Enrofloxacin resistance in Escherichia coli isolated from dogs with urinary tract infections     

Cooke CL  Singer RS  Jang SS  Hirsh DC 《Journal of the American Veterinary Medical Association》2002,220(2):190-192

OBJECTIVE: To assess the strain heterogeneity of enrofloxacin-resistant Escherichia coli associated with urinary tract infections in dogs at a veterinary medical teaching hospital (VMTH). In addition, strains from other veterinary hospitals in California were compared with the VMTH strains to assess the geographic distribution of specific enrofloxacin-resistant E. coli isolates. DESIGN: Bacteriologic study. SAMPLE POPULATION: 56 isolates of E. coli from urine samples (43 isolates from dogs at the VMTH, 13 isolates from dogs from other veterinary clinics in California). PROCEDURES: Pulsed field gel electrophoresis was performed on 56 isolates of E. coli from urine samples from 56 dogs. All 56 isolates were tested for susceptibility to amoxicillin, chloramphenicol, enrofloxacin, tetracycline, trimethoprim-sulphamethoxazole, cephalexin, and ampicillin. Enrofloxacin usage data from 1994 to 1998 were obtained from the VMTH pharmacy. RESULTS: Several strains of enrofloxacin-resistant E. coli were collected from urine samples from the VMTH, and strains identical to those from the VMTH were collected from other veterinary clinics in California. For the isolates that did share similar DNA banding patterns, variable antibiotic resistance profiles were observed. CONCLUSIONS AND CLINICAL RELEVANCE: The increased occurrence of enrofloxacin-resistant E. coli from urine samples from dogs at the VMTH was not likely attributable to a single enrofloxacin-resistant clone but may be attributed to a collective increase in enrofloxacin resistance among uropathogenic E. coli in dogs in general.  相似文献   

Rapidly growing members of the genus Mycobacterium affecting dogs and cats     

Jang SS  Hirsh DC 《Journal of the American Animal Hospital Association》2002,38(3):217-220

Rapidly growing members of the genus Mycobacterium were most often associated with chronic (2 to 72 months), nonhealing skin lesions of dogs and cats. Mycobacterium fortuitum (M. fortuitum) was the most commonly isolated mycobacterium obtained from these lesions, although M. chelonae-abscessus and M. flavescens were occasionally encountered. Isolates were tested in vitro to various antimicrobial agents and found to be susceptible to amikacin (100% of the isolates), cefoxitin (93.8%), ciprofloxacin (75%), clarithromycin (71.4%), doxycycline (28.6%), erythromycin (6.2%), gentamicin (68.8%), kanamycin (75%), minocycline (81.3%), streptomycin (14.3%), tobramycin (43.8%), trimethoprim/sulfonamides (57.1%), and vancomycin (15.4%).  相似文献   

Clinical, bacteriologic, serologic, and pathologic features of infections with atypical Taylorella equigenitalis in mares     

Katz JB  Evans LE  Hutto DL  Schroeder-Tucker LC  Carew AM  Donahue JM  Hirsh DC 《Journal of the American Veterinary Medical Association》2000,216(12):1945-1948

OBJECTIVE: To characterize clinical, serologic, bacteriologic, cytologic, and pathologic endometrial responses of mares to 2 donkey-origin atypical bacterial isolates resembling Taylorella equigenitalis. DESIGN: Prospective in vivo study. ANIMALS: 10 healthy mares. PROCEDURE: Mares in estrus (2/group) were inoculated by intrauterine infusion with 2 isolates of classic T equigenitalis or 2 isolates of atypical Taylorella sp or were sham-inoculated. Bacteriologic, serologic, clinical, uterine, cytologic, and pathologic endometrial responses were assessed 4, 11, 21, 35, and 63 days after inoculation and on day 111 in mares with positive culture results on day 63. RESULTS: One atypical isolate failed to cause infection. The second atypical isolate and both classic T equigenitalis isolates induced similar transient metritis and cervicitis. Both classic isolates and 1 atypical isolate induced anti-T equigenitalis complement-fixing antibodies detectable at day 11. Classic isolates and an atypical isolate provoked intense neutrophilic endometritis followed by a resolving, subacute, neutrophilic-mononuclear endometrial response. The atypical isolate and classic isolates were recovered from the uterus, clitoral fossa, or clitoral sinus of one or both exposed mares for as long as 111 days. CONCLUSIONS AND CLINICAL RELEVANCE: Atypical Taylorella sp infections should be considered as a differential diagnosis of equine infertility in US-origin mares, even those not exposed to stallions from countries where contagious equine metritis occurs. The origins and prevalence of atypical Taylorella sp infection in US horses and donkeys are undetermined.  相似文献   

Clostridium perfringens associated with a focal abscess in a horse.     

R J MacKay  G P Carlson  D C Hirsh 《Journal of the American Veterinary Medical Association》1979,175(1):71-72

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Susceptibility of obligate anaerobes to trimethoprim-sulfamethoxazole   总被引：2，自引：0，他引：2  

M C Indiveri  D C Hirsh 《Journal of the American Veterinary Medical Association》1986,188(1):46-48

Susceptibilities of trimethoprim and sulfamethoxazole were tested alone and in combination (1:20) against 94 isolants of obligate anaerobes from clinical specimens. Ninety percent of the isolants were inhibited by less than 0.25 microgram - less than 4.75 micrograms trimethoprim-sulfamethoxazole/ml; 5.4 micrograms trimethoprim/ml and; 900 micrograms sulfamethoxazole/ml. We concluded that trimethoprim-sulfamethoxazole would be effective in the treatment of infectious processes containing species of obligate anaerobes, including those resistant to the penicillin and cephalothin groups of antibiotics.  相似文献   

Clavulanic acid-potentiated activity of amoxicillin against Bacteroides fragilis     

M C Indiveri  D C Hirsh 《American journal of veterinary research》1985,46(10):2207-2209

Seventy-seven clinical isolates of Bacteroides fragilis from animal sources were examined for beta-lactamase production and resistance to amoxicillin. Sixty-five (84%) of the isolates produced detectable amounts of beta-lactamase. Concentrations of amoxicillin greater than 8 micrograms/ml were required to inhibit all but 13 (17%) of the isolates evaluated. Clavulanic acid, a beta-lactamase inhibitor, minimally inhibited growth of B fragilis when used alone. However, a synergistic effect was found when amoxicillin and clavulanic acid were used together against B fragilis. Ninety-nine percent of the isolates were inhibited by concentrations of 1 microgram of amoxicillin/ml in combination with 0.5 microgram of clavulanic acid/ml.  相似文献   

Hygromycin B and deaf dogs     

ADJ WATSON  DC BURNETT 《Australian veterinary journal》1989,66(9):302-303

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Common plasmid encoding resistance to ampicillin, chloramphenicol, gentamicin, and trimethoprim-sulfadiazine in two serotypes of Salmonella isolated during an outbreak of equine salmonellosis     

J S Ikeda  D C Hirsh 《American journal of veterinary research》1985,46(4):769-773

An outbreak of equine salmonellosis occurred at the Veterinary Medical Teaching Hospital, University of California, Davis, between June 1981 and March 1982. Forty-four horses were infected with Salmonella saint-paul, a serotype rarely isolated from animals at the university before the outbreak. Unlike the isolates of S saint-paul obtained at the beginning of the outbreak, almost all strains isolated near the end were resistant to ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, sulfadiazine, trimethoprim, and trimethoprim-sulfadiazine. A conjugal-resistance plasmid (R-plasmid) was responsible for resistance to these antimicrobics. This R-plasmid was identical to an R-plasmid of S krefeld, a serotype that had been isolated repeatedly throughout the hospital before, during, and after the outbreak involving S saint-paul. This finding prompted the suggestion that in vivo transfer of the R-plasmid had occurred. Whether the donor organism was S krefeld is unknown.  相似文献   

Spatial heterogeneity of Escherichia coli DNA fingerprints isolated from cellulitis lesions in chickens     

Singer RS  Jeffrey JS  Carpenter TE  Cooke CL  Chin RP  Atwill ER  Hirsh DC 《Avian diseases》1999,43(4):756-762

Avian cellulitis in broiler chickens is characterized by subcutaneous lesions that result in economic losses because of the partial or complete condemnation of the carcasses at processing. Escherichia coli is the primary causative agent of this condition. Previous research with a biotyping system found that the E. coli of cellulitis origin were unique to each ranch, suggesting that these E. coli were endemic within the ranch environment. The objective of our study was to analyze the genetic variability of E. coli isolates associated with cellulitis. We analyzed the genetic relatedness of the isolates in relation to the houses, ranches, and complexes in which the broilers were grown. This analysis enabled us to assess the spatial heterogeneity, or genetic diversity on a spatial scale, of the isolates. Forty-nine broilers with cellulitis lesions were necropsied. These broilers came from six houses on four ranches on three complexes that had been placed with chicks from the same hatchery within a 2-wk period. Isolates of E. coli from the lesions were DNA fingerprinted by pulsed-field gel electrophoresis. Relatedness among isolates was determined with the Dice coefficient and an unweighted pair group method with average linkages cluster analysis. The complexes possessed isolates with a variety of DNA fingerprints, yet each complex appeared to have isolates with a unique set of DNA fingerprints. Isolates from the same complex tended to form clusters with similarity coefficients greater than 90%. Isolates from different complexes were genetically distinct. This heterogeneity at the level of the complex suggests that isolates were not disseminated from a source common to the complexes. The spatial heterogeneity of the E. coli isolates in this study implies an endemic population of cellulitis-associated E. coli exists in the broiler house environment.  相似文献   

Evaluation of methods to diagnose Clostridium perfringens-associated diarrhea in dogs     

Marks SL  Melli A  Kass PH  Jang SS  Barkhoodarian A  Hirsh DC 《Journal of the American Veterinary Medical Association》1999,214(3):357-360

OBJECTIVE: To assess the prevalence of Clostridium perfringens enterotoxin in feces of dogs with and without diarrhea, and to compare the use of microbial cultures from fecal specimens and evaluation of stained fecal smears for endospores with the presence of enterotoxin as tools for diagnosing C perfringens-associated diarrhea. DESIGN: Prospective study. ANIMALS: 144 dogs representing hospitalized dogs with (n = 41) or without (50) diarrhea, and clinically normal dogs treated as outpatients (53). PROCEDURE: Fresh fecal specimens from all dogs were examined as Gram-stained fecal smears to determine numbers of Gram-positive spore-forming rods/100x objective field. Enterotoxin was assayed directly by use of a reverse passive latex agglutination assay. Fecal specimens were plated directly to prereduced egg yolk agar plates and incubated overnight at 37 C in an anaerobic chamber. At 24 hours, up to 3 lecithinase-positive colonies were subcultured to Brucella blood agar to evaluate for double zone hemolysis. Colonies with double zone hemolysis were tested for aerotolerance and Gram-stained. RESULTS: A significant difference was not detected among groups with respect to the presence of C perfringens as determined by culture, the presence of endospores, and the reaction patterns of fecal enterotoxin assays. An association was not found between number of endospores and the presence of fecal enterotoxin. CLINICAL IMPLICATIONS: The presence of C perfringens enterotoxin in feces of dogs, as detected by the latex agglutination assay used in this study, correlates poorly with the number of fecal endospores, regardless of the dog's clinical status.  相似文献