A cross-sectional study was conducted to determine the prevalence of Histoplasma farciminosum in 2907 carthorses using clinical and microbiological examinations at three towns (Debre Zeit, Mojo and Nazareth), Central Ethiopia, between December 1999 and January 2001. An overall prevalence of 26.2% (762/2907) was recorded; the highest prevalence (39.1%) being recorded at Mojo whereas the lowest (21.1%) was recorded at Nazareth. The difference in prevalence among the three towns was highly significant (chi2 = 76.92, P<0.0001). Carthorses found at Mojo [OR =2.4, CI=(1.9-3.0), P<0.0001] and Debre Zeit [OR=1.9, CI=(1.5-2.3), P<0.0001] were at higher risk of infection than those found at Nazareth. The mycelial and yeast forms of the Histoplasma capsulatum variety farciminosum were isolated on the Sabouraud's dextrose agar. The results of the present study showed the rampant occurrence of histoplasmosis farciminosi at the three towns and indicates the need for further nationwide investigation into the disease to design sound control strategy.
Animals ; Cross-Sectional Studies ; Ethiopia/epidemiology ; Histoplasma/classification/isolation&purification ; Histoplasmosis/*epidemiology/microbiology/pathology/veterinary ; Horse Diseases/*epidemiology/*microbiology/pathology ; Horses/*microbiology ; Odds Ratio ; Prevalence ; Risk

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.
Actinomycetales/*isolation & purification ; Actinomycetales Infections/diagnosis/microbiology/*veterinary ; Animals ; Cattle ; Cattle Diseases/*diagnosis/microbiology ; Fluorescent Dyes/*diagnostic use ; Horse Diseases/*diagnosis/microbiology ; Horses ; Limit of Detection ; Real-Time Polymerase Chain Reaction/*methods/veterinary ; Reproducibility of Results ; Sheep ; Sheep Diseases/*diagnosis/microbiology

Streptococcus (S.) dysgalactiae subsp. equisimilis is responsible for severe diseases in humans, including primary bacteraemia, pneumonia, endocarditis, and toxic shock syndrome. Infection in some animal species can also occur, although a few studies have looked into cross-species infectivity. In horses, S. equisimilis is generally considered infrequent or opportunistic, but has recently been isolated from cases of strangles-like disease. Rapid and sensitive diagnostic techniques could enable epidemiological studies and effective investigation of outbreaks involving these bacteria. In this study, PCR protocols previously described in cattle and in humans to detect the species S. dysgalactiae and the subspecies equisimilis were evaluated to detect specific sequences in equine samples. For this purpose, 99 monolateral nasal swabs were collected from horses from stud farms with a history of S. equisimilis infection and were tested blindly by bacteriological isolation and by single and duplex PCR. DNA for PCR was extracted both from the colonies grown on agar media and from enrichment broth aliquots after incubation with nasal swab samples. S. equisimilis was identified by bacteriological isolation in 23 out of 99 swab samples, and PCR assays on these colonies were fully concordant with bacteriological identification (kappa statistic = 1.00). In addition, PCR of the enrichment broth aliquots confirmed the bacteriological results and detected S. equisimilis in 6 samples more than the bacteriological examination (kappa statistic = 0.84). The PCR protocols appeared to be reliable for the rapid identification of S. equisimilis in equine nasal swab samples, and could be useful for microbiological diagnosis.
Animals ; NA, Bacterial/chemistry/genetics ; Horse Diseases/diagnosis/*microbiology ; Horses ; Limit of Detection ; Male ; Nasopharynx/microbiology ; Polymerase Chain Reaction/methods/*veterinary ; Respiratory Tract Infections/diagnosis/microbiology/*veterinary ; Sensitivity and Specificity ; Streptococcal Infections/diagnosis/microbiology/*veterinary ; Streptococcus/genetics/*isolation & purification

Infectious upper respiratory disease (IURD) of Thoroughbred racehorses has been a frequent problem (29.6% of incidence) at the Seoul Race Park (Korea). Risk factors for IURD include the season with a high transfer rate (summer and fall), the stabling period (< or = 3 months), and age (2 to 3 years old), suggesting that the movement and new environment may have depressed the immune system of the horses and decreased their ability to respond properly to pathogens. The bacterial strains (n = 98) isolated from IURD horses included Pseudomonas spp., Escherichia coli, Staphylococcus spp., Streptococcus equi subsp. equi and zooepidemicus.
Animals ; Bacteria/*isolation & purification ; Bacterial Infections/epidemiology/immunology/microbiology/*veterinary ; Horse Diseases/epidemiology/immunology/*microbiology ; Horses ; Incidence ; Microbial Sensitivity Tests ; Republic of Korea/epidemiology ; Respiratory Tract Infections/epidemiology/immunology/microbiology/*veterinary ; Risk Factors

Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 10(7) C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.
Animals ; Antibodies, Bacterial/blood/*immunology/therapeutic use ; Bacterial Proteins/immunology/therapeutic use ; Bacterial Toxins/immunology/therapeutic use ; Clostridium Infections/microbiology/prevention & control/*veterinary ; Clostridium difficile/*immunology ; Enterotoxins/immunology/therapeutic use ; Female ; Horse Diseases/microbiology/*prevention & control ; Horses ; Immune Sera/*immunology ; Immunization, Passive/*veterinary ; Mice ; Mice, Inbred C57BL ; Spores, Bacterial/immunology

OBJECTIVETo investigate the prevalence of methicillin-resistant staphylococci (MRS) which is a potencial risk factor of transmission between animals and humans in different types of horses (harness racing-horses, breeding mares and riding-horses) and to compare the antimicrobial resistance of the isolates.

METHODSA total of 191 healthy horses, housed at different locations of the Campania Region (Italy), were included in the study. Nasal swab samples were collected from each nostril of the horses. The mecA gene was detected by a nested PCR technique. Antibiotic susceptibility was tested for each isolate.

RESULTSMRS was isolated from nasal samples of 68/191 (35.6%; 95% CI: 28.9%-42.9%) healthy horses. All isolates were coagulase-negative with the exception of two coagulase-positive MRS strains, identified as Staphylococcus aureus and Staphylococcus pseudintermedius, 2/83 (2.4%; 95% CI: 0.4%-9.2%). Interestingly, both coagulase-positive MRS isolates were from harness racing-horses. These horses also presented a significantly higher positivity for MRS (53.3%; 95% CI: 40.1%-66.1%) than the breeding mares and riding-horses groups. Antibiotic susceptibility testing showed difference between isolates due to different origins except for an almost common high resistance to aminopenicillins, such as ampicillin and amoxicillin.

CONCLUSIONSIt can be concluded that harness racing-horses may act as a significant reservoir of MRS as compared to breeding mares and riding-horses.

Animals ; Anti-Bacterial Agents ; pharmacology ; Coagulase ; Drug Resistance, Multiple, Bacterial ; Female ; Horse Diseases ; epidemiology ; microbiology ; Horses ; Italy ; epidemiology ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; isolation & purification ; Microbial Sensitivity Tests ; veterinary ; Polymerase Chain Reaction ; veterinary ; Prevalence ; Staphylococcal Infections ; epidemiology ; microbiology ; veterinary