assays were performed by microtiter plate test through reading the OD490. Polymerase Chain Reaction (PCR) was applied to study the virulence factors. Results: Enterococcus faecalis was detected in 60 samples. After performing microbiological tests, all samples were positive in the molecular analysis. Strong, moderate and weak biofilm reactions reported 66.67%, 25%, and 8.33% respectively. The most resistance reported to cotrimoxazole, vancomycin and amikacin and the lowest resistance to nitrofurantoin (8.33%) was reported. Statistical analysis with Fisher's exact test showed a statistically significant relationship between biofilm production and resistance to cotrimoxazole, vancomycin and cefotaxime. Prevalence of efe A, ace, gel E, esp, cyl M, agg, cyl A and cyl B in strong biofilm formation isolates was reported 100%, 87.5%, 82%, 62.5%, 55%, 37.5% 25% and 22.5% respectively. There was a significant relationship between the frequency of efa A and strong biofilm reaction. Conclusions: The presence of E. faecalis strains resistant to co-trimoxazole and vancomycin and present of some virulence factors is alarming the researchers. Since antibiotic resistance genes are probably transmitted among enterococci, and Staphylococci, controlling infections made by enterococci as well as the appropriate administration of antibiotics could treat the nosocomial infections effectively. [ABSTRACT FROM AUTHOR]

Antibiotic resistance and especially multiresistance in Enterococci, is a serious public health issue especially in infections of immunocompromised patients. EfrAB is a heterodimeric multidrug ATP-binding cassette (ABC) transporter that causes endogenous resistance to antimicrobials including fluoroquinolones in Enterococcus spp. The aim of this study was to seek the gene expression rate and role of efrAB efflux pump in ciprofloxacin resistant Enterococcus faecalis and Multilocus Sequence Typing (MLST) of multiresistant isolates. Phenotypic and genotyping identification of 80 E. faecalis isolates were performed. Minimum inhibitory concentrations (MICs) to ciprofloxacin (CIP) were measured with and without carbonylcyanide 3-chlorophenylhydrazone (CCCP) by broth microdilution. After DNA extraction and sequencing for detection of efrA and efrB genes, the e frAB efflux positive isolates that were resistant to ciprofloxacin and showed decrease of ciprofloxacin MIC range were identified. Isolates that exhibited decrease in ciprofloxacin MIC range from two to ten folds were assessed for biofilm formation and finally, the expression levels of efrB, efrA genes were measured by quantitative Real-Time PCR (qRT-PCR). High rates of resistance to tetracycline and minocycline and low rates of resistance to the most antibiotics used in this study were detected. The results in this study indicated that the incidence of Multiple drug resistance (MDR) was 23.7% and all isolates that were resistant to ciprofloxacin revealed several degrees of overexpression in efrA and efrB genes. Our study found two ST480 and one ST847 in E. faecalis isolates. In conclusion, despite of low frequency of resistance to the most antibiotics and MDRs in our region, we found one ST480 isolate with resistance to eight antibiotics that also exists in other parts of the world. [ABSTRACT FROM AUTHOR]

This research was conducted using 50 samples of popular traditional cheeses and 160 enterococcal clinical isolates. Phenotypic and genotypic methods used for identification of enterococci. Then, the incidences of antibacterial resistance and virulence traits were investigated. In total, 165 E. faecalis and 43 E. faecium obtained from traditional cheeses and different clinical isolates were analyzed in the study. Antibiotic susceptibility testing revealed 175(84.1%) isolates with multi-drug resistance (MDR) patterns, which was more common among clinical sources. The predominant virulence profile, including gelE, asa1 and cpd was detected within 47 (22.6%) of the MDR isolates. Our results showed that traditional cheeses and clinical E. faecalis isolates have distinct patterns of virulence traits. The identified enterococci with antibiotic resistance and associated virulence factors, could provide a potential risk to the public health. [ABSTRACT FROM AUTHOR]

In the present research, we aimed to determine the characteristics of E. faecalis strains collected from an Iranian Children's Hospital for four years. Sixty-seven E. faecalis isolates with virulence genes detection, variable-number tandem repeat (VNTR), and multiple-locus variable-number tandem repeat analysis (MLVA) typing were investigated. A high frequency of virulence genes belonged to gelatinase (73%) and Enterococcus faecalis (62%). The MLVA of 67 E. faecalis isolates revealed 52 VNTR patterns and 38 MLVA types (MTs). Furthermore, genetic diversities with the majority of the MT1 as a major MT in different Wards of the Children's Hospital were found., Competing Interests: The authors declare that they have no conflict of interest. The authors alone are responsible for the content and writing of the paper.

Purpose: Over the past two decades, enterococci have emerged as an important opportunistic pathogen causing life-threatening infections in hospitals. The purpose of the present study was to examine the prevalence of genes encoding virulence factor and molecular characterization of vancomycin-resistant E. faecalis strains isolated from hospitalized patients in Isfahan, the central city of Iran. Patients and methods: A total of 53 vancomycin-resistant E. faecalis isolates (VRE) obtained from clinical samples of hospitalized patients were characterized by phenotypic and genotypic methods, and 25 selected VRE isolates from internal and ICU wards were typed by multilocus sequence typing. Results: The efa was the most prevalent virulence gene (100%) among isolates, followed by gelE (92.45%), asa1 (90.56%), ace (86.79%), esp (75.47%), cylA (39.62%), and hyl (18.86%). More than 80% of the isolates were HLGR. Multilocus sequence typing showed eight different sequence types including ST6, ST422, ST28, ST448, ST531, ST328, ST421, and ST495. STs were grouped into two clonal complex (CC) including CCA (ST6, ST422, ST448, ST531) and CCF (ST28, ST421) and two singletons (ST328, ST495). Conclusion: Our data indicated a high prevalence of virulence genes among STs described in this study. In addition, the molecular analysis demonstrated a relatively high genetic diversity among selected VRE strains from the ICU in comparison with the internal ward. Therefore, in order to prevent the colonization of virulent strains in the hospital environment, infection control procedures should be performed. [ABSTRACT FROM AUTHOR]

Background and Objectives: Enterococcus faecalis is a major cause of bacterial prostatitis, which can increase the risk of developing prostate cancer if mistreated or left untreated. The aim of this study was to evaluate resistance of E. faecalis strains isolated from patients with prostatitis to three fluoroquinolones. Methods: In this cross-sectional study, we collected urine specimen from 164 patients hospitalized in six hospitals in the Golestan Province, Iran. Biochemical and bacteriological tests were carried out to identify E. faecalis strains. Pattern of resistance to ciprofloxacin, levofloxacin and norfloxacin was studied using the agar disk diffusion method (Kirby-Bauer method). The broth microdilution test was performed to determine minimum inhibitory concentrations (MICs) of fluoroquinolones according to the CLSI M100-S25 (2015) criteria. Results: Of 164 isolates, 39 (23.8%) were identified as E. faecalis. Frequency of resistance to ciprofloxacin, norfloxacin and levofloxacin was 12.8%, 12.8% and 2.6%, respectively. The MIC90 of ciprofloxacin against the isolates was 4 μg/ml, which was 4-fold lower than that of norfloxacin (MIC90=16μg/ml) and 2-fold lower than that of levofloxacin (MIC90=8μg/ml). We found no significant difference between the isolates in terms of resistant to the fluoroquinolones (P>0.01). Conclusion: Our results show that E. faecalis is one of the most common causes of bacterial prostatitis, and fluoroquinolones are still effective for treating the infection despite the reports of fluoroquinolones resistance in Iran. Moreover, levofloxacin may be a more suitable and effective antibiotic than ciprofloxacin and norfloxacin for treatment of this infection. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize virulence factors and antibiotic resistance patterns in E. faecalis strains obtained from community-acquired urinary tract infections. A total of 70 E. faecalis isolates from Labbafinejad Hospital in Tehran were collected. Antibiotic resistance and virulence determinants were examined by phenotypic and molecular methods. Among 70 E. faecalis isolates, efba (97.1%), ace (95.7%), and gelE (94.3%) were the most prevalent virulence genes. The most common antibiotic resistance pattern was tetracycline (88.6%) and minocycline (87.1%). Multi-drug resistant phenotype was detected among 10% of them. Our results showed capability of E. faecalis strains for infection of the urinary tract in community. Involvement of virulence determinants in the pathogenesis of community acquired E. faecalis strains was proposed due to their high prevalence rates. Food producing animals were proposed as their environmental reservoirs, due to dominance of tetracycline resistance phenotype among them. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the phenotypic and genotypic characteristics of vancomycin–resistant Enterococcus faecalis and Enterococcus faecium. Antibiotic resistance and virulence genes in the aforementioned resistant isolates were studied using the epsilometer (E)-test and polymerase chain reaction (PCR). These isolates were subjected to typing by pulsed-field gel electrophoresis (PFGE). Thirty vancomycin-resistant enterococci (VRE; 18.75%) were isolated from a total of 160 various clinical specimens cultured for any bacterial growth. Of these, 11 (36.7%) isolates were identified as E. faecalis and 19 (63.3%) as E. faecium. Minimum inhibitory concentrations (MICs) of vancomycin, teicoplanin, and three alternative therapeutic options (linezolid, daptomycin, and quinupristin/dalfopristin) were determined using the E-test. Multiplex PCR was done for confirming species, identification of the resistant genotypes, and the detection of the virulence genes. Finally, the clonal relationship of all VRE strains was studied by PFGE. All VRE strains showed vancomycin MIC ≥256 μg/mL, and 27 (90%) isolates carried the vanA gene, whereas none of the isolates carried vanB. The most common resistance antibiotic pattern observed was toward rifampicin (n = 30 [100%]). Among all virulence genes studied, gelE (n = 28 [93.33%]) was found as the most prevalent virulent gene. VRE isolates exhibited 90%, 46.67%, 100%, and 66.67% resistance to teicoplanin, linezolid, quinupristin/dalfopristin, and daptomycin, respectively. Molecular typing demonstrated 16 PFGE types of VRE isolates (A–P). Although vanA was carried by most of the isolates, PFGE displayed small clonal dissemination among VR E. faecium and VR E. faecalis species. [ABSTRACT FROM AUTHOR]

Background: Enterococci are part of the normal flora of both the human and animal gastrointestinal tract. The aim of the present study was to compare vancomycin resistance and vanA gene in clinical and stool isolates in children specimens. Methods: One hundred enterococcal isolates were identified by laboratory tests and then they were examined for their antibiotic resistance. Resistant isolates were also studied by PCR for vanA gene. Results: Of 50 stool isolates, 48 were Enterococcus faecium and 2 isolates were identified as Enterococcus faecalis. In our 50 clinical isolates, 23 were belonged to Enterococcus faecium while 27 isolates were Enterococcus faecalis. The stool isolates showed higher resistance to vancomycin than those from clinical isolates. In our stool isolates the rate of vancomycin resistance was 52%, while the vancomycin resistance rate in the clinical isolates was 32%. According to PCR results, in the 26 vancomycin resistant isolates from stool specimens, vanA gene was found in 1 isolate, though in our 16 vancomycin resistant isolates from clinical specimens, vanA gene was found in 10 isolates. Conclusion: Vancomycin resistant enterococci are of public health concern, especially in hospitals. Our results showed that stool isolates had higher resistance to antibiotics than those from clinical isolates. In the stool isolates the rate of vancomycin resistance was 52%, while the vancomycin resistance rate in our clinical isolates was 32%, but vanA gene was more prevalent among clinical isolates than stool isolates. [ABSTRACT FROM AUTHOR]

Background: Different irrigating solutions with high antimicrobial activity have been introduced for cleaning of the root canal system. However, effects of Prangos ferulacea (PF), Ziziphora tenuior (ZT), Dracocephalum moldavica (DM), and Ferula gummosa (FG) on oral and dental pathogens have not been extensively evaluated due to their optimal biocompatibility and insignificant side effects. The aim of this study was to evaluate the antibacterial effects of essential oils of mentioned plants on Enterococcus faecalis. Materials and Methods: In this in vitro study the plants were collected from Zanjan Province, Iran. Analysis of the essential oil was carried out by gas chromatography/mass chromatography. Micro-broth dilution and disc diffusion methods were used for assessment of the antimicrobial activity, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. Results: All the four essential oils had antibacterial effects on E. faecalis, and ZT had the greatest antibacterial activity. Assessment of the mean diameter of the growth inhibition zone showed higher antibacterial activity of PF and ZT than that of chlorhexidine. The MIC and MBC of ZT showed that the antimicrobial activity of ZT against E. faecalis was greater than that of other plants evaluated in this study. Conclusion: The results of this study indicated significant antibacterial effects of the mentioned plants on E. faecalis. The greatest antimicrobial activity belonged to ZT. The current study suggests extraction of effective compounds in these medicinal plants to use them in the clinical setting. [ABSTRACT FROM AUTHOR]

Potential probiotic Enterococcus faecalis KUMS-T48, isolated from a kind of Iranian traditional dairy product (Tarkhineh), was assessed for its anti-pathogenic, anti-inflammatory and anti-proliferative properties against HT-29 and AGS cancer cell lines. This strain showed strong effects on Bacillus subtilis and Listeria monocytogenes and moderate effect on Yersinia enterocolitica, while indicated weak effect on Klebsiella pneumoniae and Escherichia coli. Also, neutralizing the cell-free supernatant and treating it with catalase and proteinase K enzymes reduced the antibacterial effects. Similar to Taxol, the cell-free supernatant of E. faecalis KUMS-T48 inhibited the in vitro proliferation of both cancer cells in a dose-dependent manner, but unlike Taxol, they had no activity against normal cell line (FHs-74). Pronase-treatment of the CFS of E. faecalis KUMS-T48 abrogated its anti-proliferative capacity, thereby showing the proteinaceous nature of the cell-free supernatant. Further, induction of apoptosis-based cytotoxic mechanism by E. faecalis KUMS-T48 cell-free supernatant is related to anti-apoptotic genes ErbB-2 and ErbB-3, which is different from Taxol's apoptosis induction (intrinsic mitochondria apoptosis pathway). Also, as evidenced by a decline in interleukin 1β inflammation-promoting gene expression and a rise in the anti-inflammatory interleukin-10 gene expression in the HT-29 cell line, probiotic E. faecalis KUMS-T48 cell-free supernatant demonstrated a significant anti-inflammatory impact., (© 2023. The Author(s).)

Introduction: Epidemiology of Enterococcus infections has attracted much attention. Precise identification of pathogenic strains can be effective in the control process of microorganism antibiotic resistance. This study aimed to identify the Enterococcus species isolated from hospitals in Tehran and examine their antibiotic resistance pattern by phenotypic and genotypic methods. Methods & Materials: This study was performed on 400 clinical samples from different hospitals in Tehran during 2015- 2016. Specific cultures and biochemical tests were used to identify Enterococcus, distinguish E. faecalis and E. faeacium species and PCR method was used to identify Enterococcus species. Antibiotic susceptibility was examined using Kirby-Bauer disc diffusion, and CLSI and vancomycin MIC were measured using broth dilution. Results: Of the 400 samples, 278 Enterococcus species were recognized. Phenotypic methods recognized 70.86% E. faecalis, 15.46% E. faeacium and 13.68% other species. PCR identified 72.3% E. faecalis, 10.43% E. faeacium and 17.27% other Enterococcus species. Results of the antibiograms showed the highest resistance (83.34%) to quinupristin/dalfopristin, and the lowest (1.41%) to linezolid. Also, resistance to vancomycin was observed in 5.95% with MIC ≥ 512 μμg/ml in 9 cases. Conclusion: Rapid diagnosis can prevent massive outbreaks of Enterococcus. Given the prevalence of vancomycin resistance in Enterococcus, preventive measures are imperative. The right antibiotics should be prescribed according to the resistance patterns after susceptibility test is performed for each patient. [ABSTRACT FROM AUTHOR]

Introduction: Quality of the sea water and lakes is directly related to that of their corresponding origin rivers. Most of the rivers, due to the inappropriate disposal of refuse, agricultural, industrial and hospital wastes, are seriously polluted. Objective: This research study has determined the microbial contamination of coastal water of the Caspian Sea in Gulian province, northern Iran. Materials and Methods: This study was carried out during the warm months, on the six coastal areas of the Caspian Sea in Guilan Province in 2011 and sampling was done to monitor the parameters for total coliform, Feacal coliform, Enterococcus faecalis,Temperature and pH, according to the standard methods of water and wastewater. Results: Results indicate microbial contamination of coastal water. The maximum amount of bacterial load was found to be in July. The average results of total coliform and fecal coliform, were, respectively 363 and 125.8 MPN per 100 ml of the samples. Also* the average amount of Enterococcus faecalis was 27.3 CFU per 100 ml of sample. Bacterial load was directly associated with water temperature and pollution in all the stations was more than the standard limits. The highest amount of bacterial load was observed in Pasdaran station and the amounts, were respectively, as follows: total coliform more than 1100, fecal coliform= 460 MPN per 100 ml and Enterococcus faecalis was greater than 100 CFU per 100 ml of sample. Conclusion: There is a serious risk to the health of the swimmers who go swimming during the warm months of the year, because the contamination may cause some diseases, especially meningitis and intestinal infection. Conflict of interest: non declared [ABSTRACT FROM AUTHOR]

Enterococcus spp. were isolated from Motal cheese (a traditional raw milk cheese in Iran) and some probiotic and safety properties were evaluated. Ten of the 52 isolated enterococci showed ideal survival rates under the simulated gastrointestinal tract and were therefore selected for further analysis. Based on the results, six out of ten tested isolates belonging to Enterococcus faecalis , Enterococcus faecium , Enterococcus hirae , Enterococcus avium and Enterococcus durans did not demonstrate the incidence of any major virulence factor, haemolytic activity or resistance to most of the antibiotics studied, especially vancomycin. Moreover, these six isolates inhibited the growth of Listeria monocytogenes , had adhesion ability to epithelial cells and showed high cholesterol assimilation and good auto-aggregation activities. The bottom line is that some naturally occurring Enterococcus strains isolated from Iranian Motal cheese have the potential to be used in functional food formulations due to their probiotic properties and safety. [ABSTRACT FROM AUTHOR]

The main objective of this study was to investigate the effect of enterococci isolated from traditional Lighvan cheese on the quality of Iranian UF white during ripening. Four samples of cheese were provided from four different cheese production units in Lighvan region. Strains of enterococci in these samples were isolated by standard microbiological methods and selective medium of Kanamycin Esclin Azide Agar and then identified by biochemical methods. In the second stage of research, the effect of adding isolated enterococci in traditional Lighvan cheese on the quality of Iranian UF white cheese was investigated in a 60-day period. Addition of Enterococcus spp. did not significantly (P> 0.01) affect the pH and percentage of pH 4.6-Soluble nitrogen/total nitrogen. In the cheese produced with E. faecalis and E. faecium strains, lipolysis rate was higher and flavor properties were improved. Moreover, results of measuring percentage of soluble nitrogen at pH 4.6 and urea polyacrylamide gel electrophoresis indicated an increase in proteolysis rate in the cheese containing E. faecalis and E. faecium strains compared to the control cheese. Furthermore, the highest percentage of non- protein nitrogen was observed in the cheese containing E. faecium. In conclusion, the results showed the positive effect of the E. faecalis and E. faecium on secondary proteolysis during ripening. The proteolytic activity displayed by some enterococcal strains may contribute to cheese ripening and flavor development. Because of these interesting metabolic traits, enterococci have been proposed as part of defined starter culture combination for UF white cheeses. [ABSTRACT FROM AUTHOR]

Background: Enterococci have emerged in recent years as important nosocomial pathogens. Although most enterococcal human infections are caused by Enterococcus faecalis, studies on vancomycin resistance are usually limited to Enterococcus faecium isolates and a little is known about E. faecalis. Therefore we undertook this study to obtain information about the prevalence of vancomycin-resistant E. faecalis (VREF) and genes responsible for resistance. Material and methods: Ninety-one E. faecalis isolates of different patients admitted at Children's Medical Center from August 2009 to June 2010 were included in this cross-sectional study. Antimicrobial testing was performed by Kirby-Bauer disk diffusion method according to Clinical Laboratories Standards Institute (CLSI). Results: Among all isolates, 15 (16%) were identified as VR E. faecalis. PCR analysis revealed that all VREF isolates were positive for the vanA gene. Conclusion: The present study reports the highest range of VREF in Iran. The increased frequency of VREF, as seen with rapid rise in the number of VanA isolates should be considered in infection control practices. [ABSTRACT FROM AUTHOR]

Background: Enterococcus faecalis has been widely used as a valuable microbiological pathogen for in vitro studies due to its ability to successfully colonize the root canal in a biofilm-like style, invade dentinal tubules, and resist endodontic treatment procedures. The aim of this study was to compare the bactericidal efficacy of photodynamic therapy (PDT), 2% chlorhexidine, 2.5% NaOCl, and combination of PDT and 2.5% NaOCl against E. faecalis. Materials and Methods: Sixty single-rooted teeth had their canals contaminated with E. faecalis in brain heart infusion broth and were incubated for 48 hours. The canals were then subjected to 2% chlorhexidine, 2.5% NaOCl, PDT (red light emitting diode 625 nm+ Toludine Blue) and PDT + 2.5% NaOCl. Controls consisted of no treatment (positive control) and without inoculation of bacterium (negative control). Following treatment, the canal contents were sampled with sterile paper points. The samples were dispersed in transport medium, serially diluted, and cultured on blood agar to determine the number of colony forming units (CFU). Data were analyzed by Mann-Whitney U test at 5% significance level. The significance level for all analyses was set at P <.05. Results: Combination of PDT and 2.5% NaOCl achieved maximum reduction in recovered viable bacteria, no viable bacteria was observed after treatment of PDT + 2.5% NaOCl. Conclusion: Combination of PDT and 2.5% NaOCl simultaneously is effective in the elimination of E. faecalis from dentinal tubules under the conditions of this study. [ABSTRACT FROM AUTHOR]

Propolis has traditionally been used in curing infections and healing wounds and burns. Current researches have shown that propolis has antibacterial, antifungal and antiviral actions however, the pharmacological activity of propolis is highly variable depending on its geographic origin. There have been few studies on the effects of Iranian propolis on the oral microorganisms. In this in-vitro study, the antimicrobial activity of the ethanolic and water extracts of the Iranian propolis (10%, w/v) from north-east area of Tehran was evaluated. Susceptibility of the oral strains tested (Streptococcus mutans ATCC 35668; Streptococcus salivarius ATCC 9222; Staphylococcus aureus ATCC 25923; Enterococcus facials ATCC 9854 and Lactobacillus casei ATCC 39392) was evaluated using the agar diffusion method at a concentration of 20 mg/mL of propolus and the zones of growth inhibition were measured. Antibacterial activity was determined by using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at different concentrations of propolis. The ethanolic extract showed bacteriostatic and bactericidal activity against all the strains, with MIC and MBC ranges of 250-500 ug/mL. The MIC concentrations of the water extract was 500 ug/mL against S. mutans and E. facials. The water extract showed bactericidal activity only against S. mutans (20 mg/mL). These results indicate that the ethanolic extract is probably more useful in the control of oral biofilms and subsequent dental caries development. However, to determine the consequences of the ethanolic extract of Iraniana propolis on the oral mucosa, in-vivo studies of its possible effects are needed. [ABSTRACT FROM AUTHOR]

This study investigated the antibacterial resistance among enterococci isolated in Tehran hospitals. A total of 277 Enterococcus faecalis, 123 Enterococcus faecium and 13 isolates of other enterococcal strains were collected from 1 March 2002 to 15 April 2004 from three teaching hospitals of Tehran University of Medical Sciences. The minimum inhibitory concentrations (MIC) of tested antibiotics were determined by agar dilution method. Susceptible and resistant isolates were defined according to the speciesrelated MIC breakpoints of the Clinical and Laboratory Standards Institute (CLSI) guidelines. Sixty- three percent of isolates were resistant to rifampicin (MIC90 64 μg/ml), 44% to ciprofloxacin (MIC90 16 ≤ μg/ml), 43% to erythromycin (MIC90 512 μg/ml), 32% to cefazolin (MIC90 256≤ μg/ml), 25% to penicillin (MIC90 32 μg/ml), 21% to ampicillin (MIC90 128≤ μg/ml), 8% to vancomycin (MIC90 ≤ 8 μg/ml), and 8% to teicoplanin (MIC90 16≤ μg/ml). All of the vancomycin-resistant strains carried the vanA phenotype and genotype. High level resistance to gentamicin and streptomycin were found in 52% and 83% of the isolates, respectively. The results indicated that a significant percentage of isolates are resistance to different antibiotics, pointing out the need for control strategies to avoid dissemination of resistant isolates and for continuous surveillance for the detection of emerging resistance traits. [ABSTRACT FROM AUTHOR]

Aims: Clonality among high-level gentamicin-resistant Enterococcus faecium (HLGR-EF) isolates obtained from clinical and sewage treatment plants (STP) were investigated using PhePlate system (PhP), ribotyping and pulsed-field gel electrophoresis (PFGE). Methods and Results: During 1 year study (September 2005–2006), a total of 106 HLGR-EF isolates were collected from clinical ( n = 48) and STP ( n = 58) samples in Tehran, Iran. Biochemical fingerprinting of these isolates using the PhP showed the presence of 21 PhP types (diversity index, Di = 0·97) among the clinical and 21 PhP types ( Di = 0·91) among the STP isolates. Representative isolates of each PhP type ( n = 42) were further characterized by the ribotyping method. Sixteen ribotypes were identified among the isolates with five types shared between the clinical and STP isolates. PFGE recognized 24 clonal types among these isolates with three pulsotypes shared between the clinical and STP isolates. Combination of the two techniques (PFGE and ribotyping) resulted in 24 ( Di = 0·96) and 16 ( Di = 0·93) types among the strains isolated from clinical and STP samples, respectively. Conclusions: We concluded that the combination of PhP typing, ribotyping and PFGE could be extremely discriminatory when examining HLGR-EF isolates. Significance and Impact of the Study: The emergence of highly diverse HLGR-EF population in Iran is of serious concern especially because of their multi-resistances. [ABSTRACT FROM AUTHOR]

To assess the prevalence of enterococci in pasteurized milk and characterize their virulence traits, 416 pasteurized milk samples were purchased from retail stores in the Northwest of Iran. Enterococci were isolated by conventional methods and confirmed by genus-specific PCR. Amongst the samples, 269 were identified as either Enterococcus faecalis or E. faecium , which were then subjected to genotypic and phenotypic analyses. Using enterobacterial repetitive intergenic consensus (ERIC)-PCR, E. faecalis and E. faecium strains were effectively grouped into 15 and 16 clusters, respectively. Nonetheless, ERIC-PCR was unable to accurately cluster E. faecalis and E. faecium strains according to their virulence or phenotypic characteristics. Based on the results, most of the isolates, especially E. faecalis strains, carried gelE , hyl , asa1 , esp , cylA , ace , and efaA genes. Results also revealed that E. faecalis and E. faecium isolates were highly resistant to most of the tested antibiotics. The resistance to vancomycin for E. faecalis and E. faecium was estimated at 71.9% and 77.6%, respectively. Moreover, 81% and 69% of E. faecalis and E. faecium strains were able to produce biofilm. It was concluded that pasteurized milk could be an intermediate vehicle for the transmission of multidrug-resistant virulent enterococci strains to humans. • Some of the pasteurized milk is a potential reservoir for virulent enterococci. • ERIC-PCR clustered E. faecalis and E. faecium into genetically distinct groups. • Multidrug-resistance of the enterococci isolated from pasteurized milk is alarming. • Most E. faecalis and E. faecium strains are biofilm produces. [ABSTRACT FROM AUTHOR]

Background and the purpose of the study: The low affinity penicillin-binding protein (PBP) 5 of Enterococcus faecium is responsible for intrinsic resistance to beta-lactam antibiotics. This study was conducted to determine the MICs of ampicillin against E. faecium strains cultured from Iranian patients (n=54) in Tehran hospitals and to sequence the C-terminal ends of pbp5s from selected strains (n=15) in order to determine possible mechanism of resistance to ampicllin. Methods: Initially, the minimum inhibitory concentrations (MICs) of ampicllin against 54 isolates of E. faecium were determined using broth macro-dilution assay. A PCR was designed to target pbp5 gene. The PCR products corresponding to the C-terminal ends of PBP5s for each strains (n=15) were sequenced. Results: Up to 44% of isolates were highly resistant to ampicillin (MIC ≥ 64 µg/ml). Amino acid substitutions were found at position number of 485 (Met 485 to A(T) and also an additional serine residue inserted just after Ser 466 among the high level resistant isolates (MIC ≥ 64 µg/ml). Other substitutions were also found at Q461K and V586L in these strains. Conclusion: It appears that amino acid alternations near the SDN motif, mainly the amino acid at position 485, were responsible for high-level resistance to ampicillin. Other substitutions outside of this motif (n=7) had no observable effect on resistance. [ABSTRACT FROM AUTHOR]

We investigated for the first time the occurrence, stability and antibiotic resistance of 593 enterococci in six samples collected from three urban sewage treatment plants (STPs) located in the north, south and west part of Tehran, Iran between October 2004 and September of 2005. Isolates were typed with a biochemical fingerprinting method (the PhPlate system) and tested for their resistance to six antibiotics. The most prevalent species in all three STPs were E. faecium followed by E. hirae and E. faecalis accounting for 93% of the total isolates examined. In all, 317 (55%) isolates were susceptible to all six antibiotics tested and the remaining isolates were resistant to between 1 and 6 antibiotics. Biochemical fingerprinting with PhPlate system showed a high diversity for E. faecalis ( D i = 0.95), E. hirae ( D i = 0.93) and E. faecium ( D i = 0.95) populations with an overall diversity of D i = 0.97 for the whole enterococcal populations found in all three STPs. Our data indicate a high degree of polyclonality among the enterococci populations of human origin. This study suggest that the municipal wastewaters might be an important source of dissemination of antibiotic-resistant enterococci in Iran. [ABSTRACT FROM AUTHOR]

The prevalence of resistance to high levels of gentamicin among 182 isolates of Enterococcus faecalis from 2 Iranian hospitals was 42%. Gentamicin resistance was associated with conjugative plasmids (>70 kb) in most strains. Fingerprinting using EcoRI and HindIII showed genetic variation among these plasmids and gave evidence of nosocomial outbreaks and persistence of infection in different wards of the study hospitals, as well as transfer of plasmids between genetically diverse isolates. Using EcoRI, hospital-based specific plasmid fingerprints were detected for the isolates that had previously proved to be unrelated by multilocus enzyme electrophoresis, suggesting the persistence of related plasmids at each hospital, though minor changes in these related plasmids could be detected with HindIII. [ABSTRACT FROM AUTHOR]

Conventional bacteriology techniques were used to identify enterococci isolates cultured from patients at different hospitals in Tehran during 2000–2001. The identification was confirmed using species-specific PCR targeting the D-alanyl-D-alanine ligase gene. A total of 59 isolates of Enterococcus faecalis were identified. The rates of resistance to different antibiotics were in the following order: penicillin 84%, ciprofloxacin 42%, high-level gentamicin 30%, nitrofurantoin 14%, imipenem 4%, and chloramphenicol 2%. Resistance to ampicillin was found to be rare among the Iranian isolates of E. faecalis. Multi-locus enzyme electrophoresis was then used to analyze the strains. Forty-five electrophoretic types were obtained when 10 enzyme loci were screened. Although the collection of bacterial isolates was limited in time and location, considerable heterogeneity was found. Analysis of strains for linkage disequilibrium demonstrated that the studied population is not clonal, since the index of association was not significantly different from zero (Ia = 0.0296). Enterococcus faecalis isolates recovered from patients in Tehran were genetically diverse and seemed to possess a high potential for genetic recombinations, though none were resistant to vancomycin. [ABSTRACT FROM AUTHOR]

Background: An increase in resistant gram-positive cocci, especially enterococci, requires an epidemiologic re-assay and its results may affect empirical treatments for these infections., Objective: In this study, we investigated the microbial epidemiology and resistance pattern of enterococcal bacteremia., Methods: This study was a cross-sectional study that investigated all cases of positive blood cultures with Enterococcus spp. at a tertiary referral colligates hospital in Tehran in 2018., Results: Enterococcus spp. was isolated from blood cultures of a total of 73 patients. Most of the patients were male i.e: 42 (57.7%). The mean age of the patients was 58.8 (±18.8) years. Hospital- acquired infection was the most prevalent type of infection involving enterococcal bacteremia (80.8%) compared with community-acquired (6.7%) and the health care-associated one (12.3%). Renal failure and cancer were the most underlying disease in E. faecalis and E. faecium, respectively. Mortality for Vancomycin-resistant enterococci (VRE) was approximately two times more than the sensitive ones. Between the dead/alive groups, the following items were significantly different (P.Value<0.05): Vancomycin resistance for enterococcus isolated, immunodeficiency as an underlying disease, Mechanical ventilation, hospitalization period, and the empiric regimen., Conclusion: Increased antibiotic-resistant strains, especially Vancomycin-resistant enterococci (VRE), pose a serious threat to the general public, especially hospitalized patients, causing an increase in mortality. Surveillance of microorganisms and antimicrobial resistance is a crucial part of an efficient health care system., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Introduction: The direct association between some microbial species and cancers, such as in colorectal cancer (CRC), has been disclosed., Objective: The aim of this study was to evaluate the changes in intestinal microbiota in subjects with CRC compared with healthy group., Methods: Three-hundred fecal specimens were gathered from patients with CRC and 300 from healthy individuals during March 2014 to October 2019 from two hospitals in Tehran. The informed consent form and the questionnaire were completed by the patients. Following the identification of Lactobaccilus acidophilus (L. acidophilus), Lactobacillus palntarom (L. palntarom), and Enterococcus faecalis (E. faecalis), the number of bacteria was determined using quantitative real-time PCR (qPCR)., Results: The patients' age range was 20-76 years (mean: 55.34 ± 3.66). The qPCR clarified that number of E. faecalis was 2.2-fold higher in patients with CRC compared to healthy population (p = 0.0013). Additionally, the number of L. acidophilus and L. plantarom was 3.4-fold (p < 0.0001) and 4.8-fold (p < 0.0001) higher in healthy population., Conclusion: The inhibitory effect of intestinal microflora against the CRC development was proposed by observation of the changes in intestinal microbiota and determining their composition in subjects with CRC compared with that of healthy individuals. Microbiota was considered as a goal for the prevention and treatment of CRC. The relationship between microbiota and human health would be known deeper; this knowledge provides insights into the management of intestinal microbiota and therapeutics., (© 2020. Springer Science+Business Media, LLC, part of Springer Nature.)

Infections with high levels of gentamicin-resistant (HLGR) isolates of Enterococcus faecalis are common in Tehran hospitals. Genes encoding such resistance are transmissible by conjugation at high frequency. The purpose of this study was to determine the existence of Tn5281 and its flanking aminoglycoside modifying enzyme gene aac(6′)-aph(2″) among 102 HLGR isolates of E. faecalis cultured from patients at three hospitals in Tehran, Iran. These isolates were detected by disks containing 120 μg of gentamicin and made 65% of all E. faecalis during the study period. DNA was extracted from HLGR isolates and subjected to PCR assays targeting aac(6′)-aph(2″) and conjugative transposon Tn5281. The amplified aac(6′)-aph(2″) gene was labeled with digoxigenin and probed with Tn5281 amplicons in dot blot hybridization assays. The aac(6′)-aph(2″) gene was detected in 91%-92% (n = 93) of the HLGR isolates. All isolates containing aac(6′)-aph(2″) were positive in long-PCR targeting Tn5281 and the probe hybridized with Tn5281 amplicons. The number of HLGR isolates of E. faecalis has increased considerably in Tehran hospitals. Tn5281 is the main cause of transmission of aac(6′)-aph(2″) to different isolates of E. faecalis in the hospitals studied. Les infections par des isolats d’Enterococcus faecalis résistant à de hauts niveaux de gentamycine (HLGR) sont communes dans les hôpitaux de Téhéran. Les gènes responsables de cette résistance sont transmissibles par conjugaison à de hautes fréquences. Le but de cette étude était de détecter la présence du Tn5281 et du gène adjacent aac(6′)-aph(2″) codant une enzyme de modification des aminoglycosides, parmi les 102 isolats HLGR de E. faecalis cultivés à partir de patients de trois hôpitaux de Téhéran, Iran. Ces isolats ont été détectés sur des disques contenant 120 μg de gentamycine et constituaient 65 % de tous les cas d’infection à E. faecalis à survenir pendant la période d’étude. L’ADN a été extrait des isolats HLGR et a été soumis à des essais PCR ciblant aac(6′)-aph(2″) et le transposon de conjugaison Tn5281. Le gène aac(6′)-aph(2″) amplifié a été marqué à la digoxigénine et hybridé aux amplicons Tn5281 par buvardage en point (dot blot). Le gène aac(6′)-aph(2″) a été détecté chez 91 % - 92 % (n = 93) des isolats HLGR. Tous les isolats contenant aac(6′)-aph(2″) étaient positifs en PCR longue ciblant le Tn5281 et la sonde s’hybridait avec les amplicons Tn5281. Le nombre d’isolats HLGR d’E. faecalis a considérablement augmenté dans les hôpitaux de Téhéran. Le Tn5281 est le principal responsable de la transmission de aac(6′)-aph(2″) aux différents isolats de E. faecalis dans les hôpitaux étudiés. [ABSTRACT FROM AUTHOR]

Background: Combination of a cell wall-active antibiotic with an aminoglycoside confers a synergistic effect in the treatment of some severe enterococcal infections. Unfortunately, with the emergence of enterococci with high-level resistance to aminoglycosides, particularly to gentamicin, the efficacy of the synergistic combinations has decreased. In this study, high-level gentamicin-resistant (HLGR) isolates of enterococci and the diversity of the genes encoding aminoglycoside-modifying enzymes (AMEs) as well as putative clonal dissemination of HLGR isolates were investigated in a university hospital in southeastern Iran., Methods: The minimum inhibitory concentration of gentamicin was determined and HLGR isolates were investigated for AME genes. Genetic similarity between isolates was analyzed using repetitive extragenic palindromic (rep)-Polymerase Chain Reaction (PCR) assay., Results: Of 150 Enterococcus isolates, 62 isolates including Enterococcus faecalis (n = 46) and E. faecium (n = 16) were identified as HLGR. The most prevalent AME genes in both species were as follows: aph(3 ' )-IIIa (n = 44), aac(6 ' )-Ie-aph(2 ' )-Ia (n = 36), and ant(4 ' )-Ia (n = 15). The rep-PCR analysis showed clonality among E. faecalis isolates, so that 27 isolates were grouped in seven clusters representing similarity greater than 95%., Conclusions: No link between AME determinants and clusters was found. Clonal spread of HLGR isolates of E. faecalis was found within our hospital. More rigorous recommendations are required to avoid dissemination of such resistant microorganisms in the hospital setting.

Aims and Objectives: The present work aimed to evaluate the frequency of aminoglycoside- modifying enzymes encoding genes in the E. faecalis and E. faecium and their antibiotic resistance profile., Methods: A total of 305 different clinical samples were subjected for identification and antibiotic susceptibility test. The high-level aminoglycoside resistance was identified by MIC and Kirby Bauer disc diffusion method. The prevalence of aac (6')-Ie-aph (2'')-Ia, aph (3')-IIIa and ant (4')- Ia genes was determined by multiplex- PCR. In total, 100 enterococci strains were isolated. The prevalence of E. faecalis and E. faecium isolates was 78% and 22%, respectively., Results: All isolates were susceptible to linezolid. So, all E. faecalis were susceptible to vancomycin but, 36.4% of E. faecium were resistant to it. The prevalence of multiple drug resistance strains was 100% and 67.9% of E. faecium and E. faecalis, respectively. High-level-gentamicin and streptomycin resistant rates were as follows; 26.9% and 73.1% of E. faecalis and 77.3% and 90.1% of E. faecium. Conclucion: The results of the current study showed a high frequency of aac (6')-Ie-aph (2'')-Ia genes among enterococcal isolates. A high rate of resistance to antimicrobials in Enterococcus is obviously problematic, and a novel policy is needed to decrease resistance in these microorganisms., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Enterococcal infections comprise a wide range of diseases with increasing importance due to the growing frequency of health-care-associated infections and the increasing incidence of antimicrobial resistance. Vancomycin-resistant Enterococcus (VRE) is an emerging drug-resistant organism responsible for increasing numbers of nosocomial infections in both adults and children. Few data are available on the epidemiology and impact of VRE infections in Iranians. In the present study, attempts were made to evaluate the prevalence and molecular characterization of VRE isolates from patients referred to several hospitals in Iran., Materials and Methods: Eight hundred and fourteen enterococcal clinical isolates from different patients were selected for this cross-sectional study during June 2018 and February 2019. Antimicrobial susceptibility testing was performed by standard methods according to the Clinical Laboratories Standards Institute (CLSI) guidelines. The vanA and vanB genes in VRE isolates were amplified by PCR., Results: Our findings indicated that 20.7% of the isolates were collected from hospitalized patients in the ICU. Among all the isolates, 254 (30%) were identified as VRE strains. All of the VRE isolates were sensitive to linezolid. Moreover, only 39.9% of the VRE isolates harbored the vanA gene, while none of them carried the vanB gene., Conclusion: The present study reports the highest range of VRE infections in Iran. The constant surveillance and monitoring of VRE strains are recommended to limit the occurrence and spread of VRE clones within and among hospitals and community settings., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objectives: Enterococcus faecalis as part of the normal floras of human gastrointestinal and genitourinary tracts are an important cause of nosocomial infections. The present study aimed to investigate the prevalence of genes encoding antimicrobial resistance and genetic relatedness of clinical isolates of E. faecalis among Iranian hospitalized patients., Results: Antibiotic susceptibility testing results indicated that 53 (22.8%) out of 232 E. faecalis isolates were vancomycin resistant (MIC ≥ 256 μg/ml). All of the 53 vancomycin-resistant E. faecalis isolates carried the vanA and ermB genes; whereas aac (6')-Ie aph (2″), msrA, and ermA gene were found in 96.2%, 30.2% and 3.8% of vancomycin-resistant isolates, respectively. ERIC-PCR typing revealed that 53 vancomycin-resistant isolates were classified into 14 ERIC types. In our results, the high level of resistance to gentamicin, erythromycin and vancomycin in enterococci isolates were mainly related to the presence of aac (6')-Ie aph (2″), ermB and vanA genes, respectively. Meanwhile, ERIC-PCR analysis demonstrated that most of the evaluated isolates have a close genetic relatedness.

Background: The aim of this study was to determine and compare antibiotic resistance profile, biofilm formation ability and frequency of agg and ace genes in Enterococcus spp strains isolated from patients and healthy individuals., Methods: A total of 90 non-duplicate Enterococcus spp isolates were isolated from patients and healthy individuals. Antibiotic susceptibility pattern was determined by disk diffusion and E-test method. Virulence genes and two species of enterococci were determined by PCR amplification. The capacity of biofilm formation was also evaluated by microtiter plate technique., Results: E. faecalis was the predominant species among our clinical isolates (80%). The prevalence of agg and ace genes was 37.8% and 73.3% in clinical and 8.9% and 11.1% in "healthy" samples, respectively. The rate of Multiple Drug Resistant strains was 73.3% and 11.1% in clinical and "healthy" isolates, respectively. The ability of biofilm formation was significantly higher in clinical compared to "healthy" isolates (100% vs 75.6%, P < 0.05)., Conclusion: The frequency of ace and agg genes, antibiotic resistance and biofilm formation ability were significantly higher in clinical than in "healthy" isolates (P < 0.05). Existence of agg and ace genes, biofilm formation and antibiotic resistance among the healthy enterococci isolates has a special importance since, in case these strains spread through clinical environments or reach water sources, this issue can be considered as a risk factor for health and sanitation of societY.