Speciation of clinically significant coagulase negative staphylococci and their antibiotic resistant patterns in a tertiary care hospital
Keywords:
Coagulase negative Staphylococci, Microbiota, Immunocompromised, Antibiotic susceptibility, Disk diffusion method, Ornithine decarboxylaseAbstract
Background: Coagulase negative Staphylococci (CONS) are normal human microbiota and sometimes cause infections, often associated with implanted devices, such as joint prosthesis, shunts and intravascular catheters, especially in very young, old and immunocompromised patients. These infections are difficult to treat because of the risk factors and the multiple drug resistant nature of the organisms. The study is undertaken to speculate CONS isolates from various clinical samples and to determine antibiotic susceptibility pattern of CONS by Kirby Bauer disc diffusion method.
Methods: A total of 134 clinically significant CONS isolated from pus, urine, blood, fluid, sputum, ear swabs, endotracheal tube, ophthalmic, semen and nail samples. These isolates initially identified by colony morphology, Gram staining, catalase test, slide coagulase test, tube coagulase test and mannitol fermentation.Speciation of CONS was done by novobiocin resistance test, urease activity, ornithine decarboxylase and aerobic acid production from mannose.
Results: S. epidermidis is the most frequent isolate 62 (46.3%) followed by S. saprophyticus 38(28.4%), S. haemolyticus 27(20.1%), S. lugdunensis 3(2.2%). S. warneri 3(2.2%), S. cohinii 1(0.7%). Antibiotic susceptibility testing of the isolates showed maximum resistance to penicillin 128 (95.5%) and ampicillin118 (88%) followed by erythromycin 96 (71.6%), cefoxitin 89 (66.4%), gentamicin 33(24.6%), piperacillin & tazobactam 31(23.8%), amoxicillin & clavulanic acid 25 (18.7%), linezolid 23 (17.2%), levofloxacin 9 (6.7%), vancomycin & teicoplanin 2 (1.5%), tigecycline 1 (0.7%).
Conclusion: S. epidermidis is the more common isolate identified and CONS are often resistant to multiple antibiotics (Penicillin, ampicillin) & glycopeptides have been considered as the drugs of choice for the management of infections caused by these organisms.
References
Geo. F. Brooks, Karen C. Carroll, Stephen A. Morse, Timothy A. Mietzner. Coagulase negative Staphylococci. In: Geo F. Brooks, Karen C. Carroll, Stephen A. Morse, Timothy A. Mietzner, eds. Jawetz, Melink & Adelberg’s Medical Microbiology. 26th ed. New York: McGraw Hill Education; 2013: 199-205.
Roth RR, James WD. Microbial ecology of the skin. Annu Rev Microbiol. 1988;42:441-64.
College JG, Fraser AG, Marmion BP, Simmons A. CONS. In: College JG, Fraser AG, Marmion BP, Simmons A, eds. Mackie & Mccartney Practical Microbiology. 19th ed. USA: Elsevier; 2012: 250-252.
Shubhra Singh, Gopa Banerjee, S. K. Agarwal, Anuradha Rajput, Piyush Tripathi, Mala Kumar, et al. Prevalence of MecA Gene positive coagulase negative Staphylococci in NICU of a tertiary care hospital. Biomed Res. 2009;20(2):94-8.
Koneman EW, Allen SD. Identification of bacteria. In: Koneman EW, Allen SD, eds. Colour Atlas and Text Book of Diagnostic Microbiology. 5th ed. Philadelphia: Lippincott-Roven Publishers; 1997: 547-549.
Bannerman TI. Staphylococcus, Micrococcus and other catalase positive coccid that grows aerobically. In: Murray PR, Baron EJ, Jorgensen JH, Pfaller MA, Yolken RH, eds. Manual of Clinical Microbiology. 8th ed. Washington DC: ASM Press; 2003: 384.
De Pauli AN, Predari SC. Five test simple scheme for the species level identification of clinically significant coagulase negative staphylococci. J Clin Microbiol. 2003;41:1219-24.
Baird D. Staphylococcus; cluster forming Gram-positive cocci. In: Colle JG, Fraser AG, Marimom BP, Simmons A, eds. Mackie and McCartney Practical Medical Microbiology. 14th ed. New York: Churchill Living Stone; 1996:245.
Singh S, Banerjee G. Simple method for speciation of clinically significant coagulase negative Staphylococci and its antibiotic sensitive/resistant pattern in NICU of tertiary care centre. Biomed Res. 2008;19(2):97-101.
Ahmad Farajzadeh Sheikh, Manijeh Mehdinejad. Identification and determination of coagulase-negative Staphylococci species and antimicrobial susceptibility pattern of isolates from clinical specimens. Afr J Microbiol Res. 2012 Feb;6(8):1669-74.
Surekha Y. Asangi, Mariraj J, Sathyanarayan MS, Nagabhushan, Rashm. Speciation of clinically significant Coagulase negative Staphylococci and their antibiotic resistant patterns in a tertiary care hospital. Int J Biol Med Res. 2011;2(3):735-9.
Usha MG, Shwetha DC, Vishwanath G. Speciation of coagulase negative Staphylococcal isolates from clinically significant specimens and their antibiogram. Indian J Pathol Microbiol. 2013;56(3):258-60.
Goyal R, Singh NP, Kumar A, Kaur I, Singh M, Sunita N, et al. Simple and economical method for speciation and resist typing of clinically significant coagulase negative staphylococci. Indian J Med Microbiol. 2006;24:201-4.
Sadhvi Parashar. Significance of Coagulase Negative Staphylococci with Special Reference to Species Differentiation and Antibiogram Sadhvi Parashar.
Mohan U, Jindal N, Aggarwal P. Species distribution and antibiotic sensitivity pattern of coagulase negative staphylococci isolated from various clinical specimens. Indian Med Gazette. 2014;CXLVII(7):255-8.
Silvia Natoli, Carla Fontana, Marco Favaro, Alberto Bergamini, Gian Piero Testore, Silvia Minelli, et al. Characterization of coagulase negative staphylococcal isolates from blood with reduced susceptibility to glycopeptides and therapeutic options. J Antimicrob Chemother. 1992;29:459-66.
