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  • Author or Editor: Joseph J. Kowalski x
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Abstract

Objective—To determine effects of topical antimicrobial and antimicrobial-corticosteroid preparations on the ocular flora of horses.

Animals—40 horses.

Procedure—One eye was treated 3 times daily for 2 weeks with one of the following ointments: 1) neomycinbacitracin- polymyxin B, 2) 0.6% prednisolone-0.3% gentamicin, 3) neomycin-polymyxin B-0.05% dexamethasone, or 4) treated (artificial tears) control. Contralateral eyes of treated control eyes served as untreated control eyes. Corneal and conjunctival specimens for bacterial and fungal cultures were collected prior to initiation of treatment, after 1 and 2 weeks of treatment, and 2 weeks after concluding treatment. Changes in culture growth quantity scores of bacterial and fungal species were analyzed.

Results—The most common species before treatment were the following: gram-positive bacteria included Streptomyces spp (66%) , Staphylococcus spp (46%) , Bacillus spp (32%) , and Streptococcus spp (32%); gramnegative bacteria included Moraxella spp (28%) , Escherichia coli (24%) , Acinetobacter spp (18%), and Enterobacter spp (14%); and fungi included Aspergillus nidulans (56%) , Cladosporium spp (32%), and Aspergillus fumigatus (22%). In all groups, the percentage of positive bacterial culture results, growth quantity score of gram-positive bacteria, and number of bacterial species isolated decreased at week 1 and increased at week 2, whereas growth quantity score of gram-negative bacteria decreased throughout treatment. Differences were not significant among groups. Fungal growth quantity score decreased during treatment in all groups. Repopulation of bacterial and fungal species occurred.

Conclusions and Clinical Relevance—All interventions decreased the number of microorganisms. Repopulation of normal flora occurred during and after treatment. (Am J Vet Res 2005;66:800–811)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether staphylococcal isolates cultured from pustules and carriage sites in dogs with superficial bacterial folliculitis were genotypically the same strain by use of pulsed-field gel electrophoresis (PFGE).

Animals—40 dogs with superficial bacterial folliculitis.

Procedures—Samples were obtained from 3 pustules and 3 carriage sites (anus, axillary skin, and nasal mucosa). Bacterial culture, morphologic identification, Gram staining, catalase and coagulase tests, speciation, and PFGE were performed.

Results—Of 246 isolates, 203 were Staphylococcus intermedius, 5 were Staphylococcus aureus, 15 were Staphylococcusspp, and 22 were coagulase-negative staphylococcal isolates. No dog had an isolate with the same PFGE pattern as an isolate from another dog. Coagulase-positive isolates from multiple pustules and multiple carriage sites had the same PFGE pattern in 37 of 39 (94.9%) and 22 of 39 (56.4%) dogs, respectively. Coagulase-positive staphylococcal isolates from at least 1 pustule had the same PFGE pattern as an isolate from at least 1 carriage site in 34 of 36 (94.4%) dogs. Ninety-seven of 116 (83.6%) coagulase-positive staphylococcal isolates from pustules had the same PFGE pattern as an isolate from at least 1 carriage site. Sixty-nine of 91 (75.8%) coagulase-positive staphylococcal isolates from carriage sites had the same PFGE pattern as an isolate from at least 1 pustule.

Conclusions and Clinical Relevance—Coagulasepositive staphylococcal strains were heterogeneous among dogs with superficial bacterial folliculitis. In individual dogs, strains from multiple pustules were genotypically the same, and strains from pustules were genotypically the same as strains from carriage sites.

Full access
in American Journal of Veterinary Research

SUMMARY

Prophylactic efficacy of 4 antibacterial shampoos against Staphylococcus intermedins in dogs was determined by use of a controlled quantitative technique. Ten adult Beagles were used in the study. The antibacterial agents in the shampoos were 3.0% benzoyl peroxide, 0.5% Chlorhexidine acetate, 1.0% available iodine as a polyalkyle-neglycol-iodine complex, and a combination of 0.5% triclosan, 2.0% sulfur, and 2.0% salicylic acid. Treated and control sites were challenge exposed with 5.30 ± 0.10 (log10) S intermedins colony-forming units (cfu)/cm2 of skin and occluded for 5 hours. At the end of the test period, remaining bacteria were removed with a detergent cup-scrub technique and the total number of S intermedins cfu/cm2 skin was calculated for each treated and control site.

Nontreated bacteria-challenged control sites yielded 5.62 ± 0.65 S intermedins cfu/cm2 of skin. Staphylococcus intermedins recovery (cfu/cm2) from the treated sites was 0.94 ± 0.76 for benzoyl peroxide, 1.96 ± 1.33 for Chlorhexidine acetate, 3.11 ± 0.48 for organic iodine, and 4.69 ± 0.23 for triclosan-sulfur-salicylic acid. Each S intermedins recovery value from the 4 treated sites was significantly (P < 0.05) lower than that from the nontreated S intermedins challenge-exposed control site. Bacteria recovery values were also significantly (P < 0.05) different among the 4 shampoo-treated sites.

We concluded that all shampoos had significant (P < 0.05) prophylactic activity against S intermedins over 5 hours. The shampoo containing benzoyl peroxide was determined to have the greatest efficacy among the products tested.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether coagulase-positive staphylococcal isolates that are genotypically the same strain obtained from pustules and carriage sites of individual dogs with superficial bacterial folliculitis have the same antimicrobial susceptibility phenotype.

Animals—40 dogs with superficial bacterial folliculitis.

Procedures—Samples were obtained from 3 pustules and 3 carriage sites (ie, anus, nonlesional axillary skin, and nasal mucosa) for bacterial culture, morphologic identification, Gram staining, catalase and coagulase testing, antimicrobial susceptibility testing, speciation, and pulsed-field gel electrophoresis (PFGE).

Results—223 isolates from pustules and carriage sites were included. Seventeen susceptibility phenotypes were found among isolates. One hundred twenty-eight (100%) isolates from pustules and 95 (100%) isolates from carriage sites were susceptible to cephalothin; 128 (100%) isolates from pustules and 94 (98.9%) isolates from carriage sites were susceptible to amoxicillin-clavulanic acid; 114 (89.1%) isolates from pustules and 82 (86.3%) isolates from carriage sites were susceptible to erythromycin and lincomycin hydrochloride; and 103 (80.5%) isolates from pustules and 70 (73.7%) isolates from carriage sites were susceptible to trimethoprim-sulfamethoxazole. In 37 of 39 (94.9%) dogs, isolates with the same PFGE pattern from multiple pustules had the same susceptibility phenotype. In 21 of 33 (63.6%) dogs, isolates from multiple carriage sites with the same PFGE pattern had the same susceptibility phenotype.

Conclusions and Clinical Relevance—In dogs with superficial bacterial folliculitis, most coagulase-positive staphylococcal isolates from pustules that are genotypically the same strain will have the same susceptibility phenotype and treatment may be based on empiric antimicrobial selection or susceptibility testing of 1 lesional isolate.

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in American Journal of Veterinary Research

Abstract

Objective

To determine whether Mycobacterium paratuberculosis could survive in colostrum after pasteurization. Additionally, this study investigated the effect pasteurization had on IgG concentration in colostrum.

Animals

Colostrum samples were collected from cattle (beef and dairy) owned by the state of Ohio.

Procedure

Colostrum was divided into aliquots and inoculated with variable concentrations of M paratuberculosis (ATCC No. 19698: 104, 103, and 102 colony-forming units/ml). Half the samples at each concentration were subjected to pasteurization temperatures (63 C) for 30 minutes and the remainder were kept at approximately 20 to 23 C. All samples were incubated (Herrold's egg yolk medium with and without mycobactin J) and observed for growth during the next 16 weeks. Additionally, the IgG concentration of colostrum was determined by radioimmunoassay before and after pasteurization. Samples that coagulated at pasteurization temperatures were mechanically resuspended before measurement of IgG concentration.

Results

Growth of M paratuberculosis was retarded but not eliminated by pasteurization. Growth was observed in all unpasteurized samples incubated on Herrold's egg yolk medium with mycobactin J but in only 2 of 18 pasteurized samples similarly cultured. Growth from pasteurized samples appeared 5 to 9 weeks after growth was observed from nonpasteurized samples.

Mean colostral IgG concentration was 44.4 g/L in nonpasteurized samples and 37.2 g/L in pasteurized sample, a decrease of 12.3%. High-quality colostrum (> 48 g of IgG/L) had a significantly greater loss of IgG concentration than did colostrum of lesser quality (P = 0.002).

Conclusions

Pasteurization lessened, but did not eliminate, growth of M paratuberculosis from experimentally inoculated colostrum samples. Pasteurization resulted in a significant decrease in colostral IgG concentration but not to an unmanageable level that would preclude the colostrum's use for passive transfer of immunity.

Clinical Relevance

Colostrum is macrophage rich and may serve as a source of M paratuberculosis infection to calves. Pasteurization of colostrum may lessen the risk of infection, but will not totally eliminate M paratuberculosis. (Am J Vet Res 1996;57:1580–1585)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To compare clinical efficacy of pulse administration with itraconazole versus once daily administration for the treatment of cutaneous and otic M pachydermatis infection in dogs.

Design—Randomized controlled trial.

Animals—20 dogs.

Procedure—Dogs were treated with itraconazole orally (n = 10/group), using a pulse administration regimen (5 mg/kg [2.3 mg/lb], PO, q 24 h for 2 consecutive days per week for 3 weeks) or once daily administration (5 mg/kg, PO, q 24 h for 21 days). No other treatment was permitted. On days 0 and 21, clinical severity of cutaneous and otic disease was assessed, and samples were collected for cytologic examination and yeast culture. Cytology (sum of the mean number of yeast organisms per oil immersion field for affected sites) and culture (mean of the score for extent of yeast growth for samples from affected sites) scores were calculated.

Results—For dogs in both treatment groups, clinical severity of cutaneous and otic disease was significantly decreased by day 21, but decrease in severity was not significantly different between groups. Similarly, skin cytology, skin culture, and ear culture scores were significantly decreased on day 21, compared with day 0, for both groups, but decreases were not significantly different between groups except that dogs in the pulse administration group had a significantly greater decrease in ear culture scores than did dogs in the daily administration group. However, when cytology scores only for ear samples were analyzed, day 21 score was not significantly decreased, compared with day 0 score, for either group.

Conclusions and Clinical Relevance—Results suggested that both pulse administration and once daily administration of itraconazole were efficacious in the treatment of M pachydermatis cutaneous infection in dogs. However, adjunctive treatment may be needed in dogs with M pachydermatis otitis. (J Am Vet Med Assoc 2002;220:1807–1812)

Full access
in Journal of the American Veterinary Medical Association

Objective

To compare microbial flora and antimicrobial susceptibility patterns of isolated pathogens from the horizontal ear canal and middle ear in dogs with otitis media.

Design

Prospective study.

Animals

23 dogs with chronic bilateral otitis externa.

Procedures

Swab specimens of the horizontal ear canal and middle ear were obtained for cytologic analysis, bacterial culture, and antimicrobial susceptibility testing. Integrity of the tympanic membrane was observed. If the tympanic membrane was intact, myringotomy was performed to collect specimens.

Results

Otitis media was diagnosed in 38 of 46 (82.6%) ears evaluated. The tympanic membrane was intact in 71.1 % of the ears with otitis media. The 3 most common organisms isolated from the horizontal ear canal and middle ear were Staphylococcus intermedius, yeast, and Pseudomonas spp. A difference in total isolates or susceptibility patterns between the horizontal ear canal and middle ear was found in 34 (89.5%) ears. Compared with results of bacterial culture, cytologic examination of swab specimens was not as effective for detection of rods and cocci from the middle ear.

Clinical Implications

In dogs with chronic otitis externa, otitis media often exists even when there is an intact tympanic membrane. In our study, the same isolates were rarely found in the horizontal ear canal and middle ear. Therefore, to choose appropriate antimicrobial agents, in addition to cytologic examination, bacterial culture and susceptibility testing of swab specimens from the horizontal ear canal and middle ear should be performed. (J Am Vet Med Assoc 1998; 212:534-538)

Free access
in Journal of the American Veterinary Medical Association