Surgical Site Infections Related to ESBL Pathogens Post Colon Surgery

The article by Kalakouti et al¹ from April 2018 underlines the concern about surgical site infections (SSIs) related to colorectal surgery. The authors report an overall 21% rate of SSIs (19% among elective procedures), of which 38% were related to extended-spectrum β-lactamase (ESBL) pathogens.¹ These SSI figures are similar to rates observed in a number of Spanish centers reporting data to a regional surveillance program,² which seems to be improved after a bundle of measures has been implemented.

Our institution, Hospital de Terrassa (Terrassa, Barcelona, Spain), reported a SSI rate of 7% in the patients undergoing elective colorectal surgery during the period of 2015 to 2017 by using a bundle that includes mechanical bowel preparation, oral antibiotic prophylaxis with rifaximin, intravenous antibiotic prophylaxis with amoxicillin-clavulanic acid, and a double ring 360º plastic wound retractor. Twelve SSIs were documented, according to the US Centers for Disease Control and Prevention criteria, in 176 elective patients. Twenty-two germs were isolated, mainly being Enterobacteriaceae; Escherichia coli was the most frequent germ as in the commented paper.¹ However, no ESBL strains grew from such cultures, whereas 2 cefamicinase-producing E coli and Klebsiella pneumoniae were observed.

The paper by Kalakouti et al¹ raises the unsolved question of preventing SSIs for the highest germ-containing part of the anatomy but only focuses on antibiotic resistance. Even considering the capital importance of such measure, there are other factors related to this topic that are not explained in their article¹ (ie, rate of laparoscopic approach, wound protection, oral antibiotic, control of body temperature and glycemia, skin asepsis), which are constitutive of some recommended bundles. But a determinant issue is the high rate of ESBL obtained in the microbiological samples in striking contrast with our institution’s experience. While the ESBL rate in E coli isolated from intra-abdominal infections was reported to be 16.9% for the UK,³ the rate in Spain in a comparable period of time was 9.5% in nosocomial infections.⁴ Although the samples were not matching, these different rates may indicate a lower incidence of ESBL in our geographical region but could hardly explain the dramatic figures of ESBL shown in the reported paper.¹

Perhaps a more aggressive broad-spectrum antibiotic policy would be responsible for the selection of so many ESBL-positive samples. So, a hypothetical intravenous prophylaxis with an antibiotic covering ESBL strains would help in selecting more multiresistant germs, thus generating a worse situation.

Sincerely,
Luis Oms, PhD
Hospital de Terrassa (Terrassa, Barcelona, Spain)

Author Response

Dear Sir:

Thank you for the comment to our recently published article¹ raising concerns about ESBL-producing pathogens and the threat they present in SSIs and colorectal surgery. Emerging multidrug resistance (MDR) is a public health burden and there is a pressing need to use antibiotics wisely.

It is well established that antimicrobial prophylaxis is highly applicable and beneficial in colorectal surgery,^5-7 provided it is active against the pathogens expected to contaminate the operative site.^8-10 A regimen failing to cover for these bacteria would be deficient in providing prophylactic coverage, negating the use of such regimens. The Scottish Intercollegiate Guidelines Network guidelines⁵ state: “Although it appears self-evident that the antimicrobial agent chosen should be suitable for the organisms likely to be encountered, it is easily forgotten in routine prescribing.”

The focus of our paper¹ was to stress the importance of the evolving microbial profile of SSIs in colorectal surgery and the need for strategies to be continually reviewed and adapted rather than undermine the multitude of preoperative and intra-operative factors that account for development of SSIs in colorectal surgery.

In light of the potential detrimental impact of ESBL infections in colorectal surgery, accounting for local microbiologic epidemiology and resistance patterns could and should allow for improved antibiotic stewardship. The development of antimicrobial resistance is complex at both the patient and population levels¹¹ and there are many drivers. Although good antimicrobial stewardship throughout the hospital and at the time of prophylaxis is important in comprehensively minimizing resistance, ignoring the local prevalence of ESBL carriage when constructing antibiotic algorithms is potentially detrimental to patient outcomes.

A surveillance and outbreak report published by a French MDR study group¹² for the period of 2009 to 2013 showed nationwide regional variation in ESBL rates, with an overall upward trend. The incidence was particularly high in regions such as Paris and Lyon. Proposed reasons for the observation included proximity to national borders, large university hospitals, airports, migration, and repatriations from countries with high carriage of multiresistant organisms.¹² Similarly, our institution (Chelsea and Westminster Hospital, London, UK) is placed in the heart of the most multicultural city in Europe, and our tertiary colorectal service cares for an ethnically diverse population, possibly contributing to the higher rates of ESBL carriage.^13-16

Antimicrobial stewardship along with the application of care bundles are essential to the success of infection prevention and control. We congratulate the authors of the letter for their results and for drawing attention to a topic that has been neglected for many years. The need for a proactive attitude and awareness of the changing local bacterial epidemiology and resistance profiles are essential to tackling SSIs in colorectal surgery.

Surgical site infections are a sobering reality and need an integrated and intelligent approach, coupled with strategies that prevent antibiotic resistance, improve patient outcomes and safety, continually review any unintended consequences, and ensure sustained success.

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

References

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