Gangrenous mastitis caused by Bacillus species in six goats.

CASE DESCRIPTION: 6 lactating dairy goats were examined because of acute mastitis. CLINICAL FINDINGS: Goats were considered to have endotoxemia on the basis of physical examination and clinicopathologic findings. The affected udder halves had gangrenous discolored distal portions with sharp demarcations from grossly normal tissue proximally. Udder secretions from the affected sides were serosanguineous in all cases. A Bacillus sp was isolated in pure cultures in all cases. In 1 case, the Bacillus sp was identified as Bacillus cereus. TREATMENT AND OUTCOME: Goats were treated for mastitis and endotoxemia with polyionic IV fluid therapy, systemic and intramammary antimicrobial administration, anti-inflammatory drug administration, and other supportive treatment. All goats survived to discharge. All except 1 goat had follow-up information available. The affected udder halves sloughed in 1 to 2 months following discharge. In subsequent lactations after the mastitis episodes, milk production in 2 of 5 goats was above the mean, as determined on the basis of Dairy Herd Improvement records, and 3 of 5 goats were voluntarily withdrawn from lactation. All 5 goats had successful kiddings after the Bacillus mastitis episode. CONCLUSIONS AND CLINICAL RELEVANCE: Bacillus sp should be considered as a causative agent in goats with gangrenous mastitis, especially when the Bacillus sp is isolated in a pure culture. Antimicrobial sensitivity testing is recommended for selection of an appropriate antimicrobial for treatment. Prognosis for survival appears to be good, although milk production may be decreased.

Atypical Dermatophilus congolensis infection in a three-year-old pony.

Dermatophilosis caused by Dermatophilus congolensis causes exudative dermatitis in a variety of species. The infection is generally limited to the cutaneous tissues, where infection is acquired from the environment and bacteria penetrate into keratinized epithelium through epithelial disruption. A 3-year-old pony filly was examined for enlarging mandibular lymph nodes during the preceding 10 months. Biopsy of the node revealed mixed and granulomatous inflammation and thick, filamentous Gram-positive bacteria. Dermatophilus congolensis, confirmed by biochemical testing and sequencing of the ribosomal RNA gene, was cultured from a sample aspirated from the infected site. Dermatophilus congolensis should be considered as a possible etiologic agent associated with lymphadenopathy and granulomatous inflammation in the horse.

Extraintestinal pathogenic Escherichia coli-induced pneumonia in three kittens and fecal prevalence in a clinically healthy cohort population.

Three kittens, ages 5, 9, and 17 weeks, were found dead by separate caregivers and were submitted for necropsy. At gross necropsy, each kitten had hemorrhagic or bloody fibrinoserous thoracic fluid and differing distributions of pulmonary consolidation. On histologic examination, the pulmonary lesion in each kitten was similar and was characterized by acute necrotizing and hemorrhagic pneumonia and pleuritis, with numerous intralesional small Gram-negative rods. A pure culture of a distinct serotype of Escherichia coli was identified in lung tissue from each kitten (O4H5, O6H7, O6H5). Lung isolates, genotyped by polymerase chain reaction, carried genes that are characteristic of extraintestinal pathogenic E. coli (ExPEC), including cnf-1, papG allele I, papA, papC, sfa, fim, hlyD, malX, iroN, fyuA, kpsMII, and ompT. Escherichia coli isolates from the intestines of 2 of the kittens were 100% related to the respective lung isolate, as determined by pulsed-field gel electrophoresis. Cultures of fecal samples collected from a clinically healthy cohort population of kittens revealed 16 of 19 tested kittens (84%) to be shedding hemolytic E. coli. Ten different serotypes were identified from 43 hemolytic E. coli fecal isolates from the cohort population, each of which had a genetic profile consistent with that typical of ExPEC. To the authors' knowledge, this is the first report to describe a cluster of isolated cases of pneumonia in kittens caused by distinct serotypes of ExPEC and to evaluate the prevalence of hemolytic E. coli carrying ExPEC-associated genes in the feces of a cohort population of kittens.

Fatal pulmonary hemorrhage associated with RTX toxin producing Actinobacillus equuli subspecies haemolyticus infection in an adult horse.

A case of fatal pulmonary hemorrhage in a 6-year-old American Paint mare with a 2-week history of intermittent coughing, fever, and epistaxis is described. Significant macroscopic abnormalities at postmortem examination were restricted to the respiratory system, and microscopically, severe pulmonary hemorrhage with suppurative bronchopneumonia was found. Actinobacillus equuli subsp. haemolyticus was cultured from a transtracheal wash performed antemortem as well as from the lungs at necropsy. The presence of airway-associated hemorrhage in conjunction with bacterial bronchopneumonia suggested endothelial damage caused by a locally elaborated bacterial toxin, possibly produced by the A. equuli strain isolated from the lungs. The objective of this report was to indirectly document the presence of hemolysin repeat in structural toxin (RTX) in the lungs of the reported mare. A real-time polymerase chain reaction (PCR) assay targeting the recently described aqx gene of A. equuli subsp. haemolyticus was established and validated. Transcriptional activity of the aqx gene was used as a surrogate method to document toxin production. Real-time PCR analysis of the transtracheal fluid and lung tissue of the affected mare confirmed the presence and the transcriptional activity of the aqx gene at the genomic (gDNA) and complementary DNA (cDNA) levels, respectively. The presence of pneumonia associated with hemorrhagic pulmonary fluid and the culture of large numbers of hemolytic A. equuli should prompt the clinician to consider endothelial damage caused by bacterial toxins.

In vitro evaluation of three bacterial culture systems for the recovery of Escherichia coli from equine blood.

OBJECTIVE: To evaluate the effectiveness of a commercial conventional blood culture system (BCS), a commercial resin-containing BCS, and a commercial lysis-centrifugation-based BCS for the recovery of Escherichia coli from equine blood samples inoculated with that organism. SAMPLE POPULATION: Samples of blood obtained from a clinically normal horse that were inoculated with E coli. PROCEDURES: Blood samples were aseptically collected and inoculated with an E coli specimen (50 CFUs/mL) that had been previously isolated from a foal with sepsis. Subsequently, samples were spiked with gentamicin at a concentration of 30 mug/mL, and 10 mL of each mixture was inoculated into 1 bottle or tube of each BCS. Samples were processed and incubated according to the manufacturer's guidelines and inoculated onto 5% sheep blood agar plates. Plated samples were examined macroscopically at regular intervals for as long as 72 hours. Detection of E coli and time to detection were recorded for each medium. RESULTS: Detection frequency of E coli was significantly greater by use of the resin-containing BCS (14/23 bottles) than that achieved by use of the conventional BCS (7/23 bottles) or the lysis-centrifugation-based BCS (0/10 tubes). Mean detection time (6 hours after plating) did not differ between the BCS with conventional medium and the BCS with resincontaining medium. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a BCS with resin-containing medium may provide clinical benefit in the successful recovery of E coli from the blood of foals with sepsis that have been previously administered gentamicin.