Group B streptococcus arthritis

Serious infections with group B streptococcus (streptococcus agalactiae) are rare in adults. A 81-year-old patient with cirrhosis who developed a septic arthritis due to this germ, is described. Only eleven cases of group B streptococcal arthritis have been previously reported.     

Endophthalmitis and multiple brain abscess in a patient with endocarditis due to Streptococcus agalactiae

Endogenous endophthalmitis is a rare disease caused by hematogenic germ spread from an internal focus. Infections due to Streptococcus agalactiae are infrequent in adults although new cases had been described recently associated to inmunodepression. We present a patient with endocarditis due to Streptococcus agalactiae, endophthalmitis and multiple brain abscess. We also review the literature.     

Pyogenic arthritis caused by Streptococcus agalactiae: report of four cases and a review of the literature

Most infections by group B streptococcus of the Lancefield classification (Streptococcus agalactiae), were reported in pregnant women or during the puerperal period, as well as in neonates. During the past three decades there have been reports of increasingly invasive infections in adults unrelated to pregnancy, although arthritis and osteomyelitis are still very rare. In this article, we describe four new adult patients with arthritis by S. agalactiae (two postmenopausal women and two men), two of them with affection of the sternoclavicular joint. We also review the medical literature.     

Group B streptococcal arthritis in adults

Group B beta-hemolytic streptococci (Streptococcus agalactiae) have been a rare cause of septic arthritis in adults. Only 18 cases have been cited in the literature, eight of which were described since 1976. Two additional cases occurring in the last year are described herein. Like other infections caused by group B streptococci, the incidence of septic arthritis due to these organisms appears to be increasing. A review of these 20 cases revealed a history of prior arthritis or trauma to the involved joints in 30 percent, and an additional 30 percent occurred in potentially immunocompromised hosts. Four of the patients had probable oligoarticular group B streptococcal arthritis. Although most deaths occurred in the pre-penicillin era, early recognition and treatment are essential to prevent joint destruction.     

Group B streptococcal meningitis complicating elective abortion: report of 2 cases.

The incidence of invasive disease due to Streptococcus agalactiae (group B streptococcus [GBS]) in adults is on the rise; however, meningitis in adults due to GBS remains rare. We report 2 cases of GBS meningitis complicating elective abortion, 1 of which was a septic incomplete abortion. Only 1 case of bacterial meningitis complicating elective abortion has been reported previously.     

无乳链球菌荚膜多糖疫苗的研究进展

无乳链球菌(Streptococcus agalactiae)是一种分布广泛的人兽共患性致病菌。新生儿感染可引起致命性的败血症和脑膜炎。母体免疫是预防新生儿无乳链球菌感染的最有前景的有效策略。然而,目前尚无可用的疫苗。作为无乳链球菌最重要的毒力因子之一,荚膜多糖(CPS)被认为是开发无乳链球菌疫苗的主要靶标。在此,我们综述了无乳链球菌CPS疫苗和CPS-蛋白结合疫苗的研究概况以及最新进展,旨在为无乳链球菌疫苗的研究提供参考。     

Group B streptococcus meningitis in an HIV-positive adult: case report and review

We report a new case of meningitis due to group B streptococci (S. agalactiae) in an HIV-positive patient. Only three other cases have been reported so far, and common features are discussed.     

Tricuspid valve group B streptococcal endocarditis following elective abortion

Streptococcus agalactiae, a group B streptococcus, has been a well-known cause of postpartum and postabortion endocarditis since the preantibiotic era. Streptococcus agalactiae is capable of infecting normal valves and usually produces left-sided disease. We describe a 30-year-old woman who developed tricuspid valve endocarditis due to S. agalactiae. Excision of the valve and a 4-week course of therapy with vancomycin resulted in cure.     

Endocarditis with myocardial abscesses and pericarditis in an adult: group B Streptococcus as a cause.

Group B beta-hemolytic Streptococcus, S agalactiae, is an uncommon cause of endocarditis in adults. We present the clinical, laboratory, and postmortem findings of an adult patient with group B streptococcal endocarditis and major arterial emboli. What to our knowledge are previously unreported features are purulent pericarditis and myocardial abscesses. Twenty-five cases of endocarditis caused by group B Streptococcus that are reported in the literature are reviewed.     

Group B streptococcal sepsis in adults and infants. Contrasts and comparisons

Group B streptococcal infection may result in significant morbidity and mortality in both infants and adults. The experience with group B streptococcal disease was analyzed at one medical center over a ten-year period from 1975 to 1984. Streptococcus agalactiae bacteremia was observed in 29 adults and 26 infants, with an attack rate of 0.2 cases per 1000 adult admissions and 3.2 cases per 1000 live births, respectively. The majority of adult infections apparently occurred as a result of nosocomial acquisition and was associated with a high mortality rate of 38%. Risk factors for group B streptococcal sepsis in adults include diabetes mellitus, malignancy, and hepatic failure. The majority (73%) of neonatal cases occurred within seven days of birth and occurred in a setting of maternal fever, prolonged rupture of membranes, or prematurity. The mortality rate in infants was remarkably low at only 15%. Fatalities occurred in both adults and infants, despite appropriate antimicrobial therapy. Infection control strategies against group B streptococcus must address potential nosocomial dissemination in adults as well as vertical transmission in infants.     

A study of bacterial meningitis in Hokkaido between 1999 and 2003

We evaluated 83 children with bacterial meningitis in 67 of 81 insitutions in Hokkaido, Japan between 1999 and 2003 by questionnaire. The incidence of bacterial meningitis in children aged < 5 years and 5 < or =, < 10 years was 6.3 and 0.7 cases per 100, 000 children/year. The incidences of meningitis due to Haemophilus influenzae, Streptococcus pneumoniae, and Streptococcus agalactiae in children aged < 5 years were 3.7, 1.4 and 0.8. Median age was 13 months ranging from 0 day to 9 years. Seventy-four (89.1%) of the total were less than 5 years old with 39 (47.0%) less than 1 year old. Major causative organisms were H. influenzae in 51 patients, S. pneumoniae in 18, S. agalactiae in 9 and E. coli in 3. Four deaths occurred, giving an overall case mortality rate of 4.8%. Sequelae were seen at discharge in 25.3%, predominantly epilepsy, hearing loss, and developmental delay of varying severity. The frequency of poor prognosis was 55.6% for patients with meningitis due to S. pneumoniae compared with 21.6% for H. influenzae and 22.2% for S. agalactiae.     

Role of fibrinogen-binding adhesin expression in septic arthritis and septicemia caused by Streptococcus agalactiae

BACKGROUND: Streptococcus agalactiae (group B streptococcus) is an important human pathogen that causes neonatal pneumonia, sepsis, septic arthritis, and meningitis, as well as severe infections in immunocompromised adult patients. The streptococci produce several molecules important for virulence. METHODS: We used a murine model of sepsis and septic arthritis to assess the role of FbsA, a fibrinogen-binding adhesin of S. agalactiae as a virulence determinant. NMRI mice were inoculated intravenously with S. agalactiae strains isogenic for the expression of FbsA. RESULTS: Inoculation with wild-type (wt) streptococci resulted in significantly higher mortality, more-pronounced weight decrease, and more-severe arthritis, compared with inoculation with the FbsA mutant isogenic strain. Neither active nor passive immunization with FbsA or FbsA-specific antibodies, respectively, resulted in any protection against subsequent infection with the S. agalactiae wt strain. CONCLUSION: Our results clearly indicate that the expression of FbsA by Streptococcus agalactiae is a significant virulence determinant in septic arthritis and septicemia. However, because blocking of the fibrinogen binding properties did not protect the host against the action of FbsA-expressing streptococci, we believe that the FbsA molecule has some other presently unknown biological in vivo properties.     

Group B streptococcal meningitis in adults: recent increase in Southeast Asia

Background : Meningitis caused by Streptococcus agalactiae (Group B Streptococcus) is rare in adults and usually affects patients with predisposing conditions.
Aims : To describe an increase in adult group B streptococcal meningitis occurring in parallel in Hong Kong and Singapore.
Methods : All cases of bacterial meningitis admitted to the Prince of Wales Hospital, Hong Kong and Singapore General Hospital in 1998, aged 15 years or above, were reviewed. Medical records for the previous ten years were searched for previous cases of adult group B streptococcal meningitis.
Results : In 1998, 29 adult patients with bacterial meningitis were admitted to the two hospitals. S. agalactiae was isolated in 11 cases, Streptococcus pneumoniae in three cases, Klebsiella pneumoniae in two cases, and Pseudomonas pseudomallei in one case. In 11 cases no bacteriological diagnosis could be made. Two patients with adult group B streptococcal meningitis had predisposing conditions for infection. One patient died before a definite diagnosis could be established. A ten year review of records revealed one previous case of adult group B streptococcal meningitis in a patient with multiple risk factors.
Conclusions : An increase of group B streptococcal meningitis has occurred among adults admitted to two major hospitals in two Southeast Asian cities. In the majority of cases there were no identifiable predisposing conditions. The cause of this increase of group B streptococcal remains unclear.     

Toll-like receptor-dependent discrimination of streptococci

Streptococcus pneumoniae and Streptococcus agalactiae cause distinct infectious diseases in small children. Similarly, these bacteria elicit very different host-cell responses in vitro. Inactivated S. agalactiae by far exceeds S. pneumoniae in the activation of inflammatory cytokines and upstream signaling intermediates such as the MAP kinase JNK. The inflammatory response to both Streptococcus spp. is mediated by MyD88, an essential adapter protein of Toll-like receptors (TLRs), although the specific TLRs that are involved have not been fully resolved. Furthermore, during logarithmic growth, S. pneumoniae releases pneumolysin that interacts with TLR4 whereas S. agalactiae releases diacylated molecules that interact with TLR2/6. Interaction of these soluble bacterial products with their cognate TLRs is critical for limiting bacterial dissemination and and systemic inflammation in mice. This might be due, in part, to TLR-mediated apoptosis induced by these factors. In conclusion related streptococcal species induce specific events in TLR-mediated signal transduction. Comparative analysis of the host-cell response to these bacteria reveals molecules such as JNK as valuable targets for adjunctive sepsis therapy.     

Epidemiology of rotaviral infection in adults

Although classic rotaviral gastroenteritis occurs in children between the ages of six and 24 months, infection with rotavirus is common in all age groups, including adults. Virtually all adults have been infected, as is demonstrated by the presence of serum antibodies, but previous infection does not protect against new infection with the same or a different serotype. Rotaviral infection of adults is seen in five settings: secondary contacts from pediatric cases, with variable attack rates in adults; waterborne outbreaks, which are often characterized by higher attack rates in adults than in children; travelers' diarrhea; epidemic spread in isolated or closed populations, often in the absence of contact with children; and endemic infections, which may account for 5%-10% of sporadic cases of diarrhea in adults. Frequent asymptomatic infections with rotavirus occur, and they may be important in the epidemiology of the disease. Although rotaviral infections in adults tend to be milder than those in children, death due to rotaviral infection in adults have been reported.     

Successful treatment of necrotizing fasciitis associated with diabetic nephropathy

A 50-year-old woman with a 15-year history of type 2 diabetes mellitus was admitted to our hospital due to high fever and a skin lesion with severe pain, swelling and a sensation of heat in the right thigh. Laboratory examination showed elevated C-reactive protein (CRP), thrombocytopenia, nephrotic syndrome and renal dysfunction. Her blood glucose level had been well controlled. Streptococcus agalactiae was detected in both the skin lesion and blood culture, and pathological examination revealed neutrophil infiltration in the fascia and muscle layer. The patient was diagnosed with necrotizing fasciitis, septic shock and disseminated intravascular coagulation. A combination therapy of antibiotics and surgical debridement resulted in the improvement of symptoms as supported by laboratory findings, and the skin lesion also showed improvement. Although group A streptococcus is well known to be implicated in the pathogenesis of necrotizing fasciitis, only S. agalactiae, belonging to group B streptococcus, was isolated from the tissue and blood cultures in this case. Although this organism is not virulent and rarely causes a necrotizing fasciitis, both the superficial fascial layer and underlying muscle were affected in this case. There have been only a few reports of necrotizing fasciitis due to S. agalactiae in patients with diabetes mellitus. Although the blood glucose level was well controlled in our patient, this disease might be caused by other factors, including diminished sense of touch and pain, abnormality of microcirculation and hypogammaglobulinemia due to nephrotic syndrome.     

A study of bacterial meningitis in Hokkaido between 1994 and 1998

We evaluated 82 children with bacterial meningitis in 78 institutions in Hokkaido, Japan between 1994 and 1998. The mean number of cases per year was 16.4 (range, 9 to 30). A male predominance occurred with 52 males and 30 females (1.7:1). Median age was 11 months with a range from 1 day to 11 years. Seventy-eight (95%) of the total were less than 5 years old with 55 (67%) less than 2 years old and 45 (55%) less than 1-year old. Four deaths occurred, giving an overall case fatality rate of 4.9%. Sequelae were seen at discharge in 29%, predominantly sensorineural hearing loss, epilepsy and development delay of varying severity. The main causative organisms were Haemophilus influenzae in 49 patients, Streptococcus pneumoniae in 14, Streptococcus agalactiae in 10 and Escherichia coli in 5. The frequency of poor prognosis was 50% for patients with meningitis due to S. pneumoniae or S. agalactiae compared with 27% for patients with meningitis due to H. influenzae.     

The innate immune system and its relevance to neonatal sepsis

PURPOSE OF REVIEW: The advent of human Toll-like receptors has revolutionized our understanding of innate immunity. This review summarizes recent discoveries about the role of Toll-like receptors and innate immunity in neonatal sepsis with a particular emphasis on the paradigmatic organism S. agalactiae. RECENT FINDINGS: S. agalactiae stimulates phagocytes to excessive formation of inflammatory cytokines such as tumor necrosis factor, and Toll-like receptors are essential for this response both in vivo and in vitro. On the molecular level, distinct signaling pathways are engaged by released S. agalactiae toxins such as lipoteichoic acid (Toll-like receptor-2 dependent) and cell-bound toxins (Toll-like receptor-2 independent). In contrast, complement receptors and Fc receptors, but not Toll-like receptors, are directly involved in phagocytosis and therefore elimination of S. agalactiae. Notably, neonatal phagocytes potently activate cytokines in response to S. agalactiae but are deficient in S. agalactiae uptake and killing. Interference with the Toll-like receptor-dependent mitogen activated protein kinase cJun N-terminal Kinase improves outcome in a neonatal model of S. agalactiae sepsis by inhibiting cytokine formation but preserving clearance of S. agalactiae. SUMMARY: Recent progress in the understanding of S. agalactiae recognition and phagocytic signaling in neonatal sepsis suggests intermediates in the Toll-like receptor pathways as valuable targets for adjunctive sepsis therapy.     

Infections with beta-haemolytic streptococci: detection by a universal PCR for bacterial DNA and DNA sequencing

PCR using universal bacterial primers and subsequent DNA sequence analysis of the PCR product was used to detect beta-haemolytic streptococci in clinical samples. Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae were identified in 19 primary culture-negative cases of infections from 203 patient samples with detectable bacterial DNA.     

Complete genome sequence and comparative genomic analysis of an emerging human pathogen,serotype V Streptococcus agalactiae

The 2,160,267 bp genome sequence of Streptococcus agalactiae, the leading cause of bacterial sepsis, pneumonia, and meningitis in neonates in the U.S. and Europe, is predicted to encode 2,175 genes. Genome comparisons among S. agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and the other completely sequenced genomes identified genes specific to the streptococci and to S. agalactiae. These in silico analyses, combined with comparative genome hybridization experiments between the sequenced serotype V strain 2603 V/R and 19 S. agalactiae strains from several serotypes using whole-genome microarrays, revealed the genetic heterogeneity among S. agalactiae strains, even of the same serotype, and provided insights into the evolution of virulence mechanisms.