A multi-centre retrospective study of Nocardia speciation and antimicrobial susceptibility in Queensland, Australia.

The study aims to characterise the species identification and antimicrobial susceptibility testing (AST) results of Nocardial isolates from adult patients across major public hospitals in Queensland, Australia, over a 15-year period. A multi-centre retrospective observational study of Nocardia sp. isolates was conducted from 7 major public hospitals in Queensland, Australia, over a 15-year period. Clinical samples from patients aged ≥ 18 years that isolated Nocardia sp. were included. Demographic and clinical data were collected, along with species identification and AST results. Overall, 484 Nocardia sp. were isolated. Most patients were male (297, 61%) with a mean (IQR) age of 60 (51-75) and a median (IQR) Charlson Comorbidity Index of 4 (2-6). Of these, 239 (49%) patients were immunosuppressed. Organisms were most frequently isolated from sputum (174, 36%), and superficial swabs (102, 21%). Patients presented with pulmonary infections (165, 35%) and superficial skin and soft tissue infections (87, 18%) most commonly. One hundred (21%) isolates were deemed pulmonary colonisation and were not treated. Of the speciated organisms, N. nova complex was the most common (93, 19%), followed by N. farcinica complex (79, 16%). Organisms were reliably susceptible to linezolid (240/245, 98%), amikacin (455/470, 97%), and trimethoprim/sulfamethoxazole (459/476, 96%), but less so to imipenem (243/472, 51%) and ceftriaxone (261/448, 58%). This is the largest Australian description of Nocardia sp. to date. Given antimicrobials are often commenced prior to AST results and sometimes even speciation, characterisation of local species and antibiogram data is important to guide empiric choices and local guidelines.

Molecular Epidemiology of Third-Generation-Cephalosporin-Resistant Enterobacteriaceae in Southeast Queensland, Australia.

Third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae represent a major threat to human health. Here, we captured 288 3GC-R Enterobacteriaceae clinical isolates from 264 patients presenting at a regional Australian hospital over a 14-month period. In addition to routine mass spectrometry and antibiotic sensitivity testing, isolates were examined using rapid (∼40-min) real-time PCR assays targeting the most common extended-spectrum ß-lactamases (ESBLs; blaCTX-M-1 and blaCTX-M-9 groups, plus blaTEM, blaSHV, and an internal 16S rRNA gene control). AmpC CMY ß-lactamase (blaCMY) prevalence was also examined. Escherichia coli (80.2%) and Klebsiella pneumoniae (17.0%) were dominant, with Klebsiella oxytoca, Klebsiella aerogenes, and Enterobacter cloacae infrequently identified. Ceftriaxone and cefoxitin resistance were identified in 97.0% and 24.5% of E. coli and K. pneumoniae isolates, respectively. Consistent with global findings in Enterobacteriaceae, most (98.3%) isolates harbored at least one ß-lactamase gene, with 144 (50%) harboring blaCTX-M-1 group, 92 (31.9%) harboring blaCTX-M-9 group, 48 (16.7%) harboring blaSHV, 133 (46.2%) harboring blaTEM, and 34 (11.8%) harboring blaCMY genes. A subset of isolates (n = 98) were subjected to whole-genome sequencing (WGS) to identify the presence of cryptic resistance determinants and to verify genotyping accuracy. WGS of ß-lactamase-negative or carbapenem-resistant isolates identified uncommon ESBL and carbapenemase genes, including blaNDM and blaIMP, and confirmed all PCR-positive genotypes. We demonstrate that our PCR assays enable the rapid and cost-effective identification of ESBLs in the hospital setting, which has important infection control and therapeutic implications.

Lateral temporal bone resections for peri-auricular cutaneous squamous cell carcinoma: prognostic indicators and radiological predictive values.

BACKGROUND: Lateral temporal bone resections are used in the management of locally advanced peri-auricular cutaneous squamous cell carcinomas, but there is still conflicting evidence regarding the staging, surgical and adjuvant treatment decisions. METHODS: A retrospective analysis was performed on all patients who underwent lateral temporal bone resection for cutaneous squamous cell carcinoma between January 2015 and December 2019 at a dedicated tertiary oncology referral centre. RESULTS: Twenty-nine patients were included, with a median age of 77 years. Computed tomography, magnetic resonance imaging and positron emission tomography showed good diagnostic accuracy in identifying disease in the parotid gland, external auditory canal and mastoid bone, but had poor sensitivity in identifying cervical nodal metastasis. Six patients had recurrence at a median of 4.8 months post-operatively. Tumour differentiation (p = 0.0040) and post-operative radiotherapy (p = 0.0199) were associated with significantly better recurrence-free survival. CONCLUSION: Lateral temporal bone resection for peri-auricular cutaneous squamous cell carcinoma requires careful surgical planning using clinico-radiological correlation, particularly in patients with poorly differentiated tumours.

Decontamination interventions for the reuse of surgical mask personal protective equipment: a systematic review.

BACKGROUND: The high demand for personal protective equipment during the novel coronavirus outbreak has prompted the need to develop strategies to conserve supply. Little is known regarding decontamination interventions to allow for surgical mask reuse. AIM: To identify and synthesize data from original research evaluating interventions to decontaminate surgical masks for the purpose of reuse. METHODS: MEDLINE, Embase, CENTRAL, Global Health, the WHO COVID-19 database, Google Scholar, DisasterLit, preprint servers, and prominent journals from inception to April 8th, 2020, were searched for prospective original research on decontamination interventions for surgical masks. Citation screening was conducted independently in duplicate. Study characteristics, interventions, and outcomes were extracted from included studies by two independent reviewers. Outcomes of interest included impact of decontamination interventions on surgical mask performance and germicidal effects. FINDINGS: Seven studies met eligibility criteria: one evaluated the effects of heat and chemical interventions applied after mask use on mask performance, and six evaluated interventions applied prior to mask use to enhance antimicrobial properties and/or mask performance. Mask performance and germicidal effects were evaluated with heterogeneous test conditions. Safety outcomes were infrequently evaluated. Mask performance was best preserved with dry heat decontamination. Good germicidal effects were observed in salt-, N-halamine-, and nanoparticle-coated masks. CONCLUSION: There is limited evidence on the safety or efficacy of surgical mask decontamination. Given the heterogeneous methods used in studies to date, we are unable to draw conclusions on the most efficacious and safe intervention for decontaminating surgical masks.

All-optical transversal filter with tap doubling and negative coefficients based on polarization modulation.

A novel all-optical transversal filter with negative coefficients and tap doubling is proposed and experimentally demonstrated. Based on polarization modulation using the anisotropy of the electro-optic coefficient of LiNbO(3) crystals, negative and positive coefficients are simultaneously generated. Tap doubling is also achieved by using wavelength- and polarization-dependent time delays in fiber. Due to the orthogonal polarity between the two coefficients of each wavelength, the proposed filter is free from coherent interference and the synthesis of filter taps is performed in the optical domain. The experimental results demonstrated that stable 6-tap bandpass filter characteristics can be obtained by using only three optical sources.

Clinical characteristics and prognostic risk factors of healthcare-associated pneumonia in a Korean tertiary teaching hospital.

The 2016 American Thoracic Society and Infectious Diseases Society of America (ATS/IDSA) guidelines removed the concept of healthcare-associated pneumonia (HCAP). We examined whether the 2016 ATS/IDSA guidelines are applicable in Korea.We conducted a retrospective, observational study of pneumonia patients who were hospitalized at a tertiary teaching hospital from March 2012 to February 2014. Identified pathogens that were not susceptible to ß-lactams, macrolides, and fluoroquinolones were defined as community-acquired pneumonia drug-resistant pathogens (CAP-DRPs). We analyzed the risk factors for 28-day mortality and the occurrence rate of CAP-DRPs.Of the 1046 patients, 399 were classified with HCAP and 647 with CAP. HCAP patients were older and had more comorbidities than CAP patients. Initial pneumonia severity index (PSI) was higher in patients with HCAP than with CAP. HCAP was associated with not only an increased rate of CAP-DRPs (HCAP, 19.8%; CAP, 4.0%; P < .001) but also an increased rate of inappropriate initial antibiotic therapy (IIAT) (HCAP, 16.8%; CAP, 4.6%; P < .001). HCAP was also associated with an increased 28-day mortality rate compared with CAP (HCAP, 14.5%; CAP, 6.3%; P < .001). In a multivariable analysis, PSI was an independent risk factor for 28-day mortality in HCAP patients (odds ratio 1.02, 95% confidence interval 1.01-1.04). CAP-DRPs and IIAT were not associated with mortality.Patients with HCAP revealed higher rates of CAP-DRPs, IIAT, and mortality than patients with CAP. However, CAP-DRPs and IIAT were not associated with mortality. PSI was the main predictive factor for 28-day mortality in patients with HCAP.

Prenatal ethanol exposure alters the postnatal development of the spontaneous electrical activity of dopamine neurons in the ventral tegmental area.

Prenatal ethanol exposure causes a persistent reduction in the spontaneous electrical activity of dopamine (DA) neurons in the ventral tegmental area (VTA) in adult animals. Because DA neuron activity matures into adult pattern during postnatal development, it is possible that reduced activity in VTA DA neurons after prenatal ethanol exposure is caused by impaired postnatal development. This possibility was investigated in the present study using the in vivo extracellular single-unit recording and brain stimulation techniques. The results show an age-dependent decrease in the number of spontaneously active VTA DA neurons from 2 to 4 weeks of age in both the control and prenatal ethanol-exposed animals. In ethanol-exposed animals, the age-dependent decrease was more prominent after 3 weeks of age, resulting in lower numbers of spontaneously active VTA DA neurons in 4-week-old and adult animals. In both the control and ethanol-exposed animals, there were age-dependent increases in the firing rates and burst firing activity of VTA DA neurons after 2 weeks of age. Ethanol exposure led to slightly lower firing rates in 4-week-old and adult animals and did not impact the burst firing pattern in any age groups. There were no changes in axon conduction velocity and antidromic spike characteristics of VTA DA neurons. These results indicate that reduced activity of VTA DA neurons during adulthood after prenatal ethanol exposure does not begin prenatally. Instead, it is a result of impaired postnatal development manifested only when animals reach 4 weeks of age. These results suggest that early intervention may be an effective treatment strategy for attention deficit/hyperactivity disorder, a behavioral dysfunction related to the abnormalities of DA systems and often observed in children with fetal alcohol spectrum disorder.

Assessment of pediatric hydronephrosis using output efficiency.

UNLABELLED: Diagnosing obstruction in pediatric patients with hydronephrosis, and renal impairment is often difficult. Renal output efficiency (OE) is a parameter that may improve diagnostic accuracy by allowing normalization of washout according to renal function. The aims of this study were to define a normal range for OE in infants and children and to evaluate its diagnostic accuracy in cases with hydronephrosis. METHODS: Seventy-four children (91 hydronephrotic kidneys; median age, 4 mo; 22 girls and 52 boys) underwent 99mTc-labeled mercaptoacetyl-triglycine scintigraphy using intravenous volume expansion (15 ml/kg normal saline), furosemide diuresis and urethral catheterization, if vesicoureteric reflux was present. Images were interpreted by consensus of two or more experienced observers using visual assessment of the images, differential function and clearance half-time after furosemide (T(1/2)), as well as OE. The final diagnosis was based on surgical findings (n = 23 kidneys) or follow-up for >12 mo (n = 68). RESULTS: Final diagnosis in 22 of the 91 hydronephrotic kidneys was obstruction at the pelviureteric (n = 21) or vesicoureteric (n = 1) junction and no obstruction in the remaining 69. The overall diagnostic accuracy of OE was 89%. Using exhaustive search multivariate logistic regression analysis, only reduced OE (p < 0.001) and decreased renal uptake by visual assessment (p = 0.058) were independently predictive of obstruction (R2 = 0.726). In dilated but unobstructed kidneys, mean OE was 93% +/- 7.1%. In the normal kidneys, mean OE was 96% +/- 3.1%. CONCLUSION: OE improves the diagnostic accuracy of diuretic renography in children and neonates with hydronephrosis and suspected obstruction. Output efficiency should exceed 89% in normal kidneys and 79% in unobstructed, hydronephrotic kidneys.

Volume expanded diuretic renography in the postnatal assessment of suspected uretero-pelvic junction obstruction.

Controversy surrounds the role of 99mTc-diethylenetriamine pentaacetic acid renography in suspected uretero-pelvic junction obstruction in early life. Accordingly, we retrospectively reviewed 18 patients (28 hydronephrotic kidneys) with a mean age of 2 mo (range: 1 wk-6 mo) who underwent a total of 36 scans using intravenous volume expansion (10 ml/kg) and furosemide diuresis (1 mg/kg). Initial scans were classified as obstructed, not obstructed or indeterminate using differential renal function, furosemide washout T 1/2 and visual assessment of tracer clearance. Those initially classified as obstructed (n = 8) have been surgically confirmed. In the indeterminate (n = 6) and nonobstructed (n = 14) groups, three and two kidneys, respectively, developed obstruction on progress scans. Mean follow-up in the nonsurgical patients was approximately 9 mo (range: 4-17 mo). A total of 13 kidneys had developed obstruction by renographic criteria, and to date 12 have surgical confirmation. Our data indicate that: (1) scans classified as obstructed correlate well with surgery; (2) an initial classification of indeterminate or nonobstructed does not exclude later development of obstruction; and (3) serial scans correctly stratify children with possible uretero-pelvic junction obstruction.

Reversible MR changes in the cat brain after cerebral fat embolism induced by triolein emulsion.

BACKGROUND AND PURPOSE: Clinical cerebral-fat embolism shows both reversible and irreversible changes. We used MR imaging to investigate the reversibility of embolized lesions induced with a fat-emulsion technique and to evaluate the histologic findings. METHODS: A fat emulsion was made with 0.05 mL of triolein and 20 mL of normal saline and vigorous to-and-fro movement through a three-way stopcock. In 50 cats, the internal carotid artery was infused with the fat emulsion. Cats were divided into six groups on the basis of time delay after embolization: 1 hour; 1 and 4 days; and 1, 2, and 3 weeks. MR imaging and histologic examination were performed at these times. RESULTS: Embolized lesions were hyperintense on T2-weighted images, isointense or mildly hyperintense on diffusion-weighted images, isointense on apparent diffusion coefficient maps, and enhancing on gadolinium-enhanced T1-weighted images at 1 hour. These MR imaging findings were less evident at day 1 and reverted to normal after day 4 (isointense on all images). Electron microscopy showed minimal findings in the cortical lesion in groups 1 and 2 (group 1 at 1 hour and group 2 at 1 hour and 1 day). Light microscopic findings revealed evidence of necrosis-small focal gliosis and demyelination in the periventricular white matter-in only one cat. The number of intravascular fat globules was not significantly different between groups, as visualized by oil red O staining. CONCLUSION: Cerebral-fat embolism induced by a triolein emulsion revealed reversible MR findings and minimal histologic findings.

Effect of selenium supplementation on spermatogenic cells of goats.

Selenium is an essential trace mineral that is required for many physiological functions in animals and the potential relevance of selenium to the reproductive system of livestock has been considered by many researchers. The objective of this study was to examine the effect of selenium supplementation on the spermatogenic cells of goat. Eight young male crossbred (Katjang x Boer) goats, aged between 9 to 11 months, were used in this study. The control group (CON; n = 4) was fed with a diet consisting of 60% Guinea grass and 40% concentrates while the treatment group (Se-SUP; n = 4) was fed with the same diet as the goats in the control group but with supplementation of 0.6mg selenium (sodium selenite powder) per goat daily for 100 days and were slaughtered on the 101st day. There were no significant differences (p>0.05) in the mean number of spermatogonium, spermatocytes, spermatozoa and the total number of spermatogenic cells between the CON and Se-SUP goat respectively. However, there was a significant increase (p< 0.05) of spermatid in Se-SUP goats. The mean percentage of spermatids was significantly increased (p< 0.05) while spermatozoa was significantly decreased (p< 0.05) in Se-SUP goats. In conclusion, selenium supplementation increased the percentages of spermatids and decreased the percentages of spermatozoa in the seminiferous tubules in goats.

Remifentanil for endotracheal intubation in neonates: a randomised controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of remifentanil as a premedication in neonates undergoing elective endotracheal intubation. DESIGN: A double-blind randomised controlled trial. SETTING: Tertiary care neonatal intensive care unit. PATIENTS: Haemodynamically stable term and preterm neonates requiring elective endotracheal intubation. INTERVENTIONS: Infants in the intervention arm received remifentanil (3 microg/kg) and normal saline placebo. The control group received fentanyl (2 microg/kg) and succinylcholine (2 mg/kg). Both groups also received atropine (20 microg/kg) as part of the premedication regime. MAIN OUTCOME MEASURES: The primary outcome was time to successful intubation. Secondary outcomes included time to return of spontaneous respirations, oxygen saturation, heart rate and blood pressure changes during the procedure, adverse events and a survey of intubation conditions. RESULTS: A total of 15 infants were randomised to each group. Baseline characteristics were similar in both groups. The median time to successful intubation was not statistically different (247 s in the remifentanil group vs 156 s in the fentanyl group, p=0.88). The intubation conditions were rated more favourably with fentanyl by the intubators. Although not statistically significant, chest wall rigidity was observed more commonly with remifentanil. CONCLUSIONS: Although remifentanil is comparable to fentanyl and succinylcholine in attenuating adverse physiologic responses during neonatal intubation, muscle rigidity is a concern at doses of 3 microg/kg. Further trials are required to evaluate ideal dosing regimens and combinations of agents for use with remifentanil in neonates.