Streptococcus Species Research Articles

Seasonal variations of empyema in Taiwan: A 10-year analysis

BackgroundEmpyema is a serious infection in pleural space. Finding out seasonal variations of empyema and its pathogens can help in providing preventive measures, and implicating future researches. MethodsThis study is a 10-year observational study in a single center. Patients with empyema thoracis receiving thoracoscopic decortication between January 2012 and December 2021 were included in the study. ResultsThere were 1082 empyema patients enrolled in this study. No seasonal variation was noted (spring = 25.7 %, summer =25.5 %, autumn = 24.8 %, winter = 24.0 %). However, we observed seasonal variations in pathogens. Streptococcus species had slightly higher prevalence in winter and spring than summer and autumn (54.3 % vs. 45.7 %) without significant difference (p = 0.251). On the contrary, Staphylococcus species occurred more often in summer and autumn than winter and spring (61.5 % vs. 38.5 %) (p = 0.035). Klebsiella species were more likely found in autumn (34.9 %) (p = 0.050), and Pseudomonas species showed no peak prevalence in any season (p = 0.423). The incidence of Streptococcus species increased over the years. ConclusionsAlthough no seasonal variation was found in severe empyema patients requiring surgery, there were seasonal variations for the pathogens in Taiwan. The medical community should focus on Streptococcus species in winter and spring and Staphylococcus species in summer and autumn.

Characteristics of Streptococcal Toxic Shock Syndrome Caused by Different Beta-hemolytic Streptococci Species: A Single-center Retrospective Study.

Streptococcal toxic shock syndrome (STSS) is a life-threatening condition caused by beta-hemolytic streptococci (BHS). Streptococcus pyogenes is the main causative agent of this disease; other BHS such as Streptococcus agalactiae or Streptococcus dysgalactiae could also cause STSS. However, the clinical characteristics of STSS caused by other types of BHS remain poorly understood. In this study, we evaluated the likelihood of STSS development in various streptococcal species. We conducted a retrospective observational study using adult medical records of patients with invasive BHS in a tertiary care institution from 2002 to 2022 and classified them into STSS or non-STSS groups. Multivariable analysis of bacterial species adjusted for age and diabetes mellitus was conducted. S pyogenes cases were propensity-matched (1:4) to non-pyogenes BHS cases. A total of 43 STSS and 285 non-STSS cases were identified. S pyogenes, S agalactiae, and S dysgalactiae accounted for 17, 13, and 13 STSS cases, respectively. The crude mortality of STSS was approximately 35% in all groups. A multivariable analysis suggested that STSS was less frequent in S agalactiae and S dysgalactiae cases with odds ratio 0.24 (95% confidence interval [CI], 0.10-0.54; P < .001) and 0.23 (95% CI, .10-.55; P < .001), respectively. Propensity score matching showed that S pyogenes caused STSS more frequently than other BHS cases with an odds ratio of 3.28 (95% CI 1.21-8.77; P = .010). This study described and compared the clinical characteristics of STSS caused by different BHS. We demonstrated that S pyogenes caused STSS more often than other BHS.

Genomic and functional determinants of host spectrum in Group B Streptococcus.

Group B Streptococcus (GBS) is a major human and animal pathogen that threatens public health and food security. Spill-over and spill-back between host species is possible due to adaptation and amplification of GBS in new niches but the evolutionary and functional mechanisms underpinning those phenomena are poorly known. Based on analysis of 1,254 curated genomes from all major GBS host species and six continents, we found that the global GBS population comprises host-generalist, host-adapted and host-restricted sublineages, which are found across host groups, preferentially within one host group, or exclusively within one host group, respectively, and show distinct levels of recombination. Strikingly, the association of GBS genomes with the three major host groups (humans, cattle, fish) is driven by a single accessory gene cluster per host, regardless of sublineage or the breadth of host spectrum. Moreover, those gene clusters are shared with other streptococcal species occupying the same niche and are functionally relevant for host tropism. Our findings demonstrate (1) the heterogeneity of genome plasticity within a bacterial species of public health importance, enabling the identification of high-risk clones; (2) the contribution of inter-species gene transmission to the evolution of GBS; and (3) the importance of considering the role of animal hosts, and the accessory gene pool associated with their microbiota, in the evolution of multi-host bacterial pathogens. Collectively, these phenomena may explain the adaptation and clonal expansion of GBS in animal reservoirs and the risk of spill-over and spill-back between animals and humans.

Changing Face of Antimicrobial Resistance: A Cross-Sectional Study

Introduction Infections of sterile body fluids are significant contributors to mortality and morbidity. Accurate species-level identification and understanding of the antimicrobial resistance profiles are crucial for selecting appropriate antimicrobials for empirical and targeted therapy. This study aims to examine the distribution of various bacterial species and their evolved antimicrobial resistance profiles isolated from different body fluids. Methods This retrospective study evaluated 301 body fluid samples collected at a tertiary hospital between January 2023 and December 2023. Samples were gram-stained and cultured on an appropriate media. Bacterial identification and susceptibility testing were performed using the BD Phoenix™ system, with disk diffusion method used for antibiotics not available in the system. Results Microbial growth was detected in 151 cases (50.2%), with a comparable prevalence among males and females (53.0% vs. 46.7%). The mean age was 49.81± 24.1 years. Growth rates were slightly higher in hospital-acquired infections (55.7%) than in community-acquired infections (49.2%). Cerebrospinal fluid showed the highest growth rate at 34.3%. Among the isolates, Streptococcus species were the most common (14.6%), while Escherichia coli was the predominant Gram-negative bacterium (13.2%). Sensitivity was highest with tigecycline (100%) and meropenem (92%), whereas resistance was most notable against ampicillin-sulbactam (100%) and azithromycin (95.2%). Multidrug resistance was identified in 106 isolates (70.2%). Conclusion High antibiotic resistance and multidrug-resistant strains underscore the need for rigorous antibiotic stewardship and improved infection control to address untreatable infections.

Uterine Endometrium Microbiome in Women with Repeated Implantation Failure Complicated by Endometriosis.

Objectives: This prospective study evaluated whether endometriosis is associated with chronic endometritis (CE) and affects the uterine endometrium microbiome (UEM) in women with repeated implantation failure (RIF). Methods: Forty-three women with RIF were divided into 12 with endometriosis (EM) and 31 without endometriosis (non-EM). The UEM was examined by 16S ribosomal RNA (rRNA) sequencing, and CE was determined by CD 138 staining (plasma cells > 5.15/10 mm2) simultaneously. Results: The EM group had a higher bacterial number (EM vs. non-EM; median [range], 6.5 vs. 3 [3-11, 1-16], p = 0.009), while the frequency of Lactobacillus species did not change. The rates of presence of Dialister (41.7% [5/12] vs. 3.3% [1/31], p = 0.004) and Streptococcus species (58.3% [7/12] vs. 16.1% [5/31], p = 0.017) were higher in the EM group. The prevalence of CE did not differ between the two groups. Multivariable logistic regression analysis revealed that the presence of Dialister species (odds ratio, 10.97, 95% confidence interval, 1.17-249.37, p = 0.036) was associated with endometriosis. In the EM group, five women with Dialister species had a higher number of bacterial species (10 vs. 5 [6-11, 3-7], p = 0.021) and higher Shannon diversity index (0.50 vs. 0.20 [0.19-1.39, 0.03-0.46], p = 0.026) than seven without Dialister species. Conclusions: Dialister and Streptococcus species, and the increased number of bacterial species in UEM may be related to the pathogenesis of RIF complicated by endometriosis.

Bactofencin YH, a novel bacteriocin with high inhibitory activity against clinical Streptococcus species.

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.

Use of tuf gene sequencing for Identification of Lactococci isolated from diseased rainbow trout (Oncorhynchus mykiss)

Lactococcosis is a bacterial infection that is characterized by the appearance of septicemia in fish. Traditionally, the identification of causes of disease outbreaks in aquaculture poses a major challenge due to their comparable characteristics. In this study, simple PCR and sequencing based on the tuf gene were developed to identify isolates belonging to the Streptococcaceae family. The outbreaks of lactococcosis in rainbow trout have been mainly associated with Lactococcus garvieae, but the emergence of closely related species, Lactococcus petauri and Lactococcus formosensis pose a challenge in accurate identification. The study aimed to identify Gram-positive catalase-negative cocci and differentiate between Lactococcosis-causing bacteria (LCB) in rainbow trout isolates associated with lactococcosis outbreaks in Iran. Seventy-five Gram-positive cocci strains from diseased rainbow trout were tested using a PCR and sequencing method targeting the tuf gene. Sequence and phylogenetic analyses were conducted to distinguish between closely related Lactococcus species. The PCR results revealed a successful amplification with tuf gene primers for all strains, allowing species identification. The sequence analysis showed that all 29 isolates initially identified as L.garvieae were 100% identical to L.petauri, indicating a previous misclassification. This work is the first report by L.petauri of Iran. Analysis of tuf gene sequences revealed different patterns of single nucleotide polymorphism (SNP) for accurate species differentiation and phylogenetic analysis confirmed different clusters for LCB. The study highlights the misidentification of L.petauri as L.garvieae in lactococcosis outbreaks and the importance of accurate species differentiation in disease management. The tuf gene sequencing method shows promise for practical, cost-effective, and accurate differentiation of closely related streptococcal species in aquaculture. These findings strongly indicate the need to re-evaluate the initial identification of isolates from fish with lactococcisis. The findings of this study also suggest that the tuf gene sequencing, established in this research for its practicality and cost-efficiency, could potentially be integrated into routine diagnostic procedures for Gram-positive, catalase-negative cocci associated with outbreaks of infections in aquatic animals; however, further experimental works are warranted.

Triple-function carbon-based Ca2+ ion-selective pH ring microelectrode to study real-time bacteria-mediated hydroxyapatite corrosion

BackgroundThe local pH change mediated by the pathogenic bacterial species Streptococcus mutans plays a significant role in the corrosion of hydroxyapatite (HA) present in the tooth in the dynamic oral cavity. The acid produced by the bacteria decreases the local pH and releases Ca2+ ions from the HA. We studied the bacteria-mediated demineralization of HA by scanning electrochemical microscopy (SECM) after growing S. mutans biofilm on HA for 7 days. ResultsWe notably developed a triple-function SECM-compatible tip that could be positioned above the biofilm. It can also measure the pH and [Ca2+] change simultaneously above the biofilm-HA substrate. The triple-function SECM tip is a combination of a potentiometric pH sensor deposited with iridium oxide and a dual-function carbon-based Ca2+ ion-selective membrane electrode with a slope of 67 mV/pH and 34.3 mV/log [Ca2+], respectively. The distance-controlled triple-function SECM tip monitored real-time pH and [Ca2+] changes 30 μm above the S. mutans biofilm. The high temporal resolution pH data demonstrated that after approximately 20 min of sucrose addition, S. mutans started to produce acid to titrate the solution buffer, causing a pH change from 7.2 to 6.5 for HA and from 7.2 to 5 for the glass substrate. We observed that, after 30 min of acid production, ∼300 μM of Ca2+ ions were increased at pH 6.5 above the biofilm surface as a result of the pH change in the local microenvironment. After the release of Ca2+ from HA, the pH environment again shifted toward the neutral side, from 6.5 to 7.2. Therefore, precipitation of Ca2+ happens at the top of the biofilm, thus corroding the HA from underneath. For a glass substrate, in contrast, no Ca2+ ions were released, and the pH did not change back to 7.2. We were able to observe the dynamics of the HA demineralization–remineralization process simultaneously with our newly developed triple-function SECM tip or microprobe. SignificanceThis technique could notably advance the study of similar complex processes, such as bacteria-mediated corrosion in biomedical and environmental contexts.

In Vivo Intra-Articular Antibiotic Concentrations at 24 Hours After TKA Fall Below the Minimum Inhibitory Concentration for Most Bacteria: A Randomized Study of Commercially Available Bone Cement.

The use of antibiotic-loaded bone cement (ALBC) to help reduce the risk of infection after primary total knee arthroplasty (TKA) is controversial. There is a paucity of in vivo data on the elution characteristics of ALBC. We aimed to determine whether the antibiotic concentrations of 2 commercially available ALBCs met the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) for common infecting organisms. Forty-five patients undergoing TKA were randomized to receive 1 of the following: bone cement without antibiotic (the negative control; n = 5), a commercially available formulation containing 1 g of tobramycin (n = 20), or a commercially available formulation containing 0.5 g of gentamicin (n = 20). Intra-articular drains were placed, and fluid was collected at 4 and 24 hours postoperatively. An automated immunoassay measuring antibiotic concentration was performed, and the results were compared against published MIC and MBEC thresholds. The ALBC treatment groups were predominantly of White (65%) or Black (32.5%) race and were 57.5% female and 42.4% male. The mean age (and standard deviation) was 72.6 ± 7.2 years in the gentamicin group and 67.6 ± 7.4 years in the tobramycin group. The mean antibiotic concentration in the tobramycin group was 55.1 ± 37.7 μg/mL at 4 hours and 19.5 ± 13.0 μg/mL at 24 hours, and the mean concentration in the gentamicin group was 38.4 ± 25.4 μg/mL at 4 hours and 17.7 ± 15.4 μg/mL at 24 hours. Time and antibiotic concentration had a negative linear correlation coefficient (r = -0.501). Most of the reference MIC levels were reached at 4 hours. However, at 24 hours, a considerable percentage of patients had concentrations below the MIC for many common pathogens, including Staphylococcus epidermidis (gentamicin: 65% to 100% of patients; tobramycin: 50% to 85%), methicillin-sensitive Staphylococcus aureus (gentamicin: 5% to 90%; tobramycin: 5% to 50%), methicillin-resistant S . aureus (gentamicin: 5% to 65%; tobramycin: 50%), Streptococcus species (gentamicin: 10% to 100%), and Cutibacterium acnes (gentamicin: 10% to 65%; tobramycin: 100%). The aforementioned ranges reflect variation in the MIC among different strains of each organism. Gentamicin concentrations reached MBEC threshold values at 4 hours only for the least virulent strains of S . aureus and Escherichia coli. Tobramycin concentrations did not reach the MBEC threshold for any of the bacteria at either time point. The elution of antibiotics from commercially available ALBC decreased rapidly following TKA, and only at 4 hours postoperatively did the mean antibiotic concentrations exceed the MIC for most of the pathogens. Use of commercially available ALBC may not provide substantial antimicrobial coverage following TKA. Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Guarding the walls: the multifaceted roles of Bce modules in cell envelope stress sensing and antimicrobial resistance.

Bacteria have developed diverse strategies for defending their cell envelopes from external threats. In Firmicutes, one widespread strategy is to use Bce modules-membrane protein complexes that unite a peptide-detoxifying ABC transporter with a stress response coordinating two-component system. These modules provide specific, front-line defense for a wide variety of antimicrobial peptides and small molecule antibiotics as well as coordinate responses for heat, acid, and oxidative stress. Because of these abilities, Bce modules play important roles in virulence and the development of antibiotic resistance in a variety of pathogens, including Staphylococcus, Streptococcus, and Enterococcus species. Despite their importance, Bce modules are still poorly understood, with scattered functional data in only a small number of species. In this review, we will discuss Bce module structure in light of recent cryo-electron microscopy structures of the B. subtilis BceABRS module and explore the common threads and variations-on-a-theme in Bce module mechanisms across species. We also highlight the many remaining questions about Bce module function. Understanding these multifunctional membrane complexes will enhance our understanding of bacterial stress sensing and may point toward new therapeutic targets for highly resistant pathogens.

Culture-based bacterial evaluation of the appendix lumen and antibiotic susceptibility of acute appendicitis in Japan: A single-center retrospective analysis.

The question of whether to perform an appendectomy or conservative treatment for acute appendicitis can differ depending on the facility or surgeon, but antibiotic treatment is administered regardless of whether an appendectomy or conservative treatment is selected. We investigated the contemporary bacteriology for acute appendicitis and evaluated the antibiotic sensitivity of the bacteria that are currently associated with appendicitis. We retrospectively analyzed the bacterial culture results and antibiotic susceptibility of 141 patients who underwent appendicitis surgery, including the identification and antimicrobial susceptibility of the cultured bacteria within the excised appendices. Bacterial cultures were positive in 131 cases (92.9%). The most commonly isolated bacteria were Escherichia coli (90 isolates, 66.7%), followed by Enterococcus species (n = 19, 14.5%), Pseudomonas aeruginosa (n = 18, 13.7%), Streptococcus species (n = 15, 11.5%), and Klebsiella species (n = 8, 6.1%). Eight strains (8.8%) of E coli were extended-spectrum β-lactamase producers, and ten strains (11.1%) were fluoroquinolone-resistant. Tazobactam/piperacillin and meropenem inhibited the growth of 100% of the major identified bacteria. The patients with appendicoliths had a significantly higher bacterial culture rate. Enterococcus species were frequently isolated from the patients with complicated appendicitis. For the antibiotic treatment of appendicitis, it is essential to understand the patient's microbiological profile and antibiotic susceptibilities. Research from Asian countries such as Japan can enhance our knowledge of regional antibiotic resistance patterns and inform effective treatment strategies.

The Effect of Dietary Nitrate on the Oral Microbiome and Salivary Biomarkers in Individuals with High Blood Pressure

BackgroundGreen leafy vegetables (GLV) contain inorganic nitrate, an anion with potential prebiotic effects on the oral microbiome. However, it remains unclear whether GLV and pharmacological supplementation [potassium nitrate (PN)] with a nitrate salt induce similar effects on the oral microbiome. ObjectivesThis study aimed to compare the effect of GLV with PN supplementation on the oral microbiome composition and salivary biomarkers in individuals with high blood pressure. MethodsSeventy individuals were randomly allocated to 3 different groups to follow a 5-wk dietary intervention. Group 1 consumed 300 mg/d of nitrate in form of GLV. Group 2 consumed pills with 300 mg/d of PN and low-nitrate vegetables. Group 3 consumed pills with potassium chloride (placebo: PLAC) and low-nitrate vegetables. The oral microbiome composition and salivary biomarkers of oral health were analyzed before and after the dietary intervention. ResultsThe GLV and PN groups showed similar microbial changes, probably nitrate-dependent, including an increase in the abundance of Neisseria, Capnocytophaga, Campylobacter species, and a decrease in Veillonella, Megasphaera, Actinomyces, and Eubacterium species after the treatment. Increased abundance of Rothia species, and reduced abundance of Streptococcus, Prevotella, Actinomyces, and Mogibacterium species were observed in the GLV group, which could be nitrate-independent. GLV and PN treatments increased salivary pH, but only GLV treatment showed an increase in the salivary buffering capacity and a reduction of lactate. ConclusionThe combination of nitrate-dependent and nitrate-independent microbial changes in the GLV group has a stronger effect to potentially improve oral health biomarkers compared with PN.

An updated description of bacterial pneumonia in adult horses and factors associated with death.

Available descriptive studies on equine pneumonia are outdated or focus on specific horse or bacterial populations. To describe the clinical presentation and bacterial isolates of adult horses with bacterial pneumonia and identify factors associated with death. One hundred sixteen horses >2 years old with bacterial pneumonia. Retrospective case series. Data regarding history, physical examination, clinicopathologic features, treatment, bacterial culture and sensitivity, and outcome were collected and analyzed retrospectively. Historical risk factors were present for 60% of cases, whereas abnormal vital signs on intake were present for <50%. Most horses (58%) underwent at least 1 change of antimicrobial treatment, and 67% received the highest-priority critically important antimicrobials. Streptococcus zooepidemicus was the most isolated bacteria (44%), followed by Escherichia coli (19%), Klebsiella spp. (18%), other Streptococcus species (17%), and Bacillus spp. (13%). Fusobacterium spp. were the most common anaerobic isolates (11%). Antimicrobial susceptibility varied widely. Survival to discharge was 73%. Heart rate at presentation (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.008-1.17, P = .03) and higher creatinine (OR 14.1, 95% CI 1.56-127.6, P = .02) increased the risk of death. Higher lymphocyte count (OR 0.27, 95% CI 0.08-0.94, P = .04) reduced risk. Contrasting older literature, Fusobacterium spp. were the most common anaerobes. Streptococcus zooepidemicus remained the most common isolate and was predictably susceptible to penicillin. Antimicrobial susceptibility was otherwise variable and broad applicability is limited as this was a single-center study. Increased risk of death associated with tachycardia and abnormally high serum creatinine concentration is consistent with previous studies.

Surface-Charge Tuned Polymeric Nanoemulsions for Carvacrol Delivery in Interkingdom Biofilms.

Biofilms, intricate microbial communities entrenched in extracellular polymeric substance (EPS) matrices, pose formidable challenges in infectious disease treatment, especially in the context of interkingdom biofilms prevalent in the oral environment. This study investigates the potential of carvacrol-loaded biodegradable nanoemulsions (NEs) with systematically varied surface charges─cationic guanidinium (GMT-NE) and anionic carboxylate (CMT-NE). Zeta potentials of +25 mV (GMT-NE) and -33 mV (CMT-NE) underscore successful nanoemulsion fabrication (∼250 nm). Fluorescent labeling and dynamic tracking across three dimensions expose GMT-NE's superior diffusion into oral biofilms, yielding a robust antimicrobial effect with 99.99% killing for both streptococcal and Candida species and marked reductions in bacterial cell viability compared to CMT-NE (∼4-log reduction). Oral mucosa tissue cultures affirm the biocompatibility of both NEs with no morphological or structural changes, showcasing their potential for combating intractable biofilm infections in oral environment. This study advances our understanding of NE surface charges and their interactions within interkingdom biofilms, providing insights crucial for addressing complex infections involving bacteria and fungi in the demanding oral context.

Diversity of streptococcus species isolated in the departments of purulent surgery and coloproctology of a multidisciplinary hospital and their antibiotic resistance

Diversity of streptococcus species isolated in the departments of purulent surgery and coloproctology of a multidisciplinary hospital and their antibiotic resistance

Streptococcus raffinosi sp. nov., isolated from human breast milk samples.

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).

A randomized cross-over trial of prebiotics and probiotics in multiple sclerosis: Trial feasibility, supplement tolerability and symptom abatement

BackgroundDietary supplements can modulate the gut microbial ecosystem and affect the immune system. This has potential implications for autoimmune diseases, including multiple sclerosis (MS). Prior studies explored tolerability, symptomatic improvement, and immunologic effects of probiotics in people with MS (pwMS), but no study has examined prebiotics in this population or compared prebiotics with probiotics. MethodsThis is a randomized, open-label trial of participants with relapsing-remitting MS on B-cell depletion therapy from two MS centers. 22 participants enrolled in the original cross-over study in which probiotic (Visbiome, containing Lactobacillus, Bifidobacterium and Streptococcus species) or prebiotic (Prebiotin, containing oligofructose enriched inulin) supplementation for 6 weeks was randomized, each followed by a washout period. Due to pandemic-related interruptions and expiration of the study supply of probiotics, another 15 participants enrolled in a single-arm study to receive prebiotic supplementation for 6 weeks followed by a washout period. We assessed supplement tolerability and patient-reported outcomes (PRO) relevant to MS (disability, fatigue, mood, and bowel symptoms) before and after each supplement administration period and each washout period. We bio-archived plasma, serum, peripheral blood mononuclear cells and stool samples at each timepoint for future multi-omic assessment. ResultsPrebiotics and probiotics had comparable adherence rates and both supplements were well tolerated in pwMS. Participants on either supplement reported minor adverse events, most of which were mild and self-limited. There was a subjective preference for prebiotics over probiotics. Comparing supplement-associated changes in PRO scores from baseline to 6 weeks post-supplementation, there were significant difference between prebiotics and probiotics for the change in patient-reported global symptom burden (MSRS-R Total) and bowel control (BWCS), but only probiotics statistically improved bowel control from baseline to post-supplementation. ConclusionSupplementation with either prebiotics or probiotics is reasonably well-tolerated and safe. Probiotics improved bowel control, but did not improve other PROs in a 6-week time frame. These data regarding feasibility, tolerability, adherence, and adverse events of supplements will inform future clinical trial designs to definitively compare the efficacy and safety of prebiotics and probiotics. The biological data that will be generated from this study in the future will provide mechanistic insights into the effects of these dietary supplements on MS pathophysiology.

Oral Commensals in Healthy Individuals: A Clinicocytological Study.

Background Each human being has a specific group of microorganisms that are necessary for both sustaining health and causing illness. Normally, these microorganisms maintain bio-communalism, do not harm the host, and lead to a state known as symbiosis or eubiosis. The commensal nature of these bacteria is always maintained in symbiosis and attains pathogenic potential when there is an imbalance between host immunity and microorganisms. Our study focuses on the identification and differentiation of the various commensals present in the oral cavity of healthy individuals over a given period of time. Aims and objectives This study aims to: (i) identify various commensal bacterial species present in the oral cavity; (ii) differentiate each commensal bacterial species present in the oral cavity of healthy individuals using cytological and culturing methods; (iii) identify the presence of different types of commensal bacterial species in the same individuals with the specific time intervals; (iv) compare and correlate the presence or absence of bacterial species present as a commensal in both male and female; (v) identify and characterize the commensal bacterial species present in the oral cavity of healthy individuals; (vi) investigate the consistency of commensal bacterial species presence over time and between genders. Methodology We included sixty healthy individuals between the ages of 20 and 24 from both genders, took buccal smears once every two days for ten days, stained them with Gram stain, and grew them in blood agar and Mac Conkey agar. Results The most common commensals include Gram-positive cocci, and among them, Coagulase-negative staphylococcus species (85%) are predominant, followed by Staphylococcus aureus (13.33%), and Streptococcus species (1.67%). The presence of colonies remains the same in all three samples obtained from the same healthy individuals. Conclusion Loss of balance between commensals and pathogens can lead to dysbiosis, which results in disease.

BACTERIOLOGICAL ASSESSMENT OF SOME COMMERCIALLY SOLD YOGHURT IN UTURU, ABIA STATE, NIGERIA: A PRELIMINARY STUDY

A preliminary study was carried out to determine the bacteriological quality of commercial yogurt sold in Uturu, Abia State, Nigeria. This involved isolation, characterization and antibiotics susceptibility of bacteria isolated from some commercially sold yoghurt in Uturu. Five different brands of yoghurt coded A to E were microbiologically analyzed using standard microbiological methods. The total viable count ranged from 0.9×102 cfu/ml – 2.0x103 cfu/ml, coliform count ranged from 0.4×102 cfu/ml – 1.0×103 cfu/ml, total staphylococcal count ranged from 1.1×101 to 1.8×102. Bacterial isolated include Staphylococcus species, Streptococcus species, Bacillus species and Lactobacillus species. The antibiotics susceptibility pattern of the bacterial isolates proved that drovid had the highest zones of inhibition from 31.8±1.2 mm to 36.1±0.3 mm, followed by oflaxacin (29.5±0.1 mm to 35.0±0.8 mm). The presence of coliform and Staphylococcus in the yoghurt may be as a result of unclean water used in the production, contaminated milk and unhygienic condition of the handlers. It is recommended that yoghurt producers, sellers and handlers should ensure a high level of hygiene and avoid long exposure of yoghurt before selling to consumers.

Antibiotic resistance alters the ability of Pseudomonas aeruginosa to invade bacteria from the respiratory microbiome.

The emergence and spread of antibiotic resistance in bacterial pathogens is a global health threat. One important unanswered question is how antibiotic resistance influences the ability of a pathogen to invade the host-associated microbiome. Here we investigate how antibiotic resistance impacts the ability of a bacterial pathogen to invade bacteria from the microbiome, using the opportunistic bacterial pathogen Pseudomonas aeruginosa and the respiratory microbiome as our model system. We measure the ability of P. aeruginosa spontaneous antibiotic-resistant mutants to invade pre-established cultures of commensal respiratory microbes in an assay that allows us to link specific resistance mutations with changes in invasion ability. While commensal respiratory microbes tend to provide some degree of resistance to P. aeruginosa invasion, antibiotic resistance is a double-edged sword that can either help or hinder the ability of P. aeruginosa to invade. The directionality of this help or hindrance depends on both P. aeruginosa genotype and respiratory microbe identity. Specific resistance mutations in genes involved in multidrug efflux pump regulation are shown to facilitate the invasion of P. aeruginosa into Staphylococcus lugdunensis, yet impair invasion into Rothia mucilaginosa and Staphylococcus epidermidis. Streptococcus species provide the strongest resistance to P. aeruginosa invasion, and this is maintained regardless of antibiotic resistance genotype. Our study demonstrates how the cost of mutations that provide enhanced antibiotic resistance in P. aeruginosa can crucially depend on community context. We suggest that attempts to manipulate the microbiome should focus on promoting the growth of commensals that can increase the fitness costs associated with antibiotic resistance and provide robust inhibition of both wildtype and antibiotic-resistant pathogen strains.