Increased short- and long-term mortality following infections in dementia: a nationwide registry-based cohort study

BACKGROUND AND PURPOSE

Mortality following infections in dementia has not yet been comprehensively explored. The aim of this cohort study was to investigate the short- and long-term mortality following infections in dementia.

METHODS

Follow-up was from 1 January 2000 or the 65-year birthday until death, immigration, or 31 December 2015. Exposure was incident dementia and a first infection. The outcome was all-cause mortality. Mortality rate ratios (MRRs) were calculated using Poisson regression in 4 exposure groups (dementia yes/no, infection yes/no) by sex, infection site, and time since infection.

RESULTS

1,496,436 people were followed with 12,739,135 person-years. MRR in dementia/infection was 6.52 (95% confidence interval: 6.43-6.60) and was increased for infections of all sites. Increased mortality was short term (30 days) and long term (10 years).

CONCLUSIONS

Increased mortality in people with dementia identifies them as a particularly vulnerable group that needs clinical attention.

Oral amoxicillin and amoxicillin-clavulanic acid: properties, indications and usage

BACKGROUND

Amoxicillin has been in use since the 1970s; it is the most widely used penicillin both alone and in combination with the β-lactamase clavulanic acid.

OBJECTIVES

In this narrative review, we re-examine the properties of oral amoxicillin and clavulanic acid and provide guidance on their use, with emphasis on the preferred use of amoxicillin alone.

SOURCES

Published medical literature (MEDLINE database via Pubmed).

CONTENT

While amoxicillin and clavulanic acid have similar half-lives, clavulanic acid is more protein bound and even less heat stable than amoxicillin, with primarily hepatic metabolism. It is also more strongly associated with gastrointestinal side effects, including Clostridium difficile infection, and, thus, in oral combination formulations, limits the maximum daily dose of amoxicillin that can be given. The first ratio for an amoxicillin-clavulanic acid combination was set at 4:1 due to clavulanic acid's high affinity for β-lactamases; ratios of 2:1, 7:1, 14:1 and 16:1 are currently available in various regions. Comparative effectiveness data for the different ratios are scarce. Amoxicillin-clavulanic acid is often used as empiric therapy for many of the World Health Organization's Priority Infectious Syndromes in adults and children, leading to extensive consumption, when some of these syndromes could be handled with a delayed antibiotic prescription approach or amoxicillin alone.

IMPLICATIONS

Using available epidemiological and pharmacokinetic data, we provide guidance on indications for amoxicillin versus amoxicillin-clavulanic acid and on optimal oral administration, including choice of combination ratio. More data are needed, particularly on heat stability, pharmacodynamic effects and emergence of resistance in 'real-world' clinical settings.

Analytic laboratory performance of a point of care urine culture kit for diagnosis and antibiotic susceptibility testing

Currently available point-of-care (POC) diagnostic tests for managing urinary tract infections (UTIs) in general practice are limited by poor performance characteristics, and laboratory culture generally provides results only after a few days. This laboratory evaluation compared the analytic performance of the POC UK Flexicult(™) (Statens Serum Institut) (SSI) urinary kit for quantification, identification and antibiotic susceptibility testing and routine UK National Health Service (NHS) urine processing to an advanced urine culture method. Two hundred urine samples routinely submitted to the Public Health Wales Microbiology Laboratory were divided and: (1) analysed by routine NHS microbiological tests as per local laboratory standard operating procedures, (2) inoculated onto the UK Flexicult(™) SSI urinary kit and (3) spiral plated onto Colorex Orientation UTI medium (E&O Laboratories Ltd). The results were evaluated between the NHS and Flexicult(™ )methods, and discordant results were compared to the spiral plating method. The UK Flexicult(™) SSI urinary kit was compared to routine NHS culture for identification of a pure or predominant uropathogen at ≥ 10(5) cfu/mL, with a positive discordancy rate of 13.5% and a negative discordancy rate of 3%. The sensitivity and specificity were 86.7% [95% confidence interval (CI) 73.8-93.7] and 82.6% (95% CI 75.8-87.7), respectively. The UK Flexicult(™) SSI urinary kit was comparable to routine NHS urine processing in identifying microbiologically positive UTIs in this laboratory evaluation. However, the number of false-positive samples could lead to over-prescribing of antibiotics in clinical practice. The Flexicult(™) SSI kit could be useful as a POC test for UTIs in primary care but further pragmatic evaluations are necessary.

Escherichia coli clonal group A causing bacteraemia of urinary tract origin

Escherichia coli clonal group A (CgA) causes disease in humans. This is the first study investigating the prevalence of CgA among E. coli from non-urine, extraintestinal infections in a northern European country. E. coli blood (n = 196) and paired urine (n = 195) isolates from the same patients with bacteraemia of urinary tract origin were analysed. The isolates were collected from January 2003 through May 2005 at four hospitals in Copenhagen, Denmark. Pulsed-field gel electrophoresis (PFGE) patterns, antimicrobial resistance and patient characteristics were determined for all CgA isolates; presence of virulence-associated genes (VAGs) and serotypes were determined for the blood CgA isolates. Thirty blood isolates (15%) belonged to CgA. CgA blood isolates were associated with female patients and sulfamethoxazole-trimethoprim resistance and they harboured a distinctive VAG profile. The blood and urine isolates from each pair were found to be related in 26 of 27 CgA blood/urine pairs, confirming a urinary tract origin of infection. Furthermore, a relationship between the PFGE patterns of CgA blood/urine isolates and CgA isolates from UTI patients in general practice and a CgA isolate from a community-dwelling human reported previously, was found, suggesting a community origin of CgA. The finding of CgA strains in 15% of the E. coli bloodstream infections with a urinary tract origin in Denmark suggests that CgA constitutes an important clonal lineage among extraintestinal pathogenic E. coli. A reservoir of this pathogenic E. coli group in the community causing not only UTI but also more severe infections such as bacteraemia has implications for public health.

Microbial status and product labelling of 58 original tattoo inks

BACKGROUND

European Council resolutions on tattoo ink introduce sterility and preservation of inks to protect customers. Inks used in Denmark are typically purchased over the internet from international suppliers and manufacturers from the US and the UK. In Denmark tattoo inks are regulated and labelled according to REACH as if they were plain chemicals.

OBJECTIVE

The objective of this study was to check the microbial product safety of unopened and opened tattoo ink stock bottles. Packaging, labelling, preservation, sterility and contamination with micro-organisms were studied.

METHODS

Physical inspection and culture of bacteria and fungi.

RESULTS

Six of 58 unopened stock bottles (10%) were contaminated with bacteria and one of six samples (17%) of previously used stock bottles was contaminated. The bacterial species represented bacteria considered pathogenic in humans as well as non-pathogenic environmental bacteria. Yeast or moulds were detected in none of the samples. A total of 31% of the manufacturers informed only about the brand name. No information about content, sterility, risks or expiry date was indicated on the label. A total of 42% claimed sterility of their inks. A total of 54% labelled a maximum period of durability of typically 2-3 years. The physical sealing was leaking in 28% of the products.

CONCLUSIONS

The European Council resolutions regarding safety of tattoo inks are not effective. Stock bottles of tattoo ink may contain bacteria pathogenic to humans and environmental bacteria, and packaging, labelling and preservation of inks are of inadequate quality. Claim of sterility can be erroneous.

Staphylococcus aureus bacteremia in patients with hematological malignancies and/or agranulocytosis

A total of 6,253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975-1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p less than 0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p less than 0.01), the lowest in patients with acute lymphocytic leukemia (28%, p less than 0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent.

Antibiotic treatment of Staphylococcus aureus endocarditis. A review of 119 cases

Clinical and bacteriological information of Staphylococcus aureus endocarditis was reviewed in 119 cases from all over Denmark. Overall mortality was 71%. Survival correlated with antistaphylococcal treatment, short duration from onset of infection to start of treatment, and long duration of treatment. In spite of relevant treatment, mortality was significantly lower in cases infected with penicillin-susceptible strains than when penicillin-resistant strains were isolated. There were no differences in the effect of various anti-staphylococcal treatment regimens; in particular, there were no differences in mortality with regard to beta-lactam antibiotics alone as compared to beta-lactam antibiotics in combination with aminoglycosides. However, embolic manifestations occurred more often after start of treatment with combination therapy than with beta-lactam antibiotics alone.

Neonatal colonization with Staphylococcus aureus is not associated with development of atopic dermatitis

BACKGROUND

Staphylococcus aureus in atopic skin has been associated with exacerbation of eczema. Objectives To investigate a possible association between neonatal colonization with S. aureus and the risk of atopic dermatitis (AD) during the first 3 years of life.

MATERIALS AND METHODS

The study participants were 356 children born of mothers with asthma from the Copenhagen Prospective Study on Asthma in Childhood. Swabs from the vestibulum nasi and the perineum were cultured at 1 month and 1 year, from acute eczema, and from parents (vestibulum nasi and pharynx). AD development and severity were monitored prospectively.

RESULTS

Of the neonates, 5.3% had positive swabs for S. aureus cultured from the vestibulum nasi (51.3%) and/or the perineum (11.3%). Forty-two per cent developed AD, but without association between colonization with S. aureus at 1 month of age and risk of developing AD at 3 years of age. There was a 70% concordance for S. aureus carriage between neonates and parents. At 1 year of age 11.3% children had swabs positive for S. aureus. Fourteen per cent of children tested at the 1-year visit developed AD after the visit but before 3 years of age, but again, there was no association between colonization with S. aureus and the risk of AD. In children seen at acute visits the severity of AD measured by scoring of atopic dermatitis (SCORAD) was significantly higher in children with a positive culture for S. aureus in lesions.

CONCLUSIONS

Colonization with S. aureus at 1 month of age is not associated with an increased risk of developing AD during the first 3 years of life.

Gentamicin susceptibility in Escherichia coli related to the genetic background: problems with breakpoints

In total, 120 Escherichia coli isolates positive for one of the gentamicin resistance (GEN(R)) genes aac(3)-II, aac(3)-IV or ant(2'')-I were tested for gentamicin susceptibility by the agar dilution method. Isolates positive for aac(3)-IV or ant(2'')-I had an MIC distribution of 8-64 mg/L, whereas isolates positive for aac(3)-II had MICs of 32 to >512 mg/L, suggesting a relationship between the distribution of MICs and the specific GEN(R) mechanism. The MIC distribution, regardless of the GEN(R) mechanism, was 8 - >512 mg/L, which supports the clinical breakpoint of MIC >4 mg/L suggested by EUCAST and questions the breakpoint recommended by the CLSI (> or =16 mg/L).

Increasing incidence but decreasing in-hospital mortality of adult Staphylococcus aureus bacteraemia between 1981 and 2000

Staphylococcus aureus is a leading cause of bacteraemia. This study analysed temporal trends from 18,702 adult cases of S. aureus bacteraemia in Denmark between 1981 and 2000. After stratification for mode of acquisition, 57% of cases were hospital-acquired (HA), 28% were community-acquired (CA) and 15% were of undetermined acquisition (UA). Incidence rates increased from 18.2 to 30.5 cases/100,000 population. Annual rates increased by 6.4% for CA, by 2.2% for HA and by 3.6% for UA cases, respectively. Case-mortality associated with HA bacteraemia decreased from 36.2% to 20.7% (43% rate reduction, p 0.0001), compared with a decrease from 34.5% to 26.5% (23% rate reduction, p 0.0001) for CA bacteraemia. Following multivariate analysis, age, pneumonia, endocarditis and chronic illness were associated with increased mortality, regardless of the mode of acquisition. Overall, mortality associated with S. aureus bacteraemia declined significantly between 1981 and 2000, but incidence rates doubled, so that the total number of deaths increased. These data emphasise the public health importance of S. aureus bacteraemia and the need for further preventive measures and improved care in order to reduce incidence rates and improve outcomes.

Hearing loss and cochlear damage in experimental pneumococcal meningitis, with special reference to the role of neutrophil granulocytes

Hearing loss is a well-known sequelae from meningitis, affecting up to 25% of survivors. However, the principal components of the infectious and inflammatory reaction responsible for the sensorineural hearing loss remain to be identified. The present study aimed to investigate the impact of an augmented neutrophil response on the development of hearing loss and cochlear damage in a model of experimental pneumococcal meningitis in rats. Hearing loss and cochlear damage were assessed by distortion product oto-acoustic emissions (DPOAE), auditory brainstem response (ABR) and histopathology in rats treated with ceftriaxone 28 h after infection. Rats were treated with Granulocyte Colony Stimulating Factor (G-CSF) initiated prior to infection, 28 h after infection or with ceftriaxone only. Rats were followed for 7 days, and assessment of hearing was performed before infection and 24 h and day 8 after infection. Pretreatment with G-CSF increased hearing loss 24 h after infection and on day 8 compared to untreated rats (Mann-Whitney, P = 0.012 and P = 0.013 respectively). The increased sensorineural hearing loss at day 8 was associated with significantly decreased spiral ganglion cell counts (P = 0.0006), increased damage to the organ of Corti (P = 0.007), increased areas of inflammatory infiltrates (P = 0.02) and increased white blood cell (WBC) counts in cerebrospinal fluid on day 8 after infection (P = 0.0084). Initiation of G-CSF 28 h after infection did not significantly affect hearing loss or cochlear pathology compared to controls. In conclusion, the inflammatory host reaction contributes significantly to the development of hearing loss in experimental meningitis.

Intracellular persistence of Escherichia coli in urinary bladders from mecillinam-treated mice

OBJECTIVES

It has been suggested recently that intracellular bacteria surviving antibiotic treatment might serve as a reservoir for recurrent infection. The purpose of this study was to directly examine the location of Escherichia coli bacteria in the mouse bladder after treatment with mecillinam.

METHODS

The bladders were studied by use of colony counts, in situ hybridization and electron microscopy.

RESULTS

The bacterial counts in the bladder remained approximately 10(3-4) cfu/bladder even after mecillinam treatment had finished, and re-growth in the urine was observed. In the bladder epithelium from treated mice, bacteria cells were occasionally seen, presumably representing intracellularly located bacteria.

CONCLUSIONS

This is the first in vivo study indicating that during mecillinam treatment E. coli cells can penetrate the mouse bladder epithelium and persist.

Evaluation of cefoxitin 5 and 10 μg discs for the detection of methicillin resistance in staphylococci

OBJECTIVE

To evaluate cefoxitin 5 and 10 microg discs for detection of methicillin resistance in staphylococci.

METHODS

Six hundred and forty-one Staphylococcus aureus (261 mecA-negative and 380 mecA-positive) and 344 coagulase-negative staphylococci (CoNS) (132 mecA-negative and 212 mecA-positive) were investigated. The CoNS represented nine species, Staphylococcus epidermidis being the most frequent (n = 231). All isolates were tested using semi-confluent growth on Iso-Sensitest agar (ISA), and Mueller-Hinton agar (MH) using a 5 and a 10 microg cefoxitin disc and overnight incubation in ambient air at 35-37 degrees C.

RESULTS

For S. aureus, both cefoxitin discs performed with high accuracy on both media. The sensitivity and specificity for the following proposed interpretive zone diameters were: ISA 5 microg, R < 14 mm (99.5% and 98.1%); ISA 10 microg, R < 22 mm (99.5% and 98.1%); MH 5 microg, R < 12 mm (99.7% and 98.1%); and MH 10 microg, R < 18 mm (99.5% and 98.9%), respectively. All four variants were superior to oxacillin using the former SRGA methodology. In CoNS, a substantial overlap was seen for all variants. However, by avoiding primary interpretation in the overlapping interval, highly accurate results could be obtained for 81%, 80%, 91% and 97% of the isolates, respectively.

CONCLUSION

For S. aureus, cefoxitin 5 and 10 microg discs performed with high accuracy on both ISA and MH using semi-confluent growth and standard incubation conditions. With the introduction of a defined interval in which primary interpretation should be avoided, the method could also be used for CoNS.

Microbial Threat--The Copenhagen Recommendations initiative of the EU

The Microbial Threat was the name of an invitational EU conference held in Copenhagen in 1998, which for the first time made antibiotic resistance an official EU issue. The initiative resulted in a set of conclusions, which together with a summary of the conference was published as The Copenhagen Recommendations. This was soon followed by an EU Council Recommendation in 2001 exhorting the member states to follow and enact the recommendations from the Copenhagen meeting. Funding from EU research funds was later provided for projects monitoring resistance as well as antibiotic use, both of which have been lacking in most EU countries until now. The initiative is a good example of a major health issue being lifted by a concerted and official EU action.

Urinary concentrations and urine ex-vivo effect of mecillinam and sulphamethizole

Healthy adult volunteers received 1 g of sulphamethizole orally (n = 10) and later 400 mg of pivmecillinam (274 mg of mecillinam) (n = 9). All urine was collected in defined periods over 24 h, and the drug concentrations in urine were determined. For sulphamethizole, the maximum urine concentration for seven subjects was reached in 0-3 h, and for the remaining three in 3-6 h. For mecillinam, eight of the nine subjects attained a maximum urine concentration in 0-3 h, after which the concentration declined rapidly for six subjects in 3-6 h. Strains of Escherichia coli with different MICs for sulphamethizole and mecillinam were exposed to collected urine for 2.5 h and 5 h. The results indicated that a sensitive E. coli population should be suppressed by sulphamethizole in urine for two-thirds of the time (with 1 g twice-daily) and by mecillinam in urine throughout the 24-h period (with 400 mg three times a day). There was a slight but significant correlation between the ex-vivo effect (Delta log10 CFU/mL) and the log10 concentration/MIC ratio after exposure to sulphamethizole for 5 h (r2 = 0.27, p < 0.0001), and a significant correlation between the variables with mecillinam (r2 = 0.66, p < 0.0001).

Evaluation of a cefoxitin 30 microg disc on Iso-Sensitest agar for detection of methicillin-resistant Staphylococcus aureus

OBJECTIVES

To evaluate the performance of a cefoxitin 30 microg disc on Iso-Sensitest agar, using a semi-confluent inoculum and overnight incubation at 35-36 degrees C, for detection of methicillin-resistant Staphylococcus aureus (MRSA).

METHODS

A total of 457 S. aureus, including 190 MRSA of several defined PFGE types and a number of low-level resistant isolates, were tested with a cefoxitin 30 microg disc on Iso-Sensitest agar, using a semi-confluent inoculum and overnight incubation at 35-36 degrees C. This method was compared with the standard SRGA (Swedish Reference Group for Antibiotics) method (oxacillin 1 microg disc on Iso-Sensitest agar supplemented with 5% defibrinated horse blood, confluent growth and 24 h incubation in ambient air at 30 degrees C).

RESULTS

The cefoxitin method was excellent, with a sensitivity of 100% and a specificity of 99% using an interpretative zone diameter of S > or = 29 mm and R < 29 mm. Its performance was much better than the SRGA method, which with this collection of difficult strains had a sensitivity of only 78% using the current breakpoint of S > or = 12 mm.

CONCLUSION

We suggest that the cefoxitin method should replace that currently recommended by the SRGA for the detection of MRSA, and that it would fit well into BSAC methodology.

Effects of sulfamethizole and amdinocillin against Escherichia coli strains (with various susceptibilities) in an ascending urinary tract infection mouse model

Resistance to antibiotics used for the treatment of urinary tract infections (UTIs) is increasing worldwide. The impact of in vitro resistance on clinical outcome in UTIs requires further study, since most studies of both humans and animals have evaluated only the efficacy of antibiotics toward bacteria susceptible in vitro. We were interested in evaluating the relationship between the in vitro antibacterial effect and the in vivo efficacy after antibiotic treatment. We simulated a natural ascending UTI by use of the ascending UTI mouse model and used Escherichia coli strains with various susceptibilities to amdinocillin (mecillinam) and sulfamethizole. Mice were treated for 3 days with antibiotic doses approximating human urinary tract concentrations after a standard oral dose. For a susceptible strain (MIC, 0.5 micro g/ml) and a resistant strain (MIC, 128 micro g/ml), respectively, there were significant reductions in bacterial counts in the urine, bladder, and kidneys after treatment with amdinocillin, whereas for a strain for which the MIC was 16 micro g/ml, there was a significant reduction in bacterial counts in the kidneys only (P < 0.05). Treatment with sulfamethizole resulted in a significant reduction in bacterial counts in all samples from a susceptible strain (MIC, 128 micro g/ml) and a resistant strain (MIC, 512 micro g/ml). Infection with a sulII gene-positive strain (MIC, >2,048 micro g/ml) could not be treated with sulfamethizole, as no effect could be demonstrated in the urine, bladder, or kidneys. For amdinocillin, there was no clear-cut relationship between the in vitro susceptibility and the in vivo outcome, while for sulfamethizole, we found a relationship between the MIC for the strain and the effect in the urinary tract.

In vivo pathogenicity of eight medically relevant Candida species in an animal model

BACKGROUND

The relative pathogenicity of eight medically important Candida species was investigated in a mouse model.

MATERIALS AND METHODS

Seventeen isolates were included; two isolates of Candida albicans, Candida glabrata, Candida tropicalis, Candida lusitaniae, Candida parapsilosis, Candida kefyr and Candida guilliermondii and three Candida krusei isolates. Mice in groups of three or four were inoculated with 10(5) and 10(7) CFU, respectively. On days 2 and 7 kidneys were removed, weighed and CFU/g kidney determined by the spot technique.

RESULTS

Mortality was only observed in mice inoculated with C. albicans and C. tropicalis. Inoculated with 10(7) CFU C. tropicalis, C. glabrata, C. kefyr, C. lusitaniae, C. parapsilosis, C. krusei and C. guilliermondii the median log CFU/g kidney was significantly different: 6.0, 6.0, 6.4, 7.0, 3.7, < 2 and < 2 respectively (p < 0.0001). Eye infection and histological changes of kidneys were examined for C. albicans, C. tropicalis, C. glabrata and C. krusei-infected mice. Weight loss, kidney weight, inflammation and infection and number of eyes infected decreased with the pathogenicity of the four species.

CONCLUSION

The virulence was highly different, illustrated by a 7-log difference in CFU/g kidney, a span of 0-100% mortality and histological changes in kidneys ranging from discrete to serious. The species could be divided into three groups with decreasing virulence: 1) C. albicans and C. tropicalis, 2) C. glabrata, C. kefyr and C. lusitaniae and 3) C. parapsilosis, C. krusei and C. guilliermondii. To our knowledge this is the first study with a simultaneous comparison of all eight species in an immunocompetent animal model.

Susceptibility of Danish Escherichia coli strains isolated from urinary tract infections and bacteraemia, and distribution of sul genes conferring sulphonamide resistance

Antibiotic resistance of urinary tract pathogens has increased worldwide. Our aim was to provide information regarding resistance patterns of Escherichia coli in urinary tract infections (UTIs) and E. coli bacteraemia in Denmark. The overall resistance ranged from: ampicillin 20-47%, mecillinam 0-7%, trimethoprim 10-28%, sulfamethizole 22-47% and nitrofurantoin 0-3%. In strains with sulfamethizole MICs > 2048 mg/L, 97% carried sulI, sulII or both genes, with sulII being the most common. Among the sulI gene-positive strains, 96% were intI 1 gene positive.

In vitro antimicrobial susceptibility of Aerococcus urinae to 14 antibiotics, and time-kill curves for penicillin, gentamicin and vancomycin

Aerococcus urinae is a newcomer in clinical and microbiological practice, causing urinary tract infections, bacteraemia/septicaemia and/or endocarditis. This study presents for the first time an evaluation of the activity of a representative panel of antibiotics against a large number of A. urinae isolates. The in vitro susceptibilities (MICs) of 56 isolates of A. urinae to 14 antibiotics were determined by agar dilution. In general, A. urinae isolates showed little inter-isolate variability, and had low MICs of penicillin, amoxicillin, piperacillin, cefepime, vancomycin and rifampicin. High-level aminoglycoside resistance was not found for any of the isolates. Moderate to good activity was seen with quinolones, erythromycin and tetracycline. Isolates from two patients with endocarditis were studied with time-kill curves for penicillin, gentamicin and vancomycin. Penicillin and vancomycin alone exhibited slow or no bactericidal activity against the two strains. When combining either penicillin or vancomycin with gentamicin, rapid bactericidal activity was obtained for both strains with both combinations. The treatment options for A. urinae seem to include penicillins for less severe cases. In severe cases, i.e. endocarditis, the time-kill investigations suggest a beneficial effect of combination with gentamicin. In the penicillin-allergic patient vancomycin in combination with gentamicin represents the most obvious alternative.

Transient intestinal carriage after ingestion of antibiotic-resistant Enterococcus faecium from chicken and pork

BACKGROUND

Antibiotic-resistant enterococci are often present in retail meats, but it is unclear whether the ingestion of these contaminants leads to sustained intestinal carriage.

METHODS

We conducted a randomized, double-blind study in 18 healthy volunteers. Six ingested a mixture of 10(7) colony-forming units (CFU) of two glycopeptide-resistant strains of Enterococcus faecium obtained from chicken purchased at a grocery store, six ingested 10(7) CFU of a streptogramin-resistant strain of E. faecium obtained from a pig at slaughter, and six ingested 10(7) CFU of a glycopeptide-susceptible and streptogramin-susceptible strain of E. faecium from chicken purchased at a grocery store. Suspensions of enterococci were prepared in 250 ml of whole milk and were well within the amounts deemed acceptable by Danish food regulations. Stool samples were collected before exposure, daily for 1 week after ingestion, and at 14 and 35 days. Resistant enterococci in stools were identified by selective culture techniques; further molecular characterization of the organisms was also conducted.

RESULTS

At the outset, none of the subjects were colonized with glycopeptide-resistant or streptogramin-resistant E. faecium. After ingestion of the study strains, these same strains were isolated from the stools of all subjects, in various concentrations. The test strain was isolated in stool from 8 of 12 subjects on day 6, and from 1 of 12 on day 14. All stool samples were negative at 35 days.

CONCLUSIONS

The ingestion of resistant E. faecium of animal origin leads to detectable concentrations of the resistant strain in stools for up to 14 days after ingestion. The organisms survive gastric passage and multiply.

Prevalence of and detection of resistance to ampicillin and other beta-lactam antibiotics in Haemophilus influenzae in Denmark

The susceptibility of Haemophilus influenzae to penicillin V and G, ampicillin and cefuroxime was investigated by MIC, disc and tablet diffusion methods, using chocolate agar as test medium, to determine the prevalence of ampicillin-resistant isolates and the optimal method for their detection. Eighty-six isolates were clinical isolates collected prospectively from July to September 1998 and 22 isolates were clinical isolates with decreased susceptibility to ampicillin previously referred to the reference laboratory. Eighty-seven isolates were ampicillin-susceptible and 16 were ampicillin-resistant. Thirteen produced beta-lactamases. Among the consecutive isolates 12.8% were resistant. With each of the Rosco Neo-sensitabs containing penicillin G, 2.5 microg ampicillin and 33 microg ampicillin, 3 very major errors occurred (resistant isolates misinterpreted as susceptible) and 5-13 major errors (susceptible isolates misinterpreted as resistant). The AB biodisk containing ampicillin (10 microg) was superior to the penicillin V and G discs, i.e. only 1 very major error occurred and major and minor errors were infrequent. The cefuroxime disc identified 4/8 beta-lactamase-negative ampicillin-resistant isolates. Thus, for susceptibility testing with chocolate agar as test medium, the use of an inoculum of 10(5) colony-forming units, 10 microg ampicillin discs and interpretative zone diameters of > or = 28 mm indicating susceptibility and < or = 25 mm indicating resistance was found to produce reliable identification of ampicillin-resistant isolates of H. influenzae.

Correlation of MIC methods and tentative interpretive criteria for disk diffusion susceptibility testing using NCCLS methodology for fusidic acid

Three hundred and eight staphylococci and 43 Streptococcus pyogenes were tested by agar dilution, microbroth dilution, E-test, and disk diffusion using 5, 10 and 50 microg disks, as outlined by the NCCLS, in order to correlate the different MIC methods and to establish tentative species specific interpretive zone diameter breakpoints for fusidic acid. MIC results of the three methods were comparable. For Staphylococcus aureus, using MIC breakpoints of < or = 0.5 mg/L for susceptible and > or = 2 mg/L for resistant tentative interpretive zone diameters of > or = 20 mm and > or = 21 mm for susceptible and < or = 17 mm and < or = 18 mm for resistant are suggested for the 5 microg and the 10 microg disk, respectively. The 50 microg disk did not separate susceptible from resistant isolates. For streptococci a uniform MIC distribution of 2-8 mg/L was found.

Comparison of Etest and a tablet diffusion test with the NCCLS broth microdilution method for fluconazole and amphotericin B susceptibility testing of Candida isolates

Three methods were compared for the susceptibility testing of yeast isolates to fluconazole and amphotericin B: two fagar diffusion methods (Etest and a tablet diffusion test) and the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method. Given as MIC(50)s (range), fluconazole endpoints were: for the 24 h broth microdilution test, 0.25 mg/L (0.06-32 mg/L); for the Etest, 0.38 mg/L (0.064-24 mg/L); and for the NCCLS broth microdilution test, 2 mg/L (0.06->or=64 mg/L). With breakpoints of <3 mg/L for susceptible and >16 mg/L for resistant, the Etest and the 24 h microdilution test classified the isolates in agreement with the classification obtained by the NCCLS method. Results obtained by Etest were in closer NCCLS method than those obtained with the tablet test. Amphotericin B endpoints were lower for the 24 h microdilution and Etests than MICs obtained by the NCCLS broth microdilution method. Reproducibility was high for all tests; however, disadvantages of both diffusion tests were microcolonies in the inhibition zone and dependence on stringent standardization of inoculum.

Penicillin pharmacodynamics in four experimental pneumococcal infection models

Clinical and animal studies indicate that with optimal dosing, penicillin may still be effective against penicillin-nonsusceptible pneumococci (PNSP). The present study examined whether the same strains of penicillin-susceptible pneumococci (PSP) and PNSP differed in their pharmacodynamic responses to penicillin by using comparable penicillin dosing regimens in four animal models: peritonitis, pneumonia, and thigh infection in mice and tissue cage infection in rabbits. Two multidrug-resistant isolates of Streptococcus pneumoniae type 6B were used, one for which the penicillin MIC was 0.016 microg/ml and the other for which the penicillin MIC was 1.0 microg/ml. Two additional strains of PNSP were studied in the rabbit. The animals were treated with five different penicillin regimens resulting in different maximum concentrations of drugs in serum (C(max)s) and times that the concentrations were greater than the MIC (T(>MIC)s). The endpoints were bacterial viability counts after 6 h of treatment in the mice and 24 h of treatment in the rabbits. Similar pharmacodynamic effects were observed in all models. In the mouse models bactericidal activity depended on the T(>MIC) and to a lesser extent on the Cmax/MIC and the generation time but not on the area under the concentration-time curve (AUC)/MIC. Maximal bactericidal activities were similar for both PSP and PNSP, being the highest in the peritoneum and blood (approximately 6 log10 CFU/ml), followed by the thigh (approximately 3 log10 CFU/thigh), and being the lowest in the lung (approximately 1 log10 CFU/lung). In the rabbit model the maximal effect was approximately 6 log10 CFU/ml after 24 h. In the mouse models bactericidal activity became marked when T(>MIC) was > or =65% of the experimental time and C(max) was > or =15 times the MIC, and in the rabbit model bactericidal activity became marked when T(>MIC) was > or =35%, Cmax was > or =5 times the MIC, and the AUC at 24 h/MIC exceeded 25. By optimization of the Cmax/MIC ratio and T(>MIC), the MIC of penicillin for pneumococci can be used to guide therapy and maximize therapeutic efficacy in nonmeningeal infections caused by PNSP.

[Antibiotic treatment of infections in general practice. Effect of audit assessed by prescriptions data from health insurance registry and physicians' own registration]

The aim was to study whether an audit of treatment of infections in general practice resulted in changed prescribing habits. In 1995-1996 forty-six general practitioners (GP's) from the County of Roskilde participated in an audit regarding infectious diseases (incl. course participation and preparation of treatment guidelines). The effect evaluation was done on the basis of 1) two self-registrations of antibiotic prescriptions carried out with one year's interval, and 2) prescribing data from the National Insurance database collected over two periods, before the first and second self-registration respectively. The number of patients not receiving antibiotics increased significantly from 47.2% to 52.4% after intervention. The self-registration did not show any change in choice of antibiotics, while the registry data showed a shift from broad-spectrum to narrow-spectrum penicillin. This change was, however, also found among the GP's, who did not participate in the audit. The study demonstrated that audit can result in changes in prescribing patterns, but at the same time emphasizes the need for inclusion of external data sources and control groups in the evaluation of intervention effects.

Treatment with a monocolonal antibody to IL-8 attenuates the pleocytosis in experimental pneumococcal meningitis in rabbits when given intravenously, but not intracisternally

The role of interleukin (IL)-8 as mediator in the recruitment of leucocytes into the CSF was investigated during experimental pneumococcal meningitis. Rabbits were inoculated intracisternally with approximately 10(6) CFU Streptococcus pneumoniae, and treated (i) intravenously with 5 mg of a monoclonal antibody to IL-8 (n = 7) or 5 mg of an isotype control antibody (n = 6); (ii) intracisternally with anti-IL-8, 100 microg (n = 5), 10 microg (n = 4), 1 microg (n = 4), 0.1 microg (n = 2). Ten rabbits served as untreated control group. Intravenous treatment with anti-IL-8 attenuated the pleocytosis significantly compared to untreated rabbits (P < 0.04) or rabbits treated with an isotype control antibody (P < 0.02). In contrast, intracisternal treatment with anti-IL-8 failed to attenuate the pleocytosis (P > 0.05). These results show, that IL-8 plays an important role in the recruitment of leucocytes during experimental pneumococcal meningitis, and that the functional activity of IL-8 in this process appears to be on the bloodstream side of the microvascular endothelium of the brain.

Evaluation of calibrated 1 and 10 microl loops and dipslide as compared to pipettes for detection of low count bacteriuria in vitro

Criteria for defining urinary tract infection have changed as the importance of low count bacteriuria in patients with symptoms of infection has been recognized. Little has been published, however, regarding the ability of routine laboratory methods to meet this new challenge. We compared 1 microl and 10 microl calibrated plastic loops (Nunc, Denmark), to a commonly used dipslide method (Uricult, Orion, Finland) using a 0.1 ml pipette as the gold standard. Four typical uropathogens, E. coli, P. aeruginosa, S. saprophyticus and E. faecalis, were mixed in pooled human urine in numbers representing low counts, i.e. 10(2), 10(3), and 10(4), together with 10(5) colony-forming units (cfu)/ml, and sampling with the four methods was performed 20 times for each with each bacterium and each dilution. Colony counts showed that in many cases the 1 microl loop did not deposit any bacteria on the agar plate when colony counts were lower than 10(4) cfu/ml. The 10 microl loop constantly deposited 1.5 times higher numbers of bacteria than predicted, which correlated with the results of weighing the amount of water sampled, i.e. 15.24 (1.55) microg (mean (SD)). The dipslide counts correlated with the 10 microl loop although the agar mounts on the slides absorbed water equal to about 200 microl. There were no significant differences in the counts of the four different bacteria. Variation coefficients increased with decreasing volumes sampled, but the 10 microl loop was found sufficiently exact to detect counts from 10(3) to 10(4), since only 10-fold multiples are usually reported for urine cultures.

Inhibition of leukocyte entry into the brain by the selectin blocker fucoidin decreases interleukin-1 (IL-1) levels but increases IL-8 levels in cerebrospinal fluid during experimental pneumococcal meningitis in rabbits

The polysaccharide fucoidin is a selectin blocker that inhibits leukocyte recruitment into the cerebrospinal fluid (CSF) during experimental pneumococcal meningitis. In the present study, the effect of fucoidin treatment on the release of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-8 into the CSF was investigated. Rabbits (n = 7) were treated intravenously with 10 mg of fucoidin/kg of body weight every second hour starting 4 h after intracisternal inoculation of approximately 10(6) CFU of Streptococcus pneumoniae type 3 (untreated control group, n = 7). CSF samples were obtained every second hour during a 16-h study period. Treatment with fucoidin caused a consistent and significant decrease in CSF IL-1 levels (in picograms per milliliter) between 12 and 16 h (0 versus 170, 0 versus 526, and 60 versus 1,467, respectively; P < 0.02). A less consistent decrease in CSF TNF-alpha levels was observed in the fucoidin-treated group, but with no significant difference between the two groups (P > 0.05). In contrast, there was no attenuation in CSF IL-8 levels. Indeed, there was a significant increase in CSF IL-8 levels (in picograms per milliliter) in the fucoidin-treated group at 10 and 12 h (921 versus 574 and 1,397 versus 569, respectively; P < 0.09). In conclusion, our results suggest that blood-derived leukocytes mainly are responsible for the release of IL-1 and to some degree TNF-alpha into the CSF during pneumococcal meningitis, whereas IL-8 may be produced by local cells within the brain.

[Ciprofloxacin and pivampicillin in acute epididymitis in men above the age of 40 years]

Ciprofloxacin 500 mg orally twice daily was compared to pivampicillin 700 mg orally twice daily for 10 days in 172 men (41-85 years) with acute epididymitis. Failure of treatment occurred in 48 patients, in 15/76 (19.7%) receiving ciprofloxacin versus in 33/82 (40.2%) receiving pivampicillin (p = 0.006). Ciprofloxacin 500 mg orally twice daily is more effective than pivampicillin 700 mg orally twice daily and has fewer adverse events.

[Staphylococcus aureus endocarditis in Denmark 1982-1991. Clinical picture, complications and antibiotic therapy in non-drug addicts]

The central S. aureus surveillance in Denmark made it possible to analyze the clinical features of S. aureus endocarditis in a nation-wide population of non-drug addicts. Almost all cases of bacteraemia with S. aureus are reported to the Staphylococcus laboratory, Copenhagen. The medical records were reviewed in cases from 1982 to 1991 in which the diagnosis of endocarditis was reported or suspected. Two hundred and sixty patients fulfilled the diagnostic criteria. In 83 patients the diagnosis of endocarditis was not suspected clinically. The overall mortality rate among those patients whose disease was diagnosed clinically was 46% and significantly associated with late congestive heart failure, age and involvement of the central nervous system. A more frequent use of echocardiography as a screening method seems essential to improve the prognosis of patients with S. aureus endocarditis. Involvement of the CNS constitutes a relative indication for early valve replacement.