V J Cabelli

Publications of V J Cabelli

• Evaluation of an Escherichia coli host strain for enumeration of F male-specific bacteriophages.

  Authors: J Debartolomeis, V J Cabelli

  Applied and environmental microbiology. 06/1991; 57(5):1301-5.

  A method was developed for the selective enumeration of F male-specific bacteriophages in samples of environmental waters. The host strain for the phages, Escherichia coli HS(pFamp)R, has threeA method was developed for the selective enumeration of F male-specific bacteriophages in samples of environmental waters. The host strain for the phages, Escherichia coli HS(pFamp)R, has three antibiotic resistance markers, ampicillin on the Famp plasmid, which codes for pilus production, and streptomycin and nalidixic acid on the chromosome. The strain is resistant to coliphages T2 to T7 and phi X174. More than 95% of the phages from environmental samples which plaqued on the host strain were F male specific. The host bacterium had a higher plaquing efficiency than E. coli K-12 Hfr for F-specific phages in stock suspensions and sewage effluents. The F male-specific phage levels in prechlorinated, secondary-treated sewage effluents generally were about 10(3) to 10(4) PFU/100 ml. The levels in the influents to the sewage treatment plants and in septic tank contents were about 10(5) PFU/100 ml. RNA-containing phages composed about 90% of the total F-specific phage population in sewage effluents.

• Glucose-mediated catabolite repression of the tricarboxylic acid cycle as an explanation for increased acetic acid production in suicidal Aeromonas strains.

  Authors: H Namdari, V J Cabelli

  Journal of bacteriology. 09/1990; 172(8):4721-4.

  Growth in the presence of glucose, even under highly aerobic conditions, significantly reduced the activities of three tricarboxylic acid cycle enzymes, citrate synthetase, alpha-ketoglutarateGrowth in the presence of glucose, even under highly aerobic conditions, significantly reduced the activities of three tricarboxylic acid cycle enzymes, citrate synthetase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase, in suicidal but not nonsuicidal Aeromonas strains. Pyruvate dehydrogenase activity, however, was significantly increased. The activities of all of the enzymes, as well as the glucose-mediated increase in acetic acid production, were shown to be regulated by catabolite repression. The regulator protein is the same one which regulates the utilization of several sugars.

• The suicide phenomenon in motile aeromonads.

  Authors: H Namdari, V J Cabelli

  Applied and environmental microbiology. 04/1989; 55(3):543-7.

  Certain strains of motile Aeromonas species, including all those of Aeromonas caviae examined, were shown to be suicidal. When they were grown in the presence of glucose at both 30 and 37 degrees C,Certain strains of motile Aeromonas species, including all those of Aeromonas caviae examined, were shown to be suicidal. When they were grown in the presence of glucose at both 30 and 37 degrees C, there was rapid die-off of the organisms after 12 h of incubation, and viable cells generally could not be recovered after 24 h. It was shown that this phenomenon was due to the production of relatively high levels of acetic acid by these strains, even during growth under highly aerobic conditions, and to the greater susceptibility of these strains to acetic acid-mediated death. Suicide did not occur when the pH was maintained above 6.5 or in the presence of high concentration of Pi. These observations were consistent with our inability to isolate suicidal Aeromonas spp. from acidic lakes in New England and with their recovery from alkaline waters in Israel and from sewage. Suicidal aeromonads appear to be better adapted than the nonsuicidal biotypes to anaerobic growth in low-nutrient environments.

• Phage f2 desorption from clay in estuarine water using nonionic detergents, beef extract, and chaotropic agents.

  Authors: R Armon, V J Cabelli

  Canadian journal of microbiology. 09/1988; 34(8):1022-4.

  Experimentally adsorbed bacteriophage f2 was eluted from clay particles in estuarine water using 1% Tween, 80.3% beef extract, and 0.3 M NaNO3 with 54% recovery. Replacing sodium nitrate withExperimentally adsorbed bacteriophage f2 was eluted from clay particles in estuarine water using 1% Tween, 80.3% beef extract, and 0.3 M NaNO3 with 54% recovery. Replacing sodium nitrate with tetrasodium pyrophosphate (0.4 M) increased the recovery to 81%. Estuarine sediments treated with 1% Tween 80 revealed significantly higher male-specific phage elutions.

• Effect of fecal pollution on Vibrio parahaemolyticus densities in an estuarine environment.

  Authors: W D Watkins, V J Cabelli

  Applied and environmental microbiology. 06/1985; 49(5):1307-13.

  Vibrio parahaemolyticus densities in the Narragansett Bay, R.I., estuary were found to significantly correlate with the level of fecal pollution in the water. Results of field investigations showed aVibrio parahaemolyticus densities in the Narragansett Bay, R.I., estuary were found to significantly correlate with the level of fecal pollution in the water. Results of field investigations showed a definite association between the levels of this organism and those of Escherichia coli, Clostridium perfringens, and enterococci. Densities of V. parahaemolyticus were greatest in the near-surface waters of contaminated areas and decreased sharply with both the distance from the sources of fecal pollution and the depth of the water column. A positive association with the amount of particulate matter in the water and specifically with its zooplankton content also was found. No association was obtained with any of the physical or chemical parameters examined except dissolved oxygen. The results of laboratory studies on the growth of V. parahaemolyticus in collected estuarine waters were consistent with the field observations in that nutrients in sewage did not directly produce any increase in natural or inoculated levels of the organism. Of several particulates added to the water, only chitin and net zooplankters (live or dead) supported the growth of V. parahaemolyticus. The addition of sewage to the water had no measurable effect, whether or not the various particulates also were present. The data show that wastewater effluents have an effect on V. parahaemolyticus densities in this estuary and indicate that the effect is indirect, probably mediated by biostimulation of the food chain and manifested at the level of the microfauna.

• Relationship between the mouse colonizing ability of a human fecal Escherichia coli strain and its ability to bind a specific mouse colonic mucous gel protein.

  Authors: P S Cohen, R Rossoll, V J Cabelli, S L Yang, D C Laux

  Infection and immunity. 05/1983; 40(1):62-9.

  Escherichia coli F-18, isolated from the feces of a healthy human, is an excellent colonizer of the large intestines of streptomycin-treated CD-1 mice. E. coli F-18 Col-, a poor mouse colonizerEscherichia coli F-18, isolated from the feces of a healthy human, is an excellent colonizer of the large intestines of streptomycin-treated CD-1 mice. E. coli F-18 Col-, a poor mouse colonizer relative to F-18, lacks a 3 X 10(7)-dalton plasmid present in E. coli F-18. Both strains are human type A erythrocyte hemagglutination negative, have identical surface hydrophobicities, contain the same number of lipopolysaccharide molecules with the same O-side chain length, and have identical amounts of capsule. Differences between the two strains were observed. The relative amounts of specific outer membrane proteins differed, and E. coli F-18 was less motile than E. coli F-18 Col-. The abilities of the two strains to bind mouse large intestine mucous gel was also examined. Although each strain was able to use mucous gel as the sole source of carbon and nitrogen with equal ability, E. coli F-18 bound between two and three times more mucous gel than did E. coli F-18 Col-. Most of the difference in mucous gel binding ability of the two strains was accounted for by the greater ability of E. coli F-18 lipopolysaccharide to bind a single 26,000-dalton mucous gel protein. E. coli J5-3, a typical K-12 strain that is also a poor colonizer relative to E. coli F-18, was identical to E. coli F-18 Col- with respect to mucous gel binding ability.

• Extraction of Clostridium perfringens spores from bottom sediment samples.

  Authors: D J Emerson, V J Cabelli

  Applied and environmental microbiology. 12/1982; 44(5):1144-9.

  Two extraction-separation procedures were developed and evaluated for use in conjunction with the mCP membrane filter method for the enumeration of Clostridium perfringens spores in bottom sediments.Two extraction-separation procedures were developed and evaluated for use in conjunction with the mCP membrane filter method for the enumeration of Clostridium perfringens spores in bottom sediments. In the more facile of the two procedures, a distilled-water suspension of the sediment sample is pulse sonicated for 10 s and allowed to settle. Portions of the supernatant are then removed for membrane filtration. This procedure is recommended for general use. The more complicated procedure is recommended for situations in which the presence of high levels of toxic materials is suspected or in which relatively low spore densities are present in fine silts. In this procedure, sonication is followed by a distilled water wash. The centrifuged sediment is resuspended in distilled water and mixed with the components of a two-phase separation system (50% polyethylene glycol in distilled water and 25% sucrose in 3 M phosphate buffer [pH 7.1]). After equilibration of the system and low-speed centrifugation, the top phase and interphase are removed, mixed, and membrane filtered. The recoveries of C. perfringens spores by the two procedures, when used in conjunction with the mCP method, were comparable to each other and significantly greater than those by the British most-probable-number method. It was estimated that more than 85% of the spores were recovered by the procedures. The precision of the sonicate-and-settle-mCP procedure was markedly better than that obtained theoretically by the most-probable-number method and approached that theoretically attributable to counting an average of 85 colonies on each of two plates.

• Swimming-associated gastroenteritis and water quality.

  Authors: V J Cabelli, A P Dufour, L J McCabe, M A Levin

  American journal of epidemiology. 05/1982; 115(4):606-16.

  A direct, linear relationship between swimming-associated gastrointestinal illness and the quality of the bathing water was obtained from a multi-year, multiple-location prospectiveA direct, linear relationship between swimming-associated gastrointestinal illness and the quality of the bathing water was obtained from a multi-year, multiple-location prospective epidemiologic-microbiologic research program conducted in New York City, 1973-1975, Lake Pontchartrain, Louisiana, 1977-1978, and Boston, Massachusetts, 1978. Several microbial indicators were used in attempting to define the quality of the water; and, of those examined, enterococci showed the best correlation to total and "highly credible" gastrointestinal symptoms. The frequency of gastrointestinal symptoms also had a high degree of association with distance from known sources of municipal wastewater. A striking feature of the relationship was the very low enterococcus and Escherichia coli densities in the water (10/100 ml) associated with appreciable attack rates (about 10/1000 persons) for "highly credible" gastrointestinal symptoms. Moreover, the ratio of the swimmer to nonswimmer symptom rates indicated that swimming in even marginally polluted marine bathing water is a significant route of transmission for the observed gastroenteritis.

• The effect of plasmid gene expression on the colonizing ability of E. coli HS in mice.

  Authors: D C Laux, V J Cabelli, P S Cohen

  Recombinant DNA technical bulletin. 04/1982; 5(1):1-5.

• Membrane filter method for enumerating Escherichia coli.

  Authors: A P Dufour, E R Strickland, V J Cabelli

  Applied and environmental microbiology. 06/1981; 41(5):1152-8.

  A membrane filter procedure for enumerating Escherichia coli was developed and evaluated. The method quantifies E. coli within 24 h without requiring subculture and identification of isolates. ItA membrane filter procedure for enumerating Escherichia coli was developed and evaluated. The method quantifies E. coli within 24 h without requiring subculture and identification of isolates. It incorporates a primary selective-differential medium for gram-negative, lactose-fermenting bacteria; resuscitation of weakened organisms by incubation for 2 h at 35 degrees C before incubation at 44.5 degrees C for 18 to 22 h; and an in situ urease test to differentiate E. coli from other thermotolerant, lactose-positive organisms. The recovery of E. coli from marine, estuarine, and freshwater samples exceeded 90%. Of the presumptively positive colonies, 91% were verified as E. coli. Less than 1% of all of the verified E. coli colonies failed to react typically.

• R-Plasmid Transfer to and from Escherichia coli Strains Isolated from Human Fecal Samples.

  Authors: T L Corliss, P S Cohen, V J Cabelli

  Applied and environmental microbiology. 05/1981; 41(4):959-966.

  Strains of Escherichia coli recently isolated from human feces were examined for the frequency with which they accept an R factor (R1) from a derepressed fi strain of E. coli K-12 and transfer it toStrains of Escherichia coli recently isolated from human feces were examined for the frequency with which they accept an R factor (R1) from a derepressed fi strain of E. coli K-12 and transfer it to fecal and laboratory strains. Colicins produced by some of the isolates rapidly killed the other half of the mating pair; therefore, conjugation was conducted by a membrane filtration procedure whereby this effect was minimized. The majority of fecal E. coli isolates accepted the R factor at lower frequencies than K-12 F, varying from 10 per donor cell to undetectable levels. The frequencies with which certain fecal recipients received the R-plasmid were increased when its R transconjugant was either cured of the R1-plasmid and remated with the fi strain or backcrossed into the parental strain. The former suggests the loss of an incompatibility plasmid, and the latter suggests the modification of the R1-plasmid deoxyribonucleic acid (DNA). In general, the fecal RE. coli transconjugants were less effective donors for K-12 F and heterologous fecal strains than was the fi K-12 strain, whereas the single strain of Citrobacter freundii examined was generally more competent. Passage of the R1-plasmid to strains of salmonellae reached mating frequencies of 10 per donor cell when the recipient was a Salmonella typhi previously cured of its resident R-plasmid. However, two recently isolated strains of Salmonella accepted the R1-plasmid from E. coli K-12 R or the RE. coli transconjugants at frequencies of 5 x 10 or less.

• R-plasmid transfer frequencies from environmental isolates of Escherichia coli to laboratory and fecal strains.

  Authors: D R Shaw, V J Cabelli

  Applied and environmental microbiology. 11/1980; 40(4):756-64.

  Multiple-drug-resistant strains of Escherichia coli were isolated from the water at an estuarine site. They represented about 8.3% of the total E. coli population. Fifty-five strains, representingMultiple-drug-resistant strains of Escherichia coli were isolated from the water at an estuarine site. They represented about 8.3% of the total E. coli population. Fifty-five strains, representing each of the 32 resistance patterns identified, were mated with an E. coli K-12 F- strain. Matings were performed on membrane filters, and the cells were washed to remove any colicins produced by the donors. Thirty-one strains, about 5% of the mean E. coli density in the samples, transferred drug resistance and, hence, posessed conjugative R plasmids. Of these, 80% transferred drug resistance at a frequency of about 10(-4) or less. Nine environmental R+ strains were mated with three fecal recipients. The R-plasmid transfer frequencies to the fecal strains from the environmental donors correlated well with those from a derepressed K-12 R+ laboratory donor. The R+ X K-12 F- lac- transconjugants from 16 environmental strains were "backcrossed" to a lac+ K-12 F- strain. All transfer frequencies were higher in the backcrosses than in the original matings from the environmental donor. Furthermore, 7 of 13 different transconjugants, which accepted plasmids at repressed frequencies of less than 10(-3), donated them at frequencies greater than 10(-2). This suggests that these were derepressed plasmids in a repressed host.

• Clostridium perfringens as a water pollution indicator.

  Authors: J W Bisson, V J Cabelli

  Journal - Water Pollution Control Federation. 03/1980; 52(2):241-8.

• Membrane filter procedure for enumeration of Aeromonas hydrophila in fresh waters.

  Authors: S R Rippey, V J Cabelli

  Applied and environmental microbiology. 08/1979; 38(1):108-13.

  A membrane filter method (mA) for the enumeration of Aeromonas hydrophila in natural water samples was developed. The complex, primary medium employs trehalose as a fermentable carbohydrate andA membrane filter method (mA) for the enumeration of Aeromonas hydrophila in natural water samples was developed. The complex, primary medium employs trehalose as a fermentable carbohydrate and ampicillin and ethanol as selective inhibitors. After 20 h of incubation at 37 degrees C, an in situ mannitol fermentation test followed by an in situ oxidase test is used to further differentiate A. hydrophila from other aquatic and terrestrial microorganisms present in freshwaters. The primary medium decreases background microbial growth by about two orders of magnitude. The recoveries on mA medium from suspensions of A. hydrophila prepared from pure cultures and held for 24 h at 15 degrees C exceeded 95% of the recoveries on brain-heart infusion agar spread plates. The confirmation rate for colonies designated A. hydrophila was 98%, whereas 11% of the presumptively negative colonies were, in fact, A. hydrophila. Recoveries of A. hydrophila from fresh, surface water samples exceeded recoveries by the other methods examined.

• Relationship of microbial indicators to health effects at marine bathing beaches.

  Authors: V J Cabelli, A P Dufour, M A Levin, L J McCabe, P W Haberman

  American journal of public health. 08/1979; 69(7):690-6.

  Findings are described from the second year of an epidemiological-microbiological study conducted at New York City beaches as part of the U.S. Environmental Protection Agency program to developFindings are described from the second year of an epidemiological-microbiological study conducted at New York City beaches as part of the U.S. Environmental Protection Agency program to develop health effects-recreational water quality criteria. Symptomatology rates among swimmers (defined as immersion of the head in the water) relative to nonswimming but beach-going controls at a "barely acceptable" (BA) beach and a "relatively unpolluted" (RU) beach were examined. Data were collected by contacting family groups at the beach on weekends, obtaining information on bathing activity, and then questioning them by phone some 8--10 days later. In addition measurements were made for a number of potential water quality indicators. It was observed that the symptom rates, categorized as gastrointestinal (GI), respiratory, "other", and "disabling" (stayed home, stayed in bed, consulted a physician), were higher among swimmers than nonswimmers. As in the pretest conducted the previous year, the rate of GI symptoms was significantly higher among swimmers relative to nonswimmers at the BA but not the RU beach. Children, Hispanic Americans, and the low-middle socioeconomic groups were identified as the most susceptible portions of the population.

• Limitations of the Moeller lysine and ornithine decarboxylase tests.

  Authors: R W Pilsucki, N W Clayton, V J Cabelli, P S Cohen

  Applied and environmental microbiology. 03/1979; 37(2):254-60.

  A total of 40 fecal and environmental isolates, including 26 Escherichia coli strains, 9 members of the genus Klebsiella, and 5 members of the genus Enterobacter, were tested by enzyme assay forA total of 40 fecal and environmental isolates, including 26 Escherichia coli strains, 9 members of the genus Klebsiella, and 5 members of the genus Enterobacter, were tested by enzyme assay for their endogenous and induced levels of lysine decarboxylase and ornithine decarboxylase when grown in Moeller decarboxylase medium. All of the coliforms examined had measurable lysine decarboxylase and ornithine decarboxylase activities whether or not they were positive in the Moeller test. In general, the Moeller lysine decarboxylase test reflected the inducibility of lysine decarboxylase whereas the Moeller ornithine decarboxylase test did not relect the inducibility of ornithine decarboxylase. Neither test measured the amount of intracellular enzyme; rather, they indicated whether the amount of polyamine liberated was sufficient to raise the pH of the culture medium above 7. Changing the growth conditions (i.e., the concentrations of glucose, lysine, and amino acids other than lysine) greatly influenced the lysine decarboxylase activity in coliforms. The limitations on the interpretation of the Moeller test results are discussed.

• Membrane filter enumeration method for Clostridium perfringens.

  Authors: J W Bisson, V J Cabelli

  Applied and environmental microbiology. 02/1979; 37(1):55-66.

  A membrane filter procedure has been developed for the rapid quantitation of C. perfringens in the aquatic environment. Background growth is inhibited by the use of D-cycloserine, polymyxin BA membrane filter procedure has been developed for the rapid quantitation of C. perfringens in the aquatic environment. Background growth is inhibited by the use of D-cycloserine, polymyxin B sulfate, and incubation at 45 degrees C. Differential characteristics include the fermentation of sucrose, production of acid phosphatase, and the absence of beta-D-glucosidase activity. The medium is prepared as follows (in grams per 100 ml of distilled water): tryptose, 3.0; yeast extract, 2.0; sucrose, 0.5; L-cysteine, 0.1; MgSO4. 7H2O, 0.01; bromocresol purple, 0.004; and agar, 1.5. The ingredients are dissolved, and the pH is adjusted to 7.6. After autoclaving at 121 degrees C for 15 min, the medium is allowed to cool at 50 degrees C, and the following are added per 100 ml: D-cycloserine, 40 mg; polymyxin B sulfate, 2.5 mg; indoxyl-beta-D-glucoside, 60 mg; 2.0 ml of a filter-sterilized 0.5% phenolpthalein diphosphate solution; and 0.2 ml of a filter-sterilized 4.5% FeCl3.6H2O solution. Enumeration of C. perfringens in a water sample is completed within 18 to 24 h. The verification of typical colonies was 93%. The average recovery from peptone-water spore suspensions of five strains was 79%, and that from filter-sterilized seawater suspensions was 90%. The precision of the method was approximately equal to that expected from random error alone. Confirmed recoveries of C. perfringens from water and sewage samples generally were greater than those by the Bonde pour tube method.

• Membrane filter procedure for enumeration of Vibrio parahaemolyticus.

  Authors: W D Watkins, C D Thomas, V J Cabelli

  Applied and environmental microbiology. 12/1976; 32(5):679-84.

  A membrane filtration procedure has been developed for the enumeration of Vibrio parahaemolyticus in marine waters. Background microbial growth on the primary medium was decreased through the use ofA membrane filtration procedure has been developed for the enumeration of Vibrio parahaemolyticus in marine waters. Background microbial growth on the primary medium was decreased through the use of sodium cholate and copper sulfate, high pH, 3% NaCl, and an elevated incubation temperature. A series of in situ tests was employed to obviate the picking of colonies for identification; thereby, the enumeration of V. parahaemolyticus was accomplished within 30 h. Confirmation of typical colonies approached 95%. Relative to immediate plating on brain heart infusion agar spread plates, the recovery of V. parahaemolyticus cells suspended in phosphate-buffered saline or in seawater held for 24 h at 4 to 6 degrees C was about 90%. Assay variability did not exceed that expected by chance. Recoveries of V. parahaemolyticus from coastal and estuarine surface waters exceeded those obtainable by other methods examined.

• Klebsiella densities in waters receiving wood pulp effluents.

  Authors: B E Huntley, A C Jones, V J Cabelli

  Journal - Water Pollution Control Federation. 08/1976; 48(7):1766-71.

• Charateristics of Klebsiella from textile finishing plant effluents.

  Authors: A P Dufour, V J Cabelli

  Journal - Water Pollution Control Federation. 06/1976; 48(5):872-9.