scholarly journals A65 Characterization of endolysin gene of bacteriophages infecting Listeria spp. isolated from dairy industry wastewater

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Blanco Fernández ◽  
M E Barrios ◽  
R V Cammarata ◽  
C Torres ◽  
V A Mbayed
Keyword(s):  
Host Range ◽  
High Titer ◽  
Dairy Industry ◽  
Foodborne Pathogen ◽  
Dairy Farm ◽  
Restriction Enzymes ◽  
Invasive Disease ◽  
Broad Host Range ◽  
Wide Range ◽  
Industry Wastewater

Abstract Bacteriophages and their endolysins, enzymes that degrade the cell walls of bacteria, are emerging as alternative tools to detect and inhibit growth of pathogen bacteria. Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a serious invasive disease that affects both humans and a wide range of animals. Listeria spp. are ubiquitous in the dairy farm environment and could be present in dairy-processing plants and wastewater. All Listeria-specific bacteriophages found to date are members of the Caudovirales, of the Siphoviridae or Myoviridae families. Myophages infecting Listeria have been recently classified by the ICTV in the Spounavirinae subfamily, as well as in the P100 virus genus. The aim of this work was to isolate Listeria spp. bacteriophages and their endolysin codifying genes from wastewater of a dairy industry. Wastewater with and without treatment was sampled during the course of a year, and isolation of bacteriophages was performed after an enrichment step using as hosts L. innocua, L. ivanovii, and L. monocytogenes serotypes 1/2a, 1/2b, and 4b. Bacteriophages infecting L. innocua and L. ivanovii were isolated (n = 24) from 3 out of 12 samples. Bacteriophages were purified, and the host range was determined using spot test and EOP against five collection strains and several field isolates of Listeria spp. Two bacteriophages of narrow and broad host range, vB_Lino_VEfB7, and vB_Liva_VAfA18, were selected for further characterization. High titer stocks of bacteriophages were purified by centrifugation with ammonium acetate, and morphological information on the purified bacteriophages was obtained by negative staining and transmission electronic microscopy. Their morphology, size, and contractile tails indicated that these bacteriophages belonged to the Myoviridae family. Bacteriophage genomes were extracted using phenol-chloroform, followed by ethanol precipitation, and tested by digestion with RNAsa A and DNAse I. RFLP was performed, digesting genomes with restriction enzymes HindIII and NcoI. Consistent with the morphological findings, bacteriophages contained dsDNA genomes but showed different RFLP patterns. A PCR designed to amplify conserved domains of endolysins—PGRP and CwlA—was applied to characterize this gene. Another PCR was designed to amplify the complete endolysin gene, and the complete sequence of this gene was obtained and analyzed. Substitution model selection and a maximum likelihood phylogenetic tree of the endolysin gene was carried out using IQ-Tree software. The sequences of the endolysin gene indicated that the codified enzyme is an N-acetyl-muramoyl-L-alanine amidase, related to A511 and P100 species of the recently described P100virus genus. Further evolutionary analyses are needed to evaluate their belonging to this species or their taxonomy within this genus.

scholarly journals Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  
Keyword(s):  
Dna Binding ◽  
Host Range ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Broad Host Range ◽  
Biophysical Properties ◽  
Dna Binding Sites ◽  
In Silico Studies ◽  
Wide Range

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

Limits to the host range of the highly polyphagous tephritid fruit fly Anastrepha ludens in its natural habitat

2015 ◽  
Vol 105 (6) ◽  
pp. 743-753 ◽  
Author(s):  
A. Birke ◽  
E. Acosta ◽  
M. Aluja
Keyword(s):  
Host Range ◽  
Natural Habitat ◽  
Fruit Fly ◽  
Natural Host ◽  
Pupal Weight ◽  
Anastrepha Ludens ◽  
Broad Host Range ◽  
Ripe Fruit ◽  
Natural Conditions ◽  
Wide Range

AbstractAnastepha ludens (Diptera: Tephritidae) is a highly polyphagous fruit fly that is able to develop in a wide range of hosts. Understanding the limits of this pest's host range could provide valuable information for pest management and plant breeding for pest resistance. Previous studies have shown that guavas (Psidium guajava (Myrtaceae) L.), are not attacked under natural conditions by A. ludens. To understand this phenomenon, guavas were exposed to natural infestation by A. ludens and to other fruit fly species that infest guavas in nature (Anastrepha striata Schiner, Anastepha fraterculus (Wiedemann), Anastepha obliqua (Macquart)). Once the susceptible phenological stage of guavas was determined, fruit infestation levels were compared between A. ludens and A. striata. Choice and non-choice tests were performed under field-cage conditions. Under field conditions, guavas were susceptible to A. striata and A. fraterculus attack all the way from when fruit was undeveloped to when fruit began to ripen. No infestation by A. ludens was recorded under natural conditions. Similar results were obtained when forced exposures were performed, indicating that unripe guavas were preferred by A. striata over ripe fruit, and that infestation rates were higher at early fruit maturity stages. Under forced oviposition conditions, A. ludens larvae were unable to develop in unripe guavas but did so in fully ripe fruit. However, A. ludens fitness parameters were dramatically affected, exhibiting reduced survival and reduced pupal weight compared to conspecifics that developed in a natural host, grapefruit. We confirm that P. guajava should not be treated as a natural host of this pestiferous species, and suggest that both behavioral aspects and the fact that larvae are unable to adequately develop in this fruit, indeed represent clear limits to A. ludens's broad host range.

scholarly journals Combined Use of Bacteriophage K and a Novel Bacteriophage To Reduce Staphylococcus aureus Biofilm Formation

2014 ◽  
Vol 80 (21) ◽  
pp. 6694-6703 ◽  
Author(s):  
D. R. Alves ◽  
A. Gaudion ◽  
J. E. Bean ◽  
P. Perez Esteban ◽  
T. C. Arnot ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
High Titer ◽  
Broad Host Range ◽  
Bacterial Host ◽  
Content Type ◽  
Double Stranded Dna ◽  
Patient Morbidity ◽  
Combined Use ◽  
Wide Range ◽  
Large Repertoire

ABSTRACTBiofilms are major causes of impairment of wound healing and patient morbidity. One of the most common and aggressive wound pathogens isStaphylococcus aureus, displaying a large repertoire of virulence factors and commonly reduced susceptibility to antibiotics, such as the spread of methicillin-resistantS. aureus(MRSA). Bacteriophages are obligate parasites of bacteria. They multiply intracellularly and lyse their bacterial host, releasing their progeny. We isolated a novel phage, DRA88, which has a broad host range amongS. aureusbacteria. Morphologically, the phage belongs to theMyoviridaefamily and comprises a large double-stranded DNA (dsDNA) genome of 141,907 bp. DRA88 was mixed with phage K to produce a high-titer mixture that showed strong lytic activity against a wide range ofS. aureusisolates, including representatives of the major international MRSA clones and coagulase-negativeStaphylococcus. Its efficacy was assessed both in planktonic cultures and when treating established biofilms produced by three different biofilm-producingS. aureusisolates. A significant reduction of biofilm biomass over 48 h of treatment was recorded in all cases. The phage mixture may form the basis of an effective treatment for infections caused byS. aureusbiofilms.

scholarly journals Silage Collected from Dairy Farms Harbors an Abundance of Listeriaphages with Considerable Host Range and Genome Size Diversity

2012 ◽  
Vol 78 (24) ◽  
pp. 8666-8675 ◽  
Author(s):  
Kitiya Vongkamjan ◽  
Andrea Moreno Switt ◽  
Henk C. den Bakker ◽  
Esther D. Fortes ◽  
Martin Wiedmann
Keyword(s):  
Host Range ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Genomic Diversity ◽  
Broad Host Range ◽  
Content Type ◽  
Narrow Host Range ◽  
Food Borne ◽  
Size Diversity ◽  
Range Characterization

ABSTRACTSince the food-borne pathogenListeria monocytogenesis common in dairy farm environments, it is likely that phages infecting this bacterium (“listeriaphages”) are abundant on dairy farms. To better understand the ecology and diversity of listeriaphages on dairy farms and to develop a diverse phage collection for further studies, silage samples collected on two dairy farms were screened forL. monocytogenesand listeriaphages. While only 4.5% of silage samples tested positive forL. monocytogenes, 47.8% of samples were positive for listeriaphages, containing up to >1.5 × 104PFU/g. Host range characterization of the 114 phage isolates obtained, with a reference set of 13L. monocytogenesstrains representing the nine major serotypes and four lineages, revealed considerable host range diversity; phage isolates were classified into nine lysis groups. While one serotype 3c strain was not lysed by any phage isolates, serotype 4 strains were highly susceptible to phages and were lysed by 63.2 to 88.6% of phages tested. Overall, 12.3% of phage isolates showed a narrow host range (lysing 1 to 5 strains), while 28.9% of phages represented broad host range (lysing ≥11 strains). Genome sizes of the phage isolates were estimated to range from approximately 26 to 140 kb. The extensive host range and genomic diversity of phages observed here suggest an important role of phages in the ecology ofL. monocytogeneson dairy farms. In addition, the phage collection developed here has the potential to facilitate further development of phage-based biocontrol strategies (e.g., in silage) and other phage-based tools.

scholarly journals Differential Binding of Host Complement Inhibitor Factor H by Borrelia burgdorferi Erp Surface Proteins: a Possible Mechanism Underlying the Expansive Host Range of Lyme Disease Spirochetes

2002 ◽  
Vol 70 (2) ◽  
pp. 491-497 ◽  
Author(s):  
Brian Stevenson ◽  
Nazira El-Hage ◽  
Melissa A. Hines ◽  
Jennifer C. Miller ◽  
Kelly Babb
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Host Range ◽  
General Characteristic ◽  
Factor H ◽  
Surface Proteins ◽  
Broad Host Range ◽  
Complement Inhibitor ◽  
Wide Range ◽  
Mammalian Infection

ABSTRACT The Lyme disease spirochete, Borrelia burgdorferi, is capable of infecting a wide variety of vertebrates. This broad host range implies that B. burgdorferi possesses the ability to contravene the immune defenses of many potential hosts. B. burgdorferi produces multiple different Erp proteins on its outer membrane during mammalian infection. It was reported previously that one Erp protein can bind human factor H (J. Hellwage, T. Meri, T. Heikkilä, A. Alitalo, J. Panelius, P. Lahdenne, I. J. T. Seppälä, and S. Meri, J. Biol. Chem. 276:8427–8435, 2001). In this paper we report that the ability to bind the complement inhibitor factor H is a general characteristic of Erp proteins. Furthermore, each Erp protein exhibits different relative affinities for the complement inhibitors of various potential animal hosts. The data suggest that the presence of multiple Erp proteins on the surface can allow a single B. burgdorferi bacterium to resist complement-mediated killing in any of the wide range of potential hosts that it might infect. Thus, Erp proteins likely contribute to the persistence of B. burgdorferi in nature and to the ability of this bacterium to cause Lyme disease in humans and other animals.

scholarly journals The host range of Aphis gossypii is dependent on aphid genetic background and feeding experience

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7774 ◽  
Author(s):  
Lin Ma ◽  
Meng-Yue Li ◽  
Chun-Yan Chang ◽  
Fang-Fang Chen ◽  
Yang Hu ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Host Range ◽  
Host Plants ◽  
Artificial Diet ◽  
Aphis Gossypii ◽  
Host Specialization ◽  
Broad Host Range ◽  
Feeding Experience ◽  
Wide Range ◽  
Cotton Plants

Background A polyphagous insect herbivore has a wide range of host plants. However, it has been found that many polyphagous herbivores commonly exhibit a strong preference for a subset of species in their broad host range, and various host biotypes exist in herbivore populations. Nutrition and secondary metabolites in plants affect herbivore preference and performance, but it is still not clear which factors determine the host range and host preference of polyphagous herbivores. Method Cotton-melon aphids, Aphis gossypii Glover, collected from cotton and cucumber crops, were used in this study. The genetic backgrounds of these aphids were detected using microsatellite PCR and six genotypes were evaluated. Performance of these six aphid genotypes on excised leaves and plants of cotton and cucumber seedlings were examined through a reciprocal transplant experiment. In order to detect whether the feeding experience on artificial diet would alter aphid host range, the six genotypes of aphids fed on artificial diet for seven days were transferred onto cotton and cucumber leaves, and then their population growth on these two host plants was surveyed. Results Aphids from cotton and cucumber plants could not colonize the excised leaves and intact plants of cucumber and cotton seedlings, respectively. All six genotypes of aphids collected from cotton and cucumber plants could survive and produce offspring on artificial diet, which lacked plant secondary metabolites. The feeding experience on the artificial diet did not alter the ability of all six genotypes to use their native host plants. However, after feeding on this artificial diet for seven days, two aphid genotypes from cotton and one from cucumber acquired the ability to use both of the excised leaves from cucumber and cotton plants. The two aphid genotypes from cotton conditioned by the feeding experience on artificial diet and then reared on excised cucumber leaves for >12 generations still maintained the ability to use intact cotton plants but did not establish a population on cucumber plants. However, one cucumber genotype conditioned by artificial diet and then reared on excised cotton leaves could use both the intact cotton and cucumber plants, showing that the expansion of host range was mediated by feeding experience. Conclusion Feeding experience on artificial diet induced the expansion of host range of the cucurbit-specialized A. gossypii, and this expansion was genotype-specific. We speculated that feeding on a constant set of host plants in the life cycle of aphids may contribute to the formation of host specialization.

scholarly journals Isolation and characterization of novel phage (Podoviridae ɸParuNE1) and its efficacy against multi-drug-resistant Pseudomonas aeruginosa planktonic cells and biofilm

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Nkechi V. Enwuru ◽  
Jason J. Gill ◽  
Katri P. Anttonen ◽  
Christian A. Enwuru ◽  
Ry. Young ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Host Range ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Multi Drug Resistance ◽  
Broad Host Range ◽  
Drug Resistant ◽  
Isolation And Characterization ◽  
Biofilm Removal ◽  
Wide Range

Abstract Background Bacterial pathogen (Pseudomonas aeruginosa) could form biofilm that conveys multi-drug resistance. Bacteriophage as an alternative to antibacterial resistance is useful against biofilm complications. This study evaluated antibacterial and biofilm removal activities of lytic phage, specific against multi-drug-resistant clinical P. aeruginosa. Results The phage showed a wide range of pH (5–10) and heat (7–44 °C) stability. Electron microscopy showed ɸPauNE1 phage head (60 nm in diameter) and non-contractile tail (12 nm in length by 8 nm in width); hence, the family Podoviridae and the order Caudovirales. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed structured protein of 55 kDa and double-stranded DNA of 45 kb. The phage was species specific and had broad host range activity. It inhibited bacterial growth at multiplicity of infection (MOI) 1–0.000001 pfu/ml. Inhibition was maximal at both low (1 × 105) and high (1 × 109) bacterial CFU/ml. Biofilm removal test showed that the phage removed more than 60% cell biomass within CFU/ml of 1.5 × 108, 6.0 × 108 and l.0 × 109. Conclusion Phage (ɸPauNE1) was unique and had broad host range activity. The phage exhibited strong bacteriolytic activity against biofilm forming multi-drug-resistant strains. It had no lytic effect on the heterogeneous strains and so a promising bioagent.

scholarly journals Characterization and identification of naturally transgenic species Linaria vulgaris pathogenic mycromycetes

2018 ◽  
Vol 16 (1) ◽  
pp. 27-34
Author(s):  
Sofia V. Sokornova ◽  
Elena L. Gasich ◽  
Victoria D. Bemova ◽  
Tatiana V. Matveeva
Keyword(s):  
Host Range ◽  
Large Subunit ◽  
Molecular Data ◽  
Microbial Interactions ◽  
Internal Transcribed Spacers ◽  
Broad Host Range ◽  
Narrow Host Range ◽  
Wide Range ◽  
Phoma Herbarum

In nature there are species containing homologs of T-DNA genes of agrobacteria (сT-DNA) in their genomes. Such plants are called naturally transgenic ones. Interaction with the microbiota is one of the possible functions of cT-DNA, discussed in the literature. Linaria plants are the most suitable for the investigation of the probable ecological role of T-DNA, since they widely spread. The first stage in the evaluation of plant-microbial interactions involving these plants is the description of isolates with contrasting virulence for toadflax. The search and DNA-barcoding of such isolates of Phoma-like fungi was the goal of this work. 14 strains isolated from the plants of the families Plantaginaceae and Scrophullariaceae were analyzed. The of multilocus analysis included amplification and sequencing of internal transcribed spacers, a large subunit of RNA, a tubulin gene. Based on molecular data, 9 strains were assigned to the species Boeremia exigua, which has a wide range of habitats and a wide specialization. Strains of this species were virulent against L. vulgaris, but differed in aggressiveness with respect to this plant. Thus, a collection of strains was characterized, which can later be used for a more detailed study of the immune response of the naturally-transgenic L. vulgaris plant in response to inoculation with the B. exigua phytopathogen. As a result of the work, we identified the narrow host range fungi Heterophoma novae-verbascicola, and broad host range pathogens Plectosphaerella cucumerina, Phoma herbarum and Trichothecium roseum. Among them, only P. cucumerina was a weak pathogen of L. vulgaris. These results confirm the early data on the depleted mycobiota of L. vulgaris.

scholarly journals Bacteriophage Cocktails Protect Dairy Cows Against Mastitis Caused By Drug Resistant Escherichia coli Infection

2021 ◽  
Vol 11 ◽  
Author(s):  
Mengting Guo ◽  
Ya Gao ◽  
Yibing Xue ◽  
Yuanping Liu ◽  
Xiaoyan Zeng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Alternative Therapy ◽  
Dairy Farm ◽  
Economic Loss ◽  
Inflammatory Factors ◽  
Broad Host Range ◽  
Drug Resistant ◽  
Promising Alternative ◽  
E Coli ◽  
Wide Range

Mastitis caused by Escherichia coli (E. coli) remains a threat to dairy animals and impacts animal welfare and causes great economic loss. Furthermore, antibiotic resistance and the lagged development of novel antibacterial drugs greatly challenge the livestock industry. Phage therapy has regained attention. In this study, three lytic phages, termed vB_EcoM_SYGD1 (SYGD1), vB_EcoP_SYGE1 (SYGE1), and vB_EcoM_SYGMH1 (SYGMH1), were isolated from sewage of dairy farm. The three phages showed a broad host range and high bacteriolytic efficiency against E. coli from different sources. Genome sequence and transmission electron microscope analysis revealed that SYGD1 and SYGMH1 belong to the Myoviridae, and SYGE1 belong to the Autographiviridae of the order Caudovirales. All three phages remained stable under a wide range of temperatures or pH and were almost unaffected in chloroform. Specially, a mastitis infected cow model, which challenged by a drug resistant E. coli, was used to evaluate the efficacy of phages. The results showed that the cocktails consists of three phages significantly reduced the number of bacteria, somatic cells, and inflammatory factors, alleviated the symptoms of mastitis in cattle, and achieved the same effect as antibiotic treatment. Overall, our study demonstrated that phage cocktail may be a promising alternative therapy against mastitis caused by drug resistant E. coli.

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