Acta microbiologica et immunologica Hungarica最新文献

{"title":"Detection of ESBL and AmpC producing Klebsiella pneumoniae ST11 and ST147 from urinary tract infections in Iran.","authors":"Shaghayegh Shahkolahi,&nbsp;Pegah Shakibnia,&nbsp;Shahla Shahbazi,&nbsp;Samira Sabzi,&nbsp;Farzad Badmasti,&nbsp;Mohammad Reza Asadi Karam,&nbsp;Mehri Habibi","doi":"10.1556/030.2022.01808","DOIUrl":"https://doi.org/10.1556/030.2022.01808","url":null,"abstract":"<p><p>In the present study a total of 200 Klebsiella pneumoniae isolates were collected from patients with urinary tract infections (UTIs) in Tehran, Iran. Antibiotic resistance was determined by disk diffusion and broth dilution methods. Detection of extended-spectrum β-lactamases (ESBLs) and AmpCs was performed using phenotypic tests. Polymerase chain reaction (PCR) was applied to detect the ESBL, AmpC, and integron genes. Analysis of AmpC and cassette arrays of integron genes was performed using DNA sequencing. Plasmids were analyzed by PCR-based replicon typing and conjugation. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were applied to explore the genomic relatedness among the isolates. The highest levels of resistance were observed against ampicillin (100%), followed by piperacillin (57.5%), ceftazidime (46%), trimethoprim/sulfamethoxazole (44%), ciprofloxacin (32.5%), and imipenem (19%). Approximately, 66.5% of isolates harbored at least one of the beta-lactamase genes (blaTEM, blaSHV, blaCTX-M, and blaOXA-1). In addition, 22.5% of isolates carried at least one of the AmpC genes including blaDHA and blaCIT. Integron class I was the most prevalent integron among resistant isolates. According to the results of replicon typing, IncFII, IncL/M, and IncA/C were the most frequent replicons, respectively. All selected isolates were able to transfer blaCTX-M, also two isolates transferred the blaDHA-1 gene to Escherichia coli K12 through conjugation. Finally, 21 isolates were categorized into 4 pulsotypes and 11 unique clusters in PFGE. MLST identified ST147 and ST11 sequence types but ST147 was the most prevalent in the current study.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10341834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiple detection of hypermucoviscous and hypervirulent strains of Klebsiella pneumoniae: An emergent health care threat.","authors":"Anna Ventura,&nbsp;Elena Addis,&nbsp;Anna Bertoncelli,&nbsp;Annarita Mazzariol","doi":"10.1556/030.2022.01908","DOIUrl":"https://doi.org/10.1556/030.2022.01908","url":null,"abstract":"<p><p>This study focused on the characterization of 19 hypermucoviscous Klebsiella pneumoniae strains, that were identified from 26 hypermucosal strains. In order to identify hypermucoviscous strains of K. pneumoniae, the string test was applied. This phenotype is known in the literature as one of the virulence factors of this species together with the production of biofilm and other hypervirulence factor genes such as: rmpA, rmpA2, iucA, iroB, peg-344. We also investigated presence of magA gene that correlates with the hyper-production of capsule of K1 serotype. Of the strains under study, 13 out of 19 harboured at least one virulence factor.Sequence type (ST) was determined in order to identify known high-risk clones or new emerging high-risk clones and their variability in a single clinical setting. Important STs found among these strains were ST65 and ST29. Carbapenem resistance was also investigated and 4 out of 19 strains harboured at least a carbapenemase: one strain harboured a KPC enzyme alone, one strain carried a KPC and an OXA-48 like, one strain produced OXA-48-like alone, and the last strain harboured two metallo-β-lactamases (VIM-1 and NDM-5) plus OXA-48-like. In particular, this latter strain belongs to ST383, which was recently reported in Northern Italy as a hypervirulent and XDR strain.The global spread of hypervirulent K. pneumoniae is an important epidemiological issue that should be considered in diagnostic and therapeutic managements of patients with K. pneumoniae infections.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10344224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nocardia elegans primary iliopsoas abscess: A case report and literature review.","authors":"Sofia Maraki,&nbsp;Viktoria Eirini Mavromanolaki,&nbsp;Efstathios E Detorakis,&nbsp;Dimitra Stafylaki,&nbsp;Panagiotis Moraitis,&nbsp;Effie Scoulica","doi":"10.1556/030.2022.01868","DOIUrl":"https://doi.org/10.1556/030.2022.01868","url":null,"abstract":"<p><p>Nocardia species are rare causative agents of psoas abscess, more frequently occurring as part of disseminated infection. Only sporadic cases have been reported so far, with Nocardia asteroides and Nocardia farcinica being the most common causative agents. Nocardia elegans is an opportunistic pathogen, accounting for only 0.3-0.6% of infections caused by Nocardia species, usually affecting the respiratory tract.In this study, a previously healthy 74-year-old man was admitted to the University Hospital of Heraklion with fever and intense pain radiating from the lumbar region to the groin and the left thigh, increasing with movement. Imaging findings revealed a large abscess in the left iliopsoas. Blood and pus aspirate cultures yielded a pure culture of Nocardia that was identified by 16S rRNA sequence as N. elegans. The patient was successfully treated with drainage of the abscess along with administration of ceftriaxone, linezolid and trimethoprim-sulfamethoxazole. To our knowledge, this is the first report of iliopsoas abscess caused by N. elegans. Early, accurate diagnosis and timely treatment with drainage of the abscess and long-term administration of antimicrobial agents optimize the outcome.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10334537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ginsenoside Rg1 modulates intestinal microbiota and supports re-generation of immune cells in dexamethasone-treated mice.","authors":"Sabiha Yousuf,&nbsp;He Liu,&nbsp;Zhang Yingshu,&nbsp;Danish Zahid,&nbsp;Hassan Ghayas,&nbsp;Ming Li,&nbsp;Yan Ding,&nbsp;Wenzhe Li","doi":"10.1556/030.2022.01881","DOIUrl":"https://doi.org/10.1556/030.2022.01881","url":null,"abstract":"<p><p>Ginsenoside Rg1 is one of the major ginsenosides found in roots of Panax ginseng and Panax notoginseng. Ginsenoside Rg1 is known to possess various biological activities including immunity enhancement activity. However, it is not clear whether the regulation of immune function by Rg1 is related to the intestinal microbiota. In the present study, the immuno-modulatory and gut microbiota-reshaping effects of ginsenoside Rg1 were evaluated. Ginsenoside Rg1 acts as an immune-enhancing agent to increase spleen index and the number of T, B and dendritic cells in dexamethasone (Dex)-treated mice. Ginsenoside Rg1 also increased the production of sIgA and regulated the expression of interleukin 2 (IL-2), IL-4, IL-10 and IFN-γ. Meanwhile, Rg1 administration regulated the structure of intestinal microbiota. The relative abundance of mouse intestinal microbial groups, such as Alistipes, Ruminococcaceae, Lachnospiraceae, and Roseburia were increased by Rg1 administration, whereas a decrease in the potential pathogens like Helicobacteraceae, Dubosiella, Mycoplasma, Alloprevotella, Allobaculum was observed. Moreover, Rg1 metabolites of Lachnospiraceae bacterium enhanced the proliferation of CD4+ T cells and T regulatory (Treg) cells. Ginsenoside Rg1 improved the inflammatory condition of the colonic tissue and repaired the destructed mucosal barrier. This study suggested that Rg1 strengthens immunity with regulating the homeostasis of intestinal microbiota in mice.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10343275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spa diversity and genetic characterization of t127 methicillin-resistant Staphylococcus aureus in a tertiary Greek hospital.","authors":"Katerina Tsergouli,&nbsp;Theodoros Karampatakis,&nbsp;Konstantina Kontopoulou,&nbsp;Styliani Pappa,&nbsp;Parthena Kampouridou,&nbsp;Georgia Kallasidou,&nbsp;Katerina Tsioka,&nbsp;Sophia Zotou,&nbsp;Εleftheria-Eugenia Farmaki,&nbsp;Charalampos Kotzamanidis,&nbsp;Anna Papa","doi":"10.1556/030.2022.01825","DOIUrl":"https://doi.org/10.1556/030.2022.01825","url":null,"abstract":"<p><strong>Introduction: </strong>Methicillin-resistant Staphylococcus aureus (MRSA) causes severe community and hospital acquired infections. Identification of staphylococcal cassette chromosome mec (SCCmec), multilocus-sequence typing, and sequencing of S. aureus protein A (spa) gene are used for MRSA typing. The aim was to investigate the spa types of MRSA isolates in a tertiary hospital in Greece and analyse the whole genome sequences of two t127 MRSA isolates.</p><p><strong>Methods: </strong>Totally, 39 MRSA isolates collected from July 2019 to June 2020 in \"Georgios Gennimatas\" General Hospital of Thessaloniki, Greece, were included in the study. Identification and antimicrobial susceptibility testing were performed using VITEK II automated system, and spa typing was performed. A minimum spanning tree was used to display the spa type frequencies and the genetic distances among them. Two t127-MRSA isolates (IM-MRSA and PD-MRSA) were selected for WGS.</p><p><strong>Results: </strong>Six isolates (15.4%) were resistant to mupirocin, 18 (46.2%) to fusidic acid, three (7.7%) to vancomycin and two (5.1%) to teicoplanin. Twenty-two different spa types were detected, with t002, t003, and t422 being the most frequent (5/39, 12.8% each), followed by t1994 (4/39, 10.3%). The isolates presented high genetic diversity and, taking into account the time between hospital admission and sampling, intrahospital spread did not occur. Even the two t127 isolates were assigned to different sequence types, ST9-XII-t127 and ST1-IVa-t127. Plasmids and genes conferring antimicrobial resistance and virulence were also identified.</p><p><strong>Conclusions: </strong>Various spa types were identified and together with the information about the time between hospital admission and sampling supports polyclonal MRSA spread in the hospital excluding a nosocomial infection. WGS provides a more detailed analysis distinguishing even the isolates belonging to the same spa type.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First detection of a colistin-resistant Klebsiella aerogenes isolate from a critically ill patient with septic shock in Bulgaria.","authors":"Slavil Peykov,&nbsp;Alexander Stratev,&nbsp;Boris Kirov,&nbsp;Raina Gergova,&nbsp;Tanya Strateva","doi":"10.1556/030.2022.01833","DOIUrl":"https://doi.org/10.1556/030.2022.01833","url":null,"abstract":"<p><p>Colistin is considered as the last-line antibiotic for the treatment of infections caused by extensively drug-resistant Gram-negative pathogens belonging to the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) group. The present study aimed to explore the colistin resistance mechanisms of a Klebsiella aerogenes (formerly Enterobacter aerogenes) isolate (Kae1177-1bg) obtained from a Bulgarian critically ill patient with septic shock in 2020. Antimicrobial susceptibility testing and whole-genome sequencing using DNA nanoball technology were performed. The resulting read pairs were used for draft genome assembly, MLST analysis and mutation screening in the pmrA/B, phoP/Q, and mgrB genes. Kae1177-1bg demonstrated high-level resistance to colistin, resistance to 3rd generation cephalosporins and susceptibility to all other antibiotics tested. In our strain a CMY-2-type class C cephalosporinase was the only β-lactamase identified. No mobile colistin resistance (mcr) genes were detected. A total of three missense variants in the genes for the two-component PmrA/PmrB system were identified. Two of them were located in the pmrB (pR57K and pN275K) and one in the pmrA gene (pL162M). The pN275K variant emerged as the most likely cause for colistin resistance because it affected a highly conservative position and was the only nonconservative amino acid substitution. In conclusion, to the best of our knowledge, this is the first documented clinical case of a high-level colistin-resistant K. aerogenes in Bulgaria and the first identification of the nonconservative amino acid substitution pN275K worldwide. Colistin-resistant Gram-negative pathogens of ESKAPE group are serious threat to public health and should be subjected to infection control stewardship practices.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9720561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity of meropenem-vaborbactam against different beta-lactamase producing Klebsiella pneumoniae and Escherichia coli isolates in Iran.","authors":"Samira Amereh,&nbsp;Fatemeh Zeynali Kelishomi,&nbsp;Fatemeh Ghayaz,&nbsp;Amir Javadi,&nbsp;Amir Peymani,&nbsp;Fatemeh Fardsanei,&nbsp;Ehsan Aali,&nbsp;Farhad Nikkhahi","doi":"10.1556/030.2022.01782","DOIUrl":"https://doi.org/10.1556/030.2022.01782","url":null,"abstract":"<p><p>We evaluated the activity of meropenem-vaborbactam against different beta-lactamase producing Klebsiella pneumoniae and Escherichia coli isolates. In our study antibiotic susceptibility testing, double disk synergy test, modified Hodge test were applied. Detection of ESBL, AmpC, and carbapenemase genes was performed by PCR. Multilocus sequence typing (MLST) analysis was done on OXA-48 producing K. pneumoniae strains. Our results showed that among E. coli and K. pneumoniae isolates, 41.1% and 40% of strains produced ESBL, respectively. Additionally, the prevalence of AmpC producing K. pneumoniae and E. coli was 4% and 45.5%, respectively. Altogether 64.2% of K. pneumoniae strains and one E. coli isolate produced carbapenemase. Among OXA-48 producing K. pneumoniae strains ST3500 and ST2528 were detected by MLST. Based on the phenotypic results of this study, vaborbactam was an effective inhibitor on the third-generation cephalosporin-resistant isolates (P < 0.0001). Meropenem-vaborbactam combination had the highest efficacy on KPC producing strains, and it had limited activity on isolates producing OXA-48 type beta-lactamases, whereas no effect was observed on NDM-1 producing isolates. Our study provided valuable information regarding the vaborbactam inhibitory effect on β-lactamase-producing strains.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular epidemiology, virulence and antimicrobial resistance of Bulgarian methicillin resistant Staphylococcus aureus isolates.","authors":"Raina Gergova,&nbsp;Virna-Maria Tsitou,&nbsp;Svetoslav G Dimov,&nbsp;Lyudmila Boyanova,&nbsp;Kalina Mihova,&nbsp;Tanya Strateva,&nbsp;Ivanka Gergova,&nbsp;Rumyana Markovska","doi":"10.1556/030.2022.01766","DOIUrl":"https://doi.org/10.1556/030.2022.01766","url":null,"abstract":"<p><strong>Background: </strong>Severe infections of virulent methicillin-resistant Staphylococcus aureus (MRSA) are a serious health problem. The present study aimed to investigate clonal spread, virulence and antimicrobial resistance rates of Bulgarian MRSA isolates in 2016-2020.</p><p><strong>Methods: </strong>Molecular identification and mecA gene detection were performed with PCR. Clonal relatedness was evaluated by RAPD PCR and MLST. MRSA epidemiology, virulence and resistance patterns were investigated by PCR.</p><p><strong>Results: </strong>All 27 isolates were identified as S. aureus and were mecA positive, and all were susceptible to linezolid, tigecycline and vancomycin. The toxin genes hlg (in 92.6% of isolates), seb (77.8%), sei (77.8%), seh (59.3%), sej (55.6%), and seg (48.1%), were frequently found among the isolates. Epidemiological typing by RAPD identified 4 clones (16 isolates) and 11 were with a unique profile. MLST analysis of the same MRSA isolates showed five MLST clonal complexes and 11 ST types, including CC5 (33.3%) (ST5, ST221, ST4776), CC8 (22.2%) (ST8, ST239, ST72), CC15 (ST582), CC22 (14.8%) (ST217, ST5417), CC30 (ST30) CC398 (ST398), and CC59 (ST59). The isolates from CC5 showed higher virulence potential and almost all were macrolide resistant (ermB or ermC positive). CC8 isolates showed higher level of resistance.</p><p><strong>Conclusion: </strong>To the best of our knowledge, this study is the first describing the clonal spreading of Bulgarian MRSA and the association with their virulence and resistance determinants. Monitoring of MRSA epidemiology, resistance and virulence profile can lead to better prevention and faster therapeutic choice in cases of severe infections.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time kill-assays of antibiotic combinations for multidrug resistant clinical isolates of OXA-48 carbapenemase producing Klebsiella pneumoniae.","authors":"Fatma Erdem,&nbsp;María Díez-Aguilar,&nbsp;Lutfiye Oksuz,&nbsp;Cigdem Kayacan,&nbsp;Ayham Abulaila,&nbsp;Oral Oncul,&nbsp;María Isabel Morosini,&nbsp;Rafael Cantón,&nbsp;Zerrin Aktas","doi":"10.1556/030.2022.01785","DOIUrl":"https://doi.org/10.1556/030.2022.01785","url":null,"abstract":"<p><p>Treatment of infections caused by OXA-48 carbapenemase producing multidrug-resistant isolates often necessitates combination therapy. In vitro effect of different antibiotic combinations against multidrug-resistant (MDR) Klebsiella pneumoniae isolates were evaluated in this study.Meropenem-tobramycin (MER+TOB), meropenem-ciprofloxacin (MER+CIP), colistin-meropenem (COL+MER), colistin-ciprofloxacin (COL+CIP) and colistin-tobramycin (COL+TOB) combinations were tested by time kill-assays. Each antibiotic alone and in combination at their Cmax values were tested against 4 clinical K. pneumoniae isolates at 1, 2, 4, 6, 8, 12 and 24 h. Effect of colistin and its associations were also assessed at 30 min. Bactericidal activity was defined as ≥3log10 CFU mL-1 decrease compared with initial inoculum. Synergy was defined as ≥2log10CFU mL-1 decrease by the combination compared with the most active single agent. Presence of blaOXA-48, blaNDM, blaVIM, blaIMP, blaKPC and blaCTX-M-1 genes was screened by PCR using specific primers.The blaOXA-48 gene was identified together with blaCTXM-1 group gene in all isolates. COL+MER demonstrated to be synergistic and bactericidal. MER+TOB showed synergistic and bactericidal effect on two strains although, regrowth was seen on other two strains at 24 h. MER+CIP exhibited indifferent effect on the strains.Combination therapy could be a potential alternative to treat MDR K. pneumoniae infections. This combination might prevent resistance development and secondary effects of colistin monotherapy. MER+TOB and MER+CIP might have an isolate-dependent effect, that may not always result in synergism.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of different colistin resistance mechanisms among multidrug resistant Klebsiella pneumoniae isolates in Bulgaria.","authors":"Rumyana Markovska,&nbsp;Yuliya Marteva-Proevska,&nbsp;Tzvetan Velinov,&nbsp;Ivan Pavlov,&nbsp;Radka Kaneva,&nbsp;Lyudmila Boyanova","doi":"10.1556/030.2022.01746","DOIUrl":"https://doi.org/10.1556/030.2022.01746","url":null,"abstract":"<p><p>The more frequent usage of colistin resulted in an increase of colistin resistance due to lipopolysaccharide modifications. The aim of this study was to reveal the prevalence and mechanisms of colistin resistance among multidrug-resistant Klebsiella pneumoniae isolates collected in Bulgaria. One hundred multidrug resistant K. pneumoniae isolates were collected in a period between 2017 and 2018. Among them, 29 colistin resistant and 8 heteroresistant isolates were observed and further investigated. Clonal relatedness was detected by RAPD and MLST. Сarbapenemases, two component system phoQ/phoP, pmrA/B, and mgrB were investigated by PCR amplification and Sanger sequencing. Among 37 colistin nonsusceptible isolates, we detected 25 NDM-1 producers. The isolates belonged mainly to ST11 (80%), and also to ST147, ST35, ST340, ST219 (1-2 members per clone). Nine colistin resistant isolates showed changes in mgrB. IS903B-like elements truncated mgrB in five isolates. In two isolates, premature stopcodon (Q30stopcodon) was observed and another two isolates did not amplify mgrB, possibly due to bigger deletion or insertion. No isolates showed phoQ/phoP and pmrA/B mutations except for pmrB (four isolates had R256G). All isolates with IS903B insertions belonged to ST11 clone. The mgrB alterations play major role in colistin resistance in K. pneumoniae isolates studied in the current work. We report truncation of mgrB by IS903 like element in colistin resistant NDM-1 producing K. pneumoniae ST11 clone in Bulgaria.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}