Health monitoring is an integral part of laboratory animal quality standards. However, current or past prevalence data as well as regulatory requirements dictate the frequency, type and the expanse of health monitoring. In an effort to understand the prevalence of rodent pathogens in India, a preliminary study was carried out by sero-epidemiology. Sera samples obtained from 26 public and private animal facilities were analyzed for the presence of antibodies against minute virus of mice (MVM), ectromelia virus (ECTV), lymphocytic choriomeningitis virus (LCMV), mouse hepatitis virus (MHV), Sendai virus (SeV), and Mycoplasma pulmonis in mice, and SeV, rat parvo virus (RPV), Kilham’s rat virus (KRV) and sialodacryoadenitis virus (SDAV) in rats, by sandwich ELISA. It was observed that MHV was the most prevalent agent followed by Mycoplasma pulmonis and MVM in mice, and SDAV followed by RPV were prevalent in rats. On the other hand, none of the samples were positive for ECTV in mice, or SeV or KRV in rats. Multiple infections were common in both mice and rats. The incidence of MHV and Mycoplasma pulmonis was higher in facilities maintained by public organizations than in vivaria of private organizations, although the difference was not statistically different. On the other hand the prevalence of rodent pathogens was significantly higher in the northern part of India than in the South. These studies form the groundwork for detailed sero-prevalence studies which should further lay the foundations for country-specific guidelines for health monitoring of laboratory animals.

Toll-like receptors (TLRs) are a family of patternrecognition receptors involved in innate immunity. Previous studies have shown that TLR2 inhibition protects the heart from acute stress, including myocardial infarction and doxorubicin-induced cardiotoxicity in animal models. However, the role of TLR2 in the development of aging-associated heart failure is not known. In this work, we studied agingassociated changes in structure and function of TLR2-deficient mice hearts. Whereas young TLR2-KO mice did not develop marked cardiac dysfunction, 8-and 12-months-old TLR2-KO mice exhibited spontaneous adverse cardiac remodeling and cardiac dysfunction in an age-dependent manner. The hearts of the 8-monthsold TLR2-KO mice had increased fibrosis, cell death, and reactivation of fetal genes. Moreover, TLR2-KO hearts displayed reduced infiltration by macrophages, increased numbers of myofibroblasts and atrophic cardiomyocytes, and higher levels of the atrophyrelated ubiquitin ligases MuRF-1 and Atrogin-1. Mechanistically, TLR2-deficiency impaired the PI3K/Akt signaling pathway, leading to hyperactivation of the transcription factor forkhead box protein O1 (FoxO1), and, in turn, to elevated expression of FoxO target genes involved in regulation of muscle wasting and cell death. AS1842856-mediated chemical inhibition of FoxO1 reduced the expression of the atrophy-related ubiquitin ligases and significantly reversed the adverse cardiac remodeling, while improving the contractile functions in the TLR2-KO mice. Interestingly, TLR2 levels decreased in hearts of older mice, and activation of TLR1/2 signaling improved cardiac functions in these mice. These findings suggest that TLR2 signaling is essential for protecting the heart against aging-associated adverse remodeling and contractile dysfunction in mice.

The present study attempts to chronicle the series of changes starting from the consumption of high fat diet till reproductive activity in male mice. A marginal increase in body weight was observed in male mice fed with high fat diet with 3-fold increase in total body fat and 1.4-fold increase in adipose tissue. A significant reduction in number and diameter of seminiferous tubules were observed in high fat diet fed mice compared to control mice. FACS analysis of testicular germ cells revealed very high percentage of apoptotic cells (84%) compared to control animals (2-3 %) indicative of reduced spermatogenic activity. In addition, a significant decrease in litter size (11.6%-Control to 3.66%-HFD) indicates that reproductive efficiency in high fat diet fed mice reduced to a great extent. The present study revealed high fat diet alters the fertility in male mice significantly and the first in this process appears to be apoptosis of testicular cells due to increase in ROS.

Animal models are important for biomedical research as they help us to understand the mechanisms and functions similar to humans. Microbiological analysis is an integral part of animal studies especially when looking for gut microbiota changes. Several factors such as diet, antibiotics etc. have an impact on the composition of the gut. While many conventional and molecular methods are used for the identification of microbiota, this study aimed at evaluating the usefulness of flow cytometry for identification of bacteria based on their ability to scatter light. Fresh gut samples from mice were collected and cultured on nutrient agar followed by plating on selective media. The isolates were characterized and differentiated by biochemical tests and FACS (fluorescent activated cell sorter) analysis. The major group of isolates obtained from culture methods and biochemical characterization were identified as Proteus and Klebsiella species. Forward and side scatter analysis of the samples showed two distinct patterns in the plots and correlated with the microbiological results. From the results it was found that flow cytometry can be effectively used as method of rapid detection of microorganisms from animal samples.

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