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B J Wallace

Publications and source records attributed to B J Wallace.

At least 19 recordsLinked to original sources
PubMed2006

Community-associated methicillin-resistant Staphylococcus aureus skin infections in a religious community.

In September 2004, an outbreak of community-associated methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTI) was reported among members of a religious community. We conducted a retrospective cohort study on all 175 community members; performed a nasal carriage survey, and environmental swab testing. We identified 24 MRSA cases (attack rate 14%). In multivariate analysis, sauna use [odds ratio (OR) 19.1, 95% confidence interval (CI) 2.7-206.1] and antimicrobial use within 12 months before infection (OR 11.7, 95% CI 2.9-47.6) were risk factors for infection. MRSA nasal carriage rate was 0.6% (1/174). Nine of 10 clinical isolates and an isolate from an administrative office within the community had the pulsed-field gel electrophoresis type USA300. Targeted hygiene improvement, wound care, and environmental cleaning were implemented. We describe the first reported outbreak of MRSA SSTI in a religious community. Adherence to appropriate personal and environmental hygiene might be critical factors in controlling transmission.

Adolescent↗
PubMed2001

West Nile virus: a case study in how NY State Health Information infrastructure facilitates preparation and response to disease outbreaks.

New York's (NY) Health Information Network (HIN) provided timely access to West Nile Virus (WNV) data during the initial outbreak in the late Summer 1999. In December 1999, NY developed a plan to deal with WNV in 2000 that required an integrated surveillance system for humans, birds, mammals, and mosquitoes. The HIN infrastructure allowed NY to deploy this system statewide in three months. Local health departments throughout NY used the system to report, track, and retrieve surveillance data as WNV spread throughout NY in 2000. The HIN infrastructure includes partnerships, training/support, technical capacity and architecture similar to NEDSS as proposed by the US CDC.

Animals↗
PubMed1999

Seafood-associated disease outbreaks in New York, 1980-1994.

BACKGROUND: Seafood-associated disease outbreaks in New York were examined to describe their epidemiology and to identify areas for prevention and control efforts. METHODS: We reviewed reports submitted to the New York State Department of Health (NYSDOH) of seafood-associated outbreaks occurring from January 1, 1980, through December 31, 1994. RESULTS: During 1980-1994, 339 seafood-associated outbreaks were reported, resulting in 3959 illnesses, 76 hospitalizations, and 4 deaths. During this period, seafood-associated outbreaks accounted for 19% of all reported foodborne outbreaks and 10% of foodborne illnesses. Shellfish, the most frequently implicated seafood item, accounted for 64% of seafood outbreaks, followed by finfish (31% of outbreaks). Of the 148 seafood-associated outbreaks with a confirmed etiologic agent, Norwalk virus and scombrotoxin were the most frequently identified agents: Norwalk virus accounted for 42% of outbreaks and 42% of illnesses, and scombrotoxin accounted for 44% of outbreaks and 19% of illnesses. Three of the 4 seafood-associated deaths were caused by Clostridium botulinum; the remaining death was caused by Vibrio vulnificus. CONCLUSIONS: Reducing the number of seafood outbreaks will require continued and coordinated efforts by many different agencies, including those involved with water quality; disease surveillance; consumer education; and seafood harvesting, processing, and marketing. New York's foodborne disease surveillance data highlight potential areas on which to focus prevention efforts, including: (1) commodities and associated pathogens causing the largest number of seafood-associated outbreaks and illnesses, namely shellfish-associated viral gastroenteritis and finfish-associated scombroid fish poisoning, and (2) venues at which seafood were most frequently consumed in reported outbreaks, such as commercial food establishments and catered events.

Disease Outbreaks↗
PubMed1998

Human granulocytic ehrlichiosis in New York.

BACKGROUND: Human granulocytic ehrlichiosis (HGE), a potentially fatal tick-borne disease, was first described in the upper Midwest in 1994. Following reports of suspected cases of ehrlichiosis from New York physicians, descriptive and case-control studies were conducted to characterize the epidemiology and risk factors for HGE in New York residents. METHODS: Descriptive data were gathered from surveillance and laboratory reports and hospital records. A confirmed case was defined as either (1) a 4-fold change in total antibody titer to Ehrlichia equi by indirect immunofluorescence or (2) a polymerase chain reaction assay positive for Ehrlichia phagocytophila/E equi group DNA. A probable case was defined as an acute febrile illness and either (1) a single E equi titer greater than or equal to 80 or (2) morulae on a peripheral blood smear. The case-control study included patients with confirmed HGE 18 years of age or older with the onset of disease in 1995 and 2 to 3 neighborhood-matched controls. RESULTS: During 1994 and 1995, the New York State Department of Health, Albany, received reports of 241 residents who were tested for HGE; 30 met the confirmed case definition and 34 met the probable case definition. The median age of patients was 46 years (age range, 9-90 years), 35 (55%) were male, and 25 (45%) were hospitalized. Fever, headache, malaise, and myalgia were the most frequently reported symptoms. Fifty-six (88%) of the 64 patients resided in areas in which Lyme disease is hyperendemic. In the case-control analysis, cases were more likely than controls to have sustained a tick bite during 1995 (matched odds ratio, 5.0; 95% confidence interval, 0.9-49.8). Cases and controls did not differ by occupational exposure to ticks, underlying chronic diseases, or measures taken to prevent tick bites. CONCLUSIONS: This study, which, to our knowledge, is the first population-based study of HGE, demonstrates the recent recognition of HGE in the state of New York. Control measures should be integrated with those for Lyme disease and should focus on minimizing contact with ticks and obtaining early treatment for infection.

Adolescent↗
PubMed1998

Ceratobium mosaic potyvirus: another virus from orchids.

A potyvirus, which we call ceratobium mosaic virus, has been detected in about one third of more than 100 plants representing c. 33 orchid genera in two collections in Australia. It was detected using RT-PCR with redundant primers that are Potyviridae-specific and have additional sequences corresponding to either the SP6 or T7 bacteriophage promoters at their 5'-termini. Thus the nucleotide sequence of the resulting PCR fragments, consisting of about 1.7 kb of the 3' portion of the viral genome, could be determined directly. Viral sequences obtained from five infected orchids indicate that they contained different isolates of a single potyvirus species most closely related to the bean common mosaic group of potyviruses, but clearly distinct from all whose virion protein genes have been reported to the international gene sequence databases.

Amino Acid Sequence↗
PubMed1990

Effects of respiratory activity on starvation survival of marine vibrios.

The marine bacterium Vibrio fluvialis NCTC11328 responded to nutrient depletion by a reduction in cell volume, and this was prevented by conditions that eliminated respiration as a source of energy. Addition of the protonophore, CCCP, removal of oxygen and introduction of mutations leading to defects of the respiratory chain prevented size reduction during periods of nutrient limitation. Further, survival of the wild-type strain during starvation was reduced under anaerobic conditions and survival of respiratory mutants under aerobic conditions was reduced compared with that of the parent strain. Removal by mutation of the respiratory Na+ pump from Vibrio alginolyticus did not inhibit size reduction or lead to reduced viability in starved cultures.

Aerobiosis↗
PubMed1985

Studies on the accumulation of putrescine and spermidine in Escherichia coli.

The rate of accumulation of the polyamines spermidine and putrescine by E. coli depended on growth rate. Spermidine accumulation was faster in chemostat cultures with high dilution rates than in those with low dilution rates and was slower in bacteria that had been grown for several generations with either putrescine or spermidine, suggesting that the spermidine-uptake system was repressed by exogenous polyamines. The uptake of spermidine required metabolic energy. Thus accumulation occurred in an energy-starved unc strain only upon addition of glucose (or D-lactate to a smaller extent). With glucose present accumulation occurred in an unc, frd strain under anaerobic conditions, suggesting that ATP drives uptake. However, accumulation was generally sensitive to carbonylcyanide m-chlorophenylhydrazone (CCCP), indicating that the proton motive force was involved in uptake. Unlike spermidine, putrescine accumulation was faster in slow-growing than in fast-growing cultures. This may have been due to greater efflux of putrescine at faster growth rates. Accumulation of putrescine was faster following prolonged growth with either putrescine or spermidine, suggesting induction of the putrescine-uptake system by exogenous polyamines. Like spermidine accumulation, putrescine accumulation required metabolic energy. Accumulation was insensitive to CCCP and occurred only when glucose was added to energy-starved unc bacteria, suggesting that high-energy bonds may drive the uptake of putrescine.

Biological Transport↗
PubMed1985

Respiration rate, growth rate and the accumulation of streptomycin in Escherichia coli.

Using chemostat cultures of Escherichia coli it was possible to vary respiration rates while maintaining a constant growth rate. This allowed the effect of variations in respiration rates on the accumulation of streptomycin to be studied in cultures at constant growth rates. At a particular dilution rate cultures exhibited higher respiration rates when phosphate limited growth than when carbon limited growth. A ubiquinone-deficient strain had a lower rate of respiration at a particular dilution rate than a related ubiquinone-sufficient strain. In spite of these differences in respiratory activity, the accumulation of streptomycin was identical in carbon- and in phosphate-limited chemostat cultures of ubiquinone-deficient and ubiquinone-sufficient strains. Moreover, accumulation of streptomycin in an anaerobic chemostat culture occurred at the same rate as that in an aerobic chemostat. There was however a lag of 1.5 h before accumulation commenced in the anaerobic culture, a feature that was not apparent in the aerobic culture. These results indicate that the lower rates of respiration in slow-growing bacteria are not responsible for the decreased accumulation of streptomycin in slow-growing compared to fast-growing cultures. Moreover, it seems unlikely that quinones are involved directly (e.g. as carriers) in streptomycin accumulation, since removal of 90% of cellular ubiquinone, or replacement of ubiquinone with a structural analogue, did not affect accumulation as long as mutant and parent cultures grew at the same rate.

Anaerobiosis↗
PubMed1984

Amplification and purification of plasmid-encoded thioredoxin from Escherichia coli K12.

The thioredoxin gene (trxA) from Escherichia coli K12 has been cloned on a 3-kilobase pair PvuII fragment in a derivative of pBR325 (pBHK8). Thioredoxin protein production was amplified 150-200-fold in a strain containing pBHK8 (SK3981), with the greatest increase/cell observed after cultures reached stationary phase. A simple purification procedure, involving DEAE and AcA-54 column chromatography, yielded homogeneous protein with approximately 70% yield. The high amplification of thioredoxin in these cells (i.e. 10(6) copies/cell representing 40% of total cell protein) approaches the maximum yields seen in genetically constructed cloning vehicles (Bernard, H.U., and Helinski, D.R. (1980) in Genetic Engineering (Setlow, J. K., and Hollaender, A., eds) Vol. 2, pp. 133-167, Plenum Press, New York). This tremendous overproduction of thioredoxin protein is attributed to the high plasmid copy number observed in SK3981 (1700/cell). These results suggest a role for thioredoxin in plasmid DNA replication.

Bacterial Proteins↗
PubMed1984

Nucleotide sequence of the thioredoxin gene from Escherichia coli.

The nucleotide sequence of the thioredoxin gene from Escherichia coli was determined. The structural gene was identified on a cloned 3-kb PvuII fragment by hybridization with a synthetic oligodeoxyribonucleotide corresponding to a part of the amino acid sequence of thioredoxin. Restriction-enzyme fragments were used as templates in the dideoxy sequence method, directly and after subcloning into M13mp8. A segment of 450 nucleotides was determined using both strands, alternatively, without extensive overlaps. The sequence contains the thioredoxin coding region, a potential ribosome-binding site, and a putative promotor region. The predicted amino acid sequence differs by two inversions from the previously given thioredoxin sequence. The revised sequence is presented and the results further show that thioredoxins from E. coli B and K12 are identical.

Amino Acid Sequence↗
PubMed1984

Genetic and physical analysis of the thioredoxin (trxA) gene of Escherichia coli K-12.

The trxA gene of Escherichia coli K-12 has been cloned into multicopy plasmids on DNA fragments of varying sizes. The smallest of these was a 1-kb fragment resulting from partial digestion with Sau3A (pBHK10). The complete nucleotide sequence of the trxA gene and its promoter was determined. Comparison of the DNA sequence with the published amino acid sequence revealed the inversion of two amino acid pairs and the possibility of a leader peptide 18 amino acids in length. Three-factor P1 transductional crosses and physical mapping experiments have determined a map order of ilv-trxA-uvrD-corA-metE.

Bacterial Proteins↗
PubMed1984

Effect of growth rate on streptomycin accumulation by Escherichia coli and Bacillus megaterium.

The rate of accumulation of streptomycin by streptomycin-sensitive strains of Escherichia coli and Bacillus megaterium, grown in chemostats, was related to the growth rate prior to addition of the antibiotic. For E. coli the length of the lag period that preceded accumulation was also growth rate-dependent. Thus faster growing cultures accumulated streptomycin more rapidly and with a shorter lag than slower growing cultures. The rate of efflux of streptomycin from bacteria that had accumulated streptomycin was not greatly influenced by growth rates of the cultures. At a particular growth rate, accumulation of streptomycin was found to be faster at higher concentrations of the antibiotic. Rapid accumulation of streptomycin was not observed with continuous cultures of a streptomycin-resistant strain of E. coli. Accumulation of streptomycin was abolished when growth was inhibited by either terminating the flow of fresh medium to a chemostat or by adding inhibitors that block protein synthesis. These results suggest that the rate of accumulation of streptomycin is related to the concentration of streptomycin-sensitive ribosomes that are actively engaged in protein synthesis within the bacterial cells.

Bacillus megaterium↗
PubMed1981

Characterization of a respiratory mutant of Escherichia coli with reduced uptake of aminoglycoside antibiotics.

A strain of Escherichia coli (NSW77) which is partially resistant to streptomycin was isolated by selecting for growth on plates supplemented with 12.5 micrograms/ml streptomycin, a concentration which completely inhibits growth of wild-type strains. The low-level resistance of the mutant appears to result from a reduced ability to accumulate streptomycin intracellularly. In addition, the mutant strain is unable to use succinate for growth because of a defective respiratory chain. Thus, membranes of the mutant strain were found to have approximately half the NADH and D-lactate oxidase activity of the parent strain. Moreover, membranes of the mutant were found to contain demethyl-menaquinone and, in place of ubiquinone, a structural analogue, 2-octaprenyl-3-methyl-6-methoxy-1,4 benzoquinone. The mutation responsible for both the Suc-phenotype and partial resistance to streptomycin was found to be located near minute 15 on the bacterial chromosome. Both the biochemical and genetic evidence suggests the the mutation in strain NSW77 resides in the ubi F gene. Another previously characterized ubi F strain was also found to have a reduced capacity to take up an aminoglycoside antibiotic (gentamicin). These results suggest that the respiratory defects in ubi F strains are responsible for the reduced capacity of such strains to accumulate aminoglycosides.

Biological Transport↗
PubMed1979

Isolation of mutants of Escherichia coli uncoupled in oxidative phosphorylation using hypersensitivity to streptomycin.

Mutants of Escherichia coli, harbouring the uncA401 or uncB402 alleles, were found to take up streptomycin more rapidly than the coupled parent strains. The increased rate of uptake results in greater sensitivity of the uncoupled strains, compared to the parent strains, to low concentrations of streptomycin. Studies with unc+ revertants showed that hypersensitivity to streptomycin is attributable to the mutation causing uncoupling. The uptake of streptomycin in an unc- strain is abolished by addition of the chemical uncoupler carbonylcyanide m-chlorophenylhydrazone. The phenotype of hypersensitivity to streptomycin can be used as a selection procedure for the isolation of uncoupled strains. In an experiment reported here, nine out of 12 strains isolated as being sensitive to streptomycin (at 2.5 micrograms/ml), were found to be unable to grow on succinate as a sole source of carbon. Five of the nine Suc- strains were found to be uncoupled in oxidative phosphorylation, and two of the five uncoupled strains lacked Mg2+-ATPase activity. The mutations causing uncoupling were cotransducible with the ilv genes.

Escherichia coli↗
PubMed1978

Long-term ureteral replacement prosthesis.

A silicone rubber tube with bonded Dacron felt cuffs have been implanted in dogs as a ureteral replacement prosthesis. A one-way valve has also been developed to prevent reflux so the prosthesis may be put into the bladder. The prosthesis has been implanted for periods up to nine months. Although there are some problems associated with the prosthesis, most animals have maintained a normal serum creatinine, sterile urine, and a normal excretory urogram.

Animals↗
PubMed1978

Results of large-caliber internal urethrotomy.

Thirty-five patients undergoing internal urethrotomy for urethral stricture disease were reviewed retrospectively. Eight patients had conventional urethrotomies (less than 36 F) while 27 had large-caliber urethrotomies (greater than 40 F). Large-caliber urethrotomy tends to give longer symptom-free intervals immediately postoperatively, but long-term results show little difference between the two groups.

Adult↗