[Show abstract][Hide abstract] ABSTRACT: Between 1975 and 2014, housing conditions for laboratory-housed marmosets changed dramatically after the introduction of new guidelines designed to improve their care and wellbeing. According to these guidelines, our facility provided marmosets with outside enclosures, switched to deep litter as bedding material, and discontinued the use of disinfectant agents in animal enclosures. However, both deep litter and access to outside enclosures hypothetically increase the risk of potential exposure to pathogenic microorganisms. We evaluated whether these housing and husbandry modifications constituted an increased veterinary risk for laboratory-housed common marmosets (Callithrix jacchus). After the animals had been exposed to these new housing conditions for 2.5 y, we examined their intestinal bacterial flora and feces, the deep litter, and insects present in the housing. In addition, we assessed the marmosets' general health and the effect of outdoor housing on, for example, vitamin D levels. Although numerous bacterial strains-from nonpathogenic to potentially pathogenic-were cultured, we noted no increase in illness, mortality, or breeding problems related to this environmental microflora. Housing laboratory marmosets in large enriched cages, with both indoor and outdoor enclosures, providing them with deep litter, and eliminating the use of disinfectants present an increased veterinary risk. However, after evaluating all of the collected data, we estimate that the veterinary risk of the new housing conditions is minimal to none in terms of clinical disease, disease outbreaks, abnormal behavior, and negative effects on reproduction.
Journal of the American Association for Laboratory Animal Science: JAALAS 05/2015; 54(3):273-9. · 1.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Currently, there is no animal model known that mimics natural nasal colonization by Staphylococcus aureus in humans. We investigated whether rhesus macaques are natural nasal carriers of S. aureus. Nasal swabs were taken from 731 macaques. S. aureus isolates were typed by pulsed-field gel electrophoresis (PFGE), spa repeat sequencing and multi-locus sequence typing (MLST), and compared with human strains. Furthermore, the isolates were characterized by several PCRs. Thirty-nine percent of 731 macaques were positive for S. aureus. In general, the macaque S. aureus isolates differed from human strains as they formed separate PFGE clusters, 50% of the isolates were untypeable by agr genotyping, 17 new spa types were identified, which all belonged to new sequence types (STs). Furthermore, 66% of macaque isolates were negative for all superantigen genes. To determine S. aureus nasal colonization, three nasal swabs from 48 duo-housed macaques were taken during a 5 month period. In addition, sera were analyzed for immunoglobulin G and A levels directed against 40 staphylococcal proteins using a bead-based flow cytometry technique. Nineteen percent of the animals were negative for S. aureus, and 17% were three times positive. S. aureus strains were easily exchanged between macaques. The antibody response was less pronounced in macaques compared to humans, and nasal carrier status was not associated with differences in serum anti-staphylococcal antibody levels. In conclusion, rhesus macaques are natural hosts of S. aureus, carrying host-specific lineages. Our data indicate that rhesus macaques are useful as an autologous model for studying S. aureus nasal colonization and infection prevention.
PLoS ONE 10/2011; 6(10):e26170. DOI:10.1371/journal.pone.0026170 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bakker, J., Thuesen, L. R., Braskamp, G., Skaanild, M. T., Ouwerling, B., Langermans, J. A. M., Bertelsen, M. F. Single subcutaneous dosing of cefovecin in rhesus monkeys (Macaca mulatta): a pharmacokinetic study. J. vet. Pharmacol. Therap.34, 464–468.
Cefovecin is a third-generation cephalosporin approved for antibacterial treatment with a 14-day dosing interval in dogs and cats. This antibiotic may also be useful for zoo and wildlife veterinary medicine, because of its broad spectrum and long duration of activity. The aim of the study was to determine whether cefovecin is a suitable antibiotic to prevent skin wound infection in rhesus monkeys. Therefore, the pharmacokinetics (PK) of cefovecin after a single subcutaneous injection at 8 mg/kg bodyweight in four rhesus monkeys (Macaca mulatta) and sensitivity of bacterial isolates from fresh skin wounds were determined. After administration, blood, urine, and feces were collected, and concentrations of cefovecin were determined. Further, the minimum inhibitory concentrations (MIC) for bacteria isolated from fresh skin wounds of monkeys during a health control program were determined. The mean maximum plasma concentration (Cmax) of cefovecin was 78 μg/mL and was achieved after 57 min. The mean apparent long elimination half-life (t½) was 6.6 h and excretion occurred mainly via urine. The MIC for the majority of the bacteria examined was >100 μg/mL. The PK of cefovecin in rhesus monkeys is substantially different than for dogs and cats. Cefovecin rapidly reached Cmax which however was lower than most of the MIC levels and with a very short t½. Therefore, cefovecin is not recommended for treating skin wounds in rhesus monkeys.
Journal of Veterinary Pharmacology and Therapeutics 02/2011; 34(5):464-8. DOI:10.1111/j.1365-2885.2010.01265.x · 1.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oligodendrocyte-specific protein (OSP) is a candidate autoantigen in the development of multiple sclerosis (MS). We evaluated the potential of OSP to induce EAE in rhesus monkeys, an out bred animal model for MS that is immunologically close to humans. Since OSP is a four-membrane spanning protein with highly hydrophobic regions, we synthesized recombinant proteins encompassing only the hydrophilic regions of human OSP (soluble (s)hOSP). Immunization with shOSP proteins induced clinical signs and histological features of optic neuritis in four out of ten rhesus monkeys. The development of clinical disease was associated with the presence of a strong cellular proliferative response to the immunizing shOSP protein. Analysis of the cellular responses in combination with neuropathological observations also indicates an important role for neutrophils in the disease process. Interestingly, all immunized monkeys developed antibody responses to OSP peptide 103-123, a B cell epitope previously identified in MS patients. These responses did not correlate with the development of clinical disease, but may have relevance as a biomarker for immunoreactivity towards OSP in myelin disorders. Our data demonstrate that in rhesus monkeys immune responses directed at OSP are encephalitogenic, leading to inflammatory responses throughout the central nervous system and to selective demyelination of the optic nerve.
European Journal of Immunology 06/2008; 38(5):1452-64. DOI:10.1002/eji.200737164 · 4.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Myelin oligodendrocyte glycoprotein (MOG) is a powerful encephalitogen for experimental autoimmune demyelination. However, the use of MOG peptides or recombinant proteins representing part of the protein fails to fully address the possible pathogenic role of the full-length myelin-derived protein expressing post-translational modifications. Immunization of mice with central nervous system tissues from wild-type (WT) and MOG-deficient (MOG(-/-)) mice demonstrates that MOG in myelin is necessary for the development of chronic demyelinating experimental autoimmune encephalomyelitis (EAE) in mice. While immunization with WT spinal cord homogenate (SCH) resulted in a progressive EAE phenotype, MOG(-/-) SCH induced a mild self-limiting acute disease. Following acute EAE with MOG(-/-) SCH, mice developed T cell responses to recombinant mouse MOG (rmMOG), indicating that MOG released from myelin is antigenic; however, the lack of chronic disease indicates that such responses were not pathogenic. Chronic demyelinating EAE was observed when MOG(-/-) SCH was reconstituted with a dose of rmMOG comparable to MOG in myelin (2.5% of total white matter-derived protein). These data reveal that while immunization with the full-length post-translational modified form of MOG in myelin promotes the development of a more chronic autoimmune demyelinating neurological disease, MOG (and/or other myelin proteins) released from myelin during ongoing disease do not induce destructive autoimmunity.
European Journal of Immunology 05/2005; 35(4):1311-9. DOI:10.1002/eji.200425842 · 4.03 Impact Factor