Pub Date : 2025-02-28DOI: 10.1016/j.micpath.2025.107378
Khawla E. Alsamhary
Pseudomonas aeruginosa, a formidable opportunistic pathogen, is notorious for its ability to form biofilms and produce virulence factors that favor chronic infections, especially in cystic fibrosis patients. The misuse of disinfectants, combined with environmental leakage and biodegradation, has led to widespread exposure of microorganisms to sub-lethal concentrations of disinfectants, particularly quaternary ammonium compounds (QACs). This study investigates the interaction between QACs, specifically ethylbenzalkyl dimethyl ammonium chloride (EBAC), and the quorum sensing (QS) mechanisms governing P. aeruginosa behavior. The results demonstrate that exposure to sub-minimum inhibitory concentrations (sub-MICs) of EBAC not only enhances the biofilm-forming capability of P. aeruginosa isolates but also modulates the expression of crucial QS-regulated genes. Notably, the bacteria exhibit increased production of biofilm-associated virulence factors such as pyocyanin and elastase, and altered antibiotic susceptibility profiles, indicating a shift towards persistent infection phenotypes. These findings reveal that QAC exposure can significantly increase resistance to antibiotics and external stressors like hydrogen peroxide. These results emphasize the need to reassess the efficacy of QACs in clinical disinfection settings, particularly against P. aeruginosa infections, and highlight the potential for unintended consequences of their use regarding bacterial behavior and virulence. This study provides novel insights into the role of QACs in modulating QS-mediated virulence and antibiotic resistance, offering a new perspective on the risks associated with sub-lethal disinfectant exposure.
{"title":"The effect of quaternary ammonium compounds (QACs) on quorum sensing and resistance of P. aeruginosa in clinical settings","authors":"Khawla E. Alsamhary","doi":"10.1016/j.micpath.2025.107378","DOIUrl":"10.1016/j.micpath.2025.107378","url":null,"abstract":"<div><div><em>Pseudomonas aeruginosa</em>, a formidable opportunistic pathogen, is notorious for its ability to form biofilms and produce virulence factors that favor chronic infections, especially in cystic fibrosis patients. The misuse of disinfectants, combined with environmental leakage and biodegradation, has led to widespread exposure of microorganisms to sub-lethal concentrations of disinfectants, particularly quaternary ammonium compounds (QACs). This study investigates the interaction between QACs, specifically ethylbenzalkyl dimethyl ammonium chloride (EBAC), and the quorum sensing (QS) mechanisms governing <em>P. aeruginosa</em> behavior. The results demonstrate that exposure to sub-minimum inhibitory concentrations (sub-MICs) of EBAC not only enhances the biofilm-forming capability of <em>P. aeruginosa</em> isolates but also modulates the expression of crucial QS-regulated genes. Notably, the bacteria exhibit increased production of biofilm-associated virulence factors such as pyocyanin and elastase, and altered antibiotic susceptibility profiles, indicating a shift towards persistent infection phenotypes. These findings reveal that QAC exposure can significantly increase resistance to antibiotics and external stressors like hydrogen peroxide. These results emphasize the need to reassess the efficacy of QACs in clinical disinfection settings, particularly against <em>P. aeruginosa</em> infections, and highlight the potential for unintended consequences of their use regarding bacterial behavior and virulence. This study provides novel insights into the role of QACs in modulating QS-mediated virulence and antibiotic resistance, offering a new perspective on the risks associated with sub-lethal disinfectant exposure.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107378"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.micpath.2025.107440
Shraddha S. Dandekar , Sinta Thanikkal , Arti Londhe , Pankhudi Bhutada , Ujjayni Saha , Shubhankar Pawar , Rachel Samson , Mahesh Dharne , Sunil D. Saroj , Santosh Koratkar
Phage therapy offers a promising approach to the increasing antimicrobial resistance of Klebsiella pneumoniae. This study highlights three novel lytic bacteriophages—KPAФ1, KP149Ф1, and KP149Ф2— targeting multidrug-resistant (MDR) K. pneumoniae. These phages belong to the Myoviridae and Podoviridae family and demonstrate their efficacy and stability across a wide range of temperatures (up to 60°C) and pH levels (pH 4 to 11). Genomic analysis reveals that they are free from virulence, toxicity, and antimicrobial resistance genes, making them promising candidates for therapeutic use. Among these phages, KPAФ1 showed the highest lytic activity with a 26.15% lysis against MDR K. pneumoniae isolates. Additionally, a phage cocktail comprising all three phages improved lytic efficacy to 32.30%. This study also examined the antimicrobial resistance profiles of K. pneumoniae isolates, emphasizing the critical need for alternative treatments. By effectively targeting resistant strains, these phages offer a potential candidacy to be used as a viable alternative or a complementary antimicrobial agent to traditional antibiotics, opening up the possibility for advanced phage-based therapies. The promising results from this study pave the way for developing new treatments that could significantly improve patient care and outcomes from the growing issue of resistant bacterial infections.
{"title":"Characterization of novel phages KPAФ1, KP149Ф1, and KP149Ф2 for lytic efficiency against clinical MDR Klebsiella pneumoniae infections","authors":"Shraddha S. Dandekar , Sinta Thanikkal , Arti Londhe , Pankhudi Bhutada , Ujjayni Saha , Shubhankar Pawar , Rachel Samson , Mahesh Dharne , Sunil D. Saroj , Santosh Koratkar","doi":"10.1016/j.micpath.2025.107440","DOIUrl":"10.1016/j.micpath.2025.107440","url":null,"abstract":"<div><div>Phage therapy offers a promising approach to the increasing antimicrobial resistance of <em>Klebsiella pneumoniae</em>. This study highlights three novel lytic bacteriophages—KPAФ1, KP149Ф1, and KP149Ф2— targeting multidrug-resistant (MDR) <em>K. pneumoniae.</em> These phages belong to the <em>Myoviridae</em> and <em>Podoviridae</em> family and demonstrate their efficacy and stability across a wide range of temperatures (up to 60°C) and pH levels (pH 4 to 11). Genomic analysis reveals that they are free from virulence, toxicity, and antimicrobial resistance genes, making them promising candidates for therapeutic use. Among these phages, KPAФ1 showed the highest lytic activity with a 26.15% lysis against MDR <em>K. pneumoniae</em> isolates. Additionally, a phage cocktail comprising all three phages improved lytic efficacy to 32.30%. This study also examined the antimicrobial resistance profiles of <em>K. pneumoniae</em> isolates, emphasizing the critical need for alternative treatments. By effectively targeting resistant strains, these phages offer a potential candidacy to be used as a viable alternative or a complementary antimicrobial agent to traditional antibiotics, opening up the possibility for advanced phage-based therapies. The promising results from this study pave the way for developing new treatments that could significantly improve patient care and outcomes from the growing issue of resistant bacterial infections.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107440"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.micpath.2025.107441
Chad Schou , Justus Mukavi , Jandirk Sendker , Androulla Miliotou , Vasiliki Christodoulou , Yiannis Sarigiannis , Aleksandar Jovanovic , Thomas J. Schmidt , Panagiotis Karanis
<div><h3>Background</h3><div>Phytochemicals from unexplored plant species may be vital to unlocking pharmaceutical antibiotic and antiparasitic discoveries. New compounds need to be discovered to combat antimicrobial resistance. This study aimed to investigate ethanolic leaf extracts from five endemic and four indigenous plants from Cyprus for antibacterial, antileishmanial, and antioxidant activities.</div></div><div><h3>Methods</h3><div>Ethanolic leaf extracts were screened for antibacterial activity using a broth microdilution assay and iodonitrotetrazolium chloride (INT) as a colourimetric redox indicator for determining the minimum inhibitory concentration (MIC) against four Gram-positive and two Gram-negative American Type Culture Collection (ATCC) reference bacteria. Total phenolic content (TPC), total flavonoid content (TFC) and radical scavenging activity assays were performed to screen for antioxidant potential. <em>Leishmania infantum</em> clinical culture (MCAN/CY/2005/CD57) was used to screen the extracts for <em>in vitro</em> antileishmanial activity. Their cytotoxicity <em>in vitro</em> was assessed using the resazurin fluorometric assay with a HepG2 cell line. As an estimate of <em>in vitro</em> toxicity, a brine shrimp lethality assay was performed.</div></div><div><h3>Results</h3><div>The ethanol extract of <em>Ptilostemon chamaepeuce</em> subsp. <em>cyprius</em> (Greuter) Chrtek & B. Slavik demonstrated antibacterial activity against <em>Enterococcus faecalis</em> (ATCC 29212) with minimum inhibitory concentration (MIC) < 0.625 mg/mL and antileishmanial activity against a clinical isolate of <em>L</em><em>.</em> <em>infantum</em> (MCAN/CY/2005/CD57) from an infected dog (promastigote IC<sub>50</sub> of 105.7 ± 2.5 μg/mL and amastigote IC<sub>50</sub> of 118.5 ± 4.3 μg/mL) after 48 h and compared to the activity of the reference drug, miltefosine (IC<sub>50</sub> of 3.7 ± 0.1 μg/mL and 18.5 ± 2.3 μg/mL, respectively). Liquid-chromatography-mass spectrometry (LC-MS) analysis revealed the presence of at least five sesquiterpene lactones (STLs) in <em>P. cham</em>. subsp. <em>cyprius</em> ethanolic extract. The main compound, deacylcynaropicrin, based on its high-resolution mass spectrum, is believed to be primarily responsible for the antileishmanial activity observed <em>in vitro</em>.</div><div><em>Quercus alnifolia</em> Poech ethanolic extract showed antibacterial activity against four Gram-positive and one Gram-negative bacteria with MIC values of < 0.625 mg/mL, respectively, and antioxidant capacity in DPPH radical scavenging assay with IC<sub>50</sub> of 0.155 ± 0.002 mg/mL and compared to ascorbic acid (IC<sub>50</sub> of 0.036 ± 0.000 mg/mL) and Trolox (IC<sub>50</sub> of 0.047 ± 0.001 mg/mL).</div></div><div><h3>Conclusion</h3><div>The ethanolic extract of <em>Ptilostemon chamaepeuce</em> subsp. <em>cyprius</em> demonstrated dose-dependent antileishmanial activity. This is the first data report of <em>P</em><em>
{"title":"Antileishmanial activity of Ptilostemon chamaepeuce subsp. cyprius","authors":"Chad Schou , Justus Mukavi , Jandirk Sendker , Androulla Miliotou , Vasiliki Christodoulou , Yiannis Sarigiannis , Aleksandar Jovanovic , Thomas J. Schmidt , Panagiotis Karanis","doi":"10.1016/j.micpath.2025.107441","DOIUrl":"10.1016/j.micpath.2025.107441","url":null,"abstract":"<div><h3>Background</h3><div>Phytochemicals from unexplored plant species may be vital to unlocking pharmaceutical antibiotic and antiparasitic discoveries. New compounds need to be discovered to combat antimicrobial resistance. This study aimed to investigate ethanolic leaf extracts from five endemic and four indigenous plants from Cyprus for antibacterial, antileishmanial, and antioxidant activities.</div></div><div><h3>Methods</h3><div>Ethanolic leaf extracts were screened for antibacterial activity using a broth microdilution assay and iodonitrotetrazolium chloride (INT) as a colourimetric redox indicator for determining the minimum inhibitory concentration (MIC) against four Gram-positive and two Gram-negative American Type Culture Collection (ATCC) reference bacteria. Total phenolic content (TPC), total flavonoid content (TFC) and radical scavenging activity assays were performed to screen for antioxidant potential. <em>Leishmania infantum</em> clinical culture (MCAN/CY/2005/CD57) was used to screen the extracts for <em>in vitro</em> antileishmanial activity. Their cytotoxicity <em>in vitro</em> was assessed using the resazurin fluorometric assay with a HepG2 cell line. As an estimate of <em>in vitro</em> toxicity, a brine shrimp lethality assay was performed.</div></div><div><h3>Results</h3><div>The ethanol extract of <em>Ptilostemon chamaepeuce</em> subsp. <em>cyprius</em> (Greuter) Chrtek & B. Slavik demonstrated antibacterial activity against <em>Enterococcus faecalis</em> (ATCC 29212) with minimum inhibitory concentration (MIC) < 0.625 mg/mL and antileishmanial activity against a clinical isolate of <em>L</em><em>.</em> <em>infantum</em> (MCAN/CY/2005/CD57) from an infected dog (promastigote IC<sub>50</sub> of 105.7 ± 2.5 μg/mL and amastigote IC<sub>50</sub> of 118.5 ± 4.3 μg/mL) after 48 h and compared to the activity of the reference drug, miltefosine (IC<sub>50</sub> of 3.7 ± 0.1 μg/mL and 18.5 ± 2.3 μg/mL, respectively). Liquid-chromatography-mass spectrometry (LC-MS) analysis revealed the presence of at least five sesquiterpene lactones (STLs) in <em>P. cham</em>. subsp. <em>cyprius</em> ethanolic extract. The main compound, deacylcynaropicrin, based on its high-resolution mass spectrum, is believed to be primarily responsible for the antileishmanial activity observed <em>in vitro</em>.</div><div><em>Quercus alnifolia</em> Poech ethanolic extract showed antibacterial activity against four Gram-positive and one Gram-negative bacteria with MIC values of < 0.625 mg/mL, respectively, and antioxidant capacity in DPPH radical scavenging assay with IC<sub>50</sub> of 0.155 ± 0.002 mg/mL and compared to ascorbic acid (IC<sub>50</sub> of 0.036 ± 0.000 mg/mL) and Trolox (IC<sub>50</sub> of 0.047 ± 0.001 mg/mL).</div></div><div><h3>Conclusion</h3><div>The ethanolic extract of <em>Ptilostemon chamaepeuce</em> subsp. <em>cyprius</em> demonstrated dose-dependent antileishmanial activity. This is the first data report of <em>P</em><em>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107441"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.micpath.2025.107405
Amani Sliti , Ryeong-Hui Kim , Dokyung Lee , Jae-Ho Shin
Lacticaseibacillus paracasei is widely used as a probiotic supplement and food additive in the medicinal and food industries. However, its application requires careful evaluation of safety traits associated with probiotic pathogenesis, including the transfer of antibiotic-resistance genes, the presence of virulence and pathogenicity factors, and the potential disruptions of the gut microbiome and immune system. In this study, we conducted whole genome sequencing (WGS) of L. paracasei FMT2 isolated from fecal microbiota transplantation (FMT) capsules and performed genome annotation to assess its probiotic and safety attributes. Our comparative genomic analysis assessed this novel strain's genetic attributes and functional diversity and unraveled its evolutionary relationships with other L. paracasei strains. The assembly yielded three contigs: one corresponding to the chromosome and two corresponding to plasmids. Genome annotation revealed the presence of 2838 DNA-coding sequences (CDS), 78 ribosomal RNAs (rRNAs), 60 transfer RNAs (tRNAs), three non-coding RNAs (ncRNAs), and 126 pseudogenes. The strain lacked antibiotic resistance genes and pathogenicity factors. Two intact prophages, one Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) region, and three antimicrobial peptide gene clusters were identified, highlighting the genomic stability and antimicrobial potential of the strain. Furthermore, genes linked to probiotic functions, such as mucosal colonization, stress resistance, and biofilm formation, were characterized. The pan-genome analysis identified 3358 orthologous clusters, including 1775 single-copy clusters, across all L. paracasei strains. Notably, L. paracasei FMT2 contained many unique singleton genes, potentially contributing to its distinctive probiotic properties. Our findings confirm the potential of L. paracasei FMT2 for food and therapeutic applications based on its probiotic profile and safety.
{"title":"Whole genome sequencing and In silico analysis of the safety and probiotic features of Lacticaseibacillus paracasei FMT2 isolated from fecal microbiota transplantation (FMT) capsules","authors":"Amani Sliti , Ryeong-Hui Kim , Dokyung Lee , Jae-Ho Shin","doi":"10.1016/j.micpath.2025.107405","DOIUrl":"10.1016/j.micpath.2025.107405","url":null,"abstract":"<div><div><em>Lacticaseibacillus paracasei</em> is widely used as a probiotic supplement and food additive in the medicinal and food industries. However, its application requires careful evaluation of safety traits associated with probiotic pathogenesis, including the transfer of antibiotic-resistance genes, the presence of virulence and pathogenicity factors, and the potential disruptions of the gut microbiome and immune system. In this study, we conducted whole genome sequencing (WGS) of <em>L. paracasei</em> FMT2 isolated from fecal microbiota transplantation (FMT) capsules and performed genome annotation to assess its probiotic and safety attributes. Our comparative genomic analysis assessed this novel strain's genetic attributes and functional diversity and unraveled its evolutionary relationships with other <em>L. paracasei</em> strains. The assembly yielded three contigs: one corresponding to the chromosome and two corresponding to plasmids. Genome annotation revealed the presence of 2838 DNA-coding sequences (CDS), 78 ribosomal RNAs (rRNAs), 60 transfer RNAs (tRNAs), three non-coding RNAs (ncRNAs), and 126 pseudogenes. The strain lacked antibiotic resistance genes and pathogenicity factors. Two intact prophages, one Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) region, and three antimicrobial peptide gene clusters were identified, highlighting the genomic stability and antimicrobial potential of the strain. Furthermore, genes linked to probiotic functions, such as mucosal colonization, stress resistance, and biofilm formation, were characterized. The pan-genome analysis identified 3358 orthologous clusters, including 1775 single-copy clusters, across all <em>L. paracasei</em> strains. Notably, <em>L. paracasei</em> FMT2 contained many unique singleton genes, potentially contributing to its distinctive probiotic properties. Our findings confirm the potential of <em>L. paracasei</em> FMT2 for food and therapeutic applications based on its probiotic profile and safety.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107405"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The bacteria's ability to respond to environmental changes is critical for their survival. This allows them to form intricate communities, withstand stress, and initiate virulence responses in hosts during infection, a phenomenon known as phenotypic switching. In this study, we investigated the role of shaking conditions on phenotype switch in multidrug-resistant and pathogenic Morganella morganii both under in vitro and in vivo conditions. The results demonstrate that M. morganii grown in non-shaking conditions, possibly causing low fluid shear, developed floccules or cellular aggregates, and substantially increased biofilm formation. Meanwhile, the bacterium grown in shaking conditions was non-flocculated and produced less biofilm. This phenotype switch leads to a significant change in the protein secretome and multidrug resistance profile. In the non-shaking condition, M. morganii secretes two main proteins of ∼80 and ∼100 kDa and displays multiple antibiotic resistance (MAR) values of 0.39. In contrast, the bacterial cell in a shaking flask secreted one prominent protein of ∼50 kDa and exhibited a lower MAR value of 0.31. These observations correspond with a significant reduction in both in vitro and in vivo virulence of M. morganii grown in non-shaking conditions, namely haemolysin, swimming motility, histomorphological changes, and survival assay as compared to bacterial cells in a shaking flask displayed higher virulence in both in vitro and in vivo condition. Furthermore, non-shaking tube-grown cells have higher expression of saa, astA, ibeA, papC and papG genes as compared to cells grown in the shaking flask exhibiting higher expression of kpsMT K1, kpsMT “K5”, stx1, ireA and cdt genes. Taking together, the study offers strong evidence supporting the presence of two phenotype forms in the multidrug-resistant and pathogenic M. morganii strain, showing differential phenotypes. Additionally, since water flow and movement are prevalent characteristics in aquaculture systems, they can exert fluid shear on the resident microbial communities. Therefore, our study could serve as a foundation for understanding the behavior of M. morganii in aquaculture settings and enable the possibility of monitoring and controlling this multidrug-resistant and pathogenic bacterium by steering phenotypes.
{"title":"Environmental transition navigates phenotype switching, affecting the virulence and multidrug-resistant profile of pathogenic Morganella morganii","authors":"Vikash Kumar, Basanta Kumar Das, Suvra Roy, Souvik Dhar, Kampan Bisai, Anupam Adhikari, Angana Majumder, Asim Kumar Jana","doi":"10.1016/j.micpath.2025.107430","DOIUrl":"10.1016/j.micpath.2025.107430","url":null,"abstract":"<div><div>The bacteria's ability to respond to environmental changes is critical for their survival. This allows them to form intricate communities, withstand stress, and initiate virulence responses in hosts during infection, a phenomenon known as phenotypic switching. In this study, we investigated the role of shaking conditions on phenotype switch in multidrug-resistant and pathogenic <em>Morganella morganii</em> both under <em>in vitro</em> and <em>in vivo</em> conditions. The results demonstrate that <em>M</em>. <em>morganii</em> grown in non-shaking conditions, possibly causing low fluid shear, developed floccules or cellular aggregates, and substantially increased biofilm formation. Meanwhile, the bacterium grown in shaking conditions was non-flocculated and produced less biofilm. This phenotype switch leads to a significant change in the protein secretome and multidrug resistance profile. In the non-shaking condition, <em>M. morganii</em> secretes two main proteins of ∼80 and ∼100 kDa and displays multiple antibiotic resistance (MAR) values of 0.39. In contrast, the bacterial cell in a shaking flask secreted one prominent protein of ∼50 kDa and exhibited a lower MAR value of 0.31. These observations correspond with a significant reduction in both <em>in vitro</em> and <em>in vivo</em> virulence of <em>M</em>. <em>morganii</em> grown in non-shaking conditions, namely haemolysin, swimming motility, histomorphological changes, and survival assay as compared to bacterial cells in a shaking flask displayed higher virulence in both <em>in vitro</em> and <em>in vivo</em> condition. Furthermore, non-shaking tube-grown cells have higher expression of <em>saa</em>, <em>astA</em>, <em>ibeA</em>, <em>papC</em> and <em>papG</em> genes as compared to cells grown in the shaking flask exhibiting higher expression of <em>kpsMT K</em>1, <em>kpsMT</em> “<em>K5</em>”, <em>stx</em><sub>1</sub>, <em>ireA</em> and <em>cdt</em> genes. Taking together, the study offers strong evidence supporting the presence of two phenotype forms in the multidrug-resistant and pathogenic <em>M</em>. <em>morganii</em> strain, showing differential phenotypes. Additionally, since water flow and movement are prevalent characteristics in aquaculture systems, they can exert fluid shear on the resident microbial communities. Therefore, our study could serve as a foundation for understanding the behavior of <em>M. morganii</em> in aquaculture settings and enable the possibility of monitoring and controlling this multidrug-resistant and pathogenic bacterium by steering phenotypes.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107430"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.micpath.2025.107431
Manas Manam, Sankalp Srivatsa, W. Jabez Osborne
Resistance in human bacterial pathogens and lack of novel antibiotic development has led to the need for new antibiotics. Therefore, the current study was focused on endophytic bacteria from Gracilaria edulis, an edible seaweed, capable of synthesizing novel bioactive compounds with potential applications in the inhibition of human pathogens. The endophyte, identified as Bacillus subtilis through 16S rRNA gene sequencing, exhibited significant antibacterial activity against bacterial human pathogens. Using GC-MS, FTIR and NMR the lead compound was identified as Pyrrolo[1,2-α] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) (PPDHMP). Optimized media composition using glucose, proline and valine significantly enhanced the production of PPDHMP which was observed by the increase in zone of inhibition. Molecular docking of PPDHMP indicated a high binding affinity to beta-lactamase, suggesting its potential as a beta-lactamase inhibitor. PPDHMP exhibited cell wall inhibitory activity and ADMET analysis revealed promising pharmacokinetic and toxicity profiles indicating its potential for further evaluation as an oral antibiotic candidate. Phytotoxicity assessments and hemolytic assay confirmed the non-toxic nature of the metabolites produced. This research highlights the immense potential of marine endophytes in addressing the escalating issue of antibiotic resistance and paves the way for innovative solutions in antimicrobial therapy.
{"title":"Endophytic bacteria of Gracilaria edulis in combating human bacterial pathogens by PPDHMP – A crude to single molecule product development approach","authors":"Manas Manam, Sankalp Srivatsa, W. Jabez Osborne","doi":"10.1016/j.micpath.2025.107431","DOIUrl":"10.1016/j.micpath.2025.107431","url":null,"abstract":"<div><div>Resistance in human bacterial pathogens and lack of novel antibiotic development has led to the need for new antibiotics. Therefore, the current study was focused on endophytic bacteria from <em>Gracilaria edulis,</em> an edible seaweed, capable of synthesizing novel bioactive compounds with potential applications in the inhibition of human pathogens. The endophyte, identified as <em>Bacillus subtilis</em> through 16S rRNA gene sequencing, exhibited significant antibacterial activity against bacterial human pathogens. Using GC-MS, FTIR and NMR the lead compound was identified as Pyrrolo[1,2-α] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) (PPDHMP). Optimized media composition using glucose, proline and valine significantly enhanced the production of PPDHMP which was observed by the increase in zone of inhibition. Molecular docking of PPDHMP indicated a high binding affinity to beta-lactamase, suggesting its potential as a beta-lactamase inhibitor. PPDHMP exhibited cell wall inhibitory activity and ADMET analysis revealed promising pharmacokinetic and toxicity profiles indicating its potential for further evaluation as an oral antibiotic candidate. Phytotoxicity assessments and hemolytic assay confirmed the non-toxic nature of the metabolites produced. This research highlights the immense potential of marine endophytes in addressing the escalating issue of antibiotic resistance and paves the way for innovative solutions in antimicrobial therapy.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107431"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leptospirosis is a widespread zoonotic disease that causes severe health complications with no approved vaccine which provide broad range protection. In this study, we have focused on LruC protein from the outer membrane of Leptospira spp. LruC protein has been considered as promising target for vaccine due to its immunogenicity and conservancy. We have identified total 13 conserved B-cell, CTL, and HTL epitopes from 22 different pathogenic Leptospira species and serovars, which were linked with 4 linkers and 3 adjuvants (HBHA, CTB, TLR4) to design 36 multiepitope vaccine constructs to study the effect of different components on vaccine effectiveness. The antigenicity, immunogenicity, and non-allergenicity of the constructs were confirmed through computational analyses. Physico-chemical properties, secondary structure, and tertiary models of the vaccine constructs were predicted and validated. Molecular docking studies were conducted with Toll-like receptors (TLR2, TLR4) to assess binding affinity, identifying three top vaccine candidates (HBHA-construct 6, CTB-construct 9, and TLR4-construct 12) for further investigation. Further, these candidates were successfully cloned into pVAX1 and pET30a vectors to prepare DNA and protein vaccines, respectively. Moreover, these multiepitope vaccines were tested in mice models to assess its immunogenicity. ELISA performed with antisera against vaccine antigen, as well as crude extract of pathogenic Leptospira species showed significant IgG responses, particularly in protein vaccines. Flow cytometry revealed increased IFN-γ producing CD4+ and CD8+ T cells, especially in the TLR4-adjuvanted vaccine groups. The microscopic agglutination test further confirmed the specificity of the antibody response to Leptospira serovars. Overall, this study demonstrates the potential of these multiepitope vaccine constructs in eliciting a robust immune response, laying the foundation for future challenge study and preclinical evaluation.
{"title":"Design and evaluation of potent multiepitope broad spectrum DNA and protein vaccine candidates against leptospirosis","authors":"Anita Chauhan , Dhwani Jhala , Ritik Thumar , Kopal Kapoor , Aneri Joshi , Devanshi Gajjar , Sriram Seshadri , Satyamitra Shekh , Chaitanya Joshi , Amrutlal Patel","doi":"10.1016/j.micpath.2025.107418","DOIUrl":"10.1016/j.micpath.2025.107418","url":null,"abstract":"<div><div>Leptospirosis is a widespread zoonotic disease that causes severe health complications with no approved vaccine which provide broad range protection. In this study, we have focused on LruC protein from the outer membrane of <em>Leptospira</em> spp. LruC protein has been considered as promising target for vaccine due to its immunogenicity and conservancy. We have identified total 13 conserved B-cell, CTL, and HTL epitopes from 22 different pathogenic <em>Leptospira</em> species and serovars, which were linked with 4 linkers and 3 adjuvants (HBHA, CTB, TLR4) to design 36 multiepitope vaccine constructs to study the effect of different components on vaccine effectiveness. The antigenicity, immunogenicity, and non-allergenicity of the constructs were confirmed through computational analyses. Physico-chemical properties, secondary structure, and tertiary models of the vaccine constructs were predicted and validated. Molecular docking studies were conducted with Toll-like receptors (TLR2, TLR4) to assess binding affinity, identifying three top vaccine candidates (HBHA-construct 6, CTB-construct 9, and TLR4-construct 12) for further investigation. Further, these candidates were successfully cloned into pVAX1 and pET30a vectors to prepare DNA and protein vaccines, respectively. Moreover, these multiepitope vaccines were tested in mice models to assess its immunogenicity. ELISA performed with antisera against vaccine antigen, as well as crude extract of pathogenic Leptospira species showed significant IgG responses, particularly in protein vaccines. Flow cytometry revealed increased IFN-γ producing CD4<sup>+</sup> and CD8<sup>+</sup> T cells, especially in the TLR4-adjuvanted vaccine groups. The microscopic agglutination test further confirmed the specificity of the antibody response to <em>Leptospira</em> serovars. Overall, this study demonstrates the potential of these multiepitope vaccine constructs in eliciting a robust immune response, laying the foundation for future challenge study and preclinical evaluation.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107418"},"PeriodicalIF":3.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-27DOI: 10.1016/j.micpath.2025.107439
Xilin Wang , Shihai Wu , Ning Guo , Feike Yu , Xiaofeng Xu , Xinghai Wang , Xiaohan Yu , Xiaoye Liu , Hong Dong
The Chinese poultry industry has witnessed rapid development, with laying hens playing a pivotal role. However, the escalating demand has led to an exponential increase in the population of laying hens raised, resulting in emerging challenges. Particularly during bacterial infections, substantial losses can be incurred. Presently, most farms heavily rely on antibiotics for disease prevention and control. Although this approach has yielded positive outcomes, prolonged usage may lead to the emergence of drug-resistant strains and residues. Consequently, research on alternative drugs has been initiated due to antibiotic prohibition and growing pathogen resistance. Chinese herbal medicine holds significant prominence across various domains, including animal husbandry and disease treatment, owing to its traditional roots in China. Scutellaria baicalensis is a traditional Chinese medicine derived from the dried root of the labiatae family plant Scutellaria baicalensis that possesses bitter taste and cold properties while exhibiting effects such as heat clearance, dampness elimination, lung purification, fire expulsion and heat detoxification. The aboveground components of Scutellaria baicalensis encompass stems and leaves, which yield approximately three times more than their root counterparts as traditional Chinese medicine resources. Sculltllarla bactlalensls products have been successfully applied in animal husbandry with therapeutic effects against sore throat, respiratory diseases, and heat detoxification. Therefore, in pursuit of economic sustainability, this study aims at developing an extract from Scutellaria baicalensis stems and leaves for treating respiratory bacterial infections among laying hens. The findings indicate that this extract exhibits excellent therapeutic efficacy against respiratory diseases among laying hens by reducing inflammatory cell levels within their lungs.
{"title":"Scutellaria baicalensis stem and leaf combat chicken-derived respiratory bacterial infection","authors":"Xilin Wang , Shihai Wu , Ning Guo , Feike Yu , Xiaofeng Xu , Xinghai Wang , Xiaohan Yu , Xiaoye Liu , Hong Dong","doi":"10.1016/j.micpath.2025.107439","DOIUrl":"10.1016/j.micpath.2025.107439","url":null,"abstract":"<div><div>The Chinese poultry industry has witnessed rapid development, with laying hens playing a pivotal role. However, the escalating demand has led to an exponential increase in the population of laying hens raised, resulting in emerging challenges. Particularly during bacterial infections, substantial losses can be incurred. Presently, most farms heavily rely on antibiotics for disease prevention and control. Although this approach has yielded positive outcomes, prolonged usage may lead to the emergence of drug-resistant strains and residues. Consequently, research on alternative drugs has been initiated due to antibiotic prohibition and growing pathogen resistance. Chinese herbal medicine holds significant prominence across various domains, including animal husbandry and disease treatment, owing to its traditional roots in China. <em>Scutellaria baicalensis</em> is a traditional Chinese medicine derived from the dried root of the labiatae family plant <em>Scutellaria baicalensis</em> that possesses bitter taste and cold properties while exhibiting effects such as heat clearance, dampness elimination, lung purification, fire expulsion and heat detoxification. The aboveground components of <em>Scutellaria baicalensis</em> encompass stems and leaves, which yield approximately three times more than their root counterparts as traditional Chinese medicine resources. <em>Sculltllarla bactlalensls</em> products have been successfully applied in animal husbandry with therapeutic effects against sore throat, respiratory diseases, and heat detoxification. Therefore, in pursuit of economic sustainability, this study aims at developing an extract from <em>Scutellaria baicalensis</em> stems and leaves for treating respiratory bacterial infections among laying hens. The findings indicate that this extract exhibits excellent therapeutic efficacy against respiratory diseases among laying hens by reducing inflammatory cell levels within their lungs.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107439"},"PeriodicalIF":3.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The inflammatory response in bone tissue often triggered by LPS is a complex process. Since LPS through TLR4 and in presence of IFNγ activates osteoclast differentiation and bone resorption, therefore, suppression of osteoclastogenesis through inhibition of TLR4 vs IFNγ mediated inflammation could be a reasonable strategy for the treatment of inflammatory bone loss. Administration of anti-TLR4 (30 mg/kg) and anti-IFNγ antibodies (6.6 mg/kg) were utilized before LPS (5 mg/kg) challenge and subsequently mice were treated with mouse IL-10 (0.02 mg/kg). Then RBMCs were isolated from different groups of mice and stimulated (in vitro) with M-CSF (10 ng/ml) and RANKL (10 ng/ml) to induce bone marrow cell differentiation in presence of LPS (100 ng/ml). The involvement of RANKL and M-CSF in the regulation of bone inflammation underlines the intricate signaling pathways. Furthermore, the study sheds light on the potential therapeutic effects of exogenous IL-10 possibly through STAT3 signaling in the RBMCs. The use of antibodies against TLR4 and IFNγ, in conjugation with IL-10in LPS bone damage model, appears to downregulate the activation of NF-κB, and reduction of many pro-inflammatory cytokines regulating the inflammatory cascade in RBMC. This suggests a promising avenue for the development of treatments aimed at mitigating bone inflammation associated with bacterial infections. Therefore, inhibition of TLR4 and IFNγ could be explored as potential therapeutic agents against LPS induced bone loss.
{"title":"TLR-4Ab and IFNγAb with exogenous IL-10 treated LPS induced mice shown differential inflammatory response upon RANKL-M-CSF stimulation in resident bone marrow cells","authors":"Gopinath Mukherjee, Sharmistha Samanta, Biswadev Bishayi","doi":"10.1016/j.micpath.2025.107416","DOIUrl":"10.1016/j.micpath.2025.107416","url":null,"abstract":"<div><div>The inflammatory response in bone tissue often triggered by LPS is a complex process. Since LPS through TLR4 and in presence of IFNγ activates osteoclast differentiation and bone resorption, therefore, suppression of osteoclastogenesis through inhibition of TLR4 vs IFNγ mediated inflammation could be a reasonable strategy for the treatment of inflammatory bone loss. Administration of anti-TLR4 (30 mg/kg) and anti-IFNγ antibodies (6.6 mg/kg) were utilized before LPS (5 mg/kg) challenge and subsequently mice were treated with mouse IL-10 (0.02 mg/kg). Then RBMCs were isolated from different groups of mice and stimulated (<em>in vitro</em>) with M-CSF (10 ng/ml) and RANKL (10 ng/ml) to induce bone marrow cell differentiation in presence of LPS (100 ng/ml). The involvement of RANKL and M-CSF in the regulation of bone inflammation underlines the intricate signaling pathways. Furthermore, the study sheds light on the potential therapeutic effects of exogenous IL-10 possibly through STAT3 signaling in the RBMCs. The use of antibodies against TLR4 and IFNγ, in conjugation with IL-10in LPS bone damage model, appears to downregulate the activation of NF-κB, and reduction of many pro-inflammatory cytokines regulating the inflammatory cascade in RBMC. This suggests a promising avenue for the development of treatments aimed at mitigating bone inflammation associated with bacterial infections. Therefore, inhibition of TLR4 and IFNγ could be explored as potential therapeutic agents against LPS induced bone loss.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107416"},"PeriodicalIF":3.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.micpath.2025.107435
Hamza Rasheed , Muhammad Ijaz , Arslan Ahmed , Muhammad Muddassir Ali
Mastitis is considered one of milk-producing animals' most widespread infectious diseases. The present study evaluated the prevalence of antibiotic-resistant isolates of Staphylococcus aureus (S. aureus) including methicillin-resistant S. aureus (MRSA), β-lactam-resistant S. aureus (BRSA), aminoglycoside-resistant S. aureus (ARSA), and tetracycline-resistant S. aureus (TRSA) from the udder of dromedary camels along with the associated risk factors and the antibiogram of resistant isolates. Phylogenetic analysis of antibiotic-resistant genes with NCBI sequences was performed to check their homology. A total of 384 milk samples were collected and subjected to standard microbiological procedures to isolate S. aureus. The results revealed that 177 milk samples were found positive for subclinical mastitis (SCM) out of which 101 milk samples were found positive for S. aureus. The molecular assay found the prevalence of MRSA, BRSA, ARSA, and TRSA as 48.51 %, 46.53 %, 42.57 %, and 39.60 % by targeting the mecA, blaZ, accA-aphD, and tetK genes respectively. The study isolates significant similarities to each other and to previously reported sequences from other countries that were found by in-silico analysis, indicating the possibility of pathogen transboundary transmission. This study also revealed potential risk factors that aid in the spread of mastitis in camels. Among various risk factors, the most significant were farm hygiene, physiological status of animals, type of mastitis, teat injury, use of teat dips, and milk leakage (p < 0.05). The antibiogram of antibiotic-resistant isolates of S. aureus revealed that the highest resistance was observed against penicillin followed by amoxicillin and oxytetracycline while levofloxacin was the most sensitive drug. This study highlights the high prevalence of antimicrobial-resistant S. aureus in camel mastitis. Identified risk factors provide valuable insights into management practices that contribute to disease occurrence, aiding in the development of targeted control strategies. Additionally, antimicrobial susceptibility findings offer guidance for optimizing treatment protocols to effectively manage S. aureus-induced mastitis in camels and mitigate the spread of antimicrobial resistance.
{"title":"Molecular epidemiology and antibiotic resistance profiling of Staphylococcus aureus isolates from camel mastitis","authors":"Hamza Rasheed , Muhammad Ijaz , Arslan Ahmed , Muhammad Muddassir Ali","doi":"10.1016/j.micpath.2025.107435","DOIUrl":"10.1016/j.micpath.2025.107435","url":null,"abstract":"<div><div>Mastitis is considered one of milk-producing animals' most widespread infectious diseases. The present study evaluated the prevalence of antibiotic-resistant isolates of <em>Staphylococcus aureus</em> (<em>S. aureus</em>) including methicillin-resistant <em>S. aureus</em> (MRSA), β-lactam-resistant <em>S. aureus</em> (BRSA), aminoglycoside-resistant <em>S. aureus</em> (ARSA), and tetracycline-resistant <em>S. aureus</em> (TRSA) from the udder of dromedary camels along with the associated risk factors and the antibiogram of resistant isolates. Phylogenetic analysis of antibiotic-resistant genes with NCBI sequences was performed to check their homology. A total of 384 milk samples were collected and subjected to standard microbiological procedures to isolate <em>S. aureus</em>. The results revealed that 177 milk samples were found positive for subclinical mastitis (SCM) out of which 101 milk samples were found positive for <em>S. aureus</em>. The molecular assay found the prevalence of MRSA, BRSA, ARSA, and TRSA as 48.51 %, 46.53 %, 42.57 %, and 39.60 % by targeting the <em>mecA</em>, <em>blaZ</em>, <em>accA-aphD</em>, and <em>tetK</em> genes respectively. The study isolates significant similarities to each other and to previously reported sequences from other countries that were found by <em>in-silico</em> analysis, indicating the possibility of pathogen transboundary transmission. This study also revealed potential risk factors that aid in the spread of mastitis in camels. Among various risk factors, the most significant were farm hygiene, physiological status of animals, type of mastitis, teat injury, use of teat dips, and milk leakage (<em>p</em> < 0.05). The antibiogram of antibiotic-resistant isolates of <em>S. aureus</em> revealed that the highest resistance was observed against penicillin followed by amoxicillin and oxytetracycline while levofloxacin was the most sensitive drug. This study highlights the high prevalence of antimicrobial-resistant <em>S. aureus</em> in camel mastitis. Identified risk factors provide valuable insights into management practices that contribute to disease occurrence, aiding in the development of targeted control strategies. Additionally, antimicrobial susceptibility findings offer guidance for optimizing treatment protocols to effectively manage <em>S. aureus</em>-induced mastitis in camels and mitigate the spread of antimicrobial resistance.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"202 ","pages":"Article 107435"},"PeriodicalIF":3.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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