A novel substitution I381V in the sterol 14alpha-demethylase (CYP51) of Mycosphaerella graminicola is differentially selected by azole fungicides

SUMMARY The recent reduction in the efficacy of azole fungicides in controlling Septoria leaf blotch of wheat, caused by Mycosphaerella graminicola, has prompted concerns over possible development of resistance, particularly in light of the recent emergence of widespread resistance to quinone outside inhibitors (QoIs). We have recently implicated alterations in the target-encoding sterol 14alpha-demethylase protein (CYP51), and over-expression of genes encoding efflux pumps, in reducing sensitivity to the azole class of sterol demethylation inhibitors (DMIs) in M. graminicola. Here we report on the prevalence and selection of two CYP51 alterations, substitution I381V and deletion of codons 459 and 460 (DeltaY459/G460), in populations of M. graminicola. Neither alteration has previously been identified in human or plant pathogenic fungi resistant to azoles. The presence of DeltaY459/G460 showed a continuous distribution of EC(50) values across isolates with either I381 or V381, and had no measurable effect on azole sensitivity. Data linking fungicide sensitivity with the presence of I381V in M. graminicola show for the first time that a particular CYP51 alteration is differentially selected by different azoles in field populations of a plant pathogen. Substitution I381V although not an absolute requirement for reduced azole sensitivity, is selected by tebuconazole and difenoconazole treatment, suggesting an adaptive advantage in the presence of these two compounds. Prochloraz treatments appeared to select negatively for I381V, whereas other azole treatments did not or only weakly impacted on the prevalence of this substitution. These findings suggest treatments with different members of the azole class of fungicides could offer a resistance management strategy.

Impact of changes in the target P450 CYP51 enzyme associated with altered triazole-sensitivity in fungal pathogens of cereal crops

Control of diseases caused by fungi in both medicine and agriculture is heavily dependent on the use of triazoles. As a consequence, resistance to triazoles is a threat to both human health and the sustainability of agricultural production systems. In human pathogens, particularly Candida albicans, mutations encoding alterations in the target cytochrome P450 sterol 14α-demethylase (CYP51; where CYP is cytochrome P450) enzyme are the primary determinants of triazole resistance. In fungal pathogens of cereals, CYP51A1 modifications, some at positions known to contribute to a resistant phenotype in human pathogens, have also been identified in isolates with altered triazole-sensitivity. However, unlike medicine where resistance to triazoles is a major clinical problem, failures of triazoles to control crop diseases in the field are rare with mean population sensitivities generally remaining low, perhaps due to differences in the selection pressures imposed on human and cereal pathogen populations. Nonetheless, the biological potential for resistance exists, and the question remains as to whether widespread triazole resistance can develop in an important cereal pathogen.

Role of Ascospores in Further Spread of QoI-Resistant Cytochrome b Alleles (G143A) in Field Populations of Mycosphaerella graminicola

ABSTRACT Strobilurin fungicides or quinone outside inhibitors (QoIs) have been used successfully to control Septoria leaf blotch in the United Kingdom since 1997. However, QoI-resistant isolates of Mycosphaerella graminicola were reported for the first time at Rothamsted during the summer of 2002. Sequence analysis of the cytochrome b gene revealed that all resistant isolates carried a mutation resulting in the replacement of glycine by alanine at codon 143 (G143A). Extensive monitoring using real-time polymerase chain reaction (PCR) testing revealed that fungicide treatments based on QoIs rapidly selected for isolates carrying resistant A143 (R) alleles within field populations. This selection is driven mainly by polycyclic dispersal of abundantly produced asexual conidia over short distances. In order to investigate the role of sexually produced airborne ascospores in the further spread of R alleles, a method integrating spore trapping with real-time PCR assays was developed. This method enabled us to both quantify the number of M. graminicola ascospores in air samples as well as estimate the frequency of R alleles in ascospore populations. As expected, most ascospores were produced at the end of the growing season during senescence of the wheat crop. However, a rapid increase in R-allele frequency, from 35 to 80%, was measured immediately in airborne ascospore populations sampled in a wheat plot after the first QoI application at growth stage 32. After the second QoI application, most R-allele frequencies measured for M. graminicola populations present in leaves and aerosols sampled from the treated plot exceeded 90%. Spatial sampling and testing of M. graminicola flag leaf populations derived from ascospores in the surrounding crop showed that ascospores carrying R alleles can spread readily within the crop at distances of up to 85 m. After harvest, fewer ascospores were detected in air samples and the R-allele frequencies measured were influenced by ascospores originating from nearby wheat fields.

Hip fracture in elderly patients: outcomes for function, quality of life, and type of residence

A prospective study was done to investigate functional outcome, quality of life, and type of residence after hip fracture in patients 65 years of age and older. One hundred two patients admitted consecutively to a university and a general hospital were followed up as long as 4 months after admission. The mean age of the participants was 83 years; 58% of patients came from their own home, and 42 % of patients came from institutions. Nearly 70% of patients had two or more diagnoses other than the hip fracture. Cumulative mortality was 20% at 4 months after fracture. Of surviving patients, 57% were back in their original situation for accommodation, 43% reached the same level of walking ability, and 17% achieved the same level of activities of daily living as before fracture. Patients experienced on average three complications, 26% of which were severe. Quality of life improved in the followup period of 4 months; however, the quality of life at 4 months was worse than the quality of life reported in a reference population. Average costs amounted to euro (Euro) 15.338 (which at the time was nearly equivalent to the US dollar) per patient, with nearly 50% of the costs attributable to hospital costs and 30% attributable to nursing home costs. The results of this study show a poor outcome after hip fracture in elderly patients.

Measuring disability in nursing home residents: validity and reliability of a newly developed instrument

A 24-item multidimensional nurse-administered Nursing Home Disabilities Instrument (NHDI) was developed to measure disabilities in nursing home residents. We present the psychometric features and value of this instrument, with the following domains assessed: Mobility, Activities of Daily Living (ADLs), Alertness, Resistance to Nursing Assistance, Incontinence, Cognition, and

PERCEPTION

Test-retest and interrater reliability was assessed using the Spearman correlation coefficient. Internal consistency was examined by Cronbach's alpha. Criterion validity tests were performed by comparing the scales with scales of the Elderly Residents Rating Scale (BOP). Test-retest reliability correlation coefficients ranged from 0.63 to 0.94. Interrater reliability was high for the scales Cognition, Mobility, ADL, and Incontinence (0.79 to 0.93), moderate for Resistance (0.51), and low for Perception (0.33). Cronbach's alpha of the scales was high, ranging from 0.78 (Alertness) to 0.93 (Mobility); only Perception showed a low alpha: 0.54. Criterion validity was high for Cognition, ADL, and Mobility (0.75 to 0.78), and moderate for Alertness (0.59). The NHDI appears to be a valid and efficient multidimensional instrument for measuring disabilities in nursing home residents. These findings imply that the NHDI is a useful instrument for nursing homes to achieve a reliable assessment of cognitively impaired elders.

Randomized controlled trial of seroresponses to double dose and booster influenza vaccination in frail elderly subjects

Responses to influenza vaccination are poor in frail elderly subjects who suffer the greatest morbidity and mortality due to infection. Therefore, a randomized clinical trial was performed to determine the effect of a double dose and booster vaccination on antibody responses after influenza vaccination. A total of 815 patients (median age 83 years, median disability score 8, median disease categories 2 and median number of medications 4) residing in 14 nursing homes in the Netherlands were vaccinated during the influenza season 1997-98. The first vaccine dose (15 or 30 microg) was given on Day 0 followed by a booster dose (placebo or 15 microg) on Day 84. Blood samples were taken before and 25 days after vaccination. There were four treatment groups: (i) 15 microg and placebo, (ii) 15 microg and 15 microg booster, (iii) 30 microg and placebo and (iv) 30 microg and 15 microg booster. Geometric mean antibody titers of those receiving the double vaccine dose was 15% (95% CI, 6% to 24%, P = 0.001) higher as compared to the standard 15 microg dose. A booster dose, given 84 days after the first vaccination, yielded postvaccination titters that were 14% (95% CI, 9% to 19%, P = 0.001) higher as compared to placebo. Subgroup analysis did not reveal patient groups that had a proportionally greater benefit from adapted vaccination strategies. It is concluded that higher antibody responses can be achieved in frail elderly people by a double vaccine dose or a booster vaccination.

Reduced IFN-gamma production in elderly people following in vitro stimulation with influenza vaccine and endotoxin

Cytokine interferon gamma (IFN-gamma) is pivotal in the defence against viruses and intracellular pathogens and an age-related decreased IFN-gamma production may explain the increased infectious disease morbidity and mortality in the elderly. Therefore, we performed a series of clinical experiments evaluating the influence of age and health status on IFN-gamma production following in vitro stimulation with influenza vaccine or endotoxin. Both healthy and frail elderly people produced significantly lower amounts of IFN-gamma following ex vivo stimulation with influenza vaccine or endotoxin. We conclude that ageing is accompanied by a decreased capacity to produce IFN-gamma. This may explain the increased incidence and case-fatality caused by viruses and intracellular pathogens in the elderly.

[Infections and aging]

Elderly people are exposed to infectious risks in ways different from younger people. These risks relate to environment, transmission routes and vectors, microbial colonisation of body surfaces and quality of host defence. Admission to a nursing home or a hospital may easily lead to colonisation with (resistant) potentially pathogenic micro-organisms, while pre-existing morbidity, medication and functional disability impair the quality of host defence, to a greater degree than the process of aging. In general, infections have a great impact on the elderly patient. Not only are infections in the elderly often serious, but they often have a deleterious effect on comorbidity and functional ability. Infections in elderly people with serious comorbidity face the physician with the dilemma how far to go with diagnostic procedures and therapy.

[The dentist in the circle of care of dependent elderly]

By preventing avoidable causes of death, man usually dies at advanced age after a prolonged period of increasing dependency often in homes for the elderly and in nursing homes. This dependency means problems in self care, walking, cognition, communication and in oral health. Geriatric dentistry can be incorporated in a model arranging care (the care circle) in which the dentist operates independently, or organised in teams with other caregivers or central directed by a nursing home doctor (so-called multidisciplinary dentistry). Multidisciplinary dentistry means that the dentist is a member of a multidisciplinary team, contributing to the reduction of individual problems with eating, drinking and oral health. The dentist involves the team in the indications of dental treatment. He operates within the rules of recent Dutch legislation. These laws are based on self-determination of the patient, institutional quality-assurance and individual skills-guarantees of the care provider.

The relationship between difficulties in feeding oneself and loss of weight in nursing-home patients with dementia

OBJECTIVE

to investigate the cause of unintentional weight loss in demented nursing-home patients.

DESIGN

body weight was measured at 3-month intervals and related to the primary diagnosis, problems in feeding oneself and other factors influencing food intake.

SETTING

a Dutch nursing home.

SUBJECTS

250 resident patients and 264 new and consecutively admitted patients above the age of 65.

RESULTS

for both demented and non-demented nursing-home patients, a strong relationship exists between weight loss and choosing food, bringing it to the mouth and chewing: the greater these difficulties, the lower the body weight. This relationship was more evident in existing residents than in newly admitted patients. Body weight was not well correlated with the diagnosis of dementia but was correlated with poor appetite and immobility.

CONCLUSION

disabilities resulting from dementia can lead to an inadequate intake of food and thus to weight loss in nursing-home residents.

Long-term ambulatory monitoring of urine leakage in the elderly: an evaluation of the validity and clinical applicability of thermistor signalling

This study evaluated the validity and applicability of a low-cost Urine Leakage Recording Device (ULRD) in a geriatric setting. The ULRD consisted of a thermistor, connected to a portable, digital datalogger. The thermistor was positioned on a commercially available adult diaper. Five healthy females were instructed to void urine in seven behavioural conditions comprising general motor activity patterns of the average, psychogeriatric elderly in-patient. Voids were verbally indicated by the subjects and concomitantly recorded by the ULRD and the observer. After comparing the ULRD records--scored by three independent assessors--with the subjects' reports, on average (SD) 5.3 (0.6) of a total of 10 voids were classified correctly, whereas 9.3 (1.3) false positive events were indicated. None of the subjects reported any inconvenience as a result of the recording procedure. Although the ULRD is easily applicable, we conclude that it seems to be of little value in its present form as a method for long-term ambulatory monitoring of urine leakage.

[Increased chance of dying among nursing home patients with lower body weight]

OBJECTIVE

To investigate a possible relationship between changes in weight and mortality among nursing home patients of 65 years and older, after adjustment for age, sex and main diagnosis.

DESIGN

Descriptive longitudinal study.

SETTING

Dutch nursing home in Delft, the Netherlands.

METHODS

For three years after admission the body weight of patients newly admitted from April 1st 1987 to April 1st 1989 was measured every three months under the same conditions. It was recorded if a patient died or was discharged in this three-year period. The effects of body weight at admission, sex, age and diagnostic category (psychogeriatric, neurological, orthopaedic, oncological, other) on mortality were analysed using the univariate Cox regression analysis. The effect of the time-dependent covariate body weight on mortality in the nursing home was analysed with a combined logistic regression analysis per 3-month interval.

RESULTS

The mean weight of the females increased from 59.7 kg (n = 194) at the time of admission to 63.7 kg (n = 57) three years later and that of the males from 64.7 kg (n = 70) to 70.3 (n = 11) due to the low body weight of those who died. During the first 3 months after admission mortality was high (14%) and only diagnosis related. In subsequent 3-month periods there was a significant association between mortality and weight, weight change, age and sex: the risk of mortality was higher for those with a lower body weight, weight loss, higher age and male sex.

CONCLUSION

Nursing home patients with a low body weight or loss of weight after the first 3 months after admission, have an increased risk of death.

[Use of drugs for CNSLD (asthma and COPD) in Dutch residential homes and nursing homes]

Of the 1019 residents of eight dutch homes for the elderly and 699 patients of five nursing homes, respectively 6.0 and 8.1% were administered drugs for chronic non-specific lung disease (CNSLD), which is a term covering asthma as well as copd. The treatment consisted of, usually inhaled, beta-agonists and/or anti-cholinergics in 82%, inhaled as well as oral corticosteroids in 60%, and xanthine-derivates and N-acetylcysteïne, both of which were taken orally, in 28 and 21% of the patients respectively. It was found that almost half (47%) of the patients using inhaled drugs, which 90% of them did either with or without help, made at least three mistakes during inhalation. Considering that CSNLD is probably underdiagnosed, especially when it occurs as a cause of co-morbidity and will have an unfavourable influence on the general state of health by reducing lung function, the suboptimal application of inhaled drugs should be a cause of concern for those who treat elderly patients with asthma and or copd.

Subcutaneous morphine infusion by syringe driver for terminally ill patients

The study aimed to find whether subcutaneous morphine administration by syringe driver for terminally ill patients in a Dutch nursing home led to higher morphine doses and earlier death than routine morphine administration. The data comprised the files of all patients dying over a 2 year period in a 355-bed nursing home in Delft in the Netherlands. Thirty-eight per cent of the patients had been given morphine, 29% by continuous subcutaneous syringe driver. In comparing the patients given morphine with and without a syringe driver no differences emerged in mean age, sex, length of admission, type of ward, diagnosis, duration of morphine administration and mean dose. The data indicate that subcutaneous morphine administration by syringe driver decreases dose frequency problems and improves the control of pain and other symptoms in the last week before death. There was no evidence that administration of morphine in this way shortens survival.

[Body weight of elderly patients on admission to a nursing home]

Body weight of elderly patients on admission to a 'verpleeghuis' (Nursing-home in the Netherlands) was 5 to 8 kg lower than that of healthy persons of the same age living at home. No difference in body weight was found between 'verpleeghuis' patients on admission and after long stay. Psychogeriatric men weighed more than somatic; the body weight of psychogeriatric and somatic women did not differ. Terminal patients weighed less than chronic patients and patients, who could be discharged from the 'verpleeghuis'. A relationship was found between body weight and age: the older the patient is, the lower he weighs. Body weight of women was also lower in the case of 'unmarried status' and 'admission residential homes'.

[12-year infection policy in a nursing homes]

OBJECTIVE

To evaluate the management of infections in a nursing home.

DESIGN

A descriptive study of yearly reviews of 1981-1992.

LOCATION

Nursing home De Bieslandhof, Delft.

PATIENTS AND METHOD

Of all the patients admitted during a year in the nursing home, the prescribed antimicrobial therapy differentiated by localisation of infection was registered. Whenever prescription of antimicrobial therapy was considered, the use of an indwelling catheter was limited and urine was collected for culturing.

RESULTS

From 1981-1984 the number of patients with an indwelling catheter decreased to 50% as did the number of patients who needed recurrent antimicrobial therapy. From 1985 on, the patients receiving a simple or repeated antimicrobial therapy courses were 20% and 7%, respectively, of the total population. Per 1000 patient days 0.9 urinary and 1.1 airway infections were treated; other infections played a minor part. Non-catheterised nursing home patients or non-catheterised patients just admitted from the hospital had more urinary E. coli infections than patients who had been catheterised. The choice of antimicrobial therapy did not change during the study period except for the replacement of sulfamethizole by pipemidic acid in 1989.

CONCLUSION

Nursing home doctors can collectively manage and control infections in a nursing home by using a restrictive policy on antimicrobial therapy and on the use of indwelling catheters. Infections not treated with antimicrobial agents are not included in this policy.

[Relationship between unwanted urine loss to other limitations in function]

A limited analysis of the data of the continuous health enquiry of the Central Statistics Office regarding forms of physical impairment of the non-institutionalized Dutch population and of some data on physical ability of nursing home patients, carried out in 1991 by the Health Care Information Centre Foundation, confirmed the supposition that the risk of unwanted urine loss is substantially higher in patients with disability with respect to locomotion, changing posture, purposeful action, communication and condition. This proved to be the case at all ages, in both sexes, and in those living alone and together with others. Further investigation is necessary to determine the connection of these various forms of impairment with each other and with involuntary urine loss, with a view to promoting efficient diagnostic and therapeutic coping with involuntary urine loss; special attention should be paid to the question to what extent the disorders and limitations contribute to the actual handicap.

[Cause of death in nursing homes]

Data from the Verpleeghuis Informatie Systeem (Nursing Home Information System, SIVIS) of the Stichting Informatiecentrum Gezondheidszorg (Foundation Information Centre Public Health, SIG) unlike data from the Central Bureau voor de Statistiek (Central Statistics Office, CBS) can afford insight into the primary causes of death of patients in Dutch nursing homes. We studied the question whether the causes of death of patients in somatic and psychogeriatric care differed and whether in these groups there was difference between those decreased within and after six months. Also, using the death certificates issued for the 29 patients deceased in nursing home De Bieslandhof in the first quarter of 1991, a comparison was made of reporting to the SIG and to the CBS. In 1989, data on 82.5% of the nursing home patients were registered in the SIVIS. Irrespective of the interval between admission and death and the nature of the multidisciplinary care (somatic or psychogeriatric), pneumonia was the cause of death most frequently stated (16%). Of the somatic patients decreased within six months the cause of death was mostly a malignancy. The psychogeriatric patients mostly died due to dehydration and cachexia. However, uncertainties in establishing the primary cause of death and registration errors are not made sufficiently clear in the SIVIS registration. The reporting to SIG and CBS does not always tally.

[Measurement or estimation of body length in older nursing home patients]

Measurement of body height of elderly persons can be difficult or impossible because of inability to stand or inability to stand in the right position. In seventy-five percent of elderly patients of a nursing home (n = 281) height could not be measured. Measurement of the height in a recumbent position was possible in fifty-five percent of the patients and measurement of arm span, used as a substitute for height, in sixty percent. Knee height could be measured in 95% of the patients; height can however roughly be estimated from knee height. Indices reflecting nutritional status, which require height as a variable (such as Quetelet Index), are of limited use for elderly patients in nursing homes.

[Acute obstruction of the oronasal passages in nursing home patients]

Life-threatening episodes of oronasal obstruction were observed in five bedridden, cachectic and dehydrated nursing-home patients with deviation of the nasal septum. During the episode they had swollen nasal mucosae and rhinorrhoea. The patients were found in bed with the nostrils sucked against the septum and the mouth tightly closed. They were cyanotic but conscious. After introduction of disposable catheters through the nose, dyspnoea and cyanosis were resolved in a few minutes and the patients were able to open the mouth spontaneously.

[The patient with a long-term indwelling catheter]

A working-group of the Scientific Council of the CBO has drawn up a report on infection control of patients with longterm indwelling catheterization of the urinary bladder. In the first place, restricted use of catheters and shortening of their indwelling use are intended. Furthermore preventive and diagnostic measures and treatment are recommended in case of urinary tract infection and blocking catheters.

[Fecal incontinence in the elderly]

Faecal incontinence in the elderly is not compatible with normal social function and leads to interventions and/or institutionalization. In homes for the elderly about 10% and in nursing homes 42.8% of the patients are faecally incontinent. There are predisposing, precipitating and uncleanliness factors. Four ways of faecal loss are described. The purposes of diagnosis and therapy are: 1. prevent and cure diseases, which cause unintentional faecal loss, 2. maintain lavatory visiting as long as possible and 3. prevent soiling the old patient himself and his surroundings.

Infection control in a skilled nursing facility: a 6-year survey

In 1981 an infection control programme was started in a 320-bed skilled nursing facility in The Netherlands. The programme consisted of recording the antimicrobial drugs prescribed and the site of infection, culture of urine from patients admitted from hospital and from residents with suspected symptomatic urinary tract infection, restriction of long-term indwelling urethral catheterization and restricted use of antimicrobial drugs. At a weekly staff meeting, these data were reviewed. As a result of the programme, the number of treatments for urinary tract infections decreased by 74% between 1981 and 1986, and the number of courses for recurrent urinary tract infections decreased from 18 to 6% of the total number given. The patients who did not require antimicrobial therapy increased from 51% in 1981 to 70% in 1986.

Restriction of long-term indwelling urethral catheterisation in the elderly

Eighty-nine (16%) of 543 patients admitted to a chronic care centre in 1983 had an indwelling urethral catheter. Of the 89, 51 patients (57%) received the catheter in a general hospital, 4 (5%) at home and 34 (38%) in the centre. More than half of the catheters that were inserted in the hospital could be removed within 4 weeks of admission to the centre, implying that a more restricted use of indwelling catheters in hospitals is possible. Only 18% of the indwelling catheters remained in situ for the designated period of 1 month. The other catheters were changed before that time, mainly because of obstructed drainage or leakage of urine around the catheter. The incidence of bacteriuria among catheterised patients was 90%. The bacteria were multiresistant in 37% of these cases, compared with 25% of non-catheterised patients. Multiresistant microflora were present significantly more often in the urine of patients admitted from hospitals (irrespective of whether they had a catheter) and the catheterised residents of the centre than in that of the other patients (P less than 0.001). When all patients of the centre were considered, it was found that 30.6% were treated with antimicrobial agents in the course of the year; 10.9% were treated more than once a year. This latter group of patients received 58% of all prescribed antimicrobial drugs; 37% of them had an indwelling catheter. The majority of catheterised patients (65%) did not need antimicrobial treatment. No significant influence of catheterisation on mortality could be demonstrated.

[Infections in the elderly, especially in nursing homes]

From the viewpoint of defense against micro-organisms it is diagnostically important to differentiate between frontier activity, frontier incident and invasion through the frontier. The barrier of the older body can be characterised by a multiple vulnerability, injury and pathology. Endogenous and exogenous (including therapeutic) causal factors are discussed. A management of vigilance and treatment of functional disturbances of the barrier of the old body is suggested.