Prior Antimicrobial Therapy Research Articles

Antimicrobial Resistance in Long-Term Care Facilities

During the last quarter century, numerous reports have indicated that antimicrobial resistance commonly is encountered in long-term–care facilities (LTCFs). Gramnegative uropathogens resistant to penicillin, cephalosporin, aminoglycoside, or fluoroquinolone antibiotics and methicillin-resistant Staphylococcus aureus have received the greatest attention, but other reports have described the occurrence of multiply-resistant strains of Haemophilus influenzae and vancomycin-resistant enterococci (VRE) in this setting. Antimicrobial-resistant bacteria may enter LTCFs with colonized patients transferred from the hospital, or they may arise in the facility as a result of mutation or gene transfer. Once present, resistant strains tend to persist and become endemic. Rapid dissemination also has been documented in some facilities. Person-to-person transmission via the hands of healthcare workers appears to be the most important means of spread. The LTCF patients most commonly affected are those with serious underlying disease, poor functional status, wounds such as pressure sores, invasive devices such as urinary catheters, and prior antimicrobial therapy. The presence of antimicrobial-resistant pathogens in LTCFs has serious consequences not only for residents but also for LTCFs and hospitals. Experience with control strategies for antimicrobial-resistant pathogens in LTCFs is limited; however, strategies used in hospitals often are inapplicable. Six recommendations for controlling antimicrobial resistance in LTCFs are offered, and four priorities for future research are identified (Infect Control Hosp Epidemiol 1996;17:129-140).

Tropheryma whipplei aortic valve endocarditis without systemic Whipple's disease

Culture-negative endocarditis is most often the result of prior antimicrobial therapy. Tropheryma whipplei is the etiologic agent of Whipple's disease, which is typically characterized by diarrhea, weight loss, and intra-abdominal lymphadenopathy. We present the case of a 48-year-old male with Whipple's endocarditis of the aortic valve who did not develop signs of systemic Whipple's disease. Our patient was treated with a regimen that included ceftriaxone for 6 weeks prior to his cardiac surgery, yet valve pathology demonstrated abundant T. whipplei, suggesting that a prolonged antibiotic course is necessary for the treatment of Whipple's endocarditis.

Bacillus cereus from blood cultures: virulence genes, antimicrobial susceptibility and risk factors for blood stream infection

We characterized the profiles of virulence genes and antimicrobial susceptibility of Bacillus cereus isolates from blood cultures as well as the risk factors for blood stream infections (BSIs). The diversity of virulence gene patterns was found to be wide among 15 B. cereus isolates from BSIs and also among 11 isolates from contaminated blood cultures. The MicroScan broth microdilution method yielded results corresponding with those of the agar dilution (reference) method for levofloxacin, linezolid, and vancomycin, while the Etest results were consistent with the reference results for clindamycin, gentamicin, imipenem, levofloxacin, and linezolid. Compared with the reference values, however, some isolates showed marked differences of the minimum inhibitory concentrations (MICs) for ampicillin and clindamycin when determined using the MicroScan method, or the MICs for ampicillin, meropenem, and vancomycin when determined using the Etest method. Significantly more patients were treated with antimicrobials for more than 3 days during the 3-month period before isolation in the BSI group. Prior antimicrobial therapy may be a risk factor for BSIs due to B. cereus.

Risk factors for multi-drug resistant Acinetobacter baumanniibacteremia in patients with colonization in the intensive care unit

BackgroundEpidemic outbreaks of multi-drug resistant (MDR) Acinetobacter baumannii (AB) in intensive care units (ICUs) are increasing. The incidence of MDR AB bacteremia, which develops as a result of colonization, is increasing through widespread dissemination of the pathogen, and further colonization. We sought to determine risk factors for MDR AB bacteremia in patients colonized with MDR AB in the ICU.MethodsWe conducted a retrospective, observational study of 200 patients colonized with MDR AB in the ICU at Severance Hospital, South Korea during the outbreak period between January 2008 and December 2009.ResultsOf the 200 patients colonized with MDR AB, 108 developed MDR AB bacteremia, and 92 did not. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; P = 0.035, 22.9 vs. 16.8; P < 0.001, respectively). There was no difference between the two groups in the duration of time from ICU admission to colonization (7.1 vs. 7.2 days; P = 0.923), but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; P = 0.016). A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45-10.24; P = 0.007). Multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR AB bacteremia.ConclusionsPatients in the ICU, colonized with MDR AB, should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR AB bacteremia.

Prior Use of Antimicrobial Therapy is a Risk Factor for Culture-negative Prosthetic Joint Infection

Clinical characteristics and control of the infection of patients with culture-negative (CN) prosthetic joint infection (PJI) have not been well assessed. Prior use of antimicrobial therapy has been speculated but not proven as a risk factor for CNPJI. We therefore determined whether prior use of antimicrobial therapy, prior PJI, and postoperative wound healing complications were associated with CN PJI. We performed a retrospective case-control study of 135 patients with CN PJI treated between January 1, 1985, and December 31, 2000 matched with 135 patients with culture-positive (CP) PJIs (control patients) during the study period. The time to failure of therapy compared between cases and control patients using a Kaplan-Meier analysis. The use of prior antimicrobial therapy and postoperative wound drainage after index arthroplasty were associated with increased odds of PJI being culture-negative (odds ratio, 4.7; 95% CI, 2.8-8.1 and odds ratio, 3.5; 95% CI, 1.5-8.1, respectively). The percent (+/- SE) cumulative incidence free of treatment failure at 2 years followup was similar for CN and CP PJI: 75% (+/- 4%) and 79% (+/- 4%), respectively. Prior antimicrobial therapy and postoperative wound drainage were associated with an increased risk of negative cultures among patients with PJI. Physicians should critically evaluate the need for antimicrobial therapy before establishing a microbiologic diagnosis of PJI in patients with suspected PJI. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Risk of acquiring drug-resistant (MDR) Gram-negative isolates with previous exposure to antibiotic

Prior antimicrobial therapy is one of the most important factors leading to the acquisition of MDR organisms. Formulating antibiotic policy and choice of empirical antibiotic selection will be helped by knowing the association of MDR Gram-negative organisms with a previous exposure of particular antibiotic.

Non-adherence to guidelines: an avoidable cause of failure of empirical antimicrobial therapy in the presence of difficult-to-treat bacteria

To identify the risk factors of ventilator-associated pneumonia (VAP) due to difficult-to-treat (DTT) bacteria (i.e., Pseudomonas aeruginosa, Acinetobacter baumannii and oxacillin-resistant Staphylococcus aureus), and to assess the rate and the causes of inappropriateness of empirical antimicrobial therapy. In an intensive care unit of a university hospital, patients with VAP were empirically treated with antibiotics without activity against DTT bacteria if the patients had no prior hospitalization or prior administration of antibiotics, according to local guidelines. Overall, the empirical antimicrobial therapy was appropriate in 190 (87%) out of 218 patients with VAP. Fifty (23%) patients developed problems due to DTT bacteria. The risk factors for VAP due to DTT bacteria were shock state, prior antimicrobial therapy, prior stay in long-term care facilities and late-onset VAP. Empirical antimicrobial therapy was inappropriate in 20 (40%) patients with VAP due to DTT bacteria and 8 (5%) patients with VAP due to non-DTT (P = 0.001). Guidelines violations (nine patients), bacteria not included in antibiotic spectrum (eight patients) and bacterial resistance (three patients) were the causes of inappropriateness in case of DTT bacteria. Despite the abundant information for the treatment of VAP and the establishment of guidelines, too many patients with DTT bacteria received inappropriate antimicrobial therapy. Since 45% of the cases are related to non-adherence to the local protocol, there is room for improvement by implementing educational programs. Also, since DTT bacteria are found in 23% of late-onset VAP, empirical antibiotic treatment should be directed against these pathogens.

Utility of 16S ribosomal DNA sequencing in the diagnosis of Staphylococcus lugdunensis native valve infective endocarditis: case report and literature review

We report a case of possible infective endocarditis without fever presenting with an acutely ischemic limb with prior antimicrobial therapy preventing identification by culture of a microorganism. 16S ribosomal DNA sequencing led to the identification of Staphylococcus lugdunensis from an embolus removed at surgery and subsequent successful antibiotic treatment. We review the utility of 16S ribosomal DNA sequencing in diagnosing infective endocarditis and other infectious conditions.

Nationwide survey of extended-spectrum β-lactamase-producing Enterobacteriaceae in the French community setting

The aim of this study was to assess the prevalence of the extended-spectrum beta-lactamase (ESBL)-producing enterobacteria (ESBLE) in the French community, during a 2006 survey. All enterobacteria isolated from urine samples of patients, exhibiting a decreased susceptibility to broad-spectrum cephalosporins, were analysed for their beta-lactamase content (synergy test, isoelectrofocusing, conjugation transfer, PCR amplification and/or cloning experiments and sequencing). Additional co-resistances were investigated by PCR, sequencing and/or cloning. Epidemiological relationship was studied by PFGE for all species and, in addition, for Escherichia coli by the determination of the phylogenetic group, multilocus sequence type (ST) and O25b antigen. Characteristics of CTX-M-producing E. coli carriers were compared with other ESBLE carriers. Seventy-two ESBLE were collected from 71 patients. Most of them expressed a CTX-M enzyme (n = 42, comprising 40 E. coli), with a predominance of CTX-M-15 (n = 24); 10 CTX-M-15-producing E. coli belonged to the same clone (phylogroup B2, ST131, serotype O25b). The 30 remaining strains possessed a TEM- or SHV-type ESBL. In addition, three strains presented unusual co-resistances such as DHA-1 (n = 2), QnrB4 and ArmA. Risk factors for ESBLE acquisition were substantially less frequent when the ESBL was of the CTX-M type, except for prior antimicrobial therapy. Eighteen percent of the patients were considered to have true community-acquired ESBLE; most of them harboured a CTX-M-producing E. coli. This first nationwide study reports an ESBLE prevalence of 1.1% in the French community setting in 2006, mainly related to the presence of CTX-M-producing E. coli strains; furthermore, unusual co-resistances rarely found in the community setting were occasionally observed, which may threaten future emergence.

A Phase 3, open-label, non-comparative study of tigecycline in the treatment of patients with selected serious infections due to resistant Gram-negative organisms including Enterobacter species, Acinetobacter baumannii and Klebsiella pneumoniae

To evaluate the efficacy and safety of tigecycline in patients with selected serious infections caused by resistant Gram-negative bacteria, or failures who had received prior antimicrobial therapy or were unable to tolerate other appropriate antimicrobials. Secondary objectives included an evaluation of the microbiological efficacy of tigecycline and in vitro activity of tigecycline for resistant Gram-negative bacteria. This open-label, Phase 3, non-comparative, multicentre study assessed the efficacy and safety of intravenous tigecycline (100 mg initially, then 50 mg 12 hourly for 7-28 days) in hospitalized patients with serious infections including complicated intra-abdominal infection; complicated skin and skin structure infection (cSSSI); community-acquired pneumonia (CAP); hospital-acquired pneumonia, including ventilator-associated pneumonia; or bacteraemia, including catheter-related bacteraemia. All patients had infections due to resistant Gram-negative organisms, including extended-spectrum beta-lactamase-producing strains, or had failed on prior therapy or could not receive (allergy or intolerance) one or more agents from three classes of commonly used antibiotics. The primary efficacy endpoint was clinical response in the microbiologically evaluable (ME) population at test of cure (TOC). Safety data included vital signs, laboratory tests and adverse events (AEs). In the ME population at TOC, the clinical cure rate was 72.2% [95% confidence interval (CI): 54.8-85.8], and the microbiological eradication rate was 66.7% (95% CI: 13.7-78.8). The most commonly isolated resistant Gram-negative pathogens were Acinetobacter baumannii (47%), Escherichia coli (25%), Klebsiella pneumoniae (16.7%) and Enterobacter spp. (11.0%); the most commonly diagnosed serious infection was cSSSI (67%). The most common treatment-emergent AEs were nausea (29.5%), diarrhoea (16%) and vomiting (16%), which were mild or moderate in severity. In this non-comparative study, tigecycline appeared safe and efficacious in patients with difficult-to-treat serious infections caused by resistant Gram-negative organisms.

Value of CT-guided biopsy in the diagnosis of septic discitis

Aim:To determine the role of CT-guided biopsy in the management of cases of infective discitis.Methods:Data were examined from a retrospective case series of CT-guided biopsies for the 5-year period ending...

Case Report: A Patient with Haemorrhagic Bleeding, an Acquired Factor VIII Inhibitor and Massive Pulmonary Embolism.

A female, 48-year old patient was referred to an emergency ward with dyspnoea, haemoptysis and suspected respiratory infection that had been refractory to prior antimicrobial therapy. The onset of dyspnoea dated back to a febrile episode three months prior to presentation. The patient continued to work in spite of severe shortness of breath. Her history revealed a cervical cancer which had been treated by neoadjuvant radiochemotherapy and extended hysterectomy in 2005. Upon admission, extensive spontaneous haematomas were noted on the upper extremities. Following a diagnostic puncture of the radial artery, severe haemorrhage and compartmentalization developed, and the patient was transferred to our hospital for a surgical emergency intervention and haemostaseological counselling. A decreased factor VIII activity was noted, with a prolonged partial thromboplastin time, a normal von Willebrand Factor activity and concentration, a prolonged bleeding time and a low-titer inhibitor to factor VIII. Additionally, a profound hyponatremia (117 mmol/l) awaited explanation. Haemorrhage was treated with recombinant Factor VIIa, allowing for a successful surgical de-compartmentalization. With regard to the consistent feature of dyspnoea and partial respiratory insufficiency, bronchoscopic examination revealed only minor hemorrhagic suffusion of the bronchial epithelium, but no sign of infection or major pulmonary bleeding. Chest X-ray and laboratory findings showed right ventricular enlargement, bilateral infiltrates and an excessively high NT-pro-BNP concentration in plasma (13027 ng/l). Chest X-ray radiographs performed two months previously for suspected respiratory infection showed pulmonary infiltrates of comparable size, albeit no right ventricular enlargement. Computerized tomography of the chest showed a complete obstruction of the right pulmonary artery and of the lower branch of the left pulmonary artery. Pulmonary arterial pressure was measured at 70 mm Hg. Immunosuppressive therapy was initiated, with concomitant aPTT-adjusted anticoagulation. Upon clinical deterioration with right-ventricular failure, a catheter-based disruption of the emboli was attempted, albeit with no success. A cardio-surgical intervention with thrombendectomy was performed successfully; however, the patient succumbed to sepsis and multiorgan failure ten days later. The autopsy revealed multiple thrombi, a bilateral pulmonary haemorrhagic infarction and a disseminated lymphangiosis and hemangiosis carcinomatosa of the lungs. We conclude that the acquired inhibitor to factor VIII was of paraneoplastic origin and, although detected at a low titre, clinically relevant. Based on previous radiographic findings, a massive pulmonary embolism must be assumed to have occurred months prior to presentation. The anticoagulatory effect of the acquired inhibitor to Factor VIII may have averted the timely detection of the pulmonary embolism.

Multiple peripheral pneumococcal mycotic aneurysms without aortic involvement: A unique case confirmed with the novel use of a molecular diagnostic technique

Mycotic aneurysms confer a high morbidity and mortality. Streptococcus pneumoniae aneurysms usually affect the aorta and are rare, although bacterial cultures from aneurysm tissue may be difficult following prior antimicrobial therapy. We report a unique case of mycotic femoral and popliteal artery aneurysms following pneumococcal pneumonia and meningitis, which were managed by resection, revascularization with autologous vein, and intravenous benzylpenicillin. Although blood and aneurysm sac cultures were negative, arterial wall S pneumoniae DNA was detected by polymerase chain reaction (PCR). Appropriate molecular diagnostic techniques can facilitate diagnosis and direct antimicrobial therapy; an important consideration with increasing antimicrobial resistance.

Ventilator-associated pneumonia due to colistin susceptible-only microorganisms

Acinetobacter spp. and Pseudomonas aeruginosa are common pathogens of ventilator-associated pneumonia (VAP). The presentation and outcome of VAP due to Acinetobacter spp. and P. aeruginosa susceptible to carbapenems (Carb-S; imipenem and/or meropenem) and to colistin only (Col-S) were compared in the present retrospective study in three intensive care units. A total of 61 episodes of VAP caused by Acinetobacter spp. or P. aeruginosa were studied, of which 30 isolates were Carb-S and 31 were Col-S. Demographics, worsening of renal function and mortality were not different. The univariate analysis showed that a later onset and a previous episode of VAP, prior antimicrobial therapy for >10 days and previous therapy with carbapenems during the present admission were more frequent in patients with Col-S strains. On multivariate analysis, prior antimicrobial therapy for >10 days and a previous episode of VAP remained significantly associated with Col-S VAP. Approximately 41% of the infections caused by Col-S isolates, but none of those due to Carb-S isolates, had received prior carbapenem therapy. Colistin-susceptible ventilator-associated pneumonia episodes can be effectively treated using colistin without significant renal dysfunction. This susceptibility pattern could be suspected in patients with a previous ventilator-associated pneumonia episode or prior antibiotic therapy for >10 days preceding the present ventilator-associated pneumonia episode.

Culture-Negative Surgical Site Infections

The appearance of postoperative surgical site infection (SSI) in the absence of culturable bacterial pathogens is a common dilemma for the surgeon. The literature was searched through references to primary articles, as well as a MEDLINE review, for reports of culture-negative SSIs. Potential causes of culture-negative SSIs include prior antimicrobial therapy; the presence of fastidious or slow-growing microorganisms such as mycobacteria, Mycoplasma spp., and Legionella spp.; infection caused by mundane bacteria that may be dismissed as "contaminants"; factitious infection; and others. We review the recognized causes of "culture negative" SSIs and discuss the laboratory capabilities that may enhance recognition of many of these pathogens and management options.

小児&lt;I&gt;Haemophilus influerizae&lt;/I&gt;気管支肺感染症に対するpiperacillin, tazobactam/piperacillinの臨床効果に関する検討

The prevalence of beta-lactamase-nonproducing ampicillin-resistant (BLNAR) Haemophilus influenzae (H. influenzae) has been increasing in recent years. Piperacillin (PIPC) is one of a few beta-lactams possessing good activity against BLNAR H. influenzae. We studied clinical efficacy of piperacillin and its beta-lactamase inhibitor, tazobactam/piperacillin (TAZ/PIPC) in children with lower respiratory tract infection caused by H. influenzae including resistance strains. Subjects were 20 children with lower respiratory tract infection caused by H. influenzae treated with PIPC 100mg/kg/day (7 cases) or TAZ/PIPC 125mg/kg/day (13 cases). We selected cases from which resistant H. influenzae strains might be detected. Patients received prior antimicrobial therapy within two weeks before admission, or with underlying diseases. We examined patient profiles, clinical efficacy, susceptibilities for 6 beta-lactam antibiotics [PIPC, TAZ/PIPC, ampicillin (ABPC), cefotaxime (CTX), ceftriaxone (CTRX), and meropenem (MEPM)] and analyzed 6 genotype patterns of beta-lactam resistant genes by PCR. Efficacy was 7/7 in patients in PIPC group and 12/13 in patients in TAZ/PIPC group. Diminished efficacy was seen in only one case complicated with severe RSV infection. The susceptibility of all strains but one beta-lactamase producing, ABPC resistant (BLP) strain to PIPC and of all to TAZ/ PIPC was below 0.25 microg/mL. The genotype of the 15 strains isolated from the sputum on administration was as follows; beta-lactamase nonproducing, ABPC-susceptible (gBLNAS) strains were 4, gBLP strain was 1, beta-lactamase nonproducing, and ABPC-resistant (gLow-BLNAR) strains were 2, beta-lactamase nonproducing, ABPC resistant (gBLNAR) strains were 8. PIPC and TAZ/PIPC were useful against lower respiratory tract infection caused by H. influenzae including BLNAR in children.

Turicella otitidis in a Young Adult With Otitis Externa

Turicella otitidis in a Young Adult With Otitis Externa

Prior antimicrobial therapy in the hospital and other predisposing factors influencing the usage of antibiotics in a pediatric critical care unit.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Julie Eddins, G Briassoulis, N Labrini, A Tsorva, H. Tassos; Prior antimicrobial therapy in the hospital and other predisposing factors influencing the usage of antibiotics in a pediatric critical care unit.. Journal of the Association for Vascular Access 1 September 2004; 9 (3): 168. doi: https://doi.org/10.2309/1552-8855-9.3.168a Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest Search

Molecular methods in the diagnosis of endocarditis

Advances in molecular microbiologic diagnostics have yielded new tools to diagnose infective endocarditis. These tools can detect microorganisms that are difficult to grow or are uncultivable, because of prior antimicrobial therapy or because of innate characteristics of the microorganisms. This paper reviews molecular microbiologic diagnostic techniques and their role in the diagnosis of infective endocarditis.

The predictors of outcome in immunocompetent patients with hematogenous candidasis

Objective: Clinical parameters that predict outcome in non-immunosuppressed candidemic patients are not fully understood. Methods: Eighty-one consecutive episodes of candidemia were retrospectively evaluated in 75 patients during 1998–2000. Results: Infection due to Candida albicans was common ( n=30; 37%) followed by Candida glabrata ( n=25; 31%), Candida parapsilosis ( n=14; 17%), Candida tropicalis ( n=6; 7%), Candida krusei ( n=5; 6%), and Candida lusitaniae ( n=1; 1%). Among 70 evaluable patients, 31 (44%) had fungemia-associated mortality; advanced age ( P<0.004), underlying malignancy ( P<0.025), coronary artery disease ( P<0.01), and concurrent non- Candida species fungal infection ( P<0.047) were significant prognosticators of compromised short-term survival by multivariate analysis. Mortality was higher in patients with Candida glabrata (60%) and C. tropicalis (75%) infection compared to 44% deaths in individuals with C. albicans infection ( P>0.1). 11/25 (44%) of non-immunocompromised individuals died and 20/45 (44%) immunosuppressed patients succumbed to fungemia: persistent vs. non-persistent (<3 days) Candida bloodstream invasion, neutropenia, diabetes mellitus, renal insufficiency, prior antimicrobial therapy, cirrhosis of liver, abdomino-pelvis surgery, and critical-care-unit vs. non critical-care-unit admission did not significantly impact outcome in either group. All 11 infants, including nine with prematurity survived Candida species bloodstream infection ( P<0.025). Conclusions: Short-term mortality in candidemic non-immunocompromised patients was comparable to fungemia-associated deaths in immunosuppressed patients. Ischemic heart disease has appeared as a new predictor of unfavorable outcome in patients with hematogenous candidiasis.