Infection with Leptospira kirschneri Serovar Mozdok: First Report from the Southern Hemisphere

Leptospirosis is a global zoonosis caused by pathogenic Leptospira spp. In this study, we characterized two Leptospira kirschneri serogroup Pomona serovar Mozdok isolates, one obtained from a dog and the other from a patient with severe leptospirosis, 4 years later. Histopathological analysis showed that both isolates caused severe tissue damage when used to infect hamsters. While L. kirschneri serogroup Pomona serovar Mozdok is endemic in animals in Europe, there is only one report of human leptospirosis in the literature. Although strains belonging to L. kirschneri serogroup Pomona have been identified in cases of human leptospirosis in Europe, serovar Mozdok has not yet been implicated. The 4-year interval between isolations and the fact that this is the first report of serovar Mozdok as the causative agent of human leptospirosis in the southern hemisphere, demonstrates its epidemiological importance to public health. Moreover, the presence of serovar Mozdok in Brazil has the potential to affect vaccine and diagnostic test development.Leptospirosis is a reemerging zoonotic disease, and the global burden is showing an upward trend. The original estimates in 1999¹ predicted some 500,000 annual cases compared with the latest prediction of 873,000 cases and 49,000 mortalities per year, a 74.6% increase over 15 years.² Accurate laboratory diagnosis continues to be a limiting factor, meaning that the true global burden of leptospirosis is likely to be much higher.³ In Latin America, the prevalence of severe leptospirosis is high (10,000 cases a year) due to the tropical climate and lack of appropriate sanitation.³ Although the city of Pelotas has a subtropical climate, > 50 cases of human leptospirosis per 100,000 inhabitants are reported each year, one of the highest rates in southern Brazil.⁴ The infection rate in Pelotas is higher than the Brazilian average for the same period (3.5/100,000) and other regions with similar climatic conditions (> 10/100,000).⁵At present, there are 10 pathogenic Leptospira spp. classified into > 260 serovars⁶ and Leptospira interrogans, Leptospira borgpetersenii, and Leptospira kirschneri are most commonly associated with human leptospirosis.⁷ In Brazil, L. interrogans serogroup Icterohaemorrhagiae serovars Icterohaemorrhagiae and Copenhageni are the main cause of urban leptospirosis and have been widely studied,³ whereas rural leptospirosis and the associated serovars have been largely neglected. To the best of our knowledge, L. kirschneri serogroup Pomona serovar Mozdok has only been implicated in a case of human leptospirosis in Cuba.⁸ Serovar Mozdok is endemic to Croatia where it is prevalent in wild rodents. Human leptospirosis caused by serogroup Pomona is common in that region and while serovar Mozdok has not been implicated in any human cases,⁹ it is a causative agent of canine leptospirosis in Europe.¹⁰We report the isolation and characterization of two isolates of serovar Mozdok recovered from cases of canine and human leptospirosis in Pelotas, southern Brazil. The canine strain was isolated in 2009 during a municipal dog neutering campaign. Urine samples were aseptically collected from the bladder during ovarian hysterectomy, via aspiration using an insulin 30-G needle and syringe (BD Biosciences, Franklin Lakes, NJ). The urine was immediately inoculated into unsupplemented Ellinghausen-McCullough-Johnson-Harris (EMJH; Difco, Sparks, MD) medium (100 μL urine/5 mL EMJH), incubated for 1 hour and then subcultured into EMJH containing 10% of a commercial supplement (Difco). The dog from which the strain was isolated was asymptomatic and was released after the surgical procedure. The second isolate was obtained from the blood culture of a 56-year-old female patient from a rural area of the city. The patient presented with headache, myalgia, fever, vomiting, fatigue, sleepiness, and arthralgia and reported contact with dogs, rats, pigs, cattle, and flood water. The isolate was cultured in EMJH medium as described for the canine isolate. Both isolates were identified as L. kirschneri by means of secY gene sequencing.¹¹ Multilocus sequence typing (MLST)⁷ further characterized the isolates as L. kirschneri serogroup Pomona serovar Mozdok (ST 117). All sequencing procedures were performed using the paired-end technology on an Illumina Solexa platform (Illumina, San Diego, CA; GenBank accession numbers for sequences are shown in

Identification of a series of CCK-2 receptor nonpeptide agonists: sensitivity to stereochemistry and a receptor point mutation

The search for small-molecule drugs that act at peptide hormone receptors has resulted in the identification of a wide variety of antagonists. In contrast, the discovery of nonpeptide agonists has been far more elusive. We have used a constitutively active mutant of the cholecystokinin 2 receptor (CCK-2R) as a sensitive screen to detect ligand activity. Functional assessment of structural analogs of the prototype CCK-2R antagonist, L-365,260 [3R-N- (2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl)-N'-(3-methylphenyl)urea], resulted in the identification of a series of agonists. Each of the active molecules is an S enantiomer, whereas the corresponding R stereoisomers have little or no activity. Further in vitro and in vivo assessment at the wild-type receptor indicated that efficacy of the two most active ligands approached that of the endogenous hormone. The function of selected R and S enantiomers was differentially sensitive to a point mutation, N353L, within the putative CCK-2R ligand pocket. The results of this study highlight the potential of constitutively active receptors as drug screening tools and the interdependence of ligand stereochemistry and receptor conformation in defining drug efficacy.     

Ethanol drinking experience attenuates (-)sulpiride-induced increases in extracellular dopamine levels in the nucleus accumbens of alcohol-preferring (P) rats

BACKGROUND: The reinforcing properties of ethanol may be partly mediated through the mesolimbic dopamine (DA) system. This study examines the effects of local application of the DA D(2) receptor antagonist (-)sulpiride (SUL) on ethanol drinking of alcohol-preferring (P) rats, and extracellular DA levels in the nucleus accumbens (NAc) of P rats that were either ethanol-naive or had been chronically drinking ethanol. METHODS: Microdialysis was used to sample NAc DA levels, and reverse microdialysis was used to locally administer the D(2) antagonist (-)sulpiride (SUL) into the NAc of adult female P rats that were either drinking ethanol (n = 17) or were ethanol-naive (n = 24). Stable intake of 15% (v/v) ethanol (>/=0.75 g/kg) was established for the ethanol-drinking group in daily 1-hr access periods over a minimum of 4 weeks before surgery. Naive and ethanol-drinking rats were implanted with bilateral guide cannulae aimed 4 mm above the NAc shell. After recovery from surgery, microdialysis probes (active area = 2 mm) were inserted bilaterally into the NAc. Two days later, rats in the ethanol-drinking and naive groups were each divided into two groups; one group was bilaterally perfused (1.0 microl/min) with artificial cerebrospinal fluid (aCSF) and the other group was further divided into three subgroups that were perfused with aCSF + either 50, 100, or 200 microM SUL for 240 min. During the last 60 min of perfusion, the ethanol-drinking rats were given their daily 1-hr ethanol access period. Following ethanol access, the aCSF + SUL subgroups were then given aCSF only. The entire perfusion procedure was repeated 24 hr later, but the aCSF only and aCSF + SUL group treatment conditions were transposed. RESULTS: In ethanol-drinking rats, 100 and 200 microM SUL increased extracellular NAc DA levels to approximately 200% of basal values, but did not significantly alter ethanol intake. In ethanol-naive P rats, 100 and 200 microM SUL increased extracellular NAc DA levels significantly more (450% of basal; p < 0.05) than in the ethanol-drinking group. CONCLUSIONS: The findings are consistent with the hypothesis that ethanol-drinking experience causes a desensitization or a down-regulation of D(2) autoreceptors in the NAc of P rats.     

In vitro characterization of the human recombinant soluble granulocyte- macrophage colony-stimulating factor receptor

We have cloned, expressed, and partially purified a naturally occurring, truncated, soluble form of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha subunit to investigate its biochemical and biologic properties. The soluble receptor species lacks the transmembrane and cytoplasmic domains that are presumably removed from the intact receptor cDNA by a mechanism of alternative splicing. The resulting soluble 55- to 60-kD glycosylated receptor species binds GM-CSF with a dissociation constant (kd) of 3.8 nmol/L. The soluble GM-CSF receptor successfully competes for GM-CSF binding not only with the transmembrane-anchored GM-CSF receptor alpha subunit but also with the native oligomeric high-affinity receptor complex. In addition, in human bone marrow colony-forming assays, the soluble GM-CSF receptor species can antagonize the activity of GM-CSF. Our data suggest that the soluble GM-CSF receptor may be capable of acting in vivo as a modulator of the biologic activity of GM-CSF.     

Two-Character Chinese Compound Word Processing in Chinese Children With and Without Dyslexia: ERP Evidence

Using event-related potential (ERP) measures, we examined the time course of Chinese compound word processing in 15 dyslexic and 10 normal children in a lexical decision task with three conditions including real words (e.g., (house)), reversed nonwords (e.g., can be transposed to a real word (ocean)) and random nonwords (e.g., is not a real word when transposing). Behavioral results showed that dyslexic children performed slower and less accurately than normal children did across conditions. ERP data revealed that normal children exhibited significant N400 effects across conditions. The dyslexics did not show any difference on N400, however, suggesting a possible weakness of morphological processing in dyslexic children.     

Design,content, and fieldwork procedures of the COVID‐19 Psychological Research Consortium (C19PRC) Study – Wave 4

ObjectivesThis paper outlines fieldwork procedures for Wave 4 of the COVID‐19 Psychological Research Consortium (C19PRC) Study in the UK during November–December 2020.MethodsRespondents provided data on socio‐political attitudes, beliefs, and behaviours, and mental health disorders (anxiety, depression, and posttraumatic stress). In Phase 1, adults (N = 2878) were reinvited to participate. At Phase 2, new recruitment: (i) replenished the longitudinal strand to account for attrition; and (ii) oversampled from the devolved UK nations to facilitate robust between‐country analyses for core study outcomes. Weights were calculated using a survey raking algorithm to ensure the longitudinal panel was representative of the baseline sample characteristics.ResultsIn Phase 1, 1796 adults were successfully recontacted and provided full interviews at Wave 4 (62.4% retention rate). In Phase 2, 292 new respondents were recruited to replenish the panel, as well as 1779 adults from Wales, Scotland, and Northern Ireland, who were representative of the socio‐political composition of the adult populations in these nations. The raking procedure successfully re‐balanced the longitudinal panel to within 1% of population estimates for selected socio‐demographic characteristics.ConclusionThe C19PRC Study offers a unique opportunity to facilitate and stimulate interdisciplinary research addressing important public health questions relating to the COVID‐19 pandemic.