Molecular Detection of Antibiotic Resistance Genes in Identified Coagulase Negative Staphylococci from Chickens Flocks and Hatcheries in Egypt

Results of isolation from chicken flocks with clinical signs are 9/13(69.23%) were positive. Positive samples (11/354, 3.11%) including : 3liver, 4 kidney, 2 intestine, 1 air sac and 1 nasal sinus. Out of apparent healthy flocks 8/21 (38.95%) were positive. Positive samples (15/ 588, 2.55%) including 3 liver, 2 kidney, 4 intestine, 3 lung, 2 air sac and 1 nasal sinus. Results showed that 15 positive flocks out of 34 flocks (34.09%) with 26 Staphylococcus isolates from 942 samples (2.77%) including 6 liver, 6 kidney, 6 intestine, 4 lung, 2 air-sacs and 2 nasal sinus with rate of 3.82%, 3.82%, 3.82%, 2.55%, 1.27% and 1.27%; respectively. Also12 isolates out of 26 (46.15%) were CoNS include 8 S. xylosus (75 %), 2 S. scuiri (16.67%) and 2 S. lentus (16.67%). Hatchery samples reveals the isolation of 26 staphylococcus isolates (11.76%). The tested 108 fertile eggs and dead in shell embryos resulted in 14 and 12 isolates in rate of 12.96% and 13.79%; respectively. Ten isolates were CoNS (38.46%) and represented 4.52% out of total samples including 8 S. xylosus and 2 S. scuiri. Eight S. xylosus was 6 (5.55%) from infertile eggs and 2 (2.29 %) from dead in shell, While the 2 S. scuiri (1.85%) were obtained from infertile eggs. The tested CoNS isolates showed 100% resistance to Oxytetracycline 30 μg/ml (T30), Trimethoprime + Sulphamethexole 2.25/23.75 μg/ml (SXT) , Calindamycin 2 μg/ml (DA) and Oxacillin 30 μg/ml (OX). All isolates were 100% susceptible to Vancomycin 30 μg/ml (VA) and 90% susceptibility to Enrofloxacin 5 μg/ml (ENR). Multidrug resistance was detected in form of resistance to 9, 4 and 5 out of tested 13 antibiotics in 2 S.lentus , 5 S. scuiri and 15 S. xylosis; respectively. Ten isolates were tested for the presence of 7 resistance gens including: mecA , tetK, blaZ , kan , ermC, icaD, bab gene. Seven isolates from the tested 10 (70%) having 4 resistance gens. The most detected gens are mecA tetK, blaZ and ermC where it was detected in 90, 80, 60 and 90% respectively. Kan , icaD and bab gens were detected in rate of 30.0 and 0 %; respectively. In conclusion: CoNS could isolated from healthy and diseased chicken flocks as well as from chicken hatchery. The obtained isolates were multidrug either phenotypic and /or genotypic resistant. Good hygienic measures in both chicken farms and hatchery with monitoring of drug resistance of CoNS those act as source for resistance genes to bacterial pathogens and their importance to the poultry and public health are recommended.