Characteristics of Surgical Site Infection Following Colorectal Surgery in a Tertiary Center

Extended-Spectrum beta-Lactamase-Producing Bacteria Culprits in Disease

Eliana Kalakouti, MD; Constantinos Simillis, MD; Gianluca Pellino, MD; Nabeela Mughal, MD; Oliver Warren, MD; Sarah Mills, MD; Emile Tan, MD; Christos Kontovounisios, MD; Paris P. Tekkis, MD


Wounds. 2018;30(4):108-113. 

In This Article

Abstract and Introduction


Introduction. Surgical site infection (SSI) is a well-known complication of colorectal surgery associated with increased morbidity and hospital stay. Antimicrobial prophylaxis can reduce the risk of SSI by as much as 75%. Extended-spectrum β-lactamase (ESBL)-producing pathogens make the successful use of such prophylaxis a challenge and are a real threat to patient care following colorectal surgery.

Objective. The aim of this study is to report the common characteristics of SSIs after colorectal surgery and to highlight the prevalence, risk factors, and clinical relevance of ESBL infections among these patients in a tertiary center.

Materials and Methods. All patients who underwent bowel resection operation (ie, laparoscopy, laparotomy, or laparoscopic-assisted colectomy) for benign or malignant colorectal disease were identified retrospectively from the prospective database of the colorectal department in the authors' tertiary center from March 2015 to March 2016.

Results. There were 123 patients included in this study, of which 21% (n = 26) had a SSI. The microorganisms isolated in the surgical sites included Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, Proteus mirabilis, Morganella morganii, and Enterobacter cloacae. Thirty-eight percent of the wound infections grew ESBL-producing pathogens in their wound cultures and 62% grew non-ESBL microbes.

Conclusions. More than one-third of the wound infections were due to ESBL-producing pathogens, which were resistant to the antibiotic prophylaxis given. Inappropriate antibiotic usage can delay postoperative recovery. High-risk patients for ESBL colonization may benefit from preoperative screening based on an established protocol. The cost effectiveness of an ESBL screening program needs to be further studied.


Surgical site infection (SSI) is a common complication after colorectal surgery, with a reported incidence ranging from 3% to 30%[1–3] and up to 40% in the absence of antibiotics.[4] It has been significantly and independently associated with increased length of inpatient stay, morbidity, and cost.[5] In an era of enhanced recovery, early recognition and prompt treatment of SSIs should be at the forefront of medical care for patient safety and cost effectiveness of treatment.

Introduction of prophylactic antibiotics in 1940 marked an important cornerstone in the delivery of safer surgical care. Colorectal surgery is especially prone to surgical wound infections due to the nature of visceral handling intra-operatively and dissemination of microorganisms from bowel contents. Antibiotic prophylaxis refers to the use of antimicrobials before or during surgery to suppress the growth of contaminating microorganisms, thus reducing the risk of infection.[6,7]

A meta-analysis including 182 trials and 50 different antibiotics published in the Cochrane Library of Systematic Reviews[8] revealed up to a 75% reduction in the risk of surgical wound infection after colorectal surgery with prophylactic antibiotics when compared with no treatment/placebo. This assumes that the antibiotics used provide adequate cover of the expected pathogens and account for the local microbiologic epidemiology.[9,10]

Since the introduction of preoperative prophylaxis 7 decades ago,[11] resistance to widely used antibiotics has become a sobering health burden to 21st century health care systems and providers. The emergence of extended-spectrum β-lactamases (ESBLs) appears to be a cardinal mechanism accountable for the resistance to widely used antibiotics.[12]

The ESBLs are enzymes produced by bacteria, found mainly among Enterobacteriacaea, which hydrolyse β-lactams (extended-spectrum penicillins, third-generation cephalosporins, and monobactams) conferring broad antibiotic resistance.[13,14] They often show cross-resistance to many other classes of antibiotics, further limiting treatment options. The enzymes are carried in plasmids capable of transferring to other strains and species of bacteria, allowing for resistance to spread rapidly.

It is of the utmost importance that an infection secondary to ESBL-producing organisms is prevented and well contained. The aim of this study is to report the common characteristics of SSIs after colorectal surgery and to highlight the prevalence, risk factors, and clinical relevance of ESBL infections among these patients in a tertiary center.