---

Introduction: In the 1950s vancomycin was introduced as an effective antibiotic for curing infections caused by methicillin resistant Staphylococcus aureus. Three decade after using vancomycin, resistant coagulase negative staphylococcus to this antibiotic was reported. In this study, we evaluate the Staphylococcus aurous resistant to vancomycin.
Materials and methods: During this invesitigatin which lasted for 6 months, 50 Staphylococcus aurous samples were taken from burn wards of each of two Imam-Reza and Gaem hospitals, Mashhad. All selected samples were resistant to methicillin and their MIC to vancomycin was determined.
Results: Of 50 separated bacteria from Imam-Reza and Gaem hospitals subjects, 4 patients had MIC equal to 12.5 mg/ml. In isolated samples from Gaem hospital, one case has MIC equal to 12.5 mg/ml.
Conclusion: With respect to expanding the resistant toward vancomycin, thus it is recommended to inhibit the resistance of this organism in the wards.

---

Background: Enterococcus is known as an important pathogen in Iran like all around the world. The increasing use of vancomycin makes vancomycin-resistant enterococci (VRE) an important nosocomial pathogen. Vancomycin in combination with an aminoglycoside can provide effective treatment for severe enterococcus infections, while resistance to vancomycin antibiotic is increasing in enterococci. In this study, the pattern of antibiotic resistance and prevalence of vancomycin resistance enterococci have been explored. Materials and Methods: In this experimental study, after isolating and identifying 150 strains of enterococci from clinical specimens, the antibiotic resistance pattern of these strains to erythromycin, teicoplanin, vancomycin, ciprofloxacin, tetracycline, gentamicin, co-trimoxazole and linezolid was examined. The MIC test by using micro dilution broth method was performed for the vancomycin resistance enterococci specimens with the vancomycin and teicoplanin antibiotics. Results: Antibiotic susceptibility test showed 14% and 5.3% of the samples were resistant to vancomycin and teicoplanin respectively. Resistant to erythromycin, co-trimoxazole, ciprofloxacin, tetracycline, linezolid and gentamicin were 64, 40, 38.6, 6.6, 0, 38.76 percent respectively. Fourteen samples had high resistance to vancomycin which MIC were ≥ 256 µg/ml. Conclusion: Based on the results of present study, there are vancomycin-resistant enterococci in Arak as well as other parts of the world. The percentage of vancomycin resistance enterococci is high in Arak and appropriate treatment of infections caused by enterococcus is essential

---

Background: Endophthalmitis is the most important complication after cataract surgery which its incidence can lead to severe loss of vision or even loss of vision therefore, methods of prevention are very important. This study investigated the influence of vancomycin consumption during cataract surgery on prevention of endophthalmitis.

Materials and Methods: In this experimental study, the study population included patients of cataract surgery that were admitted to Amir Kabir Hospital. The patients were randomly assigned to two groups: with and without receiveing vancomycin in serum. Demographic characteristics of the patients before surgery and incidence of endophthalmitis with the examination until two weeks after surgery were recorded. To compare the frequency (incidence) of infection, endophthalmitis in two groups, Fisher's exact test and X2 test were used.

Results: Of the 1281 patients, 539 were administered vancomycin in serum. The examination after two weeks indicated that 3 (0.23%) patients developed endophthalmitis. Of these, 2 (0.16%) patients belonged to the group without vancomycin and 1(0.07%) patient belonged to the group receiving vancomycin. Fisher's exact test did not show any significant differences between the groups receiving vancomycin and the control group in the prevalence of endophthalmitis.

Conclusion: Although the relative frequency of endophthalmitis in patients without receiving vancomycin was further than control group, the difference was not statistically significant. Thus, adding a drop of vancomycine was not effective in prevention of endophthalmitis and the causes should be sought in other cases.

---

Abstract

Background: Prevalence extension of antibiotic resistant bacteria has raised concerns about control of infections especially nosocomial infections. Many attempts have been done to replace antibiotics or limit their use. The use of antimicrobial agents produced by bacteria as antibiotic replacement has been promising in recent years. The goal of this study was to isolate Bacillus strains and evaluate their antimicrobial activity against some standard pathogens and clinical antibiotic resistant strains.

Materials and Methods: In the present study, Bacillus strains were isolated from various resources and identified by 16S rDNA PCR method. Then, the phylogenetic tree of the isolates was constructed and antimicrobial activity of the isolates was investigated against some standard pathogens and clinical antibiotic resistant strains using spotting and well diffusion methods.

Results: Eight Bacillus strains were isolated from 15 different samples. Based on the molecular identification, the isolates were identified as B.pumilus, B.coagulans, B.licheniformis, B.endophitycus and B.amiloliquefaciens. The results showed that isolates have antimicrobial activity against meticilin-resistant Staphylococcus aureus, vancomycin resistant enterococci, Klebsiella, Acinetobacter, Salmonella, Shigella, Listeria, Streptococcus and Escherichia coli.

Conclusion: In this study, isolated Bacillus strains produced antimicrobial agents against pathogens and antibiotic resistant strains and inhibited their growth.