Chlamydia muridarum Causes Persistent Subclinical Infection and Elicits Innate and Adaptive Immune Responses in C57BL/6J, BALB/cJ, and J:ARC(S) Mice Following Exposure to Shedding Mice.

Chlamydia muridarum (Cm) has reemerged as a moderately prevalent infectious agent in research mouse colonies. Despite its experimental use, few studies evaluate Cm's effects on immunocompetent mice following its natural route of infection. A Cm field isolate was administered (orogastric gavage) to 8-wk-old female BALB/cJ (C) mice.

Assessing the Biosecurity Risk of Footwear as a Fomite for Transmission of Adventitious Infectious Agents to Mice.

The soles of staff shoes accessing vivaria can become contaminated on urban streets, potentially serving as a source of fomite-mediated transmission of adventitious agents to laboratory rodents. While shoe covers may mitigate this risk, donning them can lead to hand contamination. Staff accessing our vivaria use motor-driven shoe cleaners hundreds of times daily to remove and collect particulates via a vacuum collection system from the top, sole, and sides of shoes instead of shoe covers.

Examining Intercage Transmission of : Impact of Barrier Husbandry and Cage Sanitization.

(Cm) has reemerged as a prevalent bacterial contaminant of academic research mouse colonies. A study was conducted to assess the effectiveness of husbandry and cage sanitization methods in preventing intercage transmission of Cm. To assess intercage transmission during cage change, a cage housing 2 Cm-free Swiss Webster (SW; Tac:SW) sentinel mice was placed randomly on each of 12 individually ventilated cage racks, housing cages with Cm-shedding mice, located in one of 2 animal holding rooms.

Causes Persistent Subclinical Infection and Elicits Innate and Adaptive Immune Responses in C57BL/6J, BALB/cJ and J:ARC(S) Mice Following Exposure to Shedding Mice.

(Cm) has reemerged as a moderately prevalent infectious agent in research mouse colonies. Despite its' experimental use, few studies evaluate Cm's effects on immunocompetent mice following its natural route of infection. A Cm field isolate was administered (orogastric gavage) to 8-week-old female BALB/cJ (C) mice.

Examining Intercage Transmission of : Impact of Barrier Husbandry and Cage Sanitization.

(Cm) has reemerged as a prevalent bacterial contaminant of academic research mouse colonies. A study was conducted to assess the effectiveness of husbandry and cage sanitization methods in preventing intercage transmission of Cm. To assess intercage transmission during cage change, a cage housing 2 Cm-free Swiss Webster (Tac:SW; SW) sentinel mice was placed randomly on each of 12 individually ventilated cage racks, housing cages with Cm-shedding mice, located in 1 of 2 animal holding rooms.

Successful Rearing of Nutritionally Supplemented Rotifers () at Reduced Salinity for Zebrafish () Polyculture.

Rotifers, are a valuable first exogenous feed for zebrafish because they can provide continuous nutrition for growing zebrafish larvae when used in a rotifer-zebrafish polyculture. Typically cultured at high salinities (>10 ppt), are temporarily immobilized when moved to lower salinities (5 ppt) used for polycultures, decreasing their accessibility and attractiveness to the larvae. The nutritional value of rotifers varies based on their diet, typically live algae, which has limited nutritional value and may pose biosecurity risks.

Establishing the Median Infectious Dose and Characterizing the Clinical Manifestations of Mouse, Rat, Cow, and Human Isolates in Select Immunocompromised Mouse Strains.

(Cb), the cause of hyperkeratotic dermatitis in various immunocompromised mouse strains, significantly impacts research outcomes if infected mice are used. Although Cb has been isolated from a variety of species, including mice, rats, cows, and humans, little is known about the differences in the infectivity and clinical disease that are associated with specific Cb isolates. The infectious dose that colonized 50% of the exposed population (ID ) and any associated clinical disease was determined in athymic nude mice (Hsd:Athymic Nude-Foxn1 nu ) inoculated with Cb isolates collected from mice ( = 5), rat ( = 1), cow ( = 1), and humans ( = 2) The same parameters were also determined for 2 of the mouse isolates in 2 furred immunocompromised mouse strains (NSG [NOD.

Examination of Horizontal Transmission of in Mice to Assess Biosecurity Risks.

Mice are commonly infected with (Nb) to study their immune responses. However, biosecurity measures have not been established for housing Nb-infected mice and rats. Transmission reportedly does not occur when infected mice are cohoused with naive mice.

Pathologic copulatory lock in a genetically engineered laboratory mouse breeding pair.

A breeding pair of genetically engineered laboratory mice () presented in apparent copulatory lock (coital tie). After anesthetizing the animals, gentle traction was used to separate the pair at which point a vaginal prolapse was detected and the penis was covered with black, firm, dry crusts and noted to have a solid pale, tan, firm cylindrical mass adhering to its glans. The vaginal prolapse was reduced and the female was returned to its cage.

Effects of Mouse Kidney Parvovirus on Pharmacokinetics of Chemotherapeutics and the Adenine Model of Chronic Kidney Disease.

Mouse kidney parvovirus (MKPV) causes inclusion body nephropathy in severely immunocompromised mice and renal interstitial inflammation in immunocompetent mice. Here we sought to determine the effects of MKPV on pre-clinical murine models that depend on renal function. To assess the effects of MKPV infection on the pharmacokinetics of 2 renally excreted chemotherapeutic agents, methotrexate and lenalidomide, we measured drug concentrations in the blood and urine of MKPV-infected or uninfected immunodeficient NOD.

Mechanical Washing Prevents Transmission of Bacterial, Viral, and Protozoal Murine Pathogens from Cages.

Infectious agents have varying susceptibilities to thermal inactivation and/or mechanical removal from cages by the use of heated, pressurized water. In this study, we tested whether 5 specific infectious organisms ( [segmented filamentous bacterium (SFB)], sp., mouse norovirus (MNV), sp.

Infectivity and Shedding of Mouse Kidney Parvovirus After Oronasal Inoculation of C57BL/6, CD1, and NSG Mice.

Mouse kidney parvovirus (MKPV), the etiology of murine inclusion body nephropathy, has been identified globally in mice used for research, with an estimated prevalence of 10% in academic colonies. In immunodeficient strains, MKPV causes significant morbidity and mortality, and severe renal pathology. In contrast, in immunocompetent mice, the infection is subclinical and causes minimal pathology.

Evaluation of Media Conductivity and a Combination of Iodine and Sodium Hypochlorite Surface Disinfection on Zebrafish () Embryo Viability and Morphology.

Embryo surface disinfection in either an iodine or sodium hypochlorite (NaOCl) solution is commonly performed on imported zebrafish embryos to decrease pathogen introduction into a facility. The impact of the consecutive use of these disinfectants and the conductivity of the culture media on embryo survival and development post-disinfection have not been evaluated. Iodine (12.

Reemergence of the Murine Bacterial Pathogen in Research Mouse Colonies.

(Cm) was detected in 2 colonies of mice with lymphoplasmacytic pulmonary infiltrates by using PCR and immunohistochemistry. This discovery was unexpected, as Cm infection had not been reported in laboratory mice since the 1940s. A Cm specific PCR assay was developed and testing implemented for the resident colonies of 8 vivaria from 3 academic institutions, 58 incoming mouse shipments from 39 academic institutions, and mice received from 55 commercial breeding colonies (4 vendors).

Assessing Elimination of Mouse Kidney Parvovirus from Cages by Mechanical Washing.

Mouse kidney parvovirus (MKPV), a newly identified parvovirus of the genus , causes inclusion body nephropathy in severely immunocompromised mice and is prevalent in research mouse colonies. As nonenveloped viruses, mammalian parvoviruses are stable and generally resist thermal inactivation; however, as a novel and highly divergent parvovirus, the thermal stability of MKPV is undefined. This study aimed to evaluate the ability of cage sanitization in a mechanical washer to eliminate MKPV.

Biology and Cellular Tropism of a Unique Astrovirus Strain: Murine Astrovirus 2.

Murine astrovirus 2 (MuAstV2) is a novel murine astrovirus recently identified in laboratory and wild mice. MuAstV2 readily transmits between immunocompetent mice yet fails to transmit to highly immunocompromised mouse strains-a unique characteristic when contrasted with other murine viruses including other astroviruses. We characterized the viral shedding kinetics and tissue tropism of MuAstV2 in immunocompetent C57BL/6NCrl mice and evaluated the apparent resistance of highly immunocompromised NOD- /NjuCrl mice to MuAstV2 after oral inoculation.

Impact of Pronase, Sodium Thiosulfate, and Methylene Blue Combinations on Development and Survival of Sodium Hypochlorite Surface-Disinfected Zebrafish () Embryos.

Embryo surface disinfection is utilized in aquaculture to decrease the risk of pathogen introduction into established colonies. Zebrafish embryos are commonly disinfected with unbuffered sodium hypochlorite at 25-50 ppm for 10 min with or without concurrent treatment with chemicals, including pronase (Pron), sodium thiosulfate, and/or methylene blue; however, the impact of these chemicals on embryo survival and development has not been evaluated. In this study, AB and embryos were exposed to disinfection protocols that used Pron, sodium thiosulfate, and/or methylene blue (given alone, in various combinations, or all three combined) with 50 and 100 ppm sodium hypochlorite performed 6 and 24 h postfertilization (HPF).

Serendipitous Discovery of a Novel Murine Astrovirus Contaminating a Murine Helper T-cell Line and Incapable of Infecting Highly Immunodeficient Mice.

The unexpected seroconversion of sentinel mice in our facility to murine T lymphotrophic virus (MTLV) positivity led to our identification of a novel murine astrovirus that we designated murine astrovirus 2 (MuAstV-2). During our investigation, MuAstV-2 was found to be a contaminant of the T helper cell line (D10. G4.

Mite Burden and Immunophenotypic Response to in Swiss Webster, BALB/c, C57BL/6, and NSG Mice.

Detection methods for were historically unreliable, and testing was rarely performed because its prevalence in laboratory mice was underestimated. Although infestations are unapparent in most mouse strains, burdens are higher and clinical signs detected in various immunodeficient strains. The parasite's influence on the immune system of immunocompetent mice is unknown.