Aims: This study was aimed to evaluate the potential of several carriers to formulate the phages and retain their activity under various pH and temperature conditions. Methodology and results: The skim milk, rice flour, corn flour and CalnuXan (calcium and magnesium) as carriers to formulate the isolated phage to maintain its activity under extreme pH and temperature conditions. Two phages formulated with carriers retained their viability at pH 5, pH 7 and pH 9 compared to that of the unformulated phages. Besides, the formulated phages also retained a high titre compared to the unformulated phages when they were exposed to 37 °C and 45 °C. Based on the in vitro study of the formulation, it was applied in the glass house. The plant height, leaf chlorophyll and disease scoring were recorded and analyzed. In the glass house, the rice plant treated with formulated phages showed higher plant height and chlorophyll content than those treated with unformulated or untreated phages. Nonetheless, both formulated and unformulated protected the rice plant, which showed lower disease severity than the untreated group. Conclusion, significance and impact of study Phage therapy has been used for treating plant diseases caused by pathogenic bacteria. Despite their effectiveness in killing the pathogen in vitro, the results were not reproducible in the field. Bacteriophages (phages) are sensitive to environmental factors and infection efficiency was dropped when exposed to harmful environments. However, this study successfully formulated two novels Xanthomonas phages, as biocontrol agents against bacterial leaf blight (BLB) disease in rice.
Xanthomonas ; Bacteriophages

A study was conducted on 28 burning sepsis patients treated at the National Institute of Burn. Results showed that their capacity of bacteriophage and of EA rosette formation of polynuclear neutrophil white blood cells was reduced in comparing with healthy patients and with other no burn sepsis patients, as well as burning no sepsis patients. Their white blood cells function restored gradually with the improvement of the condition. Thus the capacity of bacteriophage and EA rosette formation have reflected the state of burning conditions, and their monitoring can help the evaluation and prognosis
Bacteriophages ; Sepsis ; Leukocytes ; cells

Background: Extended-spectrum β-lactamase (ESBL) K. pneumoniae infections are emerging health problems in the Philippines. Recently, bacteriophages have been explored to target several antibiotic-resistant bacteria as a potential alternative therapeutic option to conventional antibiotics. Objectives: This study isolated extended-spectrum β-lactamase (ESBL) producing K. pneumoniae harboring different β-lactamase genes to evaluate the host range specificity of isolated bacteriophages. Methodology: K. pneumoniae were isolated from five selected hospitals in Cavite and Metro Manila, Philippines and their ESBL-production was determined through the Phenotypic Confirmatory Disc Diffusion Test (PCDDT). The identity of the isolates was then confirmed by amplification and sequencing of the 16 rRNA gene. The type of β-lactamase genes carried by the K. pneumoniae ESBL-positive strains was detected by amplification of the bla , bla , bla and bla genes. Meanwhile, bacteriophages were isolated from CTX-M TEM SHV OXA-1 water samples in Marikina River and their host range specificity was tested against the different ESBLproducing K. pneumoniae strains. Results: From a total of 25 K. pneumoniae, 6 (24%) were found to be ESBL-producers by PCDDT. Genotyping of the β-lactamase genes showed that one of the phenotypically confirmed isolates contained the bla while CTX-M another possessed both the bla and bla genes. Furthermore, another isolate harbored the bla , bla , CTXM SHV CTX-M OXA-1 and bla genes while the remaining isolates contained all the four bla genes tested. Meanwhile, two virulent SHV phages namely, KP1 and KP2 that showed the largest clearing zones against K. pneumoniae were selected to determine their host range specificity against the different ESBL-positive K. pneumoniae strains. Both phages were able to infect and lyse all ESBL-positive K. pneumoniae regardless of the type or number of bla genes they possessed. Phage KP2, which showed the highest lytic capability, was then subjected to Transmission Electron Microscopy (TEM) and was found to belong to the Order Caudovirales under the Family Myoviridae. Conclusion This study showed that phage KP2 was host-specific to the different ESBL-producing K. pneumoniae harboring single or multiple bla genes suggesting that it might hold a great potential for possible phage therapy against ESBL-producing K. pneumoniae infections.
Bacteriophages ; Phage Therapy

Bacteriophage is a bacterium dependent virus. It has unique advantages in the treatment of bacterial infection, especially infection caused by drug-resistant bacteria. Its metabolic kinetics and route of administration are the current research focus. Bacteriophage lytic enzyme, as a new therapeutic method, has more advantages than active bacteriophage. This review is focused on the recent progress in bacteriophage research, including the mechanism of bacteria lysis, the route of administration, the application of genetic engineering, etc.
Bacterial Infections ; therapy ; Bacteriophages ; Humans

The toxin-producing bacterium Vibrio cholerae can cause severe diarrhea and has caused seven global pandemics. Traditional viable cell counts and phage plaques are commonly used to evaluate the efficacy of virulent phage clearance of V. cholerae, but these operations are time-consuming and labor-intensive, and difficult to provide real-time changes. It is desirable to develop a simple and real-time method to monitor V. cholerae during phage lysis. In this study, a luminescence-generating plasmid pBBR-pmdh-luxCDABE was transformed into three O1 serogroup drug-resistant strains of V. cholerae. The results showed that the luminescence value as a monitoring index correlates well with the traditional viable cell count method. Monitoring the number of live cells of V. cholerae by measuring the luminescence allowed real-time analysis of the number of bacteria remaining during phage lysis. This method enables repeated, interference-free, continuous multiple-time-point detection of the same sample without the time delay of re-culture or plaque formation, facilitating real-time monitoring and analysis of the interaction between the phage and the host bacteria.
Bacteriophages/genetics* ; Luminescence ; Plasmids ; Vibrio cholerae

Aims: This study aims to evaluate the effectiveness of bacteriophages isolated from Klang and Penang, Malaysia against Dickeya chrysanthemi that causes soft rot disease. Methodology and results: Basic characterization such as dextrose test, citrate test, lactose fermentation test and ornithine test were carried out on D. chrysanthemi. Activity of bacteriophages against D. chrysanthemi was evaluated using spot test. Double agar overlay assay was performed to purify and enumerate the quantify of bacteriophages.Bacteriophages were also checked for its effectiveness in controlling soft rot on post-harvested vegetables: potato (Solanum tuberosum), cucumber (Cucumis sativus) and apple (Malus domestica). Results showed that D. chrysanthemiable to utilize citrate and dextrose as the source of energy, which indicated that D. chrysanthemi inclined to choose fruits and vegetables containing citrate and dextrose as the target of attack. Clear zone observed on the bacterial lawn (spot test) indicated the ability of the bacteriophages to infect and lyse D. chrysanthemi. All the bacteriophages studied herein reached the highest concentration on day 3 and were monovalent. Conclusion, significance and impact of study All the isolated bacteriophages were able to restrain the spreading of soft rot caused by D. chrysanthemi either work alone or as cocktail. This study provides information for the formulation development of bacteriophage against soft rot disease cause by D. chrysanthemi. Furthermore, this study reveals the potential of locally isolated bacteriophages against the D. chrysanthemi and paving the application of phage treatment on agriculture products that are not limited to potatoes, cucumber and apple.
Bacteriophages--isolation & ; purification ; Dickeya chrysanthemi

Objective: To establish and evaluate a method of enriching bacteriophages in natural water based on ferric trichloride-polyvinylidene fluoride (FeCl₃-PVDF)membrane filter. Methods: Based on the principle of flocculation concentration, the method of recovering bacteriophage from water sample was established by using iron ion flocculation combined with membrane filter. The titer of phage was determined by Agar double layer method. The recovery efficiency of phage was detected by phage fluorescence staining and real-time fluorescence PCR reaction. Water samples from different sources were collected for simulation experiment to evaluate the enrichment effect. At the same time, the sewage discharged from hospitals was taken as the actual water sample, and the common clinical drug-resistant bacteria were used as the host indicator bacteria to further analyze the enrichment effect of FeCl₃-PVDF membrane filter rapid enrichment method on the bacteriophage in natural water samples. Results: The method of enrichment of bacteriophages in natural water by iron ion concentration 50 mg/L and PVDF membrane filter was established. The recovery rate of this method for bacteriophage was 93%-100%. Under the multi-functional microscope, it was found that the bacteriophage of the enriched water sample increased significantly and the fluorescence value of the enriched water sample determined by the enzyme labeling instrument was about 13 times as high as that before enrichment. After concentration of the actual water samples from the hospital drainage, the positive rate of bacteriophage isolation in the concentrated group and the non-concentrated group was 23% and 4%, and the fluorescence value in the concentrated group was 2-24 times as high as that of the non-concentrated group. Conclusion: The method of FeCl₃-PVDF membrane filter is a simple, efficient and rapid method for enriching bacteriophages in different water samples.
Humans ; Bacteriophages ; Bacteria ; Iron ; Iron, Dietary ; Water

Field efficacy of enterotoxigenic Escherichia coli-specific phage (PhiCJ19) as a feed additive was evaluated in weaning piglets. Fifty-four piglets at 3~4 weeks old were allocated in three different groups and two of them were fed with bacteriophage at different concentrations (10(6) PFU/kg feed and 10(8) PFU/kg feed, respectively) for 30 days. Body weight and feed intake were measured at 10 days interval and body condition and fecal score were inspected every day. Based on the measurement, feed conversion rate (FCR) and average daily gain (ADG) of each group during 30 days were analyzed. The analysis suggests that the bacteriophage may help the improvement of FCR and ADG at 10(8) PFU/kg of bacteriophage feeding group in 30 days. A result from analysis of fecal score indicates that the bacteriophage also may help to relieve the intermittent diarrhea in post-weaning stage. Those results suggest that bacteriophage might help the growth of piglets in post-weaning stage.
Bacteriophages ; Body Weight ; Diarrhea ; Enterotoxigenic Escherichia coli ; Escherichia ; Weaning

OBJECTIVE: The aim of this study is to find out the genes which are related to ovarian cancer cell growth using large circular antisense library. METHODS: Clones for antisense library were uni-directionally sub-cloned into pBS SK (-) vector. LC-antisense molecules were then purified from the culture supernatants of the bacterial competent cells superinfected with M13K07 helper bacteriophages. The LC-antisense library to 240 unigene clone was constructed and utilized in the identification of genes functionally involved in the growth of ovarian cancer cells. RESULTS: The 17 numbers out of the 240 numbers of the antisense library exerted a marked inhibitory effect on the growth of SK-OV 3. CONCLUSION: The putative functional categorization of each gene was then conducted via public databases. These candidates may be used as target genes for drug development or adjuvant of conventional chemotherapeutic drugs.
Bacteriophages ; Clone Cells ; Estrone ; Gene Targeting ; Genetic Therapy ; Ovarian Neoplasms

Bacteriophages bind to the bacteria receptor through the receptor binding proteins (RBPs), a process that requires the involvement of complex atomic structures and conformational changes. In response to bacteriophage infection, bacteria have developed a variety of resistance mechanisms, while bacteriophages have also evolved multiple antagonistic mechanisms to escape host resistance. The exploration of the "adsorption-anti adsorption-escape process" between bacteriophages and bacteria helps us better understand the co-evolution process of bacteriophages and bacteria, which is important for the development of phage therapeutic technologies and phage-based biotechnologies. This review summarizes the bacteriophage adsorption related proteins, how bacteriophages escape host resistance based on the RBP alternations, and the recent progress of RBP-related biotechnologies.
Bacteria ; Bacteriophage Receptors ; Bacteriophages/genetics* ; Carrier Proteins ; Protein Binding