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Background. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen responsible for burn-wound infection. High incidence, infection severity and increasing resistance characterize P. aeruginosa -induced burn infection. Purpose. To estimate quorum-sensing (QS)-dependent virulence factors of P. aeruginosa isolates from burn wounds and correlate it to the presence of QS genes. Methods. A cross-sectional descriptive study included 50 P . aeruginosa isolates from burn patients in Mansoura University Plastic and Burn Hospital, Egypt. Antibiotic sensitivity tests were done. All isolates were tested for their ability to produce biofilm using a micro-titration assay method. Protease, pyocyanin and rhamnolipid virulence factors were determined using skimmed milk agar, King’s A medium and CTAB agar test, respectively. The identity of QS lasR and rhlR genes was confirmed using PCR. Results. In total, 86 % of isolates had proteolytic activity. Production of pyocyanin pigment was manifested in 66 % of isolates. Altogether, 76 % of isolates were rhamnolipid producers. Biofilm formation was detected in 96 % of isolates. QS lasR and rhlR genes were harboured by nearly all isolates except three isolates were negative for both lasR and rhlR genes and two isolates were positive for lasR gene and negative for rhlR gene. Forty-nine isolates were considered as extremely QS-proficient strains as they produced QS-dependent virulence factors. In contrast, one isolate was a QS deficient strain. Conclusions. QS affects P. aeruginosa virulence-factor production and biofilm in burn wounds. Isolates containing lasR and rhlR seem to be a crucial regulator of virulence factors and biofilm formation in P. aeruginosa whereas the lasR gene positively regulates biofilm formation, proteolytic activity, pyocyanin production and rhamnolipid biosurfactant synthesis. The QS regulatory RhlR gene affects protease and rhamnolipid production positively.

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Background:The exact aetiology of pityriasis rosea (PR) is still unknown as various researches exist aiming to explain the exact cause. The role of Human Herpes Virus(HHV)-6 & HHV-7 DNA in PR patients has been evaluated in many studies with variable results. The rationale behind the use of antiviral in PR is that the course of the disease follows that of a viral exanthem and also probable involvement of HHV 6 and 7 in its etiopathogenesis. The current case-control study aimed at evaluation of the possible relation between HHV-6 & HHV-7 and PR through detection of HHV-6 & HHV-7 DNA in PR patients in comparison to controls and also illumination the therapeutic efficacy of Acyclovir in PR treatment. Patients and methods: This study recruited 40 subjects, 30 PR patients and 10 healthy controls. All patients were subjected to detailed history taking and examination to determine the presence of constitutional symptoms, prutitus, the type of PR and ensuring the duration of PR together with lack of drug intake in the last two weeks. Skin biopsies were taken from all subjects to detect HHV-6 & HHV-7 DNA. We initiated a comparative control study to detect HHV-6 & HHV-7 DNA in lesional and nonlesional skin samples in PR patients by nested PCR. The results of nested PCR of lesional and non-lesional skin samples were compared to well-matched healthy controls. Also, the study included another comparative control study to evaluate the efficacy of oral Acyclovir (in adult 400 mg five times a day and in children 20 mg /kg/day in five divided doses) for treatment of PR patients. The results of oral acyclovir therapy in group 1 were compared to those in a well matched group II receiving no treatment apart from emollients. Results: The results revealed significant presence of HHV-6 DNA in PR lesions in comparison to controls with p=0.035, thus, support a possible relationship between HHV-6 and PR, but there was no significant difference in HHV-7 DNA in PR lesional skin compared to controls (P=0.047). Also, there was significant difference between lesional HHV-7 positive and negative cases regarding the course of the disease by the end of the second week with P-value < 0.05. In addition, there was significant improvement in PR in group 1 patients with acyclovir treatment (P= 0.05) in comparison to patients in group II without acyclovir treatment (P>0.05) by the end of the second week. Conclusion: HHV-6 and HHV-7 may play a role in the pathogenesis of PR and oral acyclovir is helpful in decreasing the severity and shortening the course of the disease in some patient.

Background: Fungal infections play important role in pathogenesis of diabetic foot infections. Objective: to investigate the prevalence of fungi among patient with diabetic foot infections. Methodology: one hundred and twenty diabetic patients hospitalized due to foot infections were enlisted in this study. Deep tissue specimens from depth of the wound and nail samples were collected from the infected sites using the standard protocol. Laboratory identification of samples was done and pathogens were identified to the species level by morpho-physiological methods. Polymerase chain reaction was used to assess the presence of fungi in samples from infected sites. Results: Fungi were found in 51.7% of the patients. Candida albicans were the most predominant isolated organism (40.1%). Amphotericin B had 100% sensitivity against all Candida isolates. The most susceptible Candida species to fluconazole were C. dubliniensis and C. albicans. The most susceptible Candida species to voriconazole were C. dubliniensis. The most susceptible Candida species to itraconazole were C. dubliniensis. Of the study population, 70.0% had bacterial infection. The predominant isolates were Klebsiella spp. (32.7%). Mixed fungal and bacterial infections were seen in 20.3% of patients. Sensitivity of Pan fungal PCR was 97.4%, specificity was 92.4%. Conclusion: Fungal infections were more in patients with poor glycemic control. The role of antifungal agents in management of diabetic foot infections needs to be evaluated further.