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Fabrizio Pantanella, Valerio Iebba, Francesco Mura, Luciana Dini, Valentina Totino, Bruna Neroni, Giulia Bonfiglio, Trancassini Maria, Claudio Passariello, Serena Schippa
The present study aimed to characterize the behavior of Bdellovibrio bacteriovorus in the presence of Staphylococcus aureus. B. bacteriovorus was co-cultured with S. aureus or Pseudomonas aeruginosa or Streptococcus mutans, in planktonic and sessile conditions. Co-cultures were studied by Field-Emission Scanning Electron Microscopy (FESEM), Scanning Transmission Electron Microscopy (STEM), turbidimetry, quantitative PCR (qPCR), and sequencing of gene Bd0108 of B. bacteriovorus. Results indicated that B. bacteriovorus comparably inhibited planktonic growth of P...
March 2, 2018: New Microbiologica
Y Li, F Qiu, H Yan, X Wan, M Wang, K Ren, Q Xu, L Lv, C Yin, X Liu, H Zhang, K Mahmoud
AIMS: (i) To obtain and identify the predatory bacteria for the control of contaminated bacteria and to promote the autotrophic growth of Chlorella USTB-01. (ii) To identify and measure the different cell numbers in microalgal culture using flow cytometer. METHODS AND RESULTS: A predatory bacterial strain was isolated using Escherichia coli BL21 as a sole prey host, which was identified as Bdellovibrio USTB-06 by the analysis of 16S rDNA sequence. A flow cytometer was successfully used to identify and measure the cell numbers of Chlorella USTB-01, the contaminated bacteria and Bdellovibrio USTB-06 simultaneously in the autotrophic culture of Chlorella USTB-01 according to the identification of the different cell sizes...
February 14, 2018: Journal of Applied Microbiology
Erkin Kuru, Carey Lambert, Jonathan Rittichier, Rob Till, Adrien Ducret, Adeline Derouaux, Joe Gray, Jacob Biboy, Waldemar Vollmer, Michael VanNieuwenhze, Yves V Brun, R Elizabeth Sockett
In the original version of this Article, a grant number and acknowledgement were omitted. The Acknowledgements section should have stated that one of the 3D SIM microscopes used for this research was supported by Medical Research Council UK grant (MR/K015753/1) to S. Foster, University of Sheffield, UK, and that the authors thank C. Walther and S. Foster for the access and their kind help with this. This has now been corrected in all versions of the Article.
January 8, 2018: Nature Microbiology
Bonnie Chaban, Izaak Coleman, Morgan Beeby
Understanding the evolution of molecular machines underpins our understanding of the development of life on earth. A well-studied case are bacterial flagellar motors that spin helical propellers for bacterial motility. Diverse motors produce different torques, but how this diversity evolved remains unknown. To gain insights into evolution of the high-torque ε-proteobacterial motor exemplified by the Campylobacter jejuni motor, we inferred ancestral states by combining phylogenetics, electron cryotomography, and motility assays to characterize motors from Wolinella succinogenes, Arcobacter butzleri and Bdellovibrio bacteriovorus...
January 8, 2018: Scientific Reports
Wonsik Mun, Heeun Kwon, Hansol Im, Seong Yeol Choi, Ajay K Monnappa, Robert J Mitchell
Predation of Chromobacterium piscinae by Bdellovibrio bacteriovorus HD100 was inhibited in dilute nutrient broth (DNB) but not in HEPES. Experiments showed that the effector responsible was present in the medium, as cell-free supernatants retained the ability to inhibit predation, and that the effector was not toxic to B. bacteriovorus Violacein, a bisindole secondary metabolite produced by C. piscinae, was not responsible. Further characterization of C. piscinae found that this species produces sufficient concentrations of cyanide (202 µM) when grown in DNB to inhibit the predatory activity of B...
December 19, 2017: MBio
Yafei Duan, Yue Zhang, Hongbiao Dong, Yun Wang, Jiasong Zhang
Poly-β-hydroxybutyrate (PHB) is a natural polymer of the short chain fatty acid β-hydroxybutyrate, which acts as a microbial control agent. The mammalian target of the rapamycin (mTOR) signaling pathway plays a crucial role in intestine inflammation and epithelial morphogenesis. In this study, we examined the composition of intestine microbiota, and mTOR signaling-related gene expression in Pacific white shrimp Litopenaeus vannamei fed diets containing different levels of PHB: 0% (Control), 1% (PHB1), 3% (PHB3), and 5% (PHB5) (w/w) for 35 days...
December 2017: Journal of Microbiology / the Microbiological Society of Korea
Fereshteh Heidari Tajabadi, Arturo Medrano-Soto, Masoud Ahmadzadeh, Gholamreza Salehi Jouzani, Milton H Saier
Bdellovibrio, δ-proteobacteria, including B. bacteriovorus (Bba) and B. exovorus (Bex), are obligate predators of other Gram-negative bacteria. While Bba grows in the periplasm of the prey cell, Bex grows externally. We have analyzed and compared the transport proteins of these 2 organisms based on the current contents of the Transporter Classification Database (TCDB; Bba has 103 transporters more than Bex, 50% more secondary carriers, and 3 times as many MFS carriers. Bba has far more metabolite transporters than Bex as expected from its larger genome, but there are 2 times more carbohydrate uptake and drug efflux systems, and 3 times more lipid transporters...
2017: Journal of Molecular Microbiology and Biotechnology
Justyna Kowalska, Marcin Włodarczyk
There are many interactions between species (including bacteria) in the environment. One of them is predation, which always leads to the death of a prey. Described in this review Bdellovibrio bacteriovorus (Deltaproteobacteria) and Micavibrio aeruginosavorus (Alfaproteobacteria) are uniflagellate, rod shaped and curved obligate predators of Gram-negative bacteria. Both species belong to the group of BALOs (Bdellovibrio and like organisms). B. bacteriovorus use periplasmic predatory strategy and M. aeruginosavorus are epibiotic hunters...
November 3, 2017: Postȩpy Higieny i Medycyny Doświadczalnej
Xing-Jian Xu, Guo-Li Lai, Chang-Qiao Chi, Jie-Yu Zhao, Ying-Chun Yan, Yong Nie, Xiao-Lei Wu
In this study, the removal of nutrients and chlorpyrifos as well as shifts of planktonic bacterial communities in constructed microcosms were investigated to evaluate the influence of Phragmites australis, Nymphaea alba, and Myriophyllum verticillatum, and their combination, on the restoration of eutrophic water containing chlorpyrifos. Plant-treated groups showed a higher pollutant removal rate than did no-remediation controls, indicating that treatment with plants is effective at remediation of eutrophic water containing chlorpyrifos...
October 31, 2017: Chemosphere
Adem Keskin, Ahmet Bursali, David E Snow, Scot E Dowd, Saban Tekin
Ticks are among the most significant human-biting ectoparasites and they play a major role in transmission of many pathogenic agents to humans. In the present study, three species of Hyalomma ticks, Hyalomma aegyptium, H. marginatum and H. excavatum, were examined for the presence of zoonotic bacteria, both male and female ticks alike. Examination of microbial diversity with tag-encoded pyrosequencing indicates that H. marginatum and H. excavatum were more diversity rich than H. aegyptium. Although numerous pathogenic and non-pathogenic bacterial genera were detected, including Acidovorax, Bacillus, Bacteroides, Bdellovibrio, Clostridium, Curvibacter, Escherichia, Flavobacterium, Limnohabitans, Paenibacillus, Ralstonia, Sarcina, Sediminibacterium, Segetibacter Stenotrophomonas and Variovorax, the predominant zoonotic bacteria represented in these ticks were genera Borrelia, Francisella, and Rickettsia...
November 9, 2017: Experimental & Applied Acarology
Hansol Im, Seong Yeol Choi, Sangmo Son, Robert J Mitchell
Violacein is a bisindole antibiotic that is effective against Gram-positive bacteria while the bacterial predator, Bdellovibrio bacteriovorus HD100, predates on Gram-negative strains. In this study, we evaluated the use of both together against multidrug resistant pathogens. The two antibacterial agents did not antagonize the activity of the other. For example, treatment of Staphylococcus aureus with violacein reduced its viability by more than 2,000-fold with or without B. bacteriovorus addition. Likewise, predation of Acinetobacter baumannii reduced the viability of this pathogen by more than 13,000-fold, regardless if violacein was present or not...
October 31, 2017: Scientific Reports
Erkin Kuru, Carey Lambert, Jonathan Rittichier, Rob Till, Adrien Ducret, Adeline Derouaux, Joe Gray, Jacob Biboy, Waldemar Vollmer, Michael VanNieuwenhze, Yves V Brun, R Elizabeth Sockett
Modification of essential bacterial peptidoglycan (PG)-containing cell walls can lead to antibiotic resistance; for example, β-lactam resistance by L,D-transpeptidase activities. Predatory Bdellovibrio bacteriovorus are naturally antibacterial and combat infections by traversing, modifying and finally destroying walls of Gram-negative prey bacteria, modifying their own PG as they grow inside prey. Historically, these multi-enzymatic processes on two similar PG walls have proved challenging to elucidate. Here, with a PG-labelling approach utilizing timed pulses of multiple fluorescent D-amino acids, we illuminate dynamic changes that predator and prey walls go through during the different phases of bacteria:bacteria invasion...
December 2017: Nature Microbiology
Juan de Dios Caballero, Rafael Vida, Marta Cobo, Luis Máiz, Lucrecia Suárez, Javier Galeano, Fernando Baquero, Rafael Cantón, Rosa Del Campo
Cystic fibrosis (CF) lung microbiota composition has recently been redefined by the application of next-generation sequencing (NGS) tools, identifying, among others, previously undescribed anaerobic and uncultivable bacteria. In the present study, we monitored the fluctuations of this ecosystem in 15 CF patients during a 1-year follow-up period, describing for the first time, as far as we know, the presence of predator bacteria in the CF lung microbiome. In addition, a new computational model was developed to ascertain the hypothetical ecological repercussions of a prey-predator interaction in CF lung microbial communities...
September 26, 2017: MBio
Sonal Dharani, Dong Hyun Kim, Robert M Q Shanks, Yohei Doi, Daniel E Kadouri
The increase in multidrug-resistant Gram-negative bacterial infections has forced the reintroduction of antibiotics such as colistin. However, the spread of the plasmid-borne mcr-1 colistin resistance gene have moved us closer to an era of untreatable Gram-negative infections. To evaluate whether predatory bacteria could be used as a potential therapeutic to treat this upcoming threat, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on several clinically relevant mcr-1-positive, colistin-resistant isolates was evaluated...
September 15, 2017: Research in Microbiology
David Negus, Chris Moore, Michelle Baker, Dhaarini Raghunathan, Jess Tyson, R Elizabeth Sockett
Bdellovibrio bacteriovorus is a small deltaproteobacterial predator that has evolved to invade, reseal, kill, and digest other gram-negative bacteria in soils and water environments. It has a broad host range and kills many antibiotic-resistant, clinical pathogens in vitro, a potentially useful capability if it could be translated to a clinical setting. We review relevant mechanisms of B. bacteriovorus predation and the physiological properties that would influence its survival in a mammalian host. Bacterial pathogens increasingly display conventional antibiotic resistance by expressing and varying surface and soluble biomolecules...
September 8, 2017: Annual Review of Microbiology
Enikö Szabó, Raquel Liébana, Malte Hermansson, Oskar Modin, Frank Persson, Britt-Marie Wilén
Granulation of activated sludge is an increasingly important area within the field of wastewater treatment. Granulation is usually achieved by high hydraulic selection pressure, which results in the wash-out of slow settling particles. The effect of the harsh wash-out conditions on the granular sludge ecosystem is not yet fully understood, but different bacterial groups may be affected to varying degrees. In this study, we used high-throughput amplicon sequencing to follow the community composition in granular sludge reactors for 12 weeks, both in the granular phase and the suspended phase (effluent)...
September 5, 2017: AMB Express
Michelle Baker, David Negus, Dhaarini Raghunathan, Paul Radford, Chris Moore, Gemma Clark, Mathew Diggle, Jess Tyson, Jamie Twycross, R Elizabeth Sockett
In worldwide conditions of increasingly antibiotic-resistant hospital infections, it is important to research alternative therapies. Bdellovibrio bacteriovorus bacteria naturally prey on Gram-negative pathogens, including antibiotic-resistant strains and so B. bacteriovorus have been proposed as "living antibiotics" to combat antimicrobially-resistant pathogens. Predator-prey interactions are complex and can be altered by environmental components. To be effective B. bacteriovorus predation needs to work in human body fluids such as serum where predation dynamics may differ to that studied in laboratory media...
August 21, 2017: Scientific Reports
Mohammed Dwidar, Yohei Yokobayashi
Bdellovibrio bacteriovorus is a predatory bacterium that feeds on Gram-negative bacteria including a wide range of pathogens and thus has potential applications as a biocontrol agent. Owing to its unique life cycle, however, there are limited tools that enable genetic manipulation of B. bacteriovorus. This work describes our first steps toward engineering the predatory bacterium for practical applications by developing basic genetic parts to control gene expression. Specifically, we evaluated four robust promoters that are active during the attack phase of B...
August 18, 2017: ACS Synthetic Biology
Hansol Im, Sangmo Son, Robert J Mitchell, Cheol-Min Ghim
We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic infections, including E. coli, Klebsiella pneumoniae and Salmonella enterica. Tests show that B. bacteriovorus HD100 is not susceptible to serum complement or its bactericidal activity. After a two hour exposure to human sera, the prey populations decreased 15- to 7,300-fold due to the serum complement activity while, in contrast, the B. bacteriovorus HD100 population showed a loss of only 33%...
July 19, 2017: Scientific Reports
David A Korasick, Harkewal Singh, Travis A Pemberton, Min Luo, Richa Dhatwalia, John J Tanner
Many enzymes form homooligomers, yet the functional significance of self-association is seldom obvious. Herein, we examine the connection between oligomerization and catalytic function for proline utilization A (PutA) enzymes. PutAs are bifunctional enzymes that catalyze both reactions of proline catabolism. Type A PutAs are the smallest members of the family, possessing a minimal domain architecture consisting of N-terminal proline dehydrogenase and C-terminal l-glutamate-γ-semialdehyde dehydrogenase modules...
September 2017: FEBS Journal
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