Prevalence and antimicrobial susceptibility pattern of coagulase-negative staphylococci (CoNS) isolated from clinical specimens in Northern of Jordan

Background: Coagulase negative Staphylococci (CoNS) are one of the most common bacteria found on human skin and on mucous membranes as a component of normal flora. The presence of CoNS in clinical specimens is frequently associated with an infectious aetiology or contamination. Objectives: We aimed to evaluate CoNS species distribution and susceptibility patterns in specimens obtained from clinics and hospitals in the Northern area of Jordan. Methods: Standard identification methods showed the presence of CoNS in 223 specimens at different local hospitals. Susceptibility testing was performed using 18 antibiotics in accordance with the Clinical and Laboratory Standards Institute (CLSI) recommendations. Results: Staphylococcus epidermidis and S. haemolyticus were found to be the most common species isolated from all specimens representing 122 (54.7%) and 52 (23.4%) of all CoNS species, respectively. Antibiotic susceptibility testing of CoNS species revealed their sensitivity to vancomycin, linozolid, rifampin and nitrofurantin, while showing a highly resistant pattern to ampicillin, penicillin, ceftriaxone, cefazolin, amoxicillin-clavulanic acid and erythromycin. Some variation of the susceptibility pattern of CoNS species were identified in specimens isolated from the ICU and paediatric hospital wards as well as from clinical specimens of urine, blood and catheter tips. Conclusion: The most common CoNS isolates were found to be S. epidermidis and S. haemolyticus with variable percentages according to the specimen source. Moreover, a high susceptibility CoNS to vancomycin, rifampin, and linezolid showed resistance to amoxicillin and penicillin.