Risk of Psychiatric Disorders, Use of Psychiatric Hospitals, and Receipt of Psychiatric Medication in Patients With Brain Abscess in Denmark.

BACKGROUND: It is unknown whether patients diagnosed with brain abscess have an increased risk of psychiatric disorders. METHODS: In this nationwide, population-based matched cohort study from Denmark, we compared the incidence of psychiatric disorders, use of psychiatric hospitals, and receipt of psychiatric medications between patients diagnosed with brain abscess and individuals from the general population, matched on date of birth, sex, and residential area. RESULTS: We included 435 patients diagnosed with brain abscess and 3909 individuals in the comparison cohort: 61% were male and median age was 54 years. Patients diagnosed with brain abscess were more likely to suffer from comorbidity. The risk of a hospital diagnosis of psychiatric disorders was increased the first 5 years of observation. In the subpopulation, who had never been in contact with psychiatric hospitals or received psychiatric medication before study inclusion, the risk of developing psychiatric disorders was close to that of the background population, especially when we excluded dementia from this outcome. There was a substantial increase in the receipt of anxiolytics and antidepressants. The difference in the proportion of individuals who received anxiolytics and antidepressants increased from 4% (95% confidence interval [CI], 0%-7%) and 2% (95% CI, -1% to 5%) 2 years before study inclusion to 17% (95% CI, 12%-21%) and 11% (95% CI, 7%-16%) in the year after study inclusion. CONCLUSIONS: Patients with brain abscess without prior psychiatric disorders or receipt of psychiatric medicine are not at increased risk psychiatric disorders diagnosed in psychiatric hospitals, but they have an increased receipt of psychiatric medication.

Dentist's Visits and Risk of Brain Abscess: A Nationwide, Population-Based Case-Control Study.

BACKGROUND: Brain abscesses are frequently caused by oral cavity bacteria, but whether dental status and invasive dental procedures are important risk factors is unknown. METHODS: A nationwide, population-based, case-control study examined the association between dentist's visits and invasive dental procedures and risk of brain abscess caused by oral cavity bacteria from 1989 through 2016. Date of brain abscess diagnosis was considered the index date. Using risk-set sampling, 10 population controls per case were individually matched by age, sex, and residential area. Conditional logistic regression was used to compute odds ratios with 95% confidence intervals (CIs), adjusted for comorbidity. RESULTS: We identified 362 patients with culture-proven brain abscess caused by oral cavity bacteria. The median age was 53 years (interquartile range, 39-65 years) and 220 (61%) were male. Invasive dental procedures within 6 months before the index date was observed in 21 of 362 (6%) patients with brain abscess and 179 of 3257 (5%) population controls (adjusted odds ratio [aOR], 1.07 [95% CI, .67-1.70]). Two hundred thirteen of 362 (59%) patients with brain abscess had visited their dentist within 1 year before the index date compared with 1944 of 3257 (60%) of population controls (aOR, 0.99 [95% CI, .77-1.26]). Using no dentist's visits as reference, we observed aORs of 0.95 (95% CI, .64-1.40) for 1-2 visits within 3 years of the index date and 1.01 (95% CI, .76-1.35) for 3 or more visits. CONCLUSIONS: Recent invasive dental procedures and number of dentist's visits were not associated with culture-verified brain abscess caused by oral cavity bacteria.

Pivmecillinam, the paradigm of an antibiotic with low resistance rates in Escherichia coli urine isolates despite high consumption.

OBJECTIVES: Pivmecillinam, the oral version of mecillinam, represents one of the major recommended and used antibiotics for empiric and targeted treatment of urinary tract infections in primary care in Denmark, Norway and Sweden. Mecillinam resistant mutants in Escherichia coli develop easily in vitro, but their fitness cost has been shown to be high. METHODS: We revisited the resistance and consumption data from the monitoring programmes in the three countries and compared pivmecillinam with ciprofloxacin from 2010 to 2020. RESULTS: Mecillinam resistance rates in Escherichia coli remained around 6% in Denmark and Norway relative to a constant consumption in Norway of 1.6-1.8 DID (defined daily doses per 1000 inhabitants per day), and even increasing in Denmark from 1.6 to 2.3 DID. In Sweden resistance was significantly lower at 4% related to the lower consumption of 0.5 DID. For ciprofloxacin, resistance rates fluctuated around 6%-12%, highest in Sweden with the highest consumption (0.8-0.6 DID) and lowest in Denmark (0.55-0.35 DID) and Norway (0.7-0.3 DID), although consumption declined significantly in all three countries. CONCLUSIONS: Pivmecillinam is an example of an antibiotic, which easily develops resistance in vitro, but apparently can be used broadly in primary care without increase in resistance rates.

Comparable Outcomes of Short-Course and Prolonged-Course Therapy in Selected Cases of Methicillin-Susceptible Staphylococcus aureus Bacteremia: A Pooled Cohort Study.

BACKGROUND: The recommended duration of antimicrobial treatment for Staphylococcus aureus bacteremia (SAB) is a minimum of 14 days. We compared the clinical outcomes of patients receiving short-course (SC; 6-10 days), or prolonged-course (PC; 11-16 days) antibiotic therapy for low-risk methicillin-susceptible SAB (MS-SAB). METHODS: Adults with MS-SAB in 1995-2018 were included from 3 independent retrospective cohorts. Logistic regression models fitted with inverse probability of treatment weighting were used to assess the association between the primary outcome of 90-day mortality and treatment duration for the individual cohorts as well as a pooled cohort analysis. RESULTS: A total of 645, 219, and 141 patients with low-risk MS-SAB were included from cohorts I, II, and III. Median treatment duration in the 3 SC groups was 8 days (interquartile range [IQR], 7-10), 9 days (IQR, 8-10), and 8 days (IQR, 7-10). In the PC groups, patients received a median therapy of 14 days (IQR, 13-15), 14 days (IQR, 13-15), and 13 days (IQR, 12-15). No significant differences in 90-day mortality were observed between the SC and PC group in cohort I (odds ratio [OR], 0.85 [95% confidence interval {CI}, .49-1.41]), cohort II (OR, 1.24 [95% CI, .60-2.62]), or cohort III (OR, 1.15 [95% CI, .24-4.01]). This result was consistent in the pooled cohort analysis (OR, 1.05 [95% CI, .71-1.51]). Furthermore, duration of therapy was not associated with the risk of relapse. CONCLUSIONS: In patients with low-risk MS-SAB, shorter courses of antimicrobial therapy yielded similar clinical outcomes as longer courses of therapy.

Effective antimicrobial combination in vivo treatment predicted with microcalorimetry screening.

OBJECTIVES: The worldwide emergence of antibiotic resistance calls for effective exploitation of existing antibiotics. Antibiotic combinations with different modes of action can synergize for successful treatment. In the present study, we used microcalorimetry screening to identify synergistic combination treatments against clinical MDR isolates. The synergistic effects were validated in a murine infection model. METHODS: The synergy of meropenem combined with colistin, rifampicin or amikacin was tested on 12 isolates (1 Escherichia coli, 5 Klebsiella pneumoniae, 3 Pseudomonas aeruginosa and 3 Acinetobacter baumannii) in an isothermal microcalorimeter measuring metabolic activity. One A. baumannii strain was tested with two individual pairings of antibiotic combinations. The microcalorimetric data were used to predict in vivo efficacy in a murine peritonitis/sepsis model. NMRI mice were inoculated intraperitoneally and after 1 h treated with saline, drug X, drug Y or X+Y. Bacterial load was determined by cfu in peritoneal fluid and blood after 4 h. RESULTS: In vitro, of the 13 combinations tested on the 12 strains, 3 of them exhibited a synergistic reduction in MIC (23% n = 3/13), 5 showed an additive effect (38.5% n = 5/13) and 5 had indifferent or antagonistic effects (38.5% n = 5/13). There was a significant correlation (P = 0.024) between microcalorimetry-screening FIC index values and the log reduction in peritoneal fluid from mice that underwent combination treatment compared with the most effective mono treatment. No such correlation could be found between chequerboard and in vivo results (P = 0.16). CONCLUSIONS: These data support microcalorimetic metabolic readout to predict additive or synergistic effects of combination treatment of MDR infections within hours.

Hospital readmissions following infections in dementia: a nationwide and registry-based cohort study.

INTRODUCTION: We aimed to investigate readmission risks following infections in dementia, identify the types of infections behind the risks, and highlight the reasons for readmissions. METHODS: Acute inpatient hospital admissions for infections in Danish residents were included from 1 January 2000, or age 65 years. Primary outcomes were 7-day readmissions risk ratios (RRs; risk following infection index admissions of people with dementia relative to those without dementia), risks by infection site, and reasons for readmission. Secondary outcomes were 30- and 90-day readmission risks. Competing risk of death was estimated. RESULTS: Seven-day readmission RR was increased in all age groups and was highest in the youngest patients (women RR: 1.37, 95% confidence interval [CI] 1.22-1.53; men RR: 1.23, 95% CI 1.12-1.35). RRs decreased with increasing age and longer follow-up. The most notable common readmissions were for infections and dehydration in dementia. CONCLUSIONS: We conclude that there is a substantially increased readmission risk in people with dementia than in those without dementia, particularly within 7 days, and for the youngest in the cohort. Readmission risks were higher for infection index admissions than for admissions for causes other than infection, and readmissions were mostly due to infections. Our findings highlight the burden of infections in people with dementia and call for in-depth investigations of determinants related to readmission risks, to inform public policy and identify avenues for interventions that can decrease or prevent potentially avoidable readmissions.

Ciprofloxacin Pharmacokinetics/Pharmacodynamics against Susceptible and Low-Level Resistant Escherichia coli Isolates in an Experimental Ascending Urinary Tract Infection Model in Mice.

The mouse ascending urinary tract infection model was used to study the pharmacokinetic/pharmacodynamic (PKPD) relationships of the effect of ciprofloxacin in subcutaneous treatment for 3 days with varying doses and dosing intervals against a susceptible Escherichia coli strain (MIC, 0.032 mg/liter). Further, a humanized dose of ciprofloxacin was administered for 3 days against three E. coli strains with low-level resistance, i.e., MICs of 0.06, 0.25, and 1 mg/liter, respectively. Against the susceptible isolate, ciprofloxacin was highly effective in clearing the urine with daily doses from 10 mg/kg, but the dosing regimen had to be divided into at least two doses for optimal effect. Ciprofloxacin could not clear the urine or kidneys for the low-level-resistant strains. PKPD correlations with all strains combined showed that for the AUC24/MIC there was a slightly higher correlation with effect in urine and kidneys (R2, 0.71 and 0.69, respectively) than the %T>MIC (R2, 0.41 and 0.61, respectively). Equal correlations for the two PKPD indices were found for reduction of colony counts (CFU) in the bladder tissue, but not even the highest dose of 28 mg/kg × 6 could clear the bladder tissue. In conclusion, ciprofloxacin is highly effective in clearing the urine and kidney tissue for fully susceptible E. coli, while even low-level resistance in E. coli obscures this effect. While the effect of ciprofloxacin is mostly AUC/MIC driven against E. coli infection in the urinary tract, the effect in urine depends on the presence of ciprofloxacin in the urine during most of a 24-h period.

A snapshot of diversity: Intraclonal variation of Escherichia coli clones as commensals and pathogens.

Whole-genome sequencing has enabled detailed studies on bacterial evolution during infection, but there is limited knowledge on intraclonal variation. In this study, we sought to provide a snapshot of the intraclonal diversity of Escherichia coli as both commensal in the faecal environment and pathogen during urinary tract infection, respectively. This was performed by whole-genome sequencing and analyses of single nucleotide polymorphisms (SNPs) and gene-content variation in ten isolates belonging to the same clone and isolated from rectal swabs or urine samples. We identified only one clone in eight of the nine urines sampled (89 %). In both the commensal and pathogenic state, the within-host diversity was limited with intraclonal SNP diversity of 0-2 non-synonymous SNPs for each clone. The genetic diversity showed variation in gene content in a range of 2-15 genes in total for all clones, including genes positioned on plasmids, and in the K- and O-antigen cluster. The observed SNP- and gene variation shows that sampling of one colony would be enough for surveillance, outbreak investigations and clonal evolution. However, for studies of adaptation during or between colonization and infection, this variation is relevant to consider.

Exposure of consumers to substandard antibiotics from selected authorised and unauthorised medicine sales outlets in Ghana.

OBJECTIVE: To assess the quality of antibiotics sampled from authorised sales outlets (ATs) (i.e. hospitals/health centres, pharmacies and licensed chemical shops) and unauthorised sales outlets (UATs) (mainly street vendors) in Ghana and to explore the health-seeking behaviour of medicine consumers. METHODS: The contents of 14 active pharmaceutical ingredients (APIs) in 348 sampled products were determined using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Data on health-seeking practices were collected through entry and exit interviews and field observations from ATs and UATs. RESULTS: It was observed that 66.38% of all sampled antibiotic products were substandard; they either contained less (<90%) or more API (>110%) than the label claim. Medicines from UATs recorded substantially less API contents than those from ATs (F(2,419)  = 43.01, P < 0.0001). For example, 90.54% of street vendor samples contained < 90% of the APIs. 75.93% of consumers often sought self-treatment with drugs without a prescription from UATs, as they perceived UATs as easily accessible, trustworthy and knowledgeable, and their medicines as inexpensive. These consumers rather thought of the formal healthcare providers as alternative sources. CONCLUSIONS: Consumers who purchase from UATs are at high risk of receiving substandard medicines. The quality of medicines in the national healthcare system, in the supply chain and in the distribution system needs to be monitored regularly to reduce the incidence of substandard medicines and their impact on antimicrobial resistance. The fight against substandard medicines needs to incorporate a full understanding of socioeconomic factors that drive consumer decisions regarding their health and choice of healthcare providers.

OBJECTIF: Evaluer la qualité des antibiotiques prélevés auprès des vendeurs autorisés (VA) (c'est-à-dire les hôpitaux/centres de santé, les pharmacies et les magasins de produits chimiques agréés) et des vendeurs non autorisés (VNA) (principalement les vendeurs de rue) au Ghana et étudier le comportement des utilisateurs de médicaments en quête de santé. MÉTHODES: Le contenu de 14 principes actifs (PA) pharmaceutiques dans 348 produits échantillonnés a été déterminé à l'aide d'une méthode validée de chromatographie liquide et de spectrométrie de masse en tandem (LC-MS/MS). Les données sur les pratiques de recherche de santé ont été collectées par le biais d'entretiens d'entrée et de sortie, et d'observations sur le terrain des VA et des VNA. RÉSULTATS: Il a été observé que 66,38% de tous les produits antibiotiques échantillonnés étaient inférieurs aux normes; ils contenaient soit moins (<90%), soit plus de PA (>110%) que ce qui était indiqué sur la notice. Les médicaments provenant des VNA ont enregistré une quantité de PA sensiblement inférieure à celle des VA (F(2,419)  = 43.01, P < 0,0001). Par exemple, 90,54% des échantillons de vendeurs de rue contenaient <90% de PA. 75,93% des utilisateurs ont souvent cherché à se soigner eux-mêmes avec des médicaments sans ordonnance des VNA, car ils ont perçu les VNA comme étant facilement accessibles, fiables et bien informés, et leurs médicaments comme étant peu coûteux. Ces utilisateurs considéraient également les prestataires de soins de santé officiels comme des sources alternatives. CONCLUSIONS: Les utilisateurs qui s'approvisionnent auprès des VNA courent un risque élevé de recevoir des médicaments de qualité inférieure. La qualité des médicaments dans le système national de santé, dans la chaîne d'approvisionnement et dans le système de distribution doit être contrôlée régulièrement pour réduire l'incidence des médicaments de qualité inférieure et leur impact sur la résistance aux antimicrobiens. La lutte contre les médicaments de qualité inférieure doit intégrer une compréhension complète des facteurs socioéconomiques qui déterminent les décisions des utilisateurs concernant leur santé et le choix des prestataires de soins de santé.

Meropenem to Children With Febrile Neutropenia Induces Monoresistant Pseudomonas aeruginosa.

Antimicrobial resistance in Pseudomonas aeruginosa is a threat to children with cancer. We explored the association between P. aeruginosa resistance and previous antibiotic exposure. All children with cancer and P. aeruginosa bacteremia in 2007 to 2016 in Denmark, a country with an overall resistance rate of ∼3%, were included. Twenty percent (10/49) of isolates from children previously exposed to meropenem were meropenem nonsusceptible. The only significant risk factor of meropenem nonsusceptibility was previous meropenem therapy (P=0.03). On the basis of these results, we suggest that meropenem should be reserved as a last resort for children with febrile neutropenia in countries with low antimicrobial resistance.

Comparative Activity of Ceftriaxone, Ciprofloxacin, and Gentamicin as a Function of Bacterial Growth Rate Probed by Escherichia coli Chromosome Replication in the Mouse Peritonitis Model.

Commonly used antibiotics exert their effects predominantly on rapidly growing bacterial cells; yet, the growth dynamics taking place during infection in a complex host environment remain largely unknown. Hence, a means to measure in situ bacterial growth rate is essential to predict the outcome of antibacterial treatment. We have recently validated chromosome replication as a readout of in situ bacterial growth rate during Escherichia coli infection in the mouse peritonitis model. By the use of two complementary methods (quantitative PCR and fluorescence microscopy) for differential genome origin and terminus copy number quantification, we demonstrated the ability to track bacterial growth rate, both on a population average level and on a single-cell level, from one single biological specimen. Here, we asked whether the in situ growth rate predicts antibiotic treatment effect during infection in the same model. Parallel in vitro growth experiments were conducted as a proof of concept. Our data demonstrate that the activities of the commonly used antibiotics ceftriaxone and gentamicin correlated with pretreatment bacterial growth rate; both drugs performed better during rapid growth than during slow growth. Conversely, ciprofloxacin was less sensitive to bacterial growth rate, both in a homogenous in vitro bacterial population and in a more heterogeneous in vivo bacterial population. The method serves as a platform to test any antibiotic's dependency on active in situ bacterial growth. Improved insight into this relationship in vivo could ultimately prove helpful in evaluating future antibacterial strategies.

Treatment duration of pivmecillinam in men, non-pregnant and pregnant women for community-acquired urinary tract infections caused by Escherichia coli: a retrospective Danish cohort study.

OBJECTIVES: To evaluate the importance of treatment duration for therapeutic efficacy of pivmecillinam for community-acquired urinary tract infections (UTIs) caused by Escherichia coli. METHODS: A retrospective cohort study was conducted between 1 January 2010 and 30 September 2016 in adults with community-acquired E. coli bacteriuria, treated empirically with pivmecillinam. Regimens of 3, 5 and 7 days were compared using clinical treatment failure (i.e. redemption of a new antibiotic or hospitalization due to UTI) within 14 and 30 days as outcome. HR and risk difference with 95% CI were estimated for treatment failure. Results were stratified by age (18-50, 51-70, >70 years) and sex. RESULTS: Of the 21864 cases of E. coli UTI that were analysed, 2524 (11.5%) were in men. In 954 cases (4.4%) E. coli produced ESBL and 125 (13.1%) of the cases were in men. The 3 day regimen increased the risk of treatment failure for all groups. The risk differences between the 3 and 5 day regimens were <10% for women, but >10% for men. Comparing the 7 day and 5 day regimens, only women aged >50 years demonstrated an increased risk of treatment failure within 14 days with the 5 day regimen, but not within 30 days. CONCLUSIONS: With the current data, where data on clinical classification of the E. coli UTI were missing, a 5 day treatment with pivmecillinam at 400 mg three times daily seems to be the rational recommendation for lower UTI in men, pregnant women and women >50 years old. A 3 day regimen seems sufficient for non-pregnant women <50 years old.

LRE-Finder, a Web tool for detection of the 23S rRNA mutations and the optrA, cfr, cfr(B) and poxtA genes encoding linezolid resistance in enterococci from whole-genome sequences.

OBJECTIVES: In enterococci, resistance to linezolid is often mediated by mutations in the V domain of the 23S rRNA gene (G2576T or G2505A). Furthermore, four genes [optrA, cfr, cfr(B) and poxtA] encode linezolid resistance in enterococci. We aimed to develop a Web tool for detection of the two mutations and the four genes encoding linezolid resistance in enterococci from whole-genome sequence data. METHODS: LRE-Finder (where LRE stands for linezolid-resistant enterococci) detected the fraction of Ts in position 2576 and the fraction of As in position 2505 of the 23S rRNA and the cfr, cfr(B), optrA and poxtA genes by aligning raw sequencing reads (fastq format) with k-mer alignment. For evaluation, fastq files from 21 LRE isolates were submitted to LRE-Finder. As negative controls, fastq files from 1473 non-LRE isolates were submitted to LRE-Finder. The MICs of linezolid were determined for the 21 LRE isolates. As LRE-negative controls, 26 VRE isolates were additionally selected for linezolid MIC determination. RESULTS: LRE-Finder was validated and showed 100% concordance with phenotypic susceptibility testing. A cut-off of 10% mutations in position 2576 and/or position 2505 was set in LRE-Finder for predicting a linezolid resistance phenotype. This cut-off allows for detection of a single mutated 23S allele in both Enterococcus faecalis and Enterococcus faecium, while ignoring low-level sequencing noise. CONCLUSIONS: A Web tool for detection of the 23S rRNA mutations (G2576T and G2505A) and the optrA, cfr, cfr(B) and poxtA genes from whole-genome sequences from enterococci is now available online.

Community-acquired meningitis caused by beta-haemolytic streptococci in adults: a nationwide population-based cohort study.

The objective of this study was to examine the clinical presentation of community-acquired beta-haemolytic streptococcal (BHS) meningitis in adults. This is a nationwide population-based cohort study of adults (≥ 16 years) with BHS meningitis verified by culture or polymerase chain reaction of the cerebrospinal fluid (CSF) from 1993 to 2005. We retrospectively evaluated clinical and laboratory features and assessed outcome by Glasgow Outcome Scale (GOS). We identified 54 adults (58% female) with a median age of 65 years (IQR 55-73). Mean incidence rate was 0.7 cases per 1,000,000 person-years. Alcohol abuse was noted among 11 (20%) patients. Group A streptococci (GAS) were found in 17 (32%) patients, group B (GBS) in 18 (34%), group C (GCS) in four (8%) and group G (GGS) in 14 (26%). Patients with GAS meningitis often had concomitant otitis media (47%) and mastoiditis (30%). Among patients with GBS, GCS or GGS meningitis, the most frequent concomitant focal infections were bone and soft tissue infections (19%) and endocarditis (16%). In-hospital mortality was 31% (95% CI 19-45), and 63% (95% CI 49-76) had an unfavourable outcome at discharge (GOS < 5). BHS meningitis in adults is primarily observed among the elderly and has a poor prognosis. GAS meningitis is primarily associated with concomitant ear-nose-throat infection.

Piperacillin/tazobactam vs carbapenems for patients with bacterial infection: Protocol for a systematic review.

INTRODUCTION: Early empirical broad-spectrum antimicrobial therapy is recommended for patients with severe infections, including sepsis. ß-lactam/ß-lactamase inhibitor combinations or carbapenems are often used to ensure coverage of likely pathogens. Piperacillin/tazobactam is proposed as a carbapenem-sparing agent to reduce the incidence of multidrug-resistant bacteria and superinfections. In the recently published MERINO trial, increased mortality from piperacillin/tazobactam was suggested in patients with bacteraemia with resistant Escherichia coli or Klebsiella species. Whether these findings also apply to empirical piperacillin/tazobactam in patients with other severe infections, including sepsis, is unknown. We aim to assess the benefits and harms of empirical and definitive piperacillin/tazobactam vs carbapenems for patients with severe bacterial infections. METHODS AND ANALYSIS: This protocol has been prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statement, the Cochrane Handbook and the Grading of Recommendations, Assessment, Development, and Evaluation approach. We will include randomised clinical trials assessing piperacillin/tazobactam vs carbapenems in patients with severe bacterial infections of any origin. The primary outcome will be all-cause short-term mortality ≤ 90 days. Secondary outcomes will include all-cause long-term mortality > 90 days, adverse events, quality of life, use of life support, secondary infections, antibiotic resistance, and length of stay. We will conduct meta-analyses, including pre-planned subgroup and sensitivity analyses for all assessed outcomes. The risk of random errors in the meta-analyses will be assessed by trial sequential analysis.

Pharmacokinetics and Pharmacodynamics of Fosfomycin and Its Activity against Extended-Spectrum-ß-Lactamase-, Plasmid-Mediated AmpC-, and Carbapenemase-Producing Escherichia coli in a Murine Urinary Tract Infection Model.

Fosfomycin has become an attractive treatment alternative for urinary tract infections (UTIs) due to increasing multidrug resistance (MDR) in Escherichia coli In this study, we evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) indices of fosfomycin and its in vivo activity in an experimental murine model of ascending UTI. Subcutaneous administration of fosfomycin showed that the mean peak plasma concentrations of fosfomycin were 36, 280, and 750 mg/liter following administration of a single dose of 0.75, 7.5, and 30 mg/mouse, respectively, with an elimination half-life of 28 min, and urine peak concentrations of 1,100, 33,400, and 70,000 mg/liter expected to be sustained above 1 mg/liter (MIC of the test strain, NU14) for 5, 8, and 9.5 h, respectively. The optimal PK/PD indices for reducing urine colony counts (number of CFU per milliliter) were determined to be the area under the concentration-time curve/MIC from 0 to 72 h and the maximum concentration/MIC on the basis of the dose-dependent bloodstream PK and the results of an evaluation of six dosing regimens. With a dosing regimen of 15 mg/mouse twice (every 36 h), fosfomycin significantly reduced the number of CFU per milliliter of all susceptible strains in urine, including clinical MDR strains, except for one clinical strain (P = 0.062). Variable degrees of reduction were observed in the bladder and kidneys. No significant reductions in the number of CFU per milliliter were observed with the resistant strains. In conclusion, fosfomycin shows concentration-dependent in vivo activity, and the results suggest that fosfomycin is an effective alternative to carbapenems in treating MDR E. coli in uncomplicated UTIs. The data on the effectiveness of fosfomycin against the MDR isolates along with the results of PK/PD modeling should facilitate the further development of improved recommendations for its clinical use.

Use of diagnostic tests and the appropriateness of the treatment decision in patients with suspected urinary tract infection in primary care in Denmark - observational study.

BACKGROUND: Inappropriate prescription of antibiotics is the leading driver of antimicrobial resistance (AMR). The majority of antibiotics are prescribed in primary care. Understanding how general practitioners (GPs) use diagnostic tests and the effect on treatment decision under daily practice conditions is important to reduce inappropriate prescription of antibiotics. The aim of the study was to investigate the use of diagnostic tests in primary care patients with suspected urinary tract infection (UTI) and to assess the appropriateness of the treatment decision (TD) under daily practice conditions in Denmark. METHODS: Prospective observational study. Symptomatic adult patients consulting general practice with suspected UTI recruited over 12 months. The diagnostic workup was registered in a standardized form. The appropriateness of the TD was assessed based on the results of a culture performed at a reference microbiological laboratory. TD was considered appropriate if a patient had a positive culture and was prescribed antibiotics or had a negative culture and was not prescribed antibiotics. TD was considered inappropriate if a patient had a negative culture and was prescribed antibiotics (overtreatment) or had a positive culture and was not prescribed antibiotics (undertreatment). RESULTS: Four hundred and eighty-eight patients were included. Dipstick was used in 98% of the patients and urine culture was used in 89% of the patients; 317 had the culture performed in practice and 117 had the culture performed at the hospital. The appropriateness of the final TD was significantly (p = 0.04) lower in patients without culture (55%) than in patients with culture performed in practice (71%) or at hospital (69%). CONCLUSION: In a context with wide availability of diagnostic tests, GPs use diagnostic tests for the decision-making process in all patients with suspected UTI. Urine culture is used in the majority of the patients and is associated with a higher proportion of appropriate treatment decisions. Performance of urine culture is therefore important in reducing inappropriate antibiotic prescribing in patients with suspected UTI seeking care in general practice in Denmark. TRIAL REGISTRATION: ClinicalTrials.gov NCT02249273 .

Whole-genome comparison of urinary pathogenic Escherichia coli and faecal isolates of UTI patients and healthy controls.

The faecal flora is a common reservoir for urinary tract infection (UTI), and Escherichia coli (E. coli) is frequently found in this reservoir without causing extraintestinal infection. We investigated these E. coli reservoirs by whole-genome sequencing a large collection of E. coli from healthy controls (faecal), who had never previously had UTI, and from UTI patients (faecal and urinary) sampled from the same geographical area. We compared MLST types, phylogenetic relationship, accessory genome content and FimH type between patient and control faecal isolates as well as between UTI and faecal-only isolates, respectively. Comparison of the accessory genome of UTI isolates to faecal isolates revealed 35 gene families which were significantly more prevalent in the UTI isolates compared to the faecal isolates, although none of these were unique to one of the two groups. Of these 35, 22 belonged to a genomic island and three putatively belonged to a type VI secretion system (T6SS). MLST types and SNP phylogeny indicated no clustering of the UTI or faecal E. coli from patients distinct from the control faecal isolates, although there was an overrepresentation of UTI isolates belonging to clonal lineages CC73 and CC12. One combination of mutations in FimH, N70S/S78N, was significantly associated to UTI, while phylogenetic analysis of FimH and fimH identified no signs of distinct adaptation of UTI isolates compared to faecal-only isolates not causing UTI. In summary, the results showed that (i) healthy women who had never previously had UTI carried faecal E. coli which were overall closely related to UTI and faecal isolates from UTI patients; (ii) UTI isolates do not cluster separately from faecal-only isolates based on SNP analysis; and (iii) 22 gene families of a genomic island, putative T6SS proteins as well as specific metabolism and virulence associated proteins were significantly more common in UTI isolates compared to faecal-only isolates and (iv) evolution of fimH for these isolates was not linked to the clinical source of the isolates, apart from the mutation combination N70S/S78N, which was correlated to UTI isolates of phylogroup B2. Combined, these findings illustrate that faecal and UTI isolates, as well as faecal-only and faecal-UTI isolates, are closely related and can only be distinguished, if at all, by their accessory genome.

Comparison of two commercial broad-range PCR and sequencing assays for identification of bacteria in culture-negative clinical samples.

BACKGROUND: Culturing has long been the gold standard for detecting aetiologic agents in bacterial infections. In some cases, however, culturing fails to detect the infection. To further investigate culture-negative samples, amplification and subsequent sequencing of the 16S rRNA gene is often applied. The aim of the present study was to compare the current method used at our Department of Clinical Microbiology, based on the MicroSeq ID system (Applied Biosystems, USA) with the Universal Microbe Detection (UMD) SelectNA kit (Molzym, Germany). METHODS: 76 culture-negative samples were first processed with the MicroSeq ID analysis, where total DNA was extracted and the 16S gene amplified and sequenced with the MicroSeq ID system. Samples were subsequently processed with the UMD SelectNA analysis, where human DNA was removed during the DNA extraction procedure and the 16S gene amplified in a real-time PCR and sequenced. RESULTS: 22 of 76 samples (28.9%) were positive for bacteria with the UMD SelectNA, which was significantly more (p = 0.0055) than the MicroSeq ID where 11 of 76 samples (14.5%) were positive. The UMD SelectNA assay identified more relevant bacterial pathogens than the MicroSeq ID analysis (p = 0.0233), but also found a number of species that were considered contaminations. CONCLUSIONS: The UMD SelectNA assay was valuable for the identification of pathogens in culture-negative samples; however, due to the sensitive nature of the assay, extreme care is suggested in order to avoid false positives.

Carriage and serotype distribution of Streptococcus agalactiae in third trimester pregnancy in southern Ghana.

BACKGROUND: The aim of this study was to determine the prevalence of Streptococcus agalactiae (group B streptococci, GBS) among healthy, pregnant women attending antenatal care at different study sites in the Greater Accra Region, Ghana. METHODS: Between 2010 and June 2013, recto-vaginal swab samples were collected from pregnant women attending antenatal care from two study sites in southern Ghana. The samples were collected within 35 and 37 weeks of the gestation period. These were inoculated into Todd-Hewitt broth followed by sub-culturing onto a sheep-blood agar plate. Identification was performed on a single subcultured colony. Gram staining was performed, and isolates were evaluated for beta-haemolytic reactions. Furthermore, the isolates were serotyped using the GBS latex serotyping kit. RESULTS: The carriage rates were found to be 25.5% (95% CI: 19.6-32.1) to 28.0% (95% CI: 21.9-34.8) for the two collection sites. The most common serotypes were serotypes VII and IX. The data showed that women below 20 years of age or above 30 years of age have a significantly (p = 0.037) higher risk of carrying GBS compared to women from the age group of 20 to 30 years. CONCLUSIONS: The findings of this study revealed that prevalence of GBS colonization in pregnant women in Greater Accra region is high and comparable to rates observed in South Africa and Western countries. The most prevalent serotypes were serotypes VII and IX, which have not been observed before in West Africa.