Different protein sources in concentrate feed for dairy cows affect cheese-making properties and yield.

Soybean meal (SBM) is a commonly used protein source in feed. Yeast microbial protein could be used as a substitute for SBM, but its effect on cheese-making properties and yield is not known. Norwegian Red dairy cows (n = 48) in early or mid lactation were divided in 3 groups and fed a ration consisting of grass silage and concentrate, where the concentrates were barley based but with different additional protein sources. These were: completely barley based with no additional protein source (BAR), additional protein from SBM, or additional protein from yeast (Cyberlindnera jadinii; YEA). The SBM and YEA concentrates had a higher protein content than the barley concentrate. Four batches of cheese were made from pooled milk from each of the 3 groups of dairy cows. Milk samples were collected 5 times during the experiment. Milk from cows fed BAR concentrate showed inferior cheese-making properties (lower casein content, longer renneting time, lower content of phosphorus, and lower cheese yield) compared with SBM and YEA concentrates. Overall, SBM or YEA bulk milk had similar cheese-making properties, but when investigating individual milk samples, YEA milk showed better coagulation properties.

Feeding concentrates with different protein sources to high-yielding, mid-lactation Norwegian Red cows: Effect on cheese ripening.

Soybean meal is one of the most important protein sources in concentrate feeds for dairy cows. The objective of the present study was to provide knowledge on the effects of using a novel yeast microbial protein source (Candida utilis) in concentrate feed for dairy cows on the production and quality of a Gouda-type cheese. Forty-eight Norwegian Red dairy cows in early to mid lactation were fed a basal diet of grass silage, which was supplemented with 3 different concentrate feeds. The protein source of the concentrates was based on conventional soybean meal (SBM), novel yeast (C. utilis; YEA), or barley (BAR; used as negative control because barley has a lower protein content). The experiment was carried out for a period of 10 wk, with the first 2 wk as an adaptation period where all dairy cows were fed grass silage and the SBM concentrate. The cows were then randomly allocated to 1 of the 3 different compound feeds: SBM, yeast, or barley. Cheeses were made during wk 8 and 9 of the experiment, with 4 batches of cheese made from milk from each of the 3 groups. The cheeses made from milk from cows fed SBM concentrate (SBM cheese) had a higher content of dl-pyroglutamic acid and free amino acids than the other cheeses, indicating a faster ripening in the SBM cheeses. Despite these differences, the sensory properties, the microbiota, and the Lactococcus population at 15 wk of ripening were not significantly different between the cheeses. This experiment showed that although the raw materials used in the concentrate feed clearly influenced the ripening of the cheeses, this did not affect cheese quality. Yeast (C. utilis) as a protein source in concentrate feed for dairy cows can be used as a replacement for soybean meal without compromising the quality of Norwegian Gouda-type cheeses.

Epidemiology and outcomes of Clostridium difficile infection in allogeneic hematopoietic cell and lung transplant recipients.

BACKGROUND: Clostridium difficile infection (CDI) is a common complication of lung and allogeneic hematopoietic cell (HCT) transplant, but the epidemiology and outcomes of CDI after transplant are poorly described. METHODS: We performed a prospective, multicenter study of CDI within 365 days post-allogeneic HCT or lung transplantation. Data were collected via patient interviews and medical chart review. Participants were followed weekly in the 12 weeks post-transplant and while hospitalized and contacted monthly up to 18 months post-transplantation. RESULTS: Six sites participated in the study with 614 total participants; 4 enrolled allogeneic HCT (385 participants) and 5 enrolled lung transplant recipients (229 participants). One hundred and fifty CDI cases occurred within 1 year of transplantation; the incidence among lung transplant recipients was 13.1% and among allogeneic HCTs was 31.2%. Median time to CDI was significantly shorter among allogeneic HCT than lung transplant recipients (27 days vs 90 days; P = .037). CDI was associated with significantly higher mortality from 31 to 180 days post-index date among the allogeneic HCT recipients (Hazard ratio [HR] = 1.80; P = .007). There was a trend towards increased mortality among lung transplant recipients from 120 to 180 days post-index date (HR = 4.7, P = .09). CONCLUSIONS: The epidemiology and outcomes of CDI vary by transplant population; surveillance for CDI should continue beyond the immediate post-transplant period.

Risk factors for hospital-acquired infection during the SARS-CoV-2 pandemic.

OBJECTIVE: To evaluate risk factors for hospital-acquired infection (HAI) in patients during the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, including historical and concurrent cohorts. DESIGN: Retrospective cohort. SETTING: Three Missouri hospitals, data from 1st January 2017 to 30th September 2020. PARTICIPANTS: Patients aged ≥18 years and admitted for ≥48 h. METHODS: Univariate and multi-variate Cox proportional hazards models incorporating the competing risk of death were used to determine risk factors for HAI. A-priori sensitivity analyses were performed to assess the robustness of the urine-, blood- and respiratory-culture-based HAI definition. RESULTS: The cohort included 254,792 admissions, with 7147 (2.8%) HAIs (1661 blood, 3407 urine, 2626 respiratory). Patients with SARS-CoV-2 had increased risk of HAI (adjusted hazards ratio 1.65, 95% confidence interval 1.38-1.96), and SARS-CoV-2 infection was one of the strongest risk factors for development of HAI. Other risk factors for HAI included certain admitting services, chronic comorbidities, intensive care unit stay during index admission, extremes of body mass index, hospital, and selected medications. Factors associated with lower risk of HAI included year of admission (declined over the course of the study), admitting service and medications. Risk factors for HAI were similar in sensitivity analyses restricted to patients with diagnostic codes for pneumonia/upper respiratory infection and urinary tract infection. CONCLUSIONS: SARS-CoV-2 was associated with significantly increased risk of HAI.

A simulational study of the indirect-geometry neutron spectrometer BIFROST at the European Spallation Source, from neutron source position to detector position.

The European Spallation Source (ESS) is intended to become the most powerful spallation neutron source in the world and the flagship of neutron science in upcoming decades. The exceptionally high neutron flux will provide unique opportunities for scientific experiments but also set high requirements for the detectors. One of the most challenging aspects is the rate capability and in particular the peak instantaneous rate capability, i.e. the number of neutrons hitting the detector per channel or cm2 at the peak of the neutron pulse. The primary purpose of this paper is to estimate the incident rates that are anticipated for the BIFROST instrument planned for ESS, and also to demonstrate the use of powerful simulation tools for the correct interpretation of neutron transport in crystalline materials. A full simulation model of the instrument from source to detector position, implemented with the use of multiple simulation software packages, is presented. For a single detector tube, instantaneous incident rates with a maximum of 1.7 GHz for a Bragg peak from a single crystal and 0.3 MHz for a vanadium sample are found. This paper also includes the first application of a new pyrolytic graphite model and a comparison of different simulation tools to highlight their strengths and weaknesses.

Risk factors for Clostridioides difficile infection in hospitalized patients and associated mortality in Japan: a multi-centre prospective cohort study.

BACKGROUND: Although population characteristics and antimicrobial prescribing practices suggest that the hospitalized population in Japan is at high risk of Clostridioides difficile infection (CDI), the epidemiology of CDI in Japan is poorly understood. AIM: This prospective cohort study aimed to investigate the epidemiology of CDI at 12 hospitals in Japan. METHODS: Patients with clinically significant diarrhoea (CSD) were enrolled. Stool specimens were tested for C. difficile by toxin A and/or B enzyme immunoassay (EIA) in the hospital laboratories, and a toxigenic culture and nucleic acid amplification tests were performed at a central laboratory. The risk factors of CDI and the impact of CDI on mortality were investigated. FINDINGS: In total, 566 patients with CSD were included in the analyses. A total of 152 patients received the diagnosis of CDI by Toxin A/B EIA, toxigenic culture, or nucleic acid amplification test. Factors associated with CDI included low albumin (adjusted odds ratio (aOR): 1.56; 95% confidence interval (CI): 1.03-2.34) and length of hospital stay before stool collection >18 days (aOR: 1.73; 95% CI: 1.09-2.75). CDI was associated with an increased mortality on univariate analysis (OR: 1.6, 95% CI: 1.0-2.6) but was not associated with an increased risk of mortality on multivariable analysis. CONCLUSION: Risk factors for CDI in Japan were similar to those identified in the USA and Europe. However, CDI was not associated with an increased risk of mortality in this population of patients with CSD.

Accuracy of Inpatient International Classification of Diseases, Ninth Revision, Clinical Modification Coding for Cytomegalovirus After Kidney Transplantation.

BACKGROUND: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) coding for cytomegalovirus (CMV) has been used as a proxy for active CMV infection or disease occurring in the inpatient setting in retrospective studies of kidney transplant recipients using large amounts of administrative data. However, the accuracy of inpatient CMV coding has not been determined. METHODS: We identified 393 kidney transplant recipients who were readmitted to Barnes-Jewish Hospital in St. Louis, Missouri from January 1, 2007 to December 31, 2011 to determine the accuracy of the ICD-9-CM diagnosis code for CMV (078.5) in identifying active CMV infection or disease (asymptomatic viremia, CMV syndrome, or tissue-invasive CMV disease) in the inpatient setting, using microbiological, histopathologic, or ophthalmologic evidence for CMV as the gold standard. RESULTS: The sensitivity and positive predictive value of CMV coding in identifying active CMV infection or disease were 0.77 and 0.71, respectively. The specificity and negative predictive value were both 0.98. The sensitivity of CMV coding in identifying CMV syndrome or tissue-invasive CMV disease was 0.93. CONCLUSIONS: CMV coding had good accuracy in identifying active CMV infection or disease among readmitted kidney transplant recipients in our hospital. Further validation studies of CMV coding in other hospitals are needed to obtain more generalizable estimates of the accuracy of CMV coding.

Recurrent Clostridium difficile infection is associated with increased mortality.

Clostridium difficile infections (CDI) are associated with decreased survival, and up to 30% of CDI patients may experience a recurrence. Data on the impact of recurrent CDI on mortality are scarce. The purpose of this study was to determine whether recurrent CDI was independently associated with decreased 6-month survival compared with patients with CDI who did not develop a recurrence. We performed a retrospective cohort study at an academic, urban, tertiary care hospital. Data were collected from the electronic medical record and chart review. CDI patients were followed for 180 days from the end of their index hospital discharge or end of index CDI antibiotic treatment, whichever was later, to determine mortality. Kaplan-Meier analysis was used to compare patient mortality by recurrent CDI status. Cox proportional hazards models were used to determine independent risk factors for death within 180 days. In all, 3958 patients aged ≥ 18 years who developed an initial CDI episode from 2003 to 2009, including 421 patients with recurrent CDI, were included in the study. Thirty-six per cent of persons with recurrent CDI died within 180 days, compared with 26% of persons without CDI recurrence (log-rank p <0.001). Recurrent CDI was associated with significantly higher hazards of death within 180 days, adjusting for demographics, comorbidities and medications received during the index CDI hospitalization (hazard ratio 1.33; 95% CI 1.12-1.58). Recurrent CDI is associated with significantly increased risk of death within 6 months after completion of their initial CDI treatment compared with CDI patients who do not develop a recurrence.

Cloning, mRNA localization and evolutionary conservation of a human 5-HT7 receptor pseudogene.

Initial experiments designed to clone novel serotonin receptor subtypes in the substantia nigra have led to the discovery of a transcribed human 5-HT7 receptor pseudogene that is expressed in a wide range of tissues. The original clone (S771) possessed greater than 90% homology to the 5-HT7 receptor sequence and was identified by a degenerate PCR approach. Expression of the pseudogene transcript was detected throughout the brain and peripheral tissues in general agreement with 5-HT7 mRNA localization. Interestingly, the transcript was detected in tissues not known to express the 5-HT7 receptor (i.e. liver and kidney). Analysis of genomic DNA explained the genesis of the human pseudogene via a processed parental transcript (retrotransposition) and led to the discovery of a species homologue in the rhesus monkey.

Site-directed mutagenesis of a single residue changes the binding properties of the serotonin 5-HT2 receptor from a human to a rat pharmacology.

Mesulergine displays approximately 50-fold higher affinity for the rat 5-HT2 receptor than for the human receptor. Comparison of the deduced amino acid sequences of cDNA clones encoding the human and rat 5-HT2 receptors reveals only 3 amino acid differences in their transmembrane domains. Only one of these differences (Ser----Ala at position 242 of TM5) is near to regions implicated in ligand binding by G protein-coupled receptors. We investigated the effect of mutating Ser242 of the human 5-HT2 receptor to an Ala residue as is found in the rat clone. Both [3H]mesulergine binding and mesulergine competition of [3H]ketanserin binding showed high affinity for rat membranes and the mutant human clone but low affinity for the native human clone, in agreement with previous studies of human postmortem tissue. These studies suggest that a single naturally occurring amino acid change between the human and the rat 5-HT2 receptors makes a major contribution to their pharmacological differences.

Identification of a human 5-HT6 receptor variant produced by alternative splicing.

The complexity of the 5-hydroxytryptamine (5-HT) (serotonin) receptor family has been increased by the findings that isoforms or splice variants exist for subtypes such as the 5-HT2B, 5-HT2C, 5-HT4 and 5-HT7 subtypes. Further molecular biological studies in our laboratory have demonstrated that a splice variant of the 5-HT6 receptor exists in the human brain. Experiments performed using a degenerate PCR approach from human caudate cDNA revealed a 5-HT6 receptor clone with a 289 bp deletion of the region coding for transmembrane IV through the third intracellular loop. This deletion produces a frameshift creating a downstream stop codon which results in a truncated protein containing 10 unique amino acids at its carboxyl end. The variant transcript occurs as a result of alternative splicing using an upstream donor site and the acceptor site from the first intron in the 5-HT6 receptor gene. The splicing pattern seen for this transcript was not detected in rat or mouse whole brain cDNA by PCR due to the lack of a consensus 5' donor site. Coexpression of the variant 5-HT6 transcript and the full length 5-HT6 transcript was observed in caudate and substantia nigra but not in hippocampus, cortex, cerebellum and thalamus. Transient transfection of a 5-HT6 variant construct into Cos-7 cells demonstrated that a truncated receptor was translocated to the membrane but appeared nonfunctional.

Comparison of four different immunoassays for detection of Toxoplasma-specific immunoglobulin G.

Serum specimens from 246 women of childbearing age were tested for immunoglobulin G (IgG) antibodies to Toxoplasma gondii by four different commercial assays: Abbott IMx microparticle enzyme immunoassay (EIA), Mercia Toxo-G EIA, Bartels Prima EIA, and bioMerieux Vitek (VIDAS) enzyme-linked fluorescent assay. A total of 27 specimens were initially positive with all four assays, 202 specimens were negative, and 17 specimens were discrepant (disagreement among the assays). After repeating tests for the 17 discrepant samples, five resolved (one was positive and four were negative). The 12 remaining discrepant samples were tested by an indirect fluorescent antibody (IFA) assay for Toxoplasma IgG antibodies; five specimens were positive for Toxoplasma IgG by IFA. The resolved sensitivities of the various kits ranged from 88% (bioMerieux VIDAS) to 94% (Abbott IMx), and the specificities were all 98%-99%. These results show that the four serologic tests used for detection of Toxoplasma IgG give very similar results and can all be readily used by clinical laboratories for screening purposes.

Evaluation of Abbott TestPack RSV for the diagnosis of respiratory syncytial virus infections.

Abbott TestPack RSV, a 20-minute enzyme immunoassay, is available for the rapid diagnosis of respiratory syncytial virus (RSV) infections. We have compared TestPack with a "gold standard" method of virus isolation in traditional tube cultures and shell vials to determine the sensitivity and specificity of this rapid method. Respiratory specimens were collected prospectively from 402 children and assayed by the rapid antigen detection method and isolation in culture. Virus was isolated by inoculation of specimen in a total of eight tubes and 2-3 shell vials. Isolation of RSV was confirmed by characteristic cytopathic effect and immunofluorescence using monoclonal antibodies to RSV. Of the 402 specimens tested, there were only 18 discrepant results (seven TestPack-positive, culture-negative, and 11 TestPack-negative, culture-positive specimens). The sensitivity of TestPack RSV versus culture was 93.6% (162 of 173) and the specificity was 97.0% (222 of 229). Using a very rigorous culture system, we have obtained high values for the sensitivity and specificity of TestPack RSV. This assay is an excellent method for the rapid diagnosis of RSV infections in young children.

Performance of the Kallestad Pathfinder enzyme immunoassay in the diagnosis of respiratory syncytial virus infections.

The Kallestad Pathfinder enzyme immunoassay (EIA) for the rapid detection of respiratory syncytial virus (RSV) antigen was compared with virus culture and direct fluorescent antibody (DFA) to determine the reliability of the EIA. During two consecutive winter respiratory seasons, 270 nasopharyngeal wash specimens were tested. RSV was detected in culture by the presence of cytopathic effect and/or an indirect immunofluorescence assay. The sensitivity of the Pathfinder EIA in comparison with isolation in tube culture was 72% (73 of 101) and the specificity was 99% (167 of 169). During the second year of the evaluation period, DFA was performed on all specimens. The sensitivity of the DFA compared with isolation in tube culture was 94%. This study indicates that the Pathfinder EIA is a very specific test for diagnosis of RSV infections, but lacks sensitivity in comparison with tube culture or direct immunofluorescence.

Comparison of the Syva Microtrak enzyme immunoassay and Abbott Chlamydiazyme in the detection of chlamydial infections in women.

An enzyme immunoassay for detection of Chlamydia trachomatis antigen, Syva Microtrak, was compared with Abbott Chlamydiazyme to evaluate the performance of the Microtrak assay in the diagnosis of chlamydial genital tract infection in women. Duplicate endocervical swabs from 550 women were tested by both methods, and discrepancies were resolved by direct immunofluorescence on pelleted material from the collection tubes. Forty-six specimens were positive by the Syva Microtrak assay (resolved sensitivity, 95%), and 34 specimens were positive by the Chlamydiazyme assay (resolved sensitivity, 79%). The results from this small study suggest that the Syva Microtrak enzyme immunoassay is more sensitive than Chlamydiazyme for the detection of chlamydial antigen in endocervical specimens. This test should be useful for the diagnosis of chlamydial genital tract infection in females.

Incidence, risk factors, and outcomes of delayed-onset cytomegalovirus disease in a large, retrospective cohort of heart transplant recipients.

BACKGROUND: Delayed-onset cytomegalovirus (CMV) disease can occur among heart transplant recipients after stopping anti-CMV prophylaxis. We evaluated a large, retrospective cohort of heart transplant recipients in the United States through the use of billing data from 3 Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SID) to determine the epidemiology of delayed-onset CMV disease coded during hospital readmission. METHODS: We identified 2280 adult heart transplant recipients from 2004 to 2010 through the use of the California, Florida, and New York SID. Demographics, comorbidities, heart failure etiology, CMV disease, and inpatient death were identified. CMV disease was classified as early-onset (≤100 days) or delayed-onset (>100 days after transplant). Possible tissue invasion by CMV was determined through the use of codes for CMV pneumonitis, hepatitis, and gastrointestinal endoscopy. Multivariate analysis was performed with the use of Cox proportional hazards models. RESULTS: Delayed-onset CMV disease occurred in 7.5% (170/2280) and early-onset CMV disease occurred in 2.0% (45/2280) of heart transplant recipients. Risk factors for delayed-onset CMV disease included residence in a non-metropolitan locale (aHR. 1.8; 95% confidence interval [CI], 1.0-3.3) and ischemic cardiomyopathy as heart failure etiology (aHR, 1.8; 95% CI, 1.3-2.5). Inpatient death >100 days after transplant was associated with delayed-onset CMV disease with possible tissue invasion (aHR, 2.0; 95% CI, 1.1-3.8), transplant failure or rejection (aHR, 4.0; 95% CI, 2.7-5.8), and renal failure (aHR, 1.5; 95% CI, 1.1-2.0). CONCLUSIONS: Delayed-onset CMV disease is more common than early-onset CMV disease among heart transplant recipients. These results suggest that delayed-onset tissue-invasive CMV disease may be associated with an increased risk of death.

Production rates of volatile fatty acids in the minke whale (Balaenoptera acutorostrata) forestomach.

Minke whales (Balaenoptera acutorostrata) have developed a compartmentalized stomach system, which includes a non-glandular forestomach containing high concentrations of indigenous bacteria. The forestomach contents serve as microbial substrate, and samples were collected from five adult minke whales eating capelin (Mallotus villosus) and crustaceans (Thysanoessa sp.). Chemical analysis of the forestomach contents revealed that they consisted of crude protein (650 (SD 58) g/kg DM), lipid (330 (SD 77) g/kg DM) and water-soluble carbohydrates (53.3 (SD 7.3) g/kg DM). The contribution of energy from volatile fatty acids (VFA), produced by forestomach bacterial fermentation, to the total energy budget was estimated. The forestomach concentration of VFA ranged from 13.2 to 68.5 mmol/l, and the pH was 5.83 (SD 0.41). VFA pool size ranged from 72.8 to 638.1 mmol and represented from 0.169 to 2.107 kJ/kg live weight (W)0-75. Maximal recorded forestomach VFA production rate was 1694 mmol/h in one capelin-eating minke whale with 42.6 litres of forestomach fluid. Energy from VFA produced by forestomach fermentation represented 6-107 kJ/kg (W)0-75 per d, which accounts for only 0.9-16.9% of the average daily energy expenditure of minke whales. This study suggests that the bacterial fermentation in the minke whale forestomach varies, depending on the volume and the quality of substrate available, influencing fermentation rates and concentration of VFA. Due to the small relative size of the forestomach, the contribution of VFA to the daily energy requirement in minke whales would be of less importance than in ruminants even when assuming the same production rate of VFA as in a ruminant.

Confirmation of positive results for chlamydial antigen by the Chlamydiazyme assay: value of repeated testing and a blocking antibody assay.

We studied the specificity of the Abbott Chlamydiazyme test for detection of Chlamydia trachomatis antigen by means of a specific blocking antibody test. A total of 457 previously positive specimens were tested; 22 did not block in the blocking antibody test, 39 did not repeat as positive, and 396 were confirmed as positive. The distribution of A492 values obtained with specimens which did not repeat as positive was nonrandom and was concentrated between the cutoff values and 0.400. The positive predictive value of the Chlamydiazyme assay after initial testing was 86.7% (396 of 457), but the positive predictive value increased to 94.7% (396 of 418) if specimens which were not repeatedly positive were considered negative. We recommend routinely repeating the Chlamydiazyme assay for all specimens which give A492 values between the cutoff and 0.400 to eliminate many false-positive results. Use of the blocking antibody reagent can then be reserved for confirming only specimens which are repeatedly positive.

Digestion of herring by indigenous bacteria in the minke whale forestomach.

Northeastern Atlantic minke whales (Balaenoptera acutorostrata) have a multichambered stomach system which includes a nonglandular forestomach resembling that of ruminants. Bacteria from the forestomachs of herring-eating whales were enumerated and isolated in an anaerobic rumen-like culture medium (M8W medium). The total viable population of anaerobic bacteria ranged from 73 x 10 to 145 x 10/ml of forestomach fluid (n = 4). Lactobacillus spp. (19.7%), Streptococcus spp. (35.9%), and Ruminococcus spp. (12.8%) were the most common of the bacterial strains (n = 117) isolated by use of M8W medium from the forestomach fluid population of two minke whales. Most of the isolates stained gram positive (93.2%), 62.4% were cocci, and all strains were strictly anaerobic. The population of lipolytic bacteria in one animal, enumerated by use of a selective lipid medium, constituted 89.7% of the viable population. The total viable population of anaerobic bacteria in freshly caught and homogenized herring (Clupea harengus) ranged from 56.7 to 95.0 cells per gram of homogenized prey (n = 3) when M8W medium was used. Pediococcus spp. (30.6%) and Aerococcus spp. (25.0%) were most common of the bacterial strains (n = 72) isolated from the homogenized herring. Most of the bacterial strains were gram positive (80.6%), and 70.8% were cocci. Unlike the forestomach bacterial population, as many as 61.1% of the strains from the herring were facultatively anaerobic. All bacterial strains isolated from the prey had phenotypic patterns different from those of strains isolated from the dominant bacterial population in the forestomach, indicating that the forestomach microbiota is indigenous. Scanning electron microscopic examinations revealed large numbers of bacteria, surrounded by a glycocalyx, attached to partly digested food particles in the forestomach. These data support the hypothesis that symbiotic microbial digestion occurs in the forestomach and that the bacteria are indigenous to minke whales.