In vitro comparison of efficacy of triclosan coated & uncoated sutures against the bacteria isolated from SSI at tertiary care hospital, Aurangabad

Most common Health Care Associated Infections (HAI) are Urinary tract infection (UTI) – 33%, Pneumonia – 15%, Surgical Site Infections (SSI) – 15%, Blood stream infections – 13%, & other miscellaneous infections – 24%. SSI is defined as infection at the surgical site that occurs within 30 days of the surgical procedure or within one year – if there is an implant or foreign body such as prosthetic heart valve or joint prosthesis. Wound infections are always multifactorial. Risk factors for SSI include co-morbidity, malnutrition, nicotine, suture and implanted foreign material. SSI increases morbidity & mortality in post surgical patients, & also increases hospital stay, it affects quality of life and increases financial burden to healthcare system. It may lead to major complications such as sepsis and death. Patient related risk factors are smoking, obesity and diabetes. Skin preparation with antiseptic and preoperative antibiotic prophylaxis for clean-contaminated and contaminated surgery have proved efficient for decreasing SSI. Sutures in contaminated tissues may enhance penetration of micro organisms in deeper tissues & biofilm formation and this may protect organisms from host defence mechanism. One of the risk factors is the foreign material which includes suture. Commonly isolated pathogens from SSI are Staphylococcus aureus, CONS, Enterococcus species, E.coli & resistant pathogens like MRSA & candida (due to widespread use of broad spectrum anti-microbial agents.) In this study we have compared in vitro efficacy of triclosan coated polyglactin 910 suture with non – coated sutures against common bacteria isolated from SSI. Materials and Methods: We have randomly selected the strains of MRSA, MRCONS, Staphylococcus hemolyticus, E. Coli, Klebsiella, & Acinetobacter species isolated from clinical samples of SSI. These isolates were tested against triclosan coated & non coated sutures which are commercially available. Similar length of (4cm) of sutures cut & tested for zone of inhibition on lawn culture made on Muller Hinton Agar (MHA) by using 0.5 McFarland standard of above strains by touching 4 to 5 colonies of each bacterium. It is incubated overnight at 370C & examined for zone of inhibition. Results: zone of inhibition of coated & uncoated sutures has been measured & compared for each strain. Conclusion: In vitro, triclosan coated sutures showed good antibacterial activity than non coated sutures & hence triclosan coated sutures may help in reducing bacterial SSI rate and thus reduce cost & duration of hospital stay for the patient. © 2020 Published by Innovative Publication. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by/4.0/)


Introduction
Most common Health Care Associated Infections (HAI) are Urinary tract infection (UTI) -33%, Pneumonia -15%, Surgical Site Infections (SSI) -15%, Blood stream infections -13%, & other miscellaneous infections -24%. 1 it affects quality of life and increases financial burden to healthcare system. [7][8][9][10] it may lead to major complications such as sepsis and death. 11 Patient related risk factors are smoking, obesity and diabetes. 10,[12][13][14] Skin preparation with antiseptic and preoperative antibiotic prophylaxis for clean-contaminated and contaminated surgery have proved efficient for decreasing SSI. 15 SSI, It's diagnosis consist of the infection with manifestations of pain, oedema, tenderness, redness, dehiscence, or positive culture from material or pus from surgical site. SSI are classified into superficial incisional SSI, deep incisional SSI, & organ/space SSI. 16 Triclosan coated sutures reduce the colonization of bacteria 7 & biofilm formation on suture material. 17 Sutures in contaminated tissues may enhance penetration of micro organisms in deeper tissues & biofilm formation and this may protect organisms from host defence mechanism. 3,18,19 One of the risk factors is the foreign material which includes suture. 16 11 Triclosan (2,4,4'-tricloro-2'-hydroxydiphenyl ether) is a broad spectrum biocide, non specifically disrupting the bacterial cell membrane, targeting the Fab I gene which blocks the bacterial fatty acid synthesis through the action of enzyme enoyl-acyl carrier protein reductase (ENR). 3 The triclosan is an antiseptic & not an antibiotic hence the risk of resistance is very low. 3 Various studies have been conducted & stated that toxicity due to triclosan are considered low & it showed highly significant results in lowering risk of SSI. 11,21 Triclosan having antimicrobial activity against Gram positive & Gram negative bacteria but less activity against P. aeroginosa. 16 In this study we compared in vitro efficacy of triclosan coated polyglactin 910 suture with non -coated suture against common bacteria isolated from SSI.

Aims and Objectives
To compare in vitro efficacy of triclosan coated polyglactin 910 sutures with uncoated sutures against organisms isolated from SSI.

Inclusion criteria
All samples received for culture & sensitivity from surgical sites within given period.

Exclusion criteria
All isolates other than surgical site infections.
The study was carried out at Department of Microbiology, MGM Medical College & Hospital Aurangabad, Maharashtra from 2 nd June 2017 to 2 nd July 2017. In this period there were total 15 samples of SSI, out of these 09 samples were positive for bacterial isolates & 06 samples were sterile.

In -Vitro testing of Triclosan coated & uncoated sutures against the bacteria isolated from SSI
We have randomly taken the strains of MRSA, MRCONS, Staphylococcus hemolyticus, E. Coli, Klebsiella, & Acinetobacter species isolated from clinical samples of SSI & these strains were tested against triclosan coated & non coated sutures which are commercially available (Ethicon). Lawn culture of isolated organisms were made on Muller Hinton Agar (MHA) plates by using 0.5 McFarland standard (corresponds to 1.5 x 10 8 bacteria/ml) 7 of above strains by touching 4 to 5 colonies of each bacterium. 16 Similar length of (4cm) of triclosan coated & non coated sutures cut with aseptic precautions & placed on half of inoculated plates each. 1 It is incubated overnight at 37 0 C & examined for zone of inhibition after 48 hr. 16 Zone of inhibition were measured perpendicular to mid-point of suture material in millimetre. 7

In -Vitro testing of triclosan coated & uncoated sutures against the bacteria isolated from SSI
Each bacterium, was tested against triclosan coated & uncoated suture. The zone of inhibition around triclosan coated & uncoated sutures were measured. Wide zone

Conclusion
In vitro antibacterial efficacy of Triclosan coated polyglactin 910 sutures is sufficient to inhibit or reduce the in vitro colonization of the suture materials by MRCONS, Acinetobacter baumanii, MRSA, Staphylococcus hemolyticus, Enterobacter cloaceae complex, E.coli, & Klebsiella pnemoniae compared to uncoated suture materials.

Limitations
The study has to be done on large number of samples for longer periods for comparison.

Acknowledgements
We would like to thank Ethicon (Johnson-Johnson) company for supply of triclosan sutures (Vicryl plus) and plain non coated suture material (Polyglactin 910 violet).
We would also like to thank Dean Sir and Department of surgery for supporting the study.

Source of Funding
None.

Conflict of Interest
None.