Looking for the X Factor in Bacterial Pathogenesis: Association of orfX-p47 Gene Clusters with Toxin Genes in Clostridial and Non-Clostridial Bacterial Species

The botulinum neurotoxin (BoNT) has been extensively researched over the years in regard to its structure, mode of action, and applications. Nevertheless, the biological roles of four proteins encoded from a number of BoNT gene clusters, i.e., OrfX1-3 and P47, are unknown. Here, we investigated the diversity of orfX-p47 gene clusters using in silico analytical tools. We show that the orfX-p47 cluster was not only present in the genomes of BoNT-producing bacteria but also in a substantially wider range of bacterial species across the bacterial phylogenetic tree. Remarkably, the orfX-p47 cluster was consistently located in proximity to genes coding for various toxins, suggesting that OrfX1-3 and P47 may have a conserved function related to toxinogenesis and/or pathogenesis, regardless of the toxin produced by the bacterium. Our work also led to the identification of a putative novel BoNT-like toxin gene cluster in a Bacillus isolate. This gene cluster shares striking similarities to the BoNT cluster, encoding a bont/ntnh-like gene and orfX-p47, but also differs from it markedly, displaying additional genes putatively encoding the components of a polymorphic ABC toxin complex. These findings provide novel insights into the biological roles of OrfX1, OrfX2, OrfX3, and P47 in toxinogenesis and pathogenesis of BoNT-producing and non-producing bacteria

Evaluating Pornography Problems Due to Moral Incongruence Model

INTRODUCTION: To date, multiple models of problematic pornography use have been proposed, but attempts to validate them have been scarce. AIM: In our study, we aimed to evaluate the Pornography Problems due to Moral Incongruence model proposing that self-appraisals of pornography addiction stem from (i) general dysregulation, (ii) habits of use, and (iii) moral incongruence between internalized norms and behavior. We investigated whether the model can be used to adequately explain the self-perceptions of addiction to pornography (model 1) and a broader phenomenon of problematic pornography use (model 2). METHODS: An online, nationally representative study was conducted on a sample of 1036 Polish adult participants, of whom, 880 declared a lifetime history of viewing pornography. MAIN OUTCOME MEASURE: The outcomes were self-perceived pornography addiction, problematic pornography use, avoidant coping, frequency of pornography use, religiosity, moral disapproval of pornography, and related variables. RESULTS: Our results indicated that avoidant coping (an indicator of general dysregulation), frequency of pornography use (indicator of habits of use), and the distress connected with incongruence between own sexual behavior and internalized norms, attitudes and beliefs positively contributed to self-perceived addiction (model 1) as well as problematic pornography use (model 2). This broadly confirms the basic shape of the PPMI model. There were, however, notable differences between the models. Moral incongruence related distress was only weakly related to self-perceived addiction (β = 0.15, P \u3c .001), with a stronger relation for problematic pornography use (β = 0.31, P \u3c .001). When controlling for other factors, religiosity weakly predicted problematic pornography use (β = 0.13, P \u3c .001), but not self-perceived addiction to pornography (β = 0.03, P = .368). Frequency of pornography use was the strongest predictor of both self-perceived addiction (β = 0.52, P \u3c .001) and problematic pornography use (β = 0.43, P \u3c .001). CLINICAL IMPLICATIONS: Factors proposed within the PPMI model are distinctly relevant intervention targets, and they should be considered in the process of diagnosis and treatment. STRENGTHS & LIMITATIONS: The presented study is the first to evaluate PPMI model. Its main limitation is that it has a cross-sectional design. CONCLUSION: The PPMI model is a promising framework for investigating the factors related to self-perceived addiction and problematic pornography use. Despite the differences between the models and in the strength of specific predictors, (i) dysregulation, (ii) habits of use, and (iii) moral incongruence all uniquely contribute to self-perceived addiction and problematic pornography use. Lewczuk, K., Glica, A., Nowakowska, I., et al. Evaluating Pornography Problems Due to Moral Incongruence Model. J Sex Med 2020;17:300-311

The neuronal structure of the dorsal nucleus of the lateral geniculate body in the common shrew (Sorex araneus) and the bank vole (Clethrionomys glareolus): Golgi and Nissl studies

The topography and neuronal structure of the dorsal nucleus of the lateral geniculate body (GLd) of the common shrew and the bank vole are similar. The lateral geniculate body of both the species examined has a homogeneous structure and no observable cytoarchitectonic lamination. On the basis of the shape of the dendritic arbours as well as the pattern of dendritic arborisations the following two types of neurons were distinguished. Type I “bushy” neurons that have multipolar or round perikarya (common shrew perikarya 9–12 µm, bank vole perikarya 10–13 µm), with 4–6 short thick dendritic trunks that subdivide into many bush-like branches. The dendritic trunks are smooth, in contrast to the distal branches, which are covered with numerous spine-like protrusions of different lengths and forms. An axon emerges from the soma, sometimes very close to one of the primary dendrites. The type I neurons are typically projection cells that send their axons to the primary visual cortex. These neurons predominate in the GLd of both species. Type II neurons, which have an elongated soma with primary dendrites arising from opposite poles of the perikaryon (common shrew perikarya 8–10 µm, bank vole perikarya 9–11 µm). The dendritic arbours of these cells are less extensive and their dendrites have fewer spines than those of the type I neurons. Axons were seldom observed. The type II neurons are presumably interneurons and are definitely less numerous than the type I neurons

The nerve cells of the neostriatum in the common shrew (Sorex araneus) and bank vole (Clethrionomys glareolus): a Golgi comparative study

The studies were carried out on 12 brains derived from adult representatives of two mammalian orders, Insectivora and Rodentia. The neostriatum was compared in the common shrew (Sorex araneus) and bank vole (Clethrionomys glareolus). Three main types of striatal neuron were distinguished in the common shrew and five types of neurons in the bank vole. The fifth type of bank vole neurons was additionally divided into two subtypes with respect to dendritic pattern

A morphometric study of the preoptic area of the guinea pig

The aim of the study was to provide the topography and morphometric characteristics of the preoptic area (POA) of the guinea pig. The study was carried out on the brains of sexually mature guinea pigs of both sexes. A uniform procedure was followed in the study of the paraffin-embedded brain tissue blocks of males and females. The blocks were cut in the coronal plane into 50 mm sections and stained according to the Nissl method. The guinea pig POA consists of four parts: the medial preoptic area (MPA), lateral preoptic area (LPA), periventricular preoptic nucleus (PPN), and median preoptic nucleus (MPN). The topography and general structure of POA parts are similar in males and females. However, the PPNa cells of females are more intensely stained and are more densely packed than the PPNa cells of males. For morphometric analysis, the MPA and LPA as well as PPN and MPN were considered respectively as uniform structures, namely MPA-LPA and PPN-MPN. The statistical analysis showed that the volume of the PPN-MPN was larger in males than in females, whereas the MPA-LPA volume did not differ between the sexes. Moreover, the numerical density and the total number of neurons were statistically larger in males than in females in both the MPA-LPA and PPN-MPN. The parameters describing POA neurons were larger for MPA-LPA neurons in comparison with the PPN-MPN neurons. However, in this respect no sex differences were observed in both studied complexes. Folia Morphol 2010; 69, 1: 15-2

The neuronal structure of the preoptic area in the mole and the rabbit: Golgi and Nissl studies

The present studies were carried out on the brains of the adult mole and rabbit. The preparations were made by means of the Golgi technique and the Nissl method. Two types of neurons were distinguished in the preoptic area (POA) of both species: bipolar and multipolar. The bipolar neurons have oval, fusiform or round perikarya and two dendritic trunks arising from the opposite poles of the cell body. The dendrites bifurcate once or twice. The dendritic branches have swellings, single spine-like and filiform processes. The multipolar neurons usually have triangular and quadrangular perikarya and from 3 to 5 dendritic trunks. The dendrites of the mole neurons branch sparsely, whereas the dendrites of the rabbit neurons display 2 or 3 divisions. On the dendritic branches varicosities and different protuberances were observed. The general morphology of the bipolar and multipolar neurons is similar in the mammals studied, although the neurons of the rabbit POA display a more complicated structure. Their dendritic branches show more divisions and possess more swellings and different processes than the dendrites of the neurons of the mole POA. Furthermore, of the multipolar neurons only the dendrites in POA of the rabbit were observed to have a rosary-like beaded appearance

A morphometric comparative study of the lateral geniculate body in selected placental mammals: the common shrew, the bank vole, the rabbit, and the fox

The lateral geniculate body (LGN) was morphometrically examined and compared in representatives of four mammalian orders (Insectivora, Rodentia, Lagomorpha, and Carnivora). In each studied species, the lateral geniculate body was divided into two distinct parts: the dorsal nucleus (LGNd) and the ventral nucleus (LGNv). The lateral geniculate body of the common shrew and the bank vole are very similar in appearance and nuclear pattern. The dorsal and ventral nuclei of these two species also have the most similar statistical characteristics. The lateral geniculate body of the fox has the most complicated morphology and multilayered structure. A significant disproportion was observed between the sizes of both geniculate nuclei in the fox, where the dorsal nucleus definitely surpassed the ventral nucleus in terms of volume. With the exception of the fox, the neuronal density of the LGN nuclei was negatively correlated with the volumes of the LGN. The mean neuronal size of the LGNd and LGNv, which was the resultant of the length, width, area, and circumference of the soma, grew correlatively to the volumes of these nuclei. In all examined species, somas of the LGNd neurons are distinctly larger and have more similar shapes than the LGNv perikarya. In addition, the numerical density of neurons in the ventral nucleus is significantly higher than in the dorsal nucleus. All these morphometric parameters clearly differentiate the LGNd from the LGNv

Construction and validation of safe Clostridium botulinum Group II surrogate strain producing inactive botulinum neurotoxin type E toxoid

Botulinum neurotoxins (BoNTs), produced by the spore-forming bacterium Clostridium botulinum, cause botulism, a rare but fatal illness affecting humans and animals. Despite causing a life-threatening disease, BoNT is a multipurpose therapeutic. Nevertheless, as the most potent natural toxin, BoNT is classified as a Select Agent in the US, placing C. botulinum research under stringent governmental regulations. The extreme toxicity of BoNT, its impact on public safety, and its diverse therapeutic applications urge to devise safe solutions to expand C. botulinum research. Accordingly, we exploited CRISPR/Cas9-mediated genome editing to introduce inactivating point mutations into chromosomal bont/e gene of C. botulinum Beluga E. The resulting Beluga Ei strain displays unchanged physiology and produces inactive BoNT (BoNT/Ei) recognized in serological assays, but lacking biological activity detectable ex- and in vivo. Neither native single-chain, nor trypsinized di-chain form of BoNT/Ei show in vivo toxicity, even if isolated from Beluga Ei sub-cultured for 25 generations. Beluga Ei strain constitutes a safe alternative for the BoNT research necessary for public health risk management, the development of food preservation strategies, understanding toxinogenesis, and for structural BoNT studies. The example of Beluga Ei generation serves as template for future development of C. botulinum producing different inactive BoNT serotypes.Peer reviewe