Use of antimicrobials for food animals in New Zealand: updated estimates to identify a baseline to measure targeted reductions

AIM

To describe the use of antimicrobial drugs for food animals in New Zealand, based on sales data reported to government for 2005-2018, to provide a baseline to determine the success of measures to reduce antimicrobial use for food animals and to compare usage to selected European countries.

METHODS

Data were sourced from official government and industry reports to update previous estimates of use (as amount sold) of antimicrobial products applied to animals in New Zealand. The data included antimicrobial sales and animal populations, weighted where appropriate by breed and age class. Antimicrobial use was estimated based on the amount of active ingredient sold, per kg of animal biomass standardised to the probable weight at time of treatment or lifetime average but not slaughter weight (population correction unit; PCU). New Zealand data for 2017 and 2018 were adjusted to account only for antimicrobials used for farm animals by discounting horticulture use, companion animal use and export.

RESULTS

Between 2014 and 2018 the estimated usage of antimicrobials in animals flattened to a 5-year rolling average of 10.40 mg/PCU. New data on use for companion animals and on exports of zinc bacitracin and tylosin, included previously in the gross New Zealand values, allow a more refined estimate of use of antimicrobials in food animals of 10.21 mg/PCU in 2018, the third lowest rate of use for countries reporting by the same methodology. The intensive industries of pigs and poultry combined use more than 500 mg/PCU whereas the extensive red meat and dairy industries use an estimated 6.25 mg/PCU. New Zealand uses proportionally more cephalosporins and macrolides, two of the critically important antimicrobial groups, when compared with European countries, but less quinolones. The most obvious difference is the extensive use of zinc bacitracin and tylosin fed to pigs and poultry in New Zealand but not in the European Union.

CONCLUSIONS

Use of antimicrobials in food animals has stabilised to a rate of approximately 10.2 mg/PCU. This baseline should be used by the animal health industry to measure future success in its efforts to reduce and make more refined use of antimicrobial drugs as New Zealand works to deliver the government's Antimicrobial Resistance Action Plan. High rates of use of zinc bacitracin and some critically important macrolides represent clear targets in attempts to reduce usage.

COMT polymorphism modulates the resting-state EEG alpha oscillatory response to acute nicotine in male non-smokers

Performance improvements in cognitive tasks requiring executive functions are evident with nicotinic acetylcholine receptor (nAChR) agonists, and activation of the underlying neural circuitry supporting these cognitive effects is thought to involve dopamine neurotransmission. As individual difference in response to nicotine may be related to a functional polymorphism in the gene encoding catechol-O-methyltransferase (COMT), an enzyme that strongly influences cortical dopamine metabolism, this study examined the modulatory effects of the COMT Val158Met polymorphism on the neural response to acute nicotine as measured with resting-state electroencephalographic (EEG) oscillations. In a sample of 62 healthy non-smoking adult males, a single dose (6 mg) of nicotine gum administered in a randomized, double-blind, placebo-controlled design was shown to affect α oscillatory activity, increasing power of upper α oscillations in frontocentral regions of Met/Met homozygotes and in parietal/occipital regions of Val/Met heterozygotes. Peak α frequency was also found to be faster with nicotine (vs. placebo) treatment in Val/Met heterozygotes, who exhibited a slower α frequency compared to Val/Val homozygotes. The data tentatively suggest that interindividual differences in brain α oscillations and their response to nicotinic agonist treatment are influenced by genetic mechanisms involving COMT.

In vivo isotopically labeled atherosclerotic aorta plaques in ApoE KO mice and molecular profiling by matrix-assisted laser desorption/ionization mass spectrometric imaging

RATIONALE

The ability to quantify rates of formation, regression and/or remodeling of atherosclerotic plaque should facilitate a better understanding of the pathogenesis and management of cardiovascular disease. In the current study, we coupled a stable isotope labeled tracer protocol with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to examine spatial and temporal lipid dynamics in atherosclerotic plaque.

METHODS

To promote plaque formation in the aorta region, ApoE KO mice were fed a high cholesterol diet (0.15% cholesterol) and orally dosed with (2,2,3,4,4,6-d(6))-cholesterol over several weeks. Tissue sections of ~10 µm thickness were analyzed by MALDI-MSI using matrix deposition by either chemical sublimation or acoustic droplet ejection.

RESULTS

MALDI-MSI yielded distinct spatial distribution information for a variety of lipid classes including specific lysophosphatidylcholines typically associated with atherosclerosis-related tissue damage such as phospholipase 2 (Lp-PLA(2)) that mediate chemotactic responses to inflammation (e.g. LPC 16:0, LPC 18:0 and LPC 18:1) as well as free cholesterol and cholesteryl esters that contribute to atheroma formation. MALDI mass spectra acquired from aorta tissue sections clearly distinguished non-esterified and esterified versions of (2,2,3,4,4,6-d(6))-cholesterol within aortic plaque regions and showed distinct spatial accumulation of the cholesterol tracer.

CONCLUSIONS

The ability to couple stable isotope based protocols with MALDI-MSI enables a novel strategy to characterize the effects of therapeutic treatments on atherosclerotic plaque formation, regression and potential remodeling of the complex lipid components with high chemical specificity and spatiotemporal information.

Vascular remodelling in the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible fibrosing interstitial pneumonia of unknown aetiology that usually leads to respiratory failure and death within 5 years of diagnosis. Alveolar epithelial cell injury, disruption of alveolar capillary membrane integrity and abnormal vascular repair and remodelling have all been proposed as possible pathogenic mechanisms. This review summarizes our current knowledge of the abnormalities in vascular remodelling observed in IPF and highlights several of the cytokines thought to play a pathogenic role, which may ultimately prove to be future therapeutic targets.

Anorectal atresia with gross terminal colonic distension in Africa

Anorectal malformation (ARM) is a group of significant birth defects with geographic variation in incidence, individual phenotypes and regional geographic subtypes occurring in approximately 1:5,000 live births. Anorectal atresia with gross terminal colonic distension in the presence of an absent anal canal has also been known as 'pouch colon' which is mainly associated with the Indian subcontinent. Its prevalence is unknown but it is rare, possibly representing a fraction of 1 % of ARM. The problem seems to revolve around the gross terminal distension of the distal pouch which remains a significant surgical challenge to surgeons resulting in poorer postoperative continence in many instances.

AIM

This study set out to collate data on ARM patients with gross terminal distension of the distal pouch from Africa to evaluate its epidemiology and outcome in African patients.

METHODS

Fifteen African paediatric surgical centres (7 South African and 8 African centres) were polled on the occurrence of anorectal atresia with gross terminal distension of the terminal bowel, an ARM variant. Data included ethnic group, age, gender as well as the anatomical pathology, classification and presence or absence of associated anomalies.

RESULTS

Of 12 respondents, 8 (67 %) responded and sufficient data to classify and analyse were obtained from six of the eight positive replies (7 new cases). Abdominal X-ray showed a grossly dilated terminal portion of the colon in the presence of an imperforate anus. A colovesical fistula was observed in four (three males and one female cloaca). Three were associated with a colonic atresia, of which two were in the transverse colon and one in the sigmoid colon. Surgical corrective procedures were carried out in six, but one patient, with a cloaca, died prior to surgical correction.

CONCLUSIONS

In this survey of 15 African centres, we have attempted to document the occurrence and presentation of anorectal atresia with gross terminal distension in Africa and report seven additional new cases. A possible association with associated conditions like colonic atresia requires further investigation.

Effects of COMT genotype on sensory gating and its modulation by nicotine: Differences in low and high P50 suppressors

Elevated smoking rates seen in schizophrenia populations may be an attempt to correct neuropathologies associated with deficient nicotinic acetylcholine receptors and/or dopaminergic systems using exogenous nicotine. However, nicotine's effects on cognitive processing and sensory gating have been shown to be baseline-dependent. Evidence of a restorative effect on sensory gating deficits by nicotine-like agonists has been demonstrated, however, its underlying mechanisms in the context of dopamine dysregulation are unclear. Catechol-O-methyltransferase (COMT), a key dopamine regulator in the brain, contains a co-dominant allele in which a valine-to-methionine substitution causes variations in enzymatic activity leading to reduced synaptic dopamine levels in the Val/Val genotype. Using a randomized, double-blind, placebo-controlled design with 57 non-smokers, this study examined the effects of COMT genotype on sensory gating and its modulation by nicotine in low vs. high suppressors. The results were consistent with the hypothesis that increased dopamine resulting from nicotine stimulation or Met allelic activity would benefit gating in low suppressors and impair gating in high suppressors, and that this gating improvement with nicotine would be more evident in Val carriers who were low suppressors, while the gating impairment would be more evident in Met carriers who were high suppressors. These findings reaffirm the importance of baseline-dependency and suggest a subtle relationship between COMT genotype and baseline-stratified levels of sensory gating, which may help to explain the variability of cognitive abilities in schizophrenia populations.

Investigation of isomeric transformations of chlorogenic acid in buffers and biological matrixes by ultraperformance liquid chromatography coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight mass spectrometry

Ultraperformance liquid chromatography coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (UPLC-IM-MS) was used to study the isomeric transformations of trans-5-caffeoylquinic acid, an extremely active compound present in multiple vegetables, fruits, and beverages. The UPLC/oa-TOF MS results proved that in phosphate buffer (pH 7.4), plasma, or urine sample, trans-5-caffeoylquinic acid first isomerizes to trans-4-caffeoylquinic acid and then to trans-3-caffeoylquinic acid by intramolecular acyl migration. When exposed to UV light, trans-3-, -4-, and -5-caffeoylquinic acids undergo cis/trans isomerization to form cis isomers. The isomerization was solely dependent on the pH of the matrix, as well as the incubation temperature, and was independent of metabolic enzymes. UPLC-IM-MS results revealed that a reversible cis/trans isomerization of caffeoylquinic acids could also be induced by the electric field in an electrospray source. Thus, understanding the possible role of electric field-induced isomerization of caffeoylquinic acids may help lessen the confusion between gas phase phenomena and liquid state chemistry when applying IM-MS analysis. The comprehensive understanding of caffeoylquinic acid isomerization transformations is crucial for the appropriate handling of samples and interpretation of experimental data.

The moderating role of the dopamine transporter 1 gene on P50 sensory gating and its modulation by nicotine

Although schizophrenia has been considered primarily a disease of dopaminergic neurotransmission, the role of dopamine in auditory sensory gating deficits in this disorder and their amelioration by smoking/nicotine is unclear. Hypothesizing that individual differences in striatal dopamine levels may moderate auditory gating and its modulation by nicotine, this preliminary study used the mid-latency (P50) auditory event-related potential (ERP) to examine the single dose (6 mg) effects of nicotine (vs. placebo) gum on sensory gating in 24 healthy nonsmokers varying in the genetic expression of the dopamine transporter (DAT). Consistent with an inverted-U relationship between dopamine level and the drug effects, individuals carrying the 9R (lower gene expression) allele, which is related to greater striatal dopamine levels, tended to evidence increased baseline gating compared to 10R (higher gene expression) allele carriers and showed a reduction in gating with acute nicotine. The present results may help to understand the link between excessive smoking and sensory gating deficits in schizophrenia and to explain the potential functional implications of genetic disposition on nicotinic treatment in schizophrenia.

Cytochrome P450-dependent metabolism of gefitinib

The in vitro metabolism of [(14)C]-gefitinib (1-3 microM) was investigated using human liver microsomes and a range of expressed human cytochrome P450 enzymes, with particular focus on the formation of O-desmethyl-gefitinib (M523595), the major metabolite observed in human plasma. High-performance liquid chromatography with ultraviolet light, radiochemical and mass spectral analysis, together with the availability of authentic standards, enabled quantification and structural identification of metabolites. On incubation with pooled human liver microsomes, [(14)C]-gefitinib underwent rapid and extensive metabolism to a number of metabolites, although M523595 was only a minor microsomal product. Formation of most metabolites was markedly decreased by ketoconazole, but M523595 production was inhibited only by quinidine. Gefitinib was metabolized extensively by expressed CYP3A4, producing a similar range of metabolites to liver microsomes, but M523595 was not formed. CYP1A2, 2C9 and 2C19 produced no measurable metabolism of gefitinib, while CYP3A5 produced a range of metabolites similar to CYP3A4, but to a much lower degree. In contrast, CYP2D6 catalysed rapid and extensive metabolism of gefitinib to M523595. While formation of M523595 was CYP2D6 mediated, the overall metabolism of gefitinib was dependent primarily on CYP3A4, and this was not obviously diminished in liver microsomes from CYP2D6 poor metabolizers.

Nicotine and smoker status moderate brain electric and mood activation induced by ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist

As the increased smoking prevalence in schizophrenics may be interpreted as an adaptive response to an underlying biological defect, investigations into nicotine's actions within N-methyl-d-aspartate (NMDA) antagonist drug models of schizophrenia may improve our understanding of the role of glutamatergic neurotransmission in initiating and maintaining nicotine dependence in this disorder. In this double-blind, placebo-controlled, randomized study, the electroencephalographic (EEG) and subjective response to a sub-psychotomimetic intravenous dose of the NMDA antagonist ketamine was examined in 20 regular smokers and 20 non-smokers pretreated with placebo or nicotine gum. Although nicotine increased EEG arousal, ketamine produced electrocerebral signs of brain activation (decreased slow wave power) and sedation (decreased fast wave power and frequency), which were not affected by nicotine pretreatment and were evident only in non-smokers. Ketamine increased a number of self-report indices of subjective arousal, some of which were attenuated and potentiated by nicotine in smokers and non-smokers, respectively. These findings suggest that long-term (evidenced by smoker vs. non-smoker comparisons) and short-term (acute) nicotine exposure may alter NMDA receptor-mediated arousal and mood systems in a way that promotes nicotine dependence in smokers, and addresses neurobiological deficiencies in smokers with schizophrenia.

Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury

BACKGROUND

Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1, a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1 plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS.

METHODS

Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was performed on BAL cells.

RESULTS

sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4-54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients (p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than those without detectable sVEGFR-1 (1415.2 (474.9-3192) pg/ml v 4761 (1349-7596.6) pg/ml, median difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased following incubation with tumour necrosis factor alpha.

CONCLUSION

This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS.

Morphological and morphometric attributes of epididymal and testicular spermatozoa following surgical sperm retrieval for obstructive and nonobstructive azoospermia

Whilst the morphological (shape) and morphometric (sperm head size) attributes of ejaculated spermatozoa have been well studied, the morphological and morphometric qualities of testicular and epididymal spermatozoa retrieved from males with obstructive and nonobstructive azoospermia is much less documented. We wished to examine the effect of aetiology of azoospermia and site of retrieval on the attributes of retrieved spermatozoa. This was a prospective observational study of 30 consecutive successful sperm retrievals, six for nonobstructive azoospermia and 24 for obstructive, of which five were retrieved from the epididymis and the remainder from the testis. The proportion of morphologically normal testicular spermatozoa in patients with obstructive and nonobstructive azoospermia was not significantly different (7% versus 7.6%, P = 0.97). Testicular spermatozoa from males with obstructive azoospermia showed an increase in frequency of sperm with small heads [47/180 (26%) versus 97/909 (11%), P = 0.036] as well as small acrosome and increasing vacuole formation over nonobstructive spermatozoa. Similarly, there was a significant increase in tail deformities and decreases in tail lengths in sperm from males with nonobstructive azoospermia. Epididymal spermatozoa showed significantly greater proportion of morphologically normal spermatozoa than testicular (20% versus 13%, P = 0.001) as well as a significant increase in acrosome vacuoles. Furthermore, morphometrically epididymal spermatozoa displayed with smaller head length, width and area than testicular spermatozoa. Testicular spermatozoa from obstructive azoospermia displayed significantly less tail defects (35% versus 57%, P = 0.003) as well as significantly longer tail lengths (30.6 microm versus 10.7 microm). These morphological and morphometric differences between epididymal and testicular and obstructive and nonobstructive spermatozoa may represent part of the natural maturation process. There were no associations between any morphological or morphometric abnormality with any significant parameter in subsequent use in ICSI.

A novel precursor ion discovery method on a hybrid quadrupole orthogonal acceleration time-of-flight (Q-TOF) mass spectrometer for studying protein phosphorylation

A tandem quadrupole time-of-flight (Q-TOF) mass spectrometer has been programmed such that phosphorylated peptides can automatically be discovered and identified in a way similar to that of the use of precursor ion or neutral loss scanning, but without the need to scan the quadrupole mass filter. Instead, the method capitalizes on the innate capability of the Q-TOF to record mass spectra and product ion spectra quickly, with good sensitivity and with good mass accuracy. Alternate mass spectra, with and without fragmentation, are recorded at high and low collision energy with the quadrupole operating in wideband mode. The method of analysis is both compatible with and dependant on liquid chromatography for separation of complex mixtures. The method has been demonstrated by searching for the neutral loss of 98 Da (H3PO4) from phosphoserine and phosphothreonine residues, or for the phosphorylated immonium ion at m/z 216 from phosphotyrosine. The method also incorporates acquisition of the product ion spectrum from any candidate precursor ions, thereby allowing confirmation of the neutral loss or product ion and providing additional sequence information to assist identification of the protein and assign the site of phosphorylation.

The quality of life impact of dysphonia

Dysphonia can affect social life and employment, but formal studies of its general health impact are lacking. The aims of this study were (i) to compare self-rated general health status as measured by the SF-36 in a large cohort of dysphonic patients with those from normative groups; and (ii) to examine the differential impact of dysphonia on the various health status domains. The 163 dysphonic voice clinic attendees (38 men, 125 women) were drawn from recruits to a prospective trial of speech therapy efficacy. The Short-Form 36 (SF-36) scores were compared with published data on 744 age-matched healthy controls. Patients with dysphonia had significantly poorer self-reported health than the controls on all eight SF-36 subscales (limitation of physical activity P < 0.05; other seven, all P < 0.001, Student's t-test). We thus conclude that dysphonia in patients without obvious laryngeal disease has an adverse impact on all health status subscales as measured by the SF-36. The study provides further evidence for the inclusion quality of life measures in otolaryngology baseline and outcome assessments.

A method for the amidation of recombinant peptides expressed as intein fusion proteins in Escherichia coli

The increasing use of peptides as pharmaceutical agents, especially in the antiviral and anti-infective therapeutic areas, requires cost-effective production on a large scale. Many peptides need carboxy amidation for full activity or prolonged bioavailability. However, this modification is not possible in prokaryotes and must be done using recombinant enzymes or by expression in transgenic milk. Methods employing recombinant enzymes are appropriate for small-scale production, whereas transgenic milk expression is suitable for making complex disulfide-containing peptides required in large quantity. Here we describe a method for making amidated peptides using a modified self-cleaving vacuolar membrane ATPase (VMA) intein expression system. This system is suitable for making amidated peptides at a laboratory scale using readily available constructs and reagents. Further improvements are possible, such as reducing the size of the intein to improve the peptide yields (the VMA intein comprises 454 amino acids) and, if necessary, secreting the fusion protein to ensure correct N-terminal processing to the peptide. With such developments, this method could form the basis of a large-scale cost-effective system for the bulk production of amidated peptides without the use of recombinant enzymes or the need to cleave fusion proteins.

Is voice therapy an effective treatment for dysphonia? A randomised controlled trial

OBJECTIVES

To assess the overall efficacy of voice therapy for dysphonia.

DESIGN

Single blind randomised controlled trial.

SETTING

Outpatient clinic in a teaching hospital.

PARTICIPANTS

204 outpatients aged 17-87 with a primary symptom of persistent hoarseness for at least two months.

INTERVENTIONS

After baseline assessments, patients were randomised to six weeks of either voice therapy or no treatment. Assessments were repeated at six weeks on the 145 (71%) patients who continued to this stage and at 12-14 weeks on the 133 (65%) patients who completed the study. The assessments at the three time points for the 70 patients who completed treatment and the 63 patients in the group given no treatment were compared.

MAIN OUTCOME MEASURES

Ratings of laryngeal features, Buffalo voice profile, amplitude and pitch perturbation, voice profile questionnaire, hospital anxiety and depression scale, clinical interview schedule, SF-36.

RESULTS

Voice therapy improved voice quality as assessed by rating by patients (P=0.001) and rating by observer (P<0.001). The treatment effects for these two outcomes were 4.1 (95% confidence interval 1.7 to 6.6) points and 0.82 (0.50 to 1.13) points. Amplitude perturbation showed improvement at six weeks (P=0.005) but not on completion of the study. Patients with dysphonia had appreciable psychological distress and lower quality of life than controls, but voice therapy had no significant impact on either of these variables.

CONCLUSION

Voice therapy is effective in improving voice quality as assessed by self rated and observer rated methods.