Interactions between the AraC/XylS-like transcriptional activator InvF of Salmonella Typhimurium, the RNA polymerase alpha subunit and the chaperone SicA.

Salmonella enterica serovar Typhimurium causes gastroenteritis and systemic infections in humans. For this bacterium the expression of a type III secretion system (T3SS) and effector proteins encoded in the Salmonella pathogenicity island-1 (SPI-1), is keystone for the virulence of this bacterium. Expression of these is controlled by a regulatory cascade starting with the transcriptional regulators HilD, HilC and RtsA that induce the expression of HilA, which then activates expression of the regulator InvF, a transcriptional regulator of the AraC/XylS family. InvF needs to interact with the chaperone SicA to activate transcription of SPI-1 genes including sicA, sopB, sptP, sopE, sopE2, and STM1239. InvF very likely acts as a classical activator; however, whether InvF interacts with the RNA polymerase alpha subunit RpoA has not been determined. Results from this study confirm the interaction between InvF with SicA and reveal that both proteins interact with the RNAP alpha subunit. Thus, our study further supports that the InvF/SicA complex acts as a classical activator. Additionally, we showed for the first time an interaction between a chaperone of T3SS effectors (SicA) and the RNAP.

Sustaining small-scale fisheries through a nation-wide Territorial Use Rights in Fisheries system.

Territorial Use rights in Fisheries (TURFs) are used around the world to manage small-scale fisheries and they've shown varying levels of success. Our understanding of what leads to different performance levels is limited due to several reasons. Firstly, these systems are often present in areas with low monitoring capacity where data is scarce. Secondly, past research has centered on the analysis of successful cases, with little attention paid to entire systems. Thirdly, research has been ahistorical, disconnected from the development process of TURF systems. Fourthly, TURFs are often viewed as homogenous ignoring the socio-ecological conditions under which they develop. To address these gaps, the study focuses on Mexico as a case study and context. The research first presents a historical overview of the development of TURF systems in Mexico, including the institutional and legal frameworks that have shaped their evolution. The paper then presents a TURF database that maps all TURF systems in Mexico, including their geographical locations and characteristics. In addition, the study presents case studies based on identified archetypes that showcase the diversity of TURF systems in Mexico, highlighting the different types of systems and the challenges they face. By presenting a comprehensive map of all TURF systems in Mexico, this research paper aims to make an important addition to the case studies in the global literature on TURF systems and provide a valuable resource for marine resource management policymakers, researchers, and practitioners.

Listeriosis neonatal un desafío diagnóstico: reporte de caso y revisión de la literatura / Neonatal listeriosis a diagnostic challenge: A case report and review of the literature

Introducción: La listeriosis es una patología de baja incidencia, con síntomas leves y autolimitados en la población en general, sin embargo, la transmisión materno-fetal, puede generar cuadros graves en neonatos, manifestados como sepsis, meningitis, endocarditis, encefalitis, meningoencefalitis. El diagnóstico oportuno por clínica y datos de laboratorio en coyuntura con la terapéutica adecuada favorecen la resolución de la enfermedad. Caso clínico: Neonato prematuro tardío de 34 semanas, 6 días de edad gestacional, nació por cesárea iterativa, al nacimiento no vigoroso con líquido amniótico meconial pesado, requirió reanimación básica y avanzada. Evolución: Por los antecedentes natales se realizó estudio de infección, con reporte positivo y desarrollo en hemocultivos de Listeria Monocytogenes, diagnóstico de sepsis, meningitis y conjuntivitis, recibió antibiótico terapia intrave-nosa, completó tratamiento y presentó evolución clínica favorable. Conclusiones: En el presente caso la listeriosis de transmisión materno-neonatal tuvo una presentación grave con aspiración de líquido meconial que requirió intubación y soporte ventilatorio, el paciente desarrolló meningitis y conjuntivitis. En la placenta se presentó corionitis.

Introduction: Listeriosis is a low-incidence pathology with mild and self-limiting symptoms in the general population; however, maternal-fetal transmission can generate severe conditions in neonates, manifested as sepsis, meningitis, endocarditis, encephalitis, meningoencephalitis. Timely diagnosis by clinical and laboratory data in conjunction with adequate therapy favors the resolution of the disease. Clinical case: Late preterm neonate of 34 weeks, six days of gestational age, was born by repetitive cesarean section at non-vigorous birth with heavy meconium amniotic fluid and required basic and advanced resuscitation. Evolution: Based on the birth history, an infection study was carried out, with a favorable report and development of Listeria Monocytogenes in blood cultures, diagnosis of sepsis, meningitis, and conjunctivitis, received intravenous antibiotic therapy, completed treatment, and presented favorable clinical evolution. Conclusions: In the present case, the listeriosis of maternal-neonatal transmission had a severe presentation with the aspiration of meconium fluid that required intubation and ventilatory support; the patient developed meningitis and conjunctivitis. Chorionitis occurs in the placenta.

GrlR, a negative regulator in enteropathogenic E. coli, also represses the expression of LEE virulence genes independently of its interaction with its cognate partner GrlA.

Introduction: Enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC) and Citrobacter rodentium (CR) belong to a group of pathogens that share the ability to form "attaching and effacing" (A/E) lesions on the intestinal epithelia. A pathogenicity island known as the locus of enterocyte effacement (LEE) contains the genes required for A/E lesion formation. The specific regulation of LEE genes relies on three LEE-encoded regulators: Ler activates the expression of the LEE operons by antagonizing the silencing effect mediated by the global regulator H-NS, GrlA activates ler expression and GrlR represses the expression of the LEE by interacting with GrlA. However, despite the existing knowledge of LEE regulation, the interplay between GrlR and GrlA and their independent roles in gene regulation in A/E pathogens are still not fully understood. Methods: To further explore the role that GrlR and GrlA in the regulation of the LEE, we used different EPEC regulatory mutants and cat transcriptional fusions, and performed protein secretion and expression assays, western blotting and native polyacrylamide gel electrophoresis. Results and discussion: We showed that the transcriptional activity of LEE operons increased under LEE-repressing growth conditions in the absence of GrlR. Interestingly, GrlR overexpression exerted a strong repression effect over LEE genes in wild-type EPEC and, unexpectedly, even in the absence of H-NS, suggesting that GrlR plays an alternative repressor role. Moreover, GrlR repressed the expression of LEE promoters in a non-EPEC background. Experiments with single and double mutants showed that GrlR and H-NS negatively regulate the expression of LEE operons at two cooperative yet independent levels. In addition to the notion that GrlR acts as a repressor by inactivating GrlA through protein-protein interactions, here we showed that a DNA-binding defective GrlA mutant that still interacts with GrlR prevented GrlR-mediated repression, suggesting that GrlA has a dual role as a positive regulator by antagonizing GrlR's alternative repressor role. In line with the importance of the GrlR-GrlA complex in modulating LEE gene expression, we showed that GrlR and GrlA are expressed and interact under both inducing and repressing conditions. Further studies will be required to determine whether the GrlR alternative repressor function depends on its interaction with DNA, RNA, or another protein. These findings provide insight into an alternative regulatory pathway that GrlR employs to function as a negative regulator of LEE genes.

Role of the YehD fimbriae in the virulence-associated properties of enteroaggregative Escherichia coli.

The interaction of enteroaggregative Escherichia coli (EAEC) strains with the colonic gut mucosa is characterized by the ability of the bacteria to form robust biofilms, to bind mucin, and induce a local inflammatory response. These events are mediated by a repertoire of five different aggregative adherence fimbriae variants (AAF/I-V) typically encoded on virulence plasmids. In this study, we report the production in EAEC strains of a new YehD fimbriae (YDF), which is encoded by the chromosomal gene cluster yehABCD, also present in most E. coli strains. Immuno-labelling of EAEC strain 042 with anti-AAF/II and anti-YDF antibodies demonstrated the presence of both AAF/II and YDF on the bacterial surface. We investigated the role of YDF in cell adherence, biofilm formation, colonization of spinach leaves, and induction of pro-inflammatory cytokines release. To this aim, we constructed yehD deletion mutants in different EAEC backgrounds (strains 17-2, 042, 55989, C1010, 278-1, J7) each harbouring one of the five AAFs. The effect of the YDF mutation was strain dependent and AAF independent as the lack of YDF had a different impact on the phenotypes manifested by the different EAECs tested. Expression of the yehABCD operon in a E. coli K12 ORN172 showed that YDF is important for biofilm formation but not for adherence to HeLa cells. Lastly, screening of pro-inflammatory cytokines in supernatants of Caco-2 cells infected with EAEC strains 042 and J7 and their isogenic ΔyehD mutants showed that these mutants were significantly defective in release of IL-8 and TNF-α. This study contributes to the understanding of the complex and diverse mechanisms of adherence of EAEC strains and identifies a new potential target for preventive measures of gastrointestinal illness caused by EAEC and other E. coli pathogroups.

Characterization of Suspected Crimes against Companion Animals in Portugal.

Animal crimes are a widespread phenomenon with serious implications for animal welfare, individual well-being and for society in general. These crimes are universal and represent a major problem in human/animal interaction. In Portugal, current law 69/2014 criminalizes the mistreatment and abandonment of companion animals. This study characterizes forensic cases received at the Laboratory of Pathology of the National Institute of Agrarian and Veterinary Investigation (Vairão) since the enforcement of the aforementioned legislation. A retrospective study was carried out based on the consult of 160 data files of forensic necropsies from 127 dogs and 33 cats. Necropsies confirmed prior crime suspicion in 38 cases (24%), from which 33 were dogs and five were cats. Among confirmed cases, most of assaulted animals were medium-size (57%), crossbreed (55%) male (58%) dogs (87%), which were the victims of blunt force trauma (31%), firearms (27%), poisoning (27%) and asphyxiation (15%). In cats, most of the assaulted animals were juvenile (60%) females (60%) of unknown breed (40%), which suffered blunt force trauma (100%) as the only cause of death. The present study shows that violence against animals is a reality, and complaints about these crimes are gradually increasing due to the population's raising awareness about animal rights. Greater communication and coordination between clinicians, veterinary pathologists, and law enforcement officers are essential to validate and legally support these cases and subject them to trial.

The transcriptional activator of the bfp operon in EPEC (PerA) interacts with the RNA polymerase alpha subunit.

Enteropathogenic E. coli virulence genes are under the control of various regulators, one of which is PerA, an AraC/XylS-like regulator. PerA directly promotes its own expression and that of the bfp operon encoding the genes involved in the biogenesis of the bundle-forming pilus (BFP); it also activates PerC expression, which in turn stimulates locus of enterocyte effacement (LEE) activation through the LEE-encoded regulator Ler. Monomeric PerA directly binds to the per and bfp regulatory regions; however, it is not known whether interactions between PerA and the RNA polymerase (RNAP) are needed to activate gene transcription as has been observed for other AraC-like regulators. Results showed that PerA interacts with the alpha subunit of the RNAP polymerase and that it is necessary for the genetic and phenotypic expression of bfpA. Furthermore, an in silico analysis shows that PerA might be interacting with specific alpha subunit amino acids residues highlighting the direction of future experiments.

A Reliable and Valid Parent Self-Report Tool to Assess Children's Global Health Needs.

PURPOSE: This study aimed to develop and validate a parent self-report questionnaire to explore global health needs in 2- to 6-year-old children. DESIGN AND METHODS: The development of the tool started with a conceptualization phase, followed by the design, pilot testing and psychometric validation of the questionnaire. The construct validity was assessed. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were carried out to explore the construct validity of the questionnaire. The normed fit index (NFI), root mean square error of approximation (RMSEA), chi square test and comparative fit index (CFI) were used to test the goodness-of-fit. Reliability was explored through Cronbach's alpha for internal consistency. RESULTS: A total of 973 parents completed the 119 items of the Necesidades de salud de la Población Infantil (NPI) questionnaire for the psychometric validation stage. The EFA identified seven factors: Lifestyles, Promotion of healthy lifestyles and influence of significant persons, Children's socioemotional aspects, Parents' socioemotional aspects, Parental self-efficacy, Situational influences, Professional advice. All the factors showed good internal consistency (Cronbach's alpha >0.7). The CFA showed good adjustment to the model (RMSEA = 0.048). The values of NFI and CFI were 0.741 and 0.779 respectively. CONCLUSIONS: The NPI questionnaire is a reliable and valid instrument. PRACTICE IMPLICATIONS: The seven-factor questionnaire will be useful for analyzing children's global health needs, designing health promotion programs according to identified needs and assessing related interventions.

Role of the YehD fimbriae in the virulence-associated properties of enteroaggregative Escherichia coli

The interaction of enteroaggregative Escherichia coli (EAEC) strains with the colonic gut mucosa is characterized by the ability of the bacteria to form robust biofilms, to bind mucin, and induce a local inflammatory response. These events are mediated by a repertoire of five different aggregative adherence fimbriae variants (AAF/I-V) typically encoded on virulence plasmids. In this study, we report the production in EAEC strains of a new YehD fimbriae (YDF), which is encoded by the chromosomal gene cluster yehABCD, also present in most E. coli strains. Immuno-labelling of EAEC strain 042 with anti-AAF/II and anti-YDF antibodies demonstrated the presence of both AAF/II and YDF on the bacterial surface. We investigated the role of YDF in cell adherence, biofilm formation, colonization of spinach leaves, and induction of pro-inflammatory cytokines release. To this aim, we constructed yehD deletion mutants in different EAEC backgrounds (strains 17-2, 042, 55989, C1010, 278-1, J7) each harbouring one of the five AAFs. The effect of the YDF mutation was strain dependent and AAF independent as the lack of YDF had a different impact on the phenotypes manifested by the different EAECs tested. Expression of the yehABCD operon in a E. coli K12 ORN172 showed that YDF is important for biofilm formation but not for adherence to HeLa cells. Lastly, screening of pro-inflammatory cytokines in supernatants of Caco-2 cells infected with EAEC strains 042 and J7 and their isogenic ΔyehD mutants showed that these mutants were significantly defective in release of IL-8 and TNF-α. This study contributes to the understanding of the complex and diverse mechanisms of adherence of EAEC strains and identifies a new potential target for preventive measures of gastrointestinal illness caused by EAEC and other E. coli pathogroups.

Lesiones cutáneas tipo perniosis durante la epidemia COVID-19 / Perniosis-like skin lesions during the COVID-19 epidemic

No disponible

Identificación de Brucella melitensis como Ochrobactrum anthropi mediante MALDI-TOF MS / Identification of Brucella melitensis as Ochrobactrum anthropi by MALDI-TOF MS

No disponible

Identification of H-type BSE in Portugal.

During the bovine spongiform encephalopathy (BSE) epidemic, Portugal was the third most affected country. As a result of a successful national eradication plan, the number of BSE affected animals has been progressively declining in Portugal with no cases identified in 2013. However, within the scope of this active surveillance scheme, we have identified the first H-type BSE case born after the introduction of the reinforced ban in fallen stock. Here, we report the phenotypic features of this case and the analysis of the protein coding sequence of prnp as well as the prnp promoter and intron 1 insertion-deletions.

Prevalence and molecular identification of Chlamydia abortus in commercial dairy goat farms in a hot region in Mexico.

The aim of this study was to determine the seroprevalence and presence of Chlamydia abortus in Saanen breed female goats from commercial dairy goat farms under intensive production in the municipality of Guanajuato, Mexico. Sera were collected to determine the prevalence of anti-C. abortus IgG antibodies using recombinant enzyme-linked immunosorbent assay (rELISA) and cell culture. Polymerase chain reaction (PCR) was used to prove the presence of the pathogen in swab samples collected from the vagina and rectum of selected animals. Additionally, foetal tissue samples from a sudden abortion were collected. C. abortus prevalence in female goats of commercial milking farms sampled in Guanajuato, Mexico, was 4.87% (n = 246). Seropositive animals were found in six out of nine (66.6%) dairy goat farms sampled, and prevalence among animals in individual farms ranged between 3.44 and 13.51%. C. abortus was detected using PCR in spleen tissue from the aborted foetus. PCR-based detection, as well as isolation from vaginal and rectal swabs, was not possible in the present study. Isolation through cell culture was also unsuccessful from aborted foetal tissue samples. In conclusion, the results from rELISA and PCR show that C. abortus is present in dairy goat farms in the state of Guanajuato, Mexico.

Further characterization of functional domains of PerA, role of amino and carboxy terminal domains in DNA binding.

PerA is a key regulator of virulence genes in enteropathogenic E. coli. PerA is a member of the AraC/XylS family of transcriptional regulators that directly regulates the expression of the bfp and per operons in response to different environmental cues. Here, we characterized mutants in both the amino (NTD) and carboxy (CTD) terminal domains of PerA that affect its ability to activate the expression of the bfp and per promoters. Mutants at residues predicted to be important for DNA binding within the CTD had a significant defect in their ability to bind to the regulatory regions of the bfp and per operons and, consequently, in transcriptional activation. Notably, mutants in specific NTD residues were also impaired to bind to DNA suggesting that this domain is involved in structuring the protein for correct DNA recognition. Mutations in residues E116 and D168, located in the vicinity of the putative linker region, significantly affected the activation of the perA promoter, without affecting PerA binding to the per or bfp regulatory sequences. Overall these results provide additional evidence of the importance of the N-terminal domain in PerA activity and suggest that the activation of these promoters involves differential interactions with the transcriptional machinery. This study further contributes to the characterization of the functional domains of PerA by identifying critical residues involved in DNA binding, differential promoter activation and, potentially, in the possible response to environmental cues.