Isolation and Identification of Mannheimia haemolytica and Pasteurella multocida Species from Ruminants in Six Different Regions in Morocco

Pasteurella species is considered the principal pathogen of the respiratory tract. Mannheimia haemolytica and Pasteurella multocida were investigated and typed from nasal swabs and tissues taken from sheep, goat and cattle. Indeed, 41 lung and 121 nasal swabs samples were collected from animals with respiratory diseases during 2015 to 2017 in six different regions in Morocco. At first, a screening of Pasteurella species using the real time PCR (RT-PCR) was carried out, then all isolated strains on agar blood were confirmed by PCR gel based assay specific for M. haemolytica and P. multocida. Pathogenicity was evaluated in mice and histopathological examination was done on some of lung tissue. The results revealed that 34 samples of which 28 (55%) from nasal swabs and six (38%) from lungs were positive for M. haemolytica and nine samples of which seven (14%) from nasal swabs and two (13%) from lungs were positive on P. multocida serogroup A. Seventy-two percent (72%) isolates were highly pathogenic to mice, which is in accordance with the results obtained by histopathology examination. This is the first report for widespread infections of Pasteurella (M. haemolytica & P. multocida) in ruminants in Morocco. Therefore, measures including development of vaccines are highly required to mitigate the impact of the bacteria in animals.