Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21.596
Filter
1.
Reprod Domest Anim ; 59(8): e14699, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39104057

ABSTRACT

Many of the reproductive tract infections in the bitches are caused by bacteria that can normally be present on the vaginal mucosa. These bacteria also might have an important role as the cause responsible for pregnancy loss and fetal deaths. The choice of antibiotic therapy for the pregnant animal is narrow and represents a severe problem in veterinary practice, especially due to increased antimicrobial resistance. Due to incorrect antimicrobials use in breeding kennels, the aim of the present study was to assess the occurrence of the bacterial flora isolated from the pregnant bitches and their antibiotic sensitivity. The study was carried out at the private Veterinary clinic in Novi Sad, Serbia. The vaginal swabs were taken from 60 bitches diagnosed with pregnancy and were sent to be laboratory tested. Based on the results, the most common isolated pathogens were Staphylococcus pseudintermedius (20%) and beta-hemolytic streptococci (18.33%). Furthermore, significant resistance to antibiotics from beta-lactams group was detected. It is of particular importance that antimicrobial treatment be evidence based in order to reduce the overuse of antimicrobials due to increased concern regarding antimicrobial resistance.


Subject(s)
Anti-Bacterial Agents , Dog Diseases , Drug Resistance, Bacterial , Staphylococcus , Vagina , Animals , Female , Dogs , Pregnancy , Vagina/microbiology , Dog Diseases/microbiology , Dog Diseases/epidemiology , Dog Diseases/drug therapy , Anti-Bacterial Agents/pharmacology , Staphylococcus/drug effects , Pregnancy Complications, Infectious/veterinary , Pregnancy Complications, Infectious/microbiology , Pregnancy Complications, Infectious/epidemiology , Prevalence , Streptococcus/drug effects , Streptococcus/isolation & purification , Serbia/epidemiology , Microbial Sensitivity Tests
2.
Gut Microbes ; 16(1): 2387139, 2024.
Article in English | MEDLINE | ID: mdl-39106231

ABSTRACT

Bacteriocins are broad or narrow-spectrum antimicrobial compounds that have received significant scientific attention due to their potential to treat infections caused by antibiotic-resistant pathogenic bacteria. The genome of Bifidobacterium pseudocatenulatum MM0196, an antimicrobial-producing, fecal isolate from a healthy pregnant woman, was shown to contain a gene cluster predicted to encode Pseudocin 196, a novel lantibiotic, in addition to proteins involved in its processing, transport and immunity. Following antimicrobial assessment against various indicator strains, protease-sensitive Pseudocin 196 was purified to homogeneity from cell-free supernatant. MALDI TOF mass spectrometry confirmed that the purified antimicrobial compound corresponds to a molecular mass of 2679 Da, which is consistent with that deduced from its genetic origin. Pseudocin 196 is classified as a lantibiotic based on its similarity to lacticin 481, a lanthionine ring-containing lantibiotic produced by Lactococcus lactis. Pseudocin 196, the first reported bacteriocin produced by a B. pseudocatenulatum species of human origin, was shown to inhibit clinically relevant pathogens, such as Clostridium spp. and Streptococcus spp. thereby highlighting the potential application of this strain as a probiotic to treat and prevent bacterial infections.


Subject(s)
Anti-Bacterial Agents , Bacteriocins , Bifidobacterium , Bacteriocins/pharmacology , Bacteriocins/genetics , Bacteriocins/metabolism , Bacteriocins/chemistry , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Bifidobacterium/genetics , Bifidobacterium/drug effects , Bifidobacterium/metabolism , Female , Clostridium/genetics , Clostridium/drug effects , Clostridium/metabolism , Feces/microbiology , Streptococcus/drug effects , Streptococcus/genetics , Streptococcus/metabolism , Pregnancy , Multigene Family , Microbial Sensitivity Tests , Genome, Bacterial , Probiotics/pharmacology
3.
Int J Mol Sci ; 25(15)2024 Jul 30.
Article in English | MEDLINE | ID: mdl-39125925

ABSTRACT

Dental plaque bacteria play an important role in the pathogenicity of periodontitis and peri-implantitis. Therefore, antimicrobial agents are one means of treatment. N-chlorotaurine (NCT) as an endogenous well-tolerated topical antiseptic could be of advantage for this purpose. Accordingly, its microbicidal activity against some dental plaque bacteria was investigated at therapeutic concentrations in vitro. In quantitative killing assays, the activity of NCT against planktonic bacteria and against biofilms grown for 48 h on implantation screws was tested. Electron microscopy was used to demonstrate the formation of biofilm and its morphological changes. The killing of planktonic bacteria of all tested species, namely Streptococcus sanguinis, Streptococcus salivarius, Streptococcus oralis, Streptococcus cristatus, Rothia aeria, and Capnocytophaga ochracea, was shown within 10-20 min by 1% NCT in 0.01 M phosphate-buffered saline at 37 °C. Bacteria grown on screws for 24 h were inactivated by 1% NCT after 15-20 min as well, but the formation of biofilm on the screws was visible in electron microscopy not before 48 h. The killing of biofilms by 1% NCT was demonstrated after 30 min (streptococci) and 40 min (R. aeria). As expected, NCT has broad activity against dental plaque bacteria as well and should be further investigated on its clinical efficacy in periodontitis and peri-implantitis.


Subject(s)
Biofilms , Dental Plaque , Taurine , Taurine/analogs & derivatives , Taurine/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Dental Plaque/microbiology , Humans , Periodontitis/microbiology , Periodontitis/drug therapy , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacteria/growth & development , Streptococcus/drug effects
5.
World J Microbiol Biotechnol ; 40(10): 290, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39102120

ABSTRACT

Strain Lactiplantibacillus plantarum D1 with bacteriocin producing ability was found in the intestine of Gambusia affinis. The bacteriocin was found to have high inhibitory activity against multiple Streptococcus species and several other Gram-positive and Gram-negative bacteria. Bacteriocin was purified from culture supernatant by ion-exchange chromatography, Sep-Pak C18 cartridge, and reverse-phase high-performance liquid chromatography (RP-HPLC). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectral analysis determined that purified bacteriocin has a molecular mass of 2,731 Da. A partial N-terminal sequence KRKKHKXQIYNNGM was obtained from the Edman analysis. The N-terminal sequence was employed to search against a translation of the draft genome of strain D1. The translated full amino acid sequence of the mature peptide is as follows: NH2- KRKKHKCQIYNNGMPTGQYRWC, which has a molecular weight of 2738 Da. A BLAST search revealed that this bacteriocin was most similar to bactofencin A but differed from it with three amino acid residues. No identical peptide or protein has been previously reported, and this peptide, termed bactofencin YH, was therefore considered to be a new bacteriocin produced by Lactiplantibacillus plantarum D1.


Subject(s)
Amino Acid Sequence , Anti-Bacterial Agents , Bacteriocins , Molecular Weight , Streptococcus , Bacteriocins/pharmacology , Bacteriocins/chemistry , Bacteriocins/isolation & purification , Bacteriocins/metabolism , Streptococcus/drug effects , Streptococcus/genetics , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Microbial Sensitivity Tests , Animals , Chromatography, High Pressure Liquid , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects
6.
BMJ Case Rep ; 17(8)2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39142840

ABSTRACT

Streptococcal toxic shock syndrome (STSS) is an uncommon disorder characterised by hypotension and multiorgan failure in the setting of streptococcal infection. Recurrent STSS is rare and has been due to recurrence of the same streptococcal species. Here, we present a case of a patient who developed recurrent STSS from a Streptococcus dysgalactiae right native joint septic arthritis and subsequently from a Streptococcus agalactiae left native joint septic arthritis.


Subject(s)
Arthritis, Infectious , Recurrence , Shock, Septic , Streptococcal Infections , Streptococcus agalactiae , Humans , Shock, Septic/microbiology , Arthritis, Infectious/microbiology , Arthritis, Infectious/diagnosis , Arthritis, Infectious/drug therapy , Streptococcal Infections/diagnosis , Streptococcal Infections/complications , Streptococcal Infections/microbiology , Streptococcal Infections/drug therapy , Streptococcus agalactiae/isolation & purification , Streptococcus/isolation & purification , Male , Anti-Bacterial Agents/therapeutic use , Female , Middle Aged
7.
BMC Microbiol ; 24(1): 310, 2024 Aug 22.
Article in English | MEDLINE | ID: mdl-39174931

ABSTRACT

BACKGROUND: Bovine mastitis results in significant economic losses for the dairy industry globally due to milk production losses and decreased herd efficiency. This research aimed to isolate, select, and characterize indigenous lactobacilli with probiotic properties. A total of 40 lactobacilli were isolated from healthy milk samples of cattle and identified at the species level through 16S rDNA sequencing. All isolates were initially screened for antimicrobial activity, and selected isolates underwent in vitro assessment of probiotic properties. RESULTS: Among the lactobacilli isolates, varying levels of activity (9 to 19 mm) against cattle mastitogens; Stapylococcus aureus (Staph. aureus), Escherichia coli (E. coli) and Streptococcus dysgalactiae (Strep. dysgalactiae) were observed in the well diffusion assay. These isolates demonstrated auto-aggregation (ranging from 14.29 ± 0.96% to 62.11 ± 1.09%) and co-aggregate (ranging from 9.21 ± 0.14% to 55.74 ± 0.74%) with mastitogens after 2 h. Lactobacillus (Lb.) plantarum CM49 showed sensitivity to most antibiotics tested and exhibited strong inhibitory effects, with mean log10 reductions of 3.46 for Staph. aureus, 2.82 for E. coli, and 1.45 for Strep. dysgalactiae in co-culture experiments. Furthermore, Lb. plantarum CM49 significantly decreased the adhesion rate of mastitogens on the bovine mammary cell line and mouse model, demonstrating its potential effectiveness in preventing mastitis. CONCLUSION: It is concluded that Lb. plantarum CM49 has remarkable probiotic potential with activity against cattle mastitogens in the laboratory and cell culture and competitively excludes mastitogens from bovine mammary cells and ameliorates Staph. aureus-induced mastitis in mice.


Subject(s)
Escherichia coli , Lactobacillus plantarum , Mastitis, Bovine , Milk , Probiotics , Staphylococcus aureus , Animals , Cattle , Probiotics/pharmacology , Mastitis, Bovine/microbiology , Mastitis, Bovine/prevention & control , Lactobacillus plantarum/physiology , Lactobacillus plantarum/isolation & purification , Lactobacillus plantarum/genetics , Female , Milk/microbiology , Staphylococcus aureus/drug effects , Mice , Escherichia coli/drug effects , Escherichia coli/genetics , RNA, Ribosomal, 16S/genetics , Anti-Bacterial Agents/pharmacology , Streptococcus/drug effects , Streptococcus/genetics , Streptococcus/physiology , Microbial Sensitivity Tests
8.
Microbiologyopen ; 13(4): e1432, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39166362

ABSTRACT

The long-read sequencing platform MinION, developed by Oxford Nanopore Technologies, enables the sequencing of bacterial genomes in resource-limited settings, such as field conditions or low- and middle-income countries. For this purpose, protocols for extracting high-molecular-weight DNA using nonhazardous, inexpensive reagents and equipment are needed, and some methods have been developed for gram-negative bacteria. However, we found that without modification, these protocols are unsuitable for gram-positive Streptococcus spp., a major threat to fish farming and food security in low- and middle-income countries. Multiple approaches were evaluated, and the most effective was an extraction method using lysozyme, sodium dodecyl sulfate, and proteinase K for lysis of bacterial cells and magnetic beads for DNA recovery. We optimized the method to consistently achieve sufficient yields of pure high-molecular-weight DNA with minimal reagents and time and developed a version of the protocol which can be performed without a centrifuge or electrical power. The suitability of the method was verified by MinION sequencing and assembly of 12 genomes of epidemiologically diverse fish-pathogenic Streptococcus iniae and Streptococcus agalactiae isolates. The combination of effective high-molecular-weight DNA extraction and MinION sequencing enabled the discovery of a naturally occurring 15 kb low-copy number mobilizable plasmid in S. iniae, which we name pSI1. We expect that our resource-limited settings-adapted protocol for high-molecular-weight DNA extraction could be implemented successfully for similarly recalcitrant-to-lysis gram-positive bacteria, and it represents a method of choice for MinION-based disease diagnostics in low- and middle-income countries.


Subject(s)
DNA, Bacterial , Nanopore Sequencing , Streptococcus , Streptococcus/genetics , Streptococcus/isolation & purification , Streptococcus/classification , DNA, Bacterial/genetics , Nanopore Sequencing/methods , Animals , Genome, Bacterial/genetics , Molecular Weight , Sequence Analysis, DNA/methods , Fishes/microbiology , Fish Diseases/microbiology , Streptococcal Infections/microbiology , Resource-Limited Settings
9.
PLoS One ; 19(7): e0300408, 2024.
Article in English | MEDLINE | ID: mdl-39052548

ABSTRACT

SARS-CoV-2, a severe respiratory disease primarily targeting the lungs, was the leading cause of death worldwide during the pandemic. Understanding the interplay between the oral microbiome and inflammatory cytokines during acute infection is crucial for elucidating host immune responses. This study aimed to explore the relationship between the oral microbiome and cytokines in COVID-19 patients, particularly those with and without sputum production. Saliva and blood samples from 50 COVID-19 patients were subjected to 16S ribosomal RNA gene sequencing for oral microbiome analysis, and 65 saliva and serum cytokines were assessed using Luminex multiplex analysis. The Mann-Whitney test was used to compare cytokine levels between individuals with and without sputum production. Logistic regression machine learning models were employed to evaluate the predictive capability of oral microbiome, salivary, and blood biomarkers for sputum production. Significant differences were observed in the membership (Jaccard dissimilarity: p = 0.016) and abundance (PhILR dissimilarity: p = 0.048; metagenomeSeq) of salivary microbial communities between patients with and without sputum production. Seven bacterial genera, including Prevotella, Streptococcus, Actinomyces, Atopobium, Filifactor, Leptotrichia, and Selenomonas, were more prevalent in patients with sputum production (p<0.05, Fisher's exact test). Nine genera, including Prevotella, Megasphaera, Stomatobaculum, Selenomonas, Leptotrichia, Veillonella, Actinomyces, Atopobium, and Corynebacteria, were significantly more abundant in the sputum-producing group, while Lachnoanaerobaculum was more prevalent in the non-sputum-producing group (p<0.05, ANCOM-BC). Positive correlations were found between salivary IFN-gamma and Eotaxin2/CCL24 with sputum production, while negative correlations were noted with serum MCP3/CCL7, MIG/CXCL9, IL1 beta, and SCF (p<0.05, Mann-Whitney test). The machine learning model using only oral bacteria input outperformed the model that included all data: blood and saliva biomarkers, as well as clinical and demographic variables, in predicting sputum production in COVID-19 subjects. The performance metrics were as follows, comparing the model with only bacteria input versus the model with all input variables: precision (95% vs. 75%), recall (100% vs. 50%), F1-score (98% vs. 60%), and accuracy (82% vs. 66%).


Subject(s)
COVID-19 , Microbiota , Saliva , Sputum , Humans , COVID-19/microbiology , Sputum/microbiology , Saliva/microbiology , Female , Male , Middle Aged , Adult , Aged , Cytokines/blood , Cytokines/metabolism , Lung/microbiology , Lung/virology , SARS-CoV-2/isolation & purification , RNA, Ribosomal, 16S/genetics , Leptotrichia , Prevotella/isolation & purification , Streptococcus/isolation & purification , Actinomyces/isolation & purification , Mouth/microbiology , Mouth/virology , Machine Learning , Biomarkers/blood
10.
Article in English | MEDLINE | ID: mdl-38958657

ABSTRACT

Novel Gram-positive, catalase-negative, α-haemolytic cocci were isolated from breast milk samples of healthy mothers living in Hanoi, Vietnam. The 16S rRNA gene sequences of these strains varied by 0-2 nucleotide polymorphisms. The 16S rRNA gene sequence of one strain, designated as BME SL 6.1T, showed the highest similarity to those of Streptococcus salivarius NCTC 8618T (99.4 %), Streptococcus vestibularis ATCC 49124T (99.4 %), and Streptococcus thermophilus ATCC 19258T (99.3 %) in the salivarius group. Whole genome sequencing was performed on three selected strains. Phylogeny based on 631 core genes clustered the three strains into the salivarius group, and the strains were clearly distinct from the other species in this group. The average nucleotide identity (ANI) value of strain BME SL 6.1T exhibited the highest identity with S. salivarius NCTC 8618T (88.4 %), followed by S. vestibularis ATCC 49124T (88.3 %) and S. thermophilus ATCC 19258T (87.4 %). The ANI and digital DNA-DNA hybridization values between strain BME SL 6.1T and other species were below the cut-off value (95 and 70 %, respectively), indicating that it represents a novel species of the genus Streptococcus. The strains were able to produce α-galactosidase and acid from raffinose and melibiose. Therefore, we propose to assign the strains to a new species of the genus Streptococcus as Streptococcus raffinosi sp. nov. The type strain is BME SL 6.1T (=VTCC 12812T=NBRC 116368T).


Subject(s)
Bacterial Typing Techniques , DNA, Bacterial , Milk, Human , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , Streptococcus , RNA, Ribosomal, 16S/genetics , Humans , Female , DNA, Bacterial/genetics , Milk, Human/microbiology , Streptococcus/genetics , Streptococcus/isolation & purification , Streptococcus/classification , Vietnam , Whole Genome Sequencing
11.
Medicina (Kaunas) ; 60(7)2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39064580

ABSTRACT

Background and Objectives: The incidence of metabolic dysfunction-associated steatohepatitis (MASH)-related hepatocellular carcinoma (HCC) is increasing worldwide, alongside the epidemic of obesity and metabolic syndrome. Based on preliminary reports regarding the potential association of HCC and periodontitis, this study aimed to analyze the involvement of periodontal bacteria as well as the oral and intestinal bacterial flora in MASH-related HCC (MASH-HCC). Materials and Methods: Forty-one patients with MASH and nineteen with MASH-HCC participated in the study, completing survey questionnaires, undergoing periodontal examinations, and providing samples of saliva, mouth-rinsed water, feces, and peripheral blood. The oral and fecal microbiome profiles were analyzed by 16S ribosomal RNA sequencing. Bayesian network analysis was used to analyze the causation between various factors, including MASH-HCC, examinations, and bacteria. Results: The genus Fusobacterium had a significantly higher occupancy rate (p = 0.002) in the intestinal microflora of the MASH-HCC group compared to the MASH group. However, Butyricicoccus (p = 0.022) and Roseburia (p < 0.05) had significantly lower occupancy rates. The Bayesian network analysis revealed the absence of periodontal pathogenic bacteria and enteric bacteria affecting HCC. However, HCC directly affected the periodontal bacterial species Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, and Prevotella intermedia in the saliva, as well as the genera Lactobacillus, Roseburia, Fusobacterium, Prevotella, Clostridium, Ruminococcus, Trabulsiella, and SMB53 in the intestine. Furthermore, P. gingivalis in the oral cavity directly affected the genera Lactobacillus and Streptococcus in the intestine. Conclusions: MASH-HCC directly affects periodontal pathogenic and intestinal bacteria, and P. gingivalis may affect the intestinal bacteria associated with gastrointestinal cancer.


Subject(s)
Carcinoma, Hepatocellular , Gingiva , Mouth , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Bacteroidaceae/classification , Bacteroidaceae/isolation & purification , Carcinoma, Hepatocellular/microbiology , Carcinoma, Hepatocellular/pathology , Cross-Sectional Studies , Enterobacteriaceae/classification , Enterobacteriaceae/isolation & purification , Fatty Liver , Feces/microbiology , Fusobacterium/classification , Fusobacterium/isolation & purification , Gingiva/microbiology , Lactobacillus/isolation & purification , Mouth/microbiology , Saliva/microbiology , Streptococcus/isolation & purification , Pilot Projects
12.
Intern Med ; 63(15): 2209-2214, 2024.
Article in English | MEDLINE | ID: mdl-39085093

ABSTRACT

A 66-year-old woman with liver cirrhosis and hemodialysis was referred with a 1-week history of pain and rash on the left lower leg. On an examination, the patient was in shock. She was administered catecholamine support for septic shock and ampicillin/sulbactam for severe cellulitis. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was isolated from the blood culture, and she was diagnosed with streptococcal toxic shock syndrome. Despite therapy, the patient died on day 7 of admission. Infective endocarditis (IE) was diagnosed during an autopsy. Clinicians should be aware that overwhelming SDSE-IE can occur even in the absence of necrotizing fasciitis, especially in immunocompromised patients.


Subject(s)
Autopsy , Endocarditis, Bacterial , Shock, Septic , Streptococcal Infections , Streptococcus , Humans , Shock, Septic/microbiology , Shock, Septic/diagnosis , Female , Aged , Streptococcal Infections/diagnosis , Streptococcal Infections/complications , Streptococcal Infections/microbiology , Streptococcus/isolation & purification , Fatal Outcome , Endocarditis, Bacterial/microbiology , Endocarditis, Bacterial/diagnosis , Endocarditis, Bacterial/complications , Endocarditis, Bacterial/drug therapy
13.
J Appl Microbiol ; 135(8)2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39066499

ABSTRACT

AIMS: This study evaluates the antibacterial characteristics and mechanisms of combined tea polyphenols (TPs), Nisin, and ε-polylysine (PL) against Streptococcus canis, Streptococcus minor, Streptococcus mutans, and Actinomyces oris, common zoonotic pathogens in companion animals. METHODS AND RESULTS: Pathogenic strains were isolated from feline oral cavities and assessed using minimum inhibitory concentration (MIC) tests, inhibition zone assays, growth kinetics, and biofilm inhibition studies. Among single agents, PL exhibited the lowest MIC values against all four pathogens. TP showed significant resistance against S. minor, and Nisin against S. mutans. The combination treatment (Comb) of TP, Nisin, and PL in a ratio of 13:5:1 demonstrated broad-spectrum antibacterial activity, maintaining low MIC values, forming large inhibition zones, prolonging the bacterial lag phase, reducing growth rates, and inhibiting biofilm formation. RNA sequencing and metabolomic analysis indicated that TP, Nisin, and PL inhibited various membrane-bound carbohydrate-specific transferases through the phosphoenolpyruvate-dependent phosphotransferase system in S. canis, disrupting carbohydrate uptake. They also downregulated glycolysis and the citric acid cycle, inhibiting cellular energy metabolism. Additionally, they modulated the activities of peptidoglycan glycosyltransferases and d-alanyl-d-alanine carboxypeptidase, interfering with peptidoglycan cross-linking and bacterial cell wall stability. CONCLUSIONS: The Comb therapy significantly enhances antibacterial efficacy by targeting multiple bacterial pathways, offering potential applications in food and pharmaceutical antimicrobials.


Subject(s)
Anti-Bacterial Agents , Biofilms , Microbial Sensitivity Tests , Nisin , Polylysine , Polyphenols , Tea , Animals , Nisin/pharmacology , Anti-Bacterial Agents/pharmacology , Polylysine/pharmacology , Polyphenols/pharmacology , Cats , Tea/chemistry , Biofilms/drug effects , Streptococcus/drug effects , Streptococcus/genetics , Transcriptome , Mouth/microbiology , Metabolomics
14.
Curr Microbiol ; 81(9): 286, 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39073451

ABSTRACT

Streptococcus spp. are important opportunistic pathogen of bacteremia in both immunocompetent and immunosuppressed patients. A streptococcal strain, designated ST2T, was isolated from the blood specimen of a bacteremic patient. Comparative analyses of 16S rRNA, rpoB and groEL gene sequences demonstrated that the novel strain ST2T is a member of the genus Streptococcus. Based on of 16S rRNA gene sequence similarities, the type strains of Streptococcus (S.) parasanguinis (99.2%), S. ilei (98.8%), S. oralis subsp. oralis (97.6%), S. australis (97.5%) and S. sanguinis (97.5%) were the closest neighbours to strain ST2T. The housekeeping gene sequences (rpoB and groEL) similarities of strain ST2T to these closely related type strains were 80.4-97.4%, respectively. The complete draft genome of strain ST2T consisted of 2,155,906 bp with a G + C content of 42.0%. Strain ST2T has an average nucleotide identity (ANI) value of 94.1 and 81.3% with S. parasanguinis ATCC 15912T and S. ilei I-G2T, respectively. The highest in silico DNA-DNA hybridization value with respect to the closest species S. parasanguinis was 55.6%, below the species cut-off of 70% hybridization. The primary cellular fatty acids of strain ST2T were C16:0, C18:1 ω9c, C18:0 and C14:0. Based on biochemical criteria and molecular genetic evidence, it is proposed that strain ST2T be assigned to a new species of the genus Streptococcus as Streptococcus taoyuanensis sp. nov. The type strain of Streptococcus taoyuanensis is ST2T (=NBRC 115928T = BCRC 81374T) as the type strain.


Subject(s)
Bacteremia , Base Composition , DNA, Bacterial , Phylogeny , RNA, Ribosomal, 16S , Streptococcal Infections , Streptococcus , Bacteremia/microbiology , Humans , RNA, Ribosomal, 16S/genetics , Streptococcus/genetics , Streptococcus/isolation & purification , Streptococcus/classification , DNA, Bacterial/genetics , Streptococcal Infections/microbiology , Sequence Analysis, DNA , Bacterial Typing Techniques , Genome, Bacterial , Fatty Acids , Nucleic Acid Hybridization , Bacterial Proteins/genetics , Male
15.
Molecules ; 29(14)2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39064988

ABSTRACT

Streptococcus dysgalactiae infection can cause bovine mastitis and lead to huge economic losses for the dairy industry. The abuse of antibiotics has resulted in growing drug resistance of S. dysgalactiae, which causes hard-to-treat infections. Bacteriophage lysin, as a novel antibacterial agent, has great potential for application against drug-resistant gram-positive bacteria. However, few studies have been conducted on the prophage lysin of S. dysgalactiae. In this study, we mined a novel prophage lysin, named Lys1644, from a clinical S. dysgalactiae isolate by genome sequencing and bioinformatic analysis. Lys1644 was expressed and purified, and the lytic activity, antibacterial spectrum, optimal pH and temperature, lytic activity in milk in vitro, and synergistic bacteriostasis with antibiotics were assessed. The Lys1644 prophage lysin showed high bacteriolysis activity specifically on S. dysgalactiae, which resulted in CFU 100-fold reduction in milk. Moreover, Lys1644 maintained high activity over a wide pH range (pH 5-10) and a wide temperature range (4-42 °C). Synergistic bacteriostatic experiments showed that the combination of low-dose Lys1644 (50 µg/mL) with a subinhibitory concentration of aminoglycoside antibiotics (kanamycin or spectinomycin) can completely inhibit bacterial growth, suggesting that the combination of Lys1644 and antibiotics could be an effective therapeutic strategy against S. dysgalactiae infection.


Subject(s)
Anti-Bacterial Agents , Prophages , Streptococcus , Streptococcus/drug effects , Prophages/genetics , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Animals , Milk/microbiology , Streptococcus Phages/genetics , Cattle , Mastitis, Bovine/microbiology , Mastitis, Bovine/drug therapy , Hydrogen-Ion Concentration , Bacteriolysis/drug effects , Streptococcal Infections/microbiology , Streptococcal Infections/drug therapy
16.
J Oral Biosci ; 66(3): 628-632, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39069173

ABSTRACT

To explore the potential storage and safety of drinking leftover bottled tea beverages from various manufacturers after direct drinking from bottles, we conducted a screening experiment on the growth of salivary bacteria in plastic bottles of tea. The diluted saliva samples from 10 participants were inoculated into the test bottled beverages, which resulted in bacteria, particularly former members of the genus Lactobacillus, growing in some green tea beverages with a neutral pH. In contrast, tea beverages with less bacterial growth contained Streptococcus spp., and the leftovers may be safe to store and drink again.


Subject(s)
Saliva , Tea , Tea/microbiology , Tea/chemistry , Humans , Saliva/microbiology , Lactobacillus/isolation & purification , Streptococcus/isolation & purification , Adult , Female , Hydrogen-Ion Concentration
18.
Dent Mater J ; 43(4): 485-494, 2024 Jul 31.
Article in English | MEDLINE | ID: mdl-38825451

ABSTRACT

Highly polished 3, 4, and 5 mol% yttria-stabilized zirconia and CAD/CAM composite resin samples were prepared, and the influence of surface roughness (Ra and Sa, 21 areas/group), wettability (contact angle and surface energy, 3 samples/group), and surface chemical composition (2 samples/group) on single-strain bacterial adhesion models (Porphyromonas gingivalis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii, and Streptococcus mutans) were compared via fluorescent staining with graphical analysis (21 areas/group). Statistical analysis was performed using the Shapiro-Wilk test followed by one-way analysis of variance with Tukey's test or the Kruskal-Wallis test with Dunn's test (α=0.05) and linear regression. For dental zirconia with the same surface roughness, the yttria content did not significantly influence the initial bacterial adhesion. However, higher bacterial adhesion was detected for the composite resin owing to its high C, O, and Si contents. There was no correlation between surface energy and bacterial adhesion for any bacterial strain (p<0.005).


Subject(s)
Bacterial Adhesion , Composite Resins , Dental Materials , Surface Properties , Zirconium , Zirconium/chemistry , Composite Resins/chemistry , Dental Materials/chemistry , In Vitro Techniques , Yttrium/chemistry , Dental Polishing/methods , Materials Testing , Streptococcus , Streptococcus mutans , Wettability , Streptococcus gordonii/physiology , Streptococcus sanguis , Porphyromonas gingivalis , Fluorescent Dyes
19.
mSphere ; 9(7): e0021424, 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-38904369

ABSTRACT

Streptococcus dysgalactiae is an emerging human and animal pathogen. Functional studies of genes involved in virulence of S. dysgalactiae and other pyogenic group streptococci are often hampered by limited genetic tractability. It is known that pyogenic streptococci carry genes required for competence for natural transformation; however, in contrast to other streptococcal subgroups, there is limited evidence for gene transfer by natural transformation in these bacteria. In this study, we systematically assessed the genomes of 179 S. dysgalactiae strains of both human and animal origins (subsp. equisimilis and dysgalactiae, respectively) for the presence of genes required for natural transformation. While a considerable fraction of the strains contained inactive genes, the majority (64.2%) of the strains had an intact gene set. In selected strains, we examined the dynamics of competence activation after addition of competence-inducing pheromones using transcriptional reporter assays and exploratory RNA-seq. Based on these findings, we were able to establish a protocol allowing us to utilize natural transformation to construct deletion mutants by allelic exchange in several S. dysgalactiae strains of both subspecies. As part of the work, we deleted putative lactose utilization genes to study their role in growth on lactose. The data presented here provide new knowledge on the potential of horizonal gene transfer by natural transformation in S. dysgalactiae and, importantly, demonstrates the possibility to exploit natural transformation for genetic engineering in these bacteria. IMPORTANCE: Numerous Streptococcus spp. exchange genes horizontally through natural transformation, which also facilitates efficient genetic engineering in these organisms. However, for the pyogenic group of streptococci, including the emerging pathogen Streptococcus dysgalactiae, there is limited experimental evidence for natural transformation. In this study, we demonstrate that natural transformation in vitro indeed is possible in S. dysgalactiae strains under optimal conditions. We utilized this method to perform gene deletion through allelic exchange in several strains, thereby paving the way for more efficient gene engineering methods in pyogenic streptococci.


Subject(s)
Streptococcus , Transformation, Bacterial , Streptococcus/genetics , Humans , Genome, Bacterial , Animals , DNA Transformation Competence/genetics , Streptococcal Infections/microbiology , Virulence/genetics
20.
Eur J Clin Microbiol Infect Dis ; 43(8): 1609-1619, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38847928

ABSTRACT

PURPOSE: The incidence of invasive Streptococcus dysgalactiae subsp. equisimilis (iSDSE) infections is increasing in developed countries, but studies on the risk factors for death in iSDSE infections are scant. Here, we aimed to clarify risk factors and predictors of mortality in adults with iSDSE infections. METHODS: A multicentre observational study of adults with iSDSE infections was conducted to investigate the effects of host factors, disease severity, biomarkers, and antibiotic regimens, and bacterial factors on 28-day mortality. RESULTS: The overall mortality rate of 588 patients was 10.4%, with a significant increase in those aged ≥ 60 years. Most of the patients (97.4%) had underlying diseases. The mortality rate (70.4%) of patients with severe disease was significantly higher than that of patients with mild-to-moderate disease (4.3%; p < 0.001). The risk factors for death identified using multivariable analysis were age ≥ 60 years (hazard ratio [HR], 3.4; 95% confidence interval [CI], 1.0-11.3, p = 0.042); severe disease (HR, 15.0; 95% CI 7.7-29.2, p < 0.001); bacteraemia without primary focus (HR, 20.5; 95% CI 2.8-152.3, p = 0.003); serum creatinine ≥ 2.0 mg/dL (HR, 2.2; 95% CI 1.2-4.0, p = 0.010); serum creatine kinase ≥ 300 IU/L (HR, 2.1; 95% CI 1.1-3.8, p = 0.019); and macrolide resistance (HR, 1.8; 95% CI 1.0-3.3, p = 0.048). Treatment regimens and emm types were not associated with poor outcomes. CONCLUSION: Evaluation of clinical manifestations and biomarkers on admission is important to predict invasive SDSE infection prognosis.


Subject(s)
Biomarkers , Streptococcal Infections , Streptococcus , Humans , Streptococcal Infections/mortality , Streptococcal Infections/microbiology , Streptococcal Infections/blood , Streptococcal Infections/drug therapy , Middle Aged , Female , Male , Aged , Biomarkers/blood , Streptococcus/isolation & purification , Risk Factors , Adult , Anti-Bacterial Agents/therapeutic use , Aged, 80 and over , Severity of Illness Index , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL