| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1001-2 | ||||
Resumo:Glanders is a zoonotic disease primarily affecting solipeds but can also pose a threat to other animals. It is classified as a category B agent of bioterrorism due to its potential impact on public health. The etiological agent of glanders is Burkholderia mallei , an aerobic, Gram-negative, non-motile bacilli that exclusively targets mammals. While most developed countries have successfully eradicated B. mallei, the pathogen persists in Brazil. Consequently, understanding the virulence of circulating strains in our country is essential for future vaccine trials and to inform updates in legislation. To investigate the virulence of the Brazilian B. mallei strain (BAC 86/19), we conducted an infection study using BALB/c mice. Female mice, aged 3-4 weeks, were challenged with varying doses of B. mallei BAC 86/19 (102, 105 or 107 CFU) via the intranasal route following anesthesia. Control mice received saline solution intranasally. The animals were monitored for 48 hours, and a humane endpoint was applied when necessary. Animals challenged with 105 or 107 CFU exhibited a significant loss of body weight as early as 24 hours after infection. Only animals challenged with 107 CFU displayed a notable decrease in body temperature. Additionally, mice challenged with 105 or 107 CFU presented clinical signs such as wheezing, apathy, bristly hair, and ocular and vaginal secretions, from which B. mallei was recovered. Interestingly, even mice challenged with a low dose of 102 CFU showed colonization of the liver, lung, and spleen with B. mallei, despite not displaying clinical signs. Significant differences in CFU counts were observed only in the liver of mice infected with 107 CFU. In conclusion, our study demonstrates that the B. mallei strain BAC 86/19, isolated from a mare in Brazil, is virulent in BALB/c mice. This strain can serve as a valuable model for determining the lethal dose 50 (LD50) and conducting further investigations on persistence and immunity. Understanding the virulence of circulating B. mallei strains is crucial for developing effective vaccines and implementing appropriate public health measures.
Palavras-chave: glanders, BALB/c mice, pathogenicity, animal models Agência de fomento:MAPA, CNPq | |||||