Biochemical characterization and antibiotic susceptibility of coagulase negative staphylococci isolates from exudates and body fluids
Coagulase negative Staphylococci (CoNS) are increasingly being recognized as significant nosocomial pathogens, partly due to the growing appreciation of this group of organisms as opportunistic pathogens or due to increase in the use of transient or permanent medical devices in seriously ill and immunocompromised patients. Aims & Objectives : 1. Isolation of CoNS from exudates and body fluids. 2. Biochemical characterization of CoNS 3. Antibiotic susceptibility pattern of CoNS. Method: 180 CoNS isolated from various exudates and body fluids such as Pus, Wound Swabs, Endotrachial Secretions, Sputum, Branchial Aspitate, Central Lining Tube were collected. All the CoNS isolates were processed in the Microbiology laboratory and identified by colony morphology, Gram staining, Catalase, slide, tube coagulase test, anaerobic acid from mannitol, Deoxyribonuclease.Bacitracin (0.04 U) and furazolidone (100 µg) susceptibilities were done to exclude Micrococcus and Stomatococcus spp. The following biochemical tests were done for the speciation of the CoNS: Urease test, Phosphatase test, Polymyxin B disc test, Novobiocin Disk Test, Ornithine decorboxylase test, Mannitol to acid, voges-proskauer test, Mannose fermentation, Trehalose fermentationand Antibiotic susceptibility testing.Result: Out of 180 isolates, 78 are S.epidermidis (43.3%), 63 are S.hemolyticus (35%), 21 are S.hominis (11.6%), 18 are S.lugdunensis (10.0%). Maximum number of CoNS were isolated from pus specimens (58.33%), followed by wound swabs (18.33%). 164 out of 180 strains were negative for both bound and free coagulase. 60 strains were bound coagulase slow positive and free coagulase negative. S. epidermidis was the most frequent isolate and 68 S. epidermidis isolates were identified if Ornithine decorboxylase was considered positive, while negative ten S. epidermidis isolates required inclusion of trehalose and mannitol for speciation. Antibiotic susceptibility testing showed maximum resistance to penicillin (78.3) followed by Chloramphenicol (41.6%). No resistance to vancomycin was seen. Conclusion: The study revealed S. epidermidis is the predominant CoNS from Endotracheal secretions and also pus samples. S.hemolyticus was isolated from pus and central lining tubes, S.hominis and S.lugdunensis were isolated mainly from wound swabs. The present study suggests; if Coagulase -ve Staphylococci are repeatedly isolated from patients with infection they should be taken seriously and ABST done on these isolates for proper diagnosis and treatment especially in nosocomial infections.Keywords: Coagulase negative staphylococci, Antibiotic susceptibility, Clinical isolates of Exudates and body fluids, Biochemical Chemical characterization
Goyal R, Singh NP, Kumar A, Kaur I, Singh M, Sunita N, Mathur M. Simple and economical method for speciation and resistotyping of clinically significant Coagulase negative staphylococci. Indian J Med Microbiol 2006; 24: 201 – 04
Kloos WE, Bannerman TL. Update on clinical significance of coagulase negative Staphylococci. Clin Microbiol Rev 1994; 7 :117-40
Goel MM, Singh AV, Mathur SK, Singh M, Singhal S, Chaturvedi UC. Resistant coagulase negative Staphylococci from clinical samples. Indian J Med Res 1991; 93 :350-2
Ieven M, Verhoeven J, Pattyn SR, Goossens H. Rapid and economical method for species identification of clinically significant Coagulase negative Staphylococci. J Clin Microbiol 1995; 33 :1060-3
Archer GL, Climo MW. Antimicrobial susceptibility of coagulase negative Staphylococci. Antimicrobial Agents Chemother 1994; 38: 2231-7.
U Mohan, N Jindal, P Aggarwal. Species distribution and antibiotic sensitivity pattern of Coagulase negative Staphylococci isolated from various clinical specimens. Indian J Med Microbiol 2002; 20: 45 – 6
NC Bodonaik, S Moonah. Coagulase negative staphylococci from blood culture contaminants or pathogens. West Indian med. J June 2006; 55(3)
Archer GL, Climo MW. Staphylococcus epidermidis and other coagulase negative staphylococci. In Mandel GL, Bennett JE, Dolin R eds. Principles and practice of Infectious Diseases. Philadelphia. Elsevier Churchill Livingston, 2005: 2352–62.
Edmond MB, Wallace SE, McClish DK, Pfaller MA, Jones RN and Wenzel RP. Nosocomial bloodstream infections in United States hospitals: a three-year analysis. Clin Infect Dis 1999; 29: 239–44.
Wisplinghoff H, Bischoff T, Tallent SM, Seifert H, Wenzel RP, Edmond MB. Nosocomial bloodstream infections in US hospitals: Analysis of 24,179 cases from a prospective nationwide surveillance study. Clin Infect Dis 2004; 39 309–17.
Carmen Betriu, Montserrat Redondo, Ana Boloix, Maria Gomez, Esther Culebras and Juan J.Picazo. Comparative activity of linezolid and other new agents against Methicillin- resistant Staphylococcus aureus and teicoplanin intermediate coagulase negative Staphylococci. Journal of antimicrobial Chemotherapy 2001; 48: 911-13.
Staphylococcus, Micrococcus, and similar organisms. Betty A.Forbes, Daniel F.Sahm, Alie S.Weissfeld. Bailey & scotts diagnostic microbiology 12th edition, International. Mosby Elsevier, 2007; 254-64
Winn WC, Allen SD, Janda WM, Koneman EW, Procop GW, Schreckenberger PC, Woods GL. Koneman’s Color Atlas and Textbook of Diagnostic Microbiology. 6th ed. Philadelphia, Lippincott Williams & Wilkins, 2006;1443–71.
Collee Ja, marmion B P, Fraser Ag, Simmons Antony Mackie & McCartney practical medical microbiology 14th edition. India Churchill Livingstone, 2006; 245- 58
Performance Standards For Antimicrobial disc susceptibility tests; Approved Standard-Eleventh Edition Clinical and Laboratory Standards Institute; International organization of Standardization Technical Committee 212 approved and draft standards. http://clsi.org/standards/micro/ M02-A11;Vol 32 No.1;January 2012. Page 1-76.
Shubhra singh, Gopa Banerjee, S.K. Agarwal, Mala Kumar, R.K.Singh. Simple method for speciation of clinically significant CoNS and its antibiotic sensitivity/resistant pattern in NICU of tertiary care centre. Biomedical Research 2008-05 - 2008-08: 19(2);
Gaikwad SS, Deodhar LP. Study of coagulase-negative Staphylococci in clinical infection.J PostgradMed. 1983; 29:162-64,(1983).
Yoshiaki Kawamura, Xiao-Gang Hou, Ferdousi Sultana, Kenji Hirose, Masaki Miyake, Sin-Ei Shu, and Takayuki Ezaki. Distribution of Staphylococcus Species among Human Clinical Specimens and Emended Description of Staphylococcus caprae. J Clin Microbiol.1998 July; 36(7):2038-2042.
This work is licensed under a Creative Commons Attribution 3.0 License.
Print ISSN: 2347-6192
Online ISSN: 2347-6206