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Background and Objectives: Helicobacter pylori causes several gastrointestinal diseases, including asymptomatic gastritis, chronic peptic ulcer, duodenal ulcer, lymphoma of the mucosa-associated lymphoid tissue (MALT), and gastric adenocarcinoma. In recent years, failure to eradicate H. pylori infections has become an alarming problem for physicians. It is now clear that the current treatment strategies may become ineffective, necessitating the development of innovative antimicrobial compounds as alternative treatments. Materials and Methods: In this experimental study, a cell-penetrating peptide-conjugated peptide nucleic acid (CPP-PNA) was used to target the cagA expression. cagA expression was evaluated using RT-qPCR assay after treatment by the CPP-PNA in cell culture and animal model. Additionally, immunogenicity and toxicity of the CPP-PNA were assessed in both cell culture and animal models. Results: Our analysis showed that cagA mRNA levels reduced in H. pylori-infected HT29 cells after treatment with CPP- PNA in a dose-dependent manner. Also, cagA expression in bacterial RNA extracted from stomach tissue of mice treated with PNA was reduced compared to that of untreated mice. The expression of inflammatory cytokines also decreased in cells and tissue of H. pylori-infected mice after PNA treatment. The tested CPP-PNA showed no significant adverse effects on cell proliferation of cultured cells and no detectable toxicity and immunogenicity were observed in mice. Conclusion: These results suggest the effectiveness of CPP-PNA in targeting CagA for various research and therapeutic purposes, offering a potential antisense therapy against H. pylori infections. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is the most common cause of chronic infection in human and is associated with gastritis, peptic ulcer disease, and adenocarcinoma of mucosa-associated lymphoid tissue cells. Peptide nucleic acid (PNA) is a synthetic compound, which can inhibit the production of a particular gene. This study aimed to investigate the effect of PNA on inhibiting the expression of cag A. After confirmation of the desired gene by polymerase chain reaction (PCR), the antisense sequence was designed against cag A gene. The minimum inhibitory concentrations of conjugated PNA against H. pylori was determined. The effect of the compound on the expression level of the cag A was investigated in HT29 cell culture using real-time PCR. The results showed 2 and 3 log reduction in bacterial count after 8- and 24-h treatment with 4 and 8 μM of the compound, respectively. The lowest expression level of the cag A gene was observed at a concentration of 8 μM after 6 h. The results of this study showed that cell-penetrating peptide antisense can be employed as effective tools for inhibiting the target gene mRNA for various purposes. Moreover, further research is necessary to assess the potency, safety, and pharmacokinetics of CPP-PNAs for clinical prevention and treatment of infections due to H. pylori. [ABSTRACT FROM AUTHOR]

Background: The relationship between rheumatoid arthritis and poor oral hygiene has longbeen proven. Colonization of Porphyromonas gingivalis in the oral cavity can play an important role in rheumatoid arthritis. The aim of this study was to determine whether there is a relationship between rheumatoid arthritis disease and the presence of P. gingivalis. Methods:sixty patients with rheumatoid arthritis and 75 controls with matched age, sex and smoking and oral health status were selected. Provided samples from dental plaque were assessed for the presence of P. gingivalis by using bacterial culture and polymerase chain reaction (PCR). Results:Results of bacterial culture and PCR showed no significant difference between rheumatoid arthritis patients and control group in terms of the presence of P. gingivalis (P = 0.9 and P = 0.1, respectively). There was also no relationship between the number of bacterial copies and the activities of rheumatoid arthritis. Conclusion:Findings showed that there was no significant relationship between the presence of P. gingivalis in dental plaque and rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Objective(s): The present study investigated the prevalence of genes encoding for exotoxins, adhesion and biofilm factors in Staphylococcus aureus isolates obtained from samples in a referral burn hospital in Tehran, Iran. Materials and Methods: S. aureus isolates obtained from patients, personnel and surfaces in the wards of a burn hospital were identified and confirmed by biochemical and molecular tests, respectively. The susceptibility of isolates was determined using the disk diffusion method. Virulence factors were detected by multiplex PCR. Results: The frequency of hla, hlb, hld, hlg, tst and pvl genes was 92.8%, 34.7%, 89.8%, 11.9%, 10.7%, and 0.5% respectively. The results revealed that the hla gene had the highest frequency among isolates (94.4% for methicillin-resistant S. aureus (MRSA) and 89.8% for methicillin-susceptible S. aureus (MSSA)). The most prevalent adhesion and biofilm-related gene was eno (85.6%). The prevalence of the remaining genes was as follows: fib (71.8%), clfB (70%), cna (59.2 %), fnbB (17.9%), icaA (72.4%), and icaD (85.6%). The incidence of fib, hlb, hlg, and tst genes was significantly higher in MRSA isolates compare to the MSSA isolates. Moreover, the resistance rates for all antibiotics were higher is MRSA isolates except for nitrofurantoin and chloramphenicol antibiotics. Conclusion: Data indicate the high prevalence rates of virulence factors among S. aureus isolates, especially MRSA strains in the burn hospital. This should to be taken into account in the development of an effective infection control policy and continuous monitoring of drug resistance in hospitals. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus, a leading cause of community-acquired and nosocomial infections, remains a major health problem worldwide. Molecular typing methods, such as spa typing, are vital for the control and, when typing can be made more timely, prevention of S. aureus spread around healthcare settings. The current study aims to review the literature to report the most common clinical spa types around the world, which is important for epidemiological surveys and nosocomial infection control policies. Methods: A search via PubMed, Google Scholar, Web of Science, Embase, the Cochrane library, and Scopus was conducted for original articles reporting the most prevalent spa types among S. aureus isolates. The search terms were "Staphylococcus aureus, spa typing." Results: The most prevalent spa types were t032, t008 and t002 in Europe; t037 and t002 in Asia; t008, t002, and t242 in America; t037, t084, and t064 in Africa; and t020 in Australia. In Europe, all the isolates related to spa type t032 were MRSA. In addition, spa type t037 in Africa and t037 and t437 in Australia also consisted exclusively of MRSA isolates. Given the fact that more than 95% of the papers we studied originated in the past decade there was no option to study the dynamics of regional clone emergence. Conclusion: This review documents the presence of the most prevalent spa types in countries, continents and worldwide and shows big local differences in clonal distribution. [ABSTRACT FROM AUTHOR]

Background: Shigellosis is a diarrheal disease caused by Shigella spp. The majority of cases and deaths occur among children less than 5 years old. In severe cases, antibiotic therapy is recommended to lessen the risk of serious complications and death. Prevalence of different Shigella species and their antibiotic resistance patterns are changing over the time. Objectives: The current study aimed at assessing the changes in the prevalence of Shigella species and their antibiotic susceptibility among 0- to 14-year-old children referred to Children’s Medical Center, Tehran, Iran, from 2009 to 2014. Methods: The results of stool cultures were retrospectively analyzed to determine the prevalence of different Shigella species, their antibiotic susceptibility patterns and their changes in the largest university affiliated pediatrics center in Tehran. Results: Among 40 700 stool cultures, 507 cases were positive for Shigella spp. Most cases occurred among children under 5 years old. Shigellosis was more prevalent among males. The most common species were Shigella sonnei and Shigella flexneri. In general, they were most sensitive to cefotaxime and most resistant to cotrimoxazole. Resistance to cefotaxime and nalidixic acid increased annually. Resistance to ampicillin had a descending trend. Resistance to cotrimoxazole remained almost constant. Conclusions: The most common species of Shigella changed from Shigella flexneri to Shigella sonnei over the years. In comparison with the previous studies, resistance to nalidixic acid increased and resistance to ampicillin decreased. The prevalence and antibiotic resistance patterns of Shigella species, at different times and regions are changing. To make appropriate decisions on treatment, it is necessary to monitor the changes. [ABSTRACT FROM AUTHOR]