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Yu-Ting Huang,1 Chia-I Yu,2 Pao-Yu Chen,3,4 Chi-Chuan Wang,1,2,5 Chien-Chih Wu1,2 1Department of Pharmacy, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; 2School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan; 3Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; 4Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; 5Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei, TaiwanCorrespondence: Chien-Chih WuDepartment of Pharmacy, National Taiwan University Hospital, College of Medicine, National Taiwan University, 7 Chung Shan S. Road, Taipei, TaiwanTel/Fax +886-2-23123456 ext. 63702/ +886-2-23310930Email 101440@ntuh.gov.twBackground: Antibiotic combination is commonly used to treat multidrug-resistant pathogens. Reports have indicated that tigecycline use is associated with hypofibrinogenemia. However, whether the bleeding risk of tigecycline is higher than that of other antibiotics remains unknown. The aim of this study was to compare the bleeding risk between colistin–tigecycline and colistin–carbapenem treatment.Methods: This retrospective cohort study enrolled adult patients treated with colistin along with tigecycline or carbapenems (doripenem, imipenem–cilastatin, or meropenem) for ˃72 hours during hospitalization. The primary outcome was major bleeding events, which were determined by a hemoglobin drop of ≥ 2 g/d and receipt of blood transfusions with whole blood or packed red blood cells. Multivariate logistic regression was applied to determine risk factors for bleeding events.Results: In total, 106 and 268 patients in the colistin–tigecycline and colistin–carbapenem groups met the criteria for analysis, respectively. The two groups did not differ significantly in demographic data, except for alanine aminotransferase (ALT), serum creatinine (SCr) and ulcer disease. The colistin–tigecycline group had a higher ALT, SCr and a lower proportion of ulcer disease. Major bleeding events did not differ significantly between the colistin–tigecycline and colistin–carbapenem groups (12.26% vs 9.33%, P = 0.40). Antibiotic duration [OR = 1.06 (1.02– 1.11), P=0.007)] and anticoagulant use [OR = 2.16 (1.05– 4.42), P=0.04] were associated with major bleeding events.Conclusion: Colistin–tigecycline treatment was not associated with a higher bleeding risk. Antibiotic duration and concurrent use of anticoagulant were the risk factors of bleeding events.Keywords: tigecycline, carbapenems, bleeding events

Hye Jin Shi, Jae Hee Wee, Joong Sik Eom Division of Infectious Diseases, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, KoreaCorrespondence: Joong Sik EomDivision of Infectious Diseases, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, (21565) 774 Beon-gil 21, Namdongdae-ro, Namdong-gu, Incheon, KoreaTel +82-32-460-2630Fax +82-32-460-2631Email helppl@gachon.ac.krBackground: Urinary tract infections (UTIs) caused by extended spectrum beta-lactamase (ESBL) producing pathogens have increased and are treated with carbapenem in general. Carbapenem use is associated with prolonged hospitalization or daily outpatient visit. The aim of this study was to investigate patients with UTIs by ESBL-producing pathogens for early discharge using an old oral antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), which is susceptible to ESBL-producing pathogens.Methods: Data on UTIs caused by ESBL-producing pathogens from a single tertiary hospital were collected retrospectively. Patients who had been treated with intravenous carbapenems or oral TMP/SMX were included. Patients’ clinical and microbiological outcomes were compared between oral TMP/SMX and ertapenem treatment groups.Results: A total of 103 patients were included, 21 of whom had been treated with TMP/SMX, whereas 82 with ertapenem. Clinical outcomes between the two groups were not significantly different (TMP/SMX: 90.5%; ertapenem: 84.1%, p = 0.73). The microbiological cure rate was higher in the TMP/SMX group than in the ertapenem group (90.5% vs 58.5%, respectively, p = 0.01). The mean duration of hospitalization was significantly shorter in the TMP/SMX group than in the ertapenem group (8.00 ± 10.50 days vs 14.00 ± 37.00 days, p = 0.07). The mean duration of antibiotic treatment was longer in the ertapenem group than in the TMP/SMX group (16.45 ± 4.77 vs 12.76 ± 5.37 days, p = 0.006).Conclusion: For susceptible pathogens, TMP/SMX may enable early discharge as an effective oral antibiotic treatment option for UTIs caused by ESBL-positive pathogens. Additionally, use of oral antibiotics can shorten hospital stays and reduce medical costs.Keywords: oral antibiotics, ESBL, UTI, TMP/SMX, outpatient treatment

Lewei Xie,1 Yaling Du,1 Xuemei Wang,1 Xinping Zhang,1 Chenxi Liu,1 Junjie Liu,2 Xi Peng,3 Xinhong Guo3 1School of Medicine and Health Management, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, Hubei, People’s Republic of China; 2School of Statistics and Mathematics, Central University of Finance and Economics, Beijing, People’s Republic of China; 3First Affiliated Hospital, School of Medicine, Shihezi University, Xinjiang, Shihezi, People’s Republic of ChinaCorrespondence: Xinping Zhang; Yaling DuSchool of Medicine and Health Management, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, Hubei, People’s Republic of ChinaTel +86 133 4995 0095; +86 180 0993 8932Email xpzhang602@hust.edu.cn; xpzhang602@163.com; 1147844190@qq.comPurpose: Carbapenem resistance due to the overuse of carbapenems has become a public health problem worldwide, particularly in low- and middle-income countries (LMICs). However, there are few policies guiding carbapenem prescription, and their effectiveness is still unclear. A regulation targeting carbapenem prescription was implemented in March 2017 in China. This study aimed to assess the effects of the regulation for providing evidence on the prudent use of carbapenems.Patients and Methods: This was an interventional, retrospective study started in January 2017. The intervention covered establishing performance appraisal indicators, special authorisation, strict prescribing restrictions, and dedicated supervision, particularly in the intensive care unit (ICU). Data on adult inpatients who received at least one carbapenems were extracted from January 2016 to December 2018. Segmented regression analysis was performed to evaluate the effect of the regulation.Results: A total of 2005 inpatients received carbapenems. Segmented regression models showed an immediate decline in the intensity of antibiotic consumption (IAC) of carbapenems (coefficient = − 9.65, p < 0.001), particularly imipenem (coefficient = − 6.82, p = 0.002), and the antibiotic consumption of carbapenems (coefficient = − 133.60, p = 0.003) in the ICU. And there is a decreasing trend in the IAC of meropenem (coefficient = − 0.03, p = 0.008) in all departments. Furthermore, the IAC of carbapenems and imipenem (coefficient = − 0.36, p = 0.035; coefficient = − 0.49, p = 0.025, respectively), and the average length of stay (ALoS) (coefficient = − 0.73, p < 0.001) showed downward trends in the ICU.Conclusion: The intervention effectively reduced the IAC of carbapenems and imipenem, carbapenem consumption and the ALoS in the ICU, and the IAC of meropenem in all departments. The effects of the intervention were significant in the ICU, which indicated an urgent need for stronger regulations focusing on critical departments in the future.Keywords: carbapenem prescription, ICU, multifaceted intervention, antimicrobial stewardship, effects assessment, segmented regression

Xiao Xu,&ast; Caifang Xu,&ast; Rabiu Bilya Salisu, Wei Xu Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Wei XuDepartment of Pediatrics, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Heping District, Shenyang, Liaoning Province, People’s Republic of ChinaEmail tomxu.123@163.comPurpose: Acinetobacter baumannii is a major cause of hospital-acquired infections. Studies showed that carbapenem resistance was related to mortality. Carbapenem resistance depends on expression of β-lactamase in adults. The present study explores the relationship between β-lactamase gene expression and carbapenem resistance and outcomes in children with A. baumannii infections.Patients and Methods: We gathered clinical data of 131 children diagnosed with hospital-associated A. baumannii infections from the pediatrics unit of Shengjing Hospital of China Medical University. We obtained 131 isolates of A. baumannii, determined the minimal inhibitory concentrations (MICs) for common antibiotics, and measured carbapenemase-encoding genes expression using real-time PCR.Results: We isolated 131 strains, 89 of which were carbapenem-resistant (MIC ≥ 8 μg/mL), and 42 carbapenem-sensitive strains. Univariate analysis identified statistically significant differences between the carbapenem-resistant group and the carbapenem-sensitive group for in-hospital days before infection, previous deep vein catheterization, previous urinary catheterization, previous treatment with a carbapenem (meropenem/imipenem), and expression of oxa-51 and oxa-23. Logistic regression analysis of factors associated with carbapenem-resistant A. baumannii infections found significant associations with oxa-23 expression (hazard ratio [HR] 0.005, confidence interval [CI] 95% 0– 0.153, P = 0.002) and previous carbapenem treatment (HR 0.031 CI 95% 0.1– 0.959, P = 0.042). Of 131 patients, 27 died within 30 days. Cox regression analysis of factors associated with 30-day mortality from A.baumannii infections showed that cephalosporin combined with sulbactam (HR 0.271, CI 95% 0.101– 0.723, P = 0.009) was associated with 30-day survival.Conclusion: The expression of oxa-23 and the use of carbapenems were independent risk factors for carbapenem resistance. The use of cephalosporins combined with sulbactam was independently associated with 30-day survival. We recommend using cephalosporins combined with sulbactam in children infected with A. baumannii.Keywords: β-lactamase geen, carbapenem resistance, Acinetobacter baumannii, prognosis, risk factors

Dan Li, 1, 2,* Pei Li, 1, 2,* Xiaoyan Yu, 3,* Xuefei Zhang, 1, 2 Qinglan Guo, 1, 2 Xiaogang Xu, 1, 2 Minggui Wang, 1, 2 Minghua Wang 1, 2 1Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China; 2Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People’s Republic of China; 3Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Minghua WangInstitute of Antibiotics, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, People’s Republic of ChinaTel +86 021 52888193Email mhwang001ster@126.comBackground: The bloodstream infections (BSI) caused by Escherichia coli pose a serious threat to human health. To explore molecular characteristics of E. coli causing BSI, we collected E. coli isolates causing BSI in Huashan Hospital, Shanghai, China during 2010– 2015.Methods: In all E. coli isolates causing BSI collected from this study, polymerase chain reaction (PCR) was used to detect ESBLs and carbapenemase genes, and minimum inhibitory concentrations (MICs) were determined with agar dilution method. Outer membrane proteins were examined by SDS-PAGE in carbapenem-resistant strains. The genetic background of blaKPC gene was investigated by combining next-generation sequencing with a PCR mapping approach. Conjugation and transformation experiments were performed to verify the mobilization of blaKPC. The transcription levels of the blaKPC gene were measured by RT-PCR.Results: During 2010– 2015, a total of 207 E. coli BSI strains were isolated. The positive rates of β-lactamase resistant genes were 0.48% (blaKPC), 57% (blaTEM), 23.67% (blaCTX-M-1), 18.84% (blaCTX-M-9), and 1.93% (blaSHV). High rates of blaTEM, blaCTX-M-1, and blaCTX-M-9 were consistent with the poor activity of third-generation cephalosporins and aztreonam in vitro, except for carbapenem and β-lactamase inhibitor combinations. Low susceptibility rates were observed for piperacillin (25.1%) in contrast to the increased susceptibility when combined with β-lactamase inhibitors, namely piperacillin-tazobactam (90.8%). Only one KPC-producing E. coli strain was detected. Despite the combination of OmpC loss, the low expression level of KPC may be responsible for its lower resistance to carbapenems compared to E. coli DH5α (pKP12-100).Conclusion: E. coli strains isolated from BSI were still highly susceptible to carbapenems and β-lactamase inhibitor combinations, and blaCTX-M was the dominant genotype of ESBLs. The low expression of blaKPC may be the reason for the low resistance to carbapenems.Keywords: Escherichia coli, bloodstream infections, resistance mechanism, ESBLs

Debao Li,1,* Keyang Li,2,* Hongliang Dong,2 Dongmei Ren,1 Dandan Gong,2 Fuguo Jiang,1 Chunhua Shi,1 Junmin Li,1 Qi Zhang,3 Wenjuan Yan,3 Yi Li3 1Department of Clinical Laboratory, Jiaozuo People’s Hospital, Jiaozuo, Henan, People’s Republic of China; 2Department of Clinical Pharmacy, Jiaozuo People’s Hospital, Jiaozuo, Henan, People’s Republic of China; 3Department of Clinical Laboratory, Henan Provincial People’s Hospital, Zhengzhou, Henan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wenjuan Yan; Yi LiDepartment of Clinical Laboratory, Henan Provincial People’s Hospital, Weiwu Road 7#, Jinshui District, Zhengzhou, 450003, Henan, People’s Republic of ChinaTel +86 15225061830; +86 15939039006Email yanwenjuan2008@126.com; liyilabmed@henu.edu.cnPurpose: Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a serious problem worldwide. Herein, we describe the evolution of ceftazidime–avibactam (CZA) resistance by sequencing clinical isolates from a patient with CRKP infection undergoing CZA treatment.Patients and Methods: In this study, six CRKP strains were isolated from sputum and blood samples of a patient with CRKP infection after intracerebral hemorrhage. Two strains were selected for whole-genome analysis.Results: Drug susceptibility testing showed that the MIC of CZA for CRKP strains isolated after 6 days of CZA treatment was 64-fold higher than that for three CRKP strains isolated before CZA treatment (4 vs > 256 μg/mL), whereas the MIC of imipenem and meropenem was 128-fold (> 32 vs 0.25 μg/mL) and 16-fold (> 32 vs 2 μg/mL) lower relatively, respectively. Multilocus sequence typing showed that all six CRKP strains isolated from the patient were ST11 and pulsed-field gel electrophoresis confirmed that they were of the same clone. Two strains were selected for whole-genome analysis. The aspartic acid residue at position 179 in the Ω loop was replaced by a tyrosine residue in the resistant strain, and the plasmid carried a blaKPC-2 to blaKPC-33 mutation. The results of the modified carbapenem inactivation method and the carbapenemase inhibitor enhancement and colloidal gold enzyme immunochromatographic assays for blaKPC-33 were negative.Conclusion: This is the first report from Henan to show that treatment with CZA for 6 days can cause mutations and change the phenotype from CZA sensitive to resistant. Therefore, routine testing for drug susceptibility and carbapenemase phenotypes should be conducted during treatment with CZA, and genotype determination is essential.Keywords: ceftazidime–avibactam, drug resistance, carbapenem-resistant Klebsiella pneumoniae, K. pneumoniae carbapenemase-2, ST11

Tsegaye Alemayehu,1 Solomon Asnake,1 Bereket Tadesse,2 Elshaday Azerefegn,2 Enkosilassie Mitiku,2 Asnakech Agegnehu,2 Netsanet Nigussie,2 Techilo H/Mariam,2 Moges Desta1 1Hawassa University College of Medicine and Health Science, School of Medical Laboratory Science, Hawassa, Ethiopia; 2Hawassa University Comprehensive Specialized Hospital Microbiology Laboratory, Hawassa, EthiopiaCorrespondence: Tsegaye AlemayehuHawassa University College of Medicine and Health Science, School of Medical Laboratory Science, P.O. Box 1560, Hawassa, Sidama, EthiopiaTel +251-91387241Email alemayehutsegaye@ymail.comBackground: Carbapenem-resistant gram-negative bacteria are an emergent source of both community-acquired and healthcare-associated infection that poses a substantial hazard to public health. This study aimed to conclude the magnitude of carbapenem resistance gram-negative bacteria from a clinical specimen at Hawassa University Comprehensive Specialized Hospital.Methods: A hospital-based cross-sectional study was accompanied from February 13 to June 7, 2020, in which consecutive patients with 103 gram-negative bacteria were encompassed. The isolates included were 54 urine, 17 blood, 17 pusses, 4 cerebrospinal fluid (CSF), 3 aspirates, 3 effusions, 2 stools, 2 ear discharges, and 1 nasal swab. A semi-structured questionnaire was used to gather socio-demographic data from the attendant and clinical data from the patient’s chart. Patients admitted in any wards and visited outpatients department were included for the study if gram-negative bacteria was identified for those who accepted the consent. A routine manual culture, Gram’s staining and biochemical tests used to identify the bacteria. Antibiotic susceptibility was determined for twelve antibiotics including cotrimoxazole, ceftazidime, meropenem, gentamycin, chloramphenicol, ampicillin, ciprofloxacin, cefotaxime, cefuroxime, nitrofurantoin, piperacillin-tazobactam, and amikacin using the Kirby-Bauer disc diffusion method. Modified carbapenem inactivation (mCIM) method was used to determine carbapenem resistance using meropenem disk as per the recommendation of Clinical and Laboratory Standards Institute guideline. Statistical package for social science software version 21 was used for data entry and analysis. The odds ratio at 95% confidence interval (CI) and p-value < 0.05 were taken as a statistically significant association.Results: Generally, 111 gram-negative bacteria were identified from 103 patients. Of 111 isolates, thirteen isolates (nine resistance and four intermediates) were identified in disk diffusion testing for meropenem. Of this, 10 isolates were carbapenemases producer with the overall rates of 9% in the Modified carbapenem inactivation method (mCIM). Pseudomonas spp. 3 (30.0%), E. coli, K. pneumonia, Acinetobacter spp. each two (20.0%), and K. oxytoca 1 (10.0%) were identified as carbapenemases positive. The rates of the multidrug, extensive, pan drug were 86.5, 43.3, and 1.8, respectively. Ampicillin 94 (97.9%), followed by cefuroxime 52 (91.2%), cefotaxime 94 (88.7%), cotrimoxazole 58 (88.1%), ceftazidime 40 (83.3%), ciprofloxacin 47 (77.1%), nitrofurantoin 35 (70.0%), gentamycin 71 (65.7%), with high level of resistance. However, piperacillin-tazobactam 41 (48.8%), chloramphenicol 25 (47.2%), meropenem 13 (11.7%), and amikacin 9 (8.5%) were with low rates of resistance. In this study, there were no variables statically associated with carbapenem resistance that is p > 0.05.Conclusion: Our study showed that carbapenem-resistant gram-negative bacilli are 9% in the study area. Our finding signposts that ampicillin, cefuroxime, cefotaxime, cotrimoxazole, ceftazidime, ciprofloxacin, nitrofurantoin, and gentamycin with a high rate of resistance > 50%. However, piperacillin-tazobactam, chloramphenicol, meropenem, and amikacin were at low rates of resistance. Therefore, a measure should be taken to contain carbapenem resistance gram-negative bacteria in the study area. Further, study with better method needs to be conducted to conclude the real scenario of carbapenem resistance.Keywords: phenotypic, carbapenem resistance, gram-negative bacilli, clinical specimen, Hawassa, Ethiopia

Chaoe Zhou,1 Longyang Jin,1 Qi Wang,1 Xiaojuan Wang,1 Fengning Chen,1 Yue Gao,1 Chunjiang Zhao,1 Hongbin Chen,1 Bin Cao,2 Hui Wang1 1Department of Clinical Microbiology, Peking University People’s Hospital, Beijing, People’s Republic of China; 2Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, National Clinical Research Center for Respiratory Diseases, Beijing, People’s Republic of ChinaCorrespondence: Hui WangDepartment of Clinical Laboratory, Peking University People’s Hospital, Beijing, 100044, People’s Republic of ChinaTel +8688326300Email whuibj@163.comPurpose: Carbapenem-resistant Enterobacterales bloodstream infections (CRE BSIs) have a high mortality. However, an optimal antimicrobial treatment has not been determined. This study was conducted to evaluate the risk factors for mortality and provided potential therapeutic options for treatment of CRE infection.Patients and Methods: We investigated patients with CRE BSIs from 18 hospitals across nine Chinese provinces from January to December 2019. Data were collected from the medical records according to a pre-established questionnaire. Antimicrobial susceptibility testing and DNA sequencing were performed to investigate the characteristics of isolates.Results: A total of 208 patients enrolled; the overall 30-day mortality rate was 46.2%. The causative pathogen was carbapenem-resistant Klebsiella pneumoniae (CRKP) (85.6%). Patients infected by ST11-KL64 CRKP had a high sepsis/septic shock incidence rate (p < 0.05). Sepsis/septic shock, short duration of antimicrobial therapy and empirical using tigecycline were independent risk factors for mortality (p < 0.05 for each risks). Appropriate therapy had better survival benefit than inappropriate therapy (p = 0.003). No difference was identified between monotherapy and combination therapy (p = 0.105). Tigecycline as a frequently used antimicrobial had poor therapeutic effect on BSI patients (p < 0.001). Carbapenem-based treatment had a better therapeutic effect on patients infected by isolates with meropenem MIC ≤ 8 mg/L (p = 0.022). The patients who received short duration of antimicrobial therapy had poorer prognosis (p < 0.001) than the patients who received long duration of antimicrobial therapy.Conclusion: Reducing the mortality of CRE BSIs need to comprehensively consider whether the antimicrobials were used appropriately, together with infection severity and CRE strains.Keywords: carbapenem-resistant Enterobacterales, bloodstream infections, risk factors, antimicrobial therapy, treatment outcomes

Wajiha Imtiaz,1,2,* Zainab Syed,1,* Zara Rafaque,3 Simon Colin Andrews,2 Javid Iqbal Dasti1 1Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; 2School of Biological Sciences, Whiteknights, University of Reading, Reading RG6 6AJ, UK; 3Department of Microbiology, Hazara University, Mansehra, Pakistan*These authors contributed equally to this workCorrespondence: Javid Iqbal DastiDepartment of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PakistanTel +92-51-90644175Email Iqbal78@hushmail.comBackground: The emergence of carbapenem-resistant and hypervirulent hypermucoviscous Klebsiella pneumoniae strains poses a significant public health challenge. We determined the MDR profiles, antibiotic resistance factors, virulence gene complement, and hypermucoviscous features of 200 clinical K. pneumoniae isolates from two major tertiary care hospitals in Islamabad and Rawalpindi, Pakistan.Methods: Susceptibility profiling and phenotypic analysis were performed according to the CLSI guidelines. Genetic determinants of antibiotic resistance and virulence were detected by PCR. Biofilm formation analysis was performed by microtiter plate assay.Results: The isolates displayed a high degree of antibiotic resistance: 36% MDR-CRKP; 38% carbapenem resistance; 55% gentamicin resistance; 53% ciprofloxacin resistance; and 59% aztreonam resistance. In particular, the level of resistance against fosfomycin (22%) and colistin (15%) is consistent with previous reports of increased resistance levels. Combined resistance to carbapenem and colistin was 7%. Genetic factors associated with colistin resistance (mcr-1 and mcr-2 genes) were detected in 12 and 9% of the isolates, respectively. Significant differences in resistance to gentamicin and levofloxacin were observed between the 200 isolates. Many of the isolates harbored genes specifying extended-spectrum and/or carbapenem-resistant β-lactamases: blaCTX-M-15 (46%), blaNDM-1 (39%), and blaOXA-48 (24%). The prevalence of the hypermucoviscous phenotype was 22% and 13% of the MDR isolates carried the rmpA gene (regulator for mucoid phenotype). Key virulence factor genes detected include those encoding: porins (ompK35 and ompK36; at 56 and 55% prevalence, respectively); adhesins (fimH, mrkD, and ycfM; at 19, 18, and 22% prevalence, respectively); and the polysaccharide regulator, bss, at 16% prevalence.Conclusion: This report highlights carbapenem-resistant K. pneumoniae (CRKP) prevalence, emerging resistance to fosfomycin, and the presence of mcr-1 and mcr-2 in colistin-resistant isolates. Further, the detection of rmpA signifies the prevalence of the hypermucoviscous trait in CRKP clinical isolates from Pakistan.Keywords: Klebsiella pneumoniae, multidrug resistance, carbapenemases, colistin resistance, hypermucoviscous K. pneumoniae

Weijie Cao,1,* Lina Guan,1,* Xiaoning Li,1 Ran Zhang,1 Li Li,1 Suping Zhang,1 Chong Wang,1 Xinsheng Xie,1 Zhongxing Jiang,1 Dingming Wan,1 Xiaohui Chi2 1Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of China; 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Weijie Cao Email caoweijie2003@126.comPurpose: To explore the epidemiological characteristics and risk factors of bloodstream infections (BSI) in patients who develop agranulocytosis fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study also provides a basis for the clinical treatment of BSI.Methods: A retrospective analysis of 397 allo-HSCT patients in the Department of Hematology of our hospital was conducted from January 2013 to December 2017 to analyze the incidence of BSI, the distribution and types of pathogenic bacteria, and drug resistance rates. We also determined whether various parameters are risk factors to BSI, including the patient age, gender, disease type, transplantation method, stem cell source, pre-treatment with anti-thymocyte globulin (ATG), and agranulocytosis time.Results: Among the 397 allo-HSCT patients, 294 had a fever during the period of agranulocytosis, and 52 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 17.7% (52/294). Among the 60 pathogens detected, 43 (71.67%), 10 (16.67%), and 7 (11.67%) were Gram negative strains, Gram positive strains, and fungi, respectively. The most common bacteria were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The detection rate of extended-spectrum β-lactamase (ESBL) was 40.0%, and carbapenem-resistant Enterobacteriaceae (CRE) accounted for 17.9%. Single-factor and multi-factor analyses showed that pre-treatment with ATG, agranulocytosis time (≥ 21 days), and stem cell source were risk factors for BSI.Conclusion: We found that in our hospital, BSIs in allo-HSCT patients are mainly caused by Gram-negative bacteria, and the resistance rate to carbapenem drugs is high. Pre-treatment with ATG, agranulocytosis time (≥ 21 days), and stem cell source are risk factors for BSI.Keywords: hematopoietic stem cell transplantation, agranulocytosis, BSI, pathogenic bacteria, risk factors

Purpose The rise of carbapenem-resistant A. baumannii (CRAB) is considered a public health problem limiting the treatment options. Our current work studied the emergence and mechanisms of colistin-resistance among CRAB isolates in Egypt. Materials and methods Seventeen clinically recovered A. baumannii were identified and screened for their antimicrobial susceptibilities using VITEK-2 system. Colistin susceptibility was evaluated using broth microdilution, and characterization of carbapenem/colistin resistance determinants was performed using whole-genome sequencing (Illumina MiSeq). Results About 52.9% (9/17) were colistin-resistant. PCR results revealed that all isolates carried bla OXA-51-like genes, bla OXA-23-like was detected in 82.3% (14/17) and bla NDM in 23.5% (4/17). Two isolates harboured bla GES-35 and bla OXA-23. Furthermore, genome analysis of seven isolates revealed six belonged to international clone 2 (IC2) while the remaining isolate was a singleton (ST158), representing a clone circulating in Mediterranean/Middle Eastern countries. Conclusion The emergence and high incidence of colistin-resistance among CRAB clinical isolates in Egypt are alarming because it further limits therapy options and requires prudent antimicrobial stewardship and stringent infection control measures. Whole-genome sequence analyses suggest that the resistance to colistin was associated with multiple mutations in the pmrCAB genes. The high incidence of the high-risk lineage IC2 harbouring bla OXA-23-like as well as bla NDM is also of concern.

Aim To compare the sensitivity and specificity before and after the addition of Triton X-100 in the modified Hodge test (MHT) and carbapenem inactivation method (CIM) for the detection of carbapenemase in Acinetobacter baumannii. Materials and methods A total of 135 isolates of A. baumannii (83 carbapenem-resistant and 52 carbapenem-sensitive) were selected and the carbapenemase genotypes were detected using PCR. Carbapenemase phenotypes were tested using the MHT, Triton-MHT (THT), CIM, modified CIM (mCIM), and Triton-CIM (TCIM). Different concentrations (0.05, 0.1, 0.25, and 0.5% v/v) of Triton X-100 were used in the TCIM. Results The sensitivity was determined to be 59.03% (MHT), 100% (THT), 6.02% (CIM), 8.43% (mCIM), 71.08% (TCIM 0.05%), 100% (TCIM 0.1%), 97.59% (TCIM 0.25%), and 96.38% (TCIM 0.5%) in 83 carbapenemase-producing isolates, and the specificity for each of these methods was 100%. Conclusion The addition of Triton X-100 while using the MHT and CIM could significantly improve the sensitivity in the detection of A. baumannii carbapenemase with a specificity of 100%. A concentration of 0.1% v/v Triton X-100 showed the best results in TCIM.

Introduction Intense livestock farming practices enforcing the farmers to use antibiotics as food supplements on a routine basis. Aberrant use of antibiotics is associated with the emergence of antibiotics resistance and resistant superbugs. Keeping in view the current scenario, the present study was designed for the first time from Pakistan with a specific aim to estimate the prevalence of the carbapenem-resistant Klebsiella pneumoniae in veterinary settings and the waste in Pakistan. Methods A total of 138 samples from various veterinary sources were collected by employing a nonprobability sampling technique. Isolation and phenotypic identification of carbapenem-resistant K. pneumoniae were performed according to the CLSI standard. Molecular detection of various antibiotic resistance genes (ARGs) was done through PCR by using specific primers against each ARG. According to the pasture scheme, the multilocus sequence typing (MLST) was performed to characterize the K. pneumoniae sequence types (STs). Results According to the results of the study, overall 9.4% (13/138) isolates were confirmed carbapenem-resistant K. pneumoniae. Among various carbapenem ARGs particularly, the bla NDM-1 was found in 92.3% (12/13) isolates followed by bla OXA-48 84.6% (11/13). MLST results revealed that overall 3 STs were found in the study which includes ST29, ST11, and ST258. Taking together, this is the first study to our best knowledge which demonstrated the prevalence of carbapenem-resistant K. pneumoniae and its various STs prevalent in veterinary settings and the waste of Pakistan. Conclusion Based on the above-mentioned facts, we suggested that veterinary settings and waste are the potential source and reservoir of carbapenem-resistant K. pneumoniae, which may be disseminated to the environment and ultimately can affect the public and companion livestock health.

Introduction Resistance to carbapenem in Gram-negative bacteria is attributable to their ability to produce carbapenemase enzymes. The main objective of this study was to detect the presence of blaOXA-48 genes in carbapenem-resistant uropathogenic Escherichia coli and Klebsiella pneumoniae isolated from urine samples from patients attending Alka Hospital, Jawalakhel, Lalitpur, Nepal. Methods A total of 1013 mid-stream urine samples were collected from patients with suspected urinary tract infection (UTI) between April and September 2018. The identified isolates underwent antibiotic susceptibility testing using the modified Kirby-Bauer disc-diffusion method. Phenotypic carbapenemase production was confirmed by the modified Hodge test, and the blaOXA-48 gene was detected using conventional polymerase chain reaction. Results Out of 1013 urine samples, 15.2% (154/1013) had bacterial growth. Among the isolates, 91.5% (141/154) were Gram-negative bacteria, and E. coli was the most common bacterial isolate (62.9%; 97/154), followed by K. pneumoniae 15.6% (24/154). Among 121 bacterial isolates (97 E. coli isolates and 24 K. pneumoniae isolates), 70.3% (52/121) were multidrug-resistant E. coli and 29.7% (22/121) were multidrug-resistant K. pneumoniae. In addition, 9.1% (11/121) were carbapenem resistant (both imipenem and meropenem resistant). Development of multidrug resistance and development of carbapenem resistance were significantly associated (p

Purpose To develop a rapid EDTA-modified carbapenem inactivation method (reCIM) combined with modified rapid carbapenem inactivation method (mrCIM) to detect carbapenemase and distinguish metallo-β-lactamases from carbapenemases in Enterobacteriaceae in 4 hrs. Materials and methods The sensitivities and specificities of mrCIM and reCIM were retrospectively evaluated in 247 carbapenem-resistant Enterobacteriaceae of which 107 were carbapenemase producers confirmed by PCR and sequencing. In addition, mrCIM and reCIM were prospectively evaluated with 47 carbapenem-resistant enterobacterial isolates. Results The sensitivity and specificity of mrCIM were 96.3% and 97.1% at 2.5 hrs post incubation, and the specificity increased to 98.6% at 3 hrs. The combined mrCIM and reCIM showed a sensitivity of 95.4% and a specificity of 100% at 2.5 hrs post incubation in identifying metallo-β-lactamases, and the sensitivity increased to 97.0% at 3 hrs. These performance characteristics are comparable to mCIM and eCIM; however, compared with mCIM and reCIM tests which need at least 24 hrs to detect results, the mrCIM and reCIM required less than 4 hrs of total work time. Conclusion The combined mrCIM and reCIM can be used to accurately and quickly detect carbapenemase and metallo-β-lactamases in Enterobacteriaceae in 4 hrs and are suitable for routine use in most clinical microbiology laboratories.

Purpose To investigate transitions in resistance mechanisms, virulence characteristics and molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) during 2003-2016 in a major Eastern Chinese medical center. Patients and methods From a total of 2299 K. pneumoniae clinical strains collected from 2003 to 2016, 214 were found to be CRKP isolates and were selected for further study. Characterization of these was conducted by molecular detection of antibiotic resistance markers and virulence determinants, modified carbapenem inactivation method and multilocus sequence typing (MLST). Results In this study, the prevalence of CRKP was increasing over the 14-year period, mirroring a national trend. These CRKP strains were resistant to most of the tested, clinically relevant drugs. The majority of these CRKP strains were positive for carbapenemases, with the Klebsiella pneumoniae carbapenemase (KPC) found to be the dominant type (207/210, 98.6%). The carrier rates of virulence genes uge, entB, fimH, mrkD and ureA increased in 2016, while the ybtA, iucA and irp2 showed a relatively constant trend. From MLST data, ST11 (88.8%, 190/214) was the preponderant sequence type (ST), followed by ST15 (1.9%, 4/214) and ST656 (1.4%, 3/214). Several strains with less common STs (ST690, ST895, ST1823 and ST1384) were also detected, and these too showed high levels of antimicrobial resistance. Conclusion The average national rise in CRKP across China is mirrored in this in-depth analysis of a single hospital, while the prevalence of hypervirulent CRKP (such as ST15) was relatively low as of 2016. Continuous monitoring is necessary to keep track of CRKP and should include the prospect of newly emerging strains with less common STs and the prospect of detecting carbapenem-resistant, carbapenemase-negative Klebsiella pneumoniae.

Background The emergence and spread of carbapenem-resistant Escherichia coli (E. coli) pose a serious threat to human health worldwide. This study aimed to investigate the molecular mechanisms underlying carbapenem resistance and their prevalence among E. coli in China. Methods A collection of 5796 E. coli clinical isolates were collected from the First Affiliated Hospital of Wenzhou Medical University from 2002 to 2017. Sensitivity to antibiotics was determined using the agar dilution method. The detection of carbapenemases production and the prevalence of resistance-associated genes were investigated through modified carbapenem inactivation method (mCIM), PCR and sequencing. The mutations in outer membrane porins genes (ompC and ompF) were also analyzed by PCR and sequencing assays. The effect of efflux pump mechanism on carbapenem resistance was also tested. E. coli were typed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Results A total of 58 strains (1.0%) of carbapenem-resistant E. coli were identified. The strains carrying bla KPC-2 and bla NDM accounted for 22.4% (13/58) and 51.7% (30/58), respectively. Among bla NDM- positive strains, 27 bla NDM genes were assigned to bla NDM-5, while the remaining three strains were bla NDM-1, whereas bla VIM, bla IMP, bla OXA-48, and bla SHV were not found. The CTX-M-type β-lactamase genes accounted for 96.6% (56/58). In addition, bla TEM-1 genes were identified in 58.6% of tested strains. In carbapenem-resistant isolates, mutations in OmpC (the majority of mutated sites were D192G and Q104_F141del, accounting for 54.5%) and OmpF (large deletions S75_V127del, W83_D135del and Q88_D135del) were detected. Of note, the antibiotic resistance was not associated with overexpression of efflux pump. Moreover, MLST categorized the 58 carbapenem-resistant isolates into 19 different sequence types. PFGE analysis revealed that homology among the carbapenem-resistant isolates was low and sporadic. Conclusion The bla NDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital. bla NDM-5 is becoming a new threat to public health and the alteration of outer membrane porins might help further increase the MIC of carbapenem.

Purpose Little is known about the epidemiology and carbapenem-resistance determinants of carbapenem-resistant K. aerogenes (CRKA) isolated from a single medical center. The present study was initiated to characterize the molecular epidemiology and the carbapenem-resistance mechanisms of CRKA isolated during 2012-2018 from a teaching hospital in southwest China, and to investigate the risk factors and clinical outcomes of CRKA infections as well. Methods Pulsed-field gel electrophoresis (PFGE) was employed for epidemiological analysis. PCR amplification and DNA sequencing were used to examine the antibiotic-resistance determinants. Plasmids were extracted and characterized by PCR-based replicon typing and conjugation assays. In order to further investigate the risk factors and clinical outcomes of CRKA infections, a retrospective case-control study was also performed. Results PFGE analysis showed 32 different PFGE patterns among the 36 non-duplicated CRKA strains collected. Most of the isolates harbored multi-drug resistance (MDR) genes, including 2 (5.6%) carrying bla NDM-1, 1 (2.8%) harboring bla KPC-2, 13 (36.1%) carrying ESBL genes, 23 (63.9%) carrying ampC genes, 34 (94.4%) carrying quinolone resistance determinants (QRD) genes and 9 (25%) carrying aminoglycoside resistance determinants (ARD) genes. The outer membrane porins, OmpE35 and OmpE36, were, respectively, lost in 4 and 2 isolates. The efflux pump inhibition experiments were positive in 25 (69.4%) of the CRKA strains. Multivariate analysis indicated that hypo-albuminaemia, invasive procedures, and carbapenem exposure were independent risk factors for acquiring CRKA infections. Conclusion No clonality relationship was identified among most of the 36 CRKA isolates. The over-expression of ESBLs and AmpC coupled with the efflux pumps contributed to carbapenem resistance in K. aerogenes. Additionally, this is the first report of CRKA isolate co-harboring bla NDM-1, bla CTX-M-15, bla EBC, bla ACC, acc (6')-Ib, armA, qnrD and loss of OmpE36 in China. Hypo-albuminaemia, invasive procedures and carbapenem exposure were associated with acquisition of CRKA infections.

Background Bacterial resistance to antibiotics has become a major public health concern. This study aimed to determine the resistance mechanisms to carbapenem in clinical isolates of Pseudomonas aeruginosa. Methods A total of 62 clinical isolates of carbapenem-resistant P. aeruginosa (CRPA) were collected from 2015 to 2017. Imipenem (IPM)-EDTA disk synergy test was used to screen strains that produced metallo-β-lactamase. In addition, the genes for outer membrane protein OprD2, metallo-β-lactamase and mexR gene were amplified and sequenced. Expression of mexA was detected by real-time PCR. Results Disk synergy test showed that 51.6% (32/62) of the strains were positive for metallo-β-lactamase. PCR showed that 84.4% of the strains were SIM-positive (27/32), 15.6% of the strains were IMP-positive (5/32), and 12.5% of the strains were VIM-positive (4/32). SPM-positive and GIM-positive strains were not detected. In addition, 5 of the 62 strains had small deletions and/or point mutations in OprD2. Three strains had a high expression of mexA, while eight strains were positive for the regulatory gene mexR with no mutations detected by DNA sequencing. Conclusion Expression of metallo-β-lactamase is the main resistance mechanism of P. aeruginosa to carbapenem. Mutations in OprD2 and/or the overexpression of efflux pump MexAB-OprM may contribute to P. aeruginosa resistance to carbapenem.

Background The emergence and spread of carbapenem-resistant Enterobacter cloacae (CR-ECL) have posed a serious threat to clinical management. This retrospective study assessed the epidemiological characteristics of CR-ECL to explore the risk factors and predictors of mortality in patients with CR-ECL infection. Methods We performed a retrospective 1:2 case-control study of hospitalized patients from January 2014 to December 2017. A total of 85 consecutive unique CR-ECL strains comprised the case group, and 170 matched patients with carbapenem-susceptible Enterobacter cloacae (CS-ECL) infection at the same period as the control group. Isolates were screened for potential resistance genes by polymerase chain reaction (PCR) and molecular typing was performed by multilocus sequence typing (MLST). Results The results of drug resistance gene detection showed that blaNDM-1 was the most common carbapenem resistance gene. The MLST results showed that ST51 was the predominant epidemic type, followed by ST88. ICU admission (P

Purpose The incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections (BSIs) is increasing globally; however, little has been reported on the risk factors and outcomes of CRKP BSIs in central China. This study aimed to determine the clinical risk factors for CRKP BSIs and the outcomes of CRKP BSIs. Patients and Methods We performed a case-control study of 239 patients with K. pneumoniae BSIs who were treated at Henan Provincial People's Hospital between July 2017 and July 2018. The cases (n=98, 41%) had CRKP BSIs, and the controls (n=141, 59%) had non-carbapenem-resistant K. pneumoniae (non-CRKP) BSIs. Antimicrobial sensitivity was determined using automated broth microdilution and an agar disk diffusion method. Data were obtained from clinical and laboratory records. Multivariate logistic regression and Pearson chi-square tests were used to identify clinical factors and outcomes associated with carbapenem resistance. Results Risk factors for carbapenem resistance included recent carbapenem use (odds ratio [OR]: 9.98, 95% confidence interval [CI]: 5.2-17.1, P

Purpose Colistin alone may not be sufficient for treating carbapenem-resistant Acinetobacter baumannii (CRAB); thus, efforts are needed to increase treatment success rates. We compared the effects of colistin plus carbapenem therapy versus colistin monotherapy in treating pneumonia caused by CRAB and attempted to identify specific populations or factors that could benefit from combination therapy. Methods We retrospectively collected data on cases of CRAB pneumonia. The patients were divided into colistin plus carbapenem therapy and colistin monotherapy groups. The primary outcome was 14-day mortality. The secondary outcomes were in-hospital mortality, clinical improvement at days 2 and 14, and microbiological improvement at day 14. Results Of 160 cases meeting criteria for CRAB pneumonia, 83 (52%) and 77 (48.0%) were treated with carbapenem combination therapy or colistin monotherapy, respectively. Among these patients, 50 (63.3%) in the combination group and 27 (39.7%) in the monotherapy group had Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II scores >24 points (p=0.010). Overall, there was no significant difference in 14-day mortality between the combination and monotherapy groups (24.1% vs 20.8%, p=0.616). Clinical improvement and sputum-negative conversion also showed no significant difference. After adjusting for disease severity according to APACHE II score, the 14-day mortality was significantly lower in the combination group than in the monotherapy group among patients with APACHE II scores of 25-29 points (9.1% vs 53.8%, P=0.020). Conclusion Despite more severe conditions, compared with colistin monotherapy, colistin plus carbapenem combination therapy showed equivalent primary mortality outcome in treating CRAB pneumonia. Combination therapy was more effective in patients with APACHE II score ranging from 25 to 29 points.

Yunying Wang,1 Hui Liu,2 Lijun Zhang,1 Bin Sun1 1Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 2Department of Blood Transfusion, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of ChinaCorrespondence: Bin SunDepartment of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, No. 74 Linjiang Road, Yuzhong District, Chongqing, People’s Republic of ChinaTel +86 23-62887812Fax +86 23-63703244Email sunbin@cqmu.edu.cnPurpose: Infection and transmission of carbapenem-resistant Aeromonas is a serious threat to public health. Rapid and accurate detection carbapenem-resistant of these organisms is essential for reasonable treatment and infection control. This study aimed to find a simple and effective method to detect carbapenem-resistant phenotype in Aeromonas.Methods: A total of 131 clinical preserved Aeromonas strains were used in this study. The carbapenemase genes were detected by PCR. Modified carbapenem inactivation method (mCIM) in conjunction with EDTA-modified carbapenem inactivation method (eCIM) and simplified carbapenem inactivation method (sCIM) were performed to detect carbapenemases. We also designed a simple method, carbapenem inactivation method using supernatant (CIM-s), to detect the carbapenemase activity in the medium.Results: Of the 131 Aeromonas strains, 79 contained carbapenemase genes, including 68 blaCphA, 6 blaKPC-2, 2 blaNDM-1 and 3 blaKPC-2+CphA. However, routine antibiotic susceptibility testing could not completely identify carbapenemase-producing Aeromonas. In phenotypic assays, the sensitivity and specificity of mCIM were 100%. The combined mCIM and eCIM could distinguish serine carbapenemase and metallo-β-carbapenemases except co-producing organisms. The sensitivity and specificity of sCIM were 92.4% and 100%, respectively, which could not detect CphA totally. CIM-s results indicate that these carbapenemases could secrete into the medium to perform their hydrolytic activities and had a sensitivity and specificity of 97.5% and 100%, respectively.Conclusion: The combination of mCIM and eCIM can effectively detect and distinguish different types of carbapenemase in Aeromonas, and could be used as an important supplement approach to the antibiotic susceptibility testing.Keywords: Aeromonas, modified carbapenem inactivation method, carbapenemase, multidrug resistant, phenotypic detection

Tesfa Addis,1,2 Shambel Araya,1 Kassu Desta1 1Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia; 2National Clinical Bacteriology and Mycology Reference Laboratory, Ethiopian Public Health Institute, Addis Ababa, EthiopiaCorrespondence: Tesfa AddisNational Clinical Bacteriology and Mycology Reference Laboratory, Ethiopian Public Health Institute, P.O. Box 1242, Addis Ababa, EthiopianTel +251 913 892 676Email tesfaaddis12@gmail.comPurpose: Pseudomonas aeruginosa is a common cause of nosocomial infections with associated morbidity and mortality because the organism is unresponsive to commonly available antimicrobials. This study was undertaken to determine the multiple drug-resistant (MDR), extensive drug-resistant (XDR) and pan drug-resistant (PDR) phenotype of P. aeruginosa and its carbapenemase production rate from presumptive isolates stored in the biobank at the Ethiopian Public Health Institute (EPHI).Methods: A cross-sectional study was conducted at the EPHI laboratory, Addis Ababa, Ethiopia from March to June 2021. Stored isolates of Pseudomonas spp. which had been characterized by manual identification methods were further processed for species-level identification (ID) and antimicrobial susceptibility testing (AST) using a Becton Dickinson (BD) Phoenix automated system. The isolates were analyzed for carbapenemase enzyme production using the modified Carbapenem Inactivation Method (mCIM). The data analysis was done using SPSS version 20 software.Results: In this study, 110 presumptive Pseudomonas isolates from a biobank were re-analyzed, 100 of them were found to be Pseudomonas and among these P. aeruginosa accounted for 98% and P. putida accounted for 2%. The majority of isolates were recovered from wound (46%) specimens followed by ear swabs (18%). The highest level of resistance was observed against ceftazidime (35%) and the lowest level of resistance was observed against amikacin (2%). Twenty-seven isolates were identified as candidates for carbapenemase enzyme production testing, of which only 3/27 (11%) isolates were detected as carbapenemase enzyme producers.Conclusion: This study shows an increasing rate of MDR and XDR isolates and the appearance of PDR in P. aeruginosa strains; this is a serious problem in Ethiopia. The lack of newer anti-pseudomonal antibiotics adds to the problem. In order to alleviate this, infection prevention activities should be promoted, and treatment of bacterial infections should be guided by antibiotic susceptibility test results.Keywords: P. aeruginosa, antimicrobial resistance, carbapenemase enzyme, Ethiopia

Background The challenge of drug resistance to carbapenems is of international concern with leading to increased hospital lengths of stay, costs, and mortality rates. How to get rid of the vicious cycle of drug resistance, new drugs, and re-resistance, and even the emergence of all-drug-resistant bacteria that humans cannot cope with, are the major challenges we face. To date, data about pharmaceutical interventions on the use of carbapenems are currently limited. Patients and methods A retrospective cohort study was conducted to compare pre- and post-intervention in Tongde Hospital of Zhejiang Province. Pharmaceutical interventions were performed in the post-intervention group, including real time monitoring of medication orders, educative group activities, and making interventions to physicians. Intervention acceptance and outcomes, including the length of hospital stay, readmission rates, 30-day mortality, and utilization of carbapenems, which was evaluated by the daily defined doses (DDDs), the days of therapy (DOTs), and the cost of carbapenems, were reviewed. Results During the study, 593 interventions were provided by clinical pharmacists with an average acceptance rate of 82.79%. Compared with the pre-intervention group, prescriptions of carbapenems for pathogen-directed therapy were improved significantly in the post-intervention group (59.27% vs 21.74%, p=0.022). The DDDs decreased from 281.96 to 174.28 and DOTs decreased from 9.19 to 5.18 after pharmaceutical intervention, and the pharmaceutical interventions had significantly lower mean total cost of carbapenems ($13,828.8 vs $8137.1, p=0.004) and length of hospital stay (9.3±1.5 vs 15.9±2.2, p=0.014). There was a significant reduction in 30-day mortality in the post-intervention group (9.46% vs 17.86%, p=0.013) while there were no differences found in the 30-day readmission (20.19% vs 20.66%, p=0.99). Conclusion Implementation of pharmaceutical interventions in our hospital successfully improved the appropriateness of carbapenem prescribing overall, and reduced the DDDs, DOTs, length of hospital day, and cost of carbapenems.

Purpose This observational study aimed to identify the independent risk factors for both the acquisition and mortality of carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) bacteremia and further assess the in vitro antimicrobial activities of ceftazidime–avibactam (CAZ/AVI) and aztreonam–avibactam (ATM/AVI) against recent CRE bacteremic isolates. Patients and methods This observational study was conducted to reveal the risk factors and mortality rate for CP-CRE bacteremia between 2012 and 2018 and also evaluate the in vitro antimicrobial activities of CAZ/AVI and ATM/AVI against recent CRE bacteremic isolates from 2016 to 2018. Results A total of 81 non-repetitive isolates were collected from 2012 to 2018, with 67.90% (55/81) being CP-CRE. Old age (P = 0.01), transfusion [odds ratio (OR): 17.19; 95% CI: 3.15–93.72; P = 0.001], longer ICU stay (P = 0.02), cancer (OR: 15.91; 95% CI: 3.56–71.37; P < 0.001), and previous carbapenem exposure (OR: 27.86; 95% CI: 5.03–154.19; P = 0.001) were identified as independent risk factors for the acquisition of CP-CRE bacteremia compared with the ESBL bacteremia. The in vitro antimicrobial activities of CAZ/AVI and ATM/AVI against the CRE bacteremic isolates from 2016 to 2018 showed a respective susceptibility rate of 70.68% (41/58) and 100.00% (58/58). Conclusion The findings indicated that both CP-CRE/non-CP-CRE stratification and CRE resistance mechanism determination were necessary for better guiding the clinical management of CRE bacteremia: ATM/AVI probably works with both non-CP-CRE and CP-CRE bacteremia, even the most notorious double-carbapenemase producer with porin loss/deficiency, whereas CAZ/AVI works with most of the non-CP-CRE and KPC-producers in the region.

Purpose Extensively drug-resistant Acinetobacter baumannii (XDRAB) is an important cause of nosocomial pneumonia with limited therapeutic options. Colistin-based regimen is the recommended treatment. Which drugs should be combined with colistin remains uncertain. The aim of this study was to investigate the clinical outcomes of patients with XDRAB pneumonia who were treated with colistin, combined with either 6-g sulbactam or carbapenems, in the setting of high MIC to sulbactam. Patients and methods In this prospective cohort study, hospitalized patients diagnosed with XDRAB pneumonia in Phramongkutklao Hospital were enrolled. The primary outcome was 28-day mortality. Secondary outcomes were 7- and 14-day mortality, length of stay, ventilator days and factors associated with mortality. Results From 1 July 2016 to 30 September 2017, 182 patients were included; 92 received colistin plus sulbactam and 90 received colistin plus carbapenems. Most of the patients were males diagnosed with ventilator-associated pneumonia in medical intensive care unit. Overall mortality rates at 7, 14, 28 days were 24.2%, 37.4%, and 53.3%, respectively. Mortality rates did not differ between sulbactam group and carbapenem groups at 7 days (19.6% vs 28.9%, p-value 0.424, adjusted HR 1.277; 95% CI = 0.702-2.322), 14 days (34.8% vs 40%, p = 0.658, adjusted HR 1.109; 95% CI = 0.703-1.749) and 28 days (51.1% vs 55.6%, p = 0.857, adjusted HR 1.038; 95% CI = 0.690-1.562). Length of stay, ICU days and ventilator days did not differ. Complications of treatment including acute kidney injury were not statistically different. Conclusion In XDRAB pneumonia with high MIC to sulbactam, differences in mortality rates were not statistically significant between colistin plus 6-g sulbactam and colistin plus carbapenems.

Background and aim: Currently, the rate of hospital-acquired infections due to drug-resistant Pseudomonas aeruginosa strains shows an increasing trend and remains one of the principal reasons for mortalilty in burn patients. This study aimed to investigate the prevalence of genes conferring resistance to carbapenems in P. aeruginosa isolates from burn patients. Methods: A total of 50 P. aeruginosa isolates were tested for antibiotic susceptibility and presence of multidrug-resistant (MDR) and extensively drug resistant (XDR) isolates, using phenotypic tests. Screening for genes conferring resistance to carbapenems was investigated by multiplex PCR method. Results: Susceptibility testing demonstrated the highest resistance against amikacin, ceftazidime (n=44/88% each), and gentamicin (84%), while colistin sulfate was the most effective antibiotic. The rate of MDR and XDR isolates was revealed as 50% and 40% respectively. We detected the following carbapenemase genes: blaNDM (32%), followed by blaOXA-48 (18%), and blaBIC-1 (14%). This study revealed a high antibiotic resistance in P. aeruginosa isolates with a total of 40% and 50% MDR and XDR isolates respectively, and 70% carbapenem resistance. The prevalence of carbapenem conferring genes tested among carbapenem-resistant isolates was demonstrated as 65.7%. Conclusion: Due to the prevalence of P. aeroginosa strains carrying blaOXA-48 and blaNDM genes in our hospital, more attention and implementation of effective control measures against nosocomial infection are recommended.

Aims and Objectives: The emergence and spread of extended-spectrum β-lactamases (ESBLs) particularly CTX-M producing multi-drug-resistant (MDR) Escherichia coli (E. coli) is one of the greatest challenges for community health globally. The study investigated the phenotypic and genotypic characteristics of ESBLs-producing E. coli recovered from pediatric patients from Shenzhen Children’s Hospital, China. Materials and methods: Present study, a total of 2,670 isolates of E. coli were collected from Shenzhen Children’s Hospital, China of which 950 were ESBLs producer. ESBLs production was confirmed by using the combination disc diffusion method, and antimicrobial susceptibility test was detected. In addition, β-lactamase-producing genes and co-existence of carbapenem/colistin resistance genes were determined by PCR assay and sequencing. The diversity and phylogenetic relationship were determined by multi-locus sequence typing method. Results: Thirty-five percent (n=950) prevalence of ESBLs-producing E. coli we reported in Shenzhen, China of which 50 ESBLs producing E. coli were randomly selected for a further characterization. All 50 ESBLs- producing E. coli isolates revealed MDR phenotype and 100% were resistant to Ampicillin/sulbactam, Ampicillin, Cefazolin, and Ceftriaxone. All 50 ESBLs producers harbored at least one type of β-lactamase gene particular blaCTX-M. The PCR and sequencing revealed the most common CTX-M subtype was blaCTX-M-15 (n=18), followed by blaCTX-M-14 (n=16), blaCTX-M-90 (n=9), blaCTX-M-55 (n=3), blaCTX-M-27, blaCTX-M-101, and blaCTX-M-211 each (n=1). Co-existence of blaCTX-M with blaTEM, blaSHV, blaGES, and blaVEB was detected in few isolates. Among identified sequence types, ST131 (12%) was more dominant in ESBLs-producing E. coli. Phylogenetic group A was the most prominent group among the ESBLs-producing E. coli based on multiplex PCR. Conclusion: Our study shows the prevalence of blaCTX-M gene in ESBLs-producing E. coli in pediatric patients in Shenzhen, China. We highlight the importance to monitor the emergence and trends of ESBLs-producing isolates in a pediatric healthcare setting.