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Bluegill fish (Lepomis macrochirus) are a popular sportfish across North America. Research involving bluegill has focused mainly on locomotion, environmental monitoring, bioaccumulation, and toxicology. With fish becoming more popular research models, bluegill use may increase. Consideration for sedation and anesthesia in bluegill is lacking. MS-222 is a commonly used anesthetic in fish that requires a 21-d washout period before entry into the food chain. Other, safer options for anesthesia should be available. In this study, we first determined a suitable MS-222 dose for general anesthesia, then compared it with 2 different concentrations of alfaxalone (5 and 10 mg/L). Both concentrations of alfaxalone were adequate to reach the desired anesthetic plane, although time to effect was dose-dependent and longer in these groups when compared with MS-222. Time to recovery was also prolonged in both alfaxalone groups compared with the MS-222 group. We also assessed anesthetic degradation in the water bath over time. In this study, we show that sedation with alfaxalone at 5 and 10 mg/L is just as effective as MS-222 with no degradation of either anesthetic over the time measured.
To maintain rodent colonies free from harmful infectious agents, laboratory animal care programs frequently employ the use of sterilized caging and supplies. Sterilized caging is important for preventing the spread of infectious pathogens from contaminated fomites, for biocontainment, and for safety. We designed several experiments to determine the effects of commonly encountered processes on steam penetration and substrate heat exposure. We used biologic indicators as a proxy for steam penetration. We used the time bedding spent above 121 °C as a proxy for substrate cumulative heat exposure. This temperature was measured using a high-temperature data logger. We first examined the effect of stacking cages with various bedding types on steam penetration. We then autoclaved soiled bedding and studied the variables of bedding type, bagging style, presence of diet and water in the cage, and amount of time between cage change out on steam penetration and cumulative heat exposure. For clean bedding, we found adequate steam penetration regardless of bedding type, cycle program, or location of the cage in the bulk autoclave. For the soiled bedding experiments, there were no differences between bedding types noted. Placement of cages inside plastic bagging increased the amount of time the bedding spent above 121 °C on average but not significantly. There was no difference in steam penetration of bedding or time spent above 121 °C for 2- or 4-wk cage change-out schedules. When cages were autoclaved with diet and water, the time the bedding spent above 121 °C was significantly less than when autoclaving bedding alone, but there was adequate steam penetration for all cages. This study demonstrates that common practices in the industry are effective. Based on the results of this study, it is recommended that each institution evaluate their autoclaving practices and confirm that those practices are sufficient and effective.
As we approach the end of 2024, we would like to briefly summarize recent and forthcoming efforts to streamline the submission and review processes for authors while ensuring that AALAS journals continue to reflect and promote excellence in the ethical conduct of animal research. In addition, we will touch on the important issues of open access and public access, which will require some changes in AALAS policies no later than October 2025 when NIH is expected to require immediate public access to NIH-funded articles accepted for publication in the Journal of the American Association for Laboratory Animal Science
A common concern in preclinical cancer research is the introduction of Corynebacterium bovis into immunodeficient mouse colonies through cancer cell lines. C. bovis is a known contaminant of patient-derived xenograft tumors passaged horizontally between immunodeficient mice. However, it is unclear if C. bovis can grow in mammalian tissue culture conditions or tissue culture media. We hypothesized that C. bovis would not grow under tissue culture conditions or media, diminishing the risk of transmission from tumor cell lines cultured in vitro. Three C. bovis isolates, CUAMC1, HAC, and ATCC-7715, were used to test our hypothesis in 3 of the most common media used to grow human cancer cell lines including RPMI 1640 + 10% FBS (RPMI), DMEM/high glucose + 10% FBS (DMEM), and DMEM/F-12 + 10% FBS (DMEM/F12). Our results confirmed propagation of each C. bovis isolate in DMEM/F12 media under tissue culture conditions after 72 h. However, these results also demonstrate diminished viability of each C. bovis isolate in RPMI and DMEM after 72 h. To assess whether antibiotics could halt the growth of C. bovis under tissue culture conditions in DMEM/F12, penicillin-streptomycin (pen/strep) was added to the experimental media. This treatment was effective in eliminating all viable C. bovis in the culture system after 72 h. Our data suggest that C. bovis growth under tissue culture conditions is possible and growth in tissue culture media is nuanced. These results highlight the importance of pathogen surveillance for tumor cell lines propagated in vitro and demonstrate the need for further investigation into C. bovis growth requirements.
During the COVID-19 pandemic, unexpected activity patterns emerged among Yucatan mini-swine models for heart failure and atrial fibrillation. As part of our laboratory research, we tracked activity data by FitBark™ collars that the Yucatan mini-swine wore. Previously, staff engaged with the swine daily, such as applying lotion and conducting 6-min treadmill runs. However, pandemic restrictions reduced interaction to 1 or 2 times a week, often for less than 10 min each session. Contrary to expectations, there was a significant increase in the swine’s activity levels during these minimal interaction periods. After cleaning, moisturizing, weighing, and FitBark data collection, staff engaged with the swine through feeding and play. Three time frames were analyzed: prepandemic, pandemic, and reentry. Prepandemic and reentry periods involved daily 15-min interactions with 2 staff members per swine to maintain cleanliness and health. During the pandemic, interaction was reduced to 1 or 2 times weekly. The hours between 1000 and 1400 were designated as ‘passive activity’, representing the swines’ isolated behavior, unaffected by staff interaction. The chronic heart failure swine (n = 3) had an average passive activity area under the curve prepandemic value of 47.23 ± 2.52 compared with pandemic 57.09 ± 2.90, pandemic 57.09 ± 2.90 compared with reentry 50.44 ± 1.61, and prepandemic compared with reentry. The atrial fibrillation swine (n = 3) had an average passive activity area under the curve minimal interaction (mimicking pandemic) value of 59.27 ± 6.67 compared with interaction (mimicking prepandemic or reentry) 37.63 ± 1.74. The heightened activity levels during minimal interaction suggest physiologic and psychologic changes in the animals due to reduced socialization. This highlights the importance of enrichment and interaction in research animals and underscores the broader impact of the COVID-19 pandemic on research outcomes. These findings could also shed light on the effects of the pandemic on human behavior.
Swine are widely used models in biomedical research due to their physiologic and anatomic similarities to humans. During transport from vendors to research facilities, pigs are subject to a number of stressors, including environmental, social, and stress as a result of deprivation from food and water. As stress can have a number of adverse psychologic and physiologic effects, an acclimation period, defined as the period of time that an animal has to adjust and stabilize in a new environment, is recommended. The literature indicates that swine should be conditioned to their new facility for 5 to 7 d prior to undergoing survival surgery; however, to date, there is no published scientific evidence to support this or any specific acclimation period for swine. To investigate whether a certain length acclimation period leads to decreased stress in swine, we measured 2 stress biomarkers, cortisol and chromogranin A (CgA), from the saliva of 12 naive Yorkshire swine (n = 6 males and 6 females) arriving at our facility for use in research protocols. Noninvasive saliva collection was performed on days 1, 3, 5, 7, 10, and 14 after arrival from the vendor (representing different acclimation periods). We hypothesized that longer acclimation periods would result in reduced levels of both cortisol and CgA, indicating reduced stress. Our data revealed that there was no statistical difference in cortisol levels over time (P = 0.8200), nor between the sexes (P = 0.9886) or individual animals (P = 0.6280). CgA, similarly to cortisol, showed no overall effect of time (P = 0.2017) or sex (P = 0.6598). For this analyte, individual animal was significant (P < 0.0001), which suggests high interanimal variation. Furthermore, there was a significant decrease (P = 0.0077) in salivary CgA from day 1 compared with day 14, suggesting that swine may benefit from an acclimation period of at least 14 d.
This corrects the article DOI:
.In an editorial published on pages 353 to 358 in Volume 63 issue 4 (July 2024) of JAALAS, the dataset used in Figure 2 was described as the number of articles published by year, but the dataset was actually the number of articles submitted by year.
The fourth sentence in the third paragraph of the editorial should be:
“Looking at the trends for JAALAS and CM since 2014 (Figure 2), the number of articles submitted per year has gradually dropped for both journals, but the trend in the drop in number of
Disinfectant application to gloved hands before handling SPF mice is standard practice to minimize transmission of pathogens and microbial contamination between cages. The risk of contamination with murine pathogens on gloves as well as the efficacy of disinfectant application for this step is largely unknown. This study aimed to determine if murine norovirus (MNV), Helicobacter spp., and Rodentibacter spp. are detectable on gloved hands and, if they are, to evaluate how effective the application of a hydrogen peroxide-based disinfectant (Rescue) or 70% ethanol is in reducing the transfer of these pathogens while handling multiple cages of mice. Mice with natural infections of these pathogens were handled without the application of any disinfectant and the gloves were swabbed for PCR testing. All pathogens were detected via PCR with Helicobacter spp. the most frequently transferred in 83% of the cages handled. The mice were then divided into 4 treatment groups based on the product applied to gloves before handling: Rescue, 70% ethanol, sterile water, and no product. Mice in each cage were briefly handled, and the gloves were swabbed with ATP swabs after each cage and swabs for PCR testing after handling 4 and 9 cages, consecutively. All pathogens were detected via PCR in all treatment groups, and neither Rescue nor 70% ethanol was superior to water or no product in reducing contamination. Rescue and 70% ethanol were effective in maintaining lower levels of organic microbial contamination than water and no product for consecutive handling of up to 3 and 4 cages of mice, respectively. This study indicates that exposure to MNV, Helicobacter spp., and Rodentibacter spp. from handling mice is a risk and the application of Rescue or 70% ethanol is not completely effective in eliminating transfer of these pathogens.
Commentary
Presented here is the second installment in the “From the Archives” series, which showcases archival content published during the 75-y history of AALAS. The content published in this issue comes from the proceedings of the fourth Annual Meeting held in December 1953, when the organization was still known as the Animal Care Panel (ACP).
By this time, the published proceedings were more polished than those distributed after the first annual meeting in 1950, being provided as a comb-bound volume with 195 pages of text and many additional inserted pages of diagrams and photos. There were 192 registered attendees listed
Medetomidine/vatinoxan (Zenalpha®) is a novel anesthetic combination used as a sedative and analgesic in dogs. Vatinoxan minimizes adverse cardiopulmonary effects associated with medetomidine administration while preserving sedation and analgesia. In this study, we evaluated the clinical safety and efficacy of 3 dosage combinations of Zenalpha with ketamine and buprenorphine extended release (ER) as compared with xylazine with ketamine and buprenorphine-ER for anesthesia of C57BL/6J mice. We hypothesized that anesthesia with 0.5 mg/kg of Zenalpha would more reliably provide a surgical anesthetic plane, lower mortality, and fewer adverse physiologic effects as compared with anesthesia with 8 mg/kg of xylazine. Ten-week-old male and female C57BL/6J mice were randomly administered 1 of 4 anesthetic cocktails subcutaneously: ketamine (80 mg/kg) and buprenorphine-ER (0.5 mg/kg) with 1) xylazine (8 mg/kg; XKB); 2) Zenalpha (0.25 mg/kg; ZKB/0.25); 3) Zenalpha (0.5 mg/kg; ZKB/0.5); or 4) Zenalpha (1.0 mg/kg; ZKB/1.0). Following drug administration, we assessed the anesthesia induction time by measuring the time to loss of righting reflex and loss of paw withdrawal reflex (PWR). Upon reaching a loss of righting reflex, physiologic parameters including heart rate, respiratory rate, oxygen saturation, indirect mean arterial blood pressure, body temperature, jaw tone, and skin color were monitored every 5 min. Thirty minutes after anesthetic drug administration (TA), atipamezole (1 mg/kg SC) was administered. Recovery time was determined through time until return of PWR, righting reflex, and ambulation. Mice were monitored for 3 d postanesthesia. Results included: 1) ZKB anesthesia caused loss of PWR in a dose-dependent manner; 2) physiologic parameters were similar between XKB and ZKB mice by TA in 100% O2; 3) ZKB groups took longer to recover and had a 20% to 30% mortality rate in the mid-to-high dosage groups. We conclude that anesthesia with 0.5 mg/kg of Zenalpha more reliably produced a surgical anesthetic plane but also led to decreased mean arterial pressure and increased mortality as compared with anesthesia with 8 mg/kg of xylazine. We recommend using Zenalpha (0.25 to 1.0 mg/kg) with 80 mg/kg ketamine and 0.5 mg/kg buprenorphine-ER to provide general anesthesia in C57BL/6 mice, along with supplemental 100% oxygen and atipamezole.