Surveillance of antimicrobial resistance in gram-negative isolates from intensive care units in Turkey: analysis of data from the last 5 years

Cefepime

Cefepime (Maxipime), Maxcef, Cepimax, Cepimex, Axepim, a parenteral fourth-generation cephalosporin, is active against many organisms causative in pneumonia. Cefepime has in vitro activity against Gram-positive organisms including Staphylococcus aureus and penicillin-sensitive, -intermediate and -resistant Streptococcus pneumoniae similar to that of cefotaxime and ceftriaxone. Cefepime also has good activity against Gram-negative organisms, including Pseudomonas aeruginosa, similar to that of ceftazidime. Importantly, cefepime is stable against many of the common plasmid- and chromosome-mediated beta-lactamases and is a poor inducer of AmpC beta-lactamases. As a result, it retains activity against Enterobacteriaceae that are resistant to third-generation cephalosporins, such as derepressed mutants of Enterobacter spp. Cefepime may be hydrolyzed by the extended-spectrum beta-lactamases produced by some members of the Enterobacteriaceae, but to a lesser extent than the third-generation cephalosporins. Monotherapy with cefepime 1 or 2g, usually administered intravenously twice daily, was as effective for clinical and bacteriological response as ceftazidime, ceftriaxone or cefotaxime monotherapy (1 or 2g two or three times daily) in a number of randomized, clinical trials in hospitalized adult, or less commonly, pediatric, patients with generally moderate to severe community-acquired or nosocomial pneumonia. More limited data indicated that monotherapy with cefepime 2g three times daily was also as effective in treating patients with nosocomial pneumonia as imipenem/cilostatin 0.5g four times daily, and when combined with amikacin, cefepime was as effective as ceftazidime plus amikacin. Patients with pneumonia who failed to respond to previous antibacterial therapy with penicillins or other cephalosporins responded to treatment with cefepime. Cefepime is generally well tolerated, with a tolerability profile similar to those of other parenteral cephalosporins. In clinical trials, the majority of adverse events experienced by cefepime recipients were mild to moderate and reversible. The most common adverse events with a causal relationship to cefepime reported in clinical trials included rash and diarrhea. Other, less common, adverse events included pruritus, urticaria, nausea, vomiting oral candidiasis, colitis, headache, fever, erythema and vaginitis.

CONCLUSION

Cefepime is an established and generally well tolerated parenteral drug with a broad spectrum of antibacterial activity which, when administered twice daily, provides coverage of most of the pathogens that may be causative in pneumonia. In randomized clinical trials in hospitalized patients with generally moderate to severe community-acquired or nosocomial pneumonia, cefepime monotherapy exhibited good clinical and bacteriological efficacy. Cefepime may become a preferred antibacterial agent for infections caused by Enterobacter spp. With prudent use in order to prevent the emergence of resistant organisms, cefepime will continue to be a suitable option for the empiric treatment of pneumonia.

The safety of cefepime in the treatment of infection

BACKGROUND

Cefepime is a fourth-generation cephalosporin usually reserved for treating severe nosocomial pneumonia, as well as empirical treatment of febrile neutropenia, uncomplicated and complicated urinary tract infections, uncomplicated skin and skin structure infections, and complicated intra-abdominal infections.

OBJECTIVE

Since reports of neurotoxic effects and of an all-cause mortality higher with cefepime than with comparators have created some concerns regarding its safety, this paper reviews data available in the PubMed database up to December 2007 on cefepime safety.

METHODS

Literature data from PubMed obtained by combining cefepime and safety, or cefepime and clinical trials, were examined.

RESULTS/CONCLUSIONS

Caution in the use of cefepime should be adopted until new evidence on cefepime safety is available.

Antimicrobial resistance pattern of Gram-negative bacilli of nosocomial origin at 2 university hospitals in Iran

The purpose of this study was to investigate the antimicrobial resistance pattern among common Gram-negative bacilli isolated from patients with nosocomial infection. A total of 200 samples of common Gram-negative bacilli (Klebsiella, Pseudomonas, Acinetobacter, and Escherichia coli) were collected from 2 university hospitals in Iran during a 1.5-year period from June 2004 to December 2005. All samples were examined for the antimicrobial activity of imipenem, cefepime, ciprofloxacin, ceftriaxone, and ceftazidime using E-test methods. The most frequent pathogens were Klebsiella spp. (38.5%) followed by Pseudomonas aeruginosa (28.5%), Acinetobacter spp. (20.5%), and E. coli (12.5%). The most active antibiotic was imipenem (84%). The susceptibility of the studied microorganisms was 25% for cefepime, 24% for ciprofloxacin, 20.5% for ceftazidime, and 11.8% for ceftriaxone. The susceptibility rates of Klebsiella to imipenem, cefepime, ciprofloxacin, ceftazidime, and ceftriaxone were 90.9%, 20.8%, 18.2%, 10.4%, and 5.2%, respectively. Likewise, these rates were 88%, 19%, 17%, 21%, and 21% for E. coli. Among Acinetobacter spp., the susceptibility rates were 77% for imipenem and 21% for ciprofloxacin. Among Pseudomonas, the rates were 75% for imipenem and 39% for ciprofloxacin. The antibiotics resistance among Gram-negative bacilli was widespread, so an antibiotic policy is urgently needed to delay the resistance development.

First national surveillance of susceptibility of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. to antimicrobials in Israel

In this 1st national surveillance study, the susceptibility pattern of 1011 consecutive isolates of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. isolated from patients hospitalized in Israel hospitals, covering 62.3% of all general hospital beds in the country, was investigated. Proportion of susceptibilities (range among institutions, MIC(50)/MIC(90) in micrograms per milliliter) were to ertapenem 95.0% (88.8-100%, 0.19/0.75), imipenem 98.8% (88.8-100%, 0.25/0.38), meropenem 98.2% (90.0-100%, 0.06/0.19), piperacillin-tazobactam 59.1% (42.6-77.0%, 16/256), ciprofloxacin 17.2% (9.0-24.6%, 32/32), levofloxacin 17.8% (9.0-24.6%, 32/32), amikacin 74.5% (63.8-98.0%, 6/32), and gentamicin 19.3% (12.3-28.5%, 96/256). Coresistance, cross-resistance, and variability between institutions were high. Only carbapenems retain predicted activity against ESBL-producing E. coli and Klebsiella spp. across Israeli hospitals.

Priorities for antibiotic resistance surveillance in Europe

Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. To achieve this, surveillance studies must have standardised methodologies, be longitudinal, and cover a sufficiently large and representative population. However, many fall short of these requirements that define good surveillance studies. Moreover, current efforts are dispersed among many, mostly small, initiatives with different objectives. These studies must be tailored to the various reservoirs of antibiotic-resistant bacteria, such as hospitalised patients, nursing homes, the community, animals and food. Two studies that could serve as examples of tailored programmes are the European Antimicrobial Resistance Surveillance System (EARSS), which collects resistance data during the diagnosis of hospitalised patients, and the DANMAP programme, which collects data in the veterinary sector. As already noted by the WHO, genetic studies that include both the typing of isolates and the characterisation of resistance determinants are necessary to understand fully the spread and development of antibiotic resistance.

PER-1 is still widespread in Turkish hospitals among Pseudomonas aeruginosa and Acinetobacter spp

PER-1 type beta-lactamases were screened among ceftazidime-resistant clinical isolates of Acinetobacter spp. and Pseudomonas aeruginosa. A total of 176 non-repetitive isolates (84 Acinetobacter spp. and 92 P. aeruginosa) were collected during a three month surveillance period. Isolates were obtained from seven intensive care units of seven university hospitals. All strains were screened for bla(PER-1) alleles by PCR. Of the strains, 31% and 55.4% of Acinetobacter spp. and P. aeruginosa were positive for bla(PER-1) type genes, respectively.

In vitro activity of three different antimicrobial agents against ESBL producing Escherichia coli and Klebsiella pneumoniae blood isolates

Extended spectrum beta-lactamases (ESBLs) usually associated with multiple drug resistance, including beta-lactam and non-beta-lactam antibiotics. This resistance can cause Limitation in the choice of drugs appropriate for using in clinical practice, especially in life-threatening infections. In this study we aimed to investigate in vitro activity of meropenem, ciprofloxacine and amikacin against ESBL-producing and non-producing blood isolates of Escherichia coli and Klebsiella pneumoniae strains. Fifty-eight E. coli (21 ESBL-producing, 37 non-ESBL producing) and 99 K. pneumoniae (54 ESBL-producing, 45 non-ESBL producing) strains were included in the study. The presence of ESBL was investigated by double disk synergy test and E-test methods. Antibiotic susceptibility test was done by microdilution method according to NCCLS guideline. In vitro susceptibilities of ESBL producing E. coli and K. pneumoniae strains were found as 100% for meropenem, 33.3% and 25.9% for ciprofloxacine, 94.5% and 83.3% for amikacin. It was observed that; meropenem was equally active agent in both ESBL-producing and non-producing strains, and its activity was not affected by ESBL production. Whereas amikacin activity was minimally affected and ciprofloxacine activity was markedly decreased by ESBL production. In conclusion, meropenem seems to be better choice of antibiotic should be used for ESBL positive life-threatening infections, because of remaining highest activity.

Surveillance for antimicrobial resistance among clinical isolates of Gram-negative bacteria from intensive care unit patients in China, 1996 to 2002

The objective is to investigate the trend of antimicrobial resistance among nosocomial gram-negative bacteria isolated from intensive care units in China. From 1996 to 2002, the minimum inhibitory concentrations (MICs) of 8 antibiotics for 10,585 isolates of gram-negative bacteria from 19 hospitals in 7 central cities were determined by Etest. From 1996 to 2002, a marked decrease in the susceptibility of Pseudomonas aeruginosa to imipenem was noticed along the years (81-62%). Percentage of multidrug resistance of strains in P. aeruginosa obviously increased (11.5% in 1996, 20.5% in 2002). Imipenem kept active against Escherichia coli (99.2-100% susceptible), Acinetobacter spp. (97.6-93.5%), Klebsiella spp. (94.9-100%), Enterobacter spp. (89-96%). Resistance to cephalosporins, ciprofloxacin, and cefoperazone/sulbactam was observed, particularly among E. coli to ciprofloxacin (42-25%) and cefotaxime (78-54%) and Enterobacter spp. to ceftazidime (51-44%) and cefotaxime (50-37%). Piperacillin/tazobactam kept stable and active against P. aeruginosa, E. coli, and Klebsiella spp. (80%), with an increasing trend, but not good, in Enterobacter spp. (63-58%). Extended-spectrum beta-lactamase-producing strains in E. coli (28.6-45.7%) and Klebsiella spp. (25.5-34.9%) increased during 2001-2002. There was no significant increase resistance in Enterobacteriaceae isolates and Acinetobacter spp. to imipenem, but it has obviously decreased activity in P. aeruginosa throughout the 7-year period in China. Resistance of tested gram-negative bacteria to most comparator antimicrobials increased at different levels from 1996 to 2002 in China.

Hospital-acquired urinary tract infections in Turkey: a nationwide multicenter point prevalence study

Hospital-acquired urinary tract infection (UTI) is the most common infection acquired in hospitals. The aim of the study was to determine the prevalence of UTIs in Turkey. A nationwide one day point-prevalence survey was conducted. Centers for Diseases Control and Prevention (CDC) standard definitions for nosocomial UTIs were used. Data were collected by detailed uniform questionnaires for each patient with UTI. A total of 13269 patients were investigated, the number of patients observed in each hospital varied from 21 to 1329 patients, an average of 458 patients per prevalence study per hospital. The overall prevalence of UTI was 1.7%. Fifty-eight (26.1%) of the patients had sepsis or septic shock. Twenty-five (11.3%) patients had culture-proven bloodstream infection. Over 60% (65.3%) of urinary tract infections were associated with urinary catheters. Overall, 78.4% of UTIs were culture-proven. Escherichia coli (32.4%) was the most common reported pathogen, followed by Klebsiella spp. (17.0%), Candida spp. (12.8%),Pseudomonas aeruginosa (11.7%) and enterococci 8.5%. The prevalence of ampicillin-resistant E. coli was 23.9% and accounted for 73.8% of all E. coli isolated from UTI 8.2%, and 24.6% of E. coli were resistant to quinolones and ceftriaxone, respectively. There were no resistance to carbapenems in E. coli but 6.25, 40.6, 59.4% of Klebsiella spp. were resistant to carbapenems, quinolones and ceftriaxone, respectively. The results of this first national point-prevalence study offers a reliable measure of the prevalence of nosocomial UTIs at hospitals in Turkey and provides a baseline for future studies which will enable the monitoring of trends over time.