{"title":"Genomic diversity of β-lactamase producing Pseudomonas aeruginosa in Iran; the impact of global high-risk clones","authors":"Nazila Ahmadi, Himen Salimizand, Abolfazl Rafati Zomorodi, Jalileh Ebn Abbas, Rashid Ramazanzadeh, Fakhri Haghi, Sepideh Hassanzadeh, Mojdeh Jahantigh, Mojtaba Shahin","doi":"10.1186/s12941-024-00668-5","DOIUrl":"https://doi.org/10.1186/s12941-024-00668-5","url":null,"abstract":"Hospital-acquired infections caused by multidrug-resistant Pseudomonas aeruginosa incline hospital stay and costs of treatment that resulted in an increased mortality rate. The frequency of P. aeruginosa high-risk clones producing carbapenemases was investigated in our clinical samples. In this cross-sectional study, 155 non-repetitive P. aeruginosa isolates were included from different medical centers of Iran. Antibiotic susceptibility testing was determined, and the presence of β-lactamases were sought by phenotypic and genotypic methods. The clonal relationship of all isolates was investigated, and multi-locus sequence typing (MLST) was used for finding the sequence types of carbapenemase-producers. The agent with highest percent susceptibility rate was recorded for colistin (94.9%). MOX and FOX were found both as low as 1.95% (3/155). The most frequent narrow spectrum β-lactamase was SHV with 7.7% (12/155) followed by PER, OXA-1, and TEM with the frequency of 7.1% (11/155), 3.2% (5/155), and 1.3% (2/155), respectively. Carbapenemases were detected in 28 isolates (18%). The most frequent carbapenemase was IMP with 9% (14/155) followed by NDM, 8.4% (13/155). OXA-48 and VIM were also detected both per one isolate (0.65%). MLST of carbapenem resistant P. aeruginosa isolates revealed that ST244, ST664, ST235, and ST357 were spread in subjected clinical settings. REP-PCR uncovered high genomic diversity in our clinical setting. Clonal proliferation of ST235 strain plays a key role in the propagation of MDR pattern in P. aeruginosa. Our data showed that high-risk clones has distributed in Iran, and programs are required to limit spreading of these clones.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139461045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular characterization of extended-spectrum β-lactamase-producing Escherichia coli isolated from lower respiratory tract samples between 2002 and 2019 in the Central Slovenia region","authors":"Katja Hrovat, Katja Molan, Katja Seme, Jerneja Ambrožič Avguštin","doi":"10.1186/s12941-023-00664-1","DOIUrl":"https://doi.org/10.1186/s12941-023-00664-1","url":null,"abstract":"Antibiotic resistance is one of the most serious global health problems and threatens the effective treatment of bacterial infections. Of greatest concern are infections caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC). The aim of our study was to evaluate the prevalence and molecular characteristics of ESBL-EC isolated over an 18-year pre-COVID period from lower respiratory tract (LRT) samples collected from selected Slovenian hospitals. All isolates were identified by MALDI-TOF and phenotypically confirmed as ESBLs by a disk diffusion assay. Using a PCR approach, 487 non-repetitive isolates were assigned to phylogroups, sequence type groups, and clonal groups. Isolates were also screened for virulence-associated genes (VAGs) and antimicrobial resistance genes. The prevalence of ESBL-EC isolates from LRT in a large university hospital was low (1.4%) in 2005 and increased to 10.8% by 2019. The resistance profile of 487 non-repetitive isolates included in the study showed a high frequency of group 1 blaCTX-M (77.4%; n = 377), blaTEM (54.4%; n = 265) and aac(6')-Ib-cr (52%; n = 253) genes and a low proportion of blaSHV and qnr genes. Isolates were predominantly assigned to phylogroup B2 (73.1%; n = 356), which was significantly associated with clonal group ST131. The ST131 group accounted for 67.6% (n = 329) of all isolates and had a higher number of virulence factor genes than the non-ST131 group. The virulence gene profile of ST131 was consistent with that of other extraintestinal pathogenic E. coli (ExPEC) strains and was significantly associated with ten of sixteen virulence factor genes tested. Using ERIC-PCR fingerprinting, isolates with the same ERIC-profile in samples from different patients, and at different locations and sampling dates were confirmed, indicating the presence of “hospital-adapted” strains. Our results suggest that the ESBL-EC isolates from LRT do not represent a specific pathotype, but rather resemble other ExPEC isolates, and may be adapted to the hospital environment. To our knowledge, this is the first study of ESBL-EC isolated from LRT samples collected over a long period of time.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139461173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impact of Helicobacter pylori colonization density and depth on gastritis severity.","authors":"Jianxiang Peng, Jinliang Xie, Dingwei Liu, Kaijie Yang, Shuang Wu, Dongsheng Liu, Deqiang Huang, Yong Xie","doi":"10.1186/s12941-024-00666-7","DOIUrl":"10.1186/s12941-024-00666-7","url":null,"abstract":"<p><strong>Background and objectives: </strong>Helicobacter pylori (H. pylori) infection is the most common etiology of chronic gastric. H. pylori gastritis would gradually evolve into gastric atrophy, intestinal metaplasia, dysplasia and malignant lesions. Herein, this study aimed to investigate the potential impact of H. pylori colonization density and depth on the severity of histological parameters of gastritis.</p><p><strong>Methods: </strong>A prospective monocentric study was conducted from December 2019 to July 2022, enrolling patients with confirmed chronic H. pylori infection via histopathological evaluation. H. pylori colonization status was detected by immunohistochemical staining, pathological changes of gastric specimens were detected by hematoxylin eosin staining. Epidemiological, endoscopic and histopathological data were collected.</p><p><strong>Results: </strong>A total of 1120 patients with a mean age of 45.8 years were included. Regardless of the previous history of H. pylori eradication treatment, significant correlations were observed between the density and depth of H. pylori colonization and the intensity of gastritis activity (all P < 0.05). Patients with the lowest level of H. pylori colonization density and depth exhibited the highest level of mild activity. In whole participants and anti-H. pylori treatment-naive participants, H. pylori colonization density and depth were markedly correlated with the severity of chronic gastritis and gastric atrophy (all P < 0.05). H. pylori colonization density (P = 0.001) and depth (P = 0.047) were significantly associated with ulcer formation in patients naive to any anti-H. pylori treatment. No significant associations were observed between the density and depth of H. pylori colonization and other histopathological findings including lymphadenia, lymphoid follicle formation and dysplasia.</p><p><strong>Conclusions: </strong>As the density and depth of H. pylori colonization increased, so did the activity and severity of gastritis, along with an elevated risk of ulcer formation.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10785438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139432097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of rapid syndromic diagnostic testing of gastrointestinal pathogens as a clinical decision support tool in a pediatric emergency department.","authors":"Hyun Mi Kang, In Hyuk Yoo, Dae Chul Jeong","doi":"10.1186/s12941-023-00662-3","DOIUrl":"10.1186/s12941-023-00662-3","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to investigate the role of rapid syndromic diagnostic testing of gastrointestinal pathogens as a clinical decision support tool in a pediatric emergency department (ED) by comparing clinical decision and patient outcome parameters pre- and post-implementation.</p><p><strong>Methods: </strong>This was a big data analytical study of children < 18 years old without any underlying diseases, that visited the ED with acute moderate to severe diarrhea during a 34-month period from 2018 to 2022 using Seoul St. Mary's hospital's healthcare corporate data warehouse to retrieve demographic, clinical, and laboratory parameters. Outcome measures pre- and post-implementation of a rapid syndromic multiplex gastrointestinal panel (GI panel) were compared.</p><p><strong>Results: </strong>A total of 4,184 patients' data were included in the analyses. Broad spectrum antibiotics were prescribed at a significantly lower rate to patients presenting with acute infectious diarrhea at discharge from the ED (9.9% vs 15.8%, P < 0.001) as well as upon admission (52.2% vs 66.0%, P < 0.001) during the post-implementation period compared to the pre-implementation period. Although the duration of ED stay was found to be significantly longer (6.5 vs 5.5 h, P < 0.0001), the rate of ED revisit due to persistent or aggravated symptoms was significantly lower (Δ in intercept, β = -0.027; SE = 0.013; P = 0.041), and the admission rate at follow up after being discharged from the ED shown to be significantly lower during the post-implementation period compared to the pre-implementation period (0.8% vs. 2.1%, P = 0.001, respectively). No significant difference in disease progression was observed (P = 1.000).</p><p><strong>Conclusion: </strong>Using the GI panel in the ED was shown to decrease broad spectrum antibiotic prescribing practices and reduce revisits or admission at follow up by aiding clinical decisions and improving patient outcome.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10770992/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139105769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sumi Yoon, Min Eui Hong, Soon Auck Hong, Tae-Hyoung Kim, Mi-Kyung Lee
{"title":"Prevalence estimation of Tropheryma whipplei in duodenal biopsy tissues of Koreans.","authors":"Sumi Yoon, Min Eui Hong, Soon Auck Hong, Tae-Hyoung Kim, Mi-Kyung Lee","doi":"10.1186/s12941-023-00658-z","DOIUrl":"10.1186/s12941-023-00658-z","url":null,"abstract":"<p><p>Whipple's disease caused by Tropheryma whipplei is difficult to diagnose because of a broad spectrum of manifestations and non-specific clinical signs. In the current global era, the incidence of duodenal infection/inflammation caused by T. whipplei in Korea may has been underestimated. Here we estimated the prevalence of T. whipplei in duodenal biopsy tissues of Koreans using real-time PCRs (RT-PCRs). A total of 252 duodenal biopsy tissues were collected from Korean patients who underwent esophagogastroduodenoscopy and duodenal biopsy. DNA extracted from the duodenal biopsy tissues was analyzed using three RT-PCRs targeting T. whipplei-specific regions of the 16S-23S rRNA intergenic spacer, hsp65, and Dig15 in parallel. In the samples positive in RT-PCRs, direct sequencing was performed for each RT-PCR target. The prevalence of T. whipplei was estimated based on the RT-PCR and sequencing results. Among the analyzed samples, T. whipplei was not detected. The prevalence of T. whipplei in duodenal biopsy tissues of Koreans was estimated to be less than 0.4%. This is the first study to attempt to detect T. whipplei in duodenal biopsy tissues of Koreans and estimate its prevalence. Our findings infer that while T. whipplei carriers exist in Korea, the incidence of duodenal infection/inflammation caused by T. whipplei is extremely rare.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10765791/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139085595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JongHoon Hyun, Myeongjee Lee, Inkyung Jung, Eunhwa Kim, Seung Min Hahn, Yu Ri Kim, Sungmin Lim, Kyong Ihn, Min Young Kim, Jong Gyun Ahn, Joon-Sup Yeom, Su Jin Jeong, Ji-Man Kang
{"title":"Changes in tuberculosis risk after transplantation in the setting of decreased community tuberculosis incidence: a national population-based study, 2008-2020.","authors":"JongHoon Hyun, Myeongjee Lee, Inkyung Jung, Eunhwa Kim, Seung Min Hahn, Yu Ri Kim, Sungmin Lim, Kyong Ihn, Min Young Kim, Jong Gyun Ahn, Joon-Sup Yeom, Su Jin Jeong, Ji-Man Kang","doi":"10.1186/s12941-023-00661-4","DOIUrl":"10.1186/s12941-023-00661-4","url":null,"abstract":"<p><strong>Background: </strong>Transplant recipients are immunocompromised and vulnerable to developing tuberculosis. However, active tuberculosis incidence is rapidly declining in South Korea, but the trend of tuberculosis infection among transplant recipients has not been elucidated. This study aimed to evaluate the risk of active tuberculosis after transplantation, including risk factors for tuberculosis and standardized incidence ratios, compared with that in the general population.</p><p><strong>Methods: </strong>This retrospective study was conducted based on the South Korean health insurance review and assessment database among those who underwent transplantation (62,484 recipients) between 2008 and 2020. Tuberculosis incidence was compared in recipients treated during higher- (2010-2012) and lower-disease burden (2016-2018) periods. Standardized incidence ratios were analyzed using the Korean Tuberculosis Surveillance System. The primary outcome was the number of new tuberculosis cases after transplantation.</p><p><strong>Results: </strong>Of 57,103 recipients analyzed, the overall cumulative incidence rate 1 year after transplantation was 0.8% (95% confidence interval [CI]: 0.7-0.8), significantly higher in the higher-burden period than in the lower-burden period (1.7% vs. 1.0% 3 years after transplantation, P < 0.001). Individuals who underwent allogeneic hematopoietic stem cell transplantation had the highest tuberculosis incidence, followed by those who underwent solid organ transplantation and autologous hematopoietic stem cell transplantation (P < 0.001). The overall standardized incidence ratio was 3.9 (95% CI 3.7-4.2) and was the highest in children aged 0-19 years, at 9.0 (95% CI 5.7-13.5). Male sex, older age, tuberculosis history, liver transplantation, and allogeneic hematopoietic stem cell transplantation were risk factors for tuberculosis.</p><p><strong>Conclusions: </strong>Transplant recipients are vulnerable to developing tuberculosis, possibly influenced by their immunocompromised status, solid organ transplant type, age, and community prevalence of tuberculosis. Tuberculosis prevalence by country, transplant type, and age should be considered to establish an appropriate tuberculosis prevention strategy for high-risk groups.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10765802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139085594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salma W. Elsayed, Reem A. Elghaish, Eman Badr, Shaimaa F. Mouftah, Nehal A. Saif, Iman S. Naga, Ahmed H. Shata, Ben Pascoe, Samuel K. Sheppard, Mohamed Elhadidy
{"title":"Recombination-mediated dissemination of Methicillin-resistant S. aureus clonal complex 1 in the Egyptian health care settings","authors":"Salma W. Elsayed, Reem A. Elghaish, Eman Badr, Shaimaa F. Mouftah, Nehal A. Saif, Iman S. Naga, Ahmed H. Shata, Ben Pascoe, Samuel K. Sheppard, Mohamed Elhadidy","doi":"10.1186/s12941-023-00659-y","DOIUrl":"https://doi.org/10.1186/s12941-023-00659-y","url":null,"abstract":"Methicillin-resistant Staphylococcus aureus (MRSA) is a rapidly evolving pathogen that is frequently associated with outbreaks and sustained epidemics. This study investigated the population structure, resistome, virulome, and the correlation between antimicrobial resistance determinants with phenotypic resistance profiles of 36 representative hospital-acquired MRSA isolates recovered from hospital settings in Egypt. The community-acquired MRSA lineage, clonal complex 1 (CC1) was the most frequently detected clone, followed by three other globally disseminated clones, CC121, CC8, and CC22. Most isolates carried SCCmec type V and more than half of isolates demonstrated multi-drug resistant phenotypes. Resistance to linezolid, a last resort antibiotic for treating multidrug resistant MRSA, was observed in 11.11% of the isolates belonging to different genetic backgrounds. Virulome analysis indicated that most isolates harboured a large pool of virulence factors and toxins. Genes encoding aureolysin, gamma hemolysins, and serine proteases were the most frequently detected virulence encoding genes. CC1 was observed to have a high pool of AMR resistance determinants including cfr, qacA, and qacB genes, which are involved in linezolid and quaternary ammonium compounds resistance, as well as high content of virulence-related genes, including both of the PVL toxin genes. Molecular clock analysis revealed that CC1 had the greatest frequency of recombination (compared to mutation) among the four major clones, supporting the role of horizontal gene transfer in modulating AMR and hypervirulence in this clone. This pilot study provided evidence on the dissemination success of CA-MRSA clone CC1 among Egyptian hospitals. Co-detection of multiple AMR and virulence genes in this lineage pose a broad public health risk, with implications for successful treatment. The results of this study, together with other surveillance studies in Egypt, should be used to develop strategies for controlling MRSA infections in Egyptian health-care settings.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138682708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ángel Rodríguez-Villodres, José Manuel Ortiz de la Rosa, Raquel Valencia-Martin, Francisco Jiménez Parrilla, Guillermo Martín-Gutiérrez, Natividad Márquez Patiño, Estela Perea Cruz, María Teresa Sánchez Jiménez, Antonio Pavón Delgado, José Miguel Cisneros, José Antonio Lepe
{"title":"Implementation of a PCR-based strategy to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit","authors":"Ángel Rodríguez-Villodres, José Manuel Ortiz de la Rosa, Raquel Valencia-Martin, Francisco Jiménez Parrilla, Guillermo Martín-Gutiérrez, Natividad Márquez Patiño, Estela Perea Cruz, María Teresa Sánchez Jiménez, Antonio Pavón Delgado, José Miguel Cisneros, José Antonio Lepe","doi":"10.1186/s12941-023-00657-0","DOIUrl":"https://doi.org/10.1186/s12941-023-00657-0","url":null,"abstract":"To evaluate the clinical and epidemiological impact of a new molecular surveillance strategy based on qPCR to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit (NICU). We design a specific qPCR for the detection of S. marcescens in rectal swabs of patients admitted to a NICU. We divided the surveillance study into two periods: (a) the pre-PCR, from the outbreak declaration to the qPCR introduction, and (b) the PCR period, from the introduction of the qPCR until the outbreak was solved. In all cases, S. marcescens isolates were recovered and their clonal relationship was analysed by PFGE. Control measures were implemented during the outbreak. Finally, the number of bloodstream infections (BSI) was investigated in order to evaluate the clinical impact of this molecular strategy. Nineteen patients colonized/infected by S. marcescens were detected in the pre-PCR period (October 2020–April 2021). On the contrary, after the PCR implementation, 16 new patients were detected. The PFGE revealed 24 different pulsotypes belonging to 7 different clonal groups, that were not overlapping at the same time. Regarding the clinical impact, 18 months after the qPCR implementation, no more outbreaks by S. marcescens have been declared in the NICU of our hospital, and only 1 episode of BSI has occurred, compared with 11 BSI episodes declared previously to the outbreak control. The implementation of this qPCR strategy has proved to be a useful tool to control the nosocomial spread of S. marcescens in the NICU.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138576650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison of the inoculum effect of in vitro antibacterial activity of Imipenem/relebactam and Ceftazidime/avibactam against ESBL-, KPC- and AmpC-producing Escherichia coli and Klebsiella pneumoniae","authors":"Xueting Wang, Luying Xiong, Yuan Wang, Kai Yang, Tingting Xiao, Xiaohui Chi, Tao Chen, Yanzi Zhou, Ping Lu, Dilimulati Dilinuer, Pin Shen, Yunbo Chen, Yonghong Xiao","doi":"10.1186/s12941-023-00660-5","DOIUrl":"https://doi.org/10.1186/s12941-023-00660-5","url":null,"abstract":"To evaluate effect of inoculum size of extended-spectrum β-Lactamase (ESBL)-producing-, AmpC-producing-, and KPC-producing Escherichia coli and Klebsiella pneumoniae on the in vitro antibacterial effects of imipenem/relebactam (IMR) and ceftazidime/avibactam (CZA). We compared the impact of inoculum size on IMR and CZA of sixteen clinical isolates and three standard isolates through antimicrobial susceptibility tests, time-kill assays and in vitro PK/PD studies. When inoculum size increased from 105 to 107 CFU/mL, an inoculum effect was observed for 26.3% (5/19) and 52.6% (10/19) of IMR and CZA, respectively; time-kill assays revealed that the concentration of CZA increased from ≥ 4 × MIC to 16 × MIC to reach 99.9% killing rate against K. pneumoniae ATCC-BAA 1705 (KPC-2-, OXA-9- and SHV-182-producing) and 60,700 (SHV-27- and DHA-1-producing). While for IMR, a concentration from 1 × MIC to 4 × MIC killed 99.9% of the four strains. When the inoculum size increased to 109 CFU/mL, neither IMR nor CZA showed a detectable antibacterial effect, even at a high concentration. An in vitro PK/PD study revealed a clear bactericidal effect when IMR administered as 1.25 g q6h when inoculum size increased. An inoculum effect on CZA was observed more frequent than that on IMR. Among the β-lactamase-producing strains, the inoculum effect was most common for SHV-producing and KPC-producing strains.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2023-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138560077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li-Ping Cheng, Qing Zhang, Hai Lou, Xiao-Na Shen, Qing-Rong Qu, Jie Cao, Wei Wei, Wei Sha, Qin Sun
{"title":"Effectiveness and safety of regimens containing linezolid for treatment of Mycobacterium abscessus pulmonary Disease.","authors":"Li-Ping Cheng, Qing Zhang, Hai Lou, Xiao-Na Shen, Qing-Rong Qu, Jie Cao, Wei Wei, Wei Sha, Qin Sun","doi":"10.1186/s12941-023-00655-2","DOIUrl":"10.1186/s12941-023-00655-2","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the effectiveness and safety of linezolid-containing regimens for treatment of M. abscessus pulmonary disease.</p><p><strong>Methods: </strong>The records of 336 patients with M. abscessus pulmonary disease who were admitted to Shanghai Pulmonary Hospital from January 2018 to December 2020 were retrospectively analyzed. A total of 164 patients received a linezolid-containing regimen and 172 controls did not. The effectiveness, safety, antibiotic susceptibility profiles, outcomes, culture conversion, cavity closure, and adverse reactions were compared in these two groups.</p><p><strong>Results: </strong>The two groups had similar treatment success (56.1% vs. 48.8%; P > 0.05), but treatment duration was shorter in the linezolid group (16.0 months [inter-quartile ranges, IQR: 15.0-17.0] vs. 18.0 months [IQR: 16.0-18.0]; P < 0.01). The rates of sputum culture conversion were similar (53.7% vs. 46.5%, P > 0.05), but time to conversion was shorter in the linezolid group (3.5 months [IQR: 2.5-4.4] vs. 5.5 months [IQR: 4.0-6.8]; P < 0.01). The linezolid group had a higher rate of cavity closure (55.2% vs. 28.6%, P < 0.05) and a shorter time to cavity closure (3.5 months [IQR: 2.5-4.4] vs. 5.5 months [IQR: 4.0-6.8]; P < 0.01). Anemia and peripheral neuropathy were more common in the linezolid group (17.7% vs. 1.7%, P < 0.01; 12.8% vs. 0.6%, P < 0.01).</p><p><strong>Conclusions: </strong>The linezolid and control groups had similar treatment success rates. The linezolid group had a shorter treatment duration, shorter time to sputum culture conversion, and higher rate and shorter time to lung cavity closure. More patients receiving linezolid developed anemia and peripheral neuropathy.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10702010/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138497601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}