Third-generation cephalosporins and vancomycin as risk factors for postoperative vancomycin-resistant enterococcus infection

Characterization of Vancomycin Resistant Enterococci and Drug Ligand Interaction between vanA of E. faecalis with the Bio-Compounds from Aegles marmelos

Objectives

Enterococcus faecalis is a gram positive diplococci, highly versatile and a normal commensal of the gut microbiome. Resistance to vancomycin is a serious issue in various health-care setting exhibited by vancomycin resistant Enterococci (VRE) due to the alteration in the peptidoglycan synthesis pathway. This study is thus aimed to detect the VRE from the patients with root caries from the clinical isolates of E. faecalis and to evaluate the in-silico interactions between vanA and the Aegles marmelos bio-compounds.

Methods

E. faecalis was phenotypically characterized from 20 root caries samples and the frequency of vanA and vanB genes was detected by polymerase chain reaction (PCR). Further crude methanolic extracts from the dried leaves of A. marmelos was assessed for its antimicrobial activity. This is followed by the selection of five A. marmelos bio-compounds for the computational approach towards the drug ligand interactions.

Results

12 strains (60%) of E. faecalis was identified from the root caries samples and vanA was detected from two strains (16%). Both the stains showed the presence of vanA and none of the strains possessed vanB. Crude extract of A. marmelos showed promising antibacterial activity against the VRE strains. In-silico analysis of the A. marmelos bio-compounds revealed Imperatonin as the best compound with high docking energy (-8.11) and hydrogen bonds with < 140 TPSA (Topological polar surface area) and zero violations.

Conclusion

The present study records the VRE strains among the root caries with imperatorin from A. marmelos as a promising drug candidate. However the study requires further experimentation and validation.

Challenges in Forecasting Antimicrobial Resistance

Antimicrobial resistance is a major threat to human health. Since the 2000s, computational tools for predicting infectious diseases have been greatly advanced; however, efforts to develop real-time forecasting models for antimicrobial-resistant organisms (AMROs) have been absent. In this perspective, we discuss the utility of AMRO forecasting at different scales, highlight the challenges in this field, and suggest future research priorities. We also discuss challenges in scientific understanding, access to high-quality data, model calibration, and implementation and evaluation of forecasting models. We further highlight the need to initiate research on AMRO forecasting using currently available data and resources to galvanize the research community and address initial practical questions.

Trend in healthcare-associated infections due to vancomycin-resistant Enterococcus at a hospital in the era of COVID-19: More than hand hygiene is needed

BACKGROUND

Variable control measures for vancomycin-resistant Enterococcus (VRE) infections were adopted among different hospitals and areas. We investigated the burden and patient characteristics of healthcare-associated VRE infections in 2018-2019 and 2020, when multiple preventive measures for COVID-19 were taken.

METHODS

During the COVID-19 pandemic, mask waring and hand hygiene were enforced in the study hospital. The incidence densities of healthcare-associated infections (HAIs), including overall HAIs, methicillin-resistant Staphylococcus aureus (MRSA) HAIs, VRE HAIs, and VRE healthcare-associated bloodstream infections (HABSIs), consumption of broad-spectrum antibiotics and hygiene products, demographic characteristics and medical conditions of affected patients, were compared before and after the pandemic.

RESULTS

The incidence density of both VRE HAIs and VRE HABSIs did not change statistically significantly, however, the highest in 2020 than that in 2018 and 2019. This was in spite of universal mask waring and increased consumption of 75% alcohol in 2020 and consistent implementation of an antibiotic stewardship program in three observed years. The increased prescriptions of broad-spectrum cephalosporins might partially explain the increase of VRE infection.

CONCLUSION

Increased mask wearing and hand hygiene may not result in the decline in the development of VRE HAIs in the hospital during the COVID-19 pandemic, and continued monitoring of the dynamics of HAIs remains indispensable.

Predictors of Vancomycin-Resistant Enterococcus spp. Intestinal Carriage among High-Risk Patients in University Hospitals in Serbia

The predictors of intestinal carriage of vancomycin-resistant Enterococcus spp. (VRE) among high-risk patients in the counties of the Southeast Europe Region are insufficiently investigated, yet they could be of key importance in infection control. The aim of the study was to identify risk factors associated with fecal VRE colonization among high-risk inpatients in university hospitals in Serbia. The study comprised 268 inpatients from three university hospitals. Data on patient demographics and clinical characteristics, length of hospital stay, therapy, and procedures were obtained from medical records. Chi-squared tests and univariate and multivariate logistic regressions were performed. Compared to the hemodialysis departments, stay in the geriatric departments, ICUs, and haemato-oncology departments increased the risk for VRE colonization 7.6, 5.4, and 5.5 times, respectively. Compared to inpatients who were hospitalized 48 h before stool sampling for VRE isolation, inpatients hospitalized 3–7, 8–15, and longer than 16 days before sampling had 5.0-, 4.7-, and 6.6-fold higher risk for VRE colonization, respectively. The use of cephalosporins and fluoroquinolones increased the risk for VRE colonization by 2.2 and 1.9 times, respectively. The age ≥ 65 years increased the risk for VRE colonization 2.3 times. In comparison to the University Clinical Centre of Serbia, the hospital stays at Zemun and Zvezdara University Medical Centres were identified as a protector factors. The obtained results could be valuable in predicting the fecal VRE colonization status at patient admission and consequent implementation of infection control measures targeting at-risk inpatients where VRE screening is not routinely performed.

Hospital-acquired infections caused by enterococci: a systematic review and meta-analysis, WHO European Region, 1 January 2010 to 4 February 2020

BackgroundHospital-acquired infections (HAI) caused by Enterococcus spp., especially vancomycin-resistant Enterococcusspp. (VRE), are of rising concern.AimWe summarised data on incidence, mortality and proportion of HAI caused by enterococci in the World Health Organization European Region.MethodsWe searched Medline and Embase for articles published between 1 January 2010 and 4 February 2020. Random-effects meta-analyses were performed to obtain pooled estimates.ResultsWe included 75 studies. Enterococcus spp. and VRE accounted for 10.9% (95% confidence interval (CI): 8.7-13.4; range: 6.1-17.5) and 1.1% (95% CI: 0.21-2.7; range: 0.39-2.0) of all pathogens isolated from patients with HAI. Hospital wide, the pooled incidence of HAI caused by Enterococcus spp. ranged between 0.7 and 24.8 cases per 1,000 patients (pooled estimate: 6.9; 95% CI: 0.76-19.0). In intensive care units (ICU), pooled incidence of HAI caused by Enterococcus spp. and VRE was 9.6 (95% CI: 6.3-13.5; range: 0.39-36.0) and 2.6 (95% CI: 0.53-5.8; range: 0-9.7). Hospital wide, the pooled vancomycin resistance proportion among Enterococcus spp. HAI isolates was 7.3% (95% CI: 1.5-16.3; range: 2.6-11.5). In ICU, this proportion was 11.5% (95% CI: 4.7-20.1; range: 0-40.0). Among patients with hospital-acquired bloodstream infections with Enterococcus spp., pooled all-cause mortality was 21.9% (95% CI: 15.7-28.9; range: 14.3-32.3); whereas all-cause mortality attributable to VRE was 33.5% (95% CI: 13.0-57.3; range: 14.3-41.3).ConclusionsInfections caused by Enterococcus spp. are frequently identified among hospital patients and associated with high mortality.

Early Outcome of Laparotomy Wounds in Pediatric Patients in TASH, Addis Ababa, Ethiopia: A Six-Months Prospective Study

Background

Surgical Site Infection (SSI) and wound dehiscence are two early complications of laparotomy causing significant morbidity and mortality. This study was conducted to determine the prevalence and risk factors of SSI and wound dehiscence in pediatric surgical patients.

Methods

We performed a prospective observational study of all pediatric surgical patients who underwent laparotomy at Tikur Anbessa Specialized Hospital, Ethiopia, from December 2017 to May 2018. Data collected included demographics, operative indication, nutritional status, prophylactic antibiotics administration, and duration of operation. Primary outcome was SSI; secondary outcomes were hospital stay and other postoperative complications, including wound dehiscence and mortality. Data were analyzed using SPSS, Version 23. Fisher's exact and Chi-squared tests used to report outcomes. Multivariable logistic regression was used to identify variables associated with SSI, wound dehiscence and other outcomes.

Results

Of 114 patients, median age was 46 months [range: 1day-13 years]; 77(67.5 %) were males. Overall SSI rate was 21.05%. Nine (7.9%) developed wound dehiscence while 3(2.6%) had abdominal contents evisceration. Overall mortality rate was 2.6%. In multivariate analysis, prophylactic antibiotics administration (AOR=13.05, (p=0.006)), duration of procedure (AOR=8.62, (p=0.012)) and wound class (AOR=16.63, (p=0.034)) were independent risk factors for SSI while SSI was an independent predictor of prolonged hospital stay, >1 week (AOR=4.7, p=.003,) and of wound dehiscence (AOR=33. 96, p=0.003). Age (p=0.004) and malnutrition (p<0.001) were significantly associated with wound dehiscence.

Conclusion

SSI and wound dehiscence are common in this setting. Wound contamination, antibiotics administration >1 hour before surgery and operative time >2 hours are independent predictors of SSI.

Design, Synthesis, and Biological Evaluation of Light-Activated Antibiotics

The spatial and temporal control of bioactivity of small molecules by light (photopharmacology) constitutes a promising approach for study of biological processes and ultimately for the treatment of diseases. In this study, we investigated two different "caged" antibiotic classes that can undergo remote activation with UV-light at λ = 365 nm, via the conjugation of deactivating and photocleavable units through a short synthetic sequence. The two widely used antibiotics vancomycin and cephalosporin were thus enhanced in their performance by rendering them photoresponsive and thereby suppressing undesired off-site activity. The antimicrobial activity against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 29213, S. aureus ATCC 43300 (MRSA), Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853 could be spatiotemporally controlled with light. Both molecular series displayed a good activity window. The vancomycin derivative displayed excellent values against Gram-positive strains after uncaging, and the next-generation caged cephalosporin derivative achieved good and broad activity against both Gram-positive and Gram-negative strains after photorelease.

Treatment with Ceftriaxone in Complicated Diverticulitis Increases the Incidence of Intra-Abdominal Enterococcus faecium Detection

Background: Complicated diverticulitis of the sigmoid colon typically is treated by resection after initial antibiotic treatment. Third-generation cephalosporins are the drugs of choice but are not effective against enterococci and can induce colonic colonization by Enterococcus faecium within hours. Infections caused by enterococci, especially E. faecium, are difficult to treat but should be considered in the strategic treatment planning of hospital-acquired peritonitis (e.g., anastomotic leakage), especially in immunocompromised patients. Methods: To determine whether the duration of pre-operative ceftriaxone treatment in complicated diverticulitis increases the incidence of intra-abdominal E. faecium detection, we analyzed all patients operated on for diverticulitis of the sigmoid colon in our department between 2008 and 2016. Results: Analyzing 516 resections performed for complicated diverticulitis, we found that E. faecium generally was detected intra-abdominally more often in the group that underwent longer pre-operative ceftriaxone treatment (≥ 4 days). During primary resection, E. faecium was detected in 2.7%, 11.1%, and 37.0% cases in the group undergoing immediate operation, 1-3 days of antibiotic treatment, and ≥4 days of antibiotic treatment, respectively. Enterococcus faecium was detected in 0, 25.0%, and 70.6% of surgical revisions and 28.6%, 14.3%, and 56.0%, respectively, of incisional surgical site infections with identified pathogens. A multivariable analysis discovered anastomotic leakage and antibiotic treatment lasting ≥4 days to be independent risk factors for intra-abdominal isolation of E. faecium. Conclusion: A ceftriaxone treatment ≥4 days led to a higher incidence of intra-abdominal E. faecium. Our data further suggested that empiric coverage of E. faecium in the treatment of hospital-acquired peritonitis could be beneficial after a long duration of ceftriaxone treatment.

Prevalence and root causes of surgical site infection among women undergoing caesarean section in Ethiopia: a systematic review and meta-analysis

Background

Surgical site infection is a common complication in women undergoing Caesarean section and the second most common cause of maternal mortality in obstetrics. In Ethiopia, prevalence and root causes of surgical site infection post-Caesarean section are highly variable. This systematic review and meta-analysis estimate the overall prevalence of surgical site infection and its root causes among women undergoing Caesarean section in Ethiopia.

Method

Systematic review and meta-analysis were conducted to assess the prevalence and root causes of surgical site infection in Ethiopia. The articles were searched from the databases such as Medline, Google Scholar and Science Direct. A total of 13 studies from different regions of Ethiopia reporting the prevalence and root causes of surgical site infection among women undergoing Caesarean section were included. A random effect meta-analysis model was computed to estimate the overall prevalence. In addition, the association between risk factor variables and surgical site infection related to Caesarean section were examined.

Results

Thirteen studies in Ethiopia showed that the overall prevalence of surgical site infection among women undergoing Caesarean section was 8.81% (95% CI: 6.34–11.28). Prolonged labor, prolonged rupture of membrane, presence of anemia, presence of chorioamnionitis, presence of meconium, vertical skin incision, greater than 2 cm thickness of subcutaneous tissue, and general anesthesia were significantly associated with surgical site infection post-Caesarean section.

Conclusion

Prevalence of surgical site infection among women undergoing Caesarean section was relatively higher in Ethiopians compared with the report of center of disease control guideline. Prolonged labor, prolonged rupture of membrane, presence of anemia, chorioamnionitis, presence of meconium, vertical skin incision, greater than 2 cm thickness of subcutaneous tissue and/or general anesthesia were significantly associated with surgical site infection post-Caesarean section.

Evaluation of ceftriaxone use in the medical ward of Halibet National Referral and teaching hospital in 2017 in Asmara, Eritrea: a cross sectional retrospective study

BACKGROUND

Antibiotic resistance due to overuse of antimicrobials is an issue that has been of concern to many health institutions and society in general. Resistant infections have high impact in low income countries since they can't afford more recent and expensive antibiotics. Studies that evaluate antibiotic use in hospitals are scarce in Eritrea. Ceftriaxone is commonly available in Halibet National Referral and teaching hospital (HNRTH). Resistance to this antibiotic would have a great impact on the hospital since there is no other available third generation cephalosporin or higher classes of antibiotics.

METHOD

A retrospective cross sectional design was used to evaluate the use of ceftriaxone in patients admitted to the medical ward in 2017. Clinical card number of inpatients who took ceftriaxone was extracted from the database of the Satellite Pharmacy Department of HNRTH and collected using a standardized data collection form. A descriptive analysis was employed and the Statistical package for social sciences (SPSS), version 20 was used for analysis.

RESULTS

A total of 120 patients were taking ceftriaxone for various indications. There were 55 (50.5%) males and 54 (49.5%) females. 59.8% of the patients were treated in the range of 0-7 days. The mean age was 56 (SD: 20.7). On average patients were under treatment for 6 days. The proportion of patients taking ceftriaxone was 11.43% out of all admissions in the medical ward. One, two or three antibiotics were co-prescribed with ceftriaxone in 39.4%. The most commonly co-prescribed antibiotic was gentamycin, accounting for 16.4% of the co-administered antibiotics. The most common indications for ceftriaxone were pneumonia, sepsis, TB, and CHF. Ceftriaxone therapy was appropriate in 30 (27.5%) cases and 68 (62.4%) cases were inappropriate in any of the four parameters of assessment used.

CONCLUSION

Inappropriate use of ceftriaxone was found to be high in the hospital. This calls for establishment of hospital and national guidelines of antimicrobial treatment. Moreover drug restriction and antibiotic stewardship implementation in the hospital should be sought to prolong the lives of important drugs like ceftriaxone.

Colorectal Surgical Site Infections and Their Causative Pathogens: Differences between Left- and Right-Side Resections

BACKGROUND

Surgical site infections (SSIs), after colorectal resection, pose a significant burden. Recognition of the spectrum of potentially involved pathogens is crucial for determining correct antibiotic prophylaxis. This study aimed to determine whether the distribution of SSI-associated pathogens depends on the location of the colorectal resection.

METHODS

We retrospectively categorized 2713 consecutive colon resections as left- or right-side operations, identified patients having concurrent peritonitis or development of postoperative SSIs and peritonitis, and assigned all subcutaneously and intra-abdominally isolated pathogens according to the location of the resection.

RESULTS

Gram-positive cocci (especially enterococci) and gram-negative bacilli (especially Pseudomonas aeruginosa) were isolated more frequently from patients in whom SSIs developed after left-side resections than after right-side resections (52.5% vs. 32.6%, p < 0.01 and 15.9% vs. 6.7%, p < 0.01, respectively); enterococci were the causative organisms in a large percentage of SSIs (46.3%). Moreover, intra-abdominal P. aeruginosa and Candida spp. were isolated more frequently during left-side resections than during right-side operations in patients with peritonitis (15.8% vs. 6.3%, p = 0.02 and 14.3% vs. 5.3%, p = 0.02, respectively).

CONCLUSIONS

Our results indicate that differences exist in the distribution of pathogens after left- or right-side colorectal resections. Our data further suggest that gram-positive cocci play an important role in SSIs occurring after colorectal resections; therefore, antibiotic prophylaxis should emphasize their coverage. Further, enterococcal coverage may be especially advantageous during left-side resections.

Clinical-epidemiological profile of acute appendicitis: retrospective analysis of 638 cases

OBJECTIVE

to describe the clinical and epidemiological profile of acute appendicitis (AA) of the patients treated at a referral center in the Juiz de Fora macro-region, Minas Gerais State, Brazil.

METHODS

we conducted a retrospective, observational study in the Dr. Mozart Geraldo TeixeiraEmergency Hospital. We selected 638 patients diagnosed with AA, and analyzed the variables gender, age, evolutionary phase, length of hospital stay, pathological diagnosis, use of antibiotics, use of drains, complications and mortality.

RESULTS

AA was more prevalent in young adults (19-44 years) and males (65.20%). The mean hospital stay was seven days and phase II was the most prevalent. We found the histopathological diagnosis of primary tumor of the appendix in six patients (0.94%), adenocarcinoma being the most common histologic type (66.7%). Regarding the use of antibiotics, 196 patients underwent antibiotic prophylaxis and 306 received antibiotic therapy. Eighty-one patients used some kind of drain, for an average of 4.8 days. Seventeen patients died (2.67%), predominantly males (70.59%), with mean age of 38.47 years.

CONCLUSION

AA has a higher prevalence in males and young adults. The length of stay is directly associated with the evolutionary phase. The most common complication is infection of the surgical site. Mortality in our service is still high when compared with developed centers.

OBJETIVO

avaliar a epidemiologia e os resultados do tratamento cirúrgico de doentes portadores de graus III e IV, mais avançados, da Síndrome de Mirizzi (SM) de acordo com a classificação de Csendes.

MÉTODOS

estudo retrospectivo, de corte transversal através da revisão de prontuários de 13 pacientes portadores de graus III e IV da SM operados de dezembro de 2001 a setembro de 2013, entre 3691 colecistectomias realizadas neste período.

RESULTADOS

a incidência da SM foi 0,6% (23 casos) e os graus III e IV perfizeram 0,35% deste número. Houve um predomínio de tipo IV (12 casos). O diagnóstico pré-operatório foi possível em 53,8% dos casos. A conduta preferencial foi derivação biliodigestiva (10 casos) e foi optado por drenagem com tubo "T" e sutura da via biliar em três ocasiões especiais. Três pacientes apresentaram fístula biliar resolvida com conduta expectante e um caso de coleperitônio necessitou reoperação. No seguimento ambulatorial dos pacientes que realizaram a anastomose biliodigestiva (oito), 50% estão assintomáticos, 25% apresentaram estenose da anastomose e 25% perderam seguimento. O tempo médio de acompanhamento foi 41,8 meses.

CONCLUSÃO

de incidência baixa e de diagnóstico pré-operatório em apenas metade dos casos, a SM em graus avançados tem na anastomose biliodigestiva sua melhor conduta, porém não isenta de morbimortalidade.

Molecular Mechanism of Drug Resistance

The treatment of microbial infections has suffered greatly in this present century of pathogen dominance. Inspite of extensive research efforts and scientific advancements, the worldwide emergence of microbial tolerance continues to plague survivability. The innate property of microbe to resist any antibiotic due to evolution is the virtue of intrinsic resistance. However, the classical genetic mutations and extrachromosomal segments causing gene exchange attribute to acquired tolerance development. Rampant use of antimicrobials causes certain selection pressure which increases the resistance frequency. Genomic duplication, enzymatic site modification, target alteration, modulation in membrane permeability, and the efflux pump mechanism are the major contributors of multidrug resistance (MDR), specifically antibiotic tolerance development. MDRs will lead to clinical failures for treatment and pose health crisis. The molecular mechanisms of antimicrobial resistance are diverse as well as complex and still are exploited for new discoveries in order to prevent the surfacing of “superbugs.” Antimicrobial chemotherapy has diminished the threat of infectious diseases to some extent. To avoid the indiscriminate use of antibiotics, the new ones licensed for use have decreased with time. Additionally, in vitro assays and genomics for anti-infectives are novel approaches used in resolving the issues of microbial resistance. Proper use of drugs can keep it under check and minimize the risk of MDR spread.

Inclusion of Vancomycin as Part of Broad-Spectrum Coverage Does Not Improve Outcomes in Patients with Intra-Abdominal Infections: A Post Hoc Analysis

BACKGROUND

Management of complicated intra-abdominal infections (cIAIs) includes broad-spectrum antimicrobial coverage and commonly includes vancomycin for the empiric coverage of methicillin-resistant Staphylococcus aureus (MRSA). Ideally, culture-guided de-escalation follows to promote robust antimicrobial stewardship. This study assessed the impact and necessity of vancomycin in cIAI treatment regimens.

PATIENTS AND METHODS

A post hoc analysis of the Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial was performed. Patients receiving piperacillin-tazobactam (P/T) and/or a carbapenem were included with categorization based on use of vancomycin. Univariate and multivariable analyses evaluated effects of including vancomycin on individual and the composite of undesirable outcomes (recurrent IAI, surgical site infection [SSI], or death).

RESULTS

The study cohort included 344 patients with 110 (32%) patients receiving vancomycin. Isolation of MRSA occurred in only eight (2.3%) patients. Vancomycin use was associated with a similar composite outcome, 29.1%, vs. no vancomycin, 22.2% (p = 0.17). Patients receiving vancomycin had (mean [standard deviation]) higher Acute Physiology and Chronic Health Evaluation II scores (13.1 [6.6] vs. 9.4 [5.7], p < 0.0001), extended length of stay (12.6 [10.2] vs. 8.6 [8.0] d, p < 0.001), and prolonged antibiotic courses (9.1 [8.0] vs. 7.1 [4.9] d, p = 0.02). After risk adjustment in a multivariate model, no significant difference existed for the measured outcomes.

CONCLUSIONS

This post hoc analysis reveals that addition of vancomycin occurred in nearly one third of patients and more often in sicker patients. Despite this selection bias, no appreciable differences in undesired outcomes were demonstrated, suggesting limited utility for adding vancomycin to cIAI treatment regimens.

Genetic relatedness and risk factor analysis of ampicillin-resistant and high-level gentamicin-resistant enterococci causing bloodstream infections in Tanzanian children

Background

While enterococci resistant to multiple antimicrobials are spreading in hospitals worldwide, causing urinary tract, wound and bloodstream infections, there is little published data on these infections from Africa.

Methods

We assessed the prevalence, susceptibility patterns, clinical outcome and genetic relatedness of enterococcal isolates causing bloodstream infections in children in a tertiary hospital in Tanzania, as part of a prospective cohort study of bloodstream infections among 1828 febrile children admitted consecutively from August 2001 to August 2002.

Results

Enterococcal bacteraemia was identified in 2.1% (39/1828) of admissions, and in 15.3% (39/255) of cases of culture-confirmed bloodstream infections. The case-fatality rate in children with Enterococcus faecalis septicaemia (28.6%, 4/14) was not significantly different from those with Enterococcus faecium septicaemia (6.7%, 1/15, p = 0.12). E. faecium isolates commonly had combined ampicillin-resistance and high-level gentamicin resistance (HLGR), (9/17), while E. faecalis frequently displayed HLGR (6/15), but were ampicillin susceptible. None of the tested enterococcal isolates displayed vancomycin resistance by Etest or PCR for vanA and vanB genes. Multi-locus sequence-typing (MLST) showed that the majority of E. faecium (7/12) belonged to the hospital associated Bayesian Analysis of Population Structure (BAPS) group 3–3. Pulsed-field gel electrophoresis (PFGE) indicated close genetic relationship particularly among E. faecium isolates, but also among E. faecalis isolates. There was also correlation between BAPS group and PFGE results. Risk factors for enterococcal bloodstream infection in univariate analysis were hospital-acquired infection and clinical diagnosis of sepsis with unknown focus. In multivariate analysis, neonates in general were relatively protected from enterococcal infection, while both prematurity and clinical sepsis were risk factors. Malnutrition was a risk factor for enterococcal bloodstream infection among HIV negative children.

Conclusion

This is the first study to describe bloodstream infections caused by ampicillin-resistant HLGR E. faecium and HLGR E. faecalis in Tanzania. The isolates of E. faecium and E. faecalis, respectively, showed high degrees of relatedness by genotyping using PFGE. The commonly used treatment regimens at the hospital are insufficient for infections caused by these microbes. The study results call for increased access to microbiological diagnostics to guide rational antibiotic use in Tanzania.

Epidemiological interpretation of studies examining the effect of antibiotic usage on resistance

Bacterial resistance to antibiotics is a growing clinical problem and public health threat. Antibiotic use is a known risk factor for the emergence of antibiotic resistance, but demonstrating the causal link between antibiotic use and resistance is challenging. This review describes different study designs for assessing the association between antibiotic use and resistance and discusses strengths and limitations of each. Approaches to measuring antibiotic use and antibiotic resistance are presented. Important methodological issues such as confounding, establishing temporality, and control group selection are examined.

Molecular epidemiology and risk factors for colonization by vancomycin-resistant Enterococcus in patients with hematologic malignancies

OBJECTIVE

To study the molecular epidemiology of vancomycin-resistant Enterococcus (VRE) colonization and to identify modifiable risk factors among patients with hematologic malignancies.

SETTING

A hematology-oncology unit with high prevalence of VRE colonization.

PARTICIPANTS

Patients with hematologic malignancies and hematopoietic stem cell transplantation recipients admitted to the hospital.

METHODS

Patients underwent weekly surveillance by means of perianal swabs for VRE colonization and, if colonized, were placed in contact isolation. We studied the molecular epidemiology in fecal and blood isolates by pulsed-field gel electrophoresis over a 1-year period. We performed a retrospective case-control study over a 3-year period. Cases were defined as patients colonized by VRE, and controls were defined as patients negative for VRE colonization. Case patients and control patients were matched by admitting service and length of observation time.

RESULTS

Molecular genotyping demonstrated the primarily polyclonal nature of VRE isolates. Colonization occurred at a median of 14 days. Colonized patients were characterized by longer hospital admissions. Previous use of ceftazidime was associated with VRE colonization (P < .001), while use of intravenous vancomycin and antibiotics with anaerobic activity did not emerge as a risk factor. There was no association with neutropenia or presence of colonic mucosal disruption, and severity of illness was similar in both groups.

CONCLUSION

Molecular studies showed that in the majority of VRE-colonized patients the strains were unique, arguing that VRE acquisition was sporadic rather than resulting from a common source of transmission. Patient-specific factors, including prior antibiotic exposure, rather than breaches in infection control likely predict for risk of fecal VRE colonization.

[Associated antimicrobial resistance in Enterococcus spp. clinical isolates]

INTRODUCTION

The increasing prevalence of enterococci strains in hospitals, particularly among isolates of vancomycin-resistant enterococci (VRE), poses important problems because of the limited effect of antimicrobial therapy for enterococcal infections.

METHODS

This work presents a retrospective investigation of quantitative in vitro susceptibility data for the range of antimicrobials against Enterococcus spp. isolates and evaluation of the association of resistance between antimicrobial agents recommended as the treatment of choice for infections caused by VRE through calculation of the relative risk.

RESULTS

Of the 156 enterococci isolates, 40 (25.6%) were resistant to 3 or more antimicrobials, including 7.7% (n = 12/156) vancomycin resistant. The association of elevated resistance was more pronounced among VRE isolates against alternative and primary antimicrobials for the treatment of infections caused by these pathogens, including ampicillin (100%, RR = 7.2), streptomycin (90.9%, RR = 4.9), rifampin (91.7%, RR = 3.1) and linezolid (50%, RR = 11.5), despite high susceptibility to this drug (94.9%).

CONCLUSIONS

The significant associated resistance to alternative and first choice antimicrobials used in the treatment of serious infections of strains with the VRE phenotype and that require a combined therapeutic regime, revealed even more limited therapeutic alternatives in the institution analyzed.

Use of aminoglycosides for peritoneal dialysis-associated peritonitis does not affect residual renal function

BACKGROUND

Aminoglycosides offer several potential benefits in their treatment of peritoneal dialysis (PD)-associated peritonitis, including low cost, activity against Gram-negative organisms (including Pseudomonas aeruginosa), synergistic bactericidal activity against some Gram-positive organisms (such as Staphylococci) and relatively low propensity to promote antimicrobial resistance. However, there is limited conflicting evidence that aminoglycosides may accelerate loss of residual renal function (RRF) in PD patients. The aim of this study was to study the effect of aminoglycoside use on slope of decline in RRF.

METHODS

The study included 2715 Australian patients receiving PD between October 2003 and December 2007 in whom at least two measurements of renal creatinine clearance were available. Patients were divided according to tertiles of slope of RRF decline (rapid, intermediate and slow). The primary outcome was the slope of RRF over time in patients who received aminoglycosides for PD peritonitis versus those who did not.

RESULTS

A total of 1412 patients (52%) experienced at least one episode of PD peritonitis. An aminoglycoside was used as the initial empiric antibiotic in 1075 patients. The slopes of RRF decline were similar in patients treated and not treated with at least one course of aminoglycoside (median [interquartile range] -0.26 [-1.17 to 0.04] mL/min/1.73 m(2)/month versus -0.22 [-1.11 to 0.01] mL/min/1.73 m(2)/month, P = 0.9). The slopes of RRF decline were also similar in patients receiving repeated courses of aminoglycoside.

CONCLUSIONS

Empiric treatment with aminoglycoside for peritonitis was not associated with an adverse effect on RRF in PD patients.

[What should and should not be covered in intraabdominal infection]

Despite improvements in our knowledge of the physiopathology of severe infection, diagnostic methods, antibiotic therapy, postoperative care and surgical techniques, a substantial number of patients with intraabdominal infection (IAI) will develop advanced stages of septic insult requiring admission to the intensive care unit. The success of treatment of IAI is multifactorial and the best antibiotic protocol may be insufficient unless adequate control of the focus of infection has been achieved. The present article discusses the appropriacy of empirical antibiotic therapy and the main pathogens associated with treatment failure. We also analyze the patients at risk of infection with microorganisms requiring broad-spectrum antimicrobial coverage. However, excessive antibiotic treatment, in terms of either spectrum or duration, could jeopardize future patients in an environment already threatened by the scarcity of research and development into new molecules required for the emergence of pathogens resistant to current antibiotics.

Correlation between antimicrobial consumption and resistance among Staphylococcus aureus and enterococci causing healthcare-associated infections at a university hospital in Taiwan from 2000 to 2009

This study investigated the correlation between antibiotic consumption and resistance among Staphylococcus aureus and enterococci causing healthcare-associated infections at a university hospital in Taiwan from 2000 to 2009. Overall, the trend of total consumption (defined daily dose [DDD] per 1,000 patient-days) of glycopeptides, including vancomycin and teicoplanin, significantly increased during 2000 to 2003 and remained stable during 2004-2009. Vancomycin consumption significantly increased during 2003 and decreased after 2004. A significant decrease in the resistance rate with time was found for oxacillin- and gentamicin-resistant S. aureus. In contrast, the rates of vancomycin- and teicoplanin-resistant enterocci increased significantly. A significant correlation was found between the increased use of extended-spectrum cephalosporins, β-lactam-β-lactamase inhibitor combinations, carbapenems and the decreased prevalence of methicillin-resistant S. aureus (MRSA). In contrast, the increased use of teicoplanin, extended-spectrum cephalosporins, β-lactam-β-lactamase inhibitor combinations, and carbapenems was correlated with the increased prevalence of vancomycin-resistant enterococci (VRE). In conclusion, this 10-year study in a single institution identified different correlations between the prescription of antibiotics and the resistance rates of MRSA and VRE. Strict implementation of infection control policy based on these correlates would be helpful in decreasing the presence of these multidrug-resistant pathogens in hospitals.

Risk factors for multidrug-resistant bacterial infection among patients with tuberculosis

Given that anti-tuberculosis medication itself has antibacterial activity and that broad-spectrum antibiotics are frequently used, the emergence of multidrug-resistant (MDR) bacteria among patients being treated for tuberculosis (TB) is likely. We used a case-control design to study the clinical predictors of MDR bacterial infection among TB patients. Both cases and controls were selected from among patients who were diagnosed and treated as having TB between 1 January 1996 and 31 August 2006. TB patients with MDR bacterial infection were included as cases and those with non-MDR bacterial infection were included as controls. Multiple logistic regression analysis was performed to elucidate the risk factors for MDR bacterial infection. During the study period 3667 patients were diagnosed with, and treated for, TB. A total of 123 experienced episodes of bacterial infection, of whom 59 (48.0%) were infected by an MDR strain at least once. The presence of chronic renal failure [adjusted odds ratio (OR): 4.96; 95% confidence interval (CI): 1.37-18.01] and the use of antimicrobials other than typical anti-TB drugs within three months (adjusted OR: 4.37; 95% CI: 1.74-10.95) were independent risk factors for MDR bacterial infection. Bacterial infection in TB patients is commonly multidrug resistant. Clinicians should be aware of the possibility of MDR bacterial infection among TB patients with chronic renal failure or recent use of other antimicrobials.

Antimicrobial Stewardship in the Intensive Care Unit: A Focus on Potential Pitfalls

Patients in the intensive care unit (ICU) have many risk factors for resistant pathogens such as prolonged length of stay, frequent and broad-spectrum antimicrobial therapy, presence of foreign materials, and proximity with other patients. However, of the risk factors associated with acquisition of resistant pathogens, inappropriate use of antimicrobial agents has been the most implicated. Thus, many health care institutions have adopted antimicrobial stewardship programs (ASPs) as a mechanism to ensure more appropriate antimicrobial use. ASPs can have a significant impact in the ICU, leading to improved antimicrobial use and resistance patterns and decreased infection rates and costs, due to the inherent nature of infections encountered and high and often inappropriate antibiotic utilization in this setting. However, certain challenges exist for ASPs in the ICU including issues with infrastructure and personnel, information technology, the core ASP strategy, patient-specific factors, conversion of intravenous to oral therapy, and dose optimization. The combination of comprehensive infection control (IC) and effective antimicrobial stewardship can prevent the emergence of resistance among microorganisms and may decrease the negative consequences associated with antimicrobial misuse.

Therapeutic options for infections due to vancomycin-resistant enterococci

BACKGROUND

Vancomycin-resistant enterococci (VRE) are an important cause of nosocomial infection occurring in critical care or immunocompromised patients.

OBJECTIVES

To provide updated information about therapeutic options for VRE infection.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify in vitro susceptibility data of VRE isolates, randomized and non-randomized controlled trials, case series, and cohort studies of VRE therapy published before 31 July 2008.

RESULTS/CONCLUSION

The updated in vitro susceptibility data for VRE show high resistance to ampicillin and aminoglycosides. Quinupristin-dalfopristin is limited by its lack of activity against vancomycin-resistant Enterococcus faealis and its musculoskeletal side effects. Emerging linezolid resistance has been reported to cause hospital spread and may be related to prolonged linezolid use. Quinupristin-dalfopristin resistance is usually linked to agricultural use of streptogramin. Nitrofurantoin and fosfomycin are alternatives in uncomplicated VRE urinary tract infection. Daptomycin and tigecycline have shown excellent potential for treating VRE infection.

Epidemiology and molecular characterization of vancomycin resistant Enterococci isolates in India

Little attention has been paid to the problem of the spread of vancomycin resistant enterococci (VRE) in India. Between August 2002 to March 2003, faecal and urine samples of patients from various wards of the Postgraduate Institute of Medical Education and Research, Chandigarh, India, were screened for vancomycin resistance. 36 VRE were isolated (18 Enterococcus gallinarum, 9 E. casseliflavus, 7 E. faecium and 2 E. faecalis). These isolates were characterized as low-, moderate- and high-level resistant strains by phenotypic as well as genotypic methods such as minimum inhibitory concentration determination, polymerase chain reaction assays, sequencing of PCR products and multiple sequence alignment of van genes. Correlations established between these results and the vancomycin resistance markers were designated as vanA (783 bp), vanB (635 bp), vanC1 (822 bp) and vanC2 (484 bp) according to the findings of earlier workers as well as comparison with existing databases. Prolonged hospital stay and vancomycin were important risk factors for both VRE UTI and colonization. Renal dialysis, renal failure, prior aminoglycoside and third generation cephalosporin were the other significant factors for VRE UTI. The study also highlights the importance of screening for VRE in clinical samples and recommends the institution of control measures to prevent the further spread of VRE.

Clinical outcome of deep wound infection after instrumented posterior spinal fusion: a matched cohort analysis

STUDY DESIGN

Retrospective case control study.

OBJECTIVE

Determine the impact of infection on clinical outcome in patients undergoing posterior spinal fusion surgery.

SUMMARY OF BACKGROUND DATA

The outcome of patients treated for infection after spinal surgery is not well established because of variability in cohort identification, definition of infection, outcomes instrument, use of a control group, and/or sample size.

METHODS

Thirty-two patients were included. Sixteen patients ("infection group") met inclusion criteria of deep wound infection after spinal fusion with posterior segmental instrumentation (including combined approach). A 1:1 matched cohort ("control group") was created based on primary or revision status, length of fusion, diagnosis, and age. Postoperative patient outcomes were evaluated using the physical components of SF-36 v2.0 with minimum 2-year follow-up.

RESULTS

No significant difference in the Physical Function, Role Physical, Bodily Pain, and General Health domains was detected between the infection group and control group. Mean follow-up was 62 months. Mean Physical Component Summary was 41.4 in the infection group and 44.3 in the control group (P = 0.6). Infection occurred early in 12 patients and late in 4 patients. Most common organisms isolated were Staphylococcus epidermidis, Enterococcus sp., and Staphylococcus aureus. Multiple debridements were significantly associated with polymicrobial infections and later pseudarthrosis requiring reoperation.

CONCLUSION

An aggressive approach to deep wound infection emphasizing early irrigation and debridement allowed preservation of instrumentation and successful fusion in most cases. At the conclusion of treatment, patients can expect a medium-term clinical outcome similar to patients in whom this complication did not occur.

Antimicrobial susceptibility pattern of microorganisms involved in the pathogenesis of surgical site infection (SSI); A 1 year of surveillance

The aim of this study is to identify the antibiotic sensitivity pattern of pathogens involved in the process of surgical site infection, in surgical wards. Changes made in the pattern of antibiotic use will result in different microorganism susceptibility patterns, which needs correct determination for precise empiric antibiotic therapy. One thousand patients (62% men and 38% women, 18- 74-years-old, with mean age 43 +/- 8)) who underwent surgical treatment, in Alzahra University Hospital, Isfahan University of Medicine, Isfahan, Iran, were studied from 2005 to 2006. Surgical wound infections, based on the reported criteria, were aspirated for culturing within 1 plus gram staining of prepared smears. Minimum Inhibitory Concentrations (MICs) were determined for samples and all derived data were compared by SPSS 13 and WHO net 5 software. The prevalence of SSI was 13.3% with 150 positive cultures, totally. Of 150 bacteria, isolated from surgical site infections Staphylococcus aureus had most frequency (43%). Resistance of isolated organisms was 41.7% in amikacin, 65 and 78.6% in ceftazidime, 85.7% in ceftriaxone, 61.5% in ciprofloxacin, 78.8% in gentamicine, 6.4% in imipenem, 13% in meropenem and 70.6% in trimethoprim/sulfamethoxazole, respectively. 78.9% of Staphylococcus aureus isolates were MRSA and vancomycine was the most effective antibiotic without any resistance. Among 10 isolates of coagulase negative Staphylococcus, no vancomycine resistance was seen, but in contrast all cases were resistant to oxacillin. The most common gram negative organism was Klebsiella (18 isolates) in which 100 and 80% were sensitive to imipenem and meropenem, respectively. Seventeen cases were E. coli, in which the most sensitivity was to meropenem (80%) and imipenem (77.8%). Thirteen cases of Pseudomonas were detected, in which 16.7% were resistant to imipenem and 8.3% to meropenem. Our results demonstrated that the total antibiotic resistance is increasing among SSIs, with an up sloping pattern, which will contact with a constant empiric antibiotic therapy. So, precise up to date antibiogram tantalize us toward balancing the rate of total antibiotic resistance to SSIs.

Risk of surgical site infection and efficacy of antibiotic prophylaxis: a cohort study of appendectomy patients in Thailand

Background

No data currently exist about use of antibiotics to prevent surgical site infections (SSI) among patients undergoing appendectomy in Thailand. We therefore examined risk factors, use, and efficacy of prophylactic antibiotics for surgical site infection SSI among patients with uncomplicated open appendectomy.

Methods

From July 1, 2003 to June 30, 2004 we conducted a prospective cohort study in eight hospitals in Thailand. We used the National Nosocomial Infection Surveillance (NNIS) system criteria to identify SSI associated with appendectomy. We used logistic regression analysis to obtain relative risk estimates for predictors of SSI.

Results

Among 2139 appendectomy patients, we identified 26 SSIs, yielding a SSI rate of 1.2 infections/100 operations. Ninety-two percent of all patients (95% CI, 91.0–93.3) received antibiotic prophylaxis. Metronidazole and gentamicin were the two most common antibiotic agents, with a combined single dose administered in 39% of cases. In 54% of cases, antibiotic prophylaxis was administered for one day. We found that a prolonged duration of operation was significantly associated with an increased SSI risk. Antibiotic prophylaxis was significantly associated with a decreased risk of SSI regardless of whether the antibiotic was administered preoperatively or intraoperatively. Compared with no antibiotic prophylaxis, SSI relative risks for combined single-dose of metronidazole and gentamicin, one-day prophylaxis, and multiple-day antibiotic prophylaxis were 0.28 (0.09–0.90), 0.30 (0.11–0.88) and 0.32 (0.10–0.98), respectively.

Conclusion

Single-dose combination of metronidazole and gentamicin seems sufficient to reduce SSIs in uncomplicated appendicitis patients despite whether the antibiotic was administered preoperatively or intraoperatively.

Rational antibiotic use in China: lessons learnt through introducing surgeons to Australian guidelines

BACKGROUND

World-wide concern about increasing antibiotic resistance has focused attention on strategies to improve antibiotic use. This research adapted Australian best-practice guidelines on the prophylactic use of antibiotics in surgery to a Beijing teaching hospital and then used them as a quality assessment and improvement tool, supplemented by educational interventions. Qualitative data about factors influencing antibiotic use was also obtained.

METHODS

Australian and international guideline materials were amalgamated with the help of Chinese experts. Antibiotics prescribed for surgical prophylaxis in 60 consecutive patients undergoing clean or clean-contaminated surgery (120 total) were then compared with guideline recommendations in three phases; a pre-intervention period from June to August, 2002, an intervention period from June to August 2003 and post-intervention period from September to November 2003. During the intervention phase, feedback about prescriptions not in accord with the guideline was discussed with around 25 prescribers every two weeks. In addition, local factors influencing antibiotic use were explored with 13 junior surgeons and 8 high level informants.

RESULTS

While agreement was reached on the principles of antibiotic surgical prophylaxis there was no consensus on detail. Of 180 patients undergoing clean surgery throughout all phases of the study, antibiotic prophylaxis was administered to 78% compared to 98% of the 180 patients undergoing clean-contaminated surgery. Second and third generation cephalosporin antibiotics predominated in both low-risk clean and clean-contaminated operations. The timing of prophylaxis was correct in virtually all patients. The duration of prophylaxis was less than 24 hours in 96% of patients undergoing clean surgery compared to only 62% of patients undergoing clean-contaminated surgery. The intervention produced no improvement in the duration of prophylaxis nor the overuse and inappropriate choice of unnecessary broad-spectrum and expensive drugs. Interviews and focus groups revealed that an important explanation for the latter problem was Chinese government policy which expected hospitals to support themselves largely through the sale of drugs.

CONCLUSION

Improving antibiotic use in China will require hospital funding reform, more authoritative best-practice guidelines, and hospital authorities embracing quality improvement.

2004 Lowbury Lecture: the Western Australian experience with vancomycin-resistant enterococci – from disaster to ongoing control

The first hospital outbreak of a vancomycin-resistant enterococcus (VRE) in Western Australia (WA) started in the Royal Perth Hospital in July 2001 and initially involved the Intensive Care Unit (ICU) and the Nephrology and Dialysis Units. The outbreak was caused by vancomycin-resistant Enterococcus faecium (VREF) of the vanB genotype. Pulsed-field gel electrophoresis and plasmid analysis of the isolates demonstrated a single-strain outbreak. Despite the isolation of carriers and implementation of all the additional precautions recommended to control VRE, VREF spread rapidly. Two months after the index patient was detected, the epidemic strain had spread to 22 wards and units and one outpatient unit (Satellite Dialysis). Four patients were infected and 64 were colonized. A Hospital VRE Executive Group, which included the Chief Executive and Directors of Clinical Services and Nursing, was formed to eradicate the outbreak and to prevent the epidemic strain from becoming endemic in the hospital. The WA Department of Health agreed to provide substantial extra funding to enable the hospital to use expensive enhanced infection control practices, as follows. Control was handicapped by the slowness of conventional laboratory methods, which took four to five days to identify VRE and allowed environmental contamination and nosocomial transmission to occur before carriers were detected and isolated. A laboratory procedure to make rapid provisional identification of VRE within 30-48h was developed by performing multiplex polymerase chain reaction (PCR) for vanA and vanB genes directly on 24-h selective enrichment broth cultures. On average, four rectal swabs, each collected on separate days, were needed to detect >90% of carriers. In total, 1977 ward contacts were screened after discharge from hospital and 54 (2.73%) were found to be carrying VREF. The electronic labelling and active follow-up of ward contacts resulted in a significant number of carriers being detected who otherwise posed a risk of initiating further outbreaks in hospital if they were re-admitted. The outbreak was terminated after five months and the cost of the enhanced infection control practices was 2,700 000 Australian dollars (1,000,000 pounds sterlings). Ongoing control has been facilitated by targeted active surveillance cultures: on admission to high-risk units (ICU, Burns, Nephrology, Haematology, Bone Marrow Transplant Unit), on transfer out of the ICU to other hospital units, by monthly screening of patients regularly attending Dialysis Units, and by opportunistic laboratory screening of inpatient faecal specimens submitted for Clostridium difficile culture and toxin. Vigilance needs to be maintained as the epidemic strain of VREF remains in the Perth community. Ward contacts of the first outbreak have caused small outbreaks in two hospitals, and seven to 19 sporadic new carriers have been detected annually since the first outbreak. The key elements of the VRE control programme are as follows: To date, this programme has prevented VRE from becoming established in any WA hospital.

Cefazolin plus netilmicin versus cefazolin plus ceftazidime for treating CAPD peritonitis: effect on residual renal function

BACKGROUND. The International Society for Peritoneal Dialysis (ISPD) treatment guidelines for continuous ambulatory peritoneal dialysis (CAPD) peritonitis 2000 recommended the use of cefazolin plus ceftazidime as the initial empirical therapy in patients with residual renal function (RRF). However, this treatment regimen has not been compared with the conventional regimen of cefazolin plus netilmicin in prospective, randomized controlled trials.

METHODS

Stable CAPD patients who developed clinical evidence of peritonitis were randomized to receive intraperitoneal (i.p.) cefazolin plus netilmicin or cefazolin plus ceftazidime once daily in the long dwell for 14 days. For patients with RRF (>1 mL/minute) before entry into the study (N= 50), RRF and 24-hour urine volume were measured at days 1, 14, and 42 after commencement of i.p. antibiotic treatment.

RESULTS

One hundred and two patients were recruited into the study. The primary cure rates of i.p. cefazolin plus netilmicin and cefazolin plus ceftazidime were 66.7% and 64.7%, respectively. The overall cure rate for the 2 treatment regimens was 82.3% for both. Seven patients (14%) from each treatment group required removal of the dialysis catheters due to treatment failure. Relapse of peritonitis occurred in 2 patients (4%) in both treatment groups. Thirty-six patients with RRF at baseline achieved primary cure of their peritonitis by the assigned antibiotics. In this subgroup of patients, their RRF and daily urine volume showed significant reduction at day 14 and returned to near baseline values at day 42. The degree of reduction in RRF and urine volume did not differ significantly between the patients treated with cefazolin plus netilmicin and cefazolin plus ceftazidime.

CONCLUSION

Intraperitoneal cefazolin plus netilmicin and cefazolin plus ceftazidime have similar efficacy as empirical treatment for CAPD peritonitis. In CAPD patients with RRF, significant but reversible reduction in RRF and 24-hour urine volume could occur after an episode of peritonitis, despite successful treatment by i.p. antibiotics. The effect of i.p. cefazolin plus netilmicin, or i.p. cefazolin plus ceftazidime on RRF in CAPD patients with peritonitis does not appear to be different. Our findings do not support the routine use of cefazolin and ceftazidime as the empirical treatment for CAPD peritonitis.

Standardized incidence rates of surgical site infection: a multicenter study in Thailand

BACKGROUND

No previous multicenter data regarding the incidence of surgical site infection (SSI) are available in Thailand. The magnitude of the problem resulting from SSI at the national level could not be assessed. The purpose of this study was to estimate the incidence of SSI in 9 hospitals, together with patterns of surgical antibiotic prophylaxis, risk factors for SSI, and common causative pathogens.

METHODS

A prospective data collection among patients undergoing surgery in 9 hospitals in Thailand was conducted. The National Nosocomial Infection Surveillance (NNIS) system criteria and method were used for identifying and diagnosing SSI. The SSI rates were benchmarked with the NNIS report by means of indirect standardization and reported in terms of standardized infection ratio (SIR). Antibiotic prophylaxis was categorized into preoperative, intraoperative, and postoperative. Risk factors for SSI were evaluated using multiple logistic regression models.

RESULTS

From July 1, 2003, to February 29, 2004, the study included 8764 patients with 8854 major operations and identified 127 SSIs, yielding an SSI rate of 1.4 infections/100 operations and a corresponding SIR of 0.6 (95% CI: 0.5-0.8). Of these, 35 SSIs (27.6%) were detected postdischarge. The 3 most common operative procedures were cesarean section, appendectomy, and hysterectomy. The 3 most common pathogens isolated were Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, which accounted for 15.3%, 8.5%, and 6.8% of infections, respectively. The 3 most common antibiotics used for prophylaxis were ampicillin/amoxicillin, cefazolin, and gentamicin. The proportion of types of antibiotic prophylaxis administered were 51.6% preoperative, 24.3% intraoperative, and 24.1% postoperative. Factors significantly associated with SSI were high degree of wound contamination, prolonged preoperative hospital stay, emergency operation, and prolonged duration of operation.

CONCLUSION

Overall SSI rates were less than the average NNIS rates. The causative pathogens of SSI were different from those of other reports. There was a crucial proportion of operations that did not comply with the antibiotic guidelines. The risk factors for SSI identified in this study were consistent with most other reports.

Nosocomial infections due to methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci at a university hospital in Taiwan from 1991 to 2003: resistance trends, antibiotic usage and in vitro activities of newer antimicrobial agents

A rapid increase of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection (from 39% in 1991 to 75% in 2003) and vancomycin-resistant enterococci (VRE) (from 1.2% in 1996 to 6.1% in 2003) at a university hospital in Taiwan was found. The noticeable rise of MRSA and VRE was significantly correlated with the increased consumption of glycopeptides, β-lactam–β-lactamase inhibitor combinations, extended-spectrum cephalosporins, carbapenems and fluoroquinolones (Pearson's correlation coefficient, P < 0.05). Minimum inhibitory concentrations (MICs) of 100 non-duplicate blood isolates of MRSA (in 2003) and of 25 non-duplicate isolates of vancomycin-resistant Enterococcus faecalis and 172 vancomycin-resistant Enterococcus faecium (in 1996–2003) causing nosocomial infection recovered from various clinical specimens of patients treated at the hospital to nine antimicrobial agents were determined by the agar dilution method. All of these isolates were susceptible to linezolid and were inhibited by 0.5 mg/L of tigecycline, and all MRSA isolates were inhibited by daptomycin 1 mg/L, including two isolates of MRSA with heteroresistance to vancomycin. Daptomycin had two-fold better activity against vancomycin-resistant E. faecalis (MIC₉₀, 2 mg/L) than against vancomycin-resistant E. faecium (MIC₉₀, 4 mg/L). Decreased susceptibilities of vancomycin-resistant E. faecium and MRSA to quinupristin/dalfopristin (non-susceptibility 25% and 8%, respectively) were found. Telithromycin had poor activity against the isolates tested (MIC₉₀, 8 mg/L). Linezolid, daptomycin and tigecycline may represent therapeutic options for infections caused by these resistant Gram-positive organisms.

Use of antimicrobial agents in United States neonatal and pediatric intensive care patients

OBJECTIVE

Antimicrobial use contributes to the development of emergence and dissemination of antimicrobial-resistant bacteria among intensive care unit (ICU) patients. There are few published data on antimicrobial use in neonatal (NICU) and pediatric ICU (PICU) patients.

METHODS

Personnel at 31 Pediatric Prevention Network hospitals participated in point prevalence surveys on August 4, 1999 (summer) and February 8, 2000 (winter). Data collected for all NICU and PICU inpatients included demographics, antimicrobials and indications for use and therapeutic interventions.

RESULTS

Data were reported for 2647 patients in 29 NICUs (827 patients in summer; 753 in winter) and 35 PICUs (512 patients in summer; 555 in winter). PICU patients were more likely than NICU patients to be receiving antimicrobials on the survey date [758 of 1070 (70.8%) versus 684 of 1582 (43.2%), P < 0.0001]. NICU patients were receiving a higher median number of antimicrobials (2 versus 1, P < 0.0001). The most common agents among NICU patients were gentamicin, ampicillin and vancomycin; the most common agents among PICU patients were cefazolin, vancomycin and cefotaxime. Use of aminoglycosides, aminopenicillins and topical antibacterials was significantly more common in NICU patients; first, second and third generation cephalosporins, extended spectrum penicillins, sulfonamides, fluoroquinolones, antianaerobic agents, systemic antifungals and systemic antivirals were more common in PICU patients.

CONCLUSIONS

This is the first U.S. national multicenter description of antimicrobial use in NICUs and PICUs and demonstrates the high prevalence of antimicrobial use among these patients. Assessment strategies targeting antimicrobial use in pediatrics are needed.

Results of an antimicrobial control program at a university hospital

PURPOSE

The results of the first five years of an ongoing antimicrobial control program are reported.

METHODS

In 1998, a multidisciplinary antimicrobial subcommittee of the pharmacy and therapeutics committee of a university hospital was formed and charged with making formulary interventions in an effort to reduce rising antimicrobial resistance rates and drug expenditures. In 1999, a number of measures were implemented for controlling antimicrobial use. Selected antimicrobials with the potential for inappropriate use or whose inappropriate use had been documented were placed in the control of physicians in the infectious diseases (ID) division. Prior approval by an ID physician was required before the pharmacy could dispense these agents. Other key interventions included removal of ceftazidime and cefotaxime from the formulary, restriction of vancomycin and carbapenem use, and replacement of ciprofloxacin with levofloxacin as the sole fluoroquinolone on the formulary. Data regarding antimicrobial use and expenditures between 1998 and 2002 were compared and analyzed.

RESULTS

Antimicrobial use was reduced by 80% for third-generation cephalosporins and 15% for vancomycin following the implementation of the new antimicrobial policies. Antimicrobial-resistance patterns for many important gram-negative pathogens, including Pseudomonas aeruginosa, demonstrated a reversal of previous increases. In addition, the rate of methicillin-resistant Staphylococcus aureus decreased by an average of 3% each year from 1999 to 2002. Pharmacy expenditures for all antimicrobials, including antiviral, antifungal, and antibacterial agents, decreased 24.7%, with a cumulative cost saving of 1,401,126 US dollars, without inflation assumptions.

CONCLUSION

The implementation of an antimicrobial control program decreased the use of selected antimicrobial agents and resulted in substantial reduction of expenditures for antimicrobials.

Emerging bacterial pathogens: a consensus of the scientific data and the risk for development of multiple organ dysfunction syndrome

Antibiotic resistance in the hospital setting is continuing to increase, particularly in intensive care units (ICUs) and other areas of the hospital such as oncology units, where the use of empiric broad-spectrum antibiotics is common. The problem of antibiotic resistance is also compounded in the immunocompromised patient. Multi-drug resistance is common among both Gram-positive and -negative bacteria, and becoming more prevalent among fungi (yeast). Two major antibiotic-resistant pathogens include extended-spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KP) and vancomycin-resistant enterococci (VRE). When infections occur with ESBL-KP, a carbapenem antibiotic is usually the drug of choice. When infection occurs with VRE, specific therapy is bacteriostatic, and the clinician may have to rely on empirically selected antibiotics or combinations of antibiotics to achieve a positive outcome. Two newly-approved agents, linezolid and quinupristin/dalfopristin can be used to treat infections caused by resistant gram-positive cocci, but the latter is approved for use against VR-E. faecium. Risk factors for the development of ESBL-KP include the use of extended-spectrum cephalosporins such as ceftazidime. Risk factors for the development of VRE include inappropriate use of vancomycin, extended-spectrum cephalosporins, and antianaerobic drug therapy such as clindamycin. Several institutions have documented a reduction in one or both of these resistant pathogens following a decrease in the use of extended-spectrum cephalosporins combined with the increased use of extended-spectrum penicillins/beta-lactamase inhibitor combinations, such as piperacillin/tazobactam, for the empiric therapy of infections. For VRE, a reduction in the inappropriate use of vancomycin is also an important interventional strategy along with improved infection control practice.

Third generation cephalosporin use in a tertiary hospital in Port of Spain, Trinidad: need for an antibiotic policy

Background

Tertiary care hospitals are a potential source for development and spread of bacterial resistance being in the loop to receive outpatients and referrals from community nursing homes and hospitals. The liberal use of third-generation cephalosporins (3GCs) in these hospitals has been associated with the emergence of extended-spectrum beta- lactamases (ESBLs) presenting concerns for bacterial resistance in therapeutics. We studied the 3GC utilization in a tertiary care teaching hospital, in warded patients (medical, surgical, gynaecology, orthopedic) prescribed these drugs.

Methods

Clinical data of patients (≥ 13 years) admitted to the General Hospital, Port of Spain (POSGH) from January to June 2000, and who had received 3GCs based on the Pharmacy records were studied. The Sanford Antibiotic Guide 2000, was used to determine appropriateness of therapy. The agency which procures drugs for the Ministry of Health supplied the cost of drugs.

Results

The prevalence rate of use of 3GCs was 9.5 per 1000 admissions and was higher in surgical and gynecological admissions (21/1000) compared with medical and orthopedic (8 /1000) services (p < 0.05). Ceftriaxone was the most frequently used 3GC. Sixty-nine (36%) patients without clinical evidence of infection received 3Gcs and prescribing was based on therapeutic recommendations in 4% of patients. At least 62% of all prescriptions were inappropriate with significant associations for patients from gynaecology (p < 0.003), empirical prescribing (p < 0.48), patients with undetermined infection sites (p < 0.007), and for single drug use compared with multiple antibiotics (p < 0.001). Treatment was twice as costly when prescribing was inappropriate

Conclusions

There is extensive inappropriate 3GC utilization in tertiary care in Trinidad. We recommend hospital laboratories undertake continuous surveillance of antibiotic resistance patterns so that appropriate changes in prescribing guidelines can be developed and implemented. Though guidelines for rational antibiotic use were developed they have not been re-visited or encouraged, suggesting urgent antibiotic review of the hospital formulary and instituting an infection control team. Monitoring antibiotic use with microbiology laboratory support can promote rational drug utilization, cut costs, halt inappropriate 3GC prescribing, and delay the emergence of resistant organisms. An ongoing antibiotic peer audit is suggested.

Failure to develop vancomycin-resistant Enterococcus with oral vancomycin treatment of Clostridium difficile

OBJECTIVE

Oral vancomycin therapy has been a risk factor for turning culture positive for vancomycin-resistant Enterococcus (VRE). VRE colonization status was reviewed for all patients who received oral vancomycin and underwent prospective cultures.

METHODS

Data were extracted from the medical records of all patients receiving oral vancomycin between August 1995 and February 2001 regarding history, hospital course, and perirectal VRE cultures. Hospital policy required contact isolation for patients receiving oral vancomycin until colonization with VRE was excluded.

RESULTS

Twenty-six courses of oral vancomycin were given to 22 patients. VRE colonization status after completion of therapy was evaluated for 23 courses in 20 (91%) of these patients. None of these patients became VRE culture positive during a median follow-up of 18 days (range, 9 to 39 days), with a median duration of treatment of 10 days (range, 3 to 58 days), and with a median total dose of 6,500 mg (range, 1,250 to 29,000 mg). All patients received other antibiotics within 30 days prior to therapy with oral vancomycin, during therapy with oral vancomycin, or both; 95% had received anti-anaerobic therapy and 35% had received parenteral vancomycin.

CONCLUSIONS

Even when other risk factors were present, no patient receiving oral vancomycin at our facility subsequently became culture positive for VRE. This suggests that oral vancomycin therapy or other antibiotic use, including anti-anaerobic therapy, may not be a significant independent risk factor for turning culture positive for VRE among patients not previously exposed to the microbe.

"Collateral damage" from cephalosporin or quinolone antibiotic therapy

"Collateral damage" is a term used to refer to ecological adverse effects of antibiotic therapy; namely, the selection of drug-resistant organisms and the unwanted development of colonization or infection with multidrug-resistant organisms. The risk of such damage can be assessed for different antibiotic classes by a variety of epidemiologic studies. Cephalosporin use has been linked to subsequent infection with vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae, beta-lactam-resistant Acinetobacter species, and Clostridium difficile. Quinolone use has been linked to infection with methicillin-resistant Staphylococcus aureus and with increasing quinolone resistance in gram-negative bacilli, such as Pseudomonas aeruginosa. Neither third-generation cephalosporins nor quinolones appear suitable for sustained use in hospitals as "workhorse" antibiotic therapy.

A consensus statement on empiric therapy for suspected gram-positive infections in surgical patients

BACKGROUND

Multidrug resistance among gram-positive pathogens in tertiary and other care centers is common. A systematic decision pathway to help select empiric antibiotic therapy for suspected gram-positive postsurgical infections is presented.

DATA SOURCES

A Medline search with regard to empiric antibiotic therapy was performed and assessed by the 15-member expert panel. Two separate panel meetings were convened and followed by a writing, editorial, and review process.

CONCLUSIONS

The main goal of empiric treatment in postsurgical patients with suspected gram-positive infections is to improve clinical status. Empiric therapy should be initiated at the earliest sign of infection in all critically ill patients. The choice of therapy should flow from beta-lactams to vancomycin to parenteral linezolid or quinupristin-dalfopristin. In patients likely to be discharged, oral linezolid is an option. Antibiotic resistance is an important issue, and in developing treatment algorithms for reduction of resistance, the utility of these new antibiotics may be extended and reduce morbidity and mortality.

Clinical Characteristics and Outcomes of Surgical Patients with Vancomycin-Resistant Enterococcal Infections

The purpose of this study is to determine risk factors associated with mortality in surgical patients with vancomycin-resistant enterococcus (VRE) infections. The hospitalizations of surgical patients with VRE infections from January 1998 to December 2001 were reviewed. Statistical analysis was performed using the Student's t test, chi square, and Fisher's exact test. Thirty-one surgical patients (male:female, 14:17) with a mean age of 51.9 years (range, 21–83 years) developed VRE infection. Infections included bacteremia (12), urinary tract (11), surgical site (seven), and soft tissue (five) infections and intra-abdominal abscess (one). Nine (29.0 per cent) patients received recent outpatient antibiotics and 20 (64.5 per cent) were on steroids. Fifteen (48.4 per cent) patients were treated with intravenous vancomycin before infection. Twelve (38.1 per cent) patients died with a trend toward advanced age (60.7 vs 46.5 years; P = 0.06). The incidence of VRE infection in kidney transplant patients was 1.8 per cent. Six transplant patients (five kidney and one kidney/pancreas) developed VRE infections with four deaths. Hypertension ( P = 0.04), coronary artery disease ( P = 0.02), and the need for intra-arterial pressure monitoring ( P = 0.04) were associated with mortality. Isolate location, gender, diabetes, renal dysfunction, respiratory disease, liver disease, and serum albumin were not associated with mortality. Kidney transplant patients have a high incidence of VRE infection. Surgical patients with VRE infections have a high mortality rate. Hypertension and coronary artery disease are risk factors for mortality.

Impact of a web-based antimicrobial approval system on broad-spectrum cephalosporin use at a teaching hospital

OBJECTIVE

To achieve sustained improvement in use of cefotaxime and ceftriaxone (CEFX) in a major teaching hospital, as measured against national antibiotic guidelines.

DESIGN AND SETTING

Pre- and post-intervention survey of CEFX use in the Royal Melbourne Hospital, a tertiary hospital in Melbourne, Victoria.

INTERVENTION

Web-based antimicrobial approval system linked to national antibiotic guidelines was developed by a multidisciplinary team and implemented in March 2001.

MAIN OUTCOME MEASURES

Change in rate of CEFX use (defined daily doses [DDDs] per 1000 acute occupied bed days) over 8 months pre- and 15 months post-intervention; concordance of indication for CEFX with national antibiotic guidelines pre- and post-intervention.

RESULTS

CEFX use decreased from a mean of 38.3 DDDs/1000 bed days pre-intervention to 15.9, 18.7 and 21.2 DDDs/1000 bed days at 1, 4 and 15 months post-intervention. Concordance with national antibiotic guidelines rose from 25% of courses pre-intervention to 51% within 5 months post-intervention (P < 0.002). Gentamicin use also increased, from a mean of 30.0 to 48.3 DDDs/1000 bed days (P = 0.0001).

CONCLUSION

The web-based antimicrobial approval system achieved a sustained reduction in CEFX use over 15 months as well as increased prescribing concordance with antibiotic guidelines. It has potential for linking to electronic prescribing and for wider use for other drugs, as well as for research into the epidemiology of antibiotic use.