Antibiotic policy: a tool for controlling resistance of hospital pathogens

An evaluation of multidrug-resistant (MDR) bacteria in patients with urinary stone disease: data from a high-volume stone management center

PURPOSE

To investigate the prevalence of MDR bacteria in patients with urinary stones and the risk factors for its formation.

METHODS

A retrospective study was performed among patients with urinary stones in Beijing Tsinghua Changgung Hospital from December 2014 to May 2018. Patients with positive urinary cultures and drug sensitivity results were included. MDR were defined as any bacteria that have resistance to at least one agent in at least three classes of antibiotics. Bacteria distribution and resistance patterns were calculated.

RESULTS

1655 patients with urinary stones were eligible for analysis, among which 367 patients had positive urinary culture, yielding 457 isolates of 45 species. Escherichia coli remained the most common organism with a prevalence of 29.3%, followed by Enterococcus faecalis (12.0%), Proteus mirabilis (10.5%), and Klebsiella pneumonia (6.8%). 44.4% isolates were identified as MDR. The three most common Gram-negative bacteria were Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae, with a MDR rate of 84.33%, 62.5%, and 48.39%, respectively. Drug-resistant rates were different between MDR and non-MDR in ampicillin, cefazolin, ceftriaxone, cefepime, gentamicin, amikacin, and levofloxacin (all with p value < 0.05). In multivariate analysis, indwelling catheters (OR 3.1, 95% CI 1.07-8.98) and antibiotics use in the last 3 months (OR 2.14, 95% CI 1.04-4.38) were significantly associated with MDR formation.

CONCLUSIONS

MDR bacteria were common among patients with urinary stones in our center and achieved high drug-resistant rates in ampicillin, first-generation and part of third-generation cephalosporins, and fluoroquinolones. Indwelling catheters and antibiotics used in the last 3 months were independent risk factors for MDR formation. Tailored antibacterial strategies still should be established according to the local bacterial spectrum and patient condition.

Safety Evaluation of Piperacillin/Tazobactam in Very Low Birth Weight Infants

An open, non-comparative study was designed to evaluate the safety and tolerance of parenteral piperacillin/tazobactam in very low birth weight infants. Twenty-seven patients were included for nosocomial sepsis with gram-negative bacteria (n = 4), nosocomial sepsis not responding to the empirical antibiotic regimen (n = 3), suspected necrotizing enterocolitis (n = 17), and infection after abdominal surgery for reasons other than necrotizing enterocolitis (n = 3). No clinical adverse events considered related to the study drug were noted, in particular, no cases of phlebitis, rash or stool changes. Several possibly related, mild and transitory abnormalities of laboratory parameters were observed. No long-lasting effect on the intestinal flora was detected. Seventeen patients (63%) were considered to have a favorable clinical response. This study demonstrates that piperacillin/tazobactam is a safe and well tolerated drug for preterm infants with bacterial infections, particularly those involving the gastrointestinal tract. Comparative clinical trials are warranted to further clarify the microbiological efficacy of piperacillin/tazobactam in this particular patient population.

Integrated Multilevel Surveillance of the World's Infecting Microbes and Their Resistance to Antimicrobial Agents

Microbial surveillance systems have varied in their source of support; type of laboratory reporting (patient care or reference); inclusiveness of reports filed; extent of microbial typing; whether single hospital, multihospital, or multicountry; proportion of total medical centers participating; and types, levels, integration across levels, and automation of analyses performed. These surveillance systems variably support the diagnosis and treatment of patients, local or regional infection control, local or national policies and guidelines, laboratory capacity building, sentinel surveillance, and patient safety. Overall, however, only a small fraction of available data are under any surveillance, and very few data are fully integrated and analyzed. Advancing informatics and genomics can make microbial surveillance far more efficient and effective at preventing infections and improving their outcomes. The world's microbiology laboratories should upload their reports each day to programs that detect events, trends, and epidemics in communities, hospitals, countries, and the world.

Perioperative use of antibiotics in intra-abdominal surgical infections

BACKGROUND

We created a questionnaire with the aim of evaluating surgeon compliance with the guidelines for antibiotic use in the perioperative period in intra-abdominal surgical infections. We discuss the problems emerging from non-adherence to these guidelines.

METHODS

In the questionnaire, we tried to correlate the type of intra-abdominal infection with: (1) Time of antibiotic administration commencement; (2) type of antibiotic(s) administered; (c) duration of antibiotic administration; and (4) modification of antibiotic type/duration of administration in the presence of factors increasing the risk of treatment failure. In order to collect and process the data more easily, the patients were divided into four groups-Group A: Community patients with intra-abdominal surgical infections and simple contamination of the peritoneal cavity according to the Surgical Infection Society (SIS) guidelines; Group B: Community patients with an intra-abdominal surgical infection evolving to secondary peritonitis per SIS guidelines; Group C: Community patients with an intra-abdominal surgical infection with a high risk of surgical site infection; and Group D: Patients with recent hospitalization or nosocomial or postoperative intra-abdominal infection.

RESULTS

The questionnaire was sent to the directors of 43 surgical clinics in northern Greece, and 27 answered (63%). In 81.5% of the clinics (median 22; range 15-24), depending on the type of infection, empirical antibiotic treatment commenced preoperatively. In Group A, on average, 29.6% of the clinics (median 8; range 5-16) administer antibiotics for as long as 24 h, and 11.1% (median 3; range 1-10) use antibiotics not recommended in the SIS guidelines (e.g., third- and fourth-generation cephalosporins, ciprofloxacin, imipenem-cilastatin, meropenem, or piperacillin/tazobactam). In Group B, 22.2% of clinics (median 6; range 2-15) administer antibiotics for three to five days, and 14.8% (median 4; range 1-11) use antibiotics outside SIS guidelines. In Group C, 40.7% of clinics (median 11; range 1-14) administer antibiotics for more than five days, and 14.8% (median 4; range 1-14) use antibiotics that are outside the SIS guidelines. In Group D, 11.1% of clinics (median 3; range 2-5) do not cover Enterococcus with the antibiotics administered.

CONCLUSIONS

There seems to be confusion in determining the situations with simple contamination of the peritoneal cavity, whose treatment requires short-duration antibiotic administration, and in the type of antibiotics administered to various patient groups, elements that lead to prolonged or erroneous administration of antibiotic drugs. Continuous discussion and surgeon training is imperative and may be the best choice to ensure familiarity with antibiotics and their proper use and thus to minimize serious adverse events and treatment failure.

Impact of a multidisciplinary approach on antibiotic consumption, cost and microbial resistance in a Czech hospital

OBJECTIVE

The study objective was to evaluate the impact of a restrictive antibiotic policy, efficacy of inpatient therapeutic and prophylactic antibiotic regimens and susceptibility patterns of infecting bacteria in 2000-2004.

SETTING

A 500-bed general hospital in the Czech Republic.

METHOD

A retrospective computerized survey of antibiotic prescribing practices over a five-year period 2000-2004, using medical records and laboratory data from the hospital information system (HIS).

MAIN OUTCOME MEASURE

Consumption of antibiotics expressed in defined daily doses (DDDs) and Euros per 1,000 bed days. Resistance to antibiotics, average length of hospital stay, rate of inpatients treated with antibiotics, number of nosocomial infections per 1,000 bed days, median length of hospital stay and total mortality.

RESULTS

Due to a restrictive antibiotic policy implemented in 2002, the use of several antibiotics in 2003 was significantly reduced but the consumption of several other antibiotics rose in 2003. In comparison with 2001 the cost of antibiotic agents (in Euro per 1,000 inpatient days) fell significantly by 31% in 2003 Euro 969.07 vs. Euro 671.34). The hospital saved about Euro 29,288 after the first year of implementation of the new antibiotic policy. The use of restricted antibiotics increased by 8%; however, the expenditure decreased by 26%. For non-restricted antibiotics, the use and expenditure decreased by 71% and 41%, respectively. Consequently, a net reduction of 55% Euro 804.36 vs. Euro 359.36) was achieved.

CONCLUSION

The intervention was effective in reducing the use and cost of antibiotics. The HIS is a helpful tool for observing and evaluating the impacts of the measures taken and can be used for assessment of pharmacotherapy outcomes.

Prescription of antibiotic agents in Swedish intensive care units is empiric and precise

Since the prescription of antibiotics in the hospital setting is often empiric, particularly in the critically ill, and therefore fraught with potential error, we analysed the use of antibiotic agents in Swedish intensive care units (ICUs). We examined indications for antibiotic treatment, agents and dosage prescribed among 393 patients admitted to 23 ICUs at 7 tertiary care centres, 11 secondary hospitals and 5 primary hospitals over a 2-week period in November 2000. Antibiotic consumption was higher among ICU patients in tertiary care centres with a median of 84% (range 58-87%) of patients on antibiotics compared to patients in secondary hospitals (67%, range 35-93%) and in primary hospitals (38%, range 24-80%). Altogether 68% of the patients received antibiotics during the ICU stay compared to 65% on admission. Cefuroxime was the most commonly prescribed antibiotic before and during admission (28% and 24% of prescriptions, respectively). A date for decision to continue or discontinue antibiotic therapy was set in 21% (6/29) of patients receiving prophylaxis, in 8% (16/205) receiving empirical treatment and in 3% (3/88) when culture-based therapy was given. No correlation between antibiotic prescription and laboratory parameters such as CRP levels, leukocyte and thrombocyte counts, was found. The treatment was empirical in 64% and prophylactic in 9% of cases. Microbiological data guided prescription more often in severe sepsis (median 50%, range 40-60% of prescriptions) than in other specified forms of infection (median 32%, range 21-50%). The empirically chosen antibiotic was found to be active in vitro against the pathogens found in 55 of 58 patients (95%) with a positive blood culture. This study showed that a high proportion of ICU patients receive antimicrobial agents and, as expected, empirical-based therapy is more common than culture-based therapy. Antibiotics given were usually active in vitro against the pathogen found in blood cultures. We ascribe this to a relatively modest antibiotic resistance problem in Swedish hospitals.

Use of quantitative cultures and reduced duration of antibiotic regimens for patients with ventilator-associated pneumonia to decrease resistance in the intensive care unit

Ventilator-associated pneumonia is responsible for approximately half of the infections acquired in the intensive care unit and represents one of the principal reasons for the prescription of antibiotics in this setting. Invasive diagnostic methods, including bronchoalveolar lavage and/or protected specimen bronchial brushing, could improve the identification of patients with true bacterial pneumonia and facilitate decisions of whether to treat. These techniques also permit rapid optimization of the choice of antibiotics in patients with proven bacterial infection, once the results of respiratory tract cultures become available, based on the identity of the specific pathogens and their susceptibility to specific antibiotics, to avoid prolonged use of a broader spectrum of antibiotic therapy than is justified by the available information. Because unnecessary prolongation of antibiotic therapy for patients with true bacterial infection may lead to the selection of multidrug-resistant microorganisms without improving clinical outcome, efforts to reduce the duration of therapy for nosocomial infections are also warranted. An 8-day regimen can probably be standard for patients with ventilator-associated pneumonia. Possible exceptions to this recommendation include immunosuppressed patients, patients who are bacteremic or whose initial antibiotic therapy was not appropriate for the causative microorganism(s), and patients whose infection is with very difficult-to-treat microorganisms and show no improvement in clinical signs of infection.

Selection of resistance during sequential use of preferential antibiotic classes

OBJECTIVE

To determine the effect of antibiotic class pressure on the susceptibility of bacteria during sequential periods of antibiotic homogeneity.

DESIGN AND SETTING

Prospective study in a mixed ICU with three separated subunits of eight, eight, and ten beds.

PATIENTS AND PARTICIPANTS

The study examined the 1,721 patients with a length of stay longer than 2 days.

INTERVENTIONS

Three different antibiotic regimens were used sequentially over 2 years as first-choice empirical treatment: cephalosporins, fluoroquinolone, or a penicillin-beta-lactamase inhibitor combination. Each regimen was applied for 8 months in each subunits of the ICU, using "latin square" design.

RESULTS

We treated 731 infections in 546 patients (32% of patients staying more than 48 h). There were 25.5 ICU-acquired infections per 1,000 patient-days. Infecting pathogens and colonizing bacteria were found in 2,739 samples from 1,666 patients (96.8%). No significant change in global antibiotic susceptibility was observed over time. However, a decrease in the susceptibility of several species was observed for antibiotics used as the first-line therapy in the unit. Selection pressure of antibiotics and occurrence of resistance during treatment was documented within an 8-month rotation period.

CONCLUSIONS

Antibiotic use for periods of several months induces bacterial resistance in common pathogens.

Is there a rationale for the continuous infusion of cefepime? A multidisciplinary approach

This review is the fruit of multidisciplinary discussions concerning the continuous administration of beta-lactams, with a special focus on cefepime. Pooling of the analyses and viewpoints of all members of the group, based on a review of the literature on this subject, has made it possible to test the hypothesis concerning the applicability of this method of administering cefepime. Cefepime is a cephalosporin for injection which exhibits a broader spectrum of activity than that of older, third-generation cephalosporins for injection (cefotaxime, ceftriaxone, ceftazidime). The specific activity of cefepime is based on its more rapid penetration (probably due to its zwitterionic structure, this molecule being both positively and negatively charged) through the outer membrane of Gram-negative bacteria, its greater affinity for penicillin-binding proteins, its weak affinity for beta-lactamases, and its stability versus certain beta-lactamases, particularly derepressed cephalosporinases. The stability of cefepime in various solutions intended for parenteral administration has been studied, and the results obtained demonstrated the good compatibility of cefepime with these different solutions. These results thus permit the administration of cefepime in a continuous infusion over a 24-h period, using two consecutive syringes.

Rational antibiotic use and academic staff

This study was devised to determine the knowledge, attitude and behaviour of an educated group of people towards antibiotic use and self-medication with antibiotics. Of 1380 members of academic staff (excluding those from the Faculty of Medicine) of Ege University, 602 were chosen by systematic sampling methods. Two groups were formed. Group A included academic staff from the Faculties of Dentistry and Pharmacy and Group B, members of all other faculties. The mean age was 37.4+/-11.0 and 47.0% were females. The mean antibiotic knowledge score was 7.16+/-3.32. Self-medication with antibiotics was admitted by 45.8% of the total samle and 15.6% of the respondents used antibiotics until their symptoms disappeared regardless of the period of prescription. In Group A 48.8% and in Group B 80.7% of the respondents believed that antibiotics could be used for common cold. It is concluded that priority should be given to knowledge-based behaviour education programmes for the more highly educated community; there must also be restriction on the sale of antibiotics without prescription.

Risk factors for infection and molecular typing in patients in the intensive care unit colonized with nosocomial Enterobacter aerogenes

OBJECTIVES

To determine the frequency of colonization by Enterobacter aerogenes in patients in the intensive care unit (ICU) for more than 48 hours and to evaluate the risk factors for infection in patients colonized by this bacteria.

DESIGN

An 8-month prospective study.

SETTING

A 12-bed medical-surgical ICU in a 450-bed, university-affiliated, tertiary-care hospital in Belgium.

METHOD

Pulsed-field gel electrophoresis was used to determine the genotypes of E. aerogenes isolates.

RESULTS

We observed two major clones of E. aerogenes in the ICU. Interestingly, 87.5% of infected patients had the same genomic profile for colonization and infection. Risk factors for infection in this particular population included younger age, prolonged hospital stay, mechanical ventilation, and bronchoscopy.

CONCLUSIONS

Colonization is a major prerequisite for infection. The identification of risk factors for infection in colonized patients can optimize the quality of treatment in the ICU.

Surveillance of antibiotic resistance in European ICUs

Antibiotic resistance among bacteria causing hospital-acquired infections poses a threat, particularly to patients in intensive care units (ICUs). In order to control the spread of resistant bacteria, local, regional and national resistance surveillance data must be used to develop efficient intervention strategies. In an attempt to identify national differences and the dynamics of antibiotic resistance in European ICUs, data have been merged from several networks of resistance surveillance performed during the 1990s. It should be stressed, however, that comparisons of results from different studies using different methods and different population samples must be made with caution. Antibiotic resistance across all species and drugs was, with some exceptions, highest in southern European countries and Russia, and lowest in Scandinavia. More effective strategies are needed to control the selection and spread of resistant organisms. Antibiotic intervention policies, efficient infection control measures and an overall awareness of the serious implications at public health level will contribute to the management of antibiotic resistance.

Cefepime microbiologic profile and update

BACKGROUND

The evolution of the cephalosporin class of antibiotics through modifications of the basic cephem structure has resulted in a new generation with improved antibacterial activity. Cefepime is a prototypic agent of this new class of fourth generation cephalosporins.

OBJECTIVE

To review the microbiologic profile of cefepime.

RESULTS

Cefepime, which is a zwitterion, has a net neutral charge that allows it to penetrate the outer membrane of Gram-negative bacteria faster than third generation cephalosporins. It is more stable against beta-lactamases because of the lower affinity of the enzymes for cefepime when compared with third generation cephalosporins. As a result of these structural attributes, cefepime has in vitro activity against pathogens that are prevalent in pediatric infections. This agent offers the advantage of Gram-positive coverage similar to that of cefotaxime and ceftriaxone, as well as good activity against Pseudomonas aeruginosa and many enteric bacilli that are resistant to third generation cephalosporins, including clinical isolates of Enterobacter spp. and Citrobacter freundii.

CONCLUSIONS

Based on its spectrum of activity cefepime is an option for the treatment of pediatric infections caused by susceptible pathogens.

Antibiotic resistance

Widespread resistance problems exist today in a global sense because of the incorporation of antibiotics with a high resistance potential into animal feeds and because of the uncontrolled use of antibiotics with a high resistance potential in the clinical setting. The only proven method of controlling nonoutbreak resistance problems in hospitals is to limit the hospital formulary to antibiotics with little or no resistance potential. The control of multiresistant organisms in outbreaks occurring in hospitals is best contained using appropriate infection control containment measures. Physicians treating infections in the community, with all other factors being equal, should preferentially select antibiotics with a low resistance potential. The titles and headings of much of the resistance literature are misleading. Articles should not contain fluoroquinolone resistant in the title when ciprofloxacin-resistant organisms are described. Many articles concerning penicillin-resistant pneumococci are entitled fluoroquinolone-resistant S. pneumoniae. These articles describe ciprofloxacin-resistant S. pneumoniae and not resistance to other fluoroquinolones. The same error is perpetuated in describing third-generation cephalosporins and carbapenems. Virtually all of the resistance problems associated with third-generation cephalosporins and carbapenems are due to ceftazidime or imipenem. More precise titling in the literature would remind physicians that antibiotic resistance is related to a specific agent and not class phenomena.

Clinical and molecular epidemiology of chromosome-mediated resistance to third-generation cephalosporins in Enterobacter isolates in eastern France

OBJECTIVE

To determine both the prevalence of group I beta-lactamase-related resistance and the clinical setting in which resistance to expanded-spectrum cephalosporins occurs.

METHODS

Isolates of Enterobacter spp. were sensitivity tested to a range of antibiotics, and selected isolates were DNA fingerprinted by pulsed-field gel electrophoresis. The medical records of all patients with positive cultures for Enterobacter spp. were reviewed to determine the effect of previous antibiotic treatment on the susceptibility profile of these organisms.

RESULTS

The crude incidence of colonization/infection (n = 315) was 0.51 per 100 patients and 0.73 per 1000 days of hospitalization. The 4-day and 7-day Kaplan-Meier rates of colonization/infection with Enterobacter were estimated to be 7.57% (standard deviation (SD = 3.26%) and 4.16% (SD = 2.88%)), respectively. The time lag to colonization/infection with isolates producing large amounts of Bush group 1 beta-lactamase (HLBL) (27.35 +/- 27.30 days) was significantly different from that to colonization/infection with wild-type isolates (13.59 +/- 17.93 days) (P = 0.036). Ninety-six isolates (30.5%) demonstrated acquired resistance to expanded-spectrum cephalosporins: 34 isolates (10.8%) produced extended-spectrum beta-lactamase, and 62 isolates (19.7%) produced HLBL. The 89 Enterobacter isolates susceptible to third-generation cephalosporins yielded 84 major DNA patterns, and the 45 HLBL isolates yielded 38 major DNA patterns. The risk of colonization/infection with HLBL-producing Enterobacter was higher in cases of antimicrobial treatment with third-generation cephalosporins or a fluoroquinolone, and in cases of urinary tract colonization/infection.

CONCLUSIONS

The judicious use in hospitals of both expanded-spectrum cephalosporins and other antibiotics such as fluoroquinolones is necessary to curtail the emergence of resistance in Enterobacter spp.

Strategies for study of the role of cycling on antimicrobial use and resistance

Resistant bacteria usually are seen first in the intensive care unit and other acute-care areas. Thus, strategies to control these organisms often are first tested in these healthcare settings. Frequent among these strategies are attempts to improve antimicrobial use. One proposed method to decrease resistance in special settings like the intensive care unit is the cycling or rotation of antimicrobials. This intervention must be evaluated in the context of other concomitant attempts to improve antimicrobial usage and must take into account other factors influencing resistance. Until such studies are done, the value of cycling and other efforts to limit prescribers' choices of drugs in endemic settings will be unclear. Studies to evaluate cycling will have to be of large scale to produce useful data. It is unlikely that many hospitals or healthcare systems will have sufficient resources on their own to develop studies of sufficient power to be applied widely. Thus, cooperative studies to provide data on this important issue should be an international priority.