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Background and Aim: Mannheimia haemolytica (Mha) is a common agent of pneumonia in ruminants globally, causing economic losses by morbidity, mortality, and treatment costs. Infection by Mha is often associated with or promoted by respiratory viral pathogens and environmental conditions. Infections due to Mha have rarely been described in small ruminants. This study reports the biological and molecular characteristics of a new Moroccan Mha isolate from small ruminants presenting typical respiratory symptoms. We also studied the cultural parameters, growth kinetics, and Lkt excretion of the isolate and its pathogenicity on laboratory animals and small ruminants. Materials and Methods: Suspected pasteurellosis cases in sheep and goat flocks in Morocco were investigated. A local strain of Mha was isolated and identified using biochemical and molecular methods. Polymerase chain reaction-targeting specific genes were used for serotyping and phylogenetic analyses; further, leukotoxin production, cytotoxicity, and pathogenicity of the isolate in mice, goats, and sheep were investigated. Results: Phylogeny analysis revealed 98.76% sequence identity with the USA isolate of 2013; the strain growth with a cycle of 9-10 h with leukotoxin secretion was detected by NETosis and quantified by cytotoxicity and mortality of mice. Goat and sheep infections cause hyperthermia, with characteristic postmortem lesions in the trachea and lung. Conclusion: A local isolate of Mha from sheep that died of pneumonia was characterized for the 1st time in North Africa using biological and molecular methods. Although growth on appropriate culture media is accompanied by intense leukotoxin secretion, experimental infections of sheep and goats cause hyperthermia and typical lesions of pneumonia.

Mycoplasma capricolum subsp. capricolum (Mcc) is an important etiological agent of contagious agalactia (CA). CA affects small ruminants and is characterized by inducing mastitis, arthritis, kerato-conjunctivitis and respiratory symptoms. The aim of this study was to isolate and characterize Mcc from Moroccan goats with contagious agalactia. A total of 300 Alpine goats were monitored. Serology analysis, molecular identification, and isolation of Mcc were realized from suspected goats. An experimental study was conducted for isolated Mcc to determine their pathogenicity. Thus, clinical observation showed that respiratory symptoms were predominant in young animals, and other symptoms, such as mastitis, keratoconjunctivitis and lameness, were more frequently detected in adult goats. Of the 80 tested blood samples, 28 sera were seropositive for Mcc antibodies. Mcc was identified by polymerase chain reaction (PCR) in milk, lung tissue and synovial liquid samples. The isolation of Mcc was successful through bacterial culture from lung tissue. LppA gene sequence of this strain revealed 98.1% similarity with the reference strain (ATCC 27343), with 11 missense variants. Experimental infection resulted in severe and generalized CA disease in sheep and goats, confirming the high pathogenicity of the Moroccan Mcc isolate.

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