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Comparative Medicine Dec 2020The internal transcribed spacer (ITS) regions of , , , , and and of a related β-hemolytic taxon isolated from laboratory rodents were studied for their feasibility...
The internal transcribed spacer (ITS) regions of , , , , and and of a related β-hemolytic taxon isolated from laboratory rodents were studied for their feasibility to discriminate among these species. The 6 species analyzed showed species-specific ITS patterns that were shared by the type strains and clinical isolates and that allowed their identification. Nevertheless, differentiating between the ITS band patterns of and is visually challenging. In all species tested, sequence analysis of the ITS fragments revealed a larger ITS, which contained the genes for tRNA and tRNA , and a smaller ITS with the tRNA gene. The ITS sequences varied among the 6 species evaluated, displaying identity levels ranging from 62% to 86% for ITS and 68% to 90% for ITS. Overall, ITS amplification proved to be a reliable method to differentiate among these important species of laboratory rodents. Moreover, the ITS sequence variations recorded here might facilitate the design of probes for specific identification of these species. The ability to diagnose these organisms to the species level could increase our understanding of their clinical significance.
Topics: Animals; DNA, Bacterial; Pasteurella pneumotropica; Pasteurellaceae; RNA, Ribosomal, 16S; RNA, Ribosomal, 23S; Rodentia; Sequence Analysis, DNA
PubMed: 33121574
DOI: 10.30802/AALAS-CM-99-990085 -
Laboratory Animals Apr 2021An otherwise healthy two-month-old female C57BL/6J mouse presented with a left-sided head tilt. Differential diagnoses included idiopathic necrotizing arteritis,...
An otherwise healthy two-month-old female C57BL/6J mouse presented with a left-sided head tilt. Differential diagnoses included idiopathic necrotizing arteritis, bacterial otitis media/interna (, , , and ), encephalitis, an abscess, neoplasia, a congenital malformation and an accidental or iatrogenic head trauma. Magnetic resonance imaging (MRI) revealed a large space-occupying right olfactory lobe intra-axial lesion with severe secondary left-sided subfalcine herniation. Following imaging, the animal was euthanized due to poor prognosis. Histopathologic examination revealed a unilateral, full-thickness bone defect at the base of the cribriform plate and nasal conchae dysplasia, resulting in the herniation of the olfactory bulb into the nasal cavity. There was also a left midline-shift of the frontal cortex and moderate catarrhal sinusitis in the left mandibular sinus. The MRI and histopathologic changes are consistent with a congenital malformation of the nasal cavity and frontal aspect of the skull known as an ethmoidal meningoencephalocele. Encephaloceles are rare abnormalities caused by herniation of contents of the brain through a defect in the skull which occur due to disruption of the neural tube closure at the level anterior neuropore or secondary to trauma, surgical complications, cleft palate or increased intracranial pressure. The etiology is incompletely understood but hypotheses include genetics, vitamin deficiency, teratogens, infectious agents and environmental factors. Ethmoidal encephaloceles have been reported in multiple species including humans but have not been reported previously in mice. There are multiple models for spontaneous and induced craniofacial malformation in mice, but none described for ethmoidal encephaloceles.
Topics: Animals; Diagnosis, Differential; Encephalocele; Ethmoid Bone; Fatal Outcome; Female; Magnetic Resonance Imaging; Meningocele; Mice; Mice, Inbred C57BL
PubMed: 32787540
DOI: 10.1177/0023677220944449 -
Veterinary World Dec 2019A total of 112 freshly dead ducks aged from 2 to 20 weeks old with a history of respiratory manifestations were investigated for the implication of family members.
AIM
A total of 112 freshly dead ducks aged from 2 to 20 weeks old with a history of respiratory manifestations were investigated for the implication of family members.
MATERIALS AND METHODS
Isolation and identification to the family level were conducted by conventional bacteriological methods, including microscopic examination and biochemical characterization. Identification to the species level was conducted by polymerase chain reaction (PCR) and analytical profile index (API) 20E kits.
RESULTS
Conventional bacteriological isolation and biochemical characterization revealed the infection of 16/112 examined birds with a prevalence rate of 14.3%. PCR confirmed the detection of family conserved genes B and z in 16/16 (100%) isolates. PCR was also used for genus and species identification of the isolated members; the results revealed that 5/16 (31.3%) of isolates were and 2/16 of isolates (12.5%) were . , , and were not detected by PCR. Biotyping by API 20E successfully identified 5/16 (31.3%) isolates that could not be typed by PCR and confirmed their belonging to . Neither the available PCR primer sets nor API 20E succeeded for species identification of 4/16 (25%) isolates. Antibiotic susceptibility profiling of isolates revealed that 16/16 (100%) of isolates demonstrated multidrug resistance (MDR) phenotypes. Moreover, 16/16 (100%) of isolates demonstrated a phenotypic resistance pattern to neomycin.
CONCLUSION
Combined genotypic, phenotypic, biotyping, and virulence characterizations are required for laboratory identification of pathogenic . Moreover, was not the prevailed member implicated in respiratory problems in ducks as , , and unidentified strains were involved with higher prevalence. Chloramphenicol and ampicillin demonstrated the highest effects on the studied . Furthermore, the prevalence of multidrug-resistant isolates signified the demand to implement targeted surveillance in the ducks' production sector, and MDR survey in poultry sectors in Egypt to apply effective control measures.
PubMed: 32095060
DOI: 10.14202/vetworld.2019.2061-2069 -
Journal of the American Association For... Jan 2020To monitor rodent colony health in research facilities, soiled-bedding sentinel (SBS) animals have traditionally been used. SBS can be tested by various methods, which...
To monitor rodent colony health in research facilities, soiled-bedding sentinel (SBS) animals have traditionally been used. SBS can be tested by various methods, which may include serology, PCR analysis, and necropsy. Several pathogens are unreliably detected by using SBS or transmitted poorly through soiled bedding, and collection and evaluation of SBS samples can be time-intensive. Recently, exhaust air dust (EAD) testing through PCR analysis has emerged as an adjunct or replacement method for rodent colony health monitoring. EAD monitoring may provide a more efficient, sensitive, and humane method for monitoring health status. Using both EAD and SBS health monitoring, we evaluated colony health over the course of 1 y in 3 research barrier rooms in which mice were housed exclusively on IVC racks. Three pathogens- spp., spp. (previously ), and murine norovirus (MNV)-were not excluded in 2 of the rooms, and we expected that these mice would test positive with some regularity. EAD monitoring was significantly more sensitive than SBS for detection of the bacterial agents. SBS failed to detect spp. at time points when EAD had 100% detection in the rooms that did not exclude the bacteria. The detection of MNV did not differ between health monitoring systems at any time point. The findings suggest that EAD is especially valuable in detecting bacteria poorly transmitted through soiled bedding. In addition, the corresponding results with MNV detection suggest that EAD surveillance can reliably be implemented as an alternative to SBS monitoring in a facility in which mice are housed exclusively on IVC racks.
Topics: Animals; Bacterial Infections; Bedding and Linens; Caliciviridae Infections; Dust; Helicobacter; Housing, Animal; Laboratory Animal Science; Mice; Norovirus; Pasteurellaceae; Rodent Diseases; Sentinel Surveillance
PubMed: 31862019
DOI: 10.30802/AALAS-JAALAS-19-000061 -
Journal of the American Association For... Jul 2019The uncertain taxonomy of [] and other rodent has hindered the acquisition of knowledge on the biology and disease for this group of bacteria. Recently, these...
The uncertain taxonomy of [] and other rodent has hindered the acquisition of knowledge on the biology and disease for this group of bacteria. Recently, these organisms have been reclassified within the new genus In this study, we documented which of the new described spp. are present in the mouse and rat microbiologic units of an experimental facility. Screening all of the microbiologic units populated with mice and rats yielded 51 isolates. Molecular and phenotypic diagnosis indicated the colonization of mice by and , whereas and were found in rats. Overall, we document the association of laboratory rodents with 3 of the newly described . Diagnostics of the spp. at the species level can decisively contribute to the progress of knowledge on these bacteria.
Topics: Animals; Laboratory Animal Science; Mice; Pasteurellaceae; Pasteurellaceae Infections; Rats; Rodent Diseases
PubMed: 31239009
DOI: 10.30802/AALAS-JAALAS-19-000001 -
Journal of the American Association For... Mar 2019Exposing immunodeficient mice to opportunistic microbes introduces risks of data variability, morbidity, mortality, and the invalidation of studies involving unique...
Exposing immunodeficient mice to opportunistic microbes introduces risks of data variability, morbidity, mortality, and the invalidation of studies involving unique human reagents, including the loss of primary human hematopoietic cells, patient-derived xenografts, and experimental therapeutics. The prevalence of 15 opportunistic microbes in a murine research facility was determined by yearlong PCR-based murine and IVC equipment surveillance comprising 1738 specimens. Of the 8 microbes detected, 3 organisms- , , and biotype Heyl-were most prevalent in both murine and IVC exhaust plenum specimens. Overall, the 8 detectable microbes were more readily PCR-detectable in IVC exhaust airways than in murine specimens, supporting the utility of PCR testing of IVC exhaust airways as a component of immunodeficient murine health surveillance. Vaporized hydrogen peroxide (VHP) exposure of IVC equipment left unassembled (that is, in a 'static-open' configuration) did not eliminate PCR detectable evidence of microbes. In contrast, VHP exposure of IVC equipment assembled 'active-closed' eliminated PCR-detectable evidence of all microbes. Ensuring data integrity and maintaining a topographically complex immunodeficient murine research environment is facilitated by knowing the prevalent opportunistic microbes to be monitored and by implementing a PCR-validated method of facility decontamination that mitigates opportunistic microbes and the risk of invalidation of studies involving immunodeficient mice.
Topics: Animals; Decontamination; Disinfectants; Hydrogen Peroxide; Mice; Nebulizers and Vaporizers; Opportunistic Infections; Polymerase Chain Reaction; Prevalence
PubMed: 30795821
DOI: 10.30802/AALAS-JAALAS-18-000112 -
BMC Microbiology Feb 2019Rodentibacter (R.) pneumotropicus colonizes the respiratory and urogenital tracts of laboratory mice with a reported moderate serological prevalence from 4 to 13%. Thus,...
BACKGROUND
Rodentibacter (R.) pneumotropicus colonizes the respiratory and urogenital tracts of laboratory mice with a reported moderate serological prevalence from 4 to 13%. Thus, regular tests to identify this pathogen in mice are recommended for animal facilities. However, a recent study indicated that current serological assays are partly insensitive, as C57BL/6 and BALB/c mice infected with R. pneumotropicus were incorrectly screened as seronegative.
RESULTS
Here, we report a systematic analysis of protein and lipopolysaccharides antigens by immunoblot and ELISA that allowed establishing a sensitive test system able to differentiate between R. pneumotropicus and the closely related species R. heylii. Furthermore, the main immunogen, designated as 'characteristic antigen for Rodentibacter of laboratory origin 1' (CARLO-1), was identified by two-dimensional gel electrophoresis followed by immunoblot and tandem mass spectrometry in a preparation of outer membrane proteins. An indirect ELISA relying on the recombinantly expressed protein provided high sensitivity, specificity, and selectivity. The corresponding carlo1 gene was highly conserved (> 97%) among 21 isolates of R. pneumotropicus and R. heylii.
CONCLUSION
The newly identified protein CARLO-1 is well suited for the sensitive and specific serological detection of Rodentibacter infections in mice. Indirect differentiation of R. pneumotropicus and R. heylii infections may be possible using an ELISA based on a whole-cell antigen preparation. All four established ELISA systems using a whole-cell preparation, lipopolysaccharides, outer-membrane proteins and protein CARLO-1 as antigen, respectively, outperformed a commercial ELISA in terms of sensitivity.
Topics: Animals; Antigens, Bacterial; Bacterial Proteins; Enzyme-Linked Immunosorbent Assay; Female; Immunoblotting; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pasteurellaceae; Pasteurellaceae Infections; Sensitivity and Specificity
PubMed: 30777007
DOI: 10.1186/s12866-019-1417-7 -
Journal of the American Association For... Sep 2018Testing sentinel animals exposed to soiled bedding from colony animals is the most common method used for health monitoring in rodent facilities. Although environmental...
Testing sentinel animals exposed to soiled bedding from colony animals is the most common method used for health monitoring in rodent facilities. Although environmental sampling is being explored-and, in many cases, has been implemented-as an alternative, exhaust plenum sampling is not effective for all ventilated rack designs. This study evaluated PCR testing of filter paper from sentinel cages on ventilated racks. We hypothesized that testing filter paper from cages containing soiled bedding would be as effective as testing sentinel mice and that periodic shaking of cages would generate sufficient particulate movement to substitute for the presence of live animals. Three cages containing soiled bedding were maintained in each of 8 rooms; one cage contained 2 Cr:NIH(S) mice, one had no mice and was shaken twice weekly, and the remaining one had no mice and was left undisturbed. For 3 consecutive months, a piece of filter paper from the undersurface of the cage lid was tested monthly for adventitial agents and then replaced. A second piece remained on the cage undersurface for 3 mo. Fecal pellets and oral and fur swabs were collected from sentinel mice at months 1 and 3 and tested for the same agents. At month 3, serology was performed on the sentinel mice; feces and oral and fur swabs from colony animals were tested concurrently for comparison. Filter paper from cages without mice and shaken were at least as effective than all other methods in detecting the presence of endemic agents, including mouse norovirus, Helicobacter spp., Pasteurella pneumotropica, Entamoeba muris, and Spironucleus muris. For IVC systems where exhaust plenum testing is ineffective, PCR testing of IVC filter tops should be considered as an alternative to soiled bedding sentinels. Environmental sampling may provide increased reliability and reduce the number of rodents used for routine health surveillance.
Topics: Animals; Bacteria; Filtration; Housing, Animal; Laboratory Animal Science; Mice; Polymerase Chain Reaction; Reproducibility of Results
PubMed: 30092857
DOI: 10.30802/AALAS-JAALAS-18-000008 -
BMC Microbiology May 2018Mice are a natural host for Rodentibacter (R.) pneumotropicus. Despite specific monitoring, it is still one of the most important infectious agents in laboratory... (Comparative Study)
Comparative Study
Comparative analysis of humoral immune responses and pathologies of BALB/c and C57BL/6 wildtype mice experimentally infected with a highly virulent Rodentibacter pneumotropicus (Pasteurella pneumotropica) strain.
BACKGROUND
Mice are a natural host for Rodentibacter (R.) pneumotropicus. Despite specific monitoring, it is still one of the most important infectious agents in laboratory animals. The objective of this study was to determine the virulence of a prevalent pathotype of R. pneumotropicus and characterize the host response in a new animal model.
RESULTS
Intranasal infection of C57BL/6 and BALB/c mice with a R. pneumotropicus strain (JF4Ni) bearing the genes of the three known repeats in toxin (RTX) toxins resulted in an unprecedented high mortality and morbidity above 50 and 80%, respectively. Morbidity was associated with severe weight loss as well as conjunctivitis and dyspnea. A main pathology was a catarrhal purulent to necrotic bronchopneumonia. Specific immune globuline (Ig) A was detected in tracheonasal lavages of most surviving mice which were still colonized by R. pneumotropicus. Furthermore, all surviving animals showed a distinct production of IgG antibodies. To differentiate T-helper cell (Th) 1 and Th2 immune responses we used subclasses of IgGs as indicators. Mean ratios of IgG2b to IgG1 were below 0.8 in sera drawn from both mice strains prior infection and from BALB/c mice post infection. In contrast, C57BL/6 mice had a mean IgG2b/IgG1 ratio of 1.6 post infection indicating a Th1 immune response in C57BL/6 versus a Th2 response in BALB/c mice associated with a tenfold higher bacterial load in the lung. In accordance with a Th1 response high antigen-specific IgG2c titers were detected in the majority of surviving C57BL/6 mice.
CONCLUSIONS
R. pneumotropicus JF4Ni is a highly virulent strain causing severe pneumonia and septicemia after intranasal infection of C57BL/6 and BALB/c mice. Persisting infections in the two mice strains are associated with Th1 and Th2 immune responses, respectively, and differences in the bacterial burden of the lung. The described model is ideally suited for future vaccination studies using the natural host.
Topics: Animals; Immunity, Humoral; Immunoglobulin G; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pasteurella Infections; Pasteurella pneumotropica; Pneumonia, Bacterial; Sepsis; Th1 Cells; Th2 Cells
PubMed: 29848308
DOI: 10.1186/s12866-018-1186-8 -
Comparative Medicine Aug 2017A colony of B6.Cg-Rag1tm1Mom Tyrp1B-w Tg(Tcra,Tcrb)9Rest (TRP1/TCR) mice presented with ocular lesions and ulcerative dermatitis. Histopathology, skin scrapes, and fur...
A colony of B6.Cg-Rag1tm1Mom Tyrp1B-w Tg(Tcra,Tcrb)9Rest (TRP1/TCR) mice presented with ocular lesions and ulcerative dermatitis. Histopathology, skin scrapes, and fur plucks confirmed the presence of Demodex spp. in all clinically affected and subclinical TRP1/TCR mice examined (n = 48). Pasteurella pneumotropica and Corynebacterium bovis, both opportunistic pathogens, were cultured from the ocular lesions and skin, respectively, and bacteria were observed microscopically in abscesses at various anatomic locations (including retroorbital sites, tympanic bullae, lymph nodes, and reproductive organs) as well as the affected epidermis. The mites were identified as Demodex musculi using the skin fragment digestion technique. Topographic analysis of the skin revealed mites in almost all areas of densely haired skin, indicating a generalized demodecosis. The percentage of infested follicles in 8- to 10-wk-old mice ranged from 0% to 21%, and the number of mites per millimeter of skin ranged from 0 to 3.7. The head, interscapular region, and middorsum had the highest proportions of infested follicles, ranging from 2.3% to 21.1% (median, 4.9%), 2.0% to 16.6% (8.1%), and 0% to 17% (7.6%), respectively. The pinnae and tail skin had few or no mites, with the proportion of follicles infested ranging from 0% to 3.3% (0%) and 0% to 1.4% (0%), respectively. The number of mites per millimeter was strongly correlated with the percentage of infested follicles. After administration of amoxicillin-impregnated feed (0.12%), suppurative infections were eliminated, and the incidence of ulcerative dermatitis was dramatically reduced. We hypothesize that the Rag1-null component of the genotype makes TRP1/TCR mice susceptible to various opportunistic infestations and infections, including Demodex mites, P. pneumotropica, and C. bovis. Therefore, Rag1-null mice may serve as a useful model to study human and canine demodecosis. D. musculi should be ruled out as a contributing factor in immunocompromised mouse strains with dermatologic manifestations.
Topics: Adaptive Immunity; Animals; Corynebacterium; Corynebacterium Infections; Female; Genetic Predisposition to Disease; Homeodomain Proteins; Host-Pathogen Interactions; Immunocompromised Host; Male; Membrane Glycoproteins; Mice, Inbred C57BL; Mice, Transgenic; Mite Infestations; Opportunistic Infections; Oxidoreductases; Parasite Load; Pasteurella Infections; Pasteurella pneumotropica; Phenotype; Receptors, Antigen, T-Cell; Risk Factors; Skin
PubMed: 28830578
DOI: No ID Found