Brazilian Journal of Microbiology最新文献

{"title":"Cold adaptation mechanisms of the psychrotolerant filamentous ascomycete Psychrophilomyces antarcticus.","authors":"Sofiya A Saharova, Elena A Ianutsevich, Olga A Danilova, Olga A Grum-Grzhimaylo, Nataliya V Groza, Vera M Tereshina","doi":"10.1007/s42770-025-01787-7","DOIUrl":"https://doi.org/10.1007/s42770-025-01787-7","url":null,"abstract":"<p><p>To adapt to cold environments, such as the Arctic and Antarctic regions, high mountain peaks, cold soils, deserts, caverns, and cryopegs, fungi employ various strategies. Crucial aspect of this adaptation is maintaining the functions of their cell membranes. To study the mechanisms of cell membrane protection, we analyzed the composition of osmolytes and membrane lipids and their fatty acids in a submerged culture of the psychrotolerant fungus Psychrophilomyces antarcticus during growth at temperatures of 20 °C and 8 °C. The object of the study exhibits a broad growth range from - 3 °C to 27 °C, with an optimal temperature of 20-22.5 °C. For adaptation to cold (8 °C), the fungus significantly increases the degree of unsaturation of phospholipids by enhancing the proportion of α-linolenic acid (40% of the total), compared to the optimal temperature (15% of the total). Additionally, the proportion of sterols in the membrane lipids is twice as low, and the amount of arabitol in the composition of osmolytes is twice as high, compared to the optimal temperature. At both temperatures, the fungus is characterized by the dominance of two osmolytes in the cytosol: trehalose and arabitol. It also shows a predominance of non-bilayer phospholipids, specifically phosphatidic acids (35-42% of the total) and phosphatidylethanolamines (~ 20% of the total), in its membrane lipid composition, along with trace amounts of sterol esters and the formation of mucus in the culture fluid. The combined adjustments in osmolyte and membrane lipid profiles contribute to the fungus' adaptation to a wide range of temperatures. These findings provide insights into the molecular basis of psychrotolerance and open up opportunities for research into potential biotechnological applications.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intersecting realms of resistance: the epidemiology of Staphylococcus aureus carriage and multidrug resistance in primary healthcare settings in Recife, Brazil.","authors":"Iago Carvalho Barbosa, Denny Parente de Sá Barreto Maia Leite, Pollyanne Raysa Fernandes de Oliveira, Órion Pedro da Silva, Maria Luisa Araújo Quinderé de Almeida, Taoana Perrelli Sarmento, Rafaela Silva Santos, José Givanildo da Silva, Maira Aparecida Scatamburlo Moreira, Tatiana Souza Porto, Rinaldo Aparecido Mota","doi":"10.1007/s42770-025-01777-9","DOIUrl":"https://doi.org/10.1007/s42770-025-01777-9","url":null,"abstract":"","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of virulent, multidrug-resistant, and genetically diverse Aeromonas hydrophila in foods of animal and aquatic origin from tribal regions of Northeastern India.","authors":"Kandhan Srinivas, Arockiasamy Arun Prince Milton, G Bhuvana Priya, Heiborkie Shilla, Lavinia Wahlang, Kasanchi M Momin, Dadimi Bhargavi, Vanita Lyngdoh, John Pynhun Lamare, Zakir Hussain, Girish Ps, Sandeep Ghatak, Samir Das","doi":"10.1007/s42770-025-01791-x","DOIUrl":"https://doi.org/10.1007/s42770-025-01791-x","url":null,"abstract":"<p><p>Aeromonas hydrophila is an emerging zoonotic foodborne bacterial pathogen that causes gastro-intestinal and extra-intestinal infections in humans. A total of 361 samples including water (n = 195) and foods of animal and aquatic origin (n = 166) collected from tribal dwelling areas of Northeastern India were screened for the microbiological presence of A. hydrophila. Upon presumptive identification and molecular confirmation, the overall occurrence was 8.31% (30/361) with the highest rate observed in edible snails (13/38, 38.24%), followed by fish (4/14, 28.57%), pork (5/18, 27.78%), chicken (5/100, 20.0%) and domestic tap water (3/195, 1.54%). Multidrug resistance was observed in 13.33% (4/30) of the isolates, with the highest phenotypic resistance observed against amoxicillin-clavulanic acid (15/30, 50.00%). Phenotypic virulence, ascertained using adhesion forming ability, identified five isolates with strong ability out of 76.67% (23/30) isolates which harboured the ability to form adhesions on abiotic surfaces. Serine protease (ser) gene featured as the predominant virulence gene (23/30, 76.67%) among the isolates followed by act (16/30, 53.33%) which codes for cytotoxic toxin. Heatmap analysis with hierarchical clustering as well as Enterobacterial Repetitive Intergenic Consensus (ERIC) and Random Amplified Polymorphic DNA (RAPD)-based fingerprinting indicated wide genetic diversity among the isolates. Overall, the study highlights the emergence and circulation of adhesion-forming, multidrug-resistant A. hydrophila strains that carry clinically important virulence genes. These findings raise a potential public health concern for the tribal population of Northeastern India, known for their distinct culinary practices and food habits.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epstein-barr virus (EBV) in cervical carcinoma detected by in situ hybridization targeting ebers and the viral genome.","authors":"Álife Diêgo Lima Silva, Julia Graziele Alves Marelli, Maria Willaiara Lira Lopes, Myrella Tavares Rodrigues, Cecília Paz Lopes, José Nairton Coelho Silva, Sávio Samuel Feitosa Machado, Racquel Oliveira da Silva Souza, Maria Aparecida Tibúrcio, Alexandre Quental Sampaio, Isabelle Joyce de Lima Silva Fernandes, Claudia do Ó Pessoa, Cláudio Gleidiston Lima da Silva, Marcos Antonio Pereira de Lima","doi":"10.1007/s42770-025-01774-y","DOIUrl":"https://doi.org/10.1007/s42770-025-01774-y","url":null,"abstract":"<p><p>Epstein-Barr virus (EBV) infection has been suggested as a potential cofactor for the development and progression of cervical cancer, collaborating with high-risk Human Papillomavirus (HR-HPV). In situ hybridization (ISH) has been considered the gold standard in the investigation of EBV in neoplasms. This study aimed to detect EBV in cervical carcinoma samples using ISH targeting EBERs (EBER-ISH) and the BamHI-W region of the viral genome (BamHI-W-ISH), and compare the results of both targets. Of the 88 cases collected, 9 were EBER-ISH positive (10.2%), while 33 (37.5%) cases were positive for EBV by BamHI-W-ISH, all showing staining in the nuclei of the malignant cells. No statistically significant results were found between the presence of EBV and carcinoma type, differentiation grade or tumor staging. The kappa agreement index between the two targets was 0.092. Only 4 cases were EBER-ISH(+) and BamHI-W-ISH(-). On the other hand, 28 cases were BamHI-W-ISH(+) and EBER-ISH(-). Altogether, 37/88 (42%) cases were EBV-positive by one or both targets. Infected lymphocytes were verified in 9 (10.2%) and 34 (38.6%) cases, by EBER-ISH and BamHI-W-ISH, respectively. The slight agreement demonstrated between the targets may be due to the lack of expression of EBERs, suggesting that EBV may present a distinct latency pattern in the cervical mucosa, or that it has entered the replicative cycle in some of these tumors, in both cases, explaining the low positivity rate verified through EBER-ISH, while calling into question the latter's gold standard status in the detection of EBV in malignancies. Our findings also indicate that the chosen viral genomic target may represent a suitable candidate for EBV detection by ISH.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular detection and prevalence of colistin-resistant Escherichia coli in poultry and humans: a one health perspective.","authors":"Muhammad Najam Ul Huda, Muhammad Zubair Shabbir, Adnan Hasan Tahir, Awais Ali Ahmad, Umar Bin Zahoor, Waqas Ahmad, Ali Raza, Farhan Afzal, Abdur Rauf Khalid, Muhammad Abu Bakr Shabbir","doi":"10.1007/s42770-025-01780-0","DOIUrl":"https://doi.org/10.1007/s42770-025-01780-0","url":null,"abstract":"<p><p>Multidrug-resistant (MDR) bacteria significantly threaten humans and animals worldwide. Colistin is the last resort of antibiotics against gram-negative bacterial infections. Its irrational use in poultry is a major factor in transmitting MDR bacteria to humans. The present study investigated the risk factors, prevalence, and molecular detection of colistin resistance associated with poultry and humans. A total of (n = 140) cloacal swabs from chickens and human stool samples (n = 140) were processed to identify E. coli using conventional methods, followed by genotypic confirmation. Phenotypic and genotypic confirmation of antibiotic resistance genes qnrA, blaTEM, tetA, aadA, and mcr genes was performed on these E. coli isolates. These isolates were confirmed at 69.3% and 62.8% in chickens and humans, respectively. Limited education and poor hygiene significantly increased the infection rate (p = 0.0001). The E. coli isolates from commercial poultry showed 100% resistance to amoxicillin/clavulanic acid, 98.9% to ampicillin, and 93.8% to tetracycline. The E. coli isolates from humans exhibited 90% resistance to ciprofloxacin, 88% to ampicillin, and 85% to ceftriaxone. Among these, MDR E. coli isolates of both commercial poultry and humans, colistin resistance was found in 78.6% and 48.1%, respectively. Genotypic confirmation of mcr genes such as mcr-1 (42%), mcr-2 (19.6%), mcr-3 (15.1%), mcr-4 (7.6%), and mcr-5 (4.5%) in commercial poultry. However, only the mcr-1 (15.6%) gene was found in human isolates. The current study findings highlight the prevalence of mcr genes in E. coli, potentially contributing to broader antibiotic resistance concerns.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of sub-inhibitory concentrations of antiseptics on biofilm formation in S. epidermidis.","authors":"Renato Geraldo da Silva Filho, Agostinho Alves de Lima E Silva, Carmen Soares de Meirelles Saramago, Maria Helena Simões Villas Bôas","doi":"10.1007/s42770-025-01702-0","DOIUrl":"10.1007/s42770-025-01702-0","url":null,"abstract":"<p><p>Clinical isolates of Staphylococcus epidermidis were evaluated for biofilm production/chemical nature, and for the effect of sub-inhibitory concentrations (sub-MICs) of ethanol and chlorhexidine on biofilm production. Moreover, some of the biofilm-positive samples were studied for the effect of sub-MICs of these antiseptics in the expression of icaA, icaR, sigB and sarA genes. Sub-MICs of ethanol (2 and/or 4%) led to an increase in biofilm production in almost all PIA-dependent and all PIA-independent strains tested, but did not induce biofilm production in primarily non- producers. Unlike ethanol, chlorhexidine sub-MICs determined reduction in biofilm production in biofilm-positive strains. In PIA-dependent strains, ethanol (1%) caused an increase in the relative expression of icaA and reduced expression of icaR, in addition to increased expression of global regulators (sarA and sigB), while the PIA-independent strain showed reduction in the expression of these global regulators. Unlike ethanol, chlorhexidine (0.5 µg/mL) determined increased expression of icaR and reduction of icaA in PIA-dependent strains, besides a reduction in the expression of sarA and sigB in the PIA-independent strain. The opposite effects of ethanol and chlorhexidine on the expression of icaA and icaR in PIA-dependent strains corroborated the phenotypic results obtained for biofilm production in isolates exposed to these antiseptics. The biofilm-inducing or -inhibiting effects of ethanol and chlorhexidine are of practical importance due to their widespread use as antiseptics in healthcare settings.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":"1823-1833"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12350973/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144156842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial resistance and virulence potential of non-faecium and non-faecalis enterococci isolated from canine rectal swabs.","authors":"Hellen Dos Santos Sabino, Lidiane Lamara Silva Coutinho, Carla Dray Marassi, Ana Maria Dieckmann, Ianick Souto Martins, Felipe Piedade Gonçalves Neves, Renata Fernandes Rabello","doi":"10.1007/s42770-025-01717-7","DOIUrl":"10.1007/s42770-025-01717-7","url":null,"abstract":"<p><p>Animals can serve as reservoirs for multidrug-resistant (MDR) enterococci with potential pathogenicity. Close contact between dogs and their owners may facilitate the interspecies transmission of these bacterial agents, potentially impacting human health. While Enterococcus faecium and Enterococcus faecalis are the main species implicated in healthcare-associated infections (HAIs), non-faecium and non-faecalis (NFF) enterococci, though less prevalent, may also contribute to infections. This study aimed to assess the antimicrobial resistance phenotypes and genotypes and virulence potential of NFF enterococci isolated from asymptomatic dogs. A total of 114 NFF enterococcal isolates were obtained from rectal swabs of dogs, between 2015 and 2017, in Rio de Janeiro, Brazil. Antimicrobial resistance was assessed using disk diffusion and agar gradient diffusion methods, and resistance and virulence genes were determined by polymerase chain reaction (PCR). The highest resistance frequencies were observed for rifampicin (38.6%), tetracycline (27.2%), and erythromycin (15.8%). One vancomycin-resistant E. gallinarum strain (MIC > 512 µg/mL) was isolated, and it also exhibited resistance to teicoplanin. High-level resistance to streptomycin (HLR-S) was found in E. canintestini (22.2%), E. gallinarum (8.5%), and E. avium (7.1%) strains. Most E. raffinosus strains were resistant to ampicillin (55%) and penicillin G (55%), and this was the only species resistant to ampicillin. MDR strains accounted for 14.9% of the strains, with MDR colonization more frequent in purebred dogs, suggesting a possible breed-related association. The resistance genes detected included ant(6)-Ia, tet(M), tet(L), erm(B), and the van operon. Virulence genes were detected in a limited number of strains: esp (11.4%), gelE (2.6%), asa1 (0.9%), and hyl (0.9%). The presence of esp was significantly associated with E. canintestini (44.4%), and E. avium (42.9%). Further studies are needed to evaluate the public health implications of these findings.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":"2069-2079"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12350984/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144474015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of rare Candida species isolated from various clinical specimens: Comparison of different methods.","authors":"Ilvana Caklovica Kucukkaya, Deniz Turan, Sertac Kucukkaya, Esma Akkoyun Bilgi, Enxhi Caglar, Gonca Erkose Genc, Zayre Erturan","doi":"10.1007/s42770-025-01725-7","DOIUrl":"10.1007/s42770-025-01725-7","url":null,"abstract":"&lt;p&gt;&lt;p&gt;In recent years, there has been an increase in invasive infections caused by \"'rare' Candida species\". The intrinsic resistance characteristics of these species along with their higher antifungal MIC values reduce the success of antifungal treatment. Although molecular and other sophisticated tests are reliable for the identification of many rare and newly emerging Candida species. Their implementation in routine laboratories is limited due to trained personnel, high costs, and specialized laboratory equipments. As a result, conventional methods and automated systems such as VITEK-2 and MALDI-TOF MS are still widely used in routine laboratories. This study evaluates and compares the identification capabilities of these commonly used tests for rare Candida species and provides guidance for rapid identification. A total of 201 isolates consist of 16 rare Candida species from various clinical samples were analyzed. Identification was performed using VITEK MS (as a gold standard) and results compared with VITEK-2, API ID 32 C, CHROMagar Candida, CHROMagar Candida Plus, and cornmeal agar with 1% Tween 80. VITEK MS identified all isolates and among them, the three most common species were Candida inconspicua (n:34; 16.9%), Candida lusitaniae (n:33; 16.4%), and Candida kefyr (n:31; 15.4%). Among these, a total of 107 isolates (53.2%) were correctly identified at the species level using the VITEK-2 system, whereas only 51 isolates (25.37%) were accurately identified with the API ID 32C system. However, when additional conventional methods (colony morphology and colour on chromogenic agar medium, Dalmau plate method, esculin hydrolysis test, growth at different temperatures) were applied, these identification rates increased to 81.5% (n = 164) and 54.7% (n = 110), respectively. Notably, even when used alone, the VITEK-2 system demonstrated a high identification success rate for Candida auris (83.3%), Candida lipolytica (85.7%), Candida lusitaniae (78.7%), Candida guilliermondii (83.8%), and Candida dubliniensis (86.4%). One of the primary reasons for misidentification was the absence of these microorganisms in the databases of the identification systems used. Additionally, all C. auris strains were correctly identified using CHROMagar Candida Plus medium, with no false-positive results observed for other Candida species. None of the identification methods, when applied alone, were able to correctly identify all 201 rare Candida species. Both VITEK-2 and API ID 32 C demonstrated limited accuracy for some rare species. However, evaluating microscopic and colony morphology on cornmeal agar and chromogenic media improved the accuracy of identification, especially for C. auris. In laboratories with limited access to MALDI-TOF MS or molecular methods, these tests should be used in combination to improve identification accuracy and provide alternative approaches for species differentiation. Also laboratories should update regular databases of their systems","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":"1775-1785"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12350910/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Corynebacterium uterequi isolates from mares in Brazil.","authors":"Julia Werle, Gabriela Tormes Nunes, Carolina Sleutjes Machado, Cassia Bagolin da Silva, Fernanda Silveira Flores Vogel, Agueda Palmira Castagna de Vargas, Juliana Felipetto Cargnelutti","doi":"10.1007/s42770-025-01726-6","DOIUrl":"10.1007/s42770-025-01726-6","url":null,"abstract":"<p><p>The genus Corynebacterium encompasses versatile bacteria that act as natural microbiota or pathogens, causing infections in humans and animals, including equine reproductive disorders. Corynebacterium uterequi (C. uterequi) is a potential pathogen in mares, associated with reproductive disorders including endometritis, embryonic loss, and infertility, raising concerns for equine reproductive health. This study aimed to characterize C. uterequi isolates from mares in southern Brazil and deepen the understanding of this species. Phenotypic, molecular, and phylogenetic analyses were performed on four C. uterequi isolates. Antimicrobial susceptibility was tested for 36 drugs by disk diffusion and five by microdilution. Biofilm formation was assessed at different glucose concentrations, and minimum inhibitory concentration (MIC) was determined for penicillin, gentamicin, doxycycline, clindamycin, and sulfamethoxazole + trimethoprim. These values were then used to evaluate biofilm eradication at concentrations up to 8× MIC. All isolates were confirmed as C. uterequi through phylogenetic analysis, clustering in the same group as others Corynebacterium spp. The isolates showed inhibition zones above Clinical & Laboratory Standards Institute and Brazilian Committee on Antimicrobial Susceptibility Testing susceptibility breakpoints for related species and formed biofilms with varying adhesion strengths. Biofilm eradication was effective during development but ineffective against mature biofilms. C. uterequi displays significant pathogenic potential in equine reproductive infections due to its ability to form persistent biofilms. Further studies are essential to optimize treatment strategies for chronic uterine infections caused by this pathogen.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":"2111-2119"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12350892/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of abilities of Pleurotus pulmonarius crude extract as a natural food additive in roasted chilli paste.","authors":"Rawita Osit, Atchara Nuphet Phoem","doi":"10.1007/s42770-025-01690-1","DOIUrl":"10.1007/s42770-025-01690-1","url":null,"abstract":"<p><p>The purpose of this study was to determine the effectiveness of the crude extracts in controlling Staphylococcus aureus and Bacillus cereus, as well as the shelf life of the roasted chilli paste. Crude extract was obtained from the volva of Indian oyster mushrooms (Pleurotus pulmonarius) and used to replace preservatives in roasted chilli paste. Thirty isolates of S. aureus and B. cereus were inhibited by crude extract through the disc diffusion method. At a concentration of 2,500 µg/ml, the crude extract inhibited 23 (76.67%) and 20 (66.67%) isolates of S. aureus and B. cereus, respectively, with an inhibition zone size of 7-10 mm. The broth microdilution method was employed in this study to determine the Minimum Inhibitory Concentration (MIC) of the crude extract, and it was observed that the extract at a concentration of 1,000 µg/ml was able to inhibit 18 (60.00%) and 16 (53.00%) isolates of S. aureus and B. cereus, respectively. For the purpose of Minimum Bactericidal Concentration (MBC), the crude extract at a concentration of 1,000 µg/ml was found to kill 16 (53.00%) and 14 (46.00%) isolates of S. aureus and B. cereus, respectively. At a concentration of 4,000 µg/ml, the crude extract had an inhibitory effect from hour 6, lowering S. aureus (Sa16 and Sa21) and B. cereus (Bc5 and Bc12) below the limit of detection (less than 2 log cfu/ml) at 24 h. The ability of the crude extract to inhibit both types of bacteria was observed to be unaffected by heat treatment to a temperature of 65ºC for 30 min (pasteurisation) as well as by no heat treatment at all. The phenolic compounds of the crude extract treated by pasteurisation and without heat treatment were higher than that of the crude extract treated by sterilisation at 121ºC for 15 min. The quality and safety of roasted chilli paste were analysed during storage at 25ºC for 8 months. The quality and safety of roasted chilli paste with crude extract were within the acceptability limit of water activity, total viable count, mould, S. aureus, B. cereus, C. perfringens, and Salmonella spp. as recommended by Thai community product standard. The ability of crude extracts to inhibit S. aureus (Sa16) and B. cereus (Bc5) in roasted chilli paste was then investigated, and it was observed that the crude extract at a concentration of 4,000 µg/ml was able to reduce the S. aureus (Sa16) and B. cereus (Bc5) population to 1.24 and 2.52 log cfu/g, respectively, at 8 months. Therefore, the use of crude extract from Indian oyster mushrooms in conjunction with heat pasteurisation can be employed to improve the shelf life of roasted chilli paste.</p>","PeriodicalId":9090,"journal":{"name":"Brazilian Journal of Microbiology","volume":" ","pages":"1695-1707"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12350893/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}