Multiplex PCR detection of erythromycin resistance genes in coagulase negative staphylococci isolated from cows in Basrah, Iraq

Abstract EN

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 in 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.