Pub Date : 2024-05-29eCollection Date: 2024-06-01DOI: 10.33073/pjm-2024-017
Yu Xiu, Yueru Dai, Shasha Yin, Quhao Wei
Acinetobacter baumannii is a non-fermentative Gram-negative bacterium that can cause nosocomial infections in critically ill patients. Carbapenem-resistant A. baumannii (CRAB) has spread rapidly in clinical settings and has become a key concern. The main objective of this study was to identify the distribution of integrons and biofilm-formation-related virulence genes in CRAB isolates. A total of 269 A. baumannii isolates (219 isolates of CRAB and 50 isolates of carbapenem-sensitive A. baumannii (CSAB)) were collected. Carbapenemase genes (blaKPC, blaVIM, blaIMP, blaNDM, and blaOXA-23-like) and biofilm-formation-related virulence genes (abal, bfms, bap, and cusE) were screened with PCR. Class 1 integron was screened with PCR, and common promoters and gene cassette arrays were determined with restriction pattern analysis combined with primer walking sequencing. Whole-genome sequencing was conducted, and data were analyzed for a blaOXA-23-like-negative isolate. All 219 CRAB isolates were negative for blaKPC, blaVIM, blaIMP, and blaNDM, while blaOXA-23-like was detected in 218 isolates. The detection rates for abal, bfms, bap, and cusE in 219 CRAB were 93.15%, 63.93%, 88.13%, and 77.63%, respectively. Class 1 integron was detected in 75 CRAB (34.25%) and in 3 CSAB. The single gene cassette array aacA4-catB8-aadA1 with relatively strong PcH2 promoter was detected in class 1 integrons. The blaOXA-23-like-negative CRAB isolate was revealed to be a new sequence type (Oxford 3272, Pasteur 2520) carrying blaOXA-72, blaOXA-259, and blaADC-26. In conclusion, blaOXA-23-like was the main reason for CRAB's resistance to carbapenems. A new (Oxford 3272, Pasteur 2520) CRAB sequence type carrying the blaOXA-72, blaOXA-259, and blaADC-26 was reported.
鲍曼不动杆菌(Acinetobacter baumannii)是一种非发酵革兰氏阴性细菌,可引起重症患者的院内感染。耐碳青霉烯鲍曼不动杆菌(CRAB)已在临床环境中迅速传播,并已成为人们关注的焦点。本研究的主要目的是鉴定 CRAB 分离物中整合子和生物膜形成相关毒力基因的分布。本研究共收集了269株鲍曼不动杆菌分离株(219株CRAB分离株和50株碳青霉烯类敏感鲍曼不动杆菌(CSAB)分离株)。用 PCR 筛选了碳青霉烯酶基因(bla KPC、bla VIM、bla IMP、bla NDM 和 bla OXA-23-like)和与生物膜形成相关的毒力基因(abal、bfms、bap 和 cusE)。用 PCR 筛选了 1 类整合子,并通过限制性模式分析和引物走行测序确定了常见启动子和基因盒阵列。进行了全基因组测序,并对 bla OXA-23 样阴性分离物进行了数据分析。所有 219 个 CRAB 分离物的 bla KPC、bla VIM、bla IMP 和 bla NDM 均为阴性,而 218 个分离物中检测到了 bla OXA-23-like。在 219 个 CRAB 分离物中,abal、bfms、bap 和 cusE 的检出率分别为 93.15%、63.93%、88.13% 和 77.63%。在 75 个 CRAB(34.25%)和 3 个 CSAB 中检测到了 1 类整合子。在 1 类整合子中检测到了带有相对较强的 PcH2 启动子的单基因盒阵列 aacA4-catB8-aadA1。bla OXA-23 样阴性的 CRAB 分离物被发现是一种新的序列类型(Oxford 3272,Pasteur 2520),携带 bla OXA-72、bla OXA-259 和 bla ADC-26。总之,类 bla OXA-23 是 CRAB 对碳青霉烯类产生耐药性的主要原因。报告了一种携带 bla OXA-72、bla OXA-259 和 bla ADC-26 的新 CRAB 序列类型(牛津 3272,巴斯德 2520)。
{"title":"Analysis of the Class 1 Integrons, Carbapenemase Genes and Biofilm Formation Genes Occurrence in <i>Acinetobacter baumannii</i> Clinical Isolates.","authors":"Yu Xiu, Yueru Dai, Shasha Yin, Quhao Wei","doi":"10.33073/pjm-2024-017","DOIUrl":"10.33073/pjm-2024-017","url":null,"abstract":"<p><p><i>Acinetobacter baumannii</i> is a non-fermentative Gram-negative bacterium that can cause nosocomial infections in critically ill patients. Carbapenem-resistant <i>A. baumannii</i> (CRAB) has spread rapidly in clinical settings and has become a key concern. The main objective of this study was to identify the distribution of integrons and biofilm-formation-related virulence genes in CRAB isolates. A total of 269 <i>A. baumannii</i> isolates (219 isolates of CRAB and 50 isolates of carbapenem-sensitive <i>A. baumannii</i> (CSAB)) were collected. Carbapenemase genes (<i>bla</i> <sub>KPC</sub>, <i>bla</i> <sub>VIM</sub>, <i>bla</i> <sub>IMP</sub>, <i>bla</i> <sub>NDM</sub>, and <i>bla</i> <sub>OXA-23-like</sub>) and biofilm-formation-related virulence genes (<i>abal</i>, <i>bfms</i>, <i>bap</i>, and <i>cusE</i>) were screened with PCR. Class 1 integron was screened with PCR, and common promoters and gene cassette arrays were determined with restriction pattern analysis combined with primer walking sequencing. Whole-genome sequencing was conducted, and data were analyzed for a <i>bla</i> <sub>OXA-23-like</sub>-negative isolate. All 219 CRAB isolates were negative for <i>bla</i> <sub>KPC</sub>, <i>bla</i> <sub>VIM</sub>, <i>bla</i> <sub>IMP</sub>, and <i>bla</i> <sub>NDM</sub>, while <i>bla</i> <sub>OXA-23-like</sub> was detected in 218 isolates. The detection rates for <i>abal</i>, <i>bfms</i>, <i>bap</i>, and <i>cusE</i> in 219 CRAB were 93.15%, 63.93%, 88.13%, and 77.63%, respectively. Class 1 integron was detected in 75 CRAB (34.25%) and in 3 CSAB. The single gene cassette array <i>aacA4-catB8-aadA1</i> with relatively strong PcH2 promoter was detected in class 1 integrons. The <i>bla</i> <sub>OXA-23-like</sub>-negative CRAB isolate was revealed to be a new sequence type (Oxford 3272, Pasteur 2520) carrying <i>bla</i> <sub>OXA-72</sub>, <i>bla</i> <sub>OXA-259</sub>, and <i>bla</i> <sub>ADC-26</sub>. In conclusion, <i>bla</i> <sub>OXA-23-like</sub> was the main reason for CRAB's resistance to carbapenems. A new (Oxford 3272, Pasteur 2520) CRAB sequence type carrying the <i>bla</i> <sub>OXA-72</sub>, <i>bla</i> <sub>OXA-259</sub>, and <i>bla</i> <sub>ADC-26</sub> was reported.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"189-197"},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192457/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141161683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens causing hemorrhagic colitis and hemolytic uremic syndrome (HUS) in children and the elderly. Stool samples were collected from 180 children hospitalized in five pediatric centers in Poland in 2018-2022. Direct stx1/stx2 gene detection by PCR in feces and E. coli isolates was performed. Antibiotic susceptibility was tested according to EUCAST v.12. Randomly selected isolates were serotyped with O157 antiserum and genotyped by pulsed-field gel electrophoresis (PFGE). A total of 44 E. coli isolates were confirmed as STEC by PCR. Among them, 84.4% were positive for stx2, and equally 6,8% for only stx1 and both stx1 and stx2 genes. The stx1 gene was also found in one Citrobacter freundii isolate. E. coli serotype O157 was present in 97.6% of the isolates. STEC infections most often occurred between June-October with a peak in July and August (51%). The highest, 77.8% of STEC isolates were found in the 1-5 years old group. No extended-spectrum β-lactamases (ESBL) were found. Resistance only to amoxicillin/clavulanic acid (24.4%), piperacillin/tazobactam (3%), cefotaxime (6%), gentamicin (6%), ciprofloxacin (3%), azithromycin (3%), trimethoprim/sulfamethoxazole (24,2%) was detected. PFGE analysis showed 18 PFGE types with no clonal distribution. Eight isolates with A, B, and C PFGE types showed genetic relatedness in the type with no detection of transmission way of distribution. STEC strains pose a serious threat to human health, therefore demographic and epidemiological characteristics are crucial for their surveillance.
{"title":"Epidemiological Characteristics of Shiga Toxin-Producing <i>Escherichia coli</i> Responsible for Infections in the Polish Pediatric Population.","authors":"Dominika Seliga-Gąsior, Beata Sokól-Leszczyñska, Jolanta Krzysztoñ-Russjan, Diana Wierzbicka, Karolina Stępieñ-Hołubczat, Paulina Lewandowska, Ewa Frankiewicz, Andrzej Cacko, Beata Leszczyñska, Urszula Demkow, Edyta Podsiadły","doi":"10.33073/pjm-2024-016","DOIUrl":"10.33073/pjm-2024-016","url":null,"abstract":"<p><p>Shiga toxin-producing <i>Escherichia coli</i> (STEC) are zoonotic pathogens causing hemorrhagic colitis and hemolytic uremic syndrome (HUS) in children and the elderly. Stool samples were collected from 180 children hospitalized in five pediatric centers in Poland in 2018-2022. Direct <i>stx1</i>/<i>stx2</i> gene detection by PCR in feces and <i>E. coli</i> isolates was performed. Antibiotic susceptibility was tested according to EUCAST v.12. Randomly selected isolates were serotyped with O157 antiserum and genotyped by pulsed-field gel electrophoresis (PFGE). A total of 44 <i>E. coli</i> isolates were confirmed as STEC by PCR. Among them, 84.4% were positive for <i>stx2</i>, and equally 6,8% for only <i>stx1</i> and both <i>stx1</i> and <i>stx2</i> genes. The <i>stx1</i> gene was also found in one <i>Citrobacter freundii</i> isolate. <i>E. coli</i> serotype O157 was present in 97.6% of the isolates. STEC infections most often occurred between June-October with a peak in July and August (51%). The highest, 77.8% of STEC isolates were found in the 1-5 years old group. No extended-spectrum β-lactamases (ESBL) were found. Resistance only to amoxicillin/clavulanic acid (24.4%), piperacillin/tazobactam (3%), cefotaxime (6%), gentamicin (6%), ciprofloxacin (3%), azithromycin (3%), trimethoprim/sulfamethoxazole (24,2%) was detected. PFGE analysis showed 18 PFGE types with no clonal distribution. Eight isolates with A, B, and C PFGE types showed genetic relatedness in the type with no detection of transmission way of distribution. STEC strains pose a serious threat to human health, therefore demographic and epidemiological characteristics are crucial for their surveillance.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"177-187"},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192175/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140900769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to investigate azole resistance mechanisms in Aspergillus flavus, which involve cyp51A and cyp51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the overexpression of cyp51A and cyp51B genes for 34 A. flavus isolates. PCR sequencing of these two genes was used to detect the presence of gene mutations. Susceptibility test found sensitivity to voriconazole (VOR) in all strains. 14.7% and 8.8% of isolates were resistant to itraconazole (IT) and posaconazole (POS), respectively, with a cross-resistance in 5.8%. For the double resistant isolates (IT/POS), the expression of cyp51A was up to 17-fold higher. PCR sequencing showed the presence of 2 mutations in cyp51A: a synonymous point mutation (P61P) in eight isolates, which did not affect the structure of CYP51A protein, and another non synonymous mutation (G206L) for only the TN-33 strain (cross IT/POS resistance) causing an amino acid change in the protein sequence. However, we noted in cyp51B the presence of the only non-synonymous mutation (L177G) causing a change in amino acids in the protein sequence for the TN-31 strain, which exhibits IT/POS cross-resistance. A short single intron of 67 bp was identified in the cyp51A gene, whereas three short introns of 54, 53, and 160 bp were identified in the cyp51B gene. According to the models provided by PatchDock software, the presence of non-synonymous mutations did not affect the interaction of CYP51A and CYP51B proteins with antifungals. In our study, the overexpression of the cyp51A and cyp51B genes is the primary mechanism responsible for resistance in A. flavus collection. Nevertheless, other resistance mechanisms can be involved.
{"title":"Investigation of Azole Resistance Involving <i>cyp</i>51A and <i>cyp</i>51B Genes in Clinical <i>Aspergillus flavus</i> Isolates.","authors":"Dhoha Ghorbel, Imen Amouri, Nahed Khemekhem, Sourour Neji, Houaida Trabelsi, Moez Elloumi, Hayet Sellami, Fattouma Makni, Ali Ayadi, Ines Hadrich","doi":"10.33073/pjm-2024-001","DOIUrl":"10.33073/pjm-2024-001","url":null,"abstract":"<p><p>This study aimed to investigate azole resistance mechanisms in <i>Aspergillus flavus,</i> which involve <i>cyp</i>51A and <i>cyp</i>51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the overexpression of <i>cyp</i>51A and <i>cyp</i>51B genes for 34 <i>A. flavus</i> isolates. PCR sequencing of these two genes was used to detect the presence of gene mutations. Susceptibility test found sensitivity to voriconazole (VOR) in all strains. 14.7% and 8.8% of isolates were resistant to itraconazole (IT) and posaconazole (POS), respectively, with a cross-resistance in 5.8%. For the double resistant isolates (IT/POS), the expression of <i>cyp</i>51A was up to 17-fold higher. PCR sequencing showed the presence of 2 mutations in <i>cyp</i>51A: a synonymous point mutation (P61P) in eight isolates, which did not affect the structure of CYP51A protein, and another non synonymous mutation (G206L) for only the TN-33 strain (cross IT/POS resistance) causing an amino acid change in the protein sequence. However, we noted in <i>cyp</i>51B the presence of the only non-synonymous mutation (L177G) causing a change in amino acids in the protein sequence for the TN-31 strain, which exhibits IT/POS cross-resistance. A short single intron of 67 bp was identified in the <i>cyp</i>51A gene, whereas three short introns of 54, 53, and 160 bp were identified in the <i>cyp</i>51B gene. According to the models provided by PatchDock software, the presence of non-synonymous mutations did not affect the interaction of CYP51A and CYP51B proteins with antifungals. In our study, the overexpression of the <i>cyp</i>51A and <i>cyp</i>51B genes is the primary mechanism responsible for resistance in <i>A. flavus</i> collection. Nevertheless, other resistance mechanisms can be involved.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"131-142"},"PeriodicalIF":0.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140854802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-28eCollection Date: 2024-06-01DOI: 10.33073/pjm-2024-015
Zhiqiang Ren, Juan Xie, Tuoxian Tang, Zhiguo Huang
Sub-high temperature Daqu, a traditional solid fermenting agent used in Chinese strong-aroma Baijiu production, is abundant in diverse microorganisms, including bacteria, yeasts, molds, and actinomycetes. Among these, yeasts are pivotal for ethanol production and flavor formation. However, counting yeasts in Daqu is challenging due to interference from molds and bacteria. Antibiotics are employed to inhibit bacterial growth, but there is no practical way to suppress molds without affecting the growth of yeasts. In this study, short-chain carboxylates (C1-C6) were added to the culture medium at various pH conditions to investigate their effects on the growth of molds and yeasts. The results demonstrated distinct inhibitory effects of the short-chain carboxylates, depending on both pH and concentration. Several tested short-chain carboxylates effectively suppressed mold growth on agar plates while leaving yeast growth unaffected. This suggests a simple and feasible method for enhancing the efficiency of yeast isolation and counting in Daqu. Such an approach is valuable for studying yeasts in diverse and complex habitats.
{"title":"Short-Chain Carboxylates Facilitate the Counting of Yeasts in Sub-High Temperature Daqu.","authors":"Zhiqiang Ren, Juan Xie, Tuoxian Tang, Zhiguo Huang","doi":"10.33073/pjm-2024-015","DOIUrl":"10.33073/pjm-2024-015","url":null,"abstract":"<p><p>Sub-high temperature Daqu, a traditional solid fermenting agent used in Chinese strong-aroma Baijiu production, is abundant in diverse microorganisms, including bacteria, yeasts, molds, and actinomycetes. Among these, yeasts are pivotal for ethanol production and flavor formation. However, counting yeasts in Daqu is challenging due to interference from molds and bacteria. Antibiotics are employed to inhibit bacterial growth, but there is no practical way to suppress molds without affecting the growth of yeasts. In this study, short-chain carboxylates (C1-C6) were added to the culture medium at various pH conditions to investigate their effects on the growth of molds and yeasts. The results demonstrated distinct inhibitory effects of the short-chain carboxylates, depending on both pH and concentration. Several tested short-chain carboxylates effectively suppressed mold growth on agar plates while leaving yeast growth unaffected. This suggests a simple and feasible method for enhancing the efficiency of yeast isolation and counting in Daqu. Such an approach is valuable for studying yeasts in diverse and complex habitats.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"167-176"},"PeriodicalIF":0.0,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192557/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140856332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-28eCollection Date: 2024-06-01DOI: 10.33073/pjm-2024-014
Tan Viet Pham, Truong Chinh Hua, Ngoc An Nguyen, Hanh Thi Dieu Nguyen
Proteases derived from Streptomyces demonstrate numerous commendable properties, rendering it extensively applicable in biotechnology and various industrial sectors. This study focused on the purification and characterization of the thermostable protease obtained from Streptomyces sp. CNXK100. The purified protease exhibited an estimated molecular weight of 27 kDa, with optimal activity at 75°C and pH 8.0. Notably, the enzyme remained active even without any metal ions and fully active in the presence of Na+, K+, Mg2+, and Cu2+metal ions. The kinetic parameters were determined with a KM value of 3.13 mg/ml and a Vmax value of 3.28 × 106 U/mg. Furthermore, the protease has demonstrated notable stability when subjected to a treatment temperature of up to 65°C for 60 minutes, and across a broad pH range extending from 5.0 to 10.0. This protease also demonstrated resilience against a spectrum of harsh conditions, including exposure to organic solvents, surfactants, bleaching agents, and proteolytic enzymes. Additionally, the enzyme maintained its activity following treatment with commercial detergents, accomplishing complete thrombus lysis at a concentration of 2.50 mg/ml within 4 hours. Remarkably, the protease exhibited stability in terms of activity and protein concentration for 70 days at 4°C. These findings underscore the potential industrial applications of the thermostable protease from Streptomyces sp. CNXK100.
{"title":"Purification and Characterization of a Small Thermostable Protease from <i>Streptomyces</i> sp. CNXK100.","authors":"Tan Viet Pham, Truong Chinh Hua, Ngoc An Nguyen, Hanh Thi Dieu Nguyen","doi":"10.33073/pjm-2024-014","DOIUrl":"10.33073/pjm-2024-014","url":null,"abstract":"<p><p>Proteases derived from <i>Streptomyces</i> demonstrate numerous commendable properties, rendering it extensively applicable in biotechnology and various industrial sectors. This study focused on the purification and characterization of the thermostable protease obtained from <i>Streptomyces</i> sp. CNXK100. The purified protease exhibited an estimated molecular weight of 27 kDa, with optimal activity at 75°C and pH 8.0. Notably, the enzyme remained active even without any metal ions and fully active in the presence of Na<sup>+</sup>, K<sup>+</sup>, Mg<sup>2+</sup>, and Cu<sup>2+</sup>metal ions. The kinetic parameters were determined with a <i>K<sub>M</sub></i> value of 3.13 mg/ml and a <i>V<sub>max</sub></i> value of 3.28 × 10<sup>6</sup> U/mg. Furthermore, the protease has demonstrated notable stability when subjected to a treatment temperature of up to 65°C for 60 minutes, and across a broad pH range extending from 5.0 to 10.0. This protease also demonstrated resilience against a spectrum of harsh conditions, including exposure to organic solvents, surfactants, bleaching agents, and proteolytic enzymes. Additionally, the enzyme maintained its activity following treatment with commercial detergents, accomplishing complete thrombus lysis at a concentration of 2.50 mg/ml within 4 hours. Remarkably, the protease exhibited stability in terms of activity and protein concentration for 70 days at 4°C. These findings underscore the potential industrial applications of the thermostable protease from <i>Streptomyces</i> sp. CNXK100.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"155-165"},"PeriodicalIF":0.0,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140858005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-27eCollection Date: 2024-06-01DOI: 10.33073/pjm-2024-013
Lei Zhou, Tuoxian Tang, Dandan Deng, Yayue Wang, Dongli Pei
Electricigens decompose organic matter and convert stored chemical energy into electrical energy through extracellular electron transfer. They are significant biocatalysts for microbial fuel cells with practical applications in green energy generation, effluent treatment, and bioremediation. A facultative anaerobic electrogenic strain SQ-1 is isolated from sludge in a biotechnology factory. The strain SQ-1 is a close relative of Klebsiella variicola. Multilayered biofilms form on the surface of a carbon electrode after the isolated bacteria are inoculated into a microbial fuel cell device. This strain produces high current densities of 625 μA cm-2 by using acetate as the carbon source in a three-electrode configuration. The electricity generation performance is also analyzed in a dual-chamber microbial fuel cell. It reaches a maximum power density of 560 mW m-2 when the corresponding output voltage is 0.59 V. The facultative strain SQ-1 utilizes hydrous ferric oxide as an electron acceptor to perform extracellular electricigenic respiration in anaerobic conditions. Since facultative strains possess better properties than anaerobic strains, Klebsiella sp. SQ-1 may be a promising exoelectrogenic strain for applications in microbial electrochemistry.
{"title":"Isolation and Electrochemical Analysis of a Facultative Anaerobic Electrogenic Strain <i>Klebsiella</i> sp. SQ-1.","authors":"Lei Zhou, Tuoxian Tang, Dandan Deng, Yayue Wang, Dongli Pei","doi":"10.33073/pjm-2024-013","DOIUrl":"10.33073/pjm-2024-013","url":null,"abstract":"<p><p>Electricigens decompose organic matter and convert stored chemical energy into electrical energy through extracellular electron transfer. They are significant biocatalysts for microbial fuel cells with practical applications in green energy generation, effluent treatment, and bioremediation. A facultative anaerobic electrogenic strain SQ-1 is isolated from sludge in a biotechnology factory. The strain SQ-1 is a close relative of <i>Klebsiella variicola</i>. Multilayered biofilms form on the surface of a carbon electrode after the isolated bacteria are inoculated into a microbial fuel cell device. This strain produces high current densities of 625 μA cm<sup>-2</sup> by using acetate as the carbon source in a three-electrode configuration. The electricity generation performance is also analyzed in a dual-chamber microbial fuel cell. It reaches a maximum power density of 560 mW m<sup>-2</sup> when the corresponding output voltage is 0.59 V. The facultative strain SQ-1 utilizes hydrous ferric oxide as an electron acceptor to perform extracellular electricigenic respiration in anaerobic conditions. Since facultative strains possess better properties than anaerobic strains, <i>Klebsiella</i> sp. SQ-1 may be a promising exoelectrogenic strain for applications in microbial electrochemistry.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"143-153"},"PeriodicalIF":0.0,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192523/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140874317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04eCollection Date: 2024-03-01DOI: 10.33073/pjm-2024-011
Zhiwen Liang, Ke Zheng, Guifeng Xie, Xiongsheng Luo, Huangjin Li
This comprehensive review explores the development of food-grade selection markers in lactic acid bacteria and yeast; some of their strains are precisely defined as safe microorganisms and are crucial in the food industry. Lactic acid bacteria, known for their ability to ferment carbohydrates into lactic acid, provide essential nutrients and contribute to immune responses. With its strong fermentation capabilities and rich nutritional profile, yeast finds use in various food products. Genetic engineering in these microorganisms has grown rapidly, enabling the expression of enzymes and secondary products for food production. However, the focus is on ensuring safety, necessitating food-grade selection markers. Traditional antibiotic and heavy metal resistance selection markers pose environmental and health risks, prompting the search for safer alternatives. Complementary selection markers, such as sugar utilization markers, offer a promising solution. These markers use carbohydrates as carbon sources for growth and are associated with the natural metabolism of lactic acid bacteria and yeast. This review discusses the use of specific sugars, such as lactose, melibiose, sucrose, D-xylose, glucosamine, and N-acetylglucosamine, as selection markers, highlighting their advantages and limitations. In summary, this review underscores the importance of food-grade selection markers in genetic engineering and offers insights into their applications, benefits, and challenges, providing valuable information for researchers in the field of food microbiology and biotechnology.
{"title":"Sugar Utilization-Associated Food-Grade Selection Markers in Lactic Acid Bacteria and Yeast.","authors":"Zhiwen Liang, Ke Zheng, Guifeng Xie, Xiongsheng Luo, Huangjin Li","doi":"10.33073/pjm-2024-011","DOIUrl":"10.33073/pjm-2024-011","url":null,"abstract":"<p><p>This comprehensive review explores the development of food-grade selection markers in lactic acid bacteria and yeast; some of their strains are precisely defined as safe microorganisms and are crucial in the food industry. Lactic acid bacteria, known for their ability to ferment carbohydrates into lactic acid, provide essential nutrients and contribute to immune responses. With its strong fermentation capabilities and rich nutritional profile, yeast finds use in various food products. Genetic engineering in these microorganisms has grown rapidly, enabling the expression of enzymes and secondary products for food production. However, the focus is on ensuring safety, necessitating food-grade selection markers. Traditional antibiotic and heavy metal resistance selection markers pose environmental and health risks, prompting the search for safer alternatives. Complementary selection markers, such as sugar utilization markers, offer a promising solution. These markers use carbohydrates as carbon sources for growth and are associated with the natural metabolism of lactic acid bacteria and yeast. This review discusses the use of specific sugars, such as lactose, melibiose, sucrose, D-xylose, glucosamine, and N-acetylglucosamine, as selection markers, highlighting their advantages and limitations. In summary, this review underscores the importance of food-grade selection markers in genetic engineering and offers insights into their applications, benefits, and challenges, providing valuable information for researchers in the field of food microbiology and biotechnology.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"73 1","pages":"3-10"},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10911659/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140029911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04eCollection Date: 2024-03-01DOI: 10.33073/pjm-2024-007
Dongfeng Shen, Xiaodong Lv, Hui Zhang, Chunyuan Fei, Jing Feng, Jiaqi Zhou, Linfeng Cao, Ying Ying, Na Li, Xiaolong Ma
This study aimed to investigate the disparities between metagenomic next-generation sequencing (mNGS) and conventional culture results in patients with bronchiectasis. Additionally, we sought to investigate the correlation between the clinical characteristics of patients and their microbiome profiles. The overarching goal was to enhance the effective management and treatment of bronchiectasis patients, providing a theoretical foundation for healthcare professionals. A retrospective survey was conducted on 67 bronchiectasis patients admitted to The First Hospital of Jiaxing from October 2019 to March 2023. Clinical baseline information, inflammatory indicators, and pathogen detection reports, including mNGS, conventional blood culture, bronchoalveolar lavage fluid (BALF) culture, and sputum culture results, were collected. By comparing the results of mNGS and conventional culture, the differences in pathogen detection rate and pathogen types were explored, and the diagnostic performance of mNGS compared to conventional culture was evaluated. Based on the various pathogens detected by mNGS, the association between clinical characteristics of bronchiectasis patients and mNGS microbiota results was analyzed. The number and types of pathogens detected by mNGS were significantly larger than those detected by conventional culture. The diagnostic efficacy of mNGS was significantly superior to conventional culture for all types of pathogens, particularly in viral detection (p < 0.01). Regarding pathogen detection rate, the bacteria with the highest detection rate were Pseudomonas aeruginosa (17/58) and Haemophilus influenzae (11/58); the fungus with the highest detection rate was Aspergillus fumigatus (10/21), and the virus with the highest detection rate was human herpes virus 4 (4/11). Differences were observed between the positive and negative groups for P. aeruginosa in terms of common scoring systems for bronchiectasis and whether the main symptom of bronchiectasis manifested as thick sputum (p < 0.05). Significant distinctions were also noted between the positive and negative groups for A. fumigatus regarding Reiff score, neutrophil percentage, bronchiectasis etiology, and alterations in treatment plans following mNGS results reporting (p < 0.05). Notably, 70% of patients with positive A. fumigatus infection opted to change their treatment plans. The correlation study between clinical characteristics of bronchiectasis patients and mNGS microbiological results revealed that bacteria, such as P. aeruginosa, and fungi, such as A. fumigatus, were associated with specific clinical features of patients. This underscored the significance of mNGS in guiding personalized treatment approaches. mNGS could identify multiple pathogens in different types of bronchiectasis samples and was a rapid and effective diagnostic tool for pathogen identification. Its use was recommended for
{"title":"Association between Clinical Characteristics and Microbiota in Bronchiectasis Patients Based on Metagenomic Next-Generation Sequencing Technology.","authors":"Dongfeng Shen, Xiaodong Lv, Hui Zhang, Chunyuan Fei, Jing Feng, Jiaqi Zhou, Linfeng Cao, Ying Ying, Na Li, Xiaolong Ma","doi":"10.33073/pjm-2024-007","DOIUrl":"10.33073/pjm-2024-007","url":null,"abstract":"<p><p>This study aimed to investigate the disparities between metagenomic next-generation sequencing (mNGS) and conventional culture results in patients with bronchiectasis. Additionally, we sought to investigate the correlation between the clinical characteristics of patients and their microbiome profiles. The overarching goal was to enhance the effective management and treatment of bronchiectasis patients, providing a theoretical foundation for healthcare professionals. A retrospective survey was conducted on 67 bronchiectasis patients admitted to The First Hospital of Jiaxing from October 2019 to March 2023. Clinical baseline information, inflammatory indicators, and pathogen detection reports, including mNGS, conventional blood culture, bronchoalveolar lavage fluid (BALF) culture, and sputum culture results, were collected. By comparing the results of mNGS and conventional culture, the differences in pathogen detection rate and pathogen types were explored, and the diagnostic performance of mNGS compared to conventional culture was evaluated. Based on the various pathogens detected by mNGS, the association between clinical characteristics of bronchiectasis patients and mNGS microbiota results was analyzed. The number and types of pathogens detected by mNGS were significantly larger than those detected by conventional culture. The diagnostic efficacy of mNGS was significantly superior to conventional culture for all types of pathogens, particularly in viral detection (<i>p</i> < 0.01). Regarding pathogen detection rate, the bacteria with the highest detection rate were <i>Pseudomonas aeruginosa</i> (17/58) and <i>Haemophilus influenzae</i> (11/58); the fungus with the highest detection rate was <i>Aspergillus fumigatus</i> (10/21), and the virus with the highest detection rate was human herpes virus 4 (4/11). Differences were observed between the positive and negative groups for <i>P. aeruginosa</i> in terms of common scoring systems for bronchiectasis and whether the main symptom of bronchiectasis manifested as thick sputum (<i>p</i> < 0.05). Significant distinctions were also noted between the positive and negative groups for <i>A. fumigatus</i> regarding Reiff score, neutrophil percentage, bronchiectasis etiology, and alterations in treatment plans following mNGS results reporting (<i>p</i> < 0.05). Notably, 70% of patients with positive <i>A. fumigatus</i> infection opted to change their treatment plans. The correlation study between clinical characteristics of bronchiectasis patients and mNGS microbiological results revealed that bacteria, such as <i>P. aeruginosa</i>, and fungi, such as <i>A. fumigatus</i>, were associated with specific clinical features of patients. This underscored the significance of mNGS in guiding personalized treatment approaches. mNGS could identify multiple pathogens in different types of bronchiectasis samples and was a rapid and effective diagnostic tool for pathogen identification. Its use was recommended for ","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"73 1","pages":"59-68"},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10911701/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140029918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feline parvovirus (FPV) is highly infectious for cats and other Felidae and often causes severe damage to young kittens. In this study, we incorporated recombinase polymerase amplification (RPA) and Cas12a-mediated detection and developed an RPA-Cas12a-based real-time or end-point fluorescence detection method to identify the NS1 gene of FPV. The total time of RPA-Cas12a-based fluorescence assay is approximately 25 min. The assay presented a limit of detection (LOD) of 1 copies/μl (25 copies/per reaction), with no cross-reactivity with several feline pathogens. The clinical performance of the assay was examined using total genomic DNA purified from 60 clinical specimens and then compared to results obtained with qPCR detection of FPV with 93.3% positive predictive agreement and 100% negative predictive agreement. Together, the rapid reaction, cost-effectiveness, and high sensitivity make the RPA-Cas12a-based fluorescence assay a fascinating diagnostic tool that will help minimize infection spread through instant detection of FPV.
{"title":"Establishment of RPA-Cas12a-Based Fluorescence Assay for Rapid Detection of Feline Parvovirus.","authors":"Ting Wang, Hao Zeng, Qiming Liu, Weidong Qian, Yongdong Li, Jian Liu, Rong Xu","doi":"10.33073/pjm-2024-005","DOIUrl":"10.33073/pjm-2024-005","url":null,"abstract":"<p><p>Feline parvovirus (FPV) is highly infectious for cats and other Felidae and often causes severe damage to young kittens. In this study, we incorporated recombinase polymerase amplification (RPA) and Cas12a-mediated detection and developed an RPA-Cas12a-based real-time or end-point fluorescence detection method to identify the NS1 gene of FPV. The total time of RPA-Cas12a-based fluorescence assay is approximately 25 min. The assay presented a limit of detection (LOD) of 1 copies/μl (25 copies/per reaction), with no cross-reactivity with several feline pathogens. The clinical performance of the assay was examined using total genomic DNA purified from 60 clinical specimens and then compared to results obtained with qPCR detection of FPV with 93.3% positive predictive agreement and 100% negative predictive agreement. Together, the rapid reaction, cost-effectiveness, and high sensitivity make the RPA-Cas12a-based fluorescence assay a fascinating diagnostic tool that will help minimize infection spread through instant detection of FPV.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"73 1","pages":"39-48"},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10911697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140029921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04eCollection Date: 2024-03-01DOI: 10.33073/pjm-2024-006
Yeping Bian, Jian Xu, Xiaojing Deng, Suming Zhou
Gut microbiota (GM) is a crucial underlying player during sepsis pathogenesis. However, the causal relationship is unclear and remains to be determined. A two-sample Mendelian randomization study was implemented. The statistical data about sepsis together with GM summarized from genome-wide association studies were evaluated. Instrumental variables were defined as single-nucleotide polymorphisms with prominent correlations with exposure. The inverse-variance-weighted test was employed as a major approach of Mendelian randomization analysis to estimate of causal relationships. The inverse-variance-weighted analysis results demonstrated that at different taxa levels, Actinobacteria and Bifidobacteriaceae influence sepsis. Actinobacteria had negative relationships to sepsis risk at the phylum (β = -0.34, SE = 0.10, p = 0.0008) and class (β = -0.23, SE = 0.07, p = 0.0011) levels in outcome coded ieu-b-69. Actinobacteria at the phylum level (β = -0.22, SE = 0.10, p = 0.027) was also negatively associated with sepsis in outcome coded ieu-b-4980. Bifidobacteriaceae at the order (β = -0.20, SE = 0.06, p = 0.0021), family (β = -0.20, SE = 0.06, p = 0.0021), and genus (β = -0.20, SE = 0.06, p = 0.0007) levels were all negatively correlated with the risk of sepsis in outcome coded ieu-b-69. The results of the Wald ratio model showed that Tyzzerella genus (OR (95%CI) = 0.6902[0.4907,0.9708], p = 0.0331) and Gastranaerophilales order (OR (95%CI) = 0.5907[0.3516,0.9926], p = 0.0468) were negatively connected with sepsis. This study implied at different taxa levels Actinobacteria and Bifidobacteriaceae, Tyzzerella genus, and Gastranaerophilales order have a causal relationship with sepsis, indicating that they are protective factors for the incidence of sepsis.
{"title":"A Mendelian Randomization Study: Roles of Gut Microbiota in Sepsis - Who is the Angle?","authors":"Yeping Bian, Jian Xu, Xiaojing Deng, Suming Zhou","doi":"10.33073/pjm-2024-006","DOIUrl":"10.33073/pjm-2024-006","url":null,"abstract":"<p><p>Gut microbiota (GM) is a crucial underlying player during sepsis pathogenesis. However, the causal relationship is unclear and remains to be determined. A two-sample Mendelian randomization study was implemented. The statistical data about sepsis together with GM summarized from genome-wide association studies were evaluated. Instrumental variables were defined as single-nucleotide polymorphisms with prominent correlations with exposure. The inverse-variance-weighted test was employed as a major approach of Mendelian randomization analysis to estimate of causal relationships. The inverse-variance-weighted analysis results demonstrated that at different taxa levels, Actinobacteria and <i>Bifidobacteriaceae</i> influence sepsis. Actinobacteria had negative relationships to sepsis risk at the phylum (β = -0.34, SE = 0.10, <i>p</i> = 0.0008) and class (β = -0.23, SE = 0.07, <i>p</i> = 0.0011) levels in outcome coded ieu-b-69. Actinobacteria at the phylum level (β = -0.22, SE = 0.10, <i>p</i> = 0.027) was also negatively associated with sepsis in outcome coded ieu-b-4980. <i>Bifidobacteriaceae</i> at the order (β = -0.20, SE = 0.06, <i>p</i> = 0.0021), family (β = -0.20, SE = 0.06, <i>p</i> = 0.0021), and genus (β = -0.20, SE = 0.06, <i>p</i> = 0.0007) levels were all negatively correlated with the risk of sepsis in outcome coded ieu-b-69. The results of the Wald ratio model showed that <i>Tyzzerella</i> genus (OR (95%CI) = 0.6902[0.4907,0.9708], <i>p</i> = 0.0331) and Gastranaerophilales order (OR (95%CI) = 0.5907[0.3516,0.9926], <i>p</i> = 0.0468) were negatively connected with sepsis. This study implied at different taxa levels Actinobacteria and <i>Bifidobacteriaceae</i>, <i>Tyzzerella</i> genus, and Gastranaerophilales order have a causal relationship with sepsis, indicating that they are protective factors for the incidence of sepsis.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"73 1","pages":"49-57"},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10911657/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140029910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}