Further Assessment of PPCPs in Feed Grade Chicken Feather Meal Including Potential Sources

The poultry and rendering industries have played important roles in both the diets of humans as well as environmentally sustainable development. However, a recent article published by Dr. D. C. Love and co-workers at Johns Hopkins Center for a Livable Future revealed concerns that pharmaceutical and personal care products (PPCPs) might be able to re-enter the human food supply by being present in feed grade chicken feather meal, i.e., be consumed by and accumulate in the tissue of chickens or other animals. Their study showed twenty-four PPCPs that were detected above the reporting limits in a total of twelve feather meal samples (five feed grade and seven fertilizer grade) bought in the United States and China. Since this publication may have controversies in terms of the specific origin of the samples of chicken feather meal, and insufficient evidence existed to support the source of the contamination found in the feather meal samples, it was thought that addition studies were warranted. Samples of raw chicken feathers and fresh chicken feather meal were either collected or received from three (3) rendering plants from different geographical regions of the country. To analyze the samples, EPA method 1694 was followed, and the conditions of an HPLC-MS/MS (high-performance liquid chromatography tandem mass spectrometer) were adjusted to test the performance of low-concentration (ppb level) drug detection of sixteen analytes: acetaminophen, erythromycin, norgestimate, sulfachloropyridazine, sulfadimethoxine, sulfamerazine, sulfamethazine, sulfamethizole, sulfamethoxazole, thiabendazole, enrofloxacin, norfloxacin, 1,7-dimethylxanthine, caffeine, ofloxacin, and diphenhydramine. The results indicated that the mass spectrometer used, which contains a quadrupole ion-trap analyzer, has a lower sensitivity and thus a higher detection limit for the aforementioned sixteen analytes than a triple quadrupole analyzer, which is the standard instrument recommended by the EPA method and AXYS Analytical Services Ltd. In order to continue the project, the samples were then sent to AXYS Analytical Services Ltd., the same firm that carried out the analyses for the Johns Hopkins study. The results showed that these samples of chicken feather meal were not nearly as contaminated as those studied in the aforementioned publication, and that the contaminants may come in part from the raw chicken feathers and accumulates in the dissolved air filtration (DAF) system. The poultry industry should take care of the source of diphenhydramine, anhydrochlortetracycline (ATCT), and sulfadimethoxine, which were in high concentrations in our samples

Relaxation time simulation method with internal-energy exchange for perfect gas at near continuum

This paper presents an internal energy exchange scheme for the relaxation time simulation method (RTSM) which solves the BGK equation for the perfect gas flow at near-continuum region discrete rotational energies are introduced to model the relaxation of internal energy modes. This development improved the agreements between RTSM and DSMC with little additional computational cost. The result shows a possibility of an improved hybrid RTSM/DSMC code for the continuum/rarefied gas flow

Comparative genomic analyses of Mycoplasma hyopneumoniae pathogenic 168 strain and its high-passaged attenuated strain

Background: Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia (EP), a mild, chronic pneumonia of swine. Despite presenting with low direct mortality, EP is responsible for major economic losses in the pig industry. To identify the virulence-associated determinants of M. hyopneumoniae, we determined the whole genome sequence of M. hyopneumoniae strain 168 and its attenuated high-passage strain 168-L and carried out comparative genomic analyses. Results: We performed the first comprehensive analysis of M. hyopneumoniae strain 168 and its attenuated strain and made a preliminary survey of coding sequences (CDSs) that may be related to virulence. The 168-L genome has a highly similar gene content and order to that of 168, but is 4,483 bp smaller because there are 60 insertions and 43 deletions in 168-L. Besides these indels, 227 single nucleotide variations (SNVs) were identified. We further investigated the variants that affected CDSs, and compared them to reported virulence determinants. Notably, almost all of the reported virulence determinants are included in these variants affected CDSs. In addition to variations previously described in mycoplasma adhesins (P97, P102, P146, P159, P216, and LppT), cell envelope proteins (P95), cell surface antigens (P36), secreted proteins and chaperone protein (DnaK), mutations in genes related to metabolism and growth may also contribute to the attenuated virulence in 168-L. Furthermore, many mutations were located in the previously described repeat motif, which may be of primary importance for virulence. Conclusions: We studied the virulence attenuation mechanism of M. hyopneumoniae by comparative genomic analysis of virulent strain 168 and its attenuated high-passage strain 168-L. Our findings provide a preliminary survey of CDSs that may be related to virulence. While these include reported virulence-related genes, other novel virulence determinants were also detected. This new information will form the foundation of future investigations into the pathogenesis of M. hyopneumoniae and facilitate the design of new vaccines