Incidence of antibiotic resistance in blood and urine isolates from hospitalized patients. Report from a European collaborative study. European Study Group on Antibiotic Resistance (ESGAR)

Multi-Drug Resistant Bacteria as Aetiological Factors of Infections in a Tertiary Multidisciplinary Hospital in Poland

Global and local initiatives were recently undertaken to reduce the burden of antibiotic resistance. The aim of the study was to describe the incidence and the aetiology of bacterial infections among hospitalized patients with special attention paid to the multidrug resistant (MDR) bacteria. This retrospective study was based on prospectively collected data from 150,529 consecutive patients hospitalized in a tertiary multidisciplinary hospital in the years 2017–2019. All consecutive microbiological tests from any biological material performed in the analyzed period were included. Microbiological screening tests (n = 10,677) were excluded. The analysis was focused on aetiological factors of bacterial infections, especially the incidence of MDR bacteria and mechanisms of antibiotic resistance. There were 58,789 microbiological tests performed in the analyzed period. The highest testing rate was noticed for intensive care unit (mean of 3.1 tests per one patient), followed by neonatal intensive care unit (2.7), internal medicine (1.9), pediatrics (1.8), and urology (1.2). Among 58,789 tests, 7690 (13.1%) were positive. MDR bacteria were responsible for 1783 infections (23.2%). The most common antibiotic resistance mechanism reported was ESBL production by Klebsiella spp. or Escherichia coli or Enterobacter spp. isolates (47.3% of all MDR cases). ESBL cases were followed by MRSA (14.7%), VRE (14.2%) and MBL producing Klebsiella spp. (5.6%). Among all infections caused by MDR bacteria, 1175 (65.9%) were diagnosed after 72 h of hospitalization (hospital-acquired infections). Apart from AmpC and ESBL producing Escherichia coli, all MDR bacteria were significantly more common in hospital-acquired infection. MDR bacteria are aetiological factors of a significant portion of infections in hospitalized patients with no remarkable change in the incidence in recent years. Production of ESBL is the most common mechanism of antibiotic resistance and should be regarded as one of the most urgent problems in clinical microbiology.

Bacterial spectrum and antimicrobial susceptibility pattern of bloodstream infections in children with febrile neutropenia: experience of single center in southeast of Turkey

Empirical antimicrobial therapy is usually started in febrile neutropenic patients without having culture results. The aim of this study was to help determine the policies of empirical antibiotic usage in febrile neutropenic children by detecting the antimicrobial susceptibility profile in this group of patients. In this study 811 blood cultures taken from neutropenic children hospitalized at the Department of Oncology of Gaziantep Children Hospital November 2007 and February 2010 were retrospectively evaluated. Blood cultures were routinely collected in aerobic and anaerobic media and incubated using the BACTEC system. Identification and antimicrobial susceptibility testing of the isolates to antimicrobial agents was performed using the Vitek2(®) system according to the recommendations of the Clinical and Laboratory Standards Institute. Of 811 isolates analyzed, 128 (56.4%) were gram positive cocci, 43 (18.9%) were gram negative bacilli and fungi accounted for 56 (24.7%). The main isolated Gram-positive bacteria from blood were coagulase-negative staphylococcus (56.7%), followed by methicillin-resistant Staphylococcus aureus (14.1%). S. aureus and Streptococcus spp. were all susceptible to linezolid, vancomycin and teicoplanin. S aureus was still susceptible to few other antimicrobial agents such as tetracycline (82.4%), chloramphenicol (55.6%). Seven E. faecium, 7 E. fecalis and 1 E. hirae was isolated from blood cultures. Vancomycin resistance was detected in 6 out of 15 (40%) Enterococcus spp. isolates. Among gram-negative bacteria E. coli (30.2%) was followed by Klebsiella pneumoniae (20.9%) and Proteus spp. (18.6%). Imipenem (89.2%), meropenem (86.6%), chloramphenicol (88.9%), amicasin (82.4%) and fosfomycin (81.3%) showed highest susceptibility in vitro activity against all Gram-negative isolates. To know the antimicrobial susceptibility profile of the pathogens frequently isolated from febrile neutropenic children and to consider this profile before starting an empirical antibiotic therapy would help the clinics which have any role in the treatment of these patients to determine the empirical antibiotic usage policies.

A multi-centre prospective study of febrile neutropenia in Norway: Microbiological findings and antimicrobial susceptibility

The urgent need to treat presumptive bacterial or fungal infections in neutropenic patients has meant that initial therapy is empiric and based on the pathogens most likely to be responsible, and drug resistance. The traditional empirical treatment in Norway has been penicillin G and an aminoglycoside, and this combination has been criticized over recent y. We wished to analyse the microbiological spectrum and susceptibility patterns of pathogens causing bacteraemia in febrile neutropenic patients. This was a prospective multicentre study. During the study period of 2 y, a total of 282 episodes of fever involving 243 neutropenic patients was observed. In 34% of episodes bacteraemia was documented. Overall, 40% of the episodes were caused by Gram-positive organisms, 41% by Gram-negative organisms and 19% were polymicrobial. The most frequently isolated bacteria were Escherichia coli (25.6%), a- and non-haemolytic streptococci (15.6%), coagulase-negative staphylococci (12.4%) and Klebsiella spp. (7.4%). None of the Gram-negative isolates was resistant to gentamicin, meropenem, ceftazidime or ciprofloxacin. Only 5 coagulase-negative staphylococci isolates were resistant to both penicillin G and aminoglycoside. The overall mortality rate was 7%, and 1.2% due to confirmed bacteraemic infection.

Bullous Erysipelas: Clinical Presentation, Staphylococcal Involvement and Methicillin Resistance

BACKGROUND

Erysipelas is a bacterial infection of the dermis and hypodermis, mostly of streptococcal origin. Bullous erysipelas represents a severe form of the disease.

OBJECTIVE

To evaluate the clinical and microbiological characteristics and treatment of bullous erysipelas.

METHODS

Patients with a diagnosis of bullous erysipelas who were treated at the Department of Dermatology, University Hospital of Heraklion, Crete, Greece, between the years 1996 and 2001 were retrospectively studied.

RESULTS

Fourteen patients (11 women, 3 men) with bullous erysipelas were evaluated. The lesions were located on the legs and face in 9 and 4 patients, respectively. The median duration of disease before hospital admission was 4 days. Eight patients had fever at presentation. Local trauma and various lesions were common causes for pathogen entry. The initial empirical antibiotic treatment included intravenous beta-lactams and was modified according to the sensitivities of the isolated strains. Staphylococcus aureus was isolated from 7 (50%), while S. warneri, Streptococcus pyogenes and Escherichia coli grew from the lesions of 3 other patients. Six out of 7 S. aureus strains were methicillin resistant (MRSA) but susceptible to several other non-beta-lactam antibiotics such as quinolones, vancomycin, rifampicin and trimethoprim/sulfamethoxazole.

CONCLUSION

Our findings suggest that S. aureus is frequently involved in and probably contributes in synergy with beta-hemolytic streptococci to the complicated course of bullous erysipelas. The frequency of MRSA isolation suggests that beta-lactam antibiotics may not be sufficient for the treatment of bullous erysipelas anymore, at least in areas with a high incidence of MRSA strains. The role of other classes of antibiotics providing adequate coverage for MRSA has to be evaluated in prospective clinical trials.

A European perspective on intravascular catheter-related infections: report on the microbiology workload, aetiology and antimicrobial susceptibility (ESGNI-005 Study)

The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology laboratories in European (European Union (EU) and non-EU) hospitals. Also included were questions requesting retrospective information for the year 2000. In total, 151 hospitals from 26 European countries participated, of which 78.1% were teaching institutions. Overall, the estimated population served by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques. Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p < 0.0001) than non-EU centres. Of the institutions surveyed, 11.4% (7.2% in EU countries and 23.7% in non-EU countries; p 0.04) used only qualitative techniques for catheter tip sample processing. On the day of the study, 167 microorganisms were recovered from significant catheter tip cultures (122 patients), of which Gram-positive bacteria represented 70.7%, Gram-negative bacteria 22.2%, and yeasts 7.2%. The five most common microorganisms were coagulase-negative staphylococci, Staphylococcus aureus, Candida spp., Enterococcus spp. and Pseudomonas spp. Overall, 19% of catheter tip cultures were polymicrobial. In the case of S. aureus, 40% of isolates were resistant to oxacillin, as were 63.4% of coagulase-negative staphylococcus isolates. Of 37 Gram-negative isolates, 35% were resistant to cefotaxime, 31% to ceftazidime, and 27% to ciprofloxacin. Imipenem and cefepime had the lowest reported rates of resistance (11%).

Surveillance of antimicrobial resistance at a tertiary hospital in Tanzania

BACKGROUND

Antimicrobial resistance is particularly harmful to infectious disease management in low-income countries since expensive second-line drugs are not readily available. The objective of this study was to implement and evaluate a computerized system for surveillance of antimicrobial resistance at a tertiary hospital in Tanzania.

METHODS

A computerized surveillance system for antimicrobial susceptibility (WHONET) was implemented at the national referral hospital in Tanzania in 1998. The antimicrobial susceptibilities of all clinical bacterial isolates received during an 18 months' period were recorded and analyzed.

RESULTS

The surveillance system was successfully implemented at the hospital. This activity increased the focus on antimicrobial resistance issues and on laboratory quality assurance issues. The study identified specific nosocomial problems in the hospital and led to the initiation of other prospective studies on prevalence and antimicrobial susceptibility of bacterial infections. Furthermore, the study provided useful data on antimicrobial patterns in bacterial isolates from the hospital. Gram-negative bacteria displayed high rates of resistance to common inexpensive antibiotics such as ampicillin, tetracycline and trimethoprim-sulfamethoxazole, leaving fluoroquinolones as the only reliable oral drugs against common Gram-negative bacilli. Gentamicin and third generation cephalosporins remain useful for parenteral therapy.

CONCLUSION

The surveillance system is a low-cost tool to generate valuable information on antimicrobial resistance, which can be used to prepare locally applicable recommendations on antimicrobial use. The system pinpoints relevant nosocomial problems and can be used to efficiently plan further research. The surveillance system also functions as a quality assurance tool, bringing attention to methodological issues in identification and susceptibility testing.

Antibiotic-resistant gram-negative bacteria in hospitalized children

Antibiotic-resistant Gram-negative bacilli are a prominent and growing problem among hospitalized children. Epidemics caused by these organisms have been implicated in many outbreaks in children's hospitals, primarily in neonatal intensive care units. These epidemics are characterized by efficient patient-to-patient transmission of the outbreak clone via the hands of caregivers and through exposure of contaminated inanimate sources. The epidemiology of these resistant organisms in pediatric hospitals during endemic periods is more complex. The isolates cultured from hospitalized individuals in the absence of an outbreak usually are unique to each individual and are derived from the patient's endogenous flora or other disparate sources. As in adults, chronic care facilities for children represent significant reservoirs of antibiotic-resistant bacilli that are circulated back into the acute care hospital environment when the child becomes ill.

Etiology and susceptibility of urinary tract isolates in Kosova

Urinary tract infections are amongst the most common pathogenic infections with an increasing resistance to antimicrobials. The objective of this study was to determine the etiology and antimicrobial susceptibility patterns of urinary tract infection pathogens isolated in Kosovo. A retrospective study was carried from urine samples of both inpatients and outpatients that were received in our laboratory throughout 2001. During the study period, 16500 urine samples were analysed, of which 4260 (25.8%) had significant bacteriuria obtained from 1420 patients. Of this, 1059 (74.6%) were collected from females and 361 (25.4%) from males. Urine samples processed from outpatients were 72.5% (1029), whereas 27.5% (391) were from hospitalised patients. Escherichia coli was the most common aetiologic agent isolated (80.5%), followed by Proteus spp. (6.1%), Klebsiella spp. (5.9%), Citrobacter (5.1%) and Mycobacterium tuberculosis (0.8%). Gram-positive bacteria accounted for only 0.3%. Pseudomonas aeruginosa was only isolated from inpatients and was responsible for 0.6% of infections. Amoxicillin, ampicillin and trimethoprim-sulphamethoxazole resistance rates were 48.7, 46.5 and 32.1%, respectively. Nitrofurantoin, cefalexin and ciprofloxacin expressed the highest susceptibility among these isolates. E. coli isolates from inpatients and outpatients showed more than 25% resistance to trimethoprim-sulphamethoxazole. Of all isolates, 16% (225) were resistant to three or more agents and considered multi-drug resistant. Current data on the prevalence of multidrug resistance among urinary tract isolates should be a consideration to change the current empiric treatment of urinary tract infections.

Different trends in antibiotic resistance rates at a university teaching hospital

OBJECTIVES

To investigate long-term trends in antibiotic resistance of common bacterial species isolated at a university hospital and in its intensive care units (ICUs).

METHODS

Levels of antibiotic resistance of common bacterial pathogens were investigated at the Karolinska Hospital during the 12-year period 1988-99. Resistance rates were analyzed for the entire hospital, as well as for ICUs combined.

RESULTS

At the Karolinska Hospital, we found increased ciprofloxacin resistance among Escherichia coli isolates, from 0% in 1991 to 11% in 1999. In the ICUs, the corresponding increase was from 0% to 4.8% during the same period. Co-trimoxazole resistance levels increased from 7.5% to 14%, with lower levels for the ICUs. For ampicillin, cefuroxime, and gentamicin, the levels of resistance were similar in the whole hospital and in the ICUs. Among Pseudomonas aeruginosa isolates, imipenem resistance was higher in the ICUs. For ciprofloxacin, resistance increased from 2.5% in 1991 to 13% in 1999 in the whole hospital, with similar figures for the ICUs.

CONCLUSION

The resistance rates at the Karolinska Hospital were still generally low, but were increasing for some antibiotic-microbe combinations. The results emphasize the importance of including all sectors of a hospital in resistance surveillance studies, and also the value of long surveillance periods.

Cefepime use in a pediatric intensive care unit reduces colonization with resistant bacilli

BACKGROUND

Cefepime has activity against many hospital-acquired Gram-negative pathogens resistant to earlier beta-lactam antibiotics. This study was designed to test whether preferential use of cefepime in a pediatric intensive care unit could reduce enteric colonization with antibiotic-resistant Gram-negative rods.

METHODS

After a 6-month period of uncontrolled antibiotic use, cefepime was preferentially used during 2 years as treatment for nosocomial or serious community-acquired infection. Rectal swab specimens were obtained daily on every patient regardless of antibiotic exposure during the 6 months of uncontrolled antibiotic use and during the first and last 6 months of the 2 years of cefepime preference. The study outcome was rectal colonization with a facultative Gram-negative rod resistant to at least one of four antibiotics: cefepime; ceftazidime; gentamicin; or piperacillin-tazobactam.

RESULTS

The incidence of colonization by a resistant organism decreased only slightly during the first 6 months of cefepime use. By contrast, the number of antibiotic-resistant bacilli isolated from rectal swab specimens diminished from 27.6/100 patients during the baseline period to 12.9/100 patients by the last 6 months of the 2 years of cefepime preference (P < 0.01). The proportion of patients harboring at least one resistant organism decreased from 11.6% to 7.4% during the same time period (P < 0.01). A decrease in colonization with resistant organisms occurred for all the tested resistance phenotypes, including cefepime.

CONCLUSION

Cefepime may possess a low potential for promoting bacillary resistance in critically ill patients, suggesting that its preferential use might be a key element in limiting the presence of antibiotic resistance in the intensive care unit.

Prevalence and bacterial susceptibility of hospital acquired urinary tract infection

PURPOSE: Urinary tract infection is the most common nosocomially acquired infection. It is important to know the etiology and antibiotic susceptibility infectious agents to guide the initial empirical treatment. OBJECTIVE: To determine the prevalence of bacterial strains and their antibiotic susceptibility in nosocomially acquired urinary tract infection in a university hospital between January and June 2003. METHODS: We analyzed the data of 188 patients with positive urine culture (= 10(5) colony-forming units/mL) following a period of 48 hours after admission. RESULTS: Half of patients were male. Mean age was 50.26 ± 22.7 (SD), range 3 months to 88 years. Gram-negative bacteria were the agent in approximately 80% of cases. The most common pathogens were E. coli (26%), Klebsiella sp. (15%), P. aeruginosa (15%) and Enterococcus sp. (11%). The overall bacteria susceptibility showed that the pathogens were more sensible to imipenem (83%), second or third generation cephalosporin and aminoglycosides; and were highly resistant to ampicillin (27%) and cefalothin (30%). It is important to note the low susceptibility to ciprofloxacin (42%) and norfloxacin (43%). CONCLUSION: This study suggests that if one can not wait the results of urine culture, the best choices to begin empiric treatment are imipenem, second or third generation cephalosporin and aminoglycosides. Cefalothin and ampicillin are quite ineffective to treat these infections.

Prevalence and drug susceptibility of pathogens causing bloodstream infections in northern Italy: a two-year study in 16 hospitals

The epidemiology of bacterial pathogens causing bloodstream infection was studied in 16 hospitals in Lombardy (northern Italy) over a 2-year period (1999 and 2000). Overall, 2924 microorganisms causing significant bacteremia were collected. The most frequent isolates were Escherichia coli ( n=663; 22.7%), Staphylococcus aureus ( n=534; 18.3%), Staphylococcus epidermidis ( n=242; 8.2%), and Pseudomonas aeruginosa ( n=176; 6.0%). Unlike Escherichia coli, which was usually acquired from the community, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa were usually acquired in hospitals. Rates of resistance to oxacillin and its associated traits were significantly higher among hospital-acquired staphylococci as compared to those of isolates from the community. Escherichia coli was highly susceptible to extended-spectrum cephalosporins, with a very low percentage of strains producing extended-spectrum ss-lactamases (ESBLs). On the contrary, production of ESBL appeared to be an important mechanism of resistance among nosocomial isolates of Klebsiella pneumoniae. Resistance to ciprofloxacin was widespread in several members of the family Enterobacteriaceae, with rates often exceeding 10%. Moreover, with regard to ciprofloxacin, there were no significant differences between rates of resistance among Enterobacteriaceae causing hospital-acquired infections versus those causing community-acquired infections. Multidrug resistance was commonly observed in Pseudomonas aeruginosa, indicating the need for new antimicrobial agents that are more active against nonfermentative gram-negative bacteria. In conclusion, epidemiological studies of the prevalence and antimicrobial susceptibility patterns of blood isolates in northern Italy appear to provide useful information for both empirical treatment of suspected infections and better management of patients.

A European perspective on nosocomial urinary tract infections I. Report on the microbiology workload, etiology and antimicrobial susceptibility (ESGNI-003 study). European Study Group on Nosocomial Infections

OBJECTIVES

To obtain information on the microbiology workload, etiology and antimicrobial susceptibility of urinary tract infection (UTI) pathogens isolated in European hospitals.

MATERIALS AND METHODS

We collected data available in the microbiology units of a large sample of European hospitals regarding the laboratory workload, diagnostic criteria, and etiology and antimicrobial resistance of the urinary isolates collected on one day (the study day).

RESULTS

Data were received from a total of 228 hospitals from 29 European countries. The average rate of urine samples cultured per 1000 admissions in 1999 was 324. The criteria to consider a positive urine culture as significant were quite variable; > or =10(4) colony-forming units (CFU)/mL for bacteria or > or =10(3) CFU/mL in the case of yeasts were the most used cut-off points. On the study day, a total of 607 micro-organisms from 522 patients with nosocomial UTI were isolated. The six most commonly isolated micro-organisms were, in decreasing order: Escherichia coli (35.6%), Enterococci (15.8%), Candida (9.4%), Klebsiella (8.3%), Proteus (7.9%) and Pseudomonas aeruginosa (6.9%). Pseudomonas was isolated more frequently in non-EU countries. The study data reveal high rates of antimicrobial resistance in UTI pathogens, especially in non-EU countries, where Pseudomonas aeruginosa presented rates of aminoglycoside resistance as high as 72% to gentamicin, 69.2% to tobramycin and 40% to amikacin.

CONCLUSIONS

Nosocomial UTI accounts for an important proportion of the workload in microbiology laboratories. A consensus on the practice and interpretation of urine cultures in Europe is needed. The levels and patterns of resistance of UTI pathogens must be a serious cause for concern and a clear reason for stricter guidelines and regulations in antimicrobial policy.

Multidrug-resistant urinary tract isolates of Escherichia coli: prevalence and patient demographics in the United States in 2000

Concurrent resistance to antimicrobials of different structural classes has arisen in a multitude of bacterial species and may complicate the therapeutic management of infections, including those of the urinary tract. To assess the current breadth of multidrug resistance among urinary isolates of Escherichia coli, the most prevalent pathogen contributing to these infections, all pertinent results in The Surveillance Network Database-USA from 1 January to 30 September 2000 were analyzed. Results were available for 38,835 urinary isolates of E. coli that had been tested against ampicillin, cephalothin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole. Of these isolates, 7.1% (2,763 of 38,835) were resistant to three or more agents and considered multidrug resistant. Among the multidrug-resistant isolates, 97.8% were resistant to ampicillin, 92.8% were resistant to trimethoprim-sulfamethoxazole, 86.6% were resistant to cephalothin, 38.8% were resistant to ciprofloxacin, and 7.7% were resistant to nitrofurantoin. The predominant phenotype among multidrug-resistant isolates (57.9%; 1,600 of 2,793) included resistance to ampicillin, cephalothin, and trimethoprim-sulfamethoxazole. This was the most common phenotype regardless of patient age, gender, or inpatient-outpatient status and in eight of the nine U.S. Bureau of the Census regions. Rates of multidrug resistance were demonstrated to be higher among males (10.4%) than females (6.6%), among patients > 65 years of age (8.7%) than patients < or = 17 (6.8%) and 18 to 65 (6.1%) years of age, and among inpatients (7.6%) than outpatients (6.9%). Regionally, the rates ranged from 4.3% in the West North Central region to 9.2% in the West South Central region. Given the current prevalence of multidrug resistance among urinary tract isolates of E. coli in the United States (7.1%), continued local, regional, and national surveillance is warranted.

Linezolid (PNU-100766) versus vancomycin in the treatment of hospitalized patients with nosocomial pneumonia: a randomized, double-blind, multicenter study

Linezolid, the first oxazolidinone, is active against gram-positive bacteria, including multidrug-resistant strains. This multinational, randomized, double-blind, controlled trial compared the efficacy, safety, and tolerability of linezolid with vancomycin in the treatment of nosocomial pneumonia. A total of 203 patients received intravenous linezolid, 600 mg twice daily, plus aztreonam, and 193 patients received vancomycin, 1 g intravenously twice daily, plus aztreonam for 7-21 days. Clinical and microbiological outcomes were evaluated at test of cure 12-28 days after treatment. Clinical cure rates (71 [66.4%] of 107 for linezolid vs. 62 [68.1%] of 91 for vancomycin) and microbiological success rates (36 [67.9%] of 53 vs. 28 [71.8%] of 39, respectively) for evaluable patients were equivalent between treatment groups. Eradication rates of methicillin-resistant Staphylococcus aureus and safety evaluations were similar between treatment groups. Resistance to either treatment was not detected. Linezolid is a well-tolerated, effective treatment for adults with gram-positive nosocomial pneumonia.

Impact of Antibiotic Resistance on the Treatment of Gram-negative Sepsis

Resistance among gram-negative organisms has greatly complicated the care of the septic patient. An understanding of the likely source of infection, the epidemiologic risk of the patient being exposed to an antibiotic-resistant organism, and the specific vulnerabilities of the host are essential to the proper selection of empiric antimicrobial therapy. In this report, we discuss the epidemiology, antibiotic resistance mechanisms, microbiology, treatment strategies, and diagnostic and therapeutic innovations in the approach to the septic patient.

In vitro activity of evernimicin and selected antibiotics against methicillin-resistant staphylococci: a 24-country study

OBJECTIVE

To collect and analyze data on susceptibility of methicillin-resistant staphylococci to evernimicin and other antimicrobial agents.

METHODS

Recent clinical isolates of methicillin-resistant staphylococci from 33 laboratories in North America, Europe and South Africa were investigated.

RESULTS

Of the antimicrobial agents tested, evernimicin had the lowest MIC90s for methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci (0.75 and 1.0 mg/L, respectively). Resistance to ciprofloxacin and erythromycin was widespread, with higher levels of resistance in North America than in other regions.

CONCLUSIONS

Susceptibility surveys help to determine the antimicrobial activity of new agents. Ciprofloxacin- and erythromycin-resistant staphylococci were prevalent throughout all regions.

Toward multinational antimicrobial resistance surveillance systems in Europe

While there is a growing concern about increasing antimicrobial resistance and international spread of resistant microorganisms, we are still lacking timely multinational, good-quality susceptibility data to guide our decisions on controlling such resistance. This review describes and compares current sources of multicentric antimicrobial susceptibility data, identifies problems responsible for the postponing of the implementation of epidemiological antimicrobial resistance surveillance systems and finally presents requirements for such systems.

A Canadian national surveillance study of urinary tract isolates from outpatients: comparison of the activities of trimethoprim-sulfamethoxazole, ampicillin, mecillinam, nitrofurantoin, and ciprofloxacin. The Canadian Urinary Isolate Study Group

Ampicillin, trimethoprim-sulfamethoxazole, mecillinam, nitrofurantoin, and ciprofloxacin mean resistance rates for 2,000 urinary tract isolates collected from outpatients across Canada in 1998 were 41.1, 19.2, 14.7, 5.0, and 1.8%, respectively. For Escherichia coli isolates alone (n = 1,681) comparable rates were 41. 0, 18.9, 7.4, 0.1, and 1.2%, respectively. The majority of E. coli isolates resistant to ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin were susceptible (MIC, <16 microg/ml) to mecillinam.

Cost of antimicrobial treatment for nosocomial infections based on a French prevalence survey

An estimate of the antibiotic cost of nosocomial infections (NI) was made in a university hospital group based on data collected in adult inpatients enrolled in the French national prevalence survey in 1996. Among the 6839 study patients, 636 (9.3%) presented with at least one NI, of these, data on antimicrobial treatment were available for 480. The overall daily antibiotic cost was estimated between FF 49,439 and 103,526, resulting in FF 103 to 216 per infected patient. The most expensive antibiotic treatment was prescribed in intensive care patients, for pneumonia for device-related NI, or for multi-resistant bacterial infections. Non-documented NI represented about 20% of the overall antibiotic cost. Beta-lactam antibiotics, especially third generation cephalosporins, and parenteral fluoroquinolones were the most expensive antimicrobial drugs. The cost of antibiotic treatment for NI represents a significant part of hospital expenditure that should be reduced by better control of highly expensive prescriptions.