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

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.

Organisms isolated from dogs and cats with anaerobic infections and susceptibility to selected antimicrobial agents

OBJECTIVE

To determine the prevalence of obligate anaerobic bacteria in bacterial infections in dogs and cats and susceptibility to selected antimicrobial agents.

DESIGN

Case series.

SAMPLE POPULATION

Specimens from 1,267 dogs and 243 cats.

PROCEDURE

Standard anaerobic and aerobic bacterial culture methods were used. Anaerobic isolates were tested for susceptibility to selected antimicrobial agents.

RESULTS

Obligate anaerobic bacteria were isolated from 199 (15.7%) and 69 (28.4%) specimens obtained from dogs and cats, respectively. More than half of the specimens that contained obligate anaerobic bacteria were from draining tracts (exclusively dogs), pleural fluid, abscesses, bones, the respiratory tract, or the abdominal cavity. The most commonly isolated obligate anaerobic bacteria (approx 70% of all isolates) were Bacteroides spp, Peptostreptococcus spp, Fusobacterium spp, and Porphyromonas spp. Eighty percent of the specimens that contained obligate anaerobic bacteria also contained facultative anaerobic or aerobic organisms. The organisms most commonly isolated in association with obligate anaerobic bacteria were members of the family Enterobacteriaceae (Escherichia coli was the most common), Pasteurella spp, and Staphylococcus intermedius. Ninety-seven obligate anaerobic isolates were tested for susceptibility to ampicillin, amoxicillin-clavulanic acid, chloramphenicol, clindamycin, and metronidazole. All were susceptible to amoxicillin-clavulanic acid and chloramphenicol, and most were susceptible to metronidazole. Only 71% of the Bacteroides isolates were susceptible to ampicillin, and only 83% were susceptible to clindamycin. Only 80% of the Clostridium isolates were susceptible to clindamycin, but all were susceptible to ampicillin.

CLINICAL IMPLICATIONS

Data on sites and conditions from which anaerobic bacteria are commonly isolated, along with results of susceptibility testing, may be useful in designing antimicrobial treatment regimens.

Microbiological study of transtracheal aspirates from dogs with suspected lower respiratory tract disease: 264 cases (1989-1995)

OBJECTIVE

To determine the most commonly isolated bacterial species associated with lower respiratory tract disease of dogs and to determine susceptibility of these isolates to antimicrobial agents.

DESIGN

Retrospective case series.

SAMPLE POPULATION

Transtracheal aspirates from 264 dogs with clinical evidence of lower respiratory tract disease.

PROCEDURE

Records of microbiological analyses of transtracheal aspirates obtained from dogs with clinical evidence of lower respiratory tract disease were reviewed. Analyses performed included bacterial culture (anaerobic and aerobic organisms) and susceptibility testing (aerobic organisms). The medical record of each affected dog was evaluated to determine signalment and underlying condition.

RESULTS

Bacteria were isolated from 116 of 264 (44%) samples, and 203 bacterial species were identified. Most (57%) of the samples from which bacteria could be isolated contained a single species, whereas 43% yielded cultures of mixed species. Bacterial species belonging to the family Enterobacteriaceae (particularly Escherichia coli) were isolated most commonly (45.7% of samples contained members of this group), followed by members of the genus Pasteurella (22.4%), obligate anaerobes (21.6%), beta-hemolytic Streptococcus (12.1%), Bordetella bronchiseptica (12.1%), nonhemolytic Streptococcus/Enterococcus sp group (12.1%), coagulase-positive Staphylococcus (9.5%), and Pseudomonas sp (7.8%). The most active antimicrobial drugs (inhibiting > 90% of the isolates) for aerobic microorganisms encountered most often (E. coli and Pasteurella sp) included amikacin, ceftizoxime sodium, enrofloxacin, and gentamicin sulfate.

CLINICAL IMPLICATIONS

Amikacin, ceftizoxime, enrofloxacin, and gentamicin may be rational choices for treatment of suspected infectious lower respiratory tract disease of dogs, before identification of the causative agent(s) and before results of susceptibility tests become available.

Somatic embryogenesis and plant regeneration in Quercus acutissima

Immature embryos of Quercus acutissima were collected weekly beginning 5 weeks post-fertilization and cultured on modified MS(Murashige and Skoog) medium containing 1,000 mg/l glutamine and 5 mM proline with different combinations of IBA(0.5-10.0 mg/l) and BA(0 or 1.0 mg/l) in light. The highest percentage of embryogenic cultures occurred on the medium containing 0.5 mg/l IBA or 1.0 mg/l BA and 0.5 mg/l IBA. Four weeks after initiation, the embryogenic cultures were transferred to MS medium without plant growth regulators and cultured for 4 weeks. The somatic embryos were then transferred to germination medium. The best germination results were achieved from WPM(Woody Plant Medium) containing 0.1 mg/l BA. Plantlets from somatic embryos were incubated on WPM supplemented with 0.2 mg/l BA for 4 weeks and plantlets with well developed shoots and roots were transplanted to perlite and peat moss(1∶1, v/v) mixtures and placed in a culture room. After being hardened off for 8 weeks, they were transferred outdoors where they grew.

Characterization, distribution, and microbiological associations of Fusobacterium spp. in clinical specimens of animal origin

During the years from 1984 through 1991, 1,067 specimens from canine, equine, exotic, feline, porcine, and ruminant animal sources were found to contain members of the genus Fusobacterium: The most common sites or conditions from which members of this genus were isolated were abscesses, the respiratory tract, and pleural and peritoneal cavities. Most specimens contained a single Fusobacterium species. The most commonly isolated species was Fusobacterium necrophorum. Almost all of the specimens contained other obligate anaerobes together with facultative and obligate aerobes. The identities of the other isolates depended upon the species of animal from which the sample was obtained.

Use of random fragments of chromosomal DNA to highlight restriction site heterogeneity for fingerprinting isolates of Salmonella typhimurium from hospitalized animals

Random fragments of DNA were obtained from a cosmid library of Salmonella agona genomic DNA. From this library, 2 fragments were chosen and pooled to probe isolates of S typhimurium obtained during an episode of salmonellosis in a veterinary medical teaching hospital. Chromosomal DNA from the Salmonella isolates was digested with restriction endonucleases, and was probed with the random fragments of chromosomal DNA. This procedure resulted in a fingerprint pattern for each isolate. We found that the method permitted discrimination between isolates involved in the disease episode and S typhimurium obtained prior to the episode. We conclude that random fragments of chromosomal DNA are useful for fingerprinting isolates of S typhimurium. Analysis of plasmid DNA obtained from the isolates was not as useful. Some isolates found to be identical by restriction site analysis, had plasmids of different molecular weight. These results indicate that plasmid analysis may not be as useful a fingerprinting tool as previously reported.

Distribution of indole-producing urease-negative pasteurellas in animals

Three hundred fifty-six animal isolates of indole-positive urease-negative cultures of Pasteurella, which would formerly have been classified as P. multocida, were examined with respect to their relationship to the recently described P. multocida subspecies (ssp.) multocida, septica, and gallicida and P. canis, P. stomatis/Taxon 16, and Pasteurella sp. B. Two hundred sixty-three (73.9%) of the cultures could be identified with one of these taxa, and 93 isolates (26.1%), representing 17 different biotypes, were unassignable. Pasteurella multocida ssp. multocida was the predominant taxon throughout and in most of the 25 animal species from which isolations were made. In dogs, P. canis was the most frequent. Different degrees of host predilection were observed also in P. multocida ssp. septica for cats, P. canis for sheep, and 2 of the unassignable biotypes for cattle and dogs, respectively. Overall, the respiratory tract was the most frequent source of isolates, but a propensity of P. multocida ssp. septica for localization in the central nervous system of cats was noted.

Normal vaginal aerobic and anaerobic bacterial flora of the rhesus macaque (Macaca mulatta)

The most common bacterial species isolated from the vaginas of 37 healthy rhesus macaques were Streptococcus viridans, coagulase negative Staphylococcus, Mobiluncus curtisii ss. curtisii, Corynebacterium renale-like organisms, Peptostreptococcus anaerobius, Gardnerella-like organisms, and other Corynebacterium species. The vaginal flora of the rhesus macaque differs from that previously reported for five other primate species. A two-year retrospective review of clinical cases of vaginitis and metritis found Escherichia coli and coagulase positive Staphylococci to be the most common pathogens isolated.

Identity of Bacteroides isolates and previously named Bacteroides spp in clinical specimens of animal origin

During the years 1984 through 1987 2,574 isolates of obligately anaerobic bacteria were isolated from samples submitted for analysis. The most common anaerobic isolates were members of the genus Bacteroides, representing 44.6% of the isolates. Of these, the most commonly isolated identifiable microorganisms were bile-resistant and nonpigmented, belonging to the B fragilis group of Bacteroides. Importantly, obvious predilections for any one species or group of Bacteroides were not apparent for animal or site (condition), except that the proportion of isolates belonging to the nonpigmented, bile-resistant group obtained from the respiratory tract was significantly (P less than 0.005) higher than that not belonging to this group. On the other hand, the proportion of isolates of the non-pigmented, bile-resistant group obtained from abscesses was significantly lower than that not belonging to this group.

Nutritionally variant streptococci associated with corneal ulcers in horses: 35 cases (1982-1988)

Nutritionally variant streptococci (NVS) are nutritionally deficient viridans streptococci that require pyridoxal for growth. Although NVS are pathogenic in human beings, they have not been considered to be pathogenic in domestic animals. In 1982 and 1983, 24 isolates of NVS were recovered from horses with ulcerative keratitis. A retrospective study was done to determine the incidence of NVS in horses with corneal disease. The medical records of 249 horses (259 eyes) examined for clinical signs of corneal disease were reviewed. Nutritionally variant streptococci were isolated from approximately 13.5% of horses with ulcerative keratitis.

Lack of supportive susceptibility data for use of ampicillin together with trimethoprim-sulfonamide as broad-spectrum antimicrobial treatment of bacterial disease in dogs

The combination of ampicillin together with trimethoprim-sulfonamide is sometimes used as a broad-spectrum antimicrobial regimen for treatment of dogs with bacterial infections of unknown etiopathogenesis. To determine whether this combination is indeed broad spectrum, we analyzed susceptibility data derived from commonly encountered bacterial agents in dogs. A total of 381 isolates from 344 cases was studied. Overall, 80 (20.9%) of the 381 isolates were resistant to ampicillin and to trimethoprim-sulfonamide; 159 (41.7%) were resistant to ampicillin, but susceptible to trimethoprim-sulfonamide; 131 (34.4%) were susceptible to both ampicillin and trimethoprim-sulfonamide; and 11 (2.9%) were susceptible to ampicillin, but resistant to trimethoprim-sulfonamide. Of isolates susceptible to ampicillin and/or trimethoprim-sulfonamide, 290 (96.3%) were susceptible to trimethoprim-sulfonamide (ampicillin increased the coverage by 3.7%). On the other hand, 142 (47.2%) were susceptible to ampicillin. In addition, with respect to agents most commonly encountered (members of the family Enterobacteriaceae and members of the genus Staphylococcus), combining ampicillin with trimethoprim-sulfonamide increased coverage by 2.2% over use of trimethoprim-sulfonamide alone. We contend, therefore, that use of ampicillin together with trimethoprim-sulfonamide does not result in an acceptable broad-spectrum antimicrobial regimen for treatment of bacterial disease in dogs.

Case-control study of risk factors associated with nosocomial Salmonella krefeld infection in dogs

In a case-control study of risk factors associated with an episode of nosocomial Salmonella krefeld infection in dogs at the veterinary medical teaching hospital, data on 20 case dogs and 75 control dogs were obtained by review of hospital records. Univariate and multivariate statistical analyses were carried out for possible risk factors for infection to obtain odds of Salmonella krefeld isolation, given exposure to each risk factor of interest. Compared with control dogs, case dogs were 11.9 times more likely to have been fed rice, 7 times more likely to have had radiography done, 10.2 times more likely to have been a resident in ward 2, 5.6 times more likely to have been given antimicrobial agents orally, 11.3 times more likely to have been given antimicrobial agents parenterally, and 37.9 times more likely to have been given antimicrobial agents orally and parenterally (P less than 0.05).

Septicemia and septic arthritis caused by Streptococcus pneumoniae in a cat: possible transmission from a child

Streptococcus pneumoniae serotype 23F was isolated from the blood and synovial fluid of an acutely ill, 15-year-old castrated male cat and from the nasopharynx of that regularly played with it, an infant child. Information presented supports the hypothesis that the infection was transmitted from child to cat.

Actinobacillus suis-like organisms in horses

Actinobacillus suis-like organisms have been recognized in equine specimens at the University of California Veterinary Medical Teaching Hospital since 1975. The most common source (65%) of the organism was transtracheal washings. The organism was gram-negative, produced hemolysis on blood agar, and gave a positive reaction for oxidase, urease, o-nitrophenyl-beta-D-galactopyranoside, and esculin. Carbohydrate reactions were variable, consisting of 4 main patterns. Actinobacillus suis-like organisms were (90%) sensitive to therapeutic concentrations of amikacin, cephalothin, chloramphenicol, gentamicin, kanamycin, tetracycline, and trimethoprim-sulfamethoxazole. Other aerobic and anaerobic bacteria were recovered frequently with the organism.

Antimicrobic susceptibility of bacterial pathogens from horses

Rational choice of an antimicrobial agent requires that the condition for which the drug is prescribed contain an infectious agent and, if so, knowledge of the susceptibility of the microorganism to antimicrobial drugs. Unfortunately, most infectious conditions necessitate the use of an antimicrobic drug before data from the microbiology laboratory are available. The data presented are meant to serve as a guide in the choice of antimicrobic drugs for treatment of infectious processes of the horse before knowledge of the nature of the microorganism isolated as well as its susceptibility to antimicrobic agents. What has been presented are the most commonly isolated microorganisms together with their susceptibility to antimicrobic drugs.

Cellulitis associated with coagulase-positive staphylococci in racehorses: nine cases (1975-1984)

Nine Thoroughbred racehorses were admitted with cellulitis (of one or more limbs) associated with coagulase-positive staphylococci. The right hindlimb was affected in 4 horses, the right forelimb in 2, the left hindlimb in 1, and both hindlimbs in 2. Typical abnormalities included high values for rectal temperature (9 horses) and heart rate (5 horses), hyperfibrinogenemia (7 horses), leukocytosis (7 horses), and neutrophilia (6 horses). The staphylococcal isolants were speciated in 3 horses and classified as Staphylococcus aureus. Complications included skin loss (5 horses), laminitis of the affected limb (2 horses), laminitis of the contralateral limb (4 horses), osteomyelitis and sequestrum formation (2 horses), and bacteremia (1 horse). Five horses were euthanatized because of the severity of the complications, ie, laminitis in 4 horses and severe skin loss in 1 horse. The remaining 4 horses were discharged from the clinic. At follow-up evaluation (mean, 16.7 months), the swelling in 3 of the horses had completely resolved. One horse returned to racing; of 2 used for pleasure riding, one was mildly lame. The remaining horse was not lame, but was used for breeding because of persistent swelling of the affected limb.

Actinomycotic mycetoma in a cat

Actinomycotic mycetoma, a chronic, progressive infection of the subcutaneous tissue characterized by tumefaction, draining sinuses, and grains, was diagnosed in the right hindlimb of a young adult, male cat. The organisms that cause actinomycetoma are soil or plant saprophytes that gain entrance to the skin through abrasion or traumatic implantation. Streptomyces griseus, an organism generally considered to be a saprophyte, was cultured bacteriologically. Despite extensive surgery and long-term antibiotic therapy, the infection persisted, and the cat was euthanatized.

Aspergillus deflectus infection in four dogs

Four cases of disseminated aspergillosis caused by Aspergillus deflectus in German Shepherds are presented. Three of the cases, which involved multiple organs, terminated in euthanasia. One case, with bony involvement of the limbs and skull, lived. The unique morphological characteristic of the conidial head resembling a briar pipe led to the identification of A. deflectus. To the authors' knowledge these are the first reported cases of infections caused by A. deflectus in man or animal.

Characteristics of Salmonella isolated from animals at a veterinary medical teaching hospital

Salmonella belonging to 47 serotypes was isolated from animals at the University of California Veterinary Medical Teaching Hospital during the years 1974 to 1983. Salmonella belonging to 12 serotypes accounted for 89% of the 725 isolates. Salmonella typhimurium (including var copenhagen) was the most commonly isolated serotype, but during 1981 to 1983, S krefeld and S saint-paul were predominant. Certain serotypes seemed to be isolated more frequently from extraintestinal sources (S typhi-suis, S dublin). Although resistance to ampicillin, kanamycin, neomycin, streptomycin, and sulfonamides was common (greater than 60% of the isolates were resistant), resistance to chloramphenicol, gentamicin, and trimethoprim-sulfonamides was infrequent, except for isolates of S krefeld and S saint-paul.

Ulcerative keratitis associated with Salmonella arizonae infection in a horse

Salmonella arizonae 61:1,5, was isolated in pure culture from the eye of a horse with unilateral ulcerative keratitis. The eye responded well to treatment with atropine sulfate and polymyxin B-bacitracin-neomycin ophthalmic ointments. In swab specimens taken after the lesion had healed, Salmonella was not found to be a constituent of the bacterial flora of the horse's eyes.

Changes in prevalence and susceptibility of obligate anaerobes in clinical veterinary practice

Of 3,133 clinical specimens obtained from domestic animals, 26% contained species of bacteria that were obligate anaerobes. Members of the genera Bacteroides, Fusobacterium, and Peptostreptococcus accounted for 77% of the isolates. On the average, 2 species of obligate anaerobes were found in each specimen, usually admixed with facultatively anaerobic bacteria. Of those specimens containing an obligate anaerobe, 20% contained one isolate that was resistant to penicillin, ampicillin, and cephalothin. These resistant isolates belonged to the genus Bacteroides, the most common being Bacteroides fragilis. Approximately one third of these penicillin-resistant isolates was resistant to tetracycline as well. All isolates were susceptible to chloramphenicol, tetracycline (excluding penicillin-resistant Bacteroides), metronidazole, and clindamycin.

Nocardia asteroides infection in horses: a review

From 1965 to 1983, Nocardia asteroides infection was diagnosed in 16 horses at the Veterinary Medical Teaching Hospital, University of California, Davis. In 2 of the cases, the infection was traumatic in origin and local in extent; the horses recovered without relevant antimicrobial therapy. Fourteen horses had pulmonary or disseminated infections that ended fatally. All 14 had various degrees of immunosuppression. Of these, 8 were Arabian foals with combined immunodeficiency disease and 3 were aged horses with hyperadrenocorticism secondary to ACTH-secreting pituitary tumors. Of the other 3, one had lymphosarcoma, another, hepatic disease presumed to be of toxic origin, and the third, a mixed disseminated bacterial infection.

Staphylococci in canine urolithiasis: species identification, using a commercially available tray micromethod

Fifty-one coagulase-positive staphylococcal isolates from canine urinary calculi or from the urine of dogs with documented urolithiasis, and 17 coagulase-positive staphylococcal isolates from human beings and cattle were identified by a commercially available tray micromethod, as well as by conventional methods. Canine isolates had previously been classified as Staphylococcus aureus on the basis of a positive tube coagulase test. After 5 hours' incubation, the tray method identified all 51 canine urolithiasis isolates as S intermedius, rather than S aureus. All human and bovine isolates were identified as S aureus. Conventional methods supported these findings.

Nutritionally variant streptococci from corneal ulcers in horses

Of 24 isolates of nutritionally variant streptococci recovered from equine corneal ulcers, 22 were tested for growth requirements, physiological and biochemical reactions, and susceptibility to different antimicrobial agents. Satisfactory growth was obtained by supplementing blood agar and Todd-Hewitt broth with pyridoxal hydrochloride, and all of the media for the culture and the biochemical testing were supplemented with 0.002% of this substance. Biochemical patterns of 12 of the isolates resembled those of two viridans streptococcal species, Streptococcus intermedius and Streptococcus constellatus. Patterns of 10 isolates did not resemble those of any recognized viridans species. All of the isolates were inhibited by less than or equal to 0.25 microgram of erythromycin per ml, less than or equal to 4 micrograms of chloramphenicol per ml, and less than or equal to 4 micrograms of gentamicin per ml, and all but two were inhibited by less than or equal to 0.1 microgram of penicillin per ml.

Canine urinary tract infections: a comparison of in vitro antimicrobial susceptibility test results and response to oral therapy with ampicillin or with trimethoprim-sulfa

In vitro susceptibility testing correctly predicted the outcome of ampicillin therapy in all 56 urinary tract infections (UTI) caused by coagulase-positive staphylococci (Staphylococcus aureus and S intermedius), in all 26 UTI caused by Proteus mirabilis, in 38 of 44 UTI caused by Escherichia coli, in 29 of 31 UTI caused by Streptococcus spp, in 8 of 10 UTI caused by Klebsiella pneumoniae, and in 16 of 20 UTI caused by other bacterial species. Thus, 173 of 187 (92.5%) isolates responded to ampicillin therapy in a manner predicted by in vitro susceptibility test results. In vitro susceptibility testing correctly predicted the outcome of therapy with trimethoprim-sulfa in 119 of 138 UTI caused by Escherichia coli, in 33 of 45 UTI caused by Klebsiella pneumoniae, in 38 of 43 UTI caused by Proteus mirabilis, in 21 of 25 UTI caused by Streptococcus spp, in 9 of 11 UTI caused by coagulase-positive staphylococci, and in 19 of 21 UTI caused by other bacterial species. Thus, 239 of 283 (84%) isolates responded to trimethoprim-sulfa therapy in a manner predicted by in vitro susceptibility test results.

Mycoplasma as a cause of canine urinary tract infection

Mycoplasmas were isolated from 60 specimens of urine obtained by cystocentesis from 41 dogs (23 males and 18 females) with urinary tract infection. Mycoplasmas were isolated in pure culture from 41 (68%) of the specimens, and were isolated in conjunction with one or more bacterial species from 19 (32%) specimens. Clinical signs of urinary tract infection were noted in 20 of 31 dogs in which mycoplasmas were isolated in pure culture, and numbers of WBC in the urine sediment were above the reported normal range in 22 of 25 urine specimens from those 20 dogs. Twenty-four of 29 mycoplasma isolates were found to be Mycoplasma canis, 4 were found to be M spumans, and 1 was identified as M cynos.

Species distribution of coagulase-positive staphylococci in animals

A total of 268 isolates of coagulase-positive staphylococci from a variety of animal species, including dogs, horses, cats, monkeys, goats, and cows, were assigned to species on the basis of the API Staph- Ident system (Analytab Products, Inc., Plainview , N.Y.). Of 195 isolates from dogs, 179 (91.8%) were Staphylococcus intermedius, as were 9 of 25 (36%) isolates from horses, 7 of 15 (46.6%) isolates from cats, and 4 of 6 (66.6%) isolates from goats. Only 1 of 10 isolates from monkeys and none of 7 isolates from cows were S. intermedius. Of the remaining 68 cultures, 63 were identified as Staphylococcus aureus and 5 as Staphylococcus hyicus. The latter identifications were rendered doubtful on the basis of conventional tests. Identification appeared to be more certain in the S. aureus sample than in the S. intermedius sample. Distribution of biotypes within the two bacterial species as represented by different API profile numbers and reactivity on test substrates showed no significant variations among the host species, except for the S. aureus biotypes in dogs. Both Staphylococcus species were represented about equally among samples from different tissues and lesions, apart from skin-related infections in dogs, which were associated exclusively with S. intermedius (P less than 0.01). Differences between S. aureus and S. intermedius in antimicrobial susceptibility patterns, prevalence of clumping factor, and occurrence of beta-toxin were found to be not significant.

Blood culture of the canine patient

Blood for bacteriologic culture was obtained from 581 sick dogs. Of these, 134 (23%) were considered to have bacteremia. The conditions most frequently associated with bacteremia were malignant neoplasms and infections of the skeletal, cardiovascular, and urogenital systems. The most frequently isolated bacteria were members of the family Enterobacteriaceae and coagulase-positive staphylococci, in sum accounting for more than 50% of the 150 isolates. Most of the dogs with bacteremia had high proportions of immature neutrophils, segmented neutrophils, and monocytes in blood. Dogs with bacteremia and osteomyelitis due to staphylococci had normal hemograms. Blood from dogs with bacteremia due to gram-negative bacteria was more likely to have a high proportion of immature and segmented neutrophil leukocytes than was blood from dogs with bacteremia due to a gram-positive species. Toxic neutrophils were observed more often in blood obtained from patients with bacteremia due to gram-negative bacteria. The development of fever correlated with the bacteremic state regardless of the species of bacteria in the blood.

In vitro susceptibilities of canine urinary bacteria to selected antimicrobial agents

Antimicrobial susceptibility tests were conducted on bacteria that were isolated from urine specimens collected by antepubic cystocentesis from dogs with urinary tract infections. Antimicrobics to which greater than or equal to 90% of these urinary bacteria were susceptible in vitro included trimethoprim-sulfamethoxazole (TMP-SMZ), nitrofurantoin, cephalexin, nalidixic acid, and gentamicin for isolates of Escherichia coli; ampicillin, TMP-SMZ, cephalexin, nalidixic acid, and gentamicin for isolates of Proteus mirabilis; ampicillin chloramphenicol, TMP-SMZ, nitrofurantoin, cephalexin, kanamycin, and gentamicin for isolates of coagulase-positive staphylococci; cephalexin, nalidixic acid, and gentamicin for isolates of Klebsiella pneumoniae; ampicillin, TMP-SMZ, and gentamicin for isolates of Streptococcus faecalis, Str faecium, and Str zymogenes; ampicillin, chloramphenicol, TMP-SMZ, and gentamicin for isolates of Str viridans; and ampicillin, chloramphenicol, TMP-SMZ, nitrofurantoin, cephalexin, kanamycin, and gentamicin for isolates of Str canis. No antimicrobial agent tested was effective in vitro at the 90% level for isolates of Pseudomonas aeruginosa, but gentamicin was closest, at 89%.

Obligate anaerobes in clinical veterinary practice

Clinical specimens obtained from domestic animals were examined to determine the relative prevalence of obligate anaerobic bacteria and the species represented. Of 3,167 samples cultured anaerobically as well as aerobically, 2,234 were bacteriologically positive. Of these positive samples, 583 (26%) contained species of obligate anaerobic bacteria in a total of 641 isolates. Most positive samples contained anaerobes admixed with aerobic species, although 6% of such samples yielded pure cultures of obligate anaerobes. The most common sites from which anaerobes were isolated were abscesses (32% of abscesses cultured contained species of obligate anaerobes), peritoneal exudates (24%), and pleural effusions (20%). Bacteroides melaninogenicus, Bacteroides spp., Peptostreptococcus anaerobius, and Bacteroides ruminicola accounted in the aggregate for approximately 50% of all anaerobic isolates. Bacteroides fragilis accounted for 1% of all the isolates, and members of the genus Clostridium accounted for 8%.

Thermonuclease seroinhibition test for distinguishing Staphylococcus aureus from other coagulase-positive staphylococci

Since coagulase-positive staphylococci from animals are heterogeneous, another test is necessary to distinguish Staphylococcus aureus from them. Staphylococcal thermonucleases appear to be heterogeneous; antisera raised against S. aureus isolated from humans inhibit thermonuclease activity as demonstrated by the metachromatic well-agar diffusion method. The serological specificity of the thermonuclease elaborated by S. aureus of human origin was demonstrated using three antisera and 407 strains of staphylococci from diverse human and animal sources.

Feline brain abscesses due to Cladosporium trichoides

Cladosporium trichoides was isolated from brain abscesses of two cats. No obvious route of entry was found in either case. The brain was the only organ cultured. No other significant lesions were observed during necropsy. These are the first reported cases of such infection in animals.

Erysipelas in a black and red tamarin

Erysipelothrix rhusiopathiae was isolated in large numbers from the kidneys and was visualized histologically in the kidneys, heart muscle, skeletal muscle, selected lymph nodes, and the submandibular salivary glands of a black and red tamarin (Saguinus nigricollis) following an acute fatal illness. Sites (heart valves, joints) usually associated with disease mediated by E rhusiopathiae appeared uninvolved.

A cat with Corynebacterium equi lymphadenitis clinically simulating lymphosarcoma

A cat with granulomatous lymphadenitis due to Corynebacterium equi is described. Clinically the cat was diagnosed as having lymphosarcoma. Bacteria were cultured from the lymph nodes.