RESUMO
Although the Guide suggests changing rodent cage components every 2 wk, it states that "decreased sanitation frequency may be justified if the microenvironment in the cages, under the condition of use ..., is not compromised." The purpose of this study was to evaluate extended sanitation intervals of cage components (automated watering valve, wire bar lid, and filter top) of mouse individually ventilated caging (IVCs) at our institution. We hypothesized that there would be no significant difference in relative light units measured by ATP luminometry of these cage components at the control time point of 14 d as compared with each extended time interval: 28, 56, and 84 d. In addition, for automated watering valves, the study was extended to 168 d. We also hypothesized that time-and-motion studies performed by moving to a sanitation interval of 84 d for all components would result in substantial time and cost savings. The components of a total of 24 cages containing 4 or 5 mice each were swabbed, and an ATP luminometer was used to detect organic matter. We found no significant differences in organic matter load between 14 d and all other time points for all cage components. Our time- and cost-savings analysis found that extending the sanitation interval of cage components from every 2 wk (14 d) to every 3 mo (84 d) for every 10,000 cages would save about 3,000 technician hours annually, for a total annual labor cost savings of about $100,000. This study is the first to validate the extended sanitation interval of automated watering valves and confirms the findings of previous studies that validated the extended sanitation frequency of wire bar lids and filter tops of rodent IVCs. Overall, extending the sanitation frequency of cage components reduces workload of animal care staff without compromising the cage microenvironment.
Assuntos
Abrigo para Animais , Saneamento , Humanos , Camundongos , Animais , Água , Criação de Animais Domésticos , Trifosfato de AdenosinaRESUMO
Insects are potential disease vectors for research animals. Therefore, implementing an effective pest control program is an essential component of any animal care and use program. The Guide for the Care and Use of Laboratory Animals emphasizes the humane use of traps; however, insect traps commonly use glue that can entrap escaped research mice, leading to their potential distress and injury. This situation is challenging for research facilities attempting to identify insect populations. In an effort to improve pest control in animal facilities, we sought to characterize the behavioral interactions of mice with common vermin traps. Three experiments using different combinations of traps (glue trap, live mouse trap with a clear viewing window, and live mouse trap with a red-tinted viewing window) were used in multiple behavioral testing arenas to address these questions. Experiments 1 and 2 were performed in a small arena, and Experiment 3 was performed in a simulated mouse housing room. Dependent measures included exploration of the test environment, grooming behavior, time spent near each trap, and latency to capture. Results indicate that mice were captured significantly more quickly by live traps than by glue traps, and were far more likely to enter a live trap as compared with a glue trap. Mice did not appear to differentiate between clear or red-tinted window live traps. Taken together, the results indicate that deploying both a live trap and a glue trap will allow humane capture of escaped mice yet will also capture insects in the same environment.
Assuntos
Controle de Pragas , Animais , Camundongos , Controle de Pragas/instrumentação , Insetos , Comportamento AnimalRESUMO
Ornithonyssus bacoti, commonly known as the tropical rat mite, is a zoonotic ectoparasite that occasionally infests research rodent colonies. Most infestations have been attributed to wild rodents that harbor the mite and spread it to research animals, often during building construction or other activity that disrupts wild rodent populations. Although infestation may be clinically silent, severe outbreaks have been reported to cause pruritis, dermatitis, decreased reproductive performance, and anemia in rodents. In mid-2020, our institution experienced increased activity of wild mice, which were found to be infested with O. bacoti, diagnosed by microscopic exam and confirmed by fur swab PCR analysis. We elected to add O. bacoti to our quarterly health monitoring exhaust air dust (EAD) testing PCR panel, increase wild mouse control measures, and treat the environment with a sustained-release synthetic pyrethroid spray in an attempt to prevent colony animal infestation. Initial quarterly EAD health monitoring results in September of 2020 were negative for O. bacoti. However, in early 2021, multiple IVC racks tested positive for O. bacoti at quarterly testing. Treatment consisted of providing permethrin-soaked nesting material and surface spray treatment of the room and hallway with a sustained-release synthetic pyrethroid. Historically in the literature, O. bacoti outbreaks of research mice were not identified until mite burden was high enough to cause dermatitis on animal care workers. Due to modern molecular diagnostics and proactive PCR-based health monitoring surveillance, we were able to identify the outbreak earlier than would have otherwise been possible. To the best of our knowledge, this is the first report to successfully identify O. bacoti using environmental health monitoring PCR techniques. This outbreak demonstrates the importance of screening for O. bacoti in facilities with the potential for wild rodent infestation and highlights unique considerations when managing O. bacoti infestations. In addition, a novel permethrin-soaked enrichment item was developed for cage-level treatment.
Assuntos
Dermatite , Infestações por Ácaros , Ácaros , Piretrinas , Animais , Preparações de Ação Retardada , Dermatite/etiologia , Camundongos , Infestações por Ácaros/diagnóstico , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/prevenção & controle , Técnicas de Diagnóstico Molecular , Permetrina , RoedoresRESUMO
Rectal prolapse (RP) is a common clinical condition in mice, that does not have a recognized or documented standard of care. At our institution, an average of 240 mice develop RP each year. Our practice has been to recommend euthanasia upon identifying a RP based on its appearance as a painful or distressful condition. This study aimed to assess treatment options that would maintain the RP mucosa and allow mice to reach their study endpoint, and to evaluate the perception of this condition as a painful or distressful event. This study used 120 mice with spontaneous RP, concurrently assigned to ongoing research protocols. Mice were randomly assigned to 1 of 3 treatment groups: petroleum jelly, lidocaine jelly, or no treatment. Fecal samples were collected for pathogen testing, and all mice received an initial base score, followed by weekly blind scores. Upon euthanasia, RP tissue was collected for histopathology. Of the 120 mice identified with RP, 47 mice were breeders; 28% successfully produced 22 additional litters after developing RP. Seventy-three were nonbreeders, with 92% reaching their research study endpoint. No statistically significant differences were detected between the 3 treatment groups based on gross mucosal health, pain and distress, or histopathology. In this study, none of the mice in any group were euthanized based on the RP endpoint scoring criteria. These findings demonstrate that treatment is unnecessary for RP, and mice with RP did not show signs of pain or distress. In adherence to the 3Rs, this study supports animal number reduction and clinical refinement, allowing mice with RPs to reach their intended research study endpoints or produce additional litters.
Assuntos
Prolapso Retal , Animais , Lidocaína , Camundongos , Dor , RetoRESUMO
With the alarming increase in heart disease and heart failure, the need for appropriate and ethical animal models of cardiac dysfunction continues to grow. Currently, many animal models of cardiomyopathy require either invasive procedures or genetic manipulation, both of which require extensive expertise, time, and cost. Serendipitous findings at our institution revealed a possible correlation between sulfadiazine-trimethoprim (SDZ-TMP) medicated diet and the development of cardiomyopathy in IcrTac:ICR mice. We hypothesized that mice fed SDZ-TMP medicated diet continuously for 3 to 6 mo would develop cardiomyocyte degeneration and fibrosis, eventually leading to dilated cardiomyopathy. A total of 44 mice (22 Hsd:ICR (CD1) and 22 Tac:SW) were enrolled in the study. Half of these 44 mice were fed standard rodent diet and the other half were fed SDZ-TMP medicated diet. Baseline samples, including weights, CBCs, select biochemistry parameters, and echocardiography were performed prior to the start of either diet. Weights were obtained monthly and all other parameters were measured at least once during the study, and again at its conclusion. After 42 wk, mice were euthanized, and heart, lung and bone marrow tissue were submitted for histopathologic evaluation. Histologically, hearts were scored for the degree of degeneration, fibrosis, inflammation, and vacuolation. The data showed that SDZ-TMP did not have a significant effect on cardiac function, RBC parameters, biochemistry parameters (ALT, AST, calcium, magnesium, creatine kinase, and creatinine), hematopoiesis, or histologic heart scores. In addition, mice fed the SDZ-TMP medicated diet gained less weight over time. In summary, we were unable to reproduce the previous findings and thus could not use this approach to develop a novel model of cardiomyopathy. However, these results indicate that SDZ-TMP medicated diet containing 1,365 ppm of SDZ and 275 ppm of TMP does not appear to have long-term detrimental effects in mice.
Assuntos
Hematologia , Trimetoprima , Administração Oral , Animais , Dieta , Camundongos , Camundongos Endogâmicos ICR , Sulfadiazina , Aumento de PesoRESUMO
Rodent vivaria have traditionally used soiled bedding sentinel (SBS) health-monitoring programs to detect and exclude adventitious pathogens that could affect research results. Given the limitations of SBS, a likely reduction in animal usage, and a decrease in animal care staff labor, exhaust air dust (EAD) health monitoring has been evaluated by several groups for its efficacy in detecting pathogens when used as a complete replacement for traditional SBS health-monitoring programs. Compared with SBS, EAD has also been shown to provide increased sensitivity for the detection of multiple pathogens. After implementing EAD at our institution, we conducted an analysis to compare the annual costs of the 2 health-monitoring programs. The EAD program was found to be 26% less expensive than SBS. In addition to these cost savings, EAD decreased the amount of time spent by the staff on heath-monitoring activities. For veterinary technicians, this decrease in time was calculated as a savings of 150 h annually, almost 3 h each week. Finally, the EAD program replaced the use of live sentinel animals, decreasing the associated yearly usage from 1,676 animals to zero.
Assuntos
Criação de Animais Domésticos/economia , Criação de Animais Domésticos/métodos , Pisos e Cobertura de Pisos/economia , Abrigo para Animais/economia , Roedores , Bem-Estar do Animal , Animais , MasculinoRESUMO
Lactate dehydrogenase elevating virus (LDV) continues to be one of the most common contaminants of cells and cell byproducts. As such, many institutions require that tumor cell lines, blood products, and products derived or passaged in rodent tissues are free of LDV as well as other pathogens that are on institutional exclusion lists prior to their use in rodents. LDV is difficult to detect by using a live-animal sentinel health monitoring program because the virus does not reliably pass to sentinel animals. After switching to an exhaust air dust health monitoring system, our animal resources center was able to detect a presumably long-standing LDV infection in a mouse colony. This health monitoring system uses IVC rack exhaust air dust collection media in conjunction with PCR analysis. Ultimately, the source of the contamination was identified as multiple LDV-positive patient-derived xenografts and multiple LDV-positive breeding animals. This case study is the first to demonstrate the use of environmental PCR testing as a method for detecting LDV infection in a mouse vivarium.
Assuntos
Infecções por Arterivirus/veterinária , Microbiologia Ambiental , Abrigo para Animais , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Camundongos , Doenças dos Roedores/virologia , Animais , Infecções por Arterivirus/virologia , Linhagem Celular Tumoral/virologia , Poeira , Xenoenxertos , Humanos , Reação em Cadeia da Polimerase , Células Tumorais Cultivadas/virologiaRESUMO
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-Helicobacter spp., Rodentibacter spp. (previously Pasteurella pneumotropica), 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 Helicobacter 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.
Assuntos
Roupas de Cama, Mesa e Banho/microbiologia , Poeira/análise , Abrigo para Animais , Camundongos , Doenças dos Roedores/diagnóstico , Doenças dos Roedores/microbiologia , Animais , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Infecções Bacterianas/veterinária , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/microbiologia , Infecções por Caliciviridae/veterinária , Helicobacter/isolamento & purificação , Ciência dos Animais de Laboratório , Norovirus/isolamento & purificação , Pasteurellaceae/isolamento & purificação , Vigilância de Evento SentinelaRESUMO
For many years, the University of Chicago administered sulfamethoxazole-trimethoprim sulfate (SMZ-TMP) oral suspension to select immunocompromised mouse colonies via the drinking water. In 2014, SMZ-TMP oral suspension was placed on back-order and medicated diet with a different sulfonamide, sulfadiazine-trimethoprim (SDZ-TMP) was used as a replacement. Months after this transition, sentinel mice from the same room as one of the remaining immunocompromised colonies on this diet were found dead or appeared sick. Necropsies revealed cardiomegaly, and histology confirmed myocardial fibrosis in the first 4 sentinel mice examined, consistent with cardiomyopathy. Subsequent sequential monitoring of 2 sentinel mice via echocardiography showed their progression toward decreased cardiac function. Investigation of the housing room revealed that the sentinel mice had been accidently placed on SDZ-TMP diet upon entering the colony housing room. This case report describes cardiomyopathy in 6 ICR mice after long term consumption of SDZ-TMP medicated feed.