The Norway rat is a globally distributed pest, known for its resilience to eradication and control programs. Efficient population control, especially in urban settings, is dependent on knowledge of rat demography and population ecology. We analyzed the relationship between four demographic outcomes, estimated by live-trapping data, and fine-scale environmental features measured at the capture site. Wounds, a proxy for agonistic interactions, were associated with mature individuals. Areas with environmental features favorable to rats, such as open sewers and unpaved earth, were associated with more mature individuals with a better body condition index. The control measures (environmental stressors) are likely to be disrupting the social structure of rat colonies, increasing the frequency and distribution of agonistic interactions, which were common in both sexes and maturity states. The relationship between the favorable environmental conditions and the demographic markers analyzed indicate possible targets for infestation control through environmental manipulation, and could be incorporated into current pest management programs to achieve long-term success. Our study indicate that urban interventions focused on removal of potential resources for rats could be potential long-term solutions by reducing the carrying capacity of the environment.

The transmission of Salmonella Enteritidis (SE) in poultry is most often by the fecal-oral route, which can be attributed to the population density. Consequently, the pathogen triggers stress response and virulence factors deploying it to survive in hosts. Therefore, this study proposed to evaluate HPMCAS-coated microparticles containing the Ctx(Ile21)-Ha antimicrobial peptide against SE in laying hens chicks infection model to determine whether Ctx(Ile21)-Ha-utilization confers a benefit in the intestinal lumen, as well as whether limits systemic infection. Importantly, while assessing whether AMP utilization confers reduction of SE in liver, it was noted that there was statistical significance between groups A (control, no Ctx(Ile21)-Ha peptide) and B (2.5 mg of Ctx(Ile21)-Ha/kg) at 2 dpi, potentially indicating the Ctx(Ile21)-Ha effectiveness in the first stage of infection by SE. Remarkably, it was also detected a statistical significance (p -value <0.0001) with lower counts of SE (~ 0 CFU) in livers at 5, 7, and 14 dpi, regardless of Ctx(Ile21)-Ha dosage (2.5 mg or 5 mg/kg - group C). By using Chi-square test, the AMP effect on SE fecal excretion was evaluated. In this regard, it was noticed statistical significance (p < 0.05) among groups B and C in comparison with control group A, since those groups had lower bacterial excretion along 21 days. In summary, the role of HPMCAS-Ctx(Ile21)-Ha peptide microcapsules against S. Enteritidis in laying hen chicks infection model was unraveled, providing a satisfactory results against this pathogen.

Studies evaluating the occurrence of enteropathogenic bacteria in urban rats (Rattus spp.) are scarce worldwide, specifically in the urban environments of tropical countries. This study aims to estimate the prevalence of Diarrheagenic Escherichia coli (DEC) and Salmonella spp. with zoonotic potential in urban slum environments. We trapped rats between April and June 2018 in Salvador, Brazil. We collected rectal swabs contents from Rattus spp., and cultured for E. coli and Salmonella spp., and screened E. coli isolates by PCR to identify pathotypes. E. coli were found in 70 % of Rattus norvegicus and were found in four Rattus rattus. DEC were isolated in 31.3 % of the 67 R. norvegicus. The pathotypes detected more frequently were shiga toxin E. coli (STEC) in 11.9 %, followed by atypical enteropathogenic E. coli (aEPEC) in 10.4 % and https://www.cambridge.org/core/terms.

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Formaldehyde (FA) and acetaldehyde (AA) were determined in the ambient air of five gas stations (GS) in the city of Salvador, Bahia State, Brazil, using three passive samplers exposed simultaneously for 8 h and analysis by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The concentration ranges found were 3.31-5.78 μg m −3 for FA and 10.5-28.2 μg m −3 for AA. These values were below the exposure limits recommended by national and international agencies for occupational environments, however, FA concentrations were above the more restrictive limit (3.30 μg m −3) stablished by Texas Commission on Environmental Quality (TCEQ) for long-term outdoor exposure. The lifetime cancer risks (LCR) found associated with the exposure of GS employees to these aldehydes over the 30-year period varied between 4.51 × 10 −6-8.00 × 10 −6 for FA and 2.46 × 10 −6-6.60 × 10 −6 for AA. These values are above the acceptable limit set by the USEPA (1.0 × 10 −6), reinforcing the need for actions to minimize the occupational exposure, mainly to FA, which is associated with nasopharyngeal cancer.