Potable water and nosocomial Legionnaires' disease--check water from all rooms in which patient has stayed.

We studied 7 patients with nosocomial Legionnaires' disease to determine the relationship between isolates of Legionella pneumophila recovered from potable water and those recovered from patients. Potable water was cultured from all rooms in which patients had stayed prior to the diagnosis of Legionnaires' disease. The 38 isolates of L.

Genomic stability of Legionella pneumophila isolates recovered from two cardiac transplant patients with nosocomial Legionnaires' disease.

Pulsed-field gel electrophoresis revealed that multiple consecutive isolates of Legionella pneumophila from two cardiac transplant patients remained genomically stable, despite exposure to host defenses and antimicrobial agents.

Discriminatory genomic fingerprinting of Legionella pneumophila by pulsed-field electrophoresis.

Eight strains of Legionella pneumophila were used to optimize cleavage of DNA with BssHII, SalI, or SpeI and separation by pulsed-field electrophoresis. Isolates from a community outbreak involving a contaminated hot tub were genomically identical. Cleavage patterns were distinctly different for unrelated environmental and nosocomial strains from a single hospital.

Linkage analysis of geographic and clinical clusters in Pseudomonas cepacia infections by multilocus enzyme electrophoresis and ribotyping.

Multilocus enzyme electrophoresis and ribotyping were used to characterize 83 strains of Pseudomonas cepacia, mostly isolated from cystic fibrosis (CF) patients, although a number of isolates from non-CF nosocomial infections and reference environmental strains were represented. Twenty enzyme electrophoretic types (ETs) were determined; of these, one clone (ET12) was associated with six of nine ribotypes (RTs) said to be geographically representative of the United Kingdom and all of the Ontario (Canada) isolates from CF patients. This clone was not associated with nosocomial infections or environmental strains and was never found in CF isolates from British Columbia or Nova Scotia, Canada, or a center in the eastern United States.

Genomic fingerprinting of Neisseria meningitidis associated with group C meningococcal disease in Canada.

A single electrophoretic type (ET15) of Neisseria meningitidis has been associated with an increased incidence of group C meningococcal disease in Canada. Genomic fingerprinting through pulsed-field gel electrophoresis of chromosomal DNA was used to characterize the clonal relationship among meningococcal isolates of different electrophoretic types and among isolates within ET15. The genomic fingerprints of the ET15 isolates, while similar as a group, were sufficiently distinct to confirm linkage for four pairs of strains from focal outbreaks and differed markedly from those of the other common electrophoretic types, ET5, ET9, and ET21.

Psychosocial correlates of drug use among Latino youth leading autonomous lives.

Drug use and psychosocial profile of young Central American immigrants in Washington, D.C., were compared to the National Household Survey of Latinos.

Streptococcal erythrogenic toxin genes: detection by polymerase chain reaction and association with disease in strains isolated in Canada from 1940 to 1991.

The presence of genes encoding pyrogenic exotoxins type A (speA), B (speB), and C (speC) and streptolysin O (slo) was determined by the polymerase chain reaction (PCR) to target specific sequences in 152 strains of group A streptococci. These included reference strains, representative M and T type strains, and strains associated with scarlet fever and pharyngitis collected between 1940 to 1991 and included strains from patients with severe invasive streptococcal infections. PCR amplicons were detected by agarose gel electrophoresis, and specificity was established by restriction fragment analysis.

Comparison of polymerase chain reaction and chlamydiazyme for the detection of Chlamydia trachomatis in clinical specimens.

An attempt was made to improve laboratory diagnosis of Chlamydia trachomatis and to validate the Abbott Chlamydiazyme confirmatory test used at present by comparing the polymerase chain reaction (PCR) procedure and the Abbott enzyme immunoassay. A total of 275 routine clinical specimens representing a range of positive and negative findings by Chlamydiazyme were retested by PCR. The procedures demonstrated 99% concordance for specimens with optical density (OD) readings above the Chlamydiazyme cut-off of 0.

Patterns of contamination by organochlorines and mercury in the eggs of two river passerines in Britain and Ireland with reference to individual PCB congeners.

Unhatched eggs were collected in 1988 and 1990 from nests of the Eurasian Dipper Cinclus cinclus and the Grey Wagtail Motacilla cinerea in Wales, eastern Scotland and south-western Ireland. Mercury concentrations in Dipper eggs (geometric means 0.45-0.

A review of the likely causal pathways relating the reduced density of breeding dippers Cinclus cinclus to the acidification of upland streams.

Previous work has shown that the breeding density of a bird characteristic of upland streams, the dipper Cinclus cinclus, is markedly reduced at low pH in both Wales and Scotland. Populations also declined when streams became more acidic. Evidence of causal explanation for these relationships is that: (1) Food quantity is reduced in acidic streams, and important prey, including those rich in calcium, are scarce; (2) Blood chemistry in pre-breeding birds differs between acid and circumneutral streams, with plasma calcium reduced in those breeding at low pH.

Detection of genes coding for listeriolysin and Listeria monocytogenes antigen A (ImaA) in Listeria spp. by the polymerase chain reaction.

Two pairs of synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) protocol to detect targeted sequences in genes coding for listeriolysin O and Listeria monocytogenes antigen A (ImaA). Strains of Listeria spp. used in this study were isolated from clinical specimens, contaminated foods, and environmental sources.

Amplification by the polymerase chain reaction of a specific target sequence in the gene coding for Escherichia coli verotoxin (VTe variant).

Synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) protocol to target a specific sequence in the gene coding for the A subunit of Escherichia coli verotoxin (VTe-variant, VTev). This PCR protocol permits the VTe-variant target sequence to be distinguished from closely related sequences in the same coding regions for type 1, type 2, and type 2 variant E. coli verotoxins.

Making it on the streets in Bogotá: a psychosocial study of street youth.

In this study, we investigated the perceptions of the life situations, experiences, psychosocial characteristics, and environments of 94 street youth in Bogotá, Columbia. We outlined the implications of our results for developmental theory, psychosocial competence theory, future research, public policy formation, program development, and direct intervention.

Identification of verotoxin type 2 variant B subunit genes in Escherichia coli by the polymerase chain reaction and restriction fragment length polymorphism analysis.

A set of synthetic oligonucleotide primers was designed for use in a polymerase chain reaction protocol to specifically detect the B subunit genes in vtx2ha and vtx2hb, which code for the production of the VT2 (Shiga-like toxin II) variant cytotoxins VT2v-a and VT2v-b, respectively. An additional set of primers amplified a fragment common to the B subunits of the VT2 and the VT2 variant genes. Subsequent restriction endonuclease digestion of this amplicon permitted prediction of specific VT2 and variant genotypes on the basis of predetermined restriction fragment length polymorphisms.

Detection of genes for enterotoxins, exfoliative toxins, and toxic shock syndrome toxin 1 in Staphylococcus aureus by the polymerase chain reaction.

Eight pairs of synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) protocol to detect genes for staphylococcal enterotoxins A to E, exfoliative toxins A and B, and toxic shock syndrome toxin 1 in Staphylococcus aureus strains isolated from clinical specimens and contaminated foods. Primers were targeted to internal regions of the toxin genes, and amplification fragments were detected after the PCR by agarose gel electrophoresis. Unequivocal discrimination of toxin genes was obtained by the PCR by using nucleic acids extracted from 88 strains of S.

The ecology of dippers Cinclus cinclus (L.) in relation to stream acidity in upland Wales: time-activity budgets and energy expenditure.

The time-activity budget and energy expenditure of a riverine bird, the dipper Cinclus cinclus, was studied from March 1988 to July 1989, across a range of streams of contrasting acidity in upland Wales. Differences in time-activity budgets of birds on acidic and circumneutral streams were consistent with documented differences in prey availability and diet. Birds spent a significantly greater proportion of their active day foraging, swimming and flying, and less time resting, on acidic streams.

Detection of the aerolysin gene in Aeromonas hydrophila by the polymerase chain reaction.

Synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) technique to detect the gene for aerolysin in strains of Aeromonas hydrophila and to screen for identical genes in A. caviae, A. sobria, and A.

Differentiation of Shiga toxin and Vero cytotoxin type 1 genes by polymerase chain reaction.

Two sets of synthetic oligonucleotide primers were used in a polymerase chain reaction technique to distinguish genes for Shiga toxin in Shigella dysenteriae 1 and type 1 Vero cytotoxin (VT1) in Escherichia coli. VT1a and VT1b primers directed at a common 130-base-pair (bp) fragment of the stx and sltI genes detected template nucleic acid in both Shiga toxin-positive S. dysenteriae 1 and VT1-producing E.