ABSTRACT
The arginine deiminase (ADI) pathway has been found in many kinds of bacteria and functions to supplement energy production and provide protection against acid stress. The Streptococcus pyogenes ADI pathway is upregulated upon exposure to various environmental stresses, including glucose starvation. However, there are several unclear points about the advantages to the organism for upregulating arginine catabolism. We show that the ADI pathway contributes to bacterial viability and pathogenesis under low-glucose conditions. S. pyogenes changes global gene expression, including upregulation of virulence genes, by catabolizing arginine. In a murine model of epicutaneous infection, S. pyogenes uses the ADI pathway to augment its pathogenicity by increasing the expression of virulence genes, including those encoding the exotoxins. We also find that arginine from stratum-corneum-derived filaggrin is a key substrate for the ADI pathway. In summary, arginine is a nutrient source that promotes the pathogenicity of S. pyogenes on the skin.
Subject(s)
Arginine/metabolism , Skin/microbiology , Streptococcus pyogenes/pathogenicity , Animals , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Filaggrin Proteins , Gene Expression Regulation, Bacterial , HaCaT Cells , Humans , Hydrolases/metabolism , Male , Mice, Inbred C57BL , Mice, Knockout , Microbial Viability , Phosphorylation , Skin/pathology , Streptococcal Infections/blood , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Streptococcus pyogenes/genetics , Transcriptome/genetics , Up-Regulation , VirulenceABSTRACT
Streptococcus pyogenes (S. pyogenes) ZUH1 was isolated and characterized using morphological, cultural and biochemical methods. The results showed that the marker genes (namely spyCEP, ssa, sic, sdaB and speG) indicating group A streptococci (GAS) were detected in the S. pyogenes genome. The results showed that the S. pyogenes strain was inhibited by Crocus sativus methanol extract (CSME), bee honey (BH) and catfish glycoprotein (CFG). The inhibitory activity of these natural agents were compared with standard antibiotics such as Ceftazidime (30 µg/mL), Cefoperazone (75 µg/mL), Cefoxitin (30 µg/mL) and Imipenem (10 µg/mL). There was a synergistic effect between certain antibiotics and CSME. GC-MS and IR analysis of CSME showed different cyclic ketones, aldehydes, esters, alcohols and acids. The main compounds were tetradecanoic acid, safranal and isophorone. Transmission electron microscopy (TEM) images of S. pyogenes cells treated with CSME showed signs of an irregular wrinkled outer surface, fragmentation, adhesion and aggregation of damaged bacterial cells or cellular debris. The marker genes (spyCEP, ssa, sic, sdaB and speG) could be used as a rapid diagnostic tool for GAS. CSME, BH and CFG showed distinctive anti-streptococcal activity either alone or in combinations with antibiotics; their action on S. pyogenes cells was studied by TEM. There was a synergistic effect between antibiotics and Crocus sativus, bee honey, and glycoprotein against S. pyogenes ZUH1. The action of natural agents on the pathogenic cells was shown using TEM.
Subject(s)
Anti-Bacterial Agents , Crocus/chemistry , Honey , Plant Extracts , Streptococcal Infections/drug therapy , Streptococcus pyogenes/growth & development , Uveitis, Intermediate/drug therapy , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Drug Therapy, Combination , Humans , Male , Methanol/chemistry , Middle Aged , Plant Extracts/chemistry , Plant Extracts/pharmacology , Streptococcal Infections/metabolism , Streptococcal Infections/pathology , Uveitis, Intermediate/microbiology , Uveitis, Intermediate/pathologySubject(s)
Brain Abscess , Streptococcal Infections , Streptococcus sanguis/pathogenicity , Thalamus/pathology , Adult , Brain Abscess/diagnostic imaging , Brain Abscess/microbiology , Brain Abscess/pathology , Brain Abscess/surgery , Humans , Male , Streptococcal Infections/diagnostic imaging , Streptococcal Infections/pathology , Streptococcal Infections/surgeryABSTRACT
Streptococcus pyogenes (S. pyogenes) causes several infectious diseases such as tonsillitis, cellulitis, and streptococcal toxic shock syndrome. The general treatment of S. pyogenes infection is by using ß-lactam antibiotics; however, the cases of treatment failure were increasing as serious problems. Lonicera caerulea var. emphyllocalyx (LCE) has been used in the folk medicine in the northern part of Japan, the northern part of China, Korea, and Russia. In this study, we investigated the efficacy of three parts (fruit, stem, and leaf) of Lonicera caerulea var. emphyllocalyx extract (LCEEs) against murine S. pyogenes infection. Oral administration of LCEEs increased the mortality in murine model, and the extracts of its stems and leaves were more effective than the fruit extract significantly. Murine splenocytes and mesenteric lymph nodal cells treated with LCEEs suppressed the excess production of inflammatory cytokine such as TNF-α in comparison to those from untreated cells. LCEEs stimulated the differentiation of pluripotent hematopoietic stem cells in those murine lymph nodal cells. It also activated the proliferative response of murine lymph nodal cells. We also found that the stem and leaf extracts seemed to be more effective than the fruit extract in those phenomena. The concentration of lignins in LCEE prepared from the stems was larger than that from leaves, and that was larger than that from the fruits. Our data suggest that LCE, especially the stems and the leaves, may be useful for the treatment of S. pyogenes infection.
Subject(s)
Lonicera/chemistry , Plant Extracts/administration & dosage , Streptococcal Infections/drug therapy , Streptococcus pyogenes/drug effects , Animals , Cytokines/genetics , Disease Models, Animal , Fruit/chemistry , Gene Expression Regulation/drug effects , Humans , Mice , Plant Extracts/chemistry , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Streptococcus pyogenes/pathogenicity , Tumor Necrosis Factor-alpha/geneticsABSTRACT
BACKGROUND: Streptococcus agalactiae is pathogenic for both animals and humans. In dairy cattle it commonly causes mastitis, with great economic losses, and there is scientific evidence of mastitis, caseous lymphadenitis, contagious skin necrosis and purulent infections associated with S. agalactiae in camels (Camelus dromedarius) as well. In humans, it is a common component of the respiratory and gastrointestinal microflora, but it can also act as a pathogen, especially in elderly people and immunocompromised patients, as well as in pregrant women and newborns. CASE PRESENTATION: A 10-year old non-pregnant female llama (Lama glama) was conferred to the Institute for Animal Health Control, in Bolzano for necropsy after sudden death. The animal had not shown unusual behaviour and had a low to normal nutritional condition (body condition score 2/5). The breeder had reported a chronic suppurative subcutaneous infection in the intermandibular area, resistant to therapy (therapy unknown). After necropsy, several samples were processed for histological, bacteriological and parasitological examinations. CONCLUSIONS: This report describes, to the best of our knowledge, the first isolation of S. agalactiae in llamas (Lama glama). The animal came from a herd that counts approximately 200 South American camelids (llamas, alpacas) along with several horses, chicken, rabbits, cats and dogs; this farm offers services, such as trekking and pet therapy activities.
Subject(s)
Camelids, New World/microbiology , Streptococcal Infections/veterinary , Streptococcus agalactiae/isolation & purification , Animals , Female , Italy/epidemiology , Liver/pathology , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , Streptococcal Infections/pathologyABSTRACT
Arachidonic acid (ARA, 20:4n-6) and dihomo-γ-linolenic acid (DGLA, 20:3n-6) are omega-6 long-chain polyunsaturated fatty acids (LC-PUFA), which are key precursors for lipid mediators of the immune system and inflammatory response. The microalga Lobosphaera incisa (WT) and its Δ5-desaturase mutant P127 (MUT) are unique photosynthetic sources for ARA and DGLA, respectively. This study explores the effect of dietary supplementation with L. incisa and P127 biomass on tissue fatty acid composition, immune function, and disease resistance in zebrafish (Danio rerio). The broken microalgal biomass was added to commercial fish feed at 7.5 and 15% (w/w), providing 21.8 mg/g feed ARA for the WT-supplemented group and 13.6 mg/g feed DGLA for the MUT-supplemented group at the 15% inclusion levels. An unsupplemented group was used as the control. After 1 month of feeding, fish were challenged with Streptococcus iniae. Fish were sampled before the challenge and 1 week after the challenge for various analyses. Tissue ARA and DGLA levels significantly increased in the liver, corresponding to microalgal supplementation levels. The elevated expression of specific immune-related genes was evident in the kidneys in all treatment groups after 1 month of feeding, including genes related to eicosanoid synthesis, lysozyme, and NF-κB. In the liver, microalgal supplementation led to the upregulation of genes related to immune function and antioxidant defense while the expression of examined genes involved in ARA metabolism was downregulated. Importantly, fish fed with 15% of both WT- and MUT-supplemented feed showed significantly (p < 0.05) higher survival percentages (78 and 68%, respectively, as compared to only 46% in the control group). The elevated expression of genes related to inflammatory and immune responses was evident post-challenge. Collectively, the results of the current study demonstrate the potential of microalgae-derived dietary ARA and DGLA in improving immune competence and resistance to bacterial infection in zebrafish as a model organism.
Subject(s)
Animal Feed , Chlorophyta , Fatty Acids, Omega-6/pharmacology , Fish Diseases , Microalgae , Streptococcal Infections , Streptococcus iniae/immunology , Zebrafish , Animals , Fish Diseases/diet therapy , Fish Diseases/immunology , Fish Diseases/pathology , Streptococcal Infections/diet therapy , Streptococcal Infections/immunology , Streptococcal Infections/pathology , Streptococcal Infections/veterinary , Zebrafish/immunology , Zebrafish/microbiologyABSTRACT
Aditoprim (ADP) has potential use as an antimicrobial agent in animals. However, its pharmacodynamic properties have not been systematically studied yet. In this study, the in vitro antibacterial activities of ADP and its main metabolites were assayed, and the in vivo antibacterial efficacy of ADP for the treatment of swine streptococcosis was evaluated. It was shown that Salmonella and Streptococcus from swine, Escherichia coli and Salmonella from chickens, E. coli, Streptococcus, Mannheimia, Pasteurella from calves, Streptococcus and Mannheimia from sheep, and E. coli, Flavobacterium columnare, Acinetobacter baumannii and Yersinia ruckeri from fishes were highly susceptible to ADP. Haemophilus parasuis from swine, Staphylococcus aureus, Aeromonas punctate, Mycobacterium tuberculosis, Streptococcus agalactiae from fishes, and Klebsiella from calves and sheep showed moderate susceptibility to ADP, whereas E. coli, Actinobacillus pleuropneumonia, Pasteurella, S. aureus, Clostridium perfringens from swine, S. aureus, C. perfringens from chickens, and S. aureus from calves were resistant to ADP. The main metabolites of ADP showed equal activity to that of their parent compound, and the prevention and therapeutic dosages of ADP recommended for swine streptococcosis were 10 and 20~40 mg/kg b.w., respectively. This study firstly showed that ADP had strong antibacterial activity and had potential to be used as a single drug in the treatment of bacterial infectious diseases.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Streptococcal Infections/drug therapy , Swine Diseases/drug therapy , Swine Diseases/microbiology , Trimethoprim/analogs & derivatives , Animals , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Swine , Treatment Outcome , Trimethoprim/metabolism , Trimethoprim/pharmacology , Trimethoprim/therapeutic useSubject(s)
Anti-Bacterial Agents/therapeutic use , Brain Abscess/drug therapy , Brain Abscess/microbiology , Streptococcal Infections/diagnosis , Streptococcal Infections/drug therapy , Thalamus/microbiology , Aged , Anti-Bacterial Agents/pharmacology , Brain Abscess/diagnosis , Brain Abscess/pathology , DNA, Bacterial/cerebrospinal fluid , DNA, Bacterial/genetics , Female , Humans , Magnetic Resonance Imaging , Microbial Sensitivity Tests , Multiplex Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Streptococcus intermedius/drug effects , Streptococcus intermedius/genetics , Taiwan , Thalamus/pathology , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
BACKGROUND: Pharmaceutical industry demands innovation for developing new molecules to improve effectiveness and safety of therapeutic medicines. Preclinical assays are the first tests performed to evaluate new therapeutic molecules using animal models. Currently, there are several models for evaluation of treatments, for dermal oedema or infection. However, the most common or usual way is to induce the inflammation with chemical substances instead of infectious agents. On the other hand, this kind of models require the implementation of histological techniques and the interpretation of pathologies to verify the effectiveness of the therapy under assessment. This work was focused on developing a quantitative model of infection and oedema in mouse pinna. The infection was achieved with a strain of Streptococcus pyogenes that was inoculated in an injury induced at the auricle of BALB/c mice, the induced oedema was recorded by measuring the ear thickness with a digital micrometer and histopathological analysis was performed to verify the damage. The presence of S. pyogenes at the infection site was determined every day by culture. RESULTS: Our results showed that S. pyogenes can infect the mouse pinna and that it can be recovered at least for up to 4 days from the infected site; we also found that S. pyogenes can induce a bigger oedema than the PBS-treated control for at least 7 days; our results were validated with an antibacterial and anti-inflammatory formulation made with ciprofloxacin and hydrocortisone. CONCLUSIONS: The model we developed led us to emulate a dermal infection and allowed us to objectively evaluate the increase or decrease of the oedema by measuring the thickness of the ear pinna, and to determine the presence of the pathogen in the infection site. We consider that the model could be useful for assessment of new anti-inflammatory or antibacterial therapies for dermal infections.
Subject(s)
Disease Models, Animal , Ear Auricle/drug effects , Ear Auricle/microbiology , Edema/drug therapy , Skin Diseases, Bacterial/drug therapy , Streptococcal Infections/drug therapy , Streptococcus pyogenes/physiology , Animals , Anti-Bacterial Agents/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Drug Evaluation, Preclinical/methods , Ear Auricle/pathology , Edema/microbiology , Edema/pathology , Female , Mice , Mice, Inbred BALB C , Skin Diseases, Bacterial/microbiology , Skin Diseases, Bacterial/pathology , Streptococcal Infections/microbiology , Streptococcal Infections/pathologyABSTRACT
BACKGROUND: Conflicting recommendations regarding antibiotic prophylaxis for contacts of patients with invasive group A streptococcal (GAS) infection exist. Close contacts of patients with such severe and rapidly progressive disease often strongly appeal to the treating clinicians for antimicrobial treatment to prevent additional cases. We aimed to use an approach based on pharyngeal culture testing of contacts and targeted antibiotic prophylaxis. METHODS: A large throat swab survey including 105 contacts was undertaken after a fulminant and fatal case of GAS necrotizing fasciitis. GAS strains were characterized by emm typing and antimicrobial susceptibility to 7 antibiotics. The presence of 30 virulence determinants was determined by polymerase chain reaction and sequencing. RESULTS: The GAS isolate recovered from the index patient was an M1T1 GAS clone susceptible to all antimicrobial agents tested. The same clone was present in the throat of 36% of close contacts who had exposure to the index patient (family households and classroom contacts) for >24 hours/week, whereas the strain was present in only 2% of the other contacts. CONCLUSIONS: Although the study does not allow firm conclusions to be drawn as to whether antibiotic prophylaxis is effective, we describe a practical approach, including an educational campaign and targeted antibiotic treatment to close contacts who have been exposed to an index patient for > 24 hours/week before the initial disease onset.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Antibiotic Prophylaxis , Fasciitis, Necrotizing/microbiology , Streptococcal Infections/prevention & control , Streptococcal Infections/transmission , Streptococcus pyogenes , Adult , Anti-Bacterial Agents/pharmacology , Antigens, Bacterial/genetics , Bacterial Outer Membrane Proteins/genetics , Bacterial Typing Techniques , Carrier Proteins/genetics , Child , Child, Preschool , Community-Acquired Infections/drug therapy , Community-Acquired Infections/pathology , Community-Acquired Infections/prevention & control , Community-Acquired Infections/transmission , Fatal Outcome , Female , Humans , Male , Microbial Sensitivity Tests , Patient Education as Topic , Pharynx/microbiology , Streptococcal Infections/drug therapy , Streptococcal Infections/pathology , Streptococcus pyogenes/classification , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/isolation & purification , Streptococcus pyogenes/pathogenicity , Virulence , Virulence Factors/geneticsABSTRACT
The aim of the present study was to investigate the chemical composition of the essential oil of Artemisia vestita and to determine the antibacterial activity of the essential oil and its two major components, grandisol and 1,8cineole, against certain respiratory infectioncausing bacterial strains, in vitro and in vivo. The chemical composition of the essential oil was analyzed using gas chromatographymass spectrometry. A microwell dilution method was used to determine the minimum inhibition concentration (MIC) values of the essential oil and its major constituents. A model of Streptococcus pyogenes infection in mice was used to determine its in vivo activities. Lung and blood samples were obtained to assess bacterial cell counts. Toxicity evaluation of the essential oil and its components was completed by performing biochemical analysis of the serum, particularly monitoring aspartate transaminase, alanine transaminase, urea and creatinine. The essential oil exhibited potent antibacterial activity, whereas the two major constituents were less potent. The essential oil exhibited MIC values between 20 and 80 µg/ml, while the values of the two constituents were between 130 and 200 µg/ml. Scanning electron microscopy results demonstrated that the essential oil inhibited biofilm formation and altered its architecture. Survival curves indicated that the essential oil led to a reduction in the viability of different bacteria. The essential oil also induced significant leakage of potassium ions from S. pyogenes. The essential oil (100 µg/mouse) and grandisol (135 µg/mouse) significantly reduced the number of viable bacterial cells in the lungs (P<0.01). However, intake of 100 µg/mouse of essential oil or grandisol 135 µg/mouse once or twice each day for 9 days did not produce any toxic effects in the mice. In conclusion, the in vitro and in vivo results suggested that the essential oil of A. vestita and one of its major constituents, grandisol, can significantly inhibit the growth of different bacterial strains.
Subject(s)
Anti-Bacterial Agents/pharmacology , Artemisia/chemistry , Biofilms/drug effects , Oils, Volatile/pharmacology , Pneumonia, Bacterial/drug therapy , Streptococcal Infections/drug therapy , Streptococcus pyogenes/drug effects , Alanine Transaminase/blood , Animals , Animals, Newborn , Anti-Bacterial Agents/isolation & purification , Aspartate Aminotransferases/blood , Bacterial Load , Biofilms/growth & development , Creatinine/blood , Cyclohexanols/isolation & purification , Cyclohexanols/pharmacology , Eucalyptol , Lung/drug effects , Lung/microbiology , Lung/pathology , Mice , Microbial Sensitivity Tests , Microbial Viability/drug effects , Monoterpenes/isolation & purification , Monoterpenes/pharmacology , Oils, Volatile/chemistry , Plant Oils/chemistry , Plant Oils/pharmacology , Pneumonia, Bacterial/blood , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/pathology , Potassium/metabolism , Streptococcal Infections/blood , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Streptococcus pyogenes/growth & development , Streptococcus pyogenes/metabolism , Terpenes/isolation & purification , Terpenes/pharmacology , Urea/bloodABSTRACT
Periodontitis is an inflammatory disease of gums involving degeneration of periodontal ligaments, creation of periodontal pocket and resorption of alveolar bone, thus disrupting the support structure of teeth causing their loosening and finally removal. Since this disease is mainly confined to the periodontal pocket, so site specific drug delivery of an antibiotic is the best suitable option. This also eradicates the demerits of oral dosing like low drug concentration reaching the target site and the various systemic side effects. In the present work, an efficient and easy technique of electrospinning has been used to develop non-woven drug loaded and biodegradable nanofiber patch with inbuilt property of high surface area to volume ratio. Hyaluronic acid (HA) has been used specifically as the polymer since it possesses remarkable properties like providing an extracellular matrix supporting tissue regeneration, anti-inflammation and mucoadhesion. A blend of this natural polymer with another polymer (Polyvinyl alcohol) has been tried since HA alone cannot be electrospun efficiently as it shows very high viscosity at very low polymer concentration. The developed formulation presented controlled release behavior with good mucoadhesive strength. The in vivo studies confirmed the maintenance of minimum inhibitory concentration (MIC) over an extended period of time in addition to a significant antiinflammatory effect. All these observations suggested that the above formulation forms a stable intra periodontal pocket drug delivery system.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Drug Liberation , Nanofibers/administration & dosage , Nanofibers/chemistry , Periodontal Pocket/drug therapy , Periodontitis/drug therapy , Animals , Anti-Bacterial Agents/pharmacology , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Female , Hyaluronic Acid/administration & dosage , Hyaluronic Acid/chemistry , Male , Microbial Sensitivity Tests , Periodontal Pocket/metabolism , Periodontal Pocket/microbiology , Periodontal Pocket/pathology , Periodontitis/metabolism , Periodontitis/microbiology , Periodontitis/pathology , Polymers/administration & dosage , Polymers/chemistry , Rats , Rats, Wistar , Streptococcal Infections/drug therapy , Streptococcal Infections/pathology , Streptococcus mutans/drug effectsABSTRACT
BACKGROUND: Necrotising soft-tissue infections (NSTIs) are rare conditions with high morbidity and mortality. Patients with NSTIs are often transferred to tertiary hospitals, but the question of whether the potential benefits of highly specialised care outweigh the risks associated with inter-hospital transfers has been raised. METHODS: Prospective study including all patients with NSTIs treated at the intensive care unit at Sahlgrenska University Hospital/East between January 2008 and December 2011. RESULTS: Twenty-nine patients with NSTIs were identified. Their median age was 54 years and 69% were men. Major co-morbidities were present in 45%. Seventeen patients (59%) were referred from other hospitals. Only 33% of the patients were correctly diagnosed or suspected of having NSTIs in the emergency department. Group Aâ Streptococcus was the most common microbiological finding (41%), followed by Enterobacteriaceae (17%). The median time from hospitalisation to the first dose of antibiotics was 6 h and the median time to primary surgery was 16 h. Hyperbaric oxygen therapy was given to 86%, and intravenous immunoglobulin was given in 52% of the cases. The 30-day mortality was 14% (4/29). The times to the first dose of antibiotics, intensive care unit admission and primary surgery did not differ between transferred and directly admitted patients, and there was no difference in outcome between the groups. CONCLUSIONS: Patients with NSTIs develop severe local and systemic symptoms and require extremely resource-demanding hospitalisation. Inter-hospital transfer was not associated with a delay in key interventions and could not be identified as a risk factor for adverse outcome.
Subject(s)
Community-Acquired Infections/epidemiology , Soft Tissue Infections/epidemiology , Streptococcus pyogenes/isolation & purification , APACHE , Adult , Aged , Amputation, Surgical/statistics & numerical data , Anti-Bacterial Agents/therapeutic use , Child, Preschool , Combined Modality Therapy , Community-Acquired Infections/microbiology , Community-Acquired Infections/pathology , Community-Acquired Infections/therapy , Comorbidity , Critical Care/methods , Critical Care/statistics & numerical data , Debridement/statistics & numerical data , Disease Susceptibility , Emergency Service, Hospital/statistics & numerical data , Female , Hospital Mortality , Hospitals, University/statistics & numerical data , Humans , Hyperbaric Oxygenation/statistics & numerical data , Length of Stay/statistics & numerical data , Male , Middle Aged , Necrosis , Patient Transfer , Respiration, Artificial/statistics & numerical data , Soft Tissue Infections/microbiology , Soft Tissue Infections/pathology , Soft Tissue Infections/therapy , Streptococcal Infections/epidemiology , Streptococcal Infections/pathology , Substance Abuse, Intravenous/epidemiology , Sweden/epidemiology , Treatment OutcomeABSTRACT
OBJECTIVE: To study the clinical characteristics, antibiotics sensitivity and outcome of group B streptococcus (GBS) meningitis in neonates in order to provide the guide for early diagnosis and appropriate treatment. METHOD: A retrospective review was performed and a total of 13 cases of neonatal purulent meningitis caused by GBS were identified in the Neonatal Intensive Care Unit of Yuying Children's Hospital of Wenzhou Medical University from January 1, 2005 to May 31, 2013. The clinical characteristics, antibiotics sensitivity test results and outcome were analyzed. RESULT: Fever, poor feeding, seizure and lethargy were common clinical signs of neonatal purulent meningitis caused by GBS. Three cases of early onset GBS meningitis received prepartum antibiotics. All 13 cases had abnormal C-reactive protein (CRP) level, and 11 cases had increased CRP within hours after admission. Of the 13 patients, 7 were cured, 4 discharged with improvement, 2 patients died during hospitalization after being given up because of serious complication. The average length of stay for recovered patients was (47 ± 21)d. Acute complications mainly included hyponatremia (5 cases), intracranial hemorrhage (3 cases) , ventriculomegaly (3 cases) , subdural collection (2 cases) , hydrocephalus (2 cases), septic shock (2 cases), cerebral hernia (1 case), encephalomalacia (1 case). One preterm patient with early onset GBS meningitis died 1 month after hospital discharge. Among 7 survivors with 10-24 months follow-up, 3 were early onset GBS meningitis, 2 with normal results of neurologic examination, 1 with delayed motor development, 4 were late onset GBS meningitis, 1 with normal results of neurologic examination, 3 were neurologically impaired with manifestations including delayed motor development (2 cases) and seizures (1 case). All the GBS strains were sensitive to penicillin and linezolid (13/13, 10/10), the susceptibility to levofloxacin, ampicillin and vancomycin were 11/12, 9/10, 8/13 respectively. CONCLUSION: The clinical manifestations of neonatal purulent meningitis caused by GBS are usually non-specific. It is associated with long hospitalization, neurological impairments and sequelae. Monitoring of serum CRP level is valuable for early diagnosis. Antepartum prophylaxis, early diagnosis and therapy are vital. Large dose penicillin is the priority choice to treat the neonatal purulent meningitis caused by GBS, linezolid should be used in intractable cases.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Meningitis, Bacterial/drug therapy , Streptococcal Infections/drug therapy , Streptococcus agalactiae , C-Reactive Protein/analysis , Drug Resistance, Bacterial , Female , Fever/diagnosis , Fever/drug therapy , Fever/pathology , Follow-Up Studies , Humans , Hyponatremia/etiology , Infant, Newborn , Leukocyte Count , Male , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/pathology , Microbial Sensitivity Tests , Penicillins/therapeutic use , Pregnancy , Pregnancy Complications, Infectious , Retrospective Studies , Streptococcal Infections/diagnosis , Streptococcal Infections/pathologyABSTRACT
Streptococcus suis is an emerging swine-associated zoonotic agent that can cause meningitis and septicemia in humans. We present, to our knowledge, the first case of S. suis arthroplasty infection and streptococcal toxic shock-like syndrome due to an nonencapsulated serotype 5 strain in North America.
Subject(s)
Arthritis/diagnosis , Prosthesis-Related Infections/diagnosis , Shock, Septic/diagnosis , Streptococcal Infections/diagnosis , Streptococcus suis/isolation & purification , Aged , Animals , Arthritis/complications , Arthritis/microbiology , Arthritis/pathology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Hip Joint/diagnostic imaging , Hip Joint/pathology , Humans , Male , Microbiological Techniques , Microscopy , Prosthesis-Related Infections/complications , Prosthesis-Related Infections/microbiology , Prosthesis-Related Infections/pathology , RNA, Ribosomal, 16S/genetics , Radiography , Sequence Analysis, DNA , Shock, Septic/pathology , Streptococcal Infections/complications , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , United StatesABSTRACT
BACKGROUND & OBJECTIVES: Increasing resistance to erythromycin has been observed worldwide in group C and group G streptococci (GCS/GGS). The information available from India is scanty. The aim of the study was to identify erythromycin resistant GCS/GGS isolates in Chennai, south India, and to compare erythromycin resistant genotypes with emm types. METHODS: One hundred and thirty one GCS/GGS isolates were tested for erythromycin resistance by disc diffusion and agar dilution methods. Erythromycin resistance genotypes [erm(A), erm(B) and mef(A)] were determined by a multiplex PCR. emm types of erythromycin resistant GCS/GGS isolates was also assessed using emm gene sequencing method. RESULTS: Sixteen of the 131 isolates (12.21%) were resistant to erythromycin. Majority of the isolates were GGS (15/16). Eight of the 16 (50%) were S. dysgalactiae subsps. equisimilis. Twelve isolates (75%) were MLS B phenotype and four (25%) were M phenotype. Of the 12 isolates which exhibited MLS B resistance, seven showed cMLS B phenotype and were positive for erm(B) gene. The remaining five were iMLS B phenotype of which three were positive for erm(A) gene and two for erm(B) gene. erm(A) was common among carriers whereas erm(B) was common among clinical isolates. INTERPRETATION & CONCLUSIONS: MLS B was the predominant phenotype and erm(B) was the common genotype in the present study. The emm type stC1400.0 was frequently associated with erythromycin resistant GCS/GGS in our study.
Subject(s)
Drug Resistance, Bacterial/genetics , Erythromycin/therapeutic use , Genotype , Streptococcal Infections/drug therapy , Streptococcus/genetics , Anti-Bacterial Agents/administration & dosage , Humans , India , Microbial Sensitivity Tests , Streptococcal Infections/genetics , Streptococcal Infections/pathology , Streptococcus/pathogenicity , Streptococcus pneumoniaeABSTRACT
Streptococcus pyogenes (group A streptococcus, GAS) is a human bacterial pathogen of global significance, causing severe invasive diseases associated with serious morbidity and mortality. To survive within the host and establish an infection, GAS requires essential nutrients, including iron. The streptococcal hemoprotein receptor (Shr) is a surface-localized GAS protein that binds heme-containing proteins and extracellular matrix components. In this study, we employ targeted allelic exchange mutagenesis to investigate the role of Shr in the pathogenesis of the globally disseminated serotype M1T1 GAS. The shr mutant exhibited a growth defect in iron-restricted medium supplemented with ferric chloride, but no significant differences were observed in neutrophil survival, antimicrobial peptide resistance, cell surface charge, fibronectin-binding or adherence to human epithelial cells and keratinocytes, compared with wild-type. However, the shr mutant displayed a reduction in human blood proliferation, laminin-binding capacity and was attenuated for virulence in in vivo models of skin and systemic infection. We conclude that Shr augments GAS adherence to laminin, an important extracellular matrix attachment component. Furthermore, Shr-mediated iron uptake contributes to GAS growth in human blood, and is required for full virulence of serotype M1T1 GAS in mouse models of invasive disease.
Subject(s)
Hemeproteins/metabolism , Iron/metabolism , Streptococcus pyogenes/metabolism , Streptococcus pyogenes/pathogenicity , Virulence Factors/metabolism , Animals , Bacteremia/microbiology , Bacteremia/pathology , Cells, Cultured , Culture Media/chemistry , Disease Models, Animal , Epithelial Cells/microbiology , Female , Gene Knockout Techniques , Gene Targeting , Humans , Keratinocytes/microbiology , Mice , Microbial Viability , Neutrophils/microbiology , Skin Diseases, Bacterial/microbiology , Skin Diseases, Bacterial/pathology , Streptococcal Infections/microbiology , Streptococcal Infections/pathology , Streptococcus pyogenes/growth & development , VirulenceABSTRACT
Streptococcus suis is an important porcine pathogen causing meningitis and other invasive diseases in piglets of different ages. Application of S. suis serotype 2 bacterins to specific-pathogen-free (SPF) weaning piglets has been demonstrated to protect against the homologous serotype. However, autogenous S. suis bacterins are also applied to sows and suckling piglets in the field. Therefore, comparative evaluation of different bacterin immunization regimes, including sow vaccination, was performed in this study. The main objectives were to determine the immunogenicity of an S. suis bacterin in sows prepartum and its influence on active immunization of piglets. Experimental infection of 6- and 8-week-old weaning piglets was performed to elucidate protective efficacies. Humoral immune responses were investigated by an enzyme-linked immunosorbent assay (ELISA) measuring muramidase-released protein (MRP)-specific IgG titers and by opsonophagocytosis assays. Bacterin application elicited high MRP-specific IgG titers in the serum and colostrum of sows, as well as opsonizing antibodies. Piglets from vaccinated sows had significantly higher MRP-specific titers than respective piglets from nonvaccinated sows until 6 weeks postpartum. Vaccination of suckling piglets did not result in high MRP-specific titers nor in induction of opsonizing antibodies. Furthermore, neither vaccination of suckling nor of weaning piglets from immunized sows was associated with a prominent active immune response and protection at 8 weeks postpartum. However, protection was observed in respective 6-week-old weaning piglets, most likely because of protective maternal immunity. In conclusion, this study provides the first results suggesting protective passive maternal immunity for S. suis serotype 2 after bacterin vaccination of sows and a strong inhibitory effect on active immunization of suckling and weaning piglets, leading to highly susceptible growers.
Subject(s)
Bacterial Vaccines/immunology , Streptococcal Infections/veterinary , Streptococcus suis/immunology , Swine Diseases/immunology , Swine Diseases/prevention & control , Animals , Antibodies, Bacterial/analysis , Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Blood/immunology , Colostrum/immunology , Enzyme-Linked Immunosorbent Assay , Female , Immunity, Maternally-Acquired , Immunoglobulin G/analysis , Immunoglobulin G/blood , Opsonin Proteins/analysis , Opsonin Proteins/blood , Pregnancy , Streptococcal Infections/immunology , Streptococcal Infections/pathology , Streptococcal Infections/prevention & control , Swine , Swine Diseases/microbiology , Swine Diseases/pathologyABSTRACT
Group A streptococcus-associated severe invasive infection (streptococcal toxic shock syndrome) has been described. Streptococcal toxic shock syndrome occurs when the infecting strain of group A streptococcus produces superantigens. Confusion and combativeness are well known as the common symptoms of streptococcal toxic shock syndrome. We encountered a child who suffered from pyogenic sacroiliitis, with confusion and combativeness. Group A streptococcus was isolated from the patient's blood culture. However, his disease did not fulfill the criteria of streptococcal toxic shock syndrome. Pyogenic sacroiliitis in children is rare, but patients with pyogenic sacroiliitis due to group A streptococcus infection could show confusion and combativeness as clinical signs, similar to the signs in streptococcal toxic shock syndrome.
Subject(s)
Aggression , Arthritis/diagnosis , Confusion/microbiology , Sacroiliac Joint/microbiology , Shock, Septic/diagnosis , Streptococcal Infections/diagnosis , Streptococcus pyogenes , Adolescent , Arthritis/microbiology , Arthritis/pathology , Humans , Male , Sacroiliac Joint/pathology , Shock, Septic/microbiology , Shock, Septic/psychology , Streptococcal Infections/complications , Streptococcal Infections/pathology , Suppuration/diagnosis , Suppuration/microbiology , Suppuration/pathologyABSTRACT
BACKGROUND: The effects of fetal alcohol exposure on the risks of neonatal lung injury and infection remain under investigation. The resident alveolar macrophage (AM) is the first line of immune defense against pulmonary infections. In utero ethanol (ETOH) exposure deranges the function of both premature and term guinea pig AM. We hypothesized that fetal ETOH exposure would increase the risk of pulmonary infection in vivo. METHODS: We developed a novel in vivo model of group B Streptococcus (GBS) pneumonia using our established guinea pig model of fetal ETOH exposure. Timed-pregnant guinea pigs were pair fed +/-ETOH and some were supplemented with the glutathione (GSH) precursor S-adenosyl-methionine (SAM-e). Term pups were given GBS intratracheally while some were pretreated with inhaled GSH prior to the experimental GBS. Neonatal lung and whole blood were evaluated for GBS while isolated AM were evaluated using fluorescent microscopy for GBS phagocytosis. RESULTS: Ethanol-exposed pups demonstrated increased lung infection and sepsis while AM phagocytosis of GBS was deficient compared with control. When SAM-e was added to the maternal diet containing ETOH, neonatal lung and systemic infection from GBS was attenuated and AM phagocytosis was improved. Inhaled GSH therapy prior to GBS similarly protected the ETOH-exposed pup from lung and systemic infection. CONCLUSIONS: In utero ETOH exposure impaired the neonatal lung's defense against experimental GBS, while maintaining GSH availability protected the ETOH-exposed lung. This study suggested that fetal alcohol exposure deranges the neonatal lung's defense against bacterial infection, and support further investigations into the potential therapeutic role for exogenous GSH to augment neonatal AM function.