This study was conducted to identify the erythromycin resistance genes in the
coagulase-negative staphylococci (CoNS) and its molecular characterization after
isolating the bacteria from the samples of domestic animals and their products during the
period from September 2016 to March 2017 from different areas in Basra city. 200
samples were collected from animals including: 40 samples from meat, 50 samples from
raw milk, 30 samples from treated milk, 40 samples from cow's nasal swabs and 40
samples from cow's teat swabs. Results showed that from 200 collected samples only 108
were CoNS distributed in 22(15.1%), 18(12.4%),10(6.8%), 26(17.9%),32(22%), from
meat, raw milk, treated milk, nasal swabs and teat swabs respectively. Samples were
planted on the selecting mannitol salt medium to isolate Staphylococcus spp. which had
the ability to grow on the mentioned medium. When the coagulation test was performed,
some isolates were not able to produce the coagulation enzyme, and the results showed
that 108 isolates were coagulase negative (54%). Twenty-two isolates of minced meat
55%, 18 isolates of cow's milk (36%), 10 isolates of milk sold (33%), 26 isolates of the
nose of the animal (65%) and 32 isolates of animal teat swabs (80%). Twenty-five
isolates of these negative staphylococci were identified using VITEK 2 kit. The result
showed that 10(40%) isolates identified as coagulase negative Staphylococcus and fall in87
four species including 4 (40%) Staphylococcus lentus, 4 (40%) Staphylococcus
gallinarum, 1 (10%) Staphylococcus haemolyticus, and 1 (10%) Staphylococcus
chromogen. When the ermA, ermB, ermC and msrA genes were investigated by PCR the
result showed that they contain the genes in a percentage 5%, 20%, 20% and 5%
respectively. By using the multiplex PCR molecular weight technique (ermA, ermC) and
(msrA, ermC), the ratio of both genes was 15% and 5% respectively.