Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine - Department of Internal Medicine and Infectious Diseases

Different species of Mycoplasma are associated with many pathological problems in small ruminants including respiratory manifestation, infectious keratoconjunctivitis and contagious agalactiae, these problems results in significant losses especially in African countries, our study aimed to isolate and identification of different Mycoplasma species from Egyptian sheep and goats with different clinical manifestations and classified them by different genetic analysis methods using PCR (polymerase chain reaction), sequencing and phylogenetic analysis, testing the effect of antimicrobial agents against these isolates invitro. A total of (437) samples were collected from sheep and goats from Giza governorate in Egypt as (142) nasal swabs from clinically affected animals, (167) pneumonic lungs, (18) samples from tracheal bifurcation, (8) samples by bronchial wash, (76) nasal swabs and (26) milk samples were cultured on PPLO media for cultivation of Mycoplasma species. PCR, sequencing and phylogenetic analysis were adopted to identify and classify the isolated Mycoplasma species.A total of (33) Mycoplasma isolates were isolated on PPLO media, identified by biochemical tests and confirmed and typed by PCR using specific primers. Ten isolates were confirmed as Mycoplasma arginini, (4) isolates as Mycoplasma ovipneumoniae, (4)isolates as Mycoplasma conjunctivae and(2) samples as Mycoplasma agalactiae by PCR and 13 isolates as undifferentiated Mycoplasma species. A purified isolate of Mycoplasma argininiand Mycoplasma ovipneumoniaewere sequenced and phylogenetic analysis was illustrated.Mycoplasmaarginini, Mycoplasma ovipneumoniae , M. conjunctivae and M. agalactiaeare prevalent in Egyptian sheep and goats.Further studies on Mycoplasma arginini are required due to its high frequency of isolation from pneumonic sheep and goats and also from animals suffer from different respiratory manifestations

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