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    William Fales

    Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities... more
    Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for blaCMY beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg
    Five isolants of Pseudomonas aeruginosa collected from clinical cases of equine genital infection and one standard strain of P. aeruginosa were exposed to various concentrations of ethylene-diaminetetraacetic acid (EDTA) and tris... more
    Five isolants of Pseudomonas aeruginosa collected from clinical cases of equine genital infection and one standard strain of P. aeruginosa were exposed to various concentrations of ethylene-diaminetetraacetic acid (EDTA) and tris (hydroxymethyl) aminomethane (tris buffer pH 8) and EDTA-tris lysozyme. Colony forming units of the isolants and minimal inhibitory concentrations for 11 antimicrobial agents were determined with each isolant before and after exposure to the EDTA solutions. Decreased cellular viability was found with all six isolants after exposure to the EDTA-tris solutions. Reversal of antimicrobial resistance was variable and unpredictable. These effects were not enhanced by the addition of lysozyme. The results suggest that EDTA-tris could be a useful adjunct in treating equine genital infections caused by Pseudomonas aeruginosa.
    The in vitro leukotoxic activity of 3 bovine isolates of Fusobacterium necrophorum which varied in pathogenicity were compared. Monolayers of mouse peritoneal macrophages were exposed to culture filtrates from each F necrophorum strain,... more
    The in vitro leukotoxic activity of 3 bovine isolates of Fusobacterium necrophorum which varied in pathogenicity were compared. Monolayers of mouse peritoneal macrophages were exposed to culture filtrates from each F necrophorum strain, and cell viability was determined, using the trypan blue dye exclusion test. Two methods were used for production of the leukotoxin: (1) medium M-1 continuous dialysis sac cultures and (2) brain-heart infusion agar plate cultures. Supernatant cultural fluids containing the leukotoxin were subjected to membrane-partition chromatography, using ultrafilters with approximate molecular weight (mol wt) exclusion limits of 100,000, 10,000, 2,000, and 500. All ultrafiltrates had a cytotoxic effect on the monolayers. Cytotoxic activity was not found in the ultrafilter residues or in the control media ultrafiltrates. Comparative study of leukotoxin production indicated that F necrophorum 2101, type A, produced the most leukotoxin; F necrophorum 2030, type AB, produced slightly less leukotoxin; and F necrophorum 2035, type B, produced small amounts of leukotoxin. Endotoxin activity, as demonstrated by the mouse lethality test, was found in the residues of the XM-100A ultrafilter (100,000 mol wt), but not in the filtrates. Culture supernatant fluids and the XM-100A ultrafiltrates were positive for endotoxin, using the limulus amebocyte lysate assay; however, the other ultrafiltrates with lower mol wt exclusion limits were negative.
    A survey for anaerobic bacteria was conducted in 314 clinical specimens from dogs and cats. A total of 187 anaerobic isolates in pure and mixed culture were isolated from 111 of the specimens that contained anaerobic bacteria. Common... more
    A survey for anaerobic bacteria was conducted in 314 clinical specimens from dogs and cats. A total of 187 anaerobic isolates in pure and mixed culture were isolated from 111 of the specimens that contained anaerobic bacteria. Common isolated included Actinomyces (9.1%), Clostridium perfringens (19.3%), other Clostridium spp (11.2%), Peptostreptococcus anaerobius (7.5%), Bacteroides melaninogenicus (13.4%), other Bacteroides spp (17.6%), and Fusobacterium necrophorum (5.3%). Anaerobic bacteria were involved in serious lesions that often were life threatening to the animals. Antibiotic susceptibility data indicated that the lincomycin family, the penicillin family, chloramphenicol, and cephaloridine are preferred drugs for treatment of anaerobic infections. Data from the survey were used in formulation of a table to aid practitioners in clinical diagnosis of disease caused by anaerobes. Clostridium perfringens was isolated in large numbers from five of six dogs with a clinical diagnosis of canine hemorrhagic gastroenteritis and from one cat with hemorrhagic diarrhea. Experimental infections were induced in rats, using caine feces as inoculum. Induced lesions contained aerobic and anaerobic bacteria similar to those bacteria isolated in the clinical survey, indicating that feces may serve as a major source of these bacteria in clinical infections of the dog.
    A method to demonstrate leukotoxic activity of Fusobacterium necrophorum in vitro is described. Continuous dialysis sac culture system, using reduced liquid medium was used to grow F necrophorum for 7-day periods. The continuous culture... more
    A method to demonstrate leukotoxic activity of Fusobacterium necrophorum in vitro is described. Continuous dialysis sac culture system, using reduced liquid medium was used to grow F necrophorum for 7-day periods. The continuous culture dialysis filtrate contained leukotoxic substance(s) which appeared to be less than 10,000 in molecular weight, heat resistant, and stable at 4 C for at least 10 days. Leukotoxic activity was demonstrated in vitro by determining the percentage of macrophages taking up trypan blue dye after these were exposed to a 1:2 solution of continuous culture dialysis filtrate and Eagle's minimal essential medium at 1, 2, 4, and 6 hours. Approximately 90% of these macrophages were destroyed during the 6-hour incubation period.
    Specimens obtained from the skin of healthy dogs and from various surgical and pyogenic lesions were culturally examined for coagulase-positive staphylococci. The isolates of Staphylococcus were biotyped, using hemolysin production,... more
    Specimens obtained from the skin of healthy dogs and from various surgical and pyogenic lesions were culturally examined for coagulase-positive staphylococci. The isolates of Staphylococcus were biotyped, using hemolysin production, coagulase production, and the biochemical tests contained in a commercial Staphylococcus identification system. A total of 72 coagulase-positive isolates were biotyped, with 70/72 identified as S intermedius and 2/72, as S aureus. All of the S intermedius isolates were coagulase-positive with canine plasma.
    Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and... more
    Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and included 7 genera, with Aspergillus sp being the most prevalent. Ten of the eyes with fungal keratitis had been treated with corticosteroids. Eleven of 38 eyes had mixed bacterial and fungal infections. Clinically, the most severe cases were those in which Aspergillus and gram-negative bacteria existed in a mixed infection. On the basis of susceptibility testing, gentamicin was highly efficacious (88.4%) against all bacterial isolates. Cephaloridine was slightly more efficacious than gentamicin against the gram-positive organisms. Only 32.3% of the gram-negative isolates were susceptible to chloramphenicol. Of the relatively small number of gram-positive organisms isolated, streptococci were more often susceptible to chloramphenicol, whereas staphylococci were more often susceptible to gentamicin.
    Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and... more
    Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and included 7 genera, with Aspergillus sp being the most prevalent. Ten of the eyes with fungal keratitis had been treated with corticosteroids. Eleven of 38 eyes had mixed bacterial and fungal infections. Clinically, the most severe cases were those in which Aspergillus and gram-negative bacteria existed in a mixed infection. On the basis of susceptibility testing, gentamicin was highly efficacious (88.4%) against all bacterial isolates. Cephaloridine was slightly more efficacious than gentamicin against the gram-positive organisms. Only 32.3% of the gram-negative isolates were susceptible to chloramphenicol. Of the relatively small number of gram-positive organisms isolated, streptococci were more often susceptible to chloramphenicol, whereas staphylococci were more often susceptible to gentamicin.
    Samples collected from both external ear canals of six adult female African elephants (Loxodonta africana) were cultured for fungi, yeasts and aerobic and anaerobic bacteria. All the samples produced heavy growths of several aerobic... more
    Samples collected from both external ear canals of six adult female African elephants (Loxodonta africana) were cultured for fungi, yeasts and aerobic and anaerobic bacteria. All the samples produced heavy growths of several aerobic bacteria, but anaerobic bacteria were rare and no fungi or yeasts were isolated. The most common bacterium isolated was Staphylococcus epidermidis, which was cultured from 11 of the 12 ears. Acinetobacter calcoaceticus lwoffi, alpha-haemolytic Streptococcus and Corynebacterium species, and Aeromonas caviae were all isolated from at least six of the 12 ears.
    ... ROBERT T. FRANKLIN, DVM, EVERETT ARONSON, DVM, RON K. FALLON, DVM, WILLIAM H. FALES, PHD., STEVE L. STOCKHAM, DVM, MS, LARRY P. THORNBURC, DVM, PHD. An eight-year-old, female, spayed Golden Retriever was referred to the University of... more
    ... ROBERT T. FRANKLIN, DVM, EVERETT ARONSON, DVM, RON K. FALLON, DVM, WILLIAM H. FALES, PHD., STEVE L. STOCKHAM, DVM, MS, LARRY P. THORNBURC, DVM, PHD. An eight-year-old, female, spayed Golden Retriever was referred to the University of Missouri ...
    This report describes the phenotypic characteristics of a novel Penicillium species, Penicillium labradorum, isolated from a 3-year-old male, castrated, Labrador retriever with disseminated fungal disease. The dog's presenting... more
    This report describes the phenotypic characteristics of a novel Penicillium species, Penicillium labradorum, isolated from a 3-year-old male, castrated, Labrador retriever with disseminated fungal disease. The dog's presenting clinical signs included lethargy, lymphadenopathy, tachypnea, moderate pitting edema, and nonweight bearing lameness associated with the right hind limb. Fine-needle aspirate biopsies from the sublumbar and prescapular lymph nodes were initially examined. The cytologic findings were consistent with pyogranulomatous inflammation with abundant extracellular and phagocytized fungal fragments and hyphae. Based on the morphology of the organisms and lack of endogenous pigment, hyalohyphomycosis was considered most likely, with Fusarium, Penicillium, and Paecilomyces species being considerations. Fungal isolates were obtained via culture of samples from the lymph nodes, and molecular identification testing originally identified an undescribed Penicillium species belonging to the Penicillium section Exilicaulis. BLAST searches and phylogenetic analyses performed approximately 1 year and 9 months after the isolation date revealed an isolate within the Penicillium parvum clade in the Penicillium section Exilicaulis but phylogenetically distant from the other species in the section, thus representing a new species, Penicillium labradorum. Antifungal susceptibility testing was also performed on the isolate and low minimum inhibitory concentrations were observed with terbinafine, voriconazole, and posaconazole, while in vitro resistance was observed with fluconazole. The dog had been previously treated with fluconazole, itraconazole, amphotericin B lipid complex, voriconazole, and terbinafine. Approximately 587 days after the initial diagnosis, the dog was euthanized due to worsening of clinical signs and concerns for quality of life.
    Economical, injectable antibiotics are beneficial when clinical manifestations of an animal model prevent the use of oral antibiotics. Ceftiofur crystalline-free acid (CCFA) is an injectable, sustained-release form of ceftiofur, a... more
    Economical, injectable antibiotics are beneficial when clinical manifestations of an animal model prevent the use of oral antibiotics. Ceftiofur crystalline-free acid (CCFA) is an injectable, sustained-release form of ceftiofur, a third-generation cephalosporin that is labeled for use in swine, cattle, and horses. Because CCFA is an economical, injectable antibiotic that could be of value for use in research dogs, the objective of this study was to determine the pharmacokinetic properties of CCFA in apparently healthy dogs and to determine the minimal inhibitory concentrations of ceftiofur for veterinary pathogens cultured during 2011 through 2014 from the respiratory system, integumentary system, and urinary system of dogs. The study population comprised of 5 dogs (age, 1 y; weight, 24.7 to 26.9 kg) that were deemed healthy after no abnormalities were found on physical exam, CBC analysis, and clinical chemistry panel. Each dog received CCFA at 5.0 mg/kg SC, and blood samples were collected before administration of CCFA and at 1, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, 168, 192, 216, and 240 h after injection. The maximal plasma concentration (mean ± 1 SD) of CCFA was 1.98 ± 0.40 μ g/mL, time to reach maximal concentration was 22.3 ± 8.9 h, half-life was 56.6 ± 16.9 h, and AUC0-last was 124.98 ± 18.45 μ g-h/mL. The minimal inhibitory concentrations of ceftiofur ranged from ≤ 0.25 to ≥ 8.0 μ g/mL; ceftiofur was most effective against Pasteurella spp., Proteus spp., and Escherichia coli haemolytica and least effective against Bordatella bronchiseptica, Enterococcus spp., and Pseudomonas aeruginosa.
    Seventy-three aerobic bacterial isolates were cultured from 64 eyes of 63 horses with infectious keratitis. Forty-two (58%) of the organisms isolated initially were gram-positive (g+, 10 genera) and 31 (42%) were gram-negative (g-, 5... more
    Seventy-three aerobic bacterial isolates were cultured from 64 eyes of 63 horses with infectious keratitis. Forty-two (58%) of the organisms isolated initially were gram-positive (g+, 10 genera) and 31 (42%) were gram-negative (g-, 5 genera). After local antimicrobial treatment, repeat cultures from samples obtained from 15 eyes of hospitalized horses yielded 21 secondary bacterial isolates. Staphylococci spp and Streptococci spp were the most common g(+) isolates and accounted for 79% of g(+) organisms isolated initially. Antibiograms revealed ticarcillin to be the most efficacious antibiotic tested on g(+) organisms, with 28 of 30 (93%) being susceptible. Of commercially available topical ophthalmic antibiotics tested on g(+) organisms, erythromycin was the most efficacious, with 32 of 35 (91%) isolates being susceptible. Pseudomonas spp, Escherichia coli, and Acinetobacter spp accounted for 68% of g(-) organisms isolated initially. Gentamicin, tobramycin, polymyxin B, and neomyci...
    A 3-year-old Texas Longhorn steer had a long history of progressive swelling of the soft tissues of the jaw and neck. At necropsy, multifocal to coalescing dermal and subcutaneous pyogranulomas were surrounded by fibrous tissue.... more
    A 3-year-old Texas Longhorn steer had a long history of progressive swelling of the soft tissues of the jaw and neck. At necropsy, multifocal to coalescing dermal and subcutaneous pyogranulomas were surrounded by fibrous tissue. Microscopically, the pyogranulomas contained aggregates of gram-negative coccobacilli surrounded by Splendore-Hoeppli material and were separated by bands of fibrovascular tissue (botryomycosis). Phylogenetic analysis of multilocus sequence-typing data revealed that the bacteria recovered in pure culture from swabs of submandibular tissue were most closely related to Bibersteinia [ Pasteurella] trehalosi. The bacterial colonies were immunohistochemically reactive with a rabbit polyclonal anti-Pasteurella class C acid phosphatase antibody. Botryomycosis is a pyogranulomatous inflammation caused by a variety of nonbranching, nonfilamentous bacteria that elicit the formation of Splendore-Hoeppli material. This case of botryomycosis is unique for its association...
    ... Thcriogeciology 47, 795-800 RATfI, D., LONG, CR, [)OBRINSK\, J. R., WELtCH, l. R., SCHREIER, LL & JOI INSON, LA (1999) In svitro prodLictioniof sexed enibrxos for genider preselectioni: high-speed sortinig of... more
    ... Thcriogeciology 47, 795-800 RATfI, D., LONG, CR, [)OBRINSK\, J. R., WELtCH, l. R., SCHREIER, LL & JOI INSON, LA (1999) In svitro prodLictioniof sexed enibrxos for genider preselectioni: high-speed sortinig of X-chrclirosome-bearinig sperm to pro-dcice pigs after emnbryo ...
    Chlamydia psittaci is a major cause of ovine abortion in the fourth to fifth months of gestation. During the lambing seasons of 1986, 1987, and 1988, fetuses from 52 cases of ovine abortion, stillbirth, or perinatal death were submitted... more
    Chlamydia psittaci is a major cause of ovine abortion in the fourth to fifth months of gestation. During the lambing seasons of 1986, 1987, and 1988, fetuses from 52 cases of ovine abortion, stillbirth, or perinatal death were submitted to the laboratory for necropsy examination. Placenta or fetal tissues from 34 cases were cultured on mouse L cells for C. psittaci. Chlamydia psittaci was identified by immunofluorescence on cultures in 20 of these cases. The major gross lesion consistently associated with Chlamydial abortion was placentitis with multifocal cotyledonary necrosis and accumulation of red-brown exudate in the intercotyledonary placenta Chlamydiae appeared as spherical organisms, less than 1 μm in diameter, in the cytoplasm of tropho-blasts in impression smears of cotyledons. Histologically, placentitis was sometimes accompanied by pneumonia or encephalitis in the fetus. Chlamydia psittaci was considered the cause for fetal death when Chlamydial isolation was associated ...
    ABSTRACT Parvovirus infection was confirmed by fluorescent antibody staining or viral culturing in 137 (22%) of 615 necropsy accessions from dogs at the Missouri Veterinary Medical Diagnostic Laboratory from Jan 1, 1987 through Sept 30,... more
    ABSTRACT Parvovirus infection was confirmed by fluorescent antibody staining or viral culturing in 137 (22%) of 615 necropsy accessions from dogs at the Missouri Veterinary Medical Diagnostic Laboratory from Jan 1, 1987 through Sept 30, 1988. Septicemic colibacillosis was diagnosed in 88 (90%) of the 98 canine parvovirus-positive accessions in which liver or lung was cultured bacteriologically. Pulmonary edema or alveolitis similar to that seen in the human adult respiratory distress syndrome was observed in 63 (69%) of the 91 canine parvovirus-positive accessions in which the lungs were examined histologically.
    To evaluate host and environmental factors associated with the development of encephalitic listeriosis in goats. Retrospective analysis of diagnostic laboratory records and survey of veterinarians and goat producers. 355 goat herds... more
    To evaluate host and environmental factors associated with the development of encephalitic listeriosis in goats. Retrospective analysis of diagnostic laboratory records and survey of veterinarians and goat producers. 355 goat herds accessible through laboratory records; 38 veterinarians who treated goats and 76 goat producers. Data regarding breed and use for goats affected with encephalitic listeriosis were obtained from surveys and case follow-up information. Listeria monocytogenes isolates from the brains of 7 affected goats were serotyped and subjected to DNA restriction analysis. Odds ratio for the development of encephalitis listeriosis in Angora (mohair-producing) goats was 22.9 by use of diagnostic laboratory records. Survey also revealed a high prevalence in herds of Angora and other breeds that subsisted on woody browse, although Angora goats feeding predominantly on hay or pasture were not affected. Listeria monocytogenes isolates from 4 Angora goats in 3 herds differed i...
    To examine Escherichia coli isolates obtained from dogs dying with diarrhea for heat-labile, heat-stable, and Shiga-like toxins and for the eaeA gene, which is associated with attaching and effacing lesions. Retrospective study. 122 dogs.... more
    To examine Escherichia coli isolates obtained from dogs dying with diarrhea for heat-labile, heat-stable, and Shiga-like toxins and for the eaeA gene, which is associated with attaching and effacing lesions. Retrospective study. 122 dogs. E coli isolates were tested by means of dot-blot hybridization of DNA extracts of cultured bacteria. Medical records of dogs from which E coli isolates with virulence genes had been isolated were examined, and histologic findings and evidence of intercurrent bacterial and viral infections were recorded. None of the E coli isolates obtained from these dogs produced heat-labile, heat-stable, or Shiga-like toxins; however, E coli isolates from 44 of 122 dogs were found to have the eaeA gene. Histologically, multifocal bacterial adherence to the epithelium and epithelial necrosis and detachment were seen in colonic specimens from 20 of 44 (45%) dogs. Escherichia coli was the sole pathogen identified in 15 of 44 (34%) dogs. Intercurrent pathogens, inclu...
    Mycoplasmosis is a well-known cause of morbidity and mortality in small ruminants. Previously recognized outbreaks have involved arthritis, and pneumonia or pleuropneumonia. Modern bacteriology procedures rely less on isolation techniques... more
    Mycoplasmosis is a well-known cause of morbidity and mortality in small ruminants. Previously recognized outbreaks have involved arthritis, and pneumonia or pleuropneumonia. Modern bacteriology procedures rely less on isolation techniques that require special media for mollicutes given that these species are notoriously difficult to isolate, and rely more on PCR tests. We report an outbreak of arthritis, pleuropneumonia, and mild meningitis affecting dairy goat kids, spanning a period of 3 y, which had unusual epidemiologic characteristics related to husbandry practices. Lesions were characterized by polyarthritis of the appendicular joints, with copious joint fluid and extension of arthritic exudate beyond the joint itself. The cause remained unknown until serendipitous isolation of a mycoplasma on blood agar. Mycoplasmosis was not detected from synovial samples by a general mycoplasma PCR, despite multiple attempts. Isolated colonies were also negative by this general PCR assay. T...

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