Biology subjects

Lipman, N. S.

Publications and source records attributed to Lipman, N. S..

4 recordsLinked to original sources

bioRxiv2023

Examining Horizontal Transmission of Nippostrongylus brasiliensis in Mice to Assess Biosecurity Risks

Nippostrongylus brasiliensis (Nb) infected mice are commonly used to study immune responses. There is no consensus regarding the biosecurity measures that should be employed when housing Nb-infected mice and rats. Transmission is reported to not occur when infected mice are co-housed with naive mice. We sought to determine what conditions, if any, favor horizontal transmission. Female NOD.Cg-Prkdcscid Il2rgtm1Wjl/Sz (NSG; n=12) and C57BL/6J (B6; n=12) mice inoculated with 750 Nb L3 larvae were cohoused with naive NSG (n=24) and B6 (n=24) mice at a ratio of 1 infected:2 naive mice per cage for 28 days within static microsiolator (MI) cages changed on a 14-day interval. We also assessed whether larval development to the L3 stage could occur when Nb egg-containing fecal pellets are maintained under 4 different environmental conditions (dry, moist, soiled bedding, and control) and whether infection results when naive NSG mice (n=9) are housed in MI cages with infective L3 larvae-spiked (10,000/cage) soiled bedding. NSG mice (n=3) were also gavaged with Nb eggs to model the potential for infection to occur following coprophagy. Both naive NSG (9 of 24) and B6 (10 of 24) mice cohoused with an infected cagemate passed Nb eggs in feces as early as 1 day and intermittently for varying periods following cohousing, presumably a result of coprophagy as adult worms were not detected at euthanasia. While eggs were able to develop into L3 larvae under 2 environmental conditions (moist and control), none of the NSG mice housed in cages with L3-spiked bedding or gavaged with eggs became infected with Nb. Findings demonstrate that horizontal transmission does not occur when mice are housed with Nb-shedding cagemates in static MI cages with a 14-day cage changing interval. Results from this study can be used to inform biosecurity practices when working with the Nb-infected mouse model.

immunology↗

bioRxiv2022

Assessing Mouse Kidney Parvovirus' Ability to Confound Research by Examining its Effects on Renally Excreted Chemotherapeutics and its Impact on Pathologic Endpoints in 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. The purpose of this 2-part study was to determine the impact that MKPV may have on preclinical models as it relates to the pharmacokinetics of chemotherapeutics as well as its impact on the adenine diet model of chronic kidney disease. To assess the impact of MKPV on pharmacokinetics of 2 renally excreted chemotherapeutics commonly used in preclinical oncology studies, methotrexate and lenalidomide, blood and urine drug concentrations were measured in MKPV-infected or uninfected immunodeficient NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) and immunocompetent C57BL/6NCrl (B6) female mice. Differences in plasma pharmacokinetics were observed for methotrexate, but not for lenalidomide. Differences were most profound between uninfected NSG and B6 mice. The area under the curve (AUC) of methotrexate was 1.5-fold higher in uninfected NSG mice compared to infected NSG mice, 1.9-fold higher in infected B6 mice compared to uninfected B6 mice, and 4.3-fold higher in uninfected NSG mice compared to uninfected B6 mice. Renal clearance of both drugs was not impacted by MKPV infection but was generally lower in NSG mice. To assess the impact of MKPV on the adenine diet model of chronic kidney disease, MKPV-infected and uninfected B6 female mice were fed a 0.2% adenine diet and clinical and histopathologic features of disease were assessed over 8 weeks. Infection with MKPV did not have a significant impact on serum biomarkers of renal function such as BUN, creatinine, and SDMA; urine chemistry; or hemogram. However, infection did impact select histologic outcomes. MKPV-infected mice had significantly more foci of interstitial lymphoplasmacytic infiltrates than uninfected mice after 4 and 8 weeks of diet consumption, and significantly less interstitial fibrosis at week 8. Macrophage infiltrates and renal tubular injury, assessed using various immunohistochemical stains, were similar between groups. Together, these findings indicate that MKPV infection had minimal impact on the renal excretion of 2 chemotherapeutics and serum biomarkers of renal function. However, infection significantly impacted select histologic features of renal disease in the adenine diet model. While MKPV-free mice should be used in biomedical research, it is of the utmost importance in studies evaluating renal histology as an experimental outcome.

pathology↗

bioRxiv2022

Establishing the Median Infectious Dose (ID50) and Characterizing the Clinical Manifestations of Mouse, Rat, Cow, and Human Corynebacterium bovis Isolates in Select Immunocompromised Mouse Strains

Corynebacterium bovis (Cb), the etiology of hyperkeratotic dermatitis in various immunocompromised mouse strains, significantly impacts research in which 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 in mice associated with unique isolates. The infectious dose yielding colonization of 50% of the exposed population (ID50) and any associated clinical disease was determined for mouse (n=3), rat (n=1), cow (n=1), and human (n=2) Cb isolates in athymic nude mice (Hsd:Athymic Nude-Foxn1nu). The same investigations were undertaken comparing 2 of these murine isolates in 2 furred immunocompromised mouse strains (NSG [NOD.Cg-PrkdcscidIl2rgtm1Wjl/Sz] and NSG-S [NOD.Cg-PrkdcscidIl2rgtm1WjlTg(CMV-IL3,CSF2,KITLG)1Eav/MloySzJ]). To determine the ID50, mice (n=6/dose; 3 of each sex) were inoculated topically with 1 to 108 bacteria (10-fold increments) of each Cb isolate. Mice were scored (0 to 5) daily based on the severity of clinical signs for 14 days. On day 7 and 14 post-inoculation (PI), buccal and dorsal skin swabs were evaluated by aerobic culture to determine infection status. The mouse isolates yielded a lower ID50 (58 to 1,000 bacteria) as compared to the bovine (6,460 to 7,498 bacteria) and rat (10,000 bacteria) Cb isolates. Mice were not colonized and disease did not result when inoculated with human isolates. Mouse isolates produced varying clinical disease severity in nude mice (max score/isolate: 0 to 5). Despite significant immunodeficiency, furred NSG and NSG-S mice required a considerably higher (1,000- to 3,000-fold) inoculum to become colonized as compared to athymic nude mice. Once colonized, clinically detectable hyperkeratosis did not develop in these strains until 18 to 22 days PI. In contrast, in athymic nude mice that developed clinically detectable disease, hyperkeratosis was observed 6 to 14 days PI. In conclusion, there are significant differences in Cbs ID50, disease course, and severity between Cb isolates and among immunodeficient mouse strains.

microbiology↗

bioRxiv2022

Reemergence of the Murine Bacterial Pathogen Chlamydia muridarum in Laboratory Mouse Colonies

Chlamydia muridarum (Cm) was detected in mice from 2 colonies with lymphoplasmacytic pulmonary infiltrates 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 resident colonies from 8 vivaria from 3 academic institutions, 58 incoming mouse shipments from 39 academic institutions, and mice received from 55 commercial breeding colonies (4 vendors). To estimate Cms global prevalence in laboratory colonies, a database containing 11,387 metagenomic fecal microbiota samples from 120 institutions and a cohort of 900 diagnostic samples from 96 institutions were examined. Results indicate significant prevalence amongst academic institutions with Cm detected in 62.9% of soiled bedding sentinels from 3 institutions; 32.7% of incoming mouse shipments from 39 academic institutions; 14.2% of 120 institutions submitting microbiota samples; and 16.2% of the diagnostic sample cohort. All samples from commercial breeding colonies were negative. Additionally, naive NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice exposed to Cm shedding mice and their soiled bedding developed clinical disease 21 to 28 days following exposure. These mice had a moderate-to-severe histiocytic and neutrophilic bronchointerstitial pneumonia with respiratory epithelium demonstrating inclusions, chlamydial major outer membrane protein immunostaining, and hybridization with a Cm reference sequence (GenBank accession no. U68436). Cm was isolated on HeLa 229 cells from lungs, cecum, and feces of a Cm infected NSG mouse. The considerable prevalence of Cm is likely attributed to widespread global interinstitutional distribution of unique mouse strains and failure to recognize that some of these mice were from enzootically infected colonies. Given that experimental Cm colonization of mice results in a robust immune response and, on occasion, pathology, natural infection may confound experimental results. Therefore, Cm should be excluded and eradicated from endemically infected laboratory mouse colonies.

microbiology↗