Prevelence of Methicillin-Resistant Staphylococcus Aureus (MRSA)‎in layer chickens with reference to its ability to form biofilm and enterotoxins

الملخص EN

This study was done on 100 pooled samples obtained from layer chickens with symptoms of arthritis and decreased egg production in Assuit Governorate, Egypt.

A total of 37 Staphylococcal isolates were recovered, of which 21 (56.8%) were identified as coagulase positive staphylococci (CoPS) and 16 (43.2%) were identified as coagulase negative staphylococci (CoNS).

Sensitivity test of CoPS isolates was performed against 10 common antibiotics.

The results showed that all the tested isolates were resistant to amoxicillin, cefoxitin, and methicillin, while all were sensitive to vancomycin and tylosin.

By using Congo Red Agar (CRA) method, 76.2 % of 21 CoPS were positive for biofilm production with variable degrees.

A total of 12 randomly chosen CoPS were screened by multiplex PCR targeting the 16S rRNA, nuc and mecA genes to discriminate strains and to detect methicillin resistant strains (MRSA).

Moreover, multiplex PCR assay targeting some Staphylococcal enterotoxin genes (SEs) and double uniplex PCR assays for detection of biofilm related genes (icaA and icaD) were used.

The 12 isolates were confirmed as S.

aureus.

Out of the 12 S.

aureus strains, 11 were mecA gene positive while one isolate was mecA negative.

Considering biofilm related genes, icaD gene was detected in 8 of11 S.aureus strains, while icaA gene was found in one strain only.

One strain harbored both icaA and icaD genes.

All the 11 mecA positive S.aureus strains harbored one enterotoxin gene at least.

Our results indicated that poultry methicillin resistant S.

aureus isolates are likely to be enterotoxigenic and biofilm producers.

So, attention must be directed toward implementation of new methods for effective control and treatment of such infections in poultry farms.