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In burn centers, Pseudomonas aeruginosa acts as a major cause of nosocomial infections. Therefore, this study aimed to characterize molecularly P. aeruginosa isolates collected from environmental samples and burn patients. A total of 78 strains (including 58 clinical and 20 environmental isolates) of the P. aeruginosa were collected from Beasat hospital of Hamadan, west of Iran, and was identified using API 20NE. The disk diffusion method according to the CLSI was applied for determination of the antimicrobial resistance. Moreover, the microtiter plate test was used for the quantification of Biofilm formation. The genomic features of the isolated strains was evaluated using Pulsed Field Gel Electrophoresis (PFGE). We found that 94.8% of clinical and 80% environmental isolates were capable of forming biofilm. The rate of MDR in clinical and environmental isolates was 51.7% and 40%, respectively. A significant relationship was observed between biofilm formation capability and multiple drug resistance (p < 0.05). PFGE typing showed 11 different clusters with two major clusters A with 30 (38.5%) and B with 14 (17.9%) members, containing up to 56.4% of all isolates. There was no relationship between biofilm formation ability and antibiotic resistance patterns with PFGE patterns. According to the results, the clonal spread of environmental P. aeruginosa isolates is associated with clinical isolates, and both environmental and clinical isolates are attributed to a high prevalence of the antibiotic resistance and biofilm formation ability. This study highlighted that the prevention programs should be implemented in the hospital environment to control the spread of P. aeruginosa in burn units.

BACKGROUND: Colorectal cancer is one of the most commonly diagnosed cancers around the world. One of the factors involved in the development of colorectal cancer is the changes in the normal flora of the intestine. OBJECTIVE: In this study, the mean copy number of Enterococcus faecalis in people with polyps and people with colorectal cancer has been evaluated in comparison with healthy controls. METHODS: In this study, 25 patients with colorectal cancer and 28 patients with intestinal polyps were selected and stool specimens were taken. In addition, 24 healthy individuals were selected as control group. Extraction of bacterial DNA from the stool sample were performed. The molecular methods of PCR for confirmation of standard strain and absolute Real Time PCR (qRT-PCR) method were used to evaluate the number of Enterococcus faecalis in the studied groups. RESULTS: The results of this study indicate that the mean copy number of Enterococcus faecalis in patients with colorectal cancer was 11.2x109 per gram of stool, and in patients with polyps was 9.4x108 per gram of stool. In healthy people, this number was 9x108 per gram of stool. There was a significant difference between the implicit copy numbers in the three groups. (P<0.05). CONCLUSION: Enterococcus faecalis in faecal flora of people with colorectal cancer was significantly higher than those with polyps and healthy people. This could potentially signify the ability of this bacterium to induce colorectal cancer. More studies are needed to prove this theory.

<b><i>Background and Aim:</i></b> <i>Helicobacter pylori</i> is one of the most common pathogenic bacteria in the human gut, and is also one of the most important factors that cause digestive disorders such as chronic inflammation, gastric ulcers, and even gastric cancer. Since the use of various antibiotics to treat <i>H. pylori</i> infection is associated with the development of resistance in this bacterium, the aim of this study was to determine the anti-<i>H. pylori</i> effects of <i>Lactobacillus acidophilus</i>, <i>L. plantarum</i>, and <i>L. rhamnosus</i> in the stomach tissue of C57BL/6 mice. <b><i>Materials and Methods:</i></b> In this experimental study, 70 mice in ten groups were evaluated from July to September 2017 in the microbiology laboratory of the School of Medicine, Alborz University of Medical Sciences, Karaj, Iran. After induction of <i>H. pylori</i> infection in mice with the standard strain of <i>H. pylori</i> (ATCC 43504), the infected mice were treated with drug and <i>Lactobacillus</i> species in different groups. Then, the anti-<i>H. pylori</i> effects of lactobacilli were evaluated by stool antigen test and tissue staining. <b><i>Results:</i></b> Based on ELISA results and histological findings, a reduction of inflammation was observed. The group which was only exposed to <i>L. rhamnosus</i> and the one which was exposed to all three strains of <i>Lactobacillus</i> showed the highest antimicrobial effect on <i>H. pylori</i>. <b><i>Conclusion:</i></b> According to the results of this study, probiotic bacteria including <i>L. acidophilus</i>, <i>L. plantarum</i>, and <i>L. rhamnosus</i> could be useful in the reduction of <i>H. pylori</i> infection in the mouse model.

BackgroundOccult hepatitis B infection (OBI) has been described in various clinical settings including after hepatitis B virus (HBV) immunization. The purpose of study was to characterize the prevalence of OBI among immunized children from a subset of general population and the parents of OBI‐positive cases.MethodsSera of 1200 children from general population who have been previously immunized by HBV vaccine were assayed for anti‐HBs. 660 were randomly selected for HBV DNA testing by different polymerase chain reaction (PCR) methods and were analysed by direct sequencing on surface genes.ResultsNone of participants were positive for HBsAg and anti‐HBc. 549 (45.7%) and 651 (54.3%) cases had anti‐HBs > 10 mIU/mL (responders) and < 10 mIU/mL (nonresponders) respectively. Of 660 selected specimens, 91 (16%) of children were positive for OBI. 23 (25.2%) and 68 (74.8%) of HBV DNA positive cases were belonged to responders and nonresponders, respectively, showing significant difference (P < .001). The mean levels of anti‐HBs in OBI‐positive and OBI‐negative groups, showed no considerable variations. The mean viral load for OBI‐positive cases showed substantial differences between responders and nonresponders (P = .007). Of 49 parents (98 individuals) of OBI‐positive children 11 (22%) and 18 (36%) were positive for anti‐HBc and anti‐HBs respectively. Molecular testing was positive in 32 subjects (16 couples, 32.6%). In total, 6 mothers and 11 fathers were positive for OBI.ConclusionA proportion of OBI‐positive vaccinated children could be existed in different populations. This finding could be arisen from vertical HBV transmission or vertical OBI possibly from their parents.