Hereditary Hemochromatosis Predisposes Mice to Yersinia pseudotuberculosis Infection Even in the Absence of the Type III Secretion System

The iron overload disorder hereditary hemochromatosis (HH) predisposes humans to serious disseminated infection with pathogenic Yersinia as well as several other pathogens. Recently, we showed that the iron-sulfur cluster coordinating transcription factor IscR is required for type III secretion in Y. pseudotuberculosis by direct control of the T3SS master regulator LcrF. In E. coli and Yersinia, IscR levels are predicted to be regulated by iron bioavailability, oxygen tension, and oxidative stress, such that iron depletion should lead to increased IscR levels. To investigate how host iron overload influences Y. pseudotuberculosis virulence and the requirement for the Ysc type III secretion system (T3SS), we utilized two distinct murine models of HH: hemojuvelin knockout mice that mimic severe, early-onset HH as well as mice with the Hfe^{C282Y∕C282Y} mutation carried by 10% of people of Northern European descent, associated with adult-onset HH. Hjv^−∕− and Hfe^{C282Y∕C282Y} transgenic mice displayed enhanced colonization of deep tissues by Y. pseudotuberculosis following oral inoculation, recapitulating enhanced susceptibility of humans with HH to disseminated infection with enteropathogenic Yersinia. Importantly, HH mice orally infected with Y. pseudotuberculosis lacking the T3SS-encoding virulence plasmid, pYV, displayed increased deep tissue colonization relative to wildtype mice. Consistent with previous reports using monocytes from HH vs. healthy donors, macrophages isolated from Hfe^{C282Y∕C282Y} mice were defective in Yersinia uptake compared to wildtype macrophages, indicating that the anti-phagocytic property of the Yersinia T3SS plays a less important role in HH animals. These data suggest that Yersinia may rely on distinct virulence factors to cause disease in healthy vs. HH hosts.

Sociodemographic profile and career decisions of Australian oral health profession students

This study collected and analyzed recent information regarding the sociodemographic profile and career decisions of Australian oral health profession students (earning B.D.Sc. and B.O.H. degrees) and the reasons for their career choice. Data were collected during the 2009-10 academic year via a web-based survey. A total of 829 students participated; the response rates for each oral health course at the seven participating universities ranged from 15.0 percent to 88.7 percent. The respondents had an average age of 21.4 years, ranging from eighteen to fifty-one. The majority of the respondents were female (61.4 percent), single (91.0 percent), and of Asian ethnicity (65.0 percent), and almost half had attended a public secondary school (49.7 percent). Most of the responding students either lived in rented accommodation (44.0 percent) or with their parents (28.6 percent), and 41.5 percent reported having an urban address. Most respondents' fathers (67.2 percent) and mothers (54.8 percent) had completed undergraduate or postgraduate education and were employed in managerial or professional occupations (68.5 percent and 54.9 percent, respectively). Most of the students said they had selected their course in high school (66.8 percent) and were most influenced in their career choice by self-motivation (85.3 percent) and caring for and helping other people (86.6 percent). The majority of the respondents reported wishing to work in a city (51.5 percent), practicing general dentistry (31.8 percent) in either the public or private sector (40.2 percent each). This article provides a preliminary look at the future dental workforce of Australia, identifying issues for further analysis and assisting each university to address current inequalities and challenges.

Information and communication technology use among Victorian and South Australian oral health professions students

The objective of this study was to determine and analyze the use of information and communication technology (ICT) by oral health professions students in Victoria and South Australia. Data were collected during the 2009 and 2010 academic years via electronic survey. Out of 1,138 students studying in Adelaide and Victorian dental schools, 740 students participated, for an overall response rate of 65 percent. The majority were dental students (n=609) with 131 seeking a Bachelor of Oral Health (B.O.H.) degree. The majority were female (62.0 percent), had home Internet access (91.7 percent), and no barriers to accessing the Internet (87.2 percent). Among those who mentioned barriers, difficult access and cost were the most common. The Internet was accessed at least once a week by the majority for general purposes (93.5 percent) and for study purposes (84.2 percent). Nonetheless, thirty-nine students (5.3 percent) were non-frequent ICT users. The probability of an oral health professions student being in the non-ICT users group was explored utilizing a logistic regression analysis. The final model contained three predictors: location of school, ethnic background, and place of Internet use (χ(2) [3]=117.7; p<0.0001). After controlling for other variables in the model, those studying in South Australia were significantly more likely (OR=2.32; 95 percent CI 1.05 to 5.11) to be in the non-users groups. In the same manner, students from an Asian background were three times more likely to be non-users (OR=3.06; 95 percent CI 1.16 to 8.08). Those who had access to the Internet at home (OR=0.02; 95 percent CI 0.01 to 0.05) were less likely to be a non-user. These results represent a preliminary evaluation of ICT use among oral health professions students in Australia. It seems that a digital divide exists among these students. The information can be utilized in planning dental education programs and incorporating the use of ICT suitable for oral health professions students and in the design and implementation of employment recruitment and retention programs.