In vitro antimicrobial susceptibility profile and occurrence of multiple drug resistance in Rhodococcus equi isolates from equine, pig, wild boars, environment, and humans with and without AIDS, against tulathromycin and other antimicrobial drugs

• Grant number: 10/17413-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2011
• Effective date (End): December 31, 2011
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Marcio Garcia Ribeiro
• Grantee: Mariana Silva Rossi
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Rhodococcus equi is a well-recognized gram positive intracellular bacterium associated with pyogranulomatous infections in animals and humans, and refractory to the conventional antimicrobial therapy. The organism is widespread in soil, particularly in faeces of foals, other herbivores and their environment. Currently, R. equi has emerged as a pulmonary pathogen among immunosuppressed human patients, particularly those infected by acquired immunodeficiency syndrome-AIDS. R. equi is frequently isolated from the lymph nodes of domestic pigs with or without apparent lesions. Commercial wild boar (Sus scrofa) breeding farms have recently been introduced in Brazil, using European wild boars. As this species is considered exotic to Brazilian fauna, the animals and farms are monitored by the Brazilian Institute of the Environment and Natural Renewable Resources. Usually, rhodococcosis therapy involves prolonged use of antimicrobials. Long-term antimicrobial therapy is recommended due to intracellular localization of agent, development of pyogranulomatous inflammatory reaction and resistant pattern strains, that lead to poor response to the conventional antimicrobial treatment. Furthermore, different authors has described occurrence of multiple drug resistance in R. equi strains obtained from animals and humans. Tulathromycin is recognized as a new antimicrobial drug from macrolide group. This drug have show good eficacy in therapy of pulmonar infecions in domestic animals. The purpose of present study is investigate the antimicrobial susceptibility profile of R. equi strains isolated from equine, pig, wild boars, environment and humans with and without AIDS, against tulathromycin and other antimicrobials recommended to treatment of rhodococcosis, as well as occurrence of multiple drug resistance of isolates.