Profile of urinary incontinent elderly in long-term care institutions.

This article presents a profile of incontinent elderly in long-term care institutions. One hundred thirty-three frail elderly women were recruited from seven nursing homes in central Pennsylvania for a three-year clinical trial to test the effectiveness of a behavioral therapy on urinary incontinence. All of the patients had more than one medical diagnosis. Eighty percent had cardiorespiratory conditions; the most prevalent diagnoses were cardiovascular diseases. Eighty percent had one or more neurological diseases, including "organic brain syndrome" (47%) and senile dementia (30%); 44% had arthritis/rheumatism. Half of the patients showed severe cognitive impairment; only 12% showed no cognitive impairment. Sixty-three percent were totally dependent; 68% used wheelchairs, 61% were chairbound; 50% had impairments in vision, one-third in hearing, and 14% in speech. Normal bladder capacity, absence of detrusor instability, and satisfactory bladder emptying, as evidenced by low residual urines, was found in 41% of the patients, suggesting that incontinence in this elderly group may not be a primary bladder problem, but rather that mental and physical disabilities may be a more important underlying cause of incontinence in these patients. An important finding in this study is that 34% of the patients had detrusor instability. It is theoretically possible that pharmacologic therapy with anticholinergic agents or imipramine could improve incontinence in this group. Five percent were found to have large residual urine volumes in association with high-capacity bladders suggesting overflow incontinence as the cause of their daily leakage. Pelvic relaxation and stress leakage was far less common in this elderly group of nursing home patients than in young and middle-aged women.

Simple urodynamic evaluation of incontinent elderly female nursing home patients. A descriptive analysis.

We present a descriptive analysis of the functional, mental, and urodynamic status of a population of incontinent elderly female nursing home patients. One hundred fifty-five intermediate care female patients with a mean age of 85.5 years were identified as being incontinent of urine at least once daily. After urologic evaluation, each patient was classified into one of four categories: incontinence with normal cystometrogram 68 (44%), detrusor instability (DI) 52 (34%), stress incontinence (SI) 27 (17%), or overflow incontinence (OI) 7 (4%). Thirteen weeks later, patients were again studied using simple water cystometry. At follow-up evaluation, 45 patients (33%) had urodynamic findings which differed from the initial evaluation. Of these women, 10 with DI, 12 with SI, and 2 with OI were found to have normal cystometric parameters at the time of follow-up study, while 19 (14%) who initially had normal cystometric findings had evidence of DI (11) or SI (3). Strong correlation between urinary incontinence in patients with normal cystometric findings and moderate to severe cognitive impairment was present. Simple urodynamic evaluation did identify patients with SI and OI who might benefit from specific therapy. Urodynamic evaluation of incontinent elderly female nursing home patients is indicated and may provide direction for planning treatment strategies.

A hot water supply as the source of Legionella pneumophila in incubators of a neonatology unit.

The humidification trays of five of seven incubators in a neonatology unit of a hospital were found to be colonized with Legionella pneumophila, serogroup 1. Bacteriological analysis of the water in the humidification trays showed very large numbers of heterotrophic bacteria, one of which also contained Pseudomonas aeruginosa. Two hot water systems supply the neonatology unit, either of which is used to add water to the humidification trays; one system (A) is maintained at about 60 degrees C, while the other system (B) is maintained at 45 degrees C. The latter was also found to be colonized with L. pneumophila, Sg1. Monoclonal antibody (Mab) subgrouping of the isolates, indicated that system B was the source of colonization of the humidification trays of the incubators.

Reducing the risk of Legionnaires' disease.

Many common aquatic bacteria like Legionella pneumophila are able to colonize man-made water systems. Poorly maintained systems or those that are seldom used provide ideal sites for growth and often also provide the means for aerosolizing the organism. Compounds leached from construction materials and the by-products of other organisms can be used as food by the Legionellaceae and can thus aid their growth. Keeping water systems clean and well serviced, keeping hot water at or above, and cold water below, recommended temperatures and additionally in cooling towers maintaining the required levels of biocide, will reduce or prevent the growth of legionellas. To be certain that the control measures are successful microbiological and chemical monitoring should be done. The results of this and the maintenance work undertaken should be kept in a log so that failures in treatment can be quickly seen and remedial action taken before any risk of infection arises. Adhering to these simple guidelines will go a long way to removing the risk of infection and will also provide systems that are more efficient and thus cheaper to run.

Monitoring of psychotropic drug prescribing in general practice.

Over 1000 repeat prescriptions of psychotropic drugs, which were given without the doctor seeing the patient, were analysed from a population of over 100 000 patients during a two-week period. The analysis showed that the longer repeat prescribing had taken place the older the patient was likely to be and the less closely were they monitored by their general practitioner.

Differences in aerosol survival between pathogenic and non-pathogenic strains of Legionella pneumophila serogroup 1.

A strain of Legionella pneumophila serogroup 1 known to be virulent for guinea-pigs was found to be least stable at a relative humidity (r.h.) of 60% when stored as a small particle aerosol. Three L. pneumophila serogroup 1 strains of different virulence for guinea-pigs were then tested at a r.h. of 60% at 20 degrees C. The most virulent strain was found to have the best survival and the avirulent strain was least stable. The strain of intermediate virulence did not survive as well as the virulent strain but was more stable than the avirulent strain. Strains of L. pneumophila serogroup epidemiologically associated with legionnaires' disease had better survival in small particle aerosols than strains which were not associated with disease. Subtyping with monoclonal antibodies also showed that the type more commonly associated with disease survived longer in aerosols than the other subtypes.

Distribution and persistence of Legionella in water systems.

The Legionellaceae are common aquatic organisms able to colonize man-made water systems. Inadequately maintained or seldom used systems provide ideal amplification sites, where the organisms grow and can be disseminated in aerosols. Legionellaceae can utilize, for growth, compounds leached from construction materials and the products of other organisms.

Isolation of Legionella pneumophila from water supplies: comparison of methods based on the guinea-pig and culture media.

The detection of Legionella pneumophila in water via guinea-pig intraperitoneal injection has been compared with direct isolation of these organisms on semiselective BCYE alpha media. Both techniques were of similar sensitivity, detecting as few as 10(2) L. pneumophila in 10 ml of water. However, at this concentration, detection using guinea-pig intraperitoneal injection was via the indirect parameters of antibody production and immunofluorescent microscopy. Isolation of L. pneumophila from guinea-pig tissue for further investigation required greater than 10(7) organisms injected and in this respect is relatively much less sensitive than direct isolation on semiselective BCYE alpha media. Since L. micdadei and L. longbeachae are inhibited by one of the selective supplements used, other supplements and techniques need to be developed in order to avoid possible inhibition of other Legionella species. This work is based on simulated water samples containing strains of L. pneumophila defined in terms of pneumonic Legionnaires' disease in the guinea-pig. As such, this work serves as a guide to technique and the need to test large numbers of naturally infected water samples in parallel by techniques outlined in this work is emphasized.

Treatment of water for aquatic bacterial growth studies.

The composition of a water is inextricably linked to its nutrient status and hence influences the behaviour of bacteria in artificial water systems. It has not yet been possible to devise a defined liquid medium representative of the complex composition of a treated water. Instead sterilized natural or distilled waters are used to study the growth or survival of aquatic bacteria in the laboratory. This has led to conflicting data and opposing opinions when the same water has proved toxic in some laboratory studies and growth-supporting in others. These differences may be explained by the variations in chemical compositions which occur when water is collected, transported and treated or stored in the laboratory. This study describes a simple, membrane filtration method of preparing a fresh sample of water collected from the environment or a building water system such that it is both sterile and chemically unaltered. The availability of such water may enhance understanding of the behaviour of bacteria in the aquatic environment.

A note on the temperature tolerance of Legionella.

A strain of Legionella pneumophila serogroup 1 isolated from the environment had a decimal reduction time in water at 50 degrees C (D50) of 111 min, a D54 of 27 min and a D58 of 6 min. There was little loss of viability at 46 degrees C. Other environmental organisms, a Pseudomonas sp., a Micrococcus sp. and a coliform survived less well at these temperatures. A species of Sarcina had a survival time greater than the L. pneumophila at all the temperatures tested. Other strains of legionellas were tested at 50 degrees C and decimal reduction times calculated. These ranged from 80 min for another strain of L. pneumophia serogroup 1 to 216 min for L. bozemannii . Legionella micdadei did not survive well at 50 degrees C.

A comparison of methods used to enumerate Escherichia coli in conventionally treated sewage sludge.

AIMS: This study examined the suitability of three analytical methods for isolating and enumerating Escherichia coli from conventionally treated sewage sludge. METHODS AND RESULTS: Crude sewage, mesophilic anaerobic digested (MAD) sludge, and final product sludge samples were taken from six sewage treatment works for analysis. Two of the three methods tested were membrane filtration techniques, utilizing chromogenic E. coli/coliform (CEC) media and membrane-lactose glucuronide agar (MLGA); the third method was a most probable number (MPN) technique utilizing Colilert in Quantitray 2000 (Idexx). The methods were evaluated for variation, consistency, false-positive and false-negative results, as well as method correlation. The methods gave good and consistent recovery of E. coli for a range of conventionally treated sewage matrices. All of the methods had a false-positive rate of <3%, although MLGA had a high false-negative rate (35.5%) compared with Colilert (3.81%) and the CEC method (6.75%). This resulted in slightly lower presumptive counts but comparable numbers of confirmed counts. CONCLUSIONS: The three detection methods tested, chromogenic, MLGA and Colilert gave comparable recoveries, and did not vary by greater than one order of magnitude (1 log). SIGNIFICANCE AND IMPACT OF THE STUDY: Forthcoming revisions to the Use of Sludge in Agriculture Regulations (1989) will categorize sewage sludge as untreated, conventionally treated or enhanced treated in accordance to microbiological standards. The standard will be based upon numbers of E. coli removed through the sludge treatment process and the numbers remaining in the final product. It is recommended that the Colilert 2000 (Idexx, Westbrook, Maine) and CEC methods would be equally suitable to assess the reduction of indigenous E. coli in conventionally treated sludges, and that MLGA be used with follow-up confirmatory testing.

A study of iron acquisition mechanisms of Legionella pneumophila grown in chemostat culture.

We recently demonstrated that the virulence of a clinical isolate of Legionella pneumophila is significantly attenuated when cultured in an iron-limited environment. In this study the influence of iron limitation on the expression of enzyme activities and iron-transport mechanisms was investigated. Expression of the important pathogenicity factor, the zinc metalloprotease, was reduced fivefold in response to iron limitation. Ferric citrate reductase activity was demonstrated in both iron-limited and replete cell fractions. Activity was located principally in the cytoplasm and periplasm, and was not enhanced by iron restriction. Optimum activity was observed with NADPH as reductant. Siderophores were not elaborated under these culture conditions. Iron-loaded transferrin enhanced the growth of steady-state, iron-limited cultures, demonstrating that transferrin represents a potentially important iron source for L. pneumophila in vivo. Although cell surface transferrin receptors were not detected, in vitro experiments demonstrated digestion of transferrin by the zinc metalloprotease activity of culture supernatants.

Influence of Plumbing Materials on Biofilm Formation and Growth of Legionella pneumophila in Potable Water Systems.

A two-stage chemostat model of a plumbing system was developed, with tap water as the sole nutrient source. The model system was populated with a naturally occurring inoculum derived from an outbreak of Legionnaires' disease and containing Legionella pneumophila along with associated bacteria and protozoa. The model system was used to develop biofilms on the surfaces of a range of eight plumbing materials under controlled, reproducible conditions. The materials varied in their abilities to support biofilm development and the growth of L. pneumophila. Elastomeric surfaces had the most abundant biofilms supporting the highest numbers of L. pneumophila CFU; this was attributed to the leaching of nutrients for bacterial growth from the materials. No direct relationship existed between total biofouling and the numbers of L. pneumophila CFU.

Further development of simple tests to differentiate the legionellas.

Current methods for the identification of the Legionellaceae to species level are suitable only for the specialist or research laboratory. As part of a continuing taxonomic study 42 simple biochemical tests were screened for their ability to differentiate species of Legionella. Only 23 of these were of practical use. These tests are able to differentiate 21 of 23 recognized species of Legionella and six new species. Phenotypic screening with these tests may prove useful to the routine microbiologist and be a viable alternative to identification techniques currently employed.

Experimental transmission of legionnaires' disease by exposure to aerosols of Legionella pneumophila.

Pyrexia and pneumonia developed in guinea-pigs after exposure to aerosols of Legionella pneumophila in a Henderson apparatus. Mortality was high 1-3 days after exposure. Histopathological changes were of an acute fibrinopurulent pneumonia, with widespread fibrin exudation and accumulation of neutrophils and macrophages in alveoli-lesions similar to those of legionella pneumonia in man. Rhesus monkeys given low doses of bacteria had slight fever and mild histological lesions in the lungs. Aerosol infection of these species offers suitable experimental models of legionnaires' disease.

Poly-3-hydroxybutyrate in Legionella pneumophila, an energy source for survival in low-nutrient environments.

Chloroform-soluble material was extracted from two strains of L. pneumophila serogroup 1 following growth in continuous culture. The purified material was identified as poly-3-hydroxybutyrate (PHB) by nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry. PHB yields of up to 16% of cell dry weight were extracted from culture samples. The PHB was located in electron-dense intracellular inclusions, which fluoresced bright yellow when stained with the lipophilic dye Nile red. A Nile red spectrofluorometric assay provided a more accurate and reliable determination of the PHB content. PHB accumulation increased threefold during iron-limited culture and was inversely related to the concentration of iron metabolized. Chemostat-grown cells survived in a culturable state for at least 600 days when incubated at 24 degreesC in a low-nutrient tap water environment. Nile red spectrofluorometry and flow cytometry demonstrated that PHB reserves were utilized during starvation. PHB utilization, as revealed by the decline in mean cellular fluorescence and cell complexity, correlated with loss of culturability. Fluorescence microscopy provided visual evidence of PHB utilization, with a marked reduction in the number of Nile red-stained granules during starvation. Heat shock treatment failed to resuscitate nonculturable cells. This study demonstrates that L. pneumophila accumulates significant intracellular reserves of PHB, which promote its long-term survival under conditions of starvation.

Influence of temperature and plumbing material selection on biofilm formation and growth of Legionella pneumophila in a model potable water system containing complex microbial flora.

Survival and growth of Legionella pneumophila in both biofilm and planktonic phases were determined with a two-stage model system. The model used filter-sterilized tap water as the sole source of nutrient to culture a naturally occurring mixed population of microorganisms including virulent L. pneumophila. At 20 degrees C, L. pneumophila accounted for a low proportion of biofilm flora on polybutylene and chlorinated polyvinyl chloride, but was absent from copper surfaces. The pathogen was most abundant on biofilms on plastics at 40 degrees C, where it accounted for up to 50% of the total biofilm flora. Copper surfaces were inhibitory to total biofouling and included only low numbers of L. pneumophila organisms. The pathogen was able to survive in biofilms on the surface of the plastic materials at 50 degrees C, but was absent from the copper surfaces at the same temperature. L. pneumophila could not be detected in the model system at 60 degrees C. In the presence of copper surfaces, biofilms forming on adjacent control glass surfaces were found to incorporate copper ions which subsequently inhibited colonization of their surfaces. This work suggests that the use of copper tubing in water systems may help to limit the colonization of water systems by L. pneumophila.

Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection.

Infection of guinea-pigs by intranasal (i.n.) instillation of 10(9) viable organisms of two newly isolated strains of Legionella pneumophila (74/81, serogroup 1; 166/81, serogroup 3) did not induce disease, but 10(4) organisms administered as a small particle aerosol (less than 5 microns diameter) produced a fatal widespread broncho-pneumonia within 3 days. Milder illness and less extensive bronchopneumonia were also produced in rhesus monkeys and marmosets by one of these two strains (74/81). Mice were resistant to induction of disease by aerosols of both these two strains, though organisms did persist in the lungs for at least 4 days. Both of these L. pneumophila strains were pathogenic for guinea-pigs by aerosol infection over a wide range of doses but the serogroup 1 type strain (NCTC 11192) was not. There was no mortality after infection of guinea-pigs by intranasal instillation of any of these strains but all proved to be fatal after intraperitoneal (i.p.) injection of large doses. Guinea-pigs, rhesus monkeys and marmosets exposed to aerosol infection with L. pneumophila provide relevant models for studying the pathogenesis of Legionnaires' disease.

Legionella pneumophila in aerosols from shower baths.

Routine examination of the water system in an establishment where showers were used by staff after work or leisure activities revealed the presence of Legionella pneumophila. Descaling and steaming cleared the system but six months later recolonization was found to have occurred. L. pneumophila was isolated from air samples collected in the shower room whilst the shower was in operation. No clinical cases have occurred. Serological examination of those using the showers throughout the six month period together with a control group showed no evidence of infection.

Survival of virulent Legionella pneumophila in aerosols.

Aqueous suspensions of virulent Legionella pneumophila grown on solid medium retained virulence and aerosol survival characteristics for several months. Significant numbers of viable organisms were recovered from aerosols held at various relative humidities (r.h.) for up to 2 h. The organisms survived best at 65% r.h. and were least stable at 55% r.h. Exponential phase broth-grown organisms survived poorly in aerosols in comparison with stationary phase broth cultures or organisms grown on solid medium, suggesting that the metabolic status of Legionella pneumophila organisms may be an important factor affecting their ability to survive in aerosols and cause respiratory disease.