Type 13a Research Articles

Which pediatric supracondylar humerus fractures are high risk for conversion to open reduction?

Supracondylar humerus fractures are common pediatric injuries encountered by orthopedic surgeons. Displaced fractures are treated operatively with closed reduction and percutaneous pinning or open reduction of injuries that cannot be adequately closed reduced. The purpose of this study is to identify preoperative injury characteristics associated with open reduction. Retrospective chart review was performed on all AO type 13A (Gartland type) supracondylar humerus fractures in patients 2-13 years old treated surgically at a single level 1 trauma center over 6 years. Preoperative demographics and radiographic parameters were obtained for all patients. Primary outcomes were closed reduction or conversion to open reduction of fractures prior to k-wire fixation. Initial bivariate analysis was done using Chi-square tests. Final multivariate analysis with Bonferonni correction was performed using a backward, stepwise regression model including potential predictor variables identified in the bivariate analysis. A total of 211 patients received surgical treatment and 18 of those patients (8.5%) failed closed reduction and underwent open reduction. Final multivariate analysis demonstrated that only flexion type [relative risk (RR), 10.2] and coronal displacement more than 7 mm (RR, 4.49) were significant preoperative factors for conversion to open reduction. Patients with significant coronal displacement and flexion-type injuries are markers of challenging reduction and are at high risk for conversion to open reduction.

Analysis of the results of surgical and conservative treatment of humeral condyle fractures

Introduction Fractures of the humeral condyle make up 0.5-5.0 % of all fractures and about 30.0 % of adult elbow fractures. Complications develop in 18.0-85.0 % of cases and 29.9 % of the injured have signs of disability, giving these fractures a reputation of injuries with a poor prognosis for functional recovery. Objective To improve the treatment results of the injured with humeral condyle fractures by developing differential treatment tactics taking into account the biomechanical characteristics of the injured anatomical structures. Material and methods The authors analyzed the results of conservative and surgical treatment of 194 patients with fractures of the humeral condyle. The average age of the patients was 50.2 years (range from 19 to 89 years); there were 75 (38.7 %) males and 119 (61.3 %) females. Based on the method of treatment, the patients were divided into 2 groups, each group included a control subgroup and the results of treatment were analyzed. The main subgroup of the clinical group 1 (surgical treatment) consisted of 99 patients with an average age of 49.1 years (range from 19 to 85 years). There were 49 (49.5 %) men and 50 (50.5 %) women. The control subgroup of the clinical group 1 (surgical treatment) consisted of 41 patients with an average age of 51.4 years (from 21 to 89 years). There were 17 (41.5 %) men and 24 (58.5 %) women. The main subgroup of the clinical group 2 (conservative treatment) consisted of 29 patients with an average age of 51.2 years (from 21 to 88 years). There were 5 (17.2 %) men and 24 (82.8 %) women. The control subgroup of the clinical group 2 (conservative treatment) consisted of 25 patients with an average age of 52.9 years (from 21 to 87 years). There were 4 (16.0 %) men and 21 (84.5 %) women. The fractures were rated according to the AO classification: type 13A – 15 (7.7 %) individuals, type 13B - 40 (20.7 %) subjects and type 13C – 139 (71.6 %) patients. Results The mean duration of follow-up was 39.0 ± 1.0 months (7 to 48 months from injury). The mean range of motion in the elbow joint was 110.5 ± 1.2º (50º to 140º), the mean score on the Mayo clinic scale was 81.7 ± 0.9 (45 to 100), and on the Score Scale was 62.7 ± 0.7 (38 to 76). Excellent functional results were obtained in 95 (49.0 %) patients (p < 0.001), good – in 41 (21.2 %) (p < 0.001), fair – in 28 (14.4 %) (p < 0.001) and poor – in 30 (15.5 %) patients (p < 0.001). Conclusion Differentiated treatment tactics in humeral condyle fractures permitted to obtain positive results in 92.2 % (p < 0.001) of the patients in comparison with 89.4 % (p < 0.001) of the control group and to decrease the number of complications by 20.2 % (p < 0.001).

Inclusion of Olecranon Osteotomy With the Posterior Approach for Fixation of Distal Humerus Fractures (OTA/AO 13) Does Not Increase Surgical Complications.

To determine if inclusion of an olecranon osteotomy to the posterior paratricipital approach for operative fixation of distal humerus fractures significantly affects surgical complication rates (OTA/AO 13). Retrospective comparative cohort study. Level 1 trauma center. Three hundred four patients underwent open reduction internal fixation of a distal humerus fracture between 2007 and 2017. Of those, 134 met inclusion criteria (≥15 years, OTA/AO fracture type 13A, B, or C, and posterior surgical approach) for the study (n = 64 with olecranon osteotomy; n = 70 without olecranon osteotomy). Open reduction internal fixation of distal humerus fractures performed using a posterior paratricipital approach with or without olecranon osteotomy. Ulnar neuropathy (UN), fracture site bony nonunion, and surgical site infection (SSI). Thirty-one (33.3%) who underwent the paratricipital approach without olecranon osteotomy, and 15 patients (26.8%) who underwent olecranon osteotomy reported postoperative UN with no significant difference between approaches (P = 0.438). There was no significant difference in rates of SSI (P = 0.418) or fracture site nonunion (P = 0.263) when comparing the approaches. Subjects with Charlson comorbidity index ≥2 were more likely to not undergo an olecranon osteotomy (P = 0.01), whereas subjects with more complex fractures by OTA/AO classification were more likely to have an olecranon osteotomy approach (P = 0.001). Addition of an olecranon osteotomy with the paratricipital approach for fixation of distal humerus fractures does not result in higher rates of UN, fracture site nonunion, or SSI. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Locking versus non-locking plates in fixation of extra-articular distal humerus fracture: a randomized controlled study.

Studies have shown that the use of nonlocking (reconstruction) plates in fixing distal humerus fractures may not yield stable fixation whichtherefore requires long immobilization and suboptimal functional results. There are reports showing that locking plates are biomechanically superior to nonlocking plates. The aim of this study was to compare elbow functional outcomes between locking and nonlocking plates in fixation of distal humerus fractures. A single-centre, randomized control study was conducted at an academic level 1 trauma centre. A total of 60 patients with type 13-A fracture (AO/OTA classification) were randomized into two equal groups, locking plates group, and nonlocking plates group. The primary outcome measure was the Mayo elbow performance score (MEPS) at one year. Secondary outcomes measures were elbow flexion/extension arc, union, operative time, and complications (e.g., infection, heterotrophic ossification). The Mayo Elbow Performance Score (MEPS) at one year was 88 ± 10.1 in locking plates group and 75.8 ± 12.8 in nonlocking plates group. The difference was found to be statically significant (P value = 0.01). Elbow flexion/extension arc of motion at one year was116° ± 15° in locking plates group and113° ± 28° in nonlocking plates. The difference was not found to be statistically significant (P value = 0.17). Both implants yield similar results, withlocking plates showing slightly better clinical scores.

Epidemiological comparison of adult fractures of distal humerus between east and west China from 2010 to 2011

Objective To compare and analyze the epidemiological features of adult patients with distal humerus fractures between the east and west China from 2010 to 2011. Methods The data of adult patients with distal humerus fracture treated from January 2010 to December 2011 in 63 hospitals in the east and west China were collected through the PACS system and case reports checking system. The data from 35 hospitals in the east China were classified as group A, and those from 28 hospitals in the west China as group B. The analytic items included gender, age and AO/OTA classification. Results A total of 2,668 cases were collected. The median age of the 1,852 cases in group A was 42 (IQR: 33) years old. The high peak age ranged from 21 to 30 years old; the gender ratio of group A was 1.18:1. The median age of the 816 cases in group B was 37 (IQR: 27) years old. The high peak age ranged from 31 to 40 years old; the gender ratio of group B was 1.80:1. Group A had a significantly lower gender ratio but a significantly higher median age than group B (P<0.05). The proportions of patients from 16 to 20 and from 31 to 40 years old in group A were significantly lower than those in group B but the proportion of patients aged above 61 years old in group A was significantly higher than that in group B (P<0.05). According to the AO/OTA classification, 1,399 cases (52.44%) were type 13-A, 682 ones (25.56%) type 13-B and 587 ones (22.00%) type 13-C. The proportions of type 13-A and type 13-A1 in group A were significantly lower than in group B (P<0.05). Conclusions Fractures of the distal humerus mostly occurred in the age range from 21 to 40 years old and in males. Type 13-A fractures were the most common. The east China had a significantly higher proportion of female patients, an older median age and a lower proportion of type 13-A1 fracture than the west China. Key words: Humeral fractures; Epidemiology; Case-control studies; Adults

Multi-provincial Salmonellosis Outbreak Related to Newly Hatched Chicks and Poults: A Genomics Perspective.

Background:A multi-provincial outbreak of Salmonella enterica serovar Enteritidis was linked to newly hatched chicks and poults from a single hatchery during the spring of 2015. In total, there were 61 human cases that were epidemiologically confirmed to be linked to the chicks and poults and the outbreak was deemed to have ended in the summer of 2015.Methods:PulseNet Canada, in coordination with the affected provinces, used genome sequencing of human and agricultural Salmonella Enteritidis isolates to aid in the epidemiological investigation, while also using traditional typing methods such as phagetyping and pulsed-field gel electrophoresis (PFGE).Results:All human outbreak cases, except one, were Phage Type (PT) 13a. Single nucleotide variant analysis (SNV) was able to provide a level of resolution commensurate with the results of the epidemiological investigation. SNV analysis was also able to separate PT13a outbreak-related isolates from isolates not linked to chicks or poults, while clustering some non-PT13a agricultural strains with the outbreak cluster.Conclusions:Based on conventional typing methods (phagetyping or PFGE), clinical and agricultural PT13a SE isolates would have been considered as part of a related cluster. In contrast, phagetyping would have led to the exclusion of several non- PT13a strains that clustered with the outbreak isolates using the genome sequence data. This study demonstrates the improved resolution of genome sequence analysis for coordinated surveillance and source attribution of both human and agricultural SE isolates.

Epidemiological survey of adult distal humeral fractures in Beijing, Tianjin and Tangshan area and the Yangtze Delta area in China from 2010 to 2011

Objective To characterize the epidemiological features of adult distal humeral fractures in the Beijing, Tianjin and Tangshan area and the Yangtze Delta area(Shanghai, Jiangsu and Zhejiang)in China from 2010 to 2011. Methods The data of adult distal humeral fractures treated from January 2010to December 2011 in 17 hospitals in the Beijing, Tianjin and Tangshan area and the Yangtze Delta area(Shanghai, Jiangsu and Zhejiang)in China were analyzed retrospectively. The patients from 9 hospitals in the Beijing, Tianjin and Tangshan area were assigned into group A while those from 8 hospitals in the Yangtze Delta area into group B. The gender, age and AO classification were analyzed and compared between the 2groups. Results A total of 789 cases were collected. The total male/female ratio was 1. 16∶1. The median age was 46 years old. The adult distal humeral fractures predominated in an age range from 21 to 30years old(16. 60%). There were 364 cases(46. 13%)of type 13-A, 199 cases of type 13-B(25. 22%), and 226 cases of type 13-C(28. 64%). There were 523 cases in group A and 266 cases in group B. The male/female ratio was 1. 29∶1 in group A and 0. 93∶1 in group B. The proportion of males in group A was significantly higher than in group B(χ2= 4. 867,P= 0. 027). The highest age proportion was the ranges of21 to 40 years old(16. 83%, 88/523)and 51 to 60 years old(16. 83%, 88/523)in group A, but the range of 21 to 30 years old(16. 17%, 84/523)in group B, showing a significant difference(P 0. 05). Conclusions Adult distal humeral fractures favored more males than females. Their peak age was from 21 to 30 years old. The high-risk type was 13-A. The Beijing, Tianjin and Tangshan area had a higher proportion of male patients and a lower mean age than the Yangtze Delta area, but there was no significant difference in constitute ratio of AO types. Key words: Humeral fracture, Epidemiology studies; Small-area analysis

Epidemiological survey of adult distal humeral fractures in the Third Affiliated Hospital to Hebei Medical University from 2008 through 2012

Objective To describe the epidemiology features of adult distal humeral fractures in the Third Affiliated Hospital to Hebei Medical University from 2008 through 2012. Methods The data of adult distal humeral fracture from January 2008 through December 2012 were collected at our institute through the PACS system and case reports checking system. The patients were divided into a young and middle-aged group (from 16 to 60 years) and a senile group (older than 60 years) . The 2 groups were analyzed in terms of gender, age, AO classification, concomitant fracture and causes. Results A total of 540 patients with 542 distal humeral fractures were collected, accounting for 23.69% (542/2, 288) of adult humeral fractures, and 1.04% (542/52, 225) of human fractures. There were 340 men and 200 women, yielding a male to female ratio of 1.70 : 1. Their ages ranged from 16 to 90 years, with a mean age of 37 years. Of them, 451 (83.21%) were young and middle-aged while 91 (16.79%) senile. In the young and middle-aged group, 70.51% were males; in the senile group, 73.63% were females. By AO classification, 50.00% of the fractures were type 13-A. 23.89% of the patients were associated with other fractures most of which occurred in the young and middle-aged (86.82%) and were high-energy injury (75.19%) . 51.71% of the young and middle-aged patients admitted to hospital suffered from high energy injury. Conclusions From 2008 through 2012, adult distal humeral fractures favored mainly young and middle-aged patients. They were chiefly caused by high-energy injury. Most of them were intra-articular ones. The senile patients were mainly female, and their fractures were chiefly caused by low-energy injury and mostly extra-articular ones. Key words: Humeral fractures; Epidemiologic studies; Age distribution; Adult

Validation of Single and Pooled Manure Drag Swabs for the Detection of Salmonella Serovar Enteritidis in Commercial Poultry Houses.

Single swabs (cultured individually) are currently used in the Food and Drug Administration (FDA) official method for sampling the environment of commercial laying hens for the detection of Salmonella enterica ssp. serovar Enteritidis (Salmonella Enteritidis). The FDA has also granted provisional acceptance of the National Poultry Improvement Plan's (NPIP) Salmonella isolation and identification methodology for samples taken from table-egg layer flock environments. The NPIP method, as with the FDA method, requires single-swab culturing for the environmental sampling of laying houses for Salmonella Enteritidis. The FDA culture protocol requires a multistep culture enrichment broth, and it is more labor intensive than the NPIP culture protocol, which requires a single enrichment broth. The main objective of this study was to compare the FDA single-swab culturing protocol with that of the NPIP culturing protocol but using a four-swab pool scheme. Single and multi-laboratory testing of replicate manure drag swab sets (n = 525 and 672, respectively) collected from a Salmonella Enteritidis-free commercial poultry flock was performed by artificially contaminating swabs with either Salmonella Enteritidis phage type 4, 8, or 13a at one of two inoculation levels: low, x¯ = 2.5 CFU (range 2.5-2.7), or medium, x¯ = 10.0 CFU (range 7.5-12). For each replicate, a single swab (inoculated), sets of two swabs (one inoculated and one uninoculated), and sets of four swabs (one inoculated and three uninoculated), testing was conducted using the FDA or NPIP culture method. For swabs inoculated with phage type 8, the NPIP method was more efficient (P < 0.05) for all swab sets at both inoculation levels than the reference method. The single swabs in the NPIP method were significantly (P < 0.05) better than four-pool swabs in detecting Salmonella Enteritidis at the lower inoculation level. In the collaborative study (n = 13 labs) using Salmonella Enteritidis phage type 13a inoculated swabs, there was no significant difference (P > 0.05) between the FDA method (single swabs) and the pooled NPIP method (four-pool swabs). The study concludes that the pooled NPIP method is not significantly different from the FDA method for the detection of Salmonella Enteritidis in drag swabs in commercial poultry laying houses. Consequently based on the FDA's Salmonella Enteritidis rule for equivalency of different methods, the pooled NPIP method should be considered equivalent. Furthermore, the pooled NPIP method was more efficient and cost effective.

Outbreak of Salmonella Enteritidis phage type 13a infection in Sweden linked to imported dried-vegetable spice mixes, December 2014 to July 2015.

From 24 December to 24 July 2015, 174 cases were reported in a nationwide salmonellosis outbreak in Sweden: 108 cases were connected to a single restaurant. A spice mix, containing dried vegetables from the restaurant tested positive for the outbreak strain. Additional spice mixes with similar content from different suppliers also tested positive. The outbreak investigation suggests there could be a risk of contaminated products being also on the market in other countries.

Temperature-Sensitive Salmonella enterica Serovar Enteritidis PT13a Expressing Essential Proteins of Psychrophilic Bacteria.

Synthetic genes based on deduced amino acid sequences of the NAD-dependent DNA ligase (ligA) and CTP synthetase (pyrG) of psychrophilic bacteria were substituted for their native homologues in the genome of Salmonella enterica serovar Enteritidis phage type 13a (PT13a). The resulting strains were rendered temperature sensitive (TS) and did not revert to temperature resistance at a detectable level. At permissive temperatures, TS strains grew like the parental strain in broth medium and in macrophage-like cells, but their growth was slowed or stopped when they were shifted to a restrictive temperature. When injected into BALB/c mice at the base of the tail, representing a cool site of the body, the strains with restrictive temperatures of 37, 38.5, and 39°C persisted for less than 1 day, 4 to 7 days, and 20 to 28 days, respectively. The wild-type strain persisted at the site of inoculation for at least 28 days. The wild-type strain, but not the TS strains, was also found in spleen-plus-liver homogenates within 1 day of inoculation of the tail and was detectable in these organs for at least 28 days. Intramuscular vaccination of White Leghorn chickens with the PT13a strain carrying the psychrophilic pyrG gene provided some protection against colonization of the reproductive tract and induced an anti-S. enterica antibody response.

Persistence of fecal shedding of Salmonella Enteritidis by experimentally infected laying hens housed in conventional or enriched cages

Salmonella Enteritidis can be deposited inside eggs laid by infected hens, so the prevalence of this pathogen in commercial egg-producing flocks is an important risk factor for human illness. Opportunities for the introduction, transmission, and persistence of salmonellae in poultry are potentially influenced by flock housing and management systems. Animal welfare concerns have spurred the development of alternatives to traditional cage-based housing. However, the consequences of poultry housing systems for food safety have not been fully resolved by prior research. The present study assessed the effects of two different housing systems (conventional cages and colony cages enriched with perching and nesting areas) on the persistence of fecal shedding of Salmonella Enteritidis by groups of experimentally infected laying hens. In each of two trials, 136 hens were distributed among cages of both housing systems and orally inoculated with doses of 108 cfu of Salmonella Enteritidis (phage type 13a in one trial and phage type 4 in the other). At weekly intervals, samples of voided feces were collected from beneath each cage and cultured to detect Salmonella Enteritidis. Fecal shedding of Salmonella Enteritidis was detected for up to 8 wk post-inoculation by hens housed in enriched colony cages and 10 wk by hens housed in conventional cages. For both trials combined, the frequency of positive fecal cultures was significantly (P < 0.05) greater for conventional cages than for enriched colony cages at 1 wk (84.7 vs. 71.5%), 2 wk (54.2 vs. 31.3%), 3 wk (21.5 vs. 7.6%), and 4 wk (9.7 vs. 2.8%) post-inoculation. These results demonstrate that the susceptibility of hens to intestinal colonization by Salmonella Enteritidis can differ between conventional and enriched cage-based production systems, although this effect does not necessarily translate into a corresponding difference in the longer-term persistence of fecal shedding.

Horizontal transmission of Salmonella Enteritidis in experimentally infected laying hens housed in conventional or enriched cages

The majority of human illnesses caused by Salmonella Enteritidis are attributed to contaminated eggs, and the prevalence of this pathogen in commercial laying flocks has been identified as a leading epidemiologic risk factor. Flock housing and management systems can affect opportunities for the introduction, transmission, and persistence of foodborne pathogens in poultry. The animal welfare implications of different types of housing for laying hens have been widely discussed in recent years, but the food safety consequences of these production systems remain incompletely understood. The present study assessed the effects of 2 different housing systems (conventional cages and colony cages enriched with perching and nesting areas) on the horizontal transmission of experimentally introduced Salmonella Enteritidis infection within groups of laying hens. In each of 2 trials, 136 hens were distributed among cages of both housing systems and approximately one-third of the hens in each cage were orally inoculated with doses of 108 cfu of Salmonella Enteritidis (phage type 13a in one trial and phage type 4 in the other). At regular intervals through 23 d postinoculation, cloacal swabs were collected from all hens (inoculated and uninoculated) and cultured for Salmonella Enteritidis. Horizontal contact transmission of infection was observed for both Salmonella Enteritidis strains, reaching peak prevalence values of 27.1% of uninoculated hens in conventional cages and 22.7% in enriched cages. However, no significant differences (P > 0.05) in the overall frequencies of horizontal Salmonella Enteritidis transmission were evident between the 2 types of housing. These results suggest that opportunities for Salmonella Enteritidis infection to spread horizontally throughout laying flocks may be similar in conventional and enriched cage-based production systems.

Parkinson's disease-associated human P5B-ATPase ATP13A2 increases spermidine uptake

P-type ion pumps are membrane transporters that have been classified into five subfamilies termed P1-P5. The ion transported by the P5-ATPases is not known. Five genes, ATP13A (ATPase type 13A) 1-ATP13A5, that belong to the P5-ATPase group have been identified in humans. Mutations of the human gene ATP13A2 underlie a form of PD (Parkinson's disease). Previous studies have suggested a relation between polyamines and P5B-ATPases. We have recently shown that the cytotoxicity induced by the polyamine analogue paraquat (1,1'-dimethyl-4,4'-bipyridinium), which is an environmental agent related to PD development, was increased in ATP13A2-expressing CHO (Chinese-hamster ovary) cells. In the present study we showed that ATP13A2-expressing CHO cells exhibit a 2-fold higher accumulation of spermidine. Increasing concentrations of spermidine reduced the viability of CHO cells stably expressing ATP13A2. The higher levels of spermidine attained by the ATP13A2-expressing CHO cells were correlated with an increase in the ATP-dependent spermidine uptake in an isolated subcellular fraction containing lysosomes and late endosomes. The results of the present study support the idea that the human P5B-ATPase ATP13A2 is involved in polyamine uptake.

Frequency and Persistence of Fecal Shedding Following Exposure of Laying Hens to Different Oral Doses of Salmonella enteritidis

Infection of egg-laying poultry with Salmonella enteritidis and the associated transmission of illness to consumers of contaminated eggs has been a prominent international public health concern for many years. Testing and risk reduction programs for laying flocks have been implemented in many nations with some success. However, several critical parameters of S. enteritidis infections in chickens, including the relationship between the magnitude of oral exposure and the frequency and duration of bacteria l shedding in voided feces, remain incompletely defined or explained. In the present study, groups of laying hens were experimentally infected with oral doses of 10 , 10 , or 10 CFU of a phage type 13a strain of S. 4 6 8 enteritidis and the frequency at which the pathogen was shed in voided feces was determined at 8 weekly post-inoculation intervals. At 1 wk post-inoculation, the frequency of fecal shedding of S. enteritidis ranged from 23.8% for the 10 CFU dose to 87.5% for the 10 CFU dose. No fecal shedding was detected after 3 wk 4 8 post-inoculation from hens inoculated with 10 CFU, but a small proportion (2.5% to 5.0%) of hens that 4 received doses of 10 or more CFU of S. enteritidis were still shedding at 8 wk post-inoculation. The results 6 of this study indicate that the oral exposure dose can significantly influence the frequency and duration of S. enteritidis fecal shedding into the environment by infected laying hens. A more complete understanding of how different levels of exposure are detected by particular sampling methods will support the effective application and interpretation of testing protocols for controlling poultry infections and preventing transmission to humans.

The Relationship Between the Numbers of Salmonella Enteritidis, Salmonella Heidelberg, or Salmonella Hadar Colonizing Reproductive Tissues of Experimentally Infected Laying Hens and Deposition Inside Eggs

Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. Salmonella Heidelberg has also been identified as an egg-transmitted pathogen. The deposition of Salmonella strains inside eggs is a consequence of reproductive tract colonization in infected laying hens, but prior research has not determined the relationship between the numbers of Salmonella that colonize reproductive organs and the associated frequency of egg contamination. In the present study, groups of laying hens in two trials were experimentally infected with large oral doses of strains of Salmonella Enteritidis (phage type 13a), Salmonella Heidelberg, or Salmonella Hadar. Reproductive tissues of selected hens were cultured to detect and enumerate Salmonella at 5 days postinoculation, and the interior contents of eggs laid between 6 and 25 days postinoculation were tested for contamination. Significantly more internally contaminated eggs were laid by hens infected with Salmonella Enteritidis (3.58%) than with strains of either Salmonella Heidelberg (0.47%) or Salmonella Hadar (0%). However, no significant differences were observed between Salmonella strains in either isolation frequency or the number of colony-forming units (CFU) isolated from ovaries or oviducts. Salmonella isolation frequencies ranged from 20.8% to 41.7% for ovaries and from 8.3% to 33.3% for oviducts. Mean Salmonella colonization levels ranged from 0.10 to 0.51 log CFU/g for ovaries and from 0.25 to 0.46 log CFU/g for oviducts. Although parallel rank-orders were observed for Salmonella enumeration (in both ovaries and oviducts) and egg contamination frequency, a statistically significant relationship could not be established between these two parameters of infection.

Evaluation of recombinant Salmonella expressing the flagellar protein fliC for persistence and enhanced antibody response in commercial turkeys

Salmonella enterica serovar Enteritidis (SE) is one of the most common causes of human foodborne illness in the United States. Previous research indicates that antibodies against the fliC protein can provide protection against Salmonella challenge in mice. To generate a vaccine that effectively protects poultry against multiple Salmonella serotypes, novel attenuated strains of SE were developed to express a fliC peptide sequence on the outer membrane protein lamB in association with an M2e (marker) epitope. In 3 separate trials, poults were immunized with 107 to 108 cfu/poult of the appropriate recombinant Salmonella strains (ΔSE-M2e or ΔSE-M2e-fliC) via oral gavage on the day of hatch and again on d 21 posthatch. Liver, spleen, and cecal tonsils were aseptically removed on d 7, 14, 21, 28, 35, and 42 posthatch for detection of Salmonella, and blood samples were obtained at these same time points for determination of an M2e-specific antibody response. In all 3 trials, the ΔSE-M2e-fliC strain exhibited significantly less invasion of the liver and spleen at d 7 and 14 when compared with ΔSE-M2e or SE phage type 13A (P < 0.05). Similarly, colonization of the cecal tonsils was decreased in the poults immunized with the ΔSE-M2e-fliC strain. By d 21, the ΔSE-M2e-fliC strain exhibited a significantly higher M2e-specific antibody response when compared with the negative control and SE phage type 13A groups (P < 0.05). However, no significant differences in M2e-specific antibody responses were observed between the ΔSE candidate vaccine strains throughout the study. Overall, these data suggest that oral live attenuated Salmonella-vectored vaccines expressing a fliC peptide sequence are able to elicit a humoral immune response in commercial poults and may contribute to a reduction in Salmonella organ invasion and colonization.

Frequency and Magnitude of Internal Organ Colonization Following Exposure of Laying Hens to Different Oral Doses of Salmonella enteritidis

Contaminated eggs produced by infected laying hens continue to pose a significant public health concern as a leading source of transmission of Salmonella enteritidis infections to humans. A recently implemented national regulatory program for egg-producing poultry in the United States seeks to control eggborne transmission of illness to consumers via a diverse program of mandatory risk reduction practices plus testing to detect infected flocks. However, many aspects of S. enteritidis infections in laying hens, including the precise relationship between the magnitude of oral exposure and infection parameters such as the numbers of bacteria that reach internal tissues, remain unresolved. In the present study, groups of laying hens were experimentally infected with oral doses of 10 , 10 , or 10 CFU of a phage type 13a strain of S. 4 6 8 enteritidis and the number of S. enteritidis cells in the livers of infected hens was determined at 5 d and 20 d post-inoculation. The frequency of S. enteritidis recovery from livers ranged from 30% (10 CFU dose) to 4 90% (10 CFU dose) at 5d post-inoculation and from 0% (10 CFU dose) to 40% (10 CFU dose) at 20 d 8 4 8 post-inoculation. Significantly (p<0.05) greater numbers of S. enteritidis were isolated from livers at both 5 d and 20 d post-inoculation following inoculation with 10 CFU than after administration of either of the two 8 lower doses. These results demonstrate that the oral exposure dose significantly affects important parameters of S. enteritidis infection in laying hens and could thereby influence the outcome of testing efforts. Interpreting the potential implications of testing results and improving the effectiveness of testing protocols are both contingent on understanding how different levels of exposure are likely to be detected by particular sampling methods.

Evaluation of recombinant Salmonella expressing CD154 for persistence and enhanced antibody response in commercial turkeys

Foodborne illness due to Salmonella is a worldwide public health concern and epidemiological evidence has identified poultry and poultry products as a significant source of human Salmonella infection. To discover an effective vaccine that protects poultry against multiple Salmonella serotypes, several novel attenuated Salmonella Enteritidis strains (DeltaSE) were developed to express variations of a potential immune-enhancing CD154 peptide sequence on the outer membrane protein lamB in association with a M2e (marker) epitope. The 3 CD154 peptide sequences evaluated in this study correspond to those naturally occurring in turkeys, humans, and chickens. In 3 separate trials, poults were immunized with 10(7) to 10(8) cfu/poult of the appropriate recombinant Salmonella strains (DeltaSE-M2e, DeltaSE-M2e-T/CD154, DeltaSE-M2e-H/CD154, DeltaSE-M2e-C/CD154) via oral gavage on day of hatch and again on 21 d posthatch. Liver, spleen, and cecal tonsils were aseptically removed on d 7, 14, 21, 28, 35, and 42 posthatch for detection of Salmonella and blood samples were obtained at these same time points for determination of an M2e-specific antibody response. In all 3 trials, DeltaSE strains exhibited significantly less invasion of the liver and spleen at d 7 when compared with Salmonella Enteritidis phage type 13A (P < 0.05). In 2 of the 3 trials, the DeltaSE strains expressing a CD154 peptide sequence further decreased invasion of the liver and spleen. Similarly, colonization of the cecal tonsils was also decreased in the poults immunized with the DeltaSE strains. However, there were no differences in colonization or invasion due to the amino acid sequence of the CD154 insert in all 3 trials. By d 21, the DeltaSE strains exhibited a significantly higher M2e-specific antibody response when compared with the negative control and SE13A groups (P < 0.05). However, no significant differences in M2e-specific antibody responses were observed between any of the DeltaSE candidate vaccine strains expressing CD154 throughout the study. Overall, these data suggest that oral live attenuated Salmonella-vectored vaccines expressing a foreign peptide sequence are able to elicit a humoral immune response in commercial poults and may contribute to a reduction in Salmonella organ invasion and colonization.

Occurrence and Characterization of Salmonella from Chicken Nuggets, Strips, and Pelleted Broiler Feed

Raw, frozen chicken nuggets and strips have been identified as a significant risk factor in contracting foodborne salmonellosis. Cases of salmonellosis as a result of consuming partly cooked chicken nuggets may be due in part to Salmonella strains originating in broiler feed. This study was undertaken to determine the occurrence and characterize the strains of Salmonella contaminating chicken nuggets, strips, and pelleted feeds, in an attempt to demonstrate whether the same Salmonella strains present in broiler feed could be isolated from raw, frozen chicken nuggets and strips available for human consumption. Salmonellae were recovered using the Health Canada MFHPB-20 method for the isolation and identification of Salmonella from foods. Strains were characterized by serotyping, phage typing, antimicrobial resistance typing (R-typing), and by pulsed-field gel electrophoresis (PFGE). Salmonellae were isolated from 25-g samples in 27% (n = 92) of nugget and strip samples, 95% (n = 20) of chicken nugget meat samples, and from 9% (n = 111) of pelleted feed samples. Salmonella Heidelberg, Salmonella Enteritidis, and Salmonella Orion were the most commonly isolated serovars from chicken nuggets and strips, nugget and strip meat, and pelleted broiler feeds, respectively. Salmonella Enteritidis phage type (PT) 13a with PFGE pattern SENXAI.0006 and R-type sensitive as well as Salmonella Enteritidis PT13a with PFGE pattern SENXAI.0068 and R-type sensitive were isolated from pelleted feed, and chicken nugget and strip meat in two separate instances. Data showed that Salmonella strains isolated from broiler feed were indistinguishable from strains isolated from packaged raw, frozen chicken nuggets and strips. However, results did not rule out the possibility that breeding stock or contamination during processing may have contributed to chicken meat contamination by Salmonella.