OBJECTIVETo scan the most resistable bacteriophage as an indicator in disinfection tests, and to study the resistance of bacteriophage T4, Phichi 174D, and f2 to the sodium dichloroisocyanurate (NaDCC) in laboratory.

METHODSThe virucidal activity of NaDCC against bacteriophage T4, Phichi 174D, and f2 were assessed by suspension test. The neutralizer was selected and be appraised by test of neutralizer. Bacteriophage T4, Phichi 174D, and f2 were detected and enumerated by the double-agar-layer plaque technique.

RESULTS(1) With 150 mg/L of available chlorine of NaDCC solution, within a contact time of 40 minutes, or 300 mg/L, 5 minutes, the reductions of bacteriophage T4 achieved the "disinfection" level [log(10) inactivation value or log(10) reduction value of bacteriophage T4 (log(10)No-log(10)Nt) > or = 4.00 log(10)]. (2) With 300 mg/L of available chlorine of NaDCC solution, within a contact time of 5 minutes, or 400 mg/L, 3 minutes, the reductions of bacteriophage Phichi 174D achieved the "disinfection" level. (3) With 2000 mg/L of available chlorine of NaDCC solution, within a contact time of 20 minutes, or 4000 mg/L, 5 minutes, the reductions of bacteriophage f2 might achieve the "disinfection" level.

CONCLUSIONThe order of resistance of the above three bacteriophages to NaDCC from greatest to smallest is as follows: bacteriophage f2 > bacteriophage T4 > bacteriophage Phichi 174D.

Bacteriophage T4 ; drug effects ; Bacteriophage phi X 174 ; drug effects ; Bacteriophages ; drug effects ; Disinfectants ; pharmacology ; Drug Resistance, Viral ; Sodium Hypochlorite ; pharmacology

BACKGROUNDTo screen for the most resistant bacteriophage as indicator in disinfection tests, the resistance of bacteriophage phi chi 174D, T4 and f2 to iodophor were observed in laboratory.

METHODSThe virucidal activity of iodophor against bacteriophage phi chi 174D, T4, and f2 were assessed by suspension test. The neutralizer is selected and appraised by testing with neutralizer. Bacteriophage phi chi 174D, T4, and f2 were detected and enumerated by the double-agar-layer plaque technique.

RESULTS(1) With 500 mg/L of available iodine of iodophor solution, within a contact time of 40 min, or 750 mg/L, 10 min, or 1000 mg/L, 5 min, the reduction of bacteriophage phi chi 174D could achieve the "disinfection" level [log10 inactivation value (LIV) or log10 reduction value (LRV) of bacteriophage phi chi 174D (log10 No-log10 Nt) was > or = 4.00 log10]. (2) With 600 mg/L of available iodine of iodophor solution, within a contact time of 40 min, or 700 mg/L, 5 min, the reductions of bacteriophage T4 could achieve the "disinfection" level. (3) With 50 mg/L of available iodine of iodophor solution, within a contact time of 10 min, or 75 mg/L, 10 min, the reductions of bacteriophage f2 could achieve the "disinfection" level.

CONCLUSIONThe order of resistance of the above three bacteriophages to iodophor from greatest to smallest is as follows: bacteriophage phi chi 174D greater than bacteriophage T4 > bacteriophage f2.

Bacteriophage T4 ; drug effects ; Bacteriophage phi X 174 ; drug effects ; Bacteriophages ; drug effects ; Disinfectants ; pharmacology ; Disinfection ; methods ; Dose-Response Relationship, Drug ; Drug Resistance, Viral ; Iodophors ; pharmacology ; Surface-Active Agents ; pharmacology ; Virus Inactivation ; drug effects

PURPOSE: Genes involved in liver cancer cell growth have been identified using an antisense library of large circular (LC-) genomic DNA of a recombinant M13 phage. MATERIALS AND METHODS: A subtracted cDNA library was constructed by combining procedures of suppression subtractive hybridization (SSH) and unidirectional cloning of the subtracted cDNA into an M13 phagemid vector. Utilizing the life cycle of M13 bacteriophages, LC-antisense molecules derived from 1, 200 random cDNA clones selected by size were prepared from the culture supernatant of bacterial transformants. The antisense molecules were arrayed for transfection on 96-well plates preseeded with HepG2. RESULTS: When examined for growth inhibition after antisense transfection, 153 out of 1, 200 LC-antisense molecules showed varying degrees of growth inhibitory effect to HepG2 cells. Sequence comparison of the 153 clones identified 58 unique genes. The observations were further extended by other cell-based assays. CONCLUSION: These results suggest that the LC-antisense library offers potential for unique high-throughput screening to find genes involved in a specific biological function, and may prove to be an effective target validation system for gene-based drug discovery.
Bacteriophage M13 ; Bacteriophages* ; Clone Cells ; Cloning, Organism ; DNA* ; DNA, Complementary ; Drug Discovery ; Gene Library ; Hep G2 Cells ; Life Cycle Stages ; Liver Neoplasms* ; Liver* ; Mass Screening ; Transfection

OBJECTIVETo study the change of nucleic acid sequence and the germicidal effect of an E. coli bacteriophage with broad host range isolated from hospital sewage as well as to study the mechanism of phage host specificity and the effect of killed bacteria by phage-disinfectant to the samples from sewage water.

METHODSTo extract the nucleic acid from phage f(2) and phage with broad host range using anti-serum-carbamidine hydrochloride assay. Purity with agarose gel electrophoresis was then evaluated. Differences of nucleic acid sequence between phage f(2) and phage with broad host range with reverse transcription-polymerase chain reaction (RT-PCR) and random amplified polymorphic DNA (RAPD)-PCR were also comparing and analysed. Through observing the germicidal test of phage f(2) and phage with broad host range to samples from environment, different sterilization effects between the two phages were compared.

RESULTSAnalystic test for nucleic acid revealed that the two phages both belonged to 6000 bp, single-stranded RNA bacteriophage. Significant differences in their specificity of RAPD-PCR and RT-PCR were found during the changed of host range; with 26 RAPD-cDNA differential fragments found that in two phages RAPD-PCR products. The RT-PCR product of phage f(2) was 450 bp cDNA fragment, but the phage with broad host range did not show PCR product. Treating the sewage water with phage under broad host range, the germicidal test showed that the cleaning rate of E. coli bacteria and phage f(2) in water samples from environment could reach 36.75% - 56.28%, 30.84% - 47.96%, 19.19% - 35.06% and 13.05% - 27.85%, respectively.

CONCLUSIONThe cleaning rates to E. coli and bacteria by phage with broad host range were obviously higher than phage f(2) (P = 0.000). Analytic test for nucleic acid indicated that host-specific lytic effect of phage with broad host range had been changed at genetic level.

Bacteriophages ; genetics ; isolation & purification ; physiology ; Colony Count, Microbial ; Escherichia coli ; virology ; F Factor ; RNA Phages ; genetics ; Sewage ; microbiology ; virology ; Water Microbiology

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

OBJECTIVETo evaluate the protective performance of a positive pressure bio-protective clothing against viral aerosol.

METHODSThe suspension of indicating virus phage Phi-X174 was made for viral aerosol generating in a hermetic cabin. The diameter of viral aerosol particles were measured with a aerodynamics size analyzer. By adjusting the inner humidity of the cabin, the protective efficiency of the positive pressure bio-protective clothing against viral aerosol in high and low windshield conditions was determined with Andersen six-stage air sampler sampling and plage forming unit (PFU) counting, respectively.

RESULTSThe mass median diameter of Phage Phi-X174 aerosol particles was about 0.922 µm and the background concentration is beyond 2 × 10⁴ particles/m³. The protective efficiency of the clothing against phage Phi-X174 aerosol particles was above 99.9% under different test conditions with the range of viral aerosol concentration between 0 - 23 PFU/m³. Airflow (P = 0.84), environment humidity conditions (P = 0.33) and sampling time (P = 0.07) did not affect the protective efficiency statistically.

CONCLUSIONThe positive pressure bio-protective clothing provided a relatively high efficiency against phage Phi-X174 aerosol regardless of airflow rate, environment humidity and sampling time.

Aerosols ; Bacteriophage phi X 174 ; Bioterrorism ; prevention & control ; Equipment Design ; Humidity ; Occupational Exposure ; prevention & control ; Pressure ; Protective Clothing ; Time Factors ; Virus Diseases ; prevention & control

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