Effects of an antimicrobial restriction system on appropriate carbapenem use in a hospital without infectious diseases consultation

Spectrum and antimicrobial resistance in acute exacerbation of chronic obstructive pulmonary disease with pneumonia: a cross-sectional prospective study from Vietnam

BACKGROUND

Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined.

METHODS

This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses.

RESULTS

The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78).

CONCLUSION

Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.

Molecular Epidemiological Characteristics of Carbapenem Resistant Aeromonas from Hospital Wastewater

Background

Hospital wastewater (HWW) promotes the spread of carbapenem resistance genes (CRGs). Aeromonas carry a large number of CRGs in HWW, they may play a role as a suitable reservoir for CRGs, while resistomes in HWW are still poorly characterized regarding carbapenem resistant Aeromonas. Thus, the aim of the study was to evaluate the molecular epidemiological characteristics of carbapenem resistant Aeromonas in HWW.

Methods

A total of 33 carbapenem resistant Aeromonas were isolated from HWW. Antimicrobial susceptibility testing and polymerase chain reaction (PCR) were used to assess the antimicrobial resistance profiles. Molecular typing was performed using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and multilocus sequence typing (MLST). The horizontal transmission mode of bla KPC was explored through conjugation and transformation experiments. The stability of bla KPC-IncP-6 plasmids was assessed through plasmid stability and in vitro competition test. The PCR mapping method was used to investigate the structural diversity of bla KPC.

Results

The detection rates of bla KPC and cphA in Aeromonas were 97.0% and 39.4% respectively. Aeromonas caviae were grouped into 13 clusters by ERIC-PCR and 12 STs by MLST. Aeromonas veronii were grouped into 11 clusters by ERIC-PCR and 4 STs by MLST. 56.3% bla KPC were located on mobilizable IncP-6 plasmids. bla KPC-IncP-6 plasmid showed high stability and low cost fitness.

Conclusion

Carbapenem resistant Aeromonas from HWW mainly carried bla KPC, which exhibited great structural diversity. Aeromonas might serve as reservoirs for bla KPC and bla KPC might spread mainly through transformation in HWW.

Antibiotics-associated pseudomembranous colitis: a disproportionality analysis of the US food and drug administration adverse event reporting system (FAERS) database

BACKGROUND

Evaluating antibiotics most commonly associated with pseudomembranous colitis (PMC) based on the real-world data is of great significance.

RESEARCH DESIGN AND METHODS

We used the data from FAERS to evaluate the potential association between antibiotics and PMC by disproportionality analyzes.

RESULTS

Eighty-one antibiotics which met the three algorithms simultaneously were enrolled. There were 1683 reports of PMC associated with the enrolled antibiotics. In the top 24 antibiotics, cefoxitin, streptomycin, fosfomycin, and micafungin had a high risk of PMC, but there were few reports in the literature.

CONCLUSIONS

This study was of great significance for healthcare professionals to realize the potential PMC risks of antibiotics.

Assessment of Knowledge, Attitude and Practice (KAP) Regarding Antimicrobial Usage and Resistance Among Animal Health Professionals of East Wallaga Zone, Oromiya, Ethiopia

Background

Antimicrobial resistance (AMR) is one of the top global public health and economic threats. The use of antimicrobials (AMs) in animal production is a major contributor to the development of AMR globally. Animal health professionals (AHPs) play a key role in ensuring judicious use of AMs.

Objective

To assess the knowledge, attitude and practice (KAP) of antimicrobial usage (AMU) and AMR among healthcare professionals in Nekemte town, Leka Dulecha and Sibu Sire districts.

Methods

A cross-sectional study was conducted with 120 purposively chosen AHPs residing in the districts and the town. A semi-structured questionnaire consisting of 49 questions was used to ascertain the KAP. The chi-square test (X2) was used to analyze the association between the knowledge score and demographic profile of the study participants.

Results

In the study the overall knowledge of the participants was moderately appreciable, and all participants had positive attitudes toward AMR and appropriate usage. In terms of knowledge of antibiotic use, the majority (93.33%) of the participants correctly answered the statement that antibiotics can kill viruses. About 84.17% of the participants correctly knew that antibiotics killed or stopped the growth of both bad and good bacteria. The majority of the participants (74.17%) always or (25.83%) sometimes rely on usage of antibiotics without a doctor's prescription. It was shown that comparing respondents from Sibu Sire, Leka Dulecha and Nekemte town, the scores of knowledge of AMU were significantly (X2=14.13, p=0.007) different. Most animal healthcare professionals from the Sibu sire have a good knowledge of AMU, and contribute to AMR development.

Conclusion

The study revealed that there was moderate knowledge and positive attitude toward AMU and resistance. This warrants continuing capacity building programs for the professionals on AM usage and resistance, and development of field-friendly disease diagnosis and management tools is essential in the need to reduce AMR.

Association between Pneumonia Development and Virulence Gene Expression in Carbapenem-Resistant Acinetobacter baumannii Isolated from Clinical Specimens

We investigated the virulence gene expression of carbapenem-resistant Acinetobacter baumanii (CRAB) isolated from the respiratory samples of patients with CRAB pneumonia and those with CRAB colonization to identify the virulence genes contributing to CRAB pneumonia's development and mortality. Patients with CRAB identified from respiratory specimens were screened at a tertiary university hospital between January 2018 and January 2019. Patients were classified into CRAB pneumonia or CRAB colonization groups according to predefined clinical criteria. A. baumannii isolated from respiratory specimens was examined for the expression levels of ompA, uspA, hfq, hisF, feoA, and bfnL by quantitative reverse-transcription polymerase chain reaction. Among 156 patients with CRAB from respiratory specimens, 17 and 24 met the criteria for inclusion in the pneumonia and colonization groups, respectively. The expression level of ompA was significantly higher in the pneumonia group than in the colonization group (1.45 vs. 0.63, P=0.03). The expression levels of ompA (1.97 vs. 0.86, P=0.02), hisF (1.06 vs. 0.10, P < 0.01), uspA (1.62 vs. 1.01, P < 0.01), and bfnL (3.14 vs. 2.14, P=0.03) were significantly higher in patients with 30-day mortality than in the surviving patients. Elevated expression of hisF (adjusted odds ratio = 5.93, P=0.03) and uspA (adjusted odds ratio = 7.36, P=0.02) were associated with 30-day mortality after adjusting for age and the Charlson score. uspA and hisF may serve as putative targets for novel therapeutic strategies.

Infection Prevalence at a Tertiary Hospital in Hail, Saudi Arabia: A Single-Center Study to Identify Strategies to Improve Antibiotic Usage

Objective

Identifying the burden of disease and the condition of the Saudi population is in high demand from both a surveillance and analytical standpoint. The objective of this study was to determine the most prevalent infections among hospitalized patients (both community-acquired and hospital-acquired), the antibiotics prescribing pattern, and their relationship with patient characteristics like age and gender.

Methods

A retrospective study was conducted comprising 2646 patients with infectious diseases or complications admitted to a tertiary hospital in the Hail region of Saudi Arabia. A standardized form was used to collect information from patient's medical records. Demographic data such as age, gender, prescribed antibiotics, and culture-sensitivity tests were included in the study.

Results

Males represented about two-thirds (66.5%, n = 1760) of the patients. Most patients (45.9%) who suffered from infectious diseases were between the ages of 20 and 39. The most prevalent infectious ailment was respiratory tract infection (17.65%, n = 467). Furthermore, the most common multiple infectious diseases were gallbladder calculi with cholecystitis (40.3%, n = 69). Similarly, COVID-19 had the greatest impact on people over 60. Beta-lactam antibiotics were the most commonly prescribed (37.6%), followed by fluoroquinolones (26.26%) and macrolides (13.45%). But performing culture sensitivity tests were rather uncommon (3.8%, n = 101). For multiple infections, beta-lactam antibiotics (such as amoxicillin and cefuroxime) were the most commonly prescribed antibiotics (2.26%, n = 60), followed by macrolides (such as azithromycin and Clindamycin) and fluoroquinolones (eg, ciprofloxacin and levofloxacin).

Conclusion

Respiratory tract infections are the most prevalent infectious disease among hospital patients, who are primarily in their 20s. The frequency of performing culture tests is low. Therefore, it is important to promote culture sensitivity testing in order to support the prudent use of antibiotics. Guidelines for anti-microbial stewardship programs are also highly recommended.

First Isolates of OXA-48-Like Carbapenemase-Producing Enterobacteriaceae in A Specialized Cancer Center

BACKGROUND

OXA-48-like carbapenemases have been found in a growing and varied number of carbapenemase-producing Enterobacteriaceae (CPE) isolates, and they are spreading to several countries. Although this oxacillinase leads to weak resistance to carbapenems without affecting broad-spectrum cephalosporin activity, when they are associated with other resistance mechanisms, the level of resistance to these antibiotics may be significantly higher. This weak resistance against carbapenems and cephalosporins, along with the absence of other resistance mechanisms, could render OXA-48-like harboring isolates undetected in the laboratory routine. In addition, the lack of a specific screening test for this enzyme complicates the detection of these isolates. This report characterizes the first isolates of OXA-48-like CPE detected in our laboratory.

MATERIALS AND METHODS

The study was carried out at the Instituto Nacional de Enfermedades Neoplasicas, Lima - Peru, between March and December 2021. OXA-48-like CPE isolates were detected as part of the routine microbiological study, and clinical data were obtained by reviewing medical records. The automated microbiological system provides the bacterial identification and antimicrobial susceptibility profile by the dilution method. Additionally, the column chromatography test is used to detect carbapenemase enzymes, including OXA-48-like. Finally, the molecular identification of the OXA-48-like enzyme was carried out by Polymerase Chain Reaction PCR amplification for the bla_OXA-48-like.

RESULTS

Seven OXA-48-like CPE strains were isolated. Notably, in all cases, the automated system issued a minimum inhibitory concentration (MIC) of ≥1 ug/mL for ertapenem and a MIC of >64/4 ug/mL for piperacillin/tazobactam. In addition, resistance category to imipenem and meropenem was found (2/7), at least one indeterminate category for any of these carbapenems (5/7), and other serine β-lactamases such as Extended-spectrum beta-lactamases (3/7) and AmpC (3/7). The immunochromatographic study confirmed the presence of the OXA-48-like enzyme in all isolates, while class A and class B were ruled out for them. Finally, the multiplex PCR, for the five isolates that could be recovered, showed amplification for carbapenemase OXA-48-like, while none of the other carpabemases was amplified for class A or class B carbapenemase genes.

CONCLUSION

We confirm the emergence of OXA-48-like CPE isolates in our cancer center and highlight the need to implement surveillance and detection measures of these strains, for controlling their dissemination. We found practical and inexpensive methodologies for the detection of OXA-48-like CPE: (1) the finding of resistance to ertapenem and piperacillin/tazobactam in the antibiogram in the absence of class A and B carbapenemases, for screening and (2) immunochromatographic study, for confirmation.

Risk Factors and Clinical Impact of Carbapenem-Resistant Enterobacterales Coinfections Among Hospitalized Patients with Clostridioides difficile Infection

Introduction

The risk factors and clinical impact of carbapenem-resistant Enterobacterales (CRE) coinfection among hospitalized patients with Clostridioides difficile infection (CDI) were analyzed in this study.

Materials and Methods

A clinical study was performed at the medical wards of Tainan Hospital, Ministry of Health and Welfare in southern Taiwan. Patients with CDI between January 2013 and April 2020 were included.

Results

Among 238 patients included for analysis, 22 (9.2%) patients developed CRE coinfections within 14 days before or after the onset of CDI. CDI patients with CRE coinfection had longer hospitalization stays (103.0 ± 97.0 days vs 42.5 ± 109.6 days, P = 0.01) than those without CRE coinfection. In the multivariate analysis, age (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01–1.10, P = 0.02) was independently associated with CRE coinfection. In contrast, underlying old stroke (OR 0.15, 95% CI 0.03–0.70, P = 0.02) was negatively linked to CRE coinfection.

Conclusion

Among patients with CDI, CRE coinfections were associated with prolonged hospitalization for CDI. Age was an independent risk factor for CRE coinfection among patients with CDI.

Effect of Colistin, Fosfomycin and Meropenem/Vaborbactam on Carbapenem-Resistant Enterobacterales in Egypt: A Cross-Sectional Study

Purpose

The increasing multi-drug carbapenem resistance among Enterobacterales are a severe health problem limiting therapeutic options and worsen the prognosis. This study characterizes carbapenemase genes and integrons among uropathogenic carbapenem resistant Enterobacterales (CRE) isolates recovered from Mansoura University Hospitals and evaluates the effect of colistin, fosfomycin and meropenem-vaborbactam on these isolates.

Patients and Methods

A total of 200 Enterobacterales isolates were collected from patients with urinary tract infections. Antimicrobial susceptibility testing was performed by the disc diffusion method. Colistin susceptibility was tested using the broth microdilution method and fosfomycin and meropenem/vaborbactam susceptibility were tested by MIC Test Strips. Carbapenem resistant isolates were screened for carbapenemase activity phenotypically using the modified carbapenem inactivation method and EDTA-modified carbapenem inactivation method and genotypically by multiplex PCR. Integrons class 1 and 2 and fosA gene were assayed by PCR. Data were statistically analyzed using the Statistical Package for Social Sciences (SPSS) version 16. The Chi-square or Fisher’s exact test was used to compare groups, as appropriate.

Results

Ninety-two Enterobacterales isolates were resistant to meropenem (46%); 52 E. coli and 40 K. pneumoniae strains. All CRE isolates were multi-drug resistant (MDR). Sensitivity of CRE isolates to colistin, fosfomycin and meropenem/vaborbactam were 67.4%, 82.6% and 58.7%, respectively. Carbapenemase genes were detected by multiplex PCR in 69.6% of CRE isolates (Carbapenemase producing Enterobacterales (CPE) mainly bla_NDM (37%). CPE isolates were significantly more resistant to meropenem/vaborbactam than non-CPE isolates; 51.6% vs 17.8%, respectively (P = 0.003) especially bla_NDM carrying isolates (70.6%). Class 1 integrons and fosA gene were detected in 91.3% and 11.9% of CRE isolates, respectively.

Conclusion

This study revealed that about half of the uropathogenic Enterobacterales isolates were MDR CRE. Carbapenemase gene bla_NDM was the main gene among CRE isolates. Meropenem/vaborbactam sensitivity was significantly higher on non-CPE than CPE isolates and limited by the predominance of bla_NDM.

The Threat of Carbapenem-Resistant Gram-Negative Bacteria in Patients with Hematological Malignancies: Unignorable Respiratory Non-Fermentative Bacteria-Derived Bloodstream Infections

Background

Carbapenem-resistant Gram-negative bacteria (CRGNB) bloodstream infection (BSI) pose a significant threat to the prognosis of hematologic malignancies (HM) patients. Understanding the distribution of pathogenic bacteria, changes in carbapenem-resistant trends, risk factors for CRGNB infections, and exploring the early detection measures can help reduce mortality.

Methods

We conducted a multicenter retrospective study of Gram-negative bacteria (GNB) BSI in patients with HM in three university-affiliated hospitals in Hunan Province, China, from January 2010 to December 2020. Demographic and clinical data were collected from the hospital electronic medical records system.

Results

CRGNB caused 138 (15.3%) of 902 GNB BSI. The detection rate of CRGNB increased from 6.4% in 2010–2012 to 35.4% in 2019–2020. The 7-day mortality rate was significantly higher in patients with CRGNB BSI than in patients with carbapenem-susceptible Gram-negative bacteria (CSGNB) BSI [31.9% (44/138) vs 9.7% (74/764), P < 0.001], and the mortality rate in patients with carbapenem-resistant non-fermenting bacteria (CRNFB) bloodstream infections was generally higher than that of carbapenem-resistant Enterobacteriaceae (CRE). Urinary catheter (OR, 2.814; CI=1.395–5.680; P=0.004) and prior exposure to carbapenem (OR, 4.372; CI=2.881–6.635; P<0.001) were independent risk factors for CRGNB BSI. Analysis of co-infections showed that 50%–85% of patients with CRGNB BSI had pulmonary infections, sputum culture results suggested that sputum culture positivity rate was as high as 57.1%–66.7% in patients with carbapenem-resistant Acinetobacter baumannii (CRAB) and Stenotrophomonas maltophilia BSI, and the results of antimicrobial susceptibility testing of sputum cultures were consistent with the blood cultures.

Conclusion

Carbapenem resistance has dramatically increased in HM patients with GNB BSI in recent years and is associated with a worse outcome, especially for non-fermenting bacteria. In high-risk patients, early screening of the respiratory tract specimens may help to detect CRNFB colonization and protect patients from breakthrough BSI.

Trends in DTR, CR, ECR, and FQR in Four Common Gram-Negative Bacteria: A Retrospective Study from 2013 to 2021

Purpose

The purpose of this study was to examine the prevalence of four important drug-resistance phenotypes: difficult-to-treat resistance (DTR), fluoroquinolone resistance (FQR), carbapenem resistance (CR), and extended-spectrum cephalosporin resistance (ECR).

Methods

DTR was defined as insensitivity to all the β-lactams and fluoroquinolones tested. We retrospectively analyzed the distribution characteristics of specific drug-resistant phenotypes of the main Gram-negative bacteria causing bloodstream infections (BSIs) in Tongji Hospital (Wuhan, China) between 2013 and 2021: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii.

Results

FQR was the main antimicrobial resistance phenotype of E. coli, accounting for 59.45% (1117/1879, 95% confidence interval, 57.21%-61.65%); the detection rates for CR and DTR were low, accounting for 1.86% (35/1879, 1.34%-2.58%), and 1.81% (34/1879, 1.30%-2.52%), respectively. However, the detection rates for CR and DTR in K. pneumoniae were 38.83% (497/1280, 36.20%-41.53%) and 35.94% (460/1280, 33.35%-38.60%), respectively. In P. aeruginosa, the detection rates of the four drug-resistant phenotypes (DTR, CR, FQR, and ECR) were all < 30%, but conversely, for A. baumannii, the detection rates were all > 80%. The changes in the data from 2013 to 2021 showed upward trends (z > 0) for CR-E. coli, DTR-E. coli, FQR-E. coli, CR-K. pneumoniae, DTR-K. pneumoniae, FQR-K. pneumoniae, and ECR-K. pneumoniae, but downward trends (z < 0) for ECR-E. coli, CR-A. baumannii, DTR-A. baumannii, FQR-A. baumannii, ECR-A. baumannii, CR-P. aeruginosa, DTR-P. aeruginosa, FQR-P. aeruginosa, and ECR-P. aeruginosa.

Conclusion

DTR warrants further attention, especially in in BSI-associated K. pneumoniae and A. baumannii, in which the detection rates were very high. Between 2013 and 2021 in this region, DTR-E. coli and CR-E. coli showed obvious upward trends, whereas DTR-P. aeruginosa and ECR-P. aeruginosa showed obvious downward trends.

Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Isolates Among Intensive Care Unit Patients and Environment

Objective

Methods

Results

Conclusion

Impact of the Expert Consensus on Carbapenem Consumption Trends and Patterns in Public Healthcare Institutes: An Interrupted Time Series Analysis, 2017-2020

Background: Carbapenems are considered the last line of defence against bacterial infections, but their high consumption and the resulting antibacterial resistance are an increasing global concern. In this context, the Chinese health authority issued an expert consensus on the clinical applications of carbapenems. However, the long- and short-term effects of the expert consensus on carbapenem use are not clear.

Methods: This study was conducted in Shaanxi, a northwest province of China. We collected all available carbapenem procurement data between January 2017 and December 2020 from the Provincial Drug Centralized Bidding Procurement System. A quasi-experimental interrupted time series analysis was used to evaluate the longitudinal effectiveness of expert consensus by measuring the change in the Defined Daily Dosesper 1,000 inhabitants per day (DID), the percentage of carbapenem expenditures to total antimicrobial expenditure, the total carbapenem expenditure, and the defined daily cost (DDDc). We used Stata SE version 15.0 for data analysis, and p < 0.05 was considered statistically significant.

Results: After the distribution of the expert consensus, the level (p = 0.769) and trend (p = 0.184) of DID decreased, but the differences were not statistically significant. The percentage of carbapenem expenditures to total antimicrobial expenditure decreased abruptly (p < 0.001) after the intervention, but the long-term trend was still upward. There was no statistically significant relationship between the release of the expert consensus and carbapenem expenditure in the long term, but there was a decreasing trend (p = 0.032). However, the expert consensus had a positive impact on the economic burden of carbapenem usage in patients, as the level (p < 0.001), and trend (p = 0.003) of DDDc significantly decreased.

Conclusion: The long-term effects of the distribution of the expert consensus on the use and expenditure of carbapenems in public health institutions in Shaanxi Province were not optimal. It is time to set up more administrative measures and scientific supervision to establish a specific index to limit the application of carbapenems.

A comprehensive assessment of carbapenem use across 90 Veterans Health Administration hospitals with defined stewardship strategies for carbapenems

OBJECTIVES

Carbapenems are an important target for antimicrobial stewardship (AS) efforts. In this study, we sought to compare different hospital-based strategies for improving carbapenem use.

METHODS

We analysed a cohort of all patients hospitalized at Veterans Health Administration (VHA) acute care hospitals during 2016 and a mandatory survey that characterized each hospital's carbapenem-specific AS strategy into one of three types: no strategy (NS), prospective audit and feedback (PAF) or restrictive policies (RP). Carbapenem use was compared using risk-adjusted generalized estimating equations that accounted for clustering within hospitals. Two infectious disease (ID) physicians independently performed manual chart reviews in 425 randomly selected cases. Auditors assessed carbapenem appropriateness with an assessment score on Day 4 of therapy.

RESULTS

There were 429 062 admissions in 90 sites (24 NS, 8 PAF, 58 RP). Carbapenem use was lower at PAF than NS sites [rate ratio (RR) 0.6 (95% CI 0.4-0.9); P = 0.01] but similar between RP and NS sites. Carbapenem prescribing was considered appropriate/acceptable in 215 (50.6%) of the reviewed cases. Assessment scores were lower (i.e. better) at RP than NS sites (mean 2.3 versus 2.7; P < 0.01) but did not differ significantly between NS and PAF sites. ID consultations were more common at PAF/RP than NS sites (51% versus 29%; P < 0.01). ID consultations were associated with lower (i.e. better) assessment scores (mean 2.3 versus 2.6; P < 0.01).

CONCLUSIONS

In this VHA cohort, PAF strategies were associated with lower carbapenem use and ID consultation and RP strategies were associated with more appropriate carbapenem prescribing. AS and ID consultations may work complementarily and hospitals could leverage both to optimize carbapenem use.

Mixed effects of restriction strategies in antimicrobial stewardship programs on antimicrobial use in 121 tertiary hospitals in China, 2013-2017

Background: The research evaluated the impact of intravenous antimicrobial restriction strategy (IARS) on different types of hospitals in China for evidence-based management, for outpatients implemented in 2016. Methods: Based on panel data on antimicrobial use in 121 tertiary hospitals in Zhejiang, China, segmented regression analysis was used to evaluate the impact of IARS in children's hospitals (CHs), obstetrics and gynecology hospitals (OGHs), women's and children's hospitals (WCHs), traditional Chinese medicine hospitals (TCMHs) and general hospitals (GHs). Antimicrobial use was measured using the percentage of total encounters with prescribing and the percentage of total drug expenditure relating to antimicrobials (APP and AEP). Results: There was a downward baseline slope of APP in all types of hospitals and AEP in WCHs, TCMHs and GHs (P < 0.01). After IARS, a level reduction in AEP in CHs (-3.14%, 95% CI = -6.21 to 0.06), WCHs (-1.33%, 95% CI = -2.44 to 0.22) and TCMHs (-0.85%, 95%CI = -1.51 to 0.18). After IARS, the slope of AEP changed significantly in OGHs (-0.42%, 95%CI = -0.81 to 0.03) and WCHs (0.29%, 95% CI = 0.08 to 0.49), and the slope of APP changed significantly in CHs (2.35%, 95%CI = 1.20 to 3.49). Conclusions: IARS had the mixed effects including positive effect in AEP and no significant change in APP, and an unexpected rise in APP in CHs needs further study.