ABSTRACT
BACKGROUND: MRT5005, a codon-optimized CFTR mRNA, delivered by aerosol in lipid nanoparticles, was designed as a genotype-agnostic treatment for CF lung disease. METHODS: This was a randomized, double-blind, placebo-controlled Phase 1/2 study performed in the US. Adults with 2 severe class I and/or II CFTR mutations and baseline ppFEV1 values between 50 and 90% were randomized 3:1 (MRT5005: placebo). Six dose levels of MRT5005 (4, 8, 12, 16, 20, and 24 mg) or placebo (0.9% Sodium Chloride) were administered by nebulization. The single ascending dose cohort was treated over a range from 8 to 24 mg; the multiple ascending dose cohort received five weekly doses (range 8-20 mg); and the daily dosing cohort received five daily doses (4 mg). RESULTS: A total of 42 subjects were assigned to MRT5005 [31] or placebo [11]. A total of 14 febrile reactions were observed in 10 MRT5005-treated participants, which were mild [3] or moderate [11] in severity; two subjects discontinued related to these events. Additionally, two MRT5005-treated patients experienced hypersensitivity reactions, which were managed conservatively. The most common treatment emergent adverse events were cough and headache. No consistent effects on FEV1 were noted. CONCLUSIONS: MRT5005 was generally safe and well tolerated through 28 days of follow-up after the last dose, though febrile and hypersensitivity reactions were noted. The majority of these reactions resolved within 1-2 days with supportive care allowing continued treatment with MRT5005 and careful monitoring. In this small first-in-human study, FEV1 remained stable after treatment, but no beneficial effects on FEV1 were observed.
Subject(s)
Cystic Fibrosis , Adult , Humans , Cystic Fibrosis/diagnosis , Cystic Fibrosis/drug therapy , Cystic Fibrosis/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/therapeutic use , RNA, Messenger , Respiratory Aerosols and Droplets , Mutation , Double-Blind MethodABSTRACT
Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.
Subject(s)
Anti-Infective Agents , Cattle Diseases , Mastitis, Bovine , Cattle , Female , Animals , Farms , Mastitis, Bovine/diagnosis , Australia , Milk/microbiology , DairyingABSTRACT
BACKGROUND: CHEC-SC is an ongoing epidemiologic study characterizing modulator-induced sweat chloride (SC) responses across the CF population, with interim results available prior to the availability of triple combination modulator therapy. METHODS: Eligible participants had been prescribed a modulator for ≥90 days with re-enrollment allowed upon establishment of a new modulator. Pre-modulator SC values were obtained from chart review; post-modulator sweat was collected and analyzed locally. SC changes were descriptively summarized with biologic sex effects adjusted for age, weight, and CFTR genotype. Heterogeneity in ivacaftor SC response was characterized in relation to published CFTR functional responses. RESULTS: 1848 participants provided 2004 SC measurements, 26.2% on ivacaftor, 39.1% on lumacaftor/ivacaftor, and 34.7% on tezacaftor/ivacaftor. Average SC changes for all modulators were consistent with those reported in previous clinical studies, with greater variation in SC response observed among rarer mutations and notable shifts in the proportion with SC <60mmol/L independent of the magnitude of SC change. Ivacaftor induced in vitro CFTR functional change was significantly correlated with ivacaftor-modulated SC response (Pearson correlation= â0.52, 95% CI: â0.773, â0.129). Average SC change from ivacaftor to tezacaftor/ivacaftor was â4.9 mmol/L (n=17,95% CI:â9.3, â0.5) and differed from those switching from lumacaftor/ivacaftor (10.0 mmol/L, n=139, 95% CI:7.8,12.3). Sex at birth was not associated with SC response. CONCLUSIONS: CHEC-SC is the largest study characterizing modulator-induced SC changes across the CF population. There was a strong association between ivacaftor induced in vitro CFTR function and SC response across a genotypically heterogenous cohort. Biological sex was not associated with SC response.
Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator , Cystic Fibrosis , Humans , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Chlorides , Sweat , Aminophenols/therapeutic use , Benzodioxoles/therapeutic use , Drug Combinations , Mutation , Chloride Channel Agonists/therapeutic useABSTRACT
The spectrum of disorders involving CFTR (cystic fibrosis transmembrane conductance regulator) dysfunction correlates with a continuous gradient of CFTR function defined by the combination of two allelic CFTR variants. CFTR-related disorders are clinical entities with features of cystic fibrosis (CF) and evidence for presence of CFTR dysfunction but not meeting criteria for diagnosis of CF. Individuals with CFTR-RDs demonstrate a wide range of CFTR activity and are still under-recognized or misclassified. The level of CFTR dysfunction may be measured in vivo (sweat testing, nasal potential difference measurements) and/or by ex vivo tests (intestinal current measurement), or indirectly indicated by CFTR variants, as alteration in sequence of the CFTR gene translates into CFTR dysfunction. CFTR bioassays can aid in the diagnosis of individuals with CF, but we lack parameters to differentiate CF from CFTR-RD. In the era of the CFTR modulators and their potential clinical benefit, it is of utmost importance to diagnose CFTR-RD as unambiguously as possible. We therefore propose the following to define compatible CFTR dysfunction in a person with a suspected diagnosis of CFTR-RD : (1) evidence of CFTR dysfunction in vivo or ex vivo in at least two different CFTR functional test types, or (2) One CFTR variant known to reduce CFTR function and evidence of CFTR dysfunction in vivo or ex vivo in at least two different CFTR functional test types, or (3) Two CFTR variants shown to reduce CFTR function, with at most one CF-causing variant.
Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator , Cystic Fibrosis , Humans , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Cystic Fibrosis/diagnosis , Cystic Fibrosis/genetics , Cystic Fibrosis/therapy , Standard of Care , Sweat/metabolism , Ion Transport , MutationABSTRACT
The objectives for this study were to (1) describe the pathogen profile in quarters from cows with clinical mastitis and in cows with subclinical mastitis in southeastern Australia; and (2) describe antimicrobial susceptibility among isolated pathogens. As a secondary objective, we aimed to compare antimicrobial resistance prevalence in pathogens isolated from clinical and subclinical mastitis samples. A convenience sample of dairy herds (n = 65) from 4 regions in southeastern Australia (Gippsland, Northern Victoria, Tasmania, Western Victoria) were invited to submit milk samples from cows with clinical and subclinical mastitis over a 14-mo period (January 2011 to March 2012). Farmers were instructed to collect aseptic quarter milk samples from the first 10 cases of clinical mastitis for each month of the study. In addition, farmers submitted composite milk samples from cows with subclinical mastitis at 1 or 2 sampling occasions during the study period. Aerobic culture and biochemical tests were used to identify isolates. Isolates were classified as susceptible, intermediate, or resistant to a panel of antimicrobial agents based on the zone of growth inhibition around antimicrobial-impregnated disks, with antimicrobial resistance (AMR) classified as nonsusceptibility by combining intermediate and resistant groups into a single category. Generalized linear mixed models were used to compare the prevalence of AMR between clinical and subclinical mastitis isolates. For clinical mastitis samples (n = 3,044), 472 samples (15.5%) were excluded for contamination. Of the remaining samples (n = 2,572), the most common results were Streptococcus uberis (39.2%), no growth (27.5%), Staphylococcus aureus (10.6%), Escherichia coli (8.4%), and Streptococcus dysgalactiae (6.4%). For subclinical mastitis samples (n = 1,072), 425 (39.6%) were excluded due to contamination. Of the remaining samples (n = 647), the most common results were no growth (29.1%), Staph. aureus (29.1%), and Strep. uberis (21.6%). The prevalence of AMR among common isolates was low for the majority of antimicrobial agents. Exploratory analysis found that the probability of Staph. aureus demonstrating resistance to penicillin was 5.16 times higher (95% confidence interval: 1.68, 15.88) in subclinical isolates relative to clinical Staph. aureus isolates. A similar association was observed for amoxicillin with subclinical Staph. aureus isolates being 4.70 times (95% confidence interval: 1.49, 14.75) more likely to be resistant than clinical Staph. aureus isolates. We concluded that the most common bacteria causing clinical mastitis in dairy herds in Australia is likely to be Strep. uberis, whereas Staph. aureus is likely to be the most common cause of subclinical mastitis. Despite decades of antimicrobial use to control these organisms, AMR appears to be uncommon.
Subject(s)
Anti-Infective Agents , Cattle Diseases , Mastitis, Bovine , Mastitis , Staphylococcal Infections , Animals , Cattle , Female , Mastitis/veterinary , Mastitis, Bovine/epidemiology , Milk , Staphylococcal Infections/drug therapy , Staphylococcal Infections/veterinary , Staphylococcus aureus , Victoria/epidemiologyABSTRACT
The objective of this observational study was to compare 4 cow-level algorithms to predict cow-level intramammary infection (IMI) status (culture and MALDI-TOF) in late-lactation US dairy cows using standard measures of test performance. Secondary objectives were to estimate the likely effect of each algorithm, if used to guide selective dry cow therapy (SDCT), on dry cow antibiotic use in US dairy herds, and to investigate the importance of including clinical mastitis criteria in algorithm-guided SDCT. Cows (n = 1,594) from 56 US dairy herds were recruited as part of a previously published cross-sectional study of bedding management and IMI in late-lactation cows. Each herd was visited twice for sampling. At each farm visit, aseptic quarter-milk samples were collected from 20 cows approaching dry-off (>180 d pregnant), which were cultured using standard bacteriological methods and MALDI-TOF for identification of isolates. Quarter-level culture results were used to establish cow-level IMI status, which was considered the reference test in this study. Clinical mastitis records and Dairy Herd Improvement Association test-day somatic cell count data were extracted from herd records and used to perform cow-level risk assessments (low vs. high risk) using 4 algorithms that have been proposed for SDCT in New Zealand, the Netherlands, United Kingdom, and the United States. Agreement between aerobic culture (reference test; IMI vs. no-IMI) and algorithm status (high vs. low risk) was described using Cohen's kappa, test sensitivity, specificity, negative predictive value, and positive predictive value. The proportion of cows classified as high risk among the 4 algorithms ranged from 0.31 to 0.63, indicating that these approaches to SDCT could reduce antibiotic use at dry-off by 37 to 69% in the average US herd. All algorithms had poor agreement with IMI status, with kappa values ranging from 0.05 to 0.13. Sensitivity varied by pathogen, with higher values observed when detecting IMI caused by Streptococcus uberis, Streptococcus dysgalactiae, Staphylococcus aureus, and Lactococcus lactis. Negative predictive values were high for major pathogens among all algorithms (≥0.87), which may explain why algorithm-guided SDCT programs have been successfully implemented in field trials, despite poor agreement with overall IMI status. Removal of clinical mastitis criteria for each algorithm had little effect on the algorithm classification of cows, indicating that algorithms based on SCC alone may have similar performance to those based on SCC and clinical mastitis criteria. We recommend that producers implementing algorithm-guided SDCT use algorithm criteria that matches their relative aspirations for reducing antibiotic use (high specificity, positive predictive value) or minimizing untreated IMI at dry-off (high sensitivity, negative predictive value).
Subject(s)
Mastitis, Bovine , Algorithms , Animals , Cattle , Cell Count/veterinary , Cross-Sectional Studies , Female , Lactation , Mammary Glands, Animal , Milk , Pregnancy , StreptococcusABSTRACT
The objectives of this study were to (1) use partial budget analysis to estimate the cash impact for herds that switch from blanket dry cow therapy (BDCT) to culture- or algorithm-guided selective dry cow therapy (SDCT) and (2) conduct a sensitivity analysis to investigate effects in situations where SDCT increased clinical and subclinical mastitis risk during the subsequent lactation. A partial budget model was created using Monte Carlo simulation with @Risk software. Expenditures associated with dry-off procedures and health outcomes (clinical and subclinical mastitis) during the first 30 d in milk were used to model herd-level effects, expressed in units of US dollars per cow dry-off. Values for each economic component were derived from findings from a recent multisite clinical trial, peer-reviewed journal articles, USDA databases, and our experiences in facilitating the implementation of SDCT on farms. Fixed values were used for variables expected to have minimal variation within the US dairy herd population (e.g., cost of rapid culture plates) and sampling distributions were used for variables that were hypothesized to vary enough to effect the herd net cash impact of one or more DCT approach(es). For Objective 1, herd-level udder health was assumed to be unaffected by the implementation of SDCT. For culture-guided SDCT, producers could expect to save an average of +$2.14 (-$2.31 to $7.23 for 5th and 95th percentiles) per cow dry-off as compared with BDCT, with 75.5% of iterations being ≥$0.00. For algorithm-guided SDCT, the mean net cash impact was +$7.85 ($3.39-12.90) per cow dry-off, with 100% of iterations being ≥$0.00. The major contributors to variance in cash impact for both SDCT approaches were percent of quarters treated at dry-off and the cost of dry cow antibiotics. For Objective 2, we repeated the partial budget model with the 30-d clinical and subclinical mastitis incidence increasing by 1, 2, and 5% (i.e., risk difference = 0.01, 0.02, and 0.05) in both SDCT groups compared with BDCT. For algorithm-guided SDCT, average net cash impacts were ≥$0.00 per cow dry-off (i.e., cost effective) when mastitis incidence increased slightly. However, as clinical mastitis incidence increased, economic returns for SDCT diminished. These findings indicate that when SDCT is implemented appropriately (i.e., no to little negative effect on health), it might be a cost-effective practice for US herds under a range of economic conditions.
Subject(s)
Cattle Diseases , Mastitis, Bovine , Algorithms , Animals , Anti-Bacterial Agents/pharmacology , Cattle , Cattle Diseases/drug therapy , Cell Count/veterinary , Dairying , Female , Lactation , Mammary Glands, Animal , Mastitis, Bovine/drug therapy , MilkABSTRACT
The objective of this prospective cohort study was to explore associations between intramammary infection (IMI) in late-lactation cows and postcalving udder health and productivity. Cows (n = 2,763) from 74 US dairy herds were recruited as part of a previously published cross-sectional study of bedding management and IMI in late-lactation cows. Each herd was visited twice for sampling. At each visit, aseptic quarter milk samples were collected from 20 cows approaching dry-off (>180 d pregnant), which were cultured using standard bacteriological methods and MALDI-TOF for identification of isolates. Quarter-level culture results were used to establish cow-level IMI status at enrollment. Cows were followed from enrollment until 120 d in milk (DIM) in the subsequent lactation. Herd records were used to establish whether subjects experienced clinical mastitis or removal from the herd, and DHIA test-day data were used to record subclinical mastitis events (somatic cell count >200,000 cells/mL) and milk yield (kg/d) during the follow-up period. Cox regression and generalized estimating equations were used to evaluate the associations between IMI and the outcome of interest. The presence of late-lactation IMI caused by major pathogens was positively associated with postcalving clinical mastitis [hazard ratio = 1.5, 95% confidence interval (CI): 1.2, 2.0] and subclinical mastitis (risk ratio = 1.5, 95% CI: 1.3, 1.9). Species within the non-aureus Staphylococcus (NAS) group varied in their associations with postcalving udder health, with some species being associated with increases in clinical and subclinical mastitis in the subsequent lactation. Late-lactation IMI caused by Streptococcus and Streptococcus (Strep)-like organisms, other than Aerococcus spp. (i.e., Enterococcus, Lactococcus, and Streptococcus spp.) were associated with increases in postcalving clinical and subclinical mastitis. Test-day milk yield from 1 to 120 DIM was lower (-0.9 kg, 95% CI: -1.6, -0.3) in late-lactation cows with any IMI compared with cows without IMI. No associations were detected between IMI in late lactation and risk for postcalving removal from the herd within the first 120 DIM. Effect estimates reported in this study may be less than the underlying quarter-level effect size for IMI at dry-off and postcalving clinical and subclinical mastitis, because of the use of late-lactation IMI as a proxy for IMI at dry-off and the use of cow-level exposure and outcome measurements. Furthermore, the large number of models run in this study (n = 94) increases the chance of identifying chance associations. Therefore, confirmatory studies should be conducted. We conclude that IMI in late lactation may increase risk of clinical and subclinical mastitis in the subsequent lactation. The relationship between IMI and postcalving health and productivity is likely to vary among pathogens, with Staphylococcus aureus, Streptococcus spp., Enterococcus spp., and Lactococcus spp. being the most important pathogens identified in the current study.
Subject(s)
Aerococcus , Cattle Diseases , Mastitis, Bovine , Animals , Cattle , Cell Count/veterinary , Cross-Sectional Studies , Enterococcus , Female , Lactation , Lactococcus , Mammary Glands, Animal , Milk , Pregnancy , Prospective Studies , Staphylococcus , StreptococcusABSTRACT
BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, ivacaftor, was first approved for people with CF and the G551D CFTR mutation. This study describes the long-term clinical effectiveness of ivacaftor in this population. METHODS: We conducted a multicenter, prospective, longitudinal, observational study of people with CF ages ≥6 years with at least one copy of the G551D CFTR mutation. Measurements of lung function, growth, quality of life, and sweat chloride were performed after ivacaftor initiation (baseline, 1 month, 3 months, 6 months, and annually thereafter until 5.5 years). RESULTS: Ninety-six participants were enrolled, with 81% completing all study measures through 5.5 years. This cohort experienced significant improvements in percent predicted forced expiratory volume in 1 second (ppFEV1) of 4.8 [2.6, 7.1] (p < 0.001) at 1.5 years, that diminished to 0.8 [-2.0, 3.6] (p = 0.57) at 5.5 years. Adults experienced larger improvements in ppFEV1 (7.4 [3.6, 11.3], p < 0.001 at 1.5 years and 4.3 [0.6, 8.1], p = 0.02 at 5.5 years) than children (2.8 [0.1, 5.6], p = 0.04 at 1.5 years and -2.0 [-5.9, 2.0], p = 0.32 at 5.5 years). Rate of lung function decline for the overall study cohort from 1 month after ivacaftor initiation through 5.5 years was estimated to be -1.22 pp/year [-1.70, -0.73]. Significant improvements in growth, quality of life measures, sweat chloride, Pseudomonas aeruginosa detection, and pulmonary exacerbation rates requiring antimicrobial therapy persisted through five years of therapy. CONCLUSIONS: These findings demonstrate the long-term benefits and disease modifying effects of ivacaftor in children and adults with CF and the G551D mutation.
Subject(s)
Aminophenols/therapeutic use , Chloride Channel Agonists/therapeutic use , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis/drug therapy , Cystic Fibrosis/genetics , Quinolones/therapeutic use , Adolescent , Adult , Child , Female , Genotype , Humans , Longitudinal Studies , Male , Mutant Proteins/genetics , Mutation , Prospective Studies , Pseudomonas Infections/microbiology , Pseudomonas Infections/prevention & control , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Quality of Life , Respiratory Function Tests , United StatesABSTRACT
Selective dry-cow therapy (SDCT) could be used to reduce antibiotic use on commercial dairy farms in the United States but is not yet widely adopted, possibly due to concerns about the potential for negative effects on cow health. The objective of this study was to compare culture- and algorithm-guided SDCT programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure, non-inferiority trial for the following quarter-level outcomes: antibiotic use at dry-off, dry period intramammary infection (IMI) cure risk, dry period new IMI risk, and IMI risk at 1 to 13 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by treating only quarters from which aseptically collected milk samples tested positive on the Minnesota Easy 4Cast plate (University of Minnesota, St. Paul, MN) after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow had either a Dairy Herd Improvement Association test somatic cell count >200,000 cells/mL during the current lactation or 2 or more clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Intramammary infection status at enrollment and at 1 to 13 DIM was determined using standard bacteriological methods. The effect of treatment group on dry period IMI cure, dry period new IMI, and IMI risk at 1 to 13 DIM was determined using generalized linear mixed models (logistic), with marginal standardization to derive risk difference (RD) estimates. Quarter-level antibiotic use at dry-off for each group was BDCT (100%), cult-SDCT (45%), and alg-SDCT (45%). The crude dry period IMI cure risk for all quarters was 87.5% (818/935), the crude dry period new IMI risk was 20.1% (764/3,794), and the prevalence of IMI at 1 to 13 DIM was 23% (961/4,173). Non-inferiority analysis indicated that culture- and algorithm-guided SDCT approaches performed at least as well as BDCT for dry period IMI cure risk. In addition, the final models indicated that the risks for each of the 3 IMI measures were similar between all 3 treatment groups (i.e., RD estimates and 95% confidence intervals all close to 0). These findings indicate that under the conditions of this trial, culture- and algorithm-guided SDCT can substantially reduce antibiotic use at dry-off without negatively affecting IMI dynamics.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Lactation , Mammary Glands, Animal/drug effects , Mastitis, Bovine/prevention & control , Animals , Cattle , Cell Count/veterinary , Cephalosporins/administration & dosage , Female , Milk/drug effects , PrevalenceABSTRACT
The objective of this study was to compare culture- and algorithm-guided selective dry-cow therapy (SDCT) programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure clinical trial for the following cow-level outcomes: clinical mastitis, removal from the herd, and Dairy Herd Improvement Association (DHIA) test-day milk yield and SCC measures during the first 120 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by only treating quarters from which aseptically collected milk samples tested positive on a rapid culture system after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow met at least one of the following criteria: (1) any DHIA test with a somatic cell count >200,000 cells/mL during the current lactation, and (2) ≥2 clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Clinical mastitis and removal from the herd events (i.e., culling or death) and DHIA test-day data from dry-off to 120 DIM were extracted from herd records. Hazard ratios (HR) for the effect of treatment group on clinical mastitis and removal from the herd during 1 to 120 DIM were determined using Cox proportional hazards regression. The effects of treatment group on test-day loge-transformed SCC and milk yield were determined using linear mixed models. Final models indicated that either SDCT program was unlikely to increase clinical mastitis risk (HRcult-SDCT/BDCT = 0.82, 95% CI: 0.58, 1.15; HRalg-SDCT/BDCT = 0.83, 95% CI: 0.63, 1.09) or test-day logeSCC (cult-SDCT minus BDCT = 0.05, 95% CI: -0.09, 0.18; alg-SDCT minus BDCT = 0.07, 95% CI: -0.07, 0.21). Risk of removal from the herd and test-day milk yield were similar between treatment groups. Findings from this study indicate that culture- or algorithm-guided SDCT can be used at dry-off without negatively affecting cow health and performance in early lactation.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Lactation/drug effects , Mammary Glands, Animal/drug effects , Mastitis, Bovine/prevention & control , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Cattle , Cell Count/veterinary , Cephalosporins/administration & dosage , Cephalosporins/adverse effects , Colostrum , Female , Milk/cytology , Pregnancy , Proportional Hazards ModelsABSTRACT
The use of an internal teat sealant (ITS) at dry-off has been repeatedly shown to improve udder health in the subsequent lactation. However, almost all ITS research conducted in North America has evaluated one product (Orbeseal, Zoetis, Parsippany, NJ). The objective of this study was to evaluate a new ITS product (Lockout, Boehringer-Ingelheim Animal Health, Duluth, GA), by comparing it directly to Orbeseal in a multi-site, randomized, positively controlled equivalence trial for health indicators during the dry period [quarter-level new intramammary infection (IMI) risk, IMI cure risk, and IMI risk at 1 to 13 d in milk, DIM] and during the first 100 DIM [clinical mastitis and culling or death risk and test-day milk somatic cell count (SCC) and milk yield]. At dry-off, cows were randomly allocated to be treated with Orbeseal or Lockout after blanket administration of a cloxacillin dry cow therapy product. Cows were then followed from dry-off until 100 DIM. Intramammary infection status at enrollment and at 1 to 13 DIM was determined using standard bacteriological methods, allowing for the measurement of IMI dynamics during the dry period (i.e., IMI cures and new IMI). The effect of ITS group on dry period IMI cure, dry period new IMI, and IMI risk at 1 to 13 DIM was determined using generalized linear mixed models (logistic). Marginal standardization was used to derive risk difference estimates. An equivalence hypothesis test was conducted to compare ITS groups for dry period new IMI risk (margin of equivalence was ±5% units). The effect of ITS group on clinical mastitis and culling or death was determined using Cox proportional hazards regression. The effect of ITS group on test-day SCC and milk yield was determined using linear mixed models. Final models indicated that measures of quarter-level IMI dynamics were similar between ITS groups (i.e., risk difference estimates and 95% confidence intervals all close to zero). Furthermore, Lockout was found to be equivalent to Orbeseal for dry period new IMI risk using an equivalence hypothesis test. Hazard ratio estimates for clinical mastitis and culling or death were close to 1 and differences in SCC and milk yield between ITS groups were close to 0, indicating negligible effects of ITS group on test-day SCC and milk yield. In most cases, these effect estimates were relatively precise (i.e., narrow 95% confidence intervals). We conclude that producers using blanket dry cow therapy could consider including Orbeseal or Lockout treatment in their programs.
Subject(s)
Anti-Bacterial Agents , Mammary Glands, Animal , Mastitis, Bovine , Tissue Adhesives , Animals , Cattle , Female , Anti-Bacterial Agents/pharmacology , Cell Count/veterinary , Cloxacillin/therapeutic use , Lactation , Mammary Glands, Animal/drug effects , Mastitis, Bovine/prevention & control , Milk/cytology , North America , Proportional Hazards Models , Tissue Adhesives/therapeutic useABSTRACT
BACKGROUND: Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides. METHODS: Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV1 from baseline to the average of Weeks 40 and 48. FINDINGS: 279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (-0.8 vs -1.8) or Week 48 (-1.7 vs -2.4). Average ppFEV1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI -1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported. INTERPRETATION: Neither ppFEV1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive.
Subject(s)
Codon, Nonsense , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis , Drug Monitoring/methods , Oxadiazoles , Administration, Oral , Cystic Fibrosis/drug therapy , Cystic Fibrosis/genetics , Cystic Fibrosis/physiopathology , Double-Blind Method , Female , Forced Expiratory Volume , Humans , Male , Oxadiazoles/administration & dosage , Oxadiazoles/adverse effects , Respiratory Function Tests/methods , Symptom Flare Up , Treatment OutcomeABSTRACT
Objectives of this study were to (1) describe the intramammary infection (IMI) prevalence and pathogen profiles in quarters of cows approaching dry-off in US dairy herds, (2) compare IMI prevalence in quarters of cows exposed to different bedding material types, and (3) identify associations between bedding bacteria count and IMI in cows approaching dry-off. Eighty herds using 1 of 4 common bedding materials (manure solids, organic non-manure, new sand, and recycled sand) were recruited in a multi-site cross-sectional study. Each herd was visited twice for sampling. At each visit, aseptic quarter-milk samples were collected from 20 cows approaching dry-off (>180 d pregnant). Samples of unused and used bedding were also collected. Aerobic culture was used to determine the IMI status of 10,448 quarters and to enumerate counts (log10 cfu/mL) of all bacteria, Staphylococcus spp., Streptococcus spp. and Streptococcus-like organisms (SSLO), coliforms, Klebsiella spp., noncoliform gram-negatives, Bacillus spp., and Prototheca spp. in unused (n = 148) and used (n = 150) bedding. The association between bedding bacteria count and IMI was determined using multivariable logistic regression with mixed effects. Quarter-level prevalence of IMI was 21.1%, which was primarily caused by non-aureus Staphylococcus spp. (11.4%) and SSLO (5.6%). Only modest differences in IMI prevalence were observed between the 4 common bedding material types. Counts of all bacteria in unused bedding was positively associated with odds of IMI caused by any pathogen [ALL-IMI; odds ratio (OR) = 1.08]. A positive association was also observed for counts of SSLO in unused bedding and SSLO-IMI (OR = 1.09). These patterns of association were generally consistent across the 4 common bedding materials. In contrast, the association between counts of all bacteria in used bedding and ALL-IMI varied by bedding type, with positive associations observed in quarters exposed to manure solids (OR = 2.29) and organic non-manure (OR = 1.51) and a negative association in quarters exposed to new sand (OR = 0.47). Findings from this study suggest that quarter-level IMI prevalence in late-lactation cows is low in US dairy herds. Furthermore, bedding material type may not be an important risk factor for IMI in late lactation. Higher levels of bacteria in bedding may increase IMI prevalence at dry-off in general, but this relationship is likely to vary according to bedding material type.
Subject(s)
Klebsiella Infections/veterinary , Mastitis, Bovine/microbiology , Milk/microbiology , Staphylococcal Infections/veterinary , Streptococcal Infections/veterinary , Animals , Bacterial Load/veterinary , Bedding and Linens/microbiology , Bedding and Linens/veterinary , Cattle , Cross-Sectional Studies , Female , Klebsiella/isolation & purification , Klebsiella Infections/epidemiology , Klebsiella Infections/microbiology , Lactation , Logistic Models , Mammary Glands, Animal/microbiology , Manure/microbiology , Mastitis, Bovine/epidemiology , Prevalence , Risk Factors , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Staphylococcus/isolation & purification , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , Streptococcus/isolation & purificationABSTRACT
Because cloth udder towels (CUT) may function as a fomite for mastitis-causing pathogens, most udder health laboratories offer towel culture services as a tool to monitor towel hygiene. However, no studies have investigated if an association exists between bacteria levels in CUT and udder health outcomes. The objectives of this cross-sectional study were to (1) describe associations between herd-level measures of towel bacteria count (ToBC) and quarter-level intramammary infection (IMI) status in late-lactation cows, (2) establish pathogen-specific target levels of bacteria in CUT to aid the interpretation of towel culture reports, and (3) identify laundering-related risk factors for high ToBC. The study was conducted in 67 herds from 10 dairy states in the United States that used CUT. These 67 herds were originally recruited as part of a larger (80 herd) cross-sectional study of bedding management. Each herd was visited once during December 2017 to April 2018 and quarter-milk samples (n = 4,656) were collected from late-gestation (>180 d pregnant) cows (n = 1,313). Two recently laundered CUT were collected and a questionnaire was used to collect information about pre-milking teat preparation and CUT management practices. Quarter-level IMI status was determined using standard bacteriologic methods. In addition, colony-forming units of all bacteria (total bacteria), Staphylococcus spp., Streptococcus spp. or Streptococcus-like organisms (SSLO), coliforms, noncoliform gram-negatives, and Bacillus spp. were determined for each pair of CUT (log10 cfu/cm2). The association between ToBC and IMI was determined using multivariable logistic regression with mixed effects. After dichotomizing ToBC into high and low categories, associations between towel management practices and ToBC category were determined using unconditional logistic regression. The quarter-level prevalence of IMI was 19.6%, which was predominantly caused by non-aureus Staphylococcus spp. (NAS; 10.2%) and SSLO (5.1%). The predominant bacteria in CUT were Bacillus spp. (median = 3.13 log10 cfu/cm2). Total bacteria count was not associated with odds of IMI (odds ratio = 1.06), likely due to the predominance of Bacillus spp. in CUT and low number of IMI caused by Bacillus spp. In contrast, counts of Staphylococcus spp. and SSLO were positively associated with odds of IMI caused by NAS (odds ratio = 1.33) and SSLO (odds ratio = 1.45), respectively. Of 12 CUT management practices evaluated, only the failure to use a dryer was identified as a clear predictor of risk for a high ToBC (risk ratio of high coliform count = 8.17). Our study findings suggest that CUT may act as a fomite for NAS and SSLO. We recommend that herds aim to keep counts of Staphylococcus spp. and SSLO in CUT below 32 cfu/cm2 (or 5 cfu/in2), and that laundered towels be completely dried in a hot air dryer.
Subject(s)
Klebsiella Infections/veterinary , Mastitis, Bovine/microbiology , Milk/microbiology , Staphylococcal Infections/veterinary , Streptococcal Infections/veterinary , Animals , Bacterial Load/veterinary , Cattle , Cross-Sectional Studies , Female , Klebsiella/isolation & purification , Klebsiella Infections/epidemiology , Klebsiella Infections/microbiology , Lactation , Logistic Models , Mammary Glands, Animal/microbiology , Manure/microbiology , Mastitis, Bovine/epidemiology , Pregnancy , Prevalence , Risk Factors , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Staphylococcus/isolation & purification , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , Streptococcus/isolation & purificationABSTRACT
Plastic sanitary sheaths over artificial insemination (AI) guns have been used at the time of AI to improve hygiene at AI and fertility in cattle, but fertility responses have been variable in studies when AI was performed by professional inseminators. The aims of this study were to investigate whether the use of a sanitary sheath at the time of AI carried out by nonprofessional (do-it-yourself, or DIY) inseminators improves pregnancy rates to AI in pasture-based dairy cows and whether effects of sheaths are greater in cows with contaminated vulvas and in cows at increased risk of extended calving to conception intervals. Lactating dairy cows located in 10 pasture-based herds in a subtropical region of northern Australia were inseminated by herd-based DIY inseminators and assigned to be inseminated with (n = 3,655) or without (n = 3,969) a sanitary sheath, with potential effects assessed using multivariable logistic regression. Overall, use of a sheath at the time of AI did not significantly affect pregnancy rates to AI (36.3% for those inseminated without a sheath vs. 36.8% for those inseminated with a sheath; odds ratio: 1.02; 95% confidence interval: 0.92-1.11). Effects of using a sheath on pregnancy rates to AI varied by herd, with lower pregnancy rates with the use of sheaths in 1 herd and some evidence of increases in 3 herds. Unexpectedly, there was evidence that the effect of sheath on pregnancy rates was less positive (or more negative) when the vulva was classified as dirty before any cleaning of the vulva before insemination compared with when the vulva was classified as clean (interaction odds ratio: 0.75; 95% CI: 0.56-1.00). Interactions between sheath and other explanatory variables that could affect fertility were not significant; thus, there was no compelling evidence that the effect of using a sheath was modified by any of these variables. We conclude that the use of sheaths during AI of pasture-based dairy cows by DIY inseminators does not, on average, markedly improve pregnancy rates to AI. However, responses may vary between herds, and the response to sheaths may be inferior (i.e., less positive or more negative) when a cow's vulva is contaminated with feces or discharge at the time of AI compared with when the vulva is clean.
Subject(s)
Cattle/physiology , Insemination, Artificial/veterinary , Pregnancy Rate , Animal Feed/analysis , Animal Technicians , Animals , Australia , Female , Fertility , Fertilization , Humans , Hygiene , Insemination, Artificial/instrumentation , Insemination, Artificial/methods , Lactation , Male , PregnancyABSTRACT
This study evaluated the effect of equine chorionic gonadotropin (eCG) on reproductive performance, when incorporated into the first Ovsynch + P4 synchronization following planned start mating (PSM) in pasture-based lactating dairy cows. Two synchrony programs were compared in a randomized controlled trial in Queensland, Australia. Lactating cows from a single dairy herd (n = 782) were randomly allocated to Control and eCG groups. Control cows had their estrous cycles synchronized by treatment with 100 µg gonadotropin releasing hormone (GnRH; im) and insertion of a progesterone (P4) releasing intravaginal device that contained 1.0 g of P4 on Day 0; removal of P4 device and administration of 500 µg of an analogue of PGF2α on Day 7 (cloprostenol; im); 100 µg im of GnRH on Day 9, and fixed-time artificial insemination (FTAI) on Day 10. The eCG group were treated the same as the Control group except for the addition of 400 IU of eCG, im on Day 7 of the first synchronized estrous cycle. Following the first insemination, non-pregnant cows from both groups had their estrous cycles synchronized with the same treatment protocol without using eCG. The effects of eCG on 42d cumulative incidence of pregnancy and pregnancy per AI (P/AI) were determined using logistic regression models. The effect of eCG on time to pregnancy was determined using Kaplan-Meier survival analysis and Cox proportional hazards models. Adjusted 42 d cumulative incidence of pregnancy for eCG and control groups were 47.2 and 39.3% respectively (Odds ratio [OR] = 1.38, 95% CI: 1.01-1.88). Hazard of pregnancy tended to be higher in eCG cows overall (Hazard ratio [HR] = 1.18, 95% CI: 0.99-1.41) and was significantly higher when restricting to the first 42 days after PSM (HR = 1.31, 95% CI: 1.04-1.64). Hazards of pregnancy were not different between groups when restricting to > Day 42 post PSM (HR = 1.00, 95% CI: 0.77-1.31). P/AI tended to be higher in eCG treated cows at the first AI (44.0 vs 37.7%, OR = 1.30, 95% CI: 0.94-1.78). P/AI for second and third AIs were not significantly different between groups. In this herd, a single treatment of eCG at the first synchronized estrus after PSM improved reproductive performance in the short term, but not at subsequent inseminations.
Subject(s)
Cattle , Estrus Synchronization/methods , Gonadotropins, Equine/pharmacology , Pregnancy, Animal , Animals , Cloprostenol/administration & dosage , Cloprostenol/pharmacology , Female , Fertility Agents/pharmacology , Gonadotropin-Releasing Hormone/administration & dosage , Gonadotropin-Releasing Hormone/pharmacology , Insemination, Artificial/veterinary , Luteolytic Agents/administration & dosage , Luteolytic Agents/pharmacology , Pregnancy , Progesterone/administration & dosage , Progesterone/pharmacology , Progestins/administration & dosage , Progestins/pharmacology , QueenslandABSTRACT
This study utilizes morphological and mechanistic endpoints to characterize the onset of bilateral atresia of the vas deferens in a recently derived cystic fibrosis (CF) rat model. Embryonic reproductive structures, including Wolffian (mesonephric) duct, Mullerian (paramesonephric) duct, mesonephric tubules, and gonad, were shown to mature normally through late embryogenesis, with involution of the vas deferens and/or epididymis typically occurring between birth and postnatal day 4 (P4), although timing and degree of atresia varied. No evidence of mucus obstruction, which is associated with pathology in other CF-affected tissues, was observed at any embryological or postnatal time point. Reduced epididymal coiling was noted post-partum and appeared to coincide with, or predate, loss of more distal vas deferens structure. Remarkably, α smooth muscle actin expression in cells surrounding duct epithelia was markedly diminished in CF animals by P2.5 when compared to wild type counterparts, indicating reduced muscle development. RNA-seq and immunohistochemical analysis of affected tissues showed disruption of developmental signaling by Wnt and related pathways. The findings have relevance to vas deferens loss in humans with CF, where timing of ductular damage is not well characterized and underlying mechanisms are not understood. If vas deferens atresia in humans begins in late gestation and continues through early postnatal life, emerging modulator therapies given perinatally might preserve and enhance integrity of the reproductive tract, which is otherwise absent or deficient in 97% of males with cystic fibrosis.
Subject(s)
Cystic Fibrosis/pathology , Epididymis/pathology , Vas Deferens/pathology , Actins/metabolism , Animals , Cystic Fibrosis/metabolism , Epididymis/metabolism , Female , Male , Mucus/metabolism , Pregnancy , Rats , Vas Deferens/metabolismABSTRACT
OBJECTIVE: To determine if a pre-milking teat disinfection protocol would reduce the incidence of clinical mastitis by greater than 50%. METHODS: Two pre-milking routines were compared in a natural exposure trial. Cows from a single dairy herd were randomly assigned to control (n = 246) and experimental (pre-milking teat disinfection [PMTD]; n = 244) groups. For cows in the control group, the pre-milking routine involved minimal teat-washing, except for cows with wet teat contamination. For cows in the PMTD group, the pre-milking routine involved washing of all teats, dipping with a commercial 0.1% available iodine solution, allowing a minimum of 30 s contact time and then drying of the teats using disposable paper towel. Clinical cases encountered during the trial were recorded and pathogens were isolated from milk samples using standard laboratory methods. RESULTS: The effect of PMTD was determined using multivariable binary logistic regression. Multiparous animals in the PMTD group had higher odds of experiencing clinical mastitis overall and of experiencing clinical mastitis caused by environmental pathogens (odds ratio (OR) 1.97 and 4.11, 95% confidence interval (CI) 1.15-3.38 and 1.49-11.3, respectively). In primiparous animals, pre-milking teat disinfection did not reduce the odds of clinical mastitis by greater than 50% (OR 1.31, 95%CI 0.52-3.29). CONCLUSION: In this herd, PMTD increased the odds of clinical mastitis. The effectiveness of PMTD to prevent clinical mastitis in pasture-based systems is likely to vary greatly between herds. We therefore recommend against the wholesale use of this practice on Australian farms.
Subject(s)
Animal Husbandry/methods , Disinfection/methods , Mammary Glands, Animal , Mastitis, Bovine/epidemiology , Mastitis, Bovine/prevention & control , Milk/microbiology , Animals , Anti-Infective Agents, Local/pharmacology , Cattle , Dairying , Female , Incidence , Iodine/pharmacology , Lactation , Logistic Models , Milk Ejection , Queensland/epidemiology , Risk FactorsABSTRACT
In patients with cystic fibrosis, cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers, such as sweat chloride concentration and/or nasal potential difference, are used as end-points of efficacy in phase-III clinical trials with the disease modifying drugs ivacaftor (VX-770), VX809 and ataluren. The aim of this project was to review the literature on reliability, validity and responsiveness of nasal potential difference, sweat chloride and intestinal current measurement in patients with cystic fibrosis. Data on clinimetric properties were collected for each biomarker and reviewed by an international team of experts. Data on reliability, validity and responsiveness were tabulated. In addition, narrative answers to four key questions were discussed and agreed by the team of experts. The data collected demonstrated the reliability, validity and responsiveness of nasal potential difference. Fewer data were found on reliability of sweat chloride concentration; however, validity and responsiveness were demonstrated. Validity was demonstrated for intestinal current measurement, but further information is required on reliability and responsiveness. For all three end-points, normal values were collected and further research requirements were proposed. This body of work adds useful information to support the promotion of CFTR biomarkers to surrogate end-points and to guide further research in the area.