Photosynthetic cyanobacteria, heterotrophic bacteria, free-living amoebae, and ciliated protozoa may support growth of Legionella pneumophila. Studies were done with two tap water cultures (WS1 and WS2) containing L. pneumophila and associated microbiota to characterize growth-supporting activity and assess the relative importance of the microbiota in supporting multiplication of L. pneumophila. The water cultures were incubated in the dark at 35°C. The growth-supporting factor(s) was separated from each culture by filtration through 1-jim-pore-size membrane filters. The retentate was then suspended in sterile tap water. Multiplication of L. pneumophila occurred when both the retentate suspension and the filtrate from either culture were inoculated into sterile tap water. L. pneumophila did not multiply in tap water inoculated with only the filtrate, even though filtration did not reduce the concentration of L. pneumophila or heterotrophic bacteria in either culture. Growth-supporting activity of the retentate suspension from WS1 was inactivated at 60°C but unaffected at 0, 25, and 45°C after 30-min incubations. Filtration experiments indicated that the growthsupporting factor(s) in WS1 was 2 to 5 jum in diameter. Ciliated protozoa were not detected in either culture. Hartmannellid amoebae were conclusively demonstrated in WS2 but not in WS1. L. pneumophila multiplied in tap water inoculated with the amoebae (103/ml) and the 1-jim filtrate of WS2. No multiplication occurred in tap water inoculated with the filtrate only. Growth-supporting activity for L. pneumophila may be present in plumbing systems; hartmannellid amoebae appear to be important determinants of multiplication of L. pneumophila in some tap water cultures.

\s=b\A qualitative and quantitative analysis of the tonsillar surface and core of children with recurrent streptococcal tonsillitis and children with obstructive tonsillar hypertrophy was performed. No qualitative difference was found within the two population groups. Haemophilus influenzae and Bacteroides melaninogenicus were the most prevalent \g=b\-lactamase\p=n-\ producing isolates in both groups. Staphylococcus aureus had the highest rate of \g=b\-lactamaseproduction on the tonsillar surface of children with recurrent tonsillitis, while Streptococcus pyogenes was more prevalent in the tonsillar surface cultures of children with obstructive tonsillar hypertrophy. The bacterial density was high but not significantly different in both groups of children. The similar microbial composition and density of both groups and the higher rate of S pyogenes recovery may signify a subclinical disease or normal flora in children with obstructive tonsillar hypertrophy.(Arch Otolaryngol Head Neck Surg.

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Studies were conducted to investigate the survival and multiplication of Legionella spp. in public drinking water supplies. An attempt was made, over a period of several years, to isolate legionellae from a municipal system. Sampling sites included the river water supply, treatment plant, finished water reservoir system, mains, and distribution taps. Despite the use of several isolation techniques, Legionella spp. could not be detected in any of the samples other than those collected from the river. It was hypothesized that this was due to the maintenance of a chlorine residual throughout this system. To investigate the potential for Legionella growth, additional water samples, collected from throughout the system, were dechlorinated, pasteurized, and inoculated with Legionella pneumophila. Subsequent growth indicated that many of these samples, especially those collected from areas affected by an accumulation of algal materials, exhibited a much greater ability to support LegioneUa multiplication than did river water prior to treatment. Chemical analyses were also performed on these samples. Correlation of chemical data and experimental growth results indicated that the chemical environment significantly affects the ability of the water to support multiplication, with turbidity, organic carbon, and certain metals being of particular importance. These studies indicate that the potential exists for Legionella growth within municipal systems and support the hypothesis that public water supplies may contaminate the plumbing systems of hospitals and other large buildings. The results also suggest that useful methods to control this contamination include adequate treatment plant filtration, maintenance of a chlorine residual throughout the treatment and distribution network, and effective covering of open reservoirs.

Lipopolysaccharides (LPS) were isolated from four species of cyanobacteria (Anabaena flos-aquae UTEX 1444. A. cylindrica, Oscillatoria tenuis, and O. brevis) frequently occurring in drinking-water supplies. The cyanobacterial LPS contained glucose, xylose, mannose, and rhamnose, but differed from the LPS derived from most gram-negative bacteria because of the variable presence of 2-keto-3-deoxyoctonate, heptose, galactose, and glucosamine. Cyanobacterial lipid A is characterized by long-chain saturated an unsaturated fatty acids and hydroxy fatty acids which show great diversity. Unlike lipid A from heterotrophic gram-negative bacteria, lipid A from cyanobacteria usually lacks phosphates. The detection of distinct O-antigen chemotypes indicates that LPS may be used for taxonomic classification. Isolated cyanobacterial LPS always induced Limulus amoebocyte lysate gelation. A. flos-aquae LPS gave a positive Schwartzman reaction. Endotoxins from A. cylindrica and O. brevis were toxic to mice when injected intraperitoneally. The cyanobacterial endotoxins showed generally lower biological activity than did LPS derived from common heterotrophic gram-negative bacteria. Nevertheless, cyanobacteria in algal blooms may be a significant source of endotoxins in water supplies.