RESUMO
Background: K99 pilus antigen is one of the major adherence factors found on enterotoxigenic Escherichia coli [ETEC] of neonatal calves. It causes severe diarrhea in newborn calves via the production of heat-stable enterotoxin [STa].With increasing concern over the spread of antimicrobial resistance, the development of alternative to conventional antibiotics such as colicin is urgently needed. Colicin is an antimicrobial peptide produced by one strain of E. coli to suppress the growth of other strains of E.coli
Objectives: The purpose of this study was to investigate the control of E.coli k99 and the efficacy of colicinogenic E.coli [CEC] in adult mice
Methods: The mice, used antibiotic were divided into four groups. The first group did not receive any inoculation. The second group was fed just with 0.5 ml colicin solution. The third group was fed just with 0.5 ml E.coli k99 suspension. The fourth group was first fed by 0.5 ml E.coli k99 suspension immediately after oral administration of CEC suspension. Fecal samples of mice in four groups were taken 1, 2, 3, 4, 5, 6 and 7 days after inoculation and colony forming units [CFUs] were monitored per gram feces
Results: The results showed that CEC has inhibitory effect against E.coli k99. There were observed significant differences between the amounts of E.coli k99 recovered from the feces of mice in fourth group with the amount of E.coli k99 recovered from the feces of mice in third group
Conclusions: The data presented here support this claim that CEC plays a significant role against E.coli k99. Furthermore, the study suggested colicin warrants further evaluation as a potential alternative to conventional antibiotics for use to control of E.coli k99
RESUMO
Caprine besnoitiosis is an economically important disease of goats. Neospora caninum, another coccidian parasite of worldwide distribution, infects several animal species and is a major cause of abortion in cattle. Combined infections of N. caninum and Besnoitia caprae can occur in geographical areas endemic for both species of parasite in goats. This experiment was conducted to investigate the possible cross-immunity between these two infections in experimentally infected BALB/c mice. Forty BALB/c mice were divided into four equal groups. The mice of Groups 1 and 4 were inoculated with 1x10[6] live virulent tachyzoites of N. caninum [NC-1], while animals of Groups 2 and 3 were inoculated with sterile tissue culture medium. Each mouse in Groups 1 and 2 was challenged 28 days later with 1 xl0[6] live virulent bradyzoites of-B. Caprae [BC-1]. Following the challenge, the mice in Groups 1 and 2 showed 100% morbidity and 100% mortality within 9 days post infection, while all the animals of Groups 3 and 4 remained alive. The dead animals were necropsied. The survivors [mice in Group 3 and 4] were euthanized 9 days after inoculation and the gross and histopathological lesions in different organs were investigated. Immunization and challenge experiments with lethal dose of B. caprae in the highly susceptible BALB/c mice showed no cross-protection between N. caninum and B. caprae
RESUMO
Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seroprevalence of Neospora antibodies in horses' worldwide. The aim of the present study was to determine serologic prevalence of Neospora infection in horses in Iran. Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutination test [N-MAT]. Antibodies to this parasite were detected in 45 [30%] of the examined serum samples. Thirty four percent of the samples had titer of 1:40 while then reduced to 30% when 1:80 serum dilution was applied as significant cut off titer. This study is the first investigation carried out on the Neospora in horses in Iran and indicates that horses in Iran are exposed to this parasite