Supersize me: Cronobacter sakazakii phage GAP32

Abstract

Cronobacter sakazakii is a Gram-negative pathogen found in milk-based formulae that causes infant meningitis. Bacteriophages have been proposed to control bacterial pathogens; however, comprehensive knowledge about a phage is required to ensure its safety before clinical application. We have characterized C. sakazakii phage vB_CsaM_GAP32 (GAP32), which possesses the second largest sequenced phage genome (358,663bp). A total of 571 genes including 545 protein coding sequences and 26 tRNAs were identified, thus more genes than in the smallest bacterium, Mycoplasma genitalium G37. BLASTP and HHpred searches, together with proteomic analyses reveal that only 23.9% of the putative proteins have defined functions. Some of the unique features of this phage include: a chromosome condensation protein, two copies of the large subunit terminase, a predicted signal-arrest-release lysin; and an RpoD-like protein, which is possibly involved in the switch from immediate early to delayed early transcription. Its closest relatives are all extremely large myoviruses, namely coliphage PBECO4 and Klebsiella phage vB_KleM-RaK2, with whom it shares approximately 44% homologous proteins. Since the homologs are not evenly distributed, we propose that these three phages belong to a new subfamily.

Cronobacter sakazakii: stress survival and virulence potential in an opportunistic foodborne pathogen

“…31,32 In this context C. sakazakii infecting bacteriophages have been isolated, including the second largest known bacteriophage; phage GAP32. 33 The applicability of bacteriophages to control C. sakazakii infections in various systems has been the subject of several studies. Two studies in particular have characterized the ability of bacteriophages to reduce and control growth of C. sakazakii in PIF.…”

Things Are Getting Hairy: Enterobacteria Bacteriophage vB_PcaM_CBB

“…NC_019526). The former three phages, GAP32, PBECO4, and Rak2 are recent discoveries, and their genomes have only been presented within the last 3 years (Kim et al, 2013; Šimolūnas et al, 2013; Abbasifar et al, 2014). These phages share a number of protein homologs with the T4-like phages, but they lack a number of universal core proteins found among the Myoviridae subfamily of Tevenvirinae .…”

“…These phages share a number of protein homologs with the T4-like phages, but they lack a number of universal core proteins found among the Myoviridae subfamily of Tevenvirinae . Due to the lack of sequence identity, the lack of an even distribution of homologs among their genomes with the T4-like phages and the possession of their own species-specific proteins, it has been proposed that these phages should be placed within a new subfamily (Abbasifar et al, 2014). More recently, there have been two additional phages that share homology to this subfamily (termed the Rak2-like phages from here onwards in this article) these are Escherichia phage 121Q (348 kbp, accession no.…”

Comparative Functional Genomic Analysis of Two Vibrio Phages Reveals Complex Metabolic Interactions with the Host Cell

“…This information suggests that viral Sir2/cobB proteins of Vibrio “schizoT4like” phages can act similarly to the bacterial and are able to deacetylase acetyl-lysines of enzymes, like ACS , and subsequently activate them. The Sir2/cobB protein is also conserved at the genomes of E. coli bacteriophage T5 (Wang et al, 2005), at Salmonella phage SPC35 (Kim and Ryu, 2011), at Cronobacter phage vB_CsaM_GAP32 (Abbasifar et al, 2014), at Pectobacter phage My1 (Lee et al, 2012) and at Klebsiella phage JD001 (Cui et al, 2012). …”