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Streptococcal group A

X Luo, G Liao, C Liu, X Jiang, M Lin, C Zhao, J Tao, Z Huang
Streptococcus agalactiae is a causative agent responsible for massive mortalities of tilapia that has led to catastrophic losses to tilapia culture globally. Bacteriophages represent a new class of antimicrobials against bacteria. In this study, we characterized the bacteriophage HN48, which formed small and round-transparent plaques on a double-layer plate. With a hexagonal head and a long tail, this phage may belong to the Caudovirales according to the International Committee on Taxonomy of Viruses. HN48 was found to have a relatively wide and highly specific host range, to be sensitive to high temperature (60-80°C) and low pH (3-5), and to be relatively stable at alkaline pH (8-10)...
August 17, 2018: Journal of Fish Diseases
Gregory J Tyrrell, Sumana Fathima, Jocelyne Kakulphimp, Christopher Bell
Background: We present an analysis of increasing rates of invasive group A streptococci (iGAS) over a 15-year period in Alberta, Canada. Methods: From 2003 to 2017, the emm type of iGAS isolates was identified from patients with iGAS disease in Alberta. Demographic, clinical, and risk factor data were collected. Results: A total of 3551 cases of iGAS were identified in Alberta by isolation of a GAS isolate from a sterile site. The age-standardized incidence rates of iGAS increased from 4...
August 2018: Open Forum Infectious Diseases
Deborah Money, Victoria M Allen
OBJECTIVE: To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes. OUTCOMES: Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use...
August 2018: Journal of Obstetrics and Gynaecology Canada: JOGC, Journal D'obstétrique et Gynécologie du Canada: JOGC
Fubo Sun, Ayaz Ahmed, Lina Wang, Ming Dong, Weidong Niu
Orthodontic treatments often include dental displacement using a fixed retainer such as braces, which may result in the accumulation of plaque that provides a suitable environment for microorganisms to cause oral infection. So, this study was designed to investigate the microbial diversity among orthodontic patients and healthy individuals. METHODS: Fifty individuals i.e. 30 orthodontic patients and 20 normal individuals were included in this study. Samples were collected during the midterm of orthodontic treatment (10-12 months)...
August 7, 2018: Microbial Pathogenesis
Viorica Munteanu, Antonella Petaccia, Nicolae Contecaru, Emanuele Amodio, Carlo Virginio Agostoni
Introduction: Acute Rheumatic Fever (ARF) is a multisystemic disease that results from an autoimmune reaction due to group A streptococcal infection. The disease affects predominantly children aged 5 to 15 years and although its incidence in developed Countries declined since the early 1900s, to date there is a paucity of data that confirm this epidemiological trend. Objective: The study aimed to assess the burden of ARF in term of hospitalization and to describe the characteristics of acute rheumatic fever (ARF) in the paediatric population of Lombardy...
2018: AIMS Public Health
Elva Bonifácio Andrade, Ana Magalhães, Ana Puga, Madalena Costa, Joana Bravo, Camila Cabral Portugal, Adília Ribeiro, Margarida Correia-Neves, Augusto Faustino, Arnaud Firon, Patrick Trieu-Cuot, Teresa Summavielle, Paula Ferreira
Group B streptococcal (GBS) meningitis remains a devastating disease. The absence of an animal model reproducing the natural infectious process has limited our understanding of the disease and, consequently, delayed the development of effective treatments. We describe here a mouse model in which bacteria are transmitted to the offspring from vaginally colonised pregnant females, the natural route of infection. We show that GBS strain BM110, belonging to the CC17 clonal complex, is more virulent in this vertical transmission model than the isogenic mutant BM110∆cylE, which is deprived of hemolysin/cytolysin...
August 7, 2018: Nature Communications
Areej Alhhazmi, Gregory J Tyrrell
The Group B streptococcus (GBS) can express a capsular polysaccharide (CPS). There are ten recognized CPSs (Ia, Ib, and II-IX). A GBS isolate is considered nontypeable (NT) when CPS cannot be identified as one of ten types. Two groups of GBS NT isolates were studied, isolates without surface sialic acid (sia(-)) and isolates with surface sialic acid (sia(+)). The first objective was to characterize NT sia(-) isolates that failed CPS identification by an immunodiffusion antisera typing assay and a RT-PCR capsule typing assay...
August 8, 2018: Emerging Microbes & Infections
Roman Deniskin, Brittany Shah, Flor M Muñoz, Anthony R Flores
We report here 18 cases of pediatric group A streptococcal toxic shock syndrome, associated clinical findings, and bacterial molecular genetic characteristics discovered through whole-genome sequencing. This comparative whole-genome sequencing revealed unique gene content (speK) and polymorphisms (dpiB) in emm87 group A Streptococcus, the relative contributions of which, in combination with the host response, in the development of streptococcal toxic shock syndrome remain to be elucidated.
July 31, 2018: Journal of the Pediatric Infectious Diseases Society
Anthony R Flores, J Chase McNeil, Brittany Shah, Chris Van Beneden, Samuel A Shelburne
Background: Bacterial infections caused by group A Streptococcus (GAS) are common in childhood. Few study reports have provided data on pediatric-specific trends in the epidemiology and bacterial strain characteristics of GAS infections. Methods: We prospectively collected GAS isolates from the clinical microbiology laboratory at Texas Children's Hospital between July 1, 2013, and June 30, 2017. Patient characteristics and GAS disease categories were determined through chart review...
August 1, 2018: Journal of the Pediatric Infectious Diseases Society
Merel N van Kassel, Merijn W Bijlsma, Arie van der Ende, Matthijs C Brouwer, Diederik van de Beek
OBJECTIVES: Streptococcus agalactiae (group B streptococcus, GBS) is an uncommon cause of bacterial meningitis in adults. We describe clinical characteristics, serotype distribution and outcome of adult GBS meningitis. PATIENTS AND METHODS: Patients aged 16 years or older with GBS cultured in cerebrospinal fluid included in two prospective nationwide cohort studies performed in the Netherlands between 1998-2002 and 2006-2017 were evaluated. RESULTS: We identified 33 patients with GBS meningitis with a median age of 58 years of whom 22 were male (67%)...
July 28, 2018: Journal of Infection
Nour Gazzaz, Timothy Mailman, Jennifer Ruth Foster
We report a previously well paediatric patient with two distinct presentations of invasive group A streptococcus (GAS) infection resulting in significant morbidity. The first episode, following GAS pharyngitis, involved multiorgan dysfunction syndrome. This included cardiorespiratory and acute hepatorenal failure and purpura fulminans that eventually necessitated four-limb amputation. The second episode occurred 12 months later, from undetermined aetiology, and resulted in septic shock. Molecular analysis of the emm gene and PCR for Serum Opacity Factor revealed that the initial isolate was M Type 4 and sof gene positive while the second isolate was M Type 1 and sof gene negative...
July 30, 2018: BMJ Case Reports
Joshua Osowicki, Andrew C Steer
AIM: Community-acquired pneumonia (CAP) complicated by pleural empyema is an important paediatric problem. Antibiotic management decisions are made on the basis of little available data and without strong specific recommendations in guidelines. METHODS: This was an online survey of paediatric infectious diseases (PID) physicians disseminated by major international professional organisations, examining empiric and targeted antibiotic choice, switch to oral antibiotics and duration of treatment for two hypothetical cases of contrasting severity...
July 27, 2018: Journal of Paediatrics and Child Health
Chacko Jobichen, Tan Ying Chong, Mahalakshmi Tirumuru Prabhakar, Digant Nayak, Debabrata Biswas, Navraj Singh Pannu, Emanuel Hanski, J Sivaraman
Group A Streptococcus (GAS; Streptococcus pyogenes) causes a wide range of infections, including pharyngitis, impetigo, and necrotizing fasciitis, and results in over half a million deaths annually. GAS ScpC (SpyCEP), a 180-kDa surface-exposed, subtilisin-like serine protease, that act as an essential virulence factor that helps S. pyogenes evade the innate immune response by cleaving and inactivating C-X-C chemokines. ScpC is thus a key candidate for the development of a vaccine against GAS and other pathogenic streptococcal species...
July 26, 2018: Biochemical Journal
Chris Bird, Gemma Winzor, Katherine Lemon, Alasdair Moffat, Tina Newton, Jim Gray
OBJECTIVE: Sore throat is a common presentation to the children's emergency department (ED), and many patients are likely prescribed antibiotics unnecessarily. We aimed to reduce antibiotic prescribing for sore throat in our UK ED through use of an established scoring system combined with a rapid diagnostic test (RDT) to detect group A streptococcal (GAS) pharyngitis. METHODS: AB single-subject and diagnostic accuracy studies were used to measure both antibiotic prescribing rates over time and the performance of the McIsaac clinical score combined with RDT to screen for and treat GAS pharyngitis...
July 24, 2018: Pediatric Emergency Care
Karita Haapasalo, Lotta L E Koskinen, Jari Suvilehto, Pekka Jousilahti, Annika Wolin, Sari Suomela, Richard Trembath, Jonathan Barker, Jaana Vuopio, Juha Kere, T Sakari Jokiranta, Päivi Saavalainen
Pharyngeal tonsillitis is one of the most common upper respiratory tract infections and Group A streptococcus is the most important bacterial pathogen causing it. While most patients experience tonsillitis only rarely, a subset of patients suffer from recurrent or chronic tonsillitis or pharyngitis. The predisposing factors for recurring or chronic form of this disease are not yet fully understood but genetic predisposition has been suggested. A genetic association study using Illumina's Immunochip SNP array was performed to search for new genetic biomarkers in pharyngeal tonsillitis...
July 23, 2018: Infection and Immunity
Giuseppe Valerio De Gaetano, Giampiero Pietrocola, Letizia Romeo, Roberta Galbo, Germana Lentini, Miriam Giardina, Carmelo Biondo, Angelina Midiri, Giuseppe Mancuso, Mario Venza, Isabella Venza, Arnaud Firon, Patrick Trieu-Cuot, Giuseppe Teti, Pietro Speziale, Concetta Beninati
Binding of microbial pathogens to host vitronectin (Vtn) is a common theme in the pathogenesis of invasive infections. In this study, we characterized the role of Vtn in the invasion of mucosal epithelial cells by Streptococcus agalactiae (i.e. group B streptococcus or GBS), a frequent human pathogen. Moreover, we identified PbsP, a previously described plasminogen-binding protein of GBS, as a dual adhesin that can also interact with human Vtn through its streptococcal surface repeat (SSURE) domains. Deletion of the pbsP gene decreases both bacterial adhesion to Vtn-coated inert surfaces and the ability of GBS to interact with epithelial cells...
July 21, 2018: Molecular Microbiology
Andrea A Tarnutzer, Federica F Andreoni, Nadia N Keller, Claudia C Zürcher, Anna A Norrby-Teglund, Reto Ra Schuepbach, Annelies As Zinkernagel
OBJECTIVES: Streptococcus pyogenes causes life-threatening invasive infections including necrotizing fasciitis (NF). Current treatment guidelines recommend the use of a cell-wall active antibiotic combined with a protein synthesis inhibitor and surgical debridement in NF patients. Adjunctive therapy with intravenous immunoglobulin (IVIG) has been proposed for superantigen-associated streptococcal toxic shock syndrome. So far, benefits of IVIG treatment remain unclear and prospective clinical studies are scarce...
July 16, 2018: Clinical Microbiology and Infection
Rebecca A Flaherty, Deborah L Donahue, Katelyn E Carothers, Jessica N Ross, Victoria A Ploplis, Francis J Castellino, Shaun W Lee
The bacterial pathogen Group A Streptococcus (GAS) has been shown to induce a variety of human diseases ranging in severity from pharyngitis to toxic shock syndrome and necrotizing fasciitis. GAS produces a powerful peptide toxin known as Streptolysin S (SLS). Though long recognized as a potent cytolysin, recent evidence from our lab has shown that SLS-dependent cytotoxicity is mediated through activation of the pro-inflammatory mediators p38 MAPK and NFκB. These findings led us to hypothesize that activation of p38 MAPK and NFκB signaling drive the production of pro-inflammatory cytokines which, in turn, serve as positive feedback signals to initiate cytotoxicity in infected host cells...
2018: Frontiers in Cellular and Infection Microbiology
Tan Duong, Shahin Shahbazi, Sung Lee
INTRODUCTION: Endogenous endophthalmitis is a rare condition that is caused by hematogenous spread of bacteria or fungi and is usually seen in patients with predisposed medical conditions. We are reporting an unusual case of group A streptococcal infection causing endogenous endophthalmitis and septic arthritis in a healthy 42-year-old man. CASE PRESENTATION: A previously healthy 42-year-old man presented to the Emergency Department with chills, fever, left wrist pain, left eye pain, and vision loss...
June 26, 2018: Permanente Journal
Joon Young Song, Jae Hyang Lim, Sangyong Lim, Zhi Yong, Ho Seong Seo
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of severe invasive disease in neonate, elderly, and immunocompromised patients worldwide. Despite recent advances in the diagnosis and intrapartum antibiotic prophylaxis (IAP) of GBS infections, it remains one of the most common causes of neonatal morbidity and mortality, causing serious infections. Furthermore, recent studies reported an increasing number of GBS infections in pregnant women and elderly. Although IAP is effective, it has several limitations, including increasing antimicrobial resistance and late GBS infection after negative antenatal screening...
July 11, 2018: Human Vaccines & Immunotherapeutics
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