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PubMed1990

Coaggregation of Streptococcus sanguis and other streptococci with Candida albicans.

Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains generally exhibited low levels of adherence to 28 degrees C-grown exponential-phase yeast cells, but starvation of yeast cells for glucose at 37 degrees C (or at 28 degrees C) increased their coaggregating activity with these streptococci by at least tenfold. This was a property common to four C. albicans strains tested, two of which were able to form mycelia (6406 and MEN) and two of which were not (MM2002 and CA2). The expression of the coaggregation adhesin during yeast cell starvation was inhibited by addition of trichodermin or amphotericin B. The strains of S. sanguis, Streptococcus gordonii, and Streptococcus oralis tested for coaggregating activity encompassed a diverse range of physiological and morphological types, yet all exhibited saturable coaggregation with starved C. albicans cells. There was no correlation of cell surface hydrophobicity, of either yeast or streptococcal cells, with their abilities to coaggregate. Strains of Streptococcus anginosus also coaggregated with starved yeast cells; Streptococcus salivarius and Streptococcus pyogenes coaggregated to a lesser degree with C. albicans, and the coaggregation with S. pyogenes was not promoted by yeast cell starvation; Streptococcus mutans and Enterococcus faecalis did not coaggregate with yeast. The coaggregation reactions of S. sanguis and S. gordonii with C. albicans were inhibited by EDTA and by heat or protease treatment of the yeast cells and were not reversible by the addition of lactose or other simple sugars. These observations extend the range of intergeneric coaggregations that are known to occur between oral microbes and suggest that coaggregations of C. albicans with viridans group streptococci may be important for colonization of oral surfaces by the yeast.

Amphotericin B↗
PubMed1989

[Lysis of oral streptococci by an extracellular enzyme from the bacterium Streptococcus mutans].

The ability of crude extracellular enzyme produced by the bacterium Streptococcus mutans AL-7 to lysis the cells of five species, sixteen strains, of oral streptococci was examined. This enzyme showed lytic activity of living cells of only Streptococcus sanguis ATCC 10558 strain, and of heated cells of Streptococcus sanguis ATCC 10558 and ST-7 strains. The long chains of Streptococcus sanguis ATCC 10558 was severed at random by this enzyme. Early log phase cells of this strain were more sensitive to this enzyme than late log phase cells. No bacteriocins or bacteriocin-like substances were produced by Streptococcus mutans AL-7 strain in chemically defined medium. In view of these results, the relationship between this lytic enzyme from Streptococcus mutans and a decrease in the number of serotype III strains of Streptococcus sanguis in dental plaque is suggested.

Bacteriolysis↗
PubMed1998

Prospective study of Streptococcus milleri hepatic abscess.

Thirty-seven cases of microbiologically demonstrated pyogenic hepatic abscess were observed in a prospective study over a seven-year period. Biliary disease was the most common source of liver abscess (42%). Streptococcus milleri was the most common cause of hepatic abscess, accounting for 51% of the cases. Hepatic abscess is due to Streptococcus milleri clinically distinct from other forms of pyogenic liver abscess due to its torpid nature and the longer duration of its symptoms [42 vs. 11 days]. Occult hepatic abscess should be suspected if the blood culture is positive for Streptococcus milleri, since 28% of bacteremia cases due to Streptococcus milleri stem from hepatic abscesses. It is important to distinguish Streptococcus milleri from other members of the viridans streptococci group, which are frequently isolated as contaminants, but only exceptionally cause hepatic abscess. Unlike other pyogenic hepatic abscesses, those caused by Streptococcus milleri are frequently monomicrobial (79%). In the present study, empirical therapy of pyogenic hepatic abscess always included a drug that is effective against Streptococcus milleri.

Female↗
PubMed1992

Streptococcus milleri group: renewed interest in an elusive pathogen.

The following review examines the bacteriological characteristics, epidemiology, pathogenicity and antimicrobial susceptibility of the "Streptococcus milleri group". "Streptococcus milleri group" is a term for a large group of streptococci which includes Streptococcus intermedius, Streptococcus constellatus and Streptococcus anginosus. Usually considered commensals, these organisms are often associated with various pyogenic infections including cardiac, abdominal, skin and central nervous system infections. Organisms of the "Streptococcus milleri group" are often unrecognized pathogens due to the lack of uniformity in classifications and difficulties in microbiological identification. Penicillin G, cephalosporins, clindamycin and vancomycin all possess activity against these streptococci. Use of agents with poor activity may promote infections with "Streptococcus milleri group" and allow it to exhibit its pathogenicity. An understanding of these organisms may aid in their recognition and proper treatment.

Animals↗
PubMed1985

Clinical significance of Streptococcus milleri.

The clinical features of infection in patients from whom Streptococcus milleri was isolated were analysed in an attempt to determine the clinical significance of this organism. During a four-year period Streptococcus milleri was isolated from 232 hospitalized patients. In 44 patients Streptococcus milleri was isolated in pure culture, in 45 patients together with obligate anaerobes, and in 143 patients together with aerobes with or without anaerobes. The 82 patients in whom isolation of Streptococcus milleri was considered significant had the following infections: bacteremia (8 patients), brain abscess (2), pleural empyema (9), lung abscess (1), maxillary sinusitis (7), intra-abdominal abscess (53), infection of pacemaker (1) and infection of vascular graft (1). The 150 patients in whom isolation of Streptococcus milleri was considered of questionable significance had the following: upper respiratory tract infection (12 patients), lower respiratory tract infection (6), acute cholecystitis (8), soft tissue abscess, cellulitis and surgical wound infections (83), bone and joint infections (14), genital infection (25) and miscellaneous infections (2). The overall incidence of infection with Streptococcus milleri was five cases per 1000 admissions. The study showed that Streptococcus milleri is of clinical significance not only in suppurative infections, as previously reported, but also in acute maxillary sinusitis and infection of implant material.

Abscess↗
PubMed2003

Continuous ambulatory peritoneal dialysis-related peritonitis caused by Streptococcus bovis.

The first case of Streptococcus bovis peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD) in a 40-year-old Chinese woman suffering from systemic lupus erythematosus is reported. Streptococcus bovis is part of the normal flora in the human intestine and, less commonly, the female genital tract. Being a rare cause of peritonitis, the possible link between genital tract colonization by Streptococcus bovis and retrograde invasion of the peritoneal cavity is postulated to be the cause of continuous ambulatory peritoneal dialysis peritonitis in this patient. Since invasive Streptococcus bovis infection is associated with gastrointestinal pathology (Streptococcus bovis biotype I) and chronic liver diseases (Streptococcus bovis biotype II), identifying the biotype of Streptococcus bovis could guide treatment by indicating that further investigation of these underlying diseases is required.

Adult↗
PubMed2002

Perinatal antibiotic usage and changes in colonization and resistance rates of group B streptococcus and other pathogens.

OBJECTIVE: To quantify current antibiotic usage during the perinatal period and impact on vaginal-rectal colonizing organism resistance rates. METHODS: Swabs were obtained for culture of group B streptococcus and other bacteria from a cohort of 1207 pregnant women in Calgary, Alberta, at 36 weeks' gestation. Those women who received antibiotics during labor or after pregnancy and a 10% subset who received no antibiotics had repeat cultures at 6 weeks postpartum. Cultured organisms were tested for sensitivity to several antibiotics. RESULTS: Group B streptococcus was identified in 235 women (19.5%) in the antepartum period. Fifty-one percent of all participants received antibiotics (31.4% intrapartum). Group B streptococcus prophylaxis was given to 215 (17.8%), whereas 83 (6.9%) group B streptococcus-negative women without fever during labor received antibiotics. Ampicillin (49%), cefazolin (28%), and penicillin (18%) were the most frequently used antibiotics. Resistance rates among group B streptococcus to erythromycin and clindamycin were 5.6% and 3.0%, respectively, whereas 20.6% of Escherichia coli were ampicillin resistant. Among antibiotic recipients, 6.3% of all bacteria that were initially sensitive on prenatal cultures to a specific antibiotic became resistant in the postnatal period, whereas 6.5% that were initially resistant became sensitive. CONCLUSION: Current prevention practices in our region were associated with perinatal antibiotic administration in over half of pregnant women. Ampicillin was the most common antibiotic administered. Some physicians are treating women who are group B streptococcus culture negative at term, a practice that is of no proven value. However, this was not associated with increased resistance for group B streptococcus or other organisms identified from maternal vaginal-rectal tracts.

Adolescent↗
PubMed1997

Group B streptococcus colonization in pregnant diabetic women.

OBJECTIVE: To evaluate the influence of maternal diabetes on the risk of group B streptococcus colonization during pregnancy. METHODS: We prospectively analyzed data on 105 pregnant women with diabetes mellitus, both pregestational and gestational, and a control group of 300 pregnant women without carbohydrate intolerance. All had singleton gestations, negative tests for human immunodeficiency virus, and intact membranes at enrollment. Culture specimens for group B streptococcus were obtained from the lower vaginal walls and rectum. Two-tailed unpaired Student t test, Mann-Whitney U test, and chi 2 test were used as appropriate. Multiple logistic regression analyses were performed to evaluate the independent influence of maternal diabetes on the rate of group B streptococcus colonization. RESULTS: Compared to controls, diabetic women had a higher colonization rate (43.8 versus 22.7%, odds ratio [OR] 2.56, 95% confidence interval [CI] 1.6, 4.1). The prevalence of group B streptococcus colonization in pregestational diabetic women was 54.1% and in women with gestational diabetes it was 35.1% (P = .05). Among women with pregestational diabetes, the prevalence of group B streptococcus colonization was 59.1% in class B and 50.0% in class C to R (P = not significant). After we adjusted for maternal age, race, and obesity, diabetic women continued to be at increased risk of group B streptococcus colonization (OR 3.1, 95% CI 1.8, 5.2). CONCLUSION: Carbohydrate intolerance appears to be an independent risk factor for group B streptococcus colonization during pregnancy.

Adult↗
PubMed1998

Timing of intrapartum ampicillin and prevention of vertical transmission of group B streptococcus.

OBJECTIVE: To evaluate the relationship between the time elapsed from the administration of ampicillin prophylaxis to delivery and its efficacy in interrupting intrapartum transmission of group B streptococcus. METHODS: During the 12-month study period, all women who came to the Virgen de las Nieves Hospital (Granada, Spain) for delivery were screened for group B streptococcus vaginal carriage by a pigment-detection culture-based procedure. Colonized women were treated with ampicillin (2 g intravenously), and the interval between ampicillin administration and delivery was recorded. Newborns from colonized mothers also were screened to detect group B streptococcus colonization. RESULTS: During the study period, 4525 women were admitted to the hospital for delivery and screened for group B streptococcus vaginal colonization. Group B streptococcus was detected in 543 women (12%), of whom 454 gave birth vaginally to 454 liveborn infants. Intrapartum ampicillin was given to 201 of these 454 women (44%), and 10% of the newborns from mothers who received intrapartum ampicillin prophylaxis were colonized by group B streptococcus. The relationship between timing of ampicillin administration and rate of neonatal group B streptococcal transmission was as follows: less than 1 hour before delivery, 46%; 1-2 hours, 29%; 2-4 hours, 2.9%; and more than 4 hours, 1.2%. Among the 253 mothers who received no intrapartum prophylaxis, colonization was found in 120 of their newborns (47%). CONCLUSION: When the time between the start of ampicillin prophylaxis and delivery is at least 2 hours, vertical transmission of group B streptococcus is minimized.

Ampicillin↗
PubMed2000

The galU gene of Streptococcus pneumoniae that codes for a UDP-glucose pyrophosphorylase is highly polymorphic and suitable for molecular typing and phylogenetic studies.

The enzyme UTP-glucose-1-phosphate uridylyltransferase (UDP-glucose pyrophosphorylase, UDPG:PP) is synthesized by practically all organisms, although prokaryotic UDPG:PPs are evolutionarily unrelated to the eukaryotic counterparts. The primary structure of prokaryotic UDPG:PPs is well conserved, although little information exists on the polymorphism of the genes coding for these enzymes. It has been reported that the galU gene encoding the Streptococcus pneumoniae UDPG:PP is absolutely required for the synthesis of the capsular polysaccharide, a sine qua non prerequisite for virulence. A 594 bp fragment covering 66% of the galU gene from 37 pneumococcal isolates and the type strains of Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii, Streptococcus sanguinis, Streptococcus salivarius, and Streptococcus sobrinus has been amplified by PCR and sequenced. Up to 21 different alleles were found in S. pneumoniae. They possess a mosaic-like structure and belong to, at least, two evolutionarily distinct families that show a sequence divergence of 15-20%. In spite of its marked polymorphism, phylogenetic relationships among pneumococcal strains deduced from the galU gene matched those previously established by using alternative approaches. Comparison of the pneumococcal galU alleles with those from other streptococci indicated the existence of a complex network of genetic interchange. The galU gene represents an informative marker to be used alone or in conjunction with other molecular typing methods.

Alleles↗
PubMed2004

Streptococcus devriesei sp. nov., from equine teeth.

Phenotypic and phylogenetic studies were performed on four unidentified Gram-positive staining, catalase-negative, alpha-hemolytic Streptococcus-like organisms recovered from the teeth of horses. SDS PAGE analysis of whole-cell proteins and comparative 16S rRNA gene sequencing demonstrated the four strains were highly related to each other but that they did not correspond to any recognised species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms form a hitherto unknown sub-line within the Streptococcus genus, displaying a close affinity with Streptococcus mutans, Streptococcus ferus and related organisms. Sequence divergence values of > 5% with these and other reference streptococcal species however demonstrated the organisms from equine sources represent a novel species. Based on the phenotypic distinctiveness of the new bacterium and molecular chemical and molecular genetic evidence, it is proposed that the unknown species be classified as Streptococcus devriesei sp. nov. The type strain of Streptococcus devriesei is CCUG 47155T (= CIP 107809T).

Animals↗
PubMed2004

Bacterial virulence factors in neonatal sepsis: group B streptococcus.

PURPOSE OF REVIEW: Group B streptococcus is a leading cause of neonatal pneumonia, septicaemia and meningitis. Up to one quarter of women in labour are now given intravenous antibiotics to prevent early-onset disease by the organism, a situation that will remain constant until a successful vaccine is available. From a molecular understanding of the pathogenicity of group B streptococcus we may be able to devise novel means for controlling disease, such as identifying inhibitors of key metabolic pathways or regulatory networks. This review summarizes our post-genomic knowledge of the regulation, metabolism and virulence of group B streptococcus. RECENT FINDINGS: Although advances have been made in the understanding of classic group B streptococcus virulence traits, such as capsular polysaccharide, beta-haemolysin, C5a peptidase, adhesins and immunogenic surface proteins, the major recent contribution to group B streptococcus pathogenesis has been the whole genome sequencing of three group B streptococcus strains, representing serotypes Ia, III and V. From these genomes, we not only see where the classic virulence genes map, but we can also gain insights into the metabolism and regulation of the organism and how these affect its virulence. SUMMARY: Knowledge of virulence factors and the organism's metabolism and gene regulation offers opportunities to find novel means of preventing group B streptococcus infection in babies.

Bacteremia↗
PubMed1998

Mutacin production by Streptococcus mutans may promote transmission of bacteria from mother to child.

The production of bacteriocin-like inhibitory substances, mutacins, by mutans streptococci varies among isolates. To find if the degree of mutacin activity of an isolate was related to its transmission between mother and her child, 19 mothers and their 18-month- to 3-year-old children were sampled for their oral mutans streptococci. In addition, the stability of mutacin activity was studied with isolates from the mothers and with isolates from five unrelated 5-year-old children in 5- to 7-year follow-up studies. A total of 145 oral mutans streptococcal isolates were serotyped by immunodiffusion, ribotyped, and mutacin typed by the stab culture technique. Mutacin was produced by 88% of the strains against more than 1 of the 14 indicator strains, representing mutans streptococci, Streptococcus sanguis, Streptococcus salivarius, Streptococcus oralis, Streptococcus gordonii, and Streptococcus pyogenes. Streptococcus mutans isolates showed more inhibitory activity than did Streptococcus sobrinus isolates. Identical ribotypes had similar mutacin activity profiles within a subject, initially and in the follow-up studies, in all but two cases. The mothers harbored a total of 37 different mutans streptococcal ribotypes. Six children were negative for mutans streptococci. Transmission was probable in 9 of 20 mother-child pairs on the basis of the presence of identical strains, as determined by ribotyping and bacteriocin (mutacin) typing. S. mutans strains shared between a mother and her child showed a broader spectrum of inhibitory activity than did nontransmitted strains. In conclusion, the mutacin activity of clinical isolates is reasonably stable, and this virulence factor seems to be of clinical importance in early colonization by S. mutans.

Adolescent↗
PubMed2002

Streptococcus sinensis sp. nov., a novel species isolated from a patient with infective endocarditis.

A bacterium was isolated from the blood culture of a patient with infective endocarditis. The cells were facultative anaerobic, nonsporulating, gram-positive cocci arranged in chains. The bacterium grows on sheep blood agar as alpha-hemolytic, gray colonies of 0.5 to 1 mm in diameter after 24 h of incubation at 37 degrees C in ambient air. Growth also occurs in 10 or 40% bile and on bile esculin agar but not in 6% NaCl. No enhancement of growth is observed in 5% CO(2). It is nongroupable with Lancefield groups A, B, C, D, F, or G antisera and is resistant to optochin and bacitracin. The organism is aflagellated and is nonmotile at both 25 and 37 degrees C. It is Voges-Proskauer test positive. It produces leucine arylamidase and beta-glucosidase but not catalase, urease, lysine decarboxylase, or ornithine decarboxylase. It hydrolyzes esculin and arginine. It utilizes glucose, lactose, salicin, sucrose, pullulan, trehalose, cellobiose, hemicellulase, mannose, maltose, and starch. 16S rRNA gene sequencing showed that there were 3.6, 3.7, 4.3, 4.7, and 5.9% differences between the 16S rRNA gene sequence of the bacterium and those of Streptococcus gordonii, Streptococcus intermedius, Streptococcus constellatus, Streptococcus sanguis, and Streptococcus anginosus, respectively. The G+C content of it (mean plus minus standard deviation) was 53.0% plus minus 2.9%. Based on phylogenetic affiliation, it belongs to the mitis or anginosus group of Streptococcus. For these reasons a new species, Streptococcus sinensis sp. nov., is proposed, for which HKU4 is the type strain. Further studies should be performed to ascertain the potential of this bacterium to become an emerging cause of infective endocarditis.

Adult↗
PubMed2004

[Microbiological, clinical and epidemiological aspects of Streptococcus pneumoniae isolates recovered over two years].

INTRODUCTION: Streptococcus pneumoniae is the most frequent cause of non-hospital acquired pneumonia and meningitis in adults, and bacterial otitis media in children. Moreover, it causes a third of all acute sinusitis cases. Penicillin has been the treatment of choice for almost 50 years. Gradually, penicillin-resistant pneumococci have appeared throughout the world. Our aim was to investigate the epidemiology, pattern of resistance and serotypes of Streptococcus pneumoniae infection in our area. METHODS: Over a period of two years (May 1997-May 1999), Streptococcus pneumoniae strains were isolated in the Clinical Microbiology Unit of the University Hospital Virgen de la Victoria in Málaga, Spain. This is a 750-bed hospital covering a population of 407,480 inhabitants, and admitting 21,500 hospitalized patients per year. Streptococcus was identified by standard procedures: serotyping was done with the Quellung test and antibiotic susceptibility study by the disk diffusion method and E-test. RESULTS: Streptococcus pneumoniae infection was diagnosed in 170 patients during the years studied. The microorganism was isolated from samples of sputum (82), blood (43), aspirated bronchial fluid, cerebrospinal fluid (6), and exudates (7). Non-hospital origin was identified in 88% of cases. The mean hospital stay was 12 days and mortality was 12.4%. Some 45.9% of the isolated strains were resistant to penicillin and 20% to cefotaxime. We found 31 different serotypes, with 77% of the isolated strains belonging to 12 serotypes. Serotypes 19, 3 and 6B were the most frequent in non-hospital infection, whereas 9V and 23F were related with nosocomial infection. Penicillin-resistant strains of Streptococcus pneumoniae belonged to 19 different serotypes; 6B, 9V, 14, 19 and 23F were the most important. CONCLUSIONS: As was expected, Streptococcus pneumoniae infections of mainly non-hospital origin in our area were characterized by elevated mortality and high-level resistance to penicillin. Immunosuppression was a predisposing factor.

Female↗
PubMed2005

Vaccination against group B streptococcus.

Streptococcus agalactiae (Group B streptococcus) is an important cause of disease in infants, pregnant women, the elderly and in immunosuppressed adults. An effective vaccine is likely to prevent the majority of infant disease (both early and late onset), as well as Group B streptococcus-related stillbirths and prematurity, to avoid the current real and theoretical limitations of intrapartum antibiotic prophylaxis, and to be cost effective. The optimal time to administer such a vaccine would be in the third trimester of pregnancy. The main limitations on the production of a Group B streptococcus vaccine are not technical or scientific, but regulatory and legal. A number of candidates including capsular conjugate vaccines using traditional carrier proteins such as tetanus toxoid and mutant diphtheria toxin CRM197, as well as Group B streptococcus-specific proteins such as C5a peptidase, protein vaccines using one or more Group B streptococcus surface proteins and mucosal vaccines, have the potential to be successful vaccines. The capsular conjugate vaccines using tetanus and CRM197 carrier proteins are the most advanced candidates, having already completed Phase II human studies including use in the target population of pregnant women (tetanus toxoid conjugate), however, no definitive protein conjugates have yet been trialed. However, unless the regulatory environment is changed specifically to allow the development of a Group B streptococcus vaccine, it is unlikely that one will ever reach the market.

Humans↗
PubMed2002

Various Streptococcus species isolated from infectious skin diseases.

An evaluation was carried out of the types of Streptococcus spp. (excluding Streptococcus pyogenes) isolated from infectious skin diseases, and their susceptibilities to eight antimicrobial drugs of the Streptococcus spp. isolated. The types of diseases were also evaluated. A total of 29 Streptococcus spp. were identified and Streptococcus agalactiae was the most common. Streptococcus spp. were found to be susceptible to the eight antimicrobials used except gentamicin; susceptibility to gentamicin varied according to species. Susceptibility to beta-lactams was 100% and this drug should be considered the antimicrobial of choice in Streptococcus spp. treatment.

Anti-Bacterial Agents↗
PubMed2004

[The inhibitive effect of IgY toothpaste against oral Streptococcus mutans].

PURPOSE: To study the effect of the toothpaste containing IgY against oral Streptococcus mutans. METHODS: 140 subjects were divided into 2 groups randomly (test group and control group). Before the beginning of the test, every subject underwent a elution period in order to lessen the other interference factors, then used different toothpastes were used respectively and the test began. Streptococcus mutans values were determined with Dentocult SM Strip just before test, at 1, 3, 7, 30 days after toothpaste used and 14 days after stopping toothpaste used. RESULTS: (1) In test group,Streptococcus mutans values decreased at 1 day after toothpaste used. In control group Streptococcus mutans values decreased at 3 days after toothpaste used. (2) Streptococcus mutans values decreased gradually in each groups after toothpaste used. (3) In test group, 2 weeks after stopping toothpaste used, Streptococcus mutans values were still suppressed. CONCLUSION: The application of the toothpaste containing IgY may reduce oral Streptococcus mutans levels significantly.

Child↗