Análisis microbiológico de canales de pollo en los mataderos del estado de Zulia, Venezuela

En este trabajo se ha realizado un estudio para evaluar la calidad y seguridad microbiológica de canales de pollo envasadas en cinco mataderos de pollos ubicados en los municipios San Francisco, Maracaibo y Mara, del estado de Zulia, Venezuela (plantas A, B, C, D y E). Para ello se han tomado un total de 30 muestras de canales de pollo envasado entre los cinco mataderos. Asimismo, se han tomado muestras en tres áreas del procesado: evisceración, pre-enfriamiento y enfriamiento. Se analizaron un total de 150 muestras (30 de contenido intestinal, 90 de canales y 30 de agua de los tanques). Sobre las muestras recogidas, se detectó la presencia de Salmonella spp. y se realizó el recuento de aerobios mesófilos, basándonos en la Norma Venezolana Covenin 2343-86 pollo beneficiado en Venezuela. Para la detección de Listeria monocytogenes, se siguió la metodología descrita en la Norma Venezolana Covenin 3718:200. Se detectó la presencia de Salmonella spp. en el 60% de las canales envasadas (IC95%, 42,47-77,53%), mientras que un 40 por ciento (IC95% 22,47- 57,53%) superó los límites tolerables para aerobios mesófilos. Asimismo, se detectó la presencia de L. monocytogenes en el 20 por ciento de las canales (IC95% 5,69-34,31%). Al analizan las distintas fases del procesado, se observa que la evisceración podría ser uno de los principales puntos críticos, debido al alto grado de contaminación de los animales que llegan al matadero. De igual modo, los resultados obtenidos reflejaron la existencia de contaminaciones cruzadas en el pre-enfriamiento y enfriamiento de las canales, imposibilitando la eliminación de estos agentes en el producto final. De acuerdo con los resultados obtenidos, se recomienda la aplicación de planes de vigilancia y control de Salmonella y Listeria en producción primaria, revisar las condiciones sanitarias en las plantas sacrificadoras, así como la adopción de códigos de buenas prácticas en el personal responsable de las explotaciones, transporte y mataderos. Finalmente se recomienda la revisión de las Norma Covenin Venezolana, adaptando la presión de muestreo, tipo de muestras, técnicas de diagnóstico y lectura de resultados a la normativa internacional, para favorecer el comercio de productos cárnicos con las máximas garantías sanitarias.A study to assess the microbiological quality and safety of chicken carcasses packaged in five chicken slaughterhouses located in San Francisco, Mara and Maracaibo, Zulia State, Venezuela (designed as plants A, B, C, D and E) was carried out. A total of 30 packaged chicken carcass in each plant were sampled. Also, three areas of processing: evisceration, pre-chiller and chiller were analyzed. A total of 150 samples (30 intestinal content, 90 carcass and 30 samples of water) were obtained. We detected the presence of Salmonella spp. and count aerobic mesophilic bacteria, based on the Norma Venezolana Covenin 2343-86 pollo beneficiado en Venezuela. For the detection of Listeria monocytogenes, the methodology described in the Norma Venezolana Covenin 3718:200 was followed. Of the thirty packed chicken carcasses analyzed, we detected the presence of Salmonella spp. in 18 (60%, 95% CI, 42.47 to 77.53), and the number of carcasses that exceeded tolerable limits for aerobic mesophilic was 40 percent (95% CI: 22.47 to 57, 53). We detected the presence of L. monocytogenes in 20 percent (95% CI 5.69 to 34.31) of the carcasses. When considering the different phases of processing, the evisceration is considered a critical point of the process, due to the high degree of contamination of the animals arrive at the slaughterhouse. Also, along the processing (pre-chiller and chiller) cross contamination is observed, avoiding the elimination of these microorganisms in the final product. According to the results, we recommend the implementation of monitoring and control of Salmonella spp. and Listeria spp. in primary production; review the sanitary conditions of the slaughterhauses, and the adoption of codes of good practice on the staff responsible for the holdings, transport and slaughter. Finally we recommend reviewing the Covenin Norma Venezolana in relation to sampling pressure, type of samples, diagnostic techniques and results interpretation according to international standards to facilitate trade of meat products with guarantees

SARS‐CoV ‐2 whole‐proteome sequences from environment as an indicator of community viral distribution, evolution and epidemiological dynamics: A cohort analysis of Austria

Several investigations have been carried out to detect SARS-CoV-2 samples from the environment such as sewage waters and surface swabs. Whole-proteome sequence analysis of 847 SARS-CoV-2 genome sequences collected from the environment in Austria during 2021 and deposited in GISAID indicates that alpha and delta are two dominant variants, coinciding with the human clinical samples with a Pearson correlation coefficient in the range of 0.58 (alpha variant) to 0.82 (delta variant). Both environmental and human samples show that Austrian SARS-CoV-2 alpha variant is found to possess N protein R203K and G204R/P mutations, whereas they are absent in the delta variant. SARS-CoV-2 delta variant is continuously seen in both the environmental and human clinical samples from the month of September 2021 and it spiked in November 2021, which is directly reflected in the increase of the number of SARS-CoV-2 infections and deaths in Austria during November 2021. Thus, the results presented here indicate that the environmental SARS-CoV-2 whole-genome sequences collected from Austria reflect the community viral distribution, evolution and the concomitant epidemiological dynamics. Since SARS-CoV-2 keeps evolving, the results presented here further suggest the need to monitor the environment for the early detection of SARS-CoV-2 variants to take appropriate precautionary measures. © 2022 Society for Applied Microbiology and John Wiley & Sons Ltd

Detailed Regulatory Mechanism of the Interaction between ZO-1 PDZ2 and Connexin43 Revealed by MD Simulations

The gap junction protein connexin43 (Cx43) binds to the second PDZ domain of Zonula occludens-1 (ZO-1) through its C-terminal tail, mediating the regulation of gap junction plaque size and dynamics. Biochemical study demonstrated that the very C-terminal 12 residues of Cx43 are necessary and sufficient for ZO-1 PDZ2 binding and phosphorylation at residues Ser (-9) and Ser (-10) of the peptide can disrupt the association. However, only a crystal structure of ZO-1 PDZ2 in complex with a shorter 9 aa peptide of connexin43 was solved experimentally. Here, the interactions between ZO-1 PDZ2 and the short, long and phosphorylated Cx43 peptides were studied using molecular dynamics (MD) simulations and free energy calculation. The short peptide bound to PDZ2 exhibits large structural variations, while the extension of three upstream residues stabilizes the peptide conformation and enhanced the interaction. Phosphorylation at Ser(-9) significantly weakens the binding and results in conformational flexibility of the peptide. Glu210 of ZO-1 PDZ2 was found to be a key regulatory point in Cx43 binding and phosphorylation induced dissociation

Mortality Risk of Hypnotics: Strengths and Limits of Evidence

Sleeping pills, more formally defined as hypnotics, are sedatives used to induce and maintain sleep. In a review of publications for the past 30 years, descriptive epidemiologic studies were identified that examined the mortality risk of hypnotics and related sedative-anxiolytics. Of the 34 studies estimating risk ratios, odds ratios, or hazard ratios, excess mortality associated with hypnotics was significant (p < 0.05) in 24 studies including all 14 of the largest, contrasted with no studies at all suggesting that hypnotics ever prolong life. The studies had many limitations: possibly tending to overestimate risk, such as possible confounding by indication with other risk factors; confusing hypnotics with drugs having other indications; possible genetic confounders; and too much heterogeneity of studies for meta-analyses. There were balancing limitations possibly tending towards underestimates of risk such as limited power, excessive follow-up intervals with possible follow-up mixing of participants taking hypnotics with controls, missing dosage data for most studies, and over-adjustment of confounders. Epidemiologic association in itself is not adequate proof of causality, but there is proof that hypnotics cause death in overdoses; there is thorough understanding of how hypnotics euthanize animals and execute humans; and there is proof that hypnotics cause potentially lethal morbidities such as depression, infection, poor driving, suppressed respiration, and possibly cancer. Combining these proofs with consistent evidence of association, the great weight of evidence is that hypnotics cause huge risks of decreasing a patient's duration of survival

Pair-Wise Regulation of Convergence and Extension Cell Movements by Four Phosphatases via RhoA

Various signaling pathways regulate shaping of the main body axis during early vertebrate development. Here, we focused on the role of protein-tyrosine phosphatase signaling in convergence and extension cell movements. We identified Ptpn20 as a structural paralogue of PTP-BL and both phosphatases were required for normal gastrulation cell movements. Interestingly, knockdowns of PTP-BL and Ptpn20 evoked similar developmental defects as knockdown of RPTPα and PTPε. Co-knockdown of RPTPα and PTP-BL, but not Ptpn20, had synergistic effects and conversely, PTPε and Ptpn20, but not PTP-BL, cooperated, demonstrating the specificity of our approach. RPTPα and PTPε knockdowns were rescued by constitutively active RhoA, whereas PTP-BL and Ptpn20 knockdowns were rescued by dominant negative RhoA. Consistently, RPTPα and PTP-BL had opposite effects on RhoA activation, both in a PTP-dependent manner. Downstream of the PTPs, we identified NGEF and Arhgap29, regulating RhoA activation and inactivation, respectively, in convergence and extension cell movements. We propose a model in which two phosphatases activate RhoA and two phosphatases inhibit RhoA, resulting in proper cell polarization and normal convergence and extension cell movements

Resource bricolage and growth of product and market scope in social enterprises

This research aims to understand how resource bricolage strategy plays a role in the growth of social enterprises in terms of their product and market. Based on interviews with nine social enterprises, our exploratory finding suggests that social enterprises often employ both internal and network resources in the process of making do. We further explore the relationship between the form of resource utilisation and the nature and scope of activities that the social enterprises embark upon, and find that only those relying on both internal and network bricolage are able to expand into new markets utilising newly developed products. We also find that social enterprises relying on only internal resources can reach the same point through incremental improvisation, by first moving towards either product extension or market expansion, before then embarking on the other. This research contributes to the social entrepreneurship literature by enhancing our understanding of the relationship between resource bricolage strategy and growth of social enterprises through product/ market scope in a penurious environment. The findings of this research also have implications for social enterprise managers and policy makers in utilising their resources and responding to environmental opportunities and challenges

ICF, An Immunodeficiency Syndrome: DNA Methyltransferase 3B Involvement, Chromosome Anomalies, and Gene Dysregulation

The immunodeficiency, centromeric region instability, and facial anomalies syndrome (ICF) is the only disease known to result from a mutated DNA methyltransferase gene, namely, DNMT3B. Characteristic of this recessive disease are decreases in serum immunoglobulins despite the presence of B cells and, in the juxtacentromeric heterochromatin of chromosomes 1 and 16, chromatin decondensation, distinctive rearrangements, and satellite DNA hypomethylation. Although DNMT3B is involved in specific associations with histone deacetylases, HP1, other DNMTs, chromatin remodelling proteins, condensin, and other nuclear proteins, it is probably the partial loss of catalytic activity that is responsible for the disease. In microarray experiments and real-time RT-PCR assays, we observed significant differences in RNA levels from ICF vs. control lymphoblasts for pro- and anti-apoptotic genes (BCL2L10, CASP1, and PTPN13); nitrous oxide, carbon monoxide, NF-κB, and TNFa signalling pathway genes (PRKCH, GUCY1A3, GUCY1B3, MAPK13; HMOX1, and MAP4K4); and transcription control genes (NR2F2 and SMARCA2). This gene dysregulation could contribute to the immunodeficiency and other symptoms of ICF and might result from the limited losses of DNA methylation although ICF-related promoter hypomethylation was not observed for six of the above examined genes. We propose that hypomethylation of satellite 2at1qh and 16qh might provoke this dysregulation gene expression by trans effects from altered sequestration of transcription factors, changes in nuclear architecture, or expression of noncoding RNAs