Isolation, identification and genetic analysis of Mannheimia haemolytica in ovine clinical mastitis in Mosul city

Abstract

The aim of this study was to identify and diagnose of M. haemolytica strains as one of the most important causes of ovine clinical mastitis in Mosul city. One hundred and thirty-three milk samples were directly obtained from the udders of ewes infected by clinical mastitis from November 2020 to January 2021.Standard and conventional methods were followed for isolation and identification of M. haemolytica. Milk samples were cultured on blood agar 7% and MacConkey agar, then it was purified and was stained by Methylene blue. Later, different biochemical tests were Conducted. Molecular identification of M. haemolytica depending on 16srRNA gene, followed by sequencing, similarity and phylogenetic tree was generated. The results showed that 62(46.61%) of samples were positive for bacterial isolation, biochemical tests and conventional PCR technique. Sequencing results showed that the positive samples were belonged to M. haemolytica strains. The similarity within strain Ib001 and within strain 39433 were 100%, and 99.47% respectively. Poor management was associated with the high level of mastitis caused by M. haemolytica, so the application of prophylactic programs should be followed to limit the spread of the disease.