Abstract Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition.
Objective— To investigate the effect of tibial plateau leveling osteotomy (TPLO) on the proximal tibial soft tissue envelope with and without use of protective gauze sponges, and to determine whether the action of an oscillating saw blade on the gauze sponges would result in retention of particulate cotton debris. Study Design— Cadaveric study. Animals— Medium to large breed dog cadavers (n=10; 20 pelvic limbs). Methods— TPLO was performed using the currently recommended technique involving dissection of the proximal tibial soft tissue envelope and its protection using cotton gauze sponges. In paired limbs, the procedure was repeated but no attempt was made to retract and protect the proximal tibial soft tissue envelope. Damage to the soft tissue envelope and presence of gross particulate cotton debris were investigated by direct observation and photographic analysis. Presence of microscopic cotton debris was investigated using light microscopic analysis of wound lavage fluid. Results— No soft‐tissue trauma was found in gauze sponge‐protected specimens. When protective gauze sponges were not used, full‐thickness (sagittal plane) lacerations to the caudoproximal tibial muscle group occurred in all specimens with a mean craniocaudal width of 9.5 mm (range 2–12 mm). The cranial tibial muscle was traumatized in only 1 specimen without protective gauze sponges. Trauma to the popliteal vessels was not identified in any specimen. No gross cotton debris was identified, but microscopic cotton fibers (diameter, 7–35 μm) were identified in lavage fluid from all gauze sponge‐protected specimens. Conclusions— Use of protective gauze sponges is effective in protecting the proximal tibial soft tissue envelope from an oscillating TPLO saw blade, but results in retention of microscopic cotton particulate debris within the operative site. Significant soft tissue trauma is seen only in the caudoproximal tibial muscle group if protective gauze sponges are not used. Clinical Relevance— Retraction and protection of the caudoproximal tibial soft tissue envelope is recommended during TPLO; however, to prevent retention of microscopic particulate cotton debris, alternatives to cotton gauze sponges should be considered as protective devices.
Bovine tuberculosis is a notifiable disease in Northern Ireland with the national eradication programme of compulsory testing and slaughter of reactor animals costing approximately £40 million per year. Backward tracing, known as Backward Check Tests (BCTs), of reactor animals is used to identify previous herds where the bTB positive animal has resided. The aim of this study was to quantify the bovine tuberculosis (bTB) risk posed by inconclusive reactors (ICs) at BCTs at both the individual animal and the herd level. ICs to the Comparative Intradermal Tuberculin Test (CITT) at a BCT, in which no reactors were found, were matched with CITT negative animals, based on age, sex, test ID and follow up period, in Northern Ireland between 1st January 2008 and 31st December 2017 (inclusive). A retrospective matched cohort study design was used with the outcome of interest being the bTB status of each animal and subsequent bTB herd breakdowns. After adjusting for herd size, IC animals at a BCT had 16 times the odds (95% confidence interval: 7.75 to 38.28, p < 0.001) of becoming bTB positive compared to CITT negative animals. The percentage population attributable risk was 0.0001%. The majority 75% (n = 71) of ICs that became bTB positive were identified at the 42 day retest. Of those that were not disclosed at the 42 day retest (n = 24), almost a third (29%) had moved to an unrestricted herd. However, after adjusting for herd size and type, herds that had ICs only identified at a BCT did not have an increased odds of a subsequent bTB herd breakdown compared to herds that had a CITT negative BCT. Given the increased risk posed by ICs at a BCT, it may be justifiable to remove them from the herd immediately or place them under lifetime movement restrictions to the herd where they were detected. However, further action regarding the herd of origin does not appear to be justified.