Pathomolecular epidemiology, antimicrobial resistance, and virulence genes of Streptococcus dysgalactiae subsp. equisimilis isolates from slaughtered pigs in India.

AIMS: We aimed to investigate the prevalence, pathology, and characterization of Streptococcus dysgalactiae subsp. equisimilis (SDSE) in slaughtered pigs of India. METHODS AND RESULTS: We collected 1254 morbid tissues (lungs-627 and spleen-627) and 627 heart-blood from 627 slaughtered pigs. The bacterial isolation, antibiogram, virulence gene profiling, and mouse pathogenicity testing were performed for the detection and characterization of SDSE. A total of 177 isolates (heart-blood-160 and tissues-17) were recovered from 627 slaughtered pigs with higher isolation rate in heart-blood (25.51%). The prevalence of SDSE was 11% in morbid tissues by polymerase chain reaction. Majority of isolates showed higher detection of streptolysin O, followed by streptokinase and extracellular phospholipase A virulence genes with higher degree of resistance to azithromycin, clindamycin, erythromycin, and penicillin antibiotics. Mouse pathogenicity testing confirmed virulence based on histopathological lesions and re-isolation of SDSE. CONCLUSIONS: Our findings highlight the high prevalence of SDSE in slaughtered pigs. The presence of virulence genes and mouse pathogenicity testing confirm their pathogenic potential.

Evaluation of Mesenchymal Stem Cells with Conditioned Media and m-EGF for Regeneration of Liver Tissue After Partial Hepatectomy in Wistar Rats.

BACKGROUND/AIMS: Liver is considered as the vital organ in the body as it performs various essential functions. Following an injury to the liver, the repair process even though initially beneficial becomes pathogenic when it is not controlled appropriately. Extensive accumulation of extracellular matrix (ECM) components can ultimately lead to cirrhosis and liver failure. Thus, the ideal strategy to treat a liver injury is to generate new hepatocytes replacing damaged cells without causing excessive ECM deposition. The objective of this study was to evaluate the potential of mesenchymal stem cells, conditioned media and murine epidermal growth factor (m-EGF) in liver regeneration following partial hepatectomy in a rat model. METHODS: The animals were anaesthetized and a midline laparotomy was done. The liver was exposed and the left lateral and median lobes were ligated and resected out (about 65-70% of total liver mass). The muscles and skin were sutured in routine fashion and thus the rat model of partial hepatectomy was prepared. The animal models were equally distributed into 4 different groups namely A, B, C and D and treated with PBS, conditioned media, mesenchymal stem cells and epidermal growth factor respectively. The liver regeneration was assessed based on clinical, haemato-biochemical, colour imaging, histopathological and immune-histochemical parameters. RESULTS: Partial hepatectomy model with surgical removal of 65-70% liver lobe was standardized and successfully used in this study. Alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), bilirubin, transaminases were significantly higher (P<0.05) in group A indicating that the liver damage was not restored properly. Colour digital imaging, histopathological and immune-histochemistry observations revealed that a better liver regeneration was observed in groups C and D, followed by groups B and A. Regeneration coefficient calculated based on liver weight was higher in groups C and D as compared to group A. CONCLUSION: Rat bone marrow-derived mesenchymal stem cells were found to induce hepatocytes proliferation; whereas EGF induced more angiogenesis. Conditioned media was not as effective as stem cells and EGF in liver tissue repair.