Biocontrol of Escherichia coli and Salmonella in poultry meat using phage cocktail.

Background: Despite advances in food management techniques, foodborne illness remains a major concern. Contamination of Salmonell a and Escherichia coli pathogens, especially in the poultry sector, is responsible for salmonellosis and other gastrointestinal illness, leading to millions of deaths worldwide. Overuse of antibiotics and other chemical treatments have further increased the emergence of antibiotic resistant bacteria. Aims: This study aimed to study the efficacy of phages cocktail to reduce the load of E. coli and Samlonella spiked on poultry meat. Methods: In this study, a broad spectrum cocktail of phages was used to lyse E. coli and Salmonella spiked on chicken meat. Results: Based on the result of the CFU drop assay, phages like E. coli 153T 3ii and Salmonella 191(3) were selected. Phage concentration of 0.01 MOI showed a reduction in E. coli and Salmonella count to 6 h and 2 h, respectively. Further, phages were tested on the surface of chicken meat. E. coli showed a 90% reduction up to 4 h, whereas Salmonella showed a 90% reduction up to 6 h. When phages were treated in combination, a significant reduction of up to 12 h was found with Salmonella phage, showing better antimicrobial activity. Conclusion: The suitable concentration of a specific phage or phage cocktail can significantly reduce the bacterial count on chicken meat. Phage mediated biocontrol can be used as an alternative approach to eliminate enteric pathogens in the poultry industry.

T4-like Escherichia coli phages from the environment carry blaCTX-M.

The resistance determinant blaCTX-M has many variants and has been the most commonly reported gene in clinical isolates of extended spectrum beta-lactamase producing Escherichia coli. Phages have been speculated as potential reservoirs of resistance genes and efficient vehicles for horizontal gene transfer. The objective of the study was to determine the prevalence and characterize bacteriophages that harbour the resistance determinant blaCTX-M . Escherichia coli specific bacteriophages were isolated from 15 samples including soil and water across Mangaluru, India using bacterial hosts that were sensitive to ß-lactams. Phenotypic and genotypic characterization based on plaque morphology, host range, restriction fragment length polymorphism (RFLP), presence of blaCTX-M and electron microscopy was performed. Of 36 phages isolated, seven were positive for Group 1 of blaCTX-M . Based on host range and RFLP pattern, the seven phages were classified into four distinct groups, each harbouring a variant of blaCTX-M . Five phages were T4-like Myoviridae by electron microscopy which was further confirmed by polymerase chain reaction (PCR) for T4 specific gp14. Generalized transduction of the CTX-M gene from these phages was also observed. The high prevalence (20%) of this gene blaCTX-M in the phage pool confirms the significant role of Myoviridae members, specifically T4-like phages in the dissemination of this resistance gene. SIGNIFICANCE AND IMPACT OF THE STUDY: The CTX-M gene that confers resistance to Beta-lactam class of drugs is widespread and diverse. Understanding mechanisms of antimicrobial resistance transfer is a key to devise methods for controlling it. Few studies indicate that bacteriophages are involved in the transfer of this gene but the type of phages involved and the degree of involvement remains to be explored. Our work has been able to identify the class of phages and the magnitude of involvement in the dissemination of this gene.

Cartilage oligomeric matrix protein forms protein complexes with synovial lubricin via non-covalent and covalent interactions.

OBJECTIVE: Understanding the cartilage surface structure, lost in arthritic disease, is essential for developing strategies to effectively restore it. Given that adherence of the lubricating protein, lubricin, to the cartilage surface is critical for boundary lubrication, an interaction with cartilage oligomeric matrix protein (COMP) was investigated. COMP, an abundant cartilage protein, is known to be important for matrix formation. DESIGN: Synovial fluid (SF) from arthritic patients was used to detect possible COMP-lubricin complexes by immunological methods. Recombinant (RC) COMP and lubricin fragments were expressed to characterize this bonding and mass spectrometry employed to specifically identify the cysteines involved in inter-protein disulfide bonds. RESULTS: COMP-lubricin complexes were identified in the SF of arthritic patients by Western blot, co-immunoprecipitation and sandwich ELISA. RC fragment solid-phase binding assays showed that the C-terminal (amino acids (AA) 518-757) of COMP bound non-covalently to the N-terminal of lubricin (AA 105-202). Mass spectrometry determined that although cysteines throughout COMP were involved in binding with lubricin, the cysteines in lubricin were primarily focused to an N-terminal region (AA 64-86). The close proximity of the non-covalent and disulfide binding domains on lubricin suggest a two-step mechanism to strongly bind lubricin to COMP. CONCLUSION: These data demonstrate that lubricin forms a complex network with COMP involving both non-covalent and covalent bonds. This complex between lubricin and the cartilage protein COMP can be identified in the SF of patients with arthritis conditions including osteoarthritis (OA) and rheumatoid arthritis (RA).

Biodegradation of perchlorate from real and synthetic effluent by Proteobacterium ARJR SMBS in a stirred tank bioreactor system.

The present work is a laboratory-scale study of perchlorate degradation using Proteobacterium ARJR SMBS in a stirred tank bioreactor (STBR). Anaerobically grown cultures of ARJR SMBS exposed to a variety of ClO4(-) levels within the range 30 to 150 mg L(-1) under anoxic conditions have been studied. The chloride released was measured and the average value found to be 43.55 mg L(-1). The average daily value of perchlorate degradation rate in this system was 17.24 mg L(-1) at optimum pH 7.5 and 0.25% NaCl salinity. The mixed liquor suspension solids of the system gradually increased from 0.025-0.156 g L(-1) during the operating period of 55 days. Mass balance indicated that the chloride produced was 0.45 mole per mole of perchlorate. The salinity of the system varied from 2.50-18.46 g L(-1), dependent primarily upon the inlet perchlorate concentration. The degradation mechanism, which obeyed a first-order substrate-utilizing kinetic model, allowed the growth rates and the half-saturation constants to be determined. The maximum observed anoxic growth rates (0.83-1.2 h(-1)) for ARJR SMBS in a synthetic effluent (SE) were considerably higher than in real effluent (RE) (0.45-0.59 h(-1)). The biomass yield of ARJR SMBS in STBR was higher in SE (1 +/- 0.4 mg L(-1)) than in RE (1 +/- 0.1 mg L(-1)). From the experimental findings, the uptake of perchlorate by the bacterium is suggested to be a non-interfacially-based mechanism. Under steady state operating condition the performance of the reactor was comparatively lower for RE than for SE but still offers significant control over the degradation of perchlorate under full-scale conditions.