Toxinotyping and molecular characterization of antimicrobial resistance in Clostridium perfringens isolated from different sources of livestock and poultry.

The present study was designed to understand the presence of antimicrobial resistance among the prevalent toxinotypes of Clostridium perfringens recovered from different animals of Tamil Nadu, India. A total of 75 (10.76%) C. perfringens were isolated from 697 multi-species fecal and intestinal content samples. C. perfringens type A (90.67%), type C (2.67%), type D (4%) and type F (2.67%) were recovered. Maximum number of isolates were recovered from dog (n = 20, 24.10%) followed by chicken (n = 19, 5.88%). Recovered isolates were resistant to gentamicin (44.00%), erythromycin (40.00%), bacitracin (40.00%), and tetracycline (26.67%), phenotypically and most of the isolates were found to be resistant to multiple antimicrobials. Genotypic characterization revealed that tetracycline (41.33%), erythromycin (34.66%) and bacitracin (17.33%) resistant genes were present individually or in combination among the isolates. Combined results of phenotypic and genotypic characterization showed the highest percentage of erythromycin resistance (26.66%) among the isolates. None of the isolates showed amplification for lincomycin resistance genes. The correlation matrix analysis of genotypic resistance showed a weak positive relationship between the tetracycline and bacitracin resistance while a weak negative relationship between the tetracycline and erythromycin resistance. The present study thus reports the presence of multiple-resistance genes among C. perfringens isolates that may be involved in the dissemination of resistance to other bacteria present across species. Further insights into the genome can help to understand the mechanism involved in gene transfer so that measures can be taken to prevent the AMR spread.

Ketoconazole-conjugated ZnO nanoparticles based semi-solid formulation and study their impacts on skin disease.

In this study, the ketoconazole-conjugated zinc oxide (ZnO) nanoparticles were prepared in a single-step approach using dextrose as an intermediate compound. The physical parameters confirmed the drug conjugation with ZnO and their size was around 70-75 nm. The drug loading and in vivo drug release studies indicated that the -CHO group from the dextrose increase the drug loading up to 65% and their release kinetics were also studied. The anti-fungal studies indicated that the prepared nanoparticles exhibit strong anti-fungal activity and the minimum concentration needed is 10 mg/ml. The nanoparticles loaded semi-solid gel was prepared using carbopol, methylparaben, propyl paraben and propylene glycol. The in vitro penetration of the ketoconazole-conjugated nanoparticles was studied using the skin. The results indicated that the semi-solid gel preparations influenced the penetration and also favoured the accumulation into the skin membrane. The veterinary clinical studies indicated that the prepared gel is highly suitable for treatment of Malassezia.