Background: The enterococci are responsible for infections including bacteremia and endocarditis which are usually resistant to multiple antibiotics. This nosocomial agent probably harbors putative virulence factors which increases their capability to colonize hospitalized patients. Objectives: This study was aimed in order to find the frequency of various virulence factors in enterococci and their relationship with multidrug resistance (MDR). Methods: The samples were collected from different hospital wards including; Intensive care unit (ICU), cardiac care unit (CCU), pediatrics department, internal wards, and transplantation. The isolates were detected by biochemical tests and in order to determine the antibiotic susceptibility pattern, disk diffusion agar (kirby-bauer) was accomplished. Then, MICs (Minimum inhibitory concentrations) of vancomycin were determined by E-test strips. For molecular examinations and detection of drug resistance genes, the simple polymerase chain reaction was used. The multiplex PCR was used in order to detect virulence factors. Results: Total of 85 isolates were obtained from one university teaching hospital in southeast of Iran. Approximately 95% of isolated which were from urine specimens and 34% of isolates were collected from pediatrics units at hospital. Tetracycline resistance (48%) has been observed with a high frequency and related to the tetM gene. Furthermore, eighteen isolates were recognized as MDR strains that carried vanA, aac (6)-Ie-aph (2)-Ia, ermB, and tetM genes. Among virulence factor genes, asa1 (69%) and gelE (55%) are more frequently observed in both species. In general, we found Enterococcus faecalis strains more prevalent. Also, E. faecium was related to antibiotic resistance genes in nosocomial infection. Conclusions:The data was indicated a high prevalence of multiple antibiotics resistance genes with virulence determinants in enterococci and also considered resistant isolate in pediatrics unit. The current results can be recommended in order to change new strategies for antibiotic therapy, because this serious pathogen is important for treatment and eradication in hospitals. Furthermore, the biofilm formation was regulated and constructed by virulence determinants that could be a candidate for enterococcal treatment.

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Enterococcus have emerged as antibiotic resistant in nosocomial infections, food pollutant and also found in root canal teeth. The presence of virulence factors leads to spreading and survive in a hospital or other environments. Different molecular studies have reported the importance of Enterococcus with putative virulence factors at infections. The host immune process is able to identify Enterococcus, although these virulence factors provided conditions to evasion from the immune system. Therefore, these determinants are the best candidates for new therapies strategy and controlling this problematic microorganism.

Background and objectives: Nosocomial infections caused by antibiotic resistant bacteria is a life threatening health challenge. This study aimed to determine the frequency of antibiotic resistance genes in clinical isolates from hospitals of Zahedan, southeast of Iran. Methods: Overall, 818 isolates were collected from different hospital wards. The isolates were identified using conventional microbiological and biochemical tests. Antibiotic susceptibility pattern was assessed by agar disc diffusion method and determination of minimum inhibitory concentration of a number of antibiotics. Multiplex PCR was performed using specific primers for the detection of resistance genes. Results: The most common species were Staphylococcus aureus (25%), Klebsiella pneumoniae (22%) and Pseudomonas aeruginosa (14%). The rate of methicillin resistance among S. aureus, S. epidermidis and S. saprophyticus was 60%, 43% and 24%, respectively. In addition, 28.5% of enterococci isolates were vancomycin resistant. Among gram-negative bacteria, 45% of A. baumannii and 24% of P. aeruginosa were identified as ESBL. A high level of resistance to ampicillin (96%), cefotaxime (89%), gentamicin (89%) and sulfamethoxazole-trimethoprime (60%) was observed in K. pneumoniae. Conclusion: Our results highlight the urgent need for an eradication program and a surveillance plan for preventing increased emergence of antibiotic resistant bacteria in the study area.