OBJECTIVE To evaluate the impact of gentamicin, silver, or both additives in polymethylmethacrylate (PMMA) beads on methicillin-resistant Staphylococcus pseudintermedius (MRSP) biofilm formation in vitro. SAMPLE 4 preparations of PMMA beads (formed with no additive [control], gentamicin, silver, and gentamicin and silver). PROCEDURES Beads from each group were exposed to 10 MRSP isolates known to be strong biofilm formers. Following incubation, the beads were rinsed to remove planktonic bacteria, then sonicated to dislodge biofilm-associated bacteria. Resulting suspensions were serially diluted, plated on blood agar, and incubated overnight; CFUs were counted. Variance of mean CFU counts following log10 transformation was analyzed among PMMA groups. RESULTS None of the PMMA additives tested completely inhibited MRSP biofilm formation. There was a significant effect of gentamicin and gentamicin plus silver on this variable, compared with controls, but not of silver alone. There was no difference between gentamicin and gentamicin plus silver. When only isolates not susceptible to gentamicin were evaluated, there were no significant differences among PMMA additive groups. Within gentamicin-susceptible isolates, there was an impact of gentamicin and gentamicin plus silver, but no impact of silver alone and no difference between gentamicin and gentamicin plus silver. CONCLUSIONS AND CLINICAL RELEVANCE Gentamicin-impregnated PMMA was effective at reducing biofilm formation of gentamicin-susceptible MRSP isolates but had no effect on isolates not susceptible to gentamicin. Silver-impregnated PMMA had no effect on MRSP biofilm formation. Results suggested that gentamicin-impregnated PMMA may not be effective in vivo against MRSP isolates not susceptible to gentamicin. Antibacterial efficacy of silver should not be assumed without proper testing of the target bacteria and specific silver compound.

OBJECTIVE To evaluate the effect of screw position on strength and stiffness of a combination locking plate–rod construct in a synthetic feline femoral gap model. SAMPLE 30 synthetic long-bone models derived from beechwood and balsa wood. PROCEDURES 3 constructs (2 locking plate–rod constructs and 1 locking plate construct; 10 specimens/construct) were tested in a diaphyseal bridge plating configuration by use of 4-point bending and torsion. Variables included screw position (near the fracture gap and far from the fracture gap) and application of an intramedullary pin. Constructs were tested to failure in each loading mode to determine strength and stiffness. Failure was defined as plastic deformation of the plate or breakage of the bone model or plate. Strength, yield angle, and stiffness were compared by use of a Wilcoxon test. RESULTS Placement of screws near the fracture gap did not increase bending or torsional stiffness in the locking plate–rod constructs, assuming the plate was placed on the tension side of the bone. Addition of an intramedullary pin resulted in a significant increase in bending strength of the construct. Screw positioning did not have a significant effect on any torsion variables. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that, in the investigated plate-rod construct, screw insertion adjacent to the fracture lacked mechanical advantages over screw insertion at the plate ends. For surgeons attempting to minimize soft tissue dissection, the decision to make additional incisions for screw placement should be considered with even more caution.

This study investigated whether changes in the vaginal electrical resistance (VER) of vaginal mucus of weaned sows during the first 7 d post-weaning are associated with time of ovulation. Time of ovulation was determined by ovarian ultrasound carried out from 91 to 146 h after weaning and at different seasons. Vaginal electrical resistance was measured at 20, 44, 68, 91, 96, 102, 115, 120, 126, 140, 146, and 164 h post-weaning and was found to decrease between 120 h and 31 h before ovulation and then increase until 40 to 50 h after ovulation. Duration and timing of the nadir was affected by the season (P < 0.01). Estrus was observed from day 4 after the lowest VER values. Ovulation occurred between late day 5 and late day 6, while VER values were still increasing. Ovulation was earlier in lower parity sows (P < 0.001). Compared to 0 h (ovulation time), VER was significantly lower from 50 to 5 h before ovulation in autumn and from 40 to 21 h in winter, but such differences were not seen in spring. Lowest VER value was not correlated with time of ovulation. It was concluded that VER increases before ovulation and, although this increase is influenced by the season, it cannot be used to accurately predict ovulation in weaned sows.

This study describes and measures the impact of different compositions and finishes of stainless steel used in equipment in the meat industry on the transfer of natural flora and selected pathogens from artificially contaminated pork skin. It is known that the adhesion to surfaces of Listeria monocytogenes and Salmonella, 2 pathogens frequently found in contaminated pork meat, depends on the nature and roughness of the surface. Our results show no statistically significant differences in microbial transfer regardless of the types of stainless steel considered, with the highest measured transfer difference being 0.18 log colony-forming units (CFUs)/800 cm2. Moreover, no differences in total microbial community were observed after transfer on the 5 types of stainless steel using single-strand conformation polymorphism (SSCP). It was concluded that the different characteristics of the stainless steel tested did not affect the initial bacterial transfer in this study.

OBJECTIVE To compare effects of training on conventional and underwater treadmills on fiber properties and metabolic responses of the superficial digital flexor (SDF) and gluteal muscles to high-speed exercise in horses. SAMPLE 6 unconditioned Quarter Horse–type horses. PROCEDURES 6 horses were walked on underwater and conventional treadmills for 5 d/wk (maximum, 40 min/d) for 8 weeks in a randomized crossover design (60-day detraining period). Horses underwent a standardized exercise test (SET) at high speed before and after training. Analyte concentrations and fiber characteristics were measured in muscle biopsy specimens obtained from horses before and after each SET. RESULTS Lactate concentration increased 2- to 3-fold in SDF and gluteal muscle after SETs. No training effect was identified on muscle fiber type composition, type II fiber diameter, muscle analyte concentrations, blood lactate concentration, or heart rate responses. Maximum diameters of type I fibers decreased significantly in gluteal muscle with conventional treadmill training and decreased in SDF muscle with both types of training, with maximum diameters greater for horses after underwater versus conventional treadmill training. No change was identified in minimum fiber diameters. CONCLUSIONS AND CLINICAL RELEVANCE SETs involving near-maximal exertion resulted in an anaerobic response in SDF and gluteal muscles of horses. Eight weeks of conventional or underwater treadmill training resulted in minor changes in type I muscle fiber sizes, with no effect on muscle metabolic or heart rate responses to SETs. After rehabilitation involving underwater treadmills, training at progressing speeds is recommended for horses to develop the required fitness for speed work.

This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout.

A convention that has been adopted in medicine is to estimate haemoglobin (HB) concentration as a third of packed cell volume (PCV) or vice versa. The present research set out to determine whether a proportional relationship exists between PCV and Hb concentration in cattle blood samples, and to assess the validity of the convention of estimating Hb concentration as a third of PCV. A total of 440 cattle in Ghana from four breeds (Ndama, 110; West African Short Horn, 110; Zebu, 110 and Sanga, 110) were bled for haematological analysis, specifically packed cell volume, using the microhaematocrit technique and haemoglobin concentration using the cyanmethaemoglobin method. Means, standard deviations, standard errors of mean and 95% confidence intervals were calculated. Trendline analyses generated linear regression equations from scatterplots. For all the cattle, a significant and consistent relationship (r= 0.74) was found between Hb concentration and PCV (%). This was expressed as Hb concentration (g/dL) = 0.28 PCV + 3.11. When the Hb concentration was estimated by calculating it as a third of PCV, the relationship was expressed in linear regression as Hb concentration (g/dL) = 0.83 calculated Hb + 3.11. The difference in the means of determined (12.2 g/dL) and calculated (10.9 g/dL) Hb concentrations for all cattle was significant (p < 0.001), whereas the difference in the means of determined Hb and corrected calculated Hb was not significant. In conclusion, a simplified relationship of Hb (g/dL) = (0.3 PCV) + 3 may provide a better estimate of Hb concentration from the PCV of cattle.

Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR) assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%), fimH (33.3%) and hlyF (24.4%). The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.

Resistance to antibiotics has continued to increase, placing future animal and human disease management in real danger. The developing countries characterised by widespread indiscriminate antibiotic use and in which 'third-generation' antibiotics are not readily available or affordable are the worst affected. A 3-year (2010-2012) retrospective survey of antibiotic usage in livestock production in three selected states of south-western Nigeria was conducted. Data obtained from eight purposively selected licensed veterinary pharmaceutical sales establishments in the area, based on keeping detailed sales records for the study period, were analysed using Stata Version 12. Results showed that tetracyclines (33.6%), fluoroquinolones (26.5%) and beta-lactams/aminoglycosides (20.4%) constituted the majority of the antibiotics used over the 3 years. The differences in the quantities of antibiotic types used within each antimicrobial class were statistically significant for tetracyclines (F = 59.87; p < 0.0001) and fluoroquinolones (F = 43.97; p < 0.0001) but not for beta-lactams/aminoglycosides (F = 3.21; p = 0.148). Furthermore, antibiotic consumption increased by 40.4% between 2010 and 2012. Although statistically insignificant (F = 0.277; p = 0.762), the increasing trend across the years was at rates of 23.5% between 2010 and 2011 and 13.8% between 2011 and 2012. In addition, the findings show a significantly higher consumption rate (t = 15.21; df = 5; p < 0.0001) during the rainy (52.5%) than the dry (47.5%) seasons. The current increasing trend in antibiotic usage holds a serious danger for the future and therefore calls for alternative plans to safeguard future livestock production, food security and human health. This becomes more imperative considering emerging resistance against tetracyclines and fluoroquinolones, the foremost remedies for livestock diseases in most developing countries.

Slaughterhouses provide a safeguard that prevents the public from consuming meat of poor quality or meat which may be infected with zoonotic diseases. This work reviews a 3-year database of cattle that were slaughtered and inspected between 2010 and 2012 at Dodoma abattoir, Tanzania. In addition, meat inspection was undertaken for 1 month (December 2013). The aim of this study was to establish causes of organ and carcass condemnations and their financial implications as well as the magnitude of slaughter of pregnant cows at Dodoma abattoir. During retrospective study, it was found that a total of 9015 (10.5%) lungs, 6276 (7.3%) intestines, 5402 (6.3%) livers, 3291 (3.8%) kidneys and 41 (0.05%) carcasses were condemned. Pulmonary emphysema (3.4%), fasciolosis (4.5%), pimply gut (5.7%), kidney congenital cysts (1.9%) and hydatidosis (3.1%) were major causes of organ condemnations. This large number of condemned edible organs and/or carcasses implies that public health considerations result in deprivation of valuable protein. Occurrence of hydatidosis, cysticercosis, fasciolosis and tuberculosis illustrates the possible public health problem and presence of environmental infections. Of the 794 cows slaughtered in December 2013, 46% were pregnant. Financial loss as a result of organ and/or carcass condemnations was estimated at $9892. Condemnation of organs and/or carcasses and indiscriminate slaughter of pregnant cows represent a significant loss of meat and revenue and a reduction in growth of future herds, which has a negative effect on the livestock industry. This justifies appropriate surveillance and disease control programmes coupled with strict enforcement of legislation governing animal welfare to curb the slaughter of pregnant animals.