Journal of medical microbiology最新文献

{"title":"Polymyxin combined with Ocimum gratissimum essential oil: one alternative strategy for combating polymyxin-resistant Klebsiella pneumoniae","authors":"Andressa Leite Ferraz de Melo, Luana Rossato, Jannaína Velasques, Virginia Lopes de Sousa, Gabriel Victor Pina Rodrigues, Cláudia Andrea Lima Cardoso, Julia Pimentel Arantes, Bruno Fernandes Lima and Simone Simionatto","doi":"10.1099/jmm.0.001891","DOIUrl":"https://doi.org/10.1099/jmm.0.001891","url":null,"abstract":"<span>Introduction.</span> Multidrug-resistant infections present a critical public health due to scarce treatment options and high mortality. <span>Ocimum gratissimum</span> L. essential oil (O.geo) is a natural resource rich in eugenol known for its antimicrobial activity.\u0000<span>Hypothesis/Gap Statement.</span> O.geo may exert effective antimicrobial activity against polymyxin-resistant Klebsiella pneumoniae and, when combined with Polymyxin B (PMB), may exhibit a synergistic effect, enhancing treatment efficacy and reducing antimicrobial resistance.\u0000<span>Aim.</span> This study aims to investigate the antimicrobial activity of O.geo against polymyxin-resistant <span>K. pneumoniae</span> using <span>in vitro</span> tests and an <span>in vivo Caenorhabditis elegans</span> model.\u0000<span>Methodology.</span> The O.geo was obtained by hydrodistillation followed by gas chromatography. The MIC and antibiofilm activity were determined using broth microdilution. Checkerboard and time-kill assays evaluated the combination of O.geo and polymyxin B (PMB), whereas a protein leakage assay verified its action.\u0000<span>Results.</span> Eugenol (39.67%) was a major constituent identified. The MIC of the O.geo alone ranged from 128 to 512 &#181;g ml<span>&#8722;1</span>. The fractional inhibitory concentration index (0.28) and time-kill assay showed a synergism. In addition, O.geo and PMB inhibited biofilm formation and increased protein leakage in the plasma membrane. The treatment was tested <span>in vivo</span> using a <span>Caenorhabditis elegans</span> model, and significantly increased survival without toxicity was observed.\u0000<span>Conclusion.</span> O.geo could be used as a potential therapeutic alternative to combat infections caused by multidrug-resistant bacteria, especially in combination with PMB.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255111","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":"The impact of agar depth on antimicrobial susceptibility testing by disc diffusion","authors":"Ioana D. Olaru, Sarah Schoeler and Frieder Schaumburg","doi":"10.1099/jmm.0.001890","DOIUrl":"https://doi.org/10.1099/jmm.0.001890","url":null,"abstract":"<span>Introduction.</span> The European Committee on Antimicrobial Susceptibility Testing (EUCAST) specifies the agar depth (4&#177;0.5&#8201;mm) when performing antimicrobial susceptibility testing (AST). Since the infrastructure to produce standardized agar may be lacking in settings with limited resources, we wanted to examine to what extent variation in agar depth affects the inhibition zone diameters of quality control (QC) strains and AST of clinical isolates.\u0000<span>Methods.</span> The inhibition zone diameters on Mueller&#8211;Hinton II agar with different depths (2&#8211;6&#8201;mm) were tested for various QC strain&#8211;antimicrobial agent combinations using <span>Escherichia coli</span> ATCC 25922, <span>Pseudomonas aeruginosa</span> ATCC 27853 and <span>Staphylococcus aureus</span> ATCC 29213. The relationship between zone diameters at different agar depths and MICs was investigated for 35 clinical isolates (<span>E. coli</span>, <span>Klebsiella pneumoniae</span>, <span>S. aureus</span> and <span>P. aeruginosa</span>) from Sierra Leone using MICs as the reference.\u0000<span>Results.</span> The inhibition zone diameters were within the acceptance ranges as defined by the EUCAST for the majority of QC strains and antimicrobials, independent of the agar depth. At extreme agar depths, inhibition zones were more frequently out of range. The accuracy of AST varied for clinical isolates at different agar depths for categorical agreement (85.8&#8211;94.6%), major error rate (0.4&#8211;2.1%) and very major error rate (VME: 3.3&#8211;12.5%).\u0000<span>Conclusions.</span> Even if the QC strains were in the acceptance range at different agar depths, this does not rule out unacceptably high VME rates (&gt;3%) in clinical isolates.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255153","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":"Antimicrobial spectrum against wound pathogens and cytotoxicity of star-arranged poly-l-lysine-based antimicrobial peptide polymers","authors":"Aaron Doherty, Robert Murphy, Andreas Heise, Fidelma Fitzpatrick and Deirdre Fitzgerald-Hughes","doi":"10.1099/jmm.0.001886","DOIUrl":"https://doi.org/10.1099/jmm.0.001886","url":null,"abstract":"<span>Introduction.</span> As growing numbers of patients are at higher risk of infection, novel topical broad-spectrum antimicrobials are urgently required for wound infection management. Robust pre-clinical studies should support the development of such novel antimicrobials.\u0000<span>Gap statement.</span> To date, evidence of robust investigation of the cytotoxicity and antimicrobial spectrum of activity of antimicrobial peptides (AMP)s is lacking in published literature. Using a more clinical lens, we address this gap in experimental approach, building on our experience with poly-<span>l</span>-lysine (PLL)-based AMP polymers.\u0000<span>Aim.</span> To evaluate the <span>in vitro</span> bactericidal activity and cytotoxicity of a PLL-based 16-armed star AMP polymer, designated 16-PLL<span>10</span>, as a novel candidate antimicrobial.\u0000<span>Methods.</span> Antimicrobial susceptibilities of clinical isolates and reference strains of ESKAPE (<span>Enterococcus</span> spp., <span>Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa</span>, <span>Enterobacter</span> spp.) pathogens, to 16-PLL<span>10</span> were investigated. Human erythrocyte haemolysis and keratinocyte viability assays were used to assess toxicity. Modifications were made to 16-PLL<span>10</span> and re-evaluated for improvement.\u0000<span>Results.</span> Minimum bactericidal concentration of 16-PLL<span>10</span> ranged from 1.25&#8201;&#181;M to &#8805;25&#8201;&#181;M. At 2.5&#8201;&#181;M, 16-PLL<span>10</span> was broadly bactericidal against ESKAPE strains/wound isolates. Log-reduction in colony forming units (c.f.u.) per millilitre after 1&#8201;h, ranged from 0.3 (<span>E. cloacae</span>) to 5.6 (<span>K. pneumoniae</span>). At bactericidal concentrations, 16-PLL<span>10</span> was toxic to human keratinocyte and erythrocytes. Conjugates of 16-PLL<span>10</span>, Trifluoroacetylated (TFA)&#8722;16-PLL<span>10</span>, and Poly-ethylene glycol (PEG)ylated 16-PLL<span>10</span>, synthesised to address toxicity, only moderately reduced cytotoxicity and haemolysis.\u0000<span>Conclusions.</span> Due to poor selectivity indices, further development of 16-PLL<span>10</span> is unlikely warranted. However, considering the unmet need for novel topical antimicrobials, the ease of AMP polymer synthesises/modification is attractive. To support more rational development, prioritising clinically relevant pathogens and human cells, to establish selective toxicity profiles <span>in vitro</span>, is critical. Further characterisation and discovery utilising artificial intelligence and computational screening approaches can accelerate future AMP nanomaterial development.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255149","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":"Gut microbiota plays a significant role in gout","authors":"Zhi-Peng Feng, Xiao-Yan Wang, Hong-Yi Xin, Shao-Li Huang, Hong-Yu Huang, Qiang Xin, Xi-He Zhang and Hong-Wu Xin","doi":"10.1099/jmm.0.001824","DOIUrl":"https://doi.org/10.1099/jmm.0.001824","url":null,"abstract":"With the development of social economy, the incidence of gout is increasing, which is closely related to people&#8217;s increasingly rich diet. Eating a diet high in purine, fat, sugar and low-fibre for a long time further aggravates gout by affecting uric acid metabolism. The renal metabolism mechanism of uric acid has been thoroughly studied. To find a new treatment method for gout, increasing studies have recently been conducted on the mechanism of intestinal excretion, metabolism and absorption of uric acid. The most important research is the relationship between intestinal microbiota and the risk of gout. Gut microbiota represent bacteria that reside in a host&#8217;s gastrointestinal tract. The composition of the gut microbiota is associated with protection against pathogen colonization and disease occurrence. This review focuses on how gut microbiota affects gout through uric acid and discusses the types of bacteria that may be involved in the occurrence and progression of gout. We also describe potential therapy for gout by restoring gut microbiota homeostasis and reducing uric acid levels. We hold the perspective that changing intestinal microbiota may become a vital method for effectively preventing or treating gout.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615559","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":"Klebsiella pneumoniae sequence type 147: a high-risk clone increasingly associated with plasmids carrying both resistance and virulence elements","authors":"Jane F. Turton, Claire Perry, Kim McGowan, Jack A. Turton and Russell Hope","doi":"10.1099/jmm.0.001823","DOIUrl":"https://doi.org/10.1099/jmm.0.001823","url":null,"abstract":"<span>Introduction.</span> The first hybrid resistance/virulence plasmid, combining elements from virulence plasmids described in hypervirulent types of <span>Klebsiella pneumoniae</span> with those from conjugative resistance plasmids, was described in an isolate of sequence type (ST) 147 from 2016. Subsequently, this type has been increasingly associated with these plasmids.\u0000<span>Hypothesis or gap statement.</span> The extent of carriage of hybrid virulence/resistance plasmids in nosocomial isolates of <span>K. pneumoniae</span> requires further investigation.\u0000<span>Aim.</span> To describe the occurrence of virulence/resistance plasmids among isolates of <span>K. pneumoniae</span> received by the UK reference laboratory, particularly among representatives of ST147, and to compare their sequences.\u0000<span>Methodology.</span> Isolates received by the laboratory during 2022 and the first half of 2023 (<span>n</span>=1278) were screened for virulence plasmids by PCR detection of <span>rmpA</span>/<span>rmpA2</span> and typed by variable-number tandem repeat analysis. Twenty-nine representatives of ST147 (including a single-locus variant) from seven hospital laboratories were subjected to long-read nanopore sequencing using high-accuracy q20 chemistry to provide complete assemblies.\u0000<span>Results.</span>\u0000<span>rmpA</span>/<span>rmpA2</span> were detected in 110 isolates, of which 59 belonged to hypervirulent K1-ST23, K2-ST86 and K2-ST65/375. Of the remainder, representatives of ST147 formed the largest group, with 22 <span>rmpA</span>/<span>rmpA2</span>-positive representatives (out of 47 isolates). Representatives were from 19 hospital laboratories, with <span>rmpA</span>/<span>rmpA2</span>-positive isolates from 10. Nanopore sequencing of 29 representatives of ST147 divided them into those with no virulence plasmid (<span>n</span>=12), those with non-New Delhi metallo-&#946;-lactamase (NDM) virulence plasmids (<span>n</span>=6) and those carrying <span>bla</span>\u0000<span>NDM-5</span> (<span>n</span>=9) or <span>bla</span>\u0000<span>NDM-1</span> (<span>n</span>=2) virulence plasmids. These plasmids were of IncFIB(pNDM-Mar)/IncHI1B(pNDM-MAR) replicon types. Most of the non-NDM virulence plasmids were highly similar to the originally described KpvST147L_NDM plasmid. Those carrying <span>bla</span>\u0000<span>NDM-5</span> were highly similar to one another and to previously described plasmids in ST383 and carried an extensive array of resistance genes. Comparison of the fully assembled chromosomes indicated multiple introductions of ST147 in UK hospitals.\u0000<span>Conclusion.</span> This study highlights the high proportion of representatives of ST147 that carry IncFIB(pNDM-Mar)/IncHI1B(pNDM-MAR) hybrid resistance virulence plasmids. It is important to be aware of the high probability that representatives of this type carry these plasmids combining resistance and virulence determinants and of the consequent increased risk to patients.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615723","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":"Evaluation of a new CT/NG/TV/MG Real-Time PCR Kit (Vircell) versus the Allplex STI Essential Assay (Seegene) for the diagnosis of sexually transmitted infections","authors":"María Aguilera-Franco, María Tarriño-León, MJ Olivares-Durán, Beatriz Espadafor, Javier Rodríguez-Granger, Juan Antonio Reguera, Fernando Cobo, Antonio Sampedro and José María Navarro","doi":"10.1099/jmm.0.001797","DOIUrl":"https://doi.org/10.1099/jmm.0.001797","url":null,"abstract":"Sexually transmitted infections (STI) are a public health problem. Real-time PCR assays are the most sensitive test for screening and diagnosis of these infections. The aim of this study was to evaluate a new CT/NG/TV/MG Real-Time PCR (RT-PCR) kit (Vircell) for the detection of <span>Chamydia trachomatis</span>, <span>Neisseria gonorrhoeae</span>, <span>Mycoplasma genitalium</span> and <span>Trichomonas vaginalis</span> for the diagnosis of sexual transmitted infections using the Allplex STI Essential Assay (Seegene) as the reference&#8217;s method. A total of 497&#8201;samples from different anatomical sites (endocervical, urethral, rectal, pharyngeal and urine) were analysed from October 2022 to February 2023. A total of 108 (21.73&#8202;%) and 106 (21.33&#8202;%) positive samples were found for any of the assays used. The most commonly detected pathogen was <span>N. gonorrhoeae</span> (52&#8201;samples; 10.46&#8202;%), and the least commonly detected was <span>T. vaginalis</span> (three&#8201;samples; 0.60&#8202;%). The anatomical site with the highest prevalence of micro-organisms was a non-urogenital site, the pharynx (26 positive samples; 5.23&#8202;%). Using the Allplex STI Essential Assay (Seegene) as the reference method, the diagnosis performance showed that the average specificity of CT/NG/TV/MG RT-PCR Kit (Vircell) was 99.84&#8202;% and the sensitivity was 99.53&#8202;%. The overall concordance was k=0.98 (CI95&#8202;%; 0.96&#8211;1). In conclusion, the CT/NG/TV/MG RT-PCR Kit (Vircell) assay shows a good sensitivity and specificity and constitutes a promising and additional alternative to routine procedures for distinct types of clinical specimen in diagnosis STI.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575248","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":"Characterization of invasive Group B Streptococcus isolates from Western Australian infants, 2004–2020","authors":"Ginger Hilpipre, Lucy L. Furfaro, Michelle Porter, Christopher C. Blyth and Daniel K. Yeoh","doi":"10.1099/jmm.0.001822","DOIUrl":"https://doi.org/10.1099/jmm.0.001822","url":null,"abstract":"<span>Background.</span> Invasive Group B <span>Streptococcus</span> (GBS; <span>Streptococcus agalactiae</span>) remains a leading cause of infant morbidity and mortality. Intrapartum antibiotic prophylaxis (IAP) has been implemented in many countries with a reduction in early-onset disease, but an effective vaccine may further reduce the disease burden. Candidate vaccines targeting capsular polysaccharides and surface proteins are now in clinical trials.\u0000<span>Methods.</span> Using whole-genome sequencing and phenotypic antimicrobial susceptibility testing, we characterized sterile-site GBS isolates recovered from Western Australian infants between 2004 and 2020. Characteristics were compared between three time periods: 2004&#8211;2008, 2009&#8211;2015 and 2016&#8211;2020.\u0000<span>Results.</span> A total of 135 isolates were identified. The proportion of serotype III (22.7&#8202;% in Period 1 to 47.9&#8202;% in Period 3, <span>P</span>=0.04) and clonal complex 17 (13.6&#8211;39.6&#8202;%, <span>P</span>=0.01) isolates increased over time. Overall coverage of vaccines currently being trialled was &gt;95&#8202;%. No isolates were penicillin resistant (MIC&gt;0.25 mg l<span>&#8211;1</span>), but 21.5&#8202;% of isolates had reduced penicillin susceptibility (MIC&gt;0.12 mg l<span>&#8211;1</span>) and penicillin MIC increased significantly over time (<span>P</span>=0.04). Clindamycin resistance increased over time to 45.8&#8202;% in the latest period.\u0000<span>Conclusions.</span> Based on comprehensive characterization of invasive infant GBS in Western Australia, we found that coverage for leading capsular polysaccharide and surface protein vaccine candidates was high. The demonstrated changes in serotype and molecular type highlight the need for ongoing surveillance, particularly with regard to future GBS vaccination programmes. The reduced susceptibility to IAP agents over time should inform changes to antibiotic guidelines.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575159","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":"CXCR2 perturbation promotes Staphylococcus aureus implant-associated infection","authors":"Mike Akaraphanth, Tara M. Nordgren and Casey M. Gries","doi":"10.1099/jmm.0.001821","DOIUrl":"https://doi.org/10.1099/jmm.0.001821","url":null,"abstract":"<span>Introduction.</span>\u0000<span>Staphylococcus aureus</span> is the leading cause of acute medical implant infections, representing a significant modern medical concern. The success of <span>S. aureus</span> as a pathogen in these cases resides in its arsenal of virulence factors, resistance to multiple antimicrobials, mechanisms of immune modulation, and ability to rapidly form biofilms associated with implant surfaces. <span>S. aureus</span> device-associated, biofilm-mediated infections are often persistent and notoriously difficult to treat, skewing innate immune responses to promote chronic reoccurring infections. While relatively little is known of the role neutrophils play in response to acute <span>S. aureus</span> biofilm infections, these effector cells must be efficiently recruited to sites of infection via directed chemotaxis. Here we investigate the effects of modulating CXC chemokine receptor 2 (CXCR2) activity, predominantly expressed on neutrophils, during <span>S. aureus</span> implant-associated infection.\u0000<span>Hypothesis.</span> We hypothesize that modulation of CXCR2 expression and/or signalling activities during <span>S. aureus</span> infection, and thus neutrophil recruitment, extravasation and antimicrobial activity, will affect infection control and bacterial burdens in a mouse model of implant-associated infection.\u0000<span>Aim.</span> This investigation aims to elucidate the impact of altered CXCR2 activity during <span>S. aureus</span> biofilm-mediated infection that may help develop a framework for an effective novel strategy to prevent morbidity and mortality associated with implant infections.\u0000<span>Methodology.</span> To examine the role of CXCR2 during <span>S. aureus</span> implant infection, we employed a mouse model of indwelling subcutaneous catheter infection using a community-associated methicillin-resistant <span>S. aureus</span> (MRSA) strain. To assess the role of CXCR2 induction or inhibition during infection, treatment groups received daily intraperitoneal doses of either Lipocalin-2 (Lcn2) or AZD5069, respectively. At the end of the study, catheters and surrounding soft tissues were analysed for bacterial burdens and dissemination, and <span>Cxcr2</span> transcription within the implant-associated tissues was quantified.\u0000<span>Results.</span> Mice treated with Lcn2 developed higher bacterial burdens within the soft tissue surrounding the implant site, which was associated with increased <span>Cxcr2</span> expression. AZD5069 treatment also resulted in increased implant- and tissues-associated bacterial titres, as well as enhanced <span>Cxcr2</span> expression.\u0000<span>Conclusion.</span> Our results demonstrate that CXCR2 plays an essential role in regulating the severity of <span>S. aureus</span> implant-associated infections. Interestingly, however, perturbation of CXCR2 expression or signalling both resulted in enhanced <span>Cxcr2</span> transcription and elevated implant-associated bacterial burdens. T","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575246","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":"Rhein kills Actinobacillus pleuropneumoniae, reduces biofilm formation, and effectively treats bacterial lung infections in mice.","authors":"Haifeng Ding, Yilin Bai, Weiyu Luo, Hao Li, Chunling Zhu, Xueqin Zhao, Huarun Sun, Yuliang Wen, Wei Zhang, Shouping Zhang, Bo Wen, Ruibiao Wang, Longfei Zhang, Xuehan Liu, Jiyuan Shen, Jianhe Hu, Lei Wang, Yueyu Bai, Chengshui Liao, Yundi Wu, Xilong Wu, Ke Ding","doi":"10.1099/jmm.0.001826","DOIUrl":"https://doi.org/10.1099/jmm.0.001826","url":null,"abstract":"Background. Actinobacillus pleuropneumoniae, a member of the Pasteurellaceae family, is known for its highly infectious nature and is the primary causative agent of infectious pleuropneumonia in pigs. This disease poses a considerable threat to the global pig industry and leads to substantial economic losses due to reduced productivity, increased mortality rates, and the need for extensive veterinary care and treatment. Due to the emergence of multi-drug-resistant strains, Chinese herbal medicine is considered one of the best alternatives to antibiotics due to its unique mechanism of action and other properties. As a type of Chinese herbal medicine, Rhein has the advantages of a wide antibacterial spectrum and is less likely to develop drug resistance, which can perfectly solve the limitations of current antibacterial treatments.Methods. The killing effect of Rhein on A. pleuropneumoniae was detected by fluorescence quantification of differential expression changes of key genes, and scanning electron microscopy was used to observe the changes in A. pleuropneumoniae status after Rhein treatment. Establishing a mouse model to observe the treatment of Rhein after A. pleuropneumoniae infection.Results. Here, in this study, we found that Rhein had a good killing effect on A. pleuropneumoniae and that the MIC was 25 µg ml-1. After 3 h of action, Rhein (4×MIC) completely kills A. pleuropneumoniae and Rhein has good stability. In addition, the treatment with Rhein (1×MIC) significantly reduced the formation of bacterial biofilms. Therapeutic evaluation in a murine model showed that Rhein protects mice from A. pleuropneumoniae and relieves lung inflammation. Quantitative RT-PCR (Quantitative reverse transcription polymerase chain reaction is a molecular biology technique that combines both reverse transcription and polymerase chain reaction methods to quantitatively detect the amount of a specific RNA molecule) results showed that Rhein treatment significantly downregulated the expression of the IL-18 (Interleukin refers to a class of cytokines produced by white blood cells), TNF-α, p65 and p38 genes. Along with the downregulation of genes such as IL-18, it means that Rhein has an inhibitory effect on the expression of these genes, thereby reducing the activation of inflammatory cells and the production of inflammatory mediators. This helps reduce inflammation and protects tissue from further damage.Conclusions. This study reports the activity of Rhein against A. pleuropneumoniae and its mechanism, and reveals the ability of Rhein to treat A. pleuropneumoniae infection in mice, laying the foundation for the development of new drugs for bacterial infections.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140784171","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":"Preliminary view of the distribution and spread of the plasmid-mediated resistance genes in Glaesserella parasuis","authors":"Huarun Sun, Minghui Li, Yilin Bai, Yawei Sun, Chunling Zhu, Xiaojing Xia, Huihui Zhang, Weiyu Luo, Wei Zhang, Yuliang Wen, Yueyu Bai, Lei Wang and Jianhe Hu","doi":"10.1099/jmm.0.001767","DOIUrl":"https://doi.org/10.1099/jmm.0.001767","url":null,"abstract":"<span>Introduction</span>. Various plasmid-mediated resistance genes have been reported in <span> <span> Glaesserella parasuis </span> </span>, but little is known about their global distribution features, evolution pattern and spread. <span>Gap Statement</span>. The potential mobilization mechanisms of resistance plasmids in <span> <span> G. parasuis </span> </span> have been poorly explored. <span>Aim</span>. The aim of the study was to investigate the prevalence and diversity of plasmid-mediated resistance genes among <span> <span> G. parasuis </span> </span> isolates, and focus on the analysis of the features of the resistance plasmids from <span> <span> G. parasuis </span> </span>. <span>Method</span>. The plasmids tested were sequenced using the Illumina HiSeq platform in conjunction with PCR and inverted PCR. The susceptibility of the host strains was determined by broth microdilution. The transfer of plasmids tested was conducted by electroporation. The sequence data were compared using bioinformatics tools and the data from our laboratory and the National Center for Biotechnology Information (NCBI) database. <span>Results</span>. Nineteen plasmids were identified from our laboratory and these resistance plasmids were functional and transferable. Moreover, we clustered five types of genetic backbones of plasmids from <span> <span> G. parasuis </span> </span> and revealed the global distribution features of the plasmid-mediated resistance genes. <span>Conclusions</span>. This is the first report of the coexistence of <span>tet</span>(H)-bearing type I plasmid and <span>lnu</span>(C)-bearing type II plasmid in one <span> <span> G. parasuis </span> </span> clinical isolate. In addition, this study provides the first view of the global distribution of plasmid-mediated resistance genes and classifies the plasmids in <span> <span> G. parasuis </span> </span> according to their backbone regions.","PeriodicalId":16343,"journal":{"name":"Journal of medical microbiology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138817280","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}