Bacteria were concentrated 500-fold from 20-liter water samples collected from 67 different lakes and rivers in the United States. The data suggest that Legionella pneumophila is part of the natural aquatic environment and that the bacterium is capable of surviving extreme ranges of environmental conditions. The data further demonstrate the effectiveness of the direct fluorescent-antibody technique for detecting L. pneumophila in natural aquatic systems. Smears of the concentrated samples were screened microscopically for serogroups of L. pneumophila by the direct fluorescent-antibody technique. Virtually all of the 793 samples were found to be positive by this method. The 318 samples containing the largest numbers of positive bacteria which were morphologically consistent with L. pneumophila were injected into guinea pigs for attempted isolations. Isolates were obtained from habitats with a wide range ofphysical, chemical, and biological parameters. Samples collected monthly from a thermally altered lake and injected into guinea pigs demonstrated a seasonality of infection, with the highest frequency of infection occurring during the summer months.

Legionella pneumophila (Legionnaires disease bacterium) of serogroup 1 was isolated from an algal-bacterial mat community growing at 450C in a man-made thermal effluent. This isolate was grown in mineral salts medium at 450C in association with the blue-green alga (cyanobacterium) Fischerella sp. over a pH range of 6.9 to 7.6. L. pneumophila was apparently using algal extracellular products as its carbon and energy sources. These observations indicate that the temperature, pH, and nutritional requirements of L. pneumophila are not as stringent as those previously observed when cultured on complex media. This association between L. pneumophila and certain blue-green algae suggests an explanation for the apparent widespread distribution of the bacterium in nature.

Study Design. Online survey. Objective. This study seeks to quantify delays faced, determine demographics of patients most likely to face delay, and determine whether delays affect surgical management and outcomes. Summary of Background Data. Patients report significant delays in diagnosis of degenerative cervical myelopathy (DCM). Methods. Seven hundred seventy-eighty patients with self-reported DCM recruited via online survey hosted on myelopathy.org. A cumulative odds ordinal logistic regression was run to determine the effects of demographic (sex, country of residence, ethnicity, household income, and educational status) on the delay in diagnosis of DCM. Chi-square tests of homogeneity were run to determine the effects of delayed diagnosis on functional outcomes (patient-derived modified Japanese Orthopaedic Association disability score, support dependence, and employment status) and surgical management (anterior/posterior approach, single-/multilevel surgery). A Kruskal-Wallis H test was used to determine whether delayed diagnosis affected the number of operations undergone. Results. The average delay in diagnosis faced was “1–2 years." Greater delays in diagnosis were faced by Black or African American patients (P = 0.010). Delayed diagnosis was predictive of greater disability as assessed by patient-derived modified Japanese Orthopaedic Association score (P = 0.001), support dependence (P = 0.040), and employment status (P < 0.0005). Delayed diagnosis did not affect the likelihood of surgery, the number of operations undergone or perioperative characteristics. Conclusion. Patients continue to face significant delays in diagnosis of DCM. Ethnicity significantly influences length of delay experienced. Longer delays do not appear to affect surgical management but are associated with greater disability. Level of Evidence: 3

The effects of temperature on protein synthesis by Escherichia coli, a mesophile, and Pseudomonas fluorescens, a psychrotroph, were investigated by using whole-cell and cell extract preparations. After shifts to 5°C, protein was synthesized at a slowly decreasing rate for 1 h by both organisms, after which P. fluorescens synthesized protein at a new rate corresponding to its 5°C growth rate, in contrast to E. coli which did not synthesize protein at a measurable rate. In vitro protein-synthesizing systems using MS-2 RNA, endogenous mRNA, and purified polysomes were utilized to investigate initiation of translation at 5°C. In these systems, P. fluorescens cell extracts synthesized protein at linear rates for up to 2 h at 50C, whereas E. coli cell extracts synthesized protein for only 25 min

The effects of high hydrostatic pressures on protein synthesis by whole cells and cell free preparations of Escherichia coli, Pseudomonas fluorescens, and Pseudomonas bathycetes were determined. Actively growing cells of P. bathycetes and P. fluorescens were less sensitive than were E. coli cells. Protein synthesis by cell free preparations of E. coli and P. fluorescens showed the same extent of inhibition as their respective whole cell preparations, whereas cell free preparations of P. bathycetes showed a marked increase in pressure sensitivity over whole cells. Protein synthesis by hybrid protein synthesizing cell free preparations (the ribosomes from one organism and the S-100 supernatant fraction from another) demonstrated that response to high pressure is dependent on the source of the ribosome employed. A hybrid system containing E. coli ribosomes and P. fluorescens S-100 shows the same sensitivity to pressure as a homologous E. coli system, whereas a hybrid containing P. fluorescens ribosomes and E. coli S-100 shows the greater pressure tolerance characteristic of the P. fluorescens homologous system.