Urban slums provide suitable conditions for infestation by rats, which harbour and shed a wide diversity of zoonotic pathogens including helminths. We aimed to identify risk factors associated with the probability and intensity of infection of helminths of the digestive tract in an urban slum population of Rattus norvegicus. Among 299 rats, eleven species/groups of helminths were identified, of which Strongyloides sp., Nippostrongylus brasiliensis and, the human pathogen, Angiostrongylus cantonensis were the most frequent (97, 41 and 39%, respectively). Sex interactions highlighted behavioural differences between males and females, as eg males were more likely to be infected with N. brasiliensis where rat signs were present, and males presented more intense infections of Strongyloides sp. Moreover, rats in poor body condition had higher intensities of N. brasiliensis. We describe a high global richness of parasites in R. norvegicus, including five species known to cause disease in humans. Among these, A. cantonensis was found in high prevalence and it was ubiquitous in the study area – knowledge which is of public health importance. A variety of environmental, demographic and body condition variables were associated with helminth species infection of rats, suggesting a comparable variety of risk factors for humans.

The cattle tick Rhipicephalus (Boophilus) microplus is responsible for major losses in the Brazilian livestock, mainly due to reduction in cattle productive performance. Resistance development to major classes of acaricide widely used nowadays has been extensively reported, as well as the occurrence of residues from these compounds in animal products and the environment. This study aimed to evaluate the efficiency of acaricides on R. (B.) microplus collected from rural properties in the North-Central region of Bahia State. Ticks were collected in several cattle farms in the cited region, and an in vitro acaricide efficiency assay was performed based on the immersion of ticks in acaricide solutions made according to manufacturers' recommendations. The results obtained in the experiments indicated varying degrees of efficiency of the several bases studied, with the products benzofenilurea, macrocyclic lactone and fipronil showing the highest levels of efficiency, 100%, 100% and 97.34%, respectively. It was possible to conclude that, for the region studied, there are different degrees of commercial acaricides efficiency, and many present less than 95% effectiveness, value determined as acceptable by the Brazilian legislation.Keywords: Ticks, cattle, drug resistance, acaricide, Brazilian Northeast. ResumoO carrapato Rhipicephalus (Boophilus) microplus é responsável por grandes perdas na pecuária brasileira, principalmente devido à redução no desempenho produtivo dos animais. A resistência do parasita a diferentes classes de acaricidas tem sido amplamente relatada, bem como os problemas de ocorrência de resíduos desses compostos em produtos de origem animal e no ambiente. Esse estudo teve como objetivo avaliar a eficiência de diversos acaricidas sobre populações de R. (B.) microplus provenientes de propriedades rurais da Região Centro-Norte do Estado da Bahia, Brasil. Teleóginas ingurgitadas foram colhidas em diferentes propriedades da região e submetidas a ensaio in vitro de eficiência de acaricidas, baseado na imersão dos carrapatos em soluções de acaricidas feitas seguindo as recomendações dos fabricantes. Os resultados obtidos indicam níveis variados de eficiência das bases estudadas, com os acaricidas benzofenilureia, lactona macrocíclica e fipronil apresentando os índices mais altos de eficiência, 100%, 100% e 97.34%, respectivamente. Pode-se concluir que, para a região estudada, os acaricidas apresentam níveis diversos de eficiência, e muitos deles possuem eficácia de menos de 95%, como recomendado pela legislação brasileira.

No abstract

No abstract

No abstract

No abstract

Rhipicephalus microplus (Canestrini) is an ectoparasite accountable for great economic losses. The use of entomopathogenic fungi to control arthropods has shown promising responses. The present study evaluated the virulence of Isaria farinosa (Holmsk.) Fr., Isaria fumosorosea (Wize) Brown and Smith, and Purpureocillium lilacinum (=Paecilomyces lilacinus) (Thom.) Samson to engorged females, eggs, and larvae of R. microplus. There were four treatment groups (10(5), 10(6), 10(7), and 10(8) conidia ml(-1)) and the control group (water and Tween 80, 0.1% v/v). The treatment was based on immersion of the specimen in 1 ml of the suspension or control solution. The study observed changes in egg viability and larval mortality after treatment. The results showed that I. farinosa, P. lilacinum, and I. fumosorosea caused alterations in the biological parameters of R. microplus ticks. I. fumosorosea presented the greatest potential to control R. microplus engorged females in vitro, causing a 49% decrease in nutritional index. All fungal isolates presented significant reduction in the egg production index. I. farinosa reduced the hatching percentage if the eggs were treated with the two highest conidial concentrations. All conidial concentrations of I. fumosorosea were able to reduce the hatching percentage significantly. All tested isolates showed pathogenicity toward unfed R. microplus larvae. As far as we know, this is the first study reporting the effect in vitro of I. farinosa, I. fumosorosea, and P. lilacinum to different developmental stages of R. microplus ticks.

In this study, Rhizophora mangle L. mangrove plants and plant growth-promoting bacteria were evaluated for their ability to degrade polycyclic aromatic hydrocarbons in diesel oil-contaminated sediment. The diesel-contaminated soil was sown with plant growth-promoting bacteria in the R. mangle L. rhizosphere and monitored for 120 days in a greenhouse. The plant growth-promoting bacteria Pseudomonas aeruginosa and Bacillus sp. were analyzed for their ability to degrade eight priority polycyclic aromatic hydrocarbons, achieving a removal rate for naphthalene (80%), acenaphthene (> 60%), anthracene (> 50%), benzo(a)anthracene (> 60%), benzo(a)pyrene (> 50%) and dibenzo(a,h)anthracene (> 90%) in the treatments with and without plants. R. mangle L. demonstrated a removal rate above 50% for acenaphthene and fluoranthene. The bacterial strains promoted the development of the plant propagule in 55% of sediment contaminated with diesel. Scanning electron microscopy revealed the formation of biofilms by the strains in the roots of the plants in contact with the diesel. Thus, the interaction between Rhizophora mangle L. and the bacterial strains (Bacillus sp. and P. aeruginosa) demonstrated the potential of the strains to degrade diesel and bioremediate mangroves impacted by diesel oil.