Efficacy of endotracheal tube disinfection strategies for elimination of Streptococcus zooepidemicus and Bordetella bronchiseptica

Comparison of four endotracheal tube cleaning protocols in anesthetized dogs

OBJECTIVE

To compare the efficacy of 4 cleaning protocols applied to endotracheal tubes (ETTs) collected from anesthetized dogs.

SAMPLE

100 ETTs (25 per protocol).

PROCEDURES

A 10-question survey designed to determine ETT reuse and cleaning practices was distributed via email to a sample of veterinary anesthesiologists. Informed by survey results, 4 ETT cleaning protocols were selected for use in a prospective clinical study. Dogs were intubated with sterile polyvinyl chloride ETTs. At extubation, each ETT was cultured for bacterial growth, randomly assigned to 1 of 4 protocols [water scrub (P1), detergent scrub (P2), detergent scrub and chlorhexidine gluconate (CHG) soak (P3), or detergent scrub and bleach soak (P4)], and cultured again after drying. Bacterial genera were identified using mass spectrometry and 16s rRNA sequencing. Proportions of ETTs exhibiting no post-cleaning growth were compared between protocols using the Fisher exact test with Bonferroni correction.

RESULTS

Half of survey respondents that reused ETTs did not sterilize them before reuse, cleaning methods varied widely, and no reported methods were evidence-based. After use, the number of ETTs exhibiting no post-cleaning bacterial growth were 15/25 (60%), 14/25 (56%), 20/25 (80%), and 17/25 (68%) for protocols P1, P2, P3, and P4, respectively. Pairwise comparisons did not reveal any statistically significant differences between protocols.

CLINICAL RELEVANCE

In small animal patients, some veterinary anesthesiologists reuse ETTs without sterilization and cleaning protocols vary widely. No differences between the studied protocols were identified. Further research is necessary to identify a safe, efficacious ETT cleaning protocol for use in small animal practice.

Risk Factors for the Acquisition of a blaNDM-5 Carbapenem-Resistant Escherichia coli in a Veterinary Hospital

Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent antibiotic resistant threat. Only sporadic reports of CRE in companion animals have been described. Our objective was to identify risk factors associated with the acquisition of a blaNDM-5 CR-Escherichia coli strain as part of an outbreak investigation at a tertiary veterinary hospital in the United States. A matched case-control study was conducted among companion animals admitted during July 1, 2018, through June 30, 2019. The 15 identified blaNDM-5 CR-E coli cases were matched 1:2 with controls (culture negative for blaNDM-5 CR-E coli) based on species and number of days of hospitalization before bacterial culture sample collection. The association between exposure to various procedures and hospital services and the acquisition of blaNDM-5 CR-E. coli was assessed through conditional logistic regression. Case patients had significantly higher odds of exposure to the anesthesia service (odds ratio [OR] = 12.8, P = .017), the surgical service (OR = 4.0, P = .046), and to endotracheal intubation (OR = 10.0, P = .03). Veterinary hospitals should be aware of the potential for transmission of CRE via anesthetic and surgical procedures, especially those that require the placement of endotracheal tubes.