Evaluation of Novel Virulent Phages Infecting the Aeromonas Hydrophila and Escherichia coli Isolated from Sewage Water Samples

Abstract

M ULTIDRUG-resistant bacteria are now emerging for almost all the present-day antibiotics. Aeromonas hydrophila D2007 and Escherichia coli W102 were isolated from fresh food and drinking water samples and they were resistant to 57.14% and 85.71% of tested common antibiotics respectively. Three bacteriophages (phages) were isolated from sewage samples. Morphological examinations suggested that phage ΦAHP7, which infects A. hydrophila D2007, belongs to the Myoviridae family and other phages ΦECP8 and ΦECP9 capable of lysing E. coil W102 belongs to Siphoviridae and Podoviridae families, respectively. For the three phages, the optimal multiplicity of infection (MOI) was calculated to be 0.001. Phages were characterized by determining their host range and stability in pHs, temperatures, and salinity. The latent periods of phages ΦAHP7, ΦECP8, and ΦECP9 were 10, 20 and 10min with average burst sizes of 53.5±0.5, 26.5±0.5 and 67.5±0.5 phages per infected cell, respectively. The three phages gradually reduced OD 600 and are able to stop the growth of A. hydrophila D2007 and E. coli W102 in vitro at a low MOI of 0.001. Phages ΦAHP7, ΦECP8, and ΦECP9 treatments achieved 1.55, 1.68 and 2.28 log CFU/g (P< 0.01) reduction of viable bacterial number in red cabbage and 1.48, 1.38 and 1.68 log CFU/g (P< 0.01) reduction in tomato after 30 min at room temperature (28°C) respectively. Applications of lytic ΦAHP7, ΦECP8, and ΦECP9 bacteriophages lead to a rapid reduction of A. hydrophila D2007 and E. coli W102 counts in fresh food for human consumption.

Identification and Bioinformatics Analysis of Coat Protein Gene of a Strain of Zucchini Yellow Mosaic Virus

“…These symptoms gradually developed from mosaic up to filiform shape. These results are in agreement with those reported by several investigations biologically identified ZYMV isolates affecting different cucurbits and differential hosts(Hseu et al 1985, Vega et al 1995, Tsai et al 2010, Usher et al 2012, Romay et al 2014, Khalifa et al 2015, Nasr-Eldin et al 2016, Mahfouzea et al 2018, Hammad et al. 2022, Ali et al 2023.…”

“…Similar results were also recorded by Abdel Ghaffar et al (1998) who stated that potyviruses including ZYMV had filamentous particles ranging from 700 to 900 nm in length. Also, Nasr-Eldin et al (2016) used transmission electron microscopy to determine the morphology of ZYMV in purified virus preparation obtained from ZYMV-infected squash plants and filamentous virus-like particles measuring 750x13 nm were present.…”

“…The ZYMV-cp gene was amplified by reverse transcripti on -polym erase chain reaction (RT -PCR), sequenced and analyzed compared to those strains or isolates documented in GenBank (Usher et al, 2012, Romay et al, 2014, Khalifa et al, 2015, Spadotti et al, 2015, Nasr-Eldin et al, 2016, Ali et al, 2023 in which identities ranging from 82 to 99% were obtained. The molecular weight of ZYMV-CP among different strains ranged from 34 to 36 kDa (Lisa et al, 1981, Lin et al, 2002.…”

“…amaranticolor. While, Huang et al (1986), Vega et al (1995), Hosseini et al (2007) and Nasr-Eldin et al (2016 showed that necrotic local lesions were induced on the leaves of Ch. amaranticolor.…”