Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Streptococcus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed1989

Group B streptococcus and premature rupture of membranes and preterm delivery.

In a population of 1,050 pregnant women the effect of maternal colonization by group B Streptococcus on premature rupture of membranes (PROM), preterm delivery, and low weight was analyzed. A significant increment was found of the prevalence of PROM for patients colonized in the vagina and/or the rectum (26.4%) versus noncarrier patients (17.8%). In vaginal and/or rectal group B Streptococcus carriers, in whom group B Streptococcus was also isolated from the cervical culture, the rate of PROM was higher (41.7%), while when the cervical culture was negative, the PROM was similar to noncarriers. THere were no significant differences with respect to colonization conditions regarding the incidence of preterm delivery or the different preterm delivery indicators analyzed.

Carrier State↗
PubMed2002

Interference of nontypeable Haemophilus influenzae and Moraxella catarrhalis by Streptococcus oralis in adenoid organ culture: a possible strategy for the treatment of the otitis-prone child.

The role of viridans group streptococci (Streptococcus oralis) in the prevention of colonization with nontypeable Haemophilus influenzae and Moraxella catarrhalis was investigated in an adenoid organ culture system. The adenoids from 100 patients who were undergoing adenoidectomy for either hypertrophy or recurrent otitis media were used. Streptococcus oralis Parker uniformly inhibited colonization with nontypeable H. influenzae or M. catarrhalis over a 24-hour period of incubation in adenoid organ culture. Streptococcus oralis Booth, a noninhibitory strain, did not significantly reduce colonization with nontypeable H. influenzae and M. catarrhalis. The results indicate that some strains of S. oralis may inhibit colonization with potential pathogens in the nasopharynx. It is therefore possible that colonization with inhibitory strains of viridans streptococci may be used in the nasopharynx as a relatively safe and inexpensive approach to prevention of recurrent otitis media in some children.

Adenoids↗
PubMed1979

Bacterial endocarditis due to penicillin-resistant Streptococcus viridans.

Bacterial endocarditis remains a formidable diagnostic and therapeutic problem for clinicians. Streptococcus viridans still accounts for 45 to 50 per cent of all cases and between 5 to 10 per cent of all clinical isolates of Streptococcus viridans from patients with bacterial endocarditis may be relatively resistant to penicillin. The case of a 9-year-old child with Tetralogy of Fallot and a Waterston shunt who subsequently developed bacterial endocarditis due to penicillin-resistant Streptococcus viridans following failure of oral penicillin dental prophylaxis is presented. In the face of penicillin resistance, additional considerations for workup, including microbiological assays for antimicrobial synergism become necessary in the selection of a therapeutic regimen.

Child↗
PubMed2006

Effects of macrolides on pneumolysin of macrolide-resistant Streptococcus pneumoniae.

To clarify the discrepancy between increasing resistance and conservative clinical effects of macrolides on macrolide-resistant Streptococcus pneumoniae, the authors evaluated the effects of sub-minimum inhibitory concentrations of macrolides on pneumolysin. In vitro, S. pneumoniae was incubated with 1, 2 and 4 microg.mL(-1) of clarithromycin (CLR) and azithromycin (AZM) for 8 h. Western blot analysis and haemolytic assay were performed to examine the production and activities of pneumolysin. In vivo, mice were infected with S. pneumoniae intra-nasally and treated with CLR (40 or 200 mg.kg(-1) twice daily) or AZM (40 or 200 mg.kg(-1) once daily) orally for 7 days. After 72 h post-infection, western blot analysis was performed to examine pneumolysin production in lungs. Survival rates were observed for 10 days. In vitro, every concentration of macrolide inhibited pneumolysin production more than the control. CLR (2 and 4 microg.mL(-1)) and AZM (4 microg.mL(-1)) reduced the pneumolysin activities more than the control. In vivo, macrolides (200 mg.kg(-1)) reduced pneumolysin in murine lungs more than the control. CLR (40 and 200 mg.kg(-1)) and AZM (200 mg.kg(-1)) improved the survival rates more than the control. The study results show that sub-minimum inhibitory concentrations of macrolides reduced pneumolysin. This might be related to the effectiveness of macrolides against pneumonia caused by high-level macrolide-resistant Streptococcus pneumoniae. Further investigations are necessary to evaluate the effects of macrolides on macrolide-resistant Streptococcus pneumoniae.

Bacterial Proteins↗
PubMed2005

Epidural abscess caused by Streptococcus milleri in a pregnant woman.

BACKGROUND: Bacteria in the Streptococcus milleri group (S. anginosus, S. constellatus, and S. intermedius) are associated with bacteremia and abscess formation. While most reports of Streptococcus milleri group (SMG) infection occur in patients with underlying medical conditions, SMG infections during pregnancy have been documented. However, SMG infections in pregnant women are associated with either neonatal or maternal puerperal sepsis. Albeit rare, S. milleri spinal-epidural abscess in pregnancy has been reported, always as a complication of spinal-epidural anesthesia. We report a case of spinal-epidural abscess caused by SMG in a young, pregnant woman without an antecedent history of spinal epidural anesthesia and without any underlying risk factors for invasive streptococcal disease. CASE PRESENTATION: A 25 year old pregnant woman developed neurological symptoms consistent with spinal cord compression at 20 weeks gestation. She underwent emergency laminectomy for decompression and was treated with ceftriaxone 2 gm IV daily for 28 days. She was ambulatory at the time of discharge from the inpatient rehabilitation unit with residual lower extremity weakness. CONCLUSION: To our knowledge, this is the first reported case of a Streptococcus milleri epidural abscess in a healthy, pregnant woman with no history of epidural anesthesia or invasive procedures. This report adds to the body of literature on SMG invasive infections. Treatment of SMG spinal-epidural abscess with neurologic manifestations should include prompt and aggressive surgical decompression coupled with targeted anti-infective therapy.

Adult↗
PubMed1980

Abnormal colonization of neonates in an ICU: conversion to normal colonization by pharyngeal implantation of alpha hemolytic streptococcus strain 215.

Normal bacterial flora provide a natural defense mechanism against infection. Our experience indicates that "normal" flora for the ICU neonate contains alpha hemolytic (alpha-) streptococci as the predominant organism. The purpose of the current investigation is to study the feasibility of implanting a carefully selected, naturally occurring strain of alpha-streptococcus in the nasopharynx of neonates considered to be at high risk of infection because of the abnormal colonization of their pharynx with potential pathogens. Twenty-two infants in the neonatal intensive care unit have received nasopharyngeal implantation with strain 215 alpha-streptococcus. In 16 infants, alpha-streptococci, including the implant strain in pure or mixed alpha-streptococcal populations, constituted the predominant pharyngeal flora within 48 to 72 hr of implantation. The implant strain was not recovered from the remaining six infants. The procedure was apparently innocuous in this small number of patients. We conclude that implantation of a streptococcus can be established in the pharynx of infants abnormally colonized with pathogenic organisms in high titer and that successful implantation of strain 215 can result in prompt development of normal pharyngeal flora, with alpha-streptococci predominant, within 48 hr. There has been no evidence of infection or other adverse reaction caused by the implant strain.

Bacterial Infections↗
PubMed1994

Molecular cloning and sequence analysis of the gene encoding the H2O2-forming NADH oxidase from Streptococcus mutans.

Streptococcus mutans induces both H2O2-forming and H2O-forming NADH oxidases in the presence of O2 [M. Higuchi, J. Gen. Microbiol., 130, 1819-1826 (1984)]. In this paper, a nox-1 gene encoding H2O2-forming NADH oxidase (NOX-1) from Streptococcus mutans was cloned, and the nucleotides sequenced. The structural gene of nox-1 consisted of 1530 base pairs, which encode a polypeptide consisting of 510 amino acids with a predicted molecular mass of 55,196 Da. The deduced N-terminal amino acid sequence was consistent with that previously found for the purified NOX-1 protein. The nox-1 gene was expressed in Escherichia coli using its own promoter. Alignment of the amino acid sequence of NOX-1 with those of NADH oxidases from other microorganisms showed identities of 55.6%, 20.8%, 20.3%, and 7.3% for those of Amphibacillus xylanus Ep01, Streptococcus faecalis 10C1, Thermoanaerobium brockii Rt8.G4, and Thermus thermophilus HB8, respectively.

Amino Acid Sequence↗
PubMed1999

Purification and properties of bacteriolytic enzymes from Bacillus licheniformis YS-1005 against Streptococcus mutans.

To find a novel lytic enzyme against cariogenic Streptococci, strains showing strong lytic activity have been screened from soil using Streptococcus mutans. A strain identified as Bacillus licheniformis secreted two kinds of lytic enzymes, which were purified by methanol precipitation, CM-cellulose chromatography, gel filtration, and hydroxyapatite chromatography. The molecular weights of these two enzymes, L27 and L45, were 27,000 and 45,000, respectively. Optimum pH and temperature of both enzymes for lytic activity were pH 8 and 37 degrees C. L27 and L45 digest the peptide linkage between L-Ala and D-Glu in peptidoglycan of Streptococcus mutans. The lytic activity was highly specific for Streptococcus mutans, suggesting their potential use as a dental care product.

Amino Acid Sequence↗
PubMed2000

Pathogenesis of porcine reproductive and respiratory syndrome virus-induced increase in susceptibility to Streptococcus suis infection.

Eighty 3-week-old crossbred pigs were randomly assigned to six groups (13-14 pigs/group). Group 1 pigs served as uninoculated controls, group 2 pigs were inoculated intranasally (i.n.) with Streptococcus suis serotype 2, group 3 pigs were inoculated i.n. with a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine, group 4 pigs were inoculated i.n. with the same vaccine and with S. suis, group 5 pigs were inoculated i.n. with VR-2385 (a high-virulence strain of PRRSV), and group 6 pigs were inoculated i.n. with VR-2385 and S. suis. Pigs exposed to both PRRSV and S. suis were inoculated with PRRSV 7 days prior to S. suis inoculation. The pigs were 26 days old when inoculated with S. suis. Respiratory disease was significantly more severe in groups 5 and 6. Mortality rate was the highest in group 6 (87.5%). This rate was significantly higher than that observed in all other groups except group 4 (37.5%). The mortality rate in group 2, inoculated with S. suis alone, was 14.3%. No pigs from groups 1, 3, or 5 died prior to the scheduled necropsies at 10 and 28 days postinoculation with PRRSV (DPI). To study the effect of PRRSV and/or S. suis on pulmonary clearance by pulmonary intravascular macrophages, six pigs from each group were intravenously infused with 3% copper phthalocyanine tetrasulfonic acid in saline prior to necropsy at 10 DPI. Mean copper levels in the lungs of pigs in groups 2, 5, and 6 were significantly lower than those in control pigs. The mean percentage of lung tissue grossly affected by pneumonia at 10 DPI was 0%, 1%, 0%, 3%, 64%, and 62% for groups 1-6, respectively. Both gross and microscopic interstitial pneumonia lesions were significantly more severe in the VR2385-inoculated groups (5 and 6). PRRSV was isolated from bronchoalveolar lavage fluid collected at necropsy from 100% of the pigs in groups 5 and 6, 71.4% of pigs in group 4, 38.5% of pigs in group 3, and none of the pigs in groups 1 or 2. Streptococcus suis serotype 2 was cultured from the internal tissues of 7.7%, 28.6%, and 78.6% of the pigs in groups 2, 4, and 6, respectively. Streptococcus suis serotype 2 was isolated from whole blood at necropsy from 7.7%, 35.7%, and 78.6% of pigs in groups 2, 4, and 6, respectively. Significantly more pigs in group 6 had S. suis isolated from whole blood and internal tissues. In summary, both high-virulence PRRSV and S. suis decreased copper clearance, and the incidence of isolation of S. suis and PRRSV was higher in dually inoculated pigs. PRRSV-induced suppression of pulmonary intravascular macrophage function may in part explain PRRSV-associated increased susceptibility to S. suis infection.

Administration, Intranasal↗
PubMed2006

Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2.

BACKGROUND: Streptococcus suis serotype 2 (S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan Province, China, appeared to be caused by more invasive deep-tissue infection with STSS, characterized by acute high fever, vascular collapse, hypotension, shock, and multiple organ failure. METHODS AND FINDINGS: We investigated this outbreak of SS2 infections in both human and pigs, which took place from July to August, 2005, through clinical observation and laboratory experiments. Clinical and pathological characterization of the human patients revealed the hallmarks of typical STSS, which to date had only been associated with GAS infection. Retrospectively, we found that this outbreak was very similar to an earlier outbreak in Jiangsu Province, China, in 1998. We isolated and analyzed 37 bacterial strains from human specimens and eight from pig specimens of the recent outbreak, as well as three human isolates and two pig isolates from the 1998 outbreak we had kept in our laboratory. The bacterial isolates were examined using light microscopy observation, pig infection experiments, multiplex-PCR assay, as well as restriction fragment length polymorphisms (RFLP) and multiple sequence alignment analyses. Multiple lines of evidence confirmed that highly virulent strains of SS2 were the causative agents of both outbreaks. CONCLUSIONS: We report, to our knowledge for the first time, two outbreaks of STSS caused by SS2, a non-GAS streptococcus. The 2005 outbreak was associated with 38 deaths out of 204 documented human cases; the 1998 outbreak with 14 deaths out of 25 reported human cases. Most of the fatal cases were characterized by STSS; some of them by meningitis or severe septicemia. The molecular mechanisms underlying these human STSS outbreaks in human beings remain unclear and an objective for further study.

Adult↗
PubMed2001

[Effect of sodium fluoride mouth rinses containing xylitol and sorbitol on the number of Streptococcus mutans from human saliva].

The objective of this study was to assess the effect of 0.05% sodium fluoride solutions containing 2.5% or 12.5% xylitol on the number of Streptococcus mutans in the human mouth. Fifty boys between 8 and 16 years of age participated in this double-blind crossover study. Of the original 50 boys, 33 finished the study. Participants were randomly divided into four groups. The following solutions were employed: placebo solution; 0.05% sodium fluoride solution; 0.05% sodium fluoride + 2.5% xylitol + 2% sorbitol; 0.05% sodium fluoride + 12.5% xylitol + 2% sorbitol. Each solution was used for a 28-day period (20 mL/day, twice a day), with a 10-day washout period between solutions. There were no significant differences (P = 0.32) between the two xylitol-containing solutions (2.5% vs. 12.5%) concerning the number of Streptococcus mutans. However, there was a significant difference between these two xylitol-containing solutions and the sodium fluoride and placebo solutions (P < 0.001). Our results suggest that the 0.05% sodium fluoride solutions containing either 2.5% or 12.5% xylitol caused a significant reduction in the number of Streptococcus mutans.

Adolescent↗
PubMed1983

Sequential mutagenesis of drug resistance in Streptococcus mutans during synchronous replication.

The frequency of nitrosoguanidine-induced mutation for streptomycin-, bacitracin- and rifampicin-resistance was measured in Streptococcus mutans during synchronous replication after release from chloramphenicol inhibition. A clear peak of mutagenesis for each marker was observed at certain times during synchronous replication. These times were different for individual markers; the times of peaks for streptomycin-, bacitracin- and rifampicin-resistance were 13, 22 and 12 min, respectively. At a definite time after the first peak, there was a second one. The distances between the first and second peaks during the synchronous replication were identical for all markers and approximately 50 min which represents the doubling time of the organisms. These results indicate that nitrosoguanidine causes sequential mutagenesis for these three markers in Streptococcus mutans when the growth is resumed after chromosome alignment, so that the methods may be useful in determining the sequence of gene replication for various markers in Streptococcus mutans.

Anti-Bacterial Agents↗
PubMed2003

A third report of "golf ball disease" in an Amazon River dolphin (Inia geoffrensis) associated with Streptococcus iniae.

An Amazon River dolphin (Inia geoffrensis) developed a dermatologic syndrome characterized by the occurrence of slow-growing, nodular, s.c. abscesses. Initial biopsies, cultures, and cytologic analysis of needle aspirates from the abscesses indicated steatitis with probable secondary, gram-negative bacterial infection. Treatment with dietary vitamin E supplement and broad-spectrum antibiotics yielded minimal improvement. Subsequent cultures revealed Streptococcus iniae in addition to several gram-negative bacteria. Vigorous surgical management of the abscesses, including lancing, debridement, and irrigation, combined with antimicrobial therapy specific for Streptococcus and gram-negative organisms, and improvement of the animal's diet and environmental water quality led to gradual recovery. When the animal was ill, it demonstrated an inflammatory leukogram and transient uremia. Streptococcus iniae is a serious pathogen of aquacultured fishes and humans and should be included in the differential diagnosis of chronic dermatopathy in river dolphins. Specific antimicrobial therapy, excellent water quality, surgical management of abscesses, and adherence to sanitary protocols should be observed in cases of suspected S. iniae infection in dolphins.

Abscess↗
PubMed1994

Amphiphilic property of chlorhexidine and its toxicity against Streptococcus mutans GS-5.

The toxicity of chlorhexidine digluconate against Streptococcus mutans GS-5 was comparatively determined by measuring its bactericidal activity, and its inhibitory effect on microbial dehydrogenases was studied by the resazurin reduction method. Both methods indicated that chlorhexidine within the range 0.75-5.00 mg/l was highly toxic to Streptococcus mutans, probably due to inhibition of dehydrogenase activity, and the extent of toxicity was closely associated with concentration. In an attempt to better understand the relationship between the amphiphilic nature of chlorhexidine and its toxicity against Streptococcus mutans, the effect of solvent polarity on dehydrogenase inhibition was investigated. A decrease in solvent polarity, induced by inclusion of 5% acetone in the reaction mixture, did not enhance the toxicity of chlorhexidine. This implies that the antimicrobial action of chlorhexidine is mainly attributable to its hydrophilicity, and that the nature of the lipophilic groups is only of secondary importance.

Acetone↗
PubMed2003

Evaluation of the surveillance program of Streptococcus agalactiae in Danish dairy herds.

The aim of this study was to evaluate the Danish surveillance program of Streptococcus agalactiae in dairy herds with respect to 1) fluctuation over time of the presence of S. agalactiae in bulk tank milk, 2) sensitivity and specificity of the bacteriological method used, and 3) contamination of bulk tank milk samples with milk from other herds. From June to September 1996, bulk tank milk was sampled from 100 Danish dairy herds seven times, with intervals of 2 wk. The samples were examined for the presence of S. agalactiae by four different methods: 1) by the method approved for the program, 2) after ultrasonic treatment of the milk before examination, 3) after freezing down the milk before examination, and 4) after selective preparation of the milk. Selected strains of S. agalactiae were examined by restriction fragment length polymorphism of the gene encoding rRNA to discriminate between the isolates. Streptococcus agalactiae was found in eight of 96 herds in which S. agalactiae had never previously been found during the surveillance program. Streptococcus agalactiae was not found in all seven sampling rounds in any of the eight herds. Comparing the approved method with supplemental findings by the other methods, the estimated sensitivity was (95% confidence limits): 0.786 (0.628; 0.892) and the estimated specificity (95% confidence limits): 0.995 (0.985; 0.999). Using all four methods on the same sample could increase the sensitivity, but by comparing the methods individually, there was no significant difference between any of them (P > 0.10). In milk samples from three herds, the ribotype of S. agalactiae was the same as in milk from herds sampled just before; therefore, it could not be ruled out that cross-contamination could occur. Taking into account that S. agalactiae in bulk tank milk reflects the presence of S. agalactiae in at least one udder quarter, this investigation gives further reason to assume that S. agalactiae can be seen sporadically in several herds. A surveillance program based on annual bulk tank milk sample examinations will only detect a limited number of S. agalactiae infected herds. If the overall aim is to identify herds where the infection is established, annual bulk tank milk sample examinations combined with the information of number of colonies of S. agalactiae in the sample will be sufficient.

Animals↗
PubMed1983

Germicidal teat dip in a herd with low prevalence of Streptococcus agalactiae and Staphylococcus aureus mastitis.

Effectiveness of an iodophor teat dip in reducing new intramammary infection and clinical mastitis was tested in a herd free of Streptococcus agalactiae and with a low prevalence of Staphylococcus aureus infections. In this 6-mo study with an average of 152 lactating cows on trial on sampling dates, right rear and left front teats were dipped after each milking while right front and left rear teats were undipped controls. Teat dipping significantly reduced new infections by Staphylococcus aureus, streptococci (other than Streptococcus agalactiae), coagulase-negative staphylococci, and Corynebacterium bovis and reduced clinical cases caused by infections established during the trial. However, the dip did not reduce new infections or clinical mastitis caused by coliform bacteria. Therefore, use of a germicidal dip is recommended for herds with a low prevalence of Streptococcus agalactiae and Staphylococcus aureus, but the practice should not be expected to control coliform mastitis.

Administration, Topical↗
PubMed1986

Influence of temperature on associative growth of Streptococcus thermophilus and Lactobacillus bulgaricus.

Compatibility of Streptococcus thermophilus and Lactobacillus bulgaricus during associative growth as dependent on optimum growth temperature was determined. Optimum growth temperatures for 9 strains of S. thermophilus and 10 strains of L. bulgaricus ranged from 35 to 42 degrees C for S. thermophilus and 43 to 46 degrees C for L. bulgaricus. Streptococcus thermophilus and L. bulgaricus strains exhibiting similar to divergent optimum growth temperatures were combined (1:1 vol/vol) and incubated in milk at 37, 42, and 45 degrees C until pH 4.2 was reached. Initial and postincubation cell numbers were determined by plate count method. Streptococcus thermophilus strains reached greater cell numbers than L. bulgaricus at 37, 42, and 45 degrees C in 93.3% of the mixed culture trials. Average rod-coccus ratios obtained at 37, 42, and 45 degrees C were 1:2.2, 1:8, and 1:2.4, respectively. Optimum growth temperatures had no influence on growth of L. bulgaricus and S. thermophilus in mixed culture. Rather, temperature appeared to influence compatibility by determining the concentration or type of stimulatory factor(s) produced by L. bulgaricus. All strains of S. thermophilus exhibited an uncoupling of growth from acid production. Optimum temperature for acid production ranged from 2 to 8 degrees C above optimum growth temperature. These findings warrant consideration in the manufacture of yogurt and other fermented milk products.

Animals↗
PubMed1987

Enhancement of immune response in mice fed with Streptococcus thermophilus and Lactobacillus acidophilus.

Swiss mice, fed for 8 consecutive d with 50 micrograms/d of viable cultures of Lactobacillus acidophilus and Streptococcus thermophilus, showed significant variation in their immune system. In order to study this phenomenon assays for macrophage and lymphocyte function were carried out. Both lactic acid bacteria enhanced significantly the enzymatic and phagocytic activity of peritoneal macrophages as checked against the controls and also accelerated the phagocytic function of the reticuloendothelial system as revealed by the carbon clearance test. On the 2nd d (100 micrograms), L. acidophilus reached a peak of K = .271, which remained high. Streptococcus thermophilus was effective only on the 2nd d and then decreased. The lymphocytic activity studied by immunoglobulin secreting cells was assayed by Jerne's method of plaque-forming cells (PFC). This activity also was increased by the two microorganisms. Streptococcus thermophilus proved more effective than L. acidophilus. Lactobacillus acidophilus and S. thermophilus activated macrophages and lymphocytes and produced the same increase in the immune response of mice whether administered orally or intraperitoneally.

Administration, Oral↗