Are Bordetella bronchiseptica Siphoviruses (Genus Vojvodinavirus) Appropriate for Phage Therapy—Bacterial Allies or Foes?

Abstract

Bordetella bronchiseptica is a respiratory animal pathogen that shows growing resistance to commonly used antibiotics, which has necessitated the examination of new antimicrobials, including bacteriophages. In this study, we examined the previously isolated and partially characterized B. bronchiseptica siphoviruses of the genus Vojvodinavirus (LK3, CN1, CN2, FP1 and MW2) for their ability to inhibit bacterial growth and biofilm, and we examined other therapeutically important properties through genomic analysis and lysogeny experiments. The phages inhibited bacterial growth at a low multiplicity of infection (MOI = 0.001) of up to 85% and at MOI = 1 for >99%. Similarly, depending on the phages and MOIs, biofilm formation inhibition ranged from 65 to 95%. The removal of biofilm by the phages was less efficient but still considerably high (40–75%). Complete genomic sequencing of Bordetella phage LK3 (59,831 bp; G + C 64.01%; 79 ORFs) showed integrase and repressor protein presence, indicating phage potential to lysogenize bacteria. Lysogeny experiments confirmed the presence of phage DNA in bacterial DNA upon infection using PCR, which showed that the LK3 phage forms more or less stable lysogens depending on the bacterial host. Bacterial infection with the LK3 phage enhanced biofilm production, sheep blood hemolysis, flagellar motility, and beta-lactam resistance. The examined phages showed considerable anti-B. bronchiseptica activity, but they are inappropriate for therapy because of their temperate nature and lysogenic conversion of the host bacterium.

Novel findings in context of molecular diversity and abundance of bacteriophages in wastewater environments of Riyadh, Saudi Arabia

“…The Bordetella phage strain variations may be attributed to difference of water sources and spatial considerations [ 43 ]. The BPP1 phage is a close relative to Bordetella bronchiseptica phage vB_BbrP_BB8 that is known for its antibacterial application against Bordetella bronchiseptica [ 44 ] recognized to cause respiratory infections [ 45 ]. On the other hand, Ralstonia virus RSA1 displayed the lowest sequence abundance of 1.04% in MN-WWTP influents and least sequence abundance in KSU-WWTP influents.…”

Biological foundations of successful bacteriophage therapy

“…Corynebacterium diphtheriae carrying the siphovirus β‐phage that encodes the diphtheria toxin Tox (Holmes, 2000 ) or enterohaemorrhagic E. coli with the lambdoid phage encoding Shiga toxins (Schmidt, 2001 )). Stable chromosomal integration is mainly a function of the phage itself (Brussow et al , 2004 ; Fortier & Sekulovic, 2013 ; Argov et al , 2019 ; Petrovic Fabijan et al , 2021 ) but also depends on host conditions; when these change (e.g. nutritional stress or DNA damage), prophages may excise from the chromosome and enter a lytic cycle that leads to bacterial cell death (Banks et al , 2003 ; Nanda et al , 2014 ; Balasubramanian et al , 2019 ; Chatterjee & Duerkop, 2019 ; Benler & Koonin, 2020 ; Filipiak et al , 2020 ).…”

“…The finger‐like bacterial fimbriae and other adhesins that are important in biofilm initiation (Déziel et al , 2001; Pohlschroder & Esquivel, 2015; Maldarelli et al , 2016; Delerue & Ramamurthi, 2021) are also common phage receptors (Phage tail machines as sophisticated infection devices). Phages have proven useful against bacteria in biofilms (Abedon, 2019; Patey et al , 2019; Melo et al , 2020b; Petrovic Fabijan et al , 2021), but the study of these systems is difficult (Abedon et al , 2021b; Pires et al , 2021). Although phages often exhibit potent in vitro activity against bacteria in biofilms, effective biofilm eradication may require combination strategies (Verma et al , 2009; Seth et al , 2013; Tkhilaishvili et al , 2018; Henriksen et al , 2019; Morris et al , 2019), with failures attributed to difficulties in accessing target cells and the development of phage‐resistant subpopulations.…”