Streptococcus Agalactiae Infections Research Articles

Streptococcus agalactiae infection in cancer patients: a five-year study.

Although the highest burden of Streptococcus agalactiae infections has been reported in industrialized countries, studies on the characterization and epidemiology are still limited in developing countries and implementation of control strategies remains undefined. The aim of this retrospective study was to assess the epidemiological, clinical, and microbiological aspects of S. agalactiae infections in cancer patients treated at a Reference Brazilian National Cancer Institute - INCA, Rio de Janeiro, Brazil. We reviewed the clinical and laboratory records of all cancer patients identified as having invasive S. agalactiae disease during 2010-2014. The isolates were identified by biochemical analysis and tested for antimicrobial susceptibility. A total of 263 strains of S. agalactiae were isolated from cancer patients who had been clinically and microbiologically classified as infected. S. agalactiae infections were mostly detected among adults with solid tumors (94%) and/or patients who have used indwelling medical devices (77.2%) or submitted to surgical procedures (71.5%). Mortality rates (in-hospital mortality during 30 days after the identification of S. agalactiae) related to invasive S. agalactiae infections (n = 28; 31.1%) for the specific category of neoplasic diseases were: gastrointestinal (46%), head and neck (25%), lung (11%), hematologic (11%), gynecologic (4%), and genitourinary (3%). We also found an increase in S. agalactiae resistance to erythromycin and clindamycin and the emergence of penicillin-less susceptible isolates. A remarkable number of cases of invasive infections due to S. agalactiae strains was identified, mostly in adult patients. Our findings reinforce the need for S. agalactiae control measures in Brazil, including cancer patients.

Demograficzne uwarunkowania świadomości w zakresie profilaktyki przeciw zakażeniom Streptococcus agalactiae (GBS) u rodzących kobiet

Demograficzne uwarunkowania świadomości w zakresie profilaktyki przeciw zakażeniom Streptococcus agalactiae (GBS) u rodzących kobiet

Identification of a virulence-related surface protein XF in piscine Streptococcus agalactiae by pre-absorbed immunoproteomics.

BackgroundSince 2009, large-scale Streptococcus agalactiae infections have broken out in cultured tilapia farms in China, resulting in considerable economic losses. Screening of the surface proteins is required to identify virulence factors or protective antigens involved in piscine S.agalactiae infections in tilapia. Pre-absorbed immunoproteomics method (PAIM) is a useful method previously established in our laboratory for identifying bacterial surface proteins.ResultsA serine-rich repeat protein family 1 (Srr-1), designated XF, was identified by PAIM in piscine S. agalactiae isolate GD201008-001. To investigate the role of XF in the pathogenesis of piscine S. agalactiae, an isogenic xf mutant strain (Δxf) and a complemented strain (CΔxf) were successfully constructed. The Δxf mutant and CΔxf showed no significant differences in growth characteristics and adherence to HEp-2 cells compared with the wild-type strain. However the 50% lethal dose of Δxf was increased (4-fold) compared with that of the parental strain in a zebrafish infection model.ConclusionsThe findings demonstrated that XF is a virulence-related, highly immunoreactive surface protein and is involved in the pathogenicity of S. agalactiae infections in fish.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-014-0259-7) contains supplementary material, which is available to authorized users.

Clinical aspects of invasive infections with Streptococcus dysgalactiae ssp. equisimilis in Japan: differences with respect to Streptococcus pyogenes and Streptococcus agalactiae infections

Streptococcus dysgalactiae ssp. equisimilis (SDSE) is increasingly being identified as a pathogen responsible for invasive and non-invasive infections. We compared the clinical features of invasive SDSE infections with those of invasive infections caused by Streptococcus pyogenes (group A streptococcus (GAS)) and Streptococcus agalactiae (group B streptococcus (GBS)). Active surveillance for invasive SDSE, GAS and GBS was maintained over 1 year at 142 medical institutions throughout Japan. Clinical information was collected together with isolates, which were characterized microbiologically. Two hundred and thirty-one invasive SDSE infections were identified, 97 other patients had infections with GAS, and 151 had infections with GBS. The median age of the SDSE patients was 75 years; 51% were male and 79% had underlying diseases. Forty-two SDSE patients (19%) presented to the emergency department. Among the 150 patients (65%) for whom follow-up was completed, 19 (13%) died and eight (5%) had post-infective sequelae (poor outcome). Insufficient white blood cell responses (<5000 cells/microL) and thrombocytopenia on admission each suggested significantly higher risk of poor outcome (ORs 3.6 and 4.5, respectively). Of 229 isolates, 55 (24%) showed an stG6792 emm type, which was significantly associated with poor outcome (OR 2.4). Clinical manifestations of invasive SDSE infections were distinct from those of invasive GBS infections. Primary-care doctors should consider invasive SDSE infections when treating elderly patients.

Streptococcus agalactiae in pregnant women: Phenotypic and genotypic characters

Streptococcus agalactiae (GBS) is considered a leading cause of neonatal sepsis. We evaluated the phenotypic and genotypic characters of 73 S. agalactiae strains isolated from different women at the 35-37 weeks of pregnancy. Isolates were characterized by serotyping (direct agglutination) and by pulsed-field-gel-electrophoresis (PFGE). Resistance to antimicrobials (penicillin, macrolides, lincosamides, quinolones and tetracyclines) was assessed. All isolates were serologically typeable and ascribable to one of the six tested serotypes (Ia, Ib, II, III, IV, and V) and many strains of the same serotype were genetically heterogeneous. Strains belonging to serotypes III, V and Ia were the most prevalent and the most resistant to macrolides. This work reports GBS colonization rate (about 18%) and the prevalent capsular serotypes among pregnant women in Turin (Italy). Penicillin and erythromycin can be still considered the first and second choice drugs for prophylaxis and treatment of early-onset GBS infections in our district. The relevance of phenotypic and genotypic characterization of strains to monitor and control Streptococcus agalactiae infections is briefly discussed.

Group B streptococcal soft tissue infections in non-pregnant adults

Skin and soft tissue infections are the most common presentations of invasive Streptococcus agalactiae infections. This study reviewed 71 patients in a medical centre in southern Taiwan with S. agalactiae soft tissue infections. The mortality rate was 7%, and 11% of patients lost their extremities following extensive tissue necrosis. Critical illness and the presence of cutaneous ulceration heralded a fatal prognosis. Risk-factors for amputation of limbs included advanced age, cutaneous ulceration and polymicrobial infection. It was concluded that invasive S. agalactiae soft tissue infections, as with infections caused by Streptococcus pyogenes, can also lead to substantial morbidity and mortality in non-pregnant adults.

Therapeutic Strategies for Contagious and Non-contagious Mastitis

In recent years veterinarians and dairymen have reevaluated the advisability of treating clinical mastitis with antibiotics in herds where most of the clinical mastitis is caused by environmental pathogens. Most of the commercial antibiotic products available in the United States were tested against subclinical infections with contagious pathogens. A review of the current literature shows that antibiotics generally make no difference in the outcome of gram-negative intramammary infections. In gram-positive infections, the benefit of antibiotics depends on the pathogen. Streptococcus agalactiae infections respond well to therapy with any of the intramammary preparations available in the US. Staphylococcus aureus infections are generally refractory to antibiotic therapy according to the labels of the commercial tubes. The success of treatment may be increased by using antibiotics in conjunction with parenteral antibiotics or for longer durations than on the label. Coagulase-negative staphylococci generally cause mild mastitis in which antibiotic therapy makes little difference. The environmental streptococci are emerging as important and tough pathogens. Antibiotic therapy increases the success rate of treatment and may help prevent relapses and chronicity, but. more research is needed in this area.&#x0D; No one protocol for treatment of clinical mastitis can be applied to all farms. Recommendations should be based on analysis of bulk tank and clinical samples and of the milking and management practices on the farm. Since clinical judgment and extralabel use of drugs is generally involved, the knowledge and advice of the veterinarian are essential in developing and evaluating treatment protocols. A suggested protocol for use in large herds that have little or no contagious mastitis will be presented.

Evaluation of teat germicides of low iodine concentrations for prevention of bovine mastitis by Staphylococcus aureus and Streptococcus agalactiae

Two iodophor teat germicides of low iodine concentration were evaluated in a controlled, experimental challenge-infection study against Staphylococcus aureus and Streptococcus agalactiae. One germicide was a 0.1% iodophor containing 0.75% glycerin, formulated to maintain 5–6 ppm free I 2. The other germicide was a 0.175% iodophor without emollient, formulated to maintain 4–6 ppm free I 2. New intramammary infections with Staphylococcus aureus and Streptococcus agalactiae were reduced 80.7 and 56.6% by the 0.1% iodophor. The 0.175% iodophor gave a 65.0% reduction in new Staphylococcus aureus intramammary infections, but the new infection rate for Streptococcus agalactiae was low in both control and dipped quarters and provided limited power to detect differences between treatment groups. Reduction in new Streptococcus agalactiae infections was 33.3% for the 0.175% iodophor. No adverse effects on teat skin condition were observed.

Evaluation of Nine Teat Dip Formulation Under Experimental Challenge to Staphylococcus Aureus and Streptococcus Agalactiae

Nine postmilking teat dips were evaluated by an experimental challenge model against either Staphylococcus aureus, Streptococcus agalactiae, or both. Formulations containing .9 and .6% sodium hypochlorite, 1% sodium dichloro-s-triazene-trione, .55% chlorhexidine gluconate, and .35% povidone iodine reduced incidence of Staphylococcus aureus infections 56.8, 28.3, 75.9, 92.5, and 77.9%. Incidence of infections with Streptococcus agalactiae was reduced 48.1 and 63.2% by 1.7 and 1% sodium dichloro-s-triazene-trione formulations. The 1% chlorhexidine gluconate and .35% povidone iodine products reduced Streptococcus agalactiae infections 71.0 and 67.0%. Three experimental 1% iodophor formulations reduced Streptococcus agalactiae infections 28.9, 44.8, and 50.7%. The experimental challenge model was refined further and provided an efficient method to determine efficacy of post-milking teat dips.

Sodium Cloxacillin for Treatment of Mastitis in Lactating Cows

Sodium cloxacillin was used to treat 107 cows affected with acute mastitis and 138 affected with subclinical mastitis. Based on the application of conservative bacteriologic criteria, the cure rate was 53% for acute staphylococci mastitis and 65% for subclinical staphylococci mastitis. The cure rate for Streptococcus agalactiae infections was 91% in acute conditions and 92% in subclinical conditions. The cure rate was 73% for the acute infections and 88% in cases of subclinical infections when Streptococcus spp. “non ag” was the cause. Daily milk production had no effect on response rate. No adverse reactions due to treatment were reported by any investigator.