Browsing by Subject "Streptococcus pyogenes"

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    Effects of artificial honey and epigallocatechin-3-gallate on streptococcus pyogenes
    (Springer, 2022-08-26) Jiang, Xiaoge; Lin, An; Li, Shijia; Shi, Yangyang; Zhou, Fangjie; Felix Gomez, Grace Gomez; Gregory, Richard L.; Zhang, Chaoliang; Chen, Song; Huang, Ruijie; Oral Pathology, Medicine and Radiology, School of Dentistry
    Background Streptococcus pyogenes is an important global human pathogen that causes pharyngitis, and antibacterial therapy has become an important part of the overall therapy for pharyngitis. As natural derivatives, honey and green tea are often recommended for patients with pharyngitis in traditional Chinese medicine without experimental theoretical basis on wether the combined effect of honey and green tea on pharyngitis is better than they alone. The aims of this study were to explore the effects of artificial honey (AH) and epigallocatechin-3-gallate (EGCG) on S. pyogenes and elucidate the possible mechanisms, which were investigated using MIC (the minimum inhibitory concentration), FIC (fractional inhibitory concentration) index, growth pattern, biofilm formation and RT-qPCR. Results The MIC of AH on S. pyogenes was 12.5% (v/v) and the MIC of EGCG was 1250 μg/ml. The FIC index of AH and EGCG was 0.5. The planktonic cell growth, growth pattern and biofilm formation assays showed that AH and EGCG mixture had stronger inhibitory effect on S. pyogenes than they alone. RT-qPCR confirmed that the expression of hasA and luxS gene were inhibited by AH and EGCG mixture. Conclusions AH and EGCG mixture can inhibit the planktonic cell growth, biofilm formation and some virulence genes expression of S. pyogenes, better than they alone. The combination of honey and green tea have the potential to treat pharyngitis as natural derivatives, avoiding drug resistance and double infection.
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    Prevalence, Clinical Features, and Antibiotic Susceptibility of Group A Streptococcal Skin Infections in Schoolchildren in Urban Western and Northern Uganda
    (Wolters Kluwer, 2019) Chang, Aileen Y.; Scheel, Amy; Dewyer, Alyssa; Hovis, Ian W.; Sarnacki, Rachel; Aliku, Twalib; Okello, Emmy; Bwanga, Freddie; Sable, Craig; Maurer, Toby A.; Beaton, Andrea Z.; Dermatology, School of Medicine
    Background: Group A Streptococcus (GAS) skin infections can lead to invasive sepsis, poststreptococcal glomerulonephritis, and potentially rheumatic heart disease (RHD). Within a study to identify predisposing factors of RHD in Ugandan schoolchildren, we determined the prevalence of skin infections and assessed the clinical features and antibiotic susceptibility of GAS skin infection. Methods: Cross-sectional study conducted at 3 urban primary schools in Western and Northern Uganda in March 2017. A dermatologist rendered clinical diagnoses and obtained a skin swab specimen from lesions with signs of bacterial infection. Beta-hemolytic colonies underwent Lancefield grouping, species identification by polymerase chain reaction and antimicrobial susceptibility testing. Results: From 3265 schoolchildren, we observed 32% with ≥1 fungal, 1.8% with ≥1 bacterial, 0.9% with ≥1 viral, and 0.2% with ≥1 ectoparasitic infection. Of 79, 25 (32%) specimens were GAS-positive, of which one-third demonstrated tetracycline resistance. Of 17 impetigo cases, 13 (76%) were located on the leg/foot and 3 (18%) on the head/neck. Prevalence of GAS skin infection was 0.8% (25 of 3265). In Northern Uganda, where subclinical definite RHD prevalence is 1.1%, GAS skin infection prevalence was 1.2% (4 of 343) and 0.9% (3 of 352). Conclusion: This study identifies tetracycline-resistant GAS in Ugandan communities, suggests modified skin examination of exposed anatomic locations may be appropriate for population-based GAS skin infection studies, and underscores need for clear case definitions of GAS skin infection. Future studies are needed to evaluate the role of GAS skin infection in development of RHD in Ugandan communities.
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    Streptococcus pyogenes Is Associated with Idiopathic Cutaneous Ulcers in Children on a Yaws-Endemic Island
    (American Society for Microbiology, 2021-01-12) Griesenauer, Brad; González-Beiras, Camila; Fortney, Katherine R.; Lin, Huaiying; Gao, Xiang; Godornes, Charmie; Nelson, David E.; Katz, Barry P.; Lukehart, Sheila A.; Mitjà, Oriol; Dong, Qunfeng; Spinola, Stanley M.; Microbiology and Immunology, School of Medicine
    Exudative cutaneous ulcers (CU) in yaws-endemic areas are associated with Treponema pallidum subsp. pertenue (TP) and Haemophilus ducreyi (HD), but one-third of CU cases are idiopathic (IU). Using mass drug administration (MDA) of azithromycin, a yaws eradication campaign on Lihir Island in Papua New Guinea reduced but failed to eradicate yaws; IU rates remained constant throughout the campaign. To identify potential etiologies of IU, we obtained swabs of CU lesions (n = 279) and of the skin of asymptomatic controls (AC; n = 233) from the Lihir Island cohort and characterized their microbiomes using a metagenomics approach. CU bacterial communities were less diverse than those of the AC. Using real-time multiplex PCR with pathogen-specific primers, we separated CU specimens into HD-positive (HD+), TP+, HD+TP+, and IU groups. Each CU subgroup formed a distinct bacterial community, defined by the species detected and/or the relative abundances of species within each group. Streptococcus pyogenes was the most abundant organism in IU (22.65%) and was enriched in IU compared to other ulcer groups. Follow-up samples (n = 31) were obtained from nonhealed ulcers; the average relative abundance of S. pyogenes was 30.11% in not improved ulcers and 0.88% in improved ulcers, suggesting that S. pyogenes in the not improved ulcers may be azithromycin resistant. Catonella morbi was enriched in IU that lacked S. pyogenes As some S. pyogenes and TP strains are macrolide resistant, penicillin may be the drug of choice for CU azithromycin treatment failures. Our study will aid in the design of diagnostic tests and selective therapies for CU.IMPORTANCE Cutaneous ulcers (CU) affect approximately 100,000 children in the tropics each year. While two-thirds of CU are caused by Treponema pallidum subspecies pertenue and Haemophilus ducreyi, the cause(s) of the remaining one-third is unknown. Given the failure of mass drug administration of azithromycin to eradicate CU, the World Health Organization recently proposed an integrated disease management strategy to control CU. Success of this strategy requires determining the unknown cause(s) of CU. By using 16S rRNA gene sequencing of swabs obtained from CU and the skin of asymptomatic children, we identified another possible cause of skin ulcers, Streptococcus pyogenes Although S. pyogenes is known to cause impetigo and cellulitis, this is the first report implicating the organism as a causal agent of CU. Inclusion of S. pyogenes into the integrated disease management plan will improve diagnostic testing and treatment of this painful and debilitating disease of children and strengthen elimination efforts.
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    Two Streptococcus pyogenes emm types and several anaerobic bacterial species are associated with idiopathic cutaneous ulcers in children after community-based mass treatment with azithromycin
    (Public Library of Science, 2022-12-19) Griesenauer, Brad; Xing, Yue; Fortney, Katherine R.; Gao, Xiang; González-Beiras, Camila; Nelson, David E.; Ren, Jie; Mitjà, Oriol; Dong, Qunfeng; Spinola, Stanley M.; Microbiology and Immunology, School of Medicine
    Background: In yaws-endemic areas, two-thirds of exudative cutaneous ulcers (CU) are associated with Treponema pallidum subsp. pertenue (TP) and Haemophilus ducreyi (HD); one-third are classified as idiopathic ulcers (IU). A yaws eradication campaign on Lihir Island in Papua New Guinea utilizing mass drug administration (MDA) of azithromycin initially reduced but failed to eradicate yaws; IU rates remained constant throughout the study. Using 16S rRNA gene sequencing, we previously determined that Streptococcus pyogenes was associated with some cases of IU. Here, we applied shotgun metagenomics to the same samples we analyzed previously by 16S rRNA sequencing to verify this result, identify additional IU-associated microorganisms, and determine why S. pyogenes-associated IU might have persisted after MDA of azithromycin. Methodology/principal findings: We sequenced DNA extracted from 244 CU specimens separated into four groups based upon microorganism-specific PCR results (HD+, TP+, TP+HD+, and TP-HD- or IU). S. pyogenes was enriched in IU (24.71% relative abundance [RA]) specimens compared to other ulcer sub-groups, confirming our prior results. We bioinformatically identified the emm (M protein gene) types found in the S. pyogenes IU specimens and found matches to emm156 and emm166. Only ~39% of IU specimens contained detectable S. pyogenes, suggesting that additional organisms could be associated with IU. In the sub-set of S. pyogenes-negative IU specimens, Criibacterium bergeronii, a member of the Peptostreptococcaceae, and Fusobacterium necrophorum (7.07% versus 0.00% RA and 2.18% versus 0.00% RA, respectively), were enriched compared to the S. pyogenes-positive sub-set. Although a broad range of viruses were detected in the CU specimens, none were specifically associated with IU. Conclusions/significance: Our observations confirm the association of S. pyogenes with IU in yaws-endemic areas, and suggest that additional anaerobic bacteria, but not other microorganisms, may be associated with this syndrome. Our results should aid in the design of diagnostic tests and selective therapies for CU.