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PubMed1966

Physical properties of single- and double-stranded coliphage ribonucleic acid.

1. The physical characteristics of single- and double-stranded coliphage RNA with regard to their sedimentation behaviour in gradients of sucrose in high or low ionic conditions were examined. The effect of heat on their sedimentation characteristics was also determined. 2. Single-stranded coliphage RNA was found to exist in three different forms having sedimentation coefficients 28s, 20s and 12s. The latter two were interchangeable, depending on ionic strength. All three were almost equally infectious to spheroplasts. 3. Double-stranded coliphage RNA was found to be non-infectious to spheroplasts and had sedimentation coefficients 15s and 12s. Thermal denaturation gave rise to infectious single-stranded 12s RNA. 4. Four possible hypotheses on the mechanism of replication of coliphage RNA are discussed.

Carbon Isotopes↗
PubMed1976

Airborne coliphages from wastewater treatment facilities.

The emission (from wastewater treatment plants) of airborne coliphages that form plaques on two strains of Escherichia coli was investigated. Two activated-sludge and two trickling-filter plants were studied. Field sampling procedures used large-volume air samplers with recirculation devices. Coliphages were enumerated by a most-probable-number (MPN) procedure. Temperature, relative humidity, windspeed, and presence of sunlight were monitored. Concurrent samples of sewage were taken during each air-sampling run. Average coliphage levels in the airborne emissions of trickling-filter beds and activated-sludge units were 2.84 X 10(-1) and 3.02 X 10(-1) MPN/m3, respectively, for all positive observations, and sewage liquor concentrations from the sources were 4.48 X 10(5) and 2.94 X 10(6) plaque-forming units/liter, respectively, depending upon the E. coli host used for assay. This work establishes minimal airborne-coliphage concentrations from the plants studied. The procedures employed will be useful in evaluating the animal virus levels in these emissions.

Air Microbiology↗
PubMed1982

Comparison of coliphage and bacterial aerosols at a wastewater spray irrigation site.

Microbiological aerosols were measured on a spray irrigation site at Fort Huachuca, Ariz. Indigenous bacteria and tracer bacteriophage were sampled from sprays of chlorinated and unchlorinated secondary-treatment wastewaters during day and night periods. Aerosol dispersal and downwind migration were determined. Bacterial and coliphage f2 aerosols were sampled by using Andersen viable type stacked-sieve and high-volume electrostatic precipitator samplers. Bacterial standard plate counts averaged 2.4 x 10(5) colony-forming units per ml in unchlorinated effluents. Bacterial aerosols reached 500 bacteria per m3 at 152 m downwind and 10,500 bacteria per m3 at 46m. Seeded coliphage f2 averaged 4.0 x 10(5) plaque-forming units per ml in the effluent and were detected 563 m downwind. Downwind microbial aerosol levels were somewhat enhanced by nighttime conditions. The median aerodynamic particle size of the microbial aerosols was approximately 5.0 micrometer. Chlorination reduced wastewater bacterial levels 99.97% and reduced aerosol concentrations to near background levels; coliphage f2 was reduced only 95.4% in the chlorinated effluent and was readily measured 137 m downwind. Microbiological source strength an meteorological data were used in conjunction with a dispersion model to generate mathematical predictions of aerosol strength at various sampler locations. The mean calculated survival of aerosolized bacteria (standard plate count) in the range 46 to 76 m downwind was 5.2%, and that of coliphage f2 was 4.3 %.

Aerosols↗
PubMed1993

Clostridium perfringens and somatic coliphages as indicators of the efficiency of drinking water treatment for viruses and protozoan cysts.

To find the most suitable indicator of viral and parasitic contamination of drinking water, large-volume samples were collected and analyzed for the presence of pathogens (cultivable human enteric viruses, Giardia lamblia cysts, and Cryptosporidium oocysts) and potential indicators (somatic and male-specific coliphages, Clostridium perfringens). The samples were obtained from three water treatment plants by using conventional or better treatments (ozonation, biological filtration). All samples of river water contained the microorganisms sought, and only C. perfringens counts were correlated with human enteric viruses, cysts, or oocysts. For settled and filtered water samples, all indicators were statistically correlated with human enteric viruses but not with cysts or oocysts. By using multiple regression, the somatic coliphage counts were the only explanatory variable for the human enteric virus counts in settled water, while in filtered water samples it was C. perfringens counts. Finished water samples of 1,000 liters each were free of all microorganisms, except for a single sample that contained low levels of cysts and oocysts of undetermined viability. Three of nine finished water samples of 20,000 liters each revealed residual levels of somatic coliphages at 0.03, 0.10, and 0.26 per 100 liters. Measured virus removal was more than 4 to 5 log10, and cyst removal was more than 4 log10. Coliphage and C. perfringens counts suggested that the total removal and inactivation was more than 7 log10 viable microorganisms. C. perfringens counts appear to be the most suitable indicator for the inactivation and removal of viruses in drinking water treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of temperature and host cell growth phase on replication of F-specific RNA coliphage Q beta.

Human enteric viruses have been found in groundwater in the absence of fecal coliforms. Because detection of human enteric viruses is costly, time-consuming, and lacking in sensitivity, F-specific RNA (FRNA) coliphages, which infect Escherichia coli by attachment to F pili, are being examined for suitability as indicators of human enteric viruses in groundwater. Temperatures and host cell growth conditions that constrain F-pilus expression will limit FRNA coliphage replication in groundwater and wastewater, as is desirable in an indicator. Below 25 degrees C F-pilus synthesis ceases; FRNA coliphage Qbeta did not replicate below this temperature in batch cultures. One-step replication studies indicated that the replicative cycle is prolonged and that fewer progeny are released as the temperature decreases. The decreases in phage replication observed in the one-step replication studies were a consequence of fewer cells infected as the temperature was lowered or as host cells entered stationary phase. The numbers of phage particles released from infected cells did not change. The minimum temperature for replication of Qbeta, 25 degrees C, is not maintained in wastewater and does not occur in Wisconsin groundwater. On the basis of temperature and host cell growth phase, we have concluded that extensive replication of FRNA coliphages does not occur in wastewater and groundwater in Wisconsin and areas with similar cool climates.

Anaerobiosis↗
PubMed1997

Coliphage and indigenous phage in Mamala Bay, Oahu, Hawaii.

Public concern over the discharge of primarily treated sewage by two offshore outfalls in Mamala Bay, Oahu, prompted a multidisciplinary study to determine the impact of such activities on the water quality in the bay and at adjacent recreational beaches. As part of this study, we determined the abundance of coliphage as an indicator of fecal pollution along with total viral direct counts and phages infective for Vibrio parahaemoltyicus 16 at stations in Mamala Bay in four quarterly samplings over 13 months. Coliphage (< 1 to 1.2 x 10(3)/liter) were found during each quarterly sampling along an offshore transect to the Sand Island waste treatment facility outfall. The nonpoint coastal stations (Pearl Harbor, Ala Wai Canal, and Ke'ehi Lagoon) had high levels of coliphage during the storm event sampling in February 1994 but much lower levels or none when sampled during dry weather. Coliphage were absent at all samplings at Waikiki Beach and at the control station off Diamond Head. Viral direct counts in eutrophic coastal stations (Pearl Harbor, Ke'ehi Lagoon, Ala Moana Beach, and Ala Wai canal) averaged 10(9)/liter, while counts at offshore stations ranged from 9 x 10(7) to 1 x 10(9) viruses/liter, values similar to those for other marine environments. Vibriophage were found mainly in eutrophic coastal environments (Ala Wai Canal, Pearl Harbor, and Ke'ehi Lagoon) and at the Sand Island Transect stations D1 and D2. The greatest abundance was found during the storm event (February 1994) sampling. These results suggest that the Sand Island outfall influenced the water quality of the immediate surrounding waters but had little effect on the quality of the recreational beaches. Nonpoint discharge sources appeared to be more important in the distribution of fecal indicators in the coastal zone.

Bacteriophages↗
PubMed1998

Detection of infectious enteroviruses, enterovirus genomes, somatic coliphages, and Bacteroides fragilis phages in treated wastewater.

In this study, three types of treated wastewater were tested for infectious enteroviruses, the enterovirus genome, somatic coliphages, and Bacteroides fragilis phages. The aim of this work was to determine whether the presence of the two types of bacteriophages or of the enterovirus genome was a good indicator of infectious enterovirus contamination. The enterovirus genome was detected by reverse transcription-polymerase chain reaction. Infectious enteroviruses were quantified by cell culturing (BGM cells), and the bacteriophages were quantified by plaque formation on the host bacterium (Escherichia coli or B. fragilis) in agar medium. Forty-eight samples of treated wastewater were analyzed. Sixteen samples had been subjected to a secondary treatment for 8 to 12 h (A), 16 had been subjected to a secondary treatment for 30 h (B1), and 16 had been subjected to both secondary and tertiary treatments (B2). The mean concentrations of somatic coliphages were 4.9 x 10(4) PFU . liter-1 for treatment line A, 9.8 x 10(3) PFU . liter-1 for B1, and 1.4 x 10(3) PFU . liter-1 for B2, with all the samples testing positive (100%). The mean concentrations of B. fragilis phages were 1.7 x 10(3) PFU . liter-1 for A (100% positive samples), 17 to 24 PFU . liter-1 for B1 (44% positive samples), and 0.8 to 13 PFU . liter-1 for B2 (6% positive samples). The mean concentrations of infectious enteroviruses were 4 most probable number of cytopathogenic units (MPNCU) . liter-1 for A (31% positive samples) and <1 MPNCU . liter-1 for B1 and B2 (0% positive samples). The percentages of samples testing positive for the enterovirus genome were 100% for A, 56% for B1, and 19% for B2. The percentages of samples testing positive for the enterovirus genome were significantly higher than those for infectious enteroviruses. This finding may have been due to the presence of noninfectious enteroviruses or to the presence of infectious enteroviruses that do not multiply in BGM cell cultures. However, under our experimental conditions, nondetection of the genome implies the absence of infectious viruses. There was a significant correlation between the concentration of somatic coliphages or B. fragilis phages and the presence of infectious enteroviruses or the presence of the enterovirus genome. However, the somatic coliphage concentration did not lead to fluctuations in the infectious enterovirus concentration, whereas the B. fragilis phage concentration did.

Bacteriophages↗
PubMed2001

Human adenoviruses and coliphages in urban runoff-impacted coastal waters of Southern California.

A nested-PCR method was used to detect the occurrence of human adenovirus in coastal waters of Southern California. Twenty- to forty-liter water samples were collected from 12 beach locations from Malibu to the border of Mexico between February and March 1999. All sampling sites were located at mouths of major rivers and creeks. Two ultrafiltration concentration methods, tangential flow filtration (TFF) and vortex flow filtration (VFF), were compared using six environmental samples. Human adenoviruses were detected in 4 of the 12 samples tested after nucleic acid extraction of VFF concentrates. The most probable number of adenoviral genomes ranged from 880 to 7,500 per liter of water. Coliphages were detected at all sites, with the concentration varying from 5.3 to 3332 PFU/liter of water. F-specific coliphages were found at 5 of the 12 sites, with the concentration ranging from 5.5 to 300 PFU/liter. The presence of human adenovirus was not significantly correlated with the concentration of coliphage (r = 0.32) but was significantly correlated (r = 0.99) with F-specific coliphage. The bacterial indicators (total coliforms, fecal coliforms, and enterococci) were found to exceed California recreational water quality daily limits at 5 of the 12 sites. However, this excess of bacterial indicators did not correlate with the presence of human adenoviruses in coastal waters. The results of this study call for both a reevaluation of our current recreational water quality standards to reflect the viral quality of recreational waters and monitoring of recreational waters for human viruses on a regular basis.

Adenoviruses, Human↗
PubMed1976

Enzymatic action of coliphage omega8 and its possible role in infection.

The receptor of coliphage omega8 is the O-specific mannan of Escherichia coli O8 in which the trisaccharide alpha-mannosyl-1,2-alpha-mannosyl-1,2-mannose is joined through alpha-mannosyl-1,3-linkages. Coliphage omega8 produces an endo-alpha-1,3-mannosidase which destroys the receptor, liberating a series of oligosaccharides (repeating trisaccharide and multiples). The enzyme is an integral part of the phage particles and also occurs in a free form in the lysates. Phage particles hydrolyze alpha-1,3-mannosyl linkages in the lipopolysaccharide, the polysaccharide (mannan) moiety, and higher oligosaccharides with an efficiency decreasing in this order. No transmannosylation could be detected. Phage particles also degrade the receptor mannan on whole bacteria, as determined with 14C-labeled E. coli O8. The values of Km and Vmax were determined with omega8 particles and free enzymes using native lipopolysaccharide and its triethylammonium salt. The latter, which was obtained after electrodialysis, has a micellar weight of 2.5 X 10(5), whereas the native lipopolysaccharide forms supermicelles with micellar weights of several millions. With coliphage omega8 as enzyme and supermicellar lipopolysaccharide as substrate Km=5 X 10(-8) M was obtained. This, together with the fact that omega8 attaches irreversibly to E. coli O8, was used in proposing a hypothesis for the possible role of the enzyme in the first steps of infection with coliphage omega8.

Adsorption↗
PubMed1970

Properties of the deoxyribonucleic acid contained in the defective particle coliphage 15.

Escherichia coli strain 15 TAU, which requires thymine, arginine, and uracil for growth and harbors an apparently defective prophage, was induced by exposure to ultraviolet light (580 ergs/mm(2)) or to mitomycin C (5 mug/ml). Phage particles (coliphage 15) were recovered from the resulting lysate by treatment with deoxyribonuclease, filtration, and several cycles of differential centrifugation. Analysis of the phage particles obtained by using cesium chloride density gradient centrifugation in a preparative ultracentrifuge resulted in the resolution of three components. The major component had a peak density of 1.52 to 1.53 g/cm(3) followed by components with densities of 1.5 and 1.49 g/cm(3). The guanine plus cytosine content of coliphage 15 deoxyribonucleic acid (DNA) was determined by both analytical ultracentrifugation in cesium chloride and by thermal denaturation in standard saline citrate buffer. Respective values of 46.4 +/- 1% and 46.6 +/- 1% guanine plus cytosine content were obtained. Coliphage 15 DNA formed molecular hybrids with messenger ribonucleic acid (RNA) from both uninduced and ultraviolet-induced cultures of E. coli 15 TAU, but did not hybridize with E. coli ribosomal RNA. The molecular weight of coliphage 15 DNA was determined by constant velocity sucrose density gradient centrifugation to be about 33 x 10(6) daltons.

Arginine↗
PubMedDate not supplied

[Research of the RNA-coliphages, in comparison with usual microbial and chemical indexes of biological pollution, for hygienic and sanitary evaluations of coast-waters (author's transl)].

Hygienic significance of the usual microbial (E. coli, Enterococci, Clostridia) and chemical (COD, NH3, NO2) indexes of sea-water biological pollution was investigated, in comparison with RNA-coliphages assay. E. coli was confirmed as an easily measurable and significant index of biological pollution (at least for routinary investigations), while the other microbial and chemical parameters do not significantly increase the hygienic selectivity of the E. coli assay. RNA-coliphages assay, on the contrary, is able to increase the hygienic selectivity of sanitary investigations, particularly in lowly polluted coast-water. This behaviour of RNA-coliphages is in accordance with their great persistance in sea-water, due to their survival-time, closely comparable with human viruses. RNA-coliphages assay is therefore proposed as a simple and useful index of "viral pollution" for a complete hygienic evaluation of sea-water environment in addition to routinary E. coli assay.

Coliphages↗
PubMed1983

A simplified method for coliphage detection in natural waters.

The ARCAT (A Rapid Coliphage Analysis Technique) method for detecting coliphages in water has been modified. Modifications to the original method include media optimization, the use of frozen host cultures, the use of a single agar coliphage assay and optimized plaque resolution with 2, 3, 4-triphenyltetrazolium chloride. Detection of 5 coliphages per 100 ml of water sample is accomplished in 6 hours for rapid estimation of water quality.

Coliphages↗
PubMed1991

Secondary structure of coliphage Q beta RNA. Analysis by electron microscopy.

The secondary structure of genomic RNA from the coliphage Q beta has been examined by electron microscopy in the presence of varying concentrations of spermidine using the Kleinschmidt spreading technique. The size and position of structural features that cover 70% of the viral genome have been mapped. The structural features that are visualized by electron microscopy in Q beta RNA are large. They range in size from 170 to 1600 nucleotides. A loop containing approximately 450 nucleotides is located at the 5' end of the RNA. It includes the initiation region for the viral maturation protein. A large hairpin containing approximately 1600 nucleotides is located in the center of the molecule. It is multibranched and includes most of the viral coat gene, the readthrough region of the A1 gene, and approximately one third of the viral replicase gene. Within the central hairpin, the initiation region for the viral replicase gene pairs with a region within the distal third of the viral coat gene. This structure may participate in the regulation of translational initiation of the viral replicase gene. Two structural variants of the central hairpin were observed. One of them brings the internal S and M viral replicase binding regions into juxtaposition. These observations suggest that the central hairpin may also participate in the regulation of translation of the viral coat gene. The secondary structures that are observed in Q beta RNA differ significantly from structures that we described previously in the genomic RNA of coliphage MS2 but are similar to structures we observed by electron microscopy in the related group B coliphage SP.

Coliphages↗
PubMed1992

Improved method for coliphage detection based on beta-galactosidase induction.

An improved method for coliphage detection based on the induction of beta-galactosidase in Escherichia coli is described. Upon infection by coliphages, the cells are lysed and a stable indolyl product that is dark blue becomes visible within each plaque. The improved method is compared to the proposed coliphage detection procedure described in Standard Methods for the Examination of Water and Wastewater.

Coliphages↗
PubMed1993

Sensitivity of naturally occurring coliphages to type I and type II restriction and modification.

Protection against lethal infections by bacteriophage may seem the most likely role of restriction-modification (R-M) systems in bacteria and the reason for their evolution. There are, however, phenomena which question this phage-mediated selection hypothesis for the maintenance of extant R-M systems. Most prominent among these are the mechanisms phage have to avoid or otherwise limit the effects of the restriction endonucleases produced by their host bacteria. To evaluate the importance of these antirestriction mechanisms in Escherichia coli, we have examined the sensitivity of coliphage from natural and laboratory sources to a series of type I and II R-M systems. The results of our study indicate that, in vivo, restriction endonucleases have no effect on a substantial fraction of naturally occurring coliphage. The absence of restriction sites appears to be the most common reason why these phage are unaffected by type II restriction endonucleases, but other antirestriction mechanisms also operate. On the other hand, the frequency of naturally occurring coliphage sensitive to restriction appears sufficiently great for phage-mediated selection to be a viable hypothesis for the maintenance of R-M in E. coli and its accessory elements.

Biological Evolution↗
PubMed1981

Recovery of coliphages from wastewater effluents and polluted lake water by the magnetite-organic flocculation method.

A magnetite-organic flocculation method was developed for the concentration of coliphages from wastewater effluents and polluted lake water. A high percent (68 to 100%) recovery of coliphages from sewage effluents was achieved by this procedure. Coliphage recovery from Lake Alice, a sewage-contaminated lake, showed phage concentrations ranging from 2.3 X 10(2) to 1.9 X 10(3) plaque-forming units per liter. This method is simple and inexpensive and may be carried out under field conditions.

Coliphages↗
PubMed1983

Concentration of coliphage from water and sewage with charge-modified filter aid.

Methods of detecting and concentrating animal viruses from large volumes of water and wastewater have experienced rapid development in recent years, but only a few methods are available for the concentration of bacteriophages. The present study describes the use of a charge-modified (Zeta Plus) filter aid (AMF Cuno, Meriden, Conn.) for the concentration of coliphages from large volumes of water and sewage. Coliphages MS-2 and f2 were efficiently adsorbed from water and sewage to the positively charged filter aid. Elution was accomplished with 4% beef extract--0.5 M NaCl adjusted to pH 9.5. The recovery of f2 from 10- to 20-liter volumes of tap water ranged between 11 and 70%, and the recovery of MS-2 ranged between 43 and 70%. The efficiency of recovery of naturally occurring coliphages from secondarily treated sewage ranged between 16 and 44%. This technique appears to be promising because it requires low-cost equipment (47-mm polypropylene filter housing), is easy to handle, and can filter large volumes of water (greater than or equal to 20 liters) with good recoveries. Filtrations can be conducted at the ambient pH of the water, and the unit cost per filtration (i.e., the cost of filter aid) comes to less than three cents per sampling. The technique could be useful in evaluation of viral water quality, study of ecology and occurrence of phages in natural waters, and isolation of rare phages from natural waters.

Coliphages↗
PubMed1994

Effect of distance from the polluting focus on relative concentrations of Bacteroides fragilis phages and coliphages in mussels.

Concentrations of fecal bacteria, somatic and F-specific coliphages, and phages infecting Bacteroides fragilis in naturally occurring black mussels (Mytilus edulis) were determined. Mussels were collected over a 7-month period at four sampling sites with different levels of fecal pollution. Concentrations of both fecal bacteria and bacteriophages in mussel meat paralleled the concentration of fecal bacteria in the overlying waters. Mussels bioaccumulated efficiently, although with different efficiencies, all of the microorganisms studied. Ratios comparing the levels of microorganisms in mussels were determined. These ratios changed in mussels collected at the different sites. They suggest that bacteriophages infecting B. fragilis and somatic coliphages have the lowest decay rates among the microorganisms studied, with the exception of Clostridium perfringens. On the contrary, concentrations of F-specific coliphages showed a greater rate of decay than the other bacteriophages at sites more distant from the focus of contamination. Additionally, levels of enteroviruses were studied in a number of samples, and in these samples, the B. fragilis bacteriophages clearly outnumbered the enteroviruses. The results of this study indicate that, under the environmental conditions studied, the fate of phages infecting B. fragilis released into the marine environment resembles that of human viruses more than any other microorganism examined.

Animals↗