Surveillance Of Bacterial Resistance Research Articles

Implications of deduplication on the detection rates of multidrug-resistant organism (MDRO) in various specimens: insights from the hospital infection surveillance program

BackgroundCurrently, different guidelines recommend using different methods to determine whether deduplication is necessary when determining the detection rates of multidrug-resistant organisms (MDROs). However, few studies have investigated the effect of deduplication on MDRO monitoring data. In this study, we aimed to investigate the influence of deduplication on the detection rates of MDROs in different specimens to assess its impact on infection surveillance outcomes.MethodsSamples were collected from hospitalized patients admitted between January 2022 and December 2022; four types of specimens were collected from key monitored MDROs, including sputum samples, urine samples, blood samples, and bronchoalveolar lavage fluid (BALF) samples. In this study, we compared and analysed the detection rates of carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Escherichia coli (CRECO), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and methicillin-resistant Staphylococcus aureus (MRSA) under two conditions: with and without deduplication.ResultsWhen all specimens were included, the detection rates of CRKP, CRAB, CRPA, and MRSA without deduplication (33.52%, 77.24%, 44.56%, and 56.58%, respectively) were significantly greater than those with deduplication (24.78%, 66.25%, 36.24%, and 50.83%, respectively) (all P < 0.05). The detection rates in sputum samples were significantly different between samples without duplication (28.39%, 76.19%, 46.95%, and 70.43%) and those with deduplication (19.99%, 63.00%, 38.05%, and 64.50%) (all P < 0.05). When deduplication was not performed, the rate of detection of CRKP in urine samples reached 30.05%, surpassing the rate observed with deduplication (21.56%) (P < 0.05). In BALF specimens, the detection rates of CRKP and CRPA without deduplication (39.78% and 53.23%, respectively) were greater than those with deduplication (31.62% and 42.20%, respectively) (P < 0.05). In blood samples, deduplication did not have a significant impact on the detection rates of MDROs.ConclusionDeduplication had a significant effect on the detection rates of MDROs in sputum, urine, and BALF samples. Based on these data, we call for the Infection Prevention and Control Organization to align its analysis rules with those of the Bacterial Resistance Surveillance Organization when monitoring MDRO detection rates.

In vitro activity of antibiotics potentially effective against difficult-to-treat strains of Gram-negative rods: retrospective study

Bacterial resistance surveillance is one of the main outputs of microbiological laboratories and its results are important part of antimicrobial stewardship (AMS). In this study, the susceptibility of specific bacteria to selected antimicrobial agents was tested. The susceptibility of 90 unique isolates of pathogens of critical priority obtained from clinically valid samples of ICU patients in 2017–2021 was tested. 50% of these fulfilled difficult-to-treat resistance (DTR) criteria and 50% were susceptible to all antibiotics included in the definition. 10 Enterobacterales strains met DTR criteria, and 2 (20%) were resistant to colistin (COL), 2 (20%) to cefiderocol (FCR), 7 (70%) to imipenem/cilastatin/relebactam (I/R), 3 (30%) to ceftazidime/avibactam (CAT) and 5 (50%) to fosfomycin (FOS). For Enterobacterales we also tested aztreonam/avibactam (AZA) for which there are no breakpoints yet. The highest MIC of AZA observed was 1 mg/l, MIC range in the susceptible cohort was 0.032–0.064 mg/l and in the DTR cohort (incl. class B beta-lactamase producers) it was 0.064–1 mg/l. Two (13.3%) isolates of Pseudomonas aeruginosa (15 DTR strains) were resistant to COL, 1 (6.7%) to FCR, 13 (86.7%) to I/R, 5 (33.3%) to CAT, and 5 (33.3%) to ceftolozane/tazobactam. All isolates of Acinetobacter baumannii with DTR were susceptible to COL and FCR, and at the same time resistant to I/R and ampicillin/sulbactam. New antimicrobial agents are not 100% effective against DTR. Therefore, it is necessary to perform susceptibility testing of these antibiotics, use the data for surveillance (including local surveillance) and conform to AMS standards.

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.

Analysis on Bacterial Distribution and Change of Drug Resistance Rate in ICUs Across Southwest China from 2018 to 2022.

To analyze the distribution of bacteria and their drug resistance changes in Intensive Care Units (ICUs) across Southwest China from 2018 to 2022 and establish the antibiogram in this region to provide a basis for early empirical antimicrobial use. Non-repetitive pathogens isolated from 109 member units with qualified data were obtained from the Antimicrobial Resistance Surveillance System in Sichuan Province, southwest China. The results obtained were interpreted with reference to CLSI M100-31th, and analyzed with WHONET 5.6 software. A total of 46,728 clinical isolates in ICUs were collected from 2018 to 2022, of which gram-negative organisms accounted for 76.1%, and gram-positive were 23.9%. The top 5 were Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, respectively. From 2018 to 2022, the resistance rates of Klebsiella pneumoniae to imipenem and meropenem changed from 14.5% and 17.8% to 14.0% and 14.4%, showing a steady downward trend. Escherichia coli was always highly sensitive to carbapenems, with a total resistance rate of 3.8%. Among non-fermented gram-negative bacteria, the resistance rates of Pseudomonas aeruginosa to imipenem and meropenem decreased significantly, changed from 25.3% and 22.9% in 2018 to 20.0% and 15.1% in 2022. However, Acinetobacter baumannii showed high resistance rates of 76.2% and 76.9% to imipenem and meropenem, respectively. MRSA and MRCNS accounted for 31.7% and 82.7%, respectively. No vancomycin and linezolid-resistant Staphylococcus aureus was isolated. Enterococcus faecalis maintained high activity to vancomycin, teicoplanin, and linezolid; no vancomycin or teicoplanin-resistant Enterococcus faecium strains were detected. From 2018 to 2022, the isolated bacteria in ICU were mainly gram-negative bacteria, and the growth of some multidrug-resistant bacteria was effectively controlled. All levels of medical institutions should continue to strengthen bacterial resistance surveillance, promote the establishment of antimicrobial stewardship program, and enhance restrictions on outpatient antimicrobial use.

A systematic synthesis of expert opinion on effective policies to tackle bacterial resistance worldwide.

Actions that are taken to preserve effective antibacterial agents and eliminate transmission of resistant organisms are crucial to prevent a catastrophic postantibiotic era. In this systematic review, we searched and appraised relevant texts and expert opinions to determine effective strategies to tackle bacterial resistance worldwide. We considered expert opinions, consensus, current discourses, comments, assumptions or assertions and discussion papers published in English. We searched following databases for expert opinion-based literature: MEDLINE, CINAHL, ISI Web of Knowledge, SCOPUS, Cochrane Central Register of Controlled Trials and World Health Organization (WHO). We extracted the textual data from texts using a standardised data extraction tool. Textual pooling was not possible, so the conclusions were presented in a narrative form. Eighteen texts were included in this review. The findings show that, the most repeated policies and strategies include implementing and strengthening bacterial resistance surveillance, developing national guidelines, improving public awareness; enhancing home and everyday life hygiene; improving prescribing patterns, improving laboratories capacity, promoting innovation and research in new drugs and technology and strengthening coordination. This review systematically gathered strategies that were recommended by textual publications. To our knowledge, this was the first systematic review of text and opinion in the field of bacterial resistance. These results can be used by policymakers, hospital managers, and governments, alongside the results of quantitative and qualitative systematic reviews.

Antimicrobial resistance profile of methicillin-resistant Staphylococcus aureus isolates in children reported from the ISPED surveillance of bacterial resistance, 2016-2021.

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious threat to public health worldwide. In December 2015, the Infectious Disease Surveillance of Pediatrics (ISPED) program was organized to monitor bacterial epidemiology and resistance trends in children. This retrospective study was conducted from January 2016-December 2021 on patients at eleven ISPED-group hospitals. From 2016-2021, a total of 13024 MRSA isolates were obtained from children. The most common age group for patients with MRSA infection was less than 3 years old, and newborns were an important group affected by MRSA infection. MRSA was most commonly isolated from the lower respiratory, an abscess, a secretion, or blood in neonates and from the lower respiratory, an abscess, or the upper respiratory in non-neonates. All isolates were susceptible to vancomycin and linezolid and resistant to penicillin; additionally, 76.88%, 54.97%, 22.30%, 5.67%, 5.14%, 3.63%, and 1.42% were resistant to erythromycin, clindamycin, tetracycline, levofloxacin, sulfamethoxazole-trimethoprim (TMP-SMX), gentamicin, and rifampin, respectively. Between 2016 and 2021, a significant increase was seen in the levofloxacin- and TMP-SMX-resistance rates (from 5.45% to 7.14% and from 4.67% to 6.50%, respectively) among MRSA isolates, along with a significant decrease in the rates of resistance to erythromycin (from 82.61% to 68.08%), clindamycin (from 60.95% to 46.82%), tetracycline (from 25.37% to 17.13%), gentamicin (from 4.53% to 2.82%), and rifampin (from 1.89% to 0.41%). The antibiotic-resistance rates varied among MRSA isolated from different sources. Because of the high antibiotic resistance rate to clindamycin, this antibiotic is not recommended for empirical treatment of MRSA infections, especially in osteomyelitis.

Multicenter Antimicrobial Resistance Surveillance of Clinical Isolates from Major Hospitals - China, 2022.

Bacterial resistance surveillance is crucial for monitoring and understanding the trends and spread of drug-resistant bacteria. The number of strains collected in 2022 increased compared to 2021. The top five bacteria, including Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, remained largely unchanged. The detection rate of methicillin-resistant strains continued to decrease. Among clinical Enterobacterales isolates, the resistance rate to carbapenems was generally below 13%, except for Klebsiellaspp., which had a resistance range of 20.4% to 21.9%. Most clinical Enterobacterales isolates were highly susceptible to tigecycline, colistin, and polymyxin B, with resistance rates ranging from 0.1% to 12.6%. The detection rate of meropenem-resistant P. aeruginosa and meropenem-resistant Acinetobacter baumannii showed a decreasing trend for the fourth consecutive year. Multidrug-resistant bacteria remain a significant public health challenge in clinical antimicrobial treatment. To effectively address bacterial resistance, it is essential to enhance both bacterial resistance surveillance and the prudent use of antimicrobial agents.

Provincial clustering and related factors analysis of clinic antimicrobial resistance in China

Antimicrobial resistance (AMR) is among the biggest and most pressing risks facing healthcare in China and globally. We aimed to describe the current status regarding the distribution of clinic AMR in China through provincial clustering and analyse the related factors. Based on the detection rates of 13 major drug-resistant bacteria in 31 provinces across the country, as reported by the National Bacterial Resistance Surveillance Network in 2019, we carried out a provincial clustering by dividing the conditions of provincial clinical AMR into different groups, and we then examined the potentially related factors, such as the use of antibiotics, economic development status, health service utilization, and health resource allocation. According to the different levels of bacterial resistance, the provinces were clustered into three categories: low, medium, and high detection rates of AMR. The three categories had notable geographic clustering and associations. Economic development status, health service utilization, such as the number of the types of antibacterial drugs (P=0.025), health resource allocations, such as low licensed pharmacist per 1000 patient visits (P=0.004) were related to AMR in China. The levels of AMR in public hospitals within the coastal areas of North China and East China were higher than those in other areas. The regions with higher levels of clinical bacterial resistance also had higher levels of health costs, health services volume and utilization, insufficient health resources per time, and higher probability of overuse of antimicrobials. Targeted measures should be taken in these areas to curb the resistance trends.

The Rapid Emergence of Ceftazidime-Avibactam Resistance Mediated by KPC Variants in Carbapenem-Resistant Klebsiella pneumoniae in Zhejiang Province, China.

Ceftazidime-avibactam (CAV) is a new treatment option against carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. However, the rapid emergence of CAV resistance mediated by KPC variants has posed a severe threat to healthcare after its clinical application. The characteristics of CAV resistance in CRKP strains needs to be determined in China. A total of 477 CRKP isolates were collected from 46 hospitals in Zhejiang Province from 2018 to 2021. The results demonstrated that CAV had a potent activity against 94.5% of all CRKP (451/477, 95% CI: 93.0–96.1%) and 86.0% of CRKP strains carrying blaKPC genes (410/477, 95% CI: 83.5–88.4%). A total of 26 CAV-resistant strains were found. Among these strains, sixteen harbored metallo-β lactamases, and two carried KPC-2 carbapenemase and mutated ompK35 and ompK36. Eight CRKP strains encoded KPC-33 or KPC-93, belonging to ST11, among which seven strains were detected in patients hospitalized in 2021 after exposure to CAV and one strain was associated with intra-hospital spread. CAV is a potent agent in vitro against CRKP strains. The rapid development of CAV resistance mediated by various KPC variants after a short period of CAV treatment has increased and brought difficulties in treating infections caused by CRKP strains, especially those belonging to ST11. The surveillance of bacterial resistance against CAV is highly recommended due to the steep development of CAV resistance and rapid evolution of KPC enzymes.

Phylogeographical Landscape of Citrobacter portucalensis Carrying Clinically Relevant Resistomes.

ABSTRACTDuring a surveillance study conducted to assess the occurrence and genomic landscape of critical priority pathogens circulating at the human-animal-environment interface in Brazil, as part of the Grand Challenges Explorations-New Approaches to Characterize the Global Burden of Antimicrobial Resistance program, two multidrug-resistant (MDR) Citrobacter portucalensis carrying blaCTX-M-15 extended-spectrum β-lactamase (ESBL) genes, isolated from green sea turtles, were characterized. Genomic and phylogeographical analysis of C. portucalensis genomes available in public databases revealed the intercontinental dissemination of clades carrying different arrays of clinically relevant genes conferring resistance to carbapenems, broad-spectrum cephalosporins, cephamycins, aminoglycosides and fluoroquinolones, disinfectants, and heavy metals. Our observations suggest that C. portucalensis could be emerging as critical priority bacteria of both public and One Health importance worldwide.IMPORTANCE The global spread of antibiotic-resistant priority pathogens beyond the hospital setting is a critical issue within a One Health context that integrates the human-animal-environment interfaces. On the other hand, next-generation sequencing technologies along with user-friendly and high-quality bioinformatics tools have improved the identification of bacterial species, and bacterial resistance surveillance. The novel Citrobacter portucalensis species was proposed in 2017 after taxonomic reclassification and definition of the strain A60T isolated in 2008. Here, we presented genomic data showing the occurrence of multidrug-resistant C. portucalensis isolates carrying blaCTX-M-15 ESBL genes in South America. Additionally, we observed the intercontinental dissemination of clades harboring a broad resistome to clinically relevant antibiotics. Therefore, these findings highlight that C. portucalensis is a global MDR bacteria that carries intrinsic blaCMY- and qnrB-type genes and has become a critical priority pathogen due to the acquisition of clinically relevant resistance determinants, such as ESBL and carbapenemase-encoding genes.

Prevalence of Extended-Spectrum β-Lactamase-Production among Clinical Gram-Negative Bacilli Isolates in A Tertiary Hospital, Southwest Nigeria

Extended spectrum β-lactamases (ESBLs) have emerged as important mechanisms of antimicrobial resistance to beta-lactam drugs in hospitals, thereby limiting the available treatment options for infections caused by these microorganisms. The objectives of this study were to determine the prevalence of ESBL production among clinical isolates of Gram-negative bacilli from Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria as part of the global efforts to provide information for the containment of the spread of antimicrobial resistance. This is a laboratory-based study of 186 consecutive non-duplicate Gram-negative bacilli (GNB) isolated from diverse clinical samples at the Microbiology laboratory of the hospital after standard aerobic cultures. The isolates were identified by conventional biochemical test scheme and commercial GNB API 20E identification kit. Antimicrobial susceptibility testing (AST) of each isolate was determined by the disk diffusion technique. Isolates presumptively identified as ESBL producers from the AST assay were confirmed by the combination disks method. Escherichia coli (n=43; 23.1%) predominated among the organisms, followed by Enterobacter spp (n=23; 12.4%) and Klebsiella spp (n=22; 11.8%). Most of the organisms (95.7%) were resistant to tetracycline and ampicillin, but the least resistance (4.3%) was exhibited to imipenem. Fifty-eight (31.2%) isolates were ESBL producers with a preponderance of E. coli (n=15; 25.9%). The ESBL producers were commonly isolated from urine samples (n=31; 53.4%), and were significantly more resistant to levofloxacin, ciprofloxacin, nalidixic acid, gentamicin, augmentin, cefepime, ceftriaxone, ceftazidime and cefotaxime (p&lt;0.05). This study has highlighted the therapeutic implications of the presence of EBSL in clinical isolates which was depicted by their multi-drug resistance phenotypes, thus emphasizing the need for continuous surveillance of bacterial resistance, institution of antimicrobial resistance stewardship in our hospital and regular screening of ESBLs in clinical isolates to prevent treatment failure.

Clinical and microbiological characteristics of nosocomial, healthcare-associated, and community-acquired Klebsiella pneumoniae infections in Guangzhou, China

BackgroundKlebsiella pneumoniae (K. pneumoniae) is a common pathogen associated with hospital and community-onset infections. This study aimed to compare the clinical and microbiological characteristics of nosocomial, healthcare-associated (HCA), and community-acquired (CA) K. pneumoniae infections.MethodsClinical data were extracted from electronic medical records and analyzed retrospectively. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) production were determined for all identified strains. Carbapenemase and ESBL genes were amplified by PCR. Genotyping of carbapenem-resistant K. pneumoniae (CRKP) and ESBL-producing strains was performed by pulsed-field gel electrophoresis (PFGE).ResultsOf 379 K. pneumoniae infections, 98 (25.9%) were nosocomial, 195 (51.5%) were healthcare-associated, and 86 (22.6%) were community-acquired. Hematological malignancy (OR = 4.467), and hypertension (OR = 2.08) and cerebral vascular disease (OR = 2.486) were associated with nosocomial and HCA infections respectively, when compared to CA infections. Overall, the incidence of antimicrobial resistance for the majority of agents tested was similar between nosocomial and HCA infections (P > 0.05) and both groups had a higher incidence than CA infections (P < 0.05). Moreover, 95.1% (78/82) of CRKP strains were isolated from the nosocomial and HCA groups. The blaKPC was the most prevalent carbapenemase gene among CRKP strains (80.5%, 66/82). ESBL-producing strains were prevalent among nosocomial (40.8%), HCA (35.9%) and CA groups (24.4%). The blaCTX-M-9-group and blaCTX-M-1-group genes were predominant in nosocomial (65.0%) and CA strains (66.7%), respectively. PFGE results showed ESBL-producing and CRKP strains were genetically diverse. Identical PFGE profiles were observed among HCA and nosocomial strains.ConclusionsNosocomial and HCA K. pneumoniae infections presented similar clinical features and antimicrobial resistance, and both two types of infections were different to CA infections. CRKP and ESBL-producing strains were disseminated mainly in HCA and nosocomial groups, and showed a clonal diversity. The cross transmission of CRKP was existed among HCA and nosocomial patients. This finding suggests that similar empirical therapy should be considered for patients with nosocomial and HCA K. pneumoniae infections and bacterial resistance surveillance of these infections is necessary.

Detection of ESBLs and NDM-1 genes among urinary Escherichia coli and Klebsiella pneumoniae from healthy students in Niger Delta University, Amassoma, Bayelsa State, Nigeria

INTRODUCTION: Increasing emergence of multidrug-resistant uropathogens among healthy individuals is a serious public health problem capable of causing difficult-to-treat urinary tract infections (UTIs) with limited treatment options. This study therefore, determined the prevalence of asymptomatic bacteriuria (ASB) and molecular characteristics of antibiotic-resistant Escherichia coli and Klebsiella pneumoniae isolated from healthy students of Niger Delta University, Amassoma, Nigeria. METHODS: mid-stream urine samples were collected from 303 healthy students and cultured for significant bacteriuria. Escherichia coli and K. pneumoniae were isolated and identified by conventional methods and Polymerase Chain Reaction (PCR). Antimicrobial susceptibility patterns of the isolates were determined by the disc diffusion technique. The isolates were screened for Extended-Spectrum Beta-Lactamases (ESBLs) production by combined disc method, ESBLs and carbapenemases genes by PCR. RESULTS: the prevalence of ASB was 21.1%, with a significantly higher proportion among the females (P < 0.0001). Escherichia coli and K. pneumoniae isolates were recovered in equal proportion (n=21; 6.9%), with E. coli significantly isolated from the females (P= 0.002). The isolates exhibited 57 - 95% resistance to cefotaxime, ceftazidime, and co-trimoxazole, and 10 - 24% resistance to levofloxacin and imipenem. Multidrug resistance (MDR) was found in 9 (42.9%) E. coli and 18 (85.7%) K. pneumoniae isolates; 60% of E. coli and 72.7% of K. pneumoniae were ESBLs producers. blaTEM (50%) and blaCTX-M (30%) were detected in E. coli while blaSHV (83.3%) and blaTEM (55.6%) were detected in K. pneumoniae. One E. coli and two K. pneumoniae isolates harboured NDM-1 gene. CONCLUSION: the ASB from this study’s healthy individuals was characterized by MDR bacteria that harboured ESBLs and NDM-1 genes. Thus, emphasizing the need for regular surveillance of bacterial resistance and proper hand hygiene to contain the spread of MDR pathogens in the community.

2037. A Novel Strategy of Antimicrobial Stewardship in Shanghai: Preliminary Practice with Integration of Three Surveillance Networks

BackgroundThe bacterial resistance surveillance networks, antimicrobial clinical use surveillance networks and provincial hospital-acquired infection (HAI) surveillance have been well established in China. They aim to inform the current situation of bacterial resistance, antimicrobial use and HAI, and to guide the rational use of antimicrobials. However, these three networks presently are running separately. To increase the data value in antimicrobial stewardship (AMS)practice, those three surveillance networks are integrated in ShanghaiMethodsThe Committee of Rational Use of Antimicrobials and AMS of Shanghai Municipal Health Commission, consisting of health administrators, clinical physicians and microbiologists, clinical pharmacologists and infection control experts, was formed in 2017. The oversight committee developed a comprehensive AMS score index mainly based on the surveillance data of the three networks to evaluate the AMS requirements in the hospitals. The AMS score index consists of 3 surveillance network indexes: resistance weight index; antimicrobial weight index and HAI weight index; each of the indexes is further divided into two parts, namely the surveillance quality score and data-related score. For example, the data-related score in the resistance index is calculated for the prevalence of 6 most important MDR/XDR bacteria (CRKP, CRAB, CRPA, ESBL, MRSA, VRE). A multi-disciplinary AMS team was convened to provide expert on-site visit of the hospitals and offered AMS support in the form of practical guidance and advice.ResultsAMS score and detailed score such as the prevalence of CRKP were ranked among 50 hospitals within the networks. These scores will support the AMS team to find out the main drivers of resistance/antibiotic use and thereby support appropriate interventions during the on-site visit. For example, a hospital visited which had a high consumption of carbapenems (ranked third in Shanghai) and also had a high percentage of carbapenems used in the department of liver transplantation. The advice of the on-site visit team was to encourage a more diverse group of antibiotics so as to spare carbapenems.ConclusionInvolvement of the multi-disciplinary team and integration of surveillance networks are very helpful in AMS practice.Disclosures All authors: No reported disclosures.

Distribution and antibiotic resistance of the clinical bacterial isolated from the ICU of Tongren Hospital during 2013-2017

Objective To analyze the distribution and antibiotic resistance of the clinical bacterial isolated from the intensive care unit (ICU) of Tongren Hospital during 2013-2017. Methods All the bacterial isolates were identified by Vitek-2 Compact system. Antimicrobial susceptibility testing was carried out using Kirby-Bauer method or automated systems. The susceptibility data were analyzed using WHONET 5.6 software. Results were interpreted according to CLSI M100-S27th breakpoints. Results A total of 1 049 clinical isolates were collected, including 331 (31.6%) strains of gram positive bacteria and 718 (68.4%) strains of gram negative bacteria. The overall prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Staphylococcus aureus and methicillin resistant coagulase negative staphylococci (MRCNS) in coagulase-negative Staphylococcus were 84.5% and 80.2%. No Staphylococcus strains were found resistant to vancomycin or linezolid. The resistance rates of E. faecalis strains to most drugs tested were lower than those of E. faecium. Polymerase chain reaction (PCR) amplification and sequencing analysis indicated that the only one vancomycin-resistant strains isolated from E. faecium was vanM type. The resistance rates to carbapenems of Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii respectively were 50.7%, 50.4%, and 82.7%. Conclusions Antibiotic resistance is still very serious in ICU. It is necessary to maintain good practice in surveillance of bacterial resistance, and strengthen management of clinical use of antimicrobial agents and hospital infection control. Key words: Intensive care units; Microbial sensitivity tests; Drug resistance, bacterial

Antimicrobial resistance changes of carbapenem-resistant Enterobacteriaceae strains isolated from children

Objective: To investigate the prevalence and resistance changes of carbapenem-resistant Enterobacteriaceae (CRE) strains isolated from children patients of Chinese Bacterial Resistance Surveillance Network (CHINET) from 2005 to 2017. Methods: Antimicrobial susceptibility testing was carried out by disk diffusion method (KB method) and automated systems. Results were analyzed according to the Clinical and Laboratory Standards Institute (CLSI) 2017 edition standards. Results: Among the 4 481 CRE clinical strains, the overall prevalence of CRE in children was 6.4%, including 8.8% in neonatal period, 7.3% in infancy, 3.8% in early childhood, 4.0% in preschool, 4.7% at school age and 7.4% of puberty. The CRE prevalence of citrobacter spp. remained stable in 2005-2017, whereas other bacteria showed an upward trend, which was higher than that of the adult group (P<0.01). Among the 4 481 CRE strains, there were 2 905 strains of Klebsiella spp. (64.8%), 813 strains of Escherichia coli (18.1%), 549 strains of Enterobacter spp.(12.3%), and 65 strains of Citrobacter spp.(1.5%). Among the 4 481 CRE strains, 20.7%, 13.3%, and 11.8% were from the intensive care unit (ICU), neonatal department and internal medicine wards, respectively. Specimens were distributed as respiratory (42.8%), urine (26.3%), and blood (14.9%). The results of antimicrobial susceptibility testing exhibited that the CRE strains were highly resistant to most commonly used antimicrobial agents in clinical practice, such as imipenem, meropenem and ertapenem, as well as penicillins and cephalosporins, etc. Conclusion: The prevalence of CRE strains in children is increasing year by year, and their antimicrobial resistance to common antibacterial agents in clinical practice is extremely serious, to which serious attention needs to be paid. According to the results of antimicrobial susceptibility testings, the antibacterial agents should be rationally selected to effectively control the spread of CRE.

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.

Surveillance of bacterial resistance in children and newborns across China from 2014 to 2017

Objective: To study bacterial resistance in children and newborns aged less than 14 years across China from 2014 to 2017. Methods: Bacterial resistance data on children and newborns were extracted from the national bacterial resistance surveillance reports from 2014 to 2017. Resistance trends in children and newborns were analyzed over the past four years, and compared with the adult and elderly groups. Results: Among all strains, the isolates collected from children and newborns from 2014 to 2017 accounted for 16.2%, 13.8%, 15.3% and 16.3%, respectively. The proportions of gram-positive bacteria among strains isolated from children and newborns, which were apparently higher than that of the adult and elderly groups, were 42.6%, 44.3%, 45.8% and 45.5%, respectively. The top five isolates of gram-positive bacteria were Staphylococcus aureus, Streptococcus pneumoniae, coagulase-negative staphylococci, Enterococcus faecium and E. faecalis. The top five isolates of gram-negative bacteria were Escherichia coli, Klebsiella pneumonia, Haemophilus influenzae, Pseudomonas aeruginosa and Acinetobacter baumannii. The proportion of urine-derived bacteria isolated from children and newborns (6.1%-7.1%) was apparently lower than that of the adult and elderly groups, while sputum (49.2%-52.8%) and blood-derived (11.4%-13.8%) were higher than the adult group. The prevalence of cefotaxime-resistant E. coli and K. pneumoniae decreased from 58.3% to 52.0% and 51.2% to 45.0%, respectively. The prevalence of imipenem-resistant E. coli and K. pneumoniae increased from 1.2% to 1.9% and 5.6% to 8.8%, respectively. The prevalence of imipenem-resistant P. aeruginosa increased from 11.0% to 12.4%, however, the prevalence of imipenem-resistant A. baumannii decreased from 27.2% to 24.6%. The prevalence of methicillin-resistant S. aureus increased from 27.5% to 29.5%. The prevalence of vancomycin-resistant-E.faecalis/E.faecium decreased from 0.6% to 0.2% and 0.9% to 0.3%, respectively. The proportion of non-cerebrospinal fluid-derived penicillin-resistant S. pneumoniae decresed from 5.1% to 2.7%. Conclusions: The prevalence of several drug-resistant bacteria isolated from children and newborns were decreasing, but the prevalence of imipenem-resistant E. coli, imipenem-resistant K. pneumoniae and methicillin-resistant S. aureus increased slowly. It is still necessary to strengthen antibiotics rational application management and hospital infection control, and maintain good practice in bacterial resistance surveillance work.

Making Sense of Antimicrobial Resistance Surveillance: A successful intervention

Background: The intensive care units are epicenters for the emergence of antibiotic resistant Gram-negative bacteria because of the high use of antibiotics, prolonged hospital stay, reduced patient immunity, use of medical devices, and the frequent contact between healthcare workers and patients. Surveillance of bacterial resistance is the key element to understand the size of the problem, drive interventions, and measures the effect of these measures. Several reports have linked the use of third generation cephalosporins with β-lactam resistance in gram-negative bacteria. Several strategies were introduced by the Antibiotic Stewardship Programs to reduce antibiotic resistance but the efficacies of these interventions are not well studied. Methods: The Microbiology Laboratory of Hamad Medical Corporation (HMC) monitors antimicrobial resistance by continuous surveillance using the National Committee for Clinical Laboratory Standards (NCCLS) - currently Clinical Laboratory Standards Institute interpretive criteria. Surveillance data were released annually and shared with clinicians and policy makers for review of the antibiotic policy and the antibiotic formulary. Results: Surveillance data in 2001 showed high level β-lactam antibiotics resistance and high level production of extended spectrum β-lactamases (ESBL) among gram-negative bacteria. As a result, the Hospital Antibiotic Policy Committee decided to withdraw ceftazidime a third –generation cephalosporin known to be a strong inducer of ESBL, from the hospital formulary. Subsequent resistance surveillance over the following three years in the Medical Intensive Care unit (MICU) demonstrated a gradual drop in the resistance of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli; the commonest isolated gram negative bacteria from MICU), not only to third and fourth generation cephalosporins, but also to Piperacillin – Tazobactam in spite of the increased use of the later drug in the MICU. Discussion and conclusion: 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. Since resistance development is an evolutionary process, constant surveillance is necessary to gain insight into the problem in a timely fashion. Several measures were taken including antibiotic cycling, antibiotic rotation and restriction. Restriction of the use of Ceftazidime resulted in a significant drop in the resistance of the common Gram-negative bacteria to the betalactam antibiotics. The sustainability and efficacy of these measures need to be monitored over time.

A multicenter, retrospective study of pathogenic bacteria distribution and drug resistance in febrile neutropenic patients with hematological diseases in Shanghai

目的了解上海地区中性粒细胞缺乏（粒缺）伴发热血液病患者致病细菌的分布及耐药情况。方法回顾性分析2012年1月至2014年12月上海市12家医院血液科粒缺伴发热住院患者的临床分离菌株，用纸片扩散法进行药敏试验，WHONET 5.6软件分析病原菌分布及药敏数据。结果从上海地区粒缺伴发热患者中共分离出1 260株细菌，其中革兰阳性菌420株（33.3%），革兰阴性菌840株（66.7%）。排在前七位的分别是肺炎克雷伯菌158株（12.5%）、嗜麦芽窄食单胞菌120株（9.5%）、大肠埃希菌115株（9.1%）、铜绿假单胞菌109株（8.7%）、鲍曼不动杆菌83株（6.6%）、金黄色葡萄球菌70株（5.6%）和屎肠球菌63株（5.0%）。呼吸道分泌物标本中，非发酵菌占56.2%（350/623）。其中嗜麦芽窄食单胞菌占15.3%（95/623）。血液标本中，肠杆菌科细菌占42.3%（104/246），凝固酶阴性葡萄球菌占34.6%（85/246）。脓液标本中肠杆菌科细菌占39.4%（76/193），肠球菌属细菌占28.5%（55/193）。耐甲氧西林金黄色葡萄球菌葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）的检出率分别为54.3%和82.5%，未发现耐利奈唑胺、万古霉素、替考拉宁葡萄球菌属菌株，耐万古霉素屎肠球菌的检出率为8.9%，肠球菌属未检出耐利奈唑胺的菌株。肠杆菌科细菌对碳青霉烯类药物高度敏感。铜绿假单胞菌对亚胺培南和美罗培南的耐药率已分别达34.1%和15.8%。嗜麦芽窄食单胞菌对米诺环素、左氧氟沙星、复方磺胺甲恶唑等药物敏感。鲍曼不动杆菌仅对头孢哌酮/舒巴坦的耐药率低于10.0%。肺炎克雷伯菌、嗜麦芽窄食单胞菌、铜绿假单胞菌、鲍曼不动杆菌等革兰阴性菌对大多常用抗菌药物的耐药率低于CHINET监测的数据。结论粒缺伴感染患者常见感染部位致病菌株分布有其特点，细菌耐药率整体低于CHINET全国医院大样本监测。