Novel macrolide-lincosamide-streptogramin B resistance gene erm(56) in Trueperella pyogenes

Whole-genome sequence analysis of a macrolide, lincosamide, streptogramin B (MLSB)-resistant Trueperella pyogenes from a dog revealed a new 23S ribosomal RNA methylase gene erm(56). Expression of the cloned erm(56) confers resistance to MLSB in T. pyogenes and Escherichia coli. The erm(56) gene was flanked by two IS6100 integrated on the chromosome next to a sul1-containing class 1 integron. GenBank query revealed additional erm(56)-containing elements in another T. pyogenes and in Rothia nasimurium from livestock. IMPORTANCE A novel 23S ribosomal RNA methylase gene erm(56) flanked by insertion sequence IS6100 was identified in a Trueperella pyogenes isolated from the abscess of a dog and was also present in another T. pyogenes and in Rothia nasimurium from livestock. It was shown to confer resistance to macrolide, lincosamide, streptogramin B antibiotics in T. pyogenes and E. coli, indicating functionality in both Gram-positive and Gram-negative bacteria. The detection of erm(56) on different elements in unrelated bacteria from different animal sources and geographical origins suggests that it has been independently acquired and likely selected by the use of antibiotics in animals.

Antinociceptive, Sedative and Excitatory Effects of Intravenous Butorphanol Administered Alone or in Combination with Detomidine in Calves: A Prospective, Randomized, Blinded Cross-Over Study

(1) Background: The diagnostic and therapeutic procedures performed under sedation or general anesthesia in bovines are numerous. The analgesic drugs that can be legally used are few, making perioperative analgesia challenging. (2) Methods: Calves were administered butorphanol 0.1 mg kg^-1 alone (SB) or combined with 0.02 mg kg^-1 of a detomidine (DB) IV. The antinociceptive effect (trigeminocervical reflex threshold (TCRt)), as well as the behavioral (sedation and excitation) and physiological (heart and respiratory rate) changes were investigated. Five time windows were defined: BL (30 min pre-injection), T1 (0-30 min post-injection (PI)), T2 (31-60 min PI), T3 (61-90 min PI) and T4 (91-120 min PI). (3) Results: Both groups had a significative increase in TCRt at T1-T4 compared to the BL. The TCRt was significatively higher in DB than in SB at T1, T2 and T4. Heart rate decreased significatively in DB compared to that in BL. Calves were significantly more sedated in the DB group, and significantly more excited in the SB group compared to the BL. (4) Conclusions: Butorphanol alone has a statistically significant antinociceptive effect, but it elicits marked excitation, limiting its clinical applicability under this dosing regimen. The co-administration of detomidine eliminated the excitatory effect and induced consistent sedation and a significantly more pronounced antinociceptive effect.

Surgical technique and comparison of autologous cancellous bone grafts from various donor sites in rats

Autologous cancellous bone graft is the gold standard in large bone defect repair. However, studies using autologous bone grafting in rats are rare. To determine the feasibility of autologous cancellous bone graft harvest from different anatomical donor sites (humerus, ilium, femur, tibia, and tail vertebrae) in rats and compare their suitability as donor sites, a total of 13 freshly euthanized rats were used to describe the surgical technique, determine the cancellous bone volume and microstructure, and compare the cancellous bone collected quantitatively and qualitatively. It was feasible to harvest cancellous bone grafts from all five anatomical sites with the humerus and tail being more surgically challenging. The microstructural analysis using micro-computed tomography showed a significantly lower bone volume fraction, bone mineral density, and trabecular thickness of the humerus and iliac crest compared to the femur, tibia, and tail vertebrae. The harvested weight and volume did not differ between the donor sites. All donor sites apart from the femur yielded primary osteogenic cells confirmed by the presence of alkaline phosphatase and Alizarin Red S stain. Bone samples from the iliac crest showed the most consistent outgrowth of osteoprogenitor cells. In conclusion, the tibia and iliac crest may be the most favorable donor sites considering the surgical approach. However, due to the differences in microstructure of the cancellous bone and the consistency of outgrowth of osteoprogenitor cells, the donor sites may have different healing properties, that need further investigation in an in vivo study.

Bovine neutrophil chemotaxis to Listeria monocytogenes in neurolisteriosis depends on microglia-released rather than bacterial factors

BACKGROUND

Listeria monocytogenes (Lm) is a bacterial pathogen of major concern for humans and ruminants due to its neuroinvasive potential and its ability to cause deadly encephalitis (neurolisteriosis). On one hand, polymorphonuclear neutrophils (PMN) are key players in the defense against Lm, but on the other hand intracerebral infiltration with PMN is associated with significant neural tissue damage. Lm-PMN interactions in neurolisteriosis are poorly investigated, and factors inducing PMN chemotaxis to infectious foci containing Lm in the central nervous system (CNS) remain unidentified.

METHODS

In this study, we assessed bovine PMN chemotaxis towards Lm and supernatants of infected endogenous brain cell populations in ex vivo chemotaxis assays, to identify chemotactic stimuli for PMN chemotaxis towards Lm in the brain. In addition, microglial secretion of IL-8 was assessed both ex vivo and in situ.

RESULTS

Our data show that neither Lm cell wall components nor intact bacteria elicit chemotaxis of bovine PMN ex vivo. Moreover, astrocytes and neural cells fail to induce bovine PMN chemotaxis upon infection. In contrast, supernatant from Lm infected microglia readily induced chemotaxis of bovine PMN. Microglial expression and secretion of IL-8 was identified during early Lm infection in vitro and in situ, although IL-8 blocking with a specific antibody could not abrogate PMN chemotaxis towards Lm infected microglial supernatant.

CONCLUSIONS

These data provide evidence that host-derived rather than bacterial factors trigger PMN chemotaxis to bacterial foci in the CNS, that microglia have a primary role as initiators of bovine PMN chemotaxis into the brain during neurolisteriosis and that blockade of these factors could be a therapeutic target to limit intrathecal PMN chemotaxis and PMN associated damage in neurolisteriosis.

Admission lactate concentration has predictive value for death or severe complications within 30 days after admission in cattle with long-bone fractures

OBJECTIVE

To determine the prognostic value of lactate concentration measurements at admission in cattle with long-bone fractures.

ANIMALS

43 cattle with long-bone fractures between July 2016 and Dec 2018.

PROCEDURES

In this prospective cohort study, lactate concentration was measured in systemic venous blood and locally in capillary blood sampled from the fractured and contralateral limbs of cattle and assessed for outcome prediction. The cutoff value was determined by maximizing the Youden index from receiver-operating characteristic curves. Multivariable logistic regression was employed to verify whether higher lactate concentrations compared with the cutoff value were an independent risk factor for poor outcomes at 30 days or 3 years after admission.

RESULTS

Poor outcome was associated with higher capillary lactate concentration in the fractured limb (P < .001) and greater difference with systemic blood (P = .005). A cutoff value of lactate difference ≥ 2.4 mmol/L (sensitivity = 0.80; specificity = 0.965) between capillary lactate in the fractured limb and systemic blood was the best predictor of death ≤ 30 days after admission (P < .001). Multivariable analysis revealed that this cutoff value was an independent risk factor for 30-day and 3-year outcomes (P < .001).

CLINICAL RELEVANCE

Admission blood lactate concentration difference ≥ 2.4 mmol/L between the fractured limb and systemic blood was a robust and independent predictor of outcome for cattle of the present report. Lactate metabolism is locally impaired in fractured limbs of nonsurviving or at higher complication risk cattle, which may help identify patients at high risk for poor outcomes.

Eye enucleation and exenteration in -cattle: a retrospective study of 38 cases (2013-2020)

INTRODUCTION

The study aimed to describe clinical indications for eye enucleation and exenteration, the occurrence of complications and long-term outcome in cattle, and examine owners' attitude towards enucleation and exenteration and their satisfaction with the surgical outcome. Medical records from the two veterinary teaching hospitals in Switzerland were reviewed to identify cattle that underwent unilateral enucleation or exenteration between January 2013 and December 2020. Data extracted included medical history, ocular examination, clinical diagnosis, surgical procedure including anesthesia, suture material and pattern used, complications, and treatment thereof. Long-term follow-up was evaluated via national animal database inquiries to determine survival time and via owners' interviews with the use of a standardized questionnaire that included questions regarding the occurrence of complications and reason for culling, production performances and perceived quality of life after surgery, concerns, factors affecting the decision to proceed with surgery, and general satisfaction with the outcome. Descriptive statistics, Fisher's exact tests and unpaired t-test were used to summarize the data and assess association between variables. Association was considered significant if p < 0,05. Thirty-eight cases were identified, with a median age of 5 years. More than half of the cases (55,3 %) were diagnosed with non-neoplastic ocular lesions represented by severe trauma with loss of globe content, globe rupture with history of infectious keratoconjunctivitis or hypopyon, or congenital malformations. The remaining cases were diagnosed with neoplastic lesions, including ocular squamous cell carcinoma (OSCC), melanoma, or sarcoma. Complications following surgery were reported in 29 % of cases and included postoperative infection and recurrence of OSCC. There was no significant association between ocular diagnosis and the occurrence of postoperative complications or survival time. Surgery did not seem to influence the animals' postoperative production performance or the perceived quality of life. Most owners (92 %) were satisfied with the surgical outcome. The occurrence of postoperative complications leading to increased overall costs and culling was the main reason for lower owner satisfaction.

Preoperative skin asepsis protocols using chlorhexidine versus povidone-iodine in veterinary surgery: A systematic review and meta-analysis

OBJECTIVE

To provide a systematic assessment of the efficacy of preoperative skin asepsis using chlorhexidine versus povidone-iodine based protocols for surgical site infection (SSI) prevention in veterinary surgery.

STUDY DESIGN

Systematic meta-analytical review according to PRISMA-P guidelines.

SAMPLE POPULATION

Studies comparing preoperative skin asepsis protocols using chlorhexidine versus povidone-iodine in veterinary surgery identified by systematic search between 1990 and 2020.

METHODS

A search using MEDLINE/Pubmed, Web of Science and CAB Abstracts was performed, followed by secondary searches of Google Scholar, Proquest Dissertation and Theses, and relevant bibliographic articles. Primary and secondary outcome measures were the efficacy of skin asepsis protocols using chlorhexidine versus povidone-iodine on SSI incidence and skin bacterial colonization, respectively. A meta-analysis was performed with a random-effect model, with effect size calculated as risk ratio (RR) or mean standard deviation (MSD) with 95% CI. Statistical significance was set at P < .05.

RESULTS

Among 1067 publications that met the initial search criteria, 9 relevant studies were eligible for analysis. No difference in the incidence of postoperative SSI or skin bacterial colonization between preoperative asepsis protocols using chlorhexidine versus povidone-iodine was found. Insufficient information and detail were frequent among studies and precluded a clear assessment of bias.

CONCLUSION

This study showed that asepsis protocols using chlorhexidine were comparable to povidone-iodine in preventing postoperative SSI and reducing skin bacterial colonization.

CLINICAL SIGNIFICANCE

Given the limitations of the studies that were included in terms of both quality and quantity, more high-quality randomized controlled trials are needed to confirm these conclusions.

Surgical debridement and primary closure of the oral mucosa for repair of open mandibular pars incisiva fractures in three neonatal calves

CASE DESCRIPTION

3 neonatal female calves (ages, < 1 to 4 days) were examined because of mandibular trauma.

CLINICAL FINDINGS

Physical examination indicated that each calf had an open fracture of the mandibular pars incisiva (rostral mandibular fracture) with ventral displacement of the incisors at the affected region. Oral radiographs were obtained for 1 calf and revealed that 5 incisors were fractured at the level of the apical dental buds.

TREATMENT AND OUTCOME

Each calf was anesthetized. The fracture site and surrounding tissues were surgically debrided and flushed with sterile 0.05% chlorhexidine solution. The laceration in the oral mucosa was closed with absorbable suture in an interrupted horizontal mattress pattern. Additionally, a Penrose drain was placed during primary closure and removed 4 days later in 1 calf. The fractured incisors were removed during primary debridement in another calf. All calves received perioperative antimicrobials and analgesics. One calf developed mild osteomyelitis of the rostral mandible, which resolved with additional surgical debridement and antimicrobial treatment. That calf and another developed mild brachygnathia. At the time of last follow-up (3 to 13 months after hospital discharge), all 3 calves were eating and growing as expected.

CLINICAL RELEVANCE

3 calves with open rostral mandibular fractures were successfully managed by surgical debridement and primary closure of the oral laceration. The procedure was easy to perform, did not require specialized equipment, and was less expensive than other repair methods. This procedure may be an effective and economic on-farm treatment alternative for calves with rostral mandibular fractures.

Solitary tracheal B-cell lymphoma in an adult alpaca (Vicugna pacos)

BACKGROUND

This report describes a case of solitary tracheal lymphoma in a 14-year-old alpaca mare.

CASE PRESENTATION

The alpaca was referred for dyspnea and inspiratory noise. The clinical examination included complete blood cell count, blood chemistry, endoscopy, ultrasound, radiographs, and computed tomography (CT). A solitary tracheal intraluminal and juxtatracheal lymphoma was diagnosed by fine needle aspiration (FNA). The owner requested euthanasia due to the uncertain prognosis. At postmortem examination, the presence of solitary lymphoma without involvement of other organs was confirmed. Immunohistochemical analysis confirmed a B-cell origin.

CONCLUSIONS

Although multicentric lymphoma is the most commonly described neoplasia affecting South American camelids (SAC), solitary forms of the disease may occur.

In vitro biomechanical properties of sole tissues: Comparison between healthy and ulcerated bovine claws

Sole ulcers are reportedly one of the most prevalent diseases associated with lameness in dairy cattle, significantly affecting animal welfare and farm profitability. The degree to which sole soft tissues, healthy or ulcerated, are able to maintain their structure and function when subjected to compressive forces remains unknown. Therefore, the aims of the present study were to assess sole tissue biomechanics in healthy and ulcerated claws and to describe correlated histology. Cylindrical samples were harvested from zones 4 and 6, as described by the international foot map, from hind lateral healthy (n = 12) and ulcerated bovine claws (n = 8; animals n = 12). Tissue biomechanics and morphology were evaluated via compressive tests and hematoxylin-eosin-phloxine-saffron staining, respectively. A 2-sample t-test was used to compare zones' mechanical properties between healthy and ulcerated tissues, and the Cochran-Mantel-Haenszel test was used to measure the effect of claw zone on histology. The fibril modulus (E_f) and permeability (k) respectively increased and decreased in ulcerated claws (E_f = 0.201 ± 0.104 MPa; k = 0.128 ± 0.069 mm²/MPa·s) compared with healthy claws (E_f = 0.105 ± 0.050 MPa; k = 0.452 ± 0.365 mm²/MPa·s) only for zone 6. Histology scores equal to or greater than 3 were associated with macroscopic presence of ulceration. A higher proportion of adipose tissue (30% or more) was associated with zone 6 compared with zone 4, but no difference was seen between healthy and ulcerated claws. Ulcerated claws had a higher prevalence of exostoses compared with healthy ones (33% vs. 8%). Sole soft tissues showed, as hypothesized, a viscoelastic behavior using unconfined compression testing, which, however, may not reflect in vivo loading conditions. Clinical and histological signs of sole ulceration were not associated with decreased strength of the supportive apparatus of the distal phalanx in zone 4 in this study.

Cheek teeth apical infection in cattle: Diagnosis, surgical extraction, and prognosis

OBJECTIVE

To report the clinical presentation, treatment, and outcome of cattle undergoing surgical extraction of apically infected cheek teeth (CT).

STUDY DESIGN

Short case series.

ANIMALS

Nine adult cattle.

METHODS

Medical records were searched for cattle having a diagnosis of apical infection of CT that were treated with surgical extraction between 2005 and 2017. Data retrieved included clinical examination, ancillary tests, surgical procedure, and outcomes.

RESULTS

The main presenting complaints were mandibular swelling and decreased appetite and milk production. In total, 7 mandibular and 3 maxillary CT were extracted, 7 molars and 3 premolars that were distributed more frequently on the left dental arcades (n = 7 CT). Two cattle had no visible external lesions. Radiograph images revealed that lucency surrounded all affected tooth roots. Mandibular teeth were removed by lateral buccotomy with removal of alveolar bone plate or retrograde repulsion, and maxillary teeth were removed by repulsion through a maxillary sinus flap. Most common bacterial isolates consisted of anaerobic bacteria (6/11 isolates) and Truperella pyogenes (3/11 isolates). The most common complications included inability to remove the tooth intact (n = 4 cattle) and surgical site infection (n = 5). All cattle remained in their herd after treatment.

CONCLUSION

Surgical extraction of CT was achieved in all 9 cattle. The postoperative morbidity was high but without long-term consequences on animal productivity.

CLINICAL SIGNIFICANCE

Surgical extraction of CT is a successful treatment for apical infection in cattle.

Radiographic Study of Haematogenous Septic Arthritis in Dairy Calves

OBJECTIVES

 (1) To develop an evaluation grid to provide a systematic interpretation of calves' articular radiographs, (2) to describe radiographic lesions of septic arthritis in dairy calves less than 6 months of age, (3) to investigate potential associations between demographic data or synovial bacteriological culture results and radiographic lesions (4) to determine whether an association is present between radiographic lesions, their severity and the long-term outcome.

METHODS

 Medical records of 54 calves less than 180 days old treated for septic arthritis between 2009 and 2014 with radiographic images performed in the first 2 days after admission were reviewed.

RESULTS

 Most common radiographic findings were increased articular joint space height (n = 49), irregularity of the articular surfaces (n = 24) and subchondral bone lysis (n = 24). The number of lesions observed and their severity were associated with older calves (p = 0.02), increased time between onset of clinical signs and admission (p = 0.0001) and the culture of Trueperella pyogenes within the joint (p = 0.02). The radiographic lesions associated with negative long-term prognosis were reduction in the joint space height (p = 0.01) and subchondral bone lysis on weight-bearing surfaces (p = 0.02).

CLINICAL SIGNIFICANCE

 An evaluation grid designed for veterinarians can facilitate systematic reading of articular radiographs and can be used for dairy calves with a presumptive diagnosis of septic arthritis. This diagnostic tool may aid in establishing a prognosis and decision-making process in terms of treatment.

Quasi-static tensile properties of the Cranial Cruciate Ligament (CrCL) in adult cattle: towards the design of a prosthetic CrCL

Mechanical properties of the Cranial Cruciate Ligament (CrCL) in adult cattle are not well documented and protocols used in the literature focus on testing a full femur-CrCL-tibia complex rather than an isolated CrCL. The aim of this study was to assess a wider range of tensile properties of the CrCL along its anatomic axis with experimental measurements of the global elongation, displacement and strain fields, in order to provide guidelines for the design of CrCL prosthetic surrogates. Fourteen bovine CrCL were harvested from seven mature cows (5.1 ± 1.3 years) weighing 631 ± 90kg. The mean CrCL length was 41.4 ± 1.5mm and its mean cross-section was 103.9 ± 23.8mm². Pre-conditioning was achieved with 30 cycles of loading from 30 to 200N at a strain rate of 0.02s^-1. Specimens were then loaded to failure at the same strain rate. The following results were obtained: the mean ultimate tensile load (UTL) 4372 ± 1485N and the median [quartiles] maximal global elongation 19.3 [17.8; 21.4] %. At first physical signs of tearing, the mean load was 3315 ± 1336N and mean elongation 13.5 ± 4.9%. The mean absorbed energy at failure was 5.23 ± 2.08 MJ.mm^-3 and the mean stiffness at various levels of elongation was: 220 ± 195N.%^-1 (5%), 285 ± 162N.%^-1 (10%), 239 ± 200N.%^-1 (15%), 146 ± 59N.%^-1 (20%), 153 ± 136N.%^-1 (25%). None of these properties were related to the bovine weight, age and side of the body (p > 0.05). An ideal prosthetic surrogate should then follow these sets of properties and the experimental data suggest that the in-vivo maximal elongation is below 13.5%.

Surgical Correction of Traumatic Lateral Patellar Luxation

OBJECTIVE

To report successful surgical repair of a grade IV lateral patellar luxation in a 437-kg heifer.

STUDY DESIGN

Case report.

ANIMAL

Seventeen-month-old Holstein heifer (437 kg).

METHODS

Diagnosis of traumatic lateral patellar luxation was made based on physical examination, and confirmed on radiographs. Arthroscopic examination of the stifle assessed joint changes. Lateral patellar luxation was surgically repaired using lateral release of the patella and medial imbrication of the joint capsule.

RESULTS

The heifer presented nonweight-bearing lameness of the left hind limb (5/5 lameness score). Unilateral grade IV lateral patellar luxation was diagnosed based on physical examination and radiography. Arthroscopic examination of the stifle showed synovitis and cartilage eburnation of the medial articular surface of the patella and of the lateral trochlear ridge of the femur. Lateral release of the patella and medial imbrication of the joint capsule was performed. The heifer remained lame (4.5/5 lameness score) and developed severe disuse muscle atrophy after surgery. By day 112, the heifer was walking easily and was completely weight bearing on the left hindlimb but did have a gait alteration (2/5 lameness score). On day 229, the heifer calved for the first time and lameness was no longer evident.

CONCLUSION

This report documents successful surgical treatment of traumatic lateral patellar luxation in a large heifer but additional case evaluation is required to provide an accurate prognosis for this condition and treatment in large cattle.

Outcome Following Partial Unilateral Hysterectomy by Standing Flank Approach in Dairy Cattle

OBJECTIVE

To describe the clinical findings, surgical treatment, and long-term outcome of dairy cattle undergoing partial hysterectomy with or without unilateral ovariectomy.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dairy cattle (n = 7).

METHODS

Medical records (June 2007-June 2014) of dairy cattle that had partial hysterectomy with or without ipsilateral ovariectomy were reviewed. Follow-up data were obtained by telephone interviews with owners and referring veterinarians between 6 months and 7 years following discharge.

RESULTS

Seven dairy cattle met the inclusion criteria. Diagnoses made intra- or postoperatively were ovarian abscess with multiorgan adhesions (4 cows), segmental aplasia of the uterus (2 cows), and uterine lymphosarcoma (1 cow). Partial hysterectomy with or without unilateral ovariectomy was performed without surgical complications by standing flank approach. All cows were successfully discharged from the hospital (short-term prognosis). Five cows became pregnant, and 4 delivered live calves and had a satisfactory productive life without long-term complications.

CONCLUSION

Partial hysterectomy by standing flank approach should be considered as a viable treatment option for unilateral ovarian or uterine problems in dairy cattle. Cattle undergoing partial hysterectomy with or without ipsilateral ovariectomy are capable of satisfactory reproduction and milk production after surgery with no short- or long-term complications.

Multiple tarsal luxations in 2 Holstein heifers

Two Holstein heifers were referred for non-weight bearing lameness. The physical examination and radiographic findings were diagnostic of tarsal luxation. Treatment and outcome are reported. A closed reduction was successfully performed in 1 heifer. The second animal was euthanized after attempts to reduce and stabilize the joint.