Optimal Antimicrobial Therapy Research Articles

1794. Impact of a Pharmacist-Driven Detailed Penicillin Allergy Interview

BackgroundIn the United States, 10% of patients report a penicillin (PCN) allergy. These self-reported allergies may be outdated or inaccurate, which may lead to usage of alternate antimicrobials that may be less effective, more toxic, and/or more expensive. While PCN skin tests (PST) can provide an accurate assessment and de-labeling of PCN allergies, they are not feasible at all institutions. An alternative solution is to conduct a detailed penicillin allergy interview (DPAI), which can potentially lead to de-escalation and/or optimization of antimicrobial therapy.MethodsPharmacist-driven DPAIs were conducted between December 26, 2017 and March 26, 2018. Adult patients admitted with a documented PCN allergy were interviewed according to a standardized questionnaire. The allergy profile within the EHR was updated and a recommendation to switch to non-carbapenem β-lactam therapy was made to the prescriber based on a decision algorithm. Objectives of this study include characterization of changes made to the allergy profile within the EHR after DPAI and measuring the number of patients successfully switched to β-lactam therapy.ResultsA total of 466 patients were admitted with a documented PCN allergy, of which 175 (37.5%) received DPAI. Of these patients, 133 (76%) required a change to their allergy profile (Table 1). One-hundred thirty-five (77.1%) patients interviewed were on an antimicrobial agent (Figure 1). Forty-two patients (31.1%) met criteria to switch to non-carbapenem β-lactam therapy, and 31 (73.8%) patients were successfully switched with no adverse events noted.Table 1:Changes to Allergy ProfileType of Change N = 175No changes42 (24)Addition of tolerance history58 (33.1)Modification of reaction details32 (18.3)Addition of tolerance history AND modification of reaction details41 (23.4)Deletion of allergy2 (1.1)Figure 1.Initial antimicrobial therapy.ConclusionA large number of admitted patients with a documented PCN allergy received a DPAI. Implementation of pharmacist-driven DPAIs led to updated, more accurate allergy information within the EHR, as well as de-escalation and/or optimization of antimicrobial therapy. Provider acceptance rate to switch to non-carbapenem β-lactam therapy was high.Disclosures All authors: No reported disclosures.

Rapid Optimization of Antibiotic Therapy for Multidrug-Resistant Gram-Negative Infections Using Nanopore Whole Genome Sequencing

Background: Standard antimicrobial susceptibility testing (AST) approaches lead to delays in the selection of optimal antimicrobial therapy. We sought to determine the accuracy of antimicrobial resistance (AMR) determinants identified by Nanopore whole genome sequencing in predicting AST results. Methods: Using a cohort of 40 clinical Klebsiella pneumoniae isolates, three separate sequencing and analysis pipelines were performed: (1) a real-time Nanopore analysis approach that identified acquired AMR genes, (2) an assembly-based Nanopore approach that identified acquired AMR genes and chromosomal mutations, and (3) a Pilon-corrected Nanopore-Illumina hybrid approach. The Pilon-corrected assemblies served as the reference standard to determine the accuracy of Nanopore sequencing results. Findings: With the real-time analysis approach, full annotation of acquired AMR genes occurred within 8 hours of subcultured isolates. Assemblies sufficient for full resistance gene and single nucleotide polymorphism annotation were available within 14 hours from subcultured isolates. The overall agreement of genotypic results and anticipated AST results for the 40 K. pneumoniae isolates was 75% (range 30-95%) and 91% (range 80-98%) for the real-time approach and the assembly approach, respectively. Evaluating the patients contributing the 40 isolates, the real-time approach and assembly approach could substantially shorten the median time to effective antibiotic therapy by 20 hours and 26 hours, respectively, compared to standard AST. Interpretations: Nanopore sequencing offers a rapid approach to both accurately identify resistance mechanisms as well as to predict AST results. Bioinformatics improvements enabling real-time alignment coupled with rapid extraction and library preparation will further enhance the accuracy and workflow of the Nanopore real-time approach. Funding Statement: The work was supported by funding from the National Institutes of Health K23-AI127935 awarded to PDT, a Canadian Institutes of Health Research fellowship awarded to YF, an R01-HG009190 awarded to WT, an R01-HG006677 awarded to MCS, and an R21-AI130608 awarded to PJS. Declaration of Interests: PDT has received research funding from Merck, outside of the submitted work. KCC has received research funding from GenMark, Inc. and Singulex outside of the submitted work. WT has two patents (8,748,091 and 8,394,584) licensed to Oxford Nanopore. WT, YF, PJS have received travel funds from Oxford Nanopore Technologies. PJS has received grants and personal fees from Accelerate Diagnostics, grants from BD Diagnostics, Inc., grants from bioMerieux, Inc., grants from Check-Points Diagnostics, BV, grants from Hardy Diagnostics, personal fees from Roche Diagnostics, personal fees from Opgen Inc, outside the submitted work. All other authors declare no competing interests. Ethics Approval Statement: The Johns Hopkins University School of Medicine Institutional Review Board approved this study, with a waiver of informed consent.

Impact of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight for the Identification of Gram-Positive Bloodstream Pathogens without Antimicrobial Stewardship Intervention in Hospitalized Children

AbstractWe performed a 2-year retrospective cohort study of inpatient children with growth of gram-positive bacteria from blood cultures identified with and without the use of matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) in the absence of an antimicrobial stewardship program. Use of MALDI-TOF reduced the time to organism identification by 15.7 hours (p < 0.0001). However, no differences in length of stay, time to optimization of antimicrobial therapy, or time to discontinuation of antibiotics for growth of contaminants were documented, suggesting that such potential patient-oriented benefits of MALDI-TOF may only be evident in the presence of a concurrent antimicrobial stewardship program.

Chromobacterium violaceum – an unusual pathogen. Perspectives to ponder!!

Human infection due to Chromobacterium violaceum is rare, even though the bacteria are ubiquitous in distribution. Without appropriate antimicrobial therapy, the consequences can be rapidly fatal if septicemia sets in. Both pigmented and nonpigmented varieties are equally virulent. Mortality rates are quite high despite treatment. The history of trauma and simultaneous exposure to water and soil should alert clinician about this entity. Fluoroquinolones and aminoglycosides show good sensitivity, whereas penicillin and early cephalosporins are poor therapeutic options. Treatment for an extended period beyond clinical cure is indispensable to prevent relapse. Combination of prompt diagnosis, optimal antimicrobial therapy, and adequate therapeutic duration for C. violaceum infection is the key for successful therapy. We present here two cases of C. violaceum infections with interesting presentations with a brief review of literature.

Microbiology of Vertebral Osteomyelitis and Implications on Empiric Therapy

BackgroundThe management of vertebral osteomyelitis (VO) includes empiric antibiotic therapy while clinical cultures are being processed. Optimal antimicrobial therapy for VO, particularly when Gram-negative (GN) organisms are involved, is an area of ongoing debate. Narrow spectrum and oral antimicrobial therapy are preferred. The objective of this study was to identify characteristics of local pathogens and to formulate an institution-specific antibiotic protocol for empiric treatment of VO.MethodsWe conducted a retrospective case series study of adults diagnosed with VO from August 1, 2010 to August 31, 2015 at Palmetto Health Hospitals in Columbia, South Carolina. Cases identified by ICD-9 codes were included in the analysis if they met clinical, imaging and microbiology, criteria.ResultsAnalysis is based on 150 cases of VO with a mean age of 61 years, a male predominance (91; 61%), and an average body mass index of 29kg/m2. Comorbidities included diabetes mellitus (69; 46%), tobacco use (33; 22%), and hemodialysis (20; 13%). Thirty-seven (25%) cases had recent related injury or vertebral surgery, and 14 (9%) had prior hardware. Bone, disc, or adjacent tissue cultures were obtained in 129 (86%) of cases; 60 (40%) of these had >1 sample taken. The remaining 14% had blood cultures alone. Thirty-six cases (24%) had culture negative VO. In the remaining 114 cases, 132 organisms were isolated. A total of 111 (84%) organisms were Gram-positive cocci (GPC). Of those, the majority was Staphylococcus aureus. (66; 59%) (26/66 were methicillin-resistant), coagulase-negative staphylococci (20; 18%) and Streptococcus spp. (17; 15%). Enterobacteriaceae accounted for 13/17 Gram-negative bacilli (GNB), with only one isolate of Pseudomonas aeruginosa. Of the GNB, 11/17 were susceptible to either ceftriaxone or ciprofloxacin.ConclusionThere was a predominance of VO due to GPC suggesting that intravenous vancomycin monotherapy may be reasonable for empiric therapy in noncritically ill patients while awaiting Gram stain and clinical culture results. Addition of either ceftriaxone or ciprofloxacin to vancomycin would increase cumulative antimicrobial coverage from 84 to 92%.Disclosures All authors: No reported disclosures.

Cumulative Effect of an Antimicrobial Stewardship and Rapid Diagnostic Testing Bundle on Early Streamlining of Antimicrobial Therapy in Gram-Negative Bloodstream Infections.

The use of rapid diagnostic tests (RDTs) enhances antimicrobial stewardship program (ASP) interventions in optimization of antimicrobial therapy. This quasi-experimental cohort study evaluated the combined impact of an ASP/RDT bundle on the appropriateness of empirical antimicrobial therapy (EAT) and time to de-escalation of broad-spectrum antimicrobial agents (BSAA) in Gram-negative bloodstream infections (GNBSI). The ASP/RDT bundle consisted of system-wide GNBSI treatment guidelines, prospective stewardship monitoring, and sequential introduction of two RDTs, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and the FilmArray blood culture identification (BCID) panel. The preintervention period was January 2010 through December 2013, and the postintervention period followed from January 2014 through June 2015. The postintervention period was conducted in two phases; phase 1 followed the introduction of MALDI-TOF MS, and phase 2 followed the introduction of the FilmArray BCID panel. The interventions resulted in significantly improved appropriateness of EAT (95% versus 91%; P = 0.02). Significant reductions in median time to de-escalation from combination antimicrobial therapy (2.8 versus 1.5 days), antipseudomonal beta-lactams (4.0 versus 2.5 days), and carbapenems (4.0 versus 2.5 days) were observed in the postintervention compared to the preintervention period (P < 0.001 for all). The reduction in median time to de-escalation from combination therapy (1.0 versus 2.0 days; P = 0.03) and antipseudomonal beta-lactams (2.2 versus 2.7 days; P = 0.04) was further augmented during phase 2 compared to phase 1 of the postintervention period. Implementation of an antimicrobial stewardship program and RDT intervention bundle in a multihospital health care system is associated with improved appropriateness of EAT for GNBSI and decreased utilization of BSAA through early de-escalation.

Causative Bacterial Strains and Sensitivityto Antimicrobial Agents in Female Acute Uncomplicated Cystitis

Recently, wide spreading of fluoloquinolone resistant Escherichia coli is a serious problem inthe treatment of urinary tract infection. To investigate the causative bacterial strains of female acute uncomplicated cystitis (AUC) in the community and their sensitivity to antimicrobial agents, we retrospectively reviewed the medical records of 215 female AUC patients treated at our clinics from April 2014 to June 2015. Two hundred and nineteen strains were isolated as the causative bacteria from the patients'urine samples, including E. coli of 179 strains (82%) followed by Klebsiella pneumoniae (5.5%). One hundred and forty five strains (81%) of the isolated E. coli were sensitive to levofloxacin, whereas 32 strains (17.9%) were levofloxacin-resistant. To fosfomycin, the isolated E. coli showed the highest sensitivity (93.9%) among all antimicrobial agents tested. In univariate analysis, factors associated with levofloxacinresistant E. coli included two or more episodes of cystitis within the past year and levofloxacin use at the latest episode of cystitis. Inmultivariate analysis, two or more episodes of cystitis withinthe past year were found to be associated with levofloxacinresistan ce (p＝0.004). To prevent the increasing prevalence of infections caused by antibiotic-resistant bacteria, it is important to confirm the sensitivity of the causative agents for optimal antimicrobial therapy. The community-based surveillance data should be collected and considered when selecting empirical antimicrobial agents.

Clinical Impact of Rapid Identification (ID) and Phenotypic Antimicrobial Susceptibility Testing (AST) by Accelerate Pheno™ System (AXDX) for Gram-negative (GNB) Bloodstream Infections

BackgroundLaboratory turn-around-times (TATs) for identification (ID) and antimicrobial susceptibilities (AST) can delay prescription of adequate and/or optimal antimicrobial (ABX) therapy in septic patients leading to poor outcomes. The Accelerate Pheno™ system (Accelerate Diagnostics, USA) (AXDX) is a rapid ID and AST system with potential to improve TATs.Figure 1:Changes in Antibiotics Ordered for Gram-negative Bacilli Bloodstream Infections following Gram, ID, and AST Results.Figure 2:Time to Actual and Potential Antibiotic Tailoring Varying by ID and AST Method.Methods70 prospective non-duplicate blood cultures with Gram-negative bacilli were loaded onto AXDX. AXDX TATs were compared with TATs associated with current methods [ID by MALDI-TOF Vitek® MS (bioMérieux) using short-incubation plates, AST by Vitek® 2 (bioMérieux)]; modified current methods (calling MALDI ID and Vitek® 2 AST and releasing Vitek® 2 AST prior to purity plate review); and former methods (ID and AST by Vitek® 2), the latter determined by laboratory data review of 134 blood cultures from 2011. Impact of the change in TAT on ABX use was determined by chart review.ResultsGram stain, ID and AST results led to tailoring of ABX in 88.6% of patients impacting 22.9%, 31.4%, and 64.3% of patients at 2.5h, 19.0h, and 62.1h respectively post positive blood culture using current methods (Figures 1 and 2). AXDX generated the shortest ID and AST TATs with the potential to shorten the time to ABX tailoring due to ID and AST to 1.3h and 6.7h respectively. Calling ID and AST results directly to physicians or releasing AST results from Vitek® 2 prior to purity plate review would also have the potential to significantly improve time to ABX change compared with current methods.ConclusionAmong the methods compared, AXDX has the greatest potential impact on time to appropriate antibiotics following reports of ID and AST results in Gram-negative bacilli bloodstream infections. Calling ID or AST results directly to physicians could also improve time to ABX tailoring. Impact of engaging antimicrobial stewardship teams requires further study.Disclosures S. M. Poutanen, Accelerate Diagnostics: Research Contractor and Scientific Advisor, Consulting fee and Research support

Antibiotic stewardship programs and the internist’s role

Antimicrobial resistance (AMR) is a worldwide issue, but with significant epidemiological diversity in different countries. A recently observed phenomenon is represented by the diffusion of AMR, initially confined to intensive-care units, to medical wards. This was predictable, since patients hospitalized in medical units are made up of more than 70% of elderly people (over 75 years of age in 1 case out of 2). They are fragile patients, with significant comorbidity (over a half with at least 3 diseases), weakened immune systems, and consequently a higher risk of infection. Given such a scenario, it becomes therefore both necessary and urgent to adopt a multifaceted approach of antimicrobial stewardship programs in order to prevent, detect and control the emergence of antimicrobial resistant organisms. The ideal antimicrobial program is led by an infectious diseases (ID) physician and clinical pharmacist with ID training, together with a list of other important staff: clinical microbiologist, information systems specialist, infection control professional, and hospital epidemiologist. In real life, not all the Italian hospitals have got an ID physician and therefore the best canditates for antimicrobial management practices are internists if provided with a specific expertise in ID and antibiotic therapy. Adhering to the principles of optimal antimicrobial therapy in their clinical practice, the internist is able to improve the care and help to reduce the resistance of a patient at his bedside. At the same time, he can achieve other key goals reducing the length of stay and reducing the cost and utilization of health care resources.

Reducing the impact of carbapenem-resistant Enterobacteriaceae on vulnerable patient groups: what can be done?

Carbapenem-resistant Enterobacteriaceae (CRE) is a worldwide challenge and associated with a high mortality rate in critically ill patients. This review focused on rapid diagnosis, optimization of antimicrobial therapy, and implication of effective infection control precautions to reduce impact of CRE on vulnerable patients. Several new diagnostic assays have recently been described for the early diagnosis of CRE. Retrospective studies are supportive for colistin plus meropenem combination for the treatment of CRE infections; however, solid evidence is still lacking. Ceftazidime-avibactam may be an effective therapeutic agent for infections caused by carbapenem-hydrolyzing oxacillinase-48 and Klebsiella pneumoniae carbapenamase-producing Enterobacteriaceae, but not for New Delhi metallo-β-lactamase producers. Gastrointestinal screening may permit early identification of patients with CRE infections. There is not enough evidence to recommend selective digestive decontamination for CRE carriers. The information for rapid diagnosis of CRE is accumulating. There are new agents with high in-vitro activity against CRE, but clinical experience is limited to case reports. Active surveillance with a high rate of compliance to basic infection control precautions seems to be the best approach to reduce the impact of CRE on vulnerable patients.

Molecular Diagnostics Can Lead To Early Optimization of Antimicrobial Therapy for Staphylococcal Bacteremia: Experience at a Large Tertiary-Care VA Medical Center

Molecular Diagnostics Can Lead To Early Optimization of Antimicrobial Therapy for Staphylococcal Bacteremia: Experience at a Large Tertiary-Care VA Medical Center

Clinical Impact and Provider Acceptability of Real-Time Antimicrobial Stewardship Decision Support for Rapid Diagnostics in Children With Positive Blood Culture Results.

Rapid diagnostic technologies for infectious diseases have the potential to improve clinical outcomes, but guideline-recommended antimicrobial stewardship (AS) strategies are not currently optimized for rapid intervention. We evaluated the clinical impact and provider acceptability of implementing real-time AS decision support for children with positive blood culture results according to the FilmArray blood culture identification panel (BCID [BioFire Diagnostics]) at Children's Hospital Colorado. A pre-post quasi-experimental design was used to compare the outcomes of 100 postintervention children with positive blood culture results matched with 200 preintervention control children. Causative organisms in the preintervention group were identified using conventional microbiologic techniques and communicated to providers by a microbiology technologist. Postintervention organisms were identified by the BCID and communicated by an AS provider in real time with interpretation and antimicrobial recommendations. The primary outcome was time to optimal antimicrobial therapy (time from blood culture collection to start of predetermined pathogen-specific regimen or antimicrobial discontinuation for contaminants) compared by a log-rank test and Kaplan-Meier analysis. Provider acceptability of the intervention was assessed via E-mailed surveys. The median time to optimal therapy decreased from 60.2 hours before intervention to 26.7 hours after intervention (P = .001). Among children with blood cultures that contained true pathogens, the time to effective antimicrobial therapy decreased from 6.9 to 3.4 hours (P = .03). Unnecessary antibiotic initiation for children with a culture that contained organisms considered to be contaminants decreased from 76% to 26% (P < .001). Providers reported a change in management as a result of BCID results in 73% of the cases and a mean overall satisfaction rating of 4.8 on a 5-point Likert scale. Real-time AS decision support for rapid diagnostics is associated with improved antimicrobial use and high satisfaction ratings by providers.

The impact of a multidisciplinary antimicrobial stewardship team on the timeliness of antimicrobial therapy in patients with positive blood cultures: a randomized controlled trial.

Antimicrobial stewardship teams play an important role in assisting with the optimization of antimicrobial use in acute care settings. We aimed to determine whether a rapid review by a multidisciplinary antimicrobial stewardship team would improve the timeliness of optimal antimicrobial therapy for patients with positive blood cultures. This prospective randomized controlled trial was undertaken in two Australian hospitals. Patients received either standard care (a clinical microbiologist, registrar or laboratory scientist communicating the positive blood culture by phone to the treating doctor) or intervention (standard care plus rapid review by a multidisciplinary antimicrobial stewardship team). Outcomes included time to appropriate and/or active antimicrobial therapy and in-hospital mortality. The trial was registered on the Australian New Zealand Clinical Trials Registry (ACTRN12614000258651). A total of 160 patients were enrolled in this study: 81 in the standard care arm and 79 in the intervention arm. Patients in the intervention arm were commenced earlier on active (HR 8.02, 95% CI: 2.15-29.91) and appropriate antimicrobials (HR 1.95, 95% CI: 1.13-3.38), with a higher proportion of patients allocated to the intervention arm receiving active therapy at 48 h (96% versus 82%) and appropriate therapy at 72 h (70% versus 54%). The majority of patients where the blood culture was a contaminant were not started on antimicrobial therapy, and there were no significant differences in time to cessation of antimicrobial therapy. Antimicrobial stewardship team review of patients with pathogenic positive blood cultures improved the time to both active and appropriate antimicrobial therapy.

Comparative analysis of male and female populations on prevalence and antibiotic resistance of Mycoplasma hominis in China, 2005–2014

The aim of this study was to estimate the prevalence and antimicrobial resistance rate of Mycoplasma hominis among male and female populations. A total of 67921 individuals were examined. All samples were isolated from patients at an outpatient clinic from January 2005 to December 2014. Species identification and antibiotic susceptibility testing were performed using Mycoplasma IST2. In this study, 523 (0.8%) and 4625 (6.8%) cultures, respectively, were positive for single M. hominis identification and simultaneous identification of both M. hominis and Ureaplasma spp. The results showed that both single and simultaneous identification were more frequent in the female than the male population. Moreover, the highest positive rates of single M. hominis identification were observed in 56-60-year-old males and 61-65-year-old females, and the rates of simultaneous identification were high in males aged >65 years and females aged 15-20 years. Among the seven antibiotics assessed, tetracycline, josamycin, doxycycline and pristinamycin were the most effective, whilst clarithromycin, ciprofloxacin and ofloxacin displayed extremely high resistance rates. Different antimicrobial susceptibility rates were observed between the two sexes, and the resistance rates to ofloxacin showed a significant difference (P<0.05). In conclusion, this study demonstrates that the prevalence of M. hominis varied significantly between the two sexes in the past 10 years and that the optimal antimicrobial therapy strategy should be directed by local susceptibility testing.

A Stewardship Approach To Optimize Antimicrobial Therapy through Use of a Rapid Microarray Assay on Blood Cultures Positive for Gram-Negative Bacteria.

A Gram-negative (GN) blood culture microarray assay with an antimicrobial stewardship program (ASP) intervention was evaluated in 126 patients with GN bacteremia. The median time to optimal therapy was shorter in the postintervention group than in the preintervention group (49.3 h versus 38.5 h, respectively; P = 0.0199). ASP can utilize microarray technology to decrease the time to optimal antimicrobial therapy.

Endotipsitis: A case report with a literature review on an emerging prosthetic related infection

To investigate the etiology and management of a poorly understood complication of transjugular intrahepatic portosystemic shunt; "endotipsitis". A MEDLINE database search was carried out, reviewing all papers with specific words in the title or abstract, and excluding appropriately. Of 283 papers that were reviewed, 22 papers reporting 53 cases in total were included in the analyses. No predominant etiology for endotipsitis was identified, but gram-positive organisms were more common among early-onset infections (P < 0.01). A higher mortality rate was associated with Staphylococcus aureus and Candida spp infections (P < 0.01). There was no trend in choice of antibiotic based on the microorganisms isolated and treatment varied from the guidelines of other vegetative prosthetic infections. In endotipsitis "high risk" organisms have been identified, emphasizing the importance of ensuring optimal antimicrobial therapy and adjunctive management strategies. Higher mortality rate was associated with Staphylococcus aureus and Candida spp infections. A prospective multicenter trial is needed before specific treatment can be recommended.

Spondylodiscitis in Romania – between the risks of prolonged antimicrobial therapy and the poor access to neurosurgery

Background Spondylodiscitis defines both vertebral osteomyelitis and discitis. Two important etiologies are involved in the pathogenesis of spondylodiscitis: Mycobacterium tuberculosis (TB-S) and pyogenic bacteria such as Staphylococcus aureus (NTB-S). Diagnosis and treatment of spondylodiscitis are constantly delayed because the symptomatology is non-specific. There are controversial opinions regarding the optimal antimicrobial therapy duration. Aims: To overview the diagnosis and therapeutic difficulties in patients with spondylodiscitis.

Prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis in female outpatients, 2009-2013.

The aim of this study was to estimate the prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis among female outpatients treated for genital infection at a Chinese hospital from January 1, 2009 to December 31, 2013. Samples from 6051 female outpatients were analyzed using Mycoplasma Identification and Antimicrobial Susceptibility Testing (ID/AST). The overall prevalence of U. urealyticum was higher than the prevalence of single M. hominis infection (31.2% vs 0.7%) and coinfections (31.2% vs. 1.9%). The percentage of U. urealyticum and/or M. hominis detected in the 30-39 year age group was greater than in the other age groups. More than 94.6% of the U. urealyticum isolates, 100% of the M. hominis isolates, and 84.3% of the isolates from coinfections were susceptible to doxycycline, minocycline, and tetracycline. More than 69.2% of the U. urealyticum isolates were susceptible to azithromycin, erythromycin, clarithromycin, and roxithromycin, but > 95.6% of the M. hominis isolates and 89.6% of the isolates from coinfections were resistant to these antibiotics. Acetylspiramycin, sparfloxacin, levofloxacin, ciprofloxacin, and ofloxacin were inactive against more than one-half of the isolates. More than 75.6% of the M. hominis isolates were susceptible to spectinomycin, but >87.1% of the U. urealyticum and 93.3% of the coinfection isolates were resistant to this antibiotic. Isolates from three coinfections were completely resistant to the 14 antibiotics. The determination of antimicrobial susceptibility of these mycoplasma species is often crucial for optimal antimicrobial therapy of infected outpatients.

Central nervous system infections due to vancomycin-resistant enterococci: case series and review of the literature

To evaluate reported cases of central nervous system (CNS) infections due to vancomycin-resistant enterococci (VRE) and describe the data necessary to better understand clinical characteristics of this rare disease process. We report two cases of VRE CNS infection and review 36 cases reported in the literature. Eighty-two percent (31/38) of cases were due to Enterococcus faecium. The median length of stay prior to diagnosis was 14 days (interquartile range 9-33). Fifty-eight percent (22/38) of cases had significant underlying non-malignant CNS disease processes and 63% (24/38) had CNS devices in situ. Forty percent (15/38) of patients had other positive culture sites. Ninety-two percent (35/38) of patients experienced microbiological cure and 74% (28/38) experienced clinical and microbiological cure following a variety of antimicrobial therapies. Seventy-four percent (14/19) of patients who experienced clinical/microbiological cure with CNS devices had them either removed or replaced. Eighteen percent (7/38) died from VRE CNS infections. VRE CNS infections are uncommon nosocomial infections that most commonly affect patients with underlying CNS disease processes. The vast majority of cases are due to E. faecium, and many cases involve multiple positive culture sites. Optimal antimicrobial therapy remains undefined, but should be coupled with removal or replacement of indwelling CNS devices.

Fallstricke bei der Resistenzbestimmung

Selection of the optimal antimicrobial therapy is often crucial for the morbidity and mortality associated with an infection. A reliable antibiogram provides the basis for antibiotic therapy optimization. In case of life-threatening infections, minimal inhibitory concentration values should be available so that, in conjunction with knowledge of the pharmacokinetic properties of the respective antibiotics, a rational selection addressing the individual case is feasible. If only categorized results (susceptible, intermediate, resistant: S-I-R) are available, they should be established according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines in order to avoid therapeutic failures.