Antimicrobial susceptibility patterns of clinical isolates of gram-negative bacteria obtained from intensive care units in a tertiary hospital in Beijing, China

In this study we investigated the prevalence of antimicrobial resistance in clinical isolates of Gram-negative bacteria obtained from intensive care units (ICUs) in the People's Liberation Army (PLA) 309 Hospital located in beijing, China. between 2007 and 2010, a total of 1949 isolates of Gram-negative bacteria were collected and tested using an antibiotic susceptibility assay. A marked decrease was observed in the susceptibility of Acinetobacter baumannii to imipenem and amikacin as compared to that described in a previous report in China. Similar results were obtained for Pseudomonas aeruginosa. However, imipenem and amikacin showed strong activity against Escherichia coli and Klebsiella pneumoniae. Overall, the high rates of antimicrobial resistance against ICU pathogens in our hospital indicated a critical condition in Beijing, China. Development of a national control and monitoring system by the government may be an ideal method to solve the present problem of managing infections due to Gram-negative bacterial pathogens.     

Antibiotic resistance among Gram-negative non-fermentative bacteria at a teaching hospital in Saudi Arabia.

The incidence and antimicrobial resistance of Gram-negative non-fermentative bacteria isolated over 1 year at King Abdulaziz University Hospital, Jeddah, Saudi Arabia were investigated. A total of 499 of these microorganisms were collected and account for 16% of all Gram-negative bacteria isolated. The most common species were Pseudomonas aeruginosa 291 (56%), Acinetobacter baumannii 170 (34%), and Stenotrophomonas maltophilia 35 (7%). 168 (34%) of these microorganisms were isolated from Intensive Care Unit (ICU), 147 (30%) from General Medicine, and 24 (25%) from Surgery wards. ICU was the main site of isolation of P. aeruginosa and S. maltophilia, while A. baumannii was more frequently isolated from medicine and surgery units. The vast majority of the isolates were resistant to many antibiotics tested. The antimicrobial resistance patterns of P. aeruginosa showed lowest resistance to imipenem (13%), amikacin (17%), and ciprofloxacin (18%). Imipenem was also the most active antimicrobial agent against A. baumannii (15%) resistance. S. maltophilia exhibited multi-drug resistance, and was susceptible only to sulfonamide (6%).     

Monitoring of antibiotic resistance in bacterial isolates from bacteremic patients

The aim of the study was to monitor the prevalence of pathogens and development of resistance in bacteria isolated from bacteremic patients. Five University Clinics and/or Regional Hospitals in the Slovak Republic participated in the study and a total of 421 isolates were collected in the second half of the year 2002. The most prevalent organisms were coagulase-negative staphylococci (CONS) (19%), Staphylococcus aureus (18.3%), among Gram-negative bacteria Escherichia coli (13.3%), Klebsiella pneumoniae (11.4%) and Pseudomonas aeruginosa (7.8%) followed by enterococci, Acinetobacter baumannii and Enterobacter sp. All CONS and S. aureus were susceptible to vancomycin; resistance to oxacillin was observed for 55% of the CONS and only for 4% of S. aureus isolates. A higher prevalence of resistance to erythromycin, clindamycin, gentamicin and ofloxacin was found in CONS in comparison to S. aureus. Enterococcus sp. isolates were fully susceptible to vancomycin and teicoplanin. Gentamicin, amoxicillin/clavulanate, third generation cephalosporins and ciprofloxacin showed good activity against E. coli. Although 17% of K. pneumoniae isolates were resistant to ciprofloxacin, it was the most effective drug against K. pneumoniae; the prevalence of resistance to other antibiotics was rather higher. Gentamicin and ciprofloxacin were the most active against Enterobacter sp. isolates and ceftazidime and meropenem against P. aeruginosa.     

Comparative in-vitro activities of ertapenem against aerobic bacterial pathogens isolated from patients with complicated intra-abdominal infections

The in vitro activities of ertapenem, ceftriaxone, amoxicillin-clavulanate, ampicillin-sulbactam, and piperacillin-tazobactam were compared against 1018 aerobic bacterial pathogens isolated from 531 patients with complicated intra-abdominal infection. Enterobacteriaceae accounted for 66.3% of the aerobic bacteria; Escherichia coli was the most common isolate. The ertapenem minimal inhibitory concentration was < or = 2 microg/mL for 74.6% of isolates and > or = 8 microg/mL for 21.9% (including isolates of enterococci, methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa). Against Enterobacteriaceae, ertapenem was the most potent and the most active drug evaluated (100% susceptible), followed by ceftriaxone (98% susceptible), piperacillin-tazobactam (96% susceptible), amoxicillin-clavulanate (80% susceptible), and ampicillin-sulbactam (64% susceptible). Piperacillin-tazobactam was the only drug evaluated with clinically useful activity against P. aeruginosa. In summary, ertapenem was highly active in vitro against many clinically important aerobic intra-abdominal bacterial pathogens, especially Enterobacteriaceae.     

In vitro activity of beta-lactam antimicrobial agents in combination with aztreonam tested against metallo-beta-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii

We evaluate the antimicrobial interactions between aztreonam and selected beta-lactams when tested against metallo-beta-lactamase (MbetaL)-producing clinical strains. Ten Pseudomonsa aeruginosa strains, including nine MbetaL-producers (IMP-1, -2, -13, -16, VIM-1, -2, -7, SPM-1 and GIM-1) and five Acinetobacter baumannii strains, including three MbetaL-producers (IMP-1 and -2) were tested using time kill/bactericidal activity methods. Aztreonam at 4, 8 and 16 mg/L was combined with four other beta-lactam antimicrobials (cefepime, ceftazidime, meropenem and piperacillin/tazobactam or ampicillin/sulbactam), each tested at the recognized susceptible breakpoint concentration. Enhanced activity (synergism or additive effect) was observed with four P. aeruginosa strains (IMP-16, VIM-2, SPM-1 and GIM-1 containing strains) and four A. baumannii strains, while antagonism was observed with two P. aeruginosa (IMP-16 and SPM-1-producing strains) and one A. baumannii (non-MbetaL) strain. All other strains showed indifferent interaction (variation of +/- 1 log10 CFU/ml) with any combination evaluated.     

食管癌术后化疗患者肺部感染的病原菌分析及耐药性分析

目的分析食管癌术后化疗患者肺部感染病原菌的特点,并探讨病原菌耐药性,指导临床选择合理抗菌药物治疗食管癌化疗后肺部感染。方法选择182例食管癌术后化疗合并肺部感染的患者,分析病原菌分布情况及耐药性。结果182例患者共分离出病原菌236株,其中革兰阴性菌151株,革兰阳性菌56株,真菌29株。革兰阳性菌中金黄色葡萄球菌占比最高,其次为表皮葡萄球菌、肺炎链球菌;革兰阴性菌中铜绿假单胞菌占比最高,其次为鲍曼不动杆菌、肺炎克雷伯菌;真菌中以白色假丝酵母菌为主。革兰阳性菌及革兰阴性菌中主要病原菌均对多种常用抗菌药物存在不同程度耐药,金黄色葡萄球菌对头孢唑林、庆大霉素、红霉素及青霉素有较严重耐药(耐药率≥70.00%),对克林霉素及万古霉素有较低耐药(耐药率<30.00%);表皮葡萄球菌对头孢唑林、头孢曲松、庆大霉素、红霉素及青霉素有较严重耐药,对万古霉素不耐药;铜绿假单胞菌对头孢唑林及复方新诺明有较严重耐药,对亚胺培南、美罗培南、头孢呲肟、哌拉西林及阿米卡星有较低耐药;鲍曼不动杆菌对头孢唑林及氨曲南有较严重耐药,对亚胺培南及美罗培南有较低耐药。结论食管癌术后化疗合并肺部感染患者的病原菌主要为革兰阴性菌、革兰阳性菌、对多种抗菌药物存在不同程度的耐药性,应针对患者病原菌类型选择具有较低耐药性的抗菌药物,以避免抗菌药物滥用,提高肺部感染治疗效果。     

Antibiotic resistance patterns of Gram-negative and Gram-positive strains isolated from inpatients with nosocomial infections in a tertiary hospital in Beijing,China from 2011 to 2014

This study was to evaluate the resistance of antimicrobial agents against pathogens from inpatients with nosocomial infection collected in Beijing, China, during 2011–2014. Measurement of minimum inhibitory concentrations (MICs) was carried out using the broth microdilution method with the Clinical and Laboratory Standards Institute (CLSI) guidelines as the indicator. A total of 5442 Gram-negative and 806 Gram-positive isolates were collected in this study in 2011–2014. Two carbapenem-resistant strains appeared among Escherichia coli (E. coli), while imipenem-resistant isolates increased in proportion from 0% to 8.2% among Klebsiella pneumonia (K. pneumonia) during 4 year. Acinetobacter baumannii (A. baumannii) revealed severe antibacterial resistance to most antimicrobial agents. In contrast, a decreasing trend on resistance had been observed among Pseudomonas aeruginosa (P. aeruginosa) especially after 2012, range from 1.8% for co-trimoxazole to 13.5% for piperacillin. The resistance of Staphylococcus aureus (S. aureus) also had the lowest resistant to linezolid and vancomycin (0.1%). In summary, antimicrobial-resistant nosocomial pathogens have gradually increased from 2011 to 2014, so improved surveillance of hospital-acquired infections and effective infection-control measures may be the best way to solve the present problem.     

In vitro evaluation of the antimicrobial activity of meropenem in combination with polymyxin B and gatifloxacin against Pseudomonas aeruginosa and Acinetobacter baumannii

The antimicrobial activity of meropenem combined with either polymyxin B or gatifloxacin was evaluated by the checkerboard method against Pseudomonas aeruginosa (10 strains) and Acinetobacter baumannii (10 strains). In addition, the triple combination of polymyxin B, gatifloxacin, and meropenem was also studied as well as the polymyxin B and gatifloxacin combination. A partial synergism interaction between meropenem and polymyxin B was observed for 80% of the A. baumannii strains. In contrast, this combination showed an indifferent effect for 80% of the P. aeruginosa strains tested. The combination of meropenem and gatifloxacin showed synergism only for two strains of A. baumannii, and partial synergism and additive effect for seven strains and indifference for four strains of both species. For the strains of P. aeruginosa, the double combination of polymyxin B and gatifloxacin and the triple combination of meropenem, polymyxin B and gatifloxacin were indifferent for the majority of the strains tested, that is, 90 and 80% respectively.     

消化系统肿瘤患者术后真菌感染病原菌分布及耐药性分析

目的 分析消化系统肿瘤患者术后真菌感染病原菌分布特点及耐药情况,从而为临床预防和诊治提供依据.方法 随机选取消化系统肿瘤术后患者1000例为调查对象,其中合并真菌感染患者91例,感染率为9.1％.收集标本,对检出的病原菌进行菌属鉴定,同时进行药敏试验.结果 年龄、远处转移以及肿瘤分期是影响肿瘤患者术后真菌感染的因素(P＜0.05).91例感染患者中,呼吸系统感染72例,占79.12％,消化系统感染17例,占18.68％,泌尿系统感染3例,占3.30％;91株真菌中,白色假丝酵母-菌59株,占64.84％,热带假丝酵母菌12株,占13.19％,光滑假丝酵母菌11株,占12.09％,克柔假丝酵母菌7株,占7.69％,其他2株,占2.20％;91例患者中,合并细菌二重感染58例,占63.74％.以革兰阴性菌为主,占94.83％,其中包括肺炎克雷伯菌、鲍氏不动杆菌、大肠埃希菌、铜绿假单胞菌等.合并革兰阳性菌占5.17％,为葡萄球菌属;白色假丝酵母菌、热带假丝酵母菌、光滑假丝酵母菌以及克柔假丝酵母菌对两性霉素、伏立康唑耐药性为0,对氟康唑和氟康唑有较低耐药率.结论 消化系统肿瘤术后患者真菌感染以白色假丝酵母菌为主,且多合并细菌感染,以革兰阴性菌为主,好发部位为呼吸道,临床上应根据药敏试验结果采取有效的药物治疗.     

晚期肺癌肺部感染细菌培养及药敏实验

目的:探究晚期肺癌肺部感染患者的细菌感染及药敏实验情况。方法:选择2013年3月-2014年7月收治的100例晚期肺癌并发肺部感染患者进行药敏实验研究,分析细菌感染以及耐药状况。结果:100例晚期肺癌并发肺部感染患者痰液标本中的细菌培养结果显示,共分离出150株病原菌,革兰氏阴性菌77株,比例51.3%,占据首位,其次是真菌53株,比例35.3%,革兰氏阳性菌20株,占据比例最小。革兰氏阴性菌中比例较大的有铜绿假单胞菌、鲍氏不动杆菌、肺炎克雷伯菌以及大肠埃希氏菌等;真菌中比例最大的是白色念珠菌,其次是热带念珠菌与光滑念珠菌;革兰氏阳性菌中比例最大的是金黄色葡萄球菌,为6.7%;通过对铜绿假单胞菌、鲍氏不动杆菌、肺炎克雷伯菌、大肠埃希氏菌、金黄色葡萄球菌以及主要真菌进行药敏实验发现,不同的细菌或真菌对不同的抗菌药物的耐药性不同。结论:晚期肺癌患者发生肺部感染,革兰氏阴性菌比例占据首位,其次是真菌,革兰氏阳性菌比例最小。药敏实验显示不同的细菌或真菌对不同的抗菌药物的耐药性不同,需合理使用抗菌药物。     

Antimicrobial resistance in gram-negative isolates from European intensive care units: data from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) programme

Susceptibility data were collected for 6243 gram-negative isolates from 29 European ICUs participating in the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Programme (1997-2000). The most commonly isolated bacteria were Pseudomonas aeruginosa (22.5%), Escherichia coli (19.8%), Klebsiella pneumoniae (10.4%), and Enterobacter cloacae (7.7%). The incidence of extended-spectrum beta-lactamase-producers was higher in Turkish, Russian and Italian ICUs (27.9-39.6%) than in other countries (2.5-10.8%). The frequency of AmpC-cephalosporin hyper-producers was 16.8-55.4%. Meropenem was more active against Proteus mirabilis than imipenem (99.0% versus 88.8% susceptibility, respectively). Against Acinetobacter baumannii, meropenem (79.6% susceptible) and imipenem (82.2%) were more active than comparators (34.3-51.6%). Meropenem and imipenem exhibited good activity against P. aeruginosa (76.1% and 68.2%, respectively; but with inter-country variation). Ciprofloxacin resistance in E. coli and K. pneumoniae increased and needs close monitoring. Meropenem (98.2-99.8% susceptibility) and imipenem (88.8-99.4%) remained potent against important species of gram-negative bacteria from European ICUs actively using meropenem.     

Gram-negative bacterial resistance to cephalosporins in community-acquired infections in Turkey

Cephalosporins are widely used and trustworthy antibiotics in daily medical practice. Although antibacterial resistance has been reported in hospital wards, there are less data for community-acquired infections. In this study we investigated the cephalosporin susceptibility profiles of community-acquired Gram-negative bacteria isolates in Sivas Kizilay Medical Center (Turkey) between March 2002 and March 2003. In our study, 949 Escherichia coli, 165 Proteus spp., 97 Enterobacter spp., 24 Klebsiella spp and 84 Pseudomonas aeruginosa strains were evaluated. Cefepime seemed to be the most effective antibiotic against our community-acquired Gram-negative isolates. Resistance to this drug was 19.3% for P. aeruginosa and around 0-10.6% for enteric bacteria. Enteric pathogen resistance ranged between 44.3-100% for cefazolin, 25-51.9% for cefuroxime, 4.8-25.3% for ceftriaxone, 5.4-14.5% for ceftazidime. Resistance in enteric pathogens to gentamicin ranged between 5.8-15.4%, to amikacin between 3.8-6.25%, to ciprofloxacin between 6.7-20%. 8.1% of P. aeruginosa were resistant to ciprofloxacin. With these profiles the aminoglycosides and ciprofloxacin resemble highly effective cephalosporins like cefepime. On the contrary, first- and second-generation cephalosporins, trimethoprim-sulfamethoxazole, ampicillin and ampicillin-sulbactam are no longer used in probable Gram-negative bacterial infections in our region. Since treatment based on cephalosporins was less efficacious than expected in community-acquired infections, urgent measures are needed to limit antibacterial resistance outside of hospitals.     

Comparative antimicrobial potency of meropenem tested against Gram-negative bacilli: report from the MYSTIC surveillance program in the United States (2004)

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program is a longitudinal resistance surveillance network of more than 100 medical centers worldwide monitoring the susceptibility of bacterial pathogens to carbapenems and other broad-spectrum agents. In 2004 (year six), the antimicrobial activity of 12 broad-spectrum agents was assessed against 2,799 Gram-negative bacterial isolates submitted from 15 United States (USA) medical centers using Clinical and Laboratory Standards Institute (CLSI; formerly NCCLS) recommended methods. Meropenem continued to demonstrate a high potency with MIC90 values 4- to 32-fold lower than imipenem against the Enterobacteriaceae. The wide spectrum of activity for meropenem against all Gram-negative isolates was demonstrated by the overall rank order of percentage susceptibility at CLSI breakpoints: amikacin (96.5%) > meropenem (96.0%) > imipenem (95.8%) > piperacillin/tazobactam (91.5%) > tobramycin (91.4%) > cefepime (91.2%) > ceftazidime (89.0%) > gentamicin (88.0%) > aztreonam (81.5%) > levofloxacin (80.5%) > ciprofloxacin (80.2%) > ceftriaxone (69.1%). Only the aminoglycosides (84.5%) and carbapenems (76.1-83.8%) exhibited acceptable levels of susceptibility against the Acinetobacter spp. isolates as this species group became more resistant to all antimicrobial classes. A continued increase in the resistance rate for both ciprofloxacin and levofloxacin over the six years was observed, most alarming among Escherichia coli (20.2-20.7%) and indole-positive Proteus species (34.4-42.2%) isolates, some documented as clonal. Continued surveillance of these broad-spectrum antimicrobial agents appears warranted to monitor the potency and spectrum of activity against Gram-negative pathogens causing serious infections and the emergence of new or novel resistance mechanisms that could compromise carbapenem therapy.     

Resistance patterns of Pseudomonas aeruginosa to carbapenems and piperacillin/tazobactam.

Pseudomonas aeruginosa is a major problem as a multiresistant nosocomial pathogen, especially in burns and other immunocompromised patients in our hospital. The present prospective study, conducted between June 1996 and December 1997, was aimed at determining the extent of its resistance against highly active antipseudomonal drugs, such as carbapenems (imipenem and meropenem) and ureidopenicillin with beta-lactamase inhibitor (piperacillin/tazobactam); existence of any cross resistance or difference in susceptibility between imipenem and meropenem; and to compare the activity of piperacillin/tazobactam with the two carbapenems against P. aeruginosa. Of the 357 P. aeruginosa isolates tested from 188 patients 37 (10.4%) were resistant to imipenem, 21 (5.9%) to meropenem and 50 (14%) to piperacillin/tazobactam. Cross resistance between the two carbapenems was observed in 5.9% of the isolates. Sixteen (43%) of the imipenem-resistant isolates were susceptible to meropenem but the reverse was observed in none. Amongst the 50 piperacillin/tazobactam-resistant isolates cross resistance with the two carbapenems was observed in 18 (36%) and in 9 (18%) only with imipenem; 23 (46%) were susceptible to both. Our results indicate that P. aeruginosa is least resistant to meropenem followed by imipenem and piperacillin/tazobactam. Cross resistance between the carbapenems and between carbapenems and piperacillin/tazobactam was found. The study further suggests that burns, cardiac-neuro-pediatric surgical, cancer and transplant patients are more susceptible to acquiring infection due to multiresistant P. aeruginosa than other types of patients and common infection sites were wounds, respiratory tract, urine, blood and intravascular lines.     

Effect of moxifloxacin on bacterial pathogenicity factors in comparison with amoxicillin, clarithromycin and ceftriaxone

Moxifloxacin is a recent fluoroquinolone with an antibacterial spectrum encompassing both aerobic Gram-negative and Gram-positive strains, as well as anaerobic bacteria. In this study the activity of moxifloxacin against Streptococcus pneumoniae, Staphylococcus aureus, Moraxella catarrhalis, Haemophilus influenzae, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa, and effects of subinhibitory concentrations on bacterial morphology and adhesion properties were compared with those of amoxicillin, clarithromycin and ceftriaxone. The in vitro activity of moxifloxacin against Gram-positive and Gram-negative pathogens was equal to or better than that of comparators. Subinhibitory concentrations of moxifloxacin significantly affected bacterial morphology of S. pneumoniae, M. catarrhalis, H. influenzae and P. aeruginosa, leading to formation of spherical forms and filaments. Moreover, bacterial adhesion to buccal cells and fibroblasts was reduced after treatment with 1/4 and 1/8 X MIC of moxifloxacin. In conclusion, subinhibitory concentrations of moxifloxacin remarkably interfere with some bacterial pathogenic factors, thereby contributing to its antimicrobial activity.     

Comparative in vitro activity of PH-027 versus linezolid and other anti-anaerobic antimicrobials against clinical isolates of Clostridium difficile and other anaerobic bacteria

PH-027 is a new 5-triazole oxazolidinone synthesized in our laboratories, which shows strong activity against gram-positive aerobic bacteria including clinical isolates. The objective of this study was to investigate the in vitro activity of this compound in comparison with linezolid and other antibiotics against gram-positive and gram-negative anaerobes. The in vitro activity of PH-027 in comparison with those of linezolid and other antimicrobial agents was evaluated against 201 clinical isolates of gram-positive and gram-negative anaerobic bacteria by agar dilution and Etest methods. PH-027 showed excellent activity, with minimum inhibitory concentrations (MIC) in the range of 0.12-4.0 microg/ml against all isolates; MIC90s being 4.0, 1.0, 2.0, 2.0 and 2.0 microg/ml against Clostridium difficile, Peptostreptococcus spp., Bacteroides fragilis, Prevotella bivia and Fusobacterium spp. respectively. In comparison, linezolid had MIC in the range of 0.5-4.0 microg/ml against all isolates, with MIC90s of 2.0, 4.0, 4.0, 4.0 and 2.0 microg/ml against the same set of bacteria respectively. PH-027 demonstrated excellent in vitro activity that is superior to linezolid against Peptostreptococcus spp., B. fragilis and P. bivia. However, against C. difficile and Fusobacterium spp, PH-027 and linezolid showed comparable in vitro activity. Against all anaerobes, metronidazole, PH-027 and, to a lesser extent, linezolid had the most potent activity. From the results of in vitro susceptibility testing, both linezolid and PH-027 show promise in the treatment of anaerobic infections.     

In-vitro activity of clinafloxacin compared to ciprofloxacin against Acinetobacter baumannii strains isolated from intensive care unit patients

The activity of clinafloxacin was compared to that of ciprofloxacin against 154 Acinetobacter baumannii strains isolated from patients treated in Intensive Care Units. Minimum inhibitory concentrations (MICs) were determined by the Epsilometer test method. The majority (87.6%) of the A. baumannii strains tested were resistant to ciprofloxacin (MIC range 0.125->32, MIC50 = >32, MIC90 = >32). On the contrary, only 9.7% of the strains tested were resistant to clinafloxacin (MIC range 0.023->4, MIC50 = 0.75, MIC90 = 2). Due to its superior activity shown against A. baumannii strains, compared to ciprofloxacin, clinafloxacin may be added to the therapeutic armamentarium for hospital-acquired infections caused by A. baumannii in Intensive Care Units.     

Ofloxacin: in vitro activity against recently isolated gram-negative bacterial strains

The activity of ofloxacin was determined against 117 Enterobacteriaceae, 13 Acinetobacter var, anitratus, 124 Pseudomonas aeruginosa in comparison with other antibiotics. Its activity was very high: against Enterobacteriaceae the minimum inhibitory concentration (MIC)50 was 0.125 micrograms/ml, the MIC90 1 micrograms/ml, and the geometric mean (GM) was 0.4 micrograms/ml against Acinetobacter var. anitratus the MIC50 1 micrograms/ml, MIC90 4 micrograms/ml, GM 1.7 micrograms/ml. Unlike other authors we found that the activity of ofloxacin was influenced by the selection of P. aeruginosa resistant to carbenicillin and gentamicin.     

Effect of a policy for restriction of selected classes of antibiotics on antimicrobial drug cost and resistance

Based on the instructions of the National Organization of Pharmaceutical Agents (Greece) from July 1, 2003, quinolones, 3( rd )and 4(th )generation cephalosporins, carbapenems, monobactams, glycopeptides, oxazolidinones, and streptogramins were considered as "restricted" antibiotics that could be used only with the approval of an Infectious Disease specialist. We analyzed the effect of the policy on the consumption and cost of antibiotics as a group and of specific classes, adjusted for the patient load, as well as on the antimicrobial resistance of isolated bacteria. We analyzed 5 trimesters (2 prior and 3 after the implementation of the new policy). A 20% and 16% reduction in adjusted consumption [in daily defined doses (DDDs)] and cost, respectively, of the restricted antibiotics was accomplished during the first trimester after implementation of the new policy. However, this was accompanied by a 36% and 56% increase in adjusted consumption and cost, respectively, of unrestricted antibiotics. A logistic regression model that we performed showed that the new policy had an independent positive effect on the in vitro antimicrobial susceptibility of Pseudomonas aeruginosa (p=0.051) but not of Acinetobacter baumannii and Escherichia coli isolates. Our data suggest that there are considerable limitations to the programs aiming to reduce the consumption of restricted antibiotics through the approval of their use by specialists, at least in some settings.     

Current and future perspectives for levofloxacin in severe Pseudomonas aeruginosa infections

The question of whether levofloxacin includes Pseudomonas aeruginosa in its spectrum of clinical activity is discussed by reviewing the major findings on this issue, mainly those published in Italy. The in vitro activity of levofloxacin against P. aeruginosa is now documented on thousands of strains worldwide. The pharmacodynamic properties of levofloxacin allow for the treatment of pseudomonal infections. The levofloxacin clinical results extrapolated from published studies document the efficacy of levofloxacin in the treatment of infections sustained by P. aeruginosa.