streptococcus mitis
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PeerJ ◽  
2022 ◽  
Vol 9 ◽  
pp. e12251
Author(s):  
Ayesha Fahim ◽  
Wan Harun Himratul-Aznita ◽  
Puteri Shafinaz Abdul-Rahman ◽  
Mohammad K. Alam

Background Polymicrobial biofilms are notorious for causing intraoral tissue destruction. Streptococcus sanguinis and Streptococcus mitis, commensals of oral cavities, have been found co-existing with C. albicans in resistant oral infections. There is an urgent need to find alternative treatment options. This study aims to assess the efficacy of garlic (G) and bakuchiol (Bk) combination against candida virulent genes and their subsequently secreted proteins. Methods In vitro single species biofilms of C. albicans, and mixed species biofilms formed in combination with streptococci were exposed to bakuchiol and garlic extract (Bk+G). Gene expression of agglutinin-like sequence (ALS1), (ALS3), adhesin-like wall proteins (HWP1) and aspartyl proteinases (SAP5) were determined using qPCR and their subsequent proteins were assessed through Western blotting. Results Virulent genes were significantly downregulated in single species biofilms when they were treated with Bk+G combination. However, Bk+G did not have significant effect on ALS1 and HWP1 gene in polymicrobial biofilms. ALS3 and SAP5 were significantly downregulated in Bk+G treated polymicrobial biofilm. Similar results were portrayed in Western blotting. Conclusion Bk+G combination exhibited antimicrobial effects against single and mixed species biofilms. The findings might provide insights for treating resistant candida infections. This combination could potentially serve as an herbal alternative to traditional antifungals following further research.


IDCases ◽  
2022 ◽  
pp. e01406
Author(s):  
Haruka Fukayama ◽  
Kensuke Shoji ◽  
Michiko Yoshida ◽  
Hiroyuki Iijima ◽  
Takanobu Maekawa ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Helina Marshall ◽  
Ricardo J. José ◽  
Mogens Kilian ◽  
Fernanda C. Petersen ◽  
Jeremy S. Brown

Streptococcus pneumoniae and Streptococcus mitis are genetically closely related and both frequently colonise the naso-oropharynx, yet S. pneumoniae is a common cause of invasive infections whereas S. mitis is only weakly pathogenic. We hypothesise that sensitivity to innate immunity may underlie these differences in virulence phenotype. We compared the sensitivity of S. pneumoniae and S. mitis strains to complement-mediated immunity, demonstrating S. mitis strains were susceptible to complement-mediated opsonophagocytosis. S. pneumoniae resistance to complement is partially dependent on binding of the complement regulator Factor H by the surface protein PspC. However, S. mitis was unable to bind factor H. The S. pneumoniae TIGR4 strain pspC was expressed in the S. mitis SK142 strain to create a S. mitis pspC+ strain. Immunoblots demonstrated the S. mitis pspC+ strain expressed PspC, and flow cytometry confirmed this resulted in Factor H binding to S. mitis, reduced susceptibility to complement and improved survival in whole human blood compared to the wild-type S. mitis strain. However, in mouse models the S. mitis pspC+ strain remained unable to establish persistent infection. Unlike S. pneumoniae strains, culture in serum or blood did not support increased CFU of the S. mitis strains. These results suggest S. mitis is highly sensitive to opsonisation with complement partially due to an inability to bind Factor H, but even when complement sensitivity was reduced by expression of pspC, poor growth in physiological fluid limited the virulence of S. mitis in mice.


2021 ◽  
Author(s):  
Dasith Perera ◽  
Anthony McLean ◽  
Viviana Morillo-López ◽  
Kaileigh Cloutier-Leblanc ◽  
Eric Almeida ◽  
...  

AbstractComplex polymicrobial biofilm communities are abundant in nature particularly in the human oral cavity where their composition and fitness can affect health. While the study of these communities during disease is essential and prevalent, little is known about interactions within the healthy plaque community. Here we describe interactions between two of the most abundant species in this healthy microbiome, Haemophilus parainfluenzae and Streptococcus mitis. We discovered that H. parainfluenzae typically exists adjacent to mitis group streptococci in vivo with which it is also positively correlated based on microbiome data. By comparing in vitro coculture data to ex vivo microscopy we revealed that this co-occurrence is density dependent and further influenced by H2O2 production. We discovered that H. parainfluenzae utilizes a more redundant, multifactorial response to H2O2 than related microorganisms and that this system’s integrity enhances streptococcal fitness. Our results indicate that mitis group streptococci are likely the in vivo source of NAD for H. parainfluenzae and also evoke patterns of carbon utilization in vitro for H. parainfluenzae similar to those observed in vivo. Our findings describe mechanistic interactions between two of the most abundant and prevalent members of healthy supragingival plaque that contribute to their in vivo survival.


2021 ◽  
Vol 9 (10) ◽  
pp. 2010
Author(s):  
Ilka D. Nix ◽  
Evgeny A. Idelevich ◽  
Andreas Schlattmann ◽  
Katrin Sparbier ◽  
Markus Kostrzewa ◽  
...  

Discrimination of Streptococcus pneumoniae from other Streptococcus mitis group (SMG) species is still challenging but very important due to their different pathogenic potential. In this study, we aimed to develop a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based optochin susceptibility test with an objective read-out. Optimal test performance was established and evaluated by testing consecutively collected respiratory isolates. Optochin in different concentrations as a potential breakpoint concentration was added to a standardized inoculum. Droplets of 6 µL with optochin and, as growth control, without optochin were spotted onto a MALDI target. Targets were incubated in a humidity chamber, followed by medium removal and on-target protein extraction with formic acid before adding matrix with an internal standard. Spectra were acquired, and results were interpreted as S. pneumoniae in the case of optochin susceptibility (no growth), or as non-S. pneumoniae in the case of optochin non-susceptibility (growth). Highest test accuracy was achieved after 20 h incubation time (95.7%). Rapid testing after 12 h incubation time (optochin breakpoint 2 µg/mL; correct classification 100%, validity 62.5%) requires improvement by optimization of assay conditions. The feasibility of the MALDI-TOF MS-based optochin susceptibility test was demonstrated in this proof-of-principle study; however, confirmation and further improvements are warranted.


2021 ◽  
Vol 7 (9) ◽  
Author(s):  
Akuzike Kalizang'oma ◽  
Chrispin Chaguza ◽  
Andrea Gori ◽  
Charlotte Davison ◽  
Sandra Beleza ◽  
...  

Streptococcus pneumoniae is an important global pathogen that causes bacterial pneumonia, sepsis and meningitis. Beta-lactam antibiotics are the first-line treatment for pneumococcal disease, however, their effectiveness is hampered by beta-lactam resistance facilitated by horizontal genetic transfer (HGT) with closely related species. Although interspecies HGT is known to occur among the species of the genus Streptococcus , the rates and effects of HGT between Streptococcus pneumoniae and its close relatives involving the penicillin binding protein (pbp) genes remain poorly understood. Here we applied the fastGEAR tool to investigate interspecies HGT in pbp genes using a global collection of whole-genome sequences of Streptococcus mitis , Streptococcus oralis and S. pneumoniae . With these data, we established that pneumococcal serotypes 6A, 13, 14, 16F, 19A, 19F, 23F and 35B were the highest-ranking serotypes with acquired pbp fragments. S. mitis was a more frequent pneumococcal donor of pbp fragments and a source of higher pbp nucleotide diversity when compared with S. oralis . Pneumococci that acquired pbp fragments were associated with a higher minimum inhibitory concentration (MIC) for penicillin compared with pneumococci without acquired fragments. Together these data indicate that S. mitis contributes to reduced β-lactam susceptibility among commonly carried pneumococcal serotypes that are associated with long carriage duration and high recombination frequencies. As pneumococcal vaccine programmes mature, placing increasing pressure on the pneumococcal population structure, it will be important to monitor the influence of antimicrobial resistance HGT from commensal streptococci such as S. mitis .


2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Gro Herredsvela Rørvik ◽  
Ali‐Oddin Naemi ◽  
Per Kristian Thorén Edvardsen ◽  
Roger Simm

2021 ◽  
Vol 62 (4) ◽  
Author(s):  
Le Minh Phu ◽  
Do Van Mai ◽  
Hoang Duc Thai ◽  
Bui Dang Minh Tri

Objective: To survey the use of carbapenem antibiotics at An Sinh General Hospital. Subjects and methods: retrospective descriptive study on 100 medical records of patients being treated in departments of An Sinh General Hospital from June 1st, 2020 to December 31st, 2020. Results: The carbapenem antibiotic used at An Sinh General Hospital mainly indicated for the treatment of pneumonia accounted for the highest percentage with 53.3%. There were 100% of strains of Haemophilus influenzae; Rhizobium radiobacter; Proteus. cp; Streptococcus mitis, which was also sensitive to carbapenem. 100% strains of Stenotrophomonas maltophilia bacteria was resistant to meropenem; 01 strain of Burkhorderia vietnamiensis was isolated against imipenem; 2 of 3 strains of Staphylococcus aereus isolated were resistant to meropenem. Carbapenem was mainly used in combination regimens. The proportion of the combination in the initial regimen was 100%. The rate of combination of 3 antibiotics was 22.7%. In the replaceable regimen, the combination rate was 82.2%. Conclusion: The carbapenem group was indicated for the treatment of pneumonia. Strains of the bacteria Haemophilus influenzae; Rhizobium radiobacter; Proteus. cp; Streptococcus mitis was also sensitive to carbapenem. Bacteria strains Stenotrophomonas maltophilia, Burkhorderia vietnamiensis and Staphylococcus aereus were resistant to meropenem. Carbapenem was mainly used in combination regimens.


2021 ◽  
Vol 62 (4) ◽  
Author(s):  
Le Minh Phu

Mục tiêu: Khảo sát tình hình sử dụng kháng sinh nhóm carbapenem tại Bệnh viện Đa khoa An Sinh. Đối tượng và phương pháp nghiên cứu: Nghiên cứu mô tả hồi cứu trên 100 bệnh án của bệnh nhân nằm điều trị tại các khoa của Bệnh viện đa khoa An Sinh trong thời gian từ 01/06/2020 đến 31/12/2020. Kết quả: Nhóm carbapenem sử dụng tại Bệnh viện đa khoa An Sinh chủ yếu được chỉ định để điều trị viêm phổi chiếm tỉ lệ cao nhất với 53,3%. Có 100% các chủng vi khuẩn Haemophilus influenzae; Rhizobium radiobacter; Proteus. cp; Streptococcus mitis còn nhạy cảm với carbapenem. Toàn bộ 100% chủng vi khuẩn Stenotrophomonas maltophilia đề kháng với meropenem; 01 chủng vi khuẩn Burkhorderia vietnamiensis phân lập được đề kháng với imipenem; 2 trong 3 chủng VK Staphylococcus aereus phân lập được đề kháng với meropenem. Carbapenem chủ yếu được sử dụng trong phác đồ phối hợp. Tỷ lệ phối hợp trong phác đồ khởi đầu là 100%. Tỉ lệ phối hợp 3 kháng sinh là 22,7%. Trong phác đồ thay thế, tỷ lệ phối hợp là 82,2%. Kết luận: Nhóm carbapenem được chỉ định để điều trị viêm phổi. Các chủng vi khuẩn Haemophilus influenzae; Rhizobium radiobacter; Proteus. cp; Streptococcus mitis còn nhạy cảm với carbapenem. Chủng vi khuẩn Stenotrophomonas maltophilia, Burkhorderia vietnamiensis và Staphylococcus aereus đề kháng với meropenem. Carbapenem chủ yếu được sử dụng trong phác đồ phối hợp.


2021 ◽  
Author(s):  
Nicolas Gisch ◽  
Katharina Peters ◽  
Simone Thomsen ◽  
Waldemar Vollmer ◽  
Dominik Schwudke ◽  
...  

The opportunistic pathogen Streptococcus mitis possesses, like other members of the Mitis group of viridans streptococci, phosphorylcholine (P-Cho)-containing teichoic acids (TAs) in its cell wall. Bioinformatic analyses predicted the presence of TAs that are almost identical with those identified in the pathogen S. pneumoniae, but a detailed analysis of S. mitis lipoteichoic acid (LTA) was not performed to date. Here we determined the structures of LTA from two S. mitis strains, the high-level beta-lactam and multiple antibiotic resistant strain B6 and the penicillin-sensitive strain NCTC10712. In agreement with bioinformatic predictions we found that the structure of one LTA (type IV) was like pneumococcal LTA, except the exchange of a glucose moiety with a galactose within the repeating units. Further genome comparisons suggested that the majority of S. mitis strains should contain the same type IV LTA as S. pneumoniae, providing a more complete understanding of the biosynthesis of these P-Cho-containing TAs in members of the Mitis group of streptococci. Remarkably, we observed besides type IV LTA an additional polymer belonging to LTA type I in both investigated S. mitis strains. This LTA consists of β-galactofuranosyl-(1,3)-diacylglycerol as glycolipid anchor and a poly-glycerol-phosphate chain at the O-6 position of the furanosidic galactose. Hence, these bacteria are capable of synthesizing two different LTA polymers, most likely produced by distinct biosynthesis pathways. Our bioinformatics analysis revealed the prevalence of the LTA synthase LtaS, most probably responsible for the second LTA version (type I), amongst S. mitis and S. pseudopneumoniae strains.


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