DIVERSITY OF STAPHYLOCOCCAL SPECIES CULTURED FROM CAPTIVE LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII) AND THEIR ENVIRONMENT.

Livingstone's fruit bats (Pteropus livingstonii) are critically endangered and a captive population has been established as part of the International Union for Conservation of Nature Species Action Plan. The largest colony, in Jersey Zoo, was sampled for staphylococcal carriage and at infection sites, as disease associated with staphylococci had previously been found. Staphylococci were cultured from swabs from 44 bats (skin, oropharynx, mouth ejecta, skin lesions) and from their enclosure. The isolates were identified by matrix-assisted laser desorption-ionization time of flight mass spectrometry; antimicrobial susceptibility testing was performed by disc diffusion and screening for mecA and mecC. Seventeen species of coagulase-negative staphylococci including Staphylococcus xylosus, S. kloosii, S. nepalensis, and S. simiae were isolated. Staphylococcus aureus was identified from both carriage and lesional sites. These findings suggest S. nepalensis may be part of the normal carriage flora of bats. Antimicrobial resistance rates were low and methicillin-resistant Staphylococcus aureus (MRSA) was not identified. Sampling of mouth ejecta for staphylococci may provide results representative for carriage sites.

Envelope following responses, noise exposure, and evidence of cochlear synaptopathy in humans: Correction and comment.

A correction and comment are provided for a recent article by Paul, Waheed, Bruce, and Roberts [(2017). J. Acoust. Soc. Am. 142(5), EL434-EL440].

Subcortical amplitude modulation encoding deficits suggest evidence of cochlear synaptopathy in normal-hearing 18-19 year olds with higher lifetime noise exposure.

Noise exposure and aging can damage cochlear synapses required for suprathreshold listening, even when cochlear structures needed for hearing at threshold remain unaffected. To control for effects of aging, behavioral amplitude modulation (AM) detection and subcortical envelope following responses (EFRs) to AM tones in 25 age-restricted (18-19 years) participants with normal thresholds, but different self-reported noise exposure histories were studied. Participants with more noise exposure had smaller EFRs and tended to have poorer AM detection than less-exposed individuals. Simulations of the EFR using a well-established cochlear model were consistent with more synaptopathy in participants reporting greater noise exposure.

Tinnitus: animal models and findings in humans.

Chronic tinnitus (ringing of the ears) is a medically untreatable condition that reduces quality of life for millions of individuals worldwide. Most cases are associated with hearing loss that may be detected by the audiogram or by more sensitive measures. Converging evidence from animal models and studies of human tinnitus sufferers indicates that, while cochlear damage is a trigger, most cases of tinnitus are not generated by irritative processes persisting in the cochlea but by changes that take place in central auditory pathways when auditory neurons lose their input from the ear. Forms of neural plasticity underlie these neural changes, which include increased spontaneous activity and neural gain in deafferented central auditory structures, increased synchronous activity in these structures, alterations in the tonotopic organization of auditory cortex, and changes in network behavior in nonauditory brain regions detected by functional imaging of individuals with tinnitus and corroborated by animal investigations. Research on the molecular mechanisms that underlie neural changes in tinnitus is in its infancy and represents a frontier for investigation.

Modulation of electrocortical brain activity by attention in individuals with and without tinnitus.

Age and hearing-level matched tinnitus and control groups were presented with a 40 Hz AM sound using a carrier frequency of either 5 kHz (in the tinnitus frequency region of the tinnitus subjects) or 500 Hz (below this region). On attended blocks subjects pressed a button after each sound indicating whether a single 40 Hz AM pulse of variable increased amplitude (target, probability 0.67) had or had not occurred. On passive blocks subjects rested and ignored the sounds. The amplitude of the 40 Hz auditory steady-state response (ASSR) localizing to primary auditory cortex (A1) increased with attention in control groups probed at 500 Hz and 5 kHz and in the tinnitus group probed at 500 Hz, but not in the tinnitus group probed at 5 kHz (128 channel EEG). N1 amplitude (this response localizing to nonprimary cortex, A2) increased with attention at both sound frequencies in controls but at neither frequency in tinnitus. We suggest that tinnitus-related neural activity occurring in the 5 kHz but not the 500 Hz region of tonotopic A1 disrupted attentional modulation of the 5 kHz ASSR in tinnitus subjects, while tinnitus-related activity in A1 distributing nontonotopically in A2 impaired modulation of N1 at both sound frequencies.

Computer-automated tinnitus assessment: noise-band matching, maskability, and residual inhibition.

BACKGROUND: Psychoacoustic measures of tinnitus typically include loudness and pitch match, minimum masking level (MML), and residual inhibition (RI). We previously developed and documented a computer-automated tinnitus evaluation system (TES) capable of subject-guided loudness and pitch matching. The TES was further developed to conduct computer-aided, subject-guided testing for noise-band matching (NBM), MML, and RI. PURPOSE: The purpose of the present study was to document the capability of the upgraded TES to obtain measures of NBM, MML, and RI, and to determine the test-retest reliability of the responses obtained. RESEARCH DESIGN: Three subject-guided, computer-automated testing protocols were developed to conduct NBM. For MML and RI testing, a 2-12 kHz band of noise was used. All testing was repeated during a second session. STUDY SAMPLE: Subjects meeting study criteria were selected from those who had previously been tested for loudness and pitch matching in our laboratory. A total of 21 subjects completed testing, including seven females and 14 males. RESULTS: The upgraded TES was found to be fairly time efficient. Subjects were generally reliable, both within and between sessions, with respect to the type of stimulus they chose as the best match to their tinnitus. Matching to bandwidth was more variable between measurements, with greater consistency seen for subjects reporting tonal tinnitus or wide-band noisy tinnitus than intermediate types. Between-session repeated MMLs were within 10 dB of each other for all but three of the subjects. Subjects who experienced RI during Session 1 tended to be those who experienced it during Session 2. CONCLUSIONS: This study may represent the first time that NBM, MML, and RI audiometric testing results have been obtained entirely through a self-contained, computer-automated system designed specifically for use in the clinic. Future plans include refinements to achieve greater testing efficiency.

A retrospective study of cases of canine demodicosis submitted to a commercial diagnostic laboratory servicing the United Kingdom and Ireland (2017-2018) part 2; Aerobic culture and antimicrobial susceptibility results.

Clinical diagnostic reports from 508 cases of canine demodicosis diagnosed either by histological or skin scraping analysis from a United Kingdom Accreditation Service (UKAS) accredited veterinary diagnostic laboratory servicing the United Kingdom (UK) and Ireland were evaluated. Of the 508 cases, 284 had skin swabs submitted for culture on the same day the skin biopsy and/or skin scraping were obtained. Dogs with juvenile-onset (JO) demodicosis represented 57.4% of these cases, whilst adult-onset (AO) cases comprised 42.6%. The data revealed that overgrowth of pathogenic bacteria was more common in AO demodicosis cases (75.2%) in comparison to the JO cases (57%). Adult-onset cases also had increased involvement of bacteria belonging to multiple genera and/or yeast (28.9%) in comparison to JO cases (18.4%). Pruritus was significantly associated with an overgrowth of Staphylococcus pseudintermedius (p < 0.001). Resistance to one or more antimicrobial classes was noted in S. pseudintermedius isolates from 56.3% of JO cases with 10.3% of these cases being classified as Multi-Drug Resistant (MDR). Similarly, 51.9% of S. pseudintermedius isolates from the AO cases were noted to be resistant to one or more antimicrobial class with 8.6% of these cases being considered MDR. Cephalosporins were the most frequently administered antimicrobial class noted in submission histories, followed by the penicillin and fluoroquinolone classes. Whilst our findings reveal a high prevalence of concurrent overgrowth of pathogenic bacteria warranting therapeutic intervention in canine demodicosis, the presence of resistance within isolates highlights the need for prudent selection and targeted use of antimicrobial therapy that encompass the key principles of antimicrobial stewardship.

A retrospective study of cases of canine demodicosis submitted to a commercial diagnostic laboratory servicing the United Kingdom and Ireland (2017-2018): Part 1 - Signalment, lesion distribution, treatments, and concurrent diseases.

Canine demodicosis, due to an overpopulation of Demodex spp. mites, remains one of the most common dermatological diseases encountered in small animal practice. The aims of this study were to interrogate submitted histories and diagnostic report results from a large cohort of dogs (n = 508) diagnosed with demodicosis either through histological analysis or the finding of Demodex spp. mites on skin scrapings by a UKAS accredited commercial laboratory servicing the United Kingdom (UK) and Ireland in the years 2017 and 2018. The main findings revealed that short-coated breeds were more likely to develop juvenile-onset (JO) demodicosis, whereas medium- and long-coated breeds were more likely to develop adult-onset (AO) disease. Pododemodicosis was reported more commonly in adult, long-coated breeds. Skin scrapings were positive in only 83.3% of samples that had a corresponding positive biopsy result; this finding highlights the necessity to perform further diagnostic tests if demodicosis remains clinically suspected despite a negative skin scraping result. Concurrent underlying diseases, potentially associated with immunosuppression, were reported in 42/221 (19%) of dogs with AO demodicosis. Serum allergy and Sarcoptes ELISA assays were positive in individual animals in both the JO and AO groups; the clinical significance of these latter findings requires careful interpretation in dogs with confirmed demodicosis.

Ringing ears: the neuroscience of tinnitus.

Tinnitus is a phantom sound (ringing of the ears) that affects quality of life for millions around the world and is associated in most cases with hearing impairment. This symposium will consider evidence that deafferentation of tonotopically organized central auditory structures leads to increased neuron spontaneous firing rates and neural synchrony in the hearing loss region. This region covers the frequency spectrum of tinnitus sounds, which are optimally suppressed following exposure to band-limited noise covering the same frequencies. Cross-modal compensations in subcortical structures may contribute to tinnitus and its modulation by jaw-clenching and eye movements. Yet many older individuals with impaired hearing do not have tinnitus, possibly because age-related changes in inhibitory circuits are better preserved. A brain network involving limbic and other nonauditory regions is active in tinnitus and may be driven when spectrotemporal information conveyed by the damaged ear does not match that predicted by central auditory processing.

Re-examining the relationship between audiometric profile and tinnitus pitch.

OBJECTIVE: We explored the relationship between audiogram shape and tinnitus pitch to answer questions arising from neurophysiological models of tinnitus: 'Is the dominant tinnitus pitch associated with the edge of hearing loss?' and 'Is such a relationship more robust in people with narrow tinnitus bandwidth or steep sloping hearing loss?' DESIGN: A broken-stick fitting objectively quantified slope, degree and edge of hearing loss up to 16 kHz. Tinnitus pitch was characterized up to 12 kHz. We used correlation and multiple regression analyses for examining relationships with many potentially predictive audiometric variables. STUDY SAMPLE: 67 people with chronic bilateral tinnitus (43 men and 24 women, aged from 22 to 81 years). RESULTS: In this ample of 67 subjects correlation failed to reveal any relationship between the tinnitus pitch and the edge frequency. The tinnitus pitch generally fell within the area of hearing loss. The pitch of the tinnitus in a subset of subjects with a narrow tinnitus bandwidth (n = 23) was associated with the audiometric edge. CONCLUSIONS: Our findings concerning subjects with narrow tinnitus bandwidth suggest that this can be used as an a priori inclusion criterion. A large group of such subjects should be tested to confirm these results.

Total remission or persistence of tinnitus and decreased sound level tolerance in adolescents with normal audiograms: A follow-up study.

BACKGROUND: Tinnitus may reflect hidden cochlear synaptic injury that does not express in the audiogram, but leads to neuroplastic changes in auditory pathways that, in turn, reduce tolerance to sounds. Such injury may follow the exposure to loud sounds. The aim of this study was to follow-up adolescents enrolled in a private school to evaluate the prevalence of tinnitus and reduced sound level tolerance (SLT) with 1-year interval, as well as to observe rates of tinnitus persistence, remission and incidence of new cases by repeat measurements. METHODS: In Study 1 (Sanchez et al., 2016), we evaluated 170 adolescents by a questionnaire about tinnitus and reduced tolerance to ordinary sounds and by measurements in a sound booth: audiometry (0.25-16kHz), Loudness Discomfort Levels (LDL, 0.5-4kHz) and tinnitus pitch/loudness matching (if present). Tinnitus measured in the booth was then called "confirmed tinnitus." In Study 2, we revaluated 54 adolescents who returned voluntarily 1 year later to repeat all measurements. RESULTS: From Study 1 to 2, the prevalence of confirmed tinnitus reduced from 28.8% (49/170) to 14.9% (8/54) in retested subjects, which includes the cases of persisting tinnitus (confirmed tinnitus in both studies, n=6/54=11.2%) and the new cases of tinnitus (confirmed tinnitus just at Study 2, n=2/54=3.7%). Among the 15 adolescents with confirmed tinnitus at Study 1 who returned for Study 2, 40% had persistent tinnitus (n=6) and 60% did not (remitted tinnitus, n=9). SLT was reduced by 17.3dB in cases with persistent tinnitus (P<0.0002), similar to the findings of Study 1, and returned to normal levels in subjects with remitted tinnitus. Hearing thresholds averaged 4.37dBHL and were <20dBHL in 97% of ears and all frequencies. At 14 and 16kHz thresholds were bilaterally elevated at Study 1 (5.07dB) and 2 (5.56dB) in adolescents with confirmed tinnitus. CONCLUSIONS: Tinnitus and reduced sound tolerance could feature early signals of hidden synaptic injury that is prevalent among adolescents and hidden from the audiogram. The strong relationship between both symptoms, in addition to low-level increases in hearing thresholds at high frequencies in the extended audiogram, poses a challenge for future hearing health and should be further evaluated as a possible intrinsic vulnerability for lesions following exposure to loud sounds. Moreover, the relationship between their spontaneous remissions may signal a possible synaptic repair, which has been reported in animal models.

A virtual biobank for companion animals: A parvovirus pilot study.

BACKGROUND: There is a lack of national population data concerning infectious disease in companion animals. Here, we piloted the feasibility of linking diagnostic laboratories, population surveillance and modern sequencing approaches to extract targeted diagnostic samples from laboratories before they were discarded, as a novel route to better understand national epidemiology of major small animal pathogens. METHODS: Samples tested for canine or feline parvovirus were requested from a national veterinary diagnostic laboratory and analysed by Sanger or next generation sequencing. Samples were linked to electronic health data held in the SAVSNET database. RESULTS: Sequences obtained from positive samples, together with associated metadata, provided new insights into the recent geographical distribution of parvovirus strains in circulation in the United Kingdom (UK). CONCLUSIONS: This collaboration with industry represents a 'National Virtual Biobank' that can rapidly be called on, to efficiently add new layers of epidemiological information of relevance to animal, and potentially human, population health.

SARS-CoV-2 neutralising antibodies in Dogs and Cats in the United Kingdom.

Companion animals are susceptible to SARS-CoV-2 infection and sporadic cases of pet infections have occurred in the United Kingdom. Here we present the first large-scale serological survey of SARS-CoV-2 neutralising antibodies in dogs and cats in the UK. Results are reported for 688 sera (454 canine, 234 feline) collected by a large veterinary diagnostic laboratory for routine haematology during three time periods; pre-COVID-19 (January 2020), during the first wave of UK human infections (April-May 2020) and during the second wave of UK human infections (September 2020-February 2021). Both pre-COVID-19 sera and those from the first wave tested negative. However, in sera collected during the second wave, 1.4% (n=4) of dogs and 2.2% (n=2) cats tested positive for neutralising antibodies. The low numbers of animals testing positive suggests pet animals are unlikely to be a major reservoir for human infection in the UK. However, continued surveillance of in-contact susceptible animals should be performed as part of ongoing population health surveillance initiatives.

SARS-CoV-2 neutralising antibodies in dogs and cats in the United Kingdom.

Companion animals are susceptible to SARS-CoV-2 infection and sporadic cases of pet infections have occurred in the United Kingdom. Here we present the first large-scale serological survey of SARS-CoV-2 neutralising antibodies in dogs and cats in the UK. Results are reported for 688 sera (454 canine, 234 feline) collected by a large veterinary diagnostic laboratory for routine haematology during three time periods; pre-COVID-19 (January 2020), during the first wave of UK human infections (April-May 2020) and during the second wave of UK human infections (September 2020-February 2021). Both pre-COVID-19 sera and those from the first wave tested negative. However, in sera collected during the second wave, 1.4% (n â€‹= â€‹4) of dogs and 2.2% (n â€‹= â€‹2) of cats tested positive for neutralising antibodies. The low numbers of animals testing positive suggests pet animals are unlikely to be a major reservoir for human infection in the UK. However, continued surveillance of in-contact susceptible animals should be performed as part of ongoing population health surveillance initiatives.

Temporal, Spatial, and Genomic Analyses of Enterobacteriaceae Clinical Antimicrobial Resistance in Companion Animals Reveals Phenotypes and Genotypes of One Health Concern.

BACKGROUND: Antimicrobial resistance (AMR) is a globally important one health threat. The impact of resistant infections on companion animals, and the potential public health implications of such infections, has not been widely explored, largely due to an absence of structured population-level data. OBJECTIVES: We aimed to efficiently capture and repurpose antimicrobial susceptibility test (AST) results data from several veterinary diagnostic laboratories (VDLs) across the United Kingdom to facilitate national companion animal clinical AMR surveillance. We also sought to harness and genotypically characterize isolates of potential AMR importance from these laboratories. METHODS: We summarized AST results for 29,330 canine and 8,279 feline Enterobacteriaceae isolates originating from companion animal clinical practice, performed between April 2016 and July 2018 from four VDLs, with submissions from 2,237 United Kingdom veterinary practice sites. RESULTS: Escherichia coli (E. coli) was the most commonly isolated Enterobacteriaceae in dogs (69.4% of AST results, 95% confidence interval, CI, 68.7-70.0) and cats (90.5%, CI 89.8-91.3). Multi-drug resistance was reported in 14.1% (CI 13.5-14.8) of canine and 12.0% (CI 11.1-12.9) of feline E. coli isolates. Referral practices were associated with increased E. coli 3rd generation ≤ cephalosporin resistance odds (dogs: odds ratio 2.0, CI 1.2-3.4). We selected 95 E. coli isolates for whole genome analyses, of which seven belonged to sequence type 131, also carrying the plasmid-associated extended spectrum ß-lactamase gene bla CTX-M- 15. The plasmid-mediated colistin resistance gene mcr-9 was also identified for the first time in companion animals. CONCLUSIONS: Linking clinical AMR data with genotypic characterization represents an efficient means of identifying important resistance trends in companion animals on a national scale.

Development of auditory phase-locked activity for music sounds.

The auditory cortex undergoes functional and anatomical development that reflects specialization for learned sounds. In humans, auditory maturation is evident in transient auditory-evoked potentials (AEPs) elicited by speech or music. However, neural oscillations at specific frequencies are also known to play an important role in perceptual processing. We hypothesized that, if oscillatory activity in different frequency bands reflects different aspects of sound processing, the development of phase-locking to stimulus attributes at these frequencies may have different trajectories. We examined the development of phase-locking of oscillatory responses to music sounds and to pure tones matched to the fundamental frequency of the music sounds. Phase-locking for theta (4-8 Hz), alpha (8-14 Hz), lower-to-mid beta (14-25 Hz), and upper-beta and gamma (25-70 Hz) bands strengthened with age. Phase-locking in the upper-beta and gamma range matured later than in lower frequencies and was stronger for music sounds than for pure tones, likely reflecting the maturation of neural networks that code spectral complexity. Phase-locking for theta, alpha, and lower-to-mid beta was sensitive to temporal onset (rise time) sound characteristics. The data were also consistent with phase-locked oscillatory effects of acoustic (spectrotemporal) complexity and timbre familiarity. Future studies are called for to evaluate developmental trajectories for oscillatory activity, using stimuli selected to address hypotheses related to familiarity and spectral and temporal encoding suggested by the current findings.

Frequency-specific modulation of population-level frequency tuning in human auditory cortex.

BACKGROUND: Under natural circumstances, attention plays an important role in extracting relevant auditory signals from simultaneously present, irrelevant noises. Excitatory and inhibitory neural activity, enhanced by attentional processes, seems to sharpen frequency tuning, contributing to improved auditory performance especially in noisy environments. In the present study, we investigated auditory magnetic fields in humans that were evoked by pure tones embedded in band-eliminated noises during two different stimulus sequencing conditions (constant vs. random) under auditory focused attention by means of magnetoencephalography (MEG). RESULTS: In total, we used identical auditory stimuli between conditions, but presented them in a different order, thereby manipulating the neural processing and the auditory performance of the listeners. Constant stimulus sequencing blocks were characterized by the simultaneous presentation of pure tones of identical frequency with band-eliminated noises, whereas random sequencing blocks were characterized by the simultaneous presentation of pure tones of random frequencies and band-eliminated noises. We demonstrated that auditory evoked neural responses were larger in the constant sequencing compared to the random sequencing condition, particularly when the simultaneously presented noises contained narrow stop-bands. CONCLUSION: The present study confirmed that population-level frequency tuning in human auditory cortex can be sharpened in a frequency-specific manner. This frequency-specific sharpening may contribute to improved auditory performance during detection and processing of relevant sound inputs characterized by specific frequency distributions in noisy environments.

Comparison of Tinnitus Loudness Measures: Matching, Rating, and Scaling.

Purpose Chronic tinnitus ("ringing in the ears") is a phantom auditory perception with no cure. A goal of treatment is often to reduce the loudness of tinnitus. However, tinnitus loudness cannot be measured objectively. It is most commonly assessed by obtaining a loudness match (LM) with a pure tone and by using a numeric rating scale (NRS). Constrained loudness scaling (CLS) is a more recent measure of tinnitus loudness that utilizes auditory training of a fixed loudness scale to guide tinnitus loudness judgments. The purpose of this study was to compare results using these 3 measures of tinnitus loudness. Method This study obtained tinnitus loudness measures of LM, NRS, and CLS with 170 participants. These participants are part of a larger study obtaining repeated measures over 6 months. Only baseline data are presented. Results Correlations between all measures were weak to moderate: LM versus CLS ( r = .46), CLS versus NRS ( r = .49), and LM versus NRS ( r = .38). Conclusion Further systematic research is needed to more fully understand the relationships between these different measures and to establish a valid measure of tinnitus loudness.

Residual inhibition functions overlap tinnitus spectra and the region of auditory threshold shift.

Animals exposed to noise trauma show augmented synchronous neural activity in tonotopically reorganized primary auditory cortex consequent on hearing loss. Diminished intracortical inhibition in the reorganized region appears to enable synchronous network activity that develops when deafferented neurons begin to respond to input via their lateral connections. In humans with tinnitus accompanied by hearing loss, this process may generate a phantom sound that is perceived in accordance with the location of the affected neurons in the cortical place map. The neural synchrony hypothesis predicts that tinnitus spectra, and heretofore unmeasured "residual inhibition functions" that relate residual tinnitus suppression to the center frequency of masking sounds, should cover the region of hearing loss in the audiogram. We confirmed these predictions in two independent cohorts totaling 90 tinnitus subjects, using computer-based tools designed to assess the psychoacoustic properties of tinnitus. Tinnitus spectra and residual inhibition functions for depth and duration increased with the amount of threshold shift over the region of hearing impairment. Residual inhibition depth was shallower when the masking sounds that were used to induce residual inhibition showed decreased correspondence with the frequency spectrum and bandwidth of the tinnitus. These findings suggest that tinnitus and its suppression in residual inhibition depend on processes that span the region of hearing impairment and not on mechanisms that enhance cortical representations for sound frequencies at the audiometric edge. Hearing thresholds measured in age-matched control subjects without tinnitus implicated hearing loss as a factor in tinnitus, although elevated thresholds alone were not sufficient to cause tinnitus.

Ureteropelvic junction obstruction in association with autosomal dominant polycystic kidney disease: a case report in a trauma patient.

Autosomal dominant polycystic kidney disease (ADPKD) is a common cause of cystic renal disease and can predispose to renal insufficiency. Although typically diagnosed and discussed in the pediatric population, ureteropelvic junction obstruction may also make patients prone to renal dysfunction and failure. These two disease processes can coexist in the same patient, which may, in turn, complicate their management. We present the case of an adult patient with known ADPKD who suffered a traumatic fall and subsequent retroperitoneal bleed, and was also diagnosed with a UPJ obstruction of the left kidney on the basis of pathological analysis of the specimen at the time of nephrectomy.