Phages be sexing up E. coli O157 in England and Wales

We used whole-genome sequencing to investigate the evolutionary context of an emerging highly pathogenic strain of Shiga toxin–producing Escherichia coli (STEC) O157:H7 in England and Wales. A timed phylogeny of sublineage IIb revealed that the emerging clone evolved from a STEC O157:H7 stx-negative ancestor ≈10 years ago after acquisition of a bacteriophage encoding Shiga toxin (stx) 2a, which in turn had evolved from a stx2c progenitor ≈20 years ago. Infection with the stx2a clone was a significant risk factor for bloody diarrhea (OR 4.61, 95% CI 2.24–9.48; p<0.001), compared with infection with other strains within sublineage IIb. Clinical symptoms of cases infected with sublineage IIb stx2c and stx-negative clones were comparable, despite the loss of stx2c. Our analysis highlighted the highly dynamic nature of STEC O157:H7 Stx-encoding bacteriophages and revealed the evolutionary history of a highly pathogenic clone emerging within sublineage IIb, a sublineage not previously associated with severe clinical symptoms.

Highly pathogenic clone of shiga toxin-producing Escherichia coli O157:H7, England and Wales, December 2018

Emerging Infectious Diseases vol. 24 no. 12

Lisa Byrne, Timothy Dallman, Natalie Adams, Amy Mikhail, Noel McCarthy, and Claire Jenkins

https://wwwnc.cdc.gov/eid/article/24/12/18-0409_article

Lunar module to control that E. coli

Escherichia coli O157:H7 is an important foodborne pathogen that causes severe bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome.

Ruminant manure is a primary source of E. coli O157:H7 contaminating the environment and food sources. Therefore, effective interventions targeted at reducing the prevalence of fecal excretion of E. coli O157:H7 by cattle and sheep and the elimination of E. coli O157:H7 contamination of meat products as well as fruits and vegetables are required.

Bacteriophages offer the prospect of sustainable alternative approaches against bacterial pathogens with the flexibility of being applied therapeutically or for biological control purposes.

This article reviews the use of phages administered orally or rectally to ruminants and by spraying or immersion of fruits and vegetables as an antimicrobial strategy for controlling E. coli O157:H7. The few reports available demonstrate the potential of phage therapy to reduce E. coli O157:H7 carriage in cattle and sheep, and preparation of commercial phage products was recently launched into commercial markets.

However, a better ecological understanding of the phage E. coli O157:H7 will improve antimicrobial effectiveness of phages for elimination of E. coli O157:H7 in vivo.

Use of bacteriophages to control Escherichia coli O157:H7 in domestic ruminants, meat products, and fruit and vegetables

Foodborne Pathogens and Disease, June 2017, ahead of print, Wang Lili, Qu Kunli, Li Xiaoyu, Cao Zhenhui, Wang Xitao, Li Zhen, Song Yaxiong, and Xu Yongping, https://doi.org/10.1089/fpd.2016.2266

http://online.liebertpub.com/doi/abs/10.1089/fpd.2016.2266

Phages used to reduce Salmonella by 90 percent in meat products

Assistant Professor Amilton de Mello, from the College of Agriculture, Biotechnology and Natural Resources at the University of Nevada, Reno, presented his research at the international American Meat Science Association’s conference June 20-22 in Texas.

Amilton de Mello“We were able to reduce salmonella by as much as 90 percent in ground poultry, ground pork and ground beef,” de Mello reported. “We’re excited to be able to show such good results, food safety is an important part of our work and salmonella is one of the most prevalent bacteria in the nation’s food supply.”

De Mello’s research treated meat products infected with four types of salmonella by applying Myoviridae bacteriophages during mixing. Bacteriophages are commonly found in our environment. They are viruses that can only harm specific bacterial cells and are harmless to humans, animals and plants.

In the experiments, the salmonella bacteria was inoculated on refrigerated meat and poultry trim, then the treatment was applied to the meat before grinding. The bacteriophages invaded the cells of the bacteria and destroyed them.

“On the final ground meat products, there was a 10-fold decrease of salmonella,” de Mello said. “The results are very encouraging and we’re hoping this can be adopted by the meat industry to increase food safety.”

Can phage control E. coli O157 on raw meatballs?

With an Escherichia coli O157:H7 virulent bacteriophage, M8AEC16, biocontrol efficiency of phages on a highly risky, ready-to-eat, traditional delicacy food called “raw meatball” under different storage conditions was investigated.

bacteriophagePhage, belonging to the Myoviridae family, was isolated from the wastewater of a local slaughterhouse and showed a broad lytic activity toward many E. coli O157:H7 strains with high efficiency of plating and O157 specificity.

Our experimental study provided favorable results, with 0.69–2.09 log colony-forming unit (cfu)/g E. coli O157:H7 reductions in the first 5 h of the replica trials. Major reductions of viable E. coli O157:H7 counts were observed in the beginning of the storage period, reaching up to 1.85 log cfu/g. Although a significant reduction in E. coli O157:H7 was observed with increased phage concentration, storage conditions had minor effect on efficiency of phage biocontrol. This is the first study in Turkey that investigates applicability of phage biocontrol for a traditional food model.

Biocontrol of shiga toxigenic Escherichia coli O157:H7 in Turkish raw meatball by bacteriophage

Wiley Online Library, Journal of Food Safety, 16 AUG 2015

Yilmaz Emre Gencay, Naim Deniz Ayaz, Gizem Copuroglu and Irfan Erol

Control of E. coli O157 on beef with bacteriophages

Efficacy of four bacteriophages (phages) and a cocktail for biocontrol of Escherichia coli O157 was assessed on beef samples stored at 4, 22 and 37 °C.

lunar.moduleSamples (3 × 3 × 1 cm) were contaminated withE. coli O157 (104 CFU/cm2) and treated with single phages: T5-like (T5), T1-like (T1), T4-like (T4) and O1-like (O1), or a cocktail at two titers: multiplicity of infection (MOI) = 1000 and MOI = 10. In contrast to previous studies, use of virucidal solution prevented over-estimation of phage efficacy. Irrespective of temperature and MOIs, T5 was most (P < 0.001) and O1 least (P < 0.05) effective for biocontrol of E. coliO157, with relative efficacy of other phages temperature dependent. At 4 °C, T1 (P < 0.05) and cocktail (P < 0.001) were more effective than T4. In contrast, T4 was equally (P = 0.08, at 37 °C) or less effective (P = 0.003, at 22 °C) than T5. Phages were more effective (P < 0.001) against E. coli O157 at warmer temperatures and high MOI.

As the beef supply chain includes hours of storage or transport at temperatures near 4 °C, this study demonstrates phages could significantly reduce E. coli O157 during this period.

Control of Escherichia coli O157 on beef at 37, 22 and 4 °C by T5-, T1-, T4-and O1-like bacteriophages

Food Microbiology Volume 51, October 2015, Pages 69–73, doi:10.1016/j.fm.2015.05.001

Liu, Y.D. Niu, R. Meng, J. Wang, J. Li, R.P. Johnson, T.A. McAllister, K. Stanford

http://www.sciencedirect.com/science/article/pii/S0740002015000878