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PubMed1999

Five-year analysis of antimicrobial susceptibility of the Streptococcus milleri group.

Susceptibility to 17 antibiotics was studied in 180 strains of the Streptococcus milleri group (88 Streptococcus anginosus, 63 Streptococcus constellatus, and 29 Streptococcus intermedius) isolated over a 5-year period. Minimum inhibitory concentrations of penicillin were in the intermediate range for 5.6% of the strains. Resistance to erythromycin and clindamycin was found in 17.1% and 16.6% of the isolates, respectively. A steady increase in the susceptibility to ciprofloxacin was observed over the study period. Imipenem was the most active beta-lactam agent tested. Glycopeptide antibiotics showed excellent activity. Only slight differences between the three species were found in terms of antibiotic susceptibility. Intermediate resistance to penicillin is appearing among the Streptococcus milleri group in our area; consequently, care must be taken when choosing a macrolide for the management of infections caused by these microorganisms.

Anti-Bacterial Agents↗
PubMed2000

Comparison of three methods for identification of Streptococcus milleri group isolates to species level.

A collection of 180 clinical isolates of Streptococcus milleri group were identified to species level using two phenotypic methods (a commercial system and the reference method based on differential phenotypic reactions) and a genotypic method (hybridisation of the 16S rRNA gene with species-specific probes) in order to evaluate the performance of the respective methods. A high level of agreement (80%) was observed between the results of the reference method and the genotypic method. The highest level of agreement was found for the species Streptococcus anginosus (83%), a high level of agreement (76%) also being achieved for Streptococcus constellatus and Streptococcus intermedius. The sensitivity of the commercial system compared to the genotypic method was 76% overall, but it was low (57.5%) for Streptococcus intermedius. Twenty-five strains belonged to the recently described CI strains.

Bacterial Typing Techniques↗
PubMed1995

Prenatal screening for group B Streptococcus. I. Impact of antepartum screening on antenatal prophylaxis and intrapartum care.

OBJECTIVE: Our purpose was to evaluate current obstetric practice regarding screening and prophylaxis for group B Streptococcus and to evaluate the impact of screening on antepartum and intrapartum care. STUDY DESIGN: A total of 1232 members of the Society of Perinatal Obstetricians were asked to indicate their practices regarding screening for group B Streptococcus. Respondents were then asked their practices regarding antepartum and intrapartum prophylaxis on the basis of screening cultures, prior antimicrobial treatment, and other risk factors for neonatal sepsis. RESULTS: Of the 925 respondents (75.1%), 30.8% performed routine screening in all pregnancies: first prenatal visit (42.3%), 26 to 28 weeks (41.3%), and 34 to 38 weeks (22.1%). In addition, 65.9% would screen patients only under high-risk situations. Although 70.5% sample multiple sites, respondents were inconsistent regarding the sites from which cultures are obtained: distal vagina (64.2%), cervix (53.9%), proximal vagina (40.0%), anal canal (38.5%), and urethra (4.3%). A total of 34.7% of respondents would treat the patient at the time of a positive culture. Knowledge of maternal group B Streptococcus carriage would significantly alter intrapartum prophylaxis in low-risk (60.3% vs 0.5%) and various high-risk populations (74.0% to 98.4% vs 11.3% to 55.0%). However, no consensus as to optimal practice was identified. CONCLUSIONS: This survey demonstrates significant inconsistencies in screening and prophylaxis for group B Streptococcus by specialists in maternal-fetal medicine. In addition, it reveals that the recommendations of The American College of Obstetricians and Gynecologists and the American Academy of Pediatrics are not routinely followed by these specialists. Knowledge of group B Streptococcus carriage significantly increases antepartum and intrapartum treatment regardless of the presence of other risk factors for neonatal sepsis. The impact of this practice on neonatal therapy warrants further evaluation.

Amoxicillin↗
PubMed1989

Natural transmission of group B Streptococcus during delivery.

This is a study of group B Streptococcus during labor of 121 patients in whom group B Streptococcus was isolated in the vagina and/or rectum before delivery. The intrapartum vaginal culture was positive in 55.2% of the antepartum carriers (32/58). When the vaginal culture during delivery was positive, the group B Streptococcus was isolated in the amniotic fluid 2 h after the rupture of membranes in 81% of the cases. The newborns of antepartum carriers, when the labor developed naturally, were colonized by group B Streptococcus in 69.2% of cases when the intrapartum vaginal and/or amniotic fluid cultures were positive (9/13), while only 5.6% of the newborns of antepartum carriers but with negative cultures during delivery were colonized by group B Streptococcus (1/18). The most frequent positive neonatal culture was in the umbilicus (83.3%) followed by the external ear (62.5%).

Amniotic Fluid↗
PubMed1990

Phylogenetic analysis of Streptococcus saccharolyticus based on 16S rRNA sequencing.

Reverse transcriptase sequencing of 16S rRNA of Streptococcus saccharolyticus was performed in order to determine the phylogenetic position of this organism. On the basis of the sequence data Streptococcus saccharolyticus formed a distinct group with Enterococcus faecalis (type species of the genus Enterococcus) and other enterococcal species. Streptococcus saccharolyticus was found to be only distantly related to members of the genus Streptococcus sensu stricto. It is therefore proposed that Streptococcus saccharolyticus be reclassified in the genus Enterococcus, as Enterococcus saccharolyticus comb. nov.

Base Sequence↗
PubMed2006

dnaJ and gyrB gene sequence relationship among species and strains of genus Streptococcus.

The dnaJ and gyrB nucleotide sequences were determined for members of the genus Streptococcus. The average similarity between the species tested was 76.4% (69.7-100%) for dnaJ and 75.9 (70.1-98.7%) for gyrB. These data indicated that the dnaJ and gyrB genes are more divergent and more discriminatory than the 16S rDNA gene. Furthermore, the variation in the dnaJ nucleotide sequences among the mitis group was greater than that of the gyrB nucleotide sequences, especially between Streptococcus pneumoniae and Streptococcus mitis. Subsequently, the high discrimination power of dnaJ within the mitis group was confirmed. Thus, we conclude that the dnaJ and gyrB genes are efficient alternative targets for the classification of the genus Streptococcus, and that dnaJ is suitable for phylogenetic analysis of closely related Streptococcus strains.

Bacterial Proteins↗
PubMed1997

Persistence of penicillin G benzathine in pregnant group B streptococcus carriers.

OBJECTIVE: To determine if streptococcicidal levels of penicillin G benzathine can be detected in maternal serum 4 weeks after treatment with 4.8 million units. METHODS: Thirty-seven pregnant women with positive group B streptococcus vaginal or urine cultures were each given 4.8 million units of penicillin G benzathine. Maternal blood samples were collected after injection and at delivery. Serum penicillin levels were measured by high-pressure liquid chromatography. Follow-up cultures were done when possible. RESULTS: None of the patients had serum penicillin levels below 0.20 microgram/mL 30 days after treatment. Cord blood levels were approximately 50% lower than maternal levels. In all but three subjects, cord blood levels exceeded 0.06 microgram/mL, the minimal inhibitory concentration for group B streptococcus. The three exceptions were patients who delivered more than 100 days after treatment. Group B streptococcus cultures were negative at the time of delivery in 72% of cases. None of the patients with positive cultures were moderately or heavily colonized. CONCLUSION: In pregnant women, penicillin G benzathine levels are high enough to inhibit the growth of group B streptococcus for more than 4 weeks after injection with 4.8 million units. Further studies are needed to evaluate whether this regimen can prevent neonatal colonization and invasive group B streptococcus disease.

Adult↗
PubMed2002

Group B Streptococcus endogenous endophthalmitis : case reports and review of the literature.

PURPOSE: To report five cases of group B Streptococcus endogenous endophthalmitis (GBSEE) and to review the literature. DESIGN: Retrospective, noncomparative, interventional case series and literature review. PATIENTS: All patients with this condition treated at the Singapore National Eye Centre from 1994 through 2001. INTERVENTIONS: Core or complete vitrectomy and intravitreal and systemic antibiotics. METHODS: A review of the systemic and ocular characteristics and treatment. MAIN OUTCOME MEASURE: Visual outcome. RESULTS: Group B Streptococcus endogenous endophthalmitis developed in four patients after the onset of septic arthritis and in one patient with cervical epidural abscess after acupuncture, presenting as a diffuse endophthalmitis. Group B Streptococcus was isolated in the blood, vitreous, and joints. Despite the use of high-dose intravenous antibiotics within 72 hours of ocular presentation, intravitreal antibiotic injection, and vitrectomy (two eyes), all eyes lost light perception and became phthisical. A survey of the literature revealed that GBSEE is rare and that 17 cases have been reported since 1985. For purposes of analysis, four of these cases were excluded because of inadequate details and our five cases were included. Group B Streptococcus endogenous endophthalmitis was found to arise from hematogenous spread from cutaneous sites of infection (16.7%), pharyngitis (11.1%), and pneumonia (11.1%). Septic arthritis (38.9%) and endocarditis (33.3%) were concomitant sites of infection along with endophthalmitis. The septic arthritis typically involved multiple joints. Four patients (22.2%) had diabetes mellitus and three had other underlying predisposing illness. Although most patients received intravenous (83.3%) and intravitreal (55.6%) antibiotics and four eyes underwent therapeutic vitrectomy, useful vision was preserved in only four eyes. Two patients died of sepsis. CONCLUSIONS: Group B Streptococcus endogenous endophthalmitis is a devastating condition often associated with septic arthritis. The visual prognosis is poor, despite therapy.

Aged↗
PubMed1999

Beta-haemolytic Streptococcus infection in burns.

Group A beta haemolytic Streptococcus has been one of the most serious infections in the burn patients resulting in severe cellulitis and sepsis. Penicillin has been used ever since its introduction as prophylaxis against these conditions. Penicillin prophylaxis was used in our burn unit as well without any serious evaluation until December 1992. This prospective study was therefore, undertaken to evaluate the incidence of beta haemolytic Streptococcus infection in burn patients, and its clinical outcome over a period of 5 years in the absence of prophylaxis with penicillin. 14 of the 1213 burn patients admitted to the Al-Babtain Centre for Plastic Surgery and Burns from January 1993 to December 1997 had either colonization or infection with Streptococcus spp. Their mean age was 15 years (range 1 month to 52 years) and the mean burn surface area was 20% (range 5 to 90%). Streptococci were isolated from burn wounds in 10 patients, throat in 3 and blood culture in 1. Group A Streptococcus was found in 5, group C in 3 and group D in 6 patients. In all patients except one the organisms were isolated > or =72 h post burn. The infections were successfully controlled by antibiotic and no detrimental effect was observed either on wound healing or skin graft take. There was no mortality amongst these 14 patients. The study showed that only 1.1% of the burn patients in our unit acquired Streptococcus of which only one third comprised of group A. This study thus demonstrates that the practice of penicillin prophylaxis during the first five post burn days may not be of any value and therefore, deserves discontinuation in units where the incidence of this organism is minuscule.

Adult↗
PubMed2003

Molecular characterization of the presence of Eubacterium spp and Streptococcus spp in endodontic infections.

Eubacterium spp. and Streptococcus spp. are virulent, commonly identified microorganisms in endodontic infections. The purpose of this study was to use molecular methods to identify these organisms in 22 infected root canals that include eight cases with preoperative clinical symptoms and five cases with a history of diabetes mellitus. The presence of Streptococcus spp. and Eubacterium spp. was examined using two sets of PCR primers specific with multiple species within the respective genera. Positive specimens had their PCR products sequenced and phylogenetically analyzed to identify the specific species. Sixteen specimens (73%) contained Eubacterium spp. and nine (41%) were positive for Streptococcus spp. Eubacterium infirmum was the most prevalent Eubacterium sp. This organism was significantly associated with a history of diabetes (OR = 9.6; P = 0.04). Streptococcus anginosus was the most common Streptococcus sp., but neither it nor any of the other streptococci were significantly associated with the clinical parameters evaluated.

Bacterial Typing Techniques↗
PubMed1999

Effect of the lactic acid bacterium Streptococcus thermophilus on ceramide levels in human keratinocytes in vitro and stratum corneum in vivo.

The effects of Streptococcus thermophilus on ceramide levels either in vitro on cultured human keratinocytes or in vivo on stratum corneum, have been investigated. In vitro, Streptococcus thermophilus enhanced the levels of ceramides in keratinocytes in a time-dependent way. The presence of high levels of neutral, glutathione-sensitive, sphingomyelinase in Streptococcus thermophilus could be responsible for the observed ceramide increase. The application of a base cream containing sonicated Streptococcus thermophilus in the forearm skin of 17 healthy volunteers for 7 d also led to a significant and relevant increase of skin ceramide amounts, which could be due to the sphingomyelin hydrolysis through bacterial neutral sphingomyelinase. Indeed, similar results were obtained with a base cream containing purified bacterial neutral sphingomyelinase. In addition, the inhibition of bacterial neutral sphingomyelinase activity through glutathione blocked the skin ceramide increase observed after the treatment. The topical application of a sonicated Streptococcus thermophilus preparation, leading to increased stratum corneum ceramide levels, could thus result in the improvement of lipid barrier and a more effective resistance against xerosis.

Adult↗
PubMed2001

Cutaneous injury induces the release of cathelicidin anti-microbial peptides active against group A Streptococcus.

Cathelicidins are a family of peptides thought to provide an innate defensive barrier against a variety of potential microbial pathogens. The human and mouse cathelicidins (LL-37 and CRAMP, respectively) are expressed at select epithelial interfaces where they have been proposed to kill a number of gram-negative and gram-positive bacteria. To determine if these peptides play a part in the protection of skin against wound infections, the anti-microbial activity of LL-37 and CRAMP was determined against the common wound pathogen group A Streptococcus, and their expression was examined after cutaneous injury. We observed a large increase in the expression of cathelicidins in human and murine skin after sterile incision, or in mouse following infection by group A Streptococcus. The appearance of cathelicidins in skin was due to both synthesis within epidermal keratinocytes and deposition from granulocyctes that migrate to the site of injury. Synthesis and deposition in the wound was accompanied by processing from the inactive prostorage form to the mature C-terminal peptide. Analysis of anti-microbial activity of this C-terminal peptide against group A Streptococcus revealed that both LL-37 and CRAMP potently inhibited bacterial growth. Action against group A Streptococcus occurred in conditions that typically abolish the activity of anti-microbial peptides against other organisms. Thus, cathelicidins are well suited to provide defense against infections due to group A Streptococcus, and represent an important element of cutaneous innate immunity.

Amino Acid Sequence↗
PubMed2002

Chlorhexidine vaginal flushings versus systemic ampicillin in the prevention of vertical transmission of neonatal group B streptococcus, at term.

OBJECTIVE: To investigate the efficacy of intrapartum vaginal flushings with chlorhexidine compared with ampicillin in preventing group B streptococcus transmission to neonates. METHODS: This was a randomized controlled study, including singleton pregnancies delivering vaginally. Rupture of membranes, when present, must not have occurred more than 6 h previously. Women with any gestational complication, with a newborn previously affected by group B streptococcus sepsis or whose cervical dilatation was greater than 5 cm were excluded. A total of 244 group B streptococcus-colonized mothers at term (screened at 36-38 weeks) were randomized to receive either 140 ml chlorhexidine 0.2% by vaginal flushings every 6 h or ampicillin 2 g intravenously every 6 h until delivery. Neonatal swabs were taken at birth, at three different sites (nose, ear and gastric juice). RESULTS: A total of 108 women were treated with ampicillin and 109 with chlorhexidine. Their ages and gestational weeks at delivery were similar in the two groups. Nulliparous women were equally distributed between the two groups (ampicillin, 87%; chlorhexidine, 89%). Clinical data such as birth weight (ampicillin, 3,365 +/- 390 g; chlorhexidine, 3,440 +/- 452 g), Apgar scores at 1 min (ampicillin, 8.4 +/- 0.9; chlorhexidine, 8.2 +/- 1.4) and at 5 min (ampicillin, 9.7 +/- 0.6; chlorhexidine, 9.6 +/- 1.1) were similar for the two groups, as was the rate of neonatal group B streptococcus colonization (chlorhexidine, 15.6%; ampicillin, 12%). Escherichia coli, on the other hand, was significantly more prevalent in the ampicillin (7.4%) than in the chlorhexidine group (1.8%, p < 0.05). Six neonates were transferred to the neonatal intensive care unit, including two cases of early-onset sepsis (one in each group). CONCLUSIONS: In this carefully screened target population, intrapartum vaginal flushings with chlorhexidine in colonized mothers display the same efficacy as ampicillin in preventing vertical transmission of group B streptococcus. Moreover, the rate of neonatal E. coli colonization was reduced by chlorhexidine.

Administration, Intravaginal↗
PubMed1999

Extensive variation in the ddl gene of penicillin-resistant Streptococcus pneumoniae results from a hitchhiking effect driven by the penicillin-binding protein 2b gene.

An internal fragment of the ddl gene, encoding the cytoplasmic enzyme D-alanyl-D-alanine ligase, was sequenced from 566 isolates of Streptococcus pneumoniae and single isolates of Streptococcus mitis and Streptococcus oralis. The 52 alleles found among the S. pneumoniae isolates fell into two groups. Group A alleles were very uniform in sequence and were present in both penicillin-susceptible and penicillin-resistant pneumococci. Group B alleles were much more diverse and were found only in penicillin-resistant isolates. The Streptococcus oralis and Streptococcus mitis alleles were less diverged from group A alleles than some of the group B pneumococcal alleles, suggesting that the latter alleles contain interspecies recombinational replacements. The ddl gene was located 783 bp downstream of the penicillin-binding protein 2b gene (pbp2b). Sequencing of the pbp2b-recR-ddl-murF region of three penicillin-resistant pneumococci that had diverged ddl alleles showed that the whole region from pbp2b to ddl (or beyond) was highly diverged (about 8%) compared with the sequences from three penicillin-susceptible isolates. The high levels of diversity in the group B ddl alleles from penicillin-resistant isolates were ascribed to a hitchhiking effect whereby interspecies recombinational exchanges at pbp2b, selected by penicillin usage, often extend into, or through, the ddl gene. The data allow the average size of the interspecies recombinational replacements to be estimated at about 6 kb.

Alleles↗
PubMedDate not supplied

Possible pseudoresistance of Streptococcus pneumoniae to penicillin G in a patient with a mixed pneumococcus-Staphylococcus aureus pneumonia.

We report the case of a 53-year-old woman with a mixed pneumococcus-staphylococcus pneumonia, in which both organisms were recovered from both sputum and blood. Streptococcus pneumoniae persisted in sputum 48 hours after initiation of high-dose intravenous penicillin G. When nafcillin was substituted for penicillin G, both pneumococci and staphylococci were eradicated from blood and sputum. This strain of Streptococcus pneumoniae was highly susceptible to penicillin G, but the associated strain of Staphylococcus aureus was not. The staphylococcus produced large amounts of a penicillin -degrading betalactamase . We reviewed the records of ten cases of pneumococcus pneumonia from the Wayne State University-Detroit Medical Center admitted from March 1978 to April 1981, in which sputum cultures were repeated within one to ten days after penicillin G had been initiated. At second cultures of sputum, Streptococcus pneumoniae was recovered in none of these latter cases. We further showed that on a blood agar culture plate in the presence of penicillin G, a beta-lactamase positive strain of Staphylococcus aureus allowed growth of Streptococcus pneumoniae. Therefore, despite penicillin therapy, Staphylococcus aureus in sputum may facilitate the persistence of Streptococcus pneumoniae.

Female↗
PubMed2006

Detection of Streptococcus species by polymerase chain reaction in infectious crystalline keratopathy.

PURPOSE: Investigation of a positive polymerase chain reaction (PCR) for Streptococcus species from an excised cornea of a patient with infectious crystalline keratopathy. METHODS: Samples microdissected from corneal intrastromal aggregates present in infectious crystalline keratopathy were subjected to PCR for 3 primer pairs respectively specific for Streptococcus, Staphylococcus, and several kinds of fungi. RESULTS: The PCR detected DNA from Streptococcus but not from Staphylococcus or fungi. Direct sequencing of the PCR products showed that the PCR products had the highest identity (99.8%) with Streptococcus mitis and Streptococcus gordoni, indicating that these species were the most probable causes of infectious crystalline keratopathy in this patient. CONCLUSION: Our findings suggest that PCR provides a good adjunct technique in the diagnosis of corneal infection.

Aged↗
PubMed1998

Identification of streptococci from Greek Kasseri cheese and description of Streptococcus macedonicus sp. nov.

Taxonomic studies were performed on some Streptococcus-like organisms isolated from naturally fermented Greek Kasseri cheese. By SDS-PAGE analysis of whole-cell proteins the group was found to be quite different from Streptococcus thermophilus. Comparative 16S and 23S rRNA sequence analyses showed that the isolates represent a new species within the genus Streptococcus, where they are most closely related to the Streptococcus bovis cluster. On the basis of these phylogenetic results and some phenotypic differences, a new species, Streptococcus macedonicus, is proposed. The type strain is ACA-DC 206.

Bacterial Proteins↗
PubMed2002

Streptococcus entericus sp. nov., isolated from cattle intestine.

Biochemical, molecular chemical and molecular genetic studies were performed on an unknown gram-positive, catalase-negative, coccus-shaped organism isolated from the intestine of a cow affected with catarrhal enteritis. The organism was tentatively identified as a streptococcal species based on results of cellular morphological and biochemical tests. 16S rRNA gene sequencing studies confirmed its provisional identification as a member of the genus Streptococcus, but the organism did not correspond to any recognized species of this genus. The nearest phylogenetic relatives of the unknown coccus from a calf were Streptococcus acidominimus and Streptococcus suis. The unknown bacterium, however, was distinguished from these species and other animal streptococci by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as a novel species of the genus Streptococcus, Streptococcus entericus sp. nov. The type strain is CECT 5353T (= CCUG 44616T).

Animals↗