Evaluation of three plant extracts against biofilm formation and expression of quorum sensing regulated virulence factors in Pseudomonas aeruginosa

Following the increasing antibiotic resistance of pathogenic bacteria, the use of medicinal herbs as antibacterial agents has attracted growing attention. Pseudomonas aeruginosa is a human opportunistic pathogen that uses quorum sensing for regulating virulence gene expression [pyocyanin, protease, and elastase production and biofilm formation]. This study examined the anti-quorum sensing activity of Quercus infectoria, Zataria multiflora and Trachyspermum copticum extracts on standard P. aeruginosa strain. The minimum inhibitory concentration [MIC] of Q. infectoria, Z. multiflora and T. copticum extracts for standard P. aeruginosa strain was determined through micro dilution. Microtiter plates were used to evaluate the anti-quorum sensing effects of the three extracts [at a sub-MIC concentration] on pyocyanin, protease, and elastase production and biofilm formation. The acetone extract of Q. infectoria showed the highest anti-quorum sensing activity and reduced the pyocyanin, protease, and elastase production and biofilm formation by 89.1%, 78%, 73.3%, and 70.1%, respectively. The corresponding values were 88.2%, 72.1%, 69%, and 61.1% for the methanol extract of Z. multiflora and 70.6%, 63.42%, 60.1%, and 59.1% for the methanol extract of T. copticum. Considering the high anti-quorum sensing activity of the studied extracts, especially the acetone extract of Q. infectoria, these herbs can be used as antipathogenic drugs

Late onset jaundice and urinary tract infection in neonates.

OBJECTIVE: To determine the prevalence and the associated parameters of urinary tract infection (UTI) in infants with late onset jaundice. METHODS: This prospective analytic study was conducted among 400 cases, selected by simple sampling from neonates with late onset jaundice admitted in two referral hospitals of Isfahan during a 9-month period. The information including the age, sex and feeding type, as well as the results of physical examination, treatment, radiology studies, etc were recorded. The etiology of jaundice was assessed by laboratory tests. Urine analysis and urine culture were performed for all subjects. XZ and t-test were used for analysis of the data in- SPSS software. RESULTS: Of the 400 icteric neonates, 147 (36.8%) were female and 253 (63.3%) were male; 23 (5.8%) were diagnosed to have UTI, 5 cases (1.3%) had G6PD deficiency, 19 (4.8%) had dysmorphic red blood cell and 3(0.75%) had ABO or RH incompatibility. The relation between the type of feeding, circumcision and UTI was significant (P< 0.05). Of the 23 neonates with UTI,4 cases (17. 39%) were found to have urogenital abnormality. CONCLUSION: UTI was found in 5.8% of infants with late onset jaundice. The study revealed significant association between breast feeding, circumcision and lower prevalence of UTI in icteric neonates. It is suggested that evaluation for UTI should be considered as a screening test in all cases of neonatal late onset jaundice.