China Antimicrobial Resistance Surveillance System Research Articles

Antimicrobial resistance of clinical bacterial isolates in China: current status and trends.

Antimicrobial resistance surveillance systems have been established in China. Two representative national surveillance networks are the China Antimicrobial Surveillance Network (CHINET) and China Antimicrobial Resistance Surveillance System (CARSS), both of which were established in 2005. For all clinical isolates collected in both of these surveillance networks, the ratio of Gram-negative bacilli to Gram-positive cocci was approximately 7:3 during the past 18 years. Generally, Gram-negative bacilli have a higher antimicrobial resistance profile in China. The prevalence of ESBLs in Escherichia coli is as high as approximately 50%. Acinetobacter baumannii-calcoaceticus complex (ABC) has a high antimicrobial resistance profile, with a carbapenem resistance rate of approximately 66%. However, the prevalence of carbapenem-resistant ABC has also shown a decreasing trend from 2018 to 2022. The prevalence of vancomycin-resistant Enterococcus was low, and the prevalence of MRSA and carbapenem-resistant Pseudomonas aeruginosa showed decreasing trends from 2005 to 2022. CHINET surveillance data demonstrated that the prevalence of carbapenem-resistant Klebsiella pneumoniae showed a remarkable increasing trend from 2.9% (imipenem resistance) in 2005 to 25.0% in 2018, and then slightly decreased to 22.6% in 2022. The decreasing trends may reflect the antimicrobial stewardship efforts in China: a professional consensus on the rational clinical use of carbapenems was issued by the National Health Commission of China and was well implemented nationally; after that, the clinical use of carbapenems decreased slightly in China.

Analyzing the correlation between quinolone-resistant Escherichia coli resistance rates and climate factors: A comprehensive analysis across 31 Chinese provinces

BackgroundThe increasing problem of bacterial resistance, particularly with quinolone-resistant Escherichia coli (QnR eco) poses a serious global health issue. MethodsWe collected data on QnR eco resistance rates and detection frequencies from 2014 to 2021 via the China Antimicrobial Resistance Surveillance System, complemented by meteorological and socioeconomic data from the China Statistical Yearbook and the China Meteorological Data Service Centre (CMDC). Comprehensive nonparametric testing and multivariate regression models were used in the analysis. ResultOur analysis revealed significant regional differences in QnR eco resistance and detection rates across China. Along the Hu Huanyong Line, resistance rates varied markedly: 49.35 in the northwest, 54.40 on the line, and 52.30 in the southeast (P = 0.001). Detection rates also showed significant geographical variation, with notable differences between regions (P < 0.001). Climate types influenced these rates, with significant variability observed across different climates (P < 0.001). Our predictive model for resistance rates, integrating climate and healthcare factors, explained 64.1% of the variance (adjusted R-squared = 0.641). For detection rates, the model accounted for 19.2% of the variance, highlighting the impact of environmental and healthcare influences. ConclusionThe study found higher resistance rates in warmer, monsoon climates and areas with more public health facilities, but lower rates in cooler, mountainous, or continental climates with more rainfall. This highlights the strong impact of climate on antibiotic resistance. Meanwhile, the predictive model effectively forecasts these resistance rates using China's diverse climate data. This is crucial for public health strategies and helps policymakers and healthcare practitioners tailor their approaches to antibiotic resistance based on local environmental conditions. These insights emphasize the importance of considering regional climates in managing antibiotic resistance.

Surveillance of bacterial resistance in children aged 0-14 years from 2018 to 2022

Objective: To understand the distribution and antimicrobial resistance of common bacteria from children aged 0-14 years from China Antimicrobial Resistance Surveillance System. Methods: Bacterial resistance data of 2 575 040 strains from children aged 0-14 years were extracted from the national bacterial resistance surveillance reports from October 2018 to September 2022 and resistance changes were further analyzed by comparing with all data in each year. Results: The total number of bacteria isolated from children in 2018-2022 ranged from 415 306-588 016 strains, accounted for 15.9% (514 193/3 234 372), 16.2% (572 107/3 528 471), 12.8% (415 306/3 249 123), 13.0% (485 418/3 743 027), and 12.2% (588 016/4 828 509), respectively. The proportions of gram-positive bacteria among children were 45.4% (233 456/514 193), 44.5% (254 869/572 107), 44.7% (185 756/415 306), 42.6% (206 903/485 418), and 41.7% (245 044/588 016), respectively. The top five isolates of gram-positive bacteria were Staphylococcus aureus (36.0%-38.8%), Streptococcus pneumoniae (27.1%-31.7%), Staphylococcus epidermidis (7.3%-9.3%), Enterococcus faecium (4.0%-4.8%), and Enterococcus faecium (2.5%-3.6%), and the top five isolates of gram-negative bacteria were Escherichia coli (21.8%-26.2%), Haemophilus influenzae (14.4%-26.4%), Klebsiella pneumoniae (10.1%-14.7%), Moraxella catarrhalis (7.3%-11.9%), and Pseudomonas aeruginosa (5.5%-6.8%). The bacteria from children aged 0-14 years commonly isolated from sputum samples (48.8%-57.0%). The prevalence of methicillin-resistant S. aureus was 28.7%-30.1%. The detection rates of vancomycin-resistant E. faecalis or E. faecium were 0.1%-0.3%. The proportions of non-cerebrospinal fluid-derived penicillin-resistant S. pneumoniae were 0.7%-1.6%. The prevalence of cefotaxime and (or) ceftriaxone-resistant E. coli and K. pneumoniae decreased were 43.7%-50.0% and 31.8%-42.7%, respectively. The resistant rates of E. coli to imipenem and meropenem were 1.2%-1.9% and 1.2%-2.0%, respectively, and the resistant rates of K. pneumoniae to imipenem and meropenem were 7.3%-10.1% and 8.2%-12.2%, respectively. About 6.6%-10.2% and 5.3%-9.6% of the P. aeruginosa isolates showed resistant to imipenem and meropenem, respectively, while 17.2%-24.0% and 19.0%-29.4% of the Acinetobacter baumannii isolates were resistant to imipenem and meropenem, respectively. Conclusions: There is no significant change in the composition of common clinical pathogens in children aged 0-14 years from 2018 to 2022. The prevalence of some resistant bacteria such as methicillin-resistant S. aureus and carbapenem-resistant Enterobacterales is decreasing. However, it is necessary to pay attention to antimicrobial resistance of bacteria from children and long-term monitoring of the prevalence of resistant bacteria should be conducted.

Pseudomonas aeruginosa-induced mitochondrial dysfunction inhibits proinflammatory cytokine secretion and enhances cytotoxicity in mouse macrophages in a reactive oxygen species (ROS)-dependent way.

Pseudomonas aeruginosa belongs to the genus Pseudomonas and is a common Gram-negative, exclusively aerobic, conditionally pathogenic bacterium with the characteristics of easy colonization, mutation, and multidrug resistance (Deng et al., 2015; Azam and Khan, 2019; Jurado-Martín et al., 2021). It is mainly distributed in the air, soil, water, intestinal tract, and skin surface of humans and domestic animals and can cause complications such as ulcerative keratitis, otitis externa, skin and soft tissue infections, respiratory infections, sepsis, osteomyelitis, endocarditis, and urinary tract infections in burned or immunocompromised patients (Azam and Khan, 2019; Chai and Xu, 2020; Voth et al., 2020). P. aeruginosa is a naturally drug-resistant bacterium that is resistant to a wide range of antibiotics, making it one of the major opportunistic pathogens leading to in-hospital infections (Pang et al., 2019; Chai and Xu, 2020; Reynolds and Kollef, 2021). According to the surveillance report of the China Antimicrobial Resistance Surveillance System (CARSS, http://www.carss.cn), Gram-negative bacteria accounted for more than 70% of all bacterial infections, and P. aeruginosa accounted for 12.4%, 12.0%, and 12.2% in 2018, 2019, and 2020, respectively. Therefore, P. aeruginosa infection has become an important concern in public health care, and it is particularly important to gain insight into the means of host immune defense against P. aeruginosa infection.

The association between ambient temperature and antimicrobial resistance of Klebsiella pneumoniae in China: a difference-in-differences analysis.

Antimicrobial resistance (AMR) of Klebsiella pneumoniae (K. pneumoniae) poses a significant global public health threat and is responsible for a high prevalence of infections and mortality. However, knowledge about how ambient temperature influences the AMR of K. pneumoniae is limited in the context of global warming. AMR data of 31 Chinese provinces was collected from the China Antimicrobial Resistance Surveillance System (CARSS) between 2014 and 2020. Socioeconomic and meteorological data were collected from the China Statistical Yearbook during the same period. A modified difference-in-differences (DID) approach was applied to estimate the association between ambient temperature and third-generation cephalosporin-resistant K. pneumoniae (3GCRKP) and carbapenem-resistant K. pneumoniae (CRKP). Furthermore, moderating effects of socioeconomic factors were also evaluated. Every 1°C increase in annual average temperature was associated with a 4.7% (relative risk (RR):1.047, 95% confidence intervals (CI): 1.031-1.082) increase in the detection rate of 3GCRKP, and a 10.7% (RR:1.107, 95% CI: 1.011-1.211) increase in the detection rate of CRKP. The relationships between ambient temperature and 3GCRKP and CRKP were found to be moderated by socioeconomic status (GDP per capita, income per capita, and consumption per capita; the interaction p-values <0.05), where higher economic status was found to strengthen the effects of temperature on the detection rate of 3GCRKP and weaken the effects on the detection rate of CRKP. Ambient temperature was found to be positively associated with AMR of K. pneumoniae, and this association was moderated by socioeconomic status. Policymakers should consider the impact of global warming and high temperatures on the spread of 3GCRKP and CRKP when developing strategies for the containment of AMR.

Estimating the effect of increasing ambient temperature on antimicrobial resistance in China: A nationwide ecological study with the difference-in-differences approach

Antimicrobial resistance (AMR) and the possible consequences of rising ambient temperatures brought on by global warming have been extensively discussed. However, the epidemiological evidence on the effects of temperature on AMR is rare and little is known about the role of socioeconomic inequities. This ecological study obtained 31 provinces AMR data of Escherichia Coli (E. coli) from the China Antimicrobial Resistance Surveillance System (CARSS) over the period from 2014 to 2020, which were linked to the meteorological and socioeconomic data published in the China Statistical Yearbook. Modified difference-in-differences (DID) analyses were performed to estimate the effect of ambient temperature on AMR of E. coli to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems, and quinolones, adjusting for variations in meteorological and socioeconomic factors. We estimated that every 1 °C increase in average ambient temperature was associated with 2.71 % (95 % confidence interval [CI]: 1.20–4.24), 32.92 % (95 % CI: 15.62–52.81), and 1.81 % (95 % CI: 0.47–3.16) increase in the prevalence of E. coli resistance to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems and quinolones, respectively. The link was more profound in the regions with lower temperature and a median level of average humidity, and the regions with lower income, lower expenditure (in economics), lower health resources, and lower hospital admissions. Neither the replacement of the temperature variable nor the alternative approaches for confounding adjustment changed the positive association between ambient temperature and AMR. In general, there exists a positive association between ambient temperature and AMR, although the strength of such an association varies by socioeconomic and health services factors. The association is possibly nonlinear, especially for E. coli resistance to third-generation cephalosporins. The findings suggest that AMR control programs should explicitly incorporate weather patterns to increase their effectiveness.

Surveillance of Multidrug-Resistant Bacterial Infections in Non-Adult Patients - Zhejiang Province, China, 2014-2019.

IntroductionAntimicrobial resistance has become a major public health threat globally. The prevalence of multidrug-resistant (MDR) bacterial infections increased substantially among inpatients under 18 years of age in recent years. In Zhejiang Province, China, the trends of drug-resistance in non-adult patients from 2014 to 2019 were monitored, aiming to determine the variation patterns and epidemiological features of MDR strains.MethodsPatient data were collected from the Annual Review of Hospital Infection Resistance Survey in Zhejiang Province, 2014–2019. Statistical analysis was performed to analyze the pattern of distribution of five key bacterial pathogens in different age groups, ward settings, and bloodstream infections.ResultsFrom 2014 to 2019, a total of 30,163 multidrug-resistant strains were identified among 212,252 clinical isolates. The prevalence of extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E), carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Acinetobacter baumannii, carbapenem-resistant Pseudomonas aeruginosa (CRPA), and methicillin-resistant Staphylococcus aureus (MRSA) were 40.6%, 2.3%, 14.7%, 9.0%, and 27.4%, respectively. The prevalence of these key pathogens was lower than that reported in the national surveillance system (China Antimicrobial Resistance Surveillance System and Infectious Diseases Surveillance of Pediatrics). The prevalence of ESBL-E and CRE decreased since 2015 but that of CRPA and MRSA increased from 2014 to 2018. ConclusionsDespite an overall decrease in the prevalence of drug-resistant bacteria in 2019, the rising prevalence of MRSA and CRPA still warrant much attention. Multidrug-resistant bacteria prevention and control strategies should be adjusted in a timely manner based on the surveillance results.

Analysis of Pathogen Distribution and Its Antimicrobial Resistance in Bloodstream Infections in Hospitalized Children in East China, 2015-2018.

This study analyzed the pathogen distribution in bloodstream-infected (BSI) children hospitalized in Shandong Province from 2015 to 2018, to identify prevention strategies and select empiric antimicrobial therapy for BSI in children. Blood sample data from 14 107 children from 162 hospitals of Shandong Province were obtained from the China Antimicrobial Resistance Surveillance System and analyzed with WHONET 5.6 software. The results of the blood culture test showed the growth of 70.6% Gram-positive and 29.4% Gram-negative bacteria. Of the 14 107 blood isolates, 59.3% were collected from males and 40.7% were from females. Coagulase-negative staphylococci (47.1%) were the most commonly distributed pathogens. The distribution of pathogens varied according to age group and season. All Staphylococcus isolates were susceptible to vancomycin, teicoplanin and linezolid. Clinically, significant declines in penicillin-resistant Streptococcus pneumonia and carbapenem-resistant Escherichia coli were observed during the study period; however, detection rates of carbapenem-resistant Klebsiella pneumoniae increased over time (p < 0.05). Empiric antimicrobial therapy should be prescribed according to corresponding regional pediatric antimicrobial-resistant data.

Addressing antimicrobial resistance in China: progress and challenges in translating political commitment into national action

Background: In 2016, 14 department ministers collaboratively launched China's five-year National Action Plan (NAP) on antimicrobial resistance (AMR). The NAP sets out strategic objectives including diagnostic innovation, mandatory prescriptions for antibiotics in human and animal use, antimicrobial stewardship (AMS) in hospitals, and professional capacity building. We conducted an interim post-implementation analysis to assess the impact of the NAP and provide critical insights about where efforts should focus next. Methods and materials: We synthesized evidence from multiple sources, including 1) the World Health Organisation (WHO) global tripartite database of country progress in addressing AMR, 2) two national surveillance networks, China Antimicrobial Resistance Surveillance System (CARSS) and China Antimicrobial Surveillance Network (CHINET), collectively reporting cross-sectional and time-series data of AMR epidemiology, and 3) published literature and government documents. The analysis was validated by key strategic and operational policy makers in China, including the Chief Advisor of the National Consultative Expert Commission of AMR Containment, who also scored a 7-dimension framework to identify levers for future change. Results: Legislative enforcement in antibiotic use in paediatric patients and food-producing animals, and national surveillance with timely mandatory reporting and data accessibility highlighted the country's progress, reflected by the reduction in broad-spectrum antibiotic consumptions for surgical prophylaxis and among hospital inpatients; and decrease in total hospital resistance and methicillin-resistant Staphylococcus aureus (MRSA) incidence. Tailored training and research has been embedded in hospitals to guide clinical practice and minimise skill and knowledge gaps in healthcare professionals. However, areas for improvement remain. AMR is absent from the nation's wider public health agenda, including Healthy China 2030, which lacks any strategic measure to address AMR. Shortages of qualified general practitioners and low utilisation of nursing workforce hindered local implementation of top-level policy directive. Organisational regulation relies on administrative power rather than dedicated professional roles. Further, pharmaceutical industry continues incentivising prescription and over-the-counter sales. Low public awareness, driven by limited health literacy about anti-infective and anti-inflammatory drugs, remains a barrier to engaging patients and citizens to promote optimal AMS and infection prevention. Conclusion: Despite the progress, China faces challenges across health systems. A whole-health-economy approach is needed to involve wider stakeholders to achieve sustainable long-term benefit.

Epidemiological analysis of pathogens causing bloodstream infections in department of hematology in Guangdong Province

目的分析广东省50家医院血液内科血标本来源细菌的构成和耐药性，了解血液内科血流感染（BSI）的流行病学特征。方法基于国家细菌耐药监测网（CARSS）平台，对2019年广东省50家医院血液内科、呼吸内科和ICU由血标本分离的病原菌分布和碳青霉烯类耐药革兰阴性菌（CRO）检出率进行分析，同时对大肠埃希菌、肺炎克雷伯菌和铜绿假单胞菌药敏特征分儿童组（≤14岁）和成人组（>14岁）进行分析。参考CLSI 2019年M100文件标准判断结果。结果共收集广东省50家医疗机构（三级医院48家）血液内科、呼吸内科、重症监护治疗病房（ICU）三个科室各1618、1026、3626株血标本分离菌完整微生物信息资料。其中血液内科革兰阴性杆菌占71.8％，革兰阳性球菌占28.2％。血液内科分离前5位细菌是：大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、凝固酶阴性葡萄球菌和草绿色链球菌群。葡萄球菌属中耐甲氧西林金黄色葡萄球菌（MRSA）、耐甲氧西林的凝固酶阴性葡萄球菌（MRSCN）的检出率分别为19.7％和80.6％，未发现对万古霉素、利奈唑胺、替考拉宁耐药的菌株，无利奈唑胺耐药的肠球菌。草绿色链球菌群对青霉素G的耐药率为6.9％，对头孢曲松和头孢噻肟耐药率均超过25.0％。肠杆菌科细菌中大肠埃希菌和肺炎克雷伯菌儿童组耐药率普遍高于成人组。成人组肺炎克雷伯菌对美罗培南耐药率为14.1％，阴沟肠杆菌对碳青霉烯类耐药率超过25.0％，非发酵菌中铜绿假单胞菌对大部分抗菌药物敏感性超过80.0％，但儿童组对美罗培南的耐药率高于成人组（11.8％对6.5％）。鲍曼不动杆菌无对替加环素耐药菌株。科室之间比较，ICU和呼吸内科血标本革兰阳性球菌比例高于血液内科。呼吸内科碳青霉烯类耐药大肠埃希菌（CREC）和碳青霉烯类耐药肺炎克雷伯菌（CRKP）检出率最低，分别为0.3％和3.7％。血液内科碳青霉烯类耐药铜绿假单胞菌（CRPA）和碳青霉烯类耐药鲍曼不动杆菌（CRAB）检出率最低，分别为8.3％和25.8％。ICU整体碳青霉烯类耐药的革兰阴性杆菌检出率都最高。结论血液内科血标本来源细菌构成比与重要细菌耐药性与呼吸内科、ICU存在差异，广东地区血液内科肺炎克雷伯菌、铜绿假单胞菌、阴沟肠杆菌及以草绿色链球菌群为主的链球菌属比例明显高于ICU和呼吸内科。

Literature review on the distribution characteristics and antimicrobial resistance of bacterial pathogens in neonatal sepsis

Purpose Neonatal sepsis (NS) has no specific clinical manifestations and blood culture analysis requires a long period of time. Knowledge of prevalent bacterial isolates and their antibiotic susceptibility is crucial when choosing an empirical therapy to decrease morbidity and mortality. This literature review summarizes the distribution characteristics and antimicrobial resistance of bacterial pathogens associated with bloodstream infections in Chinese neonates, and thus serves as a reference for pediatricians. Methods The full-text journal database, CNKI, was searched using the key words “neonatal”, “sepsis”, and “bacterial pathogen” to retrieve relevant literature published from 2016 up to April 2018. The following data were extracted from the selected papers: title, pathogen collection time, care unit name, province (city), distribution of bacterial pathogens among bloodstream infections, and antimicrobial resistance of major pathogens. Results A total of 86 articles were searched, of which 30 complied with the study requirements and thus were included in the review; all were retrospective studies. The articles covered a total of 4098 bacterial strains from 24 cities (2494 Gram-positive bacteria, 1429 Gram-negative bacteria, 176 fungi). Among the Gram-positive bacteria, the four pathogens with the highest detection rates were coagulase-negative staphylococci (CoNS) (40.23%), Streptococci (6.81%), Enterococci (6.10%), and Staphylococcus aureus (S. aureus) (5.15%); among the Gram-negative bacteria, Klebsiella (14.52%), Escherichia coli (12.12%), Enterobacter cloacae (1.90%), and Pseudomonas (1.41%) had the highest detection rates. The detection rate of Candida and other fungi was 4.29%. Among the pathogens with high clinical detection rates, S. epidermidis and S. aureus are highly resistant to both erythromycin and penicillin. Antibacterial drugs with high efficacy for both S. epidermidis and S. aureus include vancomycin, ciprofloxacin, gentamicin, linezolid, rifampicin, and tetracycline. Klebsiella pneumoniae and Escherichia coli are highly resistant to ampicillin, but there are drugs with high efficacy for both, including imipenem, piperacillin/tazobactam, aminoglycosides (gentamicin, amikacin), and quinolones (levofloxacin, ciprofloxacin). In contrast to the drug resistance data reported by the China Antimicrobial Resistance Surveillance System (CARSS) in 2017, the detection rate of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) in the blood cultures of neonates with sepsis exceeded the national average drug resistance level (p < .01). The resistance rate of K. pneumoniae to third-generation cephalosporins was higher than the national average drug resistance level (p < .01), but this organism was most sensitive to carbapenems (carbapenem resistance refers to resistance to any of imipenem, meropenem, or ertapenem). The resistance of Escherichia coli to quinolones was better than the national average level (p < .01). Conclusions Medical care-related infections in neonatal intensive care units (NICUs) were more often caused by CoNS than by S. aureus and Gram-negative bacteria. Vancomycin remains the preferred drug for treating confirmed infections, because most isolated CoNS are resistant to β-lactam drugs including penicillin. For Gram-negative enteric bacteria, aminoglycoside and carbapenem were sufficient for treatment. Compared to the CARSS data on bacterial resistance, the data in this review on the resistance of pathogens causing NS were not favorable. The next goal in antibiotic management in NICUs must be to develop strategies to reduce the use of antibiotics.

Distinct Antimicrobial Resistance Profiling Of Clinically Important Aeromonas Spp. In Southwest China: A Seven-Year Surveillance Study.

BackgroundCo-evolution of host and aeromonads has diversified their spectrums of diseases and antibiograms, while a paucity of data was concerning about this diversity in China. To fill this gap, this study was aimed to investigate and compare antimicrobial resistance (AMR) patterns of clinically important Aeromonas spp. from various clinical sources.MethodsA multicenter retrospective surveillance study was conducted in Chongqing from 2011 to 2017. Data of strains were retrieved from the database of China Antimicrobial Resistance Surveillance System (CARSS). Whonet 5.6 and Graphpad Prism 6 Software were adopted to determine and compare distribution and AMR patterns.ResultsAmong 1135 Aeromonas strains, Aeromonas hydrophila complex (65.6%, 745/1135) was the most predominant species, followed by Aeromonas veronii complex (16.7%, 190/1135) and Aeromonas caviae complex (15.3%, 174/1135). Sputum was the most frequent source of strains (27.7%), followed by wound (20.8%), bloodstream (10.8%) and urine (8.8%). Urinary strains demonstrated the highest resistance rates to ceftriaxone (65.6%), ceftazidime (52.1%), cefepime (38.3%), ciprofloxacin (47.7%) and trimethoprim-sulfamethoxazole (56.6%). Similar AMR pattern was observed in intestinal strains, with corresponding resistance rates of 29.4%, 28.9%, 22.2%, 27.3% and 45%, respectively. However, respiratory, bloodstream and skin strains exhibited resistance rates of less than 20% to most of the antimicrobials tested. In terms of species, approximately 30% of Aeromonas hydrophila complex and Aeromonas caviae complex strains were resistant to ceftriaxone and trimethoprim-sulfamethoxazole, while Aeromonas veronii complex strains harbored resistance rates of less than 20% to all tested antimicrobials. Although antibiograms of these species were distinct, they remained constant from 2011 to 2017.ConclusionsDistinct AMR patterns between species and sources highlighted the predominance of Aeromonas hydrophila complex and high resistance of strains in urine and intestine to extended-spectrum cephalosporins, ciprofloxacin and trimethoprim-sulfamethoxazole in Southwest China. Temporally constant AMR patterns should not relax the vigilance of antimicrobial resistance in clinically important Aeromonas species.

Shifting trends and age distribution of ESKAPEEc resistance in bloodstream infection, Southwest China, 2012\u20132017

BackgroundESKAPEEc contribute to a majority of bloodstream infections (BSIs) and their antibiogram have changed overtime, while data concerning about these alterations are lacking in China. Added that a paucity of studies referred to ESKAPEEc in pediatric BSIs, our study aimed to demonstrate the longitudinal alterations of ESKAPEEc distribution and antibiogram in adult and pediatric BSIs in Southwest China.MethodsA multicenter retrospective surveillance study was launched from 2012 to 2017. Data of China Antimicrobial Resistance Surveillance System (CARSS) was analyzed by Whonet 5.6 and Graphpad Prism 6 Software. Chi-square test or Fisher’s exact test was used to examine and compare temporal changes.ResultsA total of 32,259 strains was isolated, with 17.4% from pediatric BSIs. ESKAPEEc contributed to 58.67% (18,924/32,259) of BSIs, with 65.3% of adult BSIs and 27.2% of pediatric BSIs. Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) were the two predominant species. Carbapenem resistance was prevalent in 0.76, 4.60, 9.47,13.66, 59.47% of E. coli, K. pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii), respectively. The proportions of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREFM) were 28.91% and 2.20%, respectively. Between 2012-2014 and 2015–2017, E. coli and K. pneumonia showed significantly increased resistance rates to imipenem but decreased to ceftriaxone and ceftazidime, while A. baumannii exhibited reduced resistances to almost all the beta-lactams tested. The prevalence of antimicrobial resistance to most of agents against Gram-positive ESKAPEEc did not significantly varied during the same timeframe. In comparison with those from adult BSIs, K. pneumoniae from pediatric BSIs exhibited high resistance rates to all the beta-lactams tested, especially to carbapenems (12.79% vs 3.87%), while A. baumannii showed low resistance rates to all the agents.ConclusionsOngoing burden of ESKAPEEc in BSIs and increasing trend of imipenem resistance in E. coli and K. pneumoniae call for continued surveillance. Carbapenems are still active against Gram-negative ESKAPEEc, except for A. baumannii and vancomycin or linezolid is still effective against Gram-positive ESKAPEEc. Carbapenem-resistant K. pneumoniae in children and carbapenem-resistant A. baumannii in adults necessitate effective antimicrobial strategies in consideration of age stratification.

Analysis on clinical distribution and drug resistance of Klebsiella pneumoniae isolated for 5 consecutive years

Objective: To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatment for the infection of Klebsiella pneumoniae . Methods: 1,192 strains of Klebsiella pneumoniae isolated from clinical specimens from 2012 to 2016 were collected. The strains were identified by VITEK-2 Compact Microbiological Identification System, and the corresponding results of the antimicrobial susceptibility test were interpreted in accordance with the standards recommended by Clinical and Laboratory Standards Institute (CLSI). Results: 1,192 strains of Klebsiella pneumoniae were mainly isolated from sputum (65.6%), and most of them were from Respiratory Medicine Department and Medical Intensive Care Unit of Respiratory Medicine Department (MICU), accounting for 41.4%. Out of 1,192 strains, 448 strains were detected to produce extended-spectrum beta-lactamases (ESBLs), accounting for 37.6%. In addition, the detection rates of ESBL-producing Klebsiella pneumoniae for 5 consecutive years showed an increasing trend year by year, and they were higher than the national average values published by China Antimicrobial Resistance Surveillance System (CARSS) in the corresponding period. The drug resistance rate of ESBL-producing Klebsiella pneumoniae was significantly higher than that of non ESBL-producing strains. Conclusions: The infection caused by Klebsiella pneumoniae mainly occurs in the lower respiratory tract, and the drug resistance rates of Klebsiella pneumoniae to antibiotics in the drug susceptibility spectrum are maintained at a high level. Therefore, the rational selection of antibiotics for the clinical treatment of lower respiratory tract infection caused by Klebsiella pneumoniae must be based on the production of ESBLs and the results of antimicrobial susceptibility test.

Analysis on clinical distribution and drug resistance of Klebsiella pneumoniae isolated for 5 consecutive years

Objective: To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatment for the infection of Klebsiella pneumoniae . Methods: 1,192 strains of Klebsiella pneumoniae isolated from clinical specimens from 2012 to 2016 were collected. The strains were identified by VITEK-2 Compact Microbiological Identification System, and the corresponding results of the antimicrobial susceptibility test were interpreted in accordance with the standards recommended by Clinical and Laboratory Standards Institute (CLSI). Results: 1,192 strains of Klebsiella pneumoniae were mainly isolated from sputum (65.6%), and most of them were from Respiratory Medicine Department and Medical Intensive Care Unit of Respiratory Medicine Department (MICU), accounting for 41.4%. Out of 1,192 strains, 448 strains were detected to produce extended-spectrum beta-lactamases (ESBLs), accounting for 37.6%. In addition, the detection rates of ESBL-producing Klebsiella pneumoniae for 5 consecutive years showed an increasing trend year by year, and they were higher than the national average values published by China Antimicrobial Resistance Surveillance System (CARSS) in the corresponding period. The drug resistance rate of ESBL-producing Klebsiella pneumoniae was significantly higher than that of non ESBL-producing strains. Conclusions: The infection caused by Klebsiella pneumoniae mainly occurs in the lower respiratory tract, and the drug resistance rates of Klebsiella pneumoniae to antibiotics in the drug susceptibility spectrum are maintained at a high level. Therefore, the rational selection of antibiotics for the clinical treatment of lower respiratory tract infection caused by Klebsiella pneumoniae must be based on the production of ESBLs and the results of antimicrobial susceptibility test.

Current Status and Trends of Antibacterial Resistance in China.

The bacterial resistance surveillance system is relatively well established at the national, provincial, and hospital levels in China. Two representative national surveillance networks for bacterial resistance are the China Antimicrobial Resistance Surveillance System (CARSS) and the China Antimicrobial Surveillance Network (CHINET), both established in 2005. CARSS data show the different bacterial resistance rates among different provinces and autonomous regions for each specific bacterium. CHINET data mainly represent the bacterial resistance profiles of teaching hospitals and show the changing trends of bacterial resistance in China. For clinical isolates, the ratio of gram-negative bacilli to gram-positive cocci is approximately 7 to 3. In general, gram-negative bacilli have higher antimicrobial resistance profiles in China. Regarding different bacterial species, antimicrobial resistance is multifaceted. The prevalence of extended-spectrum β-lactamases is high; Acinetobacter baumannii has a high antimicrobial resistance profile; and, notably, the prevalence of CRKP has been showing a marked increase since 2005. In addition, the prevalence of vancomycin-resistant Enterococcus is low, and the prevalence of methicillin-resistant Staphylococcus aureus and antimicrobial resistance in Pseudomonas aeruginosa showed decreasing trends from 2005 to 2017.

Antimicrobial resistance of pathogens causing nosocomial bloodstream infection in Hubei Province, China, from 2014 to 2016: a multicenter retrospective study

BackgroundData on the pathogens responsible for nosocomial bloodstream infection (BSI) and their antimicrobial resistance (AMR) in Hubei province are limited. This study was conducted to determine the major pathogens causing BSI and to characterize their AMR.MethodsData from the China Antimicrobial Resistance Surveillance System (CARSS) from 2014 to 2016 were analyzed retrospectively.ResultsEscherichia coli, Staphylococcus aureus and Klebsiella pneumoniae were the most common pathogens responsible for nosocomial BSI. Individuals aged 0–5 years and ≥ 40 years old were the major demographics at risk of infection by E. coli, K. pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Enterobacter cloacae, while individuals aged 0–5 years were the major demographic at risk of infection by S. aureus, Enterococcus faecalis, E. faecium, Streptococcus pneumoniae and Stenotrophomonas maltophilia. The frequencies of E. coli and K. pneumoniae isolates resistant to cefotaxime were 59.1% and 24.3%, respectively, and the frequencies of resistant isolates to ceftazidime were 42.9% and 27.2%, respectively. From 2014 to 2016, the frequency of extended-spectrum β-lactamase (ESBL)-positive E. coli declined from 29.07 to 24.5%, and the frequency of ESBL-positive K. pneumoniae declined from 18.64 to 12.33%. The frequency of carbapenem-resistant (CR) E. coli was below 0.5%, but 1–10% of K. pneumoniae isolates were CR.ConclusionsThe emergence of methicillin-resistant S. aureus and the expansion of ESBL and fluoroquinolone resistance among Gram-negative Enterobacteriaceae increased AMR severity. Carbapenemase-producing K. pneumoniae isolates responsible for nosocomial BSI increased year over year and effective infection control measures should be taken to prevent them from spreading.

Comparison of five commonly used automated susceptibility testing methods for accuracy in the China Antimicrobial Resistance Surveillance System (CARSS) hospitals.

ObjectiveThe objective of this study was to evaluate the performance of five commonly used automated antimicrobial susceptibility testing (AST) systems in China (Vitek 2, Phoenix, Microscan, TDR, and DL).Materials and methodsTwo “unknown” isolates, S1 (ESBL-producing Escherichia coli) and S2 (KPC-producing Klebsiella pneumoniae), were sent to 886 hospitals in China for identification and AST. Using broth microdilution method (BMD) as gold standard, minimum inhibitory concentrations (MICs) were determined.ResultsMost hospitals (392, 46.1%) used Vitek 2, followed by 16% each for Phoenix, Microscan, and DL systems, and 5.9% (50) used TDR system. MICs of 22 antimicrobials were evaluated for two study isolates plus three ATCC strains. Individual susceptibility results for three ATCC strains (n=1581) were submitted by 780 (91.2%) hospitals. For each AST system, 8.7% (6/69) to 13.0% (33/253) reported MICs outside the expected range for several drugs. For the two study isolates, TDR and DL systems performed the worst in MIC determination and susceptibility categorization of cefazolin and cefepime, while the Microscan system had difficulties in susceptibility categorization for aztreonam and ertapenem. Categorical agreements were >90% for most antimicrobials tested for both the isolates, among which, using BMD, no essential agreements were noted for ampicillin, piperacillin, cefazolin, cefuroxime, ceftriaxone, and trimethoprim/sulfamethoxazole. All AST systems except Vitek 2 showed unacceptable VMEs for cefazolin (S1 and S2) and major errors for ceftazidime, cefepime, and aztreonam (isolate S1), while Vitek 2 showed a high VME rate for cefepime (10.0%) and meropenem (6.2%) for S2.ConclusionNone of the five automated systems met the criteria for acceptable AST performance, but Vitek 2 provided a relatively accurate and conservative performance for most of the antimicrobials.

Multi-level analysis of bacteria isolated from inpatients in respiratory departments in China.

With the different situation for clinical antibiotic usage and its management in different regions and medical institutions, the antimicrobial resistance varied in different level. However, the epidemiological data of multi-drug resistant (MDR) strains from the department of respiration is limited. Thus, this study aims to investigate the epidemiology of bacteria isolated from inpatients of respiratory departments, and analyze the distribution variation of major multi-drug resistant bacteria in China. Based on data from China Antimicrobial Resistance Surveillance System (CARSS) in 2015, 50,417 non-duplicate isolates obtained from inpatients of respiratory departments from 91 general hospitals in seven regions of China were enrolled in the study. The distribution of methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and Acinetobacter baumannii (CRAB), extended-spectrum β-lactamases-producing E. coli (ESBL-EC) and K. pneumoniae (ESBL-KP), were further analyzed by geographic regions, age groups, wards and specimen types. The major specimens type were sputum (81.6%, 41,131/50,417), followed by blood (5.3%, 2,649/50,417), urine (4.5%, 2,249/50,417) and bronchoalveolar lavage fluid (BALF) (3.2%, 1,620/50,417). The top four bacteria species isolated from sputum and BALF were similar: K. pneumonia (18.9% and 14.8%, respectively), P. aeruginosa (13.6% and 22.2%, respectively), A. baumannii (11.3% and 11.9%, respectively) and S. pneumonia (11.1% and 9.6%, respectively). The four most common bacteria species were K. pneumonia (17.2%), P. aeruginosa (12.1%), A. baumannii (10.4%) and S. pneumonia (10.1%) in tertiary hospitals but K. pneumonia (20.8%), P. aeruginosa (16.3%), E. coli (11.3%) and A. baumannii (6.9%) in secondary hospitals. The top four bacteria species in respiratory intensive care unit (RICU) were A. baumannii (25.8%), P. aeruginosa (13.1%), K. pneumonia (12.2%) and S. aureus (9.2%). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals was significantly higher than that in secondary hospitals (5.2% vs. 2.5%, 23.8% vs. 12.8% and 53.5% vs. 33.9%, respectively) (all P<0.05). However, the prevalence of ESBL-EC in secondary hospitals was higher than in tertiary ones (63.9% vs. 55.0%, P=0.011). The prevalence of MRSA, CRKP, CRAB, CRPA, ESBL-EC, ESBL-KP in RICU were higher than that in non-ICU respiratory departments (76.5% vs. 35.7%, 20.1% vs. 4.1%, 90.6% vs. 45.5%, 64.2% vs. 19.3%, 47.2% vs. 28.3% and 43.0% vs. 11.2%, respectively) (all P<0.01). Among seven regions in China, central area had the highest detection rates of MRSA (70.3%, 237/337), CRPA (30.9%, 376/1,218), CRAB (71.8%, 487/678) and ESBL-KP (38.8%, 241/621). The prevalence of ESBL-EC and ESBL-KP in pediatric group (68.2% and 55.3%, respectively) was higher than that in geriatric group (54.2% and 27.1%, respectively) and adult group (51.1% and 15.1%, respectively) (all P<0.001). In China, the predominant bacterial pathogens in the respiratory ward were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower respiratory tract (LRT) was revealed in primary hospitals and pediatric patients.

The composition and antimicrobial resistance of isolates from lower respiratory tract and blood in hospitalized patients in respiratory ward: a multicenter national study in China

Objective: To investigate the species and antimicrobial resistance of bacterial pathogens isolated from hospitalized patients in respiratory ward in China. Methods: This was a multicenter retrospective study based on a national epidemiological network called China Antimicrobial Resistance Surveillance System (CARSS). The non-repetitive strains isolated from lower respiratory tract and blood samples in 91 hospitals from seven geographic regions of CARSS were reviewed. The distribution of specimen type, hospital level (secondary and tertiary hospital), patient age group [geriatric (>65 years old), adult (15 to 65 years old), pediatric (28 days to 14 years old ) and newborn group (≤28 days)] and ward type (respiratory intensive care unit and general respiratory ward) were analyzed for MRSA, PRSP, CREC, CRKP, CRPA, CRAB, ESBL-EC and ESBL-KP. The categorical variables were analyzed by chi-square test using SPSS 16.0 statistical software. P<0.05 was regarded as statistically significant. Results: A total of 50 417 non-repetitive isolates [42 751 isolates from lower respiratory tract (LRT), 2 649 isolates from blood and 5 017 isolates from other samples (urine and secretions)] from 48 752 inpatients (without illness type information) were enrolled in the study. 90.2% (45 491/50 417) isolates were obtained from 63 tertiary hospitals. According to patients' age, all cases were divided into 4 groups, i. e. geriatric(46.0%, 23 177/50 417), adult(29.9%, 15 092/50 417), pediatric(24.0%, 12 112/50 417) and newborn group(0.0%, 36/50 417). All isolates were obtained from respiratory intensive care unit (6.2%, 3 129/50 417) or general respiratory wards (93.8%, 47 288/50 417). The majority of bacterial pathogens were isolated from lower respiratory and blood culture samples, which accounted for 90.0% of all the samples (45 400/50 417). Sputum accounted for 81.6% (41 131/50 417) of samples, and the leading 4 isolates were K. pneumonia (18.9%, 7 784/41 131), P. aeruginosa (13.6%, 5 580/41 131), A. baumanni (11.3%, 4 644/41 131) and S. pneumonia (11.1%, 4 564/41 131). Blood samples accounted for 5.3% (2 649/50 417) of the samples, with the leading 4 bacteria being coagulase-negative staphylococcus (42.0%, 1 112/2 649), E. coli (18.3%, 484/2 649), K. pneumonia (7.4%, 194/2 649) and S. aureus (4.9%, 131/2 649). The species distribution of pathogens isolated from bronchoalveolar lavage fluid (BALF), which accounted for 3.2% (1 620/50 417) of the samples, was similar to that of sputum, and the leading 4 bacteria were P. aeruginosa (22.0%, 360/1 620), K. pneumonia (14.8%, 239/1 620), A. baumanni (11.9%, 193/1 620) and S. pneumonia (9.6%, 155/1 620). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals [5.2% (384/7 439), 23.8% (1 260/5 304) and 53.5% (2 259/4 224), respectively] was significantly higher than that in secondary hospitals [2.5% (24/973), 12.8% (101/787) and 33.9% (109/322), respectively] (all P<0.01). In comparison, the prevalence of ESBL-EC in secondary hospitals (63.9%, 145/227) was higher than that in tertiary ones (55.0%, 1 141/2 074) (P=0.011). The prevalence of ESBL-EC and ESBL-KP in pediatric group [68.2% (283/415) and 55.3% (183/331), respectively] was higher than that in geriatric group [54.2% (684/1 263) and 27.1% (625/2 303), respectively] and adult group [51.1% (317/620) and 15.1% (272/1 804), respectively] (all P<0.001). Conclusions: In China, the predominant bacterial pathogens in the respiratory wards were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower repiratory tract was revealed in primary hospitals and pediatric patients.