Impact of veterinary pharmaceuticals on environment and their mitigation through microbial bioremediation.

Veterinary medications are constantly being used for the diagnosis, treatment, and prevention of diseases in livestock. However, untreated veterinary drug active compounds are interminably discharged into numerous water bodies and terrestrial ecosystems, during production procedures, improper disposal of empty containers, unused medication or animal feed, and treatment procedures. This exhaustive review describes the different pathways through which veterinary medications enter the environment, discussing the role of agricultural practices and improper disposal methods. The detrimental effects of veterinary drug compounds on aquatic and terrestrial ecosystems are elaborated with examples of specific veterinary drugs and their known impacts. This review also aims to detail the mechanisms by which microbes degrade veterinary drug compounds as well as highlighting successful case studies and recent advancements in microbe-based bioremediation. It also elaborates on microbial electrochemical technologies as an eco-friendly solution for removing pharmaceutical pollutants from wastewater. Lastly, we have summarized potential innovations and challenges in implementing bioremediation on a large scale under the section prospects and advancements in this field.

Isolation and characterization of novel lytic bacteriophages that infect multi drug resistant clinical strains of Escherichia coli.

The pathogenic strains of Escherichia coli (E. coli) are frequent cause of urinary tract infections including catheter-associated, soft tissue infections and sepsis. The growing antibiotic resistance in E. coli is a major health concern. Bacteriophages are specific for their bacterial host, thus providing a novel and effective alternatives. This study focuses on isolation of bacteriophages from urban sewage treatment plants. Initially 50 different bacteriophages have been isolated against non-resistant reference E. coli strain and fifty multidrug resistant clinical isolates of extraintestinal infections. Out of which only thirty-one lytic phages which gave clear plaques were further analysed for different physico-chemical aspects such as thermal inactivation, pH, effect of organic solvents and detergents. Two bacteriophages, ASEC2201 and ASEC2202, were selected for their ability to withstand temperature fluctuation from -20 to 62 °C and a pH range from 4 to 10. They also showed good survival (40-94%) in the presence of organic solvents like ethanol, acetone, DMSO and chloroform or ability to form plaques even after the treatment with detergents like SDS, CTAB and sarkosyl. Both efficiently killed reference strain and 40-44% of multidrug resistant clinical isolates of E. coli. Later ASEC2201 and ASEC2202 were subjected to morphological characterisation through transmission electron microscopy, which revealed them to be tailed phages. The genomic analysis confirmed them to be Escherichia phages which belonged to family Drexlerviridae of Caudovirales.

How Good are Bacteriophages as an Alternative Therapy to Mitigate Biofilms of Nosocomial Infections.

Bacteria survive on any surface through the generation of biofilms that provide a protective environment to grow as well as making them drug resistant. Extracellular polymeric matrix is a crucial component in biofilm formation. The presence of biofilms consisting of common opportunistic and nosocomial, drug-resistant pathogens has been reported on medical devices like catheters and prosthetics, leading to many complications. Several approaches are under investigation to combat drug-resistant bacteria. Deployment of bacteriophages is one of the promising approaches to invade biofilm that may expose bacteria to the conditions adverse for their growth. Penetration into these biofilms and their destruction by bacteriophages is brought about due to their small size and ability of their progeny to diffuse through the bacterial cell wall. The other mechanisms employed by phages to infect biofilms may include their relocation through water channels to embedded host cells, replication at local sites followed by infection to the neighboring cells and production of depolymerizing enzymes to decompose viscous biofilm matrix, etc. Various research groups are investigating intricacies involved in phage therapy to mitigate the bacterial infection and biofilm formation. Thus, bacteriophages represent a good control over different biofilms and further understanding of phage-biofilm interaction at molecular level may overcome the clinical challenges in phage therapy. The present review summarizes the comprehensive details on dynamic interaction of phages with bacterial biofilms and the role of phage-derived enzymes - endolysin and depolymerases in extenuating biofilms of clinical and medical concern. The methodology employed was an extensive literature search, using several keywords in important scientific databases, such as Scopus, Web of Science, PubMed, ScienceDirect, etc. The keywords were also used with Boolean operator "And". More than 250 relevant and recent articles were selected and reviewed to discuss the evidence-based data on the application of phage therapy with recent updates, and related potential challenges.