Microbiota bacteriana em miíases umbilicais por larvas de Cochliomyia hominivorax Coquerel, 1858 (Diptera: Calliphoridae) em bezerros naturalmente infestados

Abstract

The objective of this study was to identify the bacterial microbiota in calf navels myiasis caused by Cochliomyia hominivorax larvae. Two places were choosed to colect the material: the Nhumirim ranch belonging to Embrapa Pantanal, Corumbá-MS and the Santo Antônio ranch, Miguel Pereira-RJ. There were collected 62 cotton swabs from calf navels naturally caused by C. hominivorax larvae. After that, the cotton swabs were sent to the Veterinary Bacteriology Laboratory at UFRRJ inside carriage test tubes with agar. The primary isolation used bovine blood agar and brain heart infusion (BHI) agar. After the incubation period, the isolates were evaluated by means of Gram staining, catalase testing and 30% KOH. After stained, the isolates were evaluated by their stain morphologic and color characteristics. Species of Staphylococcus spp. were streaked in selectives agar to Staphylococcus spp. for the species identication and was used coagulase test, nitrate reduction test, VP, urease production and sugar fermentation. To Streptococcus spp. was used selective agar to Streptococcus spp. species througout inoculation in metilene blue milk, esculine test and hipurate test. The specimens of the family Enterobacteriaceae used THI test, motility in tube test, indol production test, gelatine production, urease production, citrate and malonate degradation. A total of 89 colonies were isolated; 14 genera and five families were identified. The most frequent family was Enterobacteriaceae and the genera more frequent was Bacillus and Micrococcus. Pathogenic species were isolated, but no secondary infection ocurred in the calves; some antibacterial or bacteriostatic substances may be produced by larvae of C. hominivorax or bacterial microbiota of the myiasis of the navel.