Potential of Tetradenia riparia leaf essential oil and its fractions in controlling Aedes aegypti and Rhipicephalus microplus larvae

Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a shrub, commonly known as ginger bush or false myrrh, and several studies have shown that T. riparia exhibits a variety of biological properties. This study aimed to determine the chemical composition of T. riparia essential oil and its fractions, investigate their anticholinesterase activity, and assess their larvicidal activity against the cattle tick Rhipicephalus microplus and the mosquito Aedes aegypti. Eleven essential oil fractions were obtained by fractionation and analyzed by gas chromatography/mass spectrometry. Larvicidal activity against R. microplus and third-instar A. aegypti was assessed using a larval packet test and a larval immersion test, respectively. Anticholinesterase activity was determined by a bioautographic method. Forty-nine compounds were identified in the essential oil, of which the major classes were oxygenated sesquiterpenes (45.95%) and sesquiterpene hydrocarbons (35.20%) and the major components were isospathulenol (17.40%), ß-caryophyllene (15.61%), 14-hydroxy-9-epi-caryophyllene (10.07%), 14-hydroxy-α-muurolene (8.32%), and 9ß,13ß-epoxy-7-abietene (5.53%). Bioassays showed that T. riparia essential oil (LC50 = 1.56 µg/mL) and FR3 (LC50 = 0.30 µg/mL) were the most active against R. microplus and A. aegypti larvae, respectively. The essential oil and FR1, FR2, and FR3 exhibited acetylcholinesterase inhibitory activity. These results indicate that T. riparia essential oil and its fractions hold promise in the development of novel, environmentally safe agents for the control of R. microplus and A. aegypti larvae.

Prevalência de anticorpos contra Chlamydophila abortus em ovinos da região de Londrina, Paraná, Brasil / Prevalence of antibodies to Chlamydophila abortus in ovines in the Londrina area of Paraná state, Brazil

O objetivo deste trabalho foi estimar a prevalência de anticorpos anti-Chlamydophila abortus em ovinos de propriedades localizadas na região de Londrina, estado do Paraná. A prova de fixação de complemento foi realizada em 267 amostras de soro sanguíneo de ovinos adultos, provenientes de oito propriedades e foram considerados positivos os soros com títulos ? 32. Em sete (87,50%) propriedades foram detectados 19 (7,11%) animais positivos, sendo 17 com títulos de 32, um com 64 e outro com 128. Nestas propriedades, os sinais clínicos descritos foram abortamentos, natimortalidade, nascimento de crias fracas e repetição de cio. A elevada frequência de propriedades com pelo menos um animal positivo e a ocorrência de 19 (7,11%) animais positivos na prova de fixação de complemento sugerem a presença de Chlamydophila abortus nos animais das propriedades estudadas. (AU)

The aim of this paper was to estimate the prevalence of antibodies to Chlamydophila abortus in ewes from the Londrina region of Paraná state. Blood samples from 267 adult ewes from eight herds were submitted to complement fixation testing. Tests were considered positive when the titers ? 32. Nineteen animals (7.11%) in 7 (87.50%) herds tested positive for antibodies against C. abortus. The titers were 32 in 17 animals and were 64 and 128 in the other two animals. The clinical signs recorded were abortion, stillbirth, weak newborns and heat repetition. The high frequency of herds with at least one positive animal and a seroprevalence of 7.11% suggest the presence of Chlamydophila abortus in the animals of studied herds.(AU)

Prevalência de anticorpos contra Chlamydophila abortus em ovinos da região de Londrina, Paraná, Brasil / Prevalence of antibodies to Chlamydophila abortus in ovines in the Londrina area of Paraná state, Brazil

O objetivo deste trabalho foi estimar a prevalência de anticorpos anti-Chlamydophila abortus em ovinos de propriedades localizadas na região de Londrina, estado do Paraná. A prova de fixação de complemento foi realizada em 267 amostras de soro sanguíneo de ovinos adultos, provenientes de oito propriedades e foram considerados positivos os soros com títulos ? 32. Em sete (87,50%) propriedades foram detectados 19 (7,11%) animais positivos, sendo 17 com títulos de 32, um com 64 e outro com 128. Nestas propriedades, os sinais clínicos descritos foram abortamentos, natimortalidade, nascimento de crias fracas e repetição de cio. A elevada frequência de propriedades com pelo menos um animal positivo e a ocorrência de 19 (7,11%) animais positivos na prova de fixação de complemento sugerem a presença de Chlamydophila abortus nos animais das propriedades estudadas.

The aim of this paper was to estimate the prevalence of antibodies to Chlamydophila abortus in ewes from the Londrina region of Paraná state. Blood samples from 267 adult ewes from eight herds were submitted to complement fixation testing. Tests were considered positive when the titers ? 32. Nineteen animals (7.11%) in 7 (87.50%) herds tested positive for antibodies against C. abortus. The titers were 32 in 17 animals and were 64 and 128 in the other two animals. The clinical signs recorded were abortion, stillbirth, weak newborns and heat repetition. The high frequency of herds with at least one positive animal and a seroprevalence of 7.11% suggest the presence of Chlamydophila abortus in the animals of studied herds.