Microbial populations on animal hides and beef carcasses at different stages of slaughter in plants employing multiple-sequential interventions for decontamination

Multiple-sequential interventions were applied commercially to reduce beef carcass contamination in eight packing plants. The study evaluated microbial populations on animal hides and changes in carcass microbial populations at various stages in the slaughtering process. Sponge swab samples yielded mean (log CFU/100 cm2) total plate counts (TPC), total coliform counts (TCC), and Escherichia coli counts (ECC) on the exterior hide in the ranges of 8.2 to 12.5, 6.0 to 7.9, and 5.5 to 7.5, respectively, while corresponding contamination levels on carcass surfaces, after hide removal but before application of any decontamination intervention, were in the ranges of 6.1 to 9.1, 3.0 to 6.0, and 2.6 to 5.3, respectively. Following the slaughtering process and application of multiple-sequential decontamination interventions that included steam vacuuming, pre-evisceration carcass washing, pre-evisceration organic acid solution rinsing, hot water carcass washing, postevisceration final carcass washing, and postevisceration organic acid solution rinsing, mean TPC, TCC, and ECC on carcass surfaces were 3.8 to 7.1, 1.5 to 3.7, and 1.0 to 3.0, respectively, while corresponding populations following a 24 to 36 h chilling period were 2.3 to 5.3, 0.9 to 1.3, and 0.9, respectively. The results support the concept of using sequential decontamination processes in beef packing plants as a means of improving the microbiological quality of beef carcasses.

Chemical dehairing of bovine skin to reduce pathogenic bacteria and bacteria of fecal origin

A chemical dehairing process was applied to artificially contaminated bovine hide to evaluate the effect on populations of Escherichia coli O157:H7 and Salmonella Typhimurium, as well as other strains of E. coli, total coliforms, and aerobic plate counts (APC). Pieces of hide (4 cm2) were contaminated with bovine feces inoculated with both rifampicin-resistant E. coli O157:H7 and S. Typhimurium to yield a final count of each pathogen of ca. 5.0 log10 CFU/cm2, or with noninoculated feces which produced an approximate final APC of 6.0 log10 CFU/cm2 and a coliform and E. coli count of 5.0 log10 CFU/cm2. Counts of pathogens, APC, coliforms, and E. coli were conducted before and after applying the dehairing treatment. S. Typhimurium and E. coil O157:H7 populations were significantly reduced from initial numbers (5.1 to 5.3 log10 CFU/cm2) to levels below the detection limit of 0.5 log10 CFU/cm2 after chemical dehairing. APC, coliforms, and E. coli counts were also reduced significantly after dehairing, with reductions of 3.4 for APC, 3.9 for coliforms, and > 4.3 log10 CFU/cm2 for other E. coli strains. Since the hide is a major source of fecal contamination of beef carcass surfaces, chemical dehairing may be beneficial in reducing overall contamination of carcasses.

Impact of stress-induced diabetes on outcomes in severely burned children

BACKGROUND

Post-burn hyperglycemia leads to graft failure, multiple organ failure, and death. A hyperinsulinemic-euglycemic clamp is used to keep serum glucose between 60 and 110 mg/dL. Because of frequent hypoglycemic episodes, a less-stringent sliding scale insulin protocol is used to maintain serum glucose levels between 80 and 160 mg/dL after elevations >180 mg/dL.

STUDY DESIGN

We randomized pediatric patients with massive burns into 2 groups, patients receiving sliding scale insulin to lower blood glucose levels (n = 145) and those receiving no insulin (n = 98), to determine the differences in morbidity and mortality. Patients 0 to 18 years old with burns covering ≥ 30% of the total body surface area and not randomized to receive anabolic agents were included in this study. End points included glucose levels, infections, resting energy expenditure, lean body mass, bone mineral content, fat mass, muscle strength, and serum inflammatory cytokines, hormones, and liver enzymes.

RESULTS

Maximal glucose levels occurred within 6 days of burn injury. Blood glucose levels were age dependent, with older children requiring more insulin (p < 0.05). Daily maximum and daily minimum, but not 6 am, glucose levels were significantly different based on treatment group (p < 0.05). Insulin significantly increased resting energy expenditure and improved bone mineral content (p < 0.05). Each additional wound infection increased incidence of hyperglycemia (p = 0.004). There was no mortality in patients not receiving insulin, only in patients who received insulin (p < 0.004). Muscle strength was increased in patients receiving insulin (p < 0.05).

CONCLUSIONS

Burn-induced hyperglycemia develops in a subset of severely burned children. Length of stay was reduced in the no insulin group, and there were no deaths in this group. Administration of insulin positively impacted bone mineral content and muscle strength, but increased resting energy expenditure, hypoglycemic episodes, and mortality. New glucose-lowering strategies might be needed.

Dual-component video image analysis system (VIASCAN) as a predictor of beef carcass red meat yield percentage and for augmenting application of USDA yield grades

An improved ability to quantify differences in the fabrication yields of beef carcasses would facilitate the application of value-based marketing. This study was conducted to evaluate the ability of the Dual-Component Australian VIASCAN to 1) predict fabricated beef subprimal yields as a percentage of carcass weight at each of three fat-trim levels and 2) augment USDA yield grading, thereby improving accuracy of grade placement. Steer and heifer carcasses (n = 240) were evaluated using VIASCAN, as well as by USDA expert and online graders, before fabrication of carcasses to each of three fat-trim levels. Expert yield grade (YG), online YG, VIASCAN estimates, and VIASCAN estimated ribeye area used to augment actual and expert grader estimates of the remaining YG factors (adjusted fat thickness, percentage of kidney-pelvic-heart fat, and hot carcass weight), respectively, 1) accounted for 51, 37, 46, and 55% of the variation in fabricated yields of commodity-trimmed subprimals, 2) accounted for 74, 54, 66, and 75% of the variation in fabricated yields of closely trimmed subprimals, and 3) accounted for 74, 54, 71, and 75% of the variation in fabricated yields of very closely trimmed subprimals. The VIASCAN system predicted fabrication yields more accurately than current online yield grading and, when certain VIASCAN-measured traits were combined with some USDA yield grade factors in an augmentation system, the accuracy of cutability prediction was improved, at packing plant line speeds, to a level matching that of expert graders applying grades at a comfortable rate.

Effects of different duration exercise programs in children with severe burns

INTRODUCTION

Burns lead to persistent and detrimental muscle breakdown and weakness. Standard treatment at our institution includes a voluntary 12-week rehabilitative exercise program to limit and reverse the effects of increased muscle catabolism. In the present work, we investigated if different durations of exercise, 6 or 12 weeks, produce comparable improvements in muscle strength, body composition, and cardiopulmonary fitness.

METHODS

We prospectively enrolled and randomized patients with ≥30% total body surface area (TBSA) burned to receive 6 or 12 weeks of exercise rehabilitation. Patients were evaluated for muscle strength, oxygen consumption capacity, and lean body mass at discharge (n=42) and after exercise. After 6 weeks (n=18) or 12 weeks (n=24) of exercise training, leg muscle strength was assessed as peak torque per body weight using a Biodex isokinetic dynamometer. Oxygen consumption capacity, measured as peak VO₂, was studied using a standard treadmill-based test, and lean body mass was determined using dual-energy X-ray absorptiometry.

RESULTS

Significant improvements in muscle strength, peak VO₂, and lean body mass were seen after 6 weeks of exercise training (p<0.001), with only significant improvements in peak VO₂ being seen after 6 weeks more of training.

CONCLUSION

These data suggest that a 6-week rehabilitative exercise program is sufficient for improving muscle strength, body composition, and cardiopulmonary fitness in pediatric burn patients. However, continuation of at- or near-home cardiopulmonary training following the 6 weeks of at-hospital rehabilitation may be useful.

Long-term effects of physical exercise during rehabilitation in patients with severe burns

BACKGROUND

We have reported that a 12-week exercise program is beneficial for the exercise performance of severely burned children. It is not known, however, whether the beneficial effects remain at 2 years postburn.

METHODS

Severely burned children who received no long-term anabolic drugs were consented to this Institutional Review Board-approved study. Patients chose between a voluntary exercise program (EX-group) and no exercise (NoEX-group) after discharge from the acute burn unit. Peak torque per lean leg mass, maximal oxygen consumption, and percent predicted peak heart rate were assessed. In addition, body mass index percentile and lean body mass index were recorded. Both groups were compared for up to 2 years postburn using mixed multiple analysis of variance.

RESULTS

A total of 125 patients with a mean age of 12 ± 4 years were analyzed. Demographics between the EX-group (N = 82) and NoEX-group (N = 43) were comparable. In the EX-group, peak torque per lean leg mass, percent predicted peak heart rate, and maximal oxygen consumption increased significantly with exercise (P < .01). Between discharge and 12-24 months, body mass index percentile increased significantly in the EX-Group (P < .05) but did not change in the NoEX-group. There were no significant differences between groups in body mass index percentile, lean body mass index, peak torque per lean leg mass, and maximal oxygen consumption at 24 months postburn.

CONCLUSION

Exercise significantly improves the physical performance of burned children. The benefits are limited to early time points, however, and greatly narrow with further recovery time. Continued participation in exercise activities or a maintenance exercise program is recommended for exercise-induced adaptations to continue.

Human herpes viruses in burn patients: A systematic review

OBJECTIVE

The contribution of human herpes viruses, including herpes simplex virus (HSV), cytomegalovirus (CMV), and varicella zoster virus (VZV) to morbidity and mortality after burns remains controversial. This systematic review was undertaken to assess evidence of herpes virus-related morbidity and mortality in burns.

MATERIALS AND METHODS

PubMed, Ovid, and Web of Science were searched to identify studies of HSV, CMV, or VZV infections in burn patients. Exclusion criteria included: A level of evidence (LoE) of IV or V; nonhuman in vivo studies; and non-English articles. There was no limitation by publication date.

RESULTS

Fifty articles were subjected to full-text analysis. Of these, 18 had LoE between I-III and were included in the final review (2 LoE I, 16 LoE II-III). Eight had a prospective study design, 9 had a retrospective study design, and 1 included both.

CONCLUSIONS

No direct evidence linked CMV and HSV infection with increased morbidity and mortality in burns. Following burn, CMV reactivation was more common than a primary CMV infection. Active HSV infection impaired wound healing but was not directly correlated to mortality. Infections with VZV are rare after burns but when they occur, VZV infections were associated with severe complications including mortality. The therapeutic effect of antiviral agents administered after burns warrants investigation via prospective randomized controlled trials.

Long-term effect of critical illness after severe paediatric burn injury on cardiac function in adolescent survivors: an observational study

BACKGROUND

Sepsis, trauma, and burn injury acutely depress systolic and diastolic cardiac function; data on long-term cardiac sequelae of pediatric critical illness are sparse. This study evaluated long-term systolic and diastolic function, myocardial fibrosis, and exercise tolerance in survivors of severe pediatric burn injury.

METHODS

Subjects at least 5 years after severe burn (post-burn:PB) and age-matched healthy controls (HC) underwent echocardiography to quantify systolic function (ejection fraction[EF%]), diastolic function (E/e'), and myocardial fibrosis (calibrated integrated backscatter) of the left ventricle. Exercise tolerance was quantified by oxygen consumption (VO2) and heart rate at rest and peak exercise. Demographic information, clinical data, and biomarker expression were used to predict long-term cardiac dysfunction and fibrosis.

FINDINGS

Sixty-five subjects (PB:40;HC:25) were evaluated. At study date, PB subjects were 19±5 years, were at 12±4 years postburn, and had burns over 59±19% of total body surface area, sustained at 8±5 years of age. The PB group had lower EF% (PB:52±9%;HC:61±6%; p=0.004), E/e' (PB:9.8±2.9;HC: 5.4±0.9;p<0.0001), VO2peak (PB:37.9±12;HC: 46±8.32 ml/min/kg; p=0.029), and peak heart rate (PB:161±26;HC:182±13bpm;p=0.007). The PB group had moderate (28%) or severe (15%) systolic dysfunction, moderate (50%) or severe diastolic dysfunction (21%), and myocardial fibrosis (18%). Biomarkers and clinical parameters predicted myocardial fibrosis, systolic dysfunction, and diastolic dysfunction.

INTERPRETATION

Severe pediatric burn injury may have lasting impact on cardiac function into young adulthood and is associated with myocardial fibrosis and reduced exercise tolerance. Given the strong predictive value of systolic and diastolic dysfunction, these patients might be at increased risk for early heart failure, associated morbidity, and mortality.

FUNDING

Conflicts of Interest and Sources of Funding: The authors do not have any conflicts of interest to declare. This work was supported by NIH (P50 GM060338, R01 GM056687, R01 HD049471, R01 GM112936, R01-GM56687 and T32 GM008256), NIDILRR (H133A120091, 90DP00430100), Shriners Hospitals for Children (84080, 79141, 79135, 71009, 80100, 71008, 87300 and 71000), FAER (MRTG CON14876), and the Department of Defense (W81XWH-14-2-0162 and W81XWH1420162). It was also made possible with the support of UTMB's Institute for Translational Sciences, supported in part by a Clinical and Translational Science Award (UL1TR000071) from the National Center for Advancing Translational Sciences (NIH).

Incidence of injection-site blemishes in beef top sirloin butts

The occurrence of damaged muscle tissue resulting from intramuscular injections of animal-health products represents a "quality control" problem and an economic loss to the beef industry. Five individual and sequential national audits of injection-site blemishes in beef top sirloin butts have been conducted at the steak-cutter level. During the most recent audit (March 1993), the incidence of injection-site blemishes in top sirloin butts was determined to be 10.87 +/- 2.99%, with an average weight per blemish of 123.39 +/- 5.48 g. A 5-point classification system used to partition the blemishes into chronological stages of the healing process suggested that the majority of the blemishes originated at the cow-calf or stocker levels, or early in the finishing period. Evaluation of blemish data by geographic location of plant-of-origin suggests that the problem occurs throughout the beef production sector.

Herpesviradae infections in severely burned children

OBJECTIVE

Burn-related immunosuppression can promote human herpesviridae infections. However, the effect of these infections on morbidity and mortality after pediatric burn injuries is unclear.

METHODS

We retrospectively analyzed pediatric patients with burns ≥10% of the total body surface area (TBSA) who were admitted between 2010 and 2015. On clinical suspicion of a viral infection, antiviral therapy was initiated. Viral infection was confirmed via Tzanck smear, viral culture, and/or PCR. Study endpoints were mortality, days of antiviral agent administration, type of viral test used, type of viral infection, and length of hospitalization.

RESULTS

Of the 613 patients were analyzed, 28 presented with clinically diagnosed viral infections. The use of Tzanck smears decreased over the past 5 years, whereas PCR and viral cultures have become standard. Patients with viral infections had significantly larger burns (53±15% vs. 38±18%, p<0.001); however, length of stay per TBSA burn was comparable (0.5±0.4 vs. 0.6±0.2, p=0.211). The most commonly detected herpesviridae was herpes simplex virus 1. Two patients died due to sepsis, which was accompanied by HSV infection. The mortality rate among all patients (2.7%) was comparable to that in the infected group (7.1%, p=0.898). Acyclovir was given systemically for 9±8days (N=76) and/or topically for 9±9days for HSV (N=39, combination of both N=33). Ganciclovir was prescribed in three cases for CMV.

CONCLUSIONS

Viral infections occur more commonly in patients suffering from larger burns, and HSV infections can contribute to mortality.

Buprenorphine-Sustained Release Alters Hemodynamic Parameters in a Rat Burn Model

BACKGROUND

It has been previously shown that anesthesia and analgesia can affect outcomes in the rat burn model and that buprenorphine alleviated pain without drastically altering the outcomes of interest. Recently, the use of a sustained release (SR) formulation of buprenorphine has been promoted over conventional buprenorphine. In this study, we assessed whether buprenorphine-SR altered hemodynamic parameters in our rat model of severe burn injury.

MATERIALS AND METHODS

Adult male Sprague-Dawley rats were randomized to receive either conventional buprenorphine (0.05 mg/kg) or buprenorphine-SR (1 mg/kg). Buprenorphine-SR was administered 24 h before the experiment. Buprenorphine was administered on the day of experiment. These groups were further randomized to control or scald burn (60% of total body surface area). Systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) were measured using a noninvasive blood pressure system before receiving analgesia and after 72 h.

RESULTS

As expected, HR was significantly higher after burn injury regardless of analgesic (P <0.0001). Both SBP and DBP were significantly decreased in burned animals receiving conventional buprenorphine (P < 0.0001), but neither was altered in the buprenorphine-SR-treated burned animals. However, SBP, DBP, and HR were significantly increased after 72 h in control animals receiving buprenorphine-SR (P < 0.0001).

CONCLUSIONS

These data indicate that buprenorphine-SR alters the hemodynamic response to injury and may not be an appropriate choice for a model of severe burn injury. If this analgesic is used, investigators must cautiously form conclusions, especially in experimental conditions that would be expected to alter cardiac hemodynamics.

Biventricular differences in β-adrenergic receptor signaling following burn injury

Burn injury detrimentally affects the myocardium, primarily due to over-activation of β-adrenergic receptors (β-AR). Autopsy reports from our institution reveal that patients often suffer from right ventricle (RV) failure. Since burn injury affects β-AR signaling in the left ventricle (LV), we proposed that β-AR signaling may also be altered in the RV. A rodent model with a scald burn of 60% of the total body surface area was used to test this hypothesis. Ventricles were isolated 7 days post-burn. We examined the expression of β-ARs via Western blotting and the mRNA expression of downstream signaling proteins via qRT-PCR. Cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activity were measured in membrane and cytosolic fractions, respectively, using enzyme immunoassay kits. β₁-AR protein expression was significantly increased in the RV following burn injury compared to non-burned RV but not in the LV (p = 0.0022). In contrast, β₂-AR expression was unaltered among the groups while G_αi expression was significantly higher in the LV post-burn (p = 0.023). B-arrestin-1 and G-protein coupled receptor kinase-2 mRNA expression were significantly increased in the left ventricle post-burn (p = 0.001, p<0.0001, respectively). cAMP production and PKA activity were significantly lower in the LV post-burn (p = 0.0063, 0.0042, respectively). These data indicate that burn injury affects the β-AR signaling pathway in the RV independently of the LV. Additionally, non-canonical β-AR signaling may be activated in the RV as cAMP production and PKA activity were unchanged despite changes in β₁-AR protein expression.

The Effect of Burn Trauma on Lipid and Glucose Metabolism: Implications for Insulin Sensitivity

Severe burns represent a unique form of trauma in terms of the magnitude and persistence of the stress response they incur. Given advances in acute burn care in the last quarter of a century and the resultant reduction in mortality rates, even for those with massive burns, greater emphasis is now placed on understanding the metabolic stress response to severe burn trauma in order to devise strategies that promote recovery and reduce morbidity. Derangements in metabolism including protein and lipid redistribution and altered glucose handling are hallmarks of the pathophysiological response to burn trauma. In this review article, we aim to distill and discuss the c urrent literature concerning the effect of burn trauma on lipid and glucose metabolism. Furthermore, we will discuss the implications of altered lipid metabolism with regards to insulin sensitivity and glucose control, while discussing the utility of agents and strategies aimed at restoring normal lipid and glucose metabolism in burned patients.

Slaughter weight loss attributable to pregnancy in feedlot heifers

Slaughter weight loss attributable to pregnancy in feedlot heifers was determined by immediate postmortem weighing of uteri and uterine contents of pregnant heifers. For each 10% pregnant animals within a group of slaughter heifers, the dressing percentage was reduced for the entire group by 0.66%.