rpoS-Regulated core genes involved in the competitive fitness of Salmonella enterica Serovar Kentucky in the intestines of chickens.

Salmonella enterica serovar Kentucky has become the most frequently isolated serovar from poultry in the United States over the past decade. Despite its prevalence in poultry, it causes few human illnesses in the United States. The dominance of S. Kentucky in poultry does not appear to be due to single introduction of a clonal strain, and its reduced virulence appears to correlate with the absence of virulence genes grvA, sseI, sopE, and sodC1. S. Kentucky's prevalence in poultry is possibly attributable to its metabolic adaptation to the chicken cecum. While there were no difference in the growth rate of S. Kentucky and S. Typhimurium grown microaerophilically in cecal contents, S. Kentucky persisted longer when chickens were coinfected with S. Typhimurium. The in vivo advantage that S. Kentucky has over S. Typhimurium appears to be due to differential regulation of core Salmonella genes via the stationary-phase sigma factor rpoS. Microarray analysis of Salmonella grown in cecal contents in vitro identified several metabolic genes and motility and adherence genes that are differentially activated in S. Kentucky. The contributions of four of these operons (mgl, prp, nar, and csg) to Salmonella colonization in chickens were assessed. Deletion of mgl and csg reduced S. Kentucky persistence in competition studies in chickens infected with wild-type or mutant strains. Subtle mutations affecting differential regulation of core Salmonella genes appear to be important in Salmonella's adaptation to its animal host and especially for S. Kentucky's emergence as the dominant serovar in poultry.

Respiratory Epithelial Adenomatoid Hamartoma.

BACKGROUND: Respiratory Epithelial Adenomatoid Hamartoma (REAH) is an uncommon, benign tumor of the sinonasal tract. It can, however, be confused with a sinonasal malignancy causing undo morbidity to patients. Therefore, the clinical as well as histological diagnosis is crucial in order to correctly care for patients. METHODS: This review of a patient, to include their clinical pictures, radiologic pictures, and histologic pictures, allow for the clinician to accurately evaluate and diagnose REAH. RESULTS: Our patient presented with a classic bilateral olfactory cleft mass on endoscopic exam. CT was obtained showing a non-enhancing homogenous mass, widening the olfactory cleft, with no evidence of skull base defects or bony erosion. MRI was additionally obtained, given the location, showing a homogenous cribriform mass with clearly defined borders with post-contrast enhancement on T1-weighted images and hyperintense T2-weighted images. A biopsy in clinic was done, showing small to medium, round to oval shaped glands lined with ciliated respiratory epithelium and separated by stroma. The surface epithelium extends into the submucosa, communicating with the proliferating glands. CONCLUSION: Our patient, presented in this case report, shows a classic presentation of REAH. Using these findings, patients can be better counseled on this benign entity, ranging from observation to surgical intervention.

Effect of Salmonella vaccination of breeder chickens on contamination of broiler chicken carcasses in integrated poultry operations.

While measures to control carcass contamination with Salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce Salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of Salmonella vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing Salmonella prevalences in these flocks and their broiler, meat bird progeny. For one poultry company, their young breeders were vaccinated by using a live-attenuated Salmonella enterica serovar Typhimurium vaccine (Megan VAC-1) followed by a killed Salmonella bacterin consisting of S. enterica serovar Berta and S. enterica serovar Kentucky. The other participating poultry company did not vaccinate their breeders or broilers. The analysis revealed that vaccinated hens had a lower prevalence of Salmonella in the ceca (38.3% versus 64.2%; P < 0.001) and the reproductive tracts (14.22% versus 51.7%; P < 0.001). We also observed a lower Salmonella prevalence in broiler chicks (18.1% versus 33.5%; P < 0.001), acquired from vaccinated breeders, when placed at the broiler farms contracted with the poultry company. Broiler chicken farms populated with chicks from vaccinated breeders also tended to have fewer environmental samples containing Salmonella (14.4% versus 30.1%; P < 0.001). There was a lower Salmonella prevalence in broilers entering the processing plants (23.4% versus 33.5%; P < 0.001) for the poultry company that utilized this Salmonella vaccination program for its breeders. Investigation of other company-associated factors did not indicate that the difference between companies could be attributed to measures other than the vaccination program.

Molecular characterization reveals Salmonella enterica serovar 4,[5],12:i:- from poultry is a variant Typhimurium serovar.

Although Salmonella remains one of the leading causes of foodborne illnesses in the United States, the Salmonella enterica serovars and genetic types associated with most infections appear to fluctuate over time. Recently, the Center for Disease Control and Prevention (CDC) has reported an increase in cases of salmonellosis caused by Salmonella 4,[5],12:i:-. Similarly, this unusual Salmonella serovar has been isolated from cattle and poultry in the state of Georgia. We examined the genetic relatedness of Salmonella 4,[5],12:i:-, isolated from several different poultry companies and dairy farms in Georgia, by pulsed-field gel electrophoresis (PFGE). Several Salmonella 4,[5],12:i:- isolates had PFGE patterns identical or similar to PFGE patterns of Salmonella Typhimurium isolated from numerous animal sources. We identified distinct PFGE patterns for Salmonella 4,[5],12:i:- and matching Salmonella Typhimurium PFGE patterns, identifying four "distinct" strains. We focused a more specific analysis on the poultry Salmonella 4,[5],12:i:- and Salmonella Typhimurium isolates and found that of these Salmonella 4,[5],12:i:- isolates, 32% lacked the entire phase 2 antigen gene, fljB; 61% contained partial deletion(s); and 4% had partial deletion(s) in fljB and an adjacent gene hin, 5' to fljB. Thirteen percent contained smaller deletions or point mutations not identified by our DNA probes. The Salmonella 4,[5],12:i:- isolates were positive for several genes present in the Salmonella Typhimurium, including lpfE (100%), sseI(96%), and spvC (93%). Genetic analysis indicates independent, spontaneous mutations in fljB in at least four distinct Salmonella Typhimurium strains of animal origin circulating in nature.

The effect of the 16-hour intern workday restriction on surgical residents' in-hospital activities.

OBJECTIVE: To observe the effects of the 2011 Accreditation Council on Graduate Medical Education 16-hour intern workday restrictions on surgical residents' clinical and educational activities. DESIGN: All the residents recorded the following weekly in-hospital activities during February and March 2011 (year before intern work restrictions) and 2012 (first year under new requirements): operating room (OR) and clinic; bedside procedures; rounds and ward work; on-call duties in hospital; communication (e.g., checkouts and family and patient discussions); education (conferences and study); and personal (rest and meals). Descriptive statistics were calculated in 3 resident groups (interns, first postgraduate year [PGY1]; junior, PGY2 and 3; and senior, PGY4 and 5). The unpaired t test was used to compare data between 2011 and 2012; significance was set at p< 0.05. SETTING: Medical school affiliated hospital. PARTICIPANTS: Categorical resident trainees in surgery, PGY1-5, 4 residents per level, with all 20 residents participating in the study. RESULTS: From 2011 to 2012, time spent in the hospital by the intern did not change (all results in h/wk, mean±standard deviation: 68.5±13.8 to 72.8±15.8, respectively) but the time devoted to specific activities changed significantly. In-hospital personal time decreased by 50% (5.3±4.6 to 2.6±2.0, p = 0.004). Interns spent less time placing central lines (2.1±2.2 to 0.9±1.2, p = 0.006) and more on rounds (8.8±8.8 to 14.2±9.8, p = 0.027), which included supervision with upper level residents. There was no change in the total time spent in the OR, the clinic, performing bedside procedures, and educational activities. Changes in intern work did not affect the time junior and senior residents spent on bedside procedures, time spent in the clinic, and total time spent in the hospital. In 2012, junior residents spent less time in educational activities (11.4±8.5 to 7.0±4.5, p = 0.0007) and the seniors spent more time in the OR (13.7±7.5 to 20.6±10.7, p = 0.0002). CONCLUSIONS: The 16-hour restriction preserved interns' educational activities and time spent in the OR and clinic, but changed resident work activities at all levels. The time spent on rounds increased, time spent by the juniors on conferences decreased, and time spent by senior residents in the OR increased. Duty restrictions in general and intern supervision requirements demand ongoing adjustments in resident work schedules.