Staphylococcus chromogenes as a cause of sequential mastitis episodes in a camel (Camelus dromedarius)

Staphylococcus chromogenes is a coagulase-negative Staphylococci, reported to cause mastitis in cows and other dairy animals. This report describes sequential mastitis episodes caused by S. chromogenes in a single-hump camel from Rajasthan, India. One six-year-old Mewari she camel in second lactation showed two episodes of mastitis. S. chromogenes was isolated during both episodes from affected udder quarters. The isolate from second episode was later evaluated which was catalase-positive, coagulase-negative, non-hemolytic, and positive for arginine dihydrolase 1, had ability of L-lactate alkalinisation and grow in 6.5% NaCl; but negative for phosphatase and urease test. The isolate was found sensitive to a range of antibiotics. Phylogenetic analysis using 16 S rDNA sequences revealed that the isolate had close genetic relationship with the isolates from bovine mastitis from South Africa and Turkey. However, S. borealis and S. haemolyticus isolated from earlier cases of subclinical mastitis from the same camel herd formed a separate cluster. These findings suggest that S. chromogenes may represent a potential causative agent of mastitis in dromedary camels, highlighting the need for further investigations involving a larger number of animals to confirm its role in the disease.