Detection and virulence of Lactococcus garvieae and L. petauri from four lakes in southern California

OBJECTIVE

The first objective of the study aimed to detect the presence of Lactococcus petauri, L. garvieae, and L. formosensis in fish (n = 359) and environmental (n = 161) samples from four lakes near an affected fish farm in California during an outbreak in 2020. The second objective was to compare the virulence of the Lactococcus spp. in Rainbow Trout Oncorhynchus mykiss and Largemouth Bass Micropterus salmoides.

METHODS

Standard bacterial culture methods were used to isolate Lactococcus spp. from brain and posterior kidney of sampled fish from the four lakes. Quantitative PCR (qPCR) was utilized to detect Lactococcus spp. DNA in fish tissues and environmental samples from the four lakes. Laboratory controlled challenges were conducted by injecting fish intracoelomically with representative isolates of L. petauri (n = 17), L. garvieae (n = 2), or L. formosensis (n = 4), and monitored for 14 days postchallenge (dpc).

RESULT

Lactococcus garvieae was isolated from the brains of two Largemouth Bass in one of the lakes. Lactococcus spp. were detected in 14 fish (8 Bluegills Lepomis macrochirus and 6 Largemouth Bass) from 3 out of the 4 lakes using a qPCR assay. Of the collected environmental samples, all 4 lakes tested positive for Lactococcus spp. in the soil samples, while 2 of the 4 lakes tested positive in the water samples through qPCR. Challenged Largemouth Bass did not show any signs of infection postinjection throughout the challenge period. Rainbow Trout infected with L. petauri showed clinical signs within 3 dpc and presented a significantly higher cumulative mortality (62.4%; p < 0.0001) at 14 dpc when compared to L. garvieae (0%) and L. formosensis (7.5%) treatments.

CONCLUSION

The study suggests that qPCR can be used for environmental DNA monitoring of Lactococcus spp. and demonstrates virulence diversity between the etiological agents of piscine lactococcosis.

Development of a quantitative polymerase chain reaction assay for detection of the aetiological agents of piscine lactococcosis

Piscine lactococcosis is an emergent bacterial disease that is associated with high economic losses in many farmed and wild aquatic species worldwide. Early and accurate detection of the causative agent of piscine lactococcosis is essential for management of the disease in fish farms. In this study, a TaqMan quantitative polymerase chain reaction (qPCR) targeting the 16S-23S rRNA internal transcribed spacer region was developed and validated. Validation of the qPCR was performed with DNA of previously typed L. petauri and L. garvieae recovered from different aquatic hosts from distinct geographical locations, closely related bacterial species and common pathogens in trout aquaculture. Further diagnostic sensitivity and specificity was investigated by screening of fish, water and faecal samples. The developed qPCR assay showed high specificity, sensitivity and accuracy in detection of L. petauri and L. garvieae with lack of signals from non-target pathogens, and in screening of rainbow trout (Oncorhynchus mykiss) posterior kidney and environmental samples. The detection limit of the qPCR was four amplicon copies. Moreover, the sensitivity of the qPCR assay was not affected by presence of non-target DNA from either fish or environmental samples. The robustness, specificity and sensitivity of the developed qPCR will facilitate fast and accurate diagnosis of piscine lactococcosis to establish appropriate control measures in fish farms and aquaria.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Secular trends in adolescents' diagnosed health status and healthcare consultation: examinations of Canadian national surveys from 2007 to 2016

OBJECTIVES

The objective of this study was to investigate secular trends in adolescent health status and healthcare consultations.

STUDY DESIGN

The design of this study is cross-sectional comparisons of population survey outcomes.

METHODS

Canadian national population data from 2007 to 2016 (T1 N = 14,223; T2 N = 14,247; T3 N = 13,532; T4 N = 13,184; T5 N = 11,122; Total N = 66,308) were examined to find trends in health diagnosis (chronic illnesses and mental disorders) and healthcare consultation (general health practitioners and mental health professionals). Controlling demographics, Multivariate analysis of covariances (MANCOVAs) and correlations were carried out to compare differences by age group (A1: 12-14 years N = 25,180; A2: 15-17 years N = 25,825; A3: 18-19 years N = 15,303) and gender (girls N = 32,388; boys N = 33,920) across survey years.

RESULTS

Steady increases were found in diagnosed mental disorders and consultations with a mental health professional (MP) for girls, while chronic illnesses remained stable and general practitioner consultations declined for all adolescents over these years. Gender disparity in MP consultations grew with age, much more in recent years, whereas chronic illness diagnoses curved down for all in midadolescence. More integrated relations between health status and healthcare utilization were noted in T5 than in T1.

CONCLUSIONS

Differential secular trends were shown for adolescent physical versus mental health statuses and relevant healthcare consultations. Although girls' and older adolescents' mental health declined over the years, a positive direction was also found for improved awareness of mental health.

Flight of the COVID-19 patient: experience with a Wuhan evacuee: a case report

Background

Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2, was declared a global pandemic by the World Health Organization in March 2020.

Case presentation

We report a case of a 51-year-old Chinese woman who was evacuated from Wuhan, China and diagnosed with coronavirus disease 2019 infection at a Southern California quarantine facility. Her clinical course was notable for high fevers, night sweats, productive cough, transient leukopenia, lymphopenia, thrombocytopenia, and transaminitis. Evolving hypoxia and infiltrates on chest imaging warranted the trial of an investigational antiviral drug - remdesivir. Our patient recovered and was discharged after 2 weeks of hospitalization.

Conclusions

This case highlights our patient’s clinical course, including diagnostic work-up, medical management, and challenges in defining non-infectivity in a relatively unknown disease.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

Spectroscopic speciation of aqueous Am(iii)–oxalate complexes

Speciation, thermodynamic stability, and structural information of aqueous oxalato-Am(iii) complexes were resolved by combinatorial use of UV-Vis-LWCC, TRLFS, and DFT calculations.

Widespread cortical thinning in patients with neuromyelitis optica spectrum disorder

BACKGROUND AND PURPOSE

Studies on cortical involvement and its relationship with cognitive function in patients with neuromyelitis optica spectrum disorder (NMOSD) remain scarce. The objective of this study was to compare cortical thickness on magnetic resonance imaging (MRI) between patients with NMOSD and multiple sclerosis (MS) and to investigate its relationship with clinical features and cognitive function.

METHODS

This observational clinical imaging study of 91 patients with NMOSD, 52 patients with MS and 44 healthy controls was conducted from 1 December 2013 to 30 April 2015 at the institutional referral center. Three tesla MRI of the brain and neuropsychological tests were performed. Cortical thickness was measured using three-dimensional surface-based analysis.

RESULTS

Both sets of patients exhibited cortical thinning throughout the entire brain cortex. Patients with MS showed a significantly greater reduction in cortical thickness over broad regions of the bilateral frontal and parieto-temporal cortices and the left precuneus compared to those with NMOSD. Memory functions in patients with MS were correlated with broad regional cortical thinning, whereas no significant associations were observed between cortical thickness and cognitive function in patients with NMOSD.

CONCLUSIONS

Widespread cortical thinning was observed in patients with NMOSD and MS, but the extent of cortical thinning was greater in patients with MS. The more severe cortical atrophy may contribute to memory impairment in patients with MS but not in those with NMOSD. These results provide in vivo evidence that the severity and clinical relevance of cortical thinning differ between NMOSD and MS.

Needs of children with a chronic bladder in preparation for transfer to adult care

OBJECTIVE

Transfers to adult care can be problematic, resulting in postponement due to the protective nature of pediatric care and patient dependency. It is unknown whether these findings apply specifically to urology patients. Our department is taking part in a national general transition project. In this light, our aim was to investigate the specific needs of adolescent urologic patients, regarding their independence and transition.

PATIENTS AND METHODS

80 patients, born in 1975-1998, with a chronic bladder condition received a questionnaire. They were divided into pre- and post-transfer groups. Parents (n = 7) of post-transfer patients formed a third group. Questionnaires were based on those used in the national transition study, supplemented with urological questions. Pre-transfer patients were asked about their level of independence, what subjects were discussed during consultations, and their expectations and wishes regarding transfer. Post-transfer patients and parents were asked for their opinions on the transfer process.

RESULTS

73% (n = 58) responded (55 pre-transfer and 3 post-transfer patients plus parents). It appeared that the confidence built-up with the pediatric urologist impeded the transfer. An adequate level of disease-related knowledge was reported. Relationships, sexuality and fertility were hardly talked about (respectively n = 17, 16 and 18). Parents played an important role, which patients appreciated, confirming their dependency. Despite the 49% (n = 27) who stated they can arrange their urological care themselves, 44% (n = 24) felt ill-prepared for transfer.

CONCLUSION

Although overall self-perceived knowledge is sufficient, the trust in and personal relationship with the pediatric urologist formed the greatest obstruction to successful transition. These findings have been used to improve support during transition by creating a transition protocol.

Reduction of pain on injection of propofol: combination of pretreatment of remifentanil and premixture of lidocaine with propofol

BACKGROUNDS AND OBJECTIVE

There is a high incidence of pain following intravenous injection of propofol, and many studies have been conducted to find a way of reducing this. The administration of lidocaine and, recently, remifentanil has also been used for this purpose, but it is only partially effective. Thus, the purpose of this study was to investigate the analgesic effect of a combination of pretreatment with remifentanil and premixture of lidocaine with propofol and to compare either treatment alone during propofol injection in dorsal hand-veins.

METHODS

In a prospective, randomized, double-blinded trial, we studied 141 adult patients scheduled for elective surgery. The combination of pretreatment of remifentanil (0.35 microg kg(-1) min(-1)) and a premixture of lidocaine with propofol (mixture of propofol 1% and lidocaine 1% in a 10:1 ratio) was compared with either treatment alone in the prevention of pain on propofol injection. Pain was assessed on a four-point scale (0=none, 1=mild, 2=moderate, 3=severe) during propofol injection. Patients in Group B received remifentanil (0.35 microg kg(-1) min(-1)) 30 s before the injection of propofol.

RESULTS

The reduction of pain on propofol injection was similar in both the remifentanil pretreatment and lidocaine premixture groups (62.2% vs. 62.2%). Combination therapy was associated with a higher incidence of patients without pain (91.3%) than either treatment alone (P<0.001). On analysing the injection pain scores, we found a significant reduction of the score in the remifentanil and lidocaine Group C compared with the lidocaine Group A (P<0.001) and the remifentanil Group B (P<0.001).

CONCLUSIONS

The combination of pretreatment of remifentanil and premixture of lidocaine with propofol was more effective in reducing the incidence of pain on injection of propofol than either treatment alone.

Intrathecal Implants of Microencapsulated Xenogenic Chromaffin Cells Provide a Long-Term Source of Analgesic Substances

Adrenal medullary chromaffin cells secrete several neuroactive substances including catecholamines and opioid peptides that produce analgesic effects in the central nervous system. This study was designed to investigate whether intrathecal microencapsulated chromaffin cells could release analgesic materials producing antiallodynic effects on the chronic neuropathic pain in rats induced by chronic constriction injury (CCI) of the sciatic nerve. Prior to intrathecal implantation, chromaffin cells were encapsulated with alginate and poly-L-lysine to protect them from the host immune system. Behavior tests were performed before CCI, 1 week later, and at 4, 7, 14, 21, 28 days postimplantation. At the end of study, we performed cerebrospinal fluid (CSF) collection and implant retrieval. We observed that intrathecal implantation of encapsulated xenogenic chromaffin cells reduced the mechanical and cold allodynia in a model of neuropathic pain. CSF levels of catecholamines and metenkephalin in the rats that received implants were higher than the controls. In addition, we observed chronic survival of implants. These results suggested that intrathecal microencapsulated chromaffin cells may represent a new approach to chronic neuropathic pain management.

Isolation and characterization of CO2-fixing hydrogen-oxidizing marine bacteria

A CO2-fixing bacterium, strain YN-1, that can fix CO2 under chemoautotrophic conditions but not photoautotrophic conditions was isolated from seawater. Identification of the isolate was carried out using biochemical tests and 16S rDNA sequence analysis, and its characteristics were investigated. From the results of partial 16S rDNA sequence analysis, strain YN-1 showed low identity with previously reported hydrogen-oxidizing bacteria, Hydrogenovibrio marinus MH-110 and Hydrogenophilus thermoluteolus. This result indicates that strain YN-1 may be a new hydrogen-oxidizing marine bacterium. Strain YN-1 showed considerable CO2 fixation ability during continuous cultivation even at high CO2 concentration. Strain YN-1 used H2 and CO2 as energy and carbon sources, respectively. Growth characteristics were examined in batch and continuous cultivation with a view to improving the CO2 fixation rate. The results showed that CO2 fixation occurred in the absence of a light source and that the strain exhibited good growth at high CO2 concentration (40%). On the other hand, the dry cell weight was 13.4 g/l following continuous cultivation for 76 h in 10% CO2 (0.1 l/min), and at that time the amount of fixed CO2 was 18.08 g CO2/l. This indicates that strain YN-1 can efficiently fix CO2 even at high CO2 concentrations, which would allow its application to the removal of industrially discharged CO2.