Changes in antimicrobial susceptibility of Actinobacillus pleuropneumoniae isolated from pigs in Spain during the last decade

A total of 229 Spanish Actinobacillus pleuropneumoniae isolates recovered from diseased pigs with pleuropneumonia from 1997 to 2004 was tested for their susceptibility to 11 antimicrobials in a broth microdilution method. All the isolates were susceptible to florfenicol and most of them to cephalothin; however, a high rate of resistance was observed to tetracycline. A bimodal or multimodal distribution of isolates over the MIC range were observed for penicillins, tetracycline, trimethoprim, sulfisoxazole and nalidixic acid, suggesting the development of acquired resistance. Eight resistance patterns were established, and 21.1% of the isolates were resistant to at least two antimicrobials. In addition, a considerable increase in the resistance to tetracyclines was observed during the last decade in Spain, when compared with other A. pleuropneumoniae strains isolated during 1987-1988 (Gutiérrez, C.B., Píriz, S., Vadillo, S., Rodríguez Ferri, E.F., 1993. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents. Am. J. Vet. Res. 54, 546-550); this finding was also observed for gentamicin in minor percentage.     

Aspects of future animal health: the Animal Health Foresight Project

Against a background of social, political, and environmental change, the challenge to provide the most appropriate education for future veterinarians is daunting. A consideration of the multiple roles of veterinarians in our future society indicates that a different perspective is essential for progress to be made. One example of an approach to reach such a perspective is the Animal Health Foresight Project, which was jointly sponsored in 2005 by the Canadian Food Inspection Agency and the US Department of Agriculture. A new paradigm emerged from this study. This article explores the conclusions of this project and their potential implications for the future of animal health and for veterinary medical education. Outcomes of the Foresight Project led to the development of a new paradigm. The implications for and the possible influence on future animal health and on veterinary medical education are contemplated.     

Risk factors associated with extended spectrum beta-lactamase Escherichia coli (CTX-M) on dairy farms in North West England and North Wales

This study investigated the potential spread of CTX-M-14 Escherichia coli from a known ESBL E. coli positive farm and risk factors for the presence of CTX-M E. coli on dairy farms. Between November 2009 and March 2010, 65 farms in North West England and North Wales were visited and animals sampled for E. coli producing CTX-M ESBLs. Seventeen of these were known to have received animals from a known ESBL E. coli positive 'index' farm since 2005 (linked farms). The prevalence of CTX-M E. coli in the population of linked farms was 58.8% (10/17; CI(95%) 32.9-81.6%) and in the randomly selected control population was 35.4% (17/48; CI(95%) 22.2-50.5%). There was no significant (p>0.05) linkage for the detection of any CTX-M E. coli or specifically a CTX-M-14 E. coli to the index farm. Group 1 (CTX-M-15, CTX-M-55, CTX-M-1, CTX-M-32), group 2 (CTX-M-2) and group 9 (CTX-M-14, CTX-M-14B, CTX-M-27) CTX-M E. coli were identified on the study farms. Molecular analysis revealed that three plasmids from linked farms had similar sizes (95kbp), replicon type (IncK) and backbone genes as that from the index farm. Logistic regression analysis revealed that farms that had used a 3rd or 4th generation cephalosporin (ceftiofur, cefoperazone and cefquinome) in livestock in the last 12months were nearly 4times more likely to have ESBL E. coli present (p=0.037; OR=3.93). There was no significant association between presence of CTX-M E. coli and the use of any 1st or 2nd generation cephalosporins. Several other risk factors for the presence of CTX-M E. coli were identified, such as storage of slurry in a pit, operating an open herd policy and infrequent cleaning of calf feeding equipment.     

Intra-articular stabilisation of the equine cricoarytenoid joint

Reasons for performing study: The success of laryngoplasty is limited by abduction loss in the early post operative period. Objective: To determine the efficacy of polymethylmethacrylate (PMMA) in stabilising the cricoarytenoid joint (CAJ) and reducing the force on the laryngoplasty suture. Hypothesis: Injection into the cricoarytenoid joint resists the forces produced by physiological laryngeal air flows and pressures thereby reducing the force experienced by the laryngoplasty suture. Methods: Ten cadaver larynges were collected at necropsy and PMMA was injected into one CAJ at selected random. Each larynx was subjected to physiological conditions with with constant (static) or cycling (dynamic) flow. The specimens were tested sequentially in each of 4 conditions: 1) bilateral full abduction (Control 1); 2) transection of the suture on the side without PMMA; 3) bilateral abduction achieved by replacing the suture (Control 2); and 4) cutting the suture on the PMMA side. Tracheal pressure and flow and pressure in the flow chamber were recorded using pressure and flow transducers. The strain experienced by each suture during bilateral abduction (Controls 1 and 2) was measured. Statistical comparison of the 4 conditions was performed using a mixed effect model with Tukey's post hoc test for multiple comparisons. The strain gauge data were analysed by paired comparison of the regression slopes. Results: In the static and dynamic states, tracheal pressure increased and tracheal flow decreased when the suture on the non‐cement side was cut (P<0.05). There was no significant difference in any outcome measure between PMMA injected into the CAJ and bilaterally abducted specimens (Controls 1 and 2) for either condition. The rate of increase in strain with increasing translaryngeal pressure was significantly less on the suture with PMMA placed in the CAJ (P = 0.03). Conclusions: These data provide strong evidence that injecting PMMA into the CAJ resists the collapsing effect of physiological airflows and pressures in vitro and reduces the force experienced by the laryngoplasty suture during maximal abduction. Potential relevance: Augmentation of prosthetic laryngoplasty with this technique may reduce arytenoid abduction loss in the early post operative period.     

Neuroanatomy of the equine dorsal cricoarytenoid muscle: surgical implications

Reason for performing study: Studies are required to define more accurately and completely the neuroanatomy of the equine dorsal cricoarytenoid muscle as a prerequisite for developing a neuroprosthesis for recurrent laryngeal neuropathy. Objective: To describe the anatomy, innervation, fibre types and function of the equine dorsal cricoarytenoid muscle. Methods: Thirty‐one larynges were collected at necropsy from horses with no history of upper airway disease and 25 subjected to gross dissection. Thereafter, the following preparations were made on a subset of larynges: histochemical staining (n = 5), Sihler's and acetylcholinesterase staining for motor endplates (n = 2). An additional 6 larynges were collected and used for a muscle stimulation study. Results: Two neuromuscular compartments (NMC), each innervated by a primary nerve branch of the recurrent laryngeal nerve, were identified in all larynges. Stimulation of the lateral NMC produced more lateral displacement of the arytenoid cartilage than the medial NMC (P<0.05). The medial NMC tended to rotate the arytenoid cartilage dorsally. Motor endplates were identified at the junction of the middle and caudal thirds of each NMC. If fibre type grouping was present it was always present in both NMCs. Conclusions: The equine dorsal cricoarytenoid muscle has 2 distinct muscle NMCs with discrete innervation and lines of action. The lateral NMC appears to have a larger role in increasing cross‐sectional area of the rima glottidis. Potential relevance: This information should assist in planning surgical reinnervation procedures and development of a neuroprosthesis for recurrent laryngeal neuropathy.     

菌草灵芝孢子粉增强免疫调节作用研究

120只SPF级昆明种雌性小鼠平均分成3组，菌草灵芝孢子粉分三个剂量组给小鼠灌胃，共30d。测定小鼠的体重、免疫器官脏器／体重比值、迟发型变态反应（DTH）、ConA诱导的小鼠淋巴细胞转化能力、抗体生成细胞数、半数溶血值（HC50）、单核一巨噬细胞碳廓清、巨噬细胞吞噬鸡红细胞吞噬率指标。结果：0．150g／kg．bw剂量能提高小鼠的半数溶血值（P〈0．05）；0．450g／kg．bw剂量能提高小鼠迟发型变态反应（DTH）能力、ConA诱导的淋巴细胞转化能力、增加抗体生成细胞数（P〈0．05）；菌草灵芝孢子粉对小鼠体重增长、胸噱体重比值、脾脏体重比值、单核-巨噬细胞碳廓清能力、小鼠巨噬细胞吞噬鸡红细胞的能力均无明显影响（P〉0．05）。     

Surgical advancement of the larynx (laryngeal tie-forward) as a treatment for dorsal displacement of the soft palate in horses: a prospective study 2001-2004

REASONS FOR PERFORMING STUDY: Correct placement of sutures ('laryngeal tie-forward') in experimentally created dorsal displacement of the soft palate (DDSP) has been observed to replace the function of the thyrohyoideus muscles and prevent DDSP. HYPOTHESIS: The 'laryngeal tie-forward' procedure would prevent or delay the occurrence of DDSP during exercise in horses with naturally occurring DDSP and therefore improve performance. METHODS: A clinical population (n = 116), mainly of racehorses was presented for treatment of naturally occurring exercise-induced DDSP. All horses underwent the 'laryngeal tie-forward' procedure. The relative position of the thyroid and cricoid cartilage in relation to the caudal aspect of the basihyoid bone was recorded; follow-up was obtained by telephone communication with trainers, owners and/or referring veterinarians. In addition, a performance index and earnings were determined using race records. RESULTS: Preoperatively, the median distance between the caudal aspect of the basihyoid bone and rostral aspect of the thyroid cartilage was 3.5 cm. Post operatively, the thyroid cartilage was moved a median distance of 4 cm rostrally and the larynx was shown to be in a position more rostral and dorsal than in preoperative radiographs. Of 98 horses for which follow-up was available, the performance of 87% was classified as improved, 12% as unchanged and 2% as worse. In 20 horses in which the diagnosis had been confirmed by treadmill videoendoscopy, 80% had a significantly increased performance index and earnings (P = 0.007). For the entire population, there was a significant improvement in performance index and earnings after surgery (82%) (P = 0.0001). CONCLUSIONS: Placing the larynx in a more rostral and dorsal position may have improved the performance in 80-82% of the horses affected with naturally-occurring DDSP. POTENTIAL RELEVANCE: 'Laryngeal tie-forward' is a surgical technique that has a measurable effect on the position of the larynx and offers an alternative therapy for treating horses affected with DDSP. More experience may be needed with this technique prior to its widespread use in horses with a clinical diagnosis of DDSP.