Prevention and surveillance of surgical infections: A review

A Prospective, Blinded, Open-Label Clinical Trial to Assess the Ability of Fluorescent Light Energy to Enhance Wound Healing after Mastectomy in Female Dogs

Mammary gland tumors represent the most frequently diagnosed malignant neoplasm in intact female dogs, and surgical removal represents the current gold standard treatment. To promote wound healing and prevent possible bacterial contamination, perioperative antimicrobials are commonly used in clinical practice, even though there are no publications establishing guidelines for the use of such drugs in canine mastectomy. The aim of the present study was to evaluate the ameliorative effect of fluorescent light energy on the quality of the healing process after mastectomy surgery in female dogs, in the absence of perioperative antimicrobial administration. Nine female dogs received a multiple-gland mastectomy due to gland tumors and received FLE application immediately after surgery and then five days after. The surgical incisions were evaluated by a blind investigator over time using the Modified Hollander Cosmesis and Modified Draize Wound Healing Score systems. Statistical analysis revealed a significant ameliorative effect of FLE in the control of step-off borders, contour irregularities, and excessive distortion. In addition, erythema, edema, and serous discharge were lower for those wounds managed with FLE. These results underscore the advantageous impact of FLE on the healing of post-mastectomy wounds in female dogs, offering the dual benefits of reducing potential infection risks and lessening the home care burden for pet owners.

Antimicrobial prophylaxis in companion animal surgery: A scoping review for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines

Surgical antimicrobial prophylaxis (SAP) is widely used to reduce the risk of surgical site infections (SSI), but there is uncertainty as to what the proportion of SSI reduction is. Therefore, it is difficult for surgeons to properly weigh the costs, risks and benefits for individual patients when deciding on the use of SAP, making it challenging to promote antimicrobial stewardship in primary practice settings. The objective of this study was to map the veterinary evidence focused on assessing the effect of SAP on SSI development and in order to identify surgical procedures with some research evidence and possible knowledge gaps. In October 2021 and December 2022, Scopus, CAB Abstracts, Web of Science Core Collection, Embase and MEDLINE were systematically searched. Double blinded screening of records was performed to identify studies in companion animals that reported on the use of SAP and SSI rates. Comparative data were available from 34 out of 39123 records screened including: eight randomised controlled trials (RCT), 23 cohort studies (seven prospective and 16 retrospective) and three retrospective case series representing 12476 dogs and cats in total. Extracted data described peri- or post-operative SAP in nine, and 25 studies, respectively. In the eight RCTs evaluating SAP in companion animals, surgical procedure coverage was skewed towards orthopaedic stifle surgeries in referral settings and there was large variation in SAP protocols, SSI definitions and follow-up periods. More standardized data collection and agreement of SSI definitions is needed to build stronger evidence for optimized patient care.

Neural dependency in wound healing and regeneration

In response to injury, humans and many other mammals form a fibrous scar that lacks the structure and function of the original tissue, whereas other vertebrate species can spontaneously regenerate damaged tissues and structures. Peripheral nerves have been identified as essential mediators of wound healing and regeneration in both mammalian and nonmammalian systems, interacting with the milieu of cells and biochemical signals present in the post-injury microenvironment. This review examines the diverse functions of peripheral nerves in tissue repair and regeneration, specifically during the processes of wound healing, blastema formation, and organ repair. We compare available evidence in mammalian and nonmammalian models, identifying critical nerve-mediated mechanisms for regeneration and providing future perspectives toward integrating these mechanisms into a therapeutic framework to promote regeneration.

Evaluation of a client questionnaire at diagnosing surgical site infections in an active surveillance system

OBJECTIVE

To report sensitivity, specificity, predictive values and accuracy of a client questionnaire at diagnosing surgical site infections (SSIs) and describe the impact of active surveillance on SSI detection.

STUDY DESIGN

Prospective, cohort study.

ANIMALS

Dogs and cats undergoing soft tissue or orthopedic surgery over a 12-month period at a referral hospital.

METHODS

Clients were emailed a questionnaire 30 days postoperatively, or 90 days where an implant was used. Three algorithms were developed to diagnose SSIs using one or both of two criteria: (1) presence of any wound healing problems; (2) wound dehiscence or antibiotic prescription, and either purulent discharge or two or more clinical signs (redness, pain, heat, swelling, discharge). Algorithmic diagnoses were compared to gold standard diagnoses made by veterinarians.

RESULTS

Of 754 surgical procedures, 309 responses were completed with 173 corresponding gold standard diagnoses. The most accurate algorithm determined "SSI" or "No SSI" from 90.2% of responses with 95.5% (92.4-98.6) accuracy, 82.6% (77-88.3) sensitivity, 97.7% (95.5-100) specificity, 86.4% (81.2-91.5) positive predictive value, and 97% (94.5-99.6) negative predictive value. "No SSI" was diagnosed in responses not meeting criterion 1, and "SSI" in responses meeting criteria 1 and 2. "Inconclusive" responses, comprising 9.8% of responses, met criterion 1 but not 2. Overall SSI rate was 62/754 (8.2%) and 12/62 (19.4%) SSIs were detected by active surveillance only.

CONCLUSION

Use of this client questionnaire accurately diagnosed SSIs; active surveillance increased SSI detection.

CLINICAL SIGNIFICANCE

Surveillance of SSIs should be active and can be simplified by using a client questionnaire and algorithmic diagnoses, allowing automated distribution, data collection and analysis.

Protocol for a systematic review of good surgical practice guidelines for experimental rodent surgery

Objective

Surgery is an integral part of many experimental studies. Aseptic and minimal invasive surgical technique and optimal perioperative and post-operative care are prerequisites to achieve surgical success and best possible animal welfare outcomes. Good surgical practice cannot only improve the animal’s postoperative recovery, but also study outcome and validity. There seems to be a lack of implementation of good surgical practice during rodent surgery. The aim of this systematic review is to identify, critically evaluate and compare the currently recommended standards and underlying guidelines for rodent surgery—and finally to compile a comprehensive guideline of good surgical practice for rodent surgery.

Search strategy

PubMed, Embase and Web of Science were searched to identify guidelines published in peer-reviewed journals. To identify grey literature and unpublished guidelines, we will perform a Google search for published guidelines and search laboratory animal sciences books for relevant book chapters. Additionally, we will conduct a survey among animal researchers enquiring about the guidelines they use.

Screening and study selection

For publications retrieved by the systematic search, unique references are screened by two reviewers, first for eligibility based on title and abstract and subsequently for final inclusion based on full text. Eligibility of books is based on title and content, final inclusion based on chapter full text. Guidelines are either retrieved by Google searches or a survey. Google searches will be conducted by at least four of the authors. Thereafter, guidelines will be screened by two of the authors.

Data extraction and synthesis

We will extract data from publications, book chapters and guidelines. Based on the extracted data, we will perform a descriptive synthesis of the bibliographical details, guideline development and endorsement, and the prevalence of individual recommendations, including subgroup analysis of the guidance per continent or country and differences between peer-reviewed versus non-peer-reviewed guidance.

Multidrug-resistant bacteria isolated from surgical site of dogs, surgeon's hands and operating room in a veterinary teaching hospital in Brazil

Surgical environment can play as a source of multidrug-resistance organism, what can pose as a big threat to the patients and health care professionals. This study aimed to evaluate the prevalence and antimicrobial resistance profile of Gram-positive cocci (GPC) and Gram-negative bacilli (GNB) isolated from the surgical environment. All samples were collected during the intraoperative period of clean/clean-contaminated (G1) and contaminated (G2) surgery. A total of 150 samples were collected from the superficial surgical site in the beginning (n=30) and the end (n=30) of the procedure, surgeon's hands before (n=30) and after (n=30) antisepsis, and the surgical environment (n=30). MALDI-TOF MS and antimicrobial susceptibility testing by disk diffusion method were performed for species identification, and determination of the resistance profile. Sixty-eight isolates of GPC and 15 of GNB were obtained. Staphylococcus spp. were the most frequent species isolated from surgical site (55.26% [21/38]), surgeon's hands (46.15% [6/13]), and environment (56.67% [17/30]). GPC were mostly resistance to penicillin (85.71% [54/63]), and erythromycin (77.78% [49/63]), and GNB were mostly resistance to cefazolin (58.33% [7/12]), and azithromycin (58.33% [7/12]). High incidence of multidrug resistance was observed in coagulase-negative staphylococci (86.21% [25/29]), coagulase-positive staphylococci (86.67% [13/15]), Enterococcus spp. (68.42% [13/19]) and Gram-negative bacilli (60% [9/15]). The high rate of resistance of commensal bacteria found in our study is worrying. Coagulase-negative staphylococci are community pathogens related to nosocomial infections in human and veterinary hospitals, their presence in healthy patients and in veterinary professionals represent an important source of infection in the one health context. Continuous surveillance and application of antimicrobial stewardship programs are essential in the fight against this threat.

Contamination by antimicrobial-resistant enterobacteria isolated from cell phones and hands in a veterinary hospital

Hospital infections are of great relevance in human and animal health, and fomites are important in the spread of pathogens in hospital units. The aim of this study was to investigate the frequency of enterobacteria in the operating room of a veterinary hospital, the potential cross-contamination of samples, and to characterise the susceptibility profile of the isolates to antimicrobials. Sixty-five samples were collected from five different surgical procedures. These samples came from the hands and cell phones of the surgical team and pet owners, operating tables, and patients. Species detection was performed through polymerase chain reaction, genetic diversity by pulsed-field gel electrophoresis (PFGE), and susceptibility to antimicrobials through an antibiogram. Escherichia coli and Proteus mirabilis isolates were obtained from eight samples, from the hands of the anaesthesiologist, the pet owner, and the surgeon; the surgeon's, the nurse's and the anaesthesiologist's cell phones, and two surgical tables. Furthermore, PFGE showed high genetic diversity among the isolates, which showed multidrug resistance. The identification of multidrug-resistant E. coli and P. mirabilis on cell phones of the surgical team is a major concern and, although no direct correlation was found, the isolation of these bacteria inside the clean area of the operating room shows the possibility of nosocomial transmission from cell phones to susceptible patients.

Effect of ultraviolet-C light on the environmental bacterial bioburden in various veterinary facilities

OBJECTIVE

To determine the effect of a mobile UV-C disinfection device on the environmental bacterial bioburden in veterinary facilities.

SAMPLES

40 swab samples of surfaces from the operating theaters of 3 veterinary hospitals and 1 necropsy laboratory.

PROCEDURES

Various surfaces were swabbed, and collected material was eluted from the swabs in PBSS. Then, an aliquot of the sample fluid was processed with a bacteria-specific rapid metabolic assay to quantify bacterial bioburden. Each site was then treated with UV-C light with an automated disinfection device for approximately 45 minutes. The same surfaces were swabbed following UV-C treatment, and bioburden was quantified. The bioburden at additional time points, including after a second UV-C treatment, was determined for the small animal operating theater.

RESULTS

All surfaces at all sites had a persistent viable bacterial population following manual cleaning. Disinfection with UV-C achieved a mean bioburden reduction of 94% (SD, 5.2%; range, 91% to 95%) for all surfaces, compared with manual disinfection alone. Repeated UV-C treatment of the small animal operating theater reduced mean bioburden by 99% (SD, 0.8%), including no detectable bacteria on 4 of 10 surfaces.

CONCLUSIONS AND CLINICAL RELEVANCE

Disinfection with UV-C light may be a beneficial adjunct method for terminal disinfection of veterinary operating theaters to reduce environmental bioburden. (Am J Vet Res 2021;82:582-588).

Microorganisms associated with incisional infections after gastrointestinal surgery in dogs and cats

OBJECTIVE

To determine the rate of incisional infections after gastrointestinal surgery in dogs and cats and describe the aerobic bacteria isolated from these infections.

STUDY DESIGN

Retrospective study.

ANIMALS

Client-owned dogs (n = 210) and cats (n = 66).

METHODS

Records of dogs and cats that underwent gastrointestinal surgery at the Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania were reviewed for surgical procedures, presence of an infection, bacterial species isolated, perioperative antimicrobials administered, and outcome.

RESULTS

The median duration of follow-up was 14 days (4-35). Incisional infections were recorded in 7% (20/276) of cases. Among those 20 cases, culture results were available in 12 of 20 cases. The most common bacterial isolate cultured was Escherichia coli. The most common perioperative antimicrobials administered to treat incisional infection were cefazolin and cefoxitin. Only two of the bacterial isolates were susceptible to these antimicrobials. Bacteria isolated from incisional infections were most often susceptible to chloramphenicol, imipenem, and gentamicin.

CONCLUSION

Bacterial isolates from incisional infections in this population consisted of native gastrointestinal flora, which was often resistant to the most commonly used perioperative antimicrobials.

CLINICAL SIGNIFICANCE

Contamination at time of surgery is the most likely source of incisional infection after gastrointestinal surgery. This rate of infection justifies more rigorous intraoperative hygiene protocols and evaluation of the antimicrobials' susceptibility of causative bacteria to guide antimicrobial treatment.