Epidemiology and antimicrobial susceptibility profiles of pathogens causing urinary tract infections in the Asia-Pacific region: Results from the Study for Monitoring Antimicrobial Resistance Trends (SMART), 2010-2013.

A total of 9599 isolates of Gram-negative bacteria (GNB) causing urinary tract infections (UTIs) were collected from 60 centres in 13 countries in the Asia-Pacific region from 2010-2013. These isolates comprised Enterobacteriaceae species (mainly Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Klebsiella oxytoca, Enterobacter cloacae and Morganella morganii) and non-fermentative GNB species (predominantly Pseudomonas aeruginosa and Acinetobacter baumannii). In vitro susceptibilities were determined by the agar dilution method and susceptibility profiles were determined using the minimum inhibitory concentration (MIC) interpretive breakpoints recommended by the Clinical and Laboratory Standards Institute in 2015. Production of extended-spectrum β-lactamases (ESBLs) amongst E. coli, K. pneumoniae, P. mirabilis and K. oxytoca isolates was determined by the double-disk synergy test. China, Vietnam, India, Thailand and the Philippines had the highest rates of GNB species producing ESBLs and the highest rates of cephalosporin resistance. ESBL production and hospital-acquired infection (isolates obtained ≥48 h after admission) significantly compromised the susceptibility of isolates of E. coli and K. pneumoniae to ciprofloxacin, levofloxacin and most β-lactams, with the exception of imipenem and ertapenem. However, >87% of ESBL-producing E. coli strains were susceptible to amikacin and piperacillin/tazobactam, indicating that these antibiotics might be appropriate alternatives for treating UTIs due to ESBL-producing E. coli. Fluoroquinolones were shown to be inappropriate as empirical therapy for UTIs. Antibiotic resistance is a serious problem in the Asia-Pacific region. Therefore, continuous monitoring of evolutionary trends in the susceptibility profiles of GNB causing UTIs in Asia is crucial.

Jean SS ，Coombs G ，Ling T ，Balaji V ，Rodrigues C ，Mikamo H ，Kim MJ ，Rajasekaram DG ，Mendoza M ，Tan TY ，Kiratisin P ，Ni Y ，Weinman B ，Xu Y ，Hsueh PR ... -  《-》

Epidemiology and antimicrobial susceptibility profiles of Gram-negative bacteria causing urinary tract infections in the Asia-Pacific region: 2009-2010 results from the Study for Monitoring Antimicrobial Resistance Trends (SMART).

In 2009, the Study for Monitoring Antimicrobial Resistance Trends (SMART) was expanded to include surveillance of Gram-negative pathogens causing urinary tract infections (UTIs) in the Asia-Pacific region. A total of 1762 isolates were collected from 38 centers in 11 countries from patients with UTIs in 2009 and 2010. In vitro susceptibilities were determined by the broth microdilution method and susceptibility profiles were determined using minimum inhibitory concentration (MIC) interpretive criteria, as recommended by the Clinical and Laboratory Standards Institute (CLSI) in 2010 (M100-S20), in 2011 (M100-S21), and in 2012 (M100-S22). Enterobacteriaceae comprised 86.0% of the isolates, of which Escherichia coli (56.5%) and Klebsiella pneumoniae (13.8%) were the two most common species. Amikacin was the most effective antibiotic (91.7%), followed by ertapenem (86.9%), imipenem (86.6%), and piperacillin-tazobactam (84.9%). Rates of susceptibility were 50.3% for cefoxitin and ranged from 50.3% to 74.2% for the third- and fourth-generation cephalosporins. For ciprofloxacin and levofloxacin, the susceptibility rates were 51.4% and 54.4%, respectively. Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae comprised 28.2% of all isolates. We also found a high rate of resistance to carbapenems among Acinetobacter baumannii and Pseudomonas aeruginosa causing UTI. Interestingly, according to 2012 CLSI breakpoints, approximately 33.4% of ESBL producers were still susceptible to ceftazidime. However, this in vitro efficacy of ceftazidime needs to be validated in vivo by clinical data. The lowered CLSI interpretive breakpoints for piperacillin-tazobactam, carbapenems, and some cephalosporins in 2011-2012 for Enterobacteriaceae resulted in an approximate 5% drop in susceptibility rates for each drug, with the exception of imipenem for which the susceptibility rate dropped from 99.4% according to 2010 criteria to 91.2% according to 2011 criteria. With the updated CLSI criteria, the antimicrobial resistance threat from UTI pathogens in the Asia Pacific area was revealed to be more prominent.

Lu PL ，Liu YC ，Toh HS ，Lee YL ，Liu YM ，Ho CM ，Huang CC ，Liu CE ，Ko WC ，Wang JH ，Tang HJ ，Yu KW ，Chen YS ，Chuang YC ，Xu Y ，Ni Y ，Chen YH ，Hsueh PR ... -  《-》

Epidemiology and trends in the antibiotic susceptibilities of Gram-negative bacilli isolated from patients with intra-abdominal infections in the Asia-Pacific region, 2010-2013.

This study was conducted to investigate the epidemiology and antimicrobial susceptibility patterns of Gram-negative bacilli (GNB) isolated from intra-abdominal infections (IAIs) in the Asia-Pacific region (APR) from 2010-2013. A total of 17 350 isolates were collected from 54 centres in 13 countries in the APR. The three most commonly isolated GNB were Escherichia coli (46.1%), Klebsiella pneumoniae (19.3%) and Pseudomonas aeruginosa (9.8%). Overall, the rates of extended-spectrum β-lactamase (ESBL)-producing E. coli and K. pneumoniae were 38.2% and 24.3%, respectively, and they were highest in China (66.6% and 38.7%, respectively), Thailand (49.8% and 36.5%, respectively) and Vietnam (47.9% and 30.4%, respectively). During 2010-2013, the rates of ESBL-producing E. coli and K. pneumoniae isolates causing community-associated (CA) IAIs (collected <48 h after admission) were 26.0% and 13.5%, respectively, and those causing hospital-associated (HA) IAIs were 48.0% and 30.6%, respectively. Amikacin, ertapenem and imipenem were the most effective agents against ESBL-producing isolates. Piperacillin/tazobactam displayed good in vitro activity (91.4%) against CA ESBL-producing E. coli. For other commonly isolated Enterobacteriaceae, fluoroquinolones, cefepime and carbapenems exhibited better in vitro activities than third-generation cephalosporins. Amikacin possessed high in vitro activity against all GNB isolates (>80%) causing IAIs, except for Acinetobacter calcoaceticus-baumannii (ACB) complex (30.9% for HA-IAI isolates). All of the antimicrobial agents tested exhibited <45% in vitro activity against ACB complex. Antimicrobial resistance is a persistent threat in the APR and continuous monitoring of evolutionary trends in the susceptibility patterns of GNB causing IAIs in this region is mandatory.

Chang YT ，Coombs G ，Ling T ，Balaji V ，Rodrigues C ，Mikamo H ，Kim MJ ，Rajasekaram DG ，Mendoza M ，Tan TY ，Kiratisin P ，Ni Y ，Barry W ，Xu Y ，Chen YH ，Hsueh PR ... -  《-》

Antimicrobial susceptibilities of aerobic and facultative gram-negative bacilli isolated from Chinese patients with urinary tract infections between 2010 and 2014.

Yang Q ，Zhang H ，Wang Y ，Xu Z ，Zhang G ，Chen X ，Xu Y ，Cao B ，Kong H ，Ni Y ，Yu Y ，Sun Z ，Hu B ，Huang W ，Wang Y ，Wu A ，Feng X ，Liao K ，Luo Y ，Hu Z ，Chu Y ，Lu J ，Su J ，Gui B ，Duan Q ，Zhang S ，Shao H ，Badal RE ... -  《BMC INFECTIOUS DISEASES》

Antimicrobial susceptibility and extended-spectrum beta-lactamase rates in aerobic gram-negative bacteria causing intra-abdominal infections in Vietnam: report from the Study for Monitoring Antimicrobial Resistance Trends (SMART 2009-2011).

Treatment options for multidrug-resistant pathogens remain problematic in many regions and individual countries, warranting ongoing surveillance and analysis. Limited antimicrobial susceptibility information is available for pathogens from Vietnam. This study determined the bacterial susceptibility of aerobic gram-negative pathogens of intra-abdominal infections among patients in Vietnam during 2009-2011. A total of 905 isolates were collected from 4 medical centers in this investigation as part of the Study for Monitoring Antimicrobial Resistance Trends. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) rates among the appropriate species were determined by a central laboratory using Clinical and Laboratory Standards Institute methods. Among the species collected, Escherichia coli (48.1% ESBL-positive) and Klebsiella pneumoniae (39.5% ESBL-positive) represented the majority (46.4%) of the isolates submitted for this study. Ertapenem MIC90 values were lowest for these 2 species at 0.12 and 0.25μg/mL and remained unchanged for ESBL-positive isolates. Imipenem MIC90 values were also the same for all isolates and ESBL-positive strains at 0.25 and 0.5μg/mL, respectively. Ertapenem MIC90 values for additional species with sufficient numbers for analysis, including Enterobacter cloacae, Proteus mirabilis, Acinetobacter baumannii, and Pseudomonas aeruginosa, were 1, 0.06, >4, and >4μg/mL, respectively. Analysis of beta-lactamases in a subset of 132 phenotypically ESBL-positive Enterobacteriaceae demonstrated that CTX-M variants, particularly CTX-M-27 and CTX-M-15, were the predominant enzymes. High resistance rates in Vietnam hospitals dictate continuous monitoring as antimicrobial inactivating enzymes continue to spread throughout Asia and globally.

Biedenbach DJ ，Bouchillon SK ，Hoban DJ ，Hackel M ，Phuong DM ，Nga TT ，Phuong NT ，Phuong TT ，Badal RE ... -  《-》