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Bacterial biofilms: their importance in animal health and public health | Les biofilms bactériens : leur importance en santé animale et en santé publique
2014
Tremblay, Yannick D.N. | Hathroubi, Skander | Jacques, Mario
Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared to their planktonic counterparts. The ability to form biofilms is now considered an attribute of many microorganisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Furthermore, the presence of biofilms on surfaces found at farms, slaughterhouses or food processing plants will have an impact on the efficacy of disinfection protocols. Surprisingly, biofilm formation by bacterial pathogens of veterinary or zoonotic importance has received relatively little attention. The objective of this brief Review article is to bring awareness about the importance of biofilms to animal health stakeholders.
Afficher plus [+] Moins [-]Comparison of sampling techniques for measuring the antimicrobial susceptibility of enteric Escherichia coli recovered from feedlot cattle
2002
Wagner, Bruce A. | Dargatz, David A. | Salmān, Muḥammad | Morley, Paul S. | Wittum, Thomas E. | Keefe, Thomas J.
Objective - To evaluate the effectiveness of various sampling techniques for determining antimicrobial resistance patterns in Escherichia coli isolated from feces of feedlot cattle. Sample Population - Fecal samples obtained from 328 beef steers and 6 feedlot pens in which the cattle resided. Procedure - Single fecal samples were collected from the rectum of each steer and from floors of pens in which the cattle resided. Fecal material from each single sample was combined into pools containing 5 and 10 samples. Five isolates of Escherichia coli from each single sample and each pooled sample were tested for susceptibility to 17 antimicrobials. Results - Patterns of antimicrobial resistance for fecal samples obtained from the rectum of cattle did not differ from fecal samples obtained from pen floors. Resistance patterns from pooled samples differed from patterns observed for single fecal samples. Little pen-to-pen variation in resistance prevalence was observed. Clustering of resistance phenotypes within samples was detected. Conclusions and Clinical Relevance - Studies of antimicrobial resistance in feedlot cattle can rely on fecal samples obtained from pen floors, thus avoiding the cost and effort of obtaining fecal samples from the rectum of cattle. Pooled fecal samples yielded resistance patterns that were consistent with those of single fecal samples when the prevalence of resistance to an antimicrobial was > 2%. Pooling may be a practical alternative when investigating patterns of resistance that are not rare. Apparent clustering of resistance phenotypes within samples argues for examining fewer isolates per fecal sample and more fecal samples per pen.
Afficher plus [+] Moins [-]Effects of abdominal insufflation with nitrous oxide on cardiorespiratory measurements in spontaneously breathing isoflurane-anesthetized dogs
1993
Gross, M.E. | Jones, B.D. | Bergstresser, D.R. | Rosenhauer, R.R.
Cardiorespiratory effects of abdominal insufflation were evaluated in 8 dogs during isoflurane anesthesia. Each dog was studied 3 times, in 1 of the following orders of insufflation pressures: 10-20-30, 20-30-10, 30-20-10, 10-30-20, 20-10-30, and 30-10-20 mm of Hg. Anesthesia was induced by use of a mask, dogs were intubated, and anesthesia was maintained by isoflurane in 100% oxygen. After instrumentation, baseline values were recorded (time 0), and the abdomen was insufflated with nitrous oxide. Data were recorded at 5, 10, 15, 20, 25, and 30 minutes after insufflation. The abdomen was then desufflated, with recording of data continuing at 35 and 40 minutes. Mean arterial pressure increased at 5 minutes during 20 mm of Hg insufflation pressure, and from 20 to 30 minutes during 30 mm of Hg pressure. Tidal volume decreased from 5 to 30 minutes during 10 and 20 mm of Hg pressures, and from 5 to 40 minutes during 30 mm of Hg pressure. Minute ventilation decreased at 10 and 20 minutes during 20 mm of Hg pressure. End-tidal CO2 concentration increased from 5 to 30 minutes during 20 and 30 mm of Hg pressure. The PaCO2 decreased at 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Values for pH decreased from 10 to 30 minutes during 20 and 30 mm of Hg pressures. The PaO2 decreased from 20 to 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Percentage decrease in tidal volume was greater at 5 and 15 minutes with 30 mm of Hg pressure. Differences in percentage increase in end tidal CO2 concentration were observed among the 3 pressures from 5 to 30 minutes. Although significant, these changes do not preclude use of laparoscopy if insufflation pressure > 20 mm of Hg is avoided.
Afficher plus [+] Moins [-]Use of a protected catheter brush for culture of the lower respiratory tract in horses with small airway disease
1991
Grandguillot, L. | Fairbrother, J.M. | Vrins, A.
A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheal and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy using a protected catheter brush is an easy and practical technique to obtain minimally contaminated samples for isolation of microorganisms from the lower respiratory tract of horses. However, no association was observed between isolation of high numbers of microorganisms from the bronchi and severity of small airway disease.
Afficher plus [+] Moins [-]Ignorance as a factor influencing the prevalence of onchocerciasis in some villages in Oyo State, Nigeria
2017
Akinboade, O. A. | Anong, C. I. N. | Uwalaka, E. C.
Most studies on Simulum damnosum in Nigeria has focused mainly on the problem of onchocerciasis from the ecological standpoint. However, this study is aimed at viewing it from the human angle, with focus placed on the ignorance of the rural dwellers about the influences of their environment on the increasing incidences of onchocerciasis in their population. The premise is that, as the government and the scientists are working towards finding a lasting solution to the epidemic, the rural dwellers need to wake up to the realities of their own destiny. They need to come out and collaborate with other good efforts to form a strong united force that will rid their society of this menace. A study on the level of ignorance was carried out. It is assumed that their ignorance has kept the villagers relatively inactive and passive about freeing themselves. A descriptive method was used for this research and about 450 villagers were randomly selected and verbally interviewed. A questionnaire was designed and used as the instrument of the research. The research was carried out in two different villages of Asejire and Asepari. Findings were encouraging. Some of the villagers did not know about the existence of the disease even when some of their close relatives showed the symptoms. This high level of ignorance shows that it will be difficult to attain any cooperation from them in any attempt to make their environment unfavourable for the vector.
Afficher plus [+] Moins [-]A new technique for repeated biopsies of the mammary gland in dairy cows allotted to Latin-square design studies
2016
Lima, Luciano S de | Martineau, Eric | Marchi, Francilaine F de | Palin, Marie-France | Santos, Geraldo T dos | Petit, Helene V.
The objective of this study was to develop a technique for carrying out repeated biopsies of the mammary gland of lactating dairy cows that provides enough material to monitor enzyme activities and gene expression in mammary secretory tissue. A total of 16 Holstein cows were subjected to 4 mammary biopsies each at 3-week intervals for a total of 64 biopsies. A 0.75-cm incision was made through the skin and subcutaneous tissue of the mammary gland and a trocar and cannula were inserted using a circular motion. The trocar was withdrawn and a syringe was plugged into the base of the cannula to create a vacuum for sampling mammary tissue. To reduce bleeding, hand pressure was put on the surgery site after biopsy and skin closure and ice was applied for at least 2 h after the biopsy using a cow bra. The entire procedure took an average of 25 min. Two attempts were usually enough to obtain 800 mg of tissue. Visual examination of milk samples 10 d after the biopsy indicated no trace of blood, except in samples from 2 cows. All wounds healed without infection and subcutaneous hematomas resorbed within 7 d. There was no incidence of mastitis throughout the lactation. This technique provides a new tool for biopsy of the mammary gland repeated at short intervals with the main effect being a decrease in milk production. Although secondary complications leading to illness or death are always a risk with any procedure, this biopsy technique was carried out without complications to the health of animals and with no incidence of mastitis during the lactation.
Afficher plus [+] Moins [-]Estimation of glomerular filtration rate and evaluation of renal function in ferrets (Mustela putorius furo)
1994
Esteves, M.I. | Marini, R.P. | Ryden, E.B. | Murphy, J.C. | Fox, J.G.
Three methods of determining glomerular filtration rate (GFR) were performed in adult ferrets, 9 months to 7 years old. Endogenous creatinine clearance was determined, using serum and urine creatinine values obtained during 24- and 48-hour collection periods from 27 ferrets housed in metabolic cages. Creatinine and radiolabeled inulin were administered to 12 female ferrets by constant IV infusion during isoflurane-induced anesthesia. Serial 20-minute urine collections, together with serum samples obtained at the midpoint of urine collection, provided measures for clearance calculations of these substances. Mean +/- SD endogenous creatinine clearance in ferrets for metabolic cage collections was 2.50 +/- 0.93 ml/min/ kg of body weight. There were no significant differences between the 24- and 48-hour clearance rates. Mean inulin clearance was 3.02 +/- 1.78, and mean exogenous creatinine clearance was 3.32 +/- 2.16 ml/ min/kg. Analysis of variance, using least-squared means adjustment, did not yield any significant differences between inulin and exogenous creatinine clearance rates. Exogenous creatinine clearance-to-inulin clearance ratio was 0.99 +/- 0.46, and there was significant correlation between the 2 methods (r = 0.82, P = 0.0001). Significant body temperature effects on inulin or exogenous creatinine clearance were not found. Infused inulin clearance, the generally preferred method for GFR calculation in mammalian species, was significantly (P = 0.0069) higher in younger (3.65 ml/min/kg) vs older ferrets (2.29 ml/min/kg). Results of this study indicate that inulin clearance is an adequate measure of GFR in ferrets as it is in other species. Compared with inulin clearance, exogenous creatinine clearance also provides a reliable estimate of GFR in ferrets.
Afficher plus [+] Moins [-]Leukocyte mobilization to skin lesions in dogs
1993
Wisselink, M.A. | Koeman, J.P. | Willemse, T.
A suction blister technique was used in 10 healthy dogs to remove the epidermis from the dermis in a standardized way. Collection chambers were attached to these skin windows and filled with autologous serum to attract exudative neutrophils. The chambers were emptied by fine-needle aspiration at 4-hour intervals and were refilled with serum for 24 hours after the Int aspiration. The collected cells were counted, differentiated, and stained, using the trypan blue dye-exclusion method to determine cell viability. Multiple skin biopsy specimens obtained during the procedure were examined histologically. The chamber fluid collected after 24 hours was cultured for bacteria. Increasing numbers of viable neutrophils were collected during the 24-hour period from the induced skin windows. In all but 1 dog, sufficient viable neutrophils could be collected to perform further functional tests in vitro. Our conclusion is that this technique might be useful to study chemotaxis in vivo and to perform functional tests on exudative neutrophils.
Afficher plus [+] Moins [-]Thermodilution estimation of cardiac output at high flows in anesthetized horses
1991
Dunlop, C.I. | Hodgson, D.S. | Chapman, P.L. | Grandy, J.L. | Waldron, R.D.
The purpose of this study was to compare the thermodilution technique for estimation of cardiac output with the indocyanine green dye dilution technique at flows between 10 and 39 L/min in halothane-anesthetized horses. The estimation of area of dye dilution cardiac output curves was made by using the fore-'n-aft (FA) triangle method. This shorthand technique was compared with logarithmic exponential extrapolation and summation (extrapolated area), using 64 cardiac output curves. Then, 256 simultaneous thermodilution measurements were compared with dye dilution measurements calculated by use of the FA technique. Forty milliliters of iced 0.9% NaCl solution containing 15 mg of indocyanine green dye was used as the indicator. This was delivered in < 1 second to the right atrium, using a power injector. A thermistor positioned in the pulmonary artery detected the thermal indicator. Blood was withdrawn from the carotid artery through a densitometer cuvette to measure the dye concentration. The FA estimations of area were higher than those determined by use of extrapolated area. A multiplicative adjustment of 0.837 was estimated. On average, thermodilution estimates of cardiac output exceeded the adjusted FA determinations. Using a weighted linear regression, we determined the following calibration adjustment: thermal dilution cardiac output/1.048 = indocyanine green dye dilution cardiac output.
Afficher plus [+] Moins [-]Anatomy of the laryngeal and adjacent regions as perceived by palpation of clinically normal standing horses
1990
McCarthy, P.H.
The anatomy of each feature and structure of the laryngeal and adjacent regions, as perceived by palpation, is described for clinically normal standing horses. Visible skin contours produced by some of the superficial structures are also described. Concurrent dissection was performed on fresh cadavers to confirm initial findings. The procedure of systematic palpation in relation to clinical diagnosis and surgical procedure is discussed.
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